JPS62131912A - Evaporative cooling device for internal combustion engine - Google Patents

Abstract

PURPOSE:To lower the temperature of an engine quickly in an evaporative cooling device by inducting liquid state refrigerant continuously to a water jacket from a reservoir tank whereby discharging excess liquid state refrigerant from a condenser lower tank to the reservoir tank when the engine is suspended. CONSTITUTION:A steam outlet port 7 provided to the upper section of a water jacket 2 is communicated with an upper inlet port 3a of a condenser 3 via a steam manifold 8 and a steam passage 9. A lower tank 17 of the condenser 3 is communicated with the water jacket 2 at its lower end via a refrigerant circulating passage 19, a pump 4, and No.2 solenoid valve 21, and is also communicated with a reservoir tank 31 at its upper section via No.3 solenoid valve 35 and No.1 auxiliary refrigerant passage 20. When an engine is suspended and the system temperature is high, a control device 41 makes a pump 13 for a heater feed liquid state refrigerant to the water jacket 2 from the reservoir tank 31, and also makes the pump 4 discharge liquid state refrigerant from the lower tank 17 to the reservoir tank.

Description

[Detailed Description of the Invention] Industrial Application Field This invention relates to a boiling cooling device for an internal combustion engine that stores liquid phase refrigerant up to a predetermined level in a water jacket and cools various parts of the internal combustion engine by boiling and vaporizing the liquid phase refrigerant. In particular, the present invention relates to a boiling cooling device which aims to quickly lower the temperature after the engine is stopped.

Prior Art The present applicant formed a closed-loop refrigerant circulation system mainly consisting of a water jacket, a condenser, and a refrigerant supply pump, and after guiding the refrigerant vapor generated in the water jacket to the condenser and condensing it, the liquid level sensor Various boiling cooling devices for internal combustion engines have been proposed in which the water jacket is resupplied by operating a refrigerant supply pump based on the detection of refrigerant. etc). This device uses an electric fan as a cooling fan to forcefully cool the condenser, and after the engine has stopped, this electric fan is driven for a certain period of time or until the engine temperature drops to a certain temperature to quickly lower the engine temperature. This is to prevent thermal deterioration of various parts near the engine and deterioration of restartability.

Problems to be Solved by the Invention However, when using a fan that is mechanically driven by engine output as a cooling fan for a condenser, the fan naturally stops at the same time as the engine stops. Forced cooling is not possible. Therefore,
If the system is stopped immediately after high-load operation, the high temperature state will continue for a considerable period of time, which is undesirable, and if the system is not opened after the system is stopped, there is a risk of steam blowing out.

Further, even in the case where an electric fan is used as in the conventional case, it is not preferable to operate the electric fan for a long time after the alternator water stops operating, as this increases the power consumption of the battery.

Means for Solving the Problems In order to solve the above problems, the present invention includes a reservoir tank that stores an appropriate amount of liquid phase refrigerant, and a reservoir tank that starts operating when an engine stop signal is input. A refrigerant introducing means continuously introduces liquid phase refrigerant from the tank to the water jacket of the engine, and while this refrigerant introducing means is in operation, excess liquid is removed from the condenser lower tank to keep the refrigerant liquid level in the condenser at the lowest level. A refrigerant discharge means for discharging the liquid phase refrigerant to the reservoir tank is provided.

During operation of the working engine, liquid phase refrigerant is always present in the water jacket up to a predetermined level, and various parts of the engine are cooled by boiling and vaporizing the liquid phase refrigerant.

When the engine stops, the refrigerant introducing means starts operating, and the relatively low temperature liquid refrigerant stored in the reservoir tank is introduced into the water jacket and mixed with the high temperature liquid refrigerant in the water jacket.

This immediately lowers the refrigerant temperature within the water jacket. On the other hand, the liquid phase refrigerant that was present at the bottom of the condenser is discharged to the reservoir tank by the refrigerant discharge means, and as a result, the heat dissipation area of the condenser is maximized and good heat exchange is performed.

