JPS63150414A - Cooling device for engine - Google Patents

Abstract

PURPOSE:To improve antiknock property and to increase mechanical resistance of a sliding portion of a cylinder block by cooling a cylinder head by evaporation type cooling means and cooling the cylinder block by water flow cooling means. CONSTITUTION:Liquid phase cooling medium such as water or the like can be supplied to a water jacket 16 on cylinder head side and a water jacket 18 on cylinder block side which are independently constructed in an engine main body 10 from a storage tank 20 through conduits 26, 27 respectively having solenoid switch valves 21, 22. The uppermost portion of the water jacket 16 is connected to a steam introducing portion 36 of a condenser 39 through a steam passage 32, and the upper portion of the water jacket 15 is connected to a radiator 52. The lower portions of the condenser 35 and the radiator 52 are connected to the lower portions of the water jackets 16, 18 through pumps 42, 54. The uppermost portion of the storage tank 20 is connected to a vacuum pump 45 through a solenoid switch valve 24.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an engine cooling device that cools the engine using a liquid phase refrigerant stored in a water jacket provided around the combustion chamber of the engine. .

(Prior Art) Conventionally, a cooling system for a vehicle engine includes a water jacket (a chamber through which a liquid refrigerant such as water passes, or a storage chamber thereof) and a radiator (a heat exchange means for dissipating the heat of the liquid refrigerant). A system that circulates a liquid phase refrigerant between the cooling means consisting of The stored liquid refrigerant is boiled using the heat generated by the engine, and the heat of vaporization of the liquid refrigerant at the time of boiling is used to cool the engine, and the vapor of the liquid refrigerant (vapor refrigerant) is transferred to a condenser, etc. A type of refrigerant (hereinafter referred to as a boiling type) is being considered in which the refrigerant is cooled and condensed into a liquid phase refrigerant, and then returned to the water jacket for circulation.

In a cooling device that uses such a boiling type, the capacity of the pump means for circulating the refrigerant and the heat dissipation area of the cooling means can be made smaller than those that use a flowing water type. Since the boiling point of the liquid phase refrigerant can be changed according to the pressure within the system, an advantage is obtained that the degree of cooling can be controlled in various ways according to the operating state of the engine.

On the other hand, in an engine whose compression ratio is set to a large value in order to improve thermal efficiency, one of the important issues is to suppress the occurrence of knocking. It is known that in order to suppress the occurrence of such knocking, it is sufficient to keep the surroundings (wall surfaces) of the combustion chamber at a low temperature.As a measure to keep the wall surface of the combustion chamber at a low temperature, for example, In a cooling system that uses a flowing water type, the circulating liquid phase refrigerant must be kept at a low temperature, or in a cooling system that uses a boiling type, for example, if water is used as the liquid phase refrigerant, the refrigerant must be kept at a low temperature. Possible solutions include reducing the pressure in the circulation system to lower the boiling point of the liquid refrigerant.

(Problem to be Solved by the Invention) However, in a flowing water cooling system, in order to keep the temperature of the liquid refrigerant low enough to effectively suppress the occurrence of non-king, it is necessary to adjust the circulation speed of the liquid refrigerant, the radiator In order to promote the heat radiation area of the liquid phase refrigerant and the amount of heat radiation of the liquid phase refrigerant, it is necessary to extremely increase the air flow rate of the cooling fan installed in connection with the radiator. This requires increasing the capacity of the pump that circulates the refrigerant and the space occupied by the radiator, or increasing the size of the cooling fan, which is extremely difficult in practice.

On the other hand, in boiling type cooling systems, for example, it is possible to set the boiling point of the liquid phase refrigerant extremely low as described above, so the temperature around the combustion chamber is kept at a low temperature that suppresses the occurrence of knocking. It is possible to maintain the engine's knocking resistance and effectively improve the knocking resistance of the engine. However, when a boiling method is used to cool the engine and the area around the combustion chamber is kept at a low temperature that suppresses knocking, the cylinder block becomes overcooled and the sliding of pistons, etc. There is a risk that the viscosity of the oil that lubricates the moving parts increases, resulting in an increase in the mechanical resistance of the sliding parts.

