JPH0256769B2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a temperature switch.

Conventionally, this type of temperature switch has a fixed contact 16' fixed to an external terminal 6', and a free end of a movable spring 23' fixed at one end to a movable spring fixing base 9', as shown in FIG. 4, for example. A movable contact 26' fixed to the movable spring 23' is provided so as to be contactable, and an inversion bimetal 18' disposed below the movable spring 23' comes into contact with the protrusion 11' on the movable spring fixing base 9' when inverted. It is set up like this. Therefore, when the ambient temperature reaches the set temperature, the inverted bimetal 18' is warped in the opposite direction, and its center portion comes into contact with the protrusion 11', and the movable spring 23' is pushed up, so that the bimetal 18' is bent away from the fixed contact 16'. The movable contact 26' will be opened.

However, since the above-described configuration uses only a single inverted bimetal 18', damage to the inverted bimetal 18' and fixed contact 16' and movable contact 2 can occur.
There was a fear that the temperature switch would become inoperable due to contact welding with 6'.

The present invention aims to eliminate the above-mentioned drawbacks and to provide a temperature switch which can significantly improve safety.

The temperature switch of the present invention will be explained below with reference to the drawings.

In FIGS. 1 to 3, a box-shaped housing 1 is open at one end, and the switch body 3 is accommodated in the grooves 2 formed on the inner surfaces of both side walls of the housing 1, with both side edges fitted into grooves 2 . Ru. The base 4 of the switch body 3 is made by punching a flat metal plate by press working, bending and doweling to form a switch board base, and then molding it with synthetic resin, and then forming parts corresponding to external terminals. The part corresponding to the movable contact spring fixing plate is formed independently.

To be more specific, the base 4 has a longitudinal base 5 made of molded synthetic resin, and at one end of the base 5 there is a pair of main external terminals 6 extending in the length direction.
The inner end of the auxiliary external terminal 7 is buried therein, and most of the movable spring fixing plate 9, which extends in the length direction and has a stepped portion 8 at its free end, is buried in the other end. Also, approximately in the center of the platform 5 is a low protruding platform 1.
0 is bulged out, a small push-up projection 11 is erected upward, a wall 12 that can close the open end surface of the housing 1 is bulged upward at one end, and a cylindrical column is provided at the center of the other end. A support protrusion 13 is provided upright, and semi-cylindrical locking protrusions 14 are provided on the other end edge at equal distances from the support protrusion 13.
15 are erected. In addition, the main external terminal 6
A main fixed contact 16 and an auxiliary fixed contact 17 having different sizes are fixed to the inner end of the auxiliary external terminal 7 located inside the wall 12.

On the other hand, a main reversing bimetal 18 and an auxiliary reversing bimetal 19 each having a concave curved surface having different operating temperatures are mounted on the base 4. The main and auxiliary inversion bimetals 18 and 19 have an elliptical shape when viewed from above, and their bases are located between the support protrusion 13 and the locking protrusion 14 or 15. Projection 13 and locking projection 14
Alternatively, notches 20, 20 and 21, 21 that can be engaged with 15 are formed. Therefore, the notch 2 is formed in the support protrusion 13 and the locking protrusion 14 or 15.
When 0, 20 and 21, 21 are engaged,
The main and auxiliary inverted bimetals 18 and 19 are mounted on the base 4.
9 extends toward the edge opposite to the edge where the locking protrusion 14 or 15 is located. That is, most of the main and auxiliary inverted bimetals 18 and 19 overlap each other vertically when viewed from above, and their tips intersect with each other and extend toward opposite edges of the base 4. Furthermore, a hole 22 is bored in the center of the auxiliary inversion bimetal 19 through which the small push-up projection 11 of the base 4 can be inserted.
This push-up small projection 11 separates the main and auxiliary inversion bimetals 18 and 19 from each other.

The proximal end of the movable contact spring 23 is preferably fixed to the stepped portion 8 of the movable spring fixing plate 9 via a dowel. The movable contact spring 23 is bifurcated to form a main contact spring part 24 and an auxiliary contact spring part 25.
A main movable contact 26 and an auxiliary movable contact 27, which are capable of contacting the main and auxiliary fixed contacts 16 and 17 of the main and auxiliary external terminals 6 and 7, respectively, and which are different in size from each other are fixedly provided at the free ends of the terminals. Further, a main tongue piece 28 and an auxiliary tongue piece 29 which extend downward and have different lengths are cut and raised in the main and auxiliary contact spring parts 24 and 25, and are cut and raised at the tips of the main and auxiliary reversing bimetals 18 and 19. It is provided so that it can come into contact with it. Furthermore, a blocking tongue piece 31 is extended from the side edge of the auxiliary contact spring portion 25 to rest on a downward movement blocking step portion 30 protruding from the base 4 during upward movement. In addition, the open end of the housing 1 housing the switch body 3 is filled with a sealing adhesive 32.

Further, the operation of the temperature switch according to the present invention will be explained. In the temperature switch of the present invention, the electrical circuit includes the main external terminal 6, the main fixed contact 16, the main movable contact 26, the main contact spring part 24, the auxiliary contact spring part 25, the auxiliary movable contact 27, the auxiliary fixed contact 17, and the auxiliary external terminal 7. It is formed. When the ambient temperature of the device equipped with the temperature switch reaches the normal first set temperature at which the main reversing bimetal 18 is reversed, the main reversing bimetal 18 performs a reversing operation, and the main contact spring portion 24 is activated via the main tongue piece 28. is pushed up. As a result, the main movable contact 26 of the main contact spring part 24 is separated from the main fixed contact 16 attached to the main external terminal 6, and the contact is placed in the open state.This is repeated to open and close the contact as appropriate. Ru. At this time, the auxiliary reversing bimetal 19 is not reversed, and the auxiliary fixed and movable contacts 17,
27 remains closed, but the electrical path is interrupted.

On the other hand, when a device equipped with a temperature switch reaches an abnormal second set temperature that causes the auxiliary reversing bimetal 19 to reverse due to cracks in the main reversing bimetal 18 or welding of the main fixed and movable contacts 16, 26, etc., the auxiliary reversing bimetal 19 19 is reversed, the auxiliary contact spring part 25 is pushed up via the auxiliary tongue piece 29, and the auxiliary movable contact 27 of the auxiliary contact spring part 25 is separated from the auxiliary fixed contact 17 attached to the auxiliary external terminal 7. The contacts are closed. Once the auxiliary contact spring portion 25 moves upward, its blocking tongue piece 31 rests on the downward movement blocking step portion 30, and the contact remains open.

According to the temperature switch of the present invention configured as described above, the main contact spring and the auxiliary contact spring, which are approximately U-shaped and bifurcated, are formed on the same surface, and the movable contact spring is formed on the same surface. A movable spring fixing plate that is held on a base and holds the movable contact spring, and two main and auxiliary reversing bimetals that independently operate each of the movable contact springs are placed between the movable contact spring and the base. Since one movable contact spring can be used for two types of protection, the temperature switch can be made thinner and the temperature switch can be made smaller.

[Brief explanation of drawings]

Fig. 1 is an exploded perspective view of one embodiment of the temperature switch of the present invention, Fig. 2 is an internal plan view of the same, Fig. 3 is an internal side view of the same, and Fig. 4 is a simplified side view of a conventional temperature switch. . DESCRIPTION OF SYMBOLS 1... Housing, 2... Groove, 3 ... Switch body, 4... Base, 5... Base part, 6... Main external terminal, 7... Auxiliary external terminal, 8... Step part, 9... ...Movable spring fixing plate, 10...Protrusion base part, 11...Push-up small projection, 12...Wall part, 13...Support protrusion, 1
4, 15... Locking protrusion, 16... Main fixed contact, 1
7... Auxiliary fixed contact, 18... Main reversing bimetal, 19... Auxiliary reversing bimetal, 20, 21...
...Notch, 22...hole, 23...movable contact spring,
24...Main contact spring part, 25...Auxiliary contact spring part, 26...Main movable contact, 27...Auxiliary movable contact, 28...Main tongue piece, 29...Auxiliary tongue piece, 30...
...Downward movement blocking step, 31...Blocking tongue piece, 32...Adhesive.

Claims (1)

[Claims] 1. A main contact spring having a base, a plurality of external terminals held by the base and attached with fixed contacts, and a movable contact that can come into contact with the fixed contacts, and branched into two in an approximately U-shape. and a movable contact spring in which an auxiliary contact spring is formed on the same surface, a movable spring fixing plate held on the base and holding the movable contact spring, and each of the movable contact springs independently operated. A double protection function for one circuit, in which two main and auxiliary reversing bimetals are arranged between the movable contact spring and the base, and the two bimetals are inserted in series with respect to the electrical circuit to be opened. Temperature switch with.