Circuit breaker and distribution panel

Abstract

The present invention addresses the problem of providing a circuit breaker in which the opening performance of a contact section at the time of power abnormality is improved and the temperature rise of a housing is suppressed. A circuit breaker (10) is provided with a first terminal section (11), a second terminal section (12), an electrical path (30), a contact section (20), and a housing (40). The contact section (20) includes a fixed contact portion (21) and a movable contact portion (22). A first fixed contact portion (21a) and a second fixed contact portion (21b) in the fixed contact portion (21) are arranged side by side in a direction orthogonal to a direction in which the fixed contact portion (21) and the movable contact portion (22) are adjacent to each other. At least one of the first terminal section (11) and the second terminal section (12) is disposed on the opposite side to the fixed contact portion (21) with respect to the movable contact portion (22). At least one of a first electric path (31) and a second electric path (32) in the electric path (30) is disposed so as to pass between the first fixed contact portion (21a) and the second fixed contact portion (21b).

Description

Circuit breakers and distribution boards

[0001] The present disclosure relates generally to circuit breakers and distribution boards, and more particularly to circuit breakers and distribution boards with contact portions.

[0002] As a conventional example, an electromagnetic relay (circuit breaker) described in Patent Document 1 is exemplified. The electromagnetic relay described in Patent Document 1 includes a case, a movable terminal, a first fixed terminal, and a second fixed terminal. The movable terminal has a first movable contact and a second movable contact. In the electromagnetic relay, when the first movable contact and the second movable contact come into contact with the first fixed contact and the second fixed contact, a current path from the first fixed terminal via the movable terminal to the second fixed terminal is energized. In addition, in the electromagnetic relay, when the first movable contact and the second movable contact move away from the first fixed contact and the second fixed contact, the current path is interrupted.

[0003] In conventional electromagnetic relays, when a large current such as an overcurrent flows (during a power abnormality), the movable terminals (first and second movable contacts) must immediately separate from the first and second fixed terminals to enter a cutoff state. That is, it is desirable for electromagnetic relays to have improved opening performance of the contacts during a power abnormality. Furthermore, when a large current flows through the current path, there is a concern that the temperature of the housing of the electromagnetic relay may rise.

[0004] JP 2023-003206 A

[0005] An object of the present disclosure is to provide a circuit breaker and a distribution board that improve the opening performance of the contact portion during a power abnormality and suppress a temperature rise in the housing.

[0006] A circuit breaker according to one aspect of the present disclosure includes a first terminal, a second terminal, an electrical path, a contact, and a housing. The first terminal is electrically connectable to an external power source. The second terminal is electrically connectable to a load. The electrical path electrically connects the first terminal and the second terminal and supplies power from the external power source to the load. The contact is part of the electrical path and opens when an abnormality occurs in the power. The housing houses the first terminal, the second terminal, the electrical path, and the contact. The contact has a fixed contact and a movable contact. The movable contact moves between a closed position in contact with the fixed contact and an open position away from the fixed contact. The fixed contact and the movable contact are arranged adjacent to each other. The fixed contact has a first fixed contact and a second fixed contact. The second fixed contact is electrically connectable to the first fixed contact via the movable contact. The first fixed contact and the second fixed contact are arranged side by side in a direction perpendicular to the direction in which the fixed contact portion and the movable contact portion are adjacent to each other. At least one of the first terminal portion and the second terminal portion is arranged on the opposite side of the movable contact portion from the fixed contact portion. The electrical path includes the contact portion, a first electrical path, and a second electrical path. The first electrical path electrically connects the first terminal portion and the first fixed contact. The second electrical path electrically connects the second terminal portion and the second fixed contact. At least one of the first electrical path and the second electrical path is arranged to pass between the first fixed contact and the second fixed contact.

[0007] A distribution board according to one aspect of the present disclosure includes the circuit breaker and a cabinet that houses the circuit breaker.

[0008] FIG. 1 is a perspective view of a circuit breaker according to an embodiment. FIG. 2 is a side view of the circuit breaker with a portion of the housing removed. FIG. 3 is a cross-sectional view of the circuit breaker. FIG. 4 is another cross-sectional view of the circuit breaker. FIG. 5 is a perspective view of a main part and an arc-extinguishing device of the circuit breaker. FIG. 6 is another perspective view of the main part and an arc-extinguishing device of the circuit breaker. FIG. 7 is a plan view of the main part and an arc-extinguishing device of the circuit breaker. FIG. 8 is an explanatory diagram illustrating the generation of Lorentz force at a first fixed contact portion and a first movable contact portion of the circuit breaker. FIG. 9 is an explanatory diagram illustrating the generation of Lorentz force at a second fixed contact portion and a second movable contact portion of the circuit breaker. FIG. 10 is an external view showing a portion of a distribution board equipped with the circuit breaker. FIG. 11 is a plan view of the main part and an arc-extinguishing device of a circuit breaker of a comparative example.

[0009] Circuit breakers according to embodiments will be described below with reference to the drawings. The figures described in the following embodiments are schematic diagrams, and the size and thickness ratios of the components do not necessarily reflect actual dimensional ratios. Furthermore, the configurations described in the following embodiments are merely examples of the present disclosure. The present disclosure is not limited to the following embodiments, and various modifications are possible depending on the design, etc., as long as the effects of the present disclosure can be achieved. In the following description, unless otherwise specified, the up-down, left-right, and front-to-back directions indicated by arrows in the drawings are defined as the up-down, left-to-right, and front-to-back directions of the circuit breaker 10 and the distribution board A1. However, the up-down, left-to-right, and front-to-back directions are used for convenience to facilitate understanding of the embodiments, and do not define the directions when the circuit breaker 10 and the distribution board A1 are used. Furthermore, the arrows indicating "up," "down," "left," "right," "front," and "rear" in the drawings are merely for illustrative purposes and do not have any physical meaning.

[0010] (Embodiment) (1) Distribution Board First, a distribution board A1 including a circuit breaker 10 according to an embodiment will be described with reference to FIGS. 1 to 10. FIG.

[0011] As shown in Fig. 10 , the distribution board A1 includes a main breaker 91, a plurality of branch breakers 92, a cabinet 93, and an outer cover (not shown). In this embodiment, the branch breakers 92 are circuit breakers 10 (see Fig. 1 ). In other words, the distribution board A1 includes at least the circuit breakers 10 and the cabinet 93. The distribution board A1 is installed, for example, in a residence. Note that the distribution board A1 is not limited to being installed in a residence, and may also be installed in a non-residential location.

[0012] As shown in Fig. 10 , the cabinet 93 is box-shaped (e.g., rectangular box-shaped) with an open front. The cabinet 93 is attached to, for example, the wall of a house. The cabinet 93 is made of, for example, resin. The cabinet 93 houses a main breaker 91 and a plurality of branch breakers 92. In other words, the cabinet 93 houses at least the circuit breakers 10. The outer lid is attached to the cabinet 93 so as to move between a position that closes the front of the cabinet 93 and a position that opens it. The outer lid is made of, for example, resin.

[0013] The main breaker 91 has a primary terminal (not shown) and a secondary terminal (not shown). The primary terminal of the main breaker 91 is electrically connected to an external power source (not shown). The secondary terminal of the main breaker 91 is electrically connected to a plurality of branch breakers 92. The external power source is a power source that supplies power to a load. The external power source is, for example, a system power source (commercial power source).

[0014] Each of the multiple branch breakers 92 (circuit breakers 10) includes a first terminal unit 11 (see FIG. 2 ) and a second terminal unit 12 (see FIG. 2 ), which will be described later. The first terminal unit 11 of the circuit breaker 10 is electrically connected to a secondary terminal of the main breaker 91. In other words, the first terminal unit 11 of the circuit breaker 10 is electrically connected to an external power source via the main breaker 91. One or more loads are electrically connected to the second terminal unit 12 of the circuit breaker 10. Examples of the loads include lighting fixtures, electrical equipment, hot water supply equipment, electrical outlets, and wiring devices. Examples of the wiring devices include wall switches.

[0015] (2) Circuit Breaker As shown in FIG. 2 , the circuit breaker 10 includes a first terminal 11, a second terminal 12, an electrical circuit 30, a contact 20, a housing 40, an operating handle 50, a latch mechanism 51, and an arc extinguishing device 52. The circuit breaker 10 is configured to detect an overcurrent (e.g., a short-circuit current, an overload current, etc.) and switch the contact 20 from closed to open, thereby interrupting the flow of electricity from an external power source to a load. The circuit breaker 10 is also configured to be able to switch the contact 20 from closed to open in response to operation (manual operation) of the operating handle 50. The circuit breaker 10 is also configured to be able to switch the contact 20 from open to closed in response to operation of the operating handle 50. For example, if the circuit breaker 10 detects an overcurrent and opens the contact 20, a user such as a resident of a house can close the contact 20 by operating the operating handle 50 after confirming safety.

[0016] (3) Components of the Circuit Breaker (3.1) Housing As shown in FIG. 2, the housing 40 houses the first terminal 11, the second terminal 12, the electrical circuit 30, the contact unit 20, the operating handle 50, the latch mechanism 51, and the arc extinguishing device 52. As shown in FIG. 1, the housing 40 has a flat box shape. The housing 40 is made of, for example, resin. The housing 40 includes a first block 41, a second block 42, and a third block 43. The first block 41 and the third block 43 are configured in a box shape with an open side facing each other (the left-right direction of the housing 40). More specifically, the first block 41 is configured in a box shape with an open side on the right side of the housing 40 (the third block 43 side). The third block 43 is configured in a box shape with an open side on the left side of the housing 40 (the first block 41 side). The second block 42 is configured to hold the first terminal portion 11, the second terminal portion 12, the electrical circuit 30, the contact portion 20, the latch mechanism 51, and the arc extinguishing device 52. Note that Fig. 2 shows a state in which the first block 41 and the second block 42 are removed.

[0017] 1, the first block 41 is provided with a protrusion 45. The protrusion 45 has a hole 45a through which the lever 50a of the operating handle 50 is exposed. The protrusion 45 is, for example, formed as a continuous, integrated unit with the first block 41. The material of the protrusion 45 is, for example, resin.

[0018] The operating handle 50 is configured to rotate between an ON position, which closes the contact unit 20, and an OFF position, which opens the contact unit 20. Specifically, the third block 43 is provided with a holding plate 44 (see FIG. 2) that holds the operating handle 50. The holding plate 44 is, for example, configured as a continuous, integrated unit with the third block 43. The holding plate 44 is made of, for example, resin. The holding plate 44 has a cylindrical protrusion 44a. The protrusion 44a is, for example, configured as a continuous, integrated unit with the holding plate 44. The protrusion 44a is, for example, made of resin. The operating handle 50 has a hole 50b (see FIG. 2) through which the protrusion 44a of the third block 43 is inserted. The protrusion 44a is inserted into the hole 50b of the operating handle 50 and supports the operating handle 50 so that the operating handle 50 rotates between the ON position and the OFF position.

[0019] (3.2) Terminal Section The first terminal section 11 is electrically connected to the secondary terminal of the main breaker 91. In other words, the first terminal section 11 is electrically connected to an external power source. As shown in FIG. 2 , the first terminal section 11 is disposed inside the housing 40 on the lower side in the up-down direction of the housing 40. The first terminal section 11 has a first terminal plate 13, a first terminal fitting 14, and a first screw 61. The first terminal section 11 is, for example, a screw-type terminal. The first terminal section 11 is configured to be connectable to a first electric wire (not shown) by the first screw 61. The first electric wire is an electric wire electrically connected to the main breaker 91.

[0020] The first terminal plate 13 is a conductive metal plate. For example, the first terminal plate 13 is L-shaped when viewed from the left and right. A first end 13a (see FIG. 3) of the first terminal plate 13 is attached to a first terminal fitting 14. A second end 13b (see FIG. 3) of the first terminal plate 13 is connected to a first electrical path 31 (described later).

