JP5032270B2 - Bimetal adjustment structure of circuit breaker - Google Patents

Description

  The present invention relates to an adjustment structure for adjusting the breaking characteristics of a circuit breaker, and more particularly to a bimetal adjustment structure for a circuit breaker provided with a bimetal piece.

Circuit breaker tripping methods include a thermal type, a thermal electromagnetic type, a complete electromagnetic type, and an electronic type. Among these, a bimetal piece is used for the thermal type and the thermal electromagnetic type. The tripping mechanism using the bimetal piece uses the bending action caused by the thermal deformation of the bimetal to release the latch and performs the shut-off operation. However, the structure using this bimetal tends to cause variations in the shut-off operation characteristics. Therefore, it is necessary to adjust the gap (gap) between the bimetal piece and the engaging piece at the manufacturing stage to eliminate the variation.
This adjustment is performed using a screw, and the gap is adjusted by attaching a screw to the engagement piece side (see, for example, Patent Document 1), or the gap is adjusted by changing the inclination of the bimetal piece with a screw (for example, Patent Document) 2) is widely implemented.

Japanese Patent Laid-Open No. 7-220607 JP 2000-294110 A

  However, since the adjustment process is adjusted using a screw for each bimetal piece, it is necessary to adjust two screws in the case of a 2-pole circuit breaker, and 3 in the case of a 3-pole configuration. Adjustment of the individual screws is necessary, and the adjustment process takes time. In addition, in the case of a configuration having a plurality of poles, even if the overall cutoff characteristics satisfy the standard, the operating characteristics of the individual bimetal pieces may be out of range, and may operate faster or slower. There is a possibility of tripping or energizing failure due to energization at 100% of the rated current value.

  Therefore, in view of such a problem, the present invention can perform the position adjustment of the bimetal piece as in the case of the single-pole circuit breaker even if it is a multi-pole circuit breaker including a plurality of bimetals. An object of the present invention is to provide a bimetal adjustment structure for a circuit breaker that can reduce the operation variation of the circuit breaker.

In order to solve the above-mentioned problem, the invention of claim 1 has a plurality of electric circuits, each of which is provided with a bimetal piece and a thermal or thermal electromagnetic trip structure, wherein the bimetal A circuit breaker bimetal adjustment structure in which a gap between a piece and an engagement piece that is engaged by overcurrent generation can be adjusted by an adjustment screw, wherein the base of the bimetal piece is fixed to a conductor bar on the electric circuit. The tip is a free end to be engaged with the engagement piece, the bimetal piece fixing portion or the conductor bar in the vicinity thereof is the pressing portion of the adjustment screw, and the adjustment screw can be advanced and retracted to change the gap. The pressing portions of the electric circuit are juxtaposed, and a single interlocking plate is interposed between the adjusting screw and all the pressing portions, and all the pressing portions are operated by advancing / retreating operation of one adjusting screw, so that the gap All together Characterized in that the enabling.
According to this configuration, the adjustment of the plurality of bimetal pieces can be performed with one adjustment screw, and the adjustment time can be shortened. In addition, the same force can be applied to all the pressing parts, and it is difficult for a large difference to occur in the engaging operation between each bimetal piece and the engaging piece. Only the extremely fast or slow operation is eliminated. And by using one adjustment screw, the adjustment screw space can be reduced.

According to a second aspect of the present invention, in the first aspect of the invention, the load side terminal is disposed on the front surface of the circuit breaker case and the power source side terminal is disposed on the rear surface, and the conductor bar connected to the load side terminal is directed rearward. Is placed on the bottom of the circuit breaker case, the tip end of the conductor bar is erected upward, a bimetal piece is fixed to the tip, and the conductor bar erection portion is used as a pressing portion with an adjusting screw from the rear. It is characterized by pressing.
According to this structure, the gap of a bimetal piece can be adjusted from a case back part, and it can adjust by simple operation. Further, since the adjustment screw can be arranged at the lower end of the case back, the adjustment screw can be assembled to the case with a minimum space.

  According to the present invention, adjustment of a plurality of bimetal pieces can be performed with one adjustment screw, and adjustment time can be shortened. In addition, the same force can be applied to all the pressing parts, and it is difficult for a large difference to occur in the engaging operation between each bimetal piece and the engaging piece. Only the extremely fast or slow operation is eliminated.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, embodiments of the invention will be described in detail with reference to the drawings. FIG. 1 is a longitudinal sectional view of a thermal electromagnetic circuit breaker having a bimetal adjustment structure according to the present invention, where 1 is a power supply side terminal, 2 is a load side terminal, and 3 is an operation handle for opening and closing an electric circuit. Reference numeral 4 denotes an opening / closing contact portion composed of a movable contact 5 and a fixed contact 6, and 7 an opening / closing mechanism for opening / closing the opening / closing contact portion 4 in response to the operation of the operation handle 3 and for interrupting the electric circuit in response to detection of an abnormal current. , 8 is a bimetal piece for detecting overcurrent, 9 is an engagement piece for interrupting the opening / closing mechanism 7 by the engagement operation of the bimetal piece 8, and 10 is a gap between the bimetal piece 8 and the engagement piece 9 ( An adjusting screw for adjusting the gap G), 11 is an interlocking plate for transmitting the pressing force of the adjusting screw 10 to the bimetal piece 8, 12 is an electromagnetic tripping element having a movable iron piece 12a for detecting a short-circuit current, and 13 is a breaker case. (Hereafter, simply Scan is referred to as a) a.

  This circuit breaker is a two-pole circuit breaker having two electric circuits, and the power supply side terminal 1, the load side terminal 2, the switching contact portion 4 and the bimetal piece 8 are all provided in pairs. ing. The following description will be made with the right side of the drawing provided with the load side terminal 2 as the front, the left side of the drawing provided with the power supply side terminal 1 as the rear, and the operation handle 3 mounting portion as the upper part.

The movable contact 5 and the fixed contact 6 are arranged in the vertical direction, and contacts (movable contact 5a, fixed contact 6a) are provided in the upper part. The movable contact 5 is installed so that the upper part can swing back and forth with the lower end as a fulcrum, and is connected to the bimetal piece 8 by a flexible conducting wire 16. On the other hand, the fixed contact 6 is formed integrally with the terminal fitting of the power supply side terminal 1 and is fixed in the case 13.
Then, the movable contact 5 moves back and forth in response to the opening / closing operation of the opening / closing mechanism section 7, contacts / dissociates between the movable contact 5a and the fixed contact 6a, and energization / interruption of the electric circuit is performed.

  The bimetal piece 8 is disposed in the front-rear direction, the rear base end portion is welded to the conductor bar 17 extended from the terminal fitting of the load side terminal 2, and the distal end as a free end is disposed obliquely upward. Yes. The flexible conducting wire 16 is welded in the middle of the bimetal piece 8, and the bimetal piece 8 constitutes a part of the electric circuit. On the other hand, the engagement piece 9 with which the bimetal piece 8 is engaged includes a first engagement portion 9a with which the bimetal piece 8 contacts and a second engagement portion 9b with which the electromagnetic tripping element 12 contacts.

  FIG. 2 is a rear view explanatory view in which the bimetal piece 8 connected to the conductor bar 17 and the interlocking plate 11 are extracted, and the pair of conductor bars 17, 17 and the bimetal pieces 8, 8 are arranged side by side in parallel. Has a width covering the pair of conductor bars 17 and 17 and is configured such that the tip of the adjusting screw 10 abuts at the center.

  The conductor bar 17 is disposed on the inner bottom portion of the case 13 from the load side terminal 2 and extends rearward, and a bimetal piece 8 is welded to the tip thereof. The front end portion of the conductor bar 17 has an upright portion 17a bent upward, and is further bent in the rearward direction so that the whole is bent into a bowl shape. A bimetal piece 8 is welded to the flat portion at the tip bent backward.

  The interlocking plate 11 is an insulator formed in a rod shape, and is arranged so as to abut on the standing portion 17a of the conductor bar 17 from the rear. When the adjustment screw 10 is screwed in, the upright portion 17a of the conductor bar 17 is pressed forward. The conductor bar 17 pressed in this way tilts forward in conjunction with the bimetal piece 8 attached to the tip of the conductor bar 17 because the upper portion of the upright portion 17a tilts forward. As a result, the tip extending forward is tilted downward, and the gap G between the engagement piece 9 is reduced. This operation is performed simultaneously on the left and right bimetal pieces 8 and 8.

