US20070227809A1 - Vehicle exhaust system - Google Patents
Vehicle exhaust system Download PDFInfo
- Publication number
- US20070227809A1 US20070227809A1 US11/692,824 US69282407A US2007227809A1 US 20070227809 A1 US20070227809 A1 US 20070227809A1 US 69282407 A US69282407 A US 69282407A US 2007227809 A1 US2007227809 A1 US 2007227809A1
- Authority
- US
- United States
- Prior art keywords
- silencer
- volume
- exhaust
- exhaust system
- tail pipe
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
Images
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N1/00—Silencing apparatus characterised by method of silencing
- F01N1/02—Silencing apparatus characterised by method of silencing by using resonance
- F01N1/04—Silencing apparatus characterised by method of silencing by using resonance having sound-absorbing materials in resonance chambers
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N1/00—Silencing apparatus characterised by method of silencing
- F01N1/08—Silencing apparatus characterised by method of silencing by reducing exhaust energy by throttling or whirling
- F01N1/10—Silencing apparatus characterised by method of silencing by reducing exhaust energy by throttling or whirling in combination with sound-absorbing materials
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N13/00—Exhaust or silencing apparatus characterised by constructional features ; Exhaust or silencing apparatus, or parts thereof, having pertinent characteristics not provided for in, or of interest apart from, groups F01N1/00 - F01N5/00, F01N9/00, F01N11/00
- F01N13/18—Construction facilitating manufacture, assembly, or disassembly
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N2470/00—Structure or shape of gas passages, pipes or tubes
- F01N2470/20—Dimensional characteristics of tubes, e.g. length, diameter
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N2590/00—Exhaust or silencing apparatus adapted to particular use, e.g. for military applications, airplanes, submarines
- F01N2590/04—Exhaust or silencing apparatus adapted to particular use, e.g. for military applications, airplanes, submarines for motorcycles
Definitions
- the present invention generally relates to an exhaust system for a vehicle. More particularly, the present invention relates to an exhaust system for a straddle-type vehicle and a straddle-type vehicle incorporating such an exhaust system.
- a exhaust system used in a straddle-type vehicle (for example, a motorcycle) is requested to meet two demands, that is, an exhaust efficiency, at which exhaust gases discharged from an engine should be efficiently discharged, and reduction of exhaust noise, which accompanies discharge of exhaust gases of high pressure and high temperature.
- a muffler exhaust system
- exhaust system exhaust system
- the exhaust system is extended toward the rear of a vehicle body in an attempt to avoid tight radius bends, which is difficult in many cases because of the front wheel of the motorcycle and a bank angle of the combustion chamber(s).
- a muffler having an ideal length in terms of engine performance is only seldom accommodated intact in a configuration of a motorcycle and, as compared with design of a muffler for four-wheel passenger cars, the design of a motorcycle exhaust system to meet both performance and physical constraints is significantly more challenging. That is, it is difficult in the context of a motorcycle exhaust system to achieve a length of the exhaust system that will both provide desired performance attributes and be accommodated within the space constraints of a motorcycle while maintaining a configuration that is as smooth as possible.
- a weight of a an exhaust system has a significant influence on the handling characteristics of a motorcycle. That is, because a motorcycle is relatively lightweight, even a weight of about one ( 1 ) kg has a great influence on the motorcycle. Moreover, because certain components of the exhaust system (e.g., the silencer) are usually located at a distance from a center of gravity of the motorcycle, the adverse influence of excess weight of the exhaust system on the handling characteristics of the motorcycle is increased.
- At least some of the preferred embodiments of the present invention provide an exhaust system for straddle-type vehicles, such as motorcycles, in which miniaturization is achieved while a demand for noise reduction characteristics are met.
- Certain preferred embodiments of the invention provide an exhaust system for a straddle-type vehicle, comprising an engine, and an exhaust system including an exhaust pipe connected to the engine and a silencer connected to the exhaust pipe.
- a volume of the silencer and a volume of the exhaust pipe have a ratio between about 0.7 and 1.4.
- the exhaust system described above comprises a damping means for an improvement of a damping characteristic in a low frequency range, and a volume of the exhaust pipe and a volume of the silencer are substantially equal to each other to thereby realize the damping means.
- the damping means decreases a level of a primary resonance frequency of an exhaust pipe length of the exhaust pipe in the exhaust part.
- the exhaust system described above includes a tail pipe connected to the silencer, and the volume of the silencer is a volume obtained by subtracting a volume occupied therein by the exhaust pipe and the tail pipe from an inner volume of the silencer.
- the volume of the exhaust pipe also includes a volume of a cylinder head exhaust port portion.
- the silencer of the exhaust system described above comprises an outer housing and an inner core accommodated in the outer housing. Wherein at least a portion of the inner core includes a plurality of through-holes formed therein.
- a sound absorbing material is positioned between an inner surface of the outer housing and an outer surface of the inner core. In some arrangements, the sound absorbing material comprises at least one of glass wool and stainless steel wool.
- the exhaust system described above includes a tail pipe connected to the silencer, and the tail pipe is radially offset relative to the exhaust pipe.
- a preferred embodiment of the exhaust system described above includes a tail pipe connected to the silencer, wherein the silencer comprises an outer housing and an inner core accommodated within the outer housing.
- An outside diameter of the tail pipe is smaller than an inside diameter of the inner core of the silencer.
- the inside diameter of the inner core is gradually decreased from a forward end to a rearward end, which meets up to a front end of the tail pipe.
- an air layer is provided between the tail pipe and the inner core.
- the silencer comprises an outer housing and an inner core accommodated in the outer housing.
- a sound absorbing material is positioned between an inner surface of the outer housing and an outer surface of the inner core.
- a first air layer, or air space, is provided between the inner surface of the outer housing and an outer surface of the sound absorbing material.
- the exhaust system includes a tail pipe connected to the silencer.
- a second air layer, or air space, is provided between the tail pipe and the inner core, and the sound absorbing material is positioned between the second air space and the first air space.
- a chamber is provided in the exhaust pipe, and a volume of the exhaust pipe also includes a volume of the chamber.
- a conical member is provided in the silencer. Both ends of the conical member are open. At least a portion of a wall of the conical member is formed with a plurality of through-holes.
- the silencer comprises an outer housing and an inner core within the outer housing. A tail pipe is connected to the inner core of the silencer, and the conical member is provided at an upstream end of the tail pipe. In some arrangements, a diameter of the upstream opening of the conical member is smaller than a diameter of the downstream opening.
- the exhaust system includes a tail pipe connected to the silencer.
- a first conical member is connected to the tail pipe and a second conical member at least partially overlaps the first conical member and is connected to the inner core.
- a preferred embodiment is a straddle-type vehicle incorporating any of the exhaust systems described in the above paragraphs.
- the engine of the straddle-type vehicle operates on a four-stroke combustion principle.
- the straddle-type vehicle is an off-road motorcycle.
- FIG. 1 is a side view showing a motorcycle comprising an exhaust system having certain features, aspects and advantages of the present invention.
- FIG. 2 ( a ) is a perspective view showing the exhaust system according to the embodiment of the invention.
- FIG. 2 ( b ) is a view schematically showing an engine of the motorcycle of FIG. 1 .
- FIG. 2 ( c ) is a perspective view showing an exhaust system in which the exhaust pipe includes an expansion chamber.
- FIG. 3 is a schematic view of the structure of an exhaust system according to the embodiment of the invention.
- FIGS. 4 ( a ) and 4 ( b ) are perspective views showing the structures of the muffler according to the embodiment of the invention and a muffler of a comparative example.
- FIG. 5 is a graph illustrating a comparison in damping characteristics between two embodiments of an exhaust system according to the invention and an exhaust system of a comparative example.
- FIGS. 6 ( a ) to 6 ( c ) are cross sectional views schematically showing examples of the exhaust system according to an embodiment of the invention.
- FIGS. 7 ( a ) and 7 ( b ) are cross sectional views schematically showing examples of the exhaust system according to an embodiment of the invention.
- FIGS. 8 ( a ) to 8 ( c ) are cross sectional views schematically showing examples of the exhaust system according to an embodiment of the invention.
- FIGS. 9 ( a ) and 9 ( b ) are cross sectional views schematically showing examples of the exhaust system according to an embodiment of the invention.
- FIGS. 10 ( a ) to 10 ( c ) are cross sectional views schematically showing examples of the exhaust system according to an embodiment of the invention.
- FIGS. 11 ( a ) to 11 ( c ) are cross sectional views schematically showing examples of the exhaust system according to an embodiment of the invention.
- FIG. 12 is a side view showing a motorcycle comprising the exhaust system of the comparative example.
- a volume of the silencer and a volume of the exhaust pipe are selected to have a ratio between about 0.7 to 1.4, or to be substantially equal to one another, it is possible to improve the damping characteristics of the exhaust system in a low frequency range (in particular, a primary resonance frequency of an exhaust pipe length of the exhaust pipe in the exhaust system) whereby it is possible to achieve a decrease in the noise level of the exhaust system. Since an improvement in damping characteristic can be achieved by making a volume of the exhaust pipe and a volume of the silencer close to each other, rather than by increasing the volume of the silencer, it is possible to avoid an increase in weight of the silencer, so that it is possible to realize a small-sized silencer for a straddle-type vehicle. As a result, it is possible to improve the handling characteristics of a motorcycle utilizing embodiments of the exhaust system.
- FIG. 1 shows a motorcycle 1000 , on which an exhaust device, or exhaust system, according to an embodiment of the invention is mounted.
- the motorcycle 1000 includes an engine 50 and an exhaust system 100 connected to the engine 50 .
- the exhaust system 100 includes an exhaust pipe 20 and a silencer 10 .
- the exhaust system 100 including the silencer 10 is in some cases referred to as a “muffler” in the specification of the present application for the sake of convenience.
- the muffler 100 includes the exhaust pipe 20 connected to the engine 50 of the motorcycle 1000 , and the silencer 10 connected to the exhaust pipe 20 . With a construction shown in FIG. 1 , a tail pipe 30 is connected to the silencer 10 .
