JP6262570B2 - Circuit breaker electromagnetic trip device - Google Patents

Description

  The present invention relates to an electromagnetic trip device for a circuit breaker that detects when an excessive current such as a short-circuit current flows in an electric circuit and interrupts the electric circuit.

  Conventionally, as an electromagnetic trip device for a general circuit breaker, for example, as described in Patent Document 1, a fixed electromagnetic piece bent in a substantially U shape so as to surround an electric circuit, and a lower side The plate-like part is provided with an operation part for causing the operation to cut off the electric circuit on the upper side, and is attached to the fixed electromagnetic piece so as to be rotatable at a position between the plate-like part and the operation part. Some of them have a movable electromagnetic piece in which the plate-like portion comes into contact / dissociation with the open side of the fixed electromagnetic piece by rotation, and an urging means for holding the plate-like portion in a disengaged state. When an excessive current such as a short circuit current flows through the electric circuit, an eddy current generated around the electric circuit applies an electromagnetic force (adsorption force) to the fixed electromagnetic piece side on the plate-like portion of the movable electromagnetic piece. When the plate-like portion is rotated against the holding force of the urging means, the operation portion is also rotated, and as a result, an operation for interrupting the electric circuit is caused.

Japanese Patent Laid-Open No. 9-50754

  However, in the conventional electromagnetic tripping device, a shaft portion for rotating the movable electromagnetic piece is provided at a position sandwiching the thermally responsive element fixed to the electric circuit from the left and right. Therefore, since the distance between the one end side of the movable electromagnetic piece and the fixed electromagnetic piece is increased, there is a problem that the attracting force applied to the plate-like portion of the movable electromagnetic piece is weak when an excessive current flows in the electric circuit. The place where the attractive force is most applied is the center of gravity of the movable electromagnetic piece in the plate-like portion of the movable electromagnetic piece, but the movable electromagnetic piece rotates because the distance between the center of gravity and the rotation axis of the movable electromagnetic piece is short. There is also a problem that the force generated at the operation portion of the movable electromagnetic piece, that is, the force for causing the operation of interrupting the electric path is weak.

  Therefore, the present invention has been made in view of the above problems, and has a strong attracting force applied to the plate-like portion of the movable electromagnetic piece and a large force on the operation portion of the movable electromagnetic piece when the movable electromagnetic piece rotates. It is an object of the present invention to provide an electromagnetic trip device for a circuit breaker capable of generating

  In order to achieve the above object, the present invention is assembled to a front surface of a strip-like conductive part extending in the vertical direction with respect to an electric circuit in which a thermally responsive element is fixed in a posture to stand in the vertical direction. An electromagnetic trip device for a circuit breaker that operates when a current exceeding a value flows, and a fixed electromagnetic piece fixed to the conductive portion in a state in which the conductive portion and the thermally responsive element are accommodated from the rear side, A plate-like portion that contacts / dissociates from the front side with respect to the fixed electromagnetic piece is provided on the side, and an operation portion is provided on the upper side to cause the operation of interrupting the electric circuit, and the plate-like portion and the operation portion When a current exceeding a predetermined value flows through the conductive portion, the plate is movable when the current exceeds a predetermined value. Forward to the side in contact with the fixed electromagnetic piece As the movable electromagnetic piece rotates, each of the fixed electromagnetic piece and the plate-like portion of the movable electromagnetic piece is provided with a pair of arms that protrude at least partially to the rear side of the thermally responsive element. The fixed electromagnetic piece and the movable electromagnetic piece are attached to each other at a location on the rear side of the thermal response element in the arm portion.

According to the present invention, the fixed electromagnetic piece and the plate-like portion of the movable electromagnetic piece are each provided with a pair of arms that protrude at least partially to the rear side of the thermal response element. The fixed electromagnetic piece and the movable electromagnetic piece are pivotally attached to the rear side. That is, the rotating shaft of the movable electromagnetic piece is provided on the rear side of the thermally responsive element. Therefore, the distance in the front-rear direction between the fixed electromagnetic piece in a dissociated state and the plate-like portion of the movable electromagnetic piece can be made closer than before, and when an excessive current exceeding a predetermined value such as a short circuit current flows, A larger electromagnetic force than before can be applied to the plate-like portion.
In addition, since the position of the rotation axis and the center of gravity of the plate-like portion of the movable electromagnetic piece can be separated from the conventional position, a larger force than the conventional force can be generated in the operation unit when the rotation is performed. It is possible to surely cause an operation to shut off.