Further, if the liquid phase refrigerant continues to run from the reservoir tank to the water jacket, it will eventually overflow to the condenser side, but this liquid phase refrigerant will also be returned to the reservoir tank via the refrigerant discharge means.

Embodiment FIG. 1 shows an embodiment of the purulent cooling device according to the present invention. In the figure, ■ indicates an internal combustion engine equipped with a water jacket 2, and 3 indicates a condenser for condensing a gas phase refrigerant. , 4 indicate electric refrigerant supply pumps constituting refrigerant supply means and refrigerant discharge means, respectively.

The water jacket 2 is formed across both the cylinder block 5 and the cylinder head 6 so as to surround the outer periphery of the cylinder and combustion chamber of the internal combustion engine l, and the upper part, which is normally a gas phase space, is The cylinders communicate with each other, and a plurality of steam ratio lowers are provided at appropriate positions above the cylinders. The steam ratio lowers are gathered together by a steam manifold 8 and communicated with the upper part 3a of the condenser 3 via a steam passage 9.

Reference numeral 10 denotes a heater core for heating provided in the vehicle interior, the upper inlet of which is connected to the cylinder block 5 side of the water jacket 2 via the heater inlet passage 11, and the lower outlet connected to the cylinder block 5 side of the water jacket 2 via the heater outlet passage 12. head 6
connected to the side. The liquid phase refrigerant is supplied to the water jacket 2 and the heater core 10 in the heater outlet passage 12.
A heater pump 13 is interposed to circulate the refrigerant between the refrigerant and the refrigerant, and constitute a refrigerant introducing means as described later.

Reference numeral 14 is a refrigerant mixing passage branched from the discharge side of the heater pump 13 and connected to the steam manifold 8, in which a small amount of liquid is mixed in order to prevent uneven distribution of antifreeze components in the refrigerant during winter, that is, when the heater is in use. It functions to feed the phase refrigerant to the condenser 3.

The condenser 3 is composed of an upper tank 15 having the population 3a, a core section 16 mainly consisting of fine tubes extending in the vertical direction, and a lower tank 17 that temporarily stores the liquefied refrigerant condensed in the core section 16. The cooling fan 18 is disposed at a position such as the front of the vehicle that receives wind from the vehicle running, and is further provided with a cooling fan 18 for forced cooling on the front or rear side. The cooling fan 18 is, for example, a mechanically driven fan that is linked to the engine crankshaft via a belt transmission mechanism. Further, the lower tank 17 has one end of a refrigerant circulation passage 19 connected to a relatively lower portion thereof, and one end of a first auxiliary refrigerant passage 20 connected to an upper portion thereof. The above refrigerant circulation passage 1
The other end of 9 is connected to the refrigerant port 2a provided on the upper part of the cylinder block 5 of the water jacket 2, and the refrigerant supply pump 4 is interposed in the passage thereof. A second solenoid valve 21, which is a three-way solenoid valve, is interposed on the discharge side.

3 is a reservoir tank provided outside the refrigerant circulation system mainly consisting of the water jacket 2 and condenser 3, which is open to the atmosphere via a cap 32 having a ventilation function, and is The first auxiliary refrigerant passage 20 and the second auxiliary refrigerant passage 20 are installed at approximately the same height as the water jacket 2, and are located at the bottom thereof. A third auxiliary refrigerant passage 33,34 is connected. The first auxiliary refrigerant passage 20 is provided with a normally open third solenoid valve 35 therein.