- FIG. 2 ( a ) A state, in which the muffler 100 is removed from the motorcycle 1000 , is shown in FIG. 2 ( a ).
- the exhaust pipe 20 and the silencer 10 of the muffler 100 shown in FIG. 2 ( a ) are formed with members for mounting to a vehicle body.
- the illustrated muffler 100 is one for four-stroke engines and the motorcycle 1000 shown in FIG. 1 is an off-road vehicle.
- the exhaust pipe 20 shown in FIG. 2 ( a ) its end connected to the engine 50 mounts thereto a cylinder head exhaust port 22 .
- the exhaust pipe 20 connects to an exhaust opening of the engine 50 as shown in FIG. 2 ( b ) to lead exhaust gases from the engine 50 to the silencer 10 .
- the cylinder head exhaust port 22 of the exhaust pipe 20 is connected to the engine 50 .
- the silencer 10 has a noise reducing function to discharge exhaust gases led from the exhaust pipe 20 to the environment.
- exhaust gases are discharged from the tail pipe 30 .
- an expansion chamber 21 can be further provided in the exhaust pipe 20 as shown in FIG. 2 ( c ). In this case, exhaust gases from the engine 50 are once expanded in the chamber 21 and then led to the silencer 10 to be discharged to the environment.
- FIG. 3 schematically shows the structure of the muffler 100 according to the embodiment.
- the muffler 100 according to the embodiment is structured such that a volume (Vp) of the exhaust pipe 20 is substantially equal to a volume (Vc) of the silencer 10 .
- the volume (Vc) of the silencer 10 is a volume obtained by subtracting a volume occupied therein by the exhaust pipe 20 from an interior of the silencer 10 .
- the volume (Vc) of the silencer 10 is a volume obtained by subtracting a volume occupied therein by the exhaust pipe 20 and the tail pipe 30 from an interior of the silencer 10 .
- a volume of the chamber 21 constitutes a part of a volume occupied by the exhaust pipe 20 .
- a volume (Vh) of the cylinder head exhaust port 22 also constitutes a part of a volume occupied by the exhaust pipe 20 .
- the volume of the exhaust port 22 will be known, and can be considered in the design of the exhaust pipe 20 and silencer 10 .
- the muffler 100 is structured so that the volume (Vp) of the exhaust pipe 20 and the volume (Vc) of the silencer 10 are made substantially equal to each other, it is possible to improve a damping characteristic of a low frequency range of the muffler 100 , in particular, a primary resonance frequency fl. More specifically, a primary resonance frequency fl of an exhaust pipe length of the exhaust pipe 20 ; referred below in some cases to as “a primary resonance frequency fl of a muffler” for convenience' sake.
- a primary resonance frequency fl of an exhaust pipe length of the exhaust pipe 20 referred below in some cases to as “a primary resonance frequency fl of a muffler” for convenience' sake.
- an improvement in damping characteristic can be achieved by making the volume (Vp) of the exhaust pipe 20 and the volume (Vc) of the silencer 10 close to each other instead of increasing the muffler 100 volume, so that it is possible to avoid an increase in muffler weight.
- the muffler 100 includes damping means for an improvement in damping characteristic in a low frequency range (in particular, a primary resonance frequency f 1 ) and the volume (Vp) of the exhaust pipe 20 and the volume (Vc) of the silencer 10 are made substantially equal to each other to thereby realize the damping means, so that it is not necessary to make the muffler 100 larger in volume than needed and there is no need for any separately independent, new member as damping means, thus enabling a small-sized muffler 100 to be realized.
- a low frequency range in particular, a primary resonance frequency f 1
- FIG. 4 ( a ) shows a muffler 100 having a structure according to an embodiment of the invention
- FIG. 4 ( b ) shows a muffler 200 as a comparative example.
- Exhaust pipes 20 and 20 A shown in FIGS. 4 ( a ) and 4 ( b ) are substantially equal to each other in volume but silencers 10 and 10 A are considerably different in volume from each other.
- the silencer 10 A shown in FIG. 4 ( b ) has a considerably larger volume than that of the exhaust pipe 20 A according to a typical design technique in order to obtain a favorable noise reducing characteristic (damping characteristic). Specifically, the volume of the silencer 10 A exceeds twice the volume of the exhaust pipe 20 A, and more specifically, is about 2.5 times the latter.
- the silencer 10 shown in FIG. 4 ( a ) has a volume near to the volume of the exhaust pipe 20 contrary to the typical design technique. Specifically, the volume of the silencer 10 is nearly 1.4 times or less the volume of the exhaust pipe 20 . More specifically, it is desired that the volume of the silencer 10 be in the range of 1.2 to 0.7 times the volume of the exhaust pipe 20 .
- the weight of the silencer 10 amounts only to around 60% of the weight of the silencer 10 A.
- a decrease in weight of the silencer 10 not only produces an effect of a decrease in total weight of the motorcycle 1000 but contributes much to an improvement in handling characteristics of the motorcycle 1000 since a member or members positioned distant from a vehicle body center (or, a center of gravity of a vehicle body) of the motorcycle 1000 can be reduced in weight.
- FIG. 12 shows a construction, in which the muffler 200 of a comparative example shown in FIG. 4 ( b ) is mounted to a motorcycle.
- the muffler 100 is capable of decreasing a noise value further than the muffler 200 , which is large in muffler volume. This demonstrates that the muffler 100 according to the preferred embodiments produces excellent, and unexpected, technical results.
- FIG. 5 is a graph illustrating damping characteristics of the muffler 100 and the muffler 200 of the comparative example.
- the damping characteristic of the muffler 100 according to the embodiment is indicated by plots in an Embodiment 1 and an Embodiment 2 while the damping characteristic of the muffler 200 is indicated by plots in the comparative example.
- Embodiment 1, Embodiment 2 and the comparative example are substantially the same in a damping characteristic of f 0 (damping level (dB)) but it is found that Embodiment 1 and Embodiment 2 are favorable in a damping characteristic (damping level (dB)) of f 1 (primary resonance frequency of an exhaust pipe length of the exhaust pipe in the exhaust part) as compared with the comparative example.
- Embodiment 1 and Embodiment 2 are low in noise value of fl as compared with the comparative example.
- Embodiment 1 and Embodiment 2 The reason why the noise value of f 1 is small in Embodiment 1 and Embodiment 2 is that the volume (Vc) of the silencer 10 and the volume (Vp) of the exhaust pipe 20 have a ratio between about 0.7 and 1.4 and, in some arrangements, are substantially equal to each other.
- the reason why the noise value in a low frequency range (in particular, f 1 ) can be decreased is as follows. If a muffler were composed of only the exhaust pipe 20 (without the silencer 10 ), f 1 would be a resonance frequency of 1 ⁇ 4 wavelength determined by an exhaust pipe length and be suddenly changed into a resonance frequency, at which the both parts ( 20 , 10 ) were coupled together, in a configuration, in which the silencer 10 were added to the exhaust pipe 20 .
- a strongest coupled state corresponds to the case where the both parts ( 20 , 10 ) are equal to each other in resonance frequency, which means in other acoustic terms that the both parts are equal to each other in volume.
- a sound absorbing material is filled in one of them in this state, it is possible to efficiently damp the frequency.
- the volume (Vp) of the exhaust pipe 20 may include a volume of the chamber 21 and the volume (Vp) of the exhaust pipe 20 and the volume (Vc) of the silencer 10 are made close to each other.
- the same is also the case with a volume of the cylinder head exhaust port portion 22 .
- V indicates an exhaust system volume (that is, “Vp+Vc”)
- L indicates a length of the tail pipe 30
- S indicates a cross sectional area of the tail pipe 30 .
- the exhaust pipe 20 is actually formed as shown in, for example, FIG. 4 to be bent in order to meet various design conditions and the size and weight of the silencer 10 is also determined in conformity to other conditions (vehicle body weight, vehicle body balance, etc.), however, it is unnecessary in many cases to maintain the ratio of the volume (Vp) of the exhaust pipe 20 and the volume (Vc) of the silencer 10 to an ideal 1:1 provided that an effect of a decrease in noise value is produced.
- a desired effect of a decrease in noise value is produced by making the volume (Vp) of the exhaust pipe 20 and the volume (Vc) of the silencer 10 close to each other contrary to conventional technical thought that it is desirable in a typical muffler design to make the silencer 10 large in volume (for example, Vc/Vp>2), it is possible to change a design of the exhaust pipe 20 and the silencer 10 in that range, in which such effect is produced (as an example, about 1.2 times to about 0.7 times, or about 1.4 times to about 0.7 times).
- the damping characteristic of the muffler in Embodiment 1 and Embodiment 2 is favorable (that is, noise can be decreased) in a low frequency range (for example, in the order of 600 to 800 Hz), and the comparative example demonstrates a favorable damping characteristic in a frequency range therebeyond.
- a decrease in noise component in a low frequency range is achieved by damping means (damping means for an improvement of a damping characteristic in a low frequency range), which is realized by making the volume (Vp) of the exhaust pipe 20 and the volume (Vc) of the silencer 10 substantially equal to each other, and a decrease in noise component in a frequency range therebeyond can also be achieved by other techniques.
- FIGS. 6 to 11 Modifications of the muffler 100 according to the embodiment will be described below with reference to FIGS. 6 to 11 .
- the respective figures schematically show a structure of the silencer 10 in the muffler 100 according to various embodiments of the present invention, (a) being lateral, cross sectional views, and (b) being cross sectional views as viewed from the rear of a vehicle body. In addition, (c) are partially enlarged views in (a).
- the silencer 10 shown in FIG. 6 comprises an outer housing, or cylinder 10 a, and an inner core, or cylinder 10 b, accommodated in the outer cylinder 10 a.
- Through-holes 13 are formed in at least a part (region P) of the wall of the inner cylinder 10 b of the silencer 10 and may be referred to herein as “punched holes,” although the holes 13 may be produced by any suitable method.
- the punched holes 13 are small holes formed in the silencer 10 (here, the inner cylinder 10 b ) and serve to enable energy of exhaust gases, which are introduced from the exhaust pipe 20 , to be led to the outer cylinder l 0 a through the small holes.
- a sound absorbing material 15 is positioned in a manner to come into close contact between an inner surface of the outer cylinder 1 Oa and an outer surface of the inner cylinder 10 b.
- the sound absorbing material 15 is a material capable of absorbing sound waves and can use, for example, glass wool, stainless steel wool (SUS wool), aluminum wool, ferrite, asbestos, etc. In this example, glass wool is used as the sound absorbing material 15 .
- the sound absorbing material 15 fairly absorbs a high frequency sound but is less effective in low frequency sound, so that a synergistic effect is produced when combined with the construction of the muffler 100 according to the illustrated embodiment.
- a SUS wool 15 b is provided on the outer surface of the inner cylinder 10 b and a glass wool 15 a is provided on an outer periphery thereof.
- the SUS wool 15 b is provided on the outer surface of the inner cylinder 10 b and the glass wool 15 a is provided on the inner surface of the outer cylinder 10 a.
- the inner cylinder 10 b is gradually decreased in inside diameter up to a front end of the tail pipe 30 .
- an air layer 17 is formed between a tail pipe 30 and an inner cylinder 10 b.
- an outside diameter d of the tail pipe 30 is smaller than an inside diameter D of the inner cylinder 10 b of the silencer 10 .
- punched holes (region P) are formed in as far as a region (a region, in which the air layer 17 is positioned), in which the tail pipe 30 is positioned.
- a cross sectional structure of the silencer 10 shown in FIG. 7 is substantially the same as that shown in the partially enlarged view of FIG. 6 ( c ).
- the construction shown in this example can incorporate a damping characteristic in which noise elimination is achieved by varying (enlarging) a pipe (cylinder) in cross sectional area, and such combination makes it possible to regulate the damping characteristic of the muffler 100 .
- the pipe (cylinder) is changed in cross sectional area to enable obtaining a damping characteristic, in which sounds mainly in a low frequency range are eliminated.
- the provision of the air layer 17 enables producing both effects of noise reduction by the sound absorbing material 15 and noise reduction by pipe bulging, or an expansion chamber effect.
- the silencer 10 shown in FIG. 8 has a structure similar to that in FIG. 6 , but a sound absorbing material 15 is arranged on an outer surface of an inner cylinder 1 Ob and an air layer 19 is present on an inner surface of an outer cylinder 10 a, in which no sound absorbing material 15 is filled.
- the sound absorbing material 15 comprises a combination of SUS wool 15 b and glass wool 15 a in the same manner as that shown in FIG. 6 .
- a partition 10 c which supports the sound absorbing material 15 ( 15 a , 15 b ), is provided and punched holes 13 are formed on at least a portion of the partition 10 c.
- a silencer 10 shown in FIG. 9 incorporates a feature of the structure shown in FIG. 7 into the structure shown in FIG. 8 such that an air layer 17 is formed between a tail pipe 30 and an inner cylinder 10 b.
- a structural feature that is, a structural feature that the sound absorbing material 15 is arranged between the air layer (first air layer) 19 provided between the inner surface of the outer cylinder 10 a and the outer surface of the sound absorbing material 15 and the air layer (second air layer) 17 provided between the tail pipe 30 and the inner cylinder 10 b
- a cross sectional structure of the silencer 10 shown in FIG. 9 is substantially the same as that shown in the partially enlarged view of FIG. 8 ( c ).
- the silencer 10 is not limited to a structure, which comprises the outer cylinder 10 a and the inner cylinder 10 b accommodated in the outer cylinder 10 a, but can adopt a structure shown in FIG. 10 . That is, it suffices to design a muffler 100 having a desired damping characteristic by the use of further means, which combines with damping means in a low frequency range, which is realized by making the volume (Vp) of the exhaust pipe 20 and the volume (Vc) of the silencer 10 substantially equal to each other, to enable reinforcing the damping means.
- the sound absorbing material 15 in FIG. 10 ( c ) comprises, for example, SUS wool, or glass wool, or a combination thereof.
- an axis of the tail pipe 30 is radially offset relative to an axis of the portion of the exhaust pipe 20 connecting with, or positioned within, the silencer 10 .
- the conical member 32 comprises a member, which is in the form of a cone with a tip end thereof opened and formed with punched holes 13 in a sidewall 35 of the conical member 32 .
- the provision of such a conical member can produce an effect of noise reduction or elimination and a directly transmitting sound of exhaust noise can be decreased.
- An opening 37 provided on the conical member has an opening diameter at an upstream end thereof, which is made smaller than an opening diameter at a downstream end thereof. Thereby, it is possible to prevent direct transmission of noise, thus enabling improving a damping effect. It is possible to arrange one or plural conical members 32 within the silencer 10 . According to the embodiment, the conical members 32 are provided in two locations ( 32 a , 32 b ) on the inner cylinder 10 b and an upstream end of the tail pipe 30 . In addition, it is possible to provide only one conical member 32 instead of several in number and to provide three or more conical members.
- upstream side and downstream side referred to in the specification of the present application mean an upstream side and a downstream side, respectively, in a direction, in which exhaust gases in the muffler flow.
- upstream side is that side, on which an engine is arranged
- downstream side is that side, on which exhaust gases are discharged to the environment.
- the conical member 32 is provided at an end of the tail pipe 30 .
- the conical member includes a first cone 32 a connected to the tail pipe 30 and a second cone 32 b , which covers (i.e., at least partially overlaps) the first cone 32 a and is connected to the inner cylinder 10 b.
- FIG. 1 shows an off-road motorcycle as an example of the motorcycle 1000
- the motorcycle 1000 may be constructed for on-road use as well.
- “motorcycle” or “straddle-type vehicle” in the specification of the present application refers to a motorcycle and also means any vehicle, which includes but is not limited to a bicycle with a motor (motorbike) and a scooter and other vehicles that can turn with a vehicle body inclined.
- a three-wheeler/four-wheeler at least one of a front wheel and a rear wheel of which has two or more wheels and which is three, four (or more) in the number of tires, is also intended to be included in the definition of a “motorcycle” or “straddle-type vehicle.”
- straddle-type vehicle which includes four-wheeled buggies, ATV's (All Terrain Vehicle's), and snowmobiles.
Abstract
An exhaust system for a straddle-type vehicle, such as a motorcycle, that is compact while also reducing noise output. The exhaust system communicates with an engine of an associated vehicle. The exhaust system includes an exhaust conduit, which is at least partially defined by an exhaust pipe, communicating with a combustion chamber of the engine. The exhaust system also includes a silencer. A ratio of a volume of the silencer to a volume of the exhaust conduit is between about 0.7 to 1.4. In some arrangements, the volume of the silencer and the volume of the exhaust conduit are substantially equal to each other.
Description
- This application is related to, and claims priority from, Japanese Patent Application No. 2007-031097, filed Feb. 9, 2007 and Japanese Patent Application No. 2006-092334, filed Mar. 29, 2006, the entireties of which are incorporated by reference herein and made a part of the present specification. Application Ser. Nos. ______ (Attorney Docket FY.53109US2A), ______ (Attorney Docket FY.53109US3A), and ______ (Attorney Docket FY.53109US4A), entitled VEHICLE EXHAUST SYSTEM, all filed on even date herewith, are also incorporated by reference herein in their entireties and made a part of the present specification.
- 1. Field of the Invention
- The present invention generally relates to an exhaust system for a vehicle. More particularly, the present invention relates to an exhaust system for a straddle-type vehicle and a straddle-type vehicle incorporating such an exhaust system.
- 2. Description of the Related Art
- A exhaust system used in a straddle-type vehicle (for example, a motorcycle) is requested to meet two demands, that is, an exhaust efficiency, at which exhaust gases discharged from an engine should be efficiently discharged, and reduction of exhaust noise, which accompanies discharge of exhaust gases of high pressure and high temperature.
- In particular, the demand for noise reduction or noise elimination has increased as noise regulations have been made more rigorous. Accordingly, it is increasingly desired that noise reduction or noise elimination be attained, while at the same time maintaining exhaust efficiency.
- When design of an exhaust system is considered only in terms of exhaust efficiency, a muffler (exhaust system) is preferably extended straight. However, such an exhaust system is not well accommodated in a vehicle body of a motorcycle. Accordingly, in order to lessen an exhaust resistance, the exhaust system is extended toward the rear of a vehicle body in an attempt to avoid tight radius bends, which is difficult in many cases because of the front wheel of the motorcycle and a bank angle of the combustion chamber(s). Normally, a muffler having an ideal length in terms of engine performance is only seldom accommodated intact in a configuration of a motorcycle and, as compared with design of a muffler for four-wheel passenger cars, the design of a motorcycle exhaust system to meet both performance and physical constraints is significantly more challenging. That is, it is difficult in the context of a motorcycle exhaust system to achieve a length of the exhaust system that will both provide desired performance attributes and be accommodated within the space constraints of a motorcycle while maintaining a configuration that is as smooth as possible.
- Also, not only an exhaust efficiency, but also a weight of a an exhaust system has a significant influence on the handling characteristics of a motorcycle. That is, because a motorcycle is relatively lightweight, even a weight of about one (1) kg has a great influence on the motorcycle. Moreover, because certain components of the exhaust system (e.g., the silencer) are usually located at a distance from a center of gravity of the motorcycle, the adverse influence of excess weight of the exhaust system on the handling characteristics of the motorcycle is increased.
- On the other hand, in spite of any contrivance on a construction of the exhaust system, a certain silencer (or muffler) volume is needed to some extent to provide a noise reducing effect. In order to conform to regulations on noise, which are made increasingly rigorous, a silencer cannot but be made larger in many cases. Moreover, when a metallic sheet from which the silencer is constructed is thin, it vibrates thereby increasing noise. To avoid such a situation, the silencer is by all means liable to be relatively large in weight. An increase in the weight of the silencer results in undesired handling characteristics of the associated motorcycle.
