JPS61140831A - High temperature fuse - Google Patents

Abstract

PURPOSE:To increase the vibration resistance and mechanism strength of a fusible metallic wire, and to prevent oxidation and to secure its high temperature durability for a long period by forming the fusible metallic wire in a coil spring shape, and applying a flux for coating and storing the wire in an insulator pipe. CONSTITUTION:The fusible metallic wire 2 is formed in the coil sprig shape, both terminals are connected to a couple of metallic lead wires 4 and 5, and its outer periphery is coated with the flux 3 for soldering. This fusible metallic part is inserted into the insulator pipe 6 for protection, and also put in a metallic protection pipe 1, and one lead wire 4 is connected electrically to the metallic protection pipe 1. Then, a powdery electric insulator 7 is charged in the hollow in the metallic protection pipe 1, and the other lead wire 5 is projected from a sealing material 8 to form a fuse. Thus, the fuse which has high heat resistance and vibration resistance and blows securely at specific temperature is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a high temperature fuse that can be applied to detect abnormal humidity inside a catalytic converter of an internal combustion engine used under high temperature conditions.

Conventional technology A conventional high temperature fuse will be explained with reference to FIG.

The fusible metal wire 12 is connected to a pair of metal lead wires 13a.

13b, housed in the metal protection tube 11, and grounded to the metal lead wire 13a, and the fusible metal wire 12 is connected to the insulator tube 16.
to form a space 16, and a powdered electrical insulating material 17
This is a high-temperature fuse made by filling and solidifying.

Problems to be Solved by the Invention This conventional high-temperature fuse allows the fusible metal wire to be blown out by a space within an insulator tube that protects the periphery of the fusible metal wire. However, as in internal combustion engines, where the operating conditions are high and the temperature is constantly rising and falling, the expansion and contraction due to the 0 degree difference between the inside and outside of the metal tube is significant, and vibration is constantly applied, resulting in stress. There were major problems with mechanical strength, such as breakage of the fusible metal wire. The present invention solves these problems, and is located at a location where vibrations are constantly applied at high temperatures, and where the ambient temperature is rising.
・ It maintains vibration resistance and mechanical elasticity such as tensile and compressive stress generated during expansion and contraction even under conditions of repeated temperature drops, and also ensures that the fusible metal wire is fused at the specified temperature in the event of abnormal humidity rises. The purpose is to

Means for Solving the Problem In order to solve this problem, the present invention applies Coilx, stores it in a metal protection tube, and grounds one end of the metal lead wire with the metal protection tube, and connects the fusible metal The wire portion is protected by an insulator tube and filled with powdered electrical insulation material and solidified.

Function: In the present invention, the coil spring-shaped fusible metal wire with grounded flux housed in a metal protection tube can withstand long-term high-temperature durability as an oxidation prevention material for the flux, and can be used as a preset wire in the event of an abnormal temperature rise. It can be reliably fused at a predetermined humidity.

In addition, even under conditions of vibration that occurs at a temperature lower than that of fusible metals and repeated expansion and contraction due to temperature rise and fall,
Because the fusible metal has a coil spring shape, it can expand and contract within the insulator tube that protects the fusible metal wire, so it is not affected by tensile or compressive stress due to temperature differences inside and outside the metal protection tube, and has long-term mechanical stability. Can maintain strength.

Embodiment FIGS. 1 & b and 2 are a partial sectional view and an enlarged view of essential parts showing an embodiment of the present invention. Figure 1 a - b [
In the illustrated embodiment of the present invention, 1 is a metal protection tube made of stainless steel, Incoloy, Inconel, etc., which have excellent heat resistance and corrosion resistance.

Alternatively, it is a fusible metal wire in the shape of a coil spring, and uses not only noble metals but also general waxes such as 1st wax, palladium wax, surplus wax, and alloys thereof. 3 is a flux disposed on the fusible metal wire, and a flux having a melting point lower than that of the fusible metal is mainly used for brazing.

4 and 5 are metal lead wires made of stainless steel, nichrome,
It is made of nickel wire or the like, and is welded to the fusible metal wire 9a.
, 9b are fixed. Further, one end of the metal ribbon wire 4 is grounded to the metal protection tube 1.

6 protects the fusible metal wire 2 with an insulator tube.

Sintered bodies of alumina, magnesia, silicon nitride, etc. are used as materials. 7 is a powdered electrical insulating material made of magnesia.
Alumina/silicon nitride powder and its mixture are used. 8 is a sealing material, which is made of solid glass and prevents the intrusion of oxygen, moisture, water, etc. In the embodiment shown in FIG.
1 is a metal protection tube whose diameter is reduced to one level on the tip side, and the materials used are the same as those of the embodiment shown in FIG.

Effects of the Invention In the present invention, by distributing flux to a coil spring-shaped fusible metal wire, the fusible metal wire is more reliably fused at a predetermined temperature even after long-term high-temperature durability.

Furthermore, even under conditions of constant vibration and repeated expansion and contraction due to rising and falling temperatures, the fusible metal has a coil spring shape, so even if the metal protection tube is connected to the ground, the temperature inside and outside of the metal protection tube will decrease. The fusible metal wire can expand and contract within the insulator tube even with the difference in tensile and compressive stress, and can withstand repeated durability over a long period of time. Furthermore, since it has a metal protection tube and a grounded structure, it is easy to work with and is very cost effective.

[Brief explanation of drawings]

FIG. 2 is a partial sectional view and an enlarged view of essential parts showing an embodiment of the present invention, and FIG. 3 is a partial sectional view showing a conventional example. 11... Metal protection tube, 12... Fusible metal wire, 13a, 13b... Metal lead wire, 14
...Welded part, 16...Insulator tube, 16
...Space part, 17 ... Powdered electrical insulation material

Claims (3)

[Claims] (1) Flux is applied to a coil spring-shaped fusible metal wire that has a pair of metal lead wires welded and grounded inside a metal protection tube with excellent heat resistance and corrosion resistance, and the fusible metal wire portion is protected with an insulator tube. A high temperature fuse made by filling and solidifying powdered electrical insulating material. (2) The high-temperature fuse according to claim 1, wherein the diameter of the distal end portion of the metal protection tube is reduced to be one step thinner so that it comes into close contact with the outer periphery of the insulator tube. (3) The high-temperature fuse according to claim 1 or 2, wherein the opening of the metal protection tube is completely sealed.