The second auxiliary refrigerant passage 33 is connected between the heater core 10 of the heater outlet passage 12 and the heater pump 13 via a fourth solenoid valve 36 that is a three-way solenoid valve for flow switching. . Further, the third auxiliary refrigerant passage 34 is connected to the refrigerant circulation passage 19 via the second electromagnetic valve 2I. Here, the second solenoid valve 21 is connected to the refrigerant supply pump 4.
``flow path A'' that connects the discharge boat to the reservoir tank 31 via the third auxiliary refrigerant path 34, and the refrigerant circulation path 1.
"Flow path B" which communicates with water jacket 2 via 9
”. Further, the fourth solenoid valve 36 communicates the suction port of the heater pump 13 with the reservoir tank via the second auxiliary refrigerant passage 33 and the heater core 10 via the heater outlet passage 12. It is configured so that it can be switched to "flow path B".

On the other hand, an air discharge passage 37 for discharging air in the system is connected to the upper wall of the steam manifold 8, which is the top of the refrigerant circulation system, and the liquid phase that overflows at the same time as the air is discharged. In order to recover the refrigerant, the air exhaust passage 3
The tip of 7 opens into the reservoir tank 31. A normally closed first solenoid valve 38 is interposed in the air exhaust passage 37.

The electromagnetic valves 38, 21, 35, 36, the heater pump 13, and the refrigerant supply pump 4 are controlled by a control device 41 using a so-called microcomputer system. A first liquid level sensor 42 disposed at the level, a temperature sensor 43 disposed at an appropriate position on the water jacket 2,
It includes a second liquid level sensor 44 disposed relatively above the lower tank 17 and a heater temperature sensor 46 disposed at the top of the circulation system.

Next, FIGS. 2 to 15 are flowcharts showing the details of the control executed by the control device 41, which will be explained below along the flow from starting to stopping the engine. In the figure, the refrigerant supply pump 4 is referred to as "Pump ■", the heater pump 13 is referred to as "Pump ■", and the first to fourth solenoid valves 38 are referred to as "Pump ■".
．． 21, 35, and 36 are abbreviated as "Solenoid valve ■" to "Solenoid valve ■," and the liquid level in the water jacket 2 is rC/
It is abbreviated as "H liquid level".

First, to briefly explain the outline of the control, Fig. 2 is a main flowchart showing the overall control. When the control starts when the engine starts (ignition key is turned on),
In principle, the process proceeds to warm-up control (step 4) via air discharge control (step 3), where warm-up operation is performed until a predetermined state is reached, and then the process proceeds to step 6 and subsequent steps. The processes from step 6 onwards correspond to a steady operating state in which the refrigerant boils and condenses in the system. The first liquid level sensor 4 constantly monitors the refrigerant liquid level.
At the same time, the liquid level position of the refrigerant in the condenser 3, that is, the substantial heat dissipation area, is controlled variably by the processing in steps 8 to 26, and the boiling point of the refrigerant in the water jacket 2 is maintained close to the set level in the water jacket 2 with high precision. This realizes excellent control. Therefore, as a general rule, step 6 should be performed after warming up.
The loop from 28 to 28 is repeatedly executed until the engine stops, and the warm-up control (step 4) is performed again only when the system temperature drops abnormally (step 26), such as during low load in winter.
).

Note that when the system temperature is 45° C. or higher at the time of startup, it means a restart, and air intrusion over time is not considered, so air exhaust control (step 3) is omitted.

Furthermore, FIGS. 3 and 4 show interrupt processing that is executed at regular intervals. In the interrupt process shown in FIG. 3, it is determined whether the engine is rotating (step 31), and during operation, the optimum control temperature is sequentially set for the engine operating conditions (step 3).
In addition to 4), after the engine is stopped, predetermined processing is performed as described later.

In the interrupt process (2) in FIG. 4, the operation of the heater pump 13 is controlled based on a heater switch (not shown), and the heater outlet liquid is The flow rate of the heater pump 13 is controlled based on the temperature (temperature detected by the heater temperature sensor 46) (steps 53 and 54). Incidentally, the heater pump 13 may be used for other purposes such as securing the liquid level in the water jacket 2, and during that time, interruption by the interrupt process (2) is prohibited (steps 87 and 107).
etc.) Second, FIG. 5 shows details of the air exhaust control (step 3) that is executed immediately after startup. Note that when the engine is started, the system is usually almost filled with liquid refrigerant (for example, a mixture of water and ethylene glycol), and the reservoir tank 31 is filled with an appropriate amount of liquid refrigerant. It is stored. Air discharge control is to discharge air by completely filling the system with liquid phase refrigerant from this state.The first solenoid valve 38 is opened and the heater pump 13 is used to discharge air from the reservoir tank 31. Pour liquid phase refrigerant into the system (
Step 62.63). This is preset to be sufficient to fill the system and is continued for, for example, 60 seconds (step 64). Therefore, the air remaining in the system is collected in the upper part of the system, and then is forcibly discharged outside the system to the server tank 31 side via the air discharge passage 37.

After the air is discharged, the process proceeds to warm-up control, the details of which are shown in FIG.

When warm-up control begins, the condenser 3 is filled with liquid phase refrigerant and the heat dissipation capacity is suppressed to an extremely low level, and at the same time, the liquid refrigerant in the eta jacket 2 is in a stagnation state, so it is quickly stopped. The temperature rises to . The warm-up control is performed by closing the air discharge passage 37 and keeping the system open via the first auxiliary refrigerant passage 20 (step 66), and the temperature of the refrigerant in the water jacket 2 rises to near the target set temperature. (steps 68 and 69).
When the temperature rises to "set temperature -3°C", the excess refrigerant is forcibly discharged to the reservoir tank 31 by the refrigerant supply pump 4 (step 73). This means that if boiling starts due to a sudden increase in heat load, the first auxiliary refrigerant passage 20
This is because there is a risk of an excessive rise in temperature due to a delay in the discharge of surplus refrigerant through 35 to use natural discharge (steps 75 to 77). As a result of this discharge of the refrigerant, the refrigerant liquid level in the water jacket 2 or the refrigerant liquid level in the condenser 3 becomes the first level. Second liquid level sensor 4
2. When the level falls below the set level of 44 (step 70
), or when the temperature inside the system rises to more than "set temperature + 0.5° C." (step 74), the inside of the system is sealed and the warm-up control is ended. At the end of this warm-up control, the liquid phase refrigerant in the water jacket 2 normally starts boiling under reduced pressure.

The above set temperature is optimally set within a range that does not exceed the boiling point of the refrigerant under normal pressure, for example within a range of about 80 to 110 degrees Celsius, depending on the operating conditions such as engine load and rotation speed. , as described above, is updated at regular intervals by the interrupt process (1) in FIG. 3 (steps 44 and 45). still,
Specific operating conditions include the suction negative pressure and rotational speed for gasoline engines, the pulse width and cycle of the injector drive pulse for electronically controlled fuel injection systems, and the injection pump lever opening for diesel engines. Degrees and rotational speed are used.

After the warm-up control is completed, the control loop from step 6 to step 28 is repeated as described above.

First, when the amount of heat generated by the engine and the amount of heat dissipated from the condenser 3 are in equilibrium at the boiling point of the refrigerant near the set temperature, specifically, when the refrigerant temperature is within the range of "set temperature ±3.0°C", Based on the determination in step 8, only the liquid level control (1) in step 6 is substantially executed. Figures 7 and 8 are
The details of this liquid level control (1) are shown below. That is, as a result of the start of boiling within the water jacket 2, the refrigerant liquid level gradually decreases, but when the water jacket side liquid level falls below the level set by the first liquid level sensor 42, the refrigerant supply pump 4, the liquid phase refrigerant is replenished from the condenser 3 side to the water jacket 2 (step 78.7).
9). Therefore, within the closed refrigerant circulation system, the refrigerant boils and
The condensation cycle is repeated, and the refrigerant liquid level in the water jacket 2 is always stably maintained near the level set by the first liquid level sensor 42. Here, if the refrigerant liquid level does not recover to the set level even after continuing the above refrigerant supply for 10 seconds or more (step 86), it is possible that there is no liquid phase refrigerant in the lower tank 17, so When the pressure is negative, the third solenoid valve 35 is opened to introduce the refrigerant from the reservoir tank 31, and when the pressure is positive, the heater pump 13 is used to directly introduce the refrigerant from the reservoir tank 31 to the water jacket 2. Replenish refrigerant (step 8)
8.89.90). Also, if more than 20 seconds have passed,
Replenishment is performed by the heater pump 13 regardless of the positive or negative pressure in the system. Note that if refrigerant is replenished by the heater pump 13 even though liquid-phase refrigerant is present in the lower tank 17 when cavitation occurs, there is a risk that the amount of refrigerant in the system will become excessive and cause a rise in temperature. Therefore, in that case, the third solenoid valve 35 is opened to allow the refrigerant to be naturally discharged due to the internal pressure (steps 91 to 93). Further, as described above, the flow rate of the heater pump 13 is controlled by the interrupt process (2) when the heater is activated, but the maximum flow rate is always given when replenishing the water jacket 2 (step 87).

Next, due to changes in the set temperature itself due to external disturbances such as a decrease in vehicle running wind or changes in operating conditions, the system temperature changes from the above temperature equilibrium state to ``set temperature +3.0℃'' or higher, or ``set temperature -3. 0° C. or lower, the substantial heat dissipation area of the capacitor 3 is variably controlled by the processing from step 8 onward in FIG.

First, when the temperature exceeds the set temperature +3.0°C, the process proceeds to Step 14, which is detailed in FIG. The refrigerant is discharged (step 116) to expand the substantial heat dissipation area. Furthermore, when the pressure inside the system is positive, the third solenoid valve 35 is opened to simultaneously perform natural discharge using the pressure difference inside and outside the system (step 11).
2-114). This refrigerant discharge ends when the system temperature falls below "set temperature + 2.5°C" (steps 17 to 20). The reason why the process is terminated at a temperature slightly higher than the set temperature is that there is a delay in response to a temperature change in response to a drop in the liquid level. Furthermore, if the speed of refrigerant discharge is excessively high, there is a risk that the temperature within the system will hunt due to the response delay. (
Step 12-ta), suppressing the discharge speed. Additionally, if the set temperature itself changes from a high temperature range to a low temperature range due to a change in operating conditions, it is better to improve temperature followability even if some hunting is ignored in order to suppress knocking, etc. The discharge speed is not suppressed (steps 35 and 36°11).

The liquid level on the water jacket 2 side while the refrigerant is being discharged from the condenser 3 is maintained by liquid level control (2) shown in detail in FIGS. 9 and 10. This basically performs the same operation as the control shown in FIGS. 7 and 8 above, but when replenishing the refrigerant with the heater pump 13 after 10 seconds, the refrigerant supply pump 4 The refrigerant is discharged to lower the water level in 3 (step 110.96).

However, after 20 seconds have elapsed, priority is given to securing the liquid level in the water jacket 2 (step 111.96).

On the other hand, due to load reduction, etc., the system temperature is "set temperature - 3".
, 0°C" or lower, the process proceeds to step 24, which is detailed in FIG. 14, to control the rise in the water level in the condenser, and introduces the liquid phase refrigerant into the condenser 3 from the reservoir tank 31 using the pressure difference inside and outside the system. This reduces the actual heat dissipation area.

This refrigerant introduction ends when the system temperature reaches "set temperature -2.5° C." or higher (step 26). This end temperature is also set in consideration of the responsiveness of the temperature drop. Then, as in the case of refrigerant discharge, the third solenoid valve 35
The refrigerant introduction speed is appropriately controlled by intermittent operation,
Temperature hunting is made small (steps 22 to 25).