  The adjustment screw 10 is disposed forward of the lower portion of the power supply side terminal 1, is screwed and supported by a nut 18 assembled in the case 13, and the adjustment screw 10 itself is assembled so as to be embedded in the case 13. Yes. An operation hole 19 is provided on the back surface of the case 13 for rotating the adjustment screw 10 forward and backward.

  The circuit breaker thus configured operates as follows. When the operation handle 3 is rotated backward from the off state shown in FIG. 1 and turned on, the opening / closing mechanism unit 7 operates the movable contact 5 to contact the fixed contact 6, and the circuit breaker is turned on. . This state is maintained by the action of the latch mechanism in the opening / closing function unit 7, and when an abnormal current flows through the electric circuit, the latch is released and the opening / closing mechanism unit 7 performs a blocking operation. Among the abnormal currents, the overcurrent is detected by the deformation (curvature) of the bimetal piece 8, and when the deformation is brought into contact with the first engagement portion 9 a of the engagement piece 9, the engagement piece 9 rotates. Then, the latch is released and the blocking operation is performed. Further, for the short-circuit current, the electromagnetic tripping element 12 operates, the movable iron piece 12a is engaged with the second engagement portion 9b of the engagement piece 9, and the latch is released and shut off in the same manner as in the case of overcurrent occurrence. Operate.

Thus, the adjustment of a plurality of bimetal pieces can be performed with one adjustment screw, and the adjustment time can be shortened. In addition, the same force can be applied to all pressing parts by the action of the interlocking plate, making it difficult for large differences in the engagement operation of each bimetal piece and the engagement piece, and when adjusting independently Thus, there is no such thing as operating one extremely fast or slow. And by using one adjustment screw, the adjustment screw space can be reduced.
In addition, the gap between the bimetal pieces can be adjusted from the back of the case, and it can be adjusted with simple operations. The adjustment screw can be placed at the lower end of the back of the case. It is available without.

  In addition, although the said embodiment demonstrated the case of a 2 pole type circuit breaker, it is the same also in the case of a 3 pole type circuit breaker, the three conductor bars 17 and the bimetal piece 8 are arranged in parallel, and all of them are arranged. The interlocking plate 11 may be disposed so as to cover the conductor bar 17 and the adjusting screw 10 may be disposed in the center of the interlocking plate 11. Further, although the adjustment screw 10 is adjusted from the back of the case 13, the adjustment screw 10 may be disposed upward to press the horizontal bimetal piece 8 connecting portion upward. In this case, the operation hole 19 is provided at the bottom of the case 13.

It is a section explanatory view of a circuit breaker which shows an example of a bimetal adjustment structure concerning the present invention. It is the back view explanatory drawing which extracted the bimetal piece of FIG. 1, the conductor bar, and the interlocking board.

Explanation of symbols

  1 .... Power side terminal, 2 .... Load side terminal, 8 .... Bimetal piece, 9 .... Hanging piece, 10 .... Adjustment screw, 11 .... Interlocking plate, 13 .... Battery case, 17 ... Conductor bar , 17a .. Standing part (pressing part).

Claims (2)

A gap between a plurality of electric paths, bimetal pieces provided in each electric circuit, and a thermal or thermal electromagnetic tripping structure, the bimetal pieces engaging with each other upon occurrence of overcurrent A circuit breaker bimetal adjustment structure that can be adjusted with an adjustment screw,
While fixing the base of the bimetal piece to the conductor bar on the electric circuit, the tip is a free end that engages the engagement piece,
A bimetal piece fixing part or a conductor bar in the vicinity thereof is used as a pressing part of the adjusting screw, and the adjusting screw can be advanced and retracted to change the gap, and the pressing parts of the individual electric paths are arranged side by side, One interlocking plate is interposed between the adjusting screw and all the pressing parts,
A bimetal adjustment structure for a circuit breaker, wherein the gaps can be simultaneously adjusted by operating all of the pressing portions by advancing and retracting one adjusting screw. A load side terminal is arranged on the front side of the circuit breaker case, and a power source side terminal is arranged on the back side, and a conductor bar as an electric circuit connected to the load side terminal is arranged at the bottom of the breaker case facing backward, 2. The bimetal adjustment structure for a circuit breaker according to claim 1, wherein the extended tip portion is erected upward, a bimetal piece is fixed to the tip, and the conductor bar erection portion is used as a pressing portion and pressed from behind by an adjusting screw.

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