DE19652785A1 - Return system for automotive friction hydraulic clutch - Google Patents

Abstract

The return system (1) has a housing (3), which is concentric with a shaft (10) linking the engine to a gearbox. A ring piston (11) moves axially in the housing on a guide sleeve (8) which is spaced from the inner wall (6) of the housing. The ring piston bridges the space between the guide sleeve and the housing inner wall and borders an annular pressure chamber (12). The return system also has a sensor system (17a), which registers the position of the ring piston. The sensor system incorporates an annular reverberation sensor (18), which is directly or indirectly arranged at the end face of the housing. The reverberation sensor operates with an pulser (19a), which surrounds the rotary piston (11).

Description

Field of the Invention

The invention relates to a release device for a hydraulic actuated friction clutch of vehicles with a housing that conc trisch to a connecting an internal combustion engine with a manual transmission Drive shaft is arranged, and radially spaced in the recess an inner wall, a guide sleeve is used on which an annular piston is guided axially displaceably, and the annular piston a radial distance bridged between the guide sleeve and the inner wall and thus an annular pressure chamber bounded by a pressure medium is acted upon, the disengaging device still being a sensor system includes the travel of the ring piston.

Background of the Invention

The increasing automation in vehicles requires refined, diverse Control options. Coupling systems are used in motor vehicles dung, the engine automatically when the vehicle is coasting make use of the kinetic energy with which the vehicle continues  is moved. To ensure a smooth flow of traffic, the Engine can be started without delay if necessary. This happens frequently about inertia masses, the moment of inertia about a corresponding double clutch can be transferred to the crankshaft of the engine. For the Function, d. H. is the engagement behavior of the automated clutch actuation it is necessary to determine the exact position of the release bearing. It is for that known to use sensors with which the position of the release Bearing attach ring piston can be determined. The control structure of the automated clutch actuation provides that a shift of the Ring piston, which is detected by the sensor, by means of pulses or signals an electronic unit for processing the state variables passed on becomes.

From DE-A 41 20 643 a release device for a hydraulic actuated friction clutch of vehicles known with Wegmeßeinrich lines or travel path recordings of different types can be equipped can. For example, the document shows a sensor with a separa ten slider cooperates. These additional components disadvantageously enlarge the installation space of the release device and the range of components. Another Position measuring device can be integrated within the slave cylinder. The sensor is formed by a metallic housing on the inner wall spaced, a specially coated ring piston is guided. For generation A stepless route signal can be used with sensors with a variable Resistance, alternatively with a variable capacitance or a change induction. The sensor arrangements of these known Disengaging device require an adverse increase in installation space, or special shielding to achieve a trouble-free function or the Use of special parts. Common to all orders is a high one Manufacturing effort, which adversely increases the manufacturing costs.  

Object of the invention

The object of the present invention is to provide a sensor system create that in the existing space of the release device for implementation a multiple function of individual components of the release device inexpensively and can be integrated in a space-optimized manner.

Summary of the invention

According to the invention, this object is achieved by the characterizing features of Main claim solved. Thereafter, the invention includes a sensor system that a ring arranged directly or indirectly on the end face of the housing shaped Hall sensor includes. The Hall sensor is active connection to a pulse generator, which is part of the ring piston. The Arrangement of the encoder provides for the creation of a space-optimized Solution before that the pulse generator observing the ring piston before encloses the given outer contour.

From US-PS 47 05 101 is the use of a Hall sensor in an off rear device for a hydraulically operated friction clutch known comprises a stepped sleeve, which rests non-positively on the ring piston and outside is enclosed on the side by the coil spring and its axial section in the engaged position of the friction clutch close to the housing is led. This known sensor system requires a high manufacturing and Assembly effort and has a not practical construction, because the sleeve is directly exposed to pollution and thus the function, d. H. the Measured value acquisition can be influenced by the sensor.

In contrast, the invention shows a task-oriented arrangement of individual components of the sensor system within the installation space Components of the release device. The front arrangement of the hall sensors on the housing, preferably on the axially emerging from the housing  Section in which the ring piston is guided simplifies assembly. Without The pulse generator according to the invention can also be installed at great expense Ring pistons can be arranged. A thin-walled device is sufficient as a pulse generator band-shaped, electrical conductor, for example, by the ring piston an adhesive is attached. Because of the way a Hall sensor works, the measures a so-called Hall voltage as an analog variable and this directly with the strength linked to a magnetic field, magnetic fields can be measured directly. Hall sensors measure movements or positions, preferably by one Permanent magnet is moved towards or away from the sensor. Alternatively a measuring arrangement can be provided, the structure of which is immediate provides the sensor associated with the permanent magnet. For example, on Permanent magnet preloaded Hall sensor can be used with a ferromagneti a pulse generator with a ladder structure. There Hall sensors do not require mechanical elements and the voltage Hall sensors are non-contact and therefore wear-free maintenance-free and achieve a service life that exceeds that of the vehicle.

The sensor system according to the invention advantageously enables the the Hall sensor and the pulse generator within the component configuration of the Housing and the annular piston are arranged, the possibility that this Components can be retrofitted as required.

An embodiment of the invention provides an intermediate sleeve in the housing to arrange, which serves to hold the guide sleeve, the ring flange between a first end face of the intermediate sleeve and the housing is tense. On the opposite, aligned with the friction clutch The Hall sensor is attached to the front of the intermediate sleeve encoder, arranged on the ring piston, cooperates. The arrangement of the Hall sensor on the intermediate sleeve enables this to be pre-completed Components that can be mounted as a unit in the housing.  

The sensor system according to the invention preferably comprises a pulse generator, which is cast in an annular piston made of plastic. This Measure prevents damage to the pulse generator during assembly ge and allows the use of a scraper ring between the housing or the intermediate sleeve and the annular piston, with the impurities of the circumferential surface of the ring piston be removed to avoid leg the functioning of the sensor system.

A ferromagnetic metal band is suitable as a pulse generator ben is poured. The width of the metal strip corresponds to the maxima len stroke of the release bearing.

To ensure precisely defined impulses or signals from the Sensor system can be forwarded to an evaluation device, for example, The invention provides a ladder-shaped metal band. For generation a constant path signal over the entire adjustment range of the The rungs of the metal strip are exactly spaced apart from each other by annular pistons orderly. A pulse generator, its metal band for generating the same signals is provided with several exactly spaced ladder rungs Advantage that the signals for determining an exact position of the ring piston of a counter, integrated in the evaluation circuit, registered will.

The invention further includes a pulse generator in the form of a ladder designed metal tape, at the ends of ladder rungs compared to the remaining rungs are arranged with a larger cross section. A such a pulse generator generates a signal with a significantly higher voltage the reversal points compared to the tensions in the intermediate area, because the Hall sensor is weak due to the smaller ladder rungs cheres measurement signal detected. This pulse generator connected to a logical Linking enables effective path detection and exact determination the reversal points.  

Alternatively, a metal tape can be used as a pulse generator finally in the area of the reversal points, d. H. the end positions of the ring piston Has ladder rungs so that they are connected to the Hall sensor the evaluation switch-off is only transmitted a signal when the The friction clutch is in an end position. To distinguish the Turnaround points lend themselves to ladder rungs with different ones Provide cross-sectional profiles that send different signals to the evaluators conduct circuit.

It can also be advantageous to have a cross-sectional profile of the rung of the ladder To provide metal tape that designed with different ramps is, to create directional impulses, whereby the evaluation circuit the respective direction of movement of the ring piston or the release bearing is transmitted.

In an advantageous embodiment of the invention, the Hall sensor is equipped with a Scraper provided a distance between the pulse generator and the Hall sensor bridged. The scraper with good sliding properties, the For example, made of felt, plastic or PTFE, has the task of in the measuring range, for example on the outer surface of the annular piston to remove contaminants. With this measure, a Meßsi Signal falsification effectively prevented, in particular by ferromagnetic Particles can occur.

The arrangement of the Hall sensor according to the invention on the face of the housing or on an intermediate sleeve used in the intermediate housing enables a Guiding the sensor cable on the outside of the housing. This results in an easy to install, do not affect the components of the release device de Cable management, which is a significant cost compared to previous solutions advantage.  

