JPS6040824Y2 - engine cooling system - Google Patents

Description

[Detailed explanation of the idea] The present invention relates to an engine cooling device.

A conventionally commonly used engine cooling system, which can be explained with reference to FIG. 1, consists of a radiator 1 and an engine 2.
The lower part of the radiator is connected to the cylinder body 2a via the return pipe 3 via the pump 4, and the upper part of the radiator is connected to the cylinder head 2b via the thermostat 6 via the feed pipe 5, and the vicinity of the pump 4 and the vicinity of the thermostat 6 are connected to a short-circuit pipe. Until the coolant warms up, the coolant in the engine returns to the engine via the short-circuit pipe 7 by the pump 4, and when the coolant reaches a high temperature, the thermostat 6 opens and the cylinder body Cooling water flowing through the cylinder head 2a1 enters the radiator 1 through a feed pipe 5 and returns to the engine through a return pipe 3 where it is cooled.

However, the above-mentioned engine cooling system has the following drawbacks.

That is, when accelerating the vehicle when the engine 2 is cold,
Due to the rapid high rotation of the engine, the water temperature around the cylinder head 2b, especially the combustion chamber, rises rapidly, but since there is a time delay between the thermostat 6 sensing the water temperature and the time it operates, the thermostat 6 does not open during this time, causing an abnormality. This has the disadvantage that it causes an increase in water temperature (so-called overshoot) and tends to cause cracks in the cylinder head 2b or sticks in the intake and exhaust valves.

On the other hand, in the summer when the engine 2 is frequently stopped, for example when the engine 2 is hot due to city driving, even if the thermostat 6 is open, the thermostat 6 itself becomes a resistance, causing the radiator 1 to rapidly supply high-temperature cooling water in the engine. Therefore, there is not enough cooling water to return from the radiator 1 to the engine 1.

As a result, the engine 1 is not sufficiently cooled, which causes the temperature of the fuel and the intake air-fuel mixture to rise, resulting in problems such as rough idling and engine stalling.

Conventionally, in vehicles equipped with car coolers, in order to prevent the engine from overheating during low-speed driving in cities in the summer due to the installation of the car cooler and the complexity of piping in the engine room, the thermostat is used as shown in Japanese Utility Model Publication No. 47-16420. A bypass passage 5 is provided leading to the front and rear of the
It is known that the throttle valve 6 installed in the throttle valve is opened and closed by a bimetal that operates based on the water temperature, but this opens by sensing the water temperature, and moreover, the water temperature that has already reached a high temperature inside the engine in the bypass passage 5. Therefore, as a countermeasure, it is slow and puts a heavy burden on the radiator.

Furthermore, it is not possible to immediately respond to the above-mentioned overshoot, which can occur even in cold weather, because the water temperature sensing location is far away.

The purpose of this invention is to solve the above-mentioned cold and hot problems all at once.The gist of this invention is to form a bypass path that bypasses the thermostat in the feed pipe that connects the cylinder head and the radiator 1. The system is designed to open and close depending on the temperature of the water around the combustion chamber of the cylinder head when the road is cold, and depending on the temperature of the engine's intake air when the road is hot.

The illustrated embodiment will be described in detail below. Reference numeral 8 is a bypass passage formed by bypassing the thermostat 6 of the feed pipe 5, with one end connected to the cooling manifold 2c of the engine 2 and the other end connected to the feed pipe 5. It is connected.

9 is an electromagnetic on-off valve provided in the bypass passage 8; 10 is a water temperature sensor that operates the electromagnetic on-off valve 9; this sensor 10 detects the water temperature around the combustion chamber of the cylinder head 2b, and controls the valve opening of the thermostat 6; It turns ON when the temperature is higher than a set temperature (for example, 95°C) which is higher than the temperature (for example, 82°C), and turns OFF when it is lower than that.

Further, 11 is an intake air temperature sensor that operates the electromagnetic on-off valve 9, and this sensor 11 is a set intake air temperature of the engine (
For example, when the temperature is higher than 65° C., it is ON, and when it is lower than that, it is OFF.

The water temperature sensor 10 and intake air temperature sensor 11 are each connected in parallel to a power source 12.

Therefore, even if the thermostat 6 does not reach the valve opening temperature when the engine is cold, if the temperature around the combustion chamber rises,
Since the water temperature sensor 10 operates the ONL and the electromagnetic on-off valve 9, the bypass path 8 is opened.

Then, a portion of the high temperature cooling water is sent to the radiator 1, and while exchanging heat, is supplied from the pump 4 to the cylinder body 2a and cylinder head 2b via the return pipe 3.

Therefore, an overshoot phenomenon of the thermostat 6 does not occur, and an abnormal temperature rise around the combustion chamber can be prevented.

In addition, when the intake air temperature reaches 65° during hot conditions, the intake air temperature sensor 11 is turned on and the electromagnetic on-off valve 9 is activated.

Then, the high-temperature cooling water is supplied to the radiator 1 by both flowing through the bypass passage 8 and passing through the thermostat 6, so that a large amount of cooling water that has been cooled through sufficient heat exchange is passed through the return pipe 3. and is supplied to the cylinder body 2a and cylinder head 2b by the pump 4.

Therefore, an increase in intake air temperature can be prevented and rough idle can be reduced.

In the above embodiment, the bypass path 8 is opened and closed by an electromagnetic on-off valve 9.
As shown in FIG. 2, a diaphragm valve 13 is provided in the bypass passage 8, and the diaphragm chamber 13a of the diaphragm valve 13 is communicated with the inlet manifold 14, and this passage 15 is connected to the water temperature sensor 10 and the intake air temperature sensor 11. It can also be opened and closed by a solenoid valve 16 operated by either one or both of them.

Since the present invention is constructed as described above, the overshoot phenomenon of the thermostat can be completely prevented when the engine is cold, and there is no abnormal temperature rise around the combustion chamber, resulting in cracks in the cylinder head or stickiness of the intake/exhaust valves. Never.

In addition, when the engine is hot, a large amount of high-temperature cooling water is quickly supplied to the radiator via the bypass path, so sufficiently cooled cooling water is sent to the engine, reducing the engine ruffle caused by the rise in intake air temperature. It has the effect of being able to.

[Brief explanation of drawings]

FIG. 1 is an overall view showing one embodiment of the present invention, and FIG. 2 is a schematic view of main parts showing another embodiment. 1: Radiator, 3: Return pipe, 5: Feed pipe, 6: Thermostat, 8: Bypass path, 9: Open/close valve, 10: Water temperature sensor, 11: Intake air temperature sensor 13: Diaphragm valve.

Claims (1)

[Scope of utility model registration request] Bypassing the thermostat provided in the cooling water feed pipe from the engine to the radiator, a bypass path equipped with an on-off valve is formed, and the on-off valve is connected to an intake air temperature sensor that senses the set intake air temperature when the engine is hot. engine 1
An engine cooling device characterized in that it is configured to open and close using a water temperature sensor that detects the water temperature around a combustion chamber when the engine is cold.