JP4333029B2 - Circuit breaker - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a tripping device for a circuit breaker.
[0002]
[Prior art]
FIG. 6 is a front view showing a part of a conventional circuit breaker similar to that shown in, for example, Japanese Patent Laid-Open No. 8-96689, with a part thereof broken. 7 is an enlarged view showing a tripping member of the circuit breaker of FIG. 6, wherein (A) is a front view, (B) is a side view, and (C) is a top view of (B). FIG. 8 is an enlarged side view showing the slide plate of the tripping member.
In the figure, 1 is a base and 2 is a cover. An overcurrent tripping device 3 is attached to the base 1 with a screw 5a via a relay terminal 4. The overcurrent tripping device 3 is screwed to a heater 6 electrically connected to the relay terminal 4 by a screw 5b, a bimetal 8 fixed to the heater 6 with a rivet 7, and an open end 8a of the bimetal 8. An adjustment screw 8b, a thermal tripping device 31 comprising a nut 8c for fixing the adjustment screw 8b to the bimetal 8, and a yoke 9 fixed to the heater 6 together with the bimetal 8 together with the rivet 7 are disposed. The armature 10 is attracted to the yoke 9 by the electromagnetic force generated by the flowing current, and the electromagnetic trip device 32 including the spring 11 for returning the armature 10 is configured.
[0003]
A tripping member 12 is rotatably attached to a frame 14 that is screwed to the base 1 with screws 13. As shown in FIG. 7, a trip bar 15 made of synthetic resin, and the trip bar 15 A latch 17 which is a first engaging member rotatably mounted on a shaft 16 fitted in the shaft 16, and a slide plate 18 (shown by an alternate long and short dash line) mounted so as to be movable in the longitudinal direction of the trip bar 15. It consists of As shown in FIG. 8, the slide plate 18 has a plurality of protrusions 18a and a plurality of inclined surfaces 18b, and these protrusions 18a are fitted in the long holes 15a of the trip bar 15 (shown in FIG. 7B). Together, it is formed to be movable in the direction of the arrow {shown in FIG. 7C}.
[0004]
The trip member 12 is configured to be able to adjust the thermal trip characteristic. As shown in FIG. 7, when the slide plate 18 is in the position indicated by the alternate long and short dash line, the tip of the adjustment screw 8b and the inclined surface 18b The gap between the tip of the adjusting screw 8b and the inclined surface 18b is almost the maximum when the slide plate 18 is in the position indicated by the two-dot chain line. It becomes setting. Reference numeral 19 shown in FIG. 6 denotes an opening / closing mechanism, which is a latch 20 that is a second engaging member that is rotatably held on the frame 14 by a shaft 14 a, and a third engagement that has one end engaged with the latch 20. The lever 21 is a combined member, a handle arm 22, a link mechanism (not shown), and the like.
[0005]
In such a conventional circuit breaker, a current equal to or lower than the rated current value normally flows through the overcurrent tripping device 3. Here, when the current flowing through the overcurrent tripping device 3 rises above the rated current for some reason, the bimetal 8 is heated by the Joule heat generated from the heater 6, and the open end 8a is bent in the direction of arrow A. Press the trip bar 15. When the trip bar 15 is pressed by a predetermined amount or more, the trip bar 15 is rotated in the clockwise direction, and the latch 17 attached to the shaft 16 inserted into the trip bar 15 is disengaged from the latch 20, and the latch 20 Is rotated counterclockwise about the shaft 14a by the biasing force of a latch spring (not shown). By this rotation, the lever 21 is released from the engagement with the latch 20 and is rotated in the clockwise direction, the opening / closing mechanism unit 19 such as the handle arm 22 is operated, and the movable contact 23 is separated from the fixed contact 24 and the circuit. Is cut off.
[0006]
Further, when the current flowing through the overcurrent tripping device 3 exceeds the rated current and becomes a predetermined value or more, the magnetic flux generated by the current flowing through the heater 6 passes through the yoke 9 and the armature 10 serving as magnetic paths, thereby causing the armature 10 Is generated in the direction of the yoke 9. This suction force is superior to the urging force of the spring 11 for returning the amateur 10, sucks the armature 10 and pushes the trip bar 15 at the tip 10a, and the trip bar 15 is rotated in the clockwise direction. 17 and the latch 20 are disengaged, and the opening / closing mechanism 19 is operated to disconnect the movable contact 23 from the fixed contact 24 and the circuit is interrupted.
