JPH0310593Y2 - - Google Patents

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to an improvement of a temperature fuse.

<Prior art and problems> Alloy type temperature fuses are made by joining a low melting point fusible metal body between the ends of a lead wire, storing this low melting point fusible metal body in an insulating case, and connecting each case end with the low melting point fusible metal body. It has a structure in which the space between each lead wire is sealed with resin,
If the temperature of the protected equipment rises abnormally, the low-melting point fusible metal body will melt, and this molten metal will become spheroidal at the end of each lead wire due to surface tension, and as the molten metal becomes spheroidal, the molten metal will be divided and the circuit current will be reduced. is blocked.

By the way, when the outer diameter of the low melting point fusible metal body becomes large, it becomes difficult to make the molten metal into spheres, and it becomes difficult to expect smooth division. Therefore, it is problematic to use the above-mentioned temperature fuse for large currents. In addition, it is necessary to secure a considerable distance between the low melting point fusible metal body and the inner surface of the case so that the spheroidized body does not come into contact with the inner surface of the case. The outer diameter becomes considerably large.
The overall length of the case becomes longer because it is necessary to increase the distance between the leads.

<Purpose of the invention> The purpose of the invention is to eliminate the above-mentioned disadvantages by further improving the breakability of a low-melting point fusible metal body compared to the breakability that relies only on surface tension. .

<Structure of the invention> The temperature fuse according to the invention is a temperature fuse in which a low melting point fusible metal body is joined between the ends of lead wires, and a depressurized space is provided in at least one end of the lead wire. This is a characteristic configuration.

<Explanation of Examples> The present invention will be explained below with reference to the drawings.

In the figure, 1 and 1 are lead wires, and 2 is a low melting point fusible metal body to be joined between the ends of the lead wires 1 and 1. A hole 10 is provided in the end face of the lead wire in contact with the low melting point fusible metal body 2, and this hole 10 is closed by the low melting point fusible metal body 2 under reduced pressure. Thus, there is a reduced pressure space in contact with the low melting point fusible metal body 2 at the ends of the lead wires 1,1. One of the reduced pressure spaces can also be omitted. 3 is a flux layer provided on the low melting point fusible metal body 2, and can be omitted. 4 is an insulating tubular case, such as a ceramic tube, and the above-mentioned low melting point fusible metal body 2
are housed in this case 4, and sealed with resin 5 between each case end and each lead wire.

In the above, when the low melting point fusible metal body 2 melts due to abnormal heat generation of the protected equipment, this molten body is absorbed into the reduced pressure space 10 at the end of the lead wire, and the division of the molten metal body can be promoted, resulting in only spheroidization. The separability can be improved better than in the case of the conventional method.

<Effects of the invention> As described above, in the temperature fuse according to the invention, the breakability of the low melting point fusible metal body can be improved, so even if the outer diameter of the low melting point fusible metal body is increased, the breakability of the low melting point fusible metal body can be improved. We can provide alloy type temperature fuses with good security and high current. In addition, the outer diameter of the case can be reduced (length, outer diameter) because the molten metal body can be divided without relying only on spheroidizing the molten metal body.
can be achieved.

[Brief explanation of the drawing]

The drawing is an explanatory diagram showing a temperature fuse according to the present invention. In the figure, 1 and 1 are lead wires, 2 is a low melting point fusible metal body, and 10 is a reduced pressure space.

Claims (1)

[Scope of utility model registration request] A temperature fuse in which a low melting point fusible metal body is joined between the ends of lead wires, characterized in that a reduced pressure space is provided within the end of at least one of the lead wires.