KR100944173B1 - Circuit breaker - Google Patents

Abstract

In the present invention, when the number of magnetic plates in the arc-extinguishing chamber is increased and the uppermost magnetic plate is higher than the distal end of the movable contact at the opening position, the uppermost magnetic plate is effectively used.

An insulating member 20 having a pair of side walls 21 covering the movement trajectories 28 of the movable contact 9 on both left and right sides of both legs of the plurality of magnetic plates 15 of the arc chamber 13. And the tip of the movable contact 5 in the open position protrude from the upper surface of the side wall 21 of the insulating member 20 and at the upper edge 21a of the magnetic plate 15 side of the side wall 21. ) Extends near the top magnetic plate 15. As a result, the arc transferred to the tip of the movable contact 5 is pushed out to an outer space wider than the gap between the left and right side walls 21, and the arc out of the upper edge portion 21a is guided to the uppermost magnetic plate 15. It can make it stretch well.

Description

Circuit breaker {CIRCUIT BREAKER}

1 is a longitudinal cross-sectional view of a circuit breaker showing Embodiment 1 of the present invention.

FIG. 2 is a plan view of the blocking part of FIG. 1. FIG.

3 is a cross-sectional view taken along line III-III of FIG. 2.

4 is a perspective view of the insulating member in FIG. 3.

FIG. 5 is a diagram illustrating an arc state at the time of opening of the blocking unit of FIG. 3.

6 is a perspective view of an insulating member according to a second embodiment of the present invention.

7 is a perspective view of an insulating member according to a third embodiment of the present invention.

8 is a perspective view of an insulating member according to a fourth embodiment of the present invention.

Fig. 9 is a longitudinal sectional view of a cut-off portion showing a fifth embodiment of the present invention.

10 is a longitudinal sectional view showing a breaker of a conventional circuit breaker.

FIG. 11 is a view for explaining an arc when the blocking current of the blocking unit of FIG. 10 is large.

<Description of the symbols for the main parts of the drawings>

3: fixed contactor

4: opening and closing mechanism

5: operation contactor

6: fixed contact

8: arc runner

9: movable contact

13: SOHO Room

14: support

15: magnetic plate

20: insulation member

21: sidewall

21a: upper corner of the side wall

28: moving trajectory

29: arc

30: bulkhead

31: slope

32: connection part

33: arc transition plate

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to circuit breakers such as circuit breakers and earth leakage breakers used in low voltage electrical circuits, and more particularly, to means for promoting an increase in arc voltage during current interruption.

10 shows a general configuration of the circuit breaker breaker. In Fig. 10, the fixed contact 101 fixed to a case (not shown) has a fixed contact 102 at one end, and a power supply terminal 103 is integrally formed at the other end. In the vicinity of the fixed contact 102, the arc runner 104 which is raised obliquely on the terminal side is provided. The movable contact 105 has a movable contact 106 in contact with the fixed contact 102 at one end, and the other end is pivotably connected to the movable contact holder (not shown), which is rotatably supported by the case, through the shaft 107. It is.

The arc extinguishing chamber 108 (消 弧 室) has a plurality of U-shaped magnetic plates 109 stacked and supported by a gap on a support of an insulator (not shown), and the movable contacts 106 are formed by the magnetic plates 109. It is arrange | positioned so that the movement trajectory of may be enclosed. When the current is interrupted, an arc 110 is generated between the fixed contact 102 and the movable contact 106. The arc 110 is drawn into the magnetic plate 109 to be divided and cooled, and the arc voltage becomes high and extinguished. Such a circuit breaker is described in Patent Document 1, for example.

[Patent Document 1]

Japanese Patent Laid-Open No. 60-72131

In the circuit breaker described above, in order to increase the arc voltage to improve the breaking performance, it is necessary to increase the number of the magnetic chambers of the extinguishing chamber as much as possible. On the other hand, in order to effectively use all of the magnetic plates for arc division, an opening distance of the movable contact according to the number of magnetic plates is required, and as shown in FIG. 10, the tip of the movable contact at the open position is shown. Should be higher than the magnetic plate of the highest level. Therefore, as the number of magnetic plates increases, the opening distance of the movable contact also increases, and it is necessary to change the opening / closing mechanism and enlarge the external dimensions of the circuit breaker. Attempting to increase the number of magnetic plates without changing the opening distance of the movable contactor causes the tip of the movable contactor to be lower than that of the uppermost magnetic plate so that the uppermost magnetic plate cannot be used effectively.

