JPS6137444B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an engine radiator that provides evaporative cooling.

Generally speaking, the mainstream engine cooling system is one that cools the outer wall surface of the cylinder by circulating cooling water through a water jacket formed around the cylinder and combustion chamber. The applicant has proposed an evaporative cooling system that makes it possible to efficiently remove heat with a small amount of cooling water by spraying it on the outer wall of the cylinder and evaporating it, using the latent heat of vaporization at that time.
54-107563).

Now, to explain this with reference to FIG. 1, the cooling water pressurized by the water pump 1 flows through the supply passage 2.
Then, it is sprayed from the nozzle portion 3 onto the cooling jacket 6 formed on the cylinder head 4 and cylinder block 5.

The vapor of the cooling water that evaporates by absorbing the latent heat of vaporization from the cylinder outer wall surface enters the radiator 8 via the steam passage 7, is cooled by the running wind of the vehicle or the air blown by the electric fan 9, and liquefies, and is then sucked into the water pump 1. It flows into passage 10 and is sent back to the engine where it evaporates.

The engine is cooled by repeating these steps, and since the evaporation temperature is proportional to the internal pressure of the cooling jacket 6, the cylinder wall temperature is controlled by the electric fan 9 and pressure control valve 12, which are operated by signals from the controller 11. , by controlling based on the signal from the sensor 13 that detects the internal pressure.

Therefore, according to this cooling method, cooling is performed using the large latent heat of vaporization of water, so the amount of cooling water can be reduced, making it possible to reduce the weight of the engine and shorten the warm-up time. Furthermore, since the cylinder wall temperature can be freely controlled, there is an advantage that engine combustion efficiency can be improved.

However, in order to liquefy the cooling water that has evaporated once, it is necessary to efficiently perform cooling with the radiator 8, and for this purpose, there is a tendency for the radiator 8 to become larger.

By the way, when the steam liquefies after the engine is stopped, there is an atmosphere inside the radiator 8, but this atmosphere is compressed by the steam pressure during engine operation and the volume is reduced, but in any case, the radiator 8 Since the radiator 8 occupies a part of the heat radiation space of the radiator 8, there is a problem in that the heat exchange rate of the steam decreases by that amount, and this is a factor that further promotes the increase in the size of the radiator 8.

In order to solve these problems, the present invention provides a radiator in which an air storage chamber is formed in the upper part of the radiator body, and air is forced into the chamber during engine operation, thereby increasing the radiator heat exchange rate. It is something to do.

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

In FIG. 2, the upper part of the radiator body 20 has an air storage chamber 22 connected to it via a communication passage 21.
will be established.

The volume of this air storage chamber 22 almost matches the air volume when the air occupying this heat radiation space 23 is pressurized while the engine is stopped by the pressure of the radiator heat radiation space 23 set in the normal operating range. Decide as follows.

Note that the bottom wall 22A of the air storage chamber 22 is connected to the communication path 2.
It has a gentle slope that descends towards 1.

A cutoff valve 25 is interposed in a portion of this communication passage 21, and is designed to shut off the communication passage 21 when a preset steam pressure or temperature is reached during engine operation.

In this embodiment, negative pressure is introduced into the negative pressure actuator 26 of the cutoff valve 25 via a solenoid valve (three-way valve) 27 to close the valve. However, the solenoid valve 27 performs a switching operation based on the output of a pressure sensor or a temperature sensor (not shown).

The upper reservoir 28 of the radiator body 20 is the steam passage 2
9, the lower reservoir 30 is connected to the pump suction passage 31, and the evaporatively cooled vapor is liquefied and circulated.

Next, the effect will be explained.

When evaporative cooling is started by the system shown in Figure 1 when the engine is started, the radiator heat radiation space 2
3 pressure gradually increases.

This is because the return steam pressure from the steam passage 29 pressurizes the air, which pressurizes the air that filled the heat radiation space 23 before starting the engine, and this air flows into the upper air storage chamber 22. be pushed into.

At the same temperature, air has a lower specific gravity than steam (which in this case means moist steam or microscopic water droplets), so in this way most of the air is contained as the pressure inside the system increases. It is sealed in room 22. However, although some steam may be mixed in, the proportion is small.

When the pressure or temperature reaches such a level that most of the air is confined, negative pressure from the electromagnetic valve 27 is introduced into the negative pressure actuator 26 of the shutoff valve 25, and the shutoff valve 25 shuts off the communication path 21.

Therefore, after this, the heat radiation space 23 is filled almost only with steam, and almost 100% of the effective volume of the heat radiation space 23 is used to efficiently cool and liquefy the steam.

When the pressure in the cooling system decreases due to steam condensation after the engine is stopped, the shutoff valve 25 remains open.
Air flows into the heat radiation space 23 from the air storage chamber 22, preventing the internal pressure from becoming close to vacuum and maintaining it at approximately atmospheric pressure.

Note that the steam (cooling water) condensed in the air storage chamber 22 returns to the radiator main body 20 from the communication path 21 by the inclined bottom wall 22A.

Next, the embodiment shown in FIG. 3 will be described. In this embodiment, an orifice 33 is provided in the middle of the communication path 21, and the cutoff valve 25 is removed.

Since air can be forced into the air storage chamber 22 by steam pressure during engine operation, the mechanism is simplified by omitting the shutoff valve 25.

The orifice 33 reduces heat transfer due to convection between the inside of the radiator body 20 and the air storage chamber 22. In addition, a semipermeable membrane is provided in the middle of the communication path 21 to separate air and steam, and the air storage chamber 22
It is also possible to allow only air to accumulate in the area.

As described above, according to the present invention, the effective volume of the radiator heat radiation space can be substantially expanded.
This has the effect of efficiently cooling the steam.

Further, in the present invention, since the internal space of the radiator is substantially cut off from the outside, the internal pressure of the cooling jacket can be set freely.
The evaporation temperature, that is, the cooling temperature, can be controlled according to the operating conditions according to this pressure, and thereby the engine combustion efficiency can be maintained to the maximum.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a conventional device, and FIGS. 2 and 3 are sectional views each showing an embodiment of the present invention. 20...Radiator body, 21...Communication path, 2
2...Air storage chamber, 23...Radiator heat radiation space, 25...Shutoff valve, 27...Solenoid valve, 33...
Orifice.

Claims (1)

[Scope of Claims] 1. In a device that supplies cooling water to the cooling jacket of an engine cylinder and cools the engine using latent heat of vaporization based on evaporation, there is a device connected to the upper part of the radiator body that condenses and liquefies the vapor of the cooling water. A radiator characterized by having an air storage chamber connected through a passage. 2. The radiator according to claim 1, wherein the communication passage is provided with a cutoff valve that closes when the internal pressure or temperature of the radiator body reaches a predetermined value. 3. The radiator according to claim 1, wherein an orifice is interposed in the communication passage.