JPS59146123A - Method of producing high temperature fuse - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to equipment and devices used under high temperature conditions;
For example, the present invention relates to a method of manufacturing a high-temperature fuse that is applied to detect abnormal temperatures inside a catalytic converter of an internal heat engine.

Conventional Structure and Problems In general, this type of high-temperature fuse has a fusible metal wire 8 connected to two metal lead wires 9 at both ends, as shown in FIG.
a, 9b, and housed in the metal protection tube 72 -]', and the fusible metal wire 8 portion is attached to the outer periphery of the space 12.
The outer periphery of the metal lead wire 9b is filled with a powdered electrical insulating material 13, or the outer periphery of the metal lead wire 9b is filled with a powdered electrical insulating material 13, or a fusible metal wire is used as shown in FIG. 14
f5 Bend it into a U-shape and connect the two metal lead wires 15 at both ends.
a, 15b and housed in these all-metal protective tubes Y,
The fusible metal wire 14 was filled and fixed with an electrically insulating solvent 16 and then filled with a powdered electrically insulating material 13.

The configuration shown in FIG. 1 allows the fusible metal wire 8 to be fused at a predetermined temperature by a space 12 formed by an insulating tube 11 that protects the entire periphery of the fusible metal wire 8. However, internal combustion engines and the like are used under high-temperature conditions, with repeated temperature rises and falls, resulting in significant expansion and contraction, as well as large vibrations, leading to mechanical strength problems such as unnecessary breakage of the fusible metal wire 8. Ta. ! In addition, the structure shown in FIG. 2 is fixed around the fusible metal wire 14 when the temperature rises to an abnormal temperature,
In addition, the melting agent 16, which is lower than the melting temperature of the fusible metal wire 14, is immediately melted and diffused into the minute voids of the powdered electrical insulating material 13, and the space formed in the fusible metal wire 14 portion. The fusible metal wire 14-karat gold is cut by melting, but in the case of high-temperature durability near the melting temperature of the solvent 16, the solvent 16 filled and fixed in the fusible metal wire 14 portion is
As the powdered electrical insulating material (C) begins to melt and diffuses, a space is created around the fusible metal wire 14, causing vibrations and
Fusible metal wire 1 due to heat cycles of repeated temperature drops
If the fusible metal wire 14 melts at a predetermined temperature like in an internal combustion engine, a predetermined current is applied to generate an electric signal to warn of abnormal temperature. However, the diffusion of the solvent 16 into the powdered electrical insulating material deteriorates the insulation resistance at the time of fusing.To compensate for this, a complete correction circuit is required.There are also problems from 1 meter to 1 meter. Furthermore, in terms of workability, in order to fill and fix the fusible metal wire 14 part with electrically insulating solvent 16,
In addition to requiring a lot of man-hours, the shape of the tithe was also unstable.

Purpose of the Invention The present invention takes into consideration the above-mentioned conventional problems, and provides a high-temperature fuse in which a fusible metal is housed in a metal protection tube and is completely filled with powdered electrical insulating material, at a location where vibrations are constantly applied, and at ambient temperature. It maintains its vibration resistance and mechanical strength even under usage conditions where external temperature and temperature drop are repeated, and even after long periods of high temperature impression, it can be reliably maintained at the specified temperature between 0°C and 1°C. It is the object of ffi to provide a high temperature fuse that can be blown and electrically open circuited.

Structure of the Invention In order to achieve all of the above-mentioned objects, the present invention provides a heat-resistant pipe with metal lead wires inserted outside the predetermined positions into both ends of a fusible metal pipe whose internal space is completely formed in advance, and which are welded and fixed, and then sealed at one end.
104 Manufacturing of high-temperature fuses that are housed in a metal protective tube with excellent edibility, filled with powdered electrical insulating material, reduced in diameter by swaging, etc., and then evacuated completely inside the metal protective tube. It is the law. When the high temperature fuse formed by this manufacturing method is heated to an abnormal temperature, the fusible metal tube 5 has a volume larger than that of the fusible metal tube having a space.
-・ The inner volume of the electric insulating material is reliably fused by the surface tension of all the fusible metal tube materials that melt at a predetermined temperature.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. 3 and 4. In the figure, 1 is stainless steel.

This is a metal protection tube made of Inconel material with excellent heat resistance and corrosion resistance, and the entire tip is welded and sealed by inline gas arc welding.

2 is a pipe-shaped pipe-shaped fusible metal tube made of precious metals and silver solder, palladium solder, etc., which is made of alloys of these materials and has an internal space, with stainless steel showing excellent heat resistance and corrosion resistance at both ends. .

Metal lead wire sa made of nickel, nickel wire, etc.
It is welded and fixed by 3B6 plasma welding, spot welding, etc., leaving a space 4 inside.

The metal protection tube 1 contains a fusible metal tube 2 and metal lead wires 3a and 3b welded thereto, and is further filled with a powdered electrical insulating material 6 made of magnesia and alumina powder. The powdered electrical insulating material [
5 has a high packing density, and the portion in contact with the periphery of the fusible metal tube 2 is hardened so as to form a strong cavity even after the fusible metal tube 2 is melted. When the metal protection tube 1 kj is held in a vacuum and the oxygen inside is removed, the metal protection tube 10 is opened.
The opening 11 6 is sealed with a glass adhesive or the like.

FIG. 4 shows another example of a high temperature fuse manufactured according to the present invention, in which the fusible metal tube 2 is rod-shaped.

When the high-temperature fuse manufactured by the above manufacturing method is heated to an abnormal temperature outside the fusible metal tube 2 with the space 4 formed in advance, the circumference of the fusible metal tube 2 is reduced in diameter at a predetermined temperature. It can be melted within the volume of the formed electrically insulating moon 5 and reliably fused by the surface tension of the fusible metal material to create an open circuit.

Therefore, there is no need for a separate solvent as in the conventional example.
There is no deterioration in insulation resistance after blowout. In addition, in the normal state before fusing, vibration resistance is improved due to high powder density due to diameter reduction processing, and excellent mechanical strength can be maintained at all. Furthermore, in a related matter, the opening 11 of the metal protection tube was vacuumed and then sealed at the same time, so there was no oxygen remaining in the metal protection tube, and there was no leakage from the outside. Since there is no intrusion of oxygen, reliable fusing is possible even after long-term high-temperature durability. 1 Effects of the Invention] - As is clear from the embodiments of the present invention, the high temperature fuse according to the present invention is produced by hardening the powdered electrical insulating material around the fusible metal tube by reducing the diameter of the metal protective tube. The present invention has great value because it prevents the fusible metal tube from being inadvertently cut in the electric insulator, and can be reliably cut at a predetermined temperature.

[Brief explanation of drawings]

1 and 2 are sectional side views of a conventional high temperature fuse, respectively, and FIGS. 3 and 4 are sectional side views of a high temperature fuse according to the present invention. 1... Metal protection tube, 2... Fusible metal tube, 3a. 3b... Metal lead wire, 4... Space portion, 5... Powdered electrical insulating material, 6... Sealing portion. Name of agent: Patent attorney Toshio Nakao and one other person
Salmon
Electrical range

Claims (1)

[Claims] A pair of metal lead wires are connected inside a metal protection tube with excellent heat resistance and corrosion resistance, and a fusible metal tube with an internal space is housed inside the metal protection tube, and the metal protection tube is completely filled with powdered electrical insulation. After that, the diameter of the metal protection tube is reduced, and the inside is evacuated and sealed.