[0021] 2 and 3 , the first terminal fitting 14 is tubular (e.g., rectangular) and has a hole 14a extending therethrough in the vertical direction. In this embodiment, the tip of the first electric wire is inserted into the hole 14a of the first terminal fitting 14. The first terminal fitting 14 has a hole 14c at one end (front end) 14b in the front-rear direction, into which a first screw 61 is screwed. The first screw 61 is attached to the first terminal fitting 14 with the tip of the screw threaded into the hole 14c of the first terminal fitting 14.

[0022] The first end 13a of the first terminal plate 13 is inserted into the hole 14a of the first terminal fitting 14, and when the first screw 61 is screwed in, the first end 13a moves rearward in the front-to-rear direction of the first terminal fitting 14. This allows the first terminal 11 to be connected to the first electric wire by the first screw 61.

[0023] A load is electrically connected to the second terminal 12. As shown in FIG. 2 , the second terminal 12 is disposed within the housing 40 at an upper position in the vertical direction of the housing 40. The second terminal 12 includes a second terminal plate 15, a second terminal fitting 16, and a second screw 62. The second terminal 12 is, for example, a screw-type terminal. The second terminal 12 is configured to be connectable to a second electric wire (not shown) by the second screw 62. The second electric wire is an electric wire that is electrically connected to the load.

[0024] The second terminal plate 15 is a conductive metal plate. For example, the second terminal plate 15 is L-shaped when viewed from the left and right. A first end 15a (see FIG. 4) of the second terminal plate 15 is attached to a second terminal fitting 16. A second end 15b (see FIG. 4) of the second terminal plate 15 is connected to a second electrical path 32 (described later).

[0025] 2 and 4 , the second terminal fitting 16 is tubular (e.g., rectangular) and has a hole 16a extending therethrough in the vertical direction. In this embodiment, the tip of the second electric wire is inserted into the hole 16a of the second terminal fitting 16. The second terminal fitting 16 has a hole 16c at one end (front end) 16b in the front-rear direction, into which a second screw 62 is screwed. The second screw 62 is attached to the second terminal fitting 16 with the tip of the screw threaded into the hole 16c of the second terminal fitting 16.

[0026] The first end 15a of the second terminal plate 15 is inserted into the hole 16a of the second terminal fitting 16, and when the second screw 62 is screwed in, the first end 15a moves rearward in the front-to-rear direction of the second terminal fitting 16. This allows the second terminal portion 12 to be connected to the second electric wire by the second screw 62.

[0027] (3.3) Electrical Path As shown in FIG. 7 , the electrical path 30 electrically connects the first terminal 11 and the second terminal 12. The electrical path 30 also supplies power from an external power source to a load. In short, the electrical path 30 is an electrical path that connects the first terminal 11 and the second terminal 12. The electrical path 30 includes a first electrical path 31, a second electrical path 32, and a contact portion 20. In other words, the contact portion 20 is a part of the electrical path 30.

[0028] As shown in Fig. 7 , the first electrical path 31 electrically connects the first terminal 11 and a first fixed contact 21a (described later) of the contact unit 20. The first electrical path 31 is a conductive metal plate. The first electrical path 31 is, for example, U-shaped when viewed from the front-to-rear direction. A first end 31a of the first electrical path 31 is connected to a second end 13b of the first terminal board 13. A second end 31b of the first electrical path 31 is connected to a first fixed contact 21a (described later) of the contact unit 20.

[0029] As shown in FIG. 7 , the second electrical circuit 32 electrically connects the second terminal portion 12 and a second fixed contact portion 21b (described later) of the contact portion 20. The second electrical circuit 32 is a conductive metal plate. The second electrical circuit 32 includes a connecting portion 33 and a coil 34. The connecting portion 33 is, for example, L-shaped when viewed from the front-to-rear direction. A first end 33a of the connecting portion 33 is connected to a second end 15b of the second terminal plate 15. A second end 33b of the connecting portion 33 is connected to a first end 34a of the coil 34. A second end 34b of the coil 34 is connected to the second fixed contact portion 21b.

[0030] (3.4) Contact Unit The contact unit 20 is configured to open when an abnormality occurs in the power supplied from the external power source to the load. In other words, the contact unit 20 is configured to open when an abnormal current (e.g., leakage current, short-circuit current, overload current, etc.) flows through the electric circuit 30, thereby switching the electric circuit 30 from a conducting state to a cut-off state.

[0031] As shown in Fig. 2, the contact portion 20 has a fixed contact portion 21 and a movable contact portion 22. The fixed contact portion 21 and the movable contact portion 22 are arranged adjacent to each other. More specifically, the fixed contact portion 21 and the movable contact portion 22 are arranged side by side in the up-down direction of the housing 40 within the housing 40. The fixed contact portion 21 is arranged above the movable contact portion 22 (on the second terminal portion 12 side) within the housing 40. The movable contact portion 22 is arranged below the fixed contact portion 21 (on the first terminal portion 11 side) within the housing 40.

[0032] 7, the fixed contact portion 21 has a first fixed contact portion 21a and a second fixed contact portion 21b. In other words, the fixed contact portion 21 has two fixed contact portions (the first fixed contact portion 21a and the second fixed contact portion 21b). The first fixed contact portion 21a and the second fixed contact portion 21b are electrically connected via the movable contact portion 22.

[0033] The first fixed contact portion 21a is a conductive metal plate. The first fixed contact portion 21a is, for example, substantially L-shaped (see FIG. 6 ). A first end 25 of the first fixed contact portion 21a is electrically connected to a first movable contact portion 22a (described below) of the movable contact portion 22. A second end 26 of the first fixed contact portion 21a is held by a second block 42 of the housing 40, as shown in FIG. 3 .

[0034] The second fixed contact portion 21b (see FIG. 5) is a conductive metal plate. The second fixed contact portion 21b is, for example, substantially L-shaped. A first end 27 of the second fixed contact portion 21b is connected to a second end 34b of the coil 34. A second end 28 of the second fixed contact portion 21b is held by a second block 42 of the housing 40, as shown in FIG. 4.

[0035] 7, the first fixed contact portion 21a and the second fixed contact portion 21b are arranged side by side in a direction (left and right direction of the housing 40) perpendicular to the direction in which the fixed contact portion 21 and the movable contact portion 22 are adjacent (up and down direction of the housing 40). In other words, the first fixed contact portion 21a and the second fixed contact portion 21b are arranged side by side in the left and right direction of the housing 40 within the housing 40. The first fixed contact portion 21a is arranged on the right side of the housing 40 in the left and right direction. The second fixed contact portion 21b is arranged on the left side of the housing 40 in the left and right direction.

[0036] The movable contact portion 22 is configured to come into contact with or separate from the fixed contact portion 21. In other words, the movable contact portion 22 is configured to move between a closed position in which it comes into contact with the fixed contact portion 21 and an open position in which it is separated from the fixed contact portion 21. The movable contact portion 22 is, for example, U-shaped. As shown in Figures 5 and 6, the movable contact portion 22 has a first movable contact portion 22a, a first holding portion 23a, a second movable contact portion 22b, a second holding portion 23b, and a connecting piece 24.

[0037] The first movable contact portion 22a is a conductive metal piece. The first movable contact portion 22a is configured to move between a closed position in contact with the first fixed contact portion 21a and an open position in which it is separated from the first fixed contact portion 21a. The first holding portion 23a holds the first movable contact portion 22a so that the first movable contact portion 22a moves between the closed position and the open position. The first holding portion 23a is made of a conductive metal.

[0038] The second movable contact portion 22b is a piece of conductive metal. The second movable contact portion 22b is configured to move between a closed position in contact with the second fixed contact portion 21b and an open position in which it is separated from the second fixed contact portion 21b. The second holding portion 23b holds the second movable contact portion 22b so that the second movable contact portion 22b moves between the closed position and the open position. The second holding portion 23b is made of a conductive metal.

[0039] As shown in FIG. 7 , the first movable contact portion 22a and the second movable contact portion 22b are arranged side by side in a direction perpendicular to the direction in which the fixed contact portion 21 and the movable contact portion 22 are adjacent to each other. In other words, the first movable contact portion 22a and the second movable contact portion 22b are arranged side by side in the left-right direction of the housing 40 within the housing 40. The first movable contact portion 22a is arranged on the right side of the housing 40 in the left-right direction within the housing 40. The second movable contact portion 22b is arranged on the left side of the housing 40 in the left-right direction within the housing 40. In other words, the first movable contact portion 22a is arranged at a position facing the first fixed contact portion 21a. The second movable contact portion 22b is arranged at a position facing the second fixed contact portion 21b.

[0040] As shown in FIG. 5 , the first retaining portion 23a and the second retaining portion 23b are arranged side by side in a direction perpendicular to the direction in which the fixed contact portion 21 and the movable contact portion 22 are adjacent to each other. In other words, the first retaining portion 23a and the second retaining portion 23b are arranged side by side in the left-right direction of the housing 40 within the housing 40. The first retaining portion 23a is arranged on the right side of the housing 40 in the left-right direction. The second retaining portion 23b is arranged on the left side of the housing 40 in the left-right direction within the housing 40. The first retaining portion 23a is arranged further forward than the first movable contact portion 22a in the front-rear direction of the housing 40. The second retaining portion 23b is arranged further forward than the second movable contact portion 22b in the front-rear direction of the housing 40.

[0041] The connecting piece 24 is configured to connect the first holding portion 23a and the second holding portion 23b together. The connecting piece 24 is cylindrical and conductive.

[0042] 5 and 6, the movable contact portion 22 has two movable contact portions, a first movable contact portion 22a held by a first holding portion 23a, a second movable contact portion 22b held by a second holding portion 23b, and the first holding portion 23a and the second holding portion 23b connected by a connecting piece 24. That is, the movable contact portion 22 is U-shaped. In other words, the movable contact portion 22 is bifurcated.

[0043] The contact unit 20 constitutes an electrical circuit having two fixed contact units (first fixed contact unit 21 a and second fixed contact unit 21 b) and two movable contact units (first movable contact unit 22 a and second movable contact unit 22 b). In other words, the contact unit 20 constitutes an electrical circuit having two contact devices. That is, the contact unit 20 has a bifurcated movable contact unit (movable contactor) and constitutes an electrical circuit having two contact devices. In this embodiment, when the contact unit 20 is in a closed state, the current flowing from the first terminal unit 11 via the first electrical circuit 31 flows in the following order: first fixed contact unit 21 a, first movable contact unit 22 a, first holding unit 23 a, connecting piece 24, second holding unit 23 b, second movable contact unit 22 b, and second fixed contact unit 21 b.

[0044] (3.5) Latch Mechanism The latch mechanism 51 (see FIG. 2) is configured to close the contact unit 20 in response to a closing operation (ON operation) of the operating handle 50. The latch mechanism 51 is also configured to open the contact unit 20 in response to an opening operation (OFF operation) of the operating handle 50. The closing operation of the operating handle 50 is an operation in which the operating handle 50 is set to the ON position. The opening operation of the operating handle 50 is an operation in which the operating handle 50 is set to the OFF position.

[0045] 2, the latch mechanism 51 has a first latch member 53, a second latch member 54, and an arm 55. The first latch member 53 is configured to close the contact portion 20 in response to a closing operation of the operating handle 50. The first latch member 53 is made of a material such as resin. The second latch member 54 is configured to open the contact portion 20 in response to an opening operation of the operating handle 50. The second latch member 54 is made of a material such as resin.

[0046] The arm 55 is configured to move in conjunction with the closing operation of the operating handle 50. The arm 55 is also configured to move in conjunction with the opening operation of the operating handle 50. The arm 55 is, for example, U-shaped. The material of the arm 55 is, for example, metal. A first end of the arm 55 is connected to the operating handle 50. A second end of the arm 55 is connected to the first latch member 53. The second end of the arm 55 is also connected to the second latch member 54. When the operating handle 50 is closed, the arm 55 operates the first latch member 53 to close the contact unit 20. On the other hand, when the operating handle 50 is opened, the arm 55 operates the second latch member 54 to open the contact unit 20.

[0047] (3.6) Arc-Extinguishing Device The arc-extinguishing device 52 (see FIG. 2) is configured to quickly extinguish an arc that occurs when the contact portion 20 is opened. In other words, the arc-extinguishing device 52 is configured to extend an arc that occurs when the movable contact portion 22 is separated from the fixed contact portion 21, and to cut off the arc to extinguish the arc. As shown in FIG. 6, the arc-extinguishing device 52 has a first arc-extinguishing device 52a and a second arc-extinguishing device 52b.

[0048] The first arc extinguishing device 52a is configured to quickly extinguish an arc that occurs when the first fixed contact portion 21a and the first movable contact portion 22a are separated. The second arc extinguishing device 52b is configured to quickly extinguish an arc that occurs when the second fixed contact portion 21b and the second movable contact portion 22b are separated. The first arc extinguishing device 52a and the second arc extinguishing device 52b are arranged side by side in a direction perpendicular to the direction in which the fixed contact portion 21 and the movable contact portion 22 are adjacent to each other (see FIGS. 5 and 6 ). In other words, the first arc extinguishing device 52a and the second arc extinguishing device 52b are arranged side by side in the left-right direction of the housing 40. The first arc extinguishing device 52a is arranged on the right side of the housing 40 in the left-right direction. The second arc extinguishing device 52b is arranged on the left side of the housing 40 in the left-right direction.

[0049] As shown in Figures 3 and 4, the first arc extinguishing device 52a and the second arc extinguishing device 52b are disposed within the housing 40 in a rear portion (rear section) 46 of the housing 40 in the front-to-rear direction. More specifically, as shown in Figure 3, the first arc extinguishing device 52a is disposed within the housing 40 between the second end 26 of the first fixed contact portion 21a and an inner bottom surface 47 of the housing 40 (the inner bottom surface of the rear section 46 of the housing 40). As shown in Figure 4, the second arc extinguishing device 52b is disposed within the housing 40 between the second end 28 of the second fixed contact portion 21b and the inner bottom surface 47 of the housing 40. In other words, the first arc extinguishing device 52a and the second arc extinguishing device 52b are disposed to face the inner bottom surface 47 of the housing 40.

[0050] (4) Position of the Electrical Path The first electrical path 31 is arranged to pass between the first fixed contact 21 a and the second fixed contact 21 b, as shown in Fig. 7. The first electrical path 31 is also arranged to pass between the first movable contact 22 a and the second movable contact 22 b.

[0051] Here, a circuit breaker Z1 of a comparative example will be illustrated (see FIG. 11). As shown in FIG. 11, the circuit breaker Z1 of the comparative example differs from the circuit breaker 10 of the present embodiment in that the position of the first electric circuit 100 of the circuit breaker Z1 is different. Note that, with respect to the circuit breaker Z1 of the comparative example, components similar to those of the circuit breaker 10 of the present embodiment (FIGS. 1 to 8) are denoted by the same reference numerals and description thereof will be omitted.

[0052] The first electric circuit 100 electrically connects the first terminal 11 and the first fixed contact 21a of the contact unit 20. The first electric circuit 100 is a conductive metal plate. The first electric circuit 100 is, for example, substantially L-shaped. The first end 100a of the first electric circuit 100 is connected to the second end 13b of the first terminal plate 13. The second end 100b of the first electric circuit 100 is connected to the first fixed contact 21a of the contact unit 20. The first electric circuit 100 is arranged to pass between the right side surface (third block 43) of the housing 40 in the left-right direction and the first fixed contact 21a and the first movable contact 22a. In other words, the first electric circuit 100 is not arranged to pass between the first fixed contact 21a and the second fixed contact 21b. Furthermore, the first electrical circuit 100 is not arranged to pass between the first movable contact portion 22a and the second movable contact portion 22b.

[0053] In the circuit breaker Z1 of the comparative example, the first electric circuit 100 is disposed near the right side surface (third block 43) of the housing 40, and therefore, if a large current flows through the first electric circuit 100, the temperature of the side surface of the housing 40 may increase. That is, in the circuit breaker Z1 of the comparative example, if a large current flows through the first electric circuit 100, the temperature of the housing 40 may increase.

[0054] On the other hand, in the circuit breaker 10 of this embodiment, as shown in Fig. 7, the first electrical circuit 31 is arranged to pass between the first fixed contact portion 21a and the second fixed contact portion 21b. The first electrical circuit 31 is also arranged to pass further between the first movable contact portion 22a and the second movable contact portion 22b. In other words, in the circuit breaker 10, the first electrical circuit 31 is spaced apart from the left and right side surfaces of the housing 40. This prevents the temperature of the side surfaces of the housing 40 from increasing compared to the circuit breaker Z1 of the comparative example. In other words, the circuit breaker 10 prevents the temperature of the housing 40 from increasing compared to the circuit breaker Z1 of the comparative example.

[0055] Furthermore, it is preferable that the first electrical circuit 31 is arranged so as to further pass through the center between the first fixed contact portion 21 a and the second fixed contact portion 21 b. This allows the circuit breaker 10 to further suppress temperature rise in the housing 40 compared to the circuit breaker Z1 of the comparative example. Note that the "center between the first fixed contact portion 21 a and the second fixed contact portion 21 b" is not limited to the center (middle) between the first fixed contact portion 21 a and the second fixed contact portion 21 b, but also includes the vicinity of the center between the first fixed contact portion 21 a and the second fixed contact portion 21 b.

[0056] Furthermore, it is preferable that the first electrical circuit 31 is arranged so as to pass through the center between the first movable contact 22a and the second movable contact 22b. This allows the circuit breaker 10 to further suppress temperature rise in the housing 40 compared to the circuit breaker Z1 of the comparative example. Note that the "center between the first movable contact 22a and the second movable contact 22b" is not limited to the center (middle) between the first movable contact 22a and the second movable contact 22b, but also includes the vicinity of the center between the first movable contact 22a and the second movable contact 22b.

[0057] 2, the first electrical path 31 is disposed at the same height as both the first terminal 11 and the second terminal 12, relative to the inner bottom surface 47 of the housing 40. More specifically, the first electrical path 31 is disposed at the same height as both the first terminal plate 13 of the first terminal 11 and the second terminal plate 15 of the second terminal 12, relative to the inner bottom surface 47 of the housing 40. This allows the circuit breaker 10 to have a low profile. Note that "the same height" is not limited to being exactly the same height, but also includes cases where the heights are considered to be substantially the same, that is, it includes a degree of difference due to a manufacturing error range.

[0058] (5) Current Flow in the Circuit Breaker When the contact unit 20 is in a closed state in response to a closing operation (on operation) of the operating handle 50, the first fixed contact unit 21a and the first movable contact unit 22a come into contact with each other, and the second fixed contact unit 21b and the second movable contact unit 22b come into contact with each other, thereby supplying power from the external power source to the load. Specifically, current (e.g., positive current) that travels from the external power source to the branch breaker 92 (circuit breaker 10) via the main breaker 91 (see FIG. 10 ) flows through the following path (current path): the first terminal plate 13, the first electrical circuit 31, the first fixed contact unit 21a, the first movable contact unit 22a, the first holding unit 23a, the connecting piece 24, the second holding unit 23b, the second movable contact unit 22b, the second fixed contact unit 21b, the second electrical circuit 32, and the second terminal plate 15, in that order. In the case of a negative electrode current, the current flows in the opposite direction to that in the case of a positive electrode current through the above-mentioned current path.

[0059] On the other hand, when the contact portion 20 is in the open state in response to the opening operation (off operation) of the operating handle 50, the first movable contact portion 22a moves away from the first fixed contact portion 21a and the second movable contact portion 22b moves away from the second fixed contact portion 21b, so that no power is supplied from the external power source to the load. In other words, no current flows through the current path.

[0060] When the contact unit 20 is in a closed state (ON state) and a large current (e.g., an overcurrent) flows through the current path, as shown in FIG. 8 , a first current I1 flows through the first fixed contact unit 21a in the direction of the arrow, and a second current I2 flows through the first movable contact unit 22a in the direction of the arrow. When the first current I1 and the second current I2 flow, a first magnetic field H1, a second magnetic field H2, and a third magnetic field H3 are generated. The strength of the third magnetic field H3 is stronger than the strength of the first magnetic field H1 or the second magnetic field H2 due to the first magnetic field H1 and the second magnetic field H2. Therefore, in the circuit breaker 10, a first Lorentz force F1 is generated on the first movable contact unit 22a in the direction of the arrow, causing the first movable contact unit 22a to move away from the first fixed contact unit 21a.

[0061] Furthermore, when the contact portion 20 is in a closed state (ON state), if a large current flows through the current path described above, a third current I3 flows through the second movable contact portion 22b in the direction of the arrow, and a fourth current I4 flows through the second fixed contact portion 21b in the direction of the arrow, as shown in Fig. 9. When the third current I3 and the fourth current I4 flow, a fourth magnetic field H4, a fifth magnetic field H5, and a sixth magnetic field H6 are generated. The strength of the sixth magnetic field H6 is stronger than the strength of the fourth magnetic field H4 or the fifth magnetic field H5 due to the fourth magnetic field H4 and the fifth magnetic field H5.

[0062] Therefore, in the circuit breaker 10, a second Lorentz force F2 is generated on the second movable contact portion 22b in the direction of the arrow, causing the second movable contact portion 22b to move away from the second fixed contact portion 21b. That is, in the circuit breaker 10, when a large current flows through the above-mentioned current path, a first Lorentz force F1 is generated on the first movable contact portion 22a in the direction of the arrow, and a second Lorentz force F2 is generated on the second movable contact portion 22b in the direction of the arrow, as shown in Figures 8 and 9. Therefore, in the circuit breaker 10, when a large current flows through the above-mentioned current path, the first fixed contact portion 21a moves away from the first movable contact portion 22a, and the second fixed contact portion 21b moves away from the second movable contact portion 22b, causing the contact portion 20 to immediately open.

[0063] The direction of the first Lorentz force F1 is perpendicular to the direction of the second current I2 and the direction of the third magnetic field H3, and the direction of the second Lorentz force F2 is perpendicular to the direction of the third current I3 and the direction of the sixth magnetic field H6.

[0064] 7, in the circuit breaker 10, the first electric circuit 31 is arranged so that it passes between the first fixed contact portion 21a and the second fixed contact portion 21b, and also so that the first electric circuit 31 passes between the first movable contact portion 22a and the second movable contact portion 22b. In other words, in the circuit breaker 10, the first electric circuit 31 is arranged in the center of the housing 40. As a result, in the circuit breaker 10, the magnetic field (magnetic field) around the two contact devices (the two contact devices of the first fixed contact portion 21a and the first movable contact portion 22a, and the second fixed contact portion 21b and the second movable contact portion 22b) is strengthened more than in the circuit breaker Z1 of the comparative example.

[0065] Therefore, the circuit breaker 10 of this embodiment can strengthen the first Lorentz force F1 and the second Lorentz force F2 more than the circuit breaker Z1 of the comparative example, thereby improving the opening performance of the contact unit 20 due to the Lorentz forces (first Lorentz force F1 and second Lorentz force F2). In other words, the circuit breaker 10 improves the opening performance of the contact unit 20 during a power abnormality more than the circuit breaker Z1 of the comparative example.

[0066] (6) Effects In the circuit breaker 10 of this embodiment, the first electrical circuit 31 is arranged to pass between the first fixed contact portion 21a and the second fixed contact portion 21b, as shown in Fig. 7. Therefore, the circuit breaker 10 improves the opening performance of the contact portion 20 due to the Lorentz force during a power abnormality, and suppresses a temperature rise on the side surface of the housing 40, compared to the circuit breaker Z1 of the comparative example. In other words, the circuit breaker 10 improves the opening performance of the contact portion 20 during a power abnormality, and suppresses a temperature rise in the housing 40, compared to the circuit breaker Z1 of the comparative example.

[0067] Furthermore, in the circuit breaker 10, the first electrical circuit 31 is arranged to pass further between the first movable contact 22 a and the second movable contact 22 b. As a result, the circuit breaker 10 has improved performance of opening the contact 20 due to the Lorentz force in the event of a power abnormality, and also suppresses temperature rise on the side surface of the housing 40, compared to the circuit breaker Z1 of the comparative example.

[0068] (7) Modifications In the present embodiment, the first terminal 11 is electrically connected to an external power supply, and the second terminal 12 is electrically connected to a load. However, the first terminal 11 may be electrically connected to a load, and the second terminal 12 may be electrically connected to an external power supply.

[0069] The first electrical circuit 31 is arranged to further pass between the first movable contact 22 a and the second movable contact 22 b, but this configuration is not essential. The second electrical circuit 32 includes a connecting portion 33 and a coil 34, but may consist of only the connecting portion 33. In this case, the second end 33 b of the connecting portion 33 is electrically connected to the second fixed contact 21 b.

[0070] In the present embodiment, the first terminal 11 is disposed on the opposite side of the movable contact 22 from the fixed contact 21, and the second terminal 12 is disposed on the opposite side of the fixed contact 21 from the movable contact 22. However, both the first terminal 11 and the second terminal 12 may be disposed on the opposite side of the movable contact 22 from the fixed contact 21. In other words, it is sufficient that at least one of the first terminal 11 and the second terminal 12 is disposed on the opposite side of the movable contact 22 from the fixed contact 21.

[0071] In addition, in the present embodiment, only the first electrical path 31 is arranged to pass between the first fixed contact portion 21 a and the second fixed contact portion 21 b. However, when both the first terminal portion 11 and the second terminal portion 12 are arranged on the opposite side of the movable contact portion 22 from the fixed contact portion 21 side, both the first electrical path 31 and the second electrical path 32 may be arranged to pass between the first fixed contact portion 21 a and the second fixed contact portion 21 b. In short, it is sufficient that at least one of the first electrical path 31 and the second electrical path 32 is arranged to pass between the first fixed contact portion 21 a and the second fixed contact portion 21 b.

[0072] In addition, in the present embodiment, the first electric circuit 31 is arranged to pass between the first fixed contact portion 21 a and the second fixed contact portion 21 b, but the second electric circuit 32 may be arranged to pass between the first fixed contact portion 21 a and the second fixed contact portion 21 b. In short, it is sufficient that either the first electric circuit 31 or the second electric circuit 32 is arranged to pass between the first fixed contact portion 21 a and the second fixed contact portion 21 b.

[0073] In addition, in this embodiment, only the first electrical circuit 31 is arranged to pass between the first movable contact 22 a and the second movable contact 22 b. However, when both the first terminal 11 and the second terminal 12 are arranged on the opposite side of the movable contact 22 from the fixed contact 21 side, both the first electrical circuit 31 and the second electrical circuit 32 may be arranged to pass between the first movable contact 22 a and the second movable contact 22 b. In short, it is sufficient that at least one of the first electrical circuit 31 and the second electrical circuit 32 is arranged to pass between the first movable contact 22 a and the second movable contact 22 b.

[0074] Furthermore, when both the first terminal 11 and the second terminal 12 are arranged on the opposite side of the movable contact 22 from the fixed contact 21, it is preferable that both the first electric circuit 31 and the second electric circuit 32 are arranged so as to pass through the center between the first fixed contact 21 a and the second fixed contact 21 b. In other words, it is preferable that at least one of the first electric circuit 31 and the second electric circuit 32 is arranged so as to pass through the center between the first fixed contact 21 a and the second fixed contact 21 b.

[0075] Furthermore, when both the first terminal 11 and the second terminal 12 are arranged on the opposite side of the movable contact 22 from the fixed contact 21, it is preferable that both the first electric circuit 31 and the second electric circuit 32 are arranged so as to pass further through the center between the first movable contact 22 a and the second movable contact 22 b. In short, it is preferable that at least one of the first electric circuit 31 and the second electric circuit 32 is arranged so as to pass further through the center between the first movable contact 22 a and the second movable contact 22 b.

[0076] Furthermore, the first electrical path 31 is disposed at the same height as both the first terminal 11 and the second terminal 12 relative to the inner bottom surface 47 of the housing 40, but may be disposed at the same height as either one of the first terminal 11 or the second terminal 12. The second electrical path 32 may also be disposed at the same height as both the first terminal 11 and the second terminal 12 relative to the inner bottom surface 47 of the housing 40, or may be disposed at the same height as either one of the first terminal 11 and the second terminal 12. In short, it is sufficient that at least one of the first electrical path 31 and the second electrical path 32 is disposed at the same height as at least one of the first terminal 11 and the second terminal 12 relative to the inner bottom surface 47 of the housing 40.

[0077] (Aspects) The present specification discloses the following aspects.

[0078] A circuit breaker (10) according to a first aspect includes a first terminal (11), a second terminal (12), an electrical circuit (30), a contact portion (20), and a housing (40). The first terminal (11) is electrically connectable to an external power source. The second terminal (12) is electrically connectable to a load. The electrical circuit (30) electrically connects the first terminal (11) and the second terminal (12) to supply power from the external power source to the load. The contact portion (20) is part of the electrical circuit (30) and opens when an abnormality occurs in the power. The housing (40) houses the first terminal (11), the second terminal (12), the electrical circuit (30), and the contact portion (20). The contact portion (20) has a fixed contact portion (21) and a movable contact portion (22). The movable contact portion (22) moves between a closed position in contact with the fixed contact portion (21) and an open position in which it is separated from the fixed contact portion (21). The fixed contact portion (21) and the movable contact portion (22) are arranged adjacent to each other. The fixed contact portion (21) has a first fixed contact portion (21a) and a second fixed contact portion (21b). The second fixed contact portion (21b) is electrically connectable to the first fixed contact portion (21a) via the movable contact portion (22). The first fixed contact portion (21a) and the second fixed contact portion (21b) are arranged side by side in a direction perpendicular to the direction in which the fixed contact portion (21) and the movable contact portion (22) are adjacent to each other. At least one of the first terminal portion (11) and the second terminal portion (12) is arranged on the opposite side of the movable contact portion (22) from the fixed contact portion (21). The electric circuit (30) includes a contact portion (20), a first electric circuit (31), and a second electric circuit (32). The first electric circuit (31) electrically connects the first terminal portion (11) and the first fixed contact portion (21 a). The second electric circuit (32) electrically connects the second terminal portion (12) and the second fixed contact portion (21 b). At least one of the first electric circuit (31) and the second electric circuit (32) is arranged to pass between the first fixed contact portion (21 a) and the second fixed contact portion (21 b).

[0079] According to this aspect, the opening performance of the contact portion (20) is improved in the event of a power abnormality, and the temperature rise of the housing (40) is suppressed.

[0080] In the circuit breaker (10) according to the second aspect, in the first aspect, either one of the first terminal portion (11) or the second terminal portion (12) is arranged on the opposite side of the movable contact portion (22) from the fixed contact portion (21). The remaining terminal portion of the first terminal portion (11) or the second terminal portion (12) is arranged on the opposite side of the fixed contact portion (21) from the movable contact portion (22). Either the first electric circuit (31) or the second electric circuit (32) is arranged to pass between the first fixed contact portion (21 a) and the second fixed contact portion (21 b).

[0081] A circuit breaker (10) according to a third aspect is the circuit breaker (10) of the first or second aspect, wherein the movable contact portion (22) has a first movable contact portion (22a) and a second movable contact portion (22b). The first movable contact portion (22a) moves between a closed position in contact with the first fixed contact portion (21a) and an open position in which it is separated from the first fixed contact portion (21a). The second movable contact portion (22b) moves between a closed position in contact with the second fixed contact portion (21b) and an open position in which it is separated from the second fixed contact portion (21b). At least one of the first electric circuit (31) and the second electric circuit (32) is arranged to further pass between the first movable contact portion (22a) and the second movable contact portion (22b).

[0082] According to this aspect, the opening performance of the contact portion (20) in the event of a power abnormality is further improved, and the temperature rise of the housing (40) is further suppressed.

[0083] The circuit breaker (10) according to the fourth aspect is the third aspect, in which at least one of the first electric circuit (31) and the second electric circuit (32) is arranged to pass through the center between the first fixed contact portion (21 a) and the second fixed contact portion (21 b).

[0084] According to this aspect, the opening performance of the contact portion (20) in the event of a power abnormality is further improved, and the temperature rise of the housing (40) is further suppressed.

[0085] The circuit breaker (10) according to the fifth aspect is the fourth aspect, wherein at least one of the first electric circuit (31) and the second electric circuit (32) is arranged so as to further pass through the center between the first movable contact portion (22a) and the second movable contact portion (22b).

[0086] According to this aspect, the opening performance of the contact portion (20) in the event of a power abnormality is further improved, and the temperature rise of the housing (40) is further suppressed.

[0087] The circuit breaker (10) according to the sixth aspect is any one of the first to fifth aspects, in which at least one of the first electrical circuit (31) and the second electrical circuit (32) is arranged at the same height as at least one of the first terminal portion (11) and the second terminal portion (12) with respect to the inner bottom surface (47) of the housing (40).

[0088] According to this aspect, it is possible to achieve a low profile.

[0089] A distribution board (A1) according to a seventh aspect includes the circuit breaker (10) according to any one of the first to sixth aspects and a cabinet (93). The cabinet (93) houses the circuit breaker (10).

[0090] According to this aspect, the opening performance of the contact portion (20) is improved in the event of a power abnormality, and the temperature rise of the housing (40) is suppressed.

[0091] 10 Circuit breaker 11 First terminal part 12 Second terminal part 20 Contact part 21 Fixed contact part 21a First fixed contact part 21b Second fixed contact part 22 Movable contact part 22a First movable contact part 22b Second movable contact part 30 Electrical path 31 First electric path 32 Second electric circuit 40 Housing 47 Inner bottom surface 93 Cabinet A1 Distribution board

Claims

1. A device comprising: a first terminal portion electrically connectable to an external power source; a second terminal portion electrically connectable to a load; an electric circuit electrically connecting the first terminal portion and the second terminal portion and supplying power from the external power source to the load; a contact portion that is part of the electric circuit and opens when an abnormality occurs in the power; and a housing that houses the first terminal portion, the second terminal portion, the electric circuit, and the contact portion, wherein the contact portion has a fixed contact portion and a movable contact portion that moves between a closed position in contact with the fixed contact portion and an open position away from the fixed contact portion, wherein the fixed contact portion and the movable contact portion are arranged adjacent to each other, and the fixed contact portion has a first fixed contact portion and a second fixed contact portion electrically connectable to the first fixed contact portion via the movable contact portion, wherein the first fixed contact portion and the second fixed contact portion are arranged side by side in a direction perpendicular to the direction in which the fixed contact portion and the movable contact portion are adjacent to each other, a first electric circuit electrically connecting the first terminal portion and the first fixed contact portion; and a second electric circuit electrically connecting the second terminal portion and the second fixed contact portion, wherein at least one of the first electric circuit and the second electric circuit is arranged to pass between the first fixed contact portion and the second fixed contact portion.

2. A circuit breaker as claimed in claim 1, wherein one of the first terminal portion and the second terminal portion is arranged on the opposite side of the movable contact portion from the fixed contact portion, the remaining terminal portion of the first terminal portion and the second terminal portion is arranged on the opposite side of the fixed contact portion from the movable contact portion, and one of the first electric circuit and the second electric circuit is arranged to pass between the first fixed contact portion and the second fixed contact portion.

3. A circuit breaker as claimed in claim 1 or claim 2, wherein the movable contact portion has a first movable contact portion that moves between a closed position in contact with the first fixed contact portion and an open position away from the first fixed contact portion, and a second movable contact portion that moves between a closed position in contact with the second fixed contact portion and an open position away from the second fixed contact portion, and at least one of the first electric circuit and the second electric circuit is arranged so as to further pass between the first movable contact portion and the second movable contact portion.

4. A circuit breaker according to claim 3, wherein at least one of the first electric circuit and the second electric circuit is arranged so as to pass through the center between the first fixed contact portion and the second fixed contact portion.

5. The circuit breaker according to claim 4, wherein at least one of the first and second electric paths is arranged so as to further pass through the center between the first and second movable contact portions.

6. A circuit breaker as claimed in any one of claims 1 to 5, wherein at least one of the first and second electric circuits is positioned at the same height as at least one of the first and second terminal portions, with respect to the inner bottom surface of the housing.

7. A distribution board comprising: a circuit breaker according to any one of claims 1 to 6; and a cabinet for accommodating the circuit breaker.

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