JP2013069464A - Circuit breaker - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a circuit breaker with improved waterproofness.SOLUTION: A terminal plate 9 comprises: a terminal part 91 that is exposed to outside of a housing 4 when seen from above and which an electric wire 5 is exposed to and contacts and is conducted to; a contact holding part 92 holding a stationary contact 11 in the housing 4; and a coupling part 93 interposed between the terminal part 91 and the contact holding part 92. A projection direction of the terminal part 91 from the coupling part 93 and a projection direction of the contact holding part 92 from the coupling part 93 are both upward directions. Also, the housing 4 is provided with a vent hole 42 communicating inside and outside of the housing 4 nearer a mounting face side (a left side in the drawing) than the terminal part 91. Waterproofness is improved in comparison to a case when the projection direction of the contact holding part 92 from the coupling part 93 is a downward direction, or when the vent hole 42 is provided on a side more away from the mounting face than the terminal part 91 (a right side in the drawing).

Description

  The present invention relates to a circuit breaker.

  Conventionally, a circuit breaker that detects an overcurrent or the like and interrupts the circuit has been provided (see, for example, Patent Document 1).

  An example of this type of circuit breaker is shown in FIG. The circuit breaker shown in FIG. 2 includes a fixed contact 11 and a movable contact 21, a trip device 3 that pulls the movable contact 21 away from the fixed contact 11 when an abnormal current flows between the contacts 11 and 21, and the above-described parts. And a housing 4 housed therein.

  Here, the housing 4 faces a predetermined surface (the left surface in FIG. 2) toward a substantially vertical mounting surface (not shown, for example, the inner bottom surface of the distribution board), and another predetermined surface (an upper surface in FIG. 2). ) Facing upward and fixed to the mounting surface.

  The fixed contact 11 is held by a terminal plate 9 made of a conductive material. The terminal plate 9 includes a terminal portion 91 that is exposed to the outside of the housing 4 when viewed from above, a contact holding portion 92 that holds the fixed contact 11, and a connecting portion 93 that is interposed between the terminal portion 91 and the contact holding portion 92. Have The terminal portion 91 is held in a state where the electric wire 5 is in contact and conduction by a known terminal structure such as a screw terminal.

JP 2009-158370 A

  In the above conventional example, the terminal portion 91 protrudes upward from the connecting portion 93, and the contact holding portion 92 protrudes downward from the connecting portion 93.

  However, in the conventional example, when water enters the housing 4 through the electric wire 5 as indicated by the arrow A1, the water reaches the fixed contact 11 through the terminal plate 9 as indicated by the arrow A2. It is easy to end up. The water that has reached the fixed contact 11 in this way promotes corrosion of the fixed contact 11 and leads to a shortened life.

  This invention is made | formed in view of the said reason, The objective is to provide the circuit breaker improved in waterproofness.

  The circuit breaker of the present invention includes a housing fixed to a mounting surface, a terminal plate made of a conductive material and held in the housing and holding a fixed contact in the housing, and the fixed contact stored in the housing. A movable contact that is separable from the stationary contact, and a tripping device that detects an abnormality and separates the movable contact from the fixed contact. A contact holding part for holding a fixed contact in the housing, and a connecting part interposed between the terminal part and the contact holding part, and the protruding direction of the contact holding part from the connecting part is upward. The contact holding portion is disposed closer to the mounting surface than the terminal portion, and in the housing, the space outside the housing and the housing are located closer to the mounting surface than the terminal portion. Wherein the vent holes in which the fixed contact is communicating each other and accommodated space within ing is provided.

  In the above circuit breaker, it is desirable that the vent hole is provided at a position where the fixed contact is not exposed when viewed from above.

  According to the present invention, since the contact holding portion protrudes above the connecting portion, even when water enters the housing through the electric wire connected to the terminal portion, the water is retained from the connecting portion. Difficult to progress to the part. That is, the waterproof property is improved as compared with the case where the contact holding portion protrudes below the connecting portion. Also, since the vent hole is provided on the mounting surface side of the terminal part of the terminal plate, water enters the vent hole compared to the case where the vent hole is provided on the side farther from the mounting surface than the terminal part. Waterproofing is improved in that it is difficult.

It is sectional drawing which shows embodiment of this invention. It is sectional drawing which shows a prior art example.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

  In the present embodiment, as shown in FIG. 1, two sets of fixed contacts 11 and 12 and movable contacts 21 and 22 are separated from the fixed contacts 11 and 12, respectively, when an abnormality is detected. A tripping device 3 and a box-shaped housing 4 in which the above-described parts are stored are provided. The housing 4 has a predetermined surface (the left surface in FIG. 1) directed to a substantially vertical mounting surface (not shown, for example, the inner bottom surface of the distribution board), and another predetermined surface (the upper surface in FIG. 1) upward. Toward the mounting surface. Hereinafter, the upper, lower, left and right will be described with reference to FIG.

  A first terminal 61 to which the other end of the electric wire 5 whose one end is connected to a power source (not shown) is connected is held at the upper end of the housing 4. A second terminal 62 to which the other end of an electric wire (not shown) having one end connected to a load is connected to the lower end portion of the housing 4. The first terminal 61 is electrically connected to an upper fixed contact (hereinafter referred to as “first fixed contact”) 11, and the second terminal 62 is connected to a lower fixed contact (hereinafter referred to as “second fixed contact”). Electrically connected to 12).

  The movable contacts 21 and 22 are respectively provided on the right surface of the upper end and the left surface of the lower end of the movable contact 311 made of a metal plate that is vertically long and has a thickness direction in the left-right direction. The movable contact 311 is integrated with a molded body 312 made of synthetic resin, for example, by insert molding to constitute the rotor 31. The rotor 31 is supported so as to be rotatable about an axis orthogonal to the paper surface of FIG. Then, as the rotor 31 rotates to the left and right with respect to the housing 4, the movable contacts 21 and 22 come into and out of contact with the corresponding fixed contacts 11 and 12 at substantially the same time. In a state where each movable contact 21, 22 is in contact with the corresponding fixed contact 11, 12, the first terminal 61 and the second terminal 62 are connected to the fixed contact 11, 12, the movable contact 21, 22, the movable contact 311, etc. Are electrically connected to each other.

  The trip device 3 includes a handle 32 that protrudes to the right of the housing 4 and can rotate with respect to the housing 4 by receiving an operating force, an electromagnet device 33, and a zero-phase current transformer 34. The electromagnet device 33 includes an electromagnet 331 fixed to the housing 4 and an armature 332 made of a magnetic material and driven by the magnetic force of the electromagnet 331. The electromagnet device 33 operates, for example, when a ground fault is detected by the zero-phase current transformer 34 or when an overcurrent flows between the second fixed contact 12 and the second terminal 62. The handle 32 and the electromagnet device 33 (the armature 332) are connected to the rotor 31 via appropriate links (not shown). When an abnormality such as a ground fault or an overcurrent is detected, the electromagnet device 33 operates and the rotor 31 is driven to rotate counterclockwise in FIG. , 12 and the electric circuit between the terminals 61 and 62 is interrupted. In addition, by manually rotating the handle 32, the rotor 31 can be rotated to open and close the electric circuit between the terminals 61 and 62. Since the tripping device 3 as described above can be realized by a well-known technique, detailed illustration and description thereof are omitted.

  Further, in the housing 4, a concave portion 41 is provided on the outer surface above the movable range of the first movable contact 21, and the inner peripheral surface of the concave portion 41 is a vent hole 42 that is a through hole that communicates the inside and outside of the housing 4 with each other. Is open. That is, the vent hole 42 is provided at a position where the first fixed contact 11 is not exposed when viewed from above. Further, the through direction of the vent hole 42 is a horizontal direction (the left direction in FIG. 1 and a direction orthogonal to the paper surface) that intersects the direction in which the first fixed contact 11 and the vent hole 42 are arranged (substantially up and down direction). It has become. The vent hole 42 serves as a passage for gas generated when the contact is opened.

  Furthermore, between the movable range of the first movable contact 21 and the vent hole 42, a plurality of pieces (in FIG. 1) that divide an arc generated between the first movable contact 21 and the first fixed contact 11 when the contact is opened. Three) arc-extinguishing plates 71 are arranged.

  Further, the arc extinguishing body 8 is disposed below the movable range of the second movable contact 22 (that is, the position where each of the fixed contacts 11 and 12 is sandwiched between the second movable contact 22 and the vent hole 42). The arc extinguishing body 8 is made of a material that generates gas when heated. That is, when an arc is generated between the second movable contact 22 and the second fixed contact 12, the arc extinguishing is achieved by the gas generated by heating the arc extinguishing body 8 by the arc. As a material of the arc extinguishing body 8, for example, a melamine resin or a polyamide-based resin containing magnesium hydroxide can be used.

  Here, the first fixed contact 11 is held by the terminal plate 9 made of a conductive material. The terminal plate 9 is exposed to the outside of the housing when viewed from above, constituting a part of the first terminal 61, a contact holding part 92 holding the first fixed contact 11, and the terminal part 91 and the contact holding part. And a connecting portion 93 interposed between them. The first terminal 61 holds the electric wire 5 in a state of being in contact with the terminal portion 91 of the terminal plate 9. As the structure of the first terminal 61, a known terminal structure such as a screw terminal can be appropriately employed.

  The terminal portion 91 protrudes upward from the right end portion of the connecting portion 93, and the contact holding portion 92 protrudes upward from the left end portion of the connecting portion 93.

  According to the above configuration, since the contact holding portion 92 protrudes above the connecting portion 93, even when water enters the housing 4 through the electric wire 5 connected to the terminal portion 91, the water remains It is difficult to proceed from the connecting portion 93 to the contact holding portion 92. That is, the waterproof property is improved as compared with the case where the contact holding portion 92 is provided below the connecting portion 93.

  Further, since the vent hole 42 is provided on the mounting surface side (left side in FIG. 1) with respect to the terminal portion 91 of the terminal board 9, the side farther from the mounting surface than the terminal portion 91 (right side in FIG. 1). Compared with the case where the vent hole 42 is provided in the above, the waterproof property is improved in that water does not easily enter the vent hole 42.

  Further, the vent hole 42 is provided at a position where the first fixed contact 11 is not exposed when viewed from above, so that the vent hole 42 is provided at a position where the first fixed contact 11 is exposed when viewed from above. The waterproof property is improved in that the water that has entered from the vent hole 42 does not easily reach the first fixed contact 11 or the first movable contact 21.

  In addition, when the inside of the housing 4 is divided into a plurality of spaces, the vent hole 42 only needs to communicate with a space in which the fixed contacts 11 and 12 are stored among the plurality of spaces.

3 Tripping device 4 Housing 5 Electric wire 9 Terminal plate 11 First fixed contact (fixed contact)
21 First movable contact (movable contact)
42 Ventilation hole 91 Terminal part 92 Contact holding part 93 Connection part

Claims (2)

A housing fixed to the mounting surface;
A terminal plate made of a conductive material and held in the housing to hold a fixed contact in the housing;
A movable contact housed in the housing and separable from the fixed contact;
A tripping device for detecting an abnormality and pulling the movable contact away from the fixed contact;
The terminal plate is exposed to the outside of the housing and contacts with the electric wire; a contact holding portion for holding a fixed contact in the housing; and a connection interposed between the terminal portion and the contact holding portion. And
The protruding direction of the contact holding part from the connecting part is upward,
The contact holding part is disposed closer to the mounting surface than the terminal part,
In the housing, a vent hole is provided on the mounting surface side of the terminal portion so that a space outside the housing and a space in which the fixed contact is stored in the housing communicate with each other. Circuit breaker to do.   The circuit breaker according to claim 1, wherein the vent hole is provided at a position where the fixed contact is not exposed when viewed from above.

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