JPS6236196Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a temperature fuse provided between lead wires that is reliably disconnected at a target temperature.

Conventionally, regarding temperature fuses, there is a thermocouple equipped with a temperature fuse as disclosed in Japanese Patent Application Laid-Open No. 57-79689, which was previously filed by the present applicant and published. As shown in FIG. 1, this thermocouple has lead wires 3 arranged in parallel with an insulator 1 interposed therebetween, and a metal wire 4 having a lower melting point than the lead wires 3 between the ends of each lead wire. , the insulator 1
It was connected in a state where it protruded from the distal end surface 1'.

However, as shown in Fig. 2, in the case of this temperature fuse, when the metal wire for the fuse between the ends of the lead wires melts, a molten metal ball forms at the end of one lead wire at the end surface 1' of the insulator. A thread-like connection portion may be formed between the molten ball and the tip of the other lead wire 3.

This temperature fuse can achieve its intended purpose only if it is cut at the target temperature; however, if such a thread-like connection occurs, it cannot be electrically cut, so it cannot function as a temperature fuse. There may be no.

The present invention was devised to solve this problem in view of the conventional problems, and its purpose is to prevent a thread-like connection between the ends of the lead wires when the metal wire as a temperature fuse melts at the target temperature. The purpose is to prevent this from occurring, and the key point is to prevent this from occurring at a position on the tip of the insulator sandwiched between both lead wires or between the extensions of both lead wires.
To provide a temperature fuse in which a partition made of an inorganic substance is protruded over a required length toward the tip of the metal wire at a position corresponding to the cross-sectional position of the metal wire melting on the tip surface of the insulator or in front of the tip surface of the insulator. It is in.

The details of the present invention will be explained based on the embodiments shown in FIGS. 3 to 7. In the figure, 1 is an insulator, and a lead wire 3 is inserted into a through hole 2 provided inside the insulator 1, and the tip thereof is connected to the insulator. A metal wire 4 for a temperature fuse is connected to the tip of the lead wire 3. The metal wire 4 is preferably made of an oxidation-resistant material, such as gold, silver, platinum, or an alloy thereof. Conversely, if a metal or alloy that is easily oxidized is used, an inert gas atmosphere is used for the metal wire 4. However, it is necessary that the metal melts reliably at least at the set target temperature and has a lower melting point than the lead wire.

In the embodiment shown in FIG. 3, a metal wire 4 for a temperature fuse, which is curved in a U-shape, is connected between the ends of the lead wire 3, and the lead wire 3 and the metal wire 4 are located near the end surface 1' of the insulator 1. A partition wall 5 of a required length made of an inorganic material is provided protruding from the distal end face 1' toward the distal end side of the metal wire 4 between the connecting parts. In order to prevent the formation of a thread-like connection when the metal wire 4 is melted, the partition wall portion 5 is set to a length such that at least its tip contacts the melted metal wire.
The partition wall portion 5 may be formed integrally with the insulator 1, or may be formed separately and attached to the tip end surface 1' of the insulator 1 by appropriate means.

FIG. 4 shows another embodiment in which the outer periphery of the tip of the insulator 1 is annularly protruded around the metal wire 4 for a temperature fuse to form a wall for protecting the metal wire 4.

The one shown in Fig. 5 has one lead wire 3 protruding further downward from the tip end surface 1' of the insulator 1, and a J.
A temperature fuse metal wire 4 curved into a character shape is connected, and the protruding lead wire 3 is covered with an insulator having a hole for passing the lead wire 3 through.
This is the case where this insulator is used as the partition wall portion 5'. In this case, the molten metal wire comes into contact with the partition wall portion 5' that sheaths the lead wire 3, thereby preventing the formation of thread-like connections.

The method of connecting the lead wire 3 and the temperature fuse metal wire 4 in each of these embodiments is as shown in FIGS. 6 and 7, by inserting the tip of the metal wire 4 into the lead wire 3 and The connection is made by tightening or by inserting one end of the metal wire 4 into the lead wire 3 and melting it, and furthermore, there is no possibility that the insulator 1 may fall outside the lead wire 3 during these connections or by other methods. It is also possible to protrude a prevention protrusion 6 and use the protrusion 6 to act as a stopper to prevent the insulator 1 from falling downward. This protrusion 6 forms a large molten ball when connecting the metal wire 4 and the lead wire 3 in FIG. 7, and if this is used as a stopper to prevent the insulator 1 from falling, its manufacture is It is convenient because it can be done at the same time as welding.

As described above, the temperature fuse according to the present invention has lead wires 3 arranged in parallel with an insulator 1 interposed therebetween, and a metal wire 4 having a lower melting point than that of the lead wire 3 between the ends of each lead wire 3. However, in a temperature fuse connected with all or most of it protruding from the tip surface 1' of the insulator 1, the insulator is sandwiched between both lead wires 3 or between the extensions of both lead wires 3. At a position on the tip surface 1' corresponding to the cross-sectional position of the insulator tip surface 1' or the metal wire 4 that melts in front of the insulator tip surface 1', there is a required amount of metal wire 4 directed toward the tip. Since the long partition wall 5 made of an inorganic material is provided protrudingly, the partition wall 5 serves as a member for preventing the generation of a thread-like connection when the metal wire 4 for the temperature fuse melts. metal wire 4
When the lead wires 3 are melted, the tips of the lead wires 3 can be electrically disconnected reliably. In particular, the third
If the configuration of the embodiment shown in the figure is adopted, this purpose can be achieved by simply forming a protrusion as the partition wall 5 at the tip of the insulator 1, which is not only extremely easy to manufacture, but also easy to use. There is no inconvenience whatsoever.

In addition, the temperature fuse in this invention is lead wire 3.
When a thermocouple wire is used as a thermocouple wire, the thermocouple has these temperature fuses, and when the thermocouple wire is not used, it can be used as a simple temperature fuse.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing a conventional example, Fig. 2 is an explanatory view showing its usage state, Fig. 3 is a sectional view of an embodiment according to the present invention, and Figs. 4 and 5 are sectional views of other embodiments. , FIG. 6, and FIG. 7 are explanatory cross-sectional views showing the connection state of the metal wire and the lead wire. 1...Insulator, 1'...Tip surface, 2...Through hole, 3
... Lead wire, 4 ... Metal wire, 5 ... Partition part,
5'...Partition part, 6...Protrusion.

Claims (1)

[Scope of Claim for Utility Model Registration] 1. Lead wires are arranged in parallel with insulators interposed between them, and between the ends of each lead wire there is a metal wire having a lower melting point than the lead wire, all or most of which is arranged in parallel. In the temperature fuse which is connected in a state that protrudes from the tip surface of the insulator, a position on the tip surface of the insulator sandwiched between both lead wires or an extension of both lead wires; Alternatively, a temperature fuse characterized in that a partition made of an inorganic material is provided extending toward the tip of the metal wire and extending over a required length at a position corresponding to the crossing position of the metal wire melting in front of the tip of the insulator. 2. The temperature fuse according to claim 1 of the utility model registration, which uses a thermocouple wire as a lead wire.