JPS6126588Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a cooling device that cools an internal combustion engine using cooling water that circulates between a cooling water jacket and a radiator provided in the engine.

Conventionally, this type of cooling device has a thermostat installed at the cooling water outlet of the engine to control the flow of cooling water from the outlet to the upper tank of the radiator according to the temperature, while bypassing the flow between the outlet and the cooling water pump. By connecting through the passage, the cooling water in the cooling water jacket of the engine is circulated through the bypass passage in a low temperature range when the thermostat is closed.
However, the bypass passage in this case must be made quite narrow so as not to reduce the amount of water circulating through the radiator when the temperature is high, and since the amount of water circulated only through the bypass passage is small, The temperature variation of the cooling water is large and it is not possible to cool all parts of the engine almost equally, and if this bypass passage is narrow, when the thermostat opens, a large amount of cold cooling water that has passed through the radiator will flow into the engine's cooling water jacket. After passing through the engine, it reaches the thermostat and the thermostat closes, causing large temperature fluctuations as the engine temperature drops and rises.

Furthermore, in conventional cooling systems, the cooling water is filled into the cooling system from the upper tank of the radiator, while the cooling water is discharged from the drain tank provided in the lower tank of the radiator. If there is no air flowing in or out of the thermostat installed at the outlet of the engine, it will be extremely difficult to get the cooling water in and out of the cooling system.
The thermostat here is provided with an air vent hole or jiggle pin. However, providing an air bleed hole or jiggle pin in the thermostat like this prevents the cooling water in the engine jacket from leaking from the air bleed hole or jiggle pin to the radiator when the thermostat is closed, resulting in a small amount of cooling water. Since the coolant circulates between the radiator and the engine, the temperature of the cooling water will rise slowly when the engine is cold started, and it will take a long time to warm up the engine from the cold start until the specified temperature is reached. It was hot.

In this way, when an engine is cooled by cooling water passing through its cooling water jacket, the present invention provides a thermostat that opens and closes depending on the temperature in the passage from the lower tank of the radiator to the cooling water pump. While the passage area of the bypass passage is reduced when the thermostat is opened, a drain tank is provided in the thermostat case housing the thermostat to drain the cooling water, thereby improving the conventional structure described above. This eliminates the drawbacks of

The drawings of the embodiment will be explained below. In the drawings, 1 is a water-cooled internal combustion engine having a cooling water jacket 2, 3 is a cooling water pump attached to the side of the engine 1 and for feeding cooling water into the jacket 2, 4 is a radiator having an upper tank 5 and a lower tank 6; 7 is a thermostat case disposed at the same height as or lower than the lower tank 6 of the radiator 4; A cooling fan 9 is provided which is driven by the cooling fan 9.

The cooling water outlet 10 in the engine 1 is connected to the upper tank 5 of the radiator 4 via a passage 11.
First, the lower tanks 6 of the radiator 4 are connected to the sockets 14 in the lower chamber 13 of the thermostat case 7 through the passages 12, and the sockets 16 in the upper chamber 15 of the thermostat case 7 are connected to the inlet of the cooling water pump 3. A bypass passage 1 is connected via a passage 17, and is branched from a passage 11 leading from the outlet 10 to the atspa tank 5.
8 is connected to the socket 19 in the upper chamber 15 of the thermostat case 7.

A thermostat 20 is provided within the thermostat case 7. As shown in FIG. 2, this thermostat 20 includes a valve body 23 that is pressed by a spring 22 against a valve seat 21 that defines upper and lower chambers 15 and 13, and a thermal expansion material such as wax inside. The valve body 23 is equipped with a temperature-sensing section 24 in which the temperature-sensing section 24 is enclosed.
By touching the lower end of the pin 25 that slidably projects downward from the temperature sensing portion 24 to the bracket 26 attached to the lower surface of the valve seat 21, the wax inside the temperature sensing portion 24 is removed. When the volume expands due to temperature rise, the protruding movement of the pin 25 causes the temperature sensing part 2 to
4 and the valve body 23 rise against the spring 22 to open the passage from the lower chamber 13 to the upper chamber 15, and at the same time, the temperature sensing part 24 is inserted into the connection socket 19 of the bypass passage 18 as shown by the two-dot chain line. The structure is such that the passage area is reduced.

Further, the thermostat case 7 is provided with a drain outlet socket 30 that communicates with the lower chamber 13 thereof, and a through hole 3 that communicates with the upper chamber 15 of the thermostat case 7 is provided in the drain outlet socket 30.
1, while opening the drain socket 30.
Furthermore, a drain passage 33 connected to the lowest part of the cooling water jacket 2 in the engine 1 is connected to the provided socket 32, and a drain passage 33 is connected to the drain outlet socket 3.
A drain socket 34 is removably screwed onto the drain socket 34 so as to simultaneously close the through hole 31 and the jacket 32. When the drain socket 34 is loosened as shown in FIG. 5, the lower chamber 13, the through hole 31 and the socket 3
2 is provided with a through hole 35 which allows both to be exposed to the atmosphere at the same time.

The electric circuit 28 connecting the electric motor 8 of the cooling fan 9 and the battery 27 is provided with a thermoswitch 29 that is turned on when the temperature becomes high. The thermostat 20 is provided in the passage from the lower tank 6 of the radiator 4 to the thermostat 20, such as inserted into the lower chamber 13 of the radiator 4. Further, reference numeral 36 in the figure indicates a car heater. Cooling water from the upper part of the cooling water jacket 2 of the engine is introduced into the car heater 36 through a passage 37, and cooling water flowing out from the car heater 36 is introduced into the car heater 36 through a passage 38 and the jacket. 39 into the upper chamber 15 of the thermostat case 7.

In this configuration, when the engine is cold-started and the temperature is low, the valve body 23 of the thermostat 20 in the thermostat case 7 is pressed against the valve seat 21 by the force of the spring 22, and the upper and lower chambers 15, 13 are closed.
Since the passage is closed, the cooling water in the cooling water jacket 2 in the engine does not go to the radiator 4 but is circulated only through the bypass passage 18. When the temperature of the cooling water becomes high, the valve body 23 is opened by the action of the temperature sensing part 24 in the thermostat 20, so that the cooling water is introduced into the jacket 2 cooled by the radiator 4, while the temperature sensing part 24 is connected to the bypass passage 18. Since the cooling water enters into the connection jacket 19 and reduces its passage area, the amount of circulating water passing through the bypass passage 18 is reduced, and most of the cooling water circulates between the cooling water jacket 2 and the radiator 4. When the natural ventilation of the radiator 4 is insufficient to cool the radiator 4 in the summer, and the temperature of the cooling water from the radiator 4 becomes high, the thermoswitch 29 inserted into the lower chamber 13 of the thermostat case 7 is turned on.
As a result, the electric cooling fan 9 starts operating to forcefully ventilate the radiator 4.

In this way, the present invention provides a thermostat in the passage leading from the lower tank of the radiator to the cooling water pump, and at the same time as the thermostat opens,
By configuring the bypass passage to reduce the passage area, the passage area of the bypass passage can be increased without reducing the amount of circulating water during circulation through the radiator, and when circulating only through the bypass passage, the passage area can be increased. Since the amount of water in the engine can be significantly increased, temperature unevenness in the cooling water can be eliminated, and the temperature distribution in each part of the engine can be maintained evenly.
Moreover, if the cold cooling water that passes through the radiator enters the engine due to the thermostat opening, the cold cooling water from the radiator will come into contact with the temperature-sensing part of the thermostat, and the thermostat will
The temperature of the cooling water from the bypass passage and the temperature of the cold cooling water from the radiator are maintained at an average temperature, thereby preventing a large amount of cold cooling water from flowing into the engine at once. Therefore, the temperature fluctuation of the cooling water when the thermostat is opened is much smaller than when the thermostat is installed at the outlet, as in the past, and engine temperature fluctuation can be reduced.

Further, when the drain socket 30 of the thermostat 7 is closed by the drain socket 34, the lower chamber 13, the upper chamber 15, and the cooling water jacket 2 are connected to each other via the through hole 31 and the drain passage 33. While there is no flow of cooling water in or out, by providing the thermostat case 7 containing the thermostat 20 in the passage from the lower tank 6 of the radiator 4 to the cooling water pump 3, this thermostat case 7 is connected to the cooling water system. Because it can be installed at the lowest point in the
By loosening the drain socket 34 of the drain socket 30 in the thermostat case 7 as shown in FIG. 5 and opening the filler cap 36 provided on the upper tank 5 or outlet 10 of the radiator 4, Since the upper part of the cooling water jacket 2 is opened to the atmosphere through 36 filler caps, the radiator 4, the bypass passage 18, and the cooling water in the cooling water jacket 2 are all discharged from the drain socket 30. With the drain pot 34 closed,
When cooling water is injected from the filler cap, the radiator 4, bypass passage 18, and cooling water jacket 2 are filled with cooling water while the air inside them is released to the atmosphere from the filler cap located at the highest position. This makes it easy to supply and drain cooling water to the entire cooling water system, and in this case, there is no need to provide air vent holes or jiggle pins for the thermostat in the thermostat case, as is the case in the past.
The structure of the thermostat is simplified, there is no leakage of cooling water when the thermostat is closed, and the circulation of cooling water between the engine's cooling water jacket and the radiator is almost completely eliminated when the engine is cold started. This allows the temperature of the cooling water to rise quickly, reducing the engine warm-up time.

[Brief explanation of the drawing]

Fig. 1 is a diagram showing an embodiment of the present invention, Fig. 2 is an enlarged vertical cross-sectional view of the thermostat case in Fig. 1, Fig. 3 is a cross-sectional view taken from the side in Fig. 2, and Fig.
The figure is a cross-sectional view taken from the side shown in FIG. 2, and FIG. 5 is a diagram showing a state in which the drain is removed. 1...Internal combustion engine, 2...Cooling water jacket, 1
0... Outlet, 4... Radiator, 5...
Upper tank, 6... Lower tank, 3... Cooling water pump, 7... Thermostat case, 13
... Lower chamber, 15 ... Upper chamber, 18 ... Bypass passage, 20 ... Thermostat, 24 ... Temperature sensing section, 21 ... Valve seat, 23 ... Valve body, 30 ... Drain removal socket, 34 ... Drain Kotsuku.

Claims (1)

[Scope of utility model registration request] A cooling water outlet in a water-cooled internal combustion engine is connected to an upper tank of a radiator, and a lower tank of the radiator is connected to a lower chamber of a thermostat case disposed between the lower tank and a cooling water pump, while the outlet is connected to the upper tank. The bypass passage branched from the passage is connected to the upper chamber of the thermostat case, the upper chamber of the thermostat case is connected to the intake port of the cooling water pump, and the thermostat is connected to the drain socket provided in the lower chamber of the thermostat case. A cooling device for an internal combustion engine, which communicates the upper chamber of a case with the bottom of a cooling water jacket of the engine, and has a drain socket provided in the drain socket that can be opened and closed.