Temperature-sensitive pellet type thermal fuse

Abstract

The present invention relates to a temperature-sensitive pellet type thermal fuse. Particularly, a movable terminal (40) resiliently supported by a first actuating spring (SP1) is inserted into and installed in a holding case (60) while being supported by a plurality of tip end side finger portions (53) of a sleeve (52) provided at a grip member (50) in an outer casing (10) that has a first lead wire (30) and a second lead wire (35) which are coupled to opposite tip ends thereof, respectively. The bottom wall (61) of the holding case (60) is brought into resilient contact with a temperature sensitive pellet (70) by a second actuating spring (SP2), and when the temperature sensitive pellet (70) has a gradually decreasing height while being melted by a temperature rise in the internal atmosphere of the outer casing (10), the holding case (60) slides by the decrease in the height by an acting force of the second actuating spring (SP2). As a result, the finger portions (53), provided at the tip end of the sleeve (52) of the grip member (50), release the movable terminal (40) while expanding in a recess (63) formed on the inner surface of the holding case (60) so that a first fixing contact point (32) of the first lead wire (30) and a first movable contact point (42) of the movable terminal (40) are separated from each other, thereby accomplishing a fuse-off operation of short-circuiting the first lead wire (30) and the second lead wire (35).

Description

technical field [0001] The present invention relates to a temperature-sensitive particle type thermal fuse, in particular to the temperature-sensitive particles inside the sealed cylindrical casing reacting to the sealed cylindrical casing when the internal temperature of the sealed cylindrical casing rises above a predetermined set value A temperature-sensitive particle type thermal fuse that disconnects the circuit due to internal temperature changes. Background technique [0002] As a component that detects abnormal overheating of equipment and quickly disconnects circuits, thermal fuses are used in many applications such as various household appliances, portable electronic communication equipment, office equipment, automotive electronic equipment, AC adapters, chargers, motors, batteries, etc. kind of field. [0003] The thermal fuse generally uses, as a temperature-sensitive material, a particle type molded from organic compound particles that melt at a predetermined t...

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Problems solved by technology

[0005] However, in the case of the existing thermal fuse having the structure as described above, since the cut-off operation responds sensitively to a slight difference in the urging forces of the two operating springs or a small temperature-sensitive particle Therefore, there is a problem of misoperation of disconnecting the circuit when unexpected shrinkage deformation of the temperature-sensitive particles occurs in a low-temperature region lower than the set operating temperature range

[0006] In addition, since the existing thermal fuse operates sensitively in response to the height reduction of the temperature-sensitive particles, there is a difficulty corresponding to the temperature range where the maximum reduction of the temperature-sensitive particles occurs (the temperature-sensitive particles are completely melted). temperature range) to adjust the structural disadvantages of the set temperature range

[0007] In addition, since the movable terminal is arranged in a structure in which the conductive film is bent and formed at the edge position in the conventional thermal fuse and is in sliding contact with the inner surface of the case (the second fixed contact point), there is a In the case of external impact, the movable terminal may be slightly spaced or deformed at the contact point with the housing, thereby causing a problem of poor contact with the second fixed contact point

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