In such a case, as described in Patent Literature 1, there is also a method of providing the arc transition portion in the uppermost magnetic plate. As shown in the figure, since the arc becomes difficult to bend, there is a problem that the transition to the magnetic plate at the top becomes difficult.

An object of the present invention is to make it possible to effectively use the highest magnetic plate while suppressing the opening distance of the movable contact, even when the number of magnetic plates in the arc chamber is increased to improve the breaking performance.

In order to solve the above problems, the present invention is a fixed contact having a fixed contact at one end fixed to the case, and a movable contact holder having a movable contact in contact with the fixed contact at one end and rotatably supported at the other end of the case. And a extinguishing chamber having a plurality of U-shaped magnetic plates stacked and supported through the gap and arranged to surround the movement trajectory of the movable contact, and the fixed contact and the movable contact when the current is interrupted. A circuit breaker that draws arcs generated between the magnetic plates of the arc chamber and arcs the arc, wherein the magnetic plates of the arc chamber are laminated to a position higher than the tip of the movable contact in the open position, while both legs of the magnetic plate are laminated. An insulating member having a pair of sidewalls covering the movement trajectory of the movable contact from both left and right sides inside the part, Further, the front end of the movable contact in the open position is projected from the upper surface of the side wall of the insulating member, and the upper edge of the magnetic plate side of the side wall is extended to the vicinity of the magnetic plate at the uppermost level (claim 1).

According to the invention of claim 1, a pair of side walls of the insulating member is disposed inside both legs of the magnetic plate of the arc-extinguishing chamber so as to cover the movement trajectories of the movable contacts on both the left and right sides. It is to push it into a large space. In this case, the tip of the movable contact of the open position is projected from the upper surface of the side wall of the insulating member, so that the arc arcing point on the movable contact side is quickly transferred to the tip of the movable contact, and the magnetic plate side of the side wall of the insulating member is By extending the upper edge portion near the uppermost magnetic plate, the arc pushed out of the upper edge portion enters the uppermost magnetic plate.

Accordingly, even when the number of magnetic plates is increased and the magnetic plates are stacked up to a position higher than the tip of the movable contact at the open position, the magnetic plates at the highest level can be effectively used, and the tip position of the movable contact at the time of opening is increased. The opening distance can be suppressed by not exceeding the height of the uppermost magnetic plate.

The method according to claim 1, wherein the arc of which the arc is transferred to the tip of the movable contact in the open position forms an outline of the side wall of the insulating member in accordance with the curved shape when the arc is extended and curved through the magnetic plate at the uppermost level. (Claim 2). As a result, the arc that escapes the sidewall of the insulating member may be curved in accordance with the outline of the sidewall so as to increase satisfactorily, thereby increasing the arc voltage.

In the invention of claim 1, barrier ribs for shielding the vicinity of the tip of the movable contact projecting from the upper surface of the insulating member from both legs of the magnetic plate are formed on the left and right side walls of the insulating member, It is preferable to make it wider than the mutual gap of the said side wall (claim 3).

The magnetic force from the magnetic plate is acting on the arc near the movable contactor, but when the ignition is ignitioned from the distal end of the movable contact protruding from the upper surface of the side wall of the insulating member at the opening position, the electromagnetic force is applied to the arc. At the same time, the arc length is reduced because current flows through the legs of the magnetic plates. According to the invention of claim 3, by forming a partition wall that shields the vicinity of the tip of the movable contact protruding from the upper surface of the side wall of the insulating member from both legs of the magnetic plate, it is possible to prevent the call from the legs of the magnetic plate. In this case, by making the mutual spacing of the partitions larger than the mutual spacing of the side walls, it is possible to maintain the arc arcing point at the tip of the movable contact without pushing between the partitions.

In the invention of claim 1, it is preferable to form an inclined surface such that the interval between the sidewalls gradually widens toward the front end of the upper edge portion of the sidewall (claim 4). As a result, the elongation of the arc toward the uppermost magnetic plate can be promoted. It is more effective to form the inclined surface in front of the side wall.

In the invention of claim 1, a connection portion of an insulator for connecting the left and right side walls may be provided on the side opposite to the movable contact of the tip of the movable contact in the open position (claim 5). For this reason, pyrolysis gas can be generated by the side wall connection part in the back side of the arc call point of the front end of a movable contact, and extension | stretching of an arc to the exhaust port side can be promoted.

