EP0177860B1 - Device for securing a cooling circuit of an internal-combustion engine - Google Patents

Device for securing a cooling circuit of an internal-combustion engine Download PDF

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Publication number
EP0177860B1
EP0177860B1 EP85112273A EP85112273A EP0177860B1 EP 0177860 B1 EP0177860 B1 EP 0177860B1 EP 85112273 A EP85112273 A EP 85112273A EP 85112273 A EP85112273 A EP 85112273A EP 0177860 B1 EP0177860 B1 EP 0177860B1
Authority
EP
European Patent Office
Prior art keywords
pressure relief
relief valve
container
float
valve
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
EP85112273A
Other languages
German (de)
French (fr)
Other versions
EP0177860A2 (en
EP0177860A3 (en
Inventor
Hans Dipl.-Ing. Martin
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.)
Mahle Behr GmbH and Co KG
Original Assignee
Behr GmbH and Co KG
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Behr GmbH and Co KG filed Critical Behr GmbH and Co KG
Publication of EP0177860A2 publication Critical patent/EP0177860A2/en
Publication of EP0177860A3 publication Critical patent/EP0177860A3/en
Application granted granted Critical
Publication of EP0177860B1 publication Critical patent/EP0177860B1/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
    • F01P11/14—Indicating devices; Other safety 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
    • F01P11/029—Expansion reservoirs
    • 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
    • F01P11/14—Indicating devices; Other safety devices
    • F01P11/18—Indicating devices; Other safety devices concerning coolant pressure, coolant flow, or liquid-coolant level
    • 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

Definitions

  • the invention relates to a device for securing the coolant circuit of an internal combustion engine, in particular a motor vehicle internal combustion engine, according to the preamble of patent claim 1.
  • coolant circuit It is common practice to secure the coolant circuit to an opening pressure of approximately 1.1 bar to 1.15 bar. If the pressure in the coolant circuit exceeds this value, coolant, gases or water vapor can occur via pressure relief valves. If an internal combustion engine is operated for a certain time, thereby heated and then switched off, steam can form in the coolant circuit due to local overheating, for example on the cylinder heads. If the coolant circulation is interrupted after the internal combustion engine is switched off, the steam generated cannot separate out. This vapor formation causes an increase in volume, which can lead to coolant being ejected via a pressure relief valve. This ejected coolant is then no longer available for normal operation. In order to prevent such coolant ejection after the internal combustion engine has been switched off, it would be possible to set the cooling water circuit to a higher opening pressure. However, this would lead to an undesirable increase in the stress on the parts of the cooling system in normal operation.
  • a device for securing the cooling circuit of an internal combustion engine was known (DE-3 143 749 A1), in which two pressure relief valves are arranged in the upper region of a container carrying coolant. One of the pressure relief valves is set to a lower opening pressure, the operating pressure, and the other pressure relief valve is set to an increased opening pressure.
  • the pressure relief valve set to the operating pressure is preceded by a solenoid valve which is opened when the motor is switched on and closed when the motor is switched off. By switching the motor on and off, a switch from operating pressure to the increased opening pressure is thus effected via the additional solenoid valve.
  • the invention has for its object to provide a device according to the preamble of claim 1 so that a simple construction with high functional reliability is obtained, in which a coolant ejection can be largely prevented during the shutdown phase of the internal combustion engine.
  • the pressure relief valve built into the float is connected in series with the first pressure relief valve. This results in a pressure addition between the opening pressures of the two pressure relief valves, so that the second pressure relief valve only has to be designed for the difference between the opening pressure of the first pressure relief valve and the desired increased opening pressure. If steam forms during the shutdown phase of the internal combustion engine, i.e. If there is a risk of coolant ejection, the coolant circuit is thus sealed by the added opening pressures. Since the float is guided in a cage, it moves in a defined path so that the effect of the second pressure relief valve is always maintained.
  • the float with the second pressure relief valve and the cage is designed as an insert which can be inserted sealingly into an opening of the container and contains the feed to the first pressure relief valve.
  • This insert forms a preassembled unit that is inserted as a whole into the container.
  • the insert is inserted into a filler neck of the container and has a valve seat for the valve plate of the first pressure relief valve held by means of a bayonet lock.
  • the filler neck of the container can then have a relatively simple design.
  • the insert has a tubular extension adjoining the feed to the first pressure relief valve, in which the float is guided with play and the end pointing into the container is divided into individual legs by axial slots.
  • a simple cage for guiding the float is obtained on the one hand, while on the other hand an overfill protection for the container is created.
  • a is relative large opening cross-section to the container through which the coolant can be filled. If the float reaches the unslit area of the attachment with increasing liquid level, there is only a small free cross section, so that further refilling of coolant is at least severely hindered.
  • the legs of the extension are provided at their free ends with radially inwardly directed stops.
  • the legs are slightly elastically spread when the float is inserted and secure the lowest position after the float is inserted.
  • the float can thus be easily combined with the insert to form a structural unit.
  • a throttle opening bypassing the float is guided from the interior of the container to the first pressure relief valve. This ensures that when the coolant circuit is overfilled, the pressure in the cooling water circuit can decrease to the opening pressure of the first pressure relief valve over a predeterminable period of time, so that even if the coolant circuit is overfilled, it is not exposed to the increased pressure for a prolonged period.
  • the cross section of the throttle opening is selected so that no coolant ejection occurs through the throttle opening during normal filling during the engine shutdown phase.
  • the inlet of the throttle opening is arranged in the region of the highest point of the container. As a result, the excessive pressure is released by the escape of gas or water vapor.
  • the inlet of the throttle opening is arranged at a point immersed in the cooling water. It is thereby achieved that the pressure is reduced by ejecting coolant, but only the amount of coolant given by any overfilling is ejected.
  • FIG. 1 shows an internal combustion engine 1 which has an internal coolant guide. Water, which is provided with an antifreeze, is usually used as the coolant.
  • a cooler is connected to the coolant guide of the internal combustion engine 1 via lines in which a coolant pump 2 is arranged.
  • the coolant pump 2 conveys the coolant to the internal combustion engine 1, from which it flows in the direction of the arrow A to the radiator 3.
  • a short-circuit line 5 is arranged in front of the cooler 3 and is connected to the supply line to the internal combustion engine 1 via a thermostatic valve 4.
  • an expansion tank 6 is arranged, which is located at the highest point in the coolant circuit.
  • the inlet 11 of the expansion tank 6 is connected via a line 31 to the highest point of the cooler 3.
  • the outlet 10 of the expansion tank 6 is connected via a line 30 to the suction side of the coolant pump 2.
  • the coolant is degassed, i.e.
  • the vapor or gas inclusions contained in the coolant reach the expansion tank 6 in an emulsion, in which they can be separated from the coolant and can escape via an overflow 8.
  • the coolant circuit is secured by two pressure relief valves 16 and 21 to predetermined opening pressures against excess pressure.
  • the pressure relief valve 16 is in normal operation and is set, for example, to an opening pressure P1 of approximately 1.15 bar.
  • the pressure relief valve 21, which only functions in certain operating states, is set to a higher opening pressure P2 , which can be, for example, 1.5 to 1.6 bar.
  • the pressure relief device containing the two pressure relief valves 16 and 21 is arranged on the expansion tank 6. It is of course also possible to provide them at another point in the coolant circuit, in particular on the top of the cooler 3, for example if no separate expansion tank 6 is provided in the coolant circuit.
  • An insert 30 containing the two pressure relief valves 16 and 21 is inserted into the filler neck 12 of the expansion tank 6 and has an essentially cylindrical outer contour.
  • the insert 30 engages around the edge of the flange 33 of the filler neck 12 with a flange 32 and is secured in a latching manner thereon.
  • at least two sealing rings 39 are arranged between the filler neck 12 and the insert 30.
  • a so-called bayonet lock 31 is removably attached to the flange 32 of the insert 30 and carries a valve disk 13 of the first pressure relief valve 16.
  • the valve disk 13 is guided in the axial direction on a bolt 40 of the bayonet lock 31 and is loaded by means of a compression spring 14.
  • a valve seat 15 is assigned to the valve plate 13 and is formed by a narrowed shoulder of the insert 30. Outside the valve seat 15, the insert 30 is connected to a plurality of axially directed openings 41, which lead to an annular groove-shaped circumferential channel 42, to which the overflow 8 connects, which is attached to the filler neck 12.
  • the compression spring 14 of the first pressure relief valve 16 is designed for an opening pressure in the range of approximately 1.15 bar. This pressure relief valve 16 is in the normal range drive the internal combustion engine 1 in function, ie the coolant circuit is designed for an excess pressure of about 1.15 bar. If a higher overpressure occurs, the overpressure valve 16 opens, so that gas or water vapor enclosed in the coolant can escape via the connection openings 41, the channel 42 and the overflow 8.
  • the insert 30 projects into the expansion tank 6 with a tubular extension 18.
  • the approach 18, which is closed in its upper area, is divided into individual legs 34 in its lower area by axial slots.
  • a float 19 is inserted, which can be inserted with elastic expansion of the legs 34.
  • the ends of the legs 34 are provided with radially directed stops 35 which prevent the float 19 from falling out.
  • the tubular extension 19 is bounded at the top by a valve seat 27 which has a smaller diameter than the tubular extension 18.
  • the valve seat 27 is located on a feed, designed as a cylindrical channel, to the valve seat 15 of the first pressure relief valve 16.
  • the valve seat 27 is assigned as a valve plate, the float 19, the upper side of which is provided with a sealing washer 26:
  • the float 19 is designed as a cylindrical hollow body which is tightly sealed to the outside. If there is a risk of leaks, it is expedient to provide buoyancy bodies within the hollow body of the float 19, which are made of a foam, for example.
  • the float 19 contains a second pressure relief valve 21, which releases or blocks a connection between the interior of the expansion tank 6 and the first pressure relief valve 16.
  • This pressure relief valve 21 has a valve disk 23, the bent edge of which bears from the outside against the sealing disk 26, which is arranged on the upper side of the float 19.
  • the float 19 is provided with a continuous channel 24, to which an opening of the sealing disk 26 is assigned and which is closed by the valve plate 23.
  • an extension 36 which is guided through the channel 24 of the float and on whose end protruding from the other side of the float engages a conical closing spring 22 which is supported on a securing ring 43 attached to the extension 36.
  • the other end of the closing spring 22 is supported on the underside of the float 19.
  • webs projecting inward into the channel 24 are provided, which serve to radially guide the extension 36.
  • the float 19 guided in the neck 18 of the insert 30 has two functions. In one function it serves as an overfill protection.
  • Line 17a indicates the liquid level up to which the coolant circuit is to be filled in the cold state. Up to this liquid level 17a, the float 19 is in the lowest position in which it rests on the stops 35.
  • the axial slots of the extension 18 are dimensioned such that they are sufficiently longer than the height of the float 19, so that they release a sufficient cross-section when coolant is refilled through the insert 30 with the bayonet lock 31 removed. If the coolant in the expansion tank 6 rises above the level 17a, the float 19 is raised and reaches with its upper edge in the no longer slotted area of the tubular extension 18.
  • the inflow cross section to the expansion tank 6 is due to the game between the upper Edge of the float 19 and the approach 18 limited, so that it is significantly reduced.
  • coolant liquid collects in the feed above the float until the coolant runs off via the overflow 8. Even with less careful operation, this is a sufficiently reliable indication that the further supply of coolant should be interrupted.
  • the play between the float 19 and the approach 18 is still large enough so that a perfect degassing can take place via the first pressure relief valve 16.
  • the tubular extension 18 projecting into the expansion tank 6 also ensures that an air cushion is present in any case in the upper region of the expansion tank 6.
  • the coolant circuit is designed in such a way that, due to the heating of the coolant, the increased coolant level 17b is set, at which the float 19 is still at a sufficient distance from the valve seat 27. In this operating state, only the first pressure relief valve 16 is in operation, i.e. the coolant circuit is secured to the opening pressure of this pressure relief valve 16.
  • the coolant circulation is interrupted. There is then the risk that vapor bubbles form at overheated points within the coolant guide of the internal combustion engine, which lead to an increase in the volume of the coolant in the coolant circuit.
  • the coolant then rises in the expansion tank 6 to an elevated level, which is shown, for example, by line 17c.
  • the float 19 is then moved upwards so far that it lies against the valve seat 27 with its sealing washer 26.
  • the pressure relief valve 16 is thus separated from the coolant circuit, so that it is out of function.
  • the possible overpressure in the coolant circuit is then no longer limited by the overpressure valve 16.
  • the first pressure relief valve 16 By shutting off the first pressure relief valve 16, it is prevented that, in the case of a further increase in volume due to the formation of vapor bubbles or the like. Coolant is ejected via the first pressure relief valve 16. A higher overpressure can occur within the coolant circuit, leading to this leads to further vapor bubble formation being restricted.
  • the possible overpressure is determined by the second overpressure valve 21, which is designed for a corresponding opening pressure. Since the first pressure relief valve 16 and the second pressure relief valve 21 are arranged in series one behind the other, this opening pressure is determined from the addition of the opening pressures of the first pressure relief valve 16 and the second pressure relief valve 21.
  • the second pressure relief valve 21 then becomes an opening pressure of 0.45 designed by appropriate dimensioning of the closing spring 22.
  • a throttle opening 28 is provided, which under Bypassing the float 19 and the second pressure relief valve 21 connects the interior of the expansion tank 6 to the first pressure relief valve 16.
  • this throttle opening consists of a channel 28 penetrating the valve plate 23 and the shoulder 36. The cross section of this throttle opening, i. H.
  • the channel 28 is dimensioned such that no coolant is ejected through it in the shutdown phase when there is a risk of vapor bubble formation, but after a predetermined period of time the pressure reduction to the opening pressure of the first pressure relief valve 16 is ensured.
  • the extension 36 dips into the coolant with the channel 28 serving as a throttle opening, so that the possible pressure reduction is caused by ejection of coolant, thereby reducing the overfill.
  • a throttle opening 37 which is shown in broken lines in FIG. 2, is guided through the insert 30 directly from the highest point of the expansion tank 6 to the area in front of the first pressure relief valve 16. In this case, the pressure is reduced in the event of overfilling by the escape of steam or gas or air via this throttle opening 37.

