JPH0621205Y2 - Resistor with fuse function - Google Patents

Description

TECHNICAL FIELD The present invention relates to a resistor with a fuse function used as a safety component in consumer equipment and industrial equipment.

2. Description of the Related Art Conventional examples include those shown in FIGS. 3 and 4.

In FIG. 3, reference numeral 1 is a low-melting glass applied between the grooves of the resistor element, and when the power applied to the resistor is increased,
The low-melting-point glass 1 melts due to heat generation due to increase in applied power and reacts with the resistance film between the groove cuts to melt the film, that is, has a role of fusing the resistor. Reference numeral 2 is a resistance element, and the surface thereof is spirally grooved. 3 is a ceramic case for protecting the resistor. A cement encapsulant 4 has a function of bringing the low-melting glass 1 into close contact with the resistance element 2. However, in this case, since the entire area around the resistor was hardened with the cement encapsulant, there was nothing that blocked the heat generated by the resistor when the resistor was energized, and the surface temperature of the resistor was high.

Next, in the case of FIG. 4, the low melting point glass 1, the resistor element 2,
The ceramic cases 3 are similar to those shown in FIG.
In the figure, the ceramic case 3 is not enclosed with cement, but the air insulating layer 5 is provided. 6 is an encapsulating resin.

However, this is because the resistance element is arranged in the space,
There was a concern that the adhesion of the low-melting-point glass would be imperfect in devices with particularly severe vibration, and in some cases would come off.

Problems to be Solved by the Invention As described above, the conventional product has a problem of low-melting-point glass adhesion to the surface temperature rise of the outer periphery of the resistor (including the terminal portion) and vibration as described above.

The present invention is a resistor with a fuse function that reduces the surface temperature rise around the resistor (including terminals) and does not impair the original function due to incomplete adhesion of the low melting point glass against vibration. Is to provide.

Means for Solving the Problems In order to solve this problem, the present invention uses a resistor element in which a groove is spirally cut and a low melting point glass is applied between the groove and the resistor element by a filler. It is composed of a first case sealed inside, a second case provided on the outer periphery of the first case via an air heat insulating layer, and a third case provided on the outer periphery of the second case via a filler. It is composed of a case main body and a terminal which is enclosed and fixed in the case main body so as to hold a folding resistance element body and which is pulled out to the outside of the case main body.

With this configuration, heat generated when the resistor is energized is less likely to be transmitted to the surface of the case body by providing the air heat insulating layer between the first case and the second case.

Also, by encapsulating the cement in the first case, the reliability of the adhesion of the low melting point glass to the resistor element is ensured even if it is subjected to vibration, and a part of the terminal is bent and enclosed in the case body By fixing with the filler, the terminal is securely held.

Embodiment FIG. 1 and FIG. 2 show a resistor with a fuse function according to an embodiment of the present invention. FIG. 1 is a sectional view from the front direction and FIG. 2 is a perspective view from the side. is there.

In the figure, 11 is a low-melting glass for melting the resistance film of the resistance element 12, which is applied between the grooves. Thirteen
Is a terminal for fixing the resistor element 12, which is fixed by an external cement layer 16 which is a filler. Reference numeral 14 denotes an electrode terminal, which is supported and fixed by cement in a ceramic case which is a case body. Reference numeral 15 denotes an internal cement layer which is a filler and can completely support and fix the low melting point glass 11 applied to the resistance element body 12. Reference numeral 16 is an external cement layer which is a filler and can securely fix the terminals 13 and 14 for the resistor. Reference numeral 17 denotes an air heat insulating layer located between the cement 15 and 16 layers, and the outer cement layer 1
Since heat is prevented from being transmitted to 6, heat is less likely to be transmitted to the surface of the case body. Reference numeral 18 denotes a triple ceramic case which is a case main body including first to third cases.

With the above structure, the problems of the conventional product can be solved at once.

As described above, according to the present invention, the resistance element is provided by providing the air heat insulating layer between the first case and the second case of the case body including the first to third cases. The heat generated in the case is prevented from being transmitted to the surface of the case body, and the rise in the surface temperature of the case is suppressed. Also, by interposing the terminal in the filler between the second case and the third case, the heat in the filler can be radiated from the terminal to the outside of the case body, which also results in the surface temperature of the case body. It is possible to reduce. Since the resistor element body is sealed with the filler, the low melting point glass can be completely adhered to the resistor element body, and the original fuse function is not impaired by vibration or the like. Further, by interposing a filler between the second case and the third case, it is also possible to obtain an enhanced support and fixation of the resistor element and the terminal and a heat dissipation effect.

[Brief description of drawings]

FIGS. 1 and 2 are sectional and perspective views of a resistor with a fuse function according to an embodiment of the present invention, and FIGS. 3 and 4 are partially cutaway views of a conventional resistor with a fuse function. It is a perspective view shown. 11 ... Low melting glass, 12 ... Resistor element, 13 ... Resistor fixing terminal, 14 ... Resistor electrode terminal, 15 ...
Inner cement layer, 16 ... Outer cement layer, 17 ... Air insulation layer, 18 ... Ceramic case.

Claims (1)

[Scope of utility model registration request] 1. A resistor element body having a spiral groove and a low melting point glass applied between the groove portions, a first case in which the resistor element body is sealed with a filler, and an air insulating layer. A case body composed of a second case provided on the outer circumference of the first case and a third case provided on the outer circumference of the second case via a filler, and a part of which is bent to hold the resistance element body. A resistor with a fuse function that consists of a terminal that is sealed and fixed in the case body and that is pulled out to the outside of the case body.