JPS60246524A - Temperature fuse and method of producing same - 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 (1) Field of Industrial Application This invention relates to a temperature fuse that is used by being incorporated into a small electric device, particularly a small power transformer.

(2) Conventional technology A temperature fuse is a safety device that opens a circuit when an overload current flows through an electrical device. A thin one is desired.

Therefore, in the past, as shown in Fig. 6,
43035), a method has been devised in which a lead wire 22 is welded to the end of a foil-like low-melting point metal 21, and the low-melting point metal 21 is wrapped in a film-like insulating material 23+.

(3) Problems to be solved by the invention In the conventional fuse 1, the lead wire 22 is welded to the metal 21, so the welding point is large and the thickness is sufficient. Not only is it impossible to make it thin enough to satisfy
The distance between the welding points of the two lead wires 22 is non-uniform, causing a problem in operating characteristics.

(4) Means for solving the problem The purpose of this invention is to solve the above problem, and in order to achieve this purpose, one piece of casting molding is carried out between two lead wires.
A notebook-shaped low melting point metal is provided above this, a notebook-shaped insulator is crimped on the front and back surfaces of this metal and the lead wire portion continuous with it, a gap is formed between the metal and the insulator, and this gap is filled with flux. It's Hughes.

In addition, in order to manufacture the above-mentioned temperature fuse, a flat hole is formed between the upper and lower molds, and a groove passing through both ends of the hole is formed, a lead wire is fitted into the groove, and the porous low melting point metal is cast. A fuse body is formed by casting a low melting point metal between the wires, and a sorted insulator is placed on the front and back surfaces of the L-+-- body with flux interposed therebetween, and a lead wire protrudes from the insulator. This manufacturing method involves heat-welding both insulators.

The temperature fuse manufactured in this manner is a flat type, and is used by inserting it into the coil of a transformer.

If an overcurrent flows, the low melting point metal will melt and open the circuit.

An embodiment of the present invention will be described below with reference to the accompanying drawings.

(5) Embodiment As shown in FIG. 3, a flat hole 2 is formed in the lower die 1, and an even number of grooves 3 passing through the hole 2 are also formed. Groove 3
The number of fuses to be formed corresponds to the number of fuses to be made in one mold. On the other hand, a runner 5 having a length corresponding to the hole 2f is formed on the upper surface of the second mold 4, and a weir 6 communicating from the runner 5 to the back surface is formed. The weir 6 is located between the wide grooves 3, and is symmetrically arranged between the same grooves 3 with respect to the center line in the longitudinal direction of the hole 2.
Form individuals. The depth of the hole 2 is set appropriately, and the groove 3 is made deeper than the hole 2.

After preparing the upper and lower molds 1.4 and fitting the lead wires 7 into each groove 3 as shown by the chain lines in FIG. Road 5 and a half [:t,]
A low melting point metal 8 such as f or c is poured into the hole 2 from the weir 6.
Cast inside. At this time, if the mold is vibrated or the hot water is pressurized, it will spread between the metal 8 and the holes 2.

When the metal 8 is cut out after assimilation, since the metal 8 in the hole 2 is thin, the V-shaped part 6 is attached to the runner 5 side and separated, and a through hole 9 is formed in the center. After cutting out the mold, as shown in Figure 5, 1.
Pair lead wire 7 of the book! Strain and cut, and then cut jyj between the through holes 9 as indicated by the chain lines in the figure to obtain the fuse body 1.
Since the groove is deeper than 3, as shown in Figure 2,
A step is formed between the lead wire 7 and the metal 8.

Next, the fuse body a is arranged in parallel on the sorted insulator 10 so that its lead wire 7 protrudes, and the flux 11 is placed on top of it to fill the through hole 9 and the step. 10, heat weld both insulators 10,
Cut each fuse body and remove the
A temperature fuse A shown in FIG. 2 is obtained.

If this fuse A is used by inserting it into a coil of a transformer, etc., or if an overcurrent flows and the temperature increases and the metal 8 melts, the flux 1 prevents the formation of oxides and the through hole 9 Due to the presence of voids such as and steps, the molten metal 8 is cut by surface tension, cutting off the current.

In this embodiment, the gap between the metal 8 and the insulator 10 is formed by a through hole 9 and a step 1, or a note-like low melting point metal is provided in only one of them by casting, so it is easy to manufacture. In addition, the metal can be made thinner, and the cutting operation characteristics can be stabilized.

Therefore, according to the present invention, an extremely thin thermal fuse with good operating characteristics can be obtained at a low cost.

[Brief explanation of drawings]

FIG. 1 is a perspective view of an embodiment of the temperature fuse of the present invention;
Fig. 2 is a cutaway view of Fig. 1, Fig. 3 is a perspective view of an embodiment of the manufacturing method, Fig. 4 is a sectional view of the mold shown in Fig. 3 in a tightened state, and Fig. 5 is a midway through the manufacturing process. FIG. 6 is a partially removed perspective view of a conventional thermal fuse. 1...Lower die, 2...Flat hole, 3...Groove, 4...Upper die, 7
...Lead wire, 8..Low melting point metal, 9..Through hole, 10
- Sorted insulator, 11...Flux, [...Step, a...Fuse body, A...Temperature fuse. Patent applicant Atsuma Mizuno Agent Kama 1) Bun 2

Claims (5)

[Claims] (1) A notebook-shaped low melting point metal is provided between two lead wires by casting, and a notebook-shaped insulator is crimped on the front and back surfaces of this metal and the continuous lead wire portion, and a notebook-shaped insulator is crimped between the metal and the insulator. is a temperature fuse in which a void is formed and the void is filled with flux. (2) The temperature fuse according to claim (1), wherein the void is formed through a hole in the center of the metal. (3) The temperature fuse according to claim (1), wherein the gap is formed so that the lead wire and the metal have a different thickness. (4) A flat hole is formed between the upper and lower molds, and a groove passing through both ends of the hole is formed, a lead wire is fitted into the groove, a low melting point metal is cast into the hole, and a low melting point metal is cast between the lead wires. A fuse body is formed by molding, a sheet-like insulator is applied to the front and back surfaces of the fuse body with flux interposed therebetween, so that the lead wire protrudes from the insulator, and both insulators are welded together by heat. Method of manufacturing temperature fuses. (5) The groove is made deeper than the flat hole to form a one-thickness difference between the lead wire and the low melting point metal, and the void created by this difference is filled with flux. ) The method for manufacturing the temperature fuse described in paragraph 1.