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  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Cooling, Air Intake And Gas Exhaust, And Fuel Tank Arrangements In Propulsion Units (AREA)
  • Safety Valves (AREA)
  • Motor Or Generator Cooling System (AREA)

Description

Die Erfindung betrifft eine Vorrichtung zum Absichern des Kühlmittelkreislaufes eines Verbrennungsmotors, insbesondere eines Kraftfahrzeugverbrennungsmotors, entsprechend dem Oberbegriff von Patentanspruch 1.The invention relates to a device for securing the coolant circuit of an internal combustion engine, in particular a motor vehicle internal combustion engine, according to the preamble of patent claim 1.

Es ist allgemein üblich, den Kühlmittelkreislauf auf einen Öffnungsdruck von etwa 1,1 bar bis 1,15 bar abzusichern. Überschreitet der Druck in dem Kühlmittelkreislauf diesen Wert, so können über Überdruckventile Kühlmittel, Gase oder Wasserdampf auftreten. Wird ein Verbrennungsmotor über eine gewisse Zeit betrieben, dadurch erhitzt und anschließend abgestellt, so kann durch örtliche Überhitzung, zum Beispiel an den Zylinderköpfen, Dampf in dem Kühlmittelkreislauf entstehen. Wenn die Kühlmittelzirkulation nach Abschalten des Verbrennungsmotors unterbrochen ist, kann der entstehende Dampf sich nicht abscheiden. Diese Dampfbildung bewirkt eine Volumensvergrößerung, die dazu führen kann, daß Kühlmittel über ein Überdruckventil ausgeworfen wird. Dieses ausgeworfene Kühlmittel steht dann für den Normalbetrieb nicht mehr zur Verfügung. Um einen derartigen Kühlmittelauswurf nach Abstellen des Verbrennungsmotors zu verhindern, wäre es möglich, den Kühlwasserkreislauf auf einen höheren Öffnungsdruck einzustellen. Dies würde jedoch im Normalbetrieb zu einer unerwünschten Erhöhung der Beanspruchung der Teile des Kühlsystems führen.It is common practice to secure the coolant circuit to an opening pressure of approximately 1.1 bar to 1.15 bar. If the pressure in the coolant circuit exceeds this value, coolant, gases or water vapor can occur via pressure relief valves. If an internal combustion engine is operated for a certain time, thereby heated and then switched off, steam can form in the coolant circuit due to local overheating, for example on the cylinder heads. If the coolant circulation is interrupted after the internal combustion engine is switched off, the steam generated cannot separate out. This vapor formation causes an increase in volume, which can lead to coolant being ejected via a pressure relief valve. This ejected coolant is then no longer available for normal operation. In order to prevent such coolant ejection after the internal combustion engine has been switched off, it would be possible to set the cooling water circuit to a higher opening pressure. However, this would lead to an undesirable increase in the stress on the parts of the cooling system in normal operation.

Es war eine Vorrichtung zum Absichern des Kühlkreislaufes eines Verbrennungsmotors bekannt (DE-3 143 749 A1), bei welcher im oberen Bereich eines Kühlmittel führenden Behälters zwei Überdruckventile angeordnet sind. Eines der Überdruckventile ist auf einen niedrigeren Öffnungsdruck, dem Betriebsdruck, und das andere Überdruckventil auf einen erhöhten Öffnungsdruck eingestellt. Bei dieser Bauart wird vorgesehen, daß dem auf den Betriebsdruck eingestellten Überdruckventil ein Magnetventil vorgeschaltet ist, das beim Einschalten des Motors geöffnet und bei Abschalten des Motors geschlossen wird. Durch das Ein- und Abschalten des Motors wird somit über das zusätzliche Magnetventil eine Umstellung von Betriebsdruck auf den erhöhten Öffnungsdruck bewirkt.A device for securing the cooling circuit of an internal combustion engine was known (DE-3 143 749 A1), in which two pressure relief valves are arranged in the upper region of a container carrying coolant. One of the pressure relief valves is set to a lower opening pressure, the operating pressure, and the other pressure relief valve is set to an increased opening pressure. In this design, it is provided that the pressure relief valve set to the operating pressure is preceded by a solenoid valve which is opened when the motor is switched on and closed when the motor is switched off. By switching the motor on and off, a switch from operating pressure to the increased opening pressure is thus effected via the additional solenoid valve.

Es war auch bekannt (GB-1 488 484 A) in einem Einfüllstutzen ein Schwimmerventil vorzusehen, die Verschlußkappe des Einfüllstutzens mit einem Überdruckventil zu versehen und zusätzlich ein weiteres Überdruckventil oberhalb des Schwimmerventils in dem Einfüllstutzen anzubringen. Wenn bei dieser Bauart der Flüssigkeitsspiegel derart ansteigt, daß das Schwimmerventil schließt, so werden die beiden Überdruckventile in Reihe geschaltet, so daß sich ein erhöhter Öffnungsdruck einstellt, der aus der Addition der beiden Öffnungsdrücke der Überdruckventile gebildet wird.It was also known (GB-1 488 484 A) to provide a float valve in a filler neck, to provide the closure cap of the filler neck with a pressure relief valve and in addition to install a further pressure relief valve above the float valve in the filler neck. If the liquid level rises in this design in such a way that the float valve closes, then the two pressure relief valves are connected in series, so that an increased opening pressure is produced, which is formed by adding the two opening pressures of the pressure relief valves.

Es war auch bekannt (US-1 541 073 A), ein Überdruckventil im Einfüllstutzen eines im Kühlmittelkreislauf angeordneten Behälters anzuordnen, dem ein Schwimmerventil vorgeschaltet ist. Zusätzlich war bei dieser Bauart ein weiteres Überdruckventil vorhanden, das nicht von dem Schwimmerventil verschließbar ist. Bei einem übermäßigen Flüssigkeitsanstieg in dem Behälter verschließt somit das Schwimmerventil eines der beiden Überdruckventile, während das andere in Funktion bleibt.It was also known (US Pat. No. 1,541,073 A) to arrange a pressure relief valve in the filler neck of a container arranged in the coolant circuit, which is preceded by a float valve. In addition, there was a further pressure relief valve with this design, which cannot be closed by the float valve. In the event of an excessive increase in liquid in the container, the float valve thus closes one of the two pressure relief valves while the other remains in operation.

Der Erfindung liegt die Aufgabe zugrunde, eine Vorrichtung entsprechend dem Oberbegriff des Patentanspruches 1 so auszubilden, daß eine einfache Konstruktion mit hoher Funktionssicherheit erhalten wird, bei der während der Abstellphase des Verbrennungsmotors ein Kühlmittelauswurf weitgehend verhindert werden kann.The invention has for its object to provide a device according to the preamble of claim 1 so that a simple construction with high functional reliability is obtained, in which a coolant ejection can be largely prevented during the shutdown phase of the internal combustion engine.

Diese Aufgabe wird durch die Merkmale des kennzeichnenden Teils des Patentanspruches 1 gelöst.This object is achieved by the features of the characterizing part of patent claim 1.

Das in den Schwimmer eingebaute Überdruckventil ist mit dem ersten Überdruckventil in Reihe geschaltet. Es ergibt sich dadurch eine Druckaddition zwischen den Öffnungsdrücken der beiden Überdruckventile, so daß das zweite Überdruckventil nur auf die Differenz zwischen dem Öffnungsdruck des ersten Überdruckventils und dem gewünschten erhöhten Öffnungsdruck ausgelegt werden muß. Bei einer Dampfbildung während der Abstellphase des Verbrennungsmotors, d.h. wenn die Gefahr eines Kühlmittelauswurfs besteht, ist der Kühlmittelkreislauf somit über die addierten Öffnungsdrücke abgedichtet. Da der Schwimmer in einem Käfig geführt ist, bewegt sich dieser in einer definierten Bahn, so daß auch die Wirkung des zweiten Überdruckventils immer aufrechterhalten wird.The pressure relief valve built into the float is connected in series with the first pressure relief valve. This results in a pressure addition between the opening pressures of the two pressure relief valves, so that the second pressure relief valve only has to be designed for the difference between the opening pressure of the first pressure relief valve and the desired increased opening pressure. If steam forms during the shutdown phase of the internal combustion engine, i.e. If there is a risk of coolant ejection, the coolant circuit is thus sealed by the added opening pressures. Since the float is guided in a cage, it moves in a defined path so that the effect of the second pressure relief valve is always maintained.

In weiterer Ausgestaltung der Erfindung wird vorgesehen, daß der Schwimmer mit dem zweiten Überdruckventil und dem Käfig als ein in eine Öffnung des Behälters dichtend einsetzbarer, die Zuführung zu dem ersten Überdruckventil enthaltender Einsatz ausgebildet ist. Dieser Einsatz bildet eine vormontierbare Baueinheit, die als Ganzes in den Behälter eingesetzt wird.In a further embodiment of the invention it is provided that the float with the second pressure relief valve and the cage is designed as an insert which can be inserted sealingly into an opening of the container and contains the feed to the first pressure relief valve. This insert forms a preassembled unit that is inserted as a whole into the container.

In weiterer Ausgestaltung der Erfindung wird vorgesehen, daß der Einsatz in einen Einfüllstutzen des Behälters eingesetzt ist und einen Ventilsitz für den mittels eines Renkverschlusses gehaltenen Ventilteller des ersten Überdruckventils aufweist. Damit wird eine Baueinheit aus beiden Überdruckventilen geschaffen, die als solche an dem Behälter angebracht wird. Der Einfüllstutzen des Behälters kann dann eine relativ einfache Gestaltung erfahren.In a further embodiment of the invention it is provided that the insert is inserted into a filler neck of the container and has a valve seat for the valve plate of the first pressure relief valve held by means of a bayonet lock. This creates a unit consisting of two pressure relief valves, which is attached to the container as such. The filler neck of the container can then have a relatively simple design.

In weiterer Ausgestaltung der Erfindung wird vorgesehen, daß der Einsatz einen an die Zuführung zu dem ersten Überdruckventil anschließenden rohrförmigen Ansatz aufweist, in welchem der Schwimmer mit Spiel geführt ist und dessen in den Behälter weisendes Ende durch axiale Schlitze in einzelne Schenkel unterteilt ist. Auf diese Weise wird einerseits ein einfacher Käfig für die Führung des Schwimmers erhalten, während andererseits eine Überfüllsicherung für den Behälter geschaffen wird. Solange der Schwimmer sich im Bereich der Schlitze des Ansatzes befindet, ist ein relativ großer Öffnungsquerschnitt zu dem Behälter frei, durch den das Kühlmittel eingefüllt werden kann. Wenn der Schwimmer mit steigendem Flüssigkeitsniveau in den ungeschlitzten Bereich des Ansatzes gelangt, ist nur noch ein geringer freier Querschnitt vorhanden, so daß eine weitere Nachfüllung von Kühlmittel zumindest stark behindert wird.In a further embodiment of the invention it is provided that the insert has a tubular extension adjoining the feed to the first pressure relief valve, in which the float is guided with play and the end pointing into the container is divided into individual legs by axial slots. In this way, a simple cage for guiding the float is obtained on the one hand, while on the other hand an overfill protection for the container is created. As long as the float is in the area of the slots of the approach, a is relative large opening cross-section to the container through which the coolant can be filled. If the float reaches the unslit area of the attachment with increasing liquid level, there is only a small free cross section, so that further refilling of coolant is at least severely hindered.

In vorteilhafter Ausgestaltung der Erfindung wird vorgesehen, daß die Schenkel des Ansatzes an ihren freien Enden mit radial nach innen gerichteten Anschlägen versehen sind. Die Schenkel werden bei dem Einführen des Schwimmers leicht elastisch aufgespreizt und sichern nach dem Einführen des Schwimmers dessen unterste Stellung. Der Schwimmer läßt sich somit in einfacher Weise mit dem Einsatz zu einer Baueinheit zusammenfügen.In an advantageous embodiment of the invention it is provided that the legs of the extension are provided at their free ends with radially inwardly directed stops. The legs are slightly elastically spread when the float is inserted and secure the lowest position after the float is inserted. The float can thus be easily combined with the insert to form a structural unit.

In weiterer Ausgestaltung der Erfindung wird eine den Schwimmer umgehende Drosselöffnung von dem Innenraum des Behälters vor das erste Überdruckventil geführt. Hiermit wird erreicht, daß bei Überfüllung des Kühlmittelkreislaufes sich der Druck im Kühlwasserkreislauf über einen vorbestimmbaren Zeitraum auf den Öffnungsdruck des ersten Überdruckventils abbauen kann, so daß auch bei einer Überfüllung der Kühlmittelkreislauf nicht über längere Zeit dem erhöhten Druck ausgesetzt ist. Der Querschnitt der Drosselöffnung wird so gewählt, daß durch die Drosselöffnung hindurch bei einer Normalbefüllung während der Abstellphase des Motors kein Kühlmittelauswurf eintritt. Bei einer ersten Ausführungsform ist der Eintritt der Drosselöffnung im Bereich der höchsten Stelle des Behälters angeordnet. Dadurch wird der überhöhte Druck durch Austritt von Gas oder Wasserdampf abgebaut. Bei einer anderen Ausführungsform der Erfindung ist vorgesehen, daß der Eintritt der Drosselöffnung an einer in das Kühlwasser eintauchenden Stelle angeordnet ist. Dadurch wird erreicht, daß der Druck durch Auswurf von Kühlmittel abgebaut wird, wobei allerdings nur die durch eine gegebenenfalls vorhandene Überfüllung gegebene Kühlmittelmenge ausgeworfen wird.In a further embodiment of the invention, a throttle opening bypassing the float is guided from the interior of the container to the first pressure relief valve. This ensures that when the coolant circuit is overfilled, the pressure in the cooling water circuit can decrease to the opening pressure of the first pressure relief valve over a predeterminable period of time, so that even if the coolant circuit is overfilled, it is not exposed to the increased pressure for a prolonged period. The cross section of the throttle opening is selected so that no coolant ejection occurs through the throttle opening during normal filling during the engine shutdown phase. In a first embodiment, the inlet of the throttle opening is arranged in the region of the highest point of the container. As a result, the excessive pressure is released by the escape of gas or water vapor. In another embodiment of the invention it is provided that the inlet of the throttle opening is arranged at a point immersed in the cooling water. It is thereby achieved that the pressure is reduced by ejecting coolant, but only the amount of coolant given by any overfilling is ejected.

Weitere Merkmale und Vorteile der Erfindung ergeben sich aus der nachfolgenden Beschreibung der in der Zeichnung dargestellten Ausführungsform und der Unteransprüche.

  • Fig. 1 zeigt eine schematische Darstellung eines Kühlmittelkreislaufes eines Verbrennungsmotors eines Kraftfahrzeuges mit einem an der höchsten Stelle des Systems angeordneten Ausgleichsbehälter und
  • Fig. 2 einen Schnitt in größerem Maßstab durch den Ausgleichsbehälter der Fig. 1, der mit einer erfindungsgemäßen Vorrichtung ausgerüstet ist.
Further features and advantages of the invention result from the following description of the embodiment shown in the drawing and the subclaims.
  • 1 shows a schematic illustration of a coolant circuit of an internal combustion engine of a motor vehicle with an expansion tank and located at the highest point in the system
  • Fig. 2 shows a section on a larger scale through the expansion tank of Fig. 1, which is equipped with a device according to the invention.

In Fig. 1 ist ein Verbrennungsmotor 1 dargestellt, der eine interne Kühlmittelführung besitzt. Als Kühlmittel wird üblicherweise Wasser verwendet, das mit einem Frostschutzmittel versehen ist. Mit der Kühlmittelführung des Verbrennungsmotors 1 ist ein Kühler über Leitungen verbunden, in welchen eine Kühlmittelpumpe 2 angeordnet ist. Die Kühlmittelpumpe 2 fördert das Kühlmittel zu dem Verbrennungsmotor 1, aus welchem es in Richtung des Pfeiles A zu dem Kühler 3 abströmt. Vor dem Kühler 3 ist eine Kurzschlußleitung 5 angeordnet, die über ein Thermostatventil 4 mit der Zuleitung zu dem Verbrennungsmotor 1 verbunden ist. Im Nebenstrom zwischen dem Kühler 3 und der Kühlmittelpumpe 2 ist ein Ausgleichsbehälter 6 angeordnet, der an der höchsten Stelle des Kühlmittelkreislaufes liegt. Der Zulauf 11 des Ausgleichsbehälters 6 ist über eine Leitung 31 mit dem höchsten Punkt des Kühlers 3 verbunden. Der Ablauf 10, des Ausgleichsbehälters 6 ist über eine Leitung 30 an die Saugseite der Kühlmittelpumpe 2 angeschlossen. In dem Ausgleichsbehäh ter 6 wird das Kühlmittel entgast, d.h. die in dem Kühlmittel enthaltenen Dampf- oder Gaseinschlüsse gelangen in einer Emulsion in den Ausgleichsbehälter 6, in welchem sie ggf. aus dem Kühlmittel abgeschieden werden und über einen Überlauf 8 austreten können.1 shows an internal combustion engine 1 which has an internal coolant guide. Water, which is provided with an antifreeze, is usually used as the coolant. A cooler is connected to the coolant guide of the internal combustion engine 1 via lines in which a coolant pump 2 is arranged. The coolant pump 2 conveys the coolant to the internal combustion engine 1, from which it flows in the direction of the arrow A to the radiator 3. A short-circuit line 5 is arranged in front of the cooler 3 and is connected to the supply line to the internal combustion engine 1 via a thermostatic valve 4. In the secondary flow between the cooler 3 and the coolant pump 2, an expansion tank 6 is arranged, which is located at the highest point in the coolant circuit. The inlet 11 of the expansion tank 6 is connected via a line 31 to the highest point of the cooler 3. The outlet 10 of the expansion tank 6 is connected via a line 30 to the suction side of the coolant pump 2. In the expansion tank 6, the coolant is degassed, i.e. The vapor or gas inclusions contained in the coolant reach the expansion tank 6 in an emulsion, in which they can be separated from the coolant and can escape via an overflow 8.

Der Kühlmittelkreislauf ist durch zwei Überdruckventile 16 und 21 auf vorgegebene Öffnungsdrücke gegen Überdruck abgesichert. Das Überdruckventil 16 ist im Normalbetrieb in Funktion und ist beispielsweise auf einen Öffnungsdruck P1 von etwa 1,15 bar eingestellt. Das Überdruckventil 21, das nur bei bestimmten Betriebszuständen in Funktion tritt, ist auf einen höheren Öffnungsdruck P2 eingestellt, der beispielsweise 1,5 bis 1,6 bar betragen kann. Bei dem dargestellten Ausführungsbeispiel ist die die beiden Überdruckventile 16 und 21 enthaltende Überdrucksicherung an dem Ausgleichsbehälter 6 angeordnet. Es ist selbstverständlich auch möglich, diese an einer anderen Stelle des Kühlmittelkreislaufes vorzusehen, insbesondere an der Oberseite des Kühlers 3, beispielsweise wenn kein gesonderter Ausgleichsbehälter 6 in dem Kühlmittelkreislauf vorgesehen wird.The coolant circuit is secured by two pressure relief valves 16 and 21 to predetermined opening pressures against excess pressure. The pressure relief valve 16 is in normal operation and is set, for example, to an opening pressure P1 of approximately 1.15 bar. The pressure relief valve 21, which only functions in certain operating states, is set to a higher opening pressure P2 , which can be, for example, 1.5 to 1.6 bar. In the illustrated embodiment, the pressure relief device containing the two pressure relief valves 16 and 21 is arranged on the expansion tank 6. It is of course also possible to provide them at another point in the coolant circuit, in particular on the top of the cooler 3, for example if no separate expansion tank 6 is provided in the coolant circuit.

In den Einfüllstutzen 12 des Ausgleichsbehälters 6 ist ein die beiden Überdruckventile 16 und 21 enthaltender Einsatz 30 eingesteckt, der eine im wesentlichen zylindrische Außenkontur hat. Der Einsatz 30 umgreift mit einem Flansch 32 den Rand des Flansches 33 des Einfüllstutzens 12 und ist an diesem rastend gesichert. Zur Abdichtung sind zwischen dem Einfüllstutzen 12 und dem Einsatz 30 wenigstens zwei Dichtungsringe 39 angeordnet. An dem Flansch 32 des Einsatzes 30 ist lösbar ein sogenannter Renkverschluß 31 angebracht, der einen Ventilteller 13 des ersten Überdruckventils 16 trägt. Der Ventilteller 13 ist in axialer Richtung verschiebbar auf einem Bolzen 40 des Renkverschlusses 31 geführt und mittels einer Druckfeder 14 belastet. Dem Ventilteller 13 ist ein Ventilsitz 15 zugeordnet, der von einem verengten Absatz des Einsatzes 30 gebildet wird. Außerhalb des Ventilsitzes 15 ist der Einsatz 30 mit mehreren axial gerichteten Öffnungen 41 verbunden, die zu einem ringnutförmigen umlaufenden Kanal 42 führen, an den der Überlauf 8 anschließt, der an dem Einfüllstutzen 12 angebracht ist. Die Druckfeder 14 des ersten Überdruckventils 16 ist auf einen Öffnungsdruck im Bereich von etwa 1,15 bar ausgelegt. Dieses Überdruckventil 16 ist im Normalbetrieb des Verbrennungsmotors 1 in Funktion, d.h. der Kühlmittelkreislauf ist auf einen Überdruck von etwa 1,15 bar ausgelegt. Tritt ein höherer Überdruck auf, so öffnet das Überdruckventil 16, so daß über die Verbindungsöffnungen 41, den Kanal 42 und den Überlauf 8 in dem Kühlmittel eingeschlossenes Gas oder Wasserdampf austreten können.An insert 30 containing the two pressure relief valves 16 and 21 is inserted into the filler neck 12 of the expansion tank 6 and has an essentially cylindrical outer contour. The insert 30 engages around the edge of the flange 33 of the filler neck 12 with a flange 32 and is secured in a latching manner thereon. For sealing, at least two sealing rings 39 are arranged between the filler neck 12 and the insert 30. A so-called bayonet lock 31 is removably attached to the flange 32 of the insert 30 and carries a valve disk 13 of the first pressure relief valve 16. The valve disk 13 is guided in the axial direction on a bolt 40 of the bayonet lock 31 and is loaded by means of a compression spring 14. A valve seat 15 is assigned to the valve plate 13 and is formed by a narrowed shoulder of the insert 30. Outside the valve seat 15, the insert 30 is connected to a plurality of axially directed openings 41, which lead to an annular groove-shaped circumferential channel 42, to which the overflow 8 connects, which is attached to the filler neck 12. The compression spring 14 of the first pressure relief valve 16 is designed for an opening pressure in the range of approximately 1.15 bar. This pressure relief valve 16 is in the normal range drive the internal combustion engine 1 in function, ie the coolant circuit is designed for an excess pressure of about 1.15 bar. If a higher overpressure occurs, the overpressure valve 16 opens, so that gas or water vapor enclosed in the coolant can escape via the connection openings 41, the channel 42 and the overflow 8.

Der Einsatz 30 ragt mit einem rohrförmigen Ansatz 18 in den Ausgleichsbehälter 6 hinein. Der in seinem oberen Bereich geschlossene Ansatz 18 ist in seinem unteren Bereich durch axiale Schlitze in einzelne Schenkel 34 unterteilt. In den Ansatz 18 ist ein Schwimmer 19 eingesetzt, der unter elastischen Aufweiten der Schenkel 34 eingeführt werden kann. Die Enden der Schenkel 34 sind mit radial gerichteten Anschlägen 35 versehen, die ein Herausfallen des Schwimmers 19 verhindern. Der rohrförmige Ansatz 19 ist nach oben durch einen Ventilsitz 27 begrenzt, der einen geringeren Durchmesser als der rohrförmige Ansatz 18 aufweist. Der Ventilsitz 27 befindet sich an einer als zylindrischer Kanal ausgebildeten Zuführung zu dem Ventilsitz 15 des ersten Überdruckventils 16. Dem Ventilsitz 27 ist als Ventilteller der Schwimmer 19 zugeordnet, dessen Oberseite mit einer Dichtungsscheibe 26 versehen ist:The insert 30 projects into the expansion tank 6 with a tubular extension 18. The approach 18, which is closed in its upper area, is divided into individual legs 34 in its lower area by axial slots. In the approach 18, a float 19 is inserted, which can be inserted with elastic expansion of the legs 34. The ends of the legs 34 are provided with radially directed stops 35 which prevent the float 19 from falling out. The tubular extension 19 is bounded at the top by a valve seat 27 which has a smaller diameter than the tubular extension 18. The valve seat 27 is located on a feed, designed as a cylindrical channel, to the valve seat 15 of the first pressure relief valve 16. The valve seat 27 is assigned as a valve plate, the float 19, the upper side of which is provided with a sealing washer 26:

