JPH0624119Y2 - Circuit breaker - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention relates to a circuit breaker, and more specifically, a fixed contact is formed in a U-shape, and an electromagnetic repulsive force is utilized during high-speed interruption to provide a space between the contacts. The present invention relates to a circuit breaker adapted to open the contact.

[Conventional technology]

FIGS. 4A and 4B show an example of the configuration of a conventional circuit breaker of this type. In addition, FIG.
Figure B shows the closed state. In these drawings, 1 is a case, 2 is a cover, 3 is a case fixed to the case 2, and is a fixed contactor formed in a U-shaped folded shape, 3A is a fixed contact, and 4 is from the fixed contact 3A. The arc horn 5 formed by extending the fixed contact conductor is a movable contact 5A.
A movable contactor equipped with an arc horn 4 which guides an arc generated between the fixed contactor 3 and the movable contactor 5 to the arc extinguishing chamber 6 at the time of high-speed interruption by the arc horn 4 and cools the arc in the process. Can be made.

Reference numeral 7 is a pivot pin of the movable contact 5, reference numeral 8 is a lead wire connecting the movable contact 7 to the conductor connecting piece 9, 10 is a bimetal whose one end is fixed to the conductor connecting piece 9, and 11 is an electromagnetic breaker. Is a fixed core, and 12 is a load side terminal plate.
Further, 13 is an opening / closing operation handle which is swingably held by the cover 2, 14 is an opening / closing spring, and 15 is an opening / closing link mechanism. The handle 13 operates the movable contact 5 via the opening / closing link mechanism 15, Can be opened and closed.

[Problems to be solved by the device]

However, in such a conventional circuit breaker, an excessive bending stress is generated in the fixed contactor 3 which is formed by bending the movable contactor 5 in a U-shape when the movable contactor 5 is closed and deformed. If it is easily deformed, the contact pressure is reduced, which causes a rise in temperature and poor conduction. Therefore, in order to prevent such deformation, conventionally, the cross section of the conductor forming the fixed contactor 3, that is, its thickness and width is made as large as possible to obtain bending strength. As described above, in order to perform the high-speed opening by utilizing the electromagnetic repulsive force between the parallel conductors in the U-shaped fixed contactor 3, as described later, the conductor area is reduced as much as possible and a large repulsive force is generated. You need to get it.

The purpose of the present invention is to focus on the above-mentioned conventional problems,
In order to solve the problem, it is an object of the present invention to provide a circuit breaker including a fixed contactor having a small conductor cross-sectional area, which is not deformed and which is suitable for high-speed opening.

[Means for Solving the Problems]

In order to achieve such an object, the present invention provides: 1) a first conductor portion extending from a power supply connection terminal portion, and a folded back portion parallel to the first conductor portion. An arc generated at the time of high-speed opening, which has a fixed contact formed of a second conductor portion provided and a movable contact which performs a high-speed opening operation by an electromagnetic repulsive force generated between the fixed contact and the fixed contact. In a circuit breaker equipped with an arc horn for cooling, an arc horn forming member of the conductor, wherein the arc horn is formed at a tip and the tip of the second conductor is locked. It is characterized in that the width of the second conductor portion can be narrowed by reinforcing the arc horn forming member.

[Action]

According to the present invention, the arc horn forming member is erected from the first conductor portion before being folded back in parallel to the second conductor portion to which the fixed contact after being folded back in parallel is installed, and Since the second conductor is supported by the part,
The width of the cross section of the second conductor portion after folding back in parallel can be reduced without fear of deformation, and a strong electromagnetic repulsive force can be generated.

[Embodiment] An embodiment of the present invention will be specifically described below with reference to the drawings.

1A and 1B show an embodiment of the present invention. In these drawings, there is no difference from the structure shown in FIGS. 4A and 4B except the structure related to the fixed contact, and the description thereof will be made. Omit it. Reference numeral 30 is a fixed contact according to the present invention, and 40 is an arc horn forming member according to the present invention. Therefore, in this example, the fixed contact 30 and the arc horn forming member 40 are combined and configured as shown in FIGS. 2A to 2C.

That is, in FIGS. 2A to 2C, the fixed contact 3
Reference numeral 0 denotes the first conductor portion 30A before bending, which is guided from the power source connection terminal portion 16 along the case 1 as shown in FIG. 1A.
Then, the second conductor portion 30 is folded back and guided in parallel with the first conductor portion 30A, and the fixed contact 3A is attached to the upper surface of the end portion thereof.
B, but in this example, the second conductor portion 30B
Is formed narrower than the first conductor portion 30A as shown in FIG. 2C. In addition, the arc horn 40A is attached to the fixed contact 3
In the case of this example, the arc horn 40A is formed as a member 40 separately from the fixed contact 30 as shown in FIG.

That is, in FIG. 3, 40A is an arc horn provided on the arc horn forming member 40, 40B is also provided on a part of the arc horn forming member 40, and the second conductor portion 30B is provided.
40C is a support portion that supports the end of the fixed contact 30, 40C is a leg portion that is fitted into the cutout portion 30C provided in the first conductor portion 30A of the fixed contact 30, and 40D is a rising portion that is integral with the leg portion 40C. By combining such an arc horn forming member 40 with the fixed contactor 30, a configuration as shown in FIGS. 2A to 2C is obtained, and the width of the second conductor portion 30B in the fixed contactor 30 is narrowed as shown. Even so, it can be supported by the arc horn forming member 40, and can sufficiently withstand the pressure applied during the charging operation.

In this case, the current short-circuited from the end of the second conductor portion 30B to the first conductor portion 30A via the member 40 is extremely small due to the resistance of the member 40 and the fixed contact 30 because of the contact structure. Therefore, there is no fear that the electromagnetic repulsive force will decrease. However, by narrowing the conductor width in the fixed contact 30 in this way, the effect of increasing the electromagnetic repulsive force can be obtained.

The reason will be described in detail below. The electromagnetic force F generated in such a case is such that the conductor length is L, the spacing between the conductors is S, the current is I, and the correction coefficient when the conductor cross section is rectangular is k. If
As is generally known, it is expressed by the following equation.

F = 2.04 k ^L / _S I ² × 10 ^-2 [kg] (1) Therefore, when L and S are constant, the electromagnetic force F is proportional to the correction coefficient k. Regarding the correction coefficient k, the smaller the relative width with respect to the thickness of the conductor, the larger the value. If the thickness is the same, the smaller the width is, the larger the correction coefficient k becomes. Therefore, a large electromagnetic force F can be obtained.

[Effect of device]

As described above, according to the present invention, the arc horn forming member of the conductor, in which the arc horn is formed at the tip and the folded second conductor portion is supported in the middle thereof, is the first conductor portion before folded. Since the width of the second conductor portion supported by the arc horn forming member is narrowed, the electromagnetic repulsion force generated at the time of high-speed contact opening can be further increased, and effective cutting is performed. In addition, the second conductor portion of the fixed contact is deformed due to the force applied when the power is turned on due to the reinforcement by the arc horn member, and the decrease in the contact pressure of the contact causes temperature rise and poor conduction. Can be prevented.

BRIEF DESCRIPTION OF THE DRAWINGS FIGS. 1A and 1B are sectional views showing an embodiment of the present invention in an open state and a closed state, respectively, and FIGS. 2A, 2B and 2C relate to the present invention. FIG. 3 is a side view, a top view and a perspective view showing the assembled state of the fixed contactor and the arc horn forming member, respectively. FIG. 3 is a perspective view of the arc horn forming member, and FIGS. 4A and 4B are conventional circuit breakers. 3 is a cross-sectional view showing the configuration of FIG. 2 in an open state and a closed state. 1 ... Case, 3A, 5A ... Contact, 5 ... Movable contactor, 6 ...
Arc extinguishing chamber, 30 ... Fixed contactor, 30A ... First conductor portion, 30
B ... 2nd conductor part, 30C ... Notch part, 40 ... Arc horn formation member, 40A ... Arc horn, 40B ... Support part,
40C ... leg part, 40D ... rising part.

Claims (1)

[Scope of utility model registration request] 1. A first conductor portion extending from a power supply connection terminal portion, and a second conductor portion folded back to be parallel to the first conductor portion and having a fixed contact provided on an upper surface of a tip thereof. And a movable contactor that performs a high-speed opening operation by an electromagnetic repulsive force generated between the fixed contactor and an arc horn for cooling an arc generated during the high-speed opening. In the circuit breaker described above, the arc horn is formed at the tip, and an arc horn forming member made of a conductor is provided upright from the first conductor portion so that the tip of the second conductor portion is locked. A circuit breaker, characterized in that the width of the second conductor portion can be narrowed by reinforcing the member.