[0007]
[Problems to be solved by the invention]
In the conventional circuit breaker as described above, the tripping member 12 of the thermal tripping device 31 can adjust the thermal tripping characteristics, but the tripbar 15 having a complicated shape and the tripbar 15 are fitted. It is composed of the inserted shaft 16, the latch 17, and the slide plate 18, and there is a problem that the number of parts is large and assembly work is difficult.
The trip bar 15 is a molded product having a complicated shape, and the slide plate 18 is inserted into the trip bar 15, so that when the bimetal 8 is curved, the contact position between the adjustment screw 8b and the slide plate 18 varies. There was also a problem that the thermal trip characteristic was not stable.
[0008]
The present invention has been made to solve such problems, and an object of the present invention is to obtain a thermally rated adjustable circuit breaker having a tripping member that can be easily assembled with a configuration having a small number of parts.
[0009]
[Means for Solving the Problems]
In the circuit breaker according to the present invention, a thermal trip device having a bimetal that bends in response to an energization current, an electromagnetic trip device that operates by an electromagnetic force generated when the energization current exceeds a predetermined value, In a circuit breaker comprising a tripping member driven by the operation of a thermal tripping device and an electromagnetic tripping device, and an opening / closing mechanism that operates by rotation of the tripping member, the tripping member is a round bar , A first engagement member that is integrally attached to the trip bar and engages the opening / closing mechanism, and a slide plate that is attached to the trip bar and can adjust a gap between the bimetal in a steady state. It is equipped with.
[0010]
Also, a holding groove is provided in the slide plate, and the slide plate is inserted into the trip bar from the direction perpendicular to the axial direction of the trip bar by the holding groove.
[0011]
Further, the slide plate is provided with a guide groove that is in contact with a first engagement member attached to the trip bar and is positioned so as to be slidable by a predetermined distance in the axial direction of the trip bar.
[0012]
Also, an adjustment screw for adjusting the gap between the bimetal and the slide plate is provided, and the contact surface of the slide plate with which the adjustment screw contacts is formed with an inclined surface formed in an arc shape in the same direction as the circumferential direction of the trip bar. It is a thing.
[0013]
Also, a thermal trip device having a bimetal that bends in response to an energization current, an electromagnetic trip device that operates by an electromagnetic force generated when the energization current exceeds a predetermined value, a thermal trip device, and the electromagnetic trip In a circuit breaker including a tripping member driven by the operation of the tripping device and an opening / closing mechanism that operates by rotation of the tripping member, the tripping member includes a trip bar formed of a round bar, A first engaging member that is integrally attached to the trip bar and engages with the opening / closing mechanism, and a shielding member that is attached to the trip bar and projects between the adjacent poles.
[0014]
Further, the shielding member is provided with a stopper that is positioned in contact with the first engagement member.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Embodiment 1 FIG.
FIG. 1 is a front view showing a part of a circuit breaker showing an embodiment of the present invention with a part thereof broken. 2 is an enlarged view showing a tripping member of the circuit breaker of FIG. 1, wherein (A) is a front view, (B) is a left side view, and (C) is a top view of (B). 3A and 3B are exploded views showing the tripping member, where FIG. 3A is a front exploded view and FIG. 3B is a left side exploded view. In the figure, reference numerals 1 to 11, 13, 14, and 19 to 24 are the same as those in the conventional apparatus, and the description thereof is omitted.
[0016]
Reference numeral 40 denotes a tripping member, which includes a trip bar 41, a latch 42 which is a first engagement member, and a slide plate 43, and is pivotally attached to a through hole 42e of the latch 42 as shown in FIG. And a pivot pin 44 (shown in FIG. 1) pivotally supported by the frame 14 so as to be pivotable. As shown in FIGS. 2 and 3, the trip bar 41 is formed of a round bar made of an insulating material such as synthetic resin or ceramics.
[0017]
The latch 42 is formed of a metal plate such as a carbon steel plate. As shown in FIG. 2, the latch 42 has a base 42a, a latch engaging piece 42b bent in a direction perpendicular to the center of the base 42a, and a right end of the base 42a. A first support piece 42c bent at a right angle, a second support piece 42d bent at a right angle from the left end of the base 42a, and a latch pin 44 formed on the first support piece 42c and the second support piece 42d A through hole 42e is formed to be rotatably inserted. Further, the latch engaging piece 42b of the latch 42 is engaged with one end of the latch 20 when the circuit breaker shown in FIG. Further, as shown in FIG. 3, the latch 42 is fitted into the trip bar 41 and integrally attached to a predetermined position in the axial direction of the trip bar 41.
