JPH031880Y2 - - Google Patents

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to an improvement of an overcurrent protection element.

<Prior Art> As an overcurrent protection element, an element in which a low melting point alloy body as a temperature fuse element and a resistance element are closely assembled has been proposed. How to use this overcurrent protection element is to connect the resistance element to the circuit of the electrical equipment to be protected, connect the low melting point alloy body to the power supply end of the electrical equipment, and when an overcurrent flows through the electrical equipment, the overcurrent will The purpose is to cause a resistance element to generate heat, fuse the low melting point alloy body with the generated heat, and cut off the electrical equipment from the power source by this melting.

<Problems to be Solved> However, in this type of conventional overcurrent protection element, the heat transfer between the resistance element and the low melting point alloy body is poor, the above-mentioned operation speed is slow, and the overcurrent protection element is slow. The amount of time it takes to do so becomes longer, which poses a problem.

An object of the present invention is to improve the heat transfer between the resistance element and the low melting point alloy in the overcurrent protection element, thereby increasing the operating speed.

<Technical means for solving the problem> The overcurrent element according to the present invention has a counter electrode on one side of a thermally conductive insulating plate, a low melting point alloy layer between the electrodes, and A counter electrode is provided on the surface, a resistance layer is provided between the electrodes, one electrode of each of the two counter electrodes is connected, a lead conductor is connected to each of the other electrodes, and the low melting point alloy layer is connected to the low melting point alloy layer. This is a structure characterized by using a material having a melting point that melts due to heat generation for the resistance layer caused by overcurrent.

<Example> The present invention will be explained below with reference to the drawings.

In FIG. 1, reference numeral 1 denotes an insulating plate with good thermal conductivity, and for example, a ceramic plate or a metal plate coated with insulating paint on both sides can be used. 2a, 2b
is a counter electrode provided on one side of the insulating plate 1, and can be made of copper foil, for example. Reference numeral 3 denotes a low melting point alloy layer provided on one side of the insulating plate 1 so as to span between the electrodes, and an alloy containing lead and tin as main components can be used. 4a and 4b are counter electrodes provided on the ground of the insulating plate 1. 5 has an electrode 4a on the other side of the insulating plate 1;
4b, and a plating resistance layer whose main component is cobalt, nickel, manganese, etc. is used. This resistance layer 5 and the low melting point alloy layer 3 are in a back-to-back positional relationship. 6
is a conductor that connects between the electrodes 2b and 4b, and electrically connects the low resistance layer 5 and the low melting point alloy layer 3. 71 and 72 are lead conductors connected to the electrodes.

<Effects of the invention> The overcurrent protection element according to the invention has the configuration as described above, and since a resistance layer made of plating or the like is used for the resistance element attached to the insulating plate, there is no difference between the resistance layer and the insulating plate. Thermal conductivity can be well improved due to the closeness between the two, and the low melting point alloy layer is present at the position opposite to the resistance layer, which is the heat source and the heat conductivity of the insulating plate. In combination, the heat generated by the resistor during overcurrent can be quickly transferred to the low melting point alloy, and the operating speed of the overcurrent element can be significantly increased.

In addition, the resistance layer is provided across the electrodes, and when the lead conductor is attached to the resistance layer by welding or soldering, direct heating of the resistance layer can be avoided by connecting the lead wire to the electrode. Melting of the low melting point alloy due to welding or soldering heat can be effectively prevented.

When attaching a lead conductor to a low melting point alloy by welding or soldering, direct heating of the low melting point alloy can be avoided by connecting the lead conductor to the electrode 2a, so that melting of the low melting point alloy during welding or soldering can be avoided. can also be fully prevented.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing an embodiment of the present invention. In the figure, 1 is an insulating plate, 2a and 2b are electrodes,
3 is a low melting point alloy, 4a and 4b are electrodes, 5 is a resistance layer, and 71 and 72 are lead conductors.

Claims (1)

[Scope of utility model registration request] A counter electrode is provided on one side of the thermally conductive insulating plate, a low melting point alloy layer is provided between the electrodes, a counter electrode is provided on the other side of the same insulating plate, a resistance layer is provided between the electrodes, and both of the above counter electrodes are provided. A lead conductor is connected between one electrode in each of the electrodes, and a lead conductor is connected to each of the other electrodes, and the low melting point alloy layer is made of a material with a melting point that melts due to heat generation in the resistance layer due to overcurrent. Features an overcurrent protection element.