In view of these points, the present invention cools the engine using a liquid phase refrigerant stored in a water jacket provided around the combustion chamber, and effectively improves knocking resistance. An object of the present invention is to provide an engine cooling device that can prevent an increase in mechanical resistance of sliding parts in a cylinder block.

(Means for Solving the Problems) In order to achieve the above-mentioned object, the engine cooling device according to the present invention cools the cylinder head using a boiling method and cools the cylinder block using a flowing water method. Specifically, a first water jacket provided in the cylinder head and vapor of a liquid phase refrigerant stored in the first water jacket and boiled are supplied, and this vapor is cooled and converted into a liquid phase. a refrigerant circulation system formed by comprising a condenser for condensing the refrigerant and a first pump for returning the liquid phase refrigerant obtained from the condenser to the first water jacket;
and a boiling type cooling means having a pressure control unit that controls the pressure within the refrigerant circulation system, a second water jacket provided in the cylinder block, and a liquid phase refrigerant stored in the second water jacket and heated. a radiator that is supplied to cool the liquid-phase refrigerant; and a second pump that circulates the liquid-phase refrigerant cooled by the radiator back to the second water jacket between the radiator and the second water jacket. and a type cooling means.

(Function) In the engine cooling system having the above-mentioned configuration, the cylinder head is cooled by the boiling type cooling means,
The cylinder block is cooled by a flowing water cooling means.

In this case, the pressure within the refrigerant circulation system in the boiling type cooling means is controlled by the pressure control unit. For example, when water is used as the liquid phase refrigerant, the pressure in the refrigerant circulation system is reduced and the boiling point of the liquid phase refrigerant is extremely reduced. It is considered to be low temperature. Therefore, the wall surface temperature of the combustion chamber, most of which is surrounded by the cylinder head, is kept low, thereby effectively suppressing the occurrence of knocking.

On the other hand, since the cylinder block is cooled by a flowing water type cooling means that is separate from the cylinder head, it is maintained at a higher temperature than the cylinder head.

Therefore, the cylinder block is prevented from being overcooled, and the mechanical resistance of sliding parts such as the piston is prevented from increasing.

(Example) Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows an example of an engine cooling device according to the present invention.

In FIG. 1, an engine body 10 is a cylinder head 1.
2 and a cylinder block 14, the cylinder head 12 is provided with a head side water jacket 16 so as to surround most of the combustion chamber, and the cylinder block 14 is
A block-side water jacket 18 is provided so as to surround the side circumference of the cylinder side into which the piston is inserted, and the head-side water jacket 16 and the block-side water jacket 18 are each independent and separate. ing. The head-side water jacket 16 and the block-side water jacket 18 each have an electromagnetic shut-off valve 2 from a storage tank 2° in which a liquid phase refrigerant made of water or the like is stored.
The liquid phase refrigerant is supplied through a conduit 26 in which an electromagnetic on-off valve 22 is interposed, and a conduit 27 in which an electromagnetic on-off valve 22 is interposed.

One end of a steam passage 32 is connected to the uppermost portion of the head side water jacket 16, and the other end of the steam passage 32 is connected to a steam introduction part 36 of a condenser 35. The interior of the condenser 35 has a unique structure, with a main body 38 containing a large number of heat dissipation tubes and fins for condensing steam, and a liquid phase at the bottom of the main body 38. A storage section 37 for temporarily storing refrigerant is provided. A cooling fan 40 is disposed near the condenser 35 to promote cooling of the steam passing through the condenser 35, and the cooling fan 40 is installed near the condenser 35 to cool the steam passing through the condenser 35.
6 is connected to the refrigerant return passage 44 in which a refrigerant return pump 42 for returning the liquid phase refrigerant stored in the storage section 37 to the head side water jacket 16 is interposed. Then, the above-mentioned head side water jacket l-16, steam passage 32, condenser 35. A refrigerant circulation system of an effervescent cooling means that takes a closed loop is formed by a refrigerant return pump 42, a refrigerant return passage 44, and the like.

The upstream portion of the steam passage 32 and the lowermost portion of the storage tank 20 are connected by a conduit 28 in which an electromagnetic on-off valve 23 is interposed, and the uppermost portion of the storage tank 20 is connected to a conduit 29 with an open end. The starting end is connected. In the conduit 29,
An electromagnetic on-off valve 24 and a vacuum pump 45 are interposed in order from the starting end to the terminal end. Furthermore, the upstream portion of the steam passage 32 and the electromagnetic on-off valve 24 in the conduit 29
The part between the vacuum pump 45 and the electromagnetic on-off valve 2
5 is connected by a conduit 30 interposed therebetween.

On the other hand, in the upper part of the block side water jacket 18, a radiator 52 and a pump 54 for refrigerant circulation are provided.
The starting end of the liquid phase refrigerant circulation passage 50 is connected to the
The terminal end of the liquid phase refrigerant circulation passage 50 is connected to the lowermost portion of the block side water jacket 18. The radiator 52 itself has a unique structure, and in the case of an automobile, it is installed at a location that receives wind from the vehicle. Further, a cooling fan 56 is provided in the vicinity of the radiator 52 to send forced cooling air to the radiator 52 . And block side water jacket 18. Liquid phase refrigerant circulation passage 50. A closed-loop refrigerant circulation system of flowing water cooling means is formed by the radiator 52, the refrigerant circulation pump 54, and the like.

Note that the cooling fan 40. The refrigerant return pump 42, the vacuum pump 45, and the cooling fan 56 are all electrically operated, and the refrigerant circulation pump 54 is driven by the engine.

In this example, a control unit 100 is provided to control each of the above-mentioned parts. The control unit 100 receives a detection signal Si obtained from the ignition switch 60 to indicate whether the engine is started or stopped, a detection signal Sp obtained from the pressure sensor 61 which detects the pressure inside the head side water jacket 16, and a detection signal Sp obtained from the head side water jacket 16. A detection signal sh obtained from a liquid level sensor 62 that detects the liquid level of the liquid refrigerant in the water jacket 16 (high water level) and a detection signal sh obtained from the temperature sensor 63 that detects the temperature of the liquid refrigerant in the block side water jacket 18 A signal Sw is supplied.

The control unit 100 receives the above-mentioned detection signal St,
Based on Sp, Sh and Sw, electromagnetic on-off valves 21 to 25
．． Cooling fans 40 and 56. In order to control the vacuum pump 45 and the refrigerant return pump 42, control signals Ca, Cb, Cc, Cd, Ce, and C are sent to them, respectively.
f, Cg, Cp and Cm are supplied. Control signal Ca~ from the control unit 100 to the electromagnetic on-off valves 21-25
When Ce is supplied, the electromagnetic on-off valves 21, 22 and 25 are opened, and the electromagnetic on-off valves 23 and 24 are closed, and control signals Cf and Cg are sent from the control unit 100 to the cooling fans 40 and 56. When supplied, the cooling fans 40 and 56 are respectively activated (on),
Further, control signals Cp are sent from the control unit 100 to the vacuum pump 45 and the refrigerant return pump 42, respectively.
When Cm and Cm are supplied, the vacuum pump 45 and the refrigerant return pump 42 are activated. On the other hand, on the contrary, the control unit 100
~25. Cooling fans 40 and 56, vacuum pump 4
5, and a control signal Ca- to the pump 42 for refrigerant return.
When the supply of Cg, Cp and Cm is stopped, the electromagnetic on-off valves 21, 22 and 25 are closed, and the electromagnetic on-off valves 23 and 24 are closed.
are in an open state, and cooling fans 40 and 56 . The operation of the vacuum pump 45 and the refrigerant return pump 42 is stopped.

Under the configuration as described above, first, the head side water jacket 16. Steam passage 32° condenser 35
and the inside of the refrigerant circulation system (head side refrigerant circulation system) in the boiling type cooling means formed by the refrigerant return passage 44 and the like, and the block side water jacket 18. Liquid phase refrigerant circulation passage 50. The refrigerant circulation system (block side refrigerant circulation system) in the flowing water cooling means formed by the radiator 52, the refrigerant circulation pump 54, etc. is filled with liquid phase refrigerant, and most of the air is removed from these systems. It is said to be in a state of being

Then, before the ignition switch 60 is turned on, that is, when the engine is in a stopped state before starting, the control unit 100 does not send out any of the above-mentioned control signals Ca-Cg, Cp, and Cm. Therefore, the electromagnetic on-off valves 21, 22 and 25 are in the closed state, the electromagnetic on-off valves 23 and 24 are in the open state, and the cooling fan 4 is in the open state.
The 0 and 56 degree vacuum pumps 45 and the refrigerant return pump 42 are stopped.

Next, when the ignition switch 60 is turned on and the engine is started, the control unit 100
detects it based on the detection signal Si, and immediately after that,
A control signal Ca is supplied to the electromagnetic on-off valve 21 and a control signal CC is supplied to the electromagnetic on-off valve 23 to open the electromagnetic on-off valve 21, close the electromagnetic on-off valve 23, and control the vacuum pump 45. A signal Cp is applied to put it into operation. As a result, the storage tank 20 becomes in a negative pressure state, the liquid phase refrigerant in the head side water jacket 16 is guided to the storage tank 20 via the conduit 26, and the liquid level in the head side water jacket 16 falls.

Further, the liquid phase refrigerant in the block side water jacket 18 is circulated between the block side water jacket 18 and the radiator 52 via the liquid phase refrigerant circulation passage 50 by a refrigerant circulation pump 54 driven by the engine. Based on the detection signal Sp obtained from the pressure sensor 61, the control unit 100 sends a control signal Ca to the electromagnetic opening/closing valve 21 when the pressure inside the head side water jacket 16 reaches a specified pressure lower than atmospheric pressure. Control signal Cc to valve 23 and vacuum pump 4
The supply of the control signal Cp to 5 is stopped. In this way, when the engine is brought into a normal operating state with the pressure inside the head side water jacket 16 set to the specified pressure, the liquid phase refrigerant in the head side water jacket 16 and the block side water jacket 18 flows into the engine. It is heated by the generated heat (heat of combustion) and its temperature is raised. Here, in this example, the liquid phase refrigerant has water as its main component, and the inside of the head side water jacket 16 is set at a specified pressure lower than atmospheric pressure, so the liquid phase refrigerant in the head side water jacket 16 has a boiling point. The temperature is set at a low temperature, for example, about 50°C.

Therefore, after the engine is brought into the normal operating state, the liquid phase refrigerant in the head water jacket 16 quickly boils, and the vapor is supplied to the condenser 35 via the steam passage 32, where it is mixed with outside air. The refrigerant is cooled by heat exchange and condensed into a liquid phase refrigerant, and the condensed liquid phase refrigerant is stored in the storage section 37 . When the boiling of the liquid refrigerant becomes intense and its vapor amount increases, the liquid level of the liquid refrigerant in the head side water jacket 16 becomes lower, and the evaporation space and vapor passage of the liquid refrigerant in the head side water jacket 16 become lower. The vapor pressure within 32 is increased, increasing the pressure within the entire head-side refrigerant circulation system. Therefore, the control unit 100 supplies a control signal Cm to the refrigerant return pump 42 to operate it and store the refrigerant in order to maintain the liquid level level of the liquid phase refrigerant in the head-side overjacket 16 at a predetermined value. A portion of the liquid phase refrigerant stored in the section 37 is transferred to the head side water jacket 16.
control to maintain the level of the liquid phase refrigerant in the head side water jacket 16 at a predetermined value, and also supplies a control signal Cf to the cooling fan 40 to operate it, causing the condenser 35 to be forced to cool. The air is sent to increase the amount of vapor condensed in the main body 38, thereby maintaining the liquid level of the liquid phase refrigerant in the head side water jacket 16 at a predetermined value, and reducing the pressure in the head side refrigerant circulation system. Control is performed to maintain the pressure at a specified level. When the liquid phase refrigerant is boiled under such control, the wall surface around the combustion chamber in the cylinder head 12 is cooled to an extremely low temperature by the heat of vaporization, and as a result, the occurrence of knocking is effectively prevented.

In this example, in the event of an abnormality in which the pressure within the head-side refrigerant circulation system does not decrease even though the cooling fan 40 is operated, the control unit 100 detects this as the detection signal sp obtained from the pressure sensor 61. A control signal Ce is supplied to the electromagnetic on-off valve 25 to open it, and a control signal Cp is supplied to the vacuum pump 45 to operate it. As a result, steam is released into the atmosphere via the vacuum pump 45 while the pressure within the head side refrigerant circulation system is maintained at a negative pressure. Further, at this time, since vapor is released from the head side refrigerant circulation system to the outside, the liquid level of the liquid phase refrigerant in the head side water jacket 16 becomes lower than the specified position. For this reason, the control unit 100
A control signal Ca is supplied to the electromagnetic on-off valve 21 to open it, and the storage tank 2 is connected to the head side water jacket 16.
Control is performed to maintain the liquid level at a specified position by replenishing the liquid phase refrigerant from zero. At this time, the control unit 100 warns the occupants that an abnormality has occurred in the head side refrigerant circulation system, for example by lighting up a warning light placed in the passenger compartment, and also warns the occupants that an abnormality has occurred in the head side refrigerant circulation system. If the pressure in the head-side refrigerant circulation system does not decrease even if the engine is controlled at the same time, there is a risk that knocking may occur. be made into

On the other hand, the liquid-phase refrigerant whose temperature is raised in the block-side water jacket 18 is supplied to the radiator 52 by a refrigerant circulation pump 54, and is cooled by exchanging heat with outside air. In this case, the control unit 100 controls the temperature sensor 63
The liquid phase refrigerant in the block side water jacket 18 is heated to an appropriate temperature based on the detection signal 3w obtained from the head side water jacket 16.
In order to maintain the temperature at about 0° C., a control signal Cg is appropriately supplied to the cooling fan 56 to activate it, and forced cooling air is sent to the radiator 52 to control the degree of cooling of the liquid phase refrigerant passing through the radiator 52. By doing so, the cylinder block 14 is prevented from being overcooled, and therefore the viscosity of the oil that lubricates the sliding parts such as the pistons in the cylinder block 14 is prevented from increasing, and such sliding parts are prevented from increasing. It shall not lead to an increase in mechanical resistance of moving parts.

Next, when the ignition switch 60 is turned off and the engine is stopped, the control unit 100 detects this based on the detection signal Si, and the refrigerant return pump 42. control signal Cm to the cooling fans 40 and 56;
At the same time as stopping the supply of Cf and Cg, the electromagnetic on-off valve 2
3 and the control signal C to the electromagnetic on-off valve 24.
d supply is stopped. As a result, the electromagnetic on-off valves 23 and 24 are opened, and the storage tank 20. The inside of the steam passage 32 and the head-side water jacket 16 is set to atmospheric pressure. Immediately after such a stop, the engine main body 10 is in a high temperature state and heat radiation to the liquid refrigerant continues, so the liquid refrigerant in the head side water jacket 16 boils under atmospheric pressure.
The vapor is supplied via conduit 28 to the lowermost portion of storage tank 20. In this case, most of the vapor supplied to the storage tank 20 is cooled and condensed by the liquid phase refrigerant in the storage tank 20, and only a portion of the vapor that has not been condensed is discharged to the outside through the conduit 29, so that the liquid Phase refrigerant dissipation is minimized.

Then, after the engine stops and the liquid phase refrigerant in the head side water jacket 16 finishes boiling, the vapor in the head side refrigerant circulation system condenses as the temperature of the engine body 10 decreases over time. However, the pressure in the head side refrigerant circulation system becomes negative.

Therefore, the liquid phase refrigerant is drawn from the storage tank 20 to the head side water jacket 16 side through the conduit 28, and the head side refrigerant circulation system is filled with the liquid phase refrigerant. In this case, almost no air is mixed into the head side refrigerant circulation system. Further, at such a time, the liquid phase refrigerant in the block side refrigerant circulation system is also gradually cooled. Note that if there is a risk that the liquid phase refrigerant in the block side refrigerant circulation system is insufficient and the inside thereof becomes in a negative pressure state, the control signal cb is supplied from the control unit 100 to the electromagnetic opening/closing valve 22, and the electromagnetic opening/closing is performed. The valve 22 is opened, and the block-side water jacket 18 is replenished with liquid phase refrigerant from the storage tank 20.

The control unit 100 that performs the above-mentioned control is configured using, for example, a microcomputer, and an example of a program executed by the microcomputer to control the boiling cooling means in such a case is shown in FIG. Explain with reference to brooches and other parts.

FIG. 2 shows a basic control routine program. After starting, this program takes in a detection signal Si obtained from the ignition switch 60 in a process 101, and in a subsequent decision 102 turns on the ignition switch 60 based on the detection signal Si. If it is determined that the ignition switch 60 is in the on state, the process proceeds to process 103, and if it is determined that the ignition switch 60 is not in the on state,
Returning to process 101, process 101 and decision 102 are repeated until the ignition switch 60 is turned on.

In the process 103, the electromagnetic on-off valves 21 and 23, and
A control signal Ca is sent to each vacuum pump 45.

By supplying Cc and Cp, the electromagnetic on-off valve 21 is opened, the electromagnetic on-off valve 23 is closed, and the vacuum pump 45 is activated. And then continue, process 10
After taking in the detection signal Sp obtained from the pressure sensor 61 in step 4, it is determined in decision 105 whether the pressure Px in the head side refrigerant circulation system where the detection signal Sp is received is equal to or lower than a specified pressure Pa, which is lower than atmospheric pressure, If the pressure Px is determined to be less than the specified pressure Pa, process 1
If the process proceeds to 06 and it is determined that the pressure Px exceeds the specified pressure Pa, the process returns to process 103 and processes 1
03.104 and decision 105 are repeatedly executed until the pressure Px becomes equal to or less than the specified pressure Pa.

In the process 106, the electromagnetic on-off valves 21 and 24, and
Control signal Ca to vacuum pump 45.

After stopping the supply of Cd and Cp, the process proceeds to process 107 where the detection signal sh obtained from the liquid level sensor 62 is taken in. In the subsequent decision 108, when the detection signal sh is detected, the liquid level of the liquid refrigerant in the head side water jacket 16 is detected. Determine whether the surface height Hx is less than or equal to a predetermined value Ha,
If it is determined that the liquid level height Hx is less than or equal to the predetermined value Ha, a control signal Cm is supplied to the refrigerant return pump 42 in process 109, and process 107 and decision 108 are performed so that the liquid level height Hx This is repeated until the predetermined value Ha is exceeded. Further, if it is determined that the liquid level height Hx exceeds the predetermined value Ha, the supply of the control signal Cm to the refrigerant return pump 42 is stopped in process 110, the process proceeds to process 111, and the pressure sensor The detection signal Sp obtained from 61 is taken in, and in the subsequent decision 112, the pressure P is
It is determined whether x is less than or equal to a specified pressure Pa. Then, in decision 112, the pressure Px is changed to the specified pressure Pa
If it is determined that the control signal Cf is exceeded, a control signal Cf is supplied to the cooling fan 40 in a process 113, and then a control signal Cf is supplied to the cooling fan 40 in a process 113.
1 and decision 112 are repeatedly executed until the pressure Px becomes equal to or less than the specified pressure Pa, and if it is determined that the pressure Px is equal to or less than the specified pressure Pa, process 114 is executed.
At this point, the supply of the control signal C' to the cooling fan 40 is stopped to stop its operation.

In the subsequent process 115, the detection signal Si obtained from the ignition switch 60 is taken in, and then in a decision 116 it is determined whether the ignition switch 60 is in the off state, and if it is determined that the ignition switch 60 is in the on state, Returning to process 107, if it is determined that the ignition switch 60 is in the off state, then in process 117, the electromagnetic on-off valve 23 and the 24° cooling fan 40. Pump 42 for refrigerant return. A control signal Cc to the vacuum pump 45 and the cooling fan 56,
The supply of Cd, Cf, Cm, Cp, and Cg is stopped, and the electromagnetic on-off valves 23 and 24 are opened, and the cooling fan 40. Pump 42 for refrigerant return. Vacuum pump 45 and cooling fan 56 are stopped, and process 10
Return to 1.

FIG. 3 is a schematic configuration diagram showing a second example of the engine cooling device according to the present invention.

In the example shown in FIG. 3, the head side refrigerant circulation system is slightly different from the example shown in FIG. 1, and other parts have substantially the same configuration as that shown in FIG. In FIG. 2, parts corresponding to those shown in FIG. 1 are given the same reference numerals, and detailed explanation thereof will be omitted. Pressure sensor 61. Parts of the control system, such as the liquid level sensor 62 and the temperature sensor 63, are omitted from illustration.

In the example shown in FIG. 3, the head side refrigerant circulation system includes a head side water jacket 16, a steam passage 32', and a compressor 7 interposed in this steam passage 32'.
0, a condenser 35, a refrigerant return passage 44, a pressure reducing valve 72 installed on the downstream side of this refrigerant return passage 44, and a portion thereof protruding above the liquid level of the liquid phase refrigerant during normal operation, The downstream side of the pressure reducing valve 72 in the refrigerant return passage 44 is connected to the head side water jacket 1.
6 and a retention tank 74 disposed within the steam passage 32', the downstream portion 3 of the compressor 70 in the steam passage 32'.
2B has a smaller diameter than its upstream portion 32A.

Under such a configuration, the head side walk jacket 1
6 and the upstream portion 32A of the steam passage 32' exceeds a specified pressure, the control unit 100 operates the compressor 70 to compress the steam and supply it to the condenser 35. By doing so, the temperature of the steam discharged to the downstream portion 32B becomes higher than the temperature of the steam on the upstream portion 32A side, and the temperature difference between the steam supplied to the condenser 35 and the outside air becomes as shown in FIG. It is larger than that shown in . Therefore, heat exchange between the steam and the outside air in the condenser 35 is promoted, and the condenser can be made smaller or the amount of air blown by the cooling fan 40 can be reduced. Also,
When the compressor 70 is installed in the steam passage 32'' in this way, the steam is forced into the condenser 35 in a compressed state, so that the high temperature liquid phase refrigerant accumulated in the storage section 37 is pressurized. However, in this example, since a pressure reducing valve 72 is interposed in the refrigerant return passage 44, the liquid phase refrigerant in the storage section 37 is depressurized by the pressure reducing valve 72. The refrigerant is once supplied to the rear retention tank 74 and cooled in the retention tank 74 while boiling until the temperature drops to a temperature corresponding to the pressure inside the head water jacket 16. The cooled liquid phase refrigerant is then transferred from the retention tank 74 to the head water It is mixed into the liquid phase refrigerant stored in the jacket 16. By doing this, the storage part 37
This prevents the liquid phase refrigerant stored in the head side water jacket 16 from being heated up by the high temperature liquid phase refrigerant returned from the head side water jacket 16 to the head side water jacket 16.

Note that instead of the pressure reducing valve 72 and the retention tank 74 in the example shown in FIG. 3, a nozzle 76 may be provided in the most downstream portion of the refrigerant return passage 44, as shown in FIG. In such a case, the liquid phase refrigerant returned from the storage section 37 to the head water jacket 16 is injected and returned into the head water jacket 16, and is atomized within the head water jacket 16. Its surface area is significantly increased. As a result, storage section 3
The liquid phase refrigerant returned to the head side water jacket 16 from the head side walk jacket 16 is cooled in the upper part (evaporation space) of the liquid phase refrigerant in the head side walk jacket 16. Therefore,
It is no longer necessary to provide a separate storage tank 74, and the high temperature liquid refrigerant returned from the storage section 37 to the head water jacket 16 raises the temperature of the liquid refrigerant stored in the head water jacket 16, as in the above example. This avoids the possibility of

FIGS. 5 and 6 are schematic configuration diagrams showing third and fourth examples of engine cooling devices according to the present invention, respectively. Fifth
In the example shown in the figure and FIG. 6, the low-temperature liquid refrigerant in the head side refrigerant circulation system is used to cool the liquid phase refrigerant in the block side refrigerant circulation system. The configuration is substantially the same as the example shown in FIG.

In FIGS. 5 and 6, parts corresponding to those shown in FIG. 1 are given the same reference numerals, and detailed explanation thereof is omitted. Uni Nodo 100. Pressure sensor 61. Liquid level sensor 62. Part of the control system such as the temperature sensor 63 is omitted from illustration.

The example shown in FIG.
° Liquid phase refrigerant circulation passage 5 in the block side refrigerant circulation system
0' is inserted so that the liquid refrigerant flowing through the liquid refrigerant circulation passage 50° is cooled by the low temperature liquid refrigerant stored in the storage section 37'. By doing this, a radiator is formed by a part of the head side refrigerant circulation system and a part of the liquid phase refrigerant circulation passage 50°, so there is no need to provide a cooling fan, and the cooling is generally better than air cooling. The liquid phase refrigerant in the block side refrigerant circulation system can be cooled by highly efficient liquid cooling, and therefore, the size and cost of the device can be effectively reduced.

In addition, in the example shown in FIG. 6, the liquid phase refrigerant circulation passage 50'' in the block side refrigerant circulation system passes through the part of the head side water jacket 16'' where the liquid phase refrigerant is stored, and the liquid phase The liquid-phase refrigerant flowing through the refrigerant circulation passage 50'' is cooled by the low-temperature liquid-phase refrigerant stored in the head-side water jacket 16''. By doing so, a radiator is constituted by the head side water jacket 16' and a part of the liquid phase refrigerant circulation passage 50'', and the same effect as the example shown in FIG. 5 can be obtained. In addition, when the liquid phase refrigerant in the head side water jacket 16 boils, the liquid phase refrigerant flowing through the liquid phase refrigerant circulation passage 50'' is cooled by its heat of vaporization, and its cooling efficiency is significantly increased. become.

(Effects of the Invention) As is clear from the above description, in the engine cooling device according to the present invention, the cylinder head is cooled by the boiling type cooling means, the cylinder block is cooled by the flowing water type cooling means, and the cylinder head is cooled by the boiling type cooling means. Since the pressure within the refrigerant circulation system in the type cooling means is controlled by the pressure control unit, for example, when water is used as the liquid phase refrigerant, the boiling point of the liquid phase refrigerant can be adjusted by reducing the pressure inside the refrigerant circulation system. As a result, the temperature of the wall surface of the combustion chamber, most of which is surrounded by the cylinder head, is kept low, thereby effectively suppressing the occurrence of knocking.

Furthermore, since the cylinder block is cooled by a flowing water type cooling means that is separate from the cylinder head, it is possible to avoid overcooling of the cylinder block. Therefore, even if the knocking resistance is improved, the viscosity of the oil does not increase, so it is possible to effectively prevent an increase in the mechanical resistance of sliding parts such as the piston.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram showing an example of an engine cooling system according to the present invention, and FIG. 2 is a diagram illustrating an example of a microcomputer executed when a microcomputer is used in the control unit of the example shown in FIG. FIG. 3 is a schematic configuration diagram showing another example of the engine cooling device according to the present invention; FIG.
This figure is a partial configuration diagram showing a modification of the example shown in FIG. 3, and FIGS. 5 and 6 are schematic configuration diagrams showing still other examples of the engine cooling device according to the present invention. In the figure, 10 is the engine body, 12 is the cylinder head, 1
4 is a cylinder block, 16 and 16' are a head side water jacket, 18 is a block side water jacket, 20 is a storage tank, 21 to 25 are electromagnetic on-off valves, 35 and 35° are condensers, 37 and 37'' are storage parts, 40
and 56 is a cooling fan; 42 is a refrigerant return pump; 4
4 is a refrigerant return passage, 45 is a vacuum pump, 50.5
0' and 50'' are liquid phase refrigerant circulation passages, 52 is a radiator, 54 is a pump for refrigerant circulation, 70 is a compressor, 7
2 is a pressure reducing valve, 76 is a nozzle, and 100 is a control unit.

Claims (1)

[Claims] a first water jacket provided in the cylinder head; a condenser to which vapor of a liquid phase refrigerant stored in the first water jacket and boiled is supplied; the vapor is cooled and condensed into the liquid phase refrigerant; a refrigerant circulation system formed with a first pump that returns the liquid phase refrigerant obtained from the condenser to the first water jacket; and a pressure control section that controls the pressure within the refrigerant circulation system. type cooling means and a second cooling means provided in the cylinder block.
a water jacket, a radiator to which a liquid refrigerant stored and heated in the second water jacket is supplied and cools the liquid refrigerant, and a liquid refrigerant cooled by the radiator is transferred to the second water jacket. An engine cooling device comprising: flowing water cooling means having a second pump that circulates water back into the jacket between the radiator and the second water jacket.