Der Schwimmer 19 ist als ein walzenförmiger Hohlkörper ausgebildet, der nach außen dicht verschlossen ist. Falls die Gefahr von Undichtheiten besteht, so ist es zweckmäßig, innerhalb des Hohlkörpers des Schwimmers 19 Auftriebskörper vorzusehen, die beispielsweise aus einem Schaumstoff bestehen. Der Schwimmer 19 enthält ein zweites Überdruckventil 21, das eine Verbindung zwischen den Innenraum des Ausgleichsbehälters 6 und dem ersten Überdruckventil 16 freigibt oder absperrt. Dieses Überdruckventil 21 besitzt einen Ventilteller 23, dessen abgekanteter Rand von außen an der Dichtungsscheibe 26 anliegt, die an der Oberseite des Schwimmers 19 angeordnet ist. Der Schwimmer 19 ist mit einem durchlaufenden Kanal 24 versehen, dem eine Öffnung der Dichtungsscheibe 26 zugeordnet ist und die von dem Ventilteller 23 verschlossen wird. An dem Ventilteller 23 ist ein Ansatz 36 angebracht, der durch den Kanal 24 des Schwimmers hindurchgeführt ist und an dessen aus der anderen Seite des Schwimmers herausragendes Ende eine kegelförmige Schließfeder 22 angreift, die an einem an dem Ansatz 36 angebrachten Sicherungsring 43 abgestützt ist. Das andere Ende der Schließfeder 22 stützt sich an der Unterseite des Schwimmers 19. An der Oberseite und der Unterseite des Schwimmers 19 sind nach innen in den Kanal 24 ragende Stege angebracht, die zur Radialführung des Ansatzes 36 dienen.The float 19 is designed as a cylindrical hollow body which is tightly sealed to the outside. If there is a risk of leaks, it is expedient to provide buoyancy bodies within the hollow body of the float 19, which are made of a foam, for example. The float 19 contains a second pressure relief valve 21, which releases or blocks a connection between the interior of the expansion tank 6 and the first pressure relief valve 16. This pressure relief valve 21 has a valve disk 23, the bent edge of which bears from the outside against the sealing disk 26, which is arranged on the upper side of the float 19. The float 19 is provided with a continuous channel 24, to which an opening of the sealing disk 26 is assigned and which is closed by the valve plate 23. Attached to the valve plate 23 is an extension 36 which is guided through the channel 24 of the float and on whose end protruding from the other side of the float engages a conical closing spring 22 which is supported on a securing ring 43 attached to the extension 36. The other end of the closing spring 22 is supported on the underside of the float 19. At the top and the underside of the float 19, webs projecting inward into the channel 24 are provided, which serve to radially guide the extension 36.

Der in dem Ansatz 18 des Einsatzes 30 geführte Schwimmer 19 hat zwei Funktionen. In der einen Funktion dient er als Überfüllsicherung. Mit der Linie 17a ist das Flüssigkeitsniveau angedeutet, bis zu welchem der Kühlmittelkreislauf in kaltem Zustand befüllt werden soll. Bis zu diesem Flüssigkeitsniveau 17a befindet sich der Schwimmer 19 in der untersten Stellung, in welcher er auf den Anschlägen 35 aufliegt. Die Axialschlitze des Ansatzes 18 sind so bemessen, daß sie ausreichend länger sind, als die Höhe des Schwimmers 19, so daß sie einen ausreichenden Querschnitt freigeben, wenn bei abgenommenem Renkverschluß 31 über den Einsatz 30 Kühlmittel nachgefüllt wird. Steigt das Kühlmittel in dem Ausgleichsbehälter 6 über das Niveau 17a an, so wird der Schwimmer 19 angehoben und gelangt mit seinem oberen Rand in den nicht mehr geschlitzten Bereich des rohrförmigen Ansatzes 18. Damit wird der Zuströmquerschnitt zu dem Ausgleichsbehälter 6 auf das Spiel zwischen dem oberen Rand des Schwimmers 19 und dem Ansatz 18 beschränkt, so daß er damit wesentlich verkleinert ist. Es sammelt sich bei einem weiteren Nachfüllen Kühlmittelflüssigkeit in der Zuführung oberhalb des Schwimmers an, bis die Kühlflüssigkeit über den Überlauf 8 abläuft. Dies ist auch bei wenig sorgfältiger Bedienung ein ausreichend sicheres Anzeichen dafür, daß die weitere Zufuhr von Kühlmittel unterbrochen werden sollte. Das Spiel zwischen dem Schwimmer 19 und dem Ansatz 18 ist jedoch noch groß genug, so daß eine einwandfreie Entgasung über das erste Überdruckventil 16 erfolgen kann. Durch den rohrförmigen, in den Ausgleichsbehälter 6 hineinragenden Ansatz 18 wird darüberhinaus sichergestellt, daß auf jeden Fall in dem oberen Bereich des Ausgleichsbehälters 6 ein Luftpolster vorhanden ist.The float 19 guided in the neck 18 of the insert 30 has two functions. In one function it serves as an overfill protection. Line 17a indicates the liquid level up to which the coolant circuit is to be filled in the cold state. Up to this liquid level 17a, the float 19 is in the lowest position in which it rests on the stops 35. The axial slots of the extension 18 are dimensioned such that they are sufficiently longer than the height of the float 19, so that they release a sufficient cross-section when coolant is refilled through the insert 30 with the bayonet lock 31 removed. If the coolant in the expansion tank 6 rises above the level 17a, the float 19 is raised and reaches with its upper edge in the no longer slotted area of the tubular extension 18. Thus, the inflow cross section to the expansion tank 6 is due to the game between the upper Edge of the float 19 and the approach 18 limited, so that it is significantly reduced. During a further refill, coolant liquid collects in the feed above the float until the coolant runs off via the overflow 8. Even with less careful operation, this is a sufficiently reliable indication that the further supply of coolant should be interrupted. The play between the float 19 and the approach 18 is still large enough so that a perfect degassing can take place via the first pressure relief valve 16. The tubular extension 18 projecting into the expansion tank 6 also ensures that an air cushion is present in any case in the upper region of the expansion tank 6.

Der Kühlmittelkreislauf ist so ausgelegt, daß sich aufgrund der Erwärmung des Kühlmittels das erhöhte Kühlmittelniveau 17b einstellt, bei welchem sich der Schwimmer 19 noch in ausreichendem Abstand zu dem Ventilsitz 27 befindet. In diesem Betriebszustand ist nur das erste Überdruckventil 16 in Funktion, d.h. der Kühlmittelkreislauf ist auf den Öffnungsdruck dieses Überdruckventils 16 abgesichert.The coolant circuit is designed in such a way that, due to the heating of the coolant, the increased coolant level 17b is set, at which the float 19 is still at a sufficient distance from the valve seat 27. In this operating state, only the first pressure relief valve 16 is in operation, i.e. the coolant circuit is secured to the opening pressure of this pressure relief valve 16.

Wenn der Verbrennungsmotor 1 nach einem Betrieb, insbesondere nach einem Betrieb mit erhöhter Leistungsabgabe, wie einer Bergfahrt o.dgl., abgestellt wird, so wird die Kühlmittelzirkulation unterbrochen. Es besteht dann die Gefahr, daß sich an überhitzten Stellen innerhalb der Kühlmittelführung des Verbrennungsmotors Dampfblasen ausbilden, die zu einer Volumensvergrößerung des Kühlmittels in dem Kühlmittelkreislauf führen. Das Kühlmittel steigt dann in dem Ausgleichbehälter 6 auf ein erhöhtes Niveau an, das beispielsweise mit der Linie 17c dargestellt ist. Der Schwimmer 19 wird dann soweit nach oben bewegt, daß er sich mit seiner Dichtungsscheibe 26 gegen den Ventilsitz 27 anlegt. Damit wird das Überdruckventil 16 von dem Kühlmittelkreislauf abgetrennt, so daß es außer Funktion ist. Der mögliche Überdruck in dem Kühlmittelkreislauf wird dann nicht mehr von dem Überdruckventil 16 begrenzt. Durch das Absperren des ersten Überdruckventils 16 wird damit verhindert, daß bei einer weiteren Volumensvergrößerung aufgrund von Dampfblasenbildungen o.dgl. Kühlmittel über das erste Überdruckventil 16 ausgeworfen wird. Es kann sich innerhalb des Kühlmittelkreislaufes ein höherer Überdruck einstellen, der dazu führt, daß eine weitere Dampfblasenbildung eingeschränkt wird. Der dabei mögliche Überdruck wird von dem zweiten Überdruckventil 21 bestimmt, das auf einen entsprechenden Öffnungsdruck ausgelegt ist. Da das erste Überdruckventil 16 und das zweite Überdruckventil 21 in Reihe hintereinander angeordnet sind, wird dieser Öffnungsdruck aus der Addition der Öffnungsdrücke des ersten Überdruckventils 16 und des zweiten Überdruckventils 21 bestimmt. Wenn beispielsweise für den geschilderten Zustand nach dem Abstellen des Verbrennungsmotors ein Überdruck von 1,6 bar zugelassen werden soll und das erste Überdruckventil auf einen Öffnungsdruck von 1,5 bar ausgelegt ist, so wird dann das zweite Überdruckventil 21 auf einen Öffnungsdruck von 0,45 bar durch entsprechende Bemessung der Schließfeder 22 ausgelegt.If the internal combustion engine 1 is switched off after an operation, in particular after an operation with increased power output, such as a mountain trip or the like, the coolant circulation is interrupted. There is then the risk that vapor bubbles form at overheated points within the coolant guide of the internal combustion engine, which lead to an increase in the volume of the coolant in the coolant circuit. The coolant then rises in the expansion tank 6 to an elevated level, which is shown, for example, by line 17c. The float 19 is then moved upwards so far that it lies against the valve seat 27 with its sealing washer 26. The pressure relief valve 16 is thus separated from the coolant circuit, so that it is out of function. The possible overpressure in the coolant circuit is then no longer limited by the overpressure valve 16. By shutting off the first pressure relief valve 16, it is prevented that, in the case of a further increase in volume due to the formation of vapor bubbles or the like. Coolant is ejected via the first pressure relief valve 16. A higher overpressure can occur within the coolant circuit, leading to this leads to further vapor bubble formation being restricted. The possible overpressure is determined by the second overpressure valve 21, which is designed for a corresponding opening pressure. Since the first pressure relief valve 16 and the second pressure relief valve 21 are arranged in series one behind the other, this opening pressure is determined from the addition of the opening pressures of the first pressure relief valve 16 and the second pressure relief valve 21. If, for example, an overpressure of 1.6 bar is to be permitted for the described state after the internal combustion engine has been switched off and the first pressure relief valve is designed for an opening pressure of 1.5 bar, then the second pressure relief valve 21 then becomes an opening pressure of 0.45 designed by appropriate dimensioning of the closing spring 22.

