Circuit breaker

Abstract

To provide a circuit breaker which can be downsized and stably perform a rotating operation of a movable contactor.SOLUTION: A current interruption section corresponding to each phase of a main circuit comprises a long tabular movable contactor 16 with a first movable contact 16d and a second movable contact 16e provided in both ends. In the movable contactor, a power source side spring arrangement space 19 is provided by forming a first recess on one surface in a width direction closer on a side closer to the first movable contact than a shank 16a provided in a central part in a length direction, and a load side spring arrangement space 21 is provided by forming a second recess on the other face in the width direction closer to the second movable contact than the shank. A power source side contact pressure spring 17 is arranged in the power source side spring arrangement space, and both ends of the spring are engaged to the movable contactor and a movable element holder 14. A load side contact pressure spring 18 is arranged in the load side spring arrangement space, and both ends of the spring are engaged to the movable contactor and the movable holder.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a circuit breaker applied to wiring breakers, earth leakage breakers and the like.

Background Art

[0002] A circuit breaker includes an opening / closing mechanism, an overcurrent trip device, and a current interrupting section. When an overcurrent flows through a main circuit, the opening / closing mechanism starts a tripping operation in response to a command from the overcurrent trip device, and the current interrupting section performs an opening and disconnecting operation. Circuit breakers are generally for three-phase alternating current, and three sets of two-break type current interrupting sections corresponding to respective phases are incorporated in parallel in a breaker case.

[0003] In the two-break type current interrupting section described in Patent Document 1, a power-side stationary contact, a load-side stationary contact, and a mover unit are housed in a case. The mover unit includes a mover holder, a movable contact rotatably supported by the mover holder, and a contact pressure spring configured as a tension coil spring having both ends engaged with the mover holder and the movable contact. The movable contact is an elongated plate-shaped conductor, and is rotatably supported by the mover holder at a central position in the longitudinal direction. The movable contact is formed to have the same width dimension from one end to the other end in the longitudinal direction. A first movable contact that comes into contact with and separates from a power-side stationary contact of the power-side stationary contact is provided at one end in the longitudinal direction, and a second movable contact that comes into contact with and separates from a load-side stationary contact of the load-side stationary contact is provided at the other end in the longitudinal direction.

[0004] The contact pressure springs include a power-side contact pressure spring that is engaged with one end side of the movable contact and the mover holder and applies an urging force to the movable contact so that contact pressure is applied from the first movable contact to the power-side stationary contact; and a load-side contact pressure spring that is engaged with the other end side of the movable contact and the mover holder and applies an urging force to the movable contact so that contact pressure is applied from the second movable contact to the load-side stationary contact.

Prior Art Literature

Patent Literature

[0005] [Patent Document 1] Japanese Patent Publication No. 2013-97905 [Overview of the initiative] [Problems that the invention aims to solve]

[0006] Incidentally, in the movable element unit that constitutes the two-point current interruption unit of Patent Document 1, a pair of power supply-side contact pressure springs and a pair of load-side contact pressure springs are arranged along both sides of the movable contact so as to sandwich the movable contact from the width direction. A movable element unit in which a pair of power supply-side contact pressure springs and a pair of load-side contact pressure springs are arranged on both sides of the movable contact becomes a unit with increased width.

[0007] Thus, if a current interruption unit having a movable element unit with increased width is incorporated into a circuit breaker, the width of the multiple phase current interruption units arranged in parallel may increase, potentially resulting in a larger circuit breaker. Furthermore, the movable element unit described in Patent Document 1 has a problem in terms of stable rotational operation of the movable element, as the power supply side contact pressure spring and the load side contact pressure spring, which are located on the same side of the movable element, may interfere with each other when the movable element rotates.

