JPS6153535B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a cooling device for an internal combustion engine for an automobile.

In general, a water cooling system, for example, is normally used as a cooling system for an internal combustion engine for an automobile.

In this water cooling system, cooling water is forcibly circulated by a water pump, which lowers the temperature of the structural materials in each part of the engine to maintain strength and maintain a temperature at which each sliding part can be lubricated. In addition, a thermostatic valve or the like is used to control the amount of circulating water during warm-up and supercooling to prevent a decrease in thermal efficiency due to supercooling.

However, with the commonly used water cooling system as mentioned above, the cooling performance depends on the amount of heat dissipated by the radiator and the amount of circulating water, that is, the rotational speed of the water pump. It is not possible to control the functions, and the cooling water required for cooling during full load is constantly flowing, resulting in the problem that cooling during partial load tends to be overcooling.Also, during warm-up, the cylinder block However, since a large amount of water in the cylinder head must be heated, it also has the disadvantage that it takes too much time to warm up.

As a solution to the problems of the conventional cooling methods as described above, an evaporative cooling method is considered in which the cylinder head, outer wall of the combustion chamber, etc. are cooled by evaporation of liquid (see Japanese Patent Publication No. 57-57608). The applicant has proposed the following structure which is a further improvement on this.

That is, a capillary structure made of foamed metal, foamed ceramic, or metal fiber is attached to the outer wall of the cylinder, the outer wall of the combustion chamber, etc., and a liquid as a cooling medium is supplied to the lower part of the capillary structure, so that the liquid flows into the capillary tube. It is held in the structure and absorbs heat from the cylinder outer wall and combustion chamber outer wall and evaporates to cool the engine. There are also devices that utilize steam cooling, such as the one shown in Japanese Patent Application Laid-Open No. 52-94944, which separates the gas phase and liquid phase of the cooling water in a steam/water separation tank, and uses a pressure sensor in the steam/water separation tank. Since the cylinder block is installed to detect pressure with a large pressure difference away from the combustion chamber, which is the object of control, accuracy deteriorates, and since the inside of the cylinder block is filled with liquid-phase cooling water, there is The problem is that the phase is carried out to a large extent.

In such a cooling evaporation system, the evaporation temperature of the cooling medium is constant if the pressure in the cooling chamber space is constant, so the supply of the cooling medium is controlled by sensing the pressure in the cooling chamber space. This allows the cooling function to be controlled according to the engine load, and the amount of liquid in this system can be reduced to about 1/5 to 1/10 compared to water-cooled systems, so the warm-up time is shorter than in conventional systems. It can be much shorter than the water-cooled type.

The present invention aims to further significantly shorten the warm-up time in an evaporative cooling system, and the present invention will be described in detail below with reference to illustrated embodiments.

In Fig. 1, 1 is the cylinder wall of the engine;
2 is a cylinder head; 3 is a liquid-absorbing capillary structure called a wick provided on the outer periphery of the cylinder wall 1 and the outer periphery of the combustion chamber of the cylinder head 2;
Made of foamed ceramics, etc.

4 is a radiator, 5 is an electric fan, and steam in the sealed cooling space 12 of the cylinder head 2 is guided to the radiator 4 through a steam passage 10;
Here, it is cooled down by driving the electric fan 5 and becomes liquid.

The cooling medium (liquid having an appropriate boiling point, such as water or a mixture of water and alcohol) that has become liquid in the radiator 4 is transferred to a liquid phase refrigerant passage 9 by a pump 8.
Nozzle 1 installed above the outer wall of the combustion chamber
It is configured such that it is sprayed from 1 and applied to wicks 3.

Further, the liquid cooling medium that has accumulated at the bottom of the cylinder outer wall 1 without being evaporated is returned to the downstream part of the radiator 4 through the passage 13, and is sprayed by the pump 8 from the nozzle 11.

The electric fan 5 and pump 8 are connected to the cooling chamber space 1
Controlled by a control signal from a control circuit 6 based on a signal from a pressure sensor 7 that senses the pressure inside the cooling chamber space 12, cooling is performed in proportion to the pressure inside the cooling chamber space 12, resulting in good responsiveness according to the engine load. It is now possible to perform cooling control at a constant temperature.

In the evaporative cooling system as described above, the present invention includes a valve mechanism 14 in the steam passage 10 that guides the steam generated in the cooling chamber space 12 to the radiator 4, which opens when the pressure or temperature of the steam exceeds a predetermined value. It was established.

That is, if the steam passage 10 does not have a valve mechanism to control the flow of steam, the steam generated in the space 12 will continue to flow to the radiator 4 through the steam passage 10 even during warm-up after starting the engine. As a result, warm-up of the engine is delayed due to the escape of steam.

Therefore, as in the present invention, a valve mechanism 14 is provided in the steam passage.
By providing a structure in which the valve mechanism 14 closes when the pressure or temperature of the steam during engine warm-up is low and confines the steam in the sealed cooling chamber space 12, the warm-up time can be further shortened. It is something that can be shortened.

FIG. 2 shows an embodiment of the valve mechanism 14, and shows an example in which a butterfly valve is used as the valve mechanism.

That is, the valve 141 has a shaft 142 provided near its upper portion, and both ends of the valve 141 are connected to a bearing 14 provided with a steam passage 10.
3, and the valve 141 keeps the steam passage 10 closed due to its own weight.

While the engine is warming up, the steam pressure is low, and even if the steam tries to flow toward the radiator 4 as shown by arrow A, there is no force to push up the valve 141 to open it, and the steam is trapped in the cooling chamber space 12. It is becoming. As the engine warms up and the steam pressure increases, the valve 141 gradually opens and the steam flows to the radiator 4.
It starts to flow.

Figure 3 shows the bimetal 14 in the butterfly valve 141.
In this case, when the steam temperature is low and the engine is warming up, the valve 141 closes the steam passage 10 by its own weight as in the case of FIG. As the temperature increases, bimetal 1
44 deforms in the direction of arrow B, presses the actuated member 141' provided on the valve 141 downward, opens the valve 141, and allows steam to flow to the radiator 4.

In both of the embodiments shown in FIGS. 2 and 3, the engine warm-up can be promoted by preventing the steam from flowing into the radiator before the end of warm-up when the pressure or temperature of the generated steam is low.

FIG. 4 shows an example in which a thermowax type valve mechanism 14 is used.

That is, the valve 145 is composed of a case-like member having an elastic tube 145a made of rubber or the like inside and a case-like member in which a thermally expandable liquid such as wax 145b or a substance that becomes liquid when heated is sealed around the outer circumference of the tube 145a. The tip of the shaft 146 is inserted into the inside,
The shaft 146 is connected to the steam passage 1 by a stay 146a etc.
Supported within 0.

When the steam temperature is low, the wax 145b contracts, so the valve 145 is pressed against the valve seat 148 by the spring 147, closing the passage steam 10. However, when the steam temperature rises, the wax 145b contracts.
b expands and crushes the tube 145a, causing the shaft 1
46 in the axial direction, the valve 145 moves away from the valve seat 148 against the force of the spring 147 and becomes open as shown, and the steam flows in the direction of the arrow and into the radiator 4.

It should be noted that any valve mechanism other than those shown in FIGS. 2, 3 and 4 may be used within the scope of the present invention.

As described above, in the evaporative cooling system according to the present invention, a valve mechanism that closes the steam passage until the pressure or temperature of the steam reaches a predetermined value is simply provided in the steam passage that leads the generated steam to the radiator part. With its extremely simple configuration, the engine warm-up time can be significantly shortened, and the practical effect is extremely large.

[Brief explanation of the drawing]

FIG. 1 is an overall longitudinal cross-sectional explanatory diagram showing one embodiment of the present invention, and FIGS. 2 and 3 each show an embodiment of the valve mechanism shown in FIG. FIG. FIG. 4 is a longitudinal sectional side view showing still another embodiment of the valve mechanism. 1...Cylinder outer wall, 2...Cylinder head, 3...
Wick, 4...Radiator, 5...Electric fan, 6
...Control circuit, 7...Pressure sensor, 8...Pump, 9...
Liquid phase refrigerant passage, 10... Steam passage, 13... Passage, 1
4...Valve mechanism.

Claims (1)

[Claims] 1. A cooling chamber space formed in the cylinder head;
A vapor phase space formed in the upper part of the cooling chamber space, a vapor passage that communicates the vapor phase space with the radiator, and a liquid phase that supplies liquid phase refrigerant liquefied in the radiator to the cooling chamber space through a pump. A refrigerant passage and a detection means installed in the cooling chamber space to detect internal pressure or temperature are provided, and the refrigerant liquefaction capacity of the radiator or the refrigerant supply amount of the pump is controlled according to the pressure or temperature of the cooling chamber space. In an evaporative cooling device in which the cooling temperature is controlled to a constant value by controlling at least one of them, the steam passage is provided with a valve mechanism that closes the steam passage until the pressure or temperature of the steam reaches a predetermined value. A cooling system for internal combustion engines for automobiles. 2. An internal combustion engine for an automobile according to claim 1, characterized in that the valve mechanism is a butterfly valve that is kept closed by the weight of the valve itself and opened in response to steam pressure. Cooling system. 3. The cooling device for an internal combustion engine for an automobile according to claim 1, characterized in that the valve mechanism is a bimetallic valve that opens according to the temperature of the steam. 4. The automobile according to claim 1, characterized in that the valve mechanism uses a valve that operates to open by utilizing expansion of wax or the like, and opens when the temperature of the steam reaches a predetermined value or higher. cooling system for internal combustion engines.