Um zu verhindern, daß bei einer Überfüllung des Kühlmittelkreislaufes, bei welcher sich der Schwimmer 19 in der dargestellten, das Überdruckventil 16 außer Funktion setzenden Stellung befindet, über einen längeren Zeitraum der erhöhte Überdruck in dem Kühlmittelkreislauf herrscht, ist eine Drosselöffnung 28 vorgesehen, die unter Umgehung des Schwimmers 19 und des zweiten Überdruckventils 21 den Innenraum des Ausgleichsbehälters 6 mit dem ersten Überdruckventil 16 verbindet. Diese Drosselöffnung besteht bei der dargestellten Ausführungsform aus einem den Ventilteller 23 und den Ansatz 36 durchdringenden Kanal 28. Der Querschnitt dieser Drosselöffnung, d. h. des Kanals 28, ist derart bemessen, daß durch diese hindurch in der Abstellphase bei der Gefahr einer Dampfblasenbildung kein Kühlmittel ausgeworfen wird, jedoch nach einem vorbestimmten Zeitraum die Druckreduzierung auf den Öffnungsdruck des ersten Überdruckventils 16 sichergestellt ist. Bei einer Überfüllung taucht der Ansatz 36 mit dem als Drosselöffnung dienenden Kanal 28 in die Kühlflüssigkeit ein, so daß der mögliche Druckabbau durch Auswurf von Kühlmittel bewirkt wird, wodurch die Überfüllung reduziert wird.To prevent the coolant circuit from overfilling, in which the float 19 is in the position shown, which deactivates the pressure relief valve 16, the increased overpressure prevails in the coolant circuit over a longer period of time, a throttle opening 28 is provided, which under Bypassing the float 19 and the second pressure relief valve 21 connects the interior of the expansion tank 6 to the first pressure relief valve 16. In the illustrated embodiment, this throttle opening consists of a channel 28 penetrating the valve plate 23 and the shoulder 36. The cross section of this throttle opening, i. H. of the channel 28 is dimensioned such that no coolant is ejected through it in the shutdown phase when there is a risk of vapor bubble formation, but after a predetermined period of time the pressure reduction to the opening pressure of the first pressure relief valve 16 is ensured. In the event of an overfill, the extension 36 dips into the coolant with the channel 28 serving as a throttle opening, so that the possible pressure reduction is caused by ejection of coolant, thereby reducing the overfill.

In Abwandlung der erläuterten Ausführungsform wird vorgesehen, daß eine Drosselöffnung 37, die in Fig. 2 gestrichelt dargestellt ist, durch den Einsatz 30 direkt von der höchsten Stelle des Ausgleichsbehälters 6 zu dem Bereich vor dem ersten Überdruckventil 16 geführt wird. In diesem Fall erfolgt der Druckabbau bei einer Überfüllung durch Entweichen von Dampf oder Gas oder Luft über diese Drosselöffnung 37.In a modification of the illustrated embodiment, it is provided that a throttle opening 37, which is shown in broken lines in FIG. 2, is guided through the insert 30 directly from the highest point of the expansion tank 6 to the area in front of the first pressure relief valve 16. In this case, the pressure is reduced in the event of overfilling by the escape of steam or gas or air via this throttle opening 37.

Claims (12)

1. Apparatus for protecting the coolant circuit of an internal combustion engine, in particular a motor vehicle internal combustion engine, which apparatus can be switched over from an operating pressure to an increased opening pressure and which has a container (6) for holding a coolant, in the upper region of which is disposed a first pressure relief valve (16) which is set to a fist opening pressure and a second pressure relief valve (21) which is set to a second opening pressure, wherein disposed in the container (6) is a float valve (19, 27) which, upon an excessive rise in the level of coolant in the container (16), closes off the feed from the container (6) to the first pressure relief valve (16) and connects the two pressure relief valves (16, 21) in series, characterised in that the second pressure relief valve (21) is incorporated into the float (19) which is guided in a cage (18) arranged in the container (6).
2. Apparatus according to claim 1, characterised in that the float (19) with the second pressure relief valve (21) and the cage (18) is in the form of an insert (30) which can be sealingly fitted into an opening in the container (6) and which includes the feed to the first pressure relief valve (16).
3. Apparatus according to claim 2, characterised in that the insert (30) is fitted into a filler portion (12) of the container (6) and has a valve seat (15) for the valve plate (13) of the first pressure relief valve (16), the valve plate (13) being held by means of a bayonet cap (31).
4. Apparatus according to claim 2 or 3, characterised in that the insert (30) is fixed with a flange (32) to a flange (33) of the filler portion (12) of the container (6).
5. Apparatus according to claim 4, characterised in that the flange (32) of the insert (30) positively embraces the edge of the flange (33) of the filler portion (12).
6. Apparatus according to one of claims 1 to 5, characterised in that the insert (30) has a tubular projection (18) which adjoins the feed to the first pressure relief valve (16) and in which the float (19) is guided with clearance, the end of the projection (18) which faces into the container (6) being subdivided into individual limb portions (34) by axial slots.
7. Apparatus according to claim 6, characterised in that the limb portions (34) in the projection (18) are provided at their free ends with radially inwardly directed stops (35).
8. Apparatus according to one of claims 1 to 7, characterised in that the second pressure relief valve (21) includes a valve plate (23) which is pressed by means of a compression spring (22) against the top side of the float (19), which forms a valve seat (26), the valve plate (23) being guided with a projection (36) in the float (19).
9. Apparatus according to one of claims 1 to 8, characterised in that a throttle opening (28, 37) which by-passes the float (19) extends from the interior of the container (6) to a position in front of the first pressure relief valve (16).
10. Apparatus according to claim 9, characterised in that the entrance of the throttle opening (37) is arranged in the region of the highest point of the container (6).
11. Apparatus according to claim 9, characterised in that the entrance of the throttle opening (28) is disposed at a location which is immersed in the coolant water.
12. Apparatus according to claim 11, characterised in that the projection (36) on the valve plate (23) of the second pressure relief valve (21) passes through the float (19) and is provided with the throttle opening (28) which goes through the valve plate (23) from the container (6) to the first pressure relief valve (16).
EP85112273A 1984-10-06 1985-09-27 Device for securing a cooling circuit of an internal-combustion engine Expired EP0177860B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE3436702 1984-10-06
DE19843436702 DE3436702A1 (en) 1984-10-06 1984-10-06 DEVICE FOR SECURING THE COOLANT CIRCUIT OF AN INTERNAL COMBUSTION ENGINE

Publications (3)

Publication Number Publication Date
EP0177860A2 EP0177860A2 (en) 1986-04-16
EP0177860A3 EP0177860A3 (en) 1987-03-25
EP0177860B1 true EP0177860B1 (en) 1989-12-20

Family

ID=6247260

Family Applications (1)

Application Number Title Priority Date Filing Date
EP85112273A Expired EP0177860B1 (en) 1984-10-06 1985-09-27 Device for securing a cooling circuit of an internal-combustion engine

Country Status (4)

Country Link
US (1) US4640235A (en)
EP (1) EP0177860B1 (en)
DE (2) DE3436702A1 (en)
ES (1) ES8608629A1 (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE4228185A1 (en) * 1992-08-25 1994-03-03 Daimler Benz Ag Pressure control for IC engine coolant circuit - has float monitored coolant level in expansion tank and with two-level pressure control
DE19642114A1 (en) * 1996-10-14 1997-03-27 Guenter Kuhlmann Coolant circuit safety valve with hot stop valve

Families Citing this family (23)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3517715C2 (en) * 1985-05-17 1993-10-28 Laengerer & Reich Kuehler Coolant tank for the coolant circuit of an internal combustion engine
US4739824A (en) * 1987-01-08 1988-04-26 Susan E. Lund Hermetically sealed, relatively low pressure cooling system for internal combustion engines and method therefor
DE3803165C2 (en) * 1988-02-03 1994-05-19 Laengerer & Reich Kuehler Coolant tank for liquid-cooled internal combustion engines
DE4020866C1 (en) * 1990-06-29 1991-05-23 Mercedes-Benz Aktiengesellschaft, 7000 Stuttgart, De
DE4107183C1 (en) * 1991-03-06 1992-08-06 Mercedes-Benz Aktiengesellschaft, 7000 Stuttgart, De
DE4124182C1 (en) * 1991-07-20 1992-06-04 Mercedes-Benz Aktiengesellschaft, 7000 Stuttgart, De
DE4233038C1 (en) * 1992-10-01 1993-11-25 Daimler Benz Ag Overpressure protection for a coolant circuit
DE19611095A1 (en) * 1996-03-21 1997-09-25 Bayerische Motoren Werke Ag Cooling system for a liquid-cooled internal combustion engine
DE29617824U1 (en) * 1996-10-14 1997-02-13 Kuhlmann, Günter, 83413 Fridolfing Cooling circuit safety device
DE19753592A1 (en) * 1997-12-03 1999-06-10 Heinrich Reutter Sealing cover
US6397826B1 (en) 1998-12-18 2002-06-04 Clean Fuel Technology, Inc. Fuel cooling system for fuel emulsion based compression ignition engine
DE10034762A1 (en) * 2000-03-13 2002-01-31 Heinrich Reutter Sealing cap for vehicle radiator; has inner part with valve arrangement having valve bodies biased against seal seats inside cap, where valve bodies are lifted by excess pressure inside radiator
DE10034761A1 (en) * 2000-03-31 2002-01-31 Heinrich Reutter Sealing cap, e.g. for vehicle radiator; has valve arrangement with single valve body to open or shut flow connections according to three threshold levels of radiator inner pressure
US6532910B2 (en) 2001-02-20 2003-03-18 Volvo Trucks North America, Inc. Engine cooling system
US7152555B2 (en) * 2001-02-20 2006-12-26 Volvo Trucks North America, Inc. Engine cooling system
JP2006151131A (en) * 2004-11-26 2006-06-15 Yamaha Motor Co Ltd Vehicle
DE102007051758B4 (en) * 2007-10-30 2017-11-30 Bayerische Motoren Werke Aktiengesellschaft Cover with an integrated transparent lens for a coolant expansion tank
CN102033589B (en) * 2009-09-29 2014-01-22 鸿富锦精密工业（深圳）有限公司 Water-cooling cooling system and water receiver thereof
KR101542985B1 (en) 2013-12-20 2015-08-07 현대자동차 주식회사 Semi-pressurized Type Coolant Reservoir Tank
WO2016094410A1 (en) * 2014-12-08 2016-06-16 Toledo Molding & Die, Inc. Dual chamber coolant reservoir
TWM533845U (en) * 2016-06-06 2016-12-11 Cooler Master Technology Inc Pressurized infusion device and liquid cooling system
RU168690U1 (en) * 2016-08-05 2017-02-15 Общество с ограниченной ответственностью "АЛЬСТОМ Атомэнергомаш "( ООО "ААЭМ ") EXPANSION TANK RESPIRATORY DEVICE
KR20210076445A (en) * 2019-12-16 2021-06-24 현대자동차주식회사 Integrated type riservour for a car

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1488484A (en) * 1974-11-01 1977-10-12 Chrysler Uk Header tanks for coolant radiators
DE3045357A1 (en) * 1980-12-02 1982-06-09 Daimler-Benz Ag, 7000 Stuttgart Commercial vehicle propulsion IC engine cooling system - has two pressure relief plus vacuum control valves in series, first with lower setting

Family Cites Families (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1703163A (en) * 1921-11-28 1929-02-26 Harrison Radiator Corp Cooling system
US1531579A (en) * 1923-09-26 1925-03-31 Alfred L Sohm Indicator
US1541073A (en) * 1924-09-12 1925-06-09 Alfred L Sohm Indicator
FR644445A (en) * 1927-11-24 1928-10-08 Water retaining device in automobile radiators or combustion engines
US2127271A (en) * 1936-11-17 1938-08-16 Schenk William Water protective device for automobile motors
FR1014869A (en) * 1950-03-20 1952-08-25 Tech Et Commerciale D Installa Safety device, in particular for mobile tanks for volatile flammable products
US3284004A (en) * 1964-11-18 1966-11-08 Ford Motor Co Temperature and pressure responsive filler cap
FR2109028A5 (en) * 1970-02-17 1972-05-26 Muller Jacques
JPS5417900B2 (en) * 1974-03-14 1979-07-03
FR2439922A1 (en) * 1978-10-24 1980-05-23 Perolo Claude Filling height limiting valve for underground reservoir - has two float controlled valves shutting off at two levels
FR2476790A1 (en) * 1980-02-21 1981-08-28 Lafon Georges Limiting valve for refilling of storage tank - has loose woven glass fibre adhering superficially to elastomer layer
DE3143749A1 (en) * 1981-11-04 1983-05-11 Magirus-Deutz Ag, 7900 Ulm Device for safeguarding the water pressure in the cooling water circuit of an internal combustion engine
FR2529951A1 (en) * 1982-07-08 1984-01-13 Renault Vehicules Ind DEVICE FOR PRESSURIZING THE COOLING CIRCUIT OF A THERMAL ENGINE

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1488484A (en) * 1974-11-01 1977-10-12 Chrysler Uk Header tanks for coolant radiators
DE3045357A1 (en) * 1980-12-02 1982-06-09 Daimler-Benz Ag, 7000 Stuttgart Commercial vehicle propulsion IC engine cooling system - has two pressure relief plus vacuum control valves in series, first with lower setting

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE4228185A1 (en) * 1992-08-25 1994-03-03 Daimler Benz Ag Pressure control for IC engine coolant circuit - has float monitored coolant level in expansion tank and with two-level pressure control
DE19642114A1 (en) * 1996-10-14 1997-03-27 Guenter Kuhlmann Coolant circuit safety valve with hot stop valve

Also Published As

Publication number Publication date
DE3436702A1 (en) 1986-04-10
DE3574899D1 (en) 1990-01-25
EP0177860A2 (en) 1986-04-16
ES547595A0 (en) 1986-07-16
US4640235A (en) 1987-02-03
DE3436702C2 (en) 1987-09-03
EP0177860A3 (en) 1987-03-25
ES8608629A1 (en) 1986-07-16

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