US3877443A

US3877443A - Circulating cooling installation for piston internal combustion engines

Info

Publication number: US3877443A
Application number: US453950A
Authority: US
Inventors: Richard Henning; Erwin Schweiger
Original assignee: Bayerische Motoren Werke AG
Current assignee: Bayerische Motoren Werke AG
Priority date: 1973-03-22
Filing date: 1974-03-22
Publication date: 1975-04-15
Anticipated expiration: 1992-04-15
Also published as: FR2222530B2; BR7402218D0; DE2314301C3; GB1466353A; IT1050501B; US3921600A; SE7709556L; JPS5411870B2; DE2314301A1; SE426415B; BE812691R; FR2222530A2; SU596173A3; ES424497A1; JPS5025951A; SU635893A3; SE408207B; GB1466352A; DE2314301B2

Abstract

A circulating cooling system for piston internal combustion engines with a cooling jacket and control devices which interrupt the cooling circulation through the cooling jacket at least within the area of the combustion zones up to a first predetermined limit value of the temperature of the engine and/or of the time after the cold start of the engine, above the first predetermined limit value at first confine the circulation to a closed circulation which by-passes a radiator and avoids a fresh water exchange, and above a further predetermined temperature limit value include the radiator, a heat-exchanger and/or the fresh water exchange into the cooling medium circulation whereby the control devices include a cooling medium valve and/or a cooling medium pump adapted to be shut off as well as a three-way thermostat each with a separate control element each, of which the cooling medium valve and/or the cooling medium pump are actuated after reaching the first limit value and three-way thermostat after reaching the further temperature limit value; the control element of the cooling medium valve and/or of the cooling medium pump is thereby arranged at a location, at which the at least approximately maximum occurring cooling medium temperature becomes effective when the cooling medium stands still, whereas the control element of the three-way thermostat is disposed in the flow area of the closed circulation.

Description

United States Patent [1 1 Henning et al.

[ 1 Apr. 15, 1975 1 CIRCULATING COOLING INSTALLATION FOR PISTON INTERNAL COMBUSTION ENGINES [75] Inventors: Richard Henning, Munich; Erwin Schweiger, Dachau, both of Germany [73] Assignee: Bayerische Motoren Werke Aktiengesellschaft, Munich, Germany 22 Filed: Mar. 22, 1974 21 Appl. No.: 453,950

[30] Foreign Application Priority Data Mar. 22, 1973 Germany 2314301 [52] US. Cl. l23/41.08; l23/4l.l; 236/345; 237/123 B [51] Int. Cl. FOlp 7/14 [58] Field of Search 123/4l.01, 41.02, 41.08, 123/41.1, 41.29; 237/123 B, 8 C; 236/345 [56] References Cited UNITED STATES PATENTS 1,328,855 1/1920 Sweet 123/4108 1,767,598 6/1930 Mallory..... 236/345 1,848,987 3/1932 Anibal 123/41,l 2,038,193 4/1936 Parsons 237/123 2,086,440 7/1937 Rushmore. 123/41.08 2,445,684 7/1948 Mallory l23/41.08 2,468,735 5/1949 Brubaker 123/41.08 2,706,085 4/1955 Nallinger 237/8 2,749,049 6/1956 Smith 237/123 B 3,211,374 10/1965 Matulaitis. 237/123 B 3,313,483 4/1967 Nallinger 236/345 3,851,629 12/1974 Mayr 123/4l.08

Primary ExaminerManuel A. Antonakas Assistant Examiner-Daniel J. OConnor Attorney, Agent, or FirmCraig & Antonelli [57] ABSTRACT A circulating cooling system for piston internal combustion engines with a cooling jacket and control devices which interrupt the cooling circulation through the cooling jacket at least within the area of the combustion zones up to a first predetermined limit value of the temperature of the engine and/or of the time after the cold start of the engine, above the first predetermined limit value at first confine the circulation to a closed circulation which by-passes a radiator and avoids a fresh water exchange, and above a further predetermined temperature limit value include the radiator, a heat-exchanger and/or the fresh water exchange into the cooling medium circulation whereby the control devices include a cooling medium valve and/or a cooling medium pump adapted to be shut off as well as a three-way thermostat each with a separate control element each, of which the cooling medium valve and/or the cooling medium pump are actuated after reaching the first limit value and three-way thermostat after reaching the further temperature limit value; the control element of the cooling medium valve and/or of the cooling medium pump is thereby arranged at a location, at which the at least approximately maximum occurring cooling medium temperature becomes effective when the cooling medium stands still, whereas the control element of the threeway thermostat is disposed in the flow area of the closed circulation.