Further, during the introduction of the refrigerant, the refrigerant liquid level in the water jacket 2 is maintained by the liquid level control (3) shown in detail in FIGS. 12 and 13. In this case as well, after 10 seconds have elapsed, the heater pump 13 is used to ensure the liquid level with priority. Note that since the refrigerant supply pump 4 sucks the refrigerant in the lower tank 17 that is close to the saturation temperature, cavitation is likely to occur, but the heater pump 13
Since the low-temperature liquid phase refrigerant is sucked from 1, there is no problem of cavitation, and refrigerant replenishment can always be ensured.

As described above, the actual heat radiation area of the capacitor 3 is variably controlled to maintain the system temperature near the set temperature. Even if the area is narrowed, temperature recovery may not be achieved. Therefore, if the temperature inside the system becomes too high, e.g. 76°C.
If the temperature is below, the warm-up control (step 4) is performed again as described above (step 39). Conversely, if the system temperature rises excessively without reducing the temperature, for example, if the temperature is 110°C or higher and the pressure is positive, the first
High temperature avoidance control in step 41, detailed in FIG. 5, is executed.

This high temperature avoidance control basically opens the third solenoid valve 35.
(Step 133), the pressure inside the system is partially released, and at the same time, air is pushed out from inside the condenser 3 along with the steam. Most of the causes of abnormal high temperatures are that air remains in the fine tube of the condenser 3 and prevents condensation when air is not sufficiently discharged, so normally the third solenoid valve 35 By opening the door and forcing out the air, you can effectively reduce the temperature. Furthermore, in the event that the temperature inside the system further increases to 115° C. or higher due to some kind of failure, the first solenoid valve 38 also opens at the same time, and the pressure inside the system is released through the air exhaust passage 37. In any case, the vapor in the system is discharged into the low-temperature liquid phase refrigerant in the reservoir tank 31, so most of it is condensed and recovered. The first solenoid valve 38 is closed when the temperature inside the system becomes 110° C. or less, and the third solenoid valve 35 is closed when the temperature inside the system becomes 106° C. or less or when the pressure inside the system becomes negative.

Further, even during the above-mentioned system opening, refrigerant is replenished into the water jacket 2 by the processing after step 139, and the refrigerant liquid level is maintained near the set level. In this case as well, the heater pump 13 is used after 10 seconds (
Step 147). Note that the refrigerant is discharged by the refrigerant supply pump 4 when necessary to prevent the refrigerant liquid level in the condenser 3 from rising due to the condensed refrigerant (
Steps 153-155).

Next, after the engine is stopped by turning off the ignition key, certain processing is performed by the interrupt processing (1) detailed in FIG. Specifically, when the system temperature is 95° C. or higher (step 37), the liquid phase refrigerant is continuously introduced from the reservoir tank 31 to the water jacket 2 by the heater pump 13 (step 38).
), and at the same time, excess liquid phase refrigerant is discharged from the lower tank 17 of the condenser 3 to the reservoir tank 31 using the refrigerant supply pump 4. As a result, the reservoir tank 31
The low temperature liquid phase refrigerant stored in the water jacket 2 is mixed with the liquid phase refrigerant in the water jacket 2, and the heat dissipation capacity of the condenser 3 is utilized to the maximum. Therefore, the system temperature can be quickly lowered without depending on the cooling fan 18.

Note that when the refrigerant liquid level in the condenser 3 reaches the lowest level, that is, the level set by the second liquid level sensor 44, the refrigerant supply pump 4 is stopped (step 41).

On the other hand, since the refrigerant is introduced by the heater pump 13 regardless of the first liquid level sensor 42, the liquid phase refrigerant eventually overflows from the vapor ratio lower to the condenser 3 side, but this is also immediately transferred to the reservoir tank by the refrigerant supply pump 4. 31, the heat dissipation area of the capacitor 3 is always maximized.

After the above-mentioned process, the system temperature drops to 95° C., or after 60 seconds have elapsed, the power is turned off and the series of controls ends (steps 37, 42, and 44). This power supply O
Since the third solenoid valve 35, which is a normally open type solenoid valve, is opened by the FF, liquid phase refrigerant is naturally introduced from the reservoir tank 31 as the temperature or pressure in the system decreases, and eventually the entire system becomes liquid. It will be filled with phase refrigerant and will be ready for the next startup.

Although one embodiment of the present invention has been described above in detail, the present invention is not limited to the above embodiment, and various modifications can be made. For example, independent pumps may be used as the refrigerant introducing means and the refrigerant discharging means. Further, for example, it is possible to attach a clutch operated by air pressure to the cooling fan 18 and to achieve even more precise temperature control during operation by connecting and disconnecting the clutch.

Effects of the Invention As is clear from the above explanation, the boiling cooling device for an internal combustion engine according to the present invention can quickly reduce the engine temperature without depending on the cooling fan after the engine is stopped.
It is possible to prevent thermal deterioration of various parts near the engine and deterioration of restartability. Therefore, it is possible to use a fan driven by engine output as the cooling fan, and even when an electric fan is used, the power consumption of the battery can be reduced.

[Brief explanation of drawings]

FIG. 1 is a configuration explanatory diagram showing one embodiment of the present invention, FIGS. 2, 3, 4, 5, 6, 7, 8,
9, 10, 11, and 12. FIGS. 13, 14, and 15 are flowcharts showing the details of control in this embodiment. l... Internal combustion engine, 2... Water jacket, 3.
...Condenser, 4.Refrigerant supply pump, 10.Heater core, 13.Heater pump, 17.Lower tank, 18.Cooling fan, 19.Refrigerant circulation passage,
20...First auxiliary refrigerant passage, 21...Second solenoid valve, 3
1... Reservoir tank, 33... Second auxiliary refrigerant passage, 34... Third auxiliary refrigerant passage, 35... Third solenoid valve, 36... Fourth solenoid valve, 37... Air Discharge passage, 3
8... First electromagnetic valve, 41... Control device, 42... First liquid level sensor, 43... Temperature sensor, 44... Second
Liquid level sensor. 2 others Figure 8 Figure 9 Procedural amendment 0. Eh, March 10, 1985, Patent Application No. 271942, filed in 1985, title of the invention, Boiling Cooling Device for Internal Combustion Engines 3, Relationship with the Amendment Case Applicant (399) Nissan Motor Co., Ltd. 4, Attorney Person Address: 6, Suiseikai Building, 1-29 Akashi-cho, Chuo-ku, Tokyo 104 Contents of amendment (1) “Alternator” on page 3, line 13 of the specification
is corrected to "alternator". (2) "Keep running" in the first line of page 5 of the specification is corrected to "keep sending." (3) "For the installed heater" on page 9, line 13 of the specification.
"For heaters installed at the refrigerant outlet." (4) Change “Improved followability” to “Improved followability” on page 18, line 4 of the specification.
"We have improved tracking performance," he corrected. (5) Figure 1 of the drawings will be corrected as shown in the attached sheet.

Claims (1)

[Claims] (1) A water jacket in which liquid-phase refrigerant is stored up to a predetermined level, a condenser that condenses the refrigerant vapor generated in this water jacket, and a liquid-phase refrigerant that is transferred from the lower tank of this condenser to the water jacket to maintain the above-mentioned predetermined level. In an evaporative cooling system for an internal combustion engine, the system includes a reservoir tank that stores an appropriate amount of liquid phase refrigerant, and a refrigerant supply means that starts operating when an engine stop signal is input and supplies the refrigerant from the reservoir tank. A refrigerant introduction means for continuously introducing a liquid phase refrigerant into the water jacket, and a surplus liquid phase refrigerant from the lower tank so as to keep the refrigerant liquid level in the condenser at the lowest level while the refrigerant introduction means is in operation. and a refrigerant discharge means for discharging the refrigerant into the reservoir tank.