Furthermore, the invention presents the release in the submitted end position a protected position of the sensor system. The pulse generator is thereby concentric from the intermediate sleeve and the Hall sensor from the inside ring of the release bearing enclosed.

Brief description of the drawings

The invention is explained in more detail with reference to FIGS. 1 to 6. It shows:

Figure 1 is a longitudinal section through the Ausrückvor direction according to the invention, in which the release bearing is shown in the engaged Endla ge.

Figure 2 shows the release device according to Figure 1, in which the release bearing is shown in a disengaged end position.

Fig. 3 in a simplified, schematic representation of the sensor system according to the invention with a ladder-shaped metal band as a pulse generator, which has equidistant ladder rungs and a position-positioned Hall sensor. The sensor system is assigned a diagram from which the signal course can be seen via the displacement path;

Fig. 4 shows a sensor system which, in contrast to Fig. 3, has a pulse generator which has two rungs, the position of which coincides with the reversal points of the annular piston;

FIG. 5 is a sensor arrangement corresponding to FIG. 4, the conductors of which have a different cross-sectional profile for securing different signals;

Fig. 6 shows a sensor arrangement, the pulse generator has a plurality of equally arranged ladder rungs, the ram pen are designed differently from each other;

Fig. 7 shows the structure of a sensor arrangement which comprises a pulse generator, the end-mounted ladder rungs have a larger cross-sectional profile than the ladder rungs arranged between them.

Detailed description of the drawings

Figs. 1 and 2 show the structure of a disengaging one cut in half. In Fig. 1, a release bearing 2 is shown in an engaged end position, ie the neutral position. The disengaging device 1 has a housing 3 , which is detachably fastened via an end face 4 in the installed state to a gear housing not shown in FIGS. 1 and 2. Zen trically, the housing 3 is provided with a recess 5 which has an inner wall 6 , on which an intermediate sleeve 7 is centered and sealed in the housing 3 . A guide sleeve 8 is furthermore inserted in the housing 3 at a radial distance from the intermediate sleeve 7 . For Lagepositionie tion of the guide sleeve 8 , this has an annular flange 9 which is supported on the housing 3 and on which the intermediate sleeve 7 abuts. The intermediate sleeve 8 extends coaxially over a section of a drive shaft 10 , which establishes a drive connection between an internal combustion engine and a manual transmission, which are not shown in FIGS. 1 and 2. Between the guide sleeve 8 and the intermediate sleeve 7 , the radial distance bridging, annular piston 11 is axially slidably arranged ver. The annular piston 11 axially delimiting a pressure chamber 12 is axially displaceable by means of a pressure medium. In this case, the pressure reaches medium via a feed bore 13 introduced into the housing 3 into the pressure chamber 12 , in order to achieve a displacement of the annular piston 11 and the associated release bearing 2 . A disengagement of the friction clutch 15 starts as soon as the release bearing 2 rests against release levers 14 of the friction clutch 15, and the annular piston ends when 11 the position of the annular piston 11 shown in Fig. 2 occupies the annular piston 11 that is, at an end stop 16 rests.