It is perspective explanatory drawing which showed a part of circuit breaker. FIG. 2 is an explanatory perspective view showing a state where a main body case is removed from the circuit breaker shown in FIG. 1. It is the isometric view explanatory view which showed the electromagnetic trip apparatus assembled | attached to the electrical circuit from the front side. It is perspective explanatory drawing which showed the electromagnetic trip apparatus assembled | attached to the electrical circuit from the rear side. (A) is explanatory drawing which showed the rear surface side of the electromagnetic trip apparatus assembled | attached to the electrical circuit, (b) is explanatory drawing which showed the AA line cross section in (a). It is the isometric view explanatory view which showed the electromagnetic trip apparatus in a decomposition | disassembly state including an electrical path from the front side. It is the isometric view explanatory view which showed the electromagnetic trip apparatus in a decomposition | disassembly state including an electrical path from the rear side. It is explanatory drawing which showed the electromagnetic trip apparatus in a normal state from the side. It is explanatory drawing which showed from the side the electromagnetic trip apparatus in the state which act | operated because the short circuit current flowed.

  Hereinafter, an electromagnetic trip device for a circuit breaker according to an embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a perspective explanatory view showing a part of the circuit breaker 1. FIG. 2 is a perspective explanatory view showing a state in which the main body case 5 is removed from the circuit breaker 1 shown in FIG.
The circuit breaker 1 includes a power supply side terminal 2 at a front portion of a body case 5 made of synthetic resin and a load side terminal 3 at a rear portion thereof. In order to electrically connect the load side terminal 3 to each other, three electric paths 4, 4,. Further, for each electric circuit 4, a contact part composed of a fixed contact 6 and a movable contact 7 that opens and closes the electric circuit 4, a blocking mechanism part (not shown) for opening the contact part, a short circuit current etc. in the electric circuit 4 An electromagnetic trip device 10 that operates to operate the shut-off mechanism when an excessive current flows, an operation member 8 that directly operates the shut-off mechanism by receiving the operation of the electromagnetic trip device 10 and the like are provided. Reference numeral 9 denotes an operation lever for turning on / off the electric circuit 4.

Here, the electromagnetic trip device 10 which is a main part of the present invention will be described in detail with reference to FIGS.
FIG. 3 is a perspective explanatory view showing the electromagnetic trip device 10 assembled to the electric circuit 4 from the front side. FIG. 4 is an explanatory view showing the electromagnetic tripping device 10 assembled to the electric circuit 4 from the rear side. FIG. 5A is an explanatory view showing the rear surface side of the electromagnetic trip device 10 assembled in the electric circuit 4, and FIG. 5B shows a cross section taken along the line AA in FIG. 5A. FIG. FIG. 6 is a perspective explanatory view showing the electromagnetic tripping device 10 in an exploded state including the electric circuit 4 from the front side. FIG. 7 is an explanatory perspective view showing the electromagnetic trip device 10 in an exploded state including the electric circuit 4 from the rear side. FIG. 8 is an explanatory view showing the electromagnetic tripping device 10 in a normal state from the side. FIG. 9 is an explanatory view showing the electromagnetic tripping device 10 in a state where it is activated by a short circuit current flowing from the side.

