JPH0229230Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field] The present invention relates to a device for detecting the temperature of cooling water in a water-cooled engine, and particularly relates to an installation structure for a temperature sensor.

``Prior Art and its Problems'' In a water-cooled engine, a water jacket is provided in the cylinder and the cylinder head, and cooling water is circulated between the water jacket and the radiator to cool the engine. FIG. 2 is a conceptual diagram of this, in which the water jacket 12 of the engine 11 and the radiator 14 are connected via an inlet hose 16, and the radiator 14 and the water pump 18 are similarly connected via an outlet hose 19. Cooling water is pumped into the water jacket 12 by a water pump 18. A thermostat 20 is provided within the outlet 13 provided in the outlet hose 19 to open and close the space between the water jacket 12 and the radiator 14.

As is well known, in this water-cooled engine, the thermostat 20 is closed until the water temperature in the water jacket 12 reaches a certain value or higher, and when it exceeds a certain value, it opens and cools the engine through the circulation path shown by the arrow. Water flows. That is, after the cooling water heated by the engine 11 is cooled by the radiator 14, it is pumped into the water jacket 12 again by the water pump 18.

By the way, in such a water-cooled engine or a vehicle equipped with the same, the cooling water temperature is used for controlling various devices. Examples of devices that use cooling water temperature as an input signal include electronic fuel injection devices, exhaust gas purification devices, and air conditioners. Furthermore, as control becomes more sophisticated, the cooling water temperature signal, which is closely related to the engine condition, tends to be used in a larger number of devices.

In order to provide cooling water temperature signals to such various devices, temperature sensors have conventionally been generally attached to the outlets 13 individually. FIG. 3 shows a specific example of this, in which a fixing seat 21 for the temperature sensor is provided on the wall surface of the outlet 13, and a through female thread 22 for screwing is formed on the fixing seat 21. A bolt 25 is screwed and fixed. The temperature sensor bolt 25 is a metal with good thermal conductivity, such as a copper alloy, and includes a temperature sensor (temperature sensing element, not shown), such as a thermistor or temperature-sensitive ferrite, that changes the electric value or magnetic value depending on the temperature. The tip faces into the outlet 13. The lead wire 26 is then connected to a device that receives the cooling water temperature as an input signal.

However, this conventional mounting structure for the temperature sensor bolt 25 has the following problems. First, the shape of the outlet 13 becomes complicated, making it difficult to manufacture by die-casting or the like.Furthermore, since the through female thread 22 is post-processed on the fixed seat 21, the number of man-hours is large, and the manufacturing cost is high. Especially recently, as mentioned above, the cooling water temperature is used to control many devices, and a temperature sensor bolt 25 is provided for each of these devices, so the number of fixing seats 21 and female through-threads 22 formed in the outlet 13 has increased. , this difficulty is increasing. Further, since the temperature sensor bolt 25 protrudes from the outlet 13, the engine room, which is already narrow due to the large number of devices, is further narrowed down. Second, there is a problem that the temperature sensor bolt 25 is heavy and expensive. That is, the temperature sensor bolt 25
As mentioned above, because of the structure in which the temperature-sensitive element is enclosed in, for example, a copper alloy, the external shape is a solid mass of metal, which makes it heavy, and the manufacturing process is complicated and expensive.

``Purpose of the invention'' The present invention solves the problems of conventional cooling water temperature detection devices, and is capable of detecting cooling water temperature without complicating the shape and without using a temperature sensor bolt. The purpose is to obtain equipment.

``Summary of the invention'' The present invention replaces the temperature sensor, which was conventionally installed in the cooling water channel in the form of a temperature sensor bolt, with a thermostat that opens and closes the water channel between the water jacket and the radiator. It was developed based on this idea, and is characterized by a temperature sensor fixed directly to the thermostat.

``Embodiments of the invention'' The invention will be described below with reference to illustrated embodiments. In FIG. 1, outlet 13 has the same function as outlet 13 in FIG. 2, and a thermostat 20 is supported on this outlet 13. Outlet 13 is Atspa Outlet 3
1 and lower outlet 32, both of which are
Fasten the fastening flanges 31f and 32f with the fastening bolt 3.
3 and are integrated. The atspa outlet 31 has an engine side connection port 34 connected to the water jacket 12 of the engine 11 and a bypass opening 35 connected to the water pump 18.
A radiator connection port 36 is formed in the lower outlet 32 to be connected to the radiator 14. Note that the bypass opening 35 is not shown in FIG.

As is well known, when the cooling water temperature on the water jacket 12 (engine side connection port 34) side is below a certain value, the thermostat 20 connects the engine side connection port 34 to the bypass opening 35 and closes the radiator connection port 36. When the cooling water temperature exceeds a certain value, the engine side connection port 34 is communicated with the radiator connection port 36. Although the present invention does not question the structure of the thermostat 20 itself,
The structure of the illustrated example will be explained.

Atsupa casing 41 and lower casing 42
are both capable of circulating cooling water, and the flange 43 between them is the flange 3 of the outlet 13.
It is sandwiched and held between 1f and 32f. Flange 4
The inner circumferential portion of No. 3 constitutes a valve seat 44 .

A guide needle 45 is fixed to the lower casing 42, and the valve seat 44 is attached to the guide needle 45.
A valve body 48 having an on-off valve 46 and a bypass valve 47 that move toward and away from each other is movably supported. This valve element 48 is connected to the opening/closing valve 4 by a compression spring 49.
6 is urged to move in the direction of contacting the valve seat 44, and at this time, the bypass valve 47 is moved toward the bypass opening 35.
The valve seat 50 is located far away from the valve seat 50.

A cylindrical space coaxial with the guide needle 45 is formed in the valve body 48, and wax 51 is sealed within this space. The wax 51 expands due to the rise in temperature, pushes the valve body 48 up against the compression spring 49, and separates the on-off valve 46 from the valve seat 44. Therefore, the valve body 48 moves up and down depending on the temperature of the cooling water on the water jacket 12 side, and performs the above function.

The present invention is characterized in that a temperature sensor 55 is directly fixed to one or both of the upper casing 41 and the lower casing 42 of the thermostat 20. The position and number of temperature sensors 55 to be fixed can be determined as appropriate. The lead wire 56 of the temperature sensor 55 is connected to the flange 3 of the outlet 13 with suitable sealing means.
It is led to the outside from between 1f and 32f. Temperature sensor 5
Since the thermostat 5 itself is small, it is quite possible to fix it to the upper casing 41 or the lower casing 42 of the thermostat 20 in this way, and the shapes of the thermostat 20 and the outlet 13 basically do not need to be changed. There is no. However, if the number of temperature sensors 55 to be fixed increases and the cross-sectional area of the waterway is affected, the thermostat 20,
Alternatively, the shapes of the upper outlet 31 and lower outlet 32 may be changed as appropriate.

Furthermore, although the above embodiment has been explained by taking as an example the case where the thermostat 20 is fixed to the outlet 13, the present invention can be similarly applied to the case where the thermostat 20 is installed in other parts, for example, in the vicinity of the inlet hose. Applicable.

``Effects of the invention'' As described above, this invention fixes the temperature sensor for detecting the cooling water temperature to the thermostat, making it possible to detect the water temperature without using a heavy and large sensor like the conventional temperature sensor bolt. . In addition, there is no need to form a thick mounting seat and mounting screws, which is required when installing a temperature sensor bolt, so the shape of the inlet or outlet is simplified, reducing costs and eliminating the need for protruding objects from the inlet or outlet. This allows the engine room to be made larger.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of the main parts showing an embodiment of the cooling water temperature detection device for a water-cooled engine of the present invention, Fig. 2 is a conceptual diagram showing the cooling system of a water-cooled engine, and Fig. 3 is a conventional temperature sensor bolt installation. FIG. 3 is a sectional view of main parts showing the structure. 11...Engine, 12...Water jacket, 13...Outlet, 14...Radiator, 18...Water pump, 20...Thermostat, 31...Atspa outlet, 32...
Lower outlet, 34...Engine side connection port,
35...Bypass opening, 36...Radiator connection port, 41...Atsupa casing, 42...Lower casing, 44...Valve seat, 46...Opening/closing valve, 47
...Bypass valve, 49...Compression spring, 55...Temperature sensor.

Claims (1)

[Scope of utility model registration request] In a cooling water temperature detection device for a water-cooled engine in which a temperature sensor is placed in the waterway between the water jacket and the radiator of a water-cooled engine, the temperature sensor is fixed to a thermostat that opens and closes the waterway between the water jacket and the radiator. A cooling water temperature detection device for a water-cooled engine, which is characterized by: