EP0100917B1 - Cooling system for internal-combustion engines - Google Patents

Cooling system for internal-combustion engines Download PDF

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Publication number
EP0100917B1
EP0100917B1 EP83106971A EP83106971A EP0100917B1 EP 0100917 B1 EP0100917 B1 EP 0100917B1 EP 83106971 A EP83106971 A EP 83106971A EP 83106971 A EP83106971 A EP 83106971A EP 0100917 B1 EP0100917 B1 EP 0100917B1
Authority
EP
European Patent Office
Prior art keywords
pressure
over
coolant
valve
cooling circuit
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.)
Expired
Application number
EP83106971A
Other languages
German (de)
French (fr)
Other versions
EP0100917A1 (en
Inventor
Erwin Dipl.-Ing. Schweiger
Erwin Dipl.-Ing. Starmühler
Axel Dipl.-Ing. Temmesfeld
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Bayerische Motoren Werke AG
Original Assignee
Bayerische Motoren Werke AG
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Filing date
Publication date
Application filed by Bayerische Motoren Werke AG filed Critical Bayerische Motoren Werke AG
Priority to DE8585102118T priority Critical patent/DE3374143D1/en
Publication of EP0100917A1 publication Critical patent/EP0100917A1/en
Application granted granted Critical
Publication of EP0100917B1 publication Critical patent/EP0100917B1/en
Expired legal-status Critical Current

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Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01P—COOLING OF MACHINES OR ENGINES IN GENERAL; COOLING OF INTERNAL-COMBUSTION ENGINES
    • F01P11/00—Component parts, details, or accessories not provided for in, or of interest apart from, groups F01P1/00 - F01P9/00
    • F01P11/02—Liquid-coolant filling, overflow, venting, or draining devices
    • F01P11/0204—Filling
    • F01P11/0209—Closure caps
    • F01P11/0247—Safety; Locking against opening
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01P—COOLING OF MACHINES OR ENGINES IN GENERAL; COOLING OF INTERNAL-COMBUSTION ENGINES
    • F01P11/00—Component parts, details, or accessories not provided for in, or of interest apart from, groups F01P1/00 - F01P9/00
    • F01P11/02—Liquid-coolant filling, overflow, venting, or draining devices
    • F01P11/0204—Filling
    • F01P11/0209—Closure caps
    • F01P11/0238—Closure caps with overpressure valves or vent valves
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01P—COOLING OF MACHINES OR ENGINES IN GENERAL; COOLING OF INTERNAL-COMBUSTION ENGINES
    • F01P11/00—Component parts, details, or accessories not provided for in, or of interest apart from, groups F01P1/00 - F01P9/00
    • F01P11/02—Liquid-coolant filling, overflow, venting, or draining devices
    • F01P11/028—Deaeration devices
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01P—COOLING OF MACHINES OR ENGINES IN GENERAL; COOLING OF INTERNAL-COMBUSTION ENGINES
    • F01P11/00—Component parts, details, or accessories not provided for in, or of interest apart from, groups F01P1/00 - F01P9/00
    • F01P11/02—Liquid-coolant filling, overflow, venting, or draining devices
    • F01P11/0204—Filling
    • F01P11/0209—Closure caps
    • F01P11/0247—Safety; Locking against opening
    • F01P2011/0266—Safety; Locking against opening activated by pressure

Definitions

  • the invention relates to a cooling circuit according to the design of claim 1.
  • cooling circuits of this type it is known to fill the filler neck and thus also the pressure and vacuum valves contained in the filler neck cover either in the flow area of the cooler between the cooling jacket of the internal combustion engine and the cooler - Arrange the flow water box or in the return area of the cooler between the cooler return water box and the suction side of the coolant pump (Technical Review No. 46, 1971, page 9).
  • the pressure relief valve is located at a point in the cooling circuit at which its function accordingly occurs and is at least approximately the highest pressure during operation of the machine and is limited. At this point, however, the vacuum valve cannot fully serve its purpose, because the lowest pressure in the cooling circuit occurs on the suction side of the coolant pump during operation and therefore cannot be used by the vacuum valve.
  • the pressure relief valve is due to the aforementioned relationships at a point where it cannot perform its function, while the vacuum valve is fully effective.
  • the object of the invention is to develop the cooling circuit of the known type of claim 1 so that the favorable summary of the pressure and vacuum valves in the filler cap can be maintained and still both valves on the one hand at the highest overpressure occurring in the flow area and on the other hand at the lowest negative pressure that occurs in the return area has a functional effect.
  • the invention provides the features according to the characterizing part of patent claim 1.
  • the separate control of the pressure and vacuum valves is achieved with the low construction costs of a further separate control room in the filler neck cover and a further line connection.
  • Claims 2 to 16 contain preferred refinements and developments of the invention.
  • the features of claims 2 and 3 contain the additional use and design of the line connection acting as an overpressure control line to the overpressure valve as an outflow line for the coolant to be discharged from the overpressure valve or as a continuously effective throttled vent line with a throttle connected in parallel with the overpressure valve. that secures the supply of the pre-opening pressure to the pressure relief valve without pressure drop.
  • a ventilation line that is often present in known cooling systems and is connected to the flow area.
  • Claims 4 and 5 contain preferred configurations of the invention for the arrangement of the throttle for the ventilation line.
  • the features of claim 6 provide to combine further control elements for the cooling circuit in the filler neck and filler neck cover.
  • the features of claim 7 include the arrangement and dimensioning of a further pressure relief valve, which ensures that at low engine speeds and therefore low pump delivery capacity, a lower overpressure is built up in the entire cooling circuit than is determined by the pressure relief valve controlled by the flow area according to claim 1. On the one hand, this reduces the pressure load on the cooling circuit during part-load operation of the machine and achieves the venting effect by opening the additional pressure relief valve by pushing out any air that may have accumulated at a lower pressure without, on the other hand, impairing the advantageous limitation of the coolant pressure by the pressure relief and vacuum relief valves.
  • claim 8 contain a structurally advantageous summary of the two pressure relief valve functions according to the training according to claims 1 and 7 in a double valve.
  • the features of claim 9 contain a pressure control valve which is remotely controlled from the supply pressure and which controls the coolant from the pressure region of the suction side of the coolant pump. which also promotes ventilation of the cooling system.
  • a single pressure relief valve is actuated by both pressure areas, namely the flow area and the return area, thus combining the functions of two pressure relief valves in it.
  • the features of claim 11 contain a coordination of the two overpressure opening values for the overpressure valve according to claim 10.
  • the features of claim 12 include the structural design of a cooling circuit with a pressure relief valve according to claims 10 or 11 in connection with a particularly effective ventilation device.
  • the features of claims 13 and 14 further develop the objects according to claims 10 to 12 such that according to claim 15, in connection with a bypass expansion tank with expansion air space through the pressure relief valve and the vacuum valve, only portions of the air space content - And are derived or that the ventilation bypass flow is introduced as a ventilation vortex into the expansion tank in order to effectively separate air residues distributed in the cooling circuit from the coolant.
  • Claims 16 and 17 contain features for the dimensionally reliable dimensioning of the overpressure opening value for an overpressure valve controlled by the flow area, which at the same time excludes higher overpressure values which occur with known return area control of an overpressure valve due to an aging-related increase in the cooler flow resistance.
  • An internal combustion engine 1 contains a cooling jacket 2, indicated by an arrow, into which the coolant is conveyed under pressure by means of a coolant pump 3.
  • a flow line 5 is connected with a free passage to a cooler 6.
  • the flow 5 opens into a cooler flow water tank 7.
  • a short circuit 8 branches off from the flow 5 and opens into a mixing thermostat 9, this opening being controlled by a short circuit valve 10 of the mixing thermostat 9.
  • From a cooler return water box 11, a line forming the return 12 from the cooler 6 likewise leads into the mixing thermostat 9, which contains a cooler valve 13 for controlling the mouth of the return 12.
  • a suction line 15 opens from a mixing chamber 14 of the mixing thermostat 9 and opens into the suction side 16 of the coolant pump 3.
  • a pressure relief valve 17 is connected to the cooler flow water tank 7 by means of an outflow line 18 in order to be connected to an expansion tank 19 open to the atmosphere by means of a suction line 20.
  • the expansion tank 19 is equipped with a slotted sealing disk 19 'in its filling opening.
  • the pressure relief valve 17 can alternatively be connected to the flow 5 or to the cooling jacket 2 of the machine.
  • the expansion tank 19 is connected to the suction side 16 of the coolant pump 3 via the suction line 20 and a vacuum valve 21, which preferably acts as a non-return valve.
  • the suction line 20 opens out from the interior of the expansion tank 19 near the floor.
  • One or more relatively large-area fine screens 22 and 23 in the cooler 6 and in the expansion tank 19 prevent the valves from becoming leaky due to dirt particles entrained by the coolant.
  • the pressure relief valve 17 and the vacuum relief valve 21 are combined in a filler neck 21 'to form a structural unit.
  • a further pressure relief valve 24 is arranged in the filler neck 21 ′ and is effective via the suction line 20 directly on the suction side 16 of the coolant pump 3 and thus on its suction pressure.
  • the outflow line 18 opens into the interior of the filler neck 21 'as a vent line by means of a throttle 26 for reducing the pressure difference between its connections on the one hand on the flow water tank 7 and on the other hand via the suction line 20 on the suction side 16 of the coolant pump 3.
  • a level float switch 21 " is installed, which controls a display circuit when air accumulates in the filler neck 21 ', irrespective of whether the reservoir 19 still contains an optically recognizable reserve quantity or not.
  • the pressure relief valves 17 and 24 are actuated by their respective control chambers 17 'and 2T in the opposite opening directions and in the likewise opposite closing directions by a single valve spring 24'.
  • Different overpressure opening values of, for example, 2 or 1.5 bar are achieved by an inversely proportional dimensioning of the opening cross sections of the two valves.
  • the respective connection of the outflow line 18 and the expansion tank 19 via the suction line 20 on the cover 27 takes place via sealed ring grooves 30 and 31, which are arranged between the filler neck 21 'and cover 27.
  • the first increase in speed immediately leads to the build-up of a delivery head of the coolant pump 3, which on the one hand causes the pump suction pressure to drop below the environment in the entire cooling circuit before the start pressure and on the other hand builds up an excess pressure in the coolant pump 3 downstream cooler sections, cooling jacket 2, flow 5, short circuit 8, cooler 6 and return 12. While this overpressure does not reach the opening pressure value of the overpressure valve 17, the vacuum valve 21, which responds to the slightest pressure difference and the suction line 20 from the expansion tank 19, draws coolant into the cooling circuit until the ambient pressure is reached on the suction side 16 of the coolant pump 3. During this process, the overpressure in the parts of the cooling circuit downstream of the coolant pump 3 simultaneously increases further.
  • the elastic hose lines and any residual air inclusions in this area allow an increase in the volume of coolant contained therein.
  • the Opening value of the pressure relief valve 17 of, for example, 2 bar or of the pressure relief valve 24 of, for example, 1.5 bar was reached more or less early before or after opening the cooler valve 13 of the mixing thermostat 9.
  • the engine speed is decisive because the low head of the coolant pump 3 that occurs at low to medium speeds first enables the pressure relief valve 24 to respond, which responds with an overpressure opening value that is just that pressure difference lower than the overpressure opening value of the pressure relief valve 17 that builds up between standstill or idling speed and maximum speed of the machine at the connection point of the pressure relief valve 17. At low engine speeds, the pressure relief valve 24 responds, which is connected to the suction side 16 of the coolant pump 3 via the control chamber 27 'and the suction line 20. Only in the range of the maximum speed of the machine is the overpressure opening value of the overpressure valve 17 connected via the control chamber 17 ′ and the outflow line 18 to the cooler flow water tank 7.
  • an internal pressure from the ambient pressure up to the opening pressure value of the pressure relief valve 17 and during operation of the machine 1 in the cooling jacket 2 and in the feed line 5 as well as in the short circuit 8 can therefore result in an overpressure depending on the flow resistance of the cooling circuit.
  • a pressure overload of the cooling circuit components does not exist due to this relatively low, exclusively statically effective overpressure.
  • the higher overpressure determined by the pressure relief valve 17 is limited to the operation of the machine 1 at relatively high engine speeds, at which the pressure difference between the suction side 16 of the coolant pump 3 and the connection point of the pressure relief valve 17 is greater than the difference in the pressure opening values between the pressure relief valves 17 on the one hand and 24 on the other. This higher overpressure is thus limited to a relatively small proportion of the operating time of the machine, especially when driving vehicles.
  • the durability of the cooling circuit components, in particular the cooler and the hose lines, is thereby favored.
  • the cooling circuit When the machine starts operating after the cooling circuit has been filled with coolant, the cooling circuit also begins to be vented automatically from residual air components which remain at various points during filling ben or get into the cooling circuit during operation, for example through the seals of the coolant pump 3, which are briefly loaded with negative pressure during the cold start. These residual air fractions are flushed with the flow of the coolant from the machine 1 through the free continuous flow 5 into the cooler flow water tank 7, in which only the one determined by the throttle 26 relative to the thermostat 9 during the heating of the machine with the cooler valve 13 closed low ventilation flow.
  • Venting also occurs when the overpressure opening value of approximately 2.0 bar of the overpressure valve 17 is reached in the cooler flow water tank. However, no upstream residual air fractions are removed, but only residual air fractions directly contained or dissolved in the emerging coolant are discharged into the expansion tank 19 and thus into the atmosphere.
  • a further venting and pushing out of coolant with residual air from the filler neck 21 'into the expansion tank 19 through the pressure relief valve 24 also occurs whenever, after a warm-up operating time with a high engine speed of approximately 5,000 to 6,000 / min and a high pressure difference of about 1 bar between the cooler flow water tank 7 and the suction side 16 of the coolant pump 3, the engine speed drops considerably, in particular to the idling speed.
  • the overpressure opening value of about 2 bar of the overpressure valve 17 is namely at least approximately reached at first and, in contrast, the overpressure opening value of about 1.5 bar of the further overpressure valve 24 is substantially undercut.
  • the overpressure values then largely adjust to one another, so that the overpressure in the filler neck 21 ′ increases approximately to the overpressure opening value of the overpressure valve 24 there.
  • the overpressure opening value of the pressure relief valve 24 is exceeded by the corresponding thermal expansion of the coolant.
  • the residual air which may have been upstream in the filler neck 21 ' is discharged into the expansion tank 19 together with a portion of coolant.
  • the configuration of the cooling circuit according to FIG. 2 largely corresponds to that according to FIG. 1 both in terms of structure and function. Only the filler neck 21 'is alternatively combined with a secondary flow expansion tank 28 with air space 29 or designed as a filler neck 21' without air space 29 (shown in dashed lines).
  • the evaporation line 20 'opening into the atmosphere should therefore only be provided in combination with an air space 29, while the expansion tank 19 and the suction line 20 can interact both with a secondary flow expansion tank 28 without air space 29 and with a filler neck 21' without air space.
  • a single pressure relief valve 24 and a piston 32 acting as a servomotor on this are arranged in the cover 27 of the filler neck 21 '.
  • the piston 32 is acted upon by the excess pressure in the cooler flow water tank 7 by the outflow line 18, which is only effective as a control and ventilation line.
  • a push rod 32 ' transmits the control movement of the piston 32 to the pressure relief valve 24.
  • the effective cross sections of the piston 32 and the pressure relief valve 24 are matched to the valve spring 24' of the pressure relief valve 24 in such a way that the pressure relief valve is at about 2 bar pressure on the suction side 16, for example the coolant pump 3 is opened directly by this overpressure, while it is actuated by the predominant compressive force of the piston 32 via the push rod 32 'at about 1 bar overpressure on the suction side 16 and at the same time about 2 bar overpressure in the cooler flow water tank 7.
  • a static pressure of about 2 bar is made available in the entire cooling circuit when the machine 1 is at a standstill or when the coolant pump 3 is missing or has only a low delivery head for the reheating process with an increase in temperature and pressure against boiling in the machine.
  • the pressure curve in the cooler flow water tank 7, which is subject to a relatively high local overpressure, is likewise limited to the then effective maximum value of approximately 2 bar.
  • Lower overpressure values occur on the suction side 16 of the coolant pump 3 and at all cooling circuit points which are downstream of the cooler flow water tank 7. With a maximum pressure difference of about 1 bar between the suction side 16 and the cooler flow water tank 7, the overpressure on the suction side 16 does not fall below about 1 bar, so that the boiling pressure falls below the usual maximum temperatures of about 120 ° C. at this point cannot occur.
  • the filler neck 21 ' is designed as a one-piece plastic molded part, to which a hose connection piece 34 and 35 for the outflow line 18 and for the overflow line 20' or suction line 20 are molded.
  • the outflow line 18 opens into a narrower lower cylindrical part 36 of the filler neck inner wall 37, to which an annular groove 38 of the cover 27 which is sealed on both sides is assigned.
  • the overflow or suction line 20 'or 20 opens into a further upper cylindrical part 39, which is connected to an upper space of the cover 27 outside the pressure and vacuum valves 17 and 22.
  • the cover 27 is designed as a two-part glued or welded plastic molding. It contains the pressure and vacuum valves 24 and 21 as well as the control chambers 17 'and 27' to the piston or to the diaphragm 32 of the servomotor for the pressure relief valve 24.
  • the cover 27 has holes and connection openings for the pressure relief valve 24 with valve spring 24 'and spring sleeve 40 for the last section 18 'of the outflow line 18 and for the vacuum valve 21 and for a cylindrical air separation space 41, into which a narrow vent hole 26' opens tangentially as the throttle 26 corresponding in FIG. 2.
  • the resulting gyro flow during operation favors the separation of the residual air carried in the ventilation flow.

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  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Temperature-Responsive Valves (AREA)
  • Cylinder Crankcases Of Internal Combustion Engines (AREA)
  • Heat-Exchange Devices With Radiators And Conduit Assemblies (AREA)
  • Closures For Containers (AREA)

Description

Die Erfindung betrifft einen Kühlkreis gemäß der Bauart des Patentanspruches 1. Bei Kühlkreisen dieser Bauart ist es bekannt, den Füllstutzen und damit auch die im Füllstutzen-Deckel enthaltenen Überdruck- und Unterdruckventile gemeinsam entweder im Vorlauf bereich des Kühlers zwischen dem Kühlmantel der Brennkraftmaschine und dem Kühler-Vorlauf-Wasserkasten oder im Rücklaufbereich des Kühlers zwischen Kühler-Rücklauf-Wasserkasten und Saugseite der Kühlmittelpumpe anzuordnen (Technische Rundschau Nr. 46, 1971, Seite 9).The invention relates to a cooling circuit according to the design of claim 1. In cooling circuits of this type, it is known to fill the filler neck and thus also the pressure and vacuum valves contained in the filler neck cover either in the flow area of the cooler between the cooling jacket of the internal combustion engine and the cooler - Arrange the flow water box or in the return area of the cooler between the cooler return water box and the suction side of the coolant pump (Technical Review No. 46, 1971, page 9).

Bei der erstgenannten Anordnung im Vorlaufbereich liegt zwar das Überdruckventil an einer Stelle im Kühlkreis, an der dessen Funktion entsprechend während des Betriebes der Maschine zumindest annähernd der höchste Druck auftritt und begrenzt wird. Das Unterdruckventil kann jedoch an dieser Stelle seinem Zweck nicht voll gerecht werden, weil der niedrigste Druck im Kühlkreis während des Betriebes an der Saugseite der Kühlmittelpumpe auftritt und somit vom Unterdruckventil nicht verwertet werden kann. Bei der Ansteuerung beider Ventile vom Rücklaufbereich und damit vom Druckbereich der Saugseite der Kühlmittelpumpe liegt aufgrund der vorgenannten Zusammenhänge das Überdruckventil an einer Stelle, an der es seine Funktion nicht erfüllen kann, während das Unterdruckventil hierbei voll zur Wirkung kommt.In the first-mentioned arrangement in the flow area, the pressure relief valve is located at a point in the cooling circuit at which its function accordingly occurs and is at least approximately the highest pressure during operation of the machine and is limited. At this point, however, the vacuum valve cannot fully serve its purpose, because the lowest pressure in the cooling circuit occurs on the suction side of the coolant pump during operation and therefore cannot be used by the vacuum valve. When controlling both valves from the return area and thus from the pressure area of the suction side of the coolant pump, the pressure relief valve is due to the aforementioned relationships at a point where it cannot perform its function, while the vacuum valve is fully effective.

Um vorgenannte Nachteile zu überwinden, ist es bekannt, die Überdruck- und Unterdruckventile getrennt an verschiedenen Stellen im Kühlkreis anzuordnen (US-A-2 799 260). Dabei ist jedoch ein erhöhter Bauaufwand, höheres Gewicht, höherer Raumbedarf und ein höherer Wartungs- bzw. Reparaturaufwand gegeben. Die gleichfalls bekannte, in einem Ventilgehäuse zusammengefaßte Anordnung beider Ventile innerhalb einer Bypass-Leitung mit engem Querschnitt zwischen Vor- und Rücklaufbereich (US-A-3 132634) führt neben Nachteilen bei der Wartung und Reparatur zu einer funktionell gleichfalls nachteiligen Ansteuerung beider Ventile mit einem mittleren Kühlmitteldruck zwischen den Druckwerten im Vor- und Rücklaufbereich. Ergänzend wird auf folgende Teilanmeldungen zu diesem Patent hingewiesen : EP-A-0163006 und EP-A-0157167.In order to overcome the aforementioned disadvantages, it is known to arrange the pressure and vacuum valves separately at different locations in the cooling circuit (US Pat. No. 2,799,260). However, there is an increased construction effort, higher weight, higher space requirements and a higher maintenance or repair effort. The likewise known arrangement of both valves combined in a valve housing within a bypass line with a narrow cross-section between the supply and return areas (US-A-3 132634) leads to disadvantages in maintenance and repair and to a functionally equally disadvantageous control of both valves with one average coolant pressure between the pressure values in the supply and return areas. In addition, reference is made to the following divisional applications relating to this patent: EP-A-0163006 and EP-A-0157167.

Aufgabe der Erfindung ist es, den Kühlkreis der bekannten Bauart des Patentanspruches 1 so weiterzubilden, daß die günstige Zusammenfassung der Überdruck- und Unterdruckventile im Füllstutzen-Deckel beibehalten werden kann und dennoch beide Ventile einerseits bei dem höchsten auftretenden Überdruck im Vorlaufbereich und andererseits bei dem tiefsten auftretenden Unterdruck im Rücklaufbereich funktionssichernd zur Wirkung kommen.The object of the invention is to develop the cooling circuit of the known type of claim 1 so that the favorable summary of the pressure and vacuum valves in the filler cap can be maintained and still both valves on the one hand at the highest overpressure occurring in the flow area and on the other hand at the lowest negative pressure that occurs in the return area has a functional effect.

Zur Lösung dieser Aufgabe sieht die Erfindung die Merkmale gemäß dem Kennzeichen des Patentanspruches 1 vor. Dabei wird die getrennte Ansteuerung der Überdruck- und Unterdruckventile mit dem geringen Bauaufwand eines weiteren getrennten Steuerraumes im Füllstutzen-Deckel und einer weiteren Leitungsverbindung erreicht.To achieve this object, the invention provides the features according to the characterizing part of patent claim 1. The separate control of the pressure and vacuum valves is achieved with the low construction costs of a further separate control room in the filler neck cover and a further line connection.

Die Patentansprüche 2 bis 16 enthalten bevorzugte Ausgestaltungen und Weiterbildungen der Erfindung. Die Merkmale der Ansprüche 2 und 3 enthalten die zusätzliche Nutzung und Ausbildung der als Überdruck-Steuerleitung wirkenden Leitungsverbindung zum Überdruckventil als Abströmleitung für das vom Überdruckventil abzuleitende Kühlmittel bzw. als ständig wirksam gedrosselte Entlüftungsleitung mit zum Überdruckventil parallel geschalteter Drossel. die die Zuleitung des Vortaufbereich-Überdruckes zum Überdruckventil ohne Druckabfall sichert. Zu diesen Funktionen ist die Nutzung einer bei bekannten Kühlsystemen vielfach vorhandenen, am Vorlaufbereich angeschlossenen Entlüftungsleitung möglich.Claims 2 to 16 contain preferred refinements and developments of the invention. The features of claims 2 and 3 contain the additional use and design of the line connection acting as an overpressure control line to the overpressure valve as an outflow line for the coolant to be discharged from the overpressure valve or as a continuously effective throttled vent line with a throttle connected in parallel with the overpressure valve. that secures the supply of the pre-opening pressure to the pressure relief valve without pressure drop. For these functions, it is possible to use a ventilation line that is often present in known cooling systems and is connected to the flow area.

Die Ansprüche 4 und 5 enthalten bevorzugte Ausgestaltungen der Erfindung für die Anordnung der Drossel für die Entlüftungsleitung. Die Merkmale des Anspruches 6 sehen vor, weitere Steuerelemente für den Kühlkreis im Füllstutzen und Füllstutzen-Deckel zu vereinigen.Claims 4 and 5 contain preferred configurations of the invention for the arrangement of the throttle for the ventilation line. The features of claim 6 provide to combine further control elements for the cooling circuit in the filler neck and filler neck cover.

Die Merkmale des Anspruches 7 beinhalten die Anordnung und Bemessung eines weiteren Überdruckventiles, das gewährleistet, daß bei niedrigen Motordrehzahlen und dadurch niedriger Pumpenförderleistung im gesamten Kühlkreis ein geringerer Überdruck aufgebaut wird, als er durch das vom Vorlaufbereich gesteuerte Überdruckventil nach Anspruch 1 bestimmt wird. Dadurch wird einerseits die Druckbelastung des Kühlkreises bei Teillastbetrieb der Maschine verringert und die Entlüftungswirkung durch Öffnen des weiteren Überdruckventiles mit Ausschieben von evtl. angesammelter Luft bei geringerem Druck erreicht, ohne daß andererseits die vorteilhafte Begrenzung des Kühlmitteldruckes durch die Überdruck- und Unterdruckventile beeinträchtigt wird.The features of claim 7 include the arrangement and dimensioning of a further pressure relief valve, which ensures that at low engine speeds and therefore low pump delivery capacity, a lower overpressure is built up in the entire cooling circuit than is determined by the pressure relief valve controlled by the flow area according to claim 1. On the one hand, this reduces the pressure load on the cooling circuit during part-load operation of the machine and achieves the venting effect by opening the additional pressure relief valve by pushing out any air that may have accumulated at a lower pressure without, on the other hand, impairing the advantageous limitation of the coolant pressure by the pressure relief and vacuum relief valves.

Die Merkmale des Anspruches 8 enthalten eine baulich vorteilhafte Zusammenfassung der beiden Überdruckventil-Funktionen nach den Ausbildungen gemäß Anspruch 1 und 7 in einem Doppelventil.The features of claim 8 contain a structurally advantageous summary of the two pressure relief valve functions according to the training according to claims 1 and 7 in a double valve.

Die Merkmale des Anspruches 9 enthalten ein vom Vorlaufdruck ferngesteuertes Überdruckventil, das das Kühlmittel aus dem Druckbereich der Saugseite der Kühlmittelpumpe absteuert. wodurch die Entlüftung des Kühlsystems zusätzlich begünstigt wird.The features of claim 9 contain a pressure control valve which is remotely controlled from the supply pressure and which controls the coolant from the pressure region of the suction side of the coolant pump. which also promotes ventilation of the cooling system.

Nach dem Merkmal des Anspruches 10 wird ein einziges Überdruckventil von beiden Druckbereichen, nämlich vom Vorlaufbereich und vom Rücklaufbereich, betätigt und damit die Funktionen zweier Überdruckventile in diesem vereinigt. Die Merkmale des Anspruches 11 enthalten eine Abstimmung der beiden Überdruck-Öffnungswerte für das Überdruckventil nach Anspruch 10.According to the feature of claim 10, a single pressure relief valve is actuated by both pressure areas, namely the flow area and the return area, thus combining the functions of two pressure relief valves in it. The features of claim 11 contain a coordination of the two overpressure opening values for the overpressure valve according to claim 10.