  First, the configuration of the electric circuit 4 where the electromagnetic trip device 10 is assembled will be described. The electric circuit 4 at the position includes a first electric circuit member 31 having a load seat 32 that constitutes the load-side terminal 3, and a first electric circuit. The second electric path member 33 is integrated with the member 31 and extends further forward (on the power supply side terminal 2 side), and a thermal responsive element 34 fixed to the second electric path member 33. The first electric circuit member 31 has the load seat 32 as described above, and has a strip-shaped conductive portion 35 extending forward from the load seat 32. The front end portion of the conductive portion 35 is bent upward and functions as an integrated portion for integrating with the second electric path member 33. The second electric circuit member 33 functions as a so-called heater, and includes a plate-like connecting portion 36 having a connecting hole, a fixing portion 37 raised upward from the rear end of the connecting portion 36, and a fixing portion 37. And an integrated portion 38 that is further bent from the upper end of the. And while integrating the front end of the electroconductive part 35 of the 1st electric circuit member 31, and the integrated part 38 of the 2nd electric circuit member 33, the lower part contact | abuts the front surface of the fixing | fixed part 37, and the thermoresponsive element 34, The electric circuit 4 is formed by being fixed to the fixing portion 37 in an upright posture in which the upper portion protrudes greatly upward beyond the upper end of the fixing portion 37. Reference numeral 39 denotes an operating member that is attached to the upper end portion of the thermally responsive element 34 and operates the shut-off mechanism when an excessive current flows through the electric circuit 4 and the thermally responsive element 34 is deformed. Reference numeral 40 denotes a rivet for integrating the thermally responsive element 34, the fixing portion 37, and the fixed electromagnetic piece 11 described later.

  The electromagnetic tripping device 10 assembled to the electric circuit 4 as described above is fixed to the fixed electromagnetic piece 11 fixed to the fixing portion 37 of the second electric circuit member 33, and is attached to be rotatable with respect to the fixed electromagnetic piece 11. A movable electromagnetic piece 12 in which a predetermined part (plate-like portion 12a described later) contacts / dissociates with the fixed electromagnetic piece 11 by rotation, and a coil spring 13 that holds a dissociated state between the predetermined part and the fixed electromagnetic piece 11; A shaft member 14 serving as a rotation shaft of the movable electromagnetic piece 12 is provided. The fixed electromagnetic piece 11 is made of a paramagnetic material such as iron and has a back surface portion 11a and left and right side surface portions 11b and 11b formed by being bent into a substantially U shape. The internal space formed by bending is defined as an electric circuit accommodating space 15 for accommodating the fixing portion 37 of the second electric circuit member 33. Moreover, the arm part 11c which protrudes upwards beyond the upper end of the back part 11a is provided in the upper part of each side part 11b. The arm portion 11c projects rearward and obliquely upward from the front portion of the side surface portion 11b, and a first shaft hole 16 is formed at the tip portion. Reference numeral 17 denotes a fixed hole for integrating the fixed electromagnetic piece 11 with the fixed portion 37 together with the thermally responsive element 34 on the rear surface side of the fixed portion 37.

  On the other hand, the movable electromagnetic piece 12 is formed of a paramagnetic material such as iron like the fixed electromagnetic piece 11, and has a flat plate-like portion 12a having substantially the same left-right width as the fixed electromagnetic piece 11, and left and right of the plate-like portion 12a. A left arm portion 18 and a right arm portion 19 that protrude further upward from the upper end of the side portion are provided, and the center of gravity is formed so as to be positioned substantially above the center of the plate-like portion 12a. The left arm portion 18 includes a first arm portion 18a that extends rearward and obliquely upward from the plate-like portion 12a like the arm portion 11c of the fixed electromagnetic piece 11, and a second arm that is bent from the front end of the first arm portion 18a and extends obliquely forward and upward. And a convex portion projecting forward is provided at the tip of the second arm portion 18b, and the convex portion functions as an operation portion 22 for operating the operation member 8. ing. Further, a second shaft hole 20 is formed at the tip of the first arm portion 18a (a position between the plate-like portion 12a and the operation portion 22 at the bent portion of the left arm portion 18). Further, a tongue-like locking piece 21 extending downward is provided at a position close to the plate-like portion 12a of the first arm portion 18a, and by locking with the arm portion 11c of the fixed electromagnetic piece 11, The plate-like portion 12a of the movable electromagnetic piece 12 can be restricted from rotating in the disengagement direction from the fixed electromagnetic piece 11 beyond the locking position. On the other hand, the right arm portion 19 is provided so as to face the first arm portion 18a of the left arm portion 18, and the second axis is located at the tip of the right arm portion 19 at a position facing the second shaft hole 20 of the left arm portion 18. A hole 20 is formed. The distance in the left-right direction between the left arm portion 18 and the right arm portion 19 is substantially the same as the distance between the arm portions 11c and 11c of the fixed electromagnetic piece 11.