[0018]
2 and 3, the slide plate 43 is inserted and tripped in the direction of the arrow with a plurality of inclined surfaces 43a with which the adjusting screws 8b screwed to the bimetals 8 of the respective poles of the thermal tripping device 31 abut. A plurality of holding grooves 43b to be inserted into the bar 41, and protruding portions 43c are formed at the open ends of the holding grooves 43b so as to have a dimension B slightly smaller than the outer diameter of the trip bar 41. When the bimetal 8 is curved and the tip of the adjustment screw 8b comes into contact with the inclined surface 43a, the inclined surface 43a has an adjustment screw 8b at any position in the rotation direction of the trip bar 41 (indicated by an arrow R in FIG. 2A). Even when the tip of the trip bar 41 hits the inclined surface 43a, the circumferential direction of the trip bar 41 centered on the center point C of the trip bar 41 is constant so that the gap between the tip of the adjusting screw 8b and the inclined surface 43a is always constant. It is formed in an arc shape {shown in FIG. 2A} in the direction.
[0019]
Further, by providing the holding groove 43b and the protrusion 43c at the open end of the holding groove 43b, the holding groove 43b of the slide plate 43 is arranged in the direction shown by the arrow in FIG. 3, that is, the direction orthogonal to the axial direction of the trip bar 41. When pushed in, the open end of the holding groove 43b is pushed open and inserted into the trip bar 41 by snap fit, and when inserted to a predetermined position, the trip bar 41 is held by the protruding portion 43c and the slide plate 43 trips. The bar 41 is fitted so as not to fall out. Further, as shown by a one-dot chain line in FIG. 2, a guide groove 43d is formed in the slide plate 43 so as to be movable in the direction of arrow D, and the first support portion 42c of the latch 42 is the right wall of the guide groove 43d. 43f {position in FIG. 2B} or the left wall 43h (when moved in the direction of arrow D), the latch 42 and the slide plate 43 are positioned.
[0020]
The relationship between the adjusting screw 8b screwed to the bimetal 8 of the thermal tripping device 31 and the tripping member 40 is as shown in FIG. 2 when the slide plate 43 is in the position indicated by the solid line. The gap between the tip and the inclined surface 43a is almost the minimum, and the setting is low in heat rating. When the slide plate 43 is moved to the position indicated by the alternate long and short dash line, the gap between the tip of the adjustment screw 8b and the inclined surface 43a is almost the largest. It becomes a setting of high thermal rating.
[0021]
The operation of the circuit breaker configured as described above will be described. When the current flowing through the overcurrent trip device 3 rises above the rated current for some reason, the bimetal 8 is heated by the Joule heat generated from the heater 6, and its open end 8a is in the direction of arrow A (shown in FIG. 1). And the tip of the adjustment screw 8b presses the trip bar 41 through the slide plate 43. When the trip bar 41 is pressed by a predetermined amount or more, the trip bar 41 is rotated clockwise around the latch pin 44, and the latch 42 inserted into the trip bar 41 is disengaged from the latch 20. Is rotated counterclockwise about the shaft 14a by the biasing force of a latch spring (not shown). By this rotation, the lever 21 is released from the engagement with the latch 20, the opening / closing mechanism 19 such as the handle arm 22 is operated, the movable contact 23 is separated from the fixed contact 24, and the circuit is interrupted.
[0022]
In addition, about the interruption | blocking operation | movement when the electric current which flows into the electromagnetic trip apparatus 32 becomes more than a predetermined value more than a rated current, it is the same as that of a conventional apparatus, The description is abbreviate | omitted.