Die Merkmale des Anspruches 12 beinhalten die konstruktive Ausgestaltung eines Kühlkreises mit einem Überdruckventil nach den Ansprüchen 10 oder 11 in Verbindung mit einer besonders wirksamen Entlüftungsvorrichtung. Die Merkmale der Ansprüche 13 und 14 bilden die Gegenstände nach den Ansprüchen 10 bis 12 derart weiter, daß gemäß Anspruch 15, in Verbindung mit einem Nebenstrom-Ausgleichsbehälter mit Ausdehnungs-Luftraum durch das Überdruckventil und das Unterdruckventil jeweils auch nur Anteile des Luftraum-Inhaltes zu- und abgeleitet werden bzw. daß der Entlüftungs-Nebenstrom als Entlüftungswirbel in den Ausgleichsbehälter eingeleitet wird, um im Kühlkreis verteilte Luftreste wirksam aus dem Kühlmittel auszuscheiden.The features of claim 12 include the structural design of a cooling circuit with a pressure relief valve according to claims 10 or 11 in connection with a particularly effective ventilation device. The features of claims 13 and 14 further develop the objects according to claims 10 to 12 such that according to claim 15, in connection with a bypass expansion tank with expansion air space through the pressure relief valve and the vacuum valve, only portions of the air space content - And are derived or that the ventilation bypass flow is introduced as a ventilation vortex into the expansion tank in order to effectively separate air residues distributed in the cooling circuit from the coolant.

Die Ansprüche 16 und 17 enthalten Merkmale für die bis zur Auslegungsgrenze des Kühlkreises funktionssichernde Bemessung des Überdrucköffnungswertes für ein vom Vorlaufbereich angesteuertes Überdruckventil, die zugleich höhere Überdruckwerte ausschließt, die bei bekannter Rücklaufbereich-Ansteuerung eines Überdruckventiles durch alterungsbedingten Anstieg des Kühler-Durchflußwiderstandes auftreten.Claims 16 and 17 contain features for the dimensionally reliable dimensioning of the overpressure opening value for an overpressure valve controlled by the flow area, which at the same time excludes higher overpressure values which occur with known return area control of an overpressure valve due to an aging-related increase in the cooler flow resistance.

In der Zeichnung ist die Erfindung beispielsweise dargestellt. Es zeigen :

  • Figur 1 einen Kühlkreis für Brennkraftmaschinen in schematischer Darstellung mit einem erfindungsgemäßen Überdruckventil in einem an der Saugseite der Kühlmittelpumpe angeschlossenen Füllstutzen,
  • Figur 2 einen Kühlkreis entsprechend Fig. 1 mit einem erfindungsgemäßen Überdruckventil, das an der Saugseite der Kühlmittelpumpe angeschlossen, jedoch zusätzlich über einen Stellmotor vom Druck im Vorlauf-Wasserkasten des Kühlers angesteuert ist,
  • Figur 3 einen Füllstutzen mit im Deckel eingebauten erfindungsgemäßen Ventilen für einen Nebenstrom-Ausgleichsbehälter mit Ausdehnungs-Luftraum gemäß Fig. 2 und
  • Figur 4 den Querschnitt nach der Linie IV-IV in Fig. 3.
In the drawing, the invention is shown for example. Show it :
  • 1 shows a cooling circuit for internal combustion engines in a schematic representation with a pressure relief valve according to the invention in a filler neck connected to the suction side of the coolant pump,
  • FIG. 2 shows a cooling circuit corresponding to FIG. 1 with a pressure relief valve according to the invention, which is connected to the suction side of the coolant pump, but is additionally controlled by the pressure in the supply water tank of the cooler via an actuator.
  • 3 shows a filler neck with valves according to the invention installed in the cover for a secondary flow expansion tank with expansion air space according to FIG. 2 and
  • 4 shows the cross section along the line IV-IV in Fig. 3rd

Eine Brennkraftmaschine 1 enthält einen durch einen Pfeil angedeuteten Kühlmantel 2, in den das Kühlmittel mittels einer Kühlmittelpumpe 3 unter Druck gefördert wird. Am Austritt 4 des Kühlmantels 2 ist ein Vorlauf 5 afs Leitungsverbindung mit freiem Durchgang zu einem Kühler 6 angeschlossen. Der Vorlauf 5 mündet in einen Kühler-Vorlauf-Wasserkasten 7. Vom Vorlauf 5 zweigt ein Kurzschluß 8 ab und mündet in einen Mischthermostat 9, wobei diese Mündung durch ein Kurzschlußventil 10 des Mischthermostats 9 gesteuert wird. Von einem Kühler-Rücklauf-Wasserkasten 11 führt eine den Rücklauf 12 aus dem Kühler 6 bildende Leitung gleichfalls in den Mischthermostat 9, der ein Kühlerventil 13 für die Steuerung der Einmündung des Rücklaufes 12 enthält. Von einer Mischkammer 14 des Mischthermostats 9, der ein Kühlerventil 13 für die Steuerung der Einmündung des Rücklaufes 12 enthält. Von einer Mischkammer 14 des Mischthermostats 9 mündet eine Saugleitung 15 aus und mündet in die Saugseite 16 der Kühlmittelpumpe 3.An internal combustion engine 1 contains a cooling jacket 2, indicated by an arrow, into which the coolant is conveyed under pressure by means of a coolant pump 3. At the outlet 4 of the cooling jacket 2, a flow line 5 is connected with a free passage to a cooler 6. The flow 5 opens into a cooler flow water tank 7. A short circuit 8 branches off from the flow 5 and opens into a mixing thermostat 9, this opening being controlled by a short circuit valve 10 of the mixing thermostat 9. From a cooler return water box 11, a line forming the return 12 from the cooler 6 likewise leads into the mixing thermostat 9, which contains a cooler valve 13 for controlling the mouth of the return 12. From a mixing chamber 14 of the mixing thermostat 9, which contains a cooler valve 13 for controlling the mouth of the return 12. A suction line 15 opens from a mixing chamber 14 of the mixing thermostat 9 and opens into the suction side 16 of the coolant pump 3.

Am Kühler-Vorlauf-Wasserkasten 7 ist ein Überdruckventil 17 mittels einer Abströmleitung 18 angeschlossen, um mit einem zur Atmosphäre offenen Ausgleichsbehälter 19 mittels einer Nachsaugleitung 20 verbunden. Gegen Verdunsten des Kühlmittels ist der Ausgleichsbehälter 19 in seiner Befüllöffnung mit einer geschlitzten Dichtscheibe 19' ausgestattet. Das Überdruckventil 17 kann alternativ am Vorlauf 5 oder am Kühlmantel 2 der Maschine angeschlossen sein. Über die Nachsaugleitung 20 und ein bevorzugt als Rückschlagventil drucklos ansprechendes Unterdruckventil 21 ist der Ausgleichsbehälter 19 mit der Saugseite 16 der Kühlmittelpumpe 3 verbunden. Die Nachsaugleitung 20 mündet in Bodennähe aus dem Innenraum des Ausgleichsbehälters 19 aus. Ein oder mehrere relativ großflächige Feinsiebe 22 und 23 im Kühler 6 bzw. im Ausgleichsbehälter 19 vermeiden ein durch vom Kühlmittel mitgerissene Schmutzteilchen verursachtes Undichtwerden der Ventile.A pressure relief valve 17 is connected to the cooler flow water tank 7 by means of an outflow line 18 in order to be connected to an expansion tank 19 open to the atmosphere by means of a suction line 20. To prevent the coolant from evaporating, the expansion tank 19 is equipped with a slotted sealing disk 19 'in its filling opening. The pressure relief valve 17 can alternatively be connected to the flow 5 or to the cooling jacket 2 of the machine. The expansion tank 19 is connected to the suction side 16 of the coolant pump 3 via the suction line 20 and a vacuum valve 21, which preferably acts as a non-return valve. The suction line 20 opens out from the interior of the expansion tank 19 near the floor. One or more relatively large-area fine screens 22 and 23 in the cooler 6 and in the expansion tank 19 prevent the valves from becoming leaky due to dirt particles entrained by the coolant.

Das Überdruckventil 17 und das Unterdruckventil 21 sind in einem Füllstutzen 21' zu einer Baueinheit vereinigt. Im Füllstutzen 21' ist ein weiteres Überdruckventil 24 angeordnet, das über die Nachsaugleitung 20 unmittelbar an der Saugseite 16 der Kühlmittelpumpe 3 und damit an deren Saugdruck wirksam ist. In den Innenraum des Füllstutzens 21' mündet die Abströmleitung 18 als Entlüftungsleitung mittels einer Drossel 26 zum Abbau der Druckdifferenz zwischen ihren Anschlüssen einerseits am Vorlauf-Wasserkasten 7 und andererseits über die Nachsaugleitung 20 an der Saugseite 16 der Kühlmittelpumpe 3. In den Füllstutzen 21' bzw. in den Füllstutzen-Deckel 27 ist ein Niveau-Schwimmerschalter 21" eingebaut, der bei Luftansammlung im Füllstutzen 21' einen Anzeigestromkreis ansteuert, und zwar unabhängig davon, ob im Ausgleichsbehälter 19 noch eine optisch erkennbare Reservemenge enthalten ist oder nicht.The pressure relief valve 17 and the vacuum relief valve 21 are combined in a filler neck 21 'to form a structural unit. A further pressure relief valve 24 is arranged in the filler neck 21 ′ and is effective via the suction line 20 directly on the suction side 16 of the coolant pump 3 and thus on its suction pressure. The outflow line 18 opens into the interior of the filler neck 21 'as a vent line by means of a throttle 26 for reducing the pressure difference between its connections on the one hand on the flow water tank 7 and on the other hand via the suction line 20 on the suction side 16 of the coolant pump 3. In the filler neck 21' or In the filler neck cover 27 a level float switch 21 "is installed, which controls a display circuit when air accumulates in the filler neck 21 ', irrespective of whether the reservoir 19 still contains an optically recognizable reserve quantity or not.

Die Überdruckventile 17 und 24 werden von ihnen jeweils zugeordneten Steuerkammern 17' bzw. 2T aus in den einander entgegengesetzten Öffnungsrichtungen und in den gleichfalls einander entgegengesetzten Schließrichtungen von einer einzigen Ventilfeder 24' betätigt. Unterschiedliche Überdrucköffnungswerte von beispielsweise 2 bzw. 1,5 bar werden durch eine umgekehrt proportionale Bemessung der Öffnungsquerschnitte der beiden Ventile erreicht. Der jeweilige Anschluß der Abströmleitung 18 und des Ausgleichsbehälters 19 über die Nachsaugleitung 20 am Deckel 27 erfolgt über abgedichtete Ringnuten 30 und 31, die zwischen Füllstutzen 21' und Deckel 27 angeordnet sind.The pressure relief valves 17 and 24 are actuated by their respective control chambers 17 'and 2T in the opposite opening directions and in the likewise opposite closing directions by a single valve spring 24'. Different overpressure opening values of, for example, 2 or 1.5 bar are achieved by an inversely proportional dimensioning of the opening cross sections of the two valves. The respective connection of the outflow line 18 and the expansion tank 19 via the suction line 20 on the cover 27 takes place via sealed ring grooves 30 and 31, which are arranged between the filler neck 21 'and cover 27.

Beim Betrieb der Brennkraftmaschine 1, der üblicherweise nach längerem Abkühlen mit einem Kaltstart beginnt, führt der erste Drehzahianstieg sofort zum Aufbau einer Förderhöhe der Kühlmittelpumpe 3, die einerseits ein Absinken des Pumpensaugdruckes unter den vor dem Start im gesamten Kühlkreis gegebenen Umgebungsdruck und andererseits einen Aufbau eines Überdruckes in den der Kühlmittelpumpe 3 nachgeschalteten Kühlerkreisabschnitten, Kühlmantel 2, Vorlauf 5, Kurzschluß 8, Kühler 6 und Rücklauf 12 bewirkt. Während dieser Überdruck den Öffnungsdruckwert des Überdruckventiles 17 nicht erreicht, wird durch das auf geringste Druckdifferenz ansprechende Unterdruckventil 21 und durch die Nachsaugleitung 20 aus dem Ausgleichsbehälter 19 so lange Kühlmittel in den Kühlkreis gesaugt, bis an der Saugseite 16 der Kühlmittelpumpe 3 der Umgebungsdruck erreicht ist. Bei diesem Vorgang steigt gleichzeitig der Überdruck in den der Kühlmittelpumpe 3 nachgeschalteten Teilen des Kühlkreises weiter an. Die elastischen Schlauchleitungen und evtl. Restlufteinschlüsse in diesem Bereich ermöglichen dabei eine Zunahme des darin enthaltenen Volumens an Kühlmittel.When the internal combustion engine 1 is operating, which usually begins with a cold start after a long period of cooling, the first increase in speed immediately leads to the build-up of a delivery head of the coolant pump 3, which on the one hand causes the pump suction pressure to drop below the environment in the entire cooling circuit before the start pressure and on the other hand builds up an excess pressure in the coolant pump 3 downstream cooler sections, cooling jacket 2, flow 5, short circuit 8, cooler 6 and return 12. While this overpressure does not reach the opening pressure value of the overpressure valve 17, the vacuum valve 21, which responds to the slightest pressure difference and the suction line 20 from the expansion tank 19, draws coolant into the cooling circuit until the ambient pressure is reached on the suction side 16 of the coolant pump 3. During this process, the overpressure in the parts of the cooling circuit downstream of the coolant pump 3 simultaneously increases further. The elastic hose lines and any residual air inclusions in this area allow an increase in the volume of coolant contained therein.

Während des weiteren Betriebes der Brennkraftmaschine 1 steigt aufgrund des Wärmeüberganges im Kühlmantel 2 auf das Kühlmittel dessen Temperatur stetig an bis der Öffnungstemperaturwert des Mischthermostats 9 von etwa 80 °C erreicht wird. Daran schließt sich der Regelbereich des Mischthermostats 9 mit zunehmendem Öffnen des Kühlerventils 13 und Schließen des Kurzschlußventiles 10 sowie ebenfalls zunehmendem Durchströmen des Kühlers 6 an. Ein weiterer Temperaturanstieg bis über ca. 90 °C führt über den Regelbereich des Mischthermostats 9 hinaus bei geschlossenem Kurzschlußventil 10 zum alleinigen Durchströmen des Kühlers 6 mit dadurch erhöhter Durchflußmenge, Durchflußgeschwindigkeit, Wärmeabfuhr und auch erhöhtem Strömungswiderstand und Druckaufbau im Kühlmantel 2, Vorlauf 5 und Kühler-Vorlauf-Wasserkasten 7. Je nach Volumeninhalt und Elastizität des Kühlkreises, insbesondere der Schlauchleitungen des Vorlaufes 5, des Kurzschlusses 8, des Rücklaufes 12 und der Saugseite 15, sowie ferner je nach der Ausgangstemperatur des Kühlmittels beim Startvorgang und je nach augenblicklicher Motordrehzahl wird der Öffnungswert des Überdruckventiles 17 von beispielsweise 2 bar oder des Überdruckventiles 24 von beispielsweise 1,5 bar mehr oder weniger frühzeitig vor oder nach dem Öffnen des Kühlerventiles 13 des Mischthermostats 9 erreicht. Die Motordrehzahl ist deshalb ausschlaggebend, weil die auftretende geringe Förderhöhe der Kühlmittelpumpe 3 bei niedrigen bis mittleren Drehzahlen zuerst ein Ansprechen des Überdruckventiles 24 ermöglicht, das mit einem Überdruck-Öffnungswert anspricht, der gerade um diejenige Druckdifferenz niedriger liegt als der Überdruck-Öffnungswert des Überdruckventiles 17, die sich zwischen Stillstand oder Leerlaufdrehzahl und Höchstdrehzahl der Maschine an der Anschlußstelle des Überdruckventiles 17 aufbaut. Bei geringen Motordrehzahlen spricht somit jeweils das Überdruckventil 24 an, das auf der Saugseite 16 der Kühlmittelpumpe 3 über die Steuerkammer 27' und die Nachsaugleitung 20 angeschlossen ist. Nur im Bereich der Höchstdrehzahl der Maschine ist der Überdruck-Öffnungswert des über die Steuerkammer 17' und die Abströmleitung 18 an den Kühler-Vorlauf-Wasserkasten 7 angeschlossenen Überdruckventiles 17 maßgebend. Dabei treten jedoch andererseits aufgrund der Strömungswiderstände des Kühlkreises in Strömungsrichtung nach der Anschlußstelle des Überdruckventiles 17 jeweils niedrigere Drücke auf. Der Druck an der Saugseite 16 der Kühlmittelpumpe 3 liegt dabei sogar wesentlich unter dem Überdruck-Öffnungswert des dort wirksamen Überdruckventiles 24. Dies ist in der Saugwirkung der Kühlmittelpumpe 3 und in den über den gesamten Kühlkreis verteilten Elastizitäten vor allem der Schlauchleitungen begründet. Bei niedrigster Leerlaufdrehzahl der Maschine sind die Druckdifferenzen sehr gering und damit nimmt, wie auch beim Stillstand der Maschine 1, der gesamte Kühlkreis einen Überdruck entsprechend dem Öffnungswert des Überdruckventiles 24 an.During further operation of the internal combustion engine 1, due to the heat transfer in the cooling jacket 2 to the coolant, its temperature rises steadily until the opening temperature value of the mixing thermostat 9 of approximately 80 ° C. is reached. This is followed by the control range of the mixing thermostat 9 with increasing opening of the cooler valve 13 and closing of the short-circuit valve 10 and also increasing flow through the cooler 6. A further rise in temperature to over about 90 ° C leads beyond the control range of the mixing thermostat 9 with the short-circuit valve 10 closed to only flow through the cooler 6, thereby increasing the flow rate, flow rate, heat dissipation and also increased flow resistance and pressure build-up in the cooling jacket 2, flow 5 and cooler -Flow water tank 7. Depending on the volume and elasticity of the cooling circuit, in particular the hose lines of the flow 5, the short circuit 8, the return 12 and the suction side 15, and also depending on the starting temperature of the coolant during the starting process and depending on the current engine speed, the Opening value of the pressure relief valve 17 of, for example, 2 bar or of the pressure relief valve 24 of, for example, 1.5 bar was reached more or less early before or after opening the cooler valve 13 of the mixing thermostat 9. The engine speed is decisive because the low head of the coolant pump 3 that occurs at low to medium speeds first enables the pressure relief valve 24 to respond, which responds with an overpressure opening value that is just that pressure difference lower than the overpressure opening value of the pressure relief valve 17 that builds up between standstill or idling speed and maximum speed of the machine at the connection point of the pressure relief valve 17. At low engine speeds, the pressure relief valve 24 responds, which is connected to the suction side 16 of the coolant pump 3 via the control chamber 27 'and the suction line 20. Only in the range of the maximum speed of the machine is the overpressure opening value of the overpressure valve 17 connected via the control chamber 17 ′ and the outflow line 18 to the cooler flow water tank 7. On the other hand, however, due to the flow resistances of the cooling circuit in the flow direction after the connection point of the pressure relief valve 17, lower pressures occur. The pressure on the suction side 16 of the coolant pump 3 is even substantially below the overpressure opening value of the overpressure valve 24 which is effective there. This is due to the suction effect of the coolant pump 3 and in the elasticities, especially of the hose lines, which are distributed over the entire cooling circuit. At the lowest idling speed of the machine, the pressure differences are very small and thus, as when the machine 1 is at a standstill, the entire cooling circuit assumes an overpressure corresponding to the opening value of the overpressure valve 24.

Insgesamt kann somit im Kühlkreis regelmäßig ein Innendruck vom Umgebungsdruck bis zum Öffnungsdruckwert des Überdruckventiles 17 sowie während des Betriebes der Maschine 1 im Kühlmantel 2 und im Vorlauf 5 sowie im Kurzschluß 8 ein darüber hinausgehender, vom Strömungswiderstand des Kühlkreises abhängiger Überdruck auftreten. Die eindeutige Begrenzung der Höchst- und Niedrigst-Druckwerte im Kühler-Vorlauf-Wasserkasten 7 bzw. an der Saugseite 16 der Kühlmittelpumpe 3 vermeiden einerseits eine Drucküberlastung des Kühlers 6 mit entsprechender Überdimensionierung in seiner Festigkeit und andererseits einen Druckabfall mit erhöhter Kavitationsgefahr in der Kühlmittelpumpe 3.Overall, an internal pressure from the ambient pressure up to the opening pressure value of the pressure relief valve 17 and during operation of the machine 1 in the cooling jacket 2 and in the feed line 5 as well as in the short circuit 8 can therefore result in an overpressure depending on the flow resistance of the cooling circuit. The clear limitation of the maximum and minimum pressure values in the cooler supply water tank 7 or on the suction side 16 of the coolant pump 3, on the one hand, prevents pressure overload of the cooler 6 with corresponding oversizing in its strength and, on the other hand, a pressure drop with an increased risk of cavitation in the coolant pump 3 .

Der durch die Wirkung des Überdruckventiles 24 nach dem Abstellen der Maschine im gesamten Kühlkreis einheitlich zur Verfügung stehende Überdruck wirkt einer Dampfbildung beim Nachheizen bzw. Temperaturausgleich zwischen der Maschine und dem Kühlmittel entgegen. Eine Drucküberlastung der Kühlkreis-Bauteile ist durch diesen relativ geringen ausschließlich statisch wirksamen Überdruck nicht gegeben. Der vom Überdruckventil 17 bestimmte höhere Überdruck ist auf den Betrieb der Maschine 1 mit relativ hohen Motordrehzahlen begrenzt, bei denen die Druckdifferenz zwischen der Saugseite 16 der Kühlmittelpumpe 3 und der Anschlußstelle des Überdruckventiles 17 größer ist als die Differenz der Überdruck-Öffnungswerte zwischen den Überdruckventilen 17 einerseits und 24 andererseits. Dieser höhere Überdruck ist somit auf einen relativ geringen Anteil der Betriebszeit der Maschine, insbesondere beim Antrieb von Fahrzeugen, begrenzt. Die Dauerhaltbarkeit der Kühlkreis-Bauteile, insbesondere des Kühlers und der Schlauchleitungen, wird dadurch begünstigt.The overpressure which is uniformly available in the entire cooling circuit after the machine has been switched off due to the action of the pressure relief valve 24 counteracts the formation of steam during reheating or temperature compensation between the machine and the coolant. A pressure overload of the cooling circuit components does not exist due to this relatively low, exclusively statically effective overpressure. The higher overpressure determined by the pressure relief valve 17 is limited to the operation of the machine 1 at relatively high engine speeds, at which the pressure difference between the suction side 16 of the coolant pump 3 and the connection point of the pressure relief valve 17 is greater than the difference in the pressure opening values between the pressure relief valves 17 on the one hand and 24 on the other. This higher overpressure is thus limited to a relatively small proportion of the operating time of the machine, especially when driving vehicles. The durability of the cooling circuit components, in particular the cooler and the hose lines, is thereby favored.

Mit Beginn des Betriebes der Maschine nach dem Befüllen des Kühlkreises mit Kühlmittel beginnt auch ein selbsttätiges Entlüften des Kühlkreises von Restluftanteilen, die während des Befüllens an verschiedenen Stellen zurückgeblieben sind oder während des Betriebes, beispielsweise durch die jeweils kurzzeitig beim Kaltstart mit Unterdruck belasteten Dichtungen der Kühlmittelpumpe 3, in den Kühlkreislauf gelangen. Diese Restluftanteile werden mit der Strömung des Kühlmittels von der Maschine 1 durch den frei durchgehenden Vorlauf 5 in den Kühler-Vorlauf-Wasserkasten 7 gespült, in den während des Anwärmens der Maschine bei geschlossenem Kühlerventil 13 des Thermostats 9 lediglich die von der Drossel 26 bestimmte relativ geringe Entlüftungsströmung gelangt. Dadurch kann sich nach der Abzweigung des Kurzschlusses 8 im restlichen Teil des Vorlaufes 5 und im Kühler-Vorlauf-Wasserkasten 7 bei beruhigter Strömung ein großer Teil der Restluft vom Kühlmittel abscheiden und über die Abströmleitung 18, die Ringnut 31 und die Drossel 26 zum Füllstutzen 21' abströmen und dort dem Überdruckventil 24 vorlagern. Sobald durch das Anwärmen der Maschine 1 und des Kühlmittels sowie durch die dabei gegebene Wärmedehnung und Druckerhöhung des Kühlmittels der Überdruckwert von beispielsweise 1,5 bar dieses Überdruckventiles 24 erreicht wird, öffnet dieses und läßt die gesamte Restluft durch die Nachsaugleitung 20 in den Ausgleichsbehälter 19 strömen. Dieser Vorgang setzt sich fort bzw. wiederholt sich, bis der Wärme-Beharrungszustand des Kühlkreises erreicht ist. Ein Entlüften tritt auch dann ein, wenn der Überdruck-Öffnungswert von etwa 2,0 bar des Überdruckventiles 17 im Kühler-Vorlauf-Wasserkasten erreicht wird. Jedoch werden dabei keine vorgelagerten Restluftanteile, sondern lediglich unmittelbar im austretenden Kühlmittel enthaltene oder gelöste Restluftanteile in den Ausgleichsbehälter 19 und damit an die Atmosphäre ausgeschieden. Ein weiteres Entlüften und Ausschieben von Kühlmittel mit Restluft aus dem Füllstutzen 21' in den Ausgleichsbehälter 19 durch das Überdruckventil 24 tritt auch immer dann ein, wenn nach einer Anwärm-Betriebszeit mit hoher Motordrehzahl von etwa 5 000 bis 6 000/min und hoher Druckdifferenz von etwa 1 bar zwischen Kühler-Vorlauf-Wasserkasten 7 und Saugseite 16 der Kühlmittelpumpe 3 die Motordrehzahl erheblich, insbesondere bis auf Leerlaufdrehzahl, abfällt. Der Überdruck-Öffnungswert von etwa 2 bar des Überdruckventiles 17 ist dabei nämlich zuerst wenigstens annähernd erreicht und dagegen der Überdruck-Öffnungswert von etwa 1,5 bar des weiteren Überdruckventiles 24 wesentlich unterschritten. Beim Abfallen der Motordrehzahl gleichen sich die Überdruckwerte dann weitestgehend einander an, so daß der Überdruck im Füllstutzen 21' etwa auf den Überdruck-Öffnungswert des dortigen Überdruckventiles 24 steigt. Bei der regelmäßig dann anschließenden weiteren Erwärmung des Kühlmittels durch den Temperaturausgleich zwischen der hoch aufgeheizten Maschine 1 und dem Kühlmittel wird durch die entsprechende Wärmedehnung des Kühlmittels der Überdruck-Öffnungswert des Überdruckventiles 24 überschritten. Die im Füllstutzen 21' bis dahin evtl. vorgelagerte Restluft wird dabei zusammen mit einem Anteil an Kühlmittel in den Ausgleichsbehälter 19 ausgeschieden.When the machine starts operating after the cooling circuit has been filled with coolant, the cooling circuit also begins to be vented automatically from residual air components which remain at various points during filling ben or get into the cooling circuit during operation, for example through the seals of the coolant pump 3, which are briefly loaded with negative pressure during the cold start. These residual air fractions are flushed with the flow of the coolant from the machine 1 through the free continuous flow 5 into the cooler flow water tank 7, in which only the one determined by the throttle 26 relative to the thermostat 9 during the heating of the machine with the cooler valve 13 closed low ventilation flow. As a result, after the short circuit 8 has branched off, a large part of the residual air can separate from the coolant in the remaining part of the flow 5 and in the cooler flow water tank 7 when the flow is calm and via the outflow line 18, the annular groove 31 and the throttle 26 to the filler neck 21 'flow out and upstream of the pressure relief valve 24. As soon as the overpressure value of, for example, 1.5 bar of this overpressure valve 24 is reached by heating the machine 1 and the coolant and by the given thermal expansion and pressure increase of the coolant, this opens and allows all the residual air to flow through the suction line 20 into the expansion tank 19 . This process continues or repeats itself until the heat steady state of the cooling circuit is reached. Venting also occurs when the overpressure opening value of approximately 2.0 bar of the overpressure valve 17 is reached in the cooler flow water tank. However, no upstream residual air fractions are removed, but only residual air fractions directly contained or dissolved in the emerging coolant are discharged into the expansion tank 19 and thus into the atmosphere. A further venting and pushing out of coolant with residual air from the filler neck 21 'into the expansion tank 19 through the pressure relief valve 24 also occurs whenever, after a warm-up operating time with a high engine speed of approximately 5,000 to 6,000 / min and a high pressure difference of about 1 bar between the cooler flow water tank 7 and the suction side 16 of the coolant pump 3, the engine speed drops considerably, in particular to the idling speed. The overpressure opening value of about 2 bar of the overpressure valve 17 is namely at least approximately reached at first and, in contrast, the overpressure opening value of about 1.5 bar of the further overpressure valve 24 is substantially undercut. When the engine speed drops, the overpressure values then largely adjust to one another, so that the overpressure in the filler neck 21 ′ increases approximately to the overpressure opening value of the overpressure valve 24 there. During the subsequent subsequent subsequent heating of the coolant by the temperature compensation between the highly heated machine 1 and the coolant, the overpressure opening value of the pressure relief valve 24 is exceeded by the corresponding thermal expansion of the coolant. The residual air which may have been upstream in the filler neck 21 'is discharged into the expansion tank 19 together with a portion of coolant.

Die Ausbildung des Kühlkreises nach Fig. 2 stimmt sowohl im Aufbau als auch in der Funktion weitestgehend mit derjenigen nach Fig. 1 überein. Lediglich der Füllstutzen 21' ist hierbei alternativ mit einem Nebenstrom-Ausgleichsbehälter 28 mit Luftraum 29 zusammengefaßt oder als Füllstutzen 21' ohne Luftraum 29 ausgebildet (gestrichelt eingezeichnet). Die in die Atmosphäre mündende Abdampfleitung 20' soll daher auschließlich in Kombination mit einem Luftraum 29 vorgesehen sein, während der Ausgleichsbehälter 19 und die Nachsaugleitung 20 sowohl mit einem Nebenstrom-Ausgleichsbehälter 28 ohne Luftraum 29 als auch mit einem Füllstutzen 21' ohne Luftraum zusammenwirken können.The configuration of the cooling circuit according to FIG. 2 largely corresponds to that according to FIG. 1 both in terms of structure and function. Only the filler neck 21 'is alternatively combined with a secondary flow expansion tank 28 with air space 29 or designed as a filler neck 21' without air space 29 (shown in dashed lines). The evaporation line 20 'opening into the atmosphere should therefore only be provided in combination with an air space 29, while the expansion tank 19 and the suction line 20 can interact both with a secondary flow expansion tank 28 without air space 29 and with a filler neck 21' without air space.

Bei der Ausbildung gemäß den Fig. 2 bis 4 ist ferner abweichend von Fig. 1 anstelle zweier Überdruckventile ein einziges Überdruckventil 24 und ein als Stellmotor auf dieses wirkender Kolben 32 im Deckel 27 des Füllstutzens 21' angeordnet. Der Kolben 32 wird durch die nur als Steuer- und Entlüftungsleitung wirksame Abströmleitüng 18 vom Überdruck im Kühler-Vorlauf-Wasserkasten 7 beaufschlagt. Eine Druckstange 32' überträgt die Steuerbewegung des Kolbens 32 auf das Überdruckventil 24. Die wirksamen Querschnitte des Kolbens 32 und des Überdruckventiles 24 sind mit der Ventilfeder 24' des Überdruckventiles 24 derart abgestimmt, daß das Überdruckventil beispielsweise bei etwa 2 bar Überdruck an der Saugseite 16 der Kühlmittelpumpe 3 unmittelbar von diesem Überdruck geöffnet wird, während es bei etwa 1 bar Überdruck an der Saugseite 16 und gleichzeitg etwa 2 bar Überdruck im Kühler-Vorlauf-Wasserkasten 7 von der überwiegenden Druckkraft des Kolbens 32 über die Druckstange 32' betätigt wird. Auf diese Weise wird bei Stillstand oder Leerlauf der Maschine 1 und somit fehlender bzw. nur geringer Förderhöhe der Kühlmittelpumpe 3 für den Nachheizvorgang mit Temperatur- und Druckanstieg gegen ein Nachkochen in der Maschine im gesamten Kühlkreis ein statischer Druck von etwa 2 bar zur Verfügung gestellt. Während des Betriebes der Maschine 1 wird dagegen der Druckverlauf im mit relativ hohem örtlichen Überdruck beaufschlagten Kühler-Vorlauf-Wasserkasten 7 ebenfalls auf den dann wirksamen Höchstwert von etwa 2 bar begrenzt. An der Saugseite 16 der Kühlmittelpumpe 3 und an allen Kühlkreisstellen, die in Strömungsrichtung hinter dem Kühler-Vorlauf-Wasserkasten 7 liegen, treten dabei geringere Überdruckwerte auf. Bei einer maximalen Druckdifferenz von etwa 1 bar zwischen Saugseite 16 und Kühler-Vorlauf-Wasserkasten 7 fällt somit der Überdruck an der Saugseite 16 nicht unter etwa 1 bar, so daß ein Unterschreiten des Siededruckes bei üblichen Höchsttemperaturen an dieser Stelle von ca. 120 °C nicht eintreten kann.In the embodiment according to FIGS. 2 to 4, in addition to FIG. 1, instead of two pressure relief valves, a single pressure relief valve 24 and a piston 32 acting as a servomotor on this are arranged in the cover 27 of the filler neck 21 '. The piston 32 is acted upon by the excess pressure in the cooler flow water tank 7 by the outflow line 18, which is only effective as a control and ventilation line. A push rod 32 'transmits the control movement of the piston 32 to the pressure relief valve 24. The effective cross sections of the piston 32 and the pressure relief valve 24 are matched to the valve spring 24' of the pressure relief valve 24 in such a way that the pressure relief valve is at about 2 bar pressure on the suction side 16, for example the coolant pump 3 is opened directly by this overpressure, while it is actuated by the predominant compressive force of the piston 32 via the push rod 32 'at about 1 bar overpressure on the suction side 16 and at the same time about 2 bar overpressure in the cooler flow water tank 7. In this way, a static pressure of about 2 bar is made available in the entire cooling circuit when the machine 1 is at a standstill or when the coolant pump 3 is missing or has only a low delivery head for the reheating process with an increase in temperature and pressure against boiling in the machine. In contrast, while the machine 1 is operating, the pressure curve in the cooler flow water tank 7, which is subject to a relatively high local overpressure, is likewise limited to the then effective maximum value of approximately 2 bar. Lower overpressure values occur on the suction side 16 of the coolant pump 3 and at all cooling circuit points which are downstream of the cooler flow water tank 7. With a maximum pressure difference of about 1 bar between the suction side 16 and the cooler flow water tank 7, the overpressure on the suction side 16 does not fall below about 1 bar, so that the boiling pressure falls below the usual maximum temperatures of about 120 ° C. at this point cannot occur.

In den Fig. 3 und 4 ist die konstruktive Ausbildung und Anordnung des Füllstutzens 21' und des zugehörigen schraubbaren Deckels 27 am Nebenstrom-Ausgleichsbehälter 28 mit Luftraum 29 bzw. alternativ an einem Füllstutzen 21' ohne Luftraum 29 dargestellt. Der Füllstutzen 21' ist als einteiliges Kunststoff-Formteil ausgeführt, dem je ein Schlauchanschlußstutzen 34 und 35 für die Abströmleitung 18 und für die Überlaufleitung 20' bzw. Nachsaugleitung 20 angeformt sind. Die Abströmleitung 18 mündet in einen engeren unteren zylindrischen Teil 36 der Füllstutzen-Innenwand 37, dem eine beiderseits abgedichtete Ringnut 38 des Deckels 27 zugeordnet ist. Die Überlauf- bzw. Nachsaugleitung 20' bzw. 20 mündet in einen weiteren oberen zylindrischen Teil 39, der mit einem oberen Raum des Deckels 27 außerhalb der Überdruck- und Unterdruckventile 17 und 22 verbunden ist. Der Deckel 27 ist als zweiteiliges verklebtes oder verschweißtes Kunststoff-Formteil ausgebildet. Er enthält die Über- und Unterdruckventile 24 und 21 sowie die Steuerkammern 17' und 27' zum Kolben bzw. zur Membrane 32 des Stellmotors für das Überdruckventil 24. Ferner weist der Deckel 27 Bohrungen und Verbindungsöffnungen für das Überdruckventil 24 mit Ventilfeder 24' und Federhülse 40 für den letzten Abschnitt 18' der Abströmleitung 18 und für das Unterdruckventil 21 sowie für einen zylindrischen Luftabscheideraum 41 auf, in den eine enge Entlüftungsbohrung 26' als der in Fig. 2 entsprechende Drossel 26 tangential einmündet. Die dadurch im Betrieb entstehende Kreiselströmung begünstigt das Abscheiden der im Entlüftungsstrom mitgeführten Restluft.3 and 4, the structural design and arrangement of the filler neck 21 'and of the associated screwable cover 27 on the bypass expansion tank 28 with air space 29 or alternatively on a filler neck 21 'without air space 29. The filler neck 21 'is designed as a one-piece plastic molded part, to which a hose connection piece 34 and 35 for the outflow line 18 and for the overflow line 20' or suction line 20 are molded. The outflow line 18 opens into a narrower lower cylindrical part 36 of the filler neck inner wall 37, to which an annular groove 38 of the cover 27 which is sealed on both sides is assigned. The overflow or suction line 20 'or 20 opens into a further upper cylindrical part 39, which is connected to an upper space of the cover 27 outside the pressure and vacuum valves 17 and 22. The cover 27 is designed as a two-part glued or welded plastic molding. It contains the pressure and vacuum valves 24 and 21 as well as the control chambers 17 'and 27' to the piston or to the diaphragm 32 of the servomotor for the pressure relief valve 24. Furthermore, the cover 27 has holes and connection openings for the pressure relief valve 24 with valve spring 24 'and spring sleeve 40 for the last section 18 'of the outflow line 18 and for the vacuum valve 21 and for a cylindrical air separation space 41, into which a narrow vent hole 26' opens tangentially as the throttle 26 corresponding in FIG. 2. The resulting gyro flow during operation favors the separation of the residual air carried in the ventilation flow.