  And the electromagnetic trip device 10 is assembled | attached to the electric circuit 4 as follows. First, the fixed electromagnetic piece 11 is brought into close contact with the fixed portion 37 from behind, so that the fixed portion 37 is accommodated in the electric circuit accommodating space 15, and the thermally responsive element 34, the fixed portion 37, and the fixed electromagnetic wave using the rivets 40 and 40. The pieces 11 are integrated. At this time, the end portions of the arm portions 11c and 11c of the fixed electromagnetic piece 11 (particularly, the positions where the first shaft holes 16 and 16 are drilled) are in a state of projecting to the rear side of the thermally responsive element 34. Next, with the plate-like portion 12a of the movable electromagnetic piece 12 positioned on the front side of the thermal actuator 34, the inner surface of the left arm portion 18 is disposed on the outer surface of the left arm portion 11c, and the right arm is disposed on the inner surface of the right arm portion 11c. The outer surfaces of the portions 19 are brought into contact with each other (from the left, the left arm portion 18, the left arm portion 11c, the right arm portion 19 and the right arm portion 11c are brought into contact with each other in this order) The shaft holes 16 and 16 and the second shaft holes 20 and 20 are made to coincide. Finally, the fixed electromagnetic piece 11 and the movable electromagnetic piece 12 may be attached to each other by inserting the shaft member 14 so as to penetrate both the shaft holes 16 and 20. Then, in a state in which the plate-like portion 12a of the movable electromagnetic piece 12 and the fixed electromagnetic piece 11 surround the lower portion of the fixed portion 37 and the thermally responsive element 34, the movable electromagnetic piece 12 has the left-right direction as an axis with respect to the fixed electromagnetic piece 11. It will be attached so that rotation is possible, and the assembly | attachment to the electric circuit 4 of the electromagnetic trip apparatus 10 will be completed. It should be noted that the fixed position of the fixed electromagnetic piece 11 and the movable electromagnetic piece 12 in this assembled state is naturally the rear side of the thermally responsive element 34.

  The coil spring 13 is attached so as to be wound around the shaft member 14 between the left arm portion 11 c and the right arm portion 19. At this time, the coil spring 13 is housed between the left arm portion 11c and the right arm portion 19 in a state of being contracted in the left-right direction (axial direction), and the left arm portion 11c and the right arm portion 19 are respectively outward. (In other words, the left arm portion 11c is pressed toward the contact side with the left arm portion 18 and the right arm portion 19 is pressed toward the contact side with the right arm portion 11c). Furthermore, one end of the coil spring 13 is hooked to the front edge of the second arm portion 18b of the left arm portion 18 of the movable electromagnetic piece 12, and the other end is hooked to the front edge of the right arm portion 11c of the fixed electromagnetic piece 11, The plate-like portion 12a of the movable electromagnetic piece 12 is urged in a direction to dissociate from the fixed electromagnetic piece 11, and the dissociated state between the plate-like portion 12a and the fixed electromagnetic piece 11 is maintained.

  In the electromagnetic trip device 10 assembled in the electric circuit 4 as described above, the plate-like portion 12a of the movable electromagnetic piece 12 and the open front surface of the fixed electromagnetic piece 11 are usually dissociated by the biasing force of the coil spring 13. (FIG. 8). Here, when an excessive current exceeding a predetermined value such as a short circuit current flows through the electric circuit 4, the plate-like portion 12 a of the movable electromagnetic piece 12 is fixed to the fixed electromagnetic piece 11 by the action of the eddy current generated around the second electric circuit member 33. Electromagnetic force (i.e., adsorption force) is generated in the direction in contact with the surface. As a result, the movable electromagnetic piece 12 rotates around the shaft member 14 against the urging force of the coil spring 13, and the plate-like portion 12a of the movable electromagnetic piece 12 is fixed to the fixed electromagnetic piece 11 (particularly the front end face of the left and right side surface portions 11b). ). Therefore, the operation portion 8 of the movable electromagnetic piece 12 moves forward, the operation member 9 is operated (FIG. 9), the tripping operation is performed by the blocking mechanism portion, the contact portion is dissociated, and the electric circuit 4 Is cut off.

