JPS60205933A - 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 a high-temperature heater that can be applied to detect abnormal temperatures inside a catalytic converter of an internal combustion engine used under high-temperature conditions.

Structure of the conventional example and its problems In the structure shown in FIG. 1, a fusible metal wire 2 is connected to two lead wires 3.
a, sb, and housed in the metal protection tube 1, one end of the lead wire is grounded through the metal protection tube 1, and the fusible metal wire 20
This is a high-temperature heater whose periphery is protected by an insulator tube 4 to form a space 6, and whose periphery is filled with powdered electrical insulator 5 around the lead wire 3b. This heater allows the fusible metal wire to be fused and cut by a space inside the insulator tube 4 that protects the periphery of the fusible metal wire. However, when operating conditions are high, such as in an internal combustion engine, where the temperature is constantly rising and falling repeatedly, expansion and contraction are significant, and vibration is large, the fusible metal wire 2 may be grounded inside the metal protection tube 1. Moreover, since there is a space around the fusible metal wire 1, there were major drawbacks in mechanical strength, such as wire breakage. Furthermore, due to the oxygen remaining in the space around the fusible metal wire 1 and in the filling, there was a risk that the fusible metal wire 1 would be oxidized at a high temperature after being left in the cylinder for a long time, which would impede fusing.

Purpose of the Invention The present invention is designed to provide a system for use under usage conditions in which the ambient temperature repeatedly increases and decreases.
In addition, the present invention provides a high-temperature heater that reliably melts the fusible metal at a predetermined temperature and creates an electrical open circuit while maintaining vibration resistance and mechanical strength even in locations where vibrations are constantly applied.

Structure of the Invention The present invention involves inserting a fusible metal wire or a fusible metal tube welded to a pair of metal lead wires into a two-hole calcined insulating tube, and inserting the fusible metal wire or fusible metal tube into a metal protective tube with one end welded. This is a high-temperature fuse in which the metal protection tube is housed and the diameter of the metal protection tube is reduced by swaging or the like to form the fusible metal portion into a hollow shape.

Description of examples Hereinafter, the configuration of the present invention will be explained with reference to the drawings.

In FIG. 2a, 7 is a calcined insulating tube in which two through holes 8a and 8b are formed, and is made of, for example, magnenia and alumina powder. Next, in FIG. 2, reference numeral 9 denotes a fusible metal wire or a fusible metal tube, which is made of not only noble metals but also general brazing materials such as silver solder and bassineum solder, and alloys thereof. 10a, 1 ob is
The metal lead wire is made of stainless steel wire, nickel wire, nichrome wire, etc. that exhibits excellent heat resistance, and is connected to the fusible metal shell 9 by a welding part 11 such as plasma welding or spot welding. In FIG. 2C, 12 is a metal protection tube made of Inronel material, Incoloy, and stainless steel material with excellent heat resistance and corrosion resistance, and houses the fusible metal 9 having metal lead wires 10a and 10b inserted into the insulation W7. death,
Diameter reduction processing is performed such as swaging processing. 13
is a space filled with an inert gas and neutral gas, such as nitrogen gas and argon gas, which have been replaced with a vacuum. Reference numeral 14 denotes a powdered electrical insulating material obtained by crushing and solidifying the calcined insulating tube 7 when the metal protection tube was subjected to diameter reduction processing. Reference numeral 15 denotes a sealing material that is completely sealed to prevent oxygen and moisture from entering from the outside, and is made of an adhesive or a glass adhesive with excellent heat resistance.

As described above, the fusible metal wire and the fusible metal tube 9 housed in the metal protection tube are connected to the metal lead wire parts IC)a, 10b.
The hollow 13
The fusible metal material 9 also exhibits excellent performance in terms of vibration and mechanical strength. In addition, the opening inside the metal protection tube 12 is completely sealed after removing residual oxygen in a vacuum and replacing with inert gas and neutral gas, so even after long-term high-temperature durability, soluble metal There is no high-temperature oxidation of the material 9, and reliable fusing is possible at a predetermined temperature. In forming the hollow shape around the cut fusible metal part, we use a calcined two-hole insulating tube and compress and solidify it through diameter reduction processing, making the work easy, the finishing accuracy uniform, and the cost low. can be achieved.

As described above, the present invention can provide a high-temperature heater with excellent surface heat ↑1L, vibration resistance, and the like.

[Brief explanation of drawings]

7...2-hole insulation tube in calcined state, aa, ab...
・Through hole, 9...fusible metal wire or fusible metal pipe,
I Q&. 10b・・・Metal lead wire, 11・Old welded part, 12
...Metal protection tube, 13...Space part, 1
4... Powdered electrical insulating material, 15... Sealing part. Name of agent: Patent attorney Toshio Nakao (1st person)
Figure 2

Claims (1)

[Claims] A fusible metal wire having a metal lead wire or a fusible metal tube is inserted into a metal tube whose one end is a welded material, and an electric kneaded insulator tube is placed in a hollow state around the fusible metal wire and fusible metal tube. A high-temperature heater that is stored in a manner that allows