JP2009266668A - Overcurrent trip mechanism - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an overcurrent tripping mechanism in which time required until an electric path is cut off can be obtained constantly with a small number of parts by installing a retaining member to keep a distance between a hooking piece and a bimetal constant. <P>SOLUTION: This invention relates to the overcurrent tripping mechanism installed inside a case of a circuit breaker, wherein the overcurrent tripping mechanism is composed of: the bimetal consisting of a fixed end which is formed of a long plate and of which one end is fixed, and a free end of which the other end is freely installed; a load seat which is integrally installed with the fixed end of the bimetal, and in which a sidewall is installed; and the hooking piece which is rotatably installed by installing and pinching a shaft fastening part at the sidewall of the load seat. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an overcurrent tripping mechanism in a circuit breaker.

Conventionally, in a circuit breaker using an overcurrent tripping mechanism, as described in Patent Document 1, when an abnormality such as an overcurrent, a short circuit, or a leakage occurs in a main circuit, a bimetal provided in the case 21 24. The tripping mechanism comprising 24 and the engaging piece 29 is driven to release the pressing of the movable contact by the opening / closing mechanism, and the main circuit is shut off by separating the movable contact from the fixed contact by a spring. There was a circuit breaker.
JP 2004-55173 A

  However, in the invention described in Patent Document 1, since the engaging piece is held by the case, there is a possibility that the position of the engaging piece may be changed when the case is deformed due to heat generated by the circuit breaker itself or surrounding moisture. There is. As a result, there is a drawback in that there is a possibility that variations occur in the time until the electric circuit is cut off when an overcurrent flows.

  For this reason, the problem to be solved by the present invention is to reduce the possibility that the position of the engaging piece will change due to the case being deformed by the heat generated by the circuit breaker itself or the surrounding moisture, etc. The present invention is to provide an overcurrent tripping mechanism with a small number of parts, which can obtain a constant time required until the circuit is shut off.

  The overcurrent tripping mechanism of the present invention made to solve the above-described problem is an overcurrent tripping mechanism provided inside a case of a circuit breaker, and the overcurrent tripping mechanism is formed from a long plate. A bimetal consisting of a fixed end with one end fixed and a free end with the other end freely provided, a load seat with a fixed end and one end of the bimetal provided integrally and a side wall, and a shaft fixed to the side wall of the load seat It consists of a hooking piece provided so as to be rotatable by providing a portion and sandwiching it.

  According to the overcurrent tripping mechanism of the present invention, the side wall is provided on the load seat, the shaft stopper is provided, and the engaging piece is sandwiched between the shaft stopper, so that the circuit breaker itself generates heat or the surrounding humidity. It is possible to reduce the possibility that the position of the hooking piece is changed by the deformation of the case. As a result, it is possible to obtain a constant time required until the electric circuit is interrupted when an overcurrent flows.

  In addition, since a part of the load seat is deformed to provide the side wall, it is not necessary to prepare a new part, and a configuration with the same number of parts as in the past is possible.

  In the present invention, a structure that can obtain a constant time until interruption of the electric circuit can be obtained with a small number of parts.

Embodiments of the present invention will be described below.
An overcurrent tripping mechanism provided in the case 1 of the circuit breaker, the overcurrent tripping mechanism is formed of a long plate and fixed at one end to be fixed ends 2 and 12 and freely provided at the other end Bimetals 4 and 14 comprising free ends 3 and 13, fixed ends and one ends of the bimetals 4 and 14 are provided integrally, load seats 6 and 16 provided with side walls, and shafts on the side walls 5 and 15 of the load seats. It consists of engaging pieces 9 and 19 which are provided so as to be rotatable by providing the stoppers 8 and 18 and sandwiching them. Bimetals 4 and 14 and load seats are provided on the L1 pole and the L2 pole, respectively. The side walls 5 and 15 of the L1 pole load seats 6 and 16 and the L2 pole load seat 17 are provided at positions distant from each other. The shaft stoppers 8 and 18 provided on the side walls 5 and 15 are subjected to insulation treatment to thereby engage the engagement piece 9. , 19 can prevent a short circuit from occurring due to electricity flowing. Since the engaging pieces 9 and 19 are not installed in the case 1, it is possible to reduce the possibility that the positions of the engaging pieces 9 and 19 are changed by the case 1 being deformed by the heat generated by the circuit breaker itself or the surrounding moisture. . Moreover, it is possible to obtain a constant time required until the electric circuit is interrupted when an overcurrent flows.

  As described above, according to the overcurrent tripping mechanism of the present invention, the case is deformed by the heat generated by the circuit breaker itself, the surrounding moisture, etc. by providing the side wall on the load seat and holding the engaging piece. The possibility of changing the position is reduced, and it is possible to obtain a constant time until the electric circuit is cut off when an overcurrent flows.

It is sectional drawing of the circuit breaker using the overcurrent trip mechanism in Example 1 of this invention. It is a partial disassembled perspective view of the overcurrent tripping mechanism in Embodiment 1 of the present invention. It is sectional drawing of the overcurrent trip mechanism of patent document 1 in a prior art.

Explanation of symbols

1, 11, 21 Case 2, 12 Fixed end 3, 13 Free end 4, 14, 24 Bimetal 5, 15 Side wall 6, 16 L1 pole load seat 17 L2 pole load seat 8, 18 Shaft stopper 9, 19 Engagement piece

Claims (1)

  An overcurrent tripping mechanism provided inside a case of a circuit breaker, the overcurrent tripping mechanism being formed from a long plate and having a fixed end with one end fixed and a free end with the other end provided freely A bimetal, a fixed seat and one end of the bimetal provided integrally, a load seat provided with a side wall, and a hooking piece provided so as to be rotatable by providing a shaft stopper on the side wall of the load seat. An overcurrent tripping mechanism characterized by comprising:

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