In the invention of claim 1, an arc transition plate may be formed on the upper surface of the magnetic plate at the top of the magnetic plate (claim 6). This stabilizes the arc between the tip of the movable contact and the magnetic plate on the uppermost level, making it possible to maintain the voltage of the entire arc.

EMBODIMENT OF THE INVENTION Hereinafter, embodiment of this invention is described based on FIG.

<Example 1>

1 is a longitudinal sectional view of an essential part of a central pole portion of a three-pole circuit breaker. In Fig. 1, in the insulated container composed of the case 1 and the cover 2, a block made up of the fixed contact 3 fixed to the case 1 and the movable contact 5 driven to open and close by the opening and closing mechanism 4; Is configured. In addition, although the blocking part of the center pole part is shown in FIG. 1, the inside of an insulating container is divided into three-phase spaces by phase partition walls, and each phase blocking part is accommodated in each space, respectively. The fixed contact 3 has a fixed contact 6 at one end, and the power supply side terminal 7 is integrally formed at the other end. The fixed contact 3 is attached to the arc runner 8 which ascends obliquely toward the power supply side (left side of the figure) near the fixed contact 6. The arc runner 8 may be integrally cut and bent from the fixed contact 3.

The movable contact 5 has a movable contact 9 in contact with the fixed contact 6 at one end thereof, and has a shaft 11 connected to the movable contact holder 10 of the insulator whose other end is rotatably supported by the case 1. It is connected so that rotation is possible, and is urged toward the stationary contact 3 by the contact spring 12 which consists of the torsion spring inserted between the movable contact holder 10. As shown in FIG. Reference numeral 13 denotes an arc-extinguishing chamber, which is composed of a support body 14 of an insulator and a plurality of magnetic plates 15 stacked up and down and supported at an appropriate gap on the support body 14, and the magnetic plate 15 is a movable contactor. The notch which passes (5) is provided, and is formed in U shape. The arc-extinguishing chamber 13 is arrange | positioned so that the movement trace of the movable contact 9 may be enclosed with the magnetic plate 15.

The opening and closing mechanism 4 is connected to the movable contact holder 10, and the movable contact 5 is opened and closed by the opening and closing mechanism 4 via the movable contact holder 10. An arc gas outlet 16 is provided in front of the breaker, and the arc gas outlet 16 is blocked by a shielding plate 17 of an insulator that prevents foreign matter from entering.

2 and 3 show the cut-off part, FIG. 2 is a plan view, and FIG. 3 is a sectional view taken along the line III-III of FIG. 2. 2 and 3, the support body 14 of the arc chamber 13 is bent in a U shape from a fiber plate punched into a required shape, and has a rectangular vent window 18 for passing arc gas through the center of the front wall thereof. ) Is open. The magnetic plate 15 is punched in a U-shape from an iron plate, and a cutout 19 is provided at a portion through which the movable contact 5 passes. Although the magnetic plate 15 is caulked to the support body 14 through projections on both the left and right sides, in the case of the drawing, the magnetic plate 15 has a larger number of sheets than in the prior art (for example, 7 of the conventional example of FIG. 11). 3, the position of the uppermost magnetic plate 15 is higher than the tip of the movable contact 5 at the open position shown by the broken line in FIG. The arc extinguishing chamber 13 is mounted on the bottom surface of the case 1 formed in the same shape as the lower surface of the support 14 in FIG. 1, and is fixed by restraining the upper surface with the cover 2.

Here, the insulating member 20 is provided inside the arc chamber 13. 4 is a perspective view illustrating the insulating member 20. The insulating member 20 is molded of resin such as polyamide, polyacetal, polyester, and has a pair of left and right side walls 21. The left and right side walls 21 are interconnected by the connecting portion 22 (see FIG. 3) at the bottom. Moreover, the back wall 23 which protrudes to the left-right side is integrally provided in the back side (right side of FIG. 2) of the side wall 21, The edge part 24 is formed in the shoulder part. On the other hand, as shown in FIG. 4, the inclined surfaces 25 and 26 are formed so that the edge | side may be formed in the lower surface of the side wall 21, and the protrusion part 27 is formed.

The insulating member 20 is combined with the extinguishing chamber 13 as shown in Figs. 2 and 3 so that the side wall 21 is in contact with the leg portion between which the cutout 19 of the magnetic plate 15 is interposed. 23 is in contact with the rear surface of the support 14. The insulating member 20 is positioned with the protrusion 27 fitted with a support (not shown) on the bottom of the case 1 in a state where the arc chamber 13 is mounted on the case 1 (see FIG. 1), The end part 24 of the back wall 23 is pressed and fixed to the back end part 14a (refer FIG. 3) of the support body 14. As shown in FIG. In this state, the insulating member 20 is mounted on the stationary contact 3 as described later.

