JPS59200011A - Engine cooling device - Google Patents

Abstract

PURPOSE:To improve responsiveness of a temperature sensing body by introducing a flow of cooling water from a bypass circuit to the outer periphery of the temperature sensing body of a thermostat while a bottom bypass valve is opened on the thermostat of the captioned device. CONSTITUTION:A water-cooled jacket 3 of an engine main body E, rasiator 8 and a thermostat 12 are connected with each other in order through connection pipes 7, 11, 16 and the cooling water is circulated by means of a water pump 5. On the other hand, the water-cooled jacket 3, making the detour of the radiator 8, is connected with the thermostat 12 by a bypass 24. When the temperature of the cooling water is low, since a valve body 26 of a thermostat valve 25 intercepts communication between the connection pipes 11 and 16 and further a bottom bypass valve 26, in linkage with the thermostat valve 25, opens a guide passage 39, circulation of the cooling water is performed through the bypass 24, guide passage 39, the outer periphery of a temperature sensing body 27 for the thermostat valve 25 and the connection pipe 16.

Description

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

Conventionally, this type of device has been equipped with a cooling water circulation circuit that sequentially connects the water cooling jacket, radiator, and thermostat of the engine body; and a bypass circuit that bypasses the radiator and connects the water cooling jacket and thermostat. A main thermostatic valve that opens and closes, a bottom bypass valve that closes and opens in conjunction with the opening and closing operations of that valve to open and close a bypass circuit, and a temperature sensing element that opens and closes both valves depending on the water temperature. It is known what it has.

In conventional thermostats, the cooling water from the bypass circuit simply bypasses the valve body of the bottom bypass valve and flows toward the temperature sensing element, so the cooling water flow does not reliably reach the outer periphery of the humidity sensing element, and the water temperature There is a problem in that the responsiveness of the thermosensor to changes is poor.

In view of the above, the present invention provides the engine cooling device described above, which solves the conventional problems by providing a guide passage in the thermostat and guiding the cooling water flow from the bypass circuit to the outer periphery of the moisture sensitive body through the guide passage. The purpose is to

Hereinafter, one embodiment of the present invention will be described with reference to the drawings. E indicates a four-cylinder engine, the engine body 1 has a water-cooling jacket 3 surrounding each cylinder 2, and the water-cooling jacket 3 has a A water pump 5 having a discharge port communicating therewith is disposed. First outlet 6 of water cooling jacket 3
．． is connected to an inlet 9 of a radiator 8 disposed in front of the engine body 1 via a connecting pipe 7, and an outlet 10 of the radiator 8 is connected to a thermostat 12 via a connecting pipe 11.
The outlet 15 of the casing 13 is connected to the suction port of the water pump 5 via the connecting pipe 16. Thus, the water cooling jacket 3, the radiator 8, the thermostat 12, The water pump 5 and the three connecting pipes 8°11.16 constitute a cooling water circulation circuit 11.

The second outlet 62 of the water cooling jacket 3 is connected to the inlet 21 of the riser section 20 in the intake manifold 19 via the connecting pipe 18.
The outlet 22 of the riser part 2o is connected to the connecting pipe 23.
is connected to the second population 142 of the casing 13 in the thermostat 12 via. Thus, the second outlet 62 of the water cooling jacket 3, the riser fitting O, and the second outlet 142 of the thermostat 12 constitute a bypass circuit 24 that bypasses the radiator 8.

The thermostat 12 is a conventionally known one, and a main thermostat valve 25, a bottom bypass valve 26, and a temperature sensing element 27 that opens and closes them depending on the water temperature are housed in a casing 13 of the thermostat 12. The main thermostatic valve 25 is the first valve 14. The bottom bypass valve 26 includes a valve seat 28 provided between the valve seat 28 and the outlet 15, and a valve body 29 that approaches and separates from the valve seat 28. The valve body 30 is inserted into and removed from the valve body 30 to open and close the second valve body 142.

The temperature sensor 27 has a wax case 31 filled with wax, and the wax case 31 is slidably supported on the needle 32. The valve body 29 of the main thermostat valve 25 is fixed to the outer peripheral surface of one end of the wax case 31, and the valve body 30 of the bottom bypass valve 26 is fixed to the outer peripheral surface of the wax case 31.
1 through a shaft portion 33. A wax case 31 is surrounded by the valve seat 28, and a plurality of through holes 34 are formed in the peripheral wall.
A retainer 35 having a
A spring 36 is compressed between the main thermostatic valve 25 and the valve body 29 of the main thermostatic valve 25, and is biased in the direction of closing the valve body 29 and in the direction of opening the valve body 30 of the bottom bypass valve 26.

Therefore, when the temperature of the hot water is low after starting the engine, the wax contracts and the main thermostat valve 25 closes and the bottom bypass valve 26 opens, and when the temperature of the hot water increases, the wax expands and the main thermostat valve 25 opens and the bottom bypass valve 26 opens. Valve 26 is closed.

A guide passage 39 is formed in the peripheral wall of the casing 13, with an inlet 37 opening to the second population 142 and an outlet 38 opening near the outer periphery of the retainer 35 within the casing 13. The valve 26 is opened and closed together with the second population 142 . Therefore, when the bottom bypass valve 26 is open, the cooling water flow that has passed through the bypass circuit 24 can be guided to the outer periphery of the temperature sensing element 27, that is, the wax case 31, through the guide passage 39.

Next, to explain the operation of this embodiment, when the temperature of the water after starting the engine E is low, the thermostat 12
Since the wax in the wax case 31 at is contracted, the main thermostatic valve 25 closes and the bottom bypass valve 26 opens. Therefore, the cooling water circulation circuit 17
is closed and no cooling water flows to radiator 8, so
The engine body 1 is not cooled and warm-up operation is promoted. On the other hand, the bypass circuit 24 is opened and hot water is supplied to the riser section 20 of the intake manifold 19, so that atomization of the fuel is promoted. The cooling water flow from the B/F bus circuit 24, that is, the hot water flow, is guided to the outer periphery of the wax case 31 through the guide passage 39, but when the temperature of the hot water is low, both valves 25 and 26 are opened and closed. do not have.

When the temperature of the hot water increases and the wax in the wax case 31 expands, the main thermostat valve 25 opens and the bottom bypass valve 26 closes. Therefore, the coolant circulation circuit 17 is opened, and hot water at a high temperature is supplied to the radiator 8 to radiate heat, so that the engine body 1 is controlled to an appropriate temperature. On the other hand, the bypass circuit 24 is closed and the flow rate of hot water to the intake manifold 19 is reduced, so that the air-fuel mixture is maintained at an appropriate temperature and a decrease in filling efficiency is prevented.

As described above, according to the present invention, since the thermostat is provided with a guide passage for guiding the cooling water flow from the bypass circuit to the outer periphery of the temperature sensor when the bottom bypass valve is opened, the response of the temperature sensor to changes in water temperature is improved. The main thermostat valve and bottom bypass valve can be opened and closed properly.

[Brief explanation of the drawing]

The drawing is a schematic plan view showing one embodiment of the present invention. 1...Engine body, 3...Water cooling jacket, 8.
...Radiator, 12...Thermostat l-117.
・・Cooling water circulation circuit, 24・・Bypass circuit, 25・
Main thermostatic valve, 26...Bottom bypass valve, 2
7... Temperature sensitive body, 39... Guidance path patent applicant Honda Motor Co., Ltd.

Claims (1)

[Claims] a cooling water circulation circuit that sequentially connects the water cooling jacket, radiator, and thermostat of the engine body; and a bypass circuit that bypasses the radiator and connects the water cooling jacket and the thermostat; the thermostat opens and closes the cooling water circulation circuit. a main thermostatic valve, a bottom bypass valve that opens and closes in conjunction with the opening and closing operations of the valve to open and close the bypass circuit, and a temperature sensing element that opens and closes both valves depending on the water temperature. 1. An engine cooling device comprising: a guide passage provided in the thermostat to guide a flow of cooling water from the bypass circuit to the outer periphery of the temperature sensitive body when the bottom bypass valve is opened.