Breaking mechanism portion of circuit breaker

Abstract

To provide a breaking mechanism portion of a circuit breaker that enables components to be made common between an AC circuit breakers and a DC circuit breaker.SOLUTION: A first collision target portion 37 is located on a movement locus of an action protrusion 28 during an interruption operation of an electromagnetic tripping device 20, and a rotating member 31 is located at a first position where the tip of a retaining piece 35 abuts against an AC action surface 45, whereby it is possible to configure an AC circuit breaker 1. The rotating member 31 slides to the left, a second collision target portion 38 is located on the movement locus of the action protrusion 28 during the interruption operation of the electromagnetic tripping device 20, and the rotating member 31 is located at a second position where the tip of the retaining piece 35 abuts against a DC action surface 47, whereby it is possible to configure a DC circuit breaker.SELECTED DRAWING: Figure 12

Description

[Technical field]

[0001] The present invention relates to a breaking mechanism of a circuit breaker. [Background technology]

[0002] Conventionally known circuit breakers are equipped with a breaker mechanism including an electromagnetic tripping device that detects an excessive current such as a short circuit current flowing through an electric circuit and breaks the electric circuit (for example, Patent Document 1). Conventionally, AC circuit breakers and DC circuit breakers have different components that make up the breaker mechanism. First, this is due to the difference in the way that the coil that makes up the electromagnetic tripping device attracts the movable electromagnetic piece when an excessive current flows. Second, this is due to the difference in the value of the current that flows through the electric circuit of the circuit breaker when used at a rated current of, for example, 10A.

[0003] The first reason is that when an excessive current flows, in an AC circuit breaker, the movable electromagnetic piece separates from the coil every half cycle, resulting in multiple operations before the circuit breaker mechanism performs the circuit breaker operation, whereas in a DC circuit breaker, the movable electromagnetic piece operates only once. Therefore, the strength of the shock load required when the movable electromagnetic piece operates once differs between AC circuit breakers and DC circuit breakers, which is the reason why the parts that make up the circuit breaker mechanism are different between AC circuit breakers and DC circuit breakers.

[0004] The second reason is that, for example, when a DC circuit breaker is used at a rated current of 10A, the current flowing through the circuit in the circuit breaker is 10A, but in an AC circuit breaker, the current flowing through the circuit in the circuit breaker is √2 times that amount. Therefore, the moving electromagnetic piece of an AC circuit breaker is attracted to the coil with a stronger attraction force than the moving electromagnetic piece of a DC circuit breaker. Therefore, considering that the strength of the shock load required when the moving electromagnetic piece operates once as described above, is different between AC circuit breakers and DC circuit breakers, the second reason is also one of the reasons why the parts that make up the circuit breaker mechanism are different between AC circuit breakers and DC circuit breakers. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2015-179628 A Summary of the Invention [Problem to be solved by the invention]

[0006] However, preparing separate parts for the breaking mechanism unit of an AC circuit breaker and the breaking mechanism unit of a DC circuit breaker results in a large number of parts, which in turn leads to higher costs for manufacturing and management, resulting in a problem of higher costs for the circuit breaker.

[0007] Therefore, the present invention has been made in consideration of the above problems, and aims to provide a breaking mechanism of a circuit breaker that enables components to be common between AC circuit breakers and DC circuit breakers. [Means for solving the problem]