[0023]
In the circuit breaker configured as described above, the tripping member 40 driven by the bending of the bimetal 8 of the thermal tripping device 31 is formed of a round bar as shown in FIGS. By configuring with the bar 41 and the latch 42, a fixed thermal rating circuit breaker can be obtained. Further, a slide plate 43 to be inserted into the trip bar 41 is provided, and the holding groove 43a of the slide plate 43 is fitted into the trip bar 41 into which the latch 42 is inserted by simply pushing it in a direction perpendicular to the trip bar axial direction. The slide plate 43 is moved in the axial direction of the trip bar 41, and the thermal tripping characteristic is adjusted by adjusting the gap between the tip of the adjustment screw 8b screwed to the bimetal 8 and the inclined surface 43a of the slide plate 18. Therefore, it is possible to obtain a thermally rated adjustable circuit breaker having a tripping member that can be easily assembled with a configuration having a small number of parts.
That is, it is possible to manufacture a circuit breaker with adjustable heat rating in a short period of time by allocating a standard heat rated fixed mechanism.
[0024]
Further, the contact surface of the slide plate 43 with which the adjusting screw 8b for adjusting the gap between the bimetal 8 and the slide plate 43 contacts is an arcuate inclined surface 43a in the same direction as the circumferential direction of the trip bar 41. Even if the tip of the adjustment screw 8b contacts the inclined surface 43a at any position in the rotation direction of the trip bar 41, the gap between the tip of the adjustment screw 8b and the inclined surface 43a is always constant, and the thermal tripping characteristic is Stabilize.
[0025]
Embodiment 2. FIG.
FIG. 4 is an enlarged view showing a tripping member of a circuit breaker of a circuit breaker showing Embodiment 2 of the present invention, (A) is a front view, (B) is a left side view, and (C) is a left side view. It is a top view of (B). FIG. 5 is an exploded view showing the tripping member, (A) is a front exploded view, and (B) is a left side exploded view. In the figure, reference numerals 41 and 42 are the same as those in the first embodiment, and a description thereof is omitted.
[0026]
Reference numeral 60 denotes a tripping member, which includes a trip bar 41, a latch 42, and a shielding member 63 as shown in FIG. As shown in FIGS. 4 and 5, the shielding member 63 is formed of an insulating material such as synthetic resin, and is pushed into the trip bar 41 in the direction indicated by the arrow (shown in FIG. 5), that is, the direction perpendicular to the axial direction of the trip bar 41. A pair of holding grooves 63a to be inserted, a pair of protrusions 63b formed at the open end of the holding groove 63a, a pair of stoppers 63c for positioning the latch 42, and a pair of protrusions protruding at right angles from both ends It has a protruding piece 63d.
[0027]
By providing the protrusion 63b in the holding groove 63a, the dimension E {shown in FIG. 5A} is formed slightly smaller than the outer diameter of the trip bar 41, and the shielding member 63 is fitted to the trip bar 41. When the open end of the holding groove 63a is pushed open and inserted into the trip bar 41 and inserted to a predetermined position, the trip bar 41 is held by the protruding portion 63b so that the shielding member 63 does not fall out of the trip bar 41. It is configured.
[0028]
In the circuit breaker according to the second embodiment of the present invention, a circuit breaker having a fixed thermal rating having a tripping member 41 formed of a round bar and a tripping member 60 composed of a latch 42 is configured. Since the projecting piece 63d is interposed between the adjacent poles only by inserting the shielding member 63 into the trip bar 41 of the circuit breaker, for example, when the interruption operation is performed at the center pole, the arc gas generated by the interruption is generated. Since it becomes difficult to flow into the left and right adjacent poles by hitting the protruding piece 63d, the contamination of the trip bar 42 and components on the adjacent pole side can be reduced, and the interphase insulation performance can be improved.
[0029]
The slide plate 43 shown in the first embodiment may be integrally formed with a projecting piece similar to the projecting piece 63d shown in the second embodiment, or even if a separate projecting piece is attached. There is an effect.
[0030]
【The invention's effect】
Since the present invention is configured as described above, the following effects can be obtained.
[0031]
A trip bar formed of a round bar, a first engagement member that is integrally attached to the trip bar and engages an opening / closing mechanism, and a gap between the trip bar and a bimetal in a steady state can be adjusted. Since the tripping member provided with the slide plate is provided, it is possible to obtain a thermally rated adjustable circuit breaker having a tripping member that can be easily assembled with a configuration having a small number of parts.
[0032]
Further, since the holding plate is provided with the holding groove, and the holding plate is inserted into the trip bar from the direction perpendicular to the axial direction of the trip bar, the assembling of the tripping member is facilitated.
[0033]
In addition, the slide plate is provided with a guide groove that is positioned so as to be slidable by a predetermined distance in the axial direction of the trip bar by contacting the first engagement member attached to the trip bar. It becomes easy to adjust the gap.
[0034]
In addition, an adjustment screw for adjusting the gap between the bimetal and the slide plate is provided, and the contact surface of the slide plate with which the adjustment screw contacts is formed with an inclined surface formed in an arc shape in the same direction as the circumferential direction of the trip bar. Therefore, no matter what position in the rotation direction of the trip bar the tip of the adjustment screw contacts the inclined surface, the gap between the slide plate and the adjustment screw is always constant, and the thermal tripping characteristic is stabilized.
[0035]
Also, a trip bar formed by a round bar, a first engagement member that is integrally attached to the trip bar and engages the opening / closing mechanism, and a shield that is attached to the trip bar and protrudes between adjacent poles. Since the tripping member provided with the member is provided, the arc gas generated at the time of interruption becomes difficult to flow into the adjacent pole, the trip bar on the adjacent pole side and the contamination of the component parts are reduced, and the interphase insulation performance is improved.
[0036]
Furthermore, since the stopper that is positioned in contact with the first engaging member is provided on the shielding member, it is easy to attach to the trip bar and the movement of the shielding member is prevented.
[Brief description of the drawings]
FIG. 1 is a front view showing a part of a circuit breaker according to a first embodiment of the present invention, with a part thereof broken.
FIG. 2 is an enlarged view showing a tripping member according to Embodiment 1 of the present invention.
FIG. 3 is an exploded view showing a tripping member according to Embodiment 1 of the present invention.
FIG. 4 is an enlarged view showing a tripping member according to Embodiment 2 of the present invention.
FIG. 5 is an exploded view showing a tripping member according to Embodiment 2 of the present invention.
FIG. 6 is a front view showing a part of a conventional circuit breaker with a part broken away.
FIG. 7 is an enlarged view showing a conventional tripping member.
FIG. 8 is an enlarged side view showing a conventional slide plate.
[Explanation of symbols]
8 Bimetal, 8b Adjustment screw, 19 Opening / closing mechanism,
31 Thermal trip device, 32 Electromagnetic trip device, 40 Trip member,
41 trip bar, 42 latch (first engaging member), 43 slide plate,
43a inclined surface, 43b holding groove, 43d guide groove, 60 tripping member,
63 Shielding member, 63c Stopper

Claims (6)

Thermal trip device having a bimetal that curves in response to an energization current, an electromagnetic trip device that operates by electromagnetic force generated when the energization current exceeds a predetermined value, the thermal trip device, and the electromagnetic trip In a circuit breaker comprising a tripping member driven by the operation of a tripping device and an opening / closing mechanism that operates by rotation of the tripping member, the tripping member is a trip bar formed of a round bar A first engagement member that is integrally attached to the trip bar and engages with the opening / closing mechanism, and a slide plate that is attached to the trip bar and can adjust a gap between the bimetal in a steady state. A circuit breaker comprising the circuit breaker. 2. The circuit breaker according to claim 1, wherein a holding groove is provided in the slide plate, and the slide plate is inserted into the trip bar from a direction orthogonal to the axial direction of the trip bar by the holding groove. The slide plate is provided with a guide groove which is positioned so as to be slidable by a predetermined distance in the axial direction of the trip bar in contact with a first engagement member attached to the trip bar. The circuit breaker according to claim 2. An adjustment screw for adjusting the gap between the bimetal and the slide plate is provided, and the contact surface of the slide plate with which the adjustment screw contacts is an inclined surface formed in an arc shape in the same direction as the circumferential direction of the trip bar. The circuit breaker of any one of Claims 1-3 characterized by the above-mentioned. Thermal trip device having a bimetal that curves in response to an energization current, an electromagnetic trip device that operates by electromagnetic force generated when the energization current exceeds a predetermined value, the thermal trip device, and the electromagnetic trip In a circuit breaker comprising a tripping member driven by the operation of a tripping device and an opening / closing mechanism that operates by rotation of the tripping member, the tripping member is a trip bar formed of a round bar And a first engaging member that is attached to the trip bar and engages with the opening / closing mechanism, and a shielding member that is attached to the trip bar and projects between the adjacent poles. Circuit breaker. 6. The circuit breaker according to claim 5, wherein the shielding member is provided with a stopper that is positioned in contact with the first engagement member.

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