JPH089372Y2 - Engine cooling water control thermostat - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention is directed to an engine provided in a main water channel that circulates a radiator of an engine cooling water channel, a bypass water channel that bypasses the radiator, and a heater water channel that circulates a car heater. The present invention relates to improvement of a cooling water control thermostat.

[Prior Art] A conventional general engine cooling device will be described with reference to FIG. In order to keep the engine body 1 at the proper temperature, when the temperature of the engine body 1 is lower than the proper temperature, the cooling water temperature is detected and the thermostat 10a shuts off the main water passage 2 passing through the radiator 3 and bypasses the radiator 3. The bypass water passage 4 connected in parallel to the main passage 2 is communicated. That is, in this case, the radiator 3
The heat dissipation of the cooling water due to is stopped and the cooling water temperature is raised.
Then, as the engine body 1 warms up, the cooling water temperature rises, and when it reaches a predetermined temperature, the temperature is detected and the thermostat 10a reversely connects the main water passage 2 and cuts off the bypass water passage 4, thereby cooling water. Is circulated in the engine body 1 via the radiator 3.

On the other hand, a heater water channel 6 that joins the bypass water channel 4 upstream of the water pump 5 via the heater cock 7 and the car heater 8 branched from the thermostat portion of the main water channel 2 is provided, and the heater cock 7 is opened to remove the cooling water. The parts are circulated through the car heater 8, and the heat exchanged with the cooling water by the car heater 8 is introduced into the vehicle for heating.

Referring to FIG. 6, the thermostat 10a has openings 12 and 13 formed on the top and side walls of the case 11,
Wax pellets 14 are inserted in 11. The wax pellet 14 includes a pellet main body 15 in which wax is enclosed, and a piston 16 that expands with respect to the pellet main body 15 due to volume expansion accompanying a temperature rise of the wax above a predetermined value.
And a rod 17a fixed to the bottom of the pellet body 15.

An upper valve 18 for opening and closing the main water channel 2 is slidably fitted on the outer peripheral wall of the pellet body 15, and the case 11 and the upper valve 18 are connected to each other.
A spring 19 is interposed between and to urge the upper valve 18 to seat on the valve seat portion 20.

On the other hand, a bottom valve 21 is slidably fitted to the lower end of the rod 17a, and a spring 22 is interposed between the bottom valve 21 and the pellet body 15 to crimp the valve 21 to the flange portion 17b of the rod. . The bottom valve 21 faces the valve seat portion 4a of the bypass water channel 4. With this configuration, the upper valve 18 and the bottom valve 21 selectively connect the main water passage 2 and the bypass water passage 4. And regarding the bottom valve 21,
The relationship between the cooling water temperature T, the lift amount of the upper valve 18 and the bypass water passage area is as shown by characteristics B and A in FIG. 7, and the cooling water passages T1 to T2 and above (for example, 75 to 90) are shown.
The bypass waterway 4 is fully closed at a high temperature (° C), and the radiator 3
The entire cooling water is circulated. The reference symbol A ₀ in the figure is the cross-sectional area of the bypass channel 4 (Fig. 6).

However, in such an engine cooling device, there is a problem that the effect of the car heater becomes poor at low load conditions in cold weather, especially at idling. This is because the cooling water temperature is low, the bottom valve 21 is fully opened, and the resistance of the car heater 7 is large, so that most of the cooling water flows into the bypass water passage 4 and the amount of water to the car heater 8 is small.

Regarding the engine cooling device, Japanese Utility Model Laid-Open No. 55-41570 discloses a device in which a bypass valve is provided with a water pressure sensitive valve whose flow passage area increases and decreases according to the magnitude of the discharge pressure of the water pump. Japanese Utility Model Application Laid-Open No. 62-15470 discloses a device for matching heating efficiency with heating efficiency, but does not directly solve the above-mentioned problems.

[Object of the Invention] Therefore, an object of the present invention is to provide an engine cooling water control thermostat that improves the effectiveness of the car heater at low temperature and low load.

According to the present invention, in the engine cooling water control thermostat provided at the branch portion of the main water passage that circulates the radiator of the engine cooling water passage, the bypass water passage that bypasses the radiator, and the heater water passage that circulates the car heater, A bottle valve that sits on the valve seat of the bypass channel is provided, and the outer periphery of the bottomed cylindrical portion fixed to the wax pellet body is slidably contacted with the boss hole of the bottom valve.
When the cooling water temperature is low, the thermostat side is not communicated with the bypass channel side, but is communicated when the cooling water temperature rises to a certain value, and the cylindrical portion is formed with an opening that is not communicated when the cooling water temperature rises. .

[Advantageous effects of the device] Therefore, the bypass water channel is opened in a predetermined cooling water temperature range, that is, a range other than low temperature and high temperature, and the bypass water channel is closed at low temperature, and the cooling water circulates in the heater water channel even at low load. The flow rate to the car heater can be secured and the effect of the car heater can be improved.

[Embodiment] An embodiment of the present invention will be described below with reference to the drawings.

In these drawings, parts corresponding to those in FIG. 6 are designated by the same reference numerals, and duplicate description will be omitted.

In FIG. 1, the bottom valve 21 is constantly seated on the valve seat portion 4a of the bypass channel 4 by being biased by the spring 22 interposed between the bottom body 21 and the pellet body 15, and is fixed to the lower end of the pellet body 15. The outer circumference of the bottomed cylindrical portion 17 is a bottom valve.
It is in sliding contact with 21 boss holes. The cylindrical portion 17 has four openings 23 as shown in FIG.

The vertical dimension of the opening 23 is the lift start cooling water temperature T1 (for example, 75 ° C.) of both upper valve lift characteristics B shown in FIG.
Start projecting to the bypass waterway 4 side by making the thermostat 10 side communicate with the bypass waterway 4 side, and then increase the amount of projection and the upper edge of the opening 23 is the bottom valve at the cooling water temperature T2 (eg 90 ° C).
It is adapted to be closed at the upper edge of the boss hole 21a of 21.
Therefore, as shown by the characteristic Aa shown in FIG.
Area A1 which is half the area obtained by subtracting four times the area of the opening 23 corresponding to the height of the boss hole 21a of the bottom valve 21 from the total area of
Is the maximum value of the opening channel area, that is, the bypass channel area.

Therefore, at low temperatures T0 to T1, the bypass water passage 4 is closed, the entire amount of circulating water of the cooling water flows to the heater water passage 6, and the flow rate to the car heater 8 is secured even when the load is low. As a result, the effectiveness of the car heater 8 is increased. Is improved. Then, when the cooling water warms and reaches the water temperature T1, the bypass water passage 4 is opened, and the bypass water passage 4 is closed again at the high water temperature T2.

FIG. 3 shows another embodiment of the present invention, the pellet body 15
This is an example in which a gap C is formed between the step portion 15a and the engaging step portion 18a of the pellet body 15 of the upper valve 18, and the others are formed in the same manner as in FIG. In this embodiment, as shown by the Ab characteristic in FIG. 4, the bypass water passage 4 starts to open at the cooling water temperature T1a, closes at the cooling water temperature T2, and the upper valve 18 starts to lift at the cooling water temperature T1. It is possible to start opening the bypass channel 4 at a lower cooling water temperature T1a.

[Summary] As described above, according to the present invention, the bypass water passage is closed at low temperature, and the entire amount of the circulating water of the cooling water is made to flow to the heater water passage to secure the flow rate to the car heater even at a low load. You can improve the effect.

[Brief description of drawings]

FIG. 1 is a side view showing a half section of a first embodiment of the present invention in cross section, FIG. 2 is a sectional view taken along the axis of a cylindrical portion, and FIG. 3 is a first embodiment of the present invention. FIG. 4 is a characteristic diagram of an upper valve lift amount and a bypass channel area for explaining the operation of the present invention, FIG. 5 is an explanatory diagram showing a conventional general engine cooling device, and FIG. 6 is a conventional diagram. 7 is a side sectional view showing the thermostat of FIG. 7, and FIG. 7 is a drawing corresponding to FIG. 2 ... Main waterway, 4 ... Bypass waterway, 4a ... Valve seat, 6 ... Heater waterway, 10 ... Thermostat, 15 ...
Pellet body, 17 …… Cylinder part, 18 …… Upper valve, 21
…… Bottom valve, 23 …… Opening

Claims (1)

[Scope of utility model registration request] 1. A valve seat part of a constant bypass water channel in an engine cooling water control thermostat provided at a branch portion of a main water channel that circulates a radiator of an engine cooling water channel, a bypass water channel that bypasses a radiator, and a heater water channel that circulates a car heater. There is a bottle valve to sit on,
The outer circumference of the bottomed cylindrical part fixed to the wax pellet body is slidably contacted with the boss hole of the bottom valve, and when the cooling water temperature is low, the cooling water temperature rises to a certain value without connecting the thermostat side to the bypass channel side. Then, the engine cooling water control thermostat is characterized in that the cylindrical portion is formed with an opening portion that allows the fluid to communicate with each other and that the fluid does not communicate with each other when the temperature of the cooling water rises.