  According to the electromagnetic trip device 10 having the above-described configuration, the stationary electromagnetic piece 11 is provided with the pair of arms 11c and 11c protruding rearward, and the plate-like portion 12a of the movable electromagnetic piece 12 is also provided on the rear side. By providing a pair of arm portions 18 and 19 projecting toward each other, and by attaching the fixed electromagnetic piece 11 and the movable electromagnetic piece 12 at a location on the rear side of the thermal response element 34 of each arm portion 11c, 18 and 19 The rotating shaft of the movable electromagnetic piece 12 is provided on the rear side of the thermally responsive element 34. Therefore, the distance in the front-rear direction between the fixed electromagnetic piece 11 and the plate-like part 12a of the movable electromagnetic piece 12 in the normal state (that is, the state where the plate-like part 12a and the fixed electromagnetic piece 11 are dissociated) is made closer than before. When an excessive current such as a short-circuit current flows through the electric circuit 4, it is possible to apply a larger adsorption force to the plate-like portion 12a than before.

  In addition, since the fixed electromagnetic piece 11 and the movable electromagnetic piece 12 are pivotally attached as described above, the distance between the rotating shaft and the center of gravity of the movable electromagnetic piece 12 when the movable electromagnetic piece 12 rotates is made larger than the conventional distance. be able to. Here, assuming that the same amount of suction force is applied to the center of gravity, the force generated in the operation unit 8 serving as the action point becomes stronger as the distance from the rotation axis of the center of gravity increases. Therefore, as described above, according to the electromagnetic trip device 10 in which the distance between the rotation shaft and the center of gravity of the movable electromagnetic piece 12 is larger than the conventional one, when the movable electromagnetic piece 12 is rotated, the operation unit 8 is conventionally provided. A greater force can be generated, and the blocking mechanism can be reliably operated.

Further, in the axially attached portion of the fixed electromagnetic piece 11 and the movable electromagnetic piece 12, the inner surface of the left arm portion 18 is in contact with the outer surface of the left arm portion 11c, and the outer surface of the right arm portion 19 is in contact with the inner surface of the right arm portion 11c. In addition, the coil spring 13 is accommodated between the left arm portion 11c and the right arm portion 19 in a contracted state in the left-right direction. The coil spring 13 presses the left arm portion 11c and the right arm portion 19 positioned on the inside to the outside, that is, the left arm portion 18 and the right arm portion 11c side. Therefore, it is possible to prevent the occurrence of a situation in which the movable electromagnetic piece 12 rattles in the axial direction regardless of whether the current that the movable electromagnetic piece 12 rotates does not flow, and the rotation of the movable electromagnetic piece 12. It is also possible to suppress the tingling and roaring sounds that sometimes occur.
In addition, since the arms are brought into contact with each other in the order of the left arm 18 from the left, the left arm 11c, the right arm 19 and the right arm 11c, the urging force of the coil spring 13 in the axial direction. Can be directly applied to both the fixed electromagnetic piece 11 and the movable electromagnetic piece 12, and the effects such as the prevention of rattling and the suppression of rattling and roaring sounds can be made more prominent.

  The electromagnetic trip device for a circuit breaker according to the present invention is not limited to the aspect of the above embodiment, and the overall configuration of the circuit breaker is, of course, a fixed electromagnetic piece, a movable electromagnetic piece, etc. The configuration can be appropriately changed as necessary without departing from the spirit of the present invention.

