JPH0230028A - Thermal fuse - Google Patents

Abstract

PURPOSE:To enable a conductor to be simply and rapidly secured to an apparatus and/or a circuit by providing a third conductor with a short tubular portion which covers the outer peripheral face of the opening portion of a bottomed tubular body. CONSTITUTION:A tubular body 11, which is a bottomed first conductor formed of a conductor, is in the form of a cylinder only the opening of which is lessened in thickness, and a thermalsensitive soluble body 13 is contained in its bottom portion. A spring seat metal 14, a supporting spring 15, a spring seat metal 16 and a movable conductor 17 i.e., a second conductor are provided on the thermalsensitive soluble body 13 in the same order as mentioned. A stepped columnar bushing 18 is fitted on the opening of the tubular body 11 as its smaller diameter side faces inwardly, and a pushing spring 19 is interposed between the inner end face of the busing and the movable conductor 17, which is energized toward the thermalsensitive soluble body 13 by the pushing spring. The opening end portion of the tubular body 11 retains the busing 38 in such a manner as to thrust it inwardly, and a tubular insulating cap 20 equipped with an inner flange is fitted on the opening of the tubular body 11 in such a manner that the cap covers the outer peripheral face and the end face of the opening portion, and besides a third conductor 21 is coveringly fitted on the cap. The-shaped portion of the third conductor 21 makes contact with the center of a movable conductor 16.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a temperature fuse used in electric appliances such as electric heating appliances, and more specifically, proposes a temperature fuse that does not have a lead wire and can be attached to a holder. It is something to do.

[Conventional technology]

FIG. 4 is a sectional view showing the structure of a conventionally known temperature fuse. In the figure, 1 is a bottomed cylinder made of a conductor,
It has a cylindrical shape with a bottom, and a lead wire 2 is connected to the outside of the bottom by a method such as tying.

A heat-sensitive fusible body 3, a spring washer 4, a drum-shaped support spring 5, a spring washer 6, and a movable conductor 7 are housed in the cylinder 1 from the bottom side. As shown in FIG. 5, the movable conductor 7 has a star shape with a radial portion around the circular periphery, and the radial portion is curved and press-contacted to the inner peripheral surface of the cylinder 1.

A bushing 8 made of an insulating material is fitted into the opening of the cylinder 1, and the opening end of the cylinder 1 is constricted (curled) by bending inward. A lead wire 10 passes through the bushing 8, and the tip of the lead wire 10 protruding into the cylindrical body 1 is in contact with the movable conductor 7.

The end of the bushing 8 has a curved taper and becomes thinner at the tip side. A push spring 9 fitted to this part is provided inside the cylinder 1, and the movable conductor 7 is connected to the heat-sensitive fusible body 3.
It is biased toward the side. Others 11 are adhesives for fixing the lead wires 10 to the bushing 8.

When the temperature of this temperature fuse is low, current flows through the path from the lead wire IO to the movable conductor 7 to the cylinder 1 to the lead wire 2, but when the temperature exceeds the melting temperature of the heat-sensitive fusible material 3, the heat-sensitive fusible material 3 melts or sublimates. Then, the elasticity of the push spring 9 causes the movable conductor 7 to separate from the tip of the lead wire 10. This breaks the current conduction path.

[Problem to be solved by the invention]

The temperature fuse configured as described above has the following problems. That is, in the manufacturing process, when the bushing 8 is fitted into the cylinder 1, the lead wire 10 is attached to the bushing 8.
Since it is not fixed to the base, it will wobble and bounce due to the action of the push spring 9, etc., making assembly work difficult. Also, when using it, it is necessary to solder the lead wires 2 and 10.
If the lead wire 2 is inadvertently heated to a high temperature, the heat-sensitive fusible material may melt, resulting in a disconnection state. For this reason, it is necessary to check continuity between the lead wires after soldering.

Further, electrolytic corrosion may occur at the contact portion between the lead klA2 and the cylindrical body 1 during long-term use.

The present invention has been made to solve such problems, and an object of the present invention is to provide a temperature fuse that can be attached to a holder by having a structure without lead wires.

[Means to solve the problem]

The temperature fuse according to the present invention includes a heat-sensitive fusible body housed in the bottom of a bottomed cylindrical first conductor, and a heat-sensitive fusible body housed in and in contact with the first conductor and biased toward the heat-sensitive fusible body. The second one
A conductor, and a third conductor that is in contact with the second conductor and insulated therefrom on the opening side of the first conductor, and when the heat-sensitive fusible material melts due to temperature rise, the second conductor is insulated from the second conductor. In a temperature fuse in which the third conductor is non-contact, the third conductor is connected to the first conductor.
It is characterized by having a short cylindrical portion that covers the outer peripheral surface of the opening of the conductor.

Further, the third conductor has a rod-shaped portion in the center, and this is configured to be in contact with the second conductor.

[Effect]

1st. The conduction between the third conductors is interrupted by melting and sublimation of the heat-sensitive fusible material. When in use, the first holder is attached to a pair of holders. It is sufficient to simply insert the third conductor. Then, the second conductor can be easily contacted when the third conductor is assembled.

〔Example〕

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below based on drawings showing embodiments thereof. FIG. 1 is a sectional view of the temperature fuse of the present invention, in which a bottomed cylinder 11 (the first conductor) made of a conductor has a cylindrical shape with a slightly thinner opening only, and a heat-sensitive fusible material 13 at the bottom.
It stores. On the heat-sensitive fusible body 13, a spring washer 14, a support spring 15, a spring washer 16, and a movable conductor (
The second conductors) 17 are arranged in this order. Cylinder 1
A stepped cylindrical bushing 18 is fitted into the opening of 1 with the narrow diameter side inside, and its inner end surface and movable conductor 17
A push spring 19 is interposed between the movable conductor 17 and the movable conductor 17 toward the heat-sensitive fusible body 13.

Bushing 18 is made of ceramic or a heat-resistant insulator.

The open end of the cylindrical body 11 is compressed inward to hold down the bushing 18. A cylindrical insulating cap 2 with an inner flange is attached to the opening of the cylinder 11 so as to cover the outer peripheral surface and the opening end surface.
0 is fitted, and a third conductor 21 is further fitted to cover it.

The conductor 21 has a short cylindrical portion with a bottom and a rod-like portion erected on its inner bottom surface, and the rod-like portion is inserted through a hole provided in the center of the bushing 18 and is inserted into the center of the movable conductor 16. are in contact. It is preferable that this contact end has a larger diameter than the base end in order to increase the contact area. Insulating cap 20 for the short cylindrical part
The axial dimension is a little shorter than that, and the conductor 21, the insulating cap 20, and the cylindrical body 11 are made into a single body by constricting them at appropriate positions in the circumferential direction. In order to enable this sharking, a sharking groove is provided around the bushing 18.

The fuse of the present invention having the above configuration is normally energized through the path from the conductor 21 to the movable conductor 17 to the cylindrical body 11.
When the heat-sensitive fusible material 13 melts and sublimates, the movable conductor 17 is separated toward the bottom of the cylinder 11 by the action of the push spring 19, and the conduction is broken.

FIG. 2 shows another embodiment of the invention.

In this embodiment, the diameter of the part of the cylindrical body 11 into which the bushing 18 is inserted is made larger than that of the part below it, and the inner stepped part of the bushing 18 is
For positioning, the outer step portion is used as a shark-like retaining portion at the tip of the short cylindrical portion of the third conductor 21.

Other parts corresponding to those in FIG. 1 are designated by the same reference numerals and their explanations will be omitted.

FIG. 3 shows these temperature fuses loaded between holders 31 and 31.

〔Effect of the invention〕

In the case of the present invention as described above, there is no lead wire, and therefore no soldering is required when using the device. Therefore, not only can it be easily and quickly attached to equipment and circuits, but there is no need to check continuity afterwards. Furthermore, the number of parts of the temperature fuse itself that can cause electrolytic corrosion is smaller than that of conventional fuses, so it can be expected that the life of the fuse will be extended. Furthermore, since the third conductor is fixed to the first conductor in such a way that the rod-shaped portion abuts against the second conductor during assembly, the assembly work is easier than before, and the present invention has excellent effects. play.

Note that the fuse of the present invention can also be applied to a type of holder that is housed within a cylindrical body.

[Brief explanation of the drawing]

Figures 1 and 2 are cross-sectional views showing an example of the present invention installed, Figure 3 is a perspective view showing how it is mounted on a holder, Figure 4 is a cross-sectional view of a conventional temperature fuse, and Figure 5 is a movable conductor. FIG. 11... Cylindrical body 13... Heat-sensitive fusible material 17... Movable conductor 18... Bushing 20... Insulating camp 21... Conductor time Applicant: Iida Sangyo Co., Ltd. Agent Patent attorney Noboru Kono Husband's funeral map

Claims (1)

[Claims] 1. A heat-sensitive fusible body housed in the bottom of a bottomed cylindrical first conductor; and a third conductor that is in contact with the second conductor and insulated from it on the opening side of the first conductor, and when the heat-sensitive fusible material melts due to temperature rise, the second and third conductors The third conductor has a short cylindrical portion that covers the outer peripheral surface of the opening of the first conductor. 2. The thermal fuse according to claim 1, wherein the third conductor comprises a bottomed cylindrical part and a rod-shaped part that stands upright on the inner bottom surface of the third conductor and comes into contact with the second conductor. 3. The opening of the first conductor is fitted with an insulating cap that covers the outer peripheral surface and end surface of the first conductor, and the third conductor is fitted onto the insulating cap, and the short cylindrical portion is attached to the first conductor. 2. A thermal fuse according to claim 1, further comprising: