JPS5827466Y2 - heat sensitive switch plug - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a heat-sensitive switch plug that opens and closes contacts in accordance with changes in temperature to be measured.

Automobile engines are equipped with exhaust purification devices such as catalytic converters and thermal reactors, and these exhaust purification devices use heat-sensitive overheat sensors to alert the driver when overheating occurs in order to prevent catalyst burnout and vehicle fires. An overheat warning device using a switch plug is installed.

However, since this overheat warning device operates only when an overheating condition actually occurs, it is difficult for the driver to recognize whether the heat-sensitive switch plug and the overheat warning device are functioning normally.

Therefore, if the driver drives the vehicle without knowing that the overheating warning device is malfunctioning, there is a danger that the exhaust purification device may burn out or the vehicle may catch fire.

The object of the present invention is to provide a heat-sensitive switch plug that allows a driver to easily check whether the heat-sensitive switch plug and the overheat warning device are malfunctioning when used in an overheat warning device of an automobile exhaust gas purification device.

In this invention, a cylindrical switch housing is provided on the open end side of a bottomed cylinder made of heat-resistant metal with an open upper end, and a core rod made of a heat-resistant insulating material whose coefficient of thermal expansion is smaller than that of the cylinder is inserted into the cylinder. death,
A contact terminal is provided at the upper end of the core rod, and a compression spring is interposed between the switch plug terminal and the contact terminal, which is attached to the upper part of the switch housing insulated from the housing. A switch that opens at ambient temperature, closes at a predetermined high temperature, and connects the switch plug terminal and one contact surface provided on the inner periphery of the cylindrical body or the housing to conduction between the switch plug terminal and the cylindrical body. In a heat-sensitive switch stopper, a second contact terminal that closes at ambient temperature and opens at a predetermined temperature sufficiently lower than the switch closing temperature is formed between the upward surface or side surface of the contact terminal and a corresponding surface provided on the inner periphery of the cylindrical body or housing. The main point is to configure a switch.

Next, the present invention will be explained based on an embodiment shown in the drawings.

A shows a heat-sensitive switch stopper showing one embodiment of the present invention; 1
2 is a stainless steel cylinder whose lower end is closed by the bottom plate 11 and whose upper end is open; 2 is a hollow core rod made of heat-resistant and insulating ceramic; one end 21 is closed by the bottom plate 11;
The cylinder is inserted in a state in contact with the cylinder, and is supported by a ceramic bearing 12 inserted into the bottom of the outer cylinder and a bearing 13 made of stainless steel or nickel alloy, for example, fitted to the open end of the cylinder, and slides in the axial direction. It is said to be free.

Reference numeral 3 designates a switch housing made of a metal cylinder that is fitted onto the open side of the cylinder 1 and is secured thereto, and 4 is an electric wire that is inserted into one end of the housing 3 and is secured to the switch housing.

5 is a top-shaped contact terminal in which one shaft 51 is fitted into the upper end, which is the free end of the core rod 2, and is fixed to the core rod; 6 is an annular metal plate welded to the open end surface of the cylinder; 7 is a switch plug terminal connected to the core wire 41 at the end of the electric wire 4 and fixed to the upper part of the housing insulated from the housing; 8 is attached between the switch plug terminal 7 and the contact terminal 5 to electrically connect both. This is a spring that connects and urges the contact terminal 5 and the core rod 2 toward the bottom of the cylinder.

The upper surface 14 of the bearing 13 and the brim-shaped lower flesh surface 52 of the contact terminal 5
Contact materials a and b made of gold palladium, silver palladium, etc. are welded to the contact terminals 5 to form a switch S that closes at high temperatures (for example, 900° C. or higher), and the contact terminals 5 are attached to the annular metal plate 5 somewhat upwardly at room temperature. A second switch is in a pressed state, and the upper wall surface 53 of the brim and the downward surface of the annular metal plate 6 are closed at atmospheric temperature, and are opened at a set temperature (for example, 100° C.) or higher. is formed.

This heat-sensitive switch plug A is installed with the closed side of the cylindrical body inserted into the exhaust purification device, and is connected in series with the battery V, ignition switch ■, and indicator lamp L attached to the driver's seat, as illustrated in Fig. 3. Connected and used.

At normal temperature, the second switch S2 is closed, and when the driver turns on the ignition switch I, the lamp L turns on.
lights up.

Next, the engine starts and the exhaust purification device begins to rise in temperature, and 1
When the temperature reaches 00° C., the second switch S2 is opened and the lamp L is turned off.

By turning on and turning off the light, the driver can
It is possible to detect the quality of the lamp L, circuit connections, etc.

If the exhaust gas purification device reaches a high temperature, the switch S closes and the lamp L lights up to alert the driver.

In the heat-sensitive switch faucet of the present invention, the second switch must be closed at ambient temperature, but the temperature may vary from -40°C to 60°C depending on the region, climate, solar radiation, etc.
Since the temperature changes by about 100°C, the second switch A, which is closed at low temperatures, opens at high temperatures, and at low temperatures, large pressure is applied to the Okiko rod, which can easily cause failures such as breakage.

For this reason, as in the embodiment shown in FIG. 1, the contact terminal 5 presses the elastic annular metal plate 6 to give elastic deformation, keep the second switch closed in the above temperature range, and apply pressure to the core rod. Either reduce the pressure or, as shown in FIG. 2, form a small inner diameter portion 9 with a metal ring 60 having a U-shaped cross section formed by bending a thin metal plate on the opening of the cylinder or the inner surface of the housing. A second switch is formed that slides between the inner peripheral surface 61 of the metal ring and the outer peripheral surface 54 of the collar so that the inner diameter part 9 fits closely with the contact terminal collar, and the switch is closed in the above temperature range. It is necessary to maintain the condition and prevent risks such as breakage.

As described above, the heat-sensitive switch plug of the present invention has a second switch that closes at ambient temperature and opens at a predetermined temperature.
When used as an overheat sensor in an overheat warning device of an exhaust purification device, the heat-sensitive switch plug and the overheat warning device can be easily checked, thereby reliably preventing dangers such as burnout of the exhaust purification catalyst and vehicle fire.

[Brief explanation of drawings]

Fig. 1 is a cross-sectional view showing one embodiment of the present invention, and Fig. 2 is a cross-sectional view showing an embodiment of the present invention.
FIG. 3 is a sectional view of the main parts of the embodiment, and is a circuit diagram of the alarm device. In the diagram: 1... cylinder body, 2... core rod, 3
...Switch housing, 5...Contact terminal, 8...Spring, S...Switch,
S2...Second switch.

Claims (1)

[Claims for Utility Model Registration] A cylindrical switch housing is provided on the open end side of a bottomed cylinder made of heat-resistant metal with an open upper end, and the inside of the cylinder is made of a heat-resistant insulating material having a smaller coefficient of thermal expansion than that of the cylinder. A lower rod is inserted, a contact terminal is provided at the upper end of the middle rod, and a compression spring is interposed between the switch plug terminal and the contact terminal, which is attached to the upper part of the switch housing insulated from the housing. between the inner surface of the bottom of the cylinder and one contact surface provided on the inner periphery of the cylinder or housing facing the iron surface, which opens at ambient temperature and closes at a predetermined high temperature, between the switch stopper terminal and the cylinder. In a heat-sensitive switch plug configured as a switch that conducts between A heat-sensitive switch plug comprising a second switch that opens at a low predetermined temperature. 2. Utility model registration claim 1, wherein the contact in the switch housing that faces the upper surface or side surface of the contact terminal and constitutes the second switch is in the shape of a resilient metal plate.
Heat-sensitive switch plug as described in section.