JP2000230425A - Cooling device for internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cooling device for an internal combustion engine, capable of improving fuel consumption ratio. SOLUTION: A direction controller 31 rotates a columnar member 35 according to the driving state of an engine so as to switch between a state where cooling water is introduced from a cooling water outlet of an engine main body 11 to a second chamber 17b of a housing 17 via a first bypass path 32, and a state where the cooling water is introduced to the second chamber 17b of the housing 17 via a radiator 12 and a second bypass path 33. A thermostat 21 controls the amount of cooling water that it introduces from the cooling water outlet of the engine main body 11 from a first chamber 17a of the housing 17 to the second chamber 17b via the radiator 12 and a second radiator communicating path 16 according to the temperature of the cooling water of the engine. A water pump 13 sends the cooling water in the second chamber 17a of the housing 17 to the cooling water inlet of the engine main body 11.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cooling device for a water-cooled internal combustion engine.

[0002]

2. Description of the Related Art Conventionally, as a cooling device for an internal combustion engine, for example, those shown in FIGS. 11 and 12 are known.

As shown in FIG. 11, this cooling device includes an engine body 71, a radiator 72, a water pump 73, and a cooling passage 74 for circulating cooling water.

The cooling passage 74 has an opening 71a on the cooling water outlet side of the engine body 71 and one side of the radiator 72 (FIG. 1).
The first radiator communication passage 75 that communicates with the upper side of the radiator 72, the other side of the radiator 72 (the lower side of FIG.
A second radiator communication passage 76 that communicates with the first cooling water inlet side opening 71b via a water pump 73 is provided. A housing 77 is formed on the water pump 73 side of the second radiator communication passage 76. The water pump 73 feeds the cooling water in the housing 77 into the opening 71b on the cooling water inlet side.

A thermostat 8 is provided in the housing 77.
1 is provided. And this thermostat 81
Accordingly, the housing 77 is divided into the first chamber 77a and the second chamber 7
7b. The first radiator communication passage 75 and the housing 77 (the second chamber 77b) are connected by a bypass passage 82.

The thermostat 81 is biased toward the opening (upper side in FIG. 11) of the bypass passage 82 by a spring 83 and a valve seat 86 side (lower side in FIG. 11) by a spring 85. Side) is provided. The temperature of the cooling water is, for example, 8
When the temperature is lower than 2 ° C., as shown in FIG. 11, the second valve 87 of the thermostat 81 is disposed in the valve seat 86 to shut off the space between the first chamber 77 a and the second chamber 77 b of the housing 77. That is, the thermostat 81 communicates with the bypass passage 82 and shuts off the second radiator communication passage 76. Therefore, the cooling water flowing out of the engine body 71 flows into the housing 77 (the second chamber 77b) via the bypass passage 82. Then, the cooling water flowing into the housing 77 (the second chamber 77b) is sent again to the engine body 71 by the water pump 73.

On the other hand, when the temperature of the cooling water becomes 82 ° C. or higher, the second valve 87 is set in accordance with the temperature.
5 and is separated from the valve seat 86. Then, the first chamber 7 is set in accordance with the separated distance.
The flow rate of the cooling water flowing from the 7a side to the second chamber 77b side is controlled. At this time, the first valve 84 is moved closer to the opening of the bypass passage 82. And
The flow rate of the cooling water flowing through the bypass passage 82 is controlled according to the approached distance. Here, when the temperature of the cooling water reaches, for example, 88 ° C., the second valve 87 of the thermostat 81 is fully separated from the valve seat 86 as shown in FIG.
The valve 83 closes the opening of the bypass passage 82 and shuts off the cooling water flowing through the bypass passage 82. Therefore, the cooling water flowing out of the engine main body 71 flows into the radiator 72 from the first radiator communication passage 75, and is sufficiently air-cooled here, and then from the second radiator communication passage 76 to the housing 77 (the second chamber 77b). Inflow. The cooling water that has flowed into the housing 77 (the second chamber 77b) is again sent into the engine body 11 by the water pump 13.

As described above, by changing the flow path and the flow rate of the cooling water based on the temperature of the cooling water by the thermostat 81, the engine body 71 is maintained at a predetermined temperature without overheating.

[0009]

By the way, in such a cooling device, the flow path and the flow rate of the cooling water are changed by controlling only the thermostat 81 based on the temperature of the cooling water, and the engine body 71 is set at the predetermined temperature. I try to keep it. Therefore, in consideration of the control ability of the thermostat 81, the predetermined temperature to be maintained is set to be lower as shown by a dashed line in FIG. For example, in a high-speed / high-load operation state of the engine, the engine body 71
When the temperature of the engine becomes excessively high, the cooling water from the radiator 72 passing through the thermostat 81 alone may not be able to cope with the temperature rise of the engine body 71. 82 °
The temperature is set as low as C to 88 ° C.

[0010] However, if the predetermined temperature is set lower, for example, the thermal efficiency of the engine deteriorates, and the fuel consumption rate deteriorates. An object of the present invention is to provide a cooling device for an internal combustion engine that can improve the fuel consumption rate.

[0011]

In order to achieve the above object, according to the first aspect of the present invention, a cooling water outlet and a cooling water inlet of an engine body are connected via a water pump, bypassing a radiator. A first cooling passage, second and third cooling passages for connecting a cooling water outlet and a cooling water inlet of the engine body via the radiator and the water pump, respectively, according to an operation state of the internal combustion engine; Direction control means for switching between a communication state of the first cooling passage and a communication state of the second cooling passage; and a flow control for controlling a flow rate of the third cooling passage in accordance with a temperature of cooling water of the engine. A valve, wherein the water pump switches the cooling water flowing into the water pump based on the switching state of the direction control means and the control state of the flow control valve to the engine body. As its gist the be fed into 却水 inlet.

According to a second aspect of the present invention, in the cooling device for an internal combustion engine according to the first aspect, the first cooling passage and the second cooling passage are connected via the direction control means. That is the gist.

According to a third aspect of the present invention, in the cooling device for an internal combustion engine according to the second aspect, the direction control means includes:
The gist of the present invention is to switch the communication states according to the temperature of the cooling water of the engine.

According to the first to third aspects of the present invention, the cooling water supplied to the cooling water inlet of the engine body is controlled by the switching state of the direction control means and the control state of the flow control valve. You. Then, the engine body is cooled by the cooling water sent at this time. Thus, the temperature of the engine body is more strictly controlled by controlling the cooling water sent to the cooling water inlet of the engine body based on the switching state of the direction control means and the control state of the flow control valve. Is done. Therefore, for example, even when the temperature of the engine body becomes excessively high in the high-speed and high-load operation state of the engine, the engine body can be maintained at a temperature at which a suitable fuel consumption rate is obtained without overheating.

The invention described in claim 4 is the first or second invention.
The gist of the invention is that the direction control means shuts off the first cooling passage and the second cooling passage in a cold state of the engine body.

According to this configuration, the first cooling passage and the second cooling passage are shut off when the engine body is in a cold state. Therefore, the cooling water in the engine body circulates inside the engine body, and the engine body is quickly warmed. Therefore, the warm-up property of the engine body is improved.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS (First Embodiment) A first embodiment in which the present invention is embodied in a cooling device for an internal combustion engine will be described below with reference to FIGS.

As shown in FIG. 1, the cooling device according to this embodiment includes an engine body 11, a radiator 12, a water pump 13, and a cooling passage 14 for circulating cooling water.

The cooling passage 14 has an opening 11a on the cooling water outlet side of the engine body 11 and one side of the radiator 12 (FIG. 1).
The first radiator communication path 15 communicating with the upper side of the radiator 12, the other side of the radiator 12 (lower side in FIG. 1) and the engine body 11
And the opening 11b on the cooling water inlet side of the water pump 1
And a second radiator communication passage 16 communicating with the third radiator through the third radiator 3. A housing 17 is formed on the water pump 13 side of the second radiator communication passage 16. The water pump 13 feeds the cooling water of the housing 17 into the opening 11b on the cooling water inlet side.

The housing 17 is provided with a thermostat 21 as an in-line type flow control valve, for example. The thermostat 21 divides the housing 17 into a first chamber 17a and a second chamber 17b. As shown in FIG. 5, the thermostat 21 has a rod contact portion 22a formed in a substantially cylindrical shape and a valve seat portion 22b formed at an end of the contact portion 22a, and is fixed to the housing 17. Done first case 22
And a substantially cylindrical second case 23 fixed to the outer peripheral side of the first case 22. Further, inside the first and second cases 22 and 23, one side (the upper side in FIG. 5) penetrates through the second case 23 through an arbitrary gap.
4 are provided. A valve 25 is fixed to the other side (lower side in FIG. 5) of the temperature sensing portion 24 corresponding to the position of the valve seat 22b. And this temperature sensing part 24
A spring 26 provided between the second case 23 and the valve 25 allows the first case 2
2 (valve seat portion 22b). Temperature sensing part 2
A wax is accommodated in the inside of 4, and a rod 24 a that penetrates through the valve 25 and contacts the rod contact portion 22 a of the first case 22 projects from the inside.
When the temperature reaches, for example, 92 ° C. or more, the temperature-sensitive portion 24 pushes the rod 24 a toward the rod contact portion 22 a by thermal expansion of the wax corresponding to the temperature. Thus, the rod 24a is connected to the rod contact portion 22.
By pushing the valve 25 to the side a, the valve 25 is separated from the valve seat 22b against the urging force of the spring 26. The flow rate of the cooling water flowing from the first chamber 17a to the second chamber 17b is controlled in accordance with the separated distance. When the temperature of the cooling water reaches, for example, 105 ° C., the thermostat 21 opens the valve 25.
Is fully separated from the valve seat 22b and is in a fully open state.

Between the first radiator communication passage 15 and the housing 17 (second chamber 17b), a first bypass passage 32 provided with a direction control body 31 as direction control means.
Connected by Further, the direction control body 31 is connected to a second bypass passage 33 communicating with the second radiator communication passage 16.

The direction control body 31 penetrates through the first bypass passage 32 and communicates with the second bypass passage 33 in a box-like shape having a substantially square cross section.
A cylindrical body 35 formed in a substantially cylindrical body and rotatably housed in the case 34 is provided. And the above cylindrical body 3
5 includes a first passage 36 penetrating in a predetermined radial direction and a first passage 3 extending in a radial direction orthogonal to the first passage 36.
A substantially T-shaped internal passage composed of a second passage 37 communicating the outside with the outside is formed.

The direction control body 31 having such a shape
Switches the direction of flow of cooling water based on a drive signal from an electronic control unit (hereinafter, referred to as “ECU”) 41 that performs overall control of the engine system. That is, the cylindrical body 35 of the direction control body 31 is rotated by the rotation of the electric motor included in the direction control body 31 based on the drive signal from the ECU 41. At this time, the communication direction between the first and second bypass passages 32 and 33 and the first and second passages 36 and 37 is switched, so that the flowing direction of the cooling water is switched. The ECU 41 outputs the drive signal based on the operating state of the engine detected by various sensors included in the engine system, and controls the flow direction of the cooling water.

The operation of the cooling device according to the present embodiment will be described below. When the operating state of the engine detected by the various sensors is a cold state of the engine body 11 such as when the engine is started, the ECU 41 arranges the cylindrical body 35 of the direction control body 31 as shown in FIG. The first bypass passage 32 communicates with the first bypass passage 32 and the second bypass passage 33 is shut off. At this time, since the thermostat 21 is in a closed state, the cooling water flowing out of the engine body 11 flows into the housing 17 (the second chamber 17b) via the first bypass passage 32 and the first passage 36. Incidentally, the first bypass passage 32, the first passage 36, the housing 17 (the second chamber 17b) and the like constitute a first cooling passage. The cooling water that has flowed into the housing 17 (second chamber 17b) is sent back into the engine body 11 by the water pump 13. By setting the flow path of the cooling water in this way, the cooling water is prevented from being cooled in the radiator 12, and the engine body 11 is quickly brought to a suitable temperature as shown by a thick solid line in FIG. Warmed up and its warm-up property is improved. Here, the preferable temperature means that the fuel vaporization is prevented from deteriorating, the combustion efficiency is improved, and the viscosity of the lubricating oil of the engine body 11 is reduced to reduce engine friction, thereby reducing the fuel consumption rate. It is a temperature that can be improved.

When the operating state of the engine detected by the various sensors is a predetermined vehicle speed / load operating state, the ECU 41 arranges the cylindrical body 35 of the direction control body 31 as shown in FIG. The second bypass passages 33 communicate the second bypass passage 33 with the downstream side of the first bypass passage 32 (on the side of the housing 17) and the upstream side of the first bypass passage 32 (on the side of the first radiator communication passage 15).
Shuts off. At this time, the temperature of the cooling water is, for example, 92
When the temperature is lower than ° C, the thermostat 21 is still in a closed state, so the cooling water flowing out of the engine main body 11 flows into the radiator 12 from the first radiator communication passage 15 and is cooled here by air. 2 radiator communication passage 16, second bypass passage 33 and first and second passages 3
The housing 17 (the second chamber 17b) through the sixth and the 37th
Flows into. Incidentally, these first radiator communication passages 1
5, radiator 12, second radiator communication passage 16, second
A second cooling passage is constituted by the bypass passage 33, the first and second passages 36 and 37, the housing 17 (second chamber 17b), and the like. The housing 17 (second chamber 1)
The cooling water flowing into 7b) is sent again to the engine body 11 by the water pump 13. By setting the cooling water flow path in this way, the radiator 1
The cooling water that has been air-cooled in Step 2 is sent to the engine body 11, and the engine body 11 is maintained at the above-mentioned preferable temperature without overheating.

On the other hand, the temperature of the cooling water is, for example, 92 ° C.
When the vehicle speed / load or the high speed / high load is as described above, the thermostat 21 is opened at an opening corresponding to the same temperature as shown in FIG. 3, and the cooling water having a flow rate corresponding to the opening opens the thermostat 21. It flows from the first chamber 17a of the housing 17 to the second chamber 17b. Therefore, when the temperature of the cooling water is 92 ° C. or more, the radiator 1
The cooling water that has been air-cooled in the second radiator communication passage 16,
It flows into the housing 17 (the second chamber 17b) through the second bypass passage 33 and the first and second passages 36 and 37,
At the same time, the cooling water having a flow rate corresponding to the opening degree of the thermostat 21 is also transferred from the first chamber 17a of the housing 17 to the second chamber 17.
b. By the way, the first radiator communication passage 15,
The radiator 12, the second radiator communication passage 16, and the housing 17 constitute a third cooling passage. The cooling water that has flowed into the second chamber 17b of the housing 17 as described above is sent again to the engine body 11 by the water pump 13. Thus, the housing 1
7 by changing the amount of cooling water flowing into the second chamber 17b according to the temperature, without overheating.
The high temperature engine body 11 is suitably cooled.

As described above, by appropriately setting the flow path of the cooling water as shown in FIGS. 1 to 3 according to the operating state of the engine, as shown by a thick solid line in FIG.
Is maintained at the above preferred temperature.

In order to more quickly warm the cold engine body 11 to the above-mentioned preferable temperature, the column body 35 of the direction control body 31 is arranged as shown in FIG. The second bypass passage 33 may not be communicated with the second chamber 17b of the housing 17. At this time, the cooling water in the engine main body 11 circulates mainly only inside thereof, and the engine main body 11 is warmed more quickly as shown by the broken line in FIG. And the warm-up property is remarkably improved. In order to avoid a local temperature rise when the cooling water is circulated inside, the column body 35 of the direction control body 31 is arranged as shown in FIG. 1 as appropriate.

As described in detail above, according to the present embodiment, the following effects can be obtained. (1) In the present embodiment, the warm-up property of the engine body 11 can be improved.

(2) In the present embodiment, a direction control body 31 whose rotation is controlled based on the operating state of the engine detected by various sensors, and a thermostat 21 whose flow rate is controlled at, for example, 92 ° C. or more are provided. As a result, the engine body 11 can be maintained at a suitable temperature without overheating.

(3) In the present embodiment, the deterioration of fuel vaporization is prevented to improve the combustion efficiency, and the engine body 1
(1) The viscosity of the lubricating oil can be reduced to reduce engine friction and improve the fuel consumption rate.

(Second Embodiment) A second embodiment in which the present invention is embodied in a cooling device for an internal combustion engine will be described below with reference to FIGS.

For the sake of convenience, the same components as those of the first embodiment are denoted by the same reference numerals, and the description thereof is partially omitted. In the present embodiment, the direction control body 3
In place of the first embodiment, for example, a thermostat 51 as a bottom bypass type direction control means and a housing 52 in which the thermostat 51 is provided are different from the first embodiment.

As shown in FIG. 7, one side of the housing 52 (the right side in FIG. 7) communicates with the opening 32a of the first bypass passage 32, and the other side (the left side in FIG. 7) is the second side. It communicates with the bypass passage 33. Then, the housing 52 is moved to the first position by the thermostat 51.
It is partitioned into a chamber 52a and a second chamber 52b.

As shown in FIG. 10, the thermostat 51 has a rod contact portion 53a formed in a substantially cylindrical shape and a valve seat portion 53b formed at an end of the rod contact portion 53a.
The first case 5 having the
3 and a substantially cylindrical second case 54 fixed to the outer peripheral side of the first case 53. In addition, inside the first and second cases 53 and 54, there is provided a temperature sensing part 55 whose one side (the right side in FIG. 10) penetrates the second case 54 through an arbitrary gap. One side (right side in FIG. 10) of the temperature sensing portion 55 has a first valve 5 urged by a spring 56 toward the opening 32a of the first bypass passage 32.
7 are provided. On the other hand, the other side of the temperature sensing section 55 (FIG. 10)
A second valve 58 is fixed to a position corresponding to the position of the valve seat 53b. The temperature sensing portion 55 is urged together with the second valve 58 toward the first case 53 (valve seat portion 53b) by a spring 59 provided between the second case 54 and the second valve 58. Have been. Wax is accommodated in the temperature sensing portion 55, and a rod 5 penetrating from the inside through the second valve 58 and abutting on the rod abutting portion 53 a of the first case 53.
5a is protruding. The temperature sensing part 55 is, for example, 88 °
When the temperature reaches or exceeds C, the rod 55a is connected to the rod contact portion 53a by thermal expansion of the wax corresponding to the temperature.
It pushes out to the side. By pushing the rod 55a toward the rod contact portion 53a in this manner, the second valve 58 is separated from the valve seat 53a against the urging force of the spring 59. The flow rate of the cooling water flowing from the first chamber 52a to the second chamber 52b is controlled in accordance with the separated distance. At this time, the first valve 57 is moved closer to the opening 32a of the first bypass passage 32. Then, the flow rate of the cooling water flowing through the first bypass passage 32 is controlled according to the approached distance. The temperature of the cooling water is, for example, 95 ° C.
Is reached, the thermostat 51 causes the second valve 58 to be fully separated from the valve seat 53b to a maximum extent, while the first valve 57 closes the opening 32a of the first bypass passage 32. Then, the cooling water flowing through the first bypass passage 32 is shut off.

The operation of the cooling device according to this embodiment will be described below. When the temperature of the cooling water is lower than 88 ° C. when the engine body 11 is in a cold state, the second valve 58 of the thermostat 51 is closed as shown in FIG. 32a
Is open. That is, the thermostat 5
1 communicates with the first bypass passage 32 and shuts off the second bypass passage 33. At this time, since the thermostat 21 is in the closed state, the cooling water flowing out of the engine body 11 flows into the housing 17 (the second chamber 17b) via the first bypass passage 32. Incidentally, the first bypass passage 32 and the housing 52 (second
The first cooling passage is constituted by the chamber 52b) and the housing 17 (the second chamber 17b). The cooling water that has flowed into the housing 17 (second chamber 17b) is sent back into the engine body 11 by the water pump 13. Therefore, similarly to the first embodiment, the cooling water is prevented from being cooled in the radiator 12, and the warm-up property of the engine body 11 is improved.

When the temperature of the cooling water is higher than 95 ° C. in the high-speed and high-load operation state of the engine, as shown in FIG. 8, the second valve 58 is maximally separated from the valve seat 53b. The cooling water in the second bypass passage 33 passes through the thermostat 51 and
It flows from the chamber 52a to the second chamber 52b. On the other hand, the first
The valve 57 is connected to the opening 32 a of the first bypass passage 32.
Is closed, and the cooling water flowing through the first bypass passage 32 is shut off. On the other hand, when the temperature of the cooling water is lower than 92 ° C., since the thermostat 21 is still closed, the cooling water flowing out of the engine body 11
After flowing into the radiator 12 from the radiator communication passage 15, the air is cooled here, and then flows into the housing 17 (the second chamber 17 b) via the second radiator communication passage 16, the second bypass passage 33 and the housing 52. Incidentally, the first radiator communication passage 15, the radiator 12, the second
The radiator communication passage 16, the second bypass passage 33, the housing 52, and the housing 17 (the second chamber 17b)
A second cooling passage is configured. The housing 17
The cooling water that has flowed into the (second chamber 17b) is sent back into the engine body 11 by the water pump 13. Therefore, similarly to the first embodiment, the radiator 1
The cooling water sufficiently air-cooled in the engine body 11
The engine body 11 is maintained at a suitable temperature without overheating.

When the temperature of the cooling water is 92 ° C. or higher and the vehicle speed / load or high speed / high load, FIG.
As shown in the figure, the thermostat 21 is opened at an opening corresponding to the same temperature, and a cooling water having a flow rate corresponding to the opening passes through the thermostat 21 and the first chamber 17 of the housing 17.
a to the second chamber 17b. Accordingly, when the temperature of the cooling water is equal to or higher than 92 ° C., the cooling water is air-cooled by the radiator 12 and the cooling water flows through the second radiator communication passage 16, the second bypass passage 33 and the housing 52 to the housing 17 (the second chamber 17 b). ), And cooling water having a flow rate corresponding to the opening of the thermostat 21 is also supplied to the housing 1.
7 flows into the second chamber 17b from the first chamber 17a. Incidentally, the first radiator communication passage 15, the radiator 12, the second radiator communication passage 16 and the housing 17 constitute a third cooling passage. The cooling water that has flowed into the second chamber 17b of the housing 17 as described above is sent again to the engine body 11 by the water pump 13. Therefore, similarly to the first embodiment, the housing 1
7 by changing the amount of cooling water flowing into the second chamber 17b according to the temperature, without overheating.
The high temperature engine body 11 is suitably cooled.

As described in detail above, according to the present embodiment, the following effects can be obtained in addition to the effects similar to the effects (1) and (3) of the first embodiment. (1) In the present embodiment, by providing the thermostat 51 whose flow rate is controlled at 88 ° C. or more and the thermostat 21 whose flow rate is controlled at 92 ° C. or more, it is possible to prevent overheating. Engine body 1
1 can be maintained at a suitable temperature.

The embodiment of the present invention is not limited to the above embodiment, but may be modified as follows. In the first embodiment, the rotation of the column body 35 of the direction control body 31 is performed by the electric motor. However, the rotation may be performed by using, for example, an actuator.

In the first embodiment, the direction of the cooling water is controlled by the rotation of the cylindrical body 35 (first and second passages 36 and 37) of the direction control body 31.
Instead of 5, for example, a butterfly valve may be provided, and the same direction control may be performed by turning the butterfly valve.

In the second embodiment, the temperature range in which the thermostat 51 is controlled is from 88 ° C. to 95 ° C.
Although C was set, this range is an example. In the above embodiments, the temperature range in which the thermostat 21 is controlled is set to 92 ° C. to 105 ° C.
This range is an example.

[0043]

According to the present invention, the temperature of the engine body can be more strictly controlled. Therefore, the temperature of the engine body can be maintained at a temperature at which a suitable fuel consumption rate is obtained without overheating.

According to the fourth aspect of the invention, the warm-up of the engine body can be improved.

[Brief description of the drawings]

FIG. 1 is a diagram showing the configuration and operation of a first embodiment of a cooling device for an internal combustion engine according to the present invention.

FIG. 2 is an exemplary view showing the configuration and operation of the embodiment.

FIG. 3 is an exemplary view showing the configuration and operation of the embodiment.

FIG. 4 is an exemplary view showing the configuration and operation of the embodiment.

FIG. 5 is a sectional view showing the thermostat of the embodiment.

FIG. 6 is a graph showing a relationship between time and cooling water temperature in the same embodiment.

FIG. 7 is a diagram showing the configuration and operation of a second embodiment of the cooling device for an internal combustion engine according to the present invention.

FIG. 8 is a view showing the configuration and operation of the embodiment.

FIG. 9 is a view showing the configuration and operation of the embodiment.

FIG. 10 is a sectional view showing the thermostat of the embodiment.

FIG. 11 is a configuration diagram of a conventional cooling device for an internal combustion engine.

FIG. 12 is a sectional view showing the thermostat of the embodiment.

[Explanation of symbols]

11: engine body, 12: radiator, 13: water pump, 15: first radiator communication passage, 16: second
Radiator communication passage, 17, 52 ... housing, 17a,
52a: first chamber, 17b, 52b: second chamber, 21, 51
... thermostat, 31 ... direction control body, 32 ... first bypass passage, 33 ... second bypass passage, 36 ... first passage,
37: Second passage.

Claims (4)

[Claims] A first cooling passage that connects a cooling water outlet and a cooling water inlet of the engine body to each other through a water pump, bypassing a radiator; and a cooling water outlet and a cooling water inlet of the engine body. Second and third cooling passages connected via a radiator and the water pump, respectively, and a communication state of the first cooling passage and a communication state of the second cooling passage depending on an operation state of the internal combustion engine. A direction control means for switching, and a flow control valve for controlling a flow rate of the third cooling passage in accordance with a temperature of the cooling water of the engine, wherein the water pump has a switching state of the direction control means and the flow rate control. A cooling device for an internal combustion engine, wherein cooling water flowing into the water pump is sent to a cooling water inlet of the engine body based on a control state of a valve. 2. The internal combustion engine cooling device according to claim 1, wherein said first cooling passage and said second cooling passage are connected via said direction control means. Engine cooling system. 3. The cooling device for an internal combustion engine according to claim 2, wherein the direction control unit switches the communication states according to a temperature of cooling water of the engine. . 4. The cooling device for an internal combustion engine according to claim 1, wherein the direction control unit shuts off the first cooling passage and the second cooling passage when the engine body is in a cold state. A cooling device for an internal combustion engine, comprising: