JP2009117150A - Contact structure of circuit breaker unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a contact structure in which reliability of a product is improved by greatly reducing an occurrence probability of a conduction failure between a fixed and a movable contacts due to adhesion of a foreign matter such as dust. <P>SOLUTION: A fixed contact 6 and a movable contact 7 provided in a fixed contactor 2 and a movable contactor 3 of a current breaking part are made to be a disk contact of "gable shape" of its surface consisting of two taper faces 6c, 7c and ridge line portions 6b, 7b at the center, and by arranging the ridge line portions 6b, 7b in the direction to cross each other, the fixed contact 6 and the movable contact 7 are adhered by brazing to the fixed contactor 2 and the movable contactor 3. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a contact structure of a circuit breaker intended for implementation as a circuit breaker for wiring, an earth leakage breaker or the like.

First, taking the above-mentioned circuit breaker for wiring as an example, the configuration and the structure of a current interrupting portion are shown in FIGS. 3 and 4 (see, for example, Patent Document 1). In the figure, 1 is a case of a circuit breaker, 1a is a case cover, 2 is a fixed contact that is integrated with a load side terminal corresponding to each phase of the main circuit, 3 is a movable contact, 4 is an opening / closing mechanism, Reference numeral 5 denotes an opening / closing operation handle. A fixed contact 6 and a movable contact 7 made of a contact material are fixed to the fixed contact 2 and the movable contact 3.
Next, FIG. 5 and FIG. 6 show the fixed structure of the conventional structure, the shape of the movable contact, and the closed state of the fixed / movable contact. That is, the fixed contact 6 having a conventional structure is a flat disk contact and is brazed to the seating surface of the fixed contact 2 by the brazing material 6a. On the other hand, the movable contact 7 is a trapezoidal disk contact whose contact surface has an R shape, and is brazed to the seating surface of the movable contact 3 by a brazing material 7a. With this combination of fixed / movable contacts, in the closed state of the circuit breaker, the fixed / movable contacts are electrically connected via the linear contact surface 8 as shown in FIG.
JP 2006-310030 A

The above circuit breakers and earth leakage circuit breakers have important responsibilities as protection devices for low-voltage distribution lines, and their products are always required to have high reliability in terms of energizing performance and breaking performance in actual use conditions.
By the way, depending on the working environment of the circuit breaker production line or the environmental conditions at the user site, dust or other foreign matter that has entered the case of the circuit breaker from the surroundings may adhere to the surface of the movable contact. In some cases, this may cause faulty contact or contact failure between contacts.
In this respect, in the conventional contact structure shown in FIGS. 5 and 6, the fixed / movable contact is in contact with the linear contact surface 8 extending over the entire width of the contact. If foreign matter adheres unexpectedly to any one of the parts, the connection between the contacts becomes poor. For this reason, there is a high probability that a circuit breaker will be defective due to surrounding dust and the like, and the reliability of the product will be reduced.
The present invention has been made in view of the above points, and an object of the present invention is to greatly reduce the probability of occurrence of poor conduction between fixed / movable contacts due to adhesion of foreign matters such as dust, thereby improving the reliability of the product. Another object of the present invention is to provide an improved circuit breaker contact structure.

In order to achieve the above object, according to the present invention, the stationary contact of the current interrupting part, the fixed contact and the movable contact provided on the movable contact, the surface thereof is composed of two tapered surfaces and a central ridge line part. The fixed contact and the movable contact are fixed to the fixed contact and the movable contact, respectively, with the shape of the "gable shape" being defined and the ridge lines of the "gable shape" crossing each other.
The above-mentioned fixed contact and movable contact are rectangular disk contacts cut from a “gable” shaped strip contact material in consideration of mass productivity and parts cost, and the bearing surface of the fixed contact and the movable contact. And fixed by brazing (claim 2).

According to the above configuration, in the closed state of the circuit breaker, the contact surface between the fixed contact and the movable contact is limited to a local surface area where the ridges of the “gable” shape cross each other. In the remaining surface area excluding, clearance (gap) is secured between the fixed contact and the movable contact by the "gable" tapered surface. Moreover, even if the contact point of the movable contact with respect to the fixed contact is slightly deviated, conduction between the contacts is ensured only by the displacement of the cross point of the ridge line portion. Therefore, even if foreign matter such as dust that has entered the circuit breaker case adheres to the contact surface, the contact surface between the contacts is not affected if the foreign matter adheres to the clearance area. Compared with the conventional contact structure, the probability of causing a conduction failure is greatly reduced and the reliability of the product is improved.
In addition, instead of using rivet contacts as fixed and movable contacts, a rectangular disk contact cut from the strip contact material is used to braze the fixed and movable contact surfaces, thereby reducing component costs and mass productivity. High performance can be obtained.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below based on the examples shown in FIGS. FIG. 1 is a diagram showing a closed state of fixed and movable contacts by the contact structure of the embodiment of the present invention, and FIG. 2 is a structural diagram of fixed and movable contacts, which are the same as those corresponding to FIGS. The code | symbol is attached | subjected.
That is, the fixed contact 6 and the movable contact 7 in the illustrated embodiment are trapezoidal disk contacts formed in a “gable shape” as shown in FIGS. 2A and 2B, and 6b and 7b are disk contacts. The ridge line portions 6c and 7c extending along the center of the surface of the surface are slope-like taper surfaces extending on both sides of the ridge line portions 6b and 7a.
The fixed contact 6 and the movable contact 7 are manufactured by cutting a strip contact material (hoop material) having a cross section of a “gable shape” into a required size.
And in order to fix the fixed contact 6 and the movable contact 7 of the said structure to the fixed contact 2 and the movable contact 3 of a circuit breaker, as shown in FIG.1 (c), the said ridgeline parts 6b and 7b are shown. The directions are set so as to cross at right angles to each other and brazed to the seating surfaces of the fixed contact 2 and the movable contact 3. In the illustrated embodiment, the ridge line portion 6 b of the fixed contact 6 is fixed to the fixed contact 6 fixed contact 2 in such a direction as to be along the longitudinal direction of the movable contact 3, and the ridge line portion 7 b of the movable contact 7 is a circuit. The circuit breaker is fixed in the left and right direction and fixed to the movable contact 3, but conversely, the ridge 6b of the fixed contact 6 is fixed in accordance with the horizontal direction of the circuit breaker and is movable. The contact 7 may be fixed so that the ridge line portion 7 b is oriented along the longitudinal direction of the movable contact 3.

With the above contact arrangement, in the closed state of the circuit breaker, as shown in FIG. 1, the contact surface 8 between the fixed contact 6 and the movable contact 7 is located at the center of the contact where the ridges 6b and 7b cross. In the remaining area except for the contact surface 8, the taper surfaces 6b and 7b secure a clearance (gap) that expands from the center of the contact toward the outer peripheral edge.
As a result, even if foreign matter such as dust that has entered the case adheres to the surfaces of the fixed contact 6 and the movable contact 7, if the attachment site is a clearance region excluding the contact surface 8, it affects the conduction between the contacts. There is nothing. That is, as compared with the conventional contact structure shown in FIG. 6B, the probability of causing a conduction failure between the contacts due to the adhered foreign matter is greatly reduced, and the reliability of the product is improved.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a closed state diagram of a contact structure according to an embodiment of the present invention, where (a) is a perspective view together with fixed / movable contacts, (b) and (c) are side views and schematic plan views of fixed / movable contacts. 1A and 1B are plan views and end views of a fixed contact and a movable contact, respectively. An overhead view of the internal structure with a part of the case cover cut out in the configuration diagram of the circuit breaker for wiring FIG. FIG. 4 is an enlarged view of the main part showing a state where the fixed / movable contact of FIG. 4 is closed. In the conventional contact structure diagram, (a) is a side view, (b) is a schematic plan view.

Explanation of symbols

DESCRIPTION OF SYMBOLS 2 Fixed contact 3 Mobile contact 6 Fixed contact 6a Raw material 6b Edge line part 6c Tapered surface 7 Movable contact 7a Raw material 7b Edge line part 7c Tapered surface 8 Contact surface between contacts

Claims (2)

The stationary contact of the current interrupting part, the fixed contact and the movable contact provided on the movable contact have a “gable shape” shape whose surface is composed of two tapered surfaces and a central ridge line portion, and the “gable shape” The circuit breaker contact structure is characterized in that the fixed and movable contacts are fixed to the fixed contact and the movable contact in such a manner that the ridges of "" are determined to cross each other. 2. The contact structure according to claim 1, wherein the fixed contact and the movable contact are square disk contacts cut from a “gable” shaped strip contact material, and are brazed to the seating surfaces of the fixed contact and the movable contact. Circuit breaker contact structure, characterized in that

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