To determine the position of the annular piston 11 and thus the friction clutch 15 is a sensor system 17 d, consisting of a Hall sensor 18 or Hall generator and a non-contacting pulse generator 19 a. The Hall sensor 18 is fixed in position on the face at the free end of the intermediate sleeve 7 protruding from the housing 3 . As a pulse encoder 19 a is a lateral surface 20 of the annular piston 11 , in which a ferromagnetic metal band is integrated. Ensuring clean and safe An installation position of the encoder 19a lends itself to, in a plastic Herge introduced annular piston 11 to the encoder 19 a pour. The design of the disengaging device 1 provides that the annular piston 11 is supported on the annular flange 10 in the end position shown in FIG. 1. For this purpose, the ring piston 11 is assigned a separate seal carrier 21 , in which grooved ring sealing rings 22 , 23 are inserted, which seal an annular gap between the ring piston 11 and the intermediate sleeve 7 or the ring piston 11 and the guide sleeve 8 . In the engaged end position of the disengaging device 1 (see FIG. 1), the Hall sensor 18 is largely surrounded on the outside by an inner ring 24 of the disengaging bearing 2 , so that it is protected against contamination and damage. A protected position also results for the pulse generator 19 a in this end position of the annular piston 11 , which is surrounded by the intermediate sleeve 7 . A sensor line 25 , which connects an evaluation control (not shown in FIGS. 1 and 2) to the Hall sensor 18 , is fastened to the outer contour of the intermediate sleeve 7 or the housing 3 without any necessary auxiliary measures or impairment of adjacent components. The pulse generator 19 a, designed as a permanent magnet, has a ladder-shaped structure, which results in a clocked signal when passing through the rungs 26 on the Hall sensor 18 , which is fed to the evaluation circuit for determining the position of the annular piston 11 and thus the friction clutch 15 .

In Fig. 3, the sensor system 17 a is shown schematically, to which a diagram is assigned, which shows a pulse curve over the displacement "S". The voltage "U" is plotted on the ordinate of the diagram and the path "s" on the abscissa. Due to the uniform spacing of the ladder rungs 26 and the rectangular cross-sectional structure of the ladder rungs, there is a rectified pulse pattern over the displacement path "S". The sensor arrangement 17 a is suitable for a combination of a Auswerteschal device in which a counter is integrated so that the respective position of the ring piston due to the passed rung 26 a of the pulse generator 19 a, the exact position of the friction clutch can be determined. The Hall sensor 18 is assigned a scraper 27 , which bridges the distance to the surface 20 . The arranged on the lateral surface of the scraper 27 effectively prevents contaminants such. B. ferromagnetic particles falsify the measurement signal. The insoluble, e.g. B. attached by an adhesive to the Hall sensor 18 scraper 27 is made of a lubricious material, such as felt, PTFE or plastic.

Fig. 4 shows the sensor system 17 b, the pulse generator 19 b has only two rungs 26 b, each of which is arranged at the end points of the pulse generator 19 b and the position of which coincides with the reversal points of the annular piston 11 . The associated diagram shows that, depending on the design of the pulse generator 19 b with two rung conductors 26 b, there are only two voltage fluctuations which are transmitted as pulses or signals from the Hall sensor 18 to the evaluation circuit.

The sensor system 17 c according to FIG. 5 also comprises a pulse generator 19 c equipped with two ladder bars 26 c, the ladder rungs 26 c having different cross sections. It can be seen from the associated voltage diagram that the cross-section of the rung affects the pulse voltage immediately.

A further alternative embodiment of a pulse generator is shown in FIG. 6, in which the ladder rungs 26 d each have ramps designed differently from one another in order to achieve a direction-dependent signal or pulse. According to FIG. 6, the ladder rungs 26 d show a steep, ie vertical, ramp on the side facing the Hall sensor 18 and a flattened ramp on the side facing away from it. Corresponding to the cross-section of the rung, there is an asymmetrically designed signal curve in the voltage diagram, which advantageously enables the evaluation circuit to detect direction.

In Fig. 7 the sensor system 17 e is shown, the pulse generator 19 e at the ends of the same dimensioned rung 26 e. The ladder rungs 26 f arranged at the same distance between the ladder rungs 26 e have the same cross sections, but are of smaller dimensions compared to the end ladder rungs 26 e. This pulse generator 19 e generates a voltage diagram, which at the reversal points in the area of the rung 26 e generates a significantly higher voltage "U ₂ " compared to the measurement signals in the area of the rung 26 f, the voltage of which is indicated by "U ₁ " . The voltage differences can be evaluated by means of a logical connection for the exact determination of the reversal points.