For example, in the above embodiment, the electric circuit of the assembly location of the electromagnetic trip device is constituted by the first electric circuit member and the second electric circuit member. However, instead of the first electric circuit member, the load seat and the thermally responsive element are connected to the electric wire. There is no problem even if the electric circuit is connected by, for example, an electric circuit in which the thermally responsive element is configured as a part of the electric circuit.
In the above embodiment, the operating portion is provided on the left arm portion of the movable electromagnetic piece. However, there is no problem even if the operating portion is provided on the right arm portion, and it is naturally possible to similarly provide the locking piece on the right arm portion. It is.
Furthermore, in the above-described embodiment, the arms are brought into contact with each other in the order of left to left arm, left arm, right arm, and right arm, but from left to left arm, left arm The right arm part and the right arm part are brought into contact with each other, that is, the inner and outer relations may be reversed, one arm part in the fixed electromagnetic piece and one arm part in the movable electromagnetic piece. In one set, the arm portion of the movable electromagnetic piece is positioned outside the arm portion of the fixed electromagnetic piece in one set, and the arm of the movable electromagnetic piece is positioned inside the arm portion of the fixed electromagnetic piece in the other set. The part may be located. On the other hand, in both sets, it is also possible to position the arm part of the movable electromagnetic piece outside the arm part of the fixed electromagnetic piece, or conversely position the arm part of the fixed electromagnetic piece outside the arm part of the movable electromagnetic piece. .

Further, the urging means for urging the plate-like portion of the movable electromagnetic piece in the direction of dissociating from the fixed electromagnetic piece is not limited to the coil spring of the above embodiment, and the rear surface of the plate-like portion and the heat-responsive element Another configuration such as interposing a leaf spring between the front surface and the like may be adopted.
In addition, in the above embodiment, shaft holes are provided in both the movable electromagnetic piece and the fixed electromagnetic piece, and the shaft member is attached so as to penetrate all the shaft holes, so that the movable electromagnetic piece is fixed to the fixed electromagnetic piece. Although it is rotatably attached, for example, a configuration may be employed in which a projection serving as a shaft is provided on one of the movable electromagnetic piece and the fixed electromagnetic piece, and a shaft hole through which the projection can be inserted is provided on the other.

  DESCRIPTION OF SYMBOLS 1 ... Circuit breaker 4 ... Electric circuit 8 ... Operation member 10 ... Electromagnetic tripping device 11 ... Fixed electromagnetic piece 11a ... Back part 11b ... Side part 11c ... Arm part , 12 .. Moving electromagnetic piece, 12 a .. Plate-like part, 13 .. Coil spring, 14 .. Shaft member, 15 .. Electric path housing space, 16 .. First shaft hole, 18 .. Left arm part (arm part) , 18a ··· First arm portion, 18b · · Second arm portion, 19 · · Right arm portion (arm portion), 20 · · Second shaft hole, 21 · · Locking piece, 22 · · Operation portion, 31 · · -1st electric circuit member (electric circuit), 33 ... Second electric circuit member (electric circuit), 34 ... Thermally-responsive element, 37 ... Fixed part (conductive part).

Claims (1)

A circuit breaker which is assembled to an electric circuit in which a thermally responsive element is fixed in an upright direction on the front surface of a strip-like conductive part extending in the vertical direction and operates when a current exceeding a predetermined value flows through the conductive part. Electromagnetic tripping device
A fixed electromagnetic piece fixed to the conductive portion in a state in which the conductive portion and the thermally responsive element are accommodated from the rear side;
A plate-like portion that contacts / dissociates from the front side with respect to the fixed electromagnetic piece is provided on the lower side, and an operation portion for causing an operation of interrupting the electric circuit is provided on the upper side. A movable electromagnetic piece pivotally attached to the fixed electromagnetic piece so as to be pivotable about a left-right direction at a position between the part and the fixed electromagnetic piece;
When a current exceeding a predetermined value flows through the conductive part, the movable electromagnetic piece rotates to the side where the plate-like part contacts the fixed electromagnetic piece,
The fixed electromagnetic piece and the plate-like portion of the movable electromagnetic piece are each provided with a pair of arm portions protruding at least partially to the rear side of the thermal response element, than the thermal response element in each arm portion. An electromagnetic trip device for a circuit breaker, wherein the fixed electromagnetic piece and the movable electromagnetic piece are axially attached at a location on the rear side.

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