JP2008071658A - Breaker for wiring - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a breaker for wiring of plate spring finger type easy to secure curvature amount of a bimetal, even when the whole breaker is downsized. <P>SOLUTION: A base part of a bimetal 15 and a base part of a plate spring finger 7 are respectively caulked and fixed on a base part 12 on which a magnetic path of a fixed iron member 10 of an instant tripping device is not formed. Each caulking position is separated apart slightly, and that portion becomes an electric path 16. Since a part of the base part 12 of the fixed iron member 10 of the instant tripping device is made the electric path 16, the curvature amount of the bimetal 15 becomes ease to secure by heater effect of that portion. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a relatively small circuit breaker using a leaf spring finger.

  A leaf spring finger type circuit breaker constituted by a leaf spring has been conventionally known as disclosed in Patent Document 1. In the conventional circuit breaker for wiring, the base portion of the leaf spring finger is fixed to the bimetal by caulking, welding or the like. The current flows through the leaf spring finger bimetal. When an overcurrent flows, the bimetal is bent to operate the tripping mechanism.

In such a circuit breaker, when trying to reduce the overall dimensions, the length of the bimetal is inevitably shortened, so it is difficult to secure the amount of bending of the bimetal when an overcurrent flows, and the overall size is reduced. There was also a problem of obstructing.
JP 2003-178665 A

  The present invention solves the above-described conventional problems, and the structure of the leaf spring finger portion is simple and advantageous for downsizing. Even when the bimetal is shortened for downsizing, overcurrent flows. It is made in order to provide the leaf | plate spring finger type circuit breaker for wiring which is easy to ensure the bending amount of a bimetal.

  The circuit breaker of the present invention, which has been made to solve the above problems, has a bimetal base and a leaf spring finger base between each other on the base that does not form the magnetic path of the fixed iron piece of the instantaneous trip device. Each of the fixed iron pieces is fixed with a space therebetween, and a part of the base of the fixed iron piece is used as an electric circuit. The leaf spring finger is preferably made of a copper alloy and is caulked and welded to the base of the fixed iron piece of the instantaneous trip device. In addition, it is preferable that the bimetal is fixed at the center position in the width direction of the fixed iron piece of the instantaneous trip device, and the leaf spring finger is fixed at a position deviated from the center in the width direction. The surface treatment can be at least two layers and the first layer can be copper plated.

  The circuit breaker of the present invention, on the base that does not form the magnetic path of the fixed iron piece of the instantaneous trip device, by fixing the base of the bimetal and the base of the leaf spring finger with a space between each other, Since a part of the base part of the fixed iron piece of the iron instantaneous tripping device is used as an electric circuit, the part easily generates heat, and the bimetal is heated by a heater effect. For this reason, even if the length of the bimetal is shortened, it is easy to secure a necessary bending amount, which is advantageous for downsizing. Further, since the leaf spring finger, the bimetal, and the fixed iron piece of the instantaneous trip device can be integrated, it is possible to improve the assembly workability.

Hereinafter, embodiments of the present invention will be described in detail.
1 and 2 are overall views of the circuit breaker according to the embodiment. Reference numeral 1 denotes a case, and 2 denotes a handle pivotally supported on the upper portion of the case 1. A latch 4 is provided below the handle 2 via a link 3, and an elevating member 5 is further provided below the latch 4. The elevating member 5 is always urged upward by the coil spring 6. However, when the handle 2 is operated in the on direction (left direction) from the state of FIG. 1, the elevating member 5 is pushed down by the link 3 and the latch 4. Is bent downward, and the movable contact 8 at the tip thereof contacts the fixed contact 9 and is turned on.

  3 and 4 are enlarged views showing a peripheral portion of the fixed iron piece 10 of the instantaneous trip device. This fixed iron piece 10 is formed by pressing a steel plate and bending it into a shape as shown in the figure, and the upper part is a part 11 forming a magnetic path having a horizontal cross section of a U-shape. The lower portion is a base portion 12 including a vertical portion 12a and an inclined portion 12b, and the inclined portion 12b is formed at a position deviated from the center of the fixed iron piece 10 in the width direction.

  Reference numeral 13 denotes a trip piece, which is also formed by pressing a steel plate and bending it into a substantially L shape as shown in the drawing, and its base portion is connected to the base portion 12 of the fixed iron piece 10 of the instantaneous trip device via a return spring 14. It is elastically attached. As shown in FIG. 1, the front end of the latch 4 is locked to the engaging portion of the return spring 14 located in the window hole of the tripping piece 13, and the tripping piece 13 is attached to the fixed iron piece 10 of the instantaneous tripping device. When it is adsorbed or moved in the opposite direction of the latch 4 due to the curvature of the bimetal 15, the latch 4 is detached from the pull-off piece 13 and the pull-out operation is performed as in the conventional product.

  Since the structure of the tripping piece 13 itself is not an essential part of the present invention, FIGS. 5 to 7 show drawings of the peripheral part of the fixed iron piece 10 of the instantaneous tripping device in a state where the tripping piece 13 is removed. As shown in these drawings, a bimetal 15 is provided inside the fixed iron piece 10 at the center position in the width direction. The base of the bimetal 15 is caulked and fixed to the vertical portion 12 a of the base 12 of the fixed iron piece 10.

  Further, the base portion of the leaf spring finger 7 is caulked and fixed to the inclined portion 12b at a position deviated from the center in the width direction of the fixed iron piece 10 of the instantaneous trip device. Although the leaf spring finger 7 is made of a copper alloy, the fixed iron piece 10 is made of a steel plate, so that a caulking strength greater than the conventional caulking strength can be obtained, and the caulking portion to the inclined portion 12 b is used as a fulcrum of the leaf spring finger 7. Can be used.

  Conventionally, in the case of a two-pole circuit breaker, when a leaf spring finger exists at each half-width position of the case and the bimetal is provided at the center of the half-width position of the case, the leaf spring finger has a wide base end. The leaf spring fingers and the bimetal are fixed to each other at the center of the half width of the case, but the material yield of the material is poor because it is necessary to partially widen the material width of the leaf spring fingers. However, in the present embodiment, the bimetal 15 is provided at the center position in the width direction of the fixed iron piece 10 of the instantaneous tripping device, and the leaf spring finger 7 is below the position deviated from the center position in the width direction of the fixed iron piece 10 of the instantaneous tripping device. It is provided in the extended base 12. Therefore, even in a structure in which the centers of the leaf spring fingers 7 and the bimetal 15 are shifted, the yield of the material of the leaf spring fingers is high.

  Further, in this embodiment, the fixed iron piece 10 of the instantaneous tripping device is iron and the leaf spring finger 7 is copper. Therefore, when iron and copper come into contact with each other when caulked, there is a possibility of causing different metal contact corrosion. Therefore, if the surface treatment is two layers of copper-tin and the surface treatment of the second layer is tin by caulking, for example, even if the tin is scraped, there is a first layer of copper, so it becomes a contact between copper and copper and dissimilar metal contact There is no risk of corrosion, and it is sufficient that it has at least two layers.

  Further, when the fixed iron piece 10 and the leaf spring finger 7 or the bimetal 15 of the instantaneous tripping device are caulked and fixed, a protrusion for caulking is formed on the fixed iron piece. In addition, the leaf spring finger 7 or the bimetal is formed. 15 may be formed with a protrusion / arm coupling portion for caulking.

  As described above, in the present invention, the bimetal 15 and the leaf spring finger 7 are both fixed to the base 12 of the fixed iron piece 10 of the iron instantaneous tripping device. Has a predetermined interval, and the interval portion constitutes the electric circuit 16. That is, the upper part of the bimetal 15 is connected to the power supply side terminal 18 via the stranded wire 17, and current flows from the bimetal 15 to the leaf spring finger 7 via the electric path 16.

  Since the electric circuit 16 is made of an iron material, the electric resistance is larger than that of other parts made of copper alloy, and therefore the amount of Joule heat generated when an overcurrent flows is increased. Since the amount of bending of the bimetal 15 can be increased by this heat generation, the amount of bending necessary to move the tripping piece 13 can be ensured even if the length of the bimetal 15 is shortened. It is to be noted that the distance between the tip of the bimetal 15 and the trip piece 13 is adjusted by an adjusting screw 19 provided at the tip of the trip piece 13 as in the conventional case.

  Therefore, if the configuration of the present invention is adopted, a part of the base 12 of the fixed iron piece 10 of the instantaneous tripping device made of iron is used as the electric path 16, so that it is easy to secure the bending amount of the bimetal 15 by the heater effect of that part. . For this reason, the bimetal 15 can be shortened and the circuit breaker for wiring can be reduced in size. Further, as shown in FIG. 3, since the leaf spring finger 7, the bimetal 15, and the fixed iron piece 10 of the instantaneous trip device can be integrated, the assembly workability can be improved.

  The main part of the present invention is that the base part of the bimetal 15 and the base part of the leaf spring finger 7 are fixed to the base part 12 of the fixed iron piece 10 of the instantaneous trip device with a gap, and a part of the base part 12 is connected to the electric circuit 16. Of course, the specific configuration and the configuration of the other parts of the circuit breaker for wiring are not limited to the illustrated configuration.

It is a front view showing the whole circuit breaker of an embodiment. It is a perspective view showing the whole circuit breaker of an embodiment. It is the enlarged view which took out and showed the peripheral part of the fixed iron piece of the instantaneous trip apparatus. It is the expansion perspective view which took out and showed the peripheral part of the fixed iron piece of the instantaneous trip apparatus. It is an enlarged view of the state which removed the trip piece. It is an expansion perspective view of the state where a trip piece was removed. It is an expansion perspective view of the state where a trip piece was removed.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Case 2 Handle 3 Link 4 Latch 5 Lifting member 6 Coil spring 7 Leaf spring finger 8 Movable contact 9 Fixed contact 10 Fixed iron piece 11 of instantaneous trip device 12 Base part 13 Base 13 Tripping piece 14 Return spring 15 Bimetal 16 Electric circuit 17 Stranded wire 18 Power supply side terminal 19 Adjustment screw

Claims (5)

  On the base that does not form the magnetic path of the fixed iron piece of the instantaneous trip device, the base of the bimetal and the base of the leaf spring finger are fixed with a space between each other, and a part of the base of the fixed iron piece is electrically connected A circuit breaker for wiring.   2. The circuit breaker according to claim 1, wherein the leaf spring finger is made of a copper alloy and is fixed by caulking to a base portion of a fixed iron piece of the instantaneous trip device.   2. The circuit breaker according to claim 1, wherein the leaf spring finger is made of a copper alloy and is welded to the base of the fixed iron piece of the instantaneous trip device.   2. The wiring breaker according to claim 1, wherein a bimetal is fixed at the center position in the width direction of the fixed iron piece of the instantaneous trip device, and a leaf spring finger is fixed at a position offset from the center in the width direction. vessel.   4. The circuit breaker according to claim 2, wherein the surface treatment of the fixed iron piece of the instantaneous tripping device is at least two layers and the first layer is copper plated.

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