15 Claims, 5 Drawing Figures PATENTED 1 1 5 3. 877, 443

sum 2 [1F 5 PMENTEBAPR 1 519. 5

SHEET 3 [IF 5 CIRCULATING COOLING INSTALLATION FOR PISTON INTERNAL COMBUSTION ENGINES The present invention relates to a circulating cooling installation for piston internal combustion engines with a cooling jacket and with control devices which interrupt the cooling circulation through the cooling jacket at least within the area of the combustion zones up to a first predetermined limit value of the temperature of the engine and/or of the time after the cold-start of the engine, which above the first predetermined limit value at first restrict the circulation in a closed circulation in by-passing a radiator and in avoiding a fresh water exchange, and which above a further predetermined temperature limit value incorporate the radiator, a heater heat-exchanger and/or the fresh water exchange into the cooling medium circulation, whereby the control devices include a cooling medium valve and/or a cooling medium pump adapted to be shut off as well as a conventional three-way thermostat with a separate control element each, of which the cooling medium valve and/or the cooling medium pump are actuated after reaching the first limit value and the three-way thermostat after reaching the further temperature value.

The aim of the present invention resides in further improving such a circulation cooling system. To that end, the present invention resides in that the control element of the cooling medium valve and/or of the cooling medium pump is arranged at a location of the cooling jacket and/or of the cooling-medium line system at which, at least approximately the highest cooling medium tempetature occurring or standing-still cooling medium becomes effective by heat conduction and/or thermal-siphon flow whereas the control element of the three-way thermostat is disposed within the flow area of the closed circulation. Up to the first predetermined limit value of the temperature of the cooling medium. exclusively that portion of the cooling medium can be included in this manner into the warm-up operation which is disposed in the cooling jacket itself. As a result thereof, a rapid warm'up of the engine is favored with small structural expenditures.

These and further objects, features and advantages of the present invention will become more apparent from the following description when taken in connection with the accompanying drawing which shows, for purposes of illustration only, one embodiment in accordance with the present invention, and wherein:

FIGS. 1 and 2 are schematic views of a circulating cooling installation according to the present invention in the starting control phase and in the end control phase, respectively, during the warm-up of an internal combustion engine;

FIG. 3 is a side elevational view of a thermostat housing of a circulating cooling installation according to the present invention;

FIG. 4 is a longitudinal cross-sectional view taken aong line lV-IV of FIG. 5; and

FIG. 5 is an end elevational view of the thermostat housing according to FIGS. 3 and 4.

Referring now to the drawing wherein like reference numerals are used throughout the various views to designate like parts, the circulating cooling installation, schematically illustrated in FIGS. 1 and 2, of an internal combustion engine 1 includes a conventional cooling jacket with a first area or region 2 which is arranged in the cylinder block of the internal combustion engine and includes essentially the cylinder sliding surfaces of the pistons of the internal combustion engine 1. The second area or region 3 of the cooling jacket is arranged in the cylinder head of the internal combustion engine 1. It includes, above all, the combustion zones. The latter are essentially the combustion spaces and the gas-exchange channels.

For the circulation of a cooling medium, the internal combustion engine 1 includes at the usual places a cooling medium inlet opening or aperture 4 and a cooling medium discharge opening or aperture 5 which are provided, respectively, at a geodetically low location in the first area 2 and at a geodetically high location in the second area 3 of the cooling jacket. A further geodetically high discharge opening or aperture 6 is formed in the second area 3 of the cooling jacket. Additionally, a further auxiliary discharge opening or aperture 7 may be provided in the first area 2--possibly also at the location of the discharge aperture 6.

A free, unobstructed cooling medium line 8 leads from the cooling medium discharge aperture 5 to a radiator 9 and terminates in the latter at a geodetically high place. The cooling medium line 8 passes a thermostat housing 11 at the height of a branching place 10. An expansion element 12 ofa cooling medium valve 13 protrudes into the branching place 10, which is equipped with a disk valve 14. The plate 14 is operable to close or open a control opening 15.

A radiator return line 16 leaves the radiator 9 at a geodetically low place, which connects the radiator 9 with the thermostat housing 11. The radiator return line 16 is completely or partially closed off or opened up in the thermostat housing 11 within the area of a control opening 17 by a disk valve 18. The disk valve 18, as also the disk valve 19, which is provided for the opening or closing of the control opening 20 of a by pass 20', are component parts of a three-way thermostat 21 which is arranged in the interior space of the thermostat housing 11. Both disk valves 18 and 19 are controlled by way of an expansion element 21' which carries out control movements corresponding to the temperature of the flow of the cooling medium through the control opening 17 out of the radiator 9 and through the control opening 20 out of the by-pass 20'.

A return line 23 branches off from a combining place 22 in the thermostat housing 11, which is in communication with the suction side of a cooling medium pump 24. The cooling medium pump 24 supplies the cooling medium through a cooling medium line 25 by way of the cooling medium inlet aperture 4 into the first area 2 of the internal combustion engine 1.

Furthermore, a discharge line 27 coming from a heater heat-exchanger 26 terminates in the combining place 22; the discharge line 27 is again in communication with an expansion tank 28 by way of a line 29.

Additionally, an auxiliary circulation line 30 terminates in the discharge line 27; the auxiliary circulation line 30 is thereby connected either to the discharge aperture 7indicated in dash lineor in case of omission of the discharge aperture 7, by way of an auxiliary circulation line 30' to the place 31 between discharge aperture 6 and the heater heat-exchanger 26 to the feedline 32 for the heat-exchanger 26. A heater jacket 33 for a suction-line-throttle-valve 34 and a temperature value pickup or transmitter 35 of conventional construction for a fuel metering mechanism of the internal combustion engine 1 are interconnected into this auxiliary circulation line 30. The feed line 32 is connected to the discharge aperture 6. The flow cross section of the cooling medium within the area of the discharge aperture 6 is controlled by means of a valve 36 with a disk valve 37. The control thereby takes place by way of an expansion element which projects into the second area 3.

Both the heat-exchanger 26 as also the auxiliary circulation line 30 may be connected directly to the discharge aperture 7 within the first area 2 of the cooling jacket. In this case, the discharge aperture 6 may be dispensed with. It is only important that the location of the discharge aperture 7 is so selected that a swirling or vortexing of the cooling medium disposed within the second area 3 does not occur during the warm-up operation of the internal combustion engine, and as a result thereof an accelerated warm-up of the cooling medium in the combustion zones is assured during the cold start. The last-mentioned variation in the solution is especially appropriate, when the internal combustion engine is started at extremely low ambient or outside tem peratures in order to feed to the heater for the inside space of the vehicle cooling medium heated up above the outside temperature as soon as possible.

In order that no air bubbles are enclosed during the filling up of the circulating cooling system with the cooling medium, which would endanger the troublefree operation of the cooling medium pump 24 as well as the cooling of the combustion zones, vent lines are provided according to the present invention. For purposes of venting the radiator 9, a vent line 38 is connected thereto at a geodetically high location which terminates uncontrolled in the thermostat housing 11 upstream of the control opening 17. The termination place of this vent line 38 is located in the geodetically high area of the thermostat housing 11. Adjacent to this termination place, a further vent line 39 branches off from the thermostat housing 11-also still upstream of the control aperture l7-which is connected with the expansion tank 28. A still further vent line 41 terminates within the area 40 of the further vent line 39; the still further vent line 41 thereby branches off from the combining place 22 of the thermostat housing 11. The further vent line 39 tapers within the area 40, i.e., is constricted within this area 40. The tapering or constriction place is thereby constructed as seat for a float valve 42 which with an increasing cooling medium level closes off the

further vent lines

39 and 41 against the rising cooling medium. The venting of the cooling system is ensured by the arrangement of these vent lines. At the same time, a circulation of the cooling medium through the vent lines, harmful for the rapid warm-up of the engine, is avoided by the float valve 42.

