Circuit breaker

• US 6,411,190 B1
• Filed: 08/02/2000
• Issued: 06/25/2002
• Est. Priority Date: 08/03/1999
• Status: Expired due to Fees

• Current Assignee: Yazaki Corporation
• Original Assignee: Yazaki Corporation
• Inventors: Morimoto, Mitsuaki, Takahashi, Hideo, Gohara, Takashi, Tamai, Yasuhiro, Ikuta, Yoshinori, Yamaguchi, Noboru
• Primary Examiner(s): Vortman, Anatoly
• Application Number:
  US09/631,647
• Time in Patent Office: 692 Days
• Field of Search: 337/401, 337/157, 337/404-406, 337/408, 337/409, 307/119, 307/9-- 1, 180/271, 180/274, 180/279, 180/281-283, 200/61.08, 361/115
• US Class Current: 337/401
• CPC Class Codes: H01H 2039/008 using the switch for a battery cutoff
• CPC Class Codes: H01H 39/00 Switching devices actuated by an explosion produced within the device and initiated by an electric current

Abstract

A current sensor 73 detects a current flowing through a first buss bar 11. When a current value detected by the current sensor 73 became equal to or greater than a threshold current value, a CPU 74 outputs a driving control signal to a driving circuit 77, and the driving circuit 77 operates an, ignitor 29 through a second substrate 65 and a terminal 50. Therefore, the ignitor 29 ignites, a second projection 41 is melted by heat of a heating agent 27, a compression spring 34 is expanded and a thermite case 26 jumps up. Thus, electrical connection between the thermite case 26 and the first and second buss bars 11, 19 is interrupted. Further, since an outer container 61 in which the current sensor 73, the CPU and the driving circuit 77 are accommodated is integrally assembled with the cap 14a and the resin case 14b in which the thermite case 26, the ignitor 29, the compression spring 34 and the second projection 41 are accommodated, non-operational state of the ignitor 29 due to disconnection of electric wire is not generated.

Claims

1. A circuit breaker comprising

a conductive heating portion disposed between a first connecting terminal and a second connecting terminal such that the heating portion is in contact with the first connecting terminal and the second connecting terminal and having a heating agent therein,

an ignitor accommodated in the heating portion for igniting the heating agent charged in the heating portion when abnormal conditions of a vehicle are encountered,

an expandable resilient member which is disposed such that the resilient member is in contact with the heating portion for pushing the heating portion,

a melting member for maintaining the resilient member in its compressed state,

a first container for accommodating the heating portion, the ignitor, the resilient member and the melting member,

a detecting portion for detecting an abnormality of the vehicle,

a judging portion for judging whether the vehicle is under abnormal conditions based on an output from the detecting portion and for outputting a driving control signal when the judging portion judged that the vehicle is under the abnormal conditions,

a driving portion for operating the ignitor based on the driving control signal from the judging portion, and

a second container for accommodating the detecting portion, the judging portion and the driving portion, and the second container being integrally assembled with the first container.

2. A circuit breaker according to claim 1, further comprising

a connector having a terminator whose one end is electrically connected to the ignitor, and

a substrate provided for mounting the detecting portion, the judging portion and the driving portion into the second container, wherein

the other end of the terminal is soldered to the substrate, and the driving portion and the ignitor are electrically connected to each other through the substrate and the terminal.

3. A circuit breaker according to claim 2, wherein the connector is detachable with respect to the ignitor, and the connector is disengaged from the ignitor when the ignitor is moved by ignition of the heating agent.

4. A circuit breaker according to claim 1, wherein

the detecting portion is a current sensor for detecting a current flowing through at least one of the first connecting terminal and the second connecting terminal, and

the judging portion judges whether a current value detected by the current sensor became equal to or greater than a preset threshold value, and if the current value detected by the current sensor became equal to or greater than the threshold value, the judging portion outputs the driving control signal to the driving portion.

5. A circuit breaker according to claim 1, wherein

the melting member is made of resin member which is formed in the first container and which prevents a pushing force of the resilient member against the heating portion.

6. A circuit breaker according to claim 1, wherein

an end of the heating portion is formed with a side wall, and the side wall is connected to the first connecting terminal and the second connecting terminal through a low-melting material.