In FIG. 3, the fixed contact 3 is bent in an U-shape with an end to which the fixed contact 6 is attached to form an inclined surface, and an arc runner 8 is attached to the inclined surface. As shown in Fig. 4, in the arc runner 8, both sides of the attachment end protrude from side to side, and two left and right caulking pins integrally formed in the fixed contact 3 are inserted into the hole of the protrusion, and the tip thereof is It is caulked and coupled to the stationary contact 3. As shown in FIG. 3, the insulating member 20 is placed on the upper surface of the fixed contact 3 so that the inclined surface 25 of the side wall 21 contacts the left and right protrusions of the arc runner 8, and also the side wall 21. The inclined surface 26 (see FIG. 4) of the in contact with the inclined surface of the fixed contact 3 on both sides of the fixed contact 6.

In the state of assembling the case 1 of the arc-extinguishing chamber 13 and the insulating member 20, as shown in FIG. 2, the side walls 21 of the insulating member 20 have both legs of the magnetic plate 15. On the inner side, the movement trajectory 28 (refer FIG. 3) of the movable contact 5 is covered on both the left and right sides. Here, in FIG. 3, the tip of the movable contact 5 in the open position shown by the broken line protrudes from the upper surface of the side wall 21 of the insulating member 20, and at the same time, the magnetic plate 15 at the side wall 21. The upper edge portion 21a of the inner side (left side of FIG. 3) extends to the vicinity of the uppermost magnetic plate 15.

When a large current such as a short circuit current flows in the circuit breaker shown, the electromagnetic repulsive force due to the concentrated current acts between the fixed contact 7 and the movable contact 9, so that the movable contact 5 opens against the contact spring 12. . As the movable contact 5 opens, an arc 29 is generated between the fixed and movable contacts 6 and 9 as shown in FIG. 5. The generated arc 29 is transferred to the arc gas outlet 16 (see FIG. 1) of the pyrolysis gas generated by the arc heat from the sidewalls 21 disposed on both sides of the electromagnetic force and the contacts 6 and 9 by the magnetic plate 15. It is driven to the inside of the magnetic plate 15 by the gas flow. The driven arc 29 enters between several sheets under the stacked magnetic plates 15 at the same time as the call point on the fixed contact 3 side transitions from the fixed contact 6 to the arc runner 8. Moreover, the movable contact 5 opened by the electromagnetic repulsive force is hold | maintained in the open position by the movable contact holder 10 rotationally driven by the operation of the opening-closing mechanism 4 based on the trip signal from an overcurrent trip device.

On the other hand, the call point of the movable contactor 5 similarly transitions from the movable contact 9 to the tip of the movable contactor 5, and at the same time, of the arc 29 sandwiched between the upper edge portions 21a of the side walls 21. The section is pushed out to an outer space wider than the gap between the upper edge portions 21a, and extends and curves toward the upper left of FIG. 5 to enter the uppermost magnetic plate 15. In addition, the contour of the side wall 21 in the inside of the magnetic plate 15 is a curved shape when the arc 29 extends and curves between the arc runners 8 from the tip of the movable contact through the magnetic plate at the uppermost level. The arc 29 extends and curves toward the left side of FIG. 5 so as to be pushed out to a wide space even under the upper edge portion 21a. As a result, the whole arc enters between the magnetic plates 15, and it divides and cools between them, and an arc voltage rises. In that case, since the call point of the tip of the movable contact 5 is separated from the narrow space between the side walls 21, it is difficult to return to the movable contact 9, and the curved shape of the arc 29 is stably maintained, The consumption of the movable contact 9 is also small.

<Example 2>

6 is a perspective view of an insulating member according to a second embodiment of the present invention. 6, the partition 30 which shields the front-end | tip vicinity of the movable contact 5 of the open position which protrudes from the upper surface to the left and right side wall 21 of the insulating member 20 from the both legs of the magnetic plate 15 is shown. It is different from FIG. 5 in that each is formed integrally. Moreover, the partition 30 is thinner than the side wall 21, and the mutual space | interval of the partition 30 becomes wider than the mutual space | interval of the side wall 21. As shown in FIG.

As shown in FIG. 5, when the arc 29 transitions to the tip of the movable contact 5, when the arc 29 is called at the leg of the magnetic plate 15 in the vicinity thereof, the magnetic plate 29 is formed. In addition to decreasing the electromagnetic force to be drawn into (15), the current flows through the arm of the magnetic plate 15, so the arc length is shortened and the arc voltage is lowered. In the second embodiment, since the partition wall 30 is formed on the side wall 21 of the insulating member 20, the arc 29 near the tip of the movable contact 5 is formed by the partition wall 30 by the magnetic plate ( It is shielded from the leg part of 15, and the arc 29 extends and curves toward the uppermost magnetic plate 15 without invoking on the magnetic plate 15.

<Example 3>

7 is a perspective view of an insulating member according to a third embodiment of the present invention. In FIG. 7, the inclination surface 31 is formed in the upper edge part 21a of the side wall 21 so that the mutual space | interval of the side wall 21 may gradually become wide toward the front-end | tip, and differs from FIG. According to the third embodiment, the elongation of the arc toward the uppermost magnetic plate 15 can be induced more smoothly. It is more effective if the inclined surface of the side wall 21 is formed on the front surface toward the inside of the magnetic plate 15.

<Example 4>

8 is a perspective view of an insulating member according to a fourth embodiment of the present invention. In FIG. 8, the point that the insulator connection part 32 which connects the left-right side wall 21 is provided in the opposite side to the front end movable contact 9 of the movable contact 5 in an open position is different from FIG. According to the fourth embodiment, since pyrolysis gas is generated from the rear connection portion 32 of the arc that is called out at the tip of the movable contact 5, the arc expansion to the arc gas exhaust port side is promoted. Although the connection part 32 is preferably formed integrally with the insulating member 20, you may attach a separate member.

Example 5

Fig. 9 is a longitudinal sectional view of a cut-off portion showing a fifth embodiment of the present invention. In FIG. 9, the point where the arc transition plate 33 is formed on the upper surface of the uppermost magnetic plate 15 is different from that in FIG. 5. Although the illustrated arc transition plate 33 is coupled to the magnetic plate 15 as a separate member, it may be formed by cutting and bending integrally from the magnetic plate 15. According to the fifth embodiment, since the arc transition plate 33 is provided on the uppermost magnetic plate 15, the arc 29 between the tip of the movable contact 5 and the arc transition plate 33 is stabilized. Maintains the arc voltage of the electrode.

According to the present invention, even if the number of magnetic plates is increased, the magnetic plates at the highest level can be effectively used without increasing the opening distance of the movable contact, and the arc voltage can be applied without changing the switching mechanism or expanding the circuit breaker appearance. Increase the blocking performance.

Claims (6)

A fixed contact fixed to the case and having a fixed contact at one end thereof, a movable contact having a movable contact at one end thereof contacting the fixed contact and the other end connected to a movable contact holder supported by the case so as to be rotatably supported by the case, and laminated through a gap An arc-extinguishing chamber having a plurality of U-shaped magnetic plates supported and arranged to surround the movement trajectory of the movable contact, and an arc generated between the fixed contact and the movable contact at the time of interruption of current, In the circuit breaker which draws in to board and extinguishes, Insulation having a pair of side walls for stacking the magnetic plates of the arc chamber to a position higher than the tip of the movable contact in the open position, and covering the movement trajectories of the movable contacts on both left and right sides inside both legs of the magnetic plate. The member was provided, and the front end of the movable contact in the open position was protruded from the upper surface of the side wall of the insulating member, and the upper edge portion of the magnetic plate side at the side wall was extended to the vicinity of the magnetic plate at the uppermost level. Circuit breaker. The side wall contour of the said insulating member was formed in accordance with the curved shape when the arc which the call point transitioned to the front-end | tip of the said movable contact of an opening position was extended and curved through the said magnetic plate of uppermost. Circuit breaker. 2. The barrier rib according to claim 1, wherein barrier ribs are formed on left and right side walls of the insulating member to shield the vicinity of the tip end of the movable contact from both legs of the magnetic plate. A circuit breaker characterized in that it is wider than the mutual gap of the side wall. 2. The circuit breaker according to claim 1, wherein an inclined surface is formed such that an interval between the sidewalls gradually widens toward an end of the upper edge portion of the sidewall. 2. The circuit breaker according to claim 1, wherein a connection portion of an insulator for connecting the left and right sidewalls is provided on the side opposite to the movable contact at the tip of the movable contact in the open position. The circuit breaker according to claim 1, wherein an arc transition plate is formed on an upper surface of the uppermost magnetic plate.

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