[0008] In order to achieve the above object, the invention according to claim 1 of the present invention provides a circuit breaker having a power supply side terminal at the front and a load side terminal at the rear of a main body case, the circuit breaker comprising: an electromagnetic tripping device which operates a movable electromagnetic piece when an excessive current flows in an electric circuit connecting the power supply side terminal and the load side terminal; and a common mechanism which performs an interruption operation in response to the operation of the movable electromagnetic piece, the circuit breaker interrupting mechanism performing an interruption operation of a handle for turning on / off the electric circuit in response to the interruption operation of the common mechanism, the common mechanism comprising: a first interrupting member which changes its position from a normal position to an interruption position by rotating about an axis in the left-right direction; and a second interrupting member which changes its position from the normal position to the interruption position in response to the change in position of the first interrupting member, the first interrupting member being provided with a plurality of collision portions with which the movable electromagnetic piece collides when the movable electromagnetic piece is activated; The second blocking member has a pressing portion that protrudes toward the material side, while the second blocking member has an engagement hole through which the pressing portion of the first blocking member in the blocking posture can be inserted, and a notch that is cut upward over an area wider than the left-right width of the pressing portion is provided at the upper edge of the engagement hole, so that when the first blocking member in the normal posture is in a first position, the activated movable electromagnetic piece can collide with a first collision portion, and the pressing portion abuts at a position above the engagement hole of the second blocking member in the normal posture and shifted to the left or right from the notch, while when the first blocking member in the normal posture is in a second position slid left or right from the first position, the activated movable electromagnetic piece can collide with a second collision portion, and the pressing portion abuts at a position that is above the notch of the second blocking member in the normal posture. The invention described in claim 2 is characterized in that, in the invention described in claim 1, the second collision portion is a recess that is more recessed than the first collision portion, and in relation to the distance traveled by the movable electromagnetic piece until it collides with the collision portion, the distance traveled by the movable electromagnetic piece until it collides with the second collision portion is longer than the distance traveled by the movable electromagnetic piece until it collides with the first collision portion. Effect of the Invention

[0009] According to the present invention, when the first breaking member in the normal position is in the first position, the activated movable electromagnetic piece can collide with the first collision part, and the pressing part is in contact with a position above the engagement hole of the second breaking member in the normal position and shifted to the left or right from the notch, while when the first breaking member in the normal position is in the second position slid left or right from the first position, the activated movable electromagnetic piece can collide with the second collision part, and the pressing part is in contact with a position above the notch of the second breaking member in the normal position. Therefore, when the first breaking member is in the first position, it can be configured as an AC circuit breaker, and when the first breaking member is in the second position, it can be configured as a DC circuit breaker. Therefore, the parts of the breaking mechanism part can be shared between the AC circuit breaker and the DC circuit breaker, which reduces the number of parts and the associated costs related to manufacturing and management. According to the invention described in claim 2, the second collision portion is a recess that is recessed deeper than the first collision portion, and the moving distance of the movable electromagnetic piece until it collides with the collision portion is longer than the moving distance until it collides with the second collision portion. Therefore, when the first interrupting member is positioned at the second position, a larger load is applied to the movable electromagnetic piece when it collides. Therefore, by positioning the first interrupting member at the second position, the first interrupting member can be reliably changed to the interrupting position even in a DC circuit breaker in which the movable electromagnetic piece collides only once. [Brief description of the drawings]

[0010] [Figure 1] FIG. 2 is an explanatory diagram showing the appearance of an AC circuit breaker. [Diagram 2] FIG. 2 is a cross-sectional explanatory view showing the internal structure of the AC circuit breaker. [Diagram 3] FIG. 2 is an explanatory perspective view showing a breaking mechanism of the AC circuit breaker from the right rear side. [Figure 4] FIG. 2 is a perspective explanatory view showing a breaking mechanism of the AC circuit breaker from the right front side. [Diagram 5]5 is a perspective explanatory view showing a state in which the handle is removed from FIG. 4. FIG. [Figure 6] FIG. 2 is an explanatory diagram showing a breaking mechanism of the AC circuit breaker from the right side. [Figure 7] FIG. 2 is an explanatory diagram showing an electromagnetic tripping device. [Figure 8] 13 is a perspective explanatory view showing the front side of the rotating member from above. FIG. [Figure 9] 13 is a perspective explanatory view showing the front side of the rotating member from below. FIG. [Figure 10] FIG. [Figure 11] FIG. 4 is an explanatory diagram showing a linkage state between an electromagnetic tripping device and a rotating member in a normal state in an AC circuit breaker. [Figure 12] FIG. 4 is an explanatory diagram showing a linkage state between a rotating member and a hook plate in a normal state in the AC circuit breaker. [Figure 13] FIG. 2 is a cross-sectional explanatory view showing the internal structure of an AC circuit breaker that has performed a breaking operation. [Figure 14] 1 is a perspective explanatory view showing a breaking mechanism of an AC circuit breaker that has performed a breaking operation, viewed from the right rear side. FIG. [Figure 15] FIG. 2 is an explanatory diagram showing a breaking mechanism of an AC circuit breaker performing a breaking operation, viewed from the right side. [Figure 16] 4 is an explanatory diagram showing a state of cooperation between an electromagnetic tripping device and a rotating member during a breaking operation in an AC circuit breaker. FIG. [Figure 17] 4 is an explanatory diagram showing a state of cooperation between a rotating member and a hook plate during a breaking operation of the AC circuit breaker. FIG. [Figure 18] FIG. 4 is an explanatory diagram showing a linkage state between an electromagnetic tripping device and a rotating member in a DC circuit breaker under normal conditions. [Figure 19] FIG. 4 is an explanatory diagram showing a linkage state between a rotating member and a hook plate in a DC circuit breaker under normal conditions. [Figure 20] 4 is an explanatory diagram showing a state of cooperation between an electromagnetic tripping device and a rotating member during a breaking operation in a DC circuit breaker. FIG. [Figure 21]4 is an explanatory diagram showing a state of cooperation between a rotating member and a hook plate during a breaking operation in a DC circuit breaker. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A breaking mechanism of a circuit breaker according to an embodiment of the present invention will be described in detail below with reference to the drawings.

[0012] (AC Circuit Breaker Description) First, a case where it is configured as an AC circuit breaker 1 will be described. FIG. 1 is an explanatory diagram showing the appearance of an AC circuit breaker 1. FIG. 2 is a cross-sectional explanatory diagram showing the internal structure of the AC circuit breaker 1. FIG. 3 is an explanatory perspective view showing the breaker mechanism of the AC circuit breaker 1 from the right rear side. FIG. 4 is an explanatory perspective view showing the breaker mechanism of the AC circuit breaker 1 from the right front side. FIG. 5 is an explanatory perspective view showing a state in which the handle 11 is removed from FIG. 4. FIG. 6 is an explanatory view showing the breaker mechanism of the AC circuit breaker 1 from the right side. FIG. 7 is an explanatory view showing an electromagnetic tripping device 20. FIG. 8 is an explanatory perspective view showing the front side of a rotating member 31 from above. FIG. 9 is an explanatory perspective view showing the front side of a rotating member 31 from below. FIG. 10 is an explanatory view showing a hooking plate 41. FIG. 11 is an explanatory view showing a linkage state between the electromagnetic tripping device 20 and the rotating member 31 in the AC circuit breaker 1 in a normal state. FIG. 12 is an explanatory diagram showing the interlocking state between the rotating member 31 and the latch plate 41 in the AC circuit breaker 1 in the normal state. FIG. 13 is a cross-sectional explanatory diagram showing the internal structure of the AC circuit breaker 1 that has undergone a breaking operation. FIG. 14 is a perspective explanatory diagram showing the interrupting mechanism part of the AC circuit breaker 1 that has undergone a breaking operation, from the right rear side. FIG. 15 is an explanatory diagram showing the interrupting mechanism part of the AC circuit breaker 1 that has undergone a breaking operation, from the right side. FIG. 16 is an explanatory diagram showing the interlocking state between the electromagnetic tripping device 20 and the rotating member 31 in the breaking operation of the AC circuit breaker 1. FIG. 17 is an explanatory diagram showing the interlocking state between the rotating member 31 and the latch plate 41 in the breaking operation of the AC circuit breaker 1.

[0013] The AC circuit breaker 1 has a synthetic resin main body case with a cover member 3 attached to a base 2 so as to cover the upper part of the base 2, and the main body case is provided with a power source side terminal section 4 at the front and a load side terminal section 5 at the rear. The power source side terminal section 4 has two power source side terminals 4A, 4B arranged side by side on the left and right, while the load side terminal section 5 also has two load side terminals 5A, 5B arranged side by side on the left and right.

