JP2009004166A - Circuit breaker - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a circuit breaker in which the mounting structure of an auxiliary cover is improved so that the mounting is easy and strength against the inner pressure is fully maintained. <P>SOLUTION: In the circuit breaker in which a contact part composed of both fixed and movable contacts, an open/close mechanism of the movable contact, and an open/close cut-off mechanism of an over-current trip mechanism are incorporated in a mold case and a main cover that covers the mold case, and in which the auxiliary cover covering a recessed place provided on the main cover and used for mounting attachments is connected to the main cover via a hinge part, the hinge part is composed of a connecting shaft provided on the main cover, and a pair of holding projections that hold the connecting shaft provided on the auxiliary cover, and the pair of the holding projections is formed to be thicker as compared with the auxiliary cover. Moreover, the auxiliary cover may be provided by being shifted in the shaft direction of the connecting shaft so that the pair of the holding projections do not face each other. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a circuit breaker intended for a circuit breaker for wiring, an earth leakage breaker, etc., and particularly a storage part of an auxiliary device such as an alarm switch, an auxiliary switch, a voltage trip device, an undervoltage trip device, etc. The present invention relates to a connecting structure for covering an auxiliary cover.

  The circuit breaker for wiring has a built-in accessory device as well as a contact portion having a fixed contact and a movable contact of the main circuit, an arc extinguishing device, an opening / closing mechanism for the movable contact, and an overcurrent trip mechanism. Attached devices include an auxiliary switch that electrically outputs open and closed circuits according to the opening and closing operation of the main circuit contacts, an alarm switch that electrically outputs the trip operation of the circuit breaker, and automatically when the main circuit voltage drops There is an undervoltage trip device that opens the contact portion through a trip mechanism, and a voltage trip device that applies a voltage from a distance to electrically trip a circuit breaker.

  This ancillary device can be freely attached to the delivered circuit breaker by the customer according to the customer's request. Patent Document 1 describes a case in which a pocket-shaped recess for attaching an accessory device is formed in a main cover of a mold case, and an opening on the front side of the recess is covered by an auxiliary cover. In other words, a projection formed on the main cover and an engagement groove provided on the auxiliary cover are fitted to this projection to form a hinge portion, and the auxiliary cover can be opened and closed by rotating around this hinge portion, when closed The other end of the hinge portion is elastically coupled to a hole formed in the main cover so that it cannot be easily opened.

  Further, the circuit breaker described in Patent Document 2 has a hinge insertion hole in the main cover, a hinge part protruding from the edge of the auxiliary cover, and the hinge part is rotatably inserted into the hinge insertion hole. In this state, the auxiliary cover can be attached to the main cover so that it can be opened and closed, and the attached device can be attached and detached without removing the auxiliary cover from the main cover.

JP 2001-050273 A Japanese Patent Laid-Open No. 06-139900

  In a circuit breaker, when a large current or a short-circuit current flows in the circuit, the contacts repel and a large arc is generated between the contacts, resulting in a high temperature and high pressure inside. Therefore, the case and the main cover are made of high-strength mold resin so as not to be destroyed by this pressure.

  In Patent Document 1 and Patent Document 2, the attachment structure of the auxiliary cover is constituted by a hinge portion so that the attachment of the auxiliary cover to the main cover is convenient. However, sufficient consideration is not given to the strength of the hinge part against high temperature and high pressure inside the circuit breaker.

  The present invention has been made in view of the above points, and provides a circuit breaker in which an attachment structure of an auxiliary cover is improved so that attachment is easy and strength against internal pressure can be sufficiently maintained.

  In order to solve the above-mentioned problems, the present invention incorporates a contact portion composed of both fixed and movable contacts, a movable contact switching mechanism, and an overcurrent trip mechanism switching mechanism in the main cover covering the mold case, In the circuit breaker in which the auxiliary cover that covers the recess for attaching the accessory device provided in the main cover is connected to the main cover via the hinge portion, the hinge portion is provided on the connecting shaft provided on the main cover and the auxiliary cover. It comprises a pair of clamping protrusions that sandwich the connecting shaft, and the pair of clamping protrusions are formed thicker than the auxiliary cover.

  The pair of sandwiching protrusions may be formed such that one protrusion on the main cover side is thicker than the auxiliary cover. Further, the base portion of one of the pair of sandwiching projections on the main cover side may be formed thicker than the auxiliary cover. Further, the pair of clamping protrusions may be provided on the auxiliary cover while being shifted in the axial direction of the connecting shaft so as not to face each other. The pair of sandwiching protrusions may be provided with a recess on a surface in contact with the connecting shaft.

  According to the present invention, the auxiliary cover can be easily attached to the main cover, and the attachment portion is composed of a hinge portion having sufficient strength. Therefore, the auxiliary cover is formed by the high pressure generated inside the circuit breaker. It is safe without coming off.

  Further, since the pair of sandwiching protrusions of the hinge portion of the auxiliary cover are provided so as to be shifted in the axial direction of the connecting shaft so as not to face each other, when the auxiliary cover including the sandwiching protrusion is manufactured by integral molding, Since the mold is pulled only in the vertical direction, the mold is inexpensive, the mold can be easily opened, and the manufacturing process can be shortened.

  An embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a sectional view of a circuit breaker, and FIG. 2 is a front view showing an appearance of the circuit breaker. In the figure, 1 is an outer case made of mold resin, and 2 is a main cover covering the upper surface of the outer case 1. The case 1 and the main cover 2 incorporate a contact portion composed of both fixed and movable contacts, a movable contact switching mechanism, an overcurrent trip mechanism such as an overcurrent trip mechanism. The main cover 2 is provided with a recess (described later) for attaching an accessory device.

  Reference numeral 4 denotes a handle for operating the opening / closing mechanism of the movable contact. The lower end is connected to the opening / closing mechanism, and the upper end protrudes outward from the opening 2a provided on the upper surface of the main cover 2, and can be rotated within the range of the opening 2a. ing.

  3a is an auxiliary cover for covering the recess for attaching the accessory device, and 5 is a connecting shaft provided on the main cover 2. One end of the auxiliary cover 3a is hinged to the connecting shaft 5 so as to be rotatable, and the other end is fixed to the main cover 2 with a screw 6 while covering the recess for attaching the accessory device.

  In this example, the auxiliary cover-3a is configured as a single sheet so as to cover substantially the entire width of the main cover 2. The auxiliary covers 3b and 3C in FIG. 3 have a shape obtained by dividing the auxiliary cover 3a in FIG. 2 into two parts. Further, the auxiliary cover 3C in FIG. 4 covers the right half of the main cover 2, and the right half 3C of the auxiliary cover in FIG. 3 is used.

  FIG. 5 is a perspective view of the auxiliary cover 3C shown in FIG. 2 or FIG. An insertion hole 7 for a screw 6 is formed at one end of the auxiliary cover 3C, and clamping protrusions 8 and 9 are integrally formed at the other end. The sandwiching protrusion 8 is a protrusion provided on the lower surface side (main cover 2 side) of the auxiliary cover 3C, and is formed thicker than the thickness of the auxiliary cover. The clamping protrusion 9 is a protrusion provided on the upper surface side (the side opposite to the main cover 1) of the auxiliary cover 3C, and has a thickness equivalent to the thickness of the auxiliary cover 3C. An upward concave portion 8 a is formed on the upper surface of the pinching protrusion 8, and a downward concave portion 9 a is provided on the back surface of the pinching protrusion 9.

  As described above, the sandwiching protrusion 8 is formed thick, but as shown in the sectional view of FIG. 7, the tip of the sandwiching protrusion 8 is L3 (for example, 3 mm) with respect to the thickness L1 (for example, 3 mm) of the plate of the auxiliary cover 3C. For example, the base portion is set to a thickness of L4 (for example, 5 mm). Further, a reinforcing rib 3d is formed on the root portion 3e, and the thickness in the height direction of the root portion 3e including the rib 3d is set to L4 (for example, 10 mm).

  The sandwiching protrusions 8 and 9 are arranged so as not to face each other. The direction of this shift becomes the connecting shaft direction when the clamping protrusions 8 and 9 are press-fitted into the connecting shaft (described later). According to this configuration, when the clamping protrusions 8 and 9 are integrally molded with the auxiliary cover 3C with a mold, the mold removal direction (mold opening direction) after molding is only in the vertical direction, and the mold becomes inexpensive and the mold opens. Work becomes easy and helps to reduce product cost.

  FIG. 7 shows a detailed cross section of a hinge portion for attaching the auxiliary cover 3C to the main cover 2. As shown in FIG. 2a is a recess for attaching an accessory device provided in the main cover 2, and 5 is a connecting shaft provided in the main cover 2. The connecting shaft 5 has a circular cross section, and longitudinal chamfered portions 5a (planes) are provided on both sides thereof. The auxiliary cover 3C is vertically mounted on the connecting shaft 5 in the direction of the arrow in the figure. The pinching protrusions 8 and 9 are press-fitted and attached while being slightly expanded along the chamfered portion 5 a of the connecting shaft 5 to elastically hold the chamfered portion 5 a of the connecting shaft 5. The auxiliary cover 3C in this state can be easily removed by pulling it out in the direction opposite to the arrow, and the attachment / detachment is facilitated.

  The circuit breaker is in the state shown in FIG. 6 when used with being fixed to a switchboard (not shown). The auxiliary cover 3 </ b> C can rotate from the position A to the position G around the connecting shaft 5. A is a position where the auxiliary cover 3C is attached to the main cover 2, D is a position where the auxiliary cover 3C is attached to and detached from the connecting shaft 5, and G is a position where the auxiliary cover 3C is opened widely when attaching the accessory device to the recess 2a. Shows the hung position.

  Outside the G position, the auxiliary cover 3C holds the outer peripheral surface (curved surface) other than the chamfered portion 5a (plane) of the connecting shaft 5 with the holding protrusions 8 and 9. Specifically, the pinching protrusions 8 and 9 are sandwiched by the upward concave portion 8a and the downward concave portion 9a being fitted to the outer peripheral surface (curved surface) and are not detached from the connecting shaft 5. Accordingly, when attaching the accessory device to the recess 2a, the auxiliary cover 3C can be suspended from the G position, so that the work efficiency is improved and the auxiliary cover 3C is not mistaken or lost.

  In FIG. 8, the detailed cross section of the hinge part of the main cover 2 and the auxiliary | assistant cover 3C in the said A position is shown. In this state, the circuit breaker is used. However, as described above, when a large current or a short circuit current flows in the main circuit, the contacts repel each other, a large arc is generated between the contacts, and the inside becomes high temperature and high pressure. This pressure is applied to the auxiliary cover 3C in the arrow X direction, and the clamping protrusion 8 of the auxiliary cover 3C pushes the connecting shaft 5 in the arrow Y direction. Due to the force in the direction of the arrow Y, a shearing force is applied to the sandwiching protrusion 8 on the main cover side and the root portions of the sandwiching protrusions 8 and 9. If the strength of these parts is weak, the auxiliary cover 3C may be lifted up or popped out due to shearing force, which is dangerous.

  In the present embodiment, the sandwiching protrusion 8 to which the shearing force is applied and the base portions of both the sandwiching protrusions 8 and 9 are configured to have the thicknesses L3 and L2, respectively, so that the breakage of the hinge portion can be prevented.

Sectional drawing of the circuit breaker of one Example of this invention. The front view of the circuit breaker of one Example of this invention. The front view of the circuit breaker of the other Example of this invention. The front view of the circuit breaker of further another Example of this invention. The perspective view of an auxiliary cover. Explanatory drawing which shows the open / close state of an auxiliary cover. The detailed sectional view of the hinge part at the time of attachment and detachment of an auxiliary cover. The detailed sectional view of the hinge part at the time of wearing of an auxiliary cover.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Mold case, 2 ... Main cover, 2a ... Concave for attachment apparatus 3a, 3b, 3C: Auxiliary cover, 3e ... Root part of clamping protrusion, 5: Connection shaft 5, 8, 9 ... Hinge part, 8a, 9a ... concave part, 8 ... clamping pin on the main cover side.

Claims (5)

The mold cover and the main cover that covers it have a built-in contact part consisting of both fixed and movable contacts, a movable contact open / close mechanism, and an overcurrent trip mechanism open / close mechanism. In the circuit breaker in which the auxiliary cover covering the place is connected to the main cover via the hinge part,
The hinge portion includes a connecting shaft provided on the main cover and a pair of holding protrusions sandwiching the connecting shaft provided on the auxiliary cover, and the pair of holding protrusions are formed thicker than the auxiliary cover. Feature circuit breaker.   2. The circuit breaker according to claim 1, wherein the holding protrusions on the main cover side of the pair of holding protrusions are formed thicker than the auxiliary cover. 3. The circuit breaker according to claim 1, wherein a root portion of the pair of sandwiching protrusions on the main cover side is formed thicker than the auxiliary cover. 4. The circuit breaker according to claim 1, wherein the pair of sandwiching protrusions are provided on the auxiliary cover so as not to face each other and are shifted in the axial direction of the connecting shaft. Circuit breaker to do. 5. The circuit breaker according to claim 1, 2, 3, or 4, wherein the pair of sandwiching protrusions are provided with a recess on a surface that contacts the connecting shaft.

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