In the first control phase, according to FIG. 1, the disk valve 14 of the cooling medium valve 13 and the disk valve 18 of the three-way thermostat 21 close the control apertures 15 and 17, respectively, when the engine is cold and thus the cooling medium is cold. As a result thereof. the cooling medium is cold. As a result thereof, the cooling medium present within the area of the cooling medium line 8, of the radiator 9 and the return line 16 cannot flow to the cooling medium pump 24. Since additionally, the discharge opening 6 is closed by the disk valve 37, also no circulation of the cooling medium takes place even with a running cooling medium pump. As a result thereof, the cooling medium present within the second area 3 of the cooling jacket of the engine 1 remains stationary, i.e., does not move so that a reduced heat removal from the combustion zones exists in this area and simultaneously a more rapid warm-up of the cooling medium present in this area takes place. This action is therebeyond additionally favored in that the cooling mmedium present outside of the areas 2 and 3 of the cooling jacket does not partake in the warm-up operation of the engine. In this manner, a very rapid warm-up of the walls of the combustion zones to an operating temperature is attained in the illustrated position of the disk valves 14 and 18 of FIG. 1, in which favorable combustion conditions will establish themselves in the combustion spaces both with respect to the running porperties of the' engine as also with respect to smaller proportions in harmful exhaust gas components. In particular, cold-start enrichments of the fuel-air mixture can be omitted after a particularly short period of time.

During the warm-up operation of the engine, all disk valves except for the disk valve 19 close the control openings coordinated thereto. During this control phase, a circulation of the cooling medium therefore takes place only if the discharge aperture 7 is provided within the first area 2 of the engine 1 and the auxiliary circulation line 30 is connected thereto or in case of' omission of the discharge aperture 6, the feed line 32 is connected by way of the auxiliary circulation line 30'. The cooling medium supplied by the cooling medium pump 24 thereby flows through the cooling medium line 25, enters by way of the cooling medium inlet aperture 4 into the first area 2 of the internal combustion engine 1, flows through this area-approximately along the flow paths indicated in dash and dot lines-- branches off into two streams, reaches with a first partial stream the auxiliary circulation line 30 through the discharge aperture 7, flows through the heater jacket 33, flows byy way of the temperature value pick-up or transmitter 35 into the discharge line 27, and with a second partial stream the feed line 32 through the line 30' and flows through the heat-exchanger 26 also into the discharge line 27. The recombined cooling medium stream flows again uncontrolled through the discharge line 27 into the combining place 22 of the thermostat housing 11 and then again reaches the cooling medium pump 24 by way of the return line 23. In the course of this circulation, the cooling medium follows the path indicated by the arrows 43. In order to avoid in every case during the first control phase a cooling-off of the cooling medium by the heat-exchanger 26, it is appropriate under certain circumstances not to permit the cooling medium to flow through the heat-exchanger 26 at the beginning of this control phase, for example, controlled by a time switch. Such a switch may be arranged at the location 44 and may be a conventional timer switch. The same purpose can also be achieved by the arrangement of a valve corresponding to the valve 36 at the location 44, whose control element is disposed in the cooling medium stream coming out of the discharge aperture 7 and flowing constantly and uncontrolled through the auxiliarly circulation line 30 and whose disk valve opens the auxiliary circulation line 30 to the feed line 32 only above a predetermined temperature of the cooling medium.

During this first control phaseapart from a thermosiphoning flowa swirling or vortexing of the cooling medium present in the second area 3 is thus avoided.

Overheating appearances of the internal combustion engine are precluded also under extreme loads during the warm-up operation in that the first control phase is timely terminated by response of the cooling medium valve 13.

By reference to FIG. 2, the second control phase will be described during the warm-up of the engine. The same reference numerals are thereby used for the individual parts of the cooling system as in FIG. I.

With an increase of the cooling medium temperature, the valve 36 opens the discharge aperture 6. The prere quisites for a circulation of the cooling medium according to the arrows 45 are fulfilled thereby. The cooling medium supplied by the cooling medium pump 24 thereby reaches the first area 2 by way of the cooling medium inlet aperture 4, from there reaches the second area 3 in order to flow thereafter through the discharge aperture 6 and through the feedline 32 into the heatexchanger 26. Out of the heat-exchanger 26, the cool' ing medium reaches the combining place 22 in the thermostat housing 11 by way of the discharge line 27. From there, the cooling medium returns uncontrolled to the cooling medium pump 24 by way of the return line 23. Additionally, there exists an auxiliary circulationassuming that in this embodiment the discharge aperture 7 is not present and that the auxiliary circulation line 30' starts from the place 3l-whose flow path is designated by the arrows 46. The cooling medium thereby reaches the auxiliary circulation line 30' and 30 from the feed line 32, flows through the heater jacket 33 and flows into the discharge line 27 by way of the temperature pickup 35.

The control of the valve 36 takes place by way of an expansion element which, at a predetermined temperature, so displaces the disk valve 37 that the discharge aperture 6 is opened. At this control temperature, however, the expansion elements of the cooling medium valve 13 and of the three-way thermostat 21 do not as yet respond. The associated disk valves remain in their positions closing the associated control openings. As a result thereof, neither a flow by way of the by-pass 20' through the control opening nor a flow through the radiator 9 takes place in the second control phase.

In the course of the third control phase during the warm-up operation of the engine, the valve 36 is open and the cooling medium valve 13 opens the control opening 15 as soon as the cooling medium reaches a temperature, at which the combustion zones within the area of the cooling jacket have a temperature sufficient for the operation of the engine without fuel enrichment and which is equal to or higher than the temperature at which the valve 36 open, so that now also a circulation is possible by way of the by-pass according to arrows 47. The control of the cooling medium valve 13 takes place by way of the expansion element 12 which is so arranged within the area of the geodetically high cooling medium discharge aperture 5 that it is acted upon owing to thermo-siphon flow by the highest occuring temperature of the cooling medium in the second area 3, when the cooling medium is stationary or standing-still.

On the one hand, an excessive warm-up of the combustion zones and, on the other, an excessive cooling off of the cooling medium is avoided by the by-pass circulation 47, which would otherwise take place with a conduction of the cooling medium through the radiator 9. The remaining circulations through the heat' exchanger 26 according to the arrows 45 and through the heater jacket 33 according to arrows 46 remain preserved unchanged in this control phase. A part of the cooling medium leaves the engine I through the cooling medium discharge aperture 5 during this control phase, flows around the disk valve 14 and by way of the by-pass 20', of the control opening 15 and of the open control opening 20 reaches the combining place 22 in the thermostat housing 11, in which it joins the flow path of the remaining circulations according to the

arrows

45 and 46.

The warm-up operation of the engine terminates with the fourth control phase. The cooling medium thereby reaches a temperature, at which also the disk valve 18 controlling the flow of the cooling medium through the radiator 9, which again is controlled by an expansion element, opens up the control opening 17. With the beginning of the opening of the control aperture 17, the disk valve 19 increasingly closes the control aperture 20. As a result of the adjustment of the disk valve 19, the by-pass 20' is increasingly closed so that in addition to the described circulation according to the arrows 45 and to the auxiliary circulation according to the arrows 46, the radiator-circulation according to the arrows 48 is added. The cooling medium quantity forming the radiator-circulation reaches the radiator 9 uncontrolled out of the cooling medium discharge aperture 5 through the cooling medium line 8. The cooling medium gives off heat in the radiator 9 and reaches thereafter the thermostat housing 11 by way of the return line 16. The cooling medium circumcirculates thereat the disk valve 18 and mixes in the combining place 22 with the circulation described hereinabove and designated by arrows 45, andto the extent that it is not yet completely interrupted-with the by-pass circulation 47.

A geodetic drop is provided for venting purposes, contrary to the schematic arrangement shown in FIGS. 1 and 2, between the parts of the cooling system to be vented so that the cooling medium level 28' in the expansion tank 28, which has an automatic vent mechanism of conventional construction (not shown), is disposed at all times at the geodetically highest place of the cooling system.

The thermostat housing 59 illustrated in FIGS. 3 to 5 corresponds in principle to the thermostat housing 11 in FIGS. 1 and 2. The same reference numerals will be used for the cooling medium lines and for the vent lines as have been used in connection with FIGS. 1 and 2.

The thermostat housing 59 involves a casting which is made preferably of aluminum or other known lightmetal alloys. It is composed externally essentially of a housing part 60 and of ahousing cover 61. The housing cover 61 is secured at the housing part 60 by means of bolts 62. A seal 63 is provided between the abutment surfaces of the housing part 60 and of the housing cover 61.

The housing part 60 includes a fastening flange with fastening eyes 64 and 65 (FIG. 3) for its fastening at the engine. Additionally, the connecting

nipples

66, 67 and 68 for the cooling medium line 8 leading freely or unobstructedly to the radiator, for the discharge line 27 and for the return line 23, respectively, are additionally provided at the housing part 60.

The connecting nipple 69 is provided at the housing cover 61 for the radiator return line 16. For purposes of venting the thermostat housing 59, the vent lines 38 and 39 terminate in the housing cover 61 thereof at geodetically high places. The further vent line 41 branches off from the vent line 39.

The flow directions of the cooling medium flowing into or out of the thermostat housing 59 are indicated by

arrows

70, 71, 72 and 73.

At the height of a first separating plane 74 between the housing part and the housing cover 61 termi nates an approximately cylindrical housing insert 75 within the thermostat housing 59; the housing insert 75 encloses a combining place 76 and is supported with its end opposite the first separating plane 74 against a fastening flange 78 of a cooling medium valve 79. The fas tening flange 78 rests on the sealing ring 80 which in its turn is embedded in a recess within the housing part 60. The housing insert 75 and the fastening flange 78 abut against one another in a second separating plane 81. By means of bolts 62, the housing insert 75 is retained against the sealing ring 82 and the fastening flange 83 of the three-way thermostat 84 against the shoulder 85 of a recess within the housing cover 61.

The three-way thermostat 84 and the cooling medium valve 79 are stalled into the thermostat housing 59 coaxially aligned to one another. They have essentially the same construction as can be seen from the schematic illustration in FIGS. 1 and 2. The three-way thermostat 84 includes an expansion element 86 which is supported at the bracket-like support member 88 of yoke shape by way of the piston rod 87 and, beginning with a predetermined temperature, moves in the direc tion toward the cooling medium valve 79. The

disk valves

90 and 91 mounted on the expansion element 86, which corresponds to the disk valves 18 and 19 illustrated in FIGS. 1 and 2, are thereby displaced in the same direction, on the one hand, away from the valve seat 92 and, on the other, toward the valve seat 93. As a result thereof, the

control openings

94 and 95 are, respectively, opened and closed. The movement of the expansion element 86 takes place against the resistance of a compression spring 96 which is supported, on the one hand, at a further bracket-like curved support member 97 which is connected to the fastening flange 83 and to the support member 88 and is slidingly supported on an outer surface of the expansion element 86, and on the other, at the surface of the disk valve 90 facing the curved support member 97. As a result thereof, at a temperature of the cooling medium which lies below the control temperature of the expansion element 86, the expansion element 86 and therewith also the disk valve 90 as also the disk valve 91 are moved back in a direction toward the support member 88. The disk valve 90 thereby abuts sealingly against its valve seat 92.

The disk valve 91 is axially displaceably mounted on the tapered end of the expansion element 86 and is axially secured by a ring 91 In order that a sealing abutment of the disk valve 91 at its valve seat 93 is assured, a compression spring 98 is provided which is supported at the surface of the disk valve 91 facing the curved support member 97 and at a collar 99 of the expansion element 86. The valve seat 93 may, as illustrated in this embodiment, be constructed in one piece with the housing insert 75, as a part of this housing insert or at the fastening flange 78 or at the curved bracket-like support member 100 of the cooling medium valve 79.

The construction of the cooling medium valve 79 is similar to that of the three-way thermostat 84. Also in this case the expansion element 101 is moved in the direction away from the curved support member 100 at a predetermined temperature by means of the piston rod 102 which is supported at the curved support member 100. As a result thereof, the disk valve 103 secured on the expansion element 101 is moved away from the valve seat 106 against the force of the compression spring 104 which is supported at the bracket-like, yokeshaped support member 105 and at the disk valve 103. The

support members

100 and 105, the valve seat 106 which is a part of the fastening flange and the fastening flange 78 are rigidly connected with each other.

The cooling medium valve 79 projects with its expansion element 101 into the cooling medium line 8. Up to its control temperature, the cooling medium valve 79 closes the control opening 107 and together with the alsoclosed disk valve 90 of the three-way thermostat 84, prevents thereby any cooling medium circulation through the by-pass 20 and through the radiator. With a temperature increase of the cooling medium in the cooling medium line 8 by thermo-siphoning flow out of the engine, the cooling medium valve 79 responds, and the disk valve 103 opens up the control aperture 107 so that the cooling medium reaches the return line 23 through the control opening 95 in the by-pass 20'. With a further temperature increase of the cooling medium, the three-way thermostat 84 responds, opens with its disk valve 90 the control opening 94 and closes with its disk valve 91 the control opening 95. As a result thereof, the by-pass 20' through the control opening 107 is increasingly interrupted and the cooling medium flows to the radiator 9 by way of the cooling medium line 8. From there, it returns into the housing cover 61 by way of the radiator return line 16 and flows through the control opening 94 in the combining place 76 and from there to the cooling medium pump 24 by way of the return line 23.

The connecting

nipples

109 and 110 contain parts of the vent lines 39 and 38 for the conduction of the air to the expansion tank 28 and from the radiator 9. The connecting nipple 109 is illustrated in cross section in FIG. 5 so that the float valve 111, schematically illustrated in FIGS. 1 and 2, becomes visible. The float valve 111 includes a conical valve body 112 with a cylindrical guide section 113 which are combined into a structural member. The associated valve seat 114 is constructed of complementary conical shape. The vent lines 39 and 41 terminate in the surface of the valve seat 114. The location of the discharge of the vent line 41 is designated by reference numeral 115.

As soon as the cooling medium level reaches the float valve 111 during the filling of the cooling system with cooling medium, the float valve 111 is pressed against the surface of the valve seat 114. As a result thereof, a penetration of the cooling medium into the vent line 39 leaving the thermostat housing is prevented and a cooling medium circulation through the vent lines 38 and 39 which is possible as such, by way of the expansion tank 28, of the line 29, the discharge line 27. the thermostat housing 11, the return line 23, the cooling medium pump 24, the cooling line 25, the areas 2 and 3 of the cooling jacket of the engine 1, the cooling medium line 8, the radiator 9, the radiator return line 16 and the vent line 38 in parallel thereto back into the interior of the housing cover 61 is avoided thereby. Also, a shortened cooling medium circulation which in par- 9 ticular does not include the expansion tank 28 by way of the vent line 41 is precluded.

While we have shown and described only one embodiment in accordance with the present invention, it is understood that the same is not limited thereto but is susceptible of numerous changes and modifications as known to those skilled in the art, and we therefore do not wish to be limited to the details shown and described herein but intend to cover all such changes and modifications as are encompassed by the scope of the appended claims.

We claim:

1. A circulating cooling installation for piston internal combustion engines, which comprises cooling jacket means and control means operable to limit the cooling medium circulation through the cooling jacket means at least within the area of the combustion zones of the engine up to a first predetermined limit value after the cold start of the engine, above the first predetermined limit value to initially confine the circulation to a closed circulation by-passing a radiator means and avoiding a fresh water exchange, and above a further predetermined temperature limit value to include in the cooling medium circulation the radiator means and at least one of heat-exchanger means and fresh water exchange, the control means including a first means and a three-way thermostat means each having a separate control element, the first means being actuated after reaching the first limit value and the three-way thermostat means being actuated after reaching the further temperature limit value, characterized in that the control element of said first means is arranged at a place at which at least approximately the highest occurring cooling medium temperature becomes effective when the cooling medium stands still, whereas the control element of the three-way thermostat means is disposed in the flow area of the closed circulation.

2. An installation according to claim 1, characterized in that the first predetermined limit value is a predetermined first temperature value of the engine.

3. An installation according to claim 1, characterized in that the first predetermined limit value is a predetermined period of time after the cold start of the engine.

4. An installation according to claim 3, characterized in that the first predetermined limit value is a predetermined first temperature value of the engine.

5. An installation according to claim 1, characterized in that the first means is a cooling medium valve means.

6. An installation according to claim 1, characterized in that the first means is a cooling medium pump means adapted to be shut off.