Claims (17)

1. A cooling circuit for internal combustion engines, having a coolant pump (3) arranged on the inlet side of the cooling jacket (2) of the engine (1) and effecting a coolant cycle with a drop in pressure in the cooling jacket (2), in a radiator (6), a thermostat (9) and its connecting conduits, feed (5), return (12) and short-circuit (8), and having an over-pressure valve (17) and an under-pressure valve (21) each opening to atmosphere and arranged in a filler cap (27), characterised in that the over-pressure valve (17) and the under-pressure valve (21) are separately actuated on the one hand by the coolant maximum pressure in the feed region, cooling jacket (2), feed (5) and radiator feed tank (7), and on the other hand by the coolant minimum pressure in the return region (radiator return tank 11, return 12 and suction side 16 of the coolant pump 3) each in a control chamber (27' and 17') respectively in the filler cap (27) and each through a conduit connection (annular groove 31 and outflow conduit 18) and filler pipe (21'), expansion tank (28) and re-fill conduit (20).
2. A cooling circuit according to Claim 1, characterised in that the second conduit connection is formed at the same time as the outflow conduit (18) for the coolant to be drained through the over-pressure valve (17).
3. A cooling circuit according to Claim 1, characterised in that
- the second conduit connection (outflow conduit 18) is formed at the same time as air vent conduit,
- which is connected in parallel with the over-pressure valve (17) through a constriction (26) with an air vent position (filler pipe 21') and through the first conduit connection (re-fill conduit 20) with the return region (radiator return tank (11), return (12) and suction side (16) of the coolant pump (3)).
4. A cooling circuit according to Claim 3, characterised in that the constriction (26) opens into a filler pipe (21') which is connected to the suction side (16) of the coolant pump (3).
5. A cooling circuit according to Claim 4, characterised in that the filler pipe (21') is a component of an air vent vessel and/or of a volume compensation vessel (28) with air expansion space (29).
6. A cooling circuit according to Claim 4 or 5, characterised in that the filler pipe (21') and the filler cap (27) accommodate an air vent valve and/or a level regulating float switch (21") in addition to the over-pressure valve (17), the under-pressure valve (21) and the constriction (26).
7. A cooling circuit according to any one of Claims 1 to 6, characterised in that
- a further over-pressure valve (24) is connected to the suction side (16) of the coolant pump (3),
- the over-pressure opening value of which valve lies above the boiling pressure of the coolant at maximum permissible coolant temperature by at least approximately that pressure difference (about 0.2 to 0.6 bars) which is present on the suction side (16) of the coolant pump (3) between its minimum and maximum deliveries at minimum and maximum rotation rates respectively of the engine (1).
8. A cooling circuit according to Claim 7, characterised in that
- the over-pressure valve (17) and the further over-pressure valve (24) are arranged coaxially oppositely to one another,
- in that the opening cross-sections of the two valves (17 and 24) are dimensioned in inverse size ratio to their over-pressure opening values and
- in that the two valve (17 and 24) can be held closed in opposite directions by one single valve spring (24').
9. A cooling circuit according to any one of Claims 1 and 3 to 7, characterised in that the over-pressure valve (24) comprises a servo-motor (piston or diaphragm 32) which is charged by the over-pressure in the feed region (cooling jacket 2. feed 5 and radiator feed tank 7) through the control conduit (outflow conduit 18).
10. A cooling circuit according to Claim 9, characterised in that one single over-pressure valve (24) actuated by the coolant pressure in the return region (radiator return tank 11, return 12 and suction side 16 of the coolant pump 3) is actuated both by the coolant pressure in the feed region (cooling jacket 2, feed 5 and radiator feed tank 7) through the control conduit (outflow conduit 18) and the servo-motor (piston 32 or diaphragm) and also directly by the coolant pressure in the return region (radiator return tank 11, return 12 and suction side 16 of the coolant pump 3).
11. A cooling circuit according to Claim 10, characterised in that the servo-motor (piston 32 or diaphragm) and over-pressure valve (24) are optionally adapted to one another in their pressure-charged areas and/or their closure spring forces in such a way that either equal or different over-pressure opening values of the feed region and of the return region effect the opening of the over-pressure valve (24).
12. A cooling circuit according to Claim 10 or 11, characterised in that
- the diaphragm (32) or the piston of the servo-motor limits a control chamber (17'),
- in that the control conduit (outflow conduit 18) opens into the control chamber (17') and
- in that the servo-motor (diaphragm 32 or piston) actuates the over-pressure valve (24) through a push rod (32'),
- which valve (24) closes a further control chamber (27') and is arranged coaxially with the push rod (32') and with the diaphragm (32) or the piston of the servo-motor,
- while the further control chamber (2T) is connected with the interior of the filler pipe (21') and the coolant pressure in the return region (radiator return tank 11, return 12 and suction side 16 of the coolant pump 3) acts directly upon the over-pressure valve (24).
13. A cooling circuit according to one of Claims 10 to 12, characterised in that
- the control conduit (outflow conduit 18) opens into the filler cap (27) through a radial annular groove (38) thereof and
- in that the filler pipe (21') comprises a hose connector (34 and 35) each for the control conduit (outflow conduit 18) and for an overflow conduit (20'),
- which open into a part (36) of the cylindrical filler pipe inner wall (37) in the region of the annular groove (38) of the filler cap (27) and into the cylindrical inner wall (37) of a cavity (39) lying outside the valves (24 and 21) of the filler pipe (21') and the filler cap (27) respectively.
14. A cooling circuit according to Claim 13, characterised in that the control circuit (outflow conduit 18) terminates within the filler cap (27) in a constricted bore (26') lying parallel to the servo-motor and opening tangentially into a cylindrical air separation chamber (41) open to the air chamber (29).
15. A cooling circuit according to Claim 13 or 14, characterised in that the filler pipe (21') is a component of an expansion tank (28) having an air space (29) as a thermal expansion and pressure compensation chamber.
16. A cooling circuit according to any one of Claims 1 to 15, characterised in that the over-pressure valve (17 or 24) actuated by the coolant pressure in the feed region (cooling jacket 2, feed 5 and radiator feed tank 7) has an over-pressure opening value which lies above the boiling pressure of the coolant at maximum permissible coolant temperature on the suction side (16) of the coolant pump (3) by at least approximately that pressure difference which occurs between the suction side (16) of the coolant pump (3) and the connection point of the over-pressure valve (17 or 24) when substantially the maximum delivery of the coolant pump (3) is given with the cooler valve (13) of the thermostat (9) fully opened.
17. A cooling circuit according to Claim 16, characterised in that the over-pressure valve (17 or 24) has an over-pressure opening value of 1.5 to 2.2 bars with a maximum permissible coolant temperature on the suction side (16) of the coolant pump (3) of 90 to 120 °C and with a pressure difference between the suction side (16) of the coolant pump (3) and the connection point of the over-pressure valve (17 or 24) of 0.5 to 1.2 bars.
EP83106971A 1982-07-15 1983-07-15 Cooling system for internal-combustion engines Expired EP0100917B1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
DE8585102118T DE3374143D1 (en) 1982-07-15 1983-07-15 Cooling system for internal-combustion engines

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE3226508 1982-07-15
DE3226508A DE3226508C2 (en) 1982-07-15 1982-07-15 Cooling circuit for internal combustion engines

Related Child Applications (2)

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EP85102118.8 Division-Into 1983-07-15
EP85101659.2 Division-Into 1983-07-15

Publications (2)

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EP0100917A1 EP0100917A1 (en) 1984-02-22
EP0100917B1 true EP0100917B1 (en) 1986-10-01

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EP85101659A Withdrawn EP0163006A1 (en) 1982-07-15 1983-07-15 Overpressure cooling circuit for a liquid-cooled internal-combustion engine
EP85102118A Expired EP0157167B1 (en) 1982-07-15 1983-07-15 Cooling system for internal-combustion engines
EP83106971A Expired EP0100917B1 (en) 1982-07-15 1983-07-15 Cooling system for internal-combustion engines

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EP85101659A Withdrawn EP0163006A1 (en) 1982-07-15 1983-07-15 Overpressure cooling circuit for a liquid-cooled internal-combustion engine
EP85102118A Expired EP0157167B1 (en) 1982-07-15 1983-07-15 Cooling system for internal-combustion engines

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US (1) US4510893A (en)
EP (3) EP0163006A1 (en)
JP (1) JPH071005B2 (en)
DE (3) DE3226508C2 (en)
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* Cited by examiner, † Cited by third party
Title
BUSSIEN, Automobiltechnisches Handbuch, 1979, Walter de Gruyter, Berlin New York, Seite 284, Absatz II *

Also Published As

Publication number Publication date
EP0157167A1 (en) 1985-10-09
DE3366593D1 (en) 1986-11-06
ES524135A0 (en) 1984-04-16
DE3226508C2 (en) 1985-12-12
JPS5923029A (en) 1984-02-06
EP0157167B1 (en) 1987-10-21
ES8404010A1 (en) 1984-04-16
DE3226508A1 (en) 1984-01-26
US4510893A (en) 1985-04-16
EP0100917A1 (en) 1984-02-22
EP0163006A1 (en) 1985-12-04
DE3374143D1 (en) 1987-11-26
JPH071005B2 (en) 1995-01-11

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