JP2004060580A - Cooling device of internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cooling device of an internal combustion engine capable of suppressing, with a simple structure, that when coolant from the internal combustion engine is stored in an insulated tank, coolant in the insulated tank which is discharged in place of the stored coolant is suddenly returned to the internal combustion engine. <P>SOLUTION: This cooling system comprises the insulated tank 11 storing the coolant. A circuit part 13 in which the pressure loss of a route 16 is switched according to the flow direction of the coolant is installed in the route 16 for the coolant connecting the insulated tank 11 to the engine 1. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a cooling device for an internal combustion engine having a heat retaining tank for storing a cooling liquid.
[0002]
[Prior art]
BACKGROUND ART Conventionally, as a cooling device for an internal combustion engine, for example, a cooling device described in Japanese Utility Model Laid-Open No. 6-74408 is known. The device described in the publication includes a heat retention tank (heat storage) for storing a coolant. Then, when the internal combustion engine is cold, the coolant supply path is switched to supply the coolant in the heat retaining tank, which is relatively high in temperature, only to the heater core of the air conditioner (heater), thereby realizing rapid heating. I have.
[0003]
Further, in such a cooling device for an internal combustion engine, there is also known a cooling device for supplying a cooling liquid in a heat retaining tank, which becomes relatively high when the engine is cold, to the engine to improve the warm-up property. .
[0004]
[Problems to be solved by the invention]
By the way, in such a cooling device, it is necessary to reduce the pressure loss in the supply path of the coolant from the heat retaining tank to the internal combustion engine in order to improve the warm-up property of the internal combustion engine. Thereby, the coolant in the heat retaining tank, which becomes relatively high in temperature, is quickly supplied to the internal combustion engine.
[0005]
However, after the engine is warmed up, if the coolant from the engine, which becomes relatively high in temperature by operation of the switching valve or the like, is to be stored in the thermal insulation tank, the coolant in the thermal insulation tank, which is discharged instead of this, Suddenly supplied (returned) to the internal combustion engine. In this case, the coolant in the heat retaining tank, which is relatively low in temperature, is returned to the internal combustion engine to cool the internal combustion engine, thereby deteriorating its efficiency, emission, and the like.
[0006]
For this reason, when the coolant from the engine is stored in the heat retention tank, the coolant in the heat retention tank, which is alternately discharged, is gradually returned to the internal combustion engine. Specifically, a new position of the switching valve is set so as to have a small flow rate different from the flow rate when the engine is cold, or the switching valve is frequently opened and closed to substantially reduce the flow rate. ing. In this case, another problem such as an increase in size due to the addition of the position of the switching valve or difficulty in securing reliability due to frequent opening and closing operations of the switching valve occurs.
[0007]
SUMMARY OF THE INVENTION An object of the present invention is to store a coolant from an internal combustion engine in a heat retention tank and suppress the sudden return of the coolant in the heat retention tank to the internal combustion engine instead of the coolant with a simple configuration. It is an object of the present invention to provide a cooling device for an internal combustion engine that can perform the cooling.
[0008]
[Means for Solving the Problems]
In order to solve the above problems, the invention according to claim 1 is a cooling device for an internal combustion engine including a heat retention tank that stores a coolant, wherein a cooling fluid path connecting the heat retention tank and the internal combustion engine includes: The gist of the present invention is to provide a circuit section in which the pressure loss of the passage is switched according to the flow direction of the coolant.
[0009]
According to a second aspect of the present invention, in the cooling device for an internal combustion engine according to the first aspect, the circuit unit allows a flow of a cooling liquid supplied to the internal combustion engine from the heat retaining tank, and the internal combustion engine further comprises: And a throttle provided in a passage that bypasses the one-way valve.
[0010]
According to a third aspect of the present invention, in the cooling device for an internal combustion engine according to the first or second aspect, a switching valve that switches communication / shutoff between the heat retaining tank and the internal combustion engine is provided in the path. And
[0011]
(Action)
According to the first aspect of the present invention, the circuit portion for switching the pressure loss of the cooling liquid in accordance with the flow direction of the cooling liquid is provided in the cooling liquid path connecting the heat retaining tank and the internal combustion engine. Therefore, for example, the pressure loss is reduced with respect to the flow of the coolant supplied from the heat retaining tank to the internal combustion engine, and the pressure loss is increased with respect to the flow of the coolant supplied to the thermal insulation tank from the internal combustion engine. Circuit section that switches as follows.
[0012]
Thus, when the coolant in the heat retaining tank is supplied to the internal combustion engine when the internal combustion engine is cold, the coolant is quickly supplied from the heat retaining tank to the internal combustion engine by the reduced pressure loss. Then, the engine is quickly warmed by the coolant from the heat retaining tank, which becomes relatively hot.
[0013]
On the other hand, when the coolant from the internal combustion engine is supplied to the heat retention tank and stored, the coolant is gently supplied from the internal combustion engine to the heat retention tank because the pressure loss increases. Then, the coolant in the heat retaining tank, which is discharged in place of the coolant, is also slowly returned to the internal combustion engine.
[0014]
According to the second aspect of the present invention, the circuit section has a very simple configuration including a one-way valve and a throttle provided in a passage that bypasses the one-way valve.
According to the third aspect of the present invention, a switching valve for switching communication / shutoff between the heat retaining tank and the internal combustion engine is provided in the path. Therefore, for example, during a warm-up operation of the engine, the switching valve is switched to shut off the heat retaining tank and the internal combustion engine. Thereby, the circulation of the coolant is suppressed, and the warm-up property of the internal combustion engine is improved.
[0015]
BEST MODE FOR CARRYING OUT THE INVENTION
An embodiment of the present invention will be described below with reference to FIGS. 1 to 4 are schematic configuration diagrams showing a cooling system of an internal combustion engine to which the present embodiment is applied, together with its operation. As shown in FIG. 1, the cooling system includes an engine 1 as an internal combustion engine, a mechanically driven water pump 2 drivingly connected to the engine 1, a heater 3, a thermostat 4, a radiator 5, And a heat storage system 6. Further, a coolant passage 7 for connecting the engine 1, the heater 3 and the water pump 2 is formed. A switching valve 8 is provided between the engine 1 and one side (upstream side) of the heater 3 in the path 7. The switching valve 8 is also connected to one side of the heat storage system 6 and communicates the engine 1 with one of the heater 3 and the heat storage system 6 depending on the position thereof, or connects the heater 3 and the heat storage system 6 with each other. Block communication. The position of the switching valve 8 is controlled by a control device (not shown).
[0016]
The water pump 2 is provided between the other side (downstream side) of the heater 3 and the engine 1 in the path 7. The water pump 2 circulates the coolant along the path 7 in a state where the engine 1 and the heater 3 are communicated by the switching valve 8, for example. At this time, when the temperature of the coolant is low and the thermostat 4 is in the closed state, the coolant passes through the inside of the engine 1 (such as a cylinder head) and is supplied to the heater 3. When the temperature of the coolant is high and the thermostat 4 is in the open state, a part of the coolant that has passed through the engine 1 is supplied to the radiator 5 at the same time.
[0017]
The heat storage system 6 includes a heat retention tank 11, an electric water pump 12, a one-way valve 14 and a throttle 15 that constitute a circuit unit 13. Further, between the switching valve 8 and the other side (downstream side) of the heater 3, a coolant passage 16 for connecting the circuit portion 13, the heat retaining tank 11 and the electric water pump 12 is formed. The path 16 communicates with the path 7 on the other side (downstream side) of the heater 3.
[0018]
The heat retention tank 11 is a tank having a heat retention property, and keeps the temperature of the coolant stored therein. More specifically, the heat retaining tank 11 has a coolant flow path on one side and the other side communicating with the electric water pump 12 and the circuit unit 13, respectively, and stores the coolant in the same flow path. Keep warm. Further, when the coolant is supplied from one of the one side and the other side, the heat retention tank 11 discharges the coolant from the other side instead of this. That is, the heat retention tank 11 discharges the coolant from the other as much as the coolant is supplied from one side.
[0019]
The electric water pump 12 is connected to one side of the heat retaining tank 11. For example, in a state where the engine 1 and the heat storage system 6 are communicated by the switching valve 8, the electric water pump 12 extends along a part of the path 16 and a part of the path 7. Circulate coolant.
[0020]
The one-way valve 14 of the circuit unit 13 is provided between the other side of the heat retaining tank 11 and the switching valve 8. The one-way valve 14 allows the flow of the coolant from the other side of the heat retaining tank 11 to the switching valve 8 and prohibits the flow of the coolant from the switching valve 8 side to the heat retaining tank 11. The pressure loss of the coolant flowing through the path 16 via the one-way valve 14 is set to be sufficiently small.
[0021]
The throttle 15 is provided in a passage 17 that bypasses the one-way valve 14, and increases the pressure loss of the coolant flowing through the passage 17 to reduce the flow rate thereof.
Next, the operation of the cooling system will be described. In FIGS. 1 to 4, the flow directions of the coolant corresponding to each operation are also indicated by arrows.
[0022]
FIG. 1 corresponds to the operation of preheating the engine 1 when the engine is cold, and the flow direction of the coolant at this time is indicated by an arrow. This preheat is an operation for warming the engine 1 prior to the warm-up operation of the engine 1. In this state, the switching valve 8 allows the engine 1 to communicate with the heat storage system 6 (the circuit unit 13), and shuts off the engine 1 and the heater 3. Here, when the electric water pump 12 is driven and the coolant in the path 7 is introduced and supplied to one side of the heat retaining tank 11, the heat retaining tank 11 which has been maintained at a relatively high temperature in place of this is replaced. The coolant inside is discharged from the other side. Then, the discharged coolant in the heat retaining tank 11 is supplied to the engine 1 via the circuit section 13 and the switching valve 8 to warm the engine 1. At this time, the one-way valve 14, which is in the forward direction, is opened to form a path with reduced pressure loss, so that the coolant in the heat retaining tank 11 is quickly supplied to the engine 1 and its warm-up property is improved. Is improved.
[0023]
Next, FIG. 2 corresponds to an operation during a warm-up operation of the engine 1 when the engine is cold. In this state, both the heat storage system 6 (circuit portion 13) and the heater 3 are shut off from the engine 1 by the switching valve 8. Therefore, during the warm-up operation, the coolant circulates only in the engine 1, so that the engine 1 is quickly warmed and the warm-up property is improved.
[0024]
FIG. 3 corresponds to the operation when the engine is warm (during normal running or the like), and the flow direction of the coolant at this time is indicated by an arrow. In this state, the switching valve 8 connects the engine 1 to the heater 3 and shuts off the engine 1 and the heat storage system 6 (circuit section 13). Then, the coolant is circulated along the path 7 by driving the water pump 2. As a result, the coolant that has passed through the engine 1 is supplied to the heater 3, and is supplied to, for example, room heating. At this time, when the coolant temperature is high, part of the coolant that has passed through the engine 1 by the operation of the thermostat 4 is circulated to the radiator 5 as described above.
[0025]
Next, FIG. 4 corresponds to the operation when heat is stored in the heat storage system 6 when the engine is warm, and the flow direction of the coolant at this time is indicated by an arrow. In this state, the switching valve 8 allows the engine 1 to communicate with the heat storage system 6 (the circuit unit 13), and shuts off the engine 1 and the heater 3. Here, the electric water pump 12 is not driven, and the coolant from the engine 1 is introduced into the heat storage system 6 via the switching valve 8 by driving the water pump 2 and circulates along the path 16 and the like. At this time, since the one-way valve 14 in the opposite direction is closed, the high-temperature coolant that has passed through the engine 1 is supplied to the other side of the heat-retention tank 11 through the throttle 15 provided in the passage 17. You. The supplied cooling liquid is stored in the heat retention tank 11 and kept warm, so that heat is stored in the heat storage system 6. On the other hand, instead of this, the coolant that becomes relatively low in temperature is discharged from the heat retention tank 11. At this time, since a path having an increased pressure loss through the throttle 15 is formed, the coolant in the heat retaining tank 11 is gradually discharged to the path 7 through the gap of the impeller of the electric water pump 12. . This avoids a situation in which the coolant in the heat retaining tank 11, which is relatively low in temperature, is rapidly supplied to the engine 1 to cool the engine 1.
[0026]
The heat storage in the heat storage system 6 when the engine is warm (FIG. 4) is performed for a short period of time that does not affect the heater performance while the coolant is supplied from the engine 1 to the heater 3 (FIG. 3). This is performed gradually by switching the position of the switching valve 8.
[0027]
As described in detail above, according to the present embodiment, the following effects can be obtained.
(1) In the present embodiment, a circuit section 13 that switches the pressure loss of the path 16 in accordance with the flow direction of the cooling liquid is provided in the path 16 of the cooling liquid that connects the heat retaining tank 11 and the engine 1. Then, the pressure loss is reduced with respect to the flow of the coolant supplied from the heat retaining tank 11 to the engine 1, and conversely, the pressure loss is increased with respect to the flow of the coolant supplied from the engine 1 to the thermal retention tank 11. I made it.
[0028]
Thereby, when the coolant of the heat retaining tank 11 is supplied to the engine 1 when the engine 1 is cold, the coolant is quickly supplied from the heat retaining tank 11 to the engine 1 at a large flow rate because the pressure loss is reduced. Can supply. Then, the engine 1 can be quickly warmed by the coolant from the heat retaining tank 11 which becomes relatively high in temperature, and the warm-up property is improved.
[0029]
On the other hand, when supplying the coolant from the engine 1 to the heat retention tank 11 and storing the coolant, the coolant can be gently supplied from the engine 1 to the heat retention tank 11 at a small flow rate because the pressure loss increases. Then, the coolant in the heat retaining tank 11 that is discharged in place of the coolant can also be gradually returned to the engine 1. Accordingly, it is also possible to avoid a situation in which the coolant in the heat retaining tank 11, which is relatively low in temperature, is rapidly returned to the engine 1 to cool the engine 1 and deteriorate its efficiency, emission, and the like.
[0030]
In particular, when the coolant from the engine 1 is supplied to the heat retaining tank 11 and stored therein, a new position of the switching valve (8) is set so as to have a small flow rate different from the flow rate when the engine 1 is cold. Since there is no need to perform this operation, it is possible to avoid an increase in the size of the switching valve and an increase in cost. Alternatively, since it is not necessary to frequently open and close the switching valve (8) to substantially reduce the flow rate, it is possible to eliminate the difficulty of ensuring the reliability.
[0031]
(2) In the present embodiment, the circuit section 13 can have a very simple configuration including the one-way valve 14 and the throttle 15 provided in the passage 17 that bypasses the one-way valve 14.
(3) In the present embodiment, during the warm-up operation of the engine 1, the switching of the heater 3 and the heat storage system 6 and the engine 1 is switched off by the switching valve 8, thereby suppressing the circulation of the cooling liquid and the engine 1. The warm-up property of the vehicle can be improved.
[0032]
(4) In the present embodiment, the pressure loss is automatically switched in the circuit section 13 in response to the switching of the flow direction of the coolant.
Note that the embodiment of the present invention is not limited to the above embodiment, and may be modified as follows.
[0033]
In the above embodiment, the throttle 15 may be formed by narrowing the passage 17, or a throttle valve may be separately provided.
In the above embodiment, the water pump 2 is of a mechanical drive type, but may be of an electric type.
[0034]
-In the said embodiment, the flow path structure of the cooling liquid of a cooling system is an example, and another structure may be employ | adopted.
Next, technical ideas that can be grasped from the above embodiments are described below together with their effects.
[0035]
(A) The cooling device for an internal combustion engine according to any one of claims 1 to 3, further comprising: an electric pump that creates a flow of a coolant supplied from the heat retention tank to the internal combustion engine in the path. Cooling device for an internal combustion engine. According to this configuration, the flow of the coolant supplied from the heat retaining tank to the internal combustion engine by the electric pump is easily created. Further, by setting the pump capacity, it becomes possible to appropriately adjust the supply amount of the coolant according to the standard of the internal combustion engine and the like.
[0036]
(B) In the cooling device for an internal combustion engine according to the above (a), the electric pump allows a flow of a cooling liquid supplied from the internal combustion engine to the heat retaining tank to pass therethrough. . According to this configuration, the flow of the coolant supplied from the internal combustion engine to the heat retaining tank is not interrupted by the installation of the electric pump.
[0037]
【The invention's effect】
As described in detail above, according to the first or second aspect of the invention, when the coolant from the internal combustion engine is stored in the heat retention tank, the coolant in the heat retention tank that is discharged in place of the coolant is rapidly increased. Return to the internal combustion engine can be suppressed with a simple configuration.
[0038]
According to the third aspect of the invention, the warm-up property of the internal combustion engine can be improved.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram showing the operation of an embodiment of the present invention.
FIG. 2 is a schematic configuration diagram showing the operation of the embodiment.
FIG. 3 is a schematic configuration diagram showing the operation of the embodiment.
FIG. 4 is a schematic configuration diagram showing the operation of the embodiment.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Engine as internal combustion engine 6 Thermal storage system 7, 16 Route 8 Switching valve 11 Heat retention tank 13 Circuit part 14 One-way valve 15 Throttle 17 Passage

Claims (3)

In a cooling device for an internal combustion engine having a heat retaining tank for storing a coolant,
A cooling device for an internal combustion engine, characterized in that a cooling fluid path connecting the heat retaining tank and the internal combustion engine is provided with a circuit section for switching a pressure loss of the path according to a flow direction of the cooling liquid. The cooling device for an internal combustion engine according to claim 1,
The circuit unit includes:
A one-way valve that allows the flow of the coolant supplied from the heat retention tank to the internal combustion engine and prohibits the flow of the coolant supplied from the internal combustion engine to the heat retention tank;
A throttle provided in a passage that bypasses the one-way valve. The cooling device for an internal combustion engine according to claim 1 or 2,
A cooling device for an internal combustion engine, wherein a switching valve for switching between communication and disconnection between the heat retaining tank and the internal combustion engine is provided in the path.

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