JP3052349B2 - Thermal protector - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is used for various electric devices, for example, motors or fluorescent lamp stabilizers, and is a thermal protector for preventing burnout of electric devices due to heat generation and overcurrent at abnormal times. In particular, it relates to a small thermal protector.

FIG. 6A shows a conventional thermal protector.
One having the configuration shown in FIG. 1B is known (Japanese Patent Laid-Open No. 59-189520). In this thermal protector, as shown in FIG. 7, the movable electrode body has a movable contact 13 fixed to the tip of a movable electrode plate 12 having a spring property, and a thermally responsive element plate 14 fixed to the back of the movable electrode plate 12. It is integrated. This fixing is performed by inserting the thermally responsive element plate 14 into a portion of the movable electrode plate 12 surrounded by the support portions 12a, 12b, and 12c, and positioning the thermally responsive element plate 14 on the back surface of the movable electrode plate 12, and moving these support portions 12a and 12b. It is done by caulking. In this case, the thermally responsive element plate 14 may move with a slight allowance with respect to the support portions 12a, 12b, 12c of the movable electrode plate 12 so as not to hinder the inversion and return operations of the thermally responsive element plate 14. I can do it. In addition, the movable electrode plate 12 is welded to the movable lead 15
12d is fixed to form a movable electrode body. On the other hand, the fixed contact 16 is fixed to the fixed-side lead wire 17 to form a fixed electrode body, these electrode bodies are positioned so that the movable contact 13 and the fixed contact 16 face each other, and integrated with a glass bead 18, Make up the mount. This mount is a glass container 19
And an inert gas such as nitrogen is sealed therein, and the end of the glass container 19 is heated and sealed.

The thermal protector having such a configuration is attached to a motor or the like, and in response to an excessive temperature rise and an overcurrent at the time of an abnormality, the thermally responsive element plate 14 performs an inversion return operation, and the movable electrode plate 12 corresponds. Perform the operation, the movable contact
It has a function to open and close 13 and fixed contacts 16 to prevent burnout of motors and the like.

Problems to be Solved by the Invention When a thermal protector having such a structure is miniaturized, the volume of the container becomes small, so that a glass container is used.
The gap between the thermal response element plate 19 and the thermal response element plate 14 is also reduced, and when the thermal response element plate 14 moves, the thermal response element plate 14 comes into contact with the glass container 19, and a serious disadvantage that normal inversion return operation does not occur. there were. Further, in this thermal protector, since the thermally responsive element plate 14 moves with a slight margin with respect to the movable electrode plate 12, when the thermal protector is shaken by hand, the thermally responsive element plate 14 is moved. However, there is a drawback in that the sound moves and hits the glass container 19 to make a clicking sound.

The present invention has been made in order to solve such a problem, and there is no danger that an abnormal inversion return operation will be caused even when the thermal protector is used in a motor or a fluorescent light ballast. An object of the present invention is to provide a high-quality small-sized thermal protector that does not generate noise and has stable contact resistance between contacts.

Means for Solving the Problems The thermal protector of the present invention has a fixed electrode body provided with a fixed electrode plate having a fixed contact fixed to one end, a plurality of holes at the fixed end, and a movable end at the movable end. A movable electrode body having a movable electrode plate having a movable electrode plate having a movable contact contacting and separating from the fixed contact fixed to a distal end thereof is opposed to a movable electrode body having a spring property, and the other end of the fixed electrode plate is directed toward the movable electrode body. A plurality of extending pillars are provided and penetrated and fixed to one resin insulating block, and between the one insulating block and the other resin insulating block having a plurality of holes through which the plurality of pillars are inserted. The fixed end of the movable electrode plate, when closed, is provided along the back surface of the movable electrode plate so as to push the movable electrode plate toward the fixed electrode plate side, and A fixed end portion having a plurality of holes of the thermally responsive element plate, the movable end portion of which is hooked with a slight margin by a claw portion formed by folding a tip end portion of the movable electrode plate toward the back side. Provided,
And, the column of the one insulating block is inserted into the hole of the other insulating block through the respective holes of the movable electrode plate and the thermally responsive element plate, and the tip of the column protruding from the hole is swaged. With the pair of insulating blocks, the other end of the fixed electrode plate,
A mount body integrated with a fixed end of the movable electrode plate and a fixed end of the thermally responsive element plate is provided in a container.

Effect of the Invention According to the present invention, when vibration or shock is applied to the thermal protector, the thermally responsive element plate moves and generates a sound, and the thermally responsive element plate contacts the inner wall surface of the container and does not cause a normal inversion return operation In order to prevent this, the tip of the movable end of the thermally responsive element plate is formed by folding the movable electrode plate to the back side and locked with a slight margin to the claw, and the fixed end is the movable electrode A fixed electrode plate is fixed together with a fixed end portion of the plate between a resin-molded insulating block and a holding insulating block by crimping a column of the insulating block. As a result, the movable end of the thermally responsive element plate is easily moved and locked, and the fixed end is firmly positioned and fixed, so that the thermally responsive element plate does not move in an unnecessary direction and stabilizes the thermally responsive element plate. be able to. In addition, when the movable electrode plate is closed, the movable contact plate is pressed along the back surface of the movable electrode plate so as to push the movable electrode plate toward the fixed electrode plate so that the movable contact causes the fixed contact to be pressed. Embodiments of the Invention Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

1 (a), (b), FIGS. 2 (a), (b), 3rd
4 (a), 4 (b), 5 (a), and 5 (b), a fixed contact 1 made of silver is fixed to one end of a brass plate by welding. Electrode body provided with a fixed electrode plate 2 having two holes 3a and 3
a movable electrode plate 3 having a dowel portion 3c at a center portion thereof, a movable contact portion 4 made of silver based on a movable end portion being fixed to and separated from the fixed contact portion 1 by welding to a tip portion, and The movable electrode body made of a springy thin beryllium copper plate and having a claw portion 3d formed by folding the tip in a direction opposite to the movable contact 4 side is opposed to the movable electrode body. The other end of the fixed electrode plate 2 is penetrated and fixed to one of the PBT resin insulating blocks 5 provided with two columns 5a and 5b extending toward the movable electrode body, and one of the insulating blocks 5 and the columns 5a, Five
The other PBT having two holes 6a and 6b through which b respectively passes
The movable electrode plate 3 is interposed between the insulating block 6 and the resin.
And a curved end is provided along the back surface of the movable electrode plate 3 so as to push the movable electrode plate 3 toward the fixed electrode plate 2, and the tip of the movable electrode plate is folded back toward the back surface. A fixed end having two holes 7a, 7b of a thermally responsive element plate 7 made of a bimetal whose movable end is locked with a slight margin by the formed claw 3d is provided. Here, the thermally responsive element plate 7 is curved to perform a snap action operation and to generate a pressure as if the movable contact 4 presses the fixed contact 1 when both contacts are closed. Then, the supports 5a and 5b of the one insulating block 5
Through the holes of the movable electrode plate 3 and the thermally responsive element plate 7 and into the holes 6a, 6b of the other insulating block 6, and crimp the tips of the columns 5a, 5b protruding from these holes by ultrasonic welding. In this way, the pair of insulating blocks 5 and 6 are integrated with the other end of the fixed electrode plate 2, the fixed end of the movable electrode plate 3, and the fixed end of the thermally responsive element plate 7 interposed therebetween. I have. Further, a coated lead wire 8 is welded to the tip of the fixed end of the fixed electrode plate 2 and a coated lead wire 9 is welded to the tip of the fixed end of the movable electrode plate 3 to form a mount body.

Such a mount is a small container 10 made of PBT resin having an opening at one end and having a length of 17.2 mm, a width of 6.2 mm, and a thickness of 3.6 mm.
The covered lead wire 8.9 is led out from the opening, and the opening of the container 10 is sealed with a filler 11 made of epoxy resin.

In a small thermal protector with such a structure,
A thermally responsive element plate 7 is provided along the back surface of the movable electrode plate 3 so as to push the movable electrode plate 3 toward the fixed electrode plate 2, and the movable end of the thermally responsive element plate 7 is slightly movable with respect to the movable electrode plate 3. It is locked by the claw 3d of the movable electrode plate 3 with a margin, and the fixed end is firmly positioned with a margin without being sandwiched together with the movable electrode plate 3 between the pair of insulating blocks 5 and 6 and fixed by caulking. Therefore, even if vibration or impact is applied without unnecessary movement of the thermoresponsive element plate 7, the thermoresponsive element plate 7 does not contact the inner wall surface of the container 10 and does not make noise, and It is possible to stabilize the inversion return operation so as not to hinder it. Further, when the movable electrode plate is closed, the movable contact causes a pressure on the fixed contact so that the movable electrode plate is curved along the back surface of the movable electrode plate so as to push the movable electrode plate toward the fixed electrode plate to provide the thermoresponsive element plate. And the contact resistance between the fixed contact and the movable contact can be stabilized.

On the other hand, when an electric device such as a motor is abnormal, the thermally responsive element plate 7 is inverted, and the thermally responsive element plate 7 contacts two points of the claw portion 3d and the dowel portion 3c of the movable electrode plate 3,
The movable electrode plate 3 moves in accordance with the reversal operation of the thermally responsive element plate 7, and the movable contact 4 is separated from the fixed contact 1.

This thermal protector does not require any additional components, so that it is inexpensive and small in size, but can have the same quality performance as the conventional one.

Effect of the Invention As described above, even if the present invention is downsized, since the thermoresponsive element plate can be completely mounted, not only the gap with the container can be made as small as possible, but also the normal operation of the electric equipment during normal operation. Provides a low-cost, high-performance thermal protector that is stable against thermal vibration and shock, prevents rattling of the thermal response element plate, prevents abnormal operation, and stabilizes the contact resistance between contacts. Is what you can do.

[Brief description of the drawings]

1 (a) and 1 (b) are a partially cutaway side view and a front view of a thermal protector according to an embodiment of the present invention, and FIGS. 2 (a) and 2 (b) show an example of a movable electrode body. FIGS. 3 (a) and 3 (b) are front and side views showing an example of a thermally responsive element plate, and FIGS. 4 (a) and (b) are front views showing an example of a fixed electrode body. FIGS. 5 (a) and 5 (b) are front and side views showing an example of the other insulating block, and FIGS. 6 (a) and 6 (b) are partially cutaway front views of a conventional thermal protector. 7 and FIG. 7 are perspective views of the movable electrode plate. 1 fixed contact, 2 fixed electrode plate, 3 movable electrode plate, 3a, 3b hole, 3d claw, 4 movable contact, 5, 6 insulating block, 5a, 5b …… posts, 6a, 6b…
… Hole of insulation block, 7… Thermal response element plate, 7a, 7b ……
Hole in thermo-responsive element plate.

Claims (1)

(57) [Claims] 1. A fixed electrode body having a fixed electrode plate having a fixed contact fixed to one end, a movable end having a plurality of holes at a fixed end, and a movable end contacting and separating from the fixed contact. A movable electrode body having a spring property provided with a movable electrode plate having a contact fixed to a tip end thereof, and the other end of the fixed electrode plate is provided with a plurality of columns extending toward the movable electrode body. A fixed end of the movable electrode plate between the one insulating block and the other resin insulating block having a plurality of holes through which the plurality of columns are inserted. Part, when closed, is provided curved along the back surface of the movable electrode plate so as to push the movable electrode plate toward the fixed electrode plate, and the tip of the movable electrode plate is placed on the back surface side. Folding And a fixed end portion having a plurality of holes of the thermally responsive element plate, the movable end portion of which is locked with a slight allowance by the claw portion formed in the above manner, and the support of the one insulating block is provided. The movable electrode plate and the thermally responsive element plate are respectively inserted into the holes of the other insulating block through the respective holes, and the ends of the pillars protruding from the holes are caulked to fix the pair of insulating blocks with the pair of insulating blocks. A thermal protector, wherein a mount body integrated with the other end of the electrode plate, the fixed end of the movable electrode plate, and the fixed end of the thermoresponsive element plate is provided in the container. .