JPS5912848B2 - liquid cooled internal combustion engine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The invention provides that a constant-temperature operating mixing valve regulating the coolant temperature of a coolant circuit of an internal combustion engine is always connected only to the suction connection of a circulation pump inserted into the coolant circuit. a mixing chamber; a return chamber connected to the cooling medium outlet of the cooler via a cooler return conduit and capable of being isolated from the mixing chamber by a return control valve; and a short-circuit passage connected to the coolant outlet of the internal combustion engine, such that the coolant outlet of the internal combustion engine is always connected via the cooler inlet conduit to the coolant inlet in the upper collecting chamber of the cooler; It concerns a liquid-cooled internal combustion engine which is also connected to the mixing chamber via a short-circuit control valve that is opened when the engine is cold.

Internal combustion engines of this type are known.

(Federal Republic of Germany Patent Application No. 1295255).

In this internal combustion engine, both control valves are operated by expansion elements inserted into the mixing chamber and responsive to the temperature of the coolant in the mixing chamber.

When the engine is cold, the return control valve is closed and the short circuit control valve is open.

Therefore, when filling the cooling system with coolant, significant air pockets may form in the conduit system between the cooler and the return control valve, leading to interruptions in the coolant flow.

Another type of liquid-cooled internal combustion engine is known from JP-A-50-25951, in which the mixing chamber, in contrast to the first-mentioned configuration, is additionally always connected to a second short-circuit conduit, which The second in the area of the cylinder block of an internal combustion engine
always connected to the coolant outlet of the

Furthermore, this known internal combustion engine differs from the first type of internal combustion engine in that the cooler inlet conduit and the coolant outlet of the internal combustion engine connected to it are such that when the temperature of the coolant is low, the internal combustion engine is also cool. In operation, the mixing chamber is isolated by an additional third control valve connected before the short-circuit control valve.

When filling the coolant circuit in any known internal combustion engine, the filling connection piece must first be placed in the highest position of the coolant circuit in order to avoid air pockets in the line system that always leads to the mixing chamber. This compensating vessel must be connected to a second short-circuit conduit which is always connected to the mixing chamber.

In this way, the cooling medium first fills the cooling jacket of the internal combustion engine and subsequently fills the cooler via the cooler inlet conduit.

However, this can only be done if the mixing chamber and return chamber of the mixing valve and the cooler, respectively, are opened to the atmosphere when filled with cooling medium (and are connected to an air vent connection so that the air contained in these spaces can be forced out). do not have.

Two air bleed conduits therefore emerge from the mixing valve and are combined into an air bleed collecting conduit leading to the compensating vessel, and in order to prevent air intake from the compensating vessel, a float is operated in the return chamber when the circulation pump is activated. A valve shuts off the air vent collection conduit.

In order to evacuate the cooler via this air venting conduit, in this known internal combustion engine the cooler is always connected to the return chamber via the air venting conduit.

In this known internal combustion engine, there is therefore a risk that the circulation pump sucks in air which is separated in the upper collecting chamber of the cooler and is led to the return chamber.

This is because, even if the return control valve is closed, the return chamber is located between the two of the mixing valves which are in front of the float valve in the direction of flow into the compensating vessel.
This is because, via a convergence of two air vent lines, it leads to a mixing chamber which is always connected to the suction side of the circulation pump.

The object of the invention is to avoid the formation of air pockets in the return control valve.

This problem is advantageously solved according to the invention in the following way.

In other words, the return chamber is connected by an air vent connection to an auxiliary chamber which is supplied with cooling medium from a circulation pump to produce a sealing liquid, which auxiliary chamber acts as an air separator and eliminates atmospheric pressure during filling with the cooling medium. It has an air vent connection leading to the upper collecting chamber with a fill connection piece opening towards the side.

In the internal combustion engine according to the invention, the line system is vented in front of the return control valve via a filling connection that opens towards the atmosphere when it is filled with cooling medium, so that during operation of the internal combustion engine, the return control valve is opened. If there is, the sealing liquid in the auxiliary chamber prevents air from being drawn into the circulation pump.

In contrast, in the above-mentioned known internal combustion engines in which the mixing and return chambers are vented via a compensating vessel, the venting conduit leading from the return chamber to the cooler is used to vent the cooler and thus to vent the return chamber. In the case of the internal combustion engine according to the invention, a separate air venting line as well as a compensating vessel is not required.

Another liquid-cooled internal combustion engine of a different type is also known from Japanese Utility Model Publication No. 50-38667, in which the coolant temperature is not controlled by a mixing valve, unlike the first type of internal combustion engine, and the coolant temperature of the internal combustion engine is not controlled by a mixing valve. It is controlled by a short-circuit control valve inserted into the condenser inlet conduit leading from the outlet to the upper collecting chamber of the condenser, this short-circuit control valve therefore having no mixing chamber and leading to the coolant outlet of the condenser via the condenser return conduit. It does not have a return chamber that is connected to the mixing chamber and can be shut off from the mixing chamber by a return control valve.

In contrast to the mixing valve, this known short-circuit control valve has only one valve inlet, which is connected to the condenser inlet conduit.
It is connected to the coolant outlet of the internal combustion engine through the section.

Furthermore, unlike mixing valves, known short-circuit control valves have two valve outlets, one valve outlet being connected to the cooler via another part of the cooler inlet conduit, and the other valve outlet bypassing the cooler. It is connected via a short-circuit conduit to the coolant inlet of the internal combustion engine.

In this known internal combustion engine, an air separator with a charging connection piece for charging into the coolant circuit is provided in a position above the cooler and the internal combustion engine, and is connected to the upper part of the cooler via a cooling medium fill conduit. It is connected to the icebox and via an air vent line to the upper region of the cooling jacket of the internal combustion engine.

In this known internal combustion engine, since there is no mixing valve, the problem to be solved by the invention does not arise when filling the coolant circuit.

That is, when the internal combustion engine is cold, the short-circuit valve is always in the position where the valve outlet connected to the short-circuit conduit leads to the valve inlet connected to the coolant outlet of the internal combustion engine, so that the associated The section serves as an air bleed passage from the short-circuit control valve to the air bleed conduit.

In this known internal combustion engine, therefore, no special air vent line is provided in the short-circuit control valve, so that there is no indication of the problem of the invention or of any solution to this problem.

From Utility Model Publication No. 47-24543, the cooler inflow conduit of a liquid-cooled internal combustion engine is opened to an overflow chamber in the upper collecting chamber of the cooler, and a temperature-sensitive member installed in the overflow chamber detects the drop in the liquid level of the cooler. It is also known to wet the device with a cooling medium.

However, ensuring that the temperature-sensitive element is wetted with a variable liquid level has nothing to do with the air venting problem on which the invention is based (for which the cooler liquid level is not important). .

Finally, from Utility Model Application Publication No. 49-136929, a liquid-cooled internal combustion engine is known which is different from the first mentioned type.
Here, instead of a mixing valve, a thermostatic shut-off valve is inserted into the cooler inlet conduit leading from the coolant outlet of the internal combustion engine to the upper collecting chamber of the cooler with a filling connection piece, regulating the temperature of the coolant. Bypassing the shut-off valve, the coolant inlet and coolant outlet of the internal combustion engine are connected to each other via a constricted short-circuit channel.

In such cooling medium circuits, during cooling medium filling, the air contained in the cooling jacket of the internal combustion engine reaches only via the cooler inlet conduit the filling connection piece, which opens to the atmosphere in this case. The cooler inlet conduit, unlike the cooler inlet conduit in the first type of internal combustion engine, is forced closed by a thermostatic shutoff valve when the internal combustion engine is cold.

As a result, in this known internal combustion engine, a manually opened shut-off valve is used before filling with the cooling medium, which acts on the air removal passage, which is configured as a bypass for the shut-off valve.

Even in this known internal combustion engine, the problem underlying the invention, in which the air pockets present before the closed valves are sucked in by the circulation pump when the valves are opened, does not occur.

This is because when the known thermostatic shut-off valve opens, the air pocket is not led to the circulation pump, but in any case to the upper collecting chamber, which acts as an air separator of the cooler.

Furthermore, in this known internal combustion engine, the suction side of the circulation pump is always connected via a short-circuit channel to the coolant outlet of the internal combustion engine, so that there is in any case little risk of air being sucked in.

Since this known internal combustion engine uses a vent valve which can be shut off at will as a bypass for the control valve, it does not give any indication of the design of the internal combustion engine according to the invention.

This is because, in the known internal combustion engines, the auxiliary chamber, which is supplied with sealing liquid by the circulation pump, is not provided for blocking the air extraction conduit and, in the first type of internal combustion engine, the bypass for the return control valve. Even if an air vent valve is provided as an alternative, the problem addressed by the present invention cannot be solved.

This is because the mixing chamber on one side of the return control valve is connected to the suction side of the circulation pump.

The invention will be explained in more detail below with reference to an embodiment of a liquid-cooled internal combustion engine shown in the drawings.

Cooling spaces 1 and 2 of the internal combustion engine 3 through which the cooling medium sequentially flows
is connected in a cooling medium circuit 4, which is divided into a short circuit 6 and a cooler circuit 7 by a mixing valve 5 operating at constant temperature.

The coolant inlet and outlet of the internal combustion engine 3 are designated 8 and 9.

A circulation pump 11 , which has a discharge connection 10 connected to the coolant supply 8 and is driven by the internal combustion engine 3 , is electrically connected to the mixing chamber 13 of the mixing valve 5 via a suction line 12 .

The mixing valve 5 has two communicating valve connections 14 and 15 for the coolant outlet 9 and the cooler inlet conduit 18 leading to the upper collecting chamber 16 of the cooler 11 .

The short-circuit passage 19 of the mixing valve 5 connected to the coolant outlet 9 via the valve connection 14 is connected to the mixing chamber 1 by the short-circuit control valve 20.
Connected to 3.

The lower collecting chamber 2 of the cooler 17 via the cooler return conduit 21
The return chamber 23 of the mixing valve 5 connected to the return control valve 2
4 to the mixing chamber 13.

The control valves 20 and 24 are operated, in a known manner, by an expansion element cylinder 25 filled with a temperature-sensitive expansion substance and arranged in the mixing chamber 13, the piston rod 26 of which expands into the mixing valve 5. fixed inside.

The mixing valve 5 is provided with an air vent passage indicated at 27, one end of which opens into the return chamber 23 and the other end of which opens into the air vent conduit 28.
It is familiar to

The air vent conduit 28 communicates with a groove tank 29 as an auxiliary chamber provided in the upper gathering chamber 16.

This groove tank 29 is connected to the cooler inlet conduit 1 leading to the collecting room 16.
It is arranged below the opening 30 of the gathering room connection part 31 of No. 8 and opens upward.

The upper opening 32 of the channel trough 29 as an air vent connection is located in the turbulent region of the coolant flow passing through the opening 30.

In this way, the groove tank 29 always contains the sealing liquid supplied from the circulation pump 11 via the coolant inlet conduit 18.
When return control valve 24 is open, path 28-23-1
This prevents air from being sucked in by the circulation pump 11 from the collective room 1G via the pump 2.

When filling the cooling system with cooling medium, the channel tank 29 becomes empty, so that the cooler return conduit 21 and the return chamber 23 are discharged via the air vent conduit 28 and the open filling connection piece 33 in the upper collecting chamber 16. Air is vented to the atmosphere.

In the embodiment shown in FIGS. 3 to 5, the mixing valve 5
In the housing of the mixing valve 5 there is provided an air vent connection for the return chamber 23, indicated at 27, which is filled with sealing liquid as an auxiliary chamber and via a housing passage 29' as an auxiliary chamber, which likewise extends into the housing of the mixing valve 5. It is connected to an air bleed opening 32' in the valve connection 15 of the cooler inlet conduit 18 as an air bleed connection.

When filling the cooling system with cooling medium via the open air vent connection 33 of the upper collecting chamber 16, the return control valve 24 is closed.

The air trapped in the conduit system 2L23 is transferred to route 2
7-29'-32'-18-33 and escapes to the atmosphere.

During operation of the internal combustion engine, the valve connection 1 of the cooler inlet line 18
From 5, via the air vent opening 32', water droplets always enter the housing passage 29' and act there like a sealing liquid, even if the liquid level in the cooler 11 and therefore in the cooler inlet conduit 18 drops. Air flows from the upper collecting chamber 16 to the circulation pump 1
1, thereby eliminating the possibility of interruption of the coolant flow due to air bubbles.

The mixing valve 5 includes a valve housing 34 with a separation surface 35;
The valve housing cover 36 has a corresponding separation surface 3T.
It is fastened to the separation surface 35 of the valve housing while sandwiching the edge 38 of the valve seat plate 39.

On the side of the valve seat plate 39, as is known, a short circuit control valve 20 is installed.
and mutually coaxial valve plates 40 and 41 of the return control valve 24 are provided.

The housing passage 29' has a passage portion 43 extending parallel to the common central axis 42 of the valve plates 40 and 41 and passing through the separating surfaces 35 and 3T.

The edge 38 of the valve seat plate 39 is surrounded by an annular seal 44 with a tongue 45 with a cylindrical passage 46 at the housing passage 29'.

This passage opening 46 coincides with the passage section 43 in the assembled position.

In order to secure this assembly position, the annular packing 44 has three fixing protrusions 47 on its outer periphery.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram of a cooling system for an internal combustion engine according to the present invention;
Figure 2 is a partially cutaway enlarged view of the upper gathering room in Figure 1.
3 is a schematic diagram of the cooling system of another embodiment of the internal combustion engine according to the present invention, FIG. 4 is an enlarged view of the mixing valve of FIG. 3, and FIG. 5 is a front view of the annular packing of FIG. 4. be. 1.2... Cooling space, 3... Internal combustion engine, 4... Cooling circuit, 5... Mixing valve, 6
...Short circuit, 7...Cooler circuit, 8
... Cooling medium inlet, 9 ... Cooling medium outlet, 11 ... Circulation pump, 12 ... Suction conduit, 13 ... Mixing chamber , 14, 15...
... Valve connection part, 16 ... Upper gathering chamber, 17.
...Cooler, 18...Cooler inflow conduit,
19... Short circuit passage, 20... Short circuit control valve, 21... Cooler return conduit, 22...
・Lower gathering room, 23...Return room, 24...
...Return control valve, 27...Air vent connection, 2
8... Air vent conduit, 29... Groove tank,
29'......Uji puffer passage, 32°32'.
...Opening, 40, 41...Valve plate.

Claims (1)

[Scope of Claims] 1. A mixing chamber in which a constant-temperature operating mixing valve for regulating the coolant temperature of a coolant circuit of an internal combustion engine is always connected only to the suction connection of a circulation pump inserted into the coolant circuit;
a return chamber which is connected to the cooling medium outlet of the cooler via a cooler return conduit and can be shut off to the mixing chamber by means of a return control valve; a short-circuit passage connected to the coolant outlet, so that the coolant outlet of the internal combustion engine is always connected via the cooler inlet conduit to the coolant inlet in the upper collecting chamber of the cooler, and when the internal combustion engine is cooled. In liquid-cooled internal combustion engines, which are also connected to the mixing chamber via a short-circuit control valve that is opened when 18 to an auxiliary chamber (channel trough 29 in FIGS. 1 and 2 or housing passage 29' in FIGS. 3 and 4), which is supplied with a cooling medium through the auxiliary chamber 29 or 2.
9' is an air vent connection (opening 32 in FIG. 2 or 18. in FIG. 32'). 2 a groove tank 29 which is supplied with sealing liquid to the upper collecting chamber 16 via the cooler inlet conduit 18 and is connected to the return chamber 23;
2. The internal combustion engine according to claim 1, wherein the internal combustion engine is provided as an auxiliary chamber. 3. Internal combustion engine according to claim 2, characterized in that the groove tank 29 is located below the chamber connection (opening 30) of the cooler inlet conduit 180 and in the turbulent flow region of the coolant flow. . 4 From the auxiliary room (housing passage 29') to the upper gathering room 1
2. Internal combustion engine according to claim 1, characterized in that the air bleed connection to 6 (air bleed opening 32') is connected to the cooler inlet conduit 18. 5. The mixing valve has two communicating valve connections, one of which connects the short-circuit passage to the coolant outlet of the internal combustion engine and the other connects the cooler inlet conduit to the coolant outlet of the internal combustion engine. in which the mixing valve 5 has a housing passage 29' which connects the air bleed connection 21 of the return chamber 23 to an air bleed opening 32' opening into the valve connection 15 of the cooler inlet conduit 18; An internal combustion engine according to claim 4, characterized in that: 6. The valve plate of the short-circuit control valve and the valve plate of the return control valve are mounted on one valve seat plate, with the edge of this valve seat plate between the separation surface of the valve housing and the corresponding separation surface of the valve housing cover. in which the housing passage 29' is characterized in that it has a passage section 43 extending close to the edge 38 of the valve seat plate 39, which passage section passes through the separating surfaces 35 and 37. An internal combustion engine according to claim 5. γ In those where the edge of the valve seat plate cooperates with the annular seal, the annular seal 44 has a radially extending tongue 45 which has a passage opening 46 which coincides with the passage section 43. An internal combustion engine according to claim 6, characterized in that: