EP3611744A1

EP3611744A1 - Air circuit breaker

Info

Publication number: EP3611744A1
Application number: EP17905562.9A
Authority: EP
Inventors: Sosuke Uchino; Tomoya Deguchi; Hisashi IWASHITA; Yuta Sagara; Ryunosuke IMAEDA
Original assignee: Mitsubishi Electric Corp
Current assignee: Mitsubishi Electric Corp
Priority date: 2017-04-10
Filing date: 2017-04-10
Publication date: 2020-02-19
Also published as: EP3611744A4; WO2018189778A1; JP6714947B2; KR20190105099A; CN110462775B; KR102234363B1; TW201837952A; TWI662577B; JPWO2018189778A1; CN110462775A

Abstract

There is included a mounting portion provided in part of a plurality of magnetic iron sheets of a fixed iron core; a driving shaft is pulled out through a gap provided in the magnetic iron sheets in which the mounting portion is provided; through the intermediary of the mounting portion, the fixed iron core is fixed to a rib provided in an insulated case, so that the position, with respect to the insulated case, of the center axis of the driving shaft is set.

Description

Technical Field

The present invention relates to an air circuit breaker provided with an electromagnetic operation mechanism for making a movable contact make contact with or break contact with a fixed contact.

Background Art

As is well known, as one of air circuit breakers that each make a fixed contact and a movable contact make contact with or break contact with each other, there exists an air circuit breaker provided with an electromagnetic operation mechanism for making a movable contact make contact with or break contact with a fixed contact.
A conventional air circuit breaker provided with an electromagnetic operation mechanism includes, for example,
a fixed conductor having a fixed contact,
a movable body having a movable contact and being driven so as to make the movable contact make contact with or break contact with the fixed contact,
a shaft provided pivotably on the center axis,
an operation arm that is pivotably coupled with the shaft through the intermediary of a first coupling portion in such a way as to be spaced by a first predetermined distance apart from the center axis in a direction perpendicular to the center axis and that is coupled with the movable body through the intermediary of a second coupling portion, and
an electromagnetic operation means that is coupled with the shaft through the intermediary of a third coupling portion provided at a position, in the circumferential direction of the shaft, that is different from the position of the first coupling portion, and that has a driving shaft to be driven in such a way as to travel on a straight line that is perpendicular to the center axis and spaced by a second predetermined distance away from the center axis; the electromagnetic operation means is energized so as to drive the driving shaft so that the shaft is rotated and hence the movable body is driven through the intermediary of the operation arm (for example, refer to Patent Document 1).
The foregoing electromagnetic operation mechanism, as an electromagnetic operation means, is configured in such a way that an electromagnetic coil is inserted into a fixed iron core and that when the electromagnetic coil is energized, a movable iron core having a driving shaft is attracted by the fixed iron core. To date, the fixed iron core of the electromagnetic operation mechanism has been produced, for example, by laminating and integrating a predetermined number of magnetic iron sheets, which are produced through punching (e.g., refer to Patent Document 2).

[Prior Art Reference]

[Patent Document]

[Patent Document 1] Japanese Patent Publication No. 4578433
[Patent Document 2] Japanese Patent Application Laid-Open No. H6-89808

Disclosure of the Invention

Problems to be Solved by the Invention

The electromagnetic operation mechanism, as an electromagnetic operation means, disclosed in Patent Document 1 is provided in an inner space of an insulated case, and is generally fixed in the insulated case so that the position thereof is fixed; however, because the force required to close the air circuit breaker is large and hence the output of the electromagnetic operation mechanism is also large, the number of laminated magnetic iron sheets included in the fixed iron core becomes large and hence the lamination tolerance in the sheet thickness of the magnetic iron sheet becomes large; therefore, the position of the driving shaft with respect to the insulated case may fluctuate. When the positon of the driving shaft fluctuates, the position of a link pin coupled with the driving shaft fluctuates or the driving shaft may incline; therefore, because the movable contact cannot secure a sufficient traveling amount in a predetermined direction, it may become impossible to close the air circuit breaker, in the worst case.
The present invention has been implemented in order to solve the foregoing problems in conventional air circuit breakers; the objective thereof is to provide an air circuit breaker in which fluctuation of the position, with respect to the insulated case, of the driving shaft in the electromagnetic operation mechanism is small and that makes it possible to perform stable closing operation.

Means for Solving the Problems

An air circuit breaker according to the present invention includes
a fixed conductor having a fixed contact,
a movable body having a movable contact and being driven so as to make the movable contact make contact with or break contact with the fixed contact,
a shaft provided in such a way as to be able to pivot on a center axis,
an operation arm that is pivotably coupled with the shaft through the intermediary of a first coupling portion in such a way as to be spaced by a first predetermined distance apart from the center axis in a direction perpendicular to the center axis and that is coupled with the movable body through the intermediary of a second coupling portion, and
an electromagnetic operation mechanism that is coupled with the shaft through the intermediary of a third coupling portion provided at a position, in the circumferential direction of the shaft, that is different from the position of the first coupling portion, the electromagnetic operation mechanism having a driving shaft to be driven in such a way as to travel on a straight line that is perpendicular to the center axis and spaced by a second predetermined distance away from the center axis; the air circuit breaker is characterized
in that the control unit includes
a fixed iron core,
a movable iron core that is configured with a plurality of laminated magnetic iron sheets and is provided movably with respect to the fixed iron core, and
an electromagnetic coil that is fixed to the fixed iron core and is energized so as to generate magnetic flux so that the movable iron core is made to travel,
in that the fixed iron core has a mounting portion provided in part of the plurality of magnetic iron sheets,
in that a driving shaft is pulled out through a gap provided in the magnetic iron sheets in which the mounting portion is provided, and
in that through the intermediary of the mounting portion, the fixed iron core is fixed to a rib provided in an insulated case, so that the position, with respect to the insulated case, of the center axis of the driving shaft is set.

Advantage of the Invention

In an air circuit breaker according to the present invention, the fixed iron core has a mounting portion provided in part of the plurality of magnetic iron sheets; a driving shaft is pulled out through a gap provided in the magnetic iron sheets in which the mounting portion is provided; through the intermediary of the mounting portion, the fixed iron core is fixed to a rib provided in an insulated case, so that the position, with respect to the insulated case, of the center axis of the driving shaft is set. As a result, the variation in the position, from the insulated case 1, of the center axis of the driving shaft becomes small and hence closing operation can stably be performed.

Brief Description of the Drawings

FIG. 1 is a configuration diagram illustrating an air circuit breaker according to Embodiment 1 of the present invention;
FIG. 2A is a plan view illustrating an electromagnetic operation mechanism in the air circuit breaker according to Embodiment 1 of the present invention;
FIG. 2B is a side view illustrating the electromagnetic operation mechanism in the air circuit breaker according to Embodiment 1 of the present invention;
FIG. 3 is an explanatory view illustrating a fixed state of the electromagnetic operation mechanism in the air circuit breaker according to Embodiment 1 of the present invention;
FIG. 4 is an explanatory view illustrating a fixed state of an electromagnetic operation mechanism in an air circuit breaker according to Embodiment 2 of the present invention;
FIG. 5 is an explanatory view illustrating a fixed state of an electromagnetic operation mechanism in an air circuit breaker according to Embodiment 3 of the present invention; and
FIG. 6 is an explanatory view illustrating a fixed state of an electromagnetic operation mechanism in a conventional air circuit breaker.

Best Mode for Carrying Out the Invention

Embodiment

1

Hereinafter, an air circuit breaker according to Embodiment 1 of the present invention will be explained based on the drawings . FIG. 1 is a configuration diagram illustrating the air circuit breaker according to Embodiment 1 of the present invention. In FIG. 1, an insulated case 1 contains a first space 101 and a second space 102 that are partitioned by a partition wall 103. A first fixed conductor 21 and a second fixed conductor 22 penetrate the insulated case 1 from the outside of the insulated case 1, and then extend to the first space 101 so as to be exposed in the first space 101. The first fixed conductor 21 is referred to as a power-source-side terminal and is connected with an unillustrated power-source-side conductor. The second fixed conductor 22 is referred to as a load-side terminal and is connected with an unillustrated load-side conductor. A fixed contact 211 is fixed to an end portion of the first fixed conductor 21 exposed in the first space 101 of the insulated case 1.
Amovable body 3 is pivotably supported at one end of an operation arm 7 by a link pin 4; a movable contact 311 is fixed at a position opposite to the fixed contact 211. A contact pressure spring 5 performs biasing so that the movable body 3 is made to pivot clockwise on the link pin 4, in order to exert contact pressure on the portion between the movable contact 311 and the fixed contact 211 when the both contacts make contact with each other. The movable body 3 and the second fixed conductor 22 are electrically connected with each other by a flexible conductor 6 that can be warped.
A planar coupling plate 8 provided in the second space 102 of the insulated case 1 is fixed to a shaft 9 that is pivotably supported around a center axis 91. The coupling plate 8 passes through a through-hole 1031 provided in the partition wall 103; the one end thereof is pivotably coupled with the operation arm 7 by a coupling pin 71. The other end of the operation arm 7 is pivotably coupled with the link pin 4. A coupling portion where the coupling plate 8 and the other end of the operation arm 7 are coupled with each other by the coupling pin 71 forms a first coupling portion; the first coupling portion is spaced by a first predetermined distance apart from the center axis 91 of the shaft 9 in a direction perpendicular to the center axis 91. A coupling portion where the one end of the operation arm 7 and the movable body 3 are coupled with each other by the link pin 4 forms a second coupling portion. At a position different from the position of the first coupling portion in the circumferential direction of the shaft 9, a driving shaft 13 is coupled with the coupling plate 8 by a coupling pin 81 in such a way as to be spaced by a second predetermined distance apart from the center axis 91 of the shaft 9. A coupling portion where the driving shaft 13 and the coupling plate 8 are coupled with each other by the coupling pin 81 forms a third coupling portion.
Next, an electromagnetic operation mechanism 10 will be explained. FIG. 2A is a plan view illustrating an electromagnetic operation mechanism in the air circuit breaker according to Embodiment 1 of the present invention; FIG. 2B is a side view illustrating the electromagnetic operation mechanism in the air circuit breaker according to Embodiment 1 of the present invention. As illustrated in FIGS. 1, 2A, and 2B, the electromagnetic operation mechanism 10 has a fixed iron core 11 provided with an inner space, a cylindrical tubular electromagnetic coil 12 inserted into the inner space of the fixed iron core 11 and fixed to the fixed iron core 11, a movable iron core 14 inserted into an inner space 121 of the electromagnetic coil 12, and the driving shaft 13. As described above, one end of the driving shaft 13 is coupled with the other end of the coupling plate 8; the other end thereof is fixed to the movable iron core 14.
The fixed iron core 11 has a first portion 11A, a second portion 11B, and a third portion 11C disposed between the first portion 11A and the second portion 11B. The first portion 11A, the second portion 11B, and the third portion 11C are stacked in their plate-thickness direction and are fixed integrally with one another.
Each of the first portion 11A and the second portion 11B is formed in such a way that a plurality of first magnetic iron sheets 111 that are produced through punching and have the same shape are laminated in the plate-thickness direction so as to be integrated with one another. Each of the first magnetic iron sheets 111 has a first side portion 1101, a second side portion 1102 that faces the first side portion 1101, a third side portion 1103 that is connected with one end of the first side portion 1101 and one end of the second side portion 1102, a fourth side portion 1104 that is connected with the other end of the first side portion 1101, and a fifth side portion 1105 that is connected with the other end of the second side portion 1102. A front-end portion 1104a of the fourth side portion 1104 and a front-end portion 1105a of the fifth side portion 1105 face each other via a predetermined gap.
The third portion 11C is formed in such a way that a plurality of second magnetic iron sheets 111a that are produced through punching are laminated in the plate-thickness direction so as to be integrated with one another. The second magnetic iron sheet 111a has a first mounting portion 1106 and a second mounting portion 1107 that each protrude from positions corresponding to the third side portion 1103 of the first magnetic iron sheet 111, a third mounting portion 1108 that protrudes from a position corresponding to the fourth side portion 1104 of the first magnetic iron sheet 111, and a fourth mounting portion 1109 that protrudes from a position corresponding to the fifth side portion 1105 of the first magnetic iron sheet 111. In a portion, of the second magnetic iron sheet 111a, that corresponds to the third side portion 1103 of the first magnetic iron sheets 111, there is formed a gap 1110 for making the driving shaft 13 slidably penetrate the second magnetic iron sheet 111a.
FIG. 3 is an explanatory view illustrating a fixed state of the electromagnetic operation mechanism in the air circuit breaker according to Embodiment 1 of the present invention. As illustrated in FIG. 3, the partition wall 103 of the insulated case 1 has a first rib 1041 and a second rib 1042 that each extend perpendicularly from the flat portion thereof into the second space 102. The electromagnetic operation mechanism 10 is mounted in the insulated case 1 in such a way that the fixed iron core 11 is fixed by mounting screws 16 to the respective front-end portions of the first rib 1041 and the second rib 1042. That is to say, the first mounting portion 1106 and the second mounting portion 1107 of the fixed iron core 11 are each fixed to the front-end portion of the first rib 1041 by the mounting screws 16; the third mounting portion 1108 and the fourth mounting portion 1109 of the fixed iron core 11 are each fixed to the front-end portion of the second rib 1042 by the mounting screws 16.
As illustrated in FIG. 2A, in the first mounting portion 1106 of the fixed iron core 11, there is formed a mounting hole 15a for making the mounting screw 16 penetrate the first mounting portion 1106; in the second mounting portion 1107 of the fixed iron core 11, there is formed a mounting hole 15b for making the mounting screw 16 penetrate the second mounting portion 1107; in the third mounting portion 1108 of the fixed iron core 11, there is formed a mounting hole 15c for making the mounting screw 16 penetrate the third mounting portion 1108; in the fourth mounting portion 1109 of the fixed iron core 11, there is formed a mounting hole 15d for making the mounting screw 16 penetrate the fourth mounting portion 1109.
The movable iron core 14 is inserted into the inner space 121 of the electromagnetic coil 12 in such a way as to be able to travel in a y-axis direction in FIG. 1 (in the vertical direction in FIG. 1). The driving shaft 13 fixed to the movable iron core 14 is configured in such a way as to reciprocally travel on a straight line in the y-axis direction in FIG. 1 (in the vertical direction in FIG. 1), as the movable iron core 14 travels.
In the air circuit breaker according to Embodiment 1 of the present invention, configured in such a manner as described above, when the electromagnetic coil 12 is de-energized, the movable iron core 14 is in a stop state in such a way that as illustrated in FIG. 2A, one end portion of the movable iron core 14 abuts on the respective inner walls of the fourth side portion 1104 and the fifth side portion 1105. In this situation, as illustrated in FIG. 1, the movable contact 311 is situated spaced apart from the fixed contact 211; thus, the air circuit breaker is in a tripping state.
Next, when the electromagnetic coil 12 is energized, the movable iron core 14 travels in the upward direction in FIG. 1, due to the action of magnetic flux generated by the electromagnetic coil 12, and then is attracted by the inner wall of the third side portion 1103 of the fixed iron core 11. As a result, the driving shaft 13 is driven in the upward direction in FIG. 1 so as to make the coupling plate 8 pivot in the clockwise direction in FIG. 1 on the center axis 91 of the shaft 9, through the intermediary of the coupling pin 81 in the third coupling portion. When the coupling plate 8 pivots in the clockwise direction, the operation arm 7 is driven by the coupling plate 8 through the intermediary of the coupling pin 71 in the first coupling portion in such a way as to be linearly aligned with the coupling plate 8 in the longitudinal direction of the coupling plate 8. When the operation arm 7 is driven in such a manner as described above, the movable body 3 travels while contracting the contact pressure spring 5 in the rightward direction in FIG. 1, so that the movable contact 311 abuts on the fixed contact 211. After the movable contact 311 makes contact with the fixed contact 211, the movable body 3 pivots in the clockwise direction on the link pin 4 in the second coupling portion, so that the air circuit breaker becomes in a closing state.
The air circuit breaker has an unillustrated holding mechanism that holds the foregoing closing state. When holding of the holding mechanism is released, the respective members operate in a direction opposite to the direction of the foregoing closing operation so that the tripping state illustrated in FIG. 1 occurs.
With regard to the electromagnetic operation mechanism 10 in the air circuit breaker according to Embodiment 1 of the present invention, configured in such a manner as described above, the variation in the distance from the partition wall 103 of the insulated case 1 to the center axis line X of the driving shaft 13 is determined merely by accumulation of the variation in the plate thickness of the second magnetic iron sheet 111a included in the third portion 11C. Accordingly, even when the electromagnetic operation mechanism 10 is upsized, it is made possible that without being affected by the number of the laminated first magnetic iron sheets 111 included in the first portion 11A and the second portion 11B, the electromagnetic operation mechanism 10 is fixed in such a manner that the variation in the distance from the partition wall 103 of the insulated case 1 to the center axis line X of the driving shaft 13 is small. As a result, the positional relationship among the other components coupled with the driving shaft 13 is stabilized, so that stable closing operation can be performed.

Embodiment 2

Next, an air circuit breaker according to Embodiment 2 of the present invention will be explained. FIG. 4 is an explanatory view illustrating a fixed state of an electromagnetic operation mechanism in the air circuit breaker according to Embodiment 2 of the present invention. Except for after-mentioned configurations, the air circuit breaker, illustrated in FIG. 4, according to Embodiment 2 of the present invention has substantially the same configuration as the foregoing air circuit breaker according to Embodiment 1 has, and operates in a similar manner; thus, the reference characters the same as those in FIG. 1 denote the same or equivalent elements.
In FIG. 4, a first inclination portion 1051 and a second inclination portion 1052 created through notching or the like are formed at the respective opposite side face portions of the first rib 1041 and the second rib 1042 for fixing the fixed iron core 11 of the electromagnetic operation mechanism 10. The distance Y with which the first rib 1041 and the second rib 1042 face each other is made to be substantially the same as the y-direction length of the fixed iron core 11. The fixed iron core 11 is pressed into the space where the first rib 1041 and the second rib 1042 face each other, so that the fixed iron core 11 is assembled into the insulated case 1. In this situation, because while being guided by the first inclination portion 1051 and the second inclination portion 1052, the fixed iron core 11 is pressed into the space where the first rib 1041 and the second rib 1042 face each other, the press-in is readily performed.
Because the fixed iron core 11 of the electromagnetic operation mechanism 10 is pressed into the space between the first rib 1041 and the second rib 1042, the y-axis-direction position of the electromagnetic operation mechanism 10 is sufficiently fixed. Accordingly, it is made possible to obtain the electromagnetic operation mechanism 10 having further small variation in the y-axis- direction distance from the insulated case 1 to the driving shaft 13; thus, the positional relationship among the other components coupled with the driving shaft 13 is stabilized and hence stable closing operation can be performed.

Embodiment 3

Next, an air circuit breaker according to Embodiment 3 of the present invention will be explained. FIG. 5 is an explanatory view illustrating a fixed state of an electromagnetic operation mechanism in the air circuit breaker according to Embodiment 3 of the present invention. Except for after-mentioned configurations, the air circuit breaker, illustrated in FIG. 5, according to Embodiment 3 of the present invention has substantially the same configuration as the foregoing air circuit breaker according to Embodiment 1 has, and operates in a similar manner; thus, the reference characters the same as those in FIG. 1 denote the same or equivalent elements.
A non-magnetic first spacer 171 is inserted into a space between the first rib 1041 and the mounting portions 1106 and 1107; a non-magnetic second spacer 172 is inserted into a space between the first rib 1042 and the mounting portions 1108 and 1109. The non-magnetic first and second spacers 171 and 172 make it possible to adjust the distance from the insulated case 1 to the center axis line X of the driving shaft 13; thus, the positional relationship among the other components coupled with the driving shaft 13 is stabilized and hence stable closing operation can be performed.
FIG. 6 is an explanatory view illustrating a fixed state of an electromagnetic operation mechanism in a conventional air circuit breaker. In an electromagnetic operation mechanism 10 in the conventional air circuit breaker, there is provided a mounting hole (through-hole) penetrating laminated magnetic iron sheets 1100 included in the fixed iron core 11; a mounting screw 161 is made to penetrate the through-hole so as to be fixed to the insulated case 1. However, because the number of the laminated magnetic iron sheets 1100 is large, the lamination tolerance in the plate thickness of the magnetic iron sheet 1100 becomes large and hence the distance from the insulated case 1 to the center axis line of the driving shaft 13 largely fluctuates. In particular, because the force required to close the air circuit breaker is large and hence the output of the electromagnetic operation mechanism 10 is also large, the number of the laminated magnetic iron sheets 1100 in the fixed iron core 11 becomes large and hence the distance from the insulated case 1 to the center axis line X of the driving shaft 13 largely fluctuates. When the distance from the insulated case 1 to the center axis line X of the driving shaft 13 fluctuates, the respective positions of the other constituent members coupled with the driving shaft 13 fluctuate or inclination of the driving shaft 13 with respect to the traveling direction thereof makes it impossible to secure a sufficient y-axis-direction traveling amount; as a result, it is made impossible to close the air circuit breaker, in the worst case. It is clear that an air circuit breaker according to the present invention solves the foregoing problems in conventional air circuit breakers.
The present invention is not limited to the air circuit breakers according to foregoing Embodiments 1 through 3; in the scope within the spirits of the present invention, the configurations of Embodiments 1 through 3 can appropriately be combined with one another, can partially be modified, or can partially be omitted.

Industrial Applicability

The present invention can be utilized in the field of a circuit breaker, especially, an air circuit breaker.

Description of Reference Numerals

1:: insulated case
103:: partition wall
1041:: 1st rib
1042:: 2nd rib
1051:: 1st inclination portion
1052:: 2nd inclination portion
21:: 1st fixed conductor
22:: 2nd fixed conductor
211:: fixed contact
3:: movable body
4:: link pin
5:: contact pressure spring
6:: flexible conductor
7:: operation arm
71:: coupling pin
8:: coupling plate
81:: coupling pin
9:: shaft
91:: center axis
10:: electromagnetic operation mechanism
11:: fixed iron core
111:: 1st magnetic iron sheet
111a:: 2nd magnetic iron sheet
12:: electromagnetic coil
13:: driving shaft
14:: movable iron core
16:: mounting screw
171:: 1st spacer
172:: 2nd spacer
1106:: 1st mounting portion
1107:: 2nd mounting portion
1108:: 3rd mounting portion
1109:: 4th mounting portion.

Claims

An air circuit breaker comprising:
a fixed conductor having a fixed contact;

a movable body having a movable contact and being driven so as to make the movable contact make contact with or break contact with the fixed contact;

a shaft provided in such a way as to be able to pivot on a center axis;

an operation arm that is pivotably coupled with the shaft through the intermediary of a first coupling portion in such a way as to be spaced by a first predetermined distance apart from the center axis in a direction perpendicular to the center axis and that is coupled with the movable body through the intermediary of a second coupling portion; and

an electromagnetic operation mechanism that is coupled with the shaft through the intermediary of a third coupling portion provided at a position, in the circumferential direction of the shaft, that is different from the position of the first coupling portion, the electromagnetic operation mechanism having a driving shaft to be driven in such a way as to travel on a straight line that is perpendicular to the center axis and spaced by a second predetermined distance away from the center axis,

wherein the electromagnetic operation mechanism includes

a fixed iron core,

a movable iron core that is configured with a plurality of laminated magnetic iron sheets and is provided movably with respect to the fixed iron core, and

an electromagnetic coil that is fixed to the fixed iron core and is energized so as to generate magnetic flux so that the movable iron core is made to travel,

wherein the fixed iron core has a mounting portion provided in part of the plurality of magnetic iron sheets,

wherein the driving shaft is fixed to the movable iron core, pulled out through a gap provided in the magnetic iron sheets in which the mounting portion is provided, and then is coupled with the shaft, and

wherein through the intermediary of the mounting portion, the fixed iron core is fixed to a rib provided in an insulated case, so that the position,

with respect to the insulated case, of the center axis of the driving shaft is set.
The air circuit breaker according to claim 1,
wherein the rib is configured with a pair of ribs that face each other via a predetermined gap,
wherein the pair of ribs have respective inclination portions in corresponding wall portions at corresponding sides that face each other, and
wherein the movable iron core is inserted into a space between the pair of ribs, through the intermediary of the inclination portions.
The air circuit breaker according to any one of claims 1 and 2, wherein the mounting portion of the fixed iron core is fixed to the rib through the intermediary of a spacer.