- In this manner, since a structure of an exhaust system for motorcycles is determined in terms of a variety of interrelated factors, it has been extremely difficult to realize an exhaust system in which miniaturization is achieved and a desired exhaust efficiency and noise-reduction characteristics are met.
- At least some of the preferred embodiments of the present invention provide an exhaust system for straddle-type vehicles, such as motorcycles, in which miniaturization is achieved while a demand for noise reduction characteristics are met.
- Certain preferred embodiments of the invention provide an exhaust system for a straddle-type vehicle, comprising an engine, and an exhaust system including an exhaust pipe connected to the engine and a silencer connected to the exhaust pipe. A volume of the silencer and a volume of the exhaust pipe have a ratio between about 0.7 and 1.4.
- In a preferred embodiment, the exhaust system described above comprises a damping means for an improvement of a damping characteristic in a low frequency range, and a volume of the exhaust pipe and a volume of the silencer are substantially equal to each other to thereby realize the damping means. In some arrangements, the damping means decreases a level of a primary resonance frequency of an exhaust pipe length of the exhaust pipe in the exhaust part.
- In a preferred embodiment, the exhaust system described above includes a tail pipe connected to the silencer, and the volume of the silencer is a volume obtained by subtracting a volume occupied therein by the exhaust pipe and the tail pipe from an inner volume of the silencer. In some arrangements, the volume of the exhaust pipe also includes a volume of a cylinder head exhaust port portion.
- In a preferred embodiment, the silencer of the exhaust system described above comprises an outer housing and an inner core accommodated in the outer housing. Wherein at least a portion of the inner core includes a plurality of through-holes formed therein. In some arrangements, a sound absorbing material is positioned between an inner surface of the outer housing and an outer surface of the inner core. In some arrangements, the sound absorbing material comprises at least one of glass wool and stainless steel wool.
- In a preferred embodiment, the exhaust system described above includes a tail pipe connected to the silencer, and the tail pipe is radially offset relative to the exhaust pipe.
- A preferred embodiment of the exhaust system described above includes a tail pipe connected to the silencer, wherein the silencer comprises an outer housing and an inner core accommodated within the outer housing. An outside diameter of the tail pipe is smaller than an inside diameter of the inner core of the silencer. In some arrangements, the inside diameter of the inner core is gradually decreased from a forward end to a rearward end, which meets up to a front end of the tail pipe. In some arrangements, an air layer is provided between the tail pipe and the inner core.
- In a preferred embodiment, the silencer comprises an outer housing and an inner core accommodated in the outer housing. A sound absorbing material is positioned between an inner surface of the outer housing and an outer surface of the inner core. A first air layer, or air space, is provided between the inner surface of the outer housing and an outer surface of the sound absorbing material. In some arrangements, the exhaust system includes a tail pipe connected to the silencer. A second air layer, or air space, is provided between the tail pipe and the inner core, and the sound absorbing material is positioned between the second air space and the first air space.
- In a preferred embodiment, a chamber is provided in the exhaust pipe, and a volume of the exhaust pipe also includes a volume of the chamber.
- In a preferred embodiment, a conical member is provided in the silencer. Both ends of the conical member are open. At least a portion of a wall of the conical member is formed with a plurality of through-holes. In some arrangements, the silencer comprises an outer housing and an inner core within the outer housing. A tail pipe is connected to the inner core of the silencer, and the conical member is provided at an upstream end of the tail pipe. In some arrangements, a diameter of the upstream opening of the conical member is smaller than a diameter of the downstream opening.
- In a preferred embodiment, the exhaust system includes a tail pipe connected to the silencer. A first conical member is connected to the tail pipe and a second conical member at least partially overlaps the first conical member and is connected to the inner core.
- A preferred embodiment is a straddle-type vehicle incorporating any of the exhaust systems described in the above paragraphs. In some arrangements, the engine of the straddle-type vehicle operates on a four-stroke combustion principle. In a preferred embodiment, the straddle-type vehicle is an off-road motorcycle.
- These and other features, aspects and advantages of the present invention are described below with reference to drawings of preferred embodiments, which are intended to illustrate, but not to limit the present invention. The drawings contain twelve (12) figures.
-
FIG. 1 is a side view showing a motorcycle comprising an exhaust system having certain features, aspects and advantages of the present invention. -
FIG. 2 (a) is a perspective view showing the exhaust system according to the embodiment of the invention.FIG. 2 (b) is a view schematically showing an engine of the motorcycle ofFIG. 1 .FIG. 2 (c) is a perspective view showing an exhaust system in which the exhaust pipe includes an expansion chamber. -
FIG. 3 is a schematic view of the structure of an exhaust system according to the embodiment of the invention. - FIGS. 4(a) and 4(b) are perspective views showing the structures of the muffler according to the embodiment of the invention and a muffler of a comparative example.
-
FIG. 5 is a graph illustrating a comparison in damping characteristics between two embodiments of an exhaust system according to the invention and an exhaust system of a comparative example. - FIGS. 6(a) to 6(c) are cross sectional views schematically showing examples of the exhaust system according to an embodiment of the invention.
- FIGS. 7(a) and 7(b) are cross sectional views schematically showing examples of the exhaust system according to an embodiment of the invention.
- FIGS. 8(a) to 8(c) are cross sectional views schematically showing examples of the exhaust system according to an embodiment of the invention.
- FIGS. 9(a) and 9(b) are cross sectional views schematically showing examples of the exhaust system according to an embodiment of the invention.
- FIGS. 10(a) to 10(c) are cross sectional views schematically showing examples of the exhaust system according to an embodiment of the invention.
- FIGS. 11(a) to 11(c) are cross sectional views schematically showing examples of the exhaust system according to an embodiment of the invention.
-
FIG. 12 is a side view showing a motorcycle comprising the exhaust system of the comparative example. - According to preferred embodiments of the present invention, because a volume of the silencer and a volume of the exhaust pipe are selected to have a ratio between about 0.7 to 1.4, or to be substantially equal to one another, it is possible to improve the damping characteristics of the exhaust system in a low frequency range (in particular, a primary resonance frequency of an exhaust pipe length of the exhaust pipe in the exhaust system) whereby it is possible to achieve a decrease in the noise level of the exhaust system. Since an improvement in damping characteristic can be achieved by making a volume of the exhaust pipe and a volume of the silencer close to each other, rather than by increasing the volume of the silencer, it is possible to avoid an increase in weight of the silencer, so that it is possible to realize a small-sized silencer for a straddle-type vehicle. As a result, it is possible to improve the handling characteristics of a motorcycle utilizing embodiments of the exhaust system.
- While an exhaust system for a motorcycle is designed under various restrictions, conventional design philosophy is that a noise reducing effect cannot be actually produced unless the silencer is increased in volume. On the other hand, it is not possible to avoid a phenomenon in which an increase in volume of the silencer brings about an adverse affect on the handling characteristics of the motorcycle. In a muffler in, for example, present four-stroke motocross motorcycles (in particular, sports vehicles), a silencer is increased in volume whereby noise reduction and running performance are met, so that the muffler is large and heavy.
- The present inventors have realize an exhaust device (muffler), which is small-sized and light while meeting performance criteria (exhaust property) and a noise characteristics. Embodiments of the invention are described below with reference to the drawings. In addition, the invention is not limited to the following embodiment.