7. An installation according to claim 6, characterized in that the first means is a cooling medium valve means.

8. An installation according to claim 1, characterized in that the control elements are expansion elements.

9. An installation according to claim 1, characterized in that the closed circulation includes a by-pass circulation means.

10. An installation according to claim 1, which includes a by-pass means, and in which a cooling medium valve means forming part of the first means and the three-way thermostat means are combined in a common thermostat housing means, characterized in that the cooling medium valve means and a disk valve means of the three-way thermostat means which controls the by-pass means, respectively open and close two control aperture means disposed in series with each other in the flow direction.

11. An installation with a line system with several cooling medium lines including a radiator return line and a cooling medium return line, according to claim 10, characterized in that the thermostat housing means includes two parts, and in that a simple-acting thermostat insert means is provided as cooling medium valve means and a double-acting thermostat insert means is provided as three-way thermostat means, said simpleacting thermostat insert means including one disk valve means and one expansion element while the doubleacting thermostat insert means includes two disk valve means and one expansion element, the cooling medium valve means being arranged within the area of a branching place of one of said cooling medium lines, at which a line section connected with a cooling-jacket discharge aperture means located at a geodetically high place splits up into the by-pass means and into a free cooling medium line extending to the radiator means, in such a manner and being sealingly clamped by means ofa fastening flange means connected with a valve seat means in a separating plane between the two housing parts in such a manner that the expansion element of the cooling medium valve means protrudes into said one cooling medium line, and the three-way thermostat means being arranged within the area of a combining place of the cooling medium lines, in which at least the by-pass means, the radiator return line and the return line to the cooling medium pump means terminate in such a manner and being sealingly clamped by means of a fastening flange means, at which is formed a valve seat means, between the two housing parts in such a manner that the expansion element of the thermostat means is located at least in part in the combining place and the disk valve means thereof alternately control the radiator return line and the by-pass means.

12. An installation according to claim 11, characterized in that the thermostat housing means essentially consists of a housing part containing essentially the branching and combining places, of an approximately cylindrical housing insert means which is arranged inside said housing part between the two separating planes and which includes an end face abutment collar for the support against the fastening flange means of the cooling valve means and of the three-way thermostat means as well as at least one radial aperture means for the return line to the cooling medium pump means, and of a housing cover which abuts with a flange surface in the separating plane containing the fastening flange means of the three-way thermostat means, against at least one of the two parts consisting of an end face of the housing part and an abutment collar of the housing insert means, forms a part of the radiator return line and receives a part of the three-way thermostat means.

13. An installation according to claim 12, characterized in that the control aperture means for the disk valve means of the three-way thermostat means controlling the by-pass means is arranged at the housing insert means.

14. An installation according to claim 13, characterized in that the control elements are expansion elements.

15. An installation according to claim 11, characterized in that the control aperture means for the disk valve means of the three-way thermostat means controlling the by-pass means is arranged at the housing insert means.

Claims

11. An installation with a line system with several cooling medium lines including a radiator return line and a cooling medium return line, according to claim 10, characterized in that the thermostat housing means includes two parts, and in that a simple-acting thermostat insert means is provided as cooling medium valve means and a double-acting thermostat insert means is provided as three-way thermostat means, said simple-acting thermostat insert means including one disk valve means and one expansion element while the double-acting thermostat insert means includes two disk valve means and one expansion element, the cooling medium valve means being arranged within the area of a branching place of one of said cooling medium lines, at which a line section connected with a cooling-jacket discharge aperture means located at a geodetically high place splits up into the by-pass means and into a free cooling medium line extending to the radiator means, in such a manner and being sealingly clamped by means of a fastening flange means connected with a valve seat means in a separating plane between the two housing parts in such a manner that the expansion element of the cooling medium valve means protrudes into said one cooling medium line, and the three-way thermostat means being arranged within the area of a combining place of the cooling medium lines, in which at least the by-pass means, the radiator return line and the return line to the cooling medium pump means terminate in such a manner and being sealingly clamped by means of a fastening flange means, at which is formed a valve seat means, between the two housing parts in such a manner that the expansion element of the thermostat means is located at least in part in the combining place and the disk valve means thereof alternately control the radiator return line and the by-pass means.