[0008] The present invention aims to provide a circuit breaker that can be miniaturized and that can stably perform the rotational operation of the movable contact. [Means for solving the problem]

[0009] To achieve the above objective, a circuit breaker according to one aspect of the present invention incorporates a plurality of two-point current interruption units corresponding to each phase of the main circuit in parallel within the circuit breaker case. The current interruption unit comprises, in the interruption unit case, a power supply side fixed contact having a power supply side fixed contact, a load side fixed contact having a load side fixed contact, a long plate-shaped movable contact having a first movable contact and a second movable contact at both ends that move toward and toward the power supply side fixed contact and the load side fixed contact, a movable contact holder for rotating the movable contact, a power supply side contact pressure spring that applies a biasing force to the movable contact so that contact pressure is applied from the first movable contact to the power supply side fixed contact, and a load side contact pressure spring that applies a biasing force to the movable contact so that contact pressure is applied from the second movable contact to the load side fixed contact. Furthermore, the movable contact is provided with a power supply side spring arrangement space by forming a first recess on one side in the width direction on the first movable contact side from the shaft portion located in the center in the longitudinal direction of the movable contact, and a load side spring arrangement space by forming a second recess on the other side in the width direction on the second movable contact side from the shaft portion. The power supply side contact pressure spring is arranged in the power supply side spring arrangement space, with both ends of the spring engaged with the movable contact and the movable contact holder, and the load side contact pressure spring is arranged in the load side spring arrangement space, with both ends of the spring engaged with the movable contact and the movable contact holder. [Effects of the Invention]

[0010] According to the circuit breaker of the present invention, miniaturization can be achieved by arranging the power supply side contact pressure spring and the load side contact pressure spring so that the width dimension of the movable element unit is reduced, and the rotational operation of the movable contact can be performed stably by eliminating interference between the power supply side contact pressure spring and the load side contact pressure spring. [Brief explanation of the drawing]

[0011] [Figure 1] This is a schematic diagram showing a circuit breaker equipped with a current interruption unit according to the present invention. [Figure 2] This figure shows the internal structure of the current interruption unit of the first embodiment according to the present invention. [Figure 3]This figure shows the shape of the movable contact, the power supply side contact pressure spring, and the arrangement of the load side contact pressure spring that constitute the current interruption unit of the first embodiment according to the present invention. [Figure 4] This figure shows the shape of the movable contact, the power supply side contact pressure spring, and the arrangement of the load side contact pressure spring that constitute the current interruption section of the second embodiment of the invention. [Modes for carrying out the invention]

[0012] Next, embodiments of the present invention will be described with reference to the drawings. In the following drawings, identical or similar parts are denoted by the same or similar reference numerals. However, it should be noted that the drawings are schematic, and the relationship between thickness and planar dimensions, the ratio of the thickness of each layer, etc., may differ from reality. Therefore, specific thicknesses and dimensions should be determined by referring to the following explanation. Furthermore, it should be noted that there are parts where the relationships and ratios of dimensions differ between drawings.

[0013] Furthermore, the embodiments described below illustrate devices and methods for realizing the technical concept of the present invention, and the technical concept of the present invention does not limit the materials, shapes, structures, arrangements, etc. of the components to those described below. The technical concept of the present invention can be modified in various ways within the technical scope defined by the claims described in the patent claims. The terms "one and the other in the lengthwise direction," "one and the other in the widthwise direction," and "one and the other in the widthwise direction" used in the following explanation refer to the directions shown in the attached drawings.

[0014] [First Embodiment] Figure 1 shows a circuit breaker 1 for three-phase AC according to a first embodiment of the present invention, which comprises an on / off handle 2, a toggle-type switching mechanism 3, an overcurrent tripping device 4, and a current interruption unit 5. The current interruption units 5 are assembled in parallel within the circuit breaker case, corresponding to each phase of the main circuit. The circuit breaker 1 opens and closes the current interruption units 5 for each phase via the switching mechanism 3 by the ON / OFF operation of the on / off handle 2.

[0015] FIG. 2 shows the detailed structure of the two-point cut-off type current interrupting unit 5 according to the first embodiment. The current interrupting unit 5 includes an interrupting unit case 8, a power supply-side fixed contact 9 accommodated in the interrupting unit case 8, a load-side fixed contact 10, a movable element unit 11, a power supply-side arc extinguishing unit 12, and a load-side arc extinguishing unit 13. The movable element unit 11 includes a movable element holder 14, a movable contact 16 rotatably supported by the movable element holder 14, a power supply-side contact pressure spring 17 configured as a tension coil spring having both ends engaged with the movable element holder 14 and the movable contact 16, and a load-side contact pressure spring 18 configured as a tension coil spring having both ends engaged with the movable element holder 14 and the movable contact 16.

[0016] The movable element holder 14 is a substantially cylindrical insulating member with openings at both axial ends closed, and is rotatably supported within the interrupting unit case 8 by its outer circumference sliding on curved inner walls 8a and 8b of the interrupting unit case 8. The power supply-side fixed contact 9 is disposed on one side in the longitudinal direction of the interrupting unit case 8, and is a belt-shaped conductor that curves and extends in a crank shape from one side toward the other side in the longitudinal direction. A power supply-side terminal (not shown) is connected to one end 9a of the power supply-side fixed contact 9 protruding to the outside of the interrupting unit case 8, and a fixed contact 9b is provided at the other end of the power supply-side fixed contact 9.

[0017] The load-side fixed contact 10 is disposed on the other side in the longitudinal direction of the interrupting unit case 8, and is a flat belt-shaped conductor extending in the longitudinal direction. A fixed contact 10a is provided on the inner side of the interrupting unit case 8 of the load-side fixed contact 10, and a load-side terminal (not shown) is connected to an end 10b of the load-side fixed contact 10 located on the outer side of the interrupting unit case 8. The movable contact 16 is an elongated conductor, and includes a shaft portion 16a provided at a central portion in the longitudinal direction, a power supply-side movable portion 16b extending from the shaft portion 16a toward the power supply-side fixed contact 9, and a load-side movable portion 16c extending from the shaft portion 16a toward the load-side fixed contact 10. A rotating shaft 15 penetrates the shaft portion 16a, and the movable contact 16 is rotatably supported by the movable element holder 14 via the rotating shaft 15.

[0018] FIG. 3 is a diagram illustrating the movable contact 16 of the first embodiment viewed from one side in the short-length direction. In the power-side movable portion 16b, a first power-side width surface 16b1 on one side in the width direction is formed flush with a first shaft width surface 16a1 of the shaft portion 16a, a stepped portion 16f is formed between a second power-side width surface 16b2 on the other side in the width direction and a second shaft width surface 16a2 of the shaft portion 16a, and the second power-side width surface 16b2 extends parallel to the first power-side width surface 16b1 at a position offset toward one side in the width direction. A first movable contact 16d that comes into contact with and separates from a fixed contact 9b of the power-side fixed contact 9 is formed at an end portion of the power-side movable portion 16b. The stepped portion 16f is formed obliquely along the power-side contact pressure spring 17 on the other side surface of the movable contact 16.

[0019] Further, in the power-side movable portion 16b, a stepped surface extending parallel to the first power-side width surface 16b1 is formed after the stepped portion 16f is provided between the power-side movable portion 16b and the second shaft width surface 16a2 of the shaft portion 16a, and a spring arrangement space 19 is provided by this stepped surface. An engagement pin 20 protruding toward the spring arrangement space 19 is fixed to one end portion in the short-length direction of the second power-side width surface 16b2 (see FIG. 3).

[0020] Further, in the load-side movable portion 16c, a second load-side width surface 16c2 on the other side in the width direction is formed flush with a second shaft width surface 16a2 of the shaft portion 16a, a stepped portion 16g is formed between a first load-side width surface 16c1 on one side in the width direction and a first shaft width surface 16a1 of the shaft portion 16a, and the first load-side width surface 16c1 extends parallel to the second load-side width surface 16c2 at a position offset toward the other side in the width direction. A second movable contact 16e that comes into contact with and separates from a fixed contact 10a of the load-side fixed contact 10 is formed at an end portion of the load-side movable portion 16c. The stepped portion 16g is formed obliquely along the load-side contact pressure spring 18 on one side surface of the movable contact 16.

[0021] Further, in the load-side movable portion 16c, a stepped surface extending parallel to the second load-side width surface 16c2 is formed after the stepped portion 16g is provided between the load-side movable portion 16c and the first shaft width surface 16a1 of the shaft portion 16a, and a spring arrangement space 21 is provided by this stepped surface. An engagement pin 22 protruding toward the spring arrangement space 19 is fixed to the other end portion in the short-length direction of the first load-side width surface 16c1 (see FIG. 3).

[0022] As shown in Figure 2, the engagement pin 23 is fixed to the other side of the rotation axis 15 of the movable element holder 14 in the shorter direction. The power supply side contact pressure spring 17 is positioned with one end engaged with the engagement pin 20 and the other end engaged with the engagement pin 23. As a result, as shown in Figure 3, almost the entire area of ​​the power supply side contact pressure spring 17 is positioned within the spring arrangement space 19, and the power supply side contact pressure spring 17 biases the movable contact element 16 in a tension spring state so that contact pressure acts from the first movable contact 16d to the fixed contact 9b.

[0023] Furthermore, the engagement pin 24 is fixed to a position on one side of the rotation axis 15 of the movable element holder 14 in the shorter direction. The load-side contact pressure spring 18 is positioned with one end engaged with the engagement pin 22 and the other end engaged with the engagement pin 24. As a result, as shown in Figure 3, substantially the entire area of ​​the load-side contact pressure spring 18 is positioned within the spring arrangement space 21, and the load-side contact pressure spring 18 biases the movable contact element 16 in a tension spring state so that contact pressure is applied from the second movable contact 16e to the fixed contact 10a.

[0024] As shown in Figure 2, the movable element holder 14 has through holes 25a and 25b, and a connecting shaft (not shown) is inserted through these through holes 25a and 25b and through holes (not shown) formed in the interruption unit case 8. The connecting shaft is also inserted through the movable element holder 14 of the current interruption units 5 of other phases which are arranged in parallel.

[0025] In this embodiment, when an overcurrent flows while the main circuit is energized and the overload tripping device 4 is activated, the tripping operation of the switching mechanism 3 causes the movable element holder 14 of the movable element unit 11, which constitutes the current interruption section 5 for each phase, to rotate clockwise via the connecting shaft described above. As the movable element holder 14 rotates, the first movable contact 16d of the movable contact 16 separates from the fixed contact 9b of the power supply side fixed contact 9 and becomes open, and the second movable contact 16e separates from the fixed contact 10a of the load side fixed contact 10 and becomes open.

[0026] Next, the effects of the circuit breaker 1 of this embodiment will be described. In this embodiment, the movable element unit 11 constituting the two-point current interruption section 5 of the circuit breaker 1 has a stepped portion 16f between the shaft portion 16a of the movable contact 16 and the power supply side movable portion 16b, thereby forming a spring arrangement space 19 along the second power supply side width surface 16b2, and the power supply side contact pressure spring 17 is positioned so that substantially the entire area fits into this spring arrangement space 19. Furthermore, by providing a stepped portion 16g between the shaft portion 16a of the movable contact 16 and the load side movable portion 16c, a spring arrangement space 21 is formed along the first load side width surface 16c1, and the load side contact pressure spring 18 is positioned so that substantially the entire area fits into this spring arrangement space 21. In this embodiment, the movable element unit 11 is designed to have a smaller width compared to conventional movable element units (units in which a pair of power supply-side contact springs and load-side contact springs are arranged on both sides of a movable contact element so as to sandwich the movable contact element from the width direction, as described in the problem).

[0027] As a result, by incorporating a three-phase current interruption unit 5 having a small-width movable element unit 11 in parallel inside the circuit breaker 1, the overall width of the device is reduced, making it possible to miniaturize the circuit breaker 1. Furthermore, since the load-side contact pressure spring 18 is positioned on one side of the movable contact 16 in the width direction (first load-side width surface 16c1) and the power supply-side contact pressure spring 17 is positioned on the opposite side of the movable contact 16 in the width direction (second power supply-side width surface 16b2), the power supply-side contact pressure spring 17 and the load-side contact pressure spring 18 do not interfere with each other during the rotational movement of the movable contact 16, enabling stable rotational movement of the movable contact 16.

[0028] [Second Embodiment] Next, Figure 4 is a diagram showing the shape of the movable contact 30 of the second embodiment of the present invention, viewed from one side in the short direction. Note that components identical to those shown in the first embodiment are denoted by the same reference numerals and their descriptions are omitted. The movable contact 30 of this embodiment, like the movable contact 16 of the first embodiment, is a long conductive material and comprises a shaft portion 30a located in the center of its longitudinal direction, a power supply side movable portion 30b extending from the shaft portion 30a in one longitudinal direction, and a load side movable portion 30c extending from the shaft portion 30a in the other longitudinal direction. A rotating shaft 15 passes through the shaft portion 30a, and the movable contact 16 is rotatably supported by the movable contact holder 14 via the rotating shaft 15.

