JP3582551B2 - Water temperature control device for water-cooled engine - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a water temperature control device for a water-cooled engine applied to a vehicle such as an automobile.
[0002]
[Prior art]
In a vehicle such as an automobile equipped with a water-cooled engine, the temperature of cooling water after warm-up is kept constant in order to keep the engine in good condition. As a structure for this, a cooling system is formed by connecting the cylinder head and the radiator with a water hose, and when the temperature of the cooling water exceeds a certain value, the cooling system is circulated and cooled by the radiator. Is maintained at a predetermined temperature.
[0003]
When the temperature of the cooling water does not reach a certain value, such as immediately after starting the engine, the circulation to the radiator is stopped, and the cooling water flowing out of the cooling water passage of the engine is immediately cooled by a separate bypass passage. Return to the water passage. After warming up, the flow rate to the radiator side is controlled by the temperature of the cooling water. Such circulation, stop, and flow control are performed by a thermostat provided at the outlet of the cooling water passage of the cylinder head.
[0004]
The thermostat is installed in a thermostat case provided on the side of the cylinder head, detects the temperature of the cooling water flowing through the water hose connected to the thermostat cap, and opens when the temperature reaches a predetermined value. Then, the cooling water is caused to flow to the radiator side, and the opening is increased in accordance with the temperature rise. For this reason, the thermostat must be completely immersed in the cooling water, and it is necessary to facilitate maintenance and inspection.Therefore, the thermostat case is attached to the side of the cylinder head and arranged inside. The cooling water flowing through the water hose connected to the thermostat cap mounted on the thermostat case is controlled (see Japanese Patent Application Laid-Open No. 61-168816 as a related art).
[0005]
By the way, the current car is driven with higher output, superior fuel efficiency, and reduced emission of harmful components in exhaust gas, taking into account the conditions of road surface, load, driver's operation (intention), etc. I'm trying to get For this reason, it is necessary to detect the state of the engine in more detail, and one of them is to detect the temperature of the cooling water. The water temperature sensor for detecting the temperature of the cooling water contains a thermistor in a housing having an external thread engraved on the outer periphery, and the tip of the housing is immersed in the cooling water.
[0006]
FIG. 3 is a cross-sectional view showing a conventional structure of a mounting portion of a thermostat and a water temperature sensor, and FIG. 4 is a view showing a portion in an engine. In FIG. 4, reference numeral 1 denotes an automobile engine, which comprises a cylinder head cover 2, a cylinder head 3, a cylinder block 4, and an oil pan 5. A thermostat case 7 is attached to the side of the cylinder head 3 below the distributor 6, and a thermostat cap 8 is attached to an opening (not shown).
[0007]
As shown in FIG. 3, a flange 8 a of a cylindrical thermostat cap 8 is opposed to a flange 7 a of an opening of the thermostat case 7 via a gasket 9, and female screws engraved at corresponding positions. Bolts 10 are screwed into 7b and 8b to fasten them together.
[0008]
The base end of the water hose 11 is fitted to the thermostat cap 8. A tip (not shown) of the water hose 11 is connected to a cooling water inlet of the radiator.
[0009]
The flange portion 12a of the thermostat 12 is held at the joint between the thermostat case 7 and the thermostat cap 8. The thermostat 12 circulates, stops, and controls the flow of cooling water (see arrows) from the thermostat case 7 side to the thermostat cap 8 side due to the expansion and contraction of the wax inside the thermostat 12 depending on the temperature captured by the wax storage portion 12b. It has a conventionally known structure.
[0010]
The thermostat case 7 has a protruding portion 7c formed in a direction intersecting with the flow direction of the cooling water indicated by an arrow, and is formed on a part of the outer periphery of the water temperature sensor 13 on a female screw 7d formed on an inner wall thereof. The male screw 13a is screwed. Thereby, the water temperature sensor 13 is attached to the protruding portion 7c. The water temperature sensor 13 contains a thermistor therein, and outputs a resistance value corresponding to the temperature of the cooling water in the thermostat case 7. The output signal is guided to a control circuit (not shown).
[0011]
When the water temperature sensor 13 is mounted in such an orientation, it becomes necessary to perform electronic control on a cooling device in which the water temperature sensor 13 has not been provided before, and when the water temperature sensor 13 is mounted, the wax of the thermostat 12 is used. There is a space in the vicinity of the accommodating portion 12b, and the tip of the water temperature sensor 13 can be exposed to the cooling water without largely changing the structure of the thermostat case 7.
[0012]
[Problems to be solved by the invention]
In the above structure, there is no relation to the operation of the thermostat 12 and the temperature detection of the water temperature sensor 13. However, since the water temperature sensor 13 and the thermostat 12 intersect in the structure, the flange 7a is required to mount the water temperature sensor 13. It is necessary to form a protruding portion 7c in a direction intersecting with the cylinder head. As a result, the thermostat case 7 is provided with a water temperature sensor 13 in addition to a joint surface to the cylinder head 3 and a joint surface to the thermostat cap 8 to improve liquid tightness. The three joint surfaces for holding and mounting must be precisely machined. Further, since the female screw 7d needs to be engraved not only on the flange 7a but also on the protruding portion 7c, the processing becomes complicated.
[0013]
The present invention has been made in view of this point, and despite the installation of the thermostat, eliminates a special processing location for the thermostat, simplifies the structure of the thermostat case as a whole, and also reduces the processing location of the female screw. Another object of the present invention is to provide a water temperature control device for a water-cooled engine, which can further improve assembling workability and maintainability.
[0014]
[Means for Solving the Problems]
The present invention, as a means for solving the above-mentioned problems, has a configuration in which one end of a thermostat cap is disposed on a side of a cylinder head, and the thermostat cap is provided on one side of the cylinder head. A thermostat opening and a water temperature sensor opening opposed to the opening are provided, and a thermostat is mounted on the thermostat opening and a water temperature sensor is mounted on the water temperature sensor opening, and the thermostat and the water temperature sensor are mounted side by side in the same direction, The other end of the thermostat cap is provided with a hose opening to which a water hose is connected, and the water temperature sensor is disposed above the hose opening .
[0015]
According to a second aspect of the present invention, in the first aspect of the present invention , a male screw is engraved on an outer periphery of the water temperature sensor and attached to a water temperature sensor opening of the thermostat cap and a side portion of the cylinder head. A female screw is cut into the opening of the thermostat case, the male screw and the female screw are screwed together, the thermostat cap is fastened to the thermostat case, and the thermostat cap is attached to the thermostat case by the water temperature sensor. And
[0016]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an embodiment of the present invention will be described. FIG. 1 is a sectional view showing a structure of a mounting portion of a thermostat and a water temperature sensor according to the present invention, and FIG. 2 is a view showing a portion of the structure in an engine. In FIG. 2, reference numeral 1 denotes an automobile engine, which includes a cylinder head cover 2, a cylinder head 3, a cylinder block 4, and an oil pan 5. A thermostat case 7 is attached to the side of the cylinder head 3 below the distributor 6, and a thermostat cap 8 is attached to an opening (not shown).
[0017]
As shown in FIG. 2, an opening (a part of the flange 7a) of the thermostat case 7 is larger than that of FIG. 3, and a flange 8a of a thermostat cap 8 which is dimensioned therewith is provided with a gasket 9 as shown in FIG. Are opposed to each other. Here, the flange 8 a of the thermostat cap 8 is provided with a thermostat opening for mounting the thermostat 12 and a water temperature sensor opening for mounting the water temperature sensor 13. Then, one bolt 10 and the male screw 13a of the water temperature sensor 13 are screwed to the female screws 7b and 8b, respectively, and the two are fastened. Thereby, the water temperature sensor 13 is attached to the thermostat cap 8.
[0018]
The thermostat cap 8 is provided with a hose opening, and the base end of the water hose 11 is fitted into the hose opening . A not-shown tip of the water hose 11 is connected to a cooling water inlet of the radiator.
[0019]
The flange portion 12a of the thermostat 12 is held at the joint between the thermostat case 7 and the thermostat cap 8. As a result, the thermostat 12 is supported by the thermostat cap 8 side by side in the same direction as the water temperature sensor 13. The thermostat 12 circulates, stops, and controls the flow of cooling water (see arrows) from the thermostat case 7 side to the thermostat cap 8 side due to expansion and contraction of the wax inside the thermostat 12 depending on the temperature captured by the wax storage portion 12b. .
[0020]
Also in the water temperature control device of the water-cooled engine configured as described above, the temperature of the cooling water is captured by the wax storage portion 12b of the thermostat 12, so that the cooling water is circulated, stopped, and the flow rate is controlled as described above. There is nothing different from things. The same applies to the point that the water temperature sensor 13 detects the temperature of the cooling water in the thermostat case 7 and guides the output signal to a control circuit (not shown). However, since the water temperature sensor 13 is provided side by side in the same direction as the thermostat 12, the number of finishing surfaces of the thermostat case 7 is reduced by one, and the structure of a casting mold for molding the thermostat case 7 can be simplified. For the same reason, the assembling workability and the maintainability are improved.
[0021]
【The invention's effect】
As described above, since the present invention is a water temperature control device in which a thermostat and a water temperature sensor are arranged in the same direction and attached to a thermostat cap, the shape of a thermostat case is simplified, a mold is simplified, and processing man-hours are reduced. Can also be reduced. Further, since the thermostat and the water temperature sensor are arranged in the same direction , the assembling workability and the maintainability are improved. Also, since one of the bolts for attaching the thermostat cap to the thermostat case can also serve as the water temperature sensor, the number of parts can be reduced and the number of assembling steps can be reduced.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view taken along line AA of FIG. 2, showing one embodiment of the present invention.
FIG. 2 is an explanatory view schematically showing an engine to which the present invention is applied.
FIG. 3 is a cross-sectional view taken along the line BB of FIG. 4 showing a conventional structure.
FIG. 4 is an explanatory view schematically showing an engine to which a conventional water temperature control device is applied.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Engine 3 Cylinder head 7 Thermostat case 8 Thermostat cap 12 Thermostat 13 Water temperature sensor 13a Male screw

Claims (2)

One end of a thermostat cap is arranged on the side of the cylinder head, and a thermostat opening and a water temperature sensor opening facing the opening of the side of the cylinder head are provided in the thermostat cap, and a thermostat is provided in the thermostat opening. Attach and attach a water temperature sensor to the water temperature sensor opening, attach the thermostat and the water temperature sensor side by side in the same direction, provide a hose opening to which a water hose is connected to the other end of the thermostat cap, and from the hose opening A control device for a water-cooled engine , wherein the water temperature sensor is disposed above . An external thread is engraved on the outer periphery of the water temperature sensor, and an internal thread is engraved on the water temperature sensor opening of the thermostat cap and the opening of the thermostat case attached to the side of the cylinder head. The water temperature control device for a water-cooled engine according to claim 1, wherein the thermostat cap is fastened to the thermostat case in combination with the thermostat case, and the thermostat cap is attached to the thermostat case by the water temperature sensor .

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