JPS6258011A - Evaporative-cooling device for internal combustion engine - Google Patents

Abstract

PURPOSE:To prevent the uneven distribution of a non-freezing solution component in a refrigerant by branching a refrigerant mixing path from a refrigerant path for a heater, and connecting the tip of the mixing path to the inlet part of a condenser, in addition, providing the above connected part with a thermally sensitive valve to open responding to refrigerant steam. CONSTITUTION:A standard device comprises a water jacket 2 for storing a liquid phase refrigerant, a condenser 3 into which refrigerant steam generated in the water jacket 2 is introduced, a refrigerant supplying pump 4 provided between the above components 2, 3, and a pump 14 for a heater to circulate the liquid phase refrigerant in the water jacket 2 through a heater core 11 for heating a car room. In the above constitution, the basic end of a refrigerant mixing path is branched from a heater outlet path 13, and its tip is connected near the inlet 3a of the condenser 3 to form the refrigerant mixing path 41. In addition, the bimetal type of a thermally sensitive valve 42 to open and close the tip opening 41a of the above path 41 is provided in the upper tank 15 of the condenser 3.

Description

[Detailed Description of the Invention] Industrial Application Field This invention stores a liquid phase refrigerant up to a predetermined level in a water jacket, cools various parts of an internal combustion engine by boiling and vaporizing the refrigerant, and discharges the generated refrigerant vapor. The present invention relates to a boiling cooling device for an internal combustion engine that condenses in a condenser and reuses the condensation.

Conventional Technology As a cooling device for an internal combustion engine, a boiling cooling device that utilizes the boiling and condensing cycle of a refrigerant (cooling water) was proposed in Japanese Patent Publication No. 57-57608, etc., in place of the conventional water-cooled cooling device. However, the present applicant has developed this further and has already filed various applications (for example, Japanese Patent Laid-Open No. 60-36715, Japanese Patent Application No. 59-10).
No. 0156, Japanese Patent Application No. 140378/1984, etc.). This consists of a water jacket in which liquid phase refrigerant is stored up to a predetermined level, a condenser connected via a steam passage to the vapor outlet at the top of this water jacket, and a condenser connected to the water jacket from the bottom of the condenser where liquefied refrigerant is temporarily stored. The system mainly consists of a refrigerant supply pump that circulates and supplies liquid refrigerant to the refrigerant circulation system, forming a closed refrigerant circulation system. While the non-condensable gas air is discharged, during engine operation, the refrigerant liquid level in the water jacket is monitored by a liquid level sensor and the refrigerant supply pump is controlled to maintain the liquid level at a predetermined level. It was designed to be maintained at A cooling system that utilizes the latent heat associated with the phase change of this refrigerant! By doing so, the heat exchange efficiency can be dramatically improved, and each part can be uniformly cooled to the boiling point of the refrigerant. Unlike a flowing water type cooling device, the liquid phase refrigerant in the water jacket receives combustion heat while remaining in a stagnation state after the engine is started, so there is an advantage that the warm-up time can be significantly shortened.

By the way, the refrigerant used in this type of boiling cooling device t is one in which water is mixed with an antifreeze solution such as 2000 gel alcohol, etc., and a small amount of rust preventive agent is used, in view of its ease of handling, large vaporization rate, and quality. However, since an aqueous solution of two-handed ranger liquor is a non-azeotropic mixture, the vapor of the aqueous solution contains almost no two-hander ranger liquor, and is only water vapor. Become. For example, the vapor of a 50% (by weight) aqueous solution of ethylene glycol contains only about 2 parts of two-handed range glycol.

Therefore, when the boiling cooling device described above is continuously operated, a large amount of ethylene glycol is unevenly distributed in the water jacket, and the ethylene glycol concentration becomes extremely low on the condenser side. Therefore, there is a risk that the capacitor may freeze inside the capacitor during the winter, damaging the capacitor, or that the solenoid valve or refrigerant supply pump may freeze and malfunction.