[0014] In addition, two electric circuits are arranged side by side in the main body case, a first electric circuit extending in the front-rear direction and connecting the power supply terminal 4A and the load terminal 5A, and a second electric circuit similarly connecting the power supply terminal 4B and the load terminal 5B. Each electric circuit has a first fixing bracket 6 extending forward from the load terminals 5A and 5B and serving as a component of the rear electric circuit. Each electric circuit also has a second fixing bracket 8 extending rearward from the power supply terminals 4A and 4B and constituting the front electric circuit, and a fixed contact 7 is provided at the rear end of the second fixing bracket 8. Furthermore, each electric circuit has a movable contact member 10 that electrically connects / disconnects the front electric circuit and the rear electric circuit. A movable contact 9 is provided at the front end of the movable contact member 10, and the movable contact member 10 moves the front end side up and down to bring the movable contact 9 into contact with / separate from the fixed contact 7.

[0015] Furthermore, a handle 11 that can be rotated in the forward and backward directions is provided on the top surface of the main body case, and a handle-side mechanism 12 is provided inside the main body case for operating the movable contact member 10 in response to the rotation of the handle 11 to turn the electric circuit on and off. In addition, an electromagnetic tripping device 20 is provided in the rear electric circuit of each electric circuit, which operates when an excessive current such as a short-circuit current flows in the electric circuit. A common mechanism 30 is provided in front of the electromagnetic tripping devices 20, 20 inside the main body case, which operates in response to the operation of the electromagnetic tripping device 20 and operates the movable contact member 10 via the handle-side mechanism 12 to turn off the electric circuit.

[0016] In the AC circuit breaker 1, when an abnormal current or the like occurs and an excessive current flows, the electromagnetic tripping device 20 provided on the electric circuit on the side where the excessive current flows operates, and the common mechanism 30 operates in response to the operation of the electromagnetic tripping device 20. The operation of the common mechanism 30 also operates the handle side mechanism 12, and as a result, the movable contact members 10 operate in a direction in which the movable contacts 9 move away from the fixed contacts 7, and the electric circuit is interrupted.

[0017] Here, the electromagnetic tripping device 20 and the common mechanism section 30 constituting the interrupting mechanism section, which is the main part of the present invention, will be described. First, the electromagnetic tripping device 20 will be described. The electromagnetic tripping device 20 operates in the same manner as a known electromagnetic tripping device, and includes a yoke 21, a movable electromagnetic piece 22 attached to the yoke 21, a coil section 23 that generates an electromagnetic force for attracting the movable electromagnetic piece 22 when an excessive current flows, and a tension spring 24 that biases the movable electromagnetic piece 22 toward a side that moves away from the coil section 23 (toward a normal position, described later). The movable electromagnetic piece 22 is a metal piece that integrally includes an attracted piece 25 extending in the front-rear direction and a tongue piece 26 that extends downward from the front end of the attracted piece 25. The movable electromagnetic piece 22 is attached to the yoke 21 so that the tongue piece 26 tilts in the front-rear direction around the lower end of the tongue piece 26 as an axis, and as a result, the attracted piece 25 moves up and down while moving back and forth. In addition, an insertion hole 27 is provided from the front of the attracted piece 25 of the movable electromagnetic piece 22 to the upper part of the tongue piece 26, through which a collision target piece 36 of the rotating member 31 described later can be inserted. Furthermore, the tongue piece 26 is provided with an action protrusion 28 that protrudes upward and has a tip located within the insertion hole 27.

[0018] In the electromagnetic tripping device 20 as described above, the tongue 26 of the movable electromagnetic piece 22 is usually tilted forward and the attracted piece 25 is in a normal position (as shown in FIG. 2, FIG. 6, etc.) in which it is located above and away from the coil part 23. When an excessive current flows through the electric circuit, the attracted piece 25 is attracted to the coil part 23. Therefore, the movable electromagnetic piