JP2003297215A - Circuit breaker - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a circuit breaker in which insulation degradation of an operating handle due to soot or metal particles generated by the arc and arc gas in a short-circuit break. <P>SOLUTION: This circuit breaker has a bent fiber 43 which covered an arc extinguishing device 39 from above to extinguish an arc, and the breaker forms the extinguishing chamber by insulating partition walls 2a, 2b, 3a, 3b of a mold cover 3 and a mold case 2, the bent fiber 43, a pin 51, and a rib 3f. The bent fiber 43 has a lid part 43c which is pressurized by a rib 3f protruded from the mold cover 3 and which covers an arc extinguishing grid 40 from above on the highest stage, a leg part 43b through which a movable contact 8 is turnably inserted, and protruded part 43d bent to the opposite side of the lid part 43c. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a circuit breaker that shuts off an electric circuit when an overcurrent or the like in the electric circuit is detected.

[0002]

2. Description of the Related Art Conventional Example 1 This type of circuit breaker is disclosed, for example, in Japanese Utility Model Laid-Open No. 56-13466.
No. 3 publication. 6 is a side sectional view of a conventional circuit breaker, FIG. 7 is a perspective view showing a mold base of the circuit breaker of FIG. 6, and FIG. 8 is a perspective view showing a mold cover of the circuit breaker of FIG. The state where the plate 41 is attached is shown.

The main body 1 is formed as an insulating box by a mold base 2 made of molded insulating material and a mold cover 3, and covers the charging portion of the circuit breaker except the terminals 6A and 18A, and the mold base 2 and the mold. Insulating isolation walls 2a, 2b, 3a, 3b (FIGS. 7 and 8) provided in the cover 3 are provided with respective polar chambers partitioned by combining the mold base 2 and the mold cover 3, and the central polar chamber is provided in the central polar chamber. The main components and opening / closing mechanism are stored.

The power source side terminal conductor 6 provided on the mold base 2 has an end extending into the electrode chamber and a fixed contact 7 is fixed thereto. The circuit breaker is of a three-pole type in which polar chambers are formed on the left and right of the central polar chamber, as shown in FIGS. 7 and 8. A movable contact 9 is provided at a position corresponding to the fixed contact 7 of the movable contact 8, and the cross bar 11
It is supported by and constitutes a movable contact device. The bimetal 15, which is a trip element that responds to an overcurrent for timed trip, has a lower end connected to one end of a load-side terminal conductor 18. The fixed iron core 19 of the electromagnet is supported by the electromagnet support plate 20, and the movable iron piece 21 of the electromagnet is rotatably supported by the electromagnet support plate 20 by the shaft 22.

The opening / closing operation mechanism and the tripping mechanism of the movable contact device common to all the poles are provided in the central pole, and the operation knob 23a made of an insulating material projects from the opening hole 3c (FIG. 8) provided in the mold cover 3, An operation handle 23 having an opening covering portion 23b having an arcuate cross section that moves in the polar chamber so as to cover the opening hole 3c regardless of the operation position, and a U-shaped opening / closing lever 24 fixed to the operation handle 23. This opening / closing lever 24 is rotatably connected. One end of each of the pair of toggle links 26, 27 is rotatably connected by a connecting shaft 28, and the other end of the toggle link 27 is integrated with the crossbar 11 and the movable contact 8 associated with each pole, and the movable contact shaft 10 is integrated therewith. Are connected by. The operation spring 29 includes a pair of toggle links 26,
The toggle link mechanism is formed between the connecting shaft 28 of 27 and the upper end of the opening / closing lever 24.

A trip lever 30, which releasably connects the opening / closing mechanism and the trip mechanism, is rotatably supported by a trip lever shaft 31 and engages with one end hook portion 34a of a trip latch 34 of the trip mechanism. The trip latch 34 is rotatably supported by a shaft 35. Trip bar 3
6 receives a spring force from the twisting spring 37, and responds to the adjusting screw 16 provided on the bimetal 15 of the trip element of each pole that responds to overcurrent, and the movable iron piece 21 of the instantaneous trip electromagnet that responds to excessive current. It is provided to do. The arc extinguishing device 39 provided corresponding to the movable contact device has a plurality of arc extinguishing grids 40, and further includes a movable contact 9 of the movable contact device 8 and a metal or a metal provided near the upper part of the arc extinguishing device 39. The arc gas shielding plate 41 made of an insulating material is fitted to the inner wall of the mold cover 3.

Next, the operation of the circuit breaker of Conventional Example 1 will be described. When a relatively small overload current flows, the bimetal 15 bends due to its own Joule heat generation, and the adjusting screw 16 provided at the tip of the bimetal 15 presses the trip bar 36 so that the trip latch 34 and the shaft are together. 35 around the trip lever 30, the one end hook portion 34a of the trip latch 34 is disengaged from the trip lever 30, the trip lever 30 pivots around the trip lever shaft 31, and the trip lever 30 is supported by the crossbar 11 of the trip mechanism. The movable contact 7 of the movable contact 8 of the contact device and the fixed contact 7 of the power source side terminal conductor 6 are operated by the toggle link mechanism to operate the spring 2.
The spring force of 9 makes it similar to the open state.

On the other hand, when a large overcurrent such as an overcurrent flows, the movable iron piece 21 is excited, and the shaft 22 is supported to be attracted to the fixed iron core 19, and the movable arm 21a at the tip presses the trip bar 36. To do. After that, the operation is the same as the operation by the overload current.

Conventional example 2. A circuit breaker of this type is disclosed, for example, in Japanese Utility Model Laid-Open No. 6-41043. 9 is a side sectional view showing a main part of a conventional circuit breaker, and FIG. 10 is a view for explaining an arc extinguishing device, a shield plate and a cooling body of the circuit breaker of FIG. In the figure, reference numeral 38 denotes an arc extinguishing side plate, and an end portion of an arc extinguishing grid 40 is fitted therein to form an arc extinguishing device 39. Four
4 is a shielding plate, and 44a is a collar 44e whose arc extinguishing side plate 38.
A folding lid that fits into the groove 38a of the
Reference numeral 44b is a pair of legs forming an insertion groove into which the contact 8 is inserted, reference numeral 44c is a bent portion of the folding lid 44a and leg 44b, and 44d is a shoulder portion pressed against the pressing step portion 38b of the arc-extinguishing side plate 38. Reference numeral 45 is a cooling device. Other configurations are the same as those of the first conventional example.

[0010]

In the circuit breaker of the first conventional example, the opening cover portion 23 of the insulating molded article of the operating handle 23 is provided.
Although the shield plate 41 was fixed to the position b to prevent the insulation deterioration due to the arc gas, the problem that the soot and the metal particles due to the arc gas diffuse because the shield plate 41 is away from the arc extinguishing device 39. there were.

The circuit breaker of the conventional example 2 has a folding lid 44.
a and the pair of legs 44b to operate the arc with the handle 23
Although the insulation of the insulator is covered by the opening cover 23b to prevent the insulation from being deteriorated by the arc gas, when the arc is cut off, a gap is formed above the contact 8 and the pair of legs 44b in FIG. However, there is a problem that the arc gas diffuses soot and metal particles due to the arc gas from this gap. Here, when the circuit breaker has a large breaking current, after the contact 8 jumps upward beyond the OFF position due to the electromagnetic repulsive force acting between the contacts 7 and 9 in addition to the tripping from the switching mechanism. Finally, the contact 8 stops at the OFF position. The amount of bounce from the OFF position is required as a gap.

The present invention has been made to solve the above problems, and an object thereof is to suppress the diffusion of soot and metal particles due to arc gas, and to prevent carbide from adhering to the operating handle portion.

[0013]

A circuit breaker according to the present invention includes a mold cover, a mold base which covers the mold cover and accommodates a charging section, and the inside of the mold cover and the mold base. A polar room partitioned by an insulating partition provided in
Arc-extinguishing for extinguishing an arc generated between the movable contact and the fixed contact by fixing a movable contact housed in the polar chamber and a plurality of arc-extinguishing grids housed in the polar chamber by arc-extinguishing side plates. A device, a stopper that stops the movable contact from rotating more than necessary when the arc is cut off, an opening / closing mechanism that opens and closes the movable contact, and an insulating molded product, and an operation knob protrudes into an opening hole of the mold cover. A circuit breaker provided with an opening / closing mechanism for opening / closing the opening / closing mechanism and having an opening cover portion that moves in the polar chamber so as to cover the opening hole regardless of an operation position, in the circuit breaker. A folding flap having a lid portion that covers the arc grid from above, a leg portion through which the movable contact is rotatably inserted, and a protruding portion that is bent on the side opposite to the lid portion. And a pin for positioning the protruding portion of the bent fiber, and a rib protruding from the mold cover and abutting the lid portion of the bent fiber, an insulating partition of the mold cover and the mold case, and the bent fiber When,
An arc extinguishing chamber is formed by the pin and the rib. Further, the lid portion of the bent fiber is supported by the stopper from the mold base side, and is also pushed and supported by the rib from the mold cover side at a position apart from the protruding portion of the bent fiber by the stopper.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiment 1. Hereinafter, the first embodiment will be described. 1 is a sectional view showing an open state showing an embodiment of the present invention, FIG. 2 is a perspective view showing the bending fiber of FIG. 1, and FIG. 3 is a top view of the arc extinguishing device and the bending fiber portion of FIG. . In the figure, 1 to 4
Since 0 is the same as that described in Conventional Examples 1 and 2, its description is omitted. The base 2 has a configuration similar to that of FIG. 7, and the cover 3 has the rib 3f provided by removing the shield plate 41 from FIG.

Reference numeral 43 denotes a fiber piece 43a (rib) arranged in parallel with the movable contact 8, a fiber piece 43b (leg) through which the movable contact 8 is rotatably inserted, and an uppermost arc extinguishing grid 40 (see FIG. 1 and a fiber piece 43c (cover) from above and an opening / closing mechanism (opening / closing lever 2).
4, a toggle link 26, 27, an operation spring 29, etc., and a fiber piece 43d (projection) formed to project toward the movable contact 8 opening / closing side).
It is a bent fiber that is mounted between the arc extinguishing device 39 and the opening / closing mechanism, and is formed of a material having insulating paper as a main component. This bent fiber 43
Is a bent portion 43e (43e1, 43e2, 43e) of a sheet-shaped fiber plate cut into a predetermined shape.
3, 43e4), and in particular, the bent portions 43c (lid portion) and 43d (protruding portion) are bent in different directions.

Reference numeral 43a1 is a groove which serves as a relief for bending by the bent portion 43e2, and 43b1 is an insertion end of the leg portion 43 loosely fitted between the one end portion 6a of the power source side terminal conductor 6 and the rib 2f of the base 2. . Reference numeral 50 denotes a stopper for stopping the movable contact 8, which is made of iron and covers the cover 3.
It is a rod-shaped body that is positioned and fixed by and also supports the fiber piece 43c (cover). The fiber piece 43c
The (lid portion) is pressed and positioned by the rib 3f of the cover 3 from the side opposite to the stopper 50. That is, the rib 3f is provided so as to project from the mold cover 3 and contacts the fiber piece 43c (lid portion) of the bent fiber 43. Since the rib 3f is formed integrally with the mold cover 3 and thus has a small number of parts, it is preferable that the rib 3f be a separate body from the mold cover 3. Reference numeral 51 is a pin that is provided between two mechanism plates (made of iron) (not shown) that supports and fixes the toggle link mechanism, the opening / closing lever 24, and the like, and is a pin for positioning and fixing the mechanism plates. An insulating film 51B is applied around 51A.

The incorporation of the bent fiber 43 will be described. A power source side terminal conductor 6, a load side terminal conductor 18, an opening / closing mechanism, an arc extinguishing device 39 and the like are incorporated in the base 2. Then, the fiber 43 bent and formed in advance as described above is attached to the insertion end 4 of the fiber piece 43b (leg).
3b1 is inserted from above the arc extinguishing device 39 (from above in FIG. 1) so as to enter between the one end 6a and the rib 2f. Then, the cover 3 is put on the base 2 from above (in FIG. 1), so that the ribs 3f of the cover 3 are attached to the fiber pieces 4.
After pushing 3c (cover) downward, the cover 3 is fixed to the base. In this state, the surface of the fiber piece 43c (cover) opposite to the surface on which the rib 3f abuts abuts the stopper 50, and the fiber piece 43d abuts the pin 51.

When a large overcurrent such as a short-circuit current flows, the movable contact 8 is moved to the OFF position (state shown in FIG. 1) by the opening / closing mechanism by the same operation as in the conventional example 1. When the magnitude of the overcurrent is very large, the movable contact 8 comes into contact with the stopper 50 at one end due to the electromagnetic repulsive force acting between the contacts 7 and 9, and after its kinetic energy is absorbed, it is moved to the OFF position. Move and stop. Contact 7,
The arc generated between 9 is extinguished by separating the arc extinguishing device 39 and the contacts 7 and 9.

At this time, soot is generated by the arc gas (mainly generated from the base 2 and the cover 3) and metal particles (mainly generated from the arc-extinguishing grid 40 and the contacts 7 and 9) are generated along with the generation of the arc. Also, the arc can be said to be a kind of explosion phenomenon, pressure is generated near the arc, soot and metal particles rapidly,
The gas is exhausted from the exhaust hole 46. In the case of FIG. 1, almost the entire upper surface of the arc extinguishing device 39 is covered with the fiber piece 43c (lid), and the upper side of the movable contact 8 (upper side in FIG. 1) is one of the fiber pieces 43a (rib). Part, 43b
A part of the (leg portion) is covered with a fiber piece 43d (protruding portion) protruding on the side opposite to 43c, so that soot and metal particles on the opening covering portion 23b of the handle 23 can be suppressed. Further, since the pin 51 is in contact with the fiber piece 43d (protruding portion) in the lower side in FIG. 1 and is arranged above the movable contact 8 (in FIG. 1) with a slight gap, the opening of the handle 23 is further increased. It is possible to suppress soot and metal particles on the part covering part 23b.

Further, as compared with the conventional case, the arc extinguishing device 39 is divided by the base 2, the partition walls 2a and 2b, the cover 3, the partition walls 3a and 3b, the rib 3f, the bending fiber 43, and the pin 51 except the exhaust hole 46. The arc chamber is more dense, the pressure in the arc extinguishing chamber can be increased, and the arc can be extinguished efficiently. Further, since almost the entire upper surface of the arc extinguishing device 39 is covered with the fiber piece 43c (cover), it is possible to suppress the arc gas flow from going upward (upward in FIG. 1) and to the side of the rib 3f (paper surface in FIG. 1). There may be less arc gas flow through the front and rear).

Further, since the bent fiber 43 is obtained by bending a single plate-shaped fiber, it is easy to manufacture. Further, since the rib 3f is provided on the power source side (left side in FIG. 1) with respect to the stopper 50, the tip end portion (left side portion in FIG. 1) of the fiber piece 43c (cover portion) is directed toward the uppermost arc extinguishing grid 40. When the arc-extinguishing grid 4 is bent, the gap between the tip end and the uppermost grid 40 becomes small.
It is possible to reduce the amount of the arc gas flow emitted from 0 to the power supply side that is reflected from the mold cover 3 and the mold base 2 and flows into this gap, and the opening cover portion 23b of the handle 23 can be reduced.
Soot and metal particles can be suppressed.

Embodiment 2. The second embodiment of the present invention will be described below. FIG. 4 is a sectional view showing an open state showing another embodiment according to the second embodiment of the present invention. The fiber piece 43d (projection) is provided below the pin 51, and the fiber piece 43d (projection) is substantially parallel to the bottom surface of the base 2 in the case of FIG. 1, whereas in the case of FIG. This fiber piece 43 from the bottom of the base 2
The difference is that when d (protruding portion) is viewed in the clockwise direction, it is inclined at an acute angle. The fiber piece 43d (projection portion) is preferably fixed by a pin or the like provided parallel to the pin 51 (not shown) so as not to rotate clockwise around the bent portion 43e3. The other configuration is similar to that of the first embodiment, and therefore its description is omitted.

With the above structure, the contacts 7, 9
When an arc is generated during this period, the arc gas flow has more components toward the bottom surface direction of the base 2 than the operation handle 23, so it is possible to suppress soot and metal particles on the opening covering portion 23b of the handle 23.

Embodiment 3. The third embodiment of the present invention will be described below. FIG. 5 is a sectional view showing an open state showing another embodiment according to the third embodiment of the present invention. In FIG. 5, 51C is a thick insulating rubber (elastic body) provided by inserting the metal rod 51A inside. When the movable contact 8 moves above the OFF position (the position of the movable contact 8 shown in FIG. 5) (upper side in FIG. 5) due to the electromagnetic repulsive force when the arc is cut off, the rubber 51C moves first. After contacting the rubber 51C and elastically deforming the rubber 51C, it contacts the stopper 50 and its movement is suppressed, and finally stops at the OFF position shown in FIG. Depending on the magnitude of the electromagnetic repulsive force, the rubber 51C may contact only the rubber 51C and may not contact the stopper 50. Since other configurations are similar to those of the first embodiment,
The description is omitted.

As described above, since the movable contact 8 contacts the rubber 51, which is an elastic body, before contacting the stopper 50, the distance between the movable contact 8 and the rubber 51 becomes small at the OFF position. It is possible to suppress soot and metal particles on the opening covering portion 23b of the handle 23.

[0026]

The circuit breaker according to the present invention includes a mold cover, a mold base which covers the mold cover and accommodates a charging section, and the mold cover and the mold base. Between the movable contact and the fixed contact, a polar chamber partitioned by an insulating partition, a movable contact housed in the polar chamber, and a plurality of arc-extinguishing grids housed in the polar chamber are fixed by arc-extinguishing side plates. An arc extinguishing device for extinguishing the arc generated in the arc, a stopper for stopping the unnecessary rotation of the movable contact when the arc is cut off, an opening and closing mechanism for opening and closing the movable contact, and an insulating molded article formed by the mold. An operation knob is provided in a projecting manner in the opening hole of the cover to open and close the opening / closing mechanism and to cover the opening hole regardless of the operation position. A circuit breaker including an operation handle having an opening cover that moves in the pole chamber, a lid that covers the uppermost arc-extinguishing grid from above, and a leg through which the movable contact is rotatably inserted. Portion, and a bending fiber having a protruding portion bent on the side opposite to the lid portion, a pin for positioning the protruding portion of the bending fiber, and a rib protruding from the mold cover and abutting the lid portion of the bending fiber. Since the arc-extinguishing chamber is formed by the insulating partition walls of the mold cover and the mold case, the bent fiber, the pin, and the rib, the operation handle by soot and metal particles by the arc and arc gas at the time of short-circuit interruption is provided. Insulation deterioration can be prevented.

The lid of the bent fiber is supported by the stopper from the mold base side, and
Since the rib was pressed and supported by the rib from the mold cover side at a position away from the protruding portion of the bent fiber from the stopper, the gap between the lid part of the bent fiber and the arc extinguishing grid at the uppermost stage becomes small, and when the arc is extinguished, Soot and metal particles due to the arc and arc gas passing through the gap are reduced, and the insulation deterioration of the operating handle can be further prevented.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an open circuit state showing another embodiment of the first embodiment of the present invention.

2 is a perspective view showing the bent fiber of FIG. 1. FIG.

3 is a top view of the arc extinguishing device and the folded fiber portion of FIG. 1. FIG.

FIG. 4 is a sectional view showing an open state showing another embodiment of the second embodiment of the present invention.

FIG. 5 is a sectional view showing an open state showing another embodiment according to the third embodiment of the present invention.

FIG. 6 is a side sectional view of a conventional circuit breaker.

7 is a perspective view showing a mold base of the circuit breaker of FIG.

8 is a perspective view showing a mold cover of the circuit breaker of FIG.

FIG. 9 is a side sectional view showing a main part of a conventional circuit breaker.

10 is a diagram illustrating an arc extinguishing device, a shield plate, and a cooling body of the circuit breaker of FIG.

[Explanation of symbols]

2 mold base, 2a, 2b partition, 2f
Rib, 3 mold cover, 3a, 3b rib, 3c opening hole, 3f rib, 6 power supply side terminal conductor, 6A terminal part, 6a one end part, 7
Fixed contactor, 8 movable contact, 9 movable contactor, 11 crossbar, 18 load side terminal conductor, 18A terminal part, 23 operation handle,
23a operation knob, 23b opening cover,
24 open / close lever, 26, 27 toggle link,
30 Trip lever, 38 Arc extinguishing side plate, 39
Arc extinguishing device, 40 arc extinguishing grid, 43 bending fiber, 43a fiber piece (rib), 43b
Fiber piece (leg), 43c Fiber piece (lid), 43d Fiber piece (projection), 43
e Bent part, 50 stopper, 51 pin

   ─────────────────────────────────────────────────── ─── Continued front page    F term (reference) 5G027 AA08 BA07 BB07 BC04 BC12                       BC18                 5G030 BA05 DB01 DE01 XX00 YY07

Claims (2)

[Claims] 1. A mold cover, a mold base which covers the mold cover and accommodates a charging section, and a polar chamber which is partitioned by the mold cover and an insulating partition provided inside the mold base. An extinguishing arc for extinguishing an arc generated between the movable contact and the fixed contact, by fixing a movable contact housed in the polar chamber and a plurality of arc extinguishing grids housed in the polar chamber by an arc extinguishing side plate. An arc device, and a stopper for stopping the unnecessary rotation of the movable contact when the arc is cut off,
An opening / closing mechanism for opening / closing the movable contact, and an operation knob formed of an insulating molded product and projecting from an opening hole of the mold cover to open / close the opening / closing mechanism and cover the opening hole regardless of an operation position. A circuit breaker including an operation handle having an opening covering portion that moves in the pole chamber as described above, a lid portion that covers the uppermost arc-extinguishing grid from above, and a leg through which the movable contact is rotatably inserted. Portion, and a bending fiber having a protruding portion that is bent on the side opposite to the lid portion, a pin that positions the protruding portion of the bending fiber, and a rib that protrudes from the mold cover and abuts the lid portion of the bending fiber. And an insulating partition wall of the mold cover and the mold case,
A circuit breaker, wherein an arc extinguishing chamber is formed by the bent fiber, the pin, and the rib. 2. The lid of the bent fiber is supported from the mold base side by a stopper, and is pressed and supported by a rib from the mold cover side at a position apart from the protruding portion of the bent fiber by the stopper. The circuit breaker according to claim 1, wherein the circuit breaker is a circuit breaker.