In order to deal with such problems, the applicant first proposed the third
As shown in the figure, a refrigerant mixing passage 55 is branched from the heater refrigerant passage 54 on the discharge side of the heater pump group that circulates the liquid phase refrigerant in the water jacket 51 to the heater core 52 for heating the passenger compartment, and the refrigerant mixing passage 55 is formed at the tip thereof. capacitor 56
proposed a boiling cooling device connected to the inlet side of the steam passageway 57, for example, the upstream portion of the steam passage 57 (Japanese Patent Application No. 14080/1980).

That is, by using a group of heater pumps that run in winter, the liquid phase refrigerant in the water jacket 51, where the concentration of antifreeze components is relatively high, is forcibly fed to the condenser 56f along with refrigerant vapor to equalize the concentration. (Figure 3 shows the state immediately after startup; after boiling starts, the area above the liquid level sensor becomes a vapor space).

Problems to be Solved by the Invention However, as described above, the heater pump 53 t thus transfers the liquid phase refrigerant from the water jacket 51 side to the condenser 5.
If the heater pump 53 is activated before warm-up is completed, that is, when the system is filled with liquid phase refrigerant, the inside of the water jacket 51 will be mixed in as shown by the arrow in FIG. The liquid-phase refrigerant warmed by the refrigerant is circulated through the refrigerant mixing passage 55, which may impede engine warm-up and rapid rise in the cylinder wall temperature and the temperature near the combustion chamber. In particular, in order to reliably supply liquid phase refrigerant to the condenser enclosure, the refrigerant mixing passage 55 is located near the inlet of the condenser I, for example, the condenser upper tank 5.
9, heat during warm-up will escape from the capacitor 56, making the above-mentioned problem even more noticeable.

This invention attempts to prevent the above-described uneven distribution of antifreeze components in the refrigerant without impairing the warm-up characteristics that are an advantage of the evaporative cooling system.

Means for Solving the Problems In the evaporative cooling device for an internal combustion engine according to the present invention, a refrigerant mixing passage is branched from the heater refrigerant passage on the discharge side of the heater pump, and its tip is located near the inlet of the condenser. When connected, this connection is characterized by being provided with a temperature-sensitive valve that opens in response to refrigerant vapor.

The heater pump is operated in conjunction with the heater switch when heating is required, but if the refrigerant freezes, heating is always required when the engine is running, so the heater pump is operated in conjunction with the heater switch. will be activated. By operating this heater pump, the liquid phase refrigerant on the water jacket side is sent to the condenser side ζ through the refrigerant mixing passage, thereby suppressing a decrease in the concentration of the antifreeze component on the condenser side.

On the other hand, during warm-up operation when refrigerant vapor has not yet been generated, or when the amount of vapor generated t1 is so small that it condenses before reaching the inlet of the condenser, the temperature-sensing valve closes the refrigerant mixing passage. Close the circuit. Therefore, heat does not wastefully escape to the capacitor, and engine warm-up and heater performance are not affected in any way.

Embodiment FIG. 1 shows an embodiment of the evaporative cooling system of the present invention. In the figure, 1 is an internal combustion engine equipped with a water jacket 2, and 3 is a condenser for condensing a gas phase refrigerant. , 4 indicate electric refrigerant supply pumps, respectively.

The water jacket 2 is formed across both the cylinder block 5 and the cylinder head 6 so as to enclose the outer periphery of the cylinder and combustion chamber of the internal combustion engine 1, and the upper part, which is normally a gas phase space, is Each cylinder communicates with each other, and a steam amount lower is provided at an appropriate position above the cylinders. This steam volume lower communicates with the upper part 3a of the condenser 3 via a connecting pipe 8 and a steam passage 9, and the connecting pipe 8 has a discharge fitting part 8a which is the top of the refrigerant circulation system. It is formed in an upwardly raised shape, and a cap 10 seals the upper opening.

Reference numeral 11 denotes a heater core for heating provided in the vehicle interior, and the refrigerant inlet at the lower part is connected to the cylinder block 5 side of the water jacket 2 via the heater inlet passage 12.
Moreover, the upper refrigerant outlet is connected to the cylinder head 6 side via the heater outlet passage 13. A heater pump 14 for circulating liquid phase refrigerant between the water jacket 2 and the heater core 11 is interposed in the heater outlet passage 13ζ.

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 1 is installed at a position such as the front of the vehicle that receives wind from the vehicle running, and is further provided with an electric cooling fan 18 for forced cooling on the front or back side. 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 19
The other end is connected to a refrigerant port 2a provided in the cylinder block 6 of the water jacket 2, and the refrigerant supply pump 4 is interposed in its passage (this refrigerant supply pump 4 A second solenoid valve 21 consisting of a three-way solenoid valve is interposed on the discharge side of the reservoir tank. This is open to the atmosphere through a cap 23 having a ventilation function, and is located at approximately the same height as the water jacket 2, and at the bottom thereof,
The first auxiliary refrigerant passage 20 and the second auxiliary refrigerant passage 24 are connected.

The first auxiliary refrigerant passage 20 has a normally open third solenoid valve 4 disposed therein, and the second auxiliary refrigerant passage 24 is connected to the refrigerant circulation passage 19 via the second solenoid valve 21. has been done. The second solenoid valve 21 shuts off the refrigerant circulation passage 19 to establish communication between the reservoir tank 22 and the lower tank 17 in a non-energized state, and blocks the second auxiliary refrigerant passage 24 in an energized state. The refrigerant circulation passage 19 is placed in a communicating state (flow path B). As the refrigerant supply pump 4, a pump is used which can pump the liquid phase refrigerant in both forward and reverse directions.If the refrigerant supply pump 4 is driven in the forward direction in the state of the flow path A, the lower tank The liquid phase refrigerant can be forcibly discharged from the reservoir tank 17 to the reservoir tank 22, and by driving in the opposite direction, the liquid phase refrigerant can be forcibly introduced from the reservoir tank 22 to the lower tank 17. Furthermore, in the state of the flow path B, the refrigerant supply pump 4 can be moved in the forward direction. When driven, the liquid phase refrigerant can be circulated and supplied from the lower tank 17 to the water jacket 2.

On the other hand, the discharge pipe attachment part 3a which is the top of the above-mentioned closed system
f This is an air exhaust passage 26 for exhausting air in the system.
is connected, and in order to recover the liquid phase refrigerant that overflows at the same time as the air is discharged, the tip of the air discharge passage 26 is opened into the reservoir tank n. A normally-closed first solenoid valve 27 is interposed therein.

The above-mentioned electromagnetic valves 27 , 21 , 25 , refrigerant supply pump 4 and cooling fan 18 are controlled by a control device 31 (using a newly developed microcomputer system). a first liquid level sensor 32 disposed at the level; a temperature sensor 33 disposed at an appropriate position on the water jacket 2;
The lower tank 17 includes a second liquid level tank U disposed relatively above the lower tank 17, and a diaphragm negative pressure switch 35 disposed at the top of the circulation system. In addition, the heater pump 14
It is configured to be turned on and off by a hajita switch 36.

Reference numeral 41 denotes a refrigerant mixing passage provided in order to equalize the concentration of antifreeze components.The base end of this passage is branched from the heater pump 14 discharge side of the heater outlet passage 13, and the tip thereof is a condenser. 30 near the inlet 3a, specifically connected to the upper tank 15. In the upper tank 15, as shown in detail in FIG. 2, a bimetallic temperature-sensitive valve 42 is disposed to open and close the tip opening flea of the refrigerant mixing passage 41. This temperature-sensitive valve 42 is made of a plate-shaped bimetal 43 and a valve body material, and closes the opening 41a at low temperatures and opens at high temperatures, and the valve temperature is slightly lower than the boiling point of the refrigerant. , for example 80~
The temperature is set at about 90°C. Note that 45 indicates an orifice for adjusting the flow rate.

Next, the outline of the control of the boiling cooling device and the operation of each part will be explained.

First, when the engine starts, the system is temporarily filled with liquid phase refrigerant (for example, 3
0 to 50% aqueous solution is used), and air, which is a non-condensable gas, is discharged. That is, the first solenoid valve 21 is connected to the flow path A.
'', the refrigerant supply pump 4 is driven in reverse for a certain period of time, and liquid phase refrigerant is forcibly fed into the system from the reservoir tank 22 outside the system. As a result, the air remaining in the system is collected in the upper part of the system and then exhausted to the outside of the system via the air exhaust passage 26.

Sufficient time for the system to be filled with liquid phase refrigerant (e.g.
After approximately 0 seconds have elapsed, the first magnetic valve 27 is turned on, and the third magnetic valve 27 is turned off.
-The valve 25 is opened and the refrigerant supply pump 4 is turned off.
Just wait. Since the liquid phase refrigerant in the water jacket 2 is in a stagnation state, the temperature quickly rises. Thereafter, when the temperature detected by the temperature sensor 33 reaches the target temperature, the third solenoid valve 25 is turned on to seal the inside of the system. The target temperature is successively optimally set within a range of, for example, about 80 to 110° C., depending on the operating neutrality of the engine load, rotation speed, etc.

In addition, if the target temperature is higher than the refrigerant boiling point under normal pressure,
During this warm-up operation, boiling starts, and excess liquid phase refrigerant is discharged through the third magnetic valve 25 due to vapor pressure, so that the refrigerant liquid level in the condenser 3 reaches the level set by the second liquid level sensor 34. If the temperature drops, immediately seal the system. Further, as a result of boiling, if the refrigerant liquid level in the water jacket 2 falls below the set level of the first liquid level sensor 32, the second 'tlt
The magnetic valve 21 is set as "flow path B", and the refrigerant supply pump 4 is driven in the forward direction to supply liquid phase refrigerant from the lower tank 17 to the water jacket 2.

Here, if the heater switch 36 is ON, the heater pump 14 operates, but the refrigerant vapor is hot and the tank 15ζ
At the stage where this temperature has not yet reached this level, the temperature-sensitive valve 42 closes the refrigerant mixing passage 41, so that heat does not wastefully escape to the condenser 3 side, and there is no risk of delaying warm-up.

In order to achieve even more rapid warm-up, immediately after startup, a portion of the liquid phase refrigerant in the system is discharged from the reservoir tank 22t using the refrigerant supply pump 4, and air is introduced into the upper part of the system.
Control may be performed so that air discharge by forced introduction of liquid phase refrigerant is started when the warm-up has progressed to a certain extent. Even in this case, since the temperature-sensitive valve 42 is closed until the refrigerant vapor reaches the upper tank 15, the liquid phase refrigerant does not flow through the refrigerant mixing passage 41.

After the above warm-up control is completed and the system is sealed, the refrigerant liquid level in the water jacket 2 is maintained by turning the refrigerant supply pump 4 ON (normal rotation) and OFF', and the cooling fan 18 is turned on and off.
N-OFF and temperature control by vertical movement of the refrigerant liquid level in the condenser 3 are repeatedly executed until key 077, and efficient cooling is performed using the cycle of boiling and condensation of the refrigerant. That is, the refrigerant supply pump 4 is controlled ON/OFF based on the detection signal of the first liquid level sensor 32, and liquid phase refrigerant is intermittently supplied from the lower tank 17 to the water jacket 2. This allows water jacket 2
The refrigerant liquid level within the refrigerant is always maintained close to the level set by the first liquid level sensor 32. In addition, the cooling fan 18 is turned on and off in a relatively narrow temperature range of "target (sensitivity ±0.5 degrees Celsius)".
F control. As a result, relatively fine adjustment of the condensing performance of the condenser 3 can be made with good responsiveness. Further, when the detected temperature is relatively large (for example, about 2 to 4 degrees Celsius) lower than the target temperature, liquid phase refrigerant is forcibly introduced and discharged between the reservoir tank 22 and the condenser 3.

Specifically, if the detected temperature is higher than the target temperature, the refrigerant supply pump 4 is driven in the forward direction with the second solenoid valve 21 set to "flow path A" to lower the refrigerant liquid level in the condenser 3. .

As a result, the heat dissipation capacity of the condenser 3 increases, the boiling point immediately decreases, and the system temperature quickly decreases. If the detected temperature is lower than the target temperature, the refrigerant supply pump 4 is driven in the opposite direction to raise the refrigerant liquid level in the condenser 3. As a result, the heat dissipation ability of the capacitor 3 is suppressed, and the temperature within the system quickly rises. That is, the temperature within the system can be variably controlled with high precision without being affected by external disturbances such as wind when the vehicle is running.

- If the heater switch 36 is turned on during winter, the heater pump 14 will operate, and the heater jacket 2 will operate.
The high temperature liquid phase refrigerant inside is circulated and maintained in the heater core 11.

Then, a part of the liquid phase refrigerant returning from the heater core 11 to the water jacket 2 is diverted from the heater outlet passage 13 to the refrigerant mixing passage 41# and sent to the upper tank 15. That is, the refrigerant in the water jacket 2, which has a high concentration of two-way range recall, is mixed little by little with the refrigerant on the condenser 3 side, thereby making the concentration uniform.

After the engine of the next ship is stopped, the power is turned off.Accordingly, the first solenoid valve 27, which is a normally closed solenoid valve, is closed, and the third solenoid valve 25, which is a normally closed solenoid valve, is opened. Become. Therefore, as the temperature decreases, that is, the pressure decreases, the liquid phase refrigerant moves from the reservoir tank 22 into the system. Eventually, the inside of the system will be almost completely filled with liquid phase refrigerant, preventing air from entering during the stoppage. As mentioned above, since the refrigerant in the water jacket 2 is fed into the condenser 31 little by little during operation, the difference in ethylene glycol hardness between the two is kept relatively small. Freezing of the refrigerant during stoppage can be reliably prevented.

Although one embodiment of the present invention has been described in detail above, the present invention is not limited to the above embodiment.

In the above embodiment, a bimetal type temperature-sensitive valve is used, but the temperature-sensitive valve may also be constructed using thermowax or a shape memory alloy. It goes without saying that the present invention is also applicable to cases where a refrigerant other than an aqueous ethylene glycol solution is used.

Effects of the Invention As is clear from the above explanation, the boiling cooling system for an internal combustion engine according to the present invention can reliably prevent the refrigerant from freezing in various parts such as the condenser and the refrigerant supply pump due to uneven distribution of antifreeze components in the refrigerant. It can be prevented.

Furthermore, since the refrigerant is introduced using the heater pump, there is no need for special operations in situations where freezing occurs, and problems such as an increase in the number of parts do not occur. And since the refrigerant introduction is stopped during the warm-up by using the temperature-sensing valve,
The excellent warm-up characteristics, which are an advantage of the evaporative cooling device, are not deteriorated in any way.

[Brief explanation of drawings]

FIG. 1 is a structural explanatory diagram showing one embodiment of the present invention, FIG. 2 is an enlarged cross-sectional view of a main part thereof, and FIG. 3 is a structural explanatory diagram of a boiling cooling device previously filed by the present applicant. 1... Internal combustion engine, 2... Water jacket, 3...
...Condenser, 4...Refrigerant supply pump, 11...
Heater core, 13... Heater outlet passage, 14... Heater pump, 15... Upper tank, 18... Cooling fan, 22... Reservoir tank, 31... Control device, 32... No. 1 liquid level sensor, 33... temperature sensor, 41... refrigerant mixing passage, 42... temperature sensitive valve.

Claims (1)

[Claims] (1) A water jacket in which liquid phase refrigerant is stored up to a predetermined level, a condenser into which refrigerant vapor generated in the water jacket is introduced, and a condenser disposed between the condenser and the water jacket, and the water jacket a refrigerant supply pump that replenishes liquid refrigerant from the condenser to the water jacket so as to maintain the refrigerant liquid level in the water jacket at the predetermined level; and a heater pump that circulates the liquid refrigerant in the water jacket to the heater core for heating the passenger compartment. In the evaporative cooling device for an internal combustion engine, the refrigerant mixing passage is branched from the heater refrigerant passage on the discharge side of the heater pump, and the tip thereof is connected to the vicinity of the inlet of the condenser; 1. A boiling cooling device for an internal combustion engine, comprising a temperature-sensitive valve that opens in response to refrigerant vapor.