-
FIG. 1 shows amotorcycle 1000, on which an exhaust device, or exhaust system, according to an embodiment of the invention is mounted. Themotorcycle 1000 includes anengine 50 and anexhaust system 100 connected to theengine 50. Theexhaust system 100 includes anexhaust pipe 20 and asilencer 10. In addition, theexhaust system 100 including thesilencer 10 is in some cases referred to as a “muffler” in the specification of the present application for the sake of convenience. - The
muffler 100 includes theexhaust pipe 20 connected to theengine 50 of themotorcycle 1000, and thesilencer 10 connected to theexhaust pipe 20. With a construction shown inFIG. 1 , atail pipe 30 is connected to thesilencer 10. - A state, in which the
muffler 100 is removed from themotorcycle 1000, is shown inFIG. 2 (a). Theexhaust pipe 20 and thesilencer 10 of themuffler 100 shown inFIG. 2 (a) are formed with members for mounting to a vehicle body. The illustratedmuffler 100 is one for four-stroke engines and themotorcycle 1000 shown inFIG. 1 is an off-road vehicle. In addition, in theexhaust pipe 20 shown inFIG. 2 (a), its end connected to theengine 50 mounts thereto a cylinderhead exhaust port 22. - The
exhaust pipe 20 connects to an exhaust opening of theengine 50 as shown inFIG. 2 (b) to lead exhaust gases from theengine 50 to thesilencer 10. In an example as shown, the cylinderhead exhaust port 22 of theexhaust pipe 20 is connected to theengine 50. Thesilencer 10 has a noise reducing function to discharge exhaust gases led from theexhaust pipe 20 to the environment. In the case where thetail pipe 30 is connected to thesilencer 10, exhaust gases are discharged from thetail pipe 30. In addition, anexpansion chamber 21 can be further provided in theexhaust pipe 20 as shown inFIG. 2 (c). In this case, exhaust gases from theengine 50 are once expanded in thechamber 21 and then led to thesilencer 10 to be discharged to the environment. -
FIG. 3 schematically shows the structure of themuffler 100 according to the embodiment. Themuffler 100 according to the embodiment is structured such that a volume (Vp) of theexhaust pipe 20 is substantially equal to a volume (Vc) of thesilencer 10. - The volume (Vc) of the
silencer 10 is a volume obtained by subtracting a volume occupied therein by theexhaust pipe 20 from an interior of thesilencer 10. Also, in the case where thetail pipe 30 is connected to thesilencer 10, the volume (Vc) of thesilencer 10 is a volume obtained by subtracting a volume occupied therein by theexhaust pipe 20 and thetail pipe 30 from an interior of thesilencer 10. In the case where thechamber 21 is formed in theexhaust pipe 20, a volume of thechamber 21 constitutes a part of a volume occupied by theexhaust pipe 20. Preferably, a volume (Vh) of the cylinderhead exhaust port 22 also constitutes a part of a volume occupied by theexhaust pipe 20. Thus, because an exhaust system is typically constructed for a specific vehicle, the volume of theexhaust port 22 will be known, and can be considered in the design of theexhaust pipe 20 andsilencer 10. - Since the
muffler 100 is structured so that the volume (Vp) of theexhaust pipe 20 and the volume (Vc) of thesilencer 10 are made substantially equal to each other, it is possible to improve a damping characteristic of a low frequency range of themuffler 100, in particular, a primary resonance frequency fl. More specifically, a primary resonance frequency fl of an exhaust pipe length of theexhaust pipe 20; referred below in some cases to as “a primary resonance frequency fl of a muffler” for convenience' sake. When a noise value in a low frequency range is decreased, sound waves having a large energy can be reduced in volume, so that the noise value can be decreased only by damping a noise value of a primary resonance frequency (f1) of the muffler. Specifically, damping can be achieved until noise regulations can be met. - With the illustrated arrangement, an improvement in damping characteristic can be achieved by making the volume (Vp) of the
exhaust pipe 20 and the volume (Vc) of thesilencer 10 close to each other instead of increasing themuffler 100 volume, so that it is possible to avoid an increase in muffler weight. That is, themuffler 100 according to the embodiment includes damping means for an improvement in damping characteristic in a low frequency range (in particular, a primary resonance frequency f1) and the volume (Vp) of theexhaust pipe 20 and the volume (Vc) of thesilencer 10 are made substantially equal to each other to thereby realize the damping means, so that it is not necessary to make themuffler 100 larger in volume than needed and there is no need for any separately independent, new member as damping means, thus enabling a small-sized muffler 100 to be realized. - As a specific example, the structure of the
muffler 100 according to the embodiment will be described with reference toFIG. 4 .FIG. 4 (a) shows amuffler 100 having a structure according to an embodiment of the invention andFIG. 4 (b) shows amuffler 200 as a comparative example. -
Exhaust pipes silencers - The
silencer 10A shown inFIG. 4 (b) has a considerably larger volume than that of theexhaust pipe 20A according to a typical design technique in order to obtain a favorable noise reducing characteristic (damping characteristic). Specifically, the volume of thesilencer 10A exceeds twice the volume of theexhaust pipe 20A, and more specifically, is about 2.5 times the latter. - On the other hand, the
silencer 10 shown inFIG. 4 (a) has a volume near to the volume of theexhaust pipe 20 contrary to the typical design technique. Specifically, the volume of thesilencer 10 is nearly 1.4 times or less the volume of theexhaust pipe 20. More specifically, it is desired that the volume of thesilencer 10 be in the range of 1.2 to 0.7 times the volume of theexhaust pipe 20. - Making a comparison in weight between the both, the weight of the
silencer 10 amounts only to around 60% of the weight of thesilencer 10A. A decrease in weight of thesilencer 10 not only produces an effect of a decrease in total weight of themotorcycle 1000 but contributes much to an improvement in handling characteristics of themotorcycle 1000 since a member or members positioned distant from a vehicle body center (or, a center of gravity of a vehicle body) of themotorcycle 1000 can be reduced in weight. -
FIG. 12 shows a construction, in which themuffler 200 of a comparative example shown inFIG. 4 (b) is mounted to a motorcycle. Making a comparison between both amotorcycle 2000 shown inFIG. 12 and themotorcycle 1000, according to the embodiment, shown inFIG. 1 , it is possible to understand how small the muffler becomes in size and volume. As described above, it is an unexpected result that a small-sized andlightweight muffler 100 could be provide favorable performance and favorable noise reducing characteristics, in view of the convention design theory of increasing the volume of the muffler in order to obtain a favorable noise reduction. - Also, as described below, the
muffler 100 is capable of decreasing a noise value further than themuffler 200, which is large in muffler volume. This demonstrates that themuffler 100 according to the preferred embodiments produces excellent, and unexpected, technical results. -
FIG. 5 is a graph illustrating damping characteristics of themuffler 100 and themuffler 200 of the comparative example. The damping characteristic of themuffler 100 according to the embodiment is indicated by plots in anEmbodiment 1 and an Embodiment 2 while the damping characteristic of themuffler 200 is indicated by plots in the comparative example. - In a low frequency range,
Embodiment 1, Embodiment 2 and the comparative example are substantially the same in a damping characteristic of f0 (damping level (dB)) but it is found thatEmbodiment 1 and Embodiment 2 are favorable in a damping characteristic (damping level (dB)) of f1 (primary resonance frequency of an exhaust pipe length of the exhaust pipe in the exhaust part) as compared with the comparative example. In other words,Embodiment 1 and Embodiment 2 are low in noise value of fl as compared with the comparative example. The reason why the noise value of f1 is small inEmbodiment 1 and Embodiment 2 is that the volume (Vc) of thesilencer 10 and the volume (Vp) of theexhaust pipe 20 have a ratio between about 0.7 and 1.4 and, in some arrangements, are substantially equal to each other. - With such a construction, the reason why the noise value in a low frequency range (in particular, f1) can be decreased is as follows. If a muffler were composed of only the exhaust pipe 20 (without the silencer 10), f1 would be a resonance frequency of ¼ wavelength determined by an exhaust pipe length and be suddenly changed into a resonance frequency, at which the both parts (20, 10) were coupled together, in a configuration, in which the
silencer 10 were added to theexhaust pipe 20. Here, a strongest coupled state corresponds to the case where the both parts (20, 10) are equal to each other in resonance frequency, which means in other acoustic terms that the both parts are equal to each other in volume. Moreover, when a sound absorbing material is filled in one of them in this state, it is possible to efficiently damp the frequency. - Also, when the resonance frequency f1 is to be decreased, volumes (Vp, Vc) of the
exhaust pipe 20 and thesilencer 10 are influenced thereby, but even when theexhaust pipe 20 is bent, there is caused no substantial influence, which provides a design advantage in that theexhaust pipe 20 can be designed to fit within an available or desirable space of the associated vehicle. - In addition, as described above, even in the case where, for example, the
chamber 21 is provided on theexhaust pipe 20 and a part of theexhaust pipe 20 is bulged, the volume (Vp) of theexhaust pipe 20 may include a volume of thechamber 21 and the volume (Vp) of theexhaust pipe 20 and the volume (Vc) of thesilencer 10 are made close to each other. In addition, the same is also the case with a volume of the cylinder headexhaust port portion 22. - In addition, a frequency f0 (Hz) generated by resonance of the whole muffler can be found by, for example, the following formula in the construction shown in
FIG. 3 :
f0=(c/2π)·{S/(V·L)}½ - Here, “c” indicates a velocity of sound, “V” indicates an exhaust system volume (that is, “Vp+Vc”), “L” indicates a length of the
tail pipe 30, and “S” indicates a cross sectional area of thetail pipe 30. - When a ratio of the volume (Vp) of the
exhaust pipe 20 and the volume (Vc) of thesilencer 10 is ideally made 1:1 in the graph of damping characteristic shown inFIG. 5 , the noise value of f1 inEmbodiment 1 and Embodiment 2 can be further damped. - Since the
exhaust pipe 20 is actually formed as shown in, for example,FIG. 4 to be bent in order to meet various design conditions and the size and weight of thesilencer 10 is also determined in conformity to other conditions (vehicle body weight, vehicle body balance, etc.), however, it is unnecessary in many cases to maintain the ratio of the volume (Vp) of theexhaust pipe 20 and the volume (Vc) of thesilencer 10 to an ideal 1:1 provided that an effect of a decrease in noise value is produced. That is, provided that a desired effect of a decrease in noise value is produced by making the volume (Vp) of theexhaust pipe 20 and the volume (Vc) of thesilencer 10 close to each other contrary to conventional technical thought that it is desirable in a typical muffler design to make thesilencer 10 large in volume (for example, Vc/Vp>2), it is possible to change a design of theexhaust pipe 20 and thesilencer 10 in that range, in which such effect is produced (as an example, about 1.2 times to about 0.7 times, or about 1.4 times to about 0.7 times). - In the graph shown in
FIG. 5 , it is found that the damping characteristic of the muffler inEmbodiment 1 and Embodiment 2 is favorable (that is, noise can be decreased) in a low frequency range (for example, in the order of 600 to 800 Hz), and the comparative example demonstrates a favorable damping characteristic in a frequency range therebeyond. Accordingly, with themuffler 100 according to the embodiment of the invention, a decrease in noise component in a low frequency range is achieved by damping means (damping means for an improvement of a damping characteristic in a low frequency range), which is realized by making the volume (Vp) of theexhaust pipe 20 and the volume (Vc) of thesilencer 10 substantially equal to each other, and a decrease in noise component in a frequency range therebeyond can also be achieved by other techniques. - Modifications of the
muffler 100 according to the embodiment will be described below with reference to FIGS. 6 to 11. The respective figures schematically show a structure of thesilencer 10 in themuffler 100 according to various embodiments of the present invention, (a) being lateral, cross sectional views, and (b) being cross sectional views as viewed from the rear of a vehicle body. In addition, (c) are partially enlarged views in (a). - The
silencer 10 shown inFIG. 6 comprises an outer housing, orcylinder 10 a, and an inner core, orcylinder 10 b, accommodated in theouter cylinder 10 a. Through-holes 13 are formed in at least a part (region P) of the wall of theinner cylinder 10 b of thesilencer 10 and may be referred to herein as “punched holes,” although theholes 13 may be produced by any suitable method. - The punched holes 13 are small holes formed in the silencer 10 (here, the
inner cylinder 10 b) and serve to enable energy of exhaust gases, which are introduced from theexhaust pipe 20, to be led to the outer cylinder l0 a through the small holes. In an example shown inFIG. 6 , asound absorbing material 15 is positioned in a manner to come into close contact between an inner surface of the outer cylinder 1Oa and an outer surface of theinner cylinder 10 b. - The
sound absorbing material 15 is a material capable of absorbing sound waves and can use, for example, glass wool, stainless steel wool (SUS wool), aluminum wool, ferrite, asbestos, etc. In this example, glass wool is used as thesound absorbing material 15. Thesound absorbing material 15 fairly absorbs a high frequency sound but is less effective in low frequency sound, so that a synergistic effect is produced when combined with the construction of themuffler 100 according to the illustrated embodiment. - In this example, a
SUS wool 15 b is provided on the outer surface of theinner cylinder 10 b and aglass wool 15 a is provided on an outer periphery thereof. In other words, theSUS wool 15 b is provided on the outer surface of theinner cylinder 10 b and theglass wool 15 a is provided on the inner surface of theouter cylinder 10 a. Also, theinner cylinder 10 b is gradually decreased in inside diameter up to a front end of thetail pipe 30. With asilencer 10 as shown inFIG. 7 , anair layer 17, or air space, is formed between atail pipe 30 and aninner cylinder 10 b. Specifically, an outside diameter d of thetail pipe 30 is smaller than an inside diameter D of theinner cylinder 10 b of thesilencer 10. In this example, punched holes (region P) are formed in as far as a region (a region, in which theair layer 17 is positioned), in which thetail pipe 30 is positioned. In addition, a cross sectional structure of thesilencer 10 shown inFIG. 7 is substantially the same as that shown in the partially enlarged view ofFIG. 6 (c). - The construction shown in this example can incorporate a damping characteristic in which noise elimination is achieved by varying (enlarging) a pipe (cylinder) in cross sectional area, and such combination makes it possible to regulate the damping characteristic of the
muffler 100. Specifically, the pipe (cylinder) is changed in cross sectional area to enable obtaining a damping characteristic, in which sounds mainly in a low frequency range are eliminated. Also, the provision of theair layer 17 enables producing both effects of noise reduction by thesound absorbing material 15 and noise reduction by pipe bulging, or an expansion chamber effect. - The
silencer 10 shown inFIG. 8 has a structure similar to that inFIG. 6 , but asound absorbing material 15 is arranged on an outer surface of an inner cylinder 1Ob and anair layer 19 is present on an inner surface of anouter cylinder 10 a, in which nosound absorbing material 15 is filled. - Here, the
sound absorbing material 15 comprises a combination ofSUS wool 15 b andglass wool 15 a in the same manner as that shown inFIG. 6 . In addition, as shown inFIG. 8 (c), apartition 10 c, which supports the sound absorbing material 15 (15 a, 15 b), is provided and punchedholes 13 are formed on at least a portion of thepartition 10 c. - With such construction, it is possible to regulate a damping characteristic of the
muffler 100 according to the embodiment owing to both effects of noise reduction by thesound absorbing material 15 and noise reduction by an expansion chamber effect. - A
silencer 10 shown inFIG. 9 incorporates a feature of the structure shown inFIG. 7 into the structure shown inFIG. 8 such that anair layer 17 is formed between atail pipe 30 and aninner cylinder 10 b. Such a structural feature (that is, a structural feature that thesound absorbing material 15 is arranged between the air layer (first air layer) 19 provided between the inner surface of theouter cylinder 10 a and the outer surface of thesound absorbing material 15 and the air layer (second air layer) 17 provided between thetail pipe 30 and theinner cylinder 10 b) regulates a damping characteristic of themuffler 100. In addition, a cross sectional structure of thesilencer 10 shown inFIG. 9 is substantially the same as that shown in the partially enlarged view ofFIG. 8 (c). - In addition, the
silencer 10 according to the embodiment is not limited to a structure, which comprises theouter cylinder 10 a and theinner cylinder 10 b accommodated in theouter cylinder 10 a, but can adopt a structure shown inFIG. 10 . That is, it suffices to design amuffler 100 having a desired damping characteristic by the use of further means, which combines with damping means in a low frequency range, which is realized by making the volume (Vp) of theexhaust pipe 20 and the volume (Vc) of thesilencer 10 substantially equal to each other, to enable reinforcing the damping means. Here, thesound absorbing material 15 inFIG. 10 (c) comprises, for example, SUS wool, or glass wool, or a combination thereof. - Also, with a
silencer 10 shown inFIG. 10 , an axis of thetail pipe 30 is radially offset relative to an axis of the portion of theexhaust pipe 20 connecting with, or positioned within, thesilencer 10. With such a structure, even when an air layer about theexhaust pipe 20 is decreased in cross sectional area by asound absorbing material 15, such a decrease can be compensated for by a cross sectional area of thetail pipe 30. - A construction, in which at least one
conical member 32 is arranged in asilencer 10 as shown in, for example,FIG. 11 , can be adopted as an example of such a further means to create a damping effect. Theconical member 32 comprises a member, which is in the form of a cone with a tip end thereof opened and formed with punchedholes 13 in asidewall 35 of theconical member 32. The provision of such a conical member can produce an effect of noise reduction or elimination and a directly transmitting sound of exhaust noise can be decreased. - An
opening 37 provided on the conical member has an opening diameter at an upstream end thereof, which is made smaller than an opening diameter at a downstream end thereof. Thereby, it is possible to prevent direct transmission of noise, thus enabling improving a damping effect. It is possible to arrange one or pluralconical members 32 within thesilencer 10. According to the embodiment, theconical members 32 are provided in two locations (32 a, 32 b) on theinner cylinder 10 b and an upstream end of thetail pipe 30. In addition, it is possible to provide only oneconical member 32 instead of several in number and to provide three or more conical members. - In addition, “upstream” side and “downstream” side referred to in the specification of the present application mean an upstream side and a downstream side, respectively, in a direction, in which exhaust gases in the muffler flow. In other words, “upstream” side is that side, on which an engine is arranged, and “downstream” side is that side, on which exhaust gases are discharged to the environment.
- In the example shown in
FIG. 11 , theconical member 32 is provided at an end of thetail pipe 30. Specifically, the conical member includes afirst cone 32 a connected to thetail pipe 30 and asecond cone 32 b, which covers (i.e., at least partially overlaps) thefirst cone 32 a and is connected to theinner cylinder 10 b. By providing a plurality (32 a, 32 b) of theconical members 32, it is possible to further improve a damping effect. - In addition, while
FIG. 1 shows an off-road motorcycle as an example of themotorcycle 1000, themotorcycle 1000 may be constructed for on-road use as well. Also, “motorcycle” or “straddle-type vehicle” in the specification of the present application refers to a motorcycle and also means any vehicle, which includes but is not limited to a bicycle with a motor (motorbike) and a scooter and other vehicles that can turn with a vehicle body inclined. Accordingly, a three-wheeler/four-wheeler, at least one of a front wheel and a rear wheel of which has two or more wheels and which is three, four (or more) in the number of tires, is also intended to be included in the definition of a “motorcycle” or “straddle-type vehicle.” Thus, applicability of the present invention is not limited to a motorcycle but to other vehicles capable of making use of the effect of the invention, for example, a so-called straddle-type vehicle, which includes four-wheeled buggies, ATV's (All Terrain Vehicle's), and snowmobiles. - While the invention has been described with respect to preferred embodiments, such descriptions are not limitative but various modifications are of course possible. According to preferred embodiments of the invention, it is possible to provide a muffler for a straddle-type vehicle, which achieves miniaturization while meeting a demand for a noise reducing characteristic.
- Although this invention has been disclosed in the context of certain preferred embodiments and examples, it will be understood by those skilled in the art that the present invention extends beyond the specifically disclosed embodiments to other alternative embodiments and/or uses of the invention and obvious modifications and equivalents thereof. In particular, while the present exhaust system and vehicle incorporating the exhaust system have been described in the context of particularly preferred embodiments, the skilled artisan will appreciate, in view of the present disclosure, that certain advantages, features and aspects of the system may be realized in a variety of other applications, many of which have been noted above. Additionally, it is contemplated that various aspects and features of the invention described can be practiced separately, combined together, or substituted for one another, and that a variety of combination and subcombinations of the features and aspects can be made and still fall within the scope of the invention. Thus, it is intended that the scope of the present invention herein disclosed should not be limited by the particular disclosed embodiments described above, but should be determined only by a fair reading of the claims.
Claims (24)
1. An exhaust system for a vehicle, comprising:
an exhaust conduit having a first end communicating with a combustion chamber of an engine of the vehicle; and
a silencer, a second end of the exhaust conduit communicating with the silencer;
wherein a ratio of a volume of the silencer to a volume of the exhaust conduit is between about 0.7 and about 1.4.
2. The exhaust system of claim 1 , wherein the ratio between the volume of the silencer and the volume of the exhaust conduit is selected to improve a noise damping characteristic of the exhaust system in a low frequency range.
3. The exhaust system of claim 1 , wherein a portion of the exhaust conduit is defined by an exhaust pipe and the ratio between the volume of the silencer and the volume of the exhaust conduit is selected to decrease a level of a primary resonance frequency of the exhaust pipe.
4. The exhaust system of claim 1 , further comprising a tail pipe communicating with the silencer, wherein the volume of the silencer is defined by an interior volume of the silencer minus a volume of the tail pipe that is within the interior volume of the silencer.
5. The exhaust system of claim 4 , wherein the volume of the exhaust conduit includes a volume of an exhaust port of the engine of the vehicle.
6. The exhaust system of claim 1 , wherein the volume of the silencer and the volume of the exhaust conduit are substantially equal.
7. The exhaust system of claim 1 , wherein the silencer comprises an outer housing and an inner core accommodated within the outer housing, and wherein at least a portion of the inner core includes a plurality of through-holes.
8. The exhaust system of claim 7 , wherein a sound absorbing material is positioned between an inner surface of the outer housing and an outer surface of the inner core of the silencer.
9. The exhaust system of claim 8 , further comprising a tail pipe communicating with the silencer, wherein an axis of the tail pipe is radially offset from an axis of the second end of the exhaust conduit that communicates with the silencer.
10. The exhaust system of claim 8 , wherein the sound absorbing material comprises at least one of glass wool and stainless steel wool.
11. The exhaust system of claim 1 , further comprising a tail pipe connected to the silencer, the silencer comprising an outer housing and an inner core within the outer housing, wherein an outside diameter of the tail pipe is smaller than an inside diameter of the inner core.
12. The exhaust system of claim 11 , wherein the inside diameter of the inner core gradually decreases from a forward end toward a rearward end, wherein the rearward end meets up with a forward end of the tail pipe.
13. The exhaust system of claim 11 , wherein an air space is provided between the tail pipe and the inner core.
14. The exhaust system of claim 1 , wherein the silencer comprises an outer housing and an inner core within the outer housing, and wherein a sound absorbing material is positioned between an inner surface of the outer housing and an outer surface of the inner core, further comprising a first air space between the inner surface of the outer housing and an outer surface of the sound absorbing material.
15. The exhaust system of claim 14 , further comprising a tail pipe connected to the silencer, wherein a second air space is provided between the tail pipe and the inner core, and the sound absorbing material is positioned between the second air space and the first air space.
16. The exhaust system of claim 1 , wherein a chamber is provided in the exhaust conduit, and a volume of the exhaust conduit includes a volume of the chamber.
17. The exhaust system of claim 1 , further comprising at least one conical member within the silencer, wherein a plurality of through-holes are formed in a wall of the conical member and each end of the conical member is open.
18. The exhaust system of claim 17 , wherein the silencer comprises an outer housing and an inner core within the outer housing, and wherein a tail pipe is connected to the inner core, the at least one conical member being positioned at an upstream end of the tail pipe.
19. The exhaust system of claim 18 , wherein an upstream opening of the at least one conical member is smaller than a downstream opening of the conical member.
20. The exhaust system of claim 17 , wherein the exhaust system includes a tail pipe connected to the silencer, the at least one conical member comprising a first conical member connected to the tail pipe and a second conical member connected to the inner core, wherein the second conical member overlaps at least a portion of the first conical member.
21. A straddle-type vehicle, comprising:
an engine comprising at least one combustion chamber;
an exhaust conduit having a first end communicating with the combustion chamber; and
a silencer, a second end of the exhaust conduit communicating with the silencer;
wherein a ratio of a volume of the silencer to a volume of the exhaust conduit is between about 0.7 and about 1.4.
22. The straddle-type vehicle of claim 21 , wherein the volume of the exhaust conduit includes a volume of an exhaust port of the engine.
23. The straddle-type vehicle of claim 21 , wherein the engine operates on a four- stroke principle.
24. The straddle-type vehicle of claim 23 , wherein the vehicle is an off-road motorcycle.
Applications Claiming Priority (4)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2006-092334 | 2006-03-29 | ||
JP2006092334 | 2006-03-29 | ||
JP2007-031097 | 2007-02-09 | ||
JP2007031097A JP2007292046A (en) | 2006-03-29 | 2007-02-09 | Exhaust apparatus for straddle-type vehicle and straddle-type vehicle |
Publications (1)
Publication Number | Publication Date |
---|---|
US20070227809A1 true US20070227809A1 (en) | 2007-10-04 |
Family
ID=38151132
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US11/692,824 Abandoned US20070227809A1 (en) | 2006-03-29 | 2007-03-28 | Vehicle exhaust system |
Country Status (5)
Country | Link |
---|---|
US (1) | US20070227809A1 (en) |
EP (1) | EP1840342B1 (en) |
JP (1) | JP2007292046A (en) |
AT (1) | ATE505632T1 (en) |
DE (1) | DE602007013831D1 (en) |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20070205044A1 (en) * | 2006-02-07 | 2007-09-06 | Bae Seong W | Silencer |
US20100300072A1 (en) * | 2007-05-14 | 2010-12-02 | Renault S.A.S. | Coupling of a turbocharger with an oxidation catalyst of an exhaust line of an internal combustion engine |
ES2388023A1 (en) * | 2009-03-16 | 2012-10-05 | Honda Motor Co. Ltd | Exhaust device for engine |
Families Citing this family (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2009133288A (en) | 2007-11-30 | 2009-06-18 | Yamaha Motor Co Ltd | Exhaust device for straddle-type vehicle and straddle-type vehicle |
JP5906663B2 (en) * | 2011-10-27 | 2016-04-20 | スズキ株式会社 | Engine exhaust system |
JP2019056310A (en) * | 2017-09-20 | 2019-04-11 | 中川産業株式会社 | Tail pipe |
Citations (39)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US1820972A (en) * | 1929-07-05 | 1931-09-01 | Buffalo Pressed Steel Company | Muffler |
US1844105A (en) * | 1929-05-08 | 1932-02-09 | Burgess Lab Inc C F | Exhaust muffler |
US1991014A (en) * | 1931-10-14 | 1935-02-12 | John J Compo | Muffler |
US2008964A (en) * | 1933-12-26 | 1935-07-23 | Ellsworth H Munford | Muffler |
US2065343A (en) * | 1930-11-13 | 1936-12-22 | M & M Engineering Corp | Exhaust muffler |
US2115128A (en) * | 1936-12-14 | 1938-04-26 | Buffalo Pressed Steel Company | Muffler |
US2150530A (en) * | 1937-10-14 | 1939-03-14 | Martin L Warsing | Muffler |
US2234612A (en) * | 1938-02-23 | 1941-03-11 | Wold Wilhelm Petersen | Silencer for internal combustion engines |
US2512155A (en) * | 1949-02-19 | 1950-06-20 | Gordon C Hill | Muffler with plural perforated conical baffles |
US2523260A (en) * | 1946-03-28 | 1950-09-26 | John M Campbell | Baffle type muffler with refractory lining |
US2543461A (en) * | 1949-07-20 | 1951-02-27 | Aero Sonic Corp | Muffler with plural side branch chambers |
US2640557A (en) * | 1950-12-13 | 1953-06-02 | Fuller Co | Retroverted passage type muffler with outer conduit formed of sound absorbing material |
US3710891A (en) * | 1971-08-25 | 1973-01-16 | R Flugger | Automotive muffler |
US3786791A (en) * | 1972-01-27 | 1974-01-22 | Hoehn A | Exhaust control method and apparatus |
US3982605A (en) * | 1975-05-05 | 1976-09-28 | The Carborundum Company | Nozzle noise silencer |
US4108275A (en) * | 1977-05-31 | 1978-08-22 | Black William M | Muffler |
US4192402A (en) * | 1977-05-27 | 1980-03-11 | Honda Giken Kogyo Kabushiki Kaisha | Muffler for internal combustion engines |
US4360076A (en) * | 1976-03-24 | 1982-11-23 | Nihon Rajieeta Kabushiki Kaisha (Nihon Radiator Co., Ltd.) | Muffler |
US4580656A (en) * | 1984-04-06 | 1986-04-08 | Sankei Giken Kogyo Kabushiki Kaisha | Absorbent retainer for absorbent type muffler |
US4589517A (en) * | 1983-11-30 | 1986-05-20 | Saikei Giken Kogyo Kabushiki Kaisha | Muffler |
US4595073A (en) * | 1984-05-14 | 1986-06-17 | Nelson Industries Inc. | Plug-type muffler section |
US4674594A (en) * | 1984-05-07 | 1987-06-23 | Johannes Pedersen | Silencer and a method of manufacturing the silencer |
US4700805A (en) * | 1984-09-20 | 1987-10-20 | Mitsubishi Denki Kabushiki Kaisha | Muffler for exhaust gas from internal combustion engine |
US5107953A (en) * | 1988-07-15 | 1992-04-28 | Nippon Petrochemicals Co., Ltd. | Muffler |
US5350888A (en) * | 1992-05-01 | 1994-09-27 | Tennessee Gas Pipeline Company | Broad band low frequency passive muffler |
US5365025A (en) * | 1992-01-24 | 1994-11-15 | Tennessee Gas Pipeline Company | Low backpressure straight-through reactive and dissipative muffler |
US5371331A (en) * | 1993-06-25 | 1994-12-06 | Wall; Alan T. | Modular muffler for motor vehicles |
US5509947A (en) * | 1994-04-04 | 1996-04-23 | Burton; John E. | Supplemental spark arrester and silencer |
US5661272A (en) * | 1995-01-27 | 1997-08-26 | Iannetti; Francesco E. | Engine noise reduction apparatus |
US5663537A (en) * | 1995-05-16 | 1997-09-02 | Ko; Tse-Hao | Assembly of an exhaust pipe unit and a muffling device |
US5902970A (en) * | 1995-07-17 | 1999-05-11 | Ferri; Alain | Muffler for internal combustion engines, especially in aviation of improved geometry and material |
US5962821A (en) * | 1995-01-27 | 1999-10-05 | Iannetti; Francesco E. | Internal combustion engine noise reduction apparatus |
US5969299A (en) * | 1997-03-25 | 1999-10-19 | Honda Giken Kogyo Kabushiki Kaisha | Exhaust system for vehicle |
US6026930A (en) * | 1996-10-31 | 2000-02-22 | Honda Giken Kogyo Kabushiki Kaisha | Exhaust apparatus of vehicles |
US6070695A (en) * | 1995-01-11 | 2000-06-06 | Kabushiki Kaisha Yutaka Giken | Silencer |
US6260659B1 (en) * | 1999-02-09 | 2001-07-17 | Honda Giken Kogyo Kabushiki Kaisha | Silencer for internal combustion engine |
US20020134614A1 (en) * | 2001-03-23 | 2002-09-26 | Shun-Lai Chen | Structure of a muffler at the rear of exhaust pipe |
US6571910B2 (en) * | 2000-12-20 | 2003-06-03 | Quiet Storm, Llc | Method and apparatus for improved noise attenuation in a dissipative internal combustion engine exhaust muffler |
US20030136607A1 (en) * | 2001-12-19 | 2003-07-24 | Noriyuki Kawamata | Exhaust apparatus for vehicle |
Family Cites Families (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
FR1347893A (en) * | 1962-11-23 | 1964-01-04 | Silencer for pulsating gas flow | |
GB8411431D0 (en) * | 1984-05-03 | 1984-06-06 | Dixon Racing Ltd | Exhaust silencer |
JPH0681901B2 (en) * | 1986-06-19 | 1994-10-19 | ヤマハ発動機株式会社 | Exhaust system for 2-cycle engine |
JP2687549B2 (en) * | 1989-03-01 | 1997-12-08 | スズキ株式会社 | Exhaust system for four-cycle four-cylinder engine |
-
2007
- 2007-02-09 JP JP2007031097A patent/JP2007292046A/en not_active Withdrawn
- 2007-03-28 US US11/692,824 patent/US20070227809A1/en not_active Abandoned
- 2007-03-28 EP EP07251315A patent/EP1840342B1/en not_active Not-in-force
- 2007-03-28 AT AT07251315T patent/ATE505632T1/en not_active IP Right Cessation
- 2007-03-28 DE DE602007013831T patent/DE602007013831D1/en active Active
Patent Citations (40)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US1844105A (en) * | 1929-05-08 | 1932-02-09 | Burgess Lab Inc C F | Exhaust muffler |
US1820972A (en) * | 1929-07-05 | 1931-09-01 | Buffalo Pressed Steel Company | Muffler |
US2065343A (en) * | 1930-11-13 | 1936-12-22 | M & M Engineering Corp | Exhaust muffler |
US1991014A (en) * | 1931-10-14 | 1935-02-12 | John J Compo | Muffler |
US2008964A (en) * | 1933-12-26 | 1935-07-23 | Ellsworth H Munford | Muffler |
US2115128A (en) * | 1936-12-14 | 1938-04-26 | Buffalo Pressed Steel Company | Muffler |
US2150530A (en) * | 1937-10-14 | 1939-03-14 | Martin L Warsing | Muffler |
US2234612A (en) * | 1938-02-23 | 1941-03-11 | Wold Wilhelm Petersen | Silencer for internal combustion engines |
US2523260A (en) * | 1946-03-28 | 1950-09-26 | John M Campbell | Baffle type muffler with refractory lining |
US2512155A (en) * | 1949-02-19 | 1950-06-20 | Gordon C Hill | Muffler with plural perforated conical baffles |
US2543461A (en) * | 1949-07-20 | 1951-02-27 | Aero Sonic Corp | Muffler with plural side branch chambers |
US2640557A (en) * | 1950-12-13 | 1953-06-02 | Fuller Co | Retroverted passage type muffler with outer conduit formed of sound absorbing material |
US3710891A (en) * | 1971-08-25 | 1973-01-16 | R Flugger | Automotive muffler |
US3786791A (en) * | 1972-01-27 | 1974-01-22 | Hoehn A | Exhaust control method and apparatus |
US3982605A (en) * | 1975-05-05 | 1976-09-28 | The Carborundum Company | Nozzle noise silencer |
US4360076A (en) * | 1976-03-24 | 1982-11-23 | Nihon Rajieeta Kabushiki Kaisha (Nihon Radiator Co., Ltd.) | Muffler |
US4192402A (en) * | 1977-05-27 | 1980-03-11 | Honda Giken Kogyo Kabushiki Kaisha | Muffler for internal combustion engines |
US4108275A (en) * | 1977-05-31 | 1978-08-22 | Black William M | Muffler |
US4589517A (en) * | 1983-11-30 | 1986-05-20 | Saikei Giken Kogyo Kabushiki Kaisha | Muffler |
US4580656A (en) * | 1984-04-06 | 1986-04-08 | Sankei Giken Kogyo Kabushiki Kaisha | Absorbent retainer for absorbent type muffler |
US4674594A (en) * | 1984-05-07 | 1987-06-23 | Johannes Pedersen | Silencer and a method of manufacturing the silencer |
US4595073A (en) * | 1984-05-14 | 1986-06-17 | Nelson Industries Inc. | Plug-type muffler section |
US4700805A (en) * | 1984-09-20 | 1987-10-20 | Mitsubishi Denki Kabushiki Kaisha | Muffler for exhaust gas from internal combustion engine |
US5107953A (en) * | 1988-07-15 | 1992-04-28 | Nippon Petrochemicals Co., Ltd. | Muffler |
US5365025A (en) * | 1992-01-24 | 1994-11-15 | Tennessee Gas Pipeline Company | Low backpressure straight-through reactive and dissipative muffler |
US5350888A (en) * | 1992-05-01 | 1994-09-27 | Tennessee Gas Pipeline Company | Broad band low frequency passive muffler |
US5371331A (en) * | 1993-06-25 | 1994-12-06 | Wall; Alan T. | Modular muffler for motor vehicles |
US5509947A (en) * | 1994-04-04 | 1996-04-23 | Burton; John E. | Supplemental spark arrester and silencer |
US6070695A (en) * | 1995-01-11 | 2000-06-06 | Kabushiki Kaisha Yutaka Giken | Silencer |
US5962821A (en) * | 1995-01-27 | 1999-10-05 | Iannetti; Francesco E. | Internal combustion engine noise reduction apparatus |
US5661272A (en) * | 1995-01-27 | 1997-08-26 | Iannetti; Francesco E. | Engine noise reduction apparatus |
US5663537A (en) * | 1995-05-16 | 1997-09-02 | Ko; Tse-Hao | Assembly of an exhaust pipe unit and a muffling device |
US5902970A (en) * | 1995-07-17 | 1999-05-11 | Ferri; Alain | Muffler for internal combustion engines, especially in aviation of improved geometry and material |
US6026930A (en) * | 1996-10-31 | 2000-02-22 | Honda Giken Kogyo Kabushiki Kaisha | Exhaust apparatus of vehicles |
US5969299A (en) * | 1997-03-25 | 1999-10-19 | Honda Giken Kogyo Kabushiki Kaisha | Exhaust system for vehicle |
US6260659B1 (en) * | 1999-02-09 | 2001-07-17 | Honda Giken Kogyo Kabushiki Kaisha | Silencer for internal combustion engine |
US6571910B2 (en) * | 2000-12-20 | 2003-06-03 | Quiet Storm, Llc | Method and apparatus for improved noise attenuation in a dissipative internal combustion engine exhaust muffler |
US20020134614A1 (en) * | 2001-03-23 | 2002-09-26 | Shun-Lai Chen | Structure of a muffler at the rear of exhaust pipe |
US20030136607A1 (en) * | 2001-12-19 | 2003-07-24 | Noriyuki Kawamata | Exhaust apparatus for vehicle |
US6968922B2 (en) * | 2001-12-19 | 2005-11-29 | Honda Giken Kogyo Kabushiki Kaisha | Exhaust apparatus for vehicle |
Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20070205044A1 (en) * | 2006-02-07 | 2007-09-06 | Bae Seong W | Silencer |
US7624841B2 (en) * | 2006-02-07 | 2009-12-01 | Lg Electronics Inc. | Silencer |
US20100300072A1 (en) * | 2007-05-14 | 2010-12-02 | Renault S.A.S. | Coupling of a turbocharger with an oxidation catalyst of an exhaust line of an internal combustion engine |
US8584450B2 (en) * | 2007-05-14 | 2013-11-19 | Renault S.A.S. | Coupling of a turbocharger with an oxidation catalyst of an exhaust line of an internal combustion engine |
ES2388023A1 (en) * | 2009-03-16 | 2012-10-05 | Honda Motor Co. Ltd | Exhaust device for engine |
Also Published As
Publication number | Publication date |
---|---|
EP1840342A1 (en) | 2007-10-03 |
JP2007292046A (en) | 2007-11-08 |
ATE505632T1 (en) | 2011-04-15 |
EP1840342B1 (en) | 2011-04-13 |
DE602007013831D1 (en) | 2011-05-26 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US7549510B2 (en) | Vehicle exhaust system | |
EP1840343B1 (en) | Exhaust apparatus for straddle-type vehicles and straddle-type vehicle | |
US7997383B2 (en) | Vehicle exhaust system | |
US7942236B2 (en) | Exhaust device for straddle-type vehicle and straddle-type vehicle | |
US7510050B2 (en) | Vehicle exhaust systems | |
US7426980B2 (en) | Internal combustion engine exhaust system | |
US7997382B2 (en) | Exhaust device for straddle-type vehicle and straddle-type vehicle | |
US20070227809A1 (en) | Vehicle exhaust system | |
AU2005201864A1 (en) | Exhaust device for vehicle engine | |
US8136627B2 (en) | Exhaust silencer device for internal combustion engine | |
US20180051608A1 (en) | Structure of muffler | |
JP2010196545A (en) | Vehicle | |
EP3073087B1 (en) | Silencer | |
JP7006030B2 (en) | Exhaust device | |
JP3159285U (en) | Exhaust device for saddle riding type vehicle and saddle riding type vehicle | |
JP3158481U (en) | Exhaust device for saddle riding type vehicle and saddle riding type vehicle | |
JP4260585B2 (en) | Motorcycle muffler | |
JP3344239B2 (en) | Automotive exhaust silencer | |
JP2007187089A (en) | Vehicular exhaust structure |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
AS | Assignment |
Owner name: YAMAHA HATSUDOKI KABUSHIKI KAISHA, JAPAN Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:SAKURAI, TAISUKE;HAGIWARA, ITSUROU;REEL/FRAME:019431/0351 Effective date: 20070330 |
|
STCB | Information on status: application discontinuation |
Free format text: EXPRESSLY ABANDONED -- DURING EXAMINATION |