Reference list

1

Release device

2nd

Release bearing

3rd

casing

4th

Face

5

Recess

6

Inner wall

7

Intermediate sleeve

8th

Guide sleeve

9

Ring flange

10th

drive shaft

11

Ring piston

12th

Pressure room

13

Feed hole

14

Release lever

15

Friction clutch

16

End stop

17th

a sensor system

17th

b Sensor system

17th

c Sensor system

17th

d sensor system

17th

e Sensor system

18th

Hall sensor

19th

a Impulse generator

19th

b Pulse generator

19th

c Pulse generator

19th

d pulse generator

19th

e Impulse generator

20th

Lateral surface

21

Seal carrier

22

Grooved ring seal

23

Grooved ring seal

24th

Inner ring

25th

Sensor cable

26

a ladder rung

26

b Ladder rung

26

c Ladder rung

26

d Ladder rung

26

e Ladder rung

26

f Ladder rung

27

Wipers

Claims (12)

1. disengaging device ( 1 ) for a hydraulically operated friction clutch ( 15 ) of vehicles with a housing ( 3 ) which is arranged concentrically with an internal combustion engine with a manual transmission connecting drive shaft ( 10 ) and radially spaced in the recess ( 5 ) to an inner wall ( 6 ) a guide sleeve ( 8 ) is used, on which an annular piston ( 11 ) is axially displaceably bridged a radial distance between the Füh guide sleeve ( 8 ) and the inner wall ( 6 ) and thus an annular Limited pressure space ( 12 ), which can be acted upon by a pressure medium, the disengaging device ( 1 ) further comprises a sensor system ( 17 a to 17 d) for detecting the travel of the annular piston ( 11 ), characterized by an arrangement of the sensor system ( 17 a to 17 d ), which comprises a ring-shaped Hall sensor ( 18 ) which is arranged directly or indirectly on the end face of the housing ( 3 ) and which a pulse generator ( 19 a to 19 d) surrounding the ring piston ( 11 ) cooperates. 2. disengaging device according to claim 1, characterized in that the Hall sensor ( 18 ) is arranged on the end face of an intermediate sleeve ( 7 ) which is positioned in the housing ( 3 ) and on which an annular flange ( 9 ) of the guide sleeve ( 8 ) is supported . 3. disengaging device according to claim 1, characterized in that the pulse generator ( 19 a to 19 d) is cast in an annular piston ( 11 ) made of plastic. 4. disengaging device according to claim 1, characterized in that as a pulse generator ( 19 a to 19 d) a ferromagnetic provided with rungs metal strip is provided, which is designed as a permanent magnet. 5. disengaging device according to claim 4, characterized by a ladder-shaped metal strip, the ladder rungs ( 26 a) have a precisely defined spacing Be ( Fig. 3). 6. disengaging device according to claim 4, characterized in that the sensor system ( 17 e) comprises a pulse generator ( 19 e), consisting of a ladder-shaped metal strip which at the ends of ladder rungs ( 26 e) has the same distance between them, compared to the Ladder rungs ( 26 e) smaller ladder rungs ( 26 f) are arranged ( Fig. 7). 7. disengaging device according to claim 4, characterized by a pulse generator ( 19 b, 19 c), the reversal points of the ring cylinder ( 11 ) is provided with ladder rungs ( 26 b, 26 c), the signals when passing through the Hall sensor ( 18 ) trigger, which are registered by a counter integrated in an evaluation circuit. 8. disengaging device according to claim 7, characterized in that the pulse generator ( 19 c) at the ends of ladder rungs ( 26 c) having a different cross-sectional profile ( Fig. 5). 9. disengaging device according to claim 4, characterized in that the ladder rungs ( 26 d) have differently designed ramps to achieve a direction-dependent signal from each other ( Fig. 6). 10. Disengaging device according to claim 1, characterized in that the Hall sensor ( 18 ) with a distance between the pulse generator ( 19 a) and the Hall sensor ( 18 ) bridging scraper ( 27 ) is provided ( Fig. 3). 11. disengaging device according to claim 1, characterized by a sensor system ( 17 a to 17 d) having a sensor line ( 25 ) which is attached to the intermediate sleeve or to the housing ( 3 ). 12. Release device according to claim 1, characterized by a sensor system ( 17 a to 17 d), the Hall sensor ( 18 ) in the engaged end position of the release device ( 1 ) on the outside by an inner ring ( 24 ) of the release bearing ( 2 ) is enclosed.