JP3201843B2 - Engine cooling system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cooling system for an engine having a passage for cooling a high temperature portion of the engine and a passage for cooling a low temperature portion of the engine.

[0002]

2. Description of the Related Art Japanese Patent Application Laid-Open Publication No. HEI 9-123568 discloses a cooling water passage for an engine which is composed of a first cooling water passage for cooling a high temperature portion of the engine and a second cooling water passage for cooling a low temperature portion of the engine. No. 57-159916. According to the above publication, when the temperature of the cooling water in the engine is equal to or lower than the first set temperature, the supply of the cooling water from the water pump is stopped, and the temperature of the cooling water in the engine is equal to or higher than the first set temperature.
When the temperature is equal to or lower than the set temperature, the cooling water is supplied only to the first cooling water passage. When the temperature of the cooling water in the engine is equal to or higher than the second set temperature, the cooling water is supplied to the first cooling water passage and the second cooling water passage. Feeding facilitates warm-up of the engine when cold.

[0003]

However, according to the above-mentioned publication, when the cooling water is always left in the engine and the temperature of the cooling water is lowered more than necessary in a cold region or the like, the method of the above-mentioned publication discloses the method. It takes time to warm up the engine, and at the same time it leads to worse fuel efficiency and emissions. Here, it is conceivable that the cooling water is drained from the engine for a certain period of time and the water jacket is made into an air layer state to promote the warm-up of the engine, but the cooling water drained from the engine is stored in another place. At the same time as the need, when the cooling water is introduced again into the engine whose warm-up is promoted, there is a possibility that a cooling loss due to a decrease in wall temperature of the engine may become a problem.

When the cooling water is drained from the engine, it must be released to the atmosphere. Conversely, when the cooling water is released to the engine when the cooling water is introduced into the engine, air is released into the cooling water. There is a possibility that air may be introduced into the engine.

Accordingly, an object of the present invention is to solve the above-mentioned problem by temporarily draining the cooling water in the engine to promote warming-up of the engine and to introduce the cooling water again when the cooling water is introduced again. It is an object of the present invention to provide an engine cooling device that prevents a decrease in engine wall temperature and the incorporation of air.

[0006]

Means for Solving the Problems In order to achieve the above object, the constitution of the present invention is as follows.

According to the first aspect, the first cooling water passage through which the cooling water flows from the radiator for cooling the engine cooling water to the high temperature portion of the engine, and the cooling water from the radiator to the low temperature portion of the engine. An engine cooling device including a second cooling water passage, a first control device provided in the middle of the second cooling water passage to control an inflow of cooling water to the low-temperature portion; A recovery tank communicating with the cooling water passage via a third cooling water passage; and a second control which is provided in the middle of the third cooling water passage and controls the flow of the cooling water from the low-temperature portion to the recovery tank when the engine temperature is lower than a predetermined temperature. A third control device provided in the middle of a fourth cooling water passage for introducing cooling water from the recovery tank to the radiator upstream, and controlling the introduction of cooling water from the recovery tank to the radiator upstream. When the temperature is equal to or lower than the predetermined temperature, the cooling water in the recovery tank flows only into the high-temperature portion. When the temperature is equal to or higher than the predetermined temperature, the cooling water in the recovery tank flows into the low-temperature portion and the cooling water flows into the high-temperature portion. Thus, the control means for controlling each of the above control devices is provided. According to the second aspect, each of the control devices is configured by a valve. According to the third aspect of the present invention, when the cooling water in the recovery tank is supplied to the low-temperature section, a suppression means for suppressing a rapid temperature drop in the low-temperature section is provided.

According to a fourth aspect of the present invention, the suppression means is provided in a fifth cooling water passage communicating the high temperature section with the recovery tank, and is provided in the middle of the fifth cooling water passage. A fourth control device controls the flow of the cooling water from the high temperature section to the recovery tank at the following times.

According to a fifth aspect of the present invention, when the cooling water in the recovery tank is supplied to the low temperature section, the suppression means gradually increases the opening of the valve for opening and closing the second cooling water passage. Means.

According to a sixth aspect of the present invention, the recovery tank includes a communication passage communicating with the atmosphere, and the communication passage supplies cooling water in the recovery tank to the low-temperature portion, and then connects the communication passage to the low-temperature section. A fifth control device is provided for closing the control.

[0011]

According to the structure of the first aspect,
When the engine is at or below a predetermined temperature, the cooling water in the recovery tank is allowed to flow only into the high-temperature portion without flowing into the low-temperature portion, and when the engine is at or above the predetermined temperature, the cooling water in the recovery tank is allowed to flow into the low-temperature portion. At the same time, since the respective control devices are controlled so that the cooling water flows into the high-temperature portion, the warm-up of the engine can be promoted, and the fuel efficiency and the emission can be improved. According to the configuration described in claim 2, since each of the control devices is configured by a valve,
The effects of the configuration according to claim 1 can be achieved with an easy configuration.

According to the third aspect of the present invention, when the cooling water in the recovery tank is supplied to the low-temperature section, the suppression means for suppressing a rapid temperature drop in the low-temperature section is provided. When water is introduced again into the engine, it is possible to prevent a sharp decrease in the wall temperature of the engine, and to reduce the cooling loss.

According to the fourth aspect of the present invention, when the engine is at or below the predetermined temperature, the fourth control device is controlled so that the cooling water flows from the high temperature section into the recovery tank. Since the warmed cooling water in the high temperature section is warmed and the warmed cooling water is introduced into the engine, the same effect as the structure according to the third aspect is obtained.

According to the fifth aspect of the present invention, when supplying the cooling water in the recovery tank to the low temperature section, the opening of the valve for opening and closing the second cooling water passage is gradually increased. Therefore, cold cooling water is supplied little by little to the low-temperature portion, and the existing structure is used to make the third embodiment.
The same effect as the effect of the configuration described in (1) is achieved.

According to a sixth aspect of the present invention, the collection tank has a communication passage communicating with the atmosphere, and the communication passage supplies the cooling water in the collection tank to the low-temperature section, and then supplies the cooling water to the low-temperature section. Since the fifth control device for closing the passage is provided, it is possible to prevent air from being introduced from the cooling water recovery tank into the engine without introducing unnecessary air into the recovery tank.

[0016]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a diagram of a cooling system according to a first embodiment of the present invention, FIG. 2 is an operation system diagram of each valve, FIG. 3 is an enlarged view of a main part of FIG. 1, FIG. FIG. 5 is a diagram showing the circulation of the cooling water A line, FIG. 6 is a diagram showing the circulation of the cooling water B line, FIG. 7 is a diagram showing the circulation of the cooling water C line, and FIG. Diagram showing circulation,
FIG. 9 shows a second embodiment of the present invention. The present invention will be described in detail using a rotary engine as an example.

The rotary engine 1 (hereinafter referred to as the engine 1) comprises a high-temperature portion 1a located around the spark plug and a low-temperature portion 1b located other than around the spark plug.
A first water jacket 2 through which the engine cooling water passes is formed in the high temperature section 1a, and a second water jacket 3 through which the engine cooling water passes is formed in the low temperature section 1b.

Radiator 4 for cooling engine cooling water
The engine 1 and the engine 1 are communicated with each other through a forward path 5 through which cooling water flows from the radiator 4 to the engine 1 and a return path 6 through which cooling water flows from the engine 1 to the radiator 4.

A water pump 7 for pumping cooling water is disposed in the middle of the forward path 5, and downstream of the water pump 7, a first cooling water passage through which the cooling water flows into the high temperature section 1a. 8 and a second cooling water passage 9 through which cooling water flows into the low temperature section 1b. In the middle of the second cooling water passage 9, a first valve 10 as a first control device for controlling the flow of the cooling water into the low temperature section 1b is provided.

In the middle of the return path 6, a steam separation tank 11 for separating steam from steam is provided. A second valve 14 for controlling the outflow of the cooling water from the second water jacket 3 is provided in the return path 6 between the steam / water separation tank 11 and the engine 1. A thermostat 12 that opens and closes depending on temperature is provided in the return path 6 between the steam-water separation tank 11 and the radiator 4. The thermostat 12 and the outward path 5 upstream of the water pump 7 are communicated with each other through a bypass passage 13.

The recovery tank 15 for recovering the engine cooling water in the second water jacket 3 is provided in the third cooling water passage 1.
6 and communicate with the second water jacket 3. In the middle of the third cooling water passage 16, a third valve 17 that opens and closes by the pressure of the cooling water, and a fourth valve as a second control device that controls the flow of the cooling water from the second water jacket 3 to the collection tank 15. A valve 18 is provided. The collection tank 15 communicates with a sub-tank 19 that is open to the atmosphere via a communication passage 20. In the middle of the communication path 20, a sixth valve 31 is provided as a fifth control device that opens and closes so that air does not enter the collection tank 15. A level sensor 28 for detecting a water level in the collection tank 15 is provided on a side wall of the collection tank 15.

The recovery tank 15 is connected to one end of a fourth cooling water passage 22 for returning the engine cooling water to the return path 6, and the other end of the fourth cooling water path 22 is connected to the return path 6, and is indirectly connected to the recovery tank 15. The radiator 4 and the collection tank 15 are communicated. In the middle of the fourth cooling water passage 22, a fifth valve 27 as a third control device for controlling the flow of the cooling water from the recovery tank 15 to the return path 6 is arranged. The steam separation tank 11 and the sub tank 19 are connected via a pipe 21.

First water jacket 2 of engine 1
Is connected to one end of a sixth cooling water passage 23, and the other end of the sixth cooling water passage 23 is connected to the fourth cooling water passage 22. Therefore, the sixth cooling water passage 23 and the radiator 4
And are indirectly communicated.

As shown in FIG. 2, each valve has a water temperature sensor 24 for detecting the temperature of the engine cooling water, a pressure sensor 25 for detecting the negative pressure of the intake air, and a crank angle sensor 26 for detecting the number of revolutions of the engine. And the signal from the ignition 29 for starting the engine 1
After being input to 0, the ECU 30 controls opening and closing.

When the engine 1 is stopped and a long time has passed, the cooling water in the second water jacket 3 is recovered in the recovery tank 15 and the cooling water is introduced only into the first water jacket. is there. From the above state,
Start the engine 1.

The ignition 29 sends an ON signal to the ECU.
30, the first valve 10, the second valve 14, the fifth valve
The ECU 30 is on standby in such a manner that the valve 27 opens and the fourth valve 18 closes. Further, the sixth valve 31 is closed after a lapse of a certain set time (after a lapse of time when the cooling water flowing into the second water jacket flows out of the recovery tank 15).

Then, the temperature of the engine cooling water is equal to or higher than the set water temperature (here, equal to or higher than 60 ° C.), the intake pressure is equal to or higher than the set pressure (here, equal to or higher than −300 mmHg), and the engine speed is equal to or higher than the set speed (here, 4,000 rpm or more), the first valve 1
0, the second valve 14, and the fifth valve 27 are all opened, the fourth valve 18 is closed, and engine cooling water flows into the second water jacket 3 to cool the engine 1. At this time, the ECU 30 is controlled so that the valve opening speed of only the first valve 10 is reduced, that is, the valve opening degree is gradually increased. Further, the set number of revolutions is set low so that the valve is always opened after the elapse of the warm-up end time of the engine 1 (400 here).
0 rpm → 800 rpm). The warm-up end time is set in the ECU 30 by a timer.

The level sensor 28 provided on the side wall of the recovery tank 15 detects the level of the cooling water in the recovery tank 15. When the level of the cooling water is detected, a signal is sent to the ECU 30 and the fifth valve 27 is detected. Is controlled to close. (See FIG. 3) When the above conditions are not satisfied, the first valve 10, the second valve 14, and the fifth valve 27 are all closed, and the fourth valve 18 is opened. Inside, engine cooling water does not flow,
The warm-up of the engine 1 is promoted. Further, the first water jacket 2 is a high temperature part 1 of the engine 1 which is extremely heated.
a, the engine cooling water is constantly circulated to promote cooling.

The thermostat 12 opens the valve so that the engine cooling water is circulated to the radiator 4 when the engine cooling water reaches a certain set temperature (here, 82 ° C.), thereby cooling the engine cooling water. Water temperature is 60 ℃
In the following cases, the flow of the cooling water is set to the A-line circulation shown in FIG.

When the water temperature is 60 ° C. or more and 82 ° C. or less and one of the set pressure and the set number of revolutions is equal to or less than a set value, the flow of the cooling water is set to the A line circulation. You.

When the water temperature is not lower than 60 ° C. and not higher than 82 ° C., when both the set pressure and the set number of revolutions satisfy the condition of not less than the set value, the flow of the cooling water is the same as the A line circulation. 6 and the B-line circulation shown in FIG.

When the water temperature is equal to or higher than 82 ° C. and one of the set pressure and the set rotation speed is equal to or lower than the set value, the flow of the cooling water is set to the D line circulation shown in FIG. You.

When the water temperature is equal to or higher than 82 ° C. and both the set pressure and the set number of revolutions satisfy the conditions equal to or higher than the set values, the flow of the cooling water is controlled by the A line circulation and the B line.
Line circulation and C line circulation shown in FIG.

The engine cooling water passing through the return path 6 and entering the steam separator tank 11 is separated therefrom from the air, and the separated air is discharged from the sub tank 19 to the atmosphere through the pipe 21.

After the engine is stopped, that is, when the ignition 29 sends an OFF signal to the ECU 30, the first valve 10, the second valve 14, and the fifth valve 27 are closed, and the fourth valve 18 is opened. Is controlled by the ECU 30. The sixth valve 31 is opened.

If the engine cooling water is immediately drained from the second water jacket 3, the engine 3 may be burned. Therefore, the engine cooling water should be drained after the water temperature has dropped to some extent (the pressure must be reduced before the valve ), The set pressure of the third valve 17 (the set pressure>
Atmospheric pressure) is set. When the set pressure is reached, the third valve 17 opens, and the engine cooling water in the second water jacket 3 is collected in the collection tank 15.
Next, a second embodiment of the present invention will be described.

The second embodiment has the structure shown in FIG.
Compared with FIG. 1, a seventh valve 32 as a fourth control device and a fifth cooling water passage 33 that connects the seventh valve 32 to the recovery tank 15 are added in the middle of the sixth cooling water passage 23. Have been.

The seventh valve 32 is a three-way valve. When the first valve 10 and the second valve 14 are closed (when cooling water is not supplied to the second water jacket 3), the first valve 32 is closed. After passing through the jacket 2, the cooling water passes through the seventh valve 32, passes through the fifth cooling water passage 33, and enters the recovery tank 15. The first valve 10 and the second
When the valve 14 is open (when cooling water is supplied to the second water jacket 3), the cooling water that has passed through the first water jacket 2 is supplied to the seventh valve 32.
After passing through the sixth cooling water passage 23, the air flows into the fourth cooling water passage 22.

Therefore, when the cooling water is not supplied to the second water jacket 3, the cooling water in the recovery tank 15 is warmed by the warm engine cooling water that has passed through the first water jacket 2. Engine cooling water is constantly introduced into the first water jacket 2,
Cool a.

Next, when cooling water is supplied from the recovery tank 15 to the second water jacket 3, the warmed cooling water enters the second water jacket 3. Therefore, the first water jacket 2 and the second water jacket 3 are cooled.

Due to the above operation, the fifth valve 27 opens when the ignition 29 sends an ON signal to the ECU 30 (when the engine is started).
The valve is closed when an OFF signal is sent to the ECU 30 (when the engine is stopped).

According to the present embodiment, a certain set temperature (60
C) or lower, the engine cooling water in the recovery tank 15 does not flow into the second water jacket 3 in the low temperature section 1b, but the engine cooling water flows only into the first water jacket 2 in the high temperature section 1a. Above temperature,
Since the above valves are controlled so that the cooling water in the recovery tank 15 flows into the second water jacket 3 of the low temperature section 1b and the engine cooling water flows into the first water jacket 2 of the high temperature section 1a. Engine 1
Can be promoted, fuel efficiency can be improved, and emissions can be improved.

When the engine cooling water in the recovery tank 15 is supplied to the second water jacket 3 of the low temperature section 1b, the opening of the first valve 10 is gradually increased. Second water jacket 3
The engine cooling water flows into the engine 1 little by little, and the wall temperature of the engine 1 rises sharply when the engine cooling water is re-introduced into the engine 1 with a slight change in the valve control while using the existing structure. The cooling loss can be prevented, and the cooling loss can be reduced.

As another method, in the configuration as in the second embodiment, the engine cooling water warmed in advance is introduced into the second water jacket 3 in which the warm-up is promoted. When the cooling water is introduced into the engine 1 again, it is possible to prevent a sharp decrease in the wall temperature of the engine 1 and reduce the cooling loss.

The recovery tank 15 is provided with a communication passage 20 communicating with the atmosphere.
The sixth valve 31 is provided such that the sixth valve 31 closes after a lapse of a certain set time (after a lapse of time when the cooling water flowing into the second water jacket flows out of the recovery tank 15). Because of the control, it is possible to prevent air from entering the engine 1 from the cooling water recovery tank. In this embodiment, the rotary engine is used. However, the present invention can be applied to a reciprocating engine. In the present embodiment, the control device is a valve, but may be controlled using a pump or the like. In the present embodiment, the temperature is detected based on the temperature of the engine cooling water. Alternatively, the temperature may be detected based on the wall temperature of the engine.

[Brief description of the drawings]

FIG. 1 is a diagram of a cooling system according to a first embodiment of the present invention.

FIG. 2 is an operation system diagram of each valve.

FIG. 3 is an enlarged view of a main part of FIG. 1;

FIG. 4 is a flowchart of the basic system of the present invention.

FIG. 5 is a diagram showing A-line circulation of cooling water.

FIG. 6 is a diagram showing the circulation of cooling water in the B line.

FIG. 7 is a diagram showing C line circulation of cooling water.

FIG. 8 is a diagram showing D line circulation of cooling water.

FIG. 9 is a cooling system diagram according to a second embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Rotary engine (engine) 1a High temperature part 1b Low temperature part 4 Radiator 8 First cooling water passage 9 Second cooling water passage 10 First valve (first control device) 15 Recovery tank 16 Third cooling water passage 18 Fourth valve ( 2nd control device) 20 communication path 22 4th cooling water passage 27 5th valve (3rd control device) 31 6th valve (5th control device) 32 7th valve (4th control device) 33 5th cooling water passage (4th cooling water passage)

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) F01P 7/16 505 F01P 3/02 F01P 3/20

Claims (6)

(57) [Claims] 1. A a first cooling water passage Ru allowed to flow into the cooling water from the radiator for cooling the engine cooling water to the hot section of the engine, the second cooling water passage Ru allowed to flow into the cooling water from the radiator to the low temperature portion of the engine in the cooling system for an engine equipped with a preparative, provided in the middle of the second coolant passage, a first control device for controlling the flow of cooling water to the upper <br/> SL low temperature portion,
A recovery tank which is communicated through the third cooling water passage in the low temperature portion, provided in the middle of the third cooling water passage, the e Nji <br/> down to a collection tank from the low-temperature portion when less than a predetermined temperature a second control device for controlling the flow of cooling water, provided in the middle of the fourth cooling water passage for introducing the cooling water from the recovery tank to the radiator upstream the radiator upstream from recovered tank
And a third control unit for controlling the introduction of cooling water to the side,
When the temperature is equal to or lower than the predetermined temperature, the cooling water in the collection tank is caused to flow only into the high-temperature portion, and when the temperature is equal to or higher than the predetermined temperature, the cooling water in the collection tank is caused to flow into the low-temperature portion and the cooling water is caused to flow into the high-temperature portion. An engine cooling device, further comprising control means for controlling each of the control devices. 2. The engine cooling device according to claim 1, wherein each of the control devices is constituted by a valve. 3. The engine according to claim 2, further comprising a suppression means for suppressing a rapid temperature drop in the low temperature section when supplying the cooling water in the recovery tank to the low temperature section. Cooling system. Wherein said inhibiting means includes a fifth coolant passage connecting the collection tank with the high temperature portion, provided <br/> middle of fifth coolant passage, engine following a predetermined temperature 4. The engine cooling device according to claim 3, further comprising a fourth control device for controlling the flow of the cooling water from the high temperature section to the recovery tank. 5. The cooling device according to claim 1, wherein when the cooling water in the recovery tank is supplied to the low-temperature portion, the opening of the valve that opens and closes the second cooling water passage is gradually increased. The cooling device for an engine according to claim 3. 6. The recovery tank has a communication path communicating with the atmosphere, and a fifth control device that closes the communication path after supplying cooling water in the recovery tank to the low-temperature section is provided in the communication path. cooling device provided engine according to claim 3, characterized in Rukoto.