JPS60205932A - 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 the Invention The present invention relates to a high-temperature fuse 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 fixed to a pair of gold oval lead wires 32L, 3b, housed in a metal protection tube 1, and one end of the metal lead wire is fixed. A fusible metal wire 2 grounded to the metal protection tube
This is a high-temperature fuse whose periphery is protected by an insulating tube 4, a space 6 is completely formed, and the space is filled with a powdered electrical insulating material 5. This high-temperature heater enables the fusible metal wire to be blown out by a space inside an insulating tube that protects the periphery of the fusible metal wire. However, when the 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 may ground inside the metal protection tube, and the fusible metal wire may ground inside the metal protection tube. Since there is space around the metal wire, it had major drawbacks in mechanical strength, such as wire breakage. Further, due to the oxygen remaining in the space around the fusible metal wire, the fusible metal wire may be oxidized at high temperature during long-term high-temperature durability, which may impede fusing.

Purpose of the Invention The present invention involves inserting and fixing a pair of metal lead wires into a pipe-shaped fusible metal tube that has a space larger than the volume of the fusible metal, and storing the wires in a metal protective tube with one end sealed.
A high temperature fuse is provided which is filled with a powdered electrical insulating material.

Structure of the Invention The present invention provides a pipe-shaped fusible metal tube with a pair of metal lead wires and an internal space larger than its volume, which is housed in a metal protective tube with excellent heat resistance and corrosion resistance that is completely welded at one end. The tube portion is filled and fixed with vitreous powder and ceramic fixing material, the metal lead wire portion in the metal protection tube is filled with powdered electrical insulating material, and the diameter of the metal lead wire portion is reduced by swaging or the like. , a high-temperature fuse made by compressing and solidifying the powdered electrical insulating material.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to FIG. 1 is a metal protection tube made of stainless steel, Incoloy, Inconel, etc. with excellent heat resistance and corrosion resistance, and the entire tip is sealed by inert gas arc welding or the like. 8 is precious metal and silver wax.

It is a fusible metal tube in the form of a pipe, which is made of general solder materials such as palladium solder, or alloys thereof, and has an internal space. 9a and 9b are metal lead wires made of stainless steel, nickel, nichrome wire, etc. with excellent heat resistance and corrosion resistance, which are inserted from both sides into the fusible metal tube 8 to a predetermined position, and welded by plasma welding, spot welding, etc. It is fixed.

Reference numeral 10 denotes a space formed after the metal lead wires 9a and 9b are welded and fixed, and has an internal volume larger than the volume of the fusible metal tube. Reference numeral 11 is a glassy powder having a melting point lower than that of the fusible metal tube, and is filled and interposed around the fusible metal tube. 12 is an electrically insulating filler made of magnesia, alumina, silicon tinide powder, etc., which is compressed and solidified by reducing the diameter of the metal protection tube by swaging, etc.
Holds the metal lead wire firmly. Note that instead of the glassy powder, a ceramic fixing material made of activated alumina powder or the like may be used. Reference numeral 14 denotes a sealing material with excellent heat resistance, which is made of an epoxy resin and a glassy adhesive.

As described above, the pipe-shaped fusible metal tube 8 having a space larger than the volume of the fusible metal has a melting point lower than that of the fusible metal 8 even when it expands and contracts due to vibration and repeated temperature increases and decreases. In addition to being fixed to the molten part of the glass material 11 shown in FIG. Holds enough. This prevents the fusible metal pipe from being accidentally disconnected or deformed.

It can be reliably fused at a predetermined temperature.

Effects of the Invention As described above, according to the present invention, a high-temperature heater with excellent heat resistance, vibration resistance, etc. can be provided.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a main part of a conventional high temperature fuse, and FIG. 2 is a sectional view of a main part of a high temperature fuse of the present invention. 1... Metal protection tube, 8... Fusible metal tube, 9a. 9b... Metal lead wire, 1o... Space, 11... Glassy powder, 12... Powdered electrical insulating material, 13... - Ceramic fixing material, 14... Sealing material. Name of agent: Patent attorney Toshio Nakao (1st person)
Figure 2

Claims (1)

[Claims] Insert and secure metal lead wires to predetermined positions from both ends of a fusible metal tube that forms an internal space larger than the volume, and store this in a metal protection tube whose one end is welded and sealed.
A high temperature fuse comprising the fusible metal tube portion filled with a powder having a melting point lower than the melting point of the fusible metal, and the metal lead wire portion filled with a powdered electrical insulating material.