[0029] A first movable contact 30d is formed at the end of the power supply side movable part 30b, which moves in and out of contact with the fixed contact 9b of the power supply side fixed contact 9, and a second movable contact 30e is formed at the end of the load side movable part 30c, which moves in and out of contact with the fixed contact 10a of the load side fixed contact 10. Here, the straight line indicated by reference numeral L1 in Figure 4 is the widthwise center line of the movable contact 30. In this embodiment, the power supply side movable part 30b has a V-shaped notch 31 formed in a part of the second power supply side width surface 30b2 on the other side in the width direction, toward the first power supply side width surface 30b1. This notch 31 is formed to a depth that intersects the center line L1 in the width direction, and the space inside this notch 31 is used as a spring arrangement space 32. In addition, an engagement pin 20 is fixed to the bottom of the notch 31, protruding toward the spring arrangement space 32.

[0030] The load-side movable part 30c has a V-shaped notch 33 formed in a portion of the first load-side width surface 30c1 on one side in the width direction, extending toward the second load-side width surface 30c2. This notch 33 is also formed to a depth that intersects the width direction center line L1, and the space inside this notch 33 is used as a spring placement space 34. An engagement pin 22 is fixed to the bottom of the notch 33, protruding toward the spring placement space 34.

[0031] In this embodiment, the power supply side contact pressure spring 17 is positioned in a tension spring state, with one end engaging with the engagement pin 20 and the other end engaging with the engagement pin 23 fixed to the movable element holder 14. As a result, substantially the entire area of ​​the power supply side contact pressure spring 17 is positioned within the spring placement space 32. Furthermore, in this embodiment, the load-side contact pressure spring 18 is positioned in a tension spring state, with one end engaging with the engagement pin 22 and the other end engaging with the engagement pin 24 fixed to the movable element holder 14. As a result, substantially the entire area of ​​the load-side contact pressure spring 18 is positioned within the spring arrangement space 34.

[0032] Next, the effects of the circuit breaker 1 equipped with the movable contact 30 of this embodiment will be described. In this embodiment, the movable contactor unit 11 equipped with the movable contactor 30 has a V-shaped notch 31 in the power supply side movable part 30b, which creates a spring arrangement space 32, and the power supply side contact pressure spring 17 is positioned so that substantially its entire area fits into this spring arrangement space 32. In addition, a V-shaped notch 33 is provided in the load side movable part 30c, which creates a spring arrangement space 34, and the load side contact pressure spring 18 is positioned so that substantially its entire area fits into this spring arrangement space 34. In this embodiment, the movable element unit 11 is designed so that substantially the entire area of ​​the power supply side contact pressure spring 17 is located within the spring arrangement space 32 of the movable contact element 30, and substantially the entire area of ​​the load side contact pressure spring 18 is located within the spring arrangement space 34. As a result, the unit can be designed to have a smaller width compared to conventional movable element units. When a three-phase current interruption unit 5 having this movable element unit 11 is incorporated in parallel inside the circuit breaker 1, the overall width of the equipment is reduced, thus enabling miniaturization of the circuit breaker 1.

[0033] Furthermore, since the load-side contact pressure spring 18 is positioned on one side of the movable contact 30 in the width direction (first load-side width surface 30c1) and the power supply-side contact pressure spring 17 is positioned on the opposite side of the movable contact 16 in the width direction (second power supply-side width surface 30b2), the power supply-side contact pressure spring 17 and the load-side contact pressure spring 18 do not interfere with each other during the rotational movement of the movable contact 30, enabling stable rotational movement of the movable contact 16.

[0034] Furthermore, since the notches 31 of the power supply side movable part 30b and 33 of the load side movable part 30c are provided so as to intersect the widthwise centerline L1 of the movable contact 30, the power supply side contact pressure spring 17 located in the spring arrangement space 32 generates a biasing force on the movable contact 30 near the widthwise center position of the movable contact 30, and the load side contact pressure spring 18 located in the spring arrangement space 34 generates a biasing force on the movable contact 30 near the widthwise center position of the movable contact 30. As a result, the power supply side contact pressure spring 17 and the load side contact pressure spring 18 do not act on the movable contact 30 with rotational force around the widthwise centerline L1, the first movable contact 30d can act on the fixed contact 9b of the power supply side fixed contact 9 with optimal contact pressure, and the second movable contact 30e can act on the fixed contact 10a of the load side fixed contact 10 with optimal contact pressure. [Explanation of symbols]

[0035] 1 Circuit breaker 2. Opening / closing handle 3. Opening and closing mechanism 4. Overcurrent tripping device 5 Current interruption section 8. Shut-off section case 8a,8b Curvature inner wall 9 Power supply side fixed contact 9b Fixed contact 10 Load side fixed contact 10a Fixed Contact 11. Movable Unit 12 Arc extinguishing section on power supply side 13. Load-side arc extinguishing section 14. Movable element holder 15 Rotation axis 16 Movable contact 16a Shaft 16a1 1st axis width surface 16a2 2nd axis width surface 16b Power supply side movable part 16b1 1st power supply side width surface 16b2 2nd power supply side width surface 16c Load side moving part 16c1 1st load side width surface 16c2 2nd load side width surface 16d 1st movable contact 16e 2nd movable contact 16f, 16g stepped section 17 Power supply side contact pressure spring 18. Load-side contact pressure spring 19. Spring placement space (power supply side spring placement space) 21. Spring placement space (load-side spring placement space) 20, 22, 23, 24 Engaging pins 25a,25b through hole 30 Movable contactor 30a Shaft 30a 30b Power supply side movable part 30b1 1st power supply side width surface 30b2 2nd power supply side width surface 30c Load side moving part 30c1 1st load side width surface 30c2 2nd load side width surface 30d 1st movable contact 30e 2nd movable contact 31 Notch (First notch) 32 Spring placement space (power supply side spring placement space) 33 Notch (Second notch) 34. Spring placement space (power supply side spring placement space)

Claims

1. In a circuit breaker in which multiple two-point current interruption units corresponding to each phase of the main circuit are incorporated in parallel within the circuit breaker case, The current interruption unit comprises, in an interruption unit case, a power supply side fixed contact having a power supply side fixed contact, a load side fixed contact having a load side fixed contact, a long plate-shaped movable contact having a first movable contact and a second movable contact at both ends that move toward and toward the power supply side fixed contact and the load side fixed contact, a movable contact holder for rotating the movable contact, a power supply side contact pressure spring that applies a biasing force to the movable contact so that contact pressure is applied from the first movable contact to the power supply side fixed contact, and a load side contact pressure spring that applies a biasing force to the movable contact so that contact pressure is applied from the second movable contact to the load side fixed contact, The movable contact is provided with a power supply side spring arrangement space by forming a first recess on one side in the width direction on the first movable contact side of the shaft portion located in the center in the longitudinal direction, and a load side spring arrangement space by forming a second recess on the other side in the width direction on the second movable contact side of the shaft portion. The power supply side contact pressure spring is positioned in the power supply side spring arrangement space, and both ends of the spring are engaged with the movable contact and the movable contact holder. The circuit breaker is characterized in that the load-side contact pressure spring is arranged in the load-side spring arrangement space, and both ends of the spring are engaged with the movable contact and the movable contact holder.

2. The first recess has a stepped surface formed by providing a stepped portion from one side in the width direction of the shaft portion, extending toward the first movable contact side, and the power supply side spring arrangement space is provided by this stepped surface. The circuit breaker according to claim 1, characterized in that the second recess has a stepped surface extending toward the second movable contact side by providing a stepped portion from the other side in the width direction of the shaft portion, and the load-side spring arrangement space is provided by the stepped surface.

3. The first recess is a first notch formed on a part of one side surface in the width direction on the side of the shaft that is closer to the first movable contact, and the power supply side spring arrangement space is provided by this first notch. The circuit breaker according to claim 1, characterized in that the second recess is a second notch formed on a part of the other side surface in the width direction on the side of the shaft that is on the second movable contact side, and the load-side spring arrangement space is provided by the second notch.

4. The circuit breaker according to claim 3, characterized in that the first notch and the second notch are formed to a depth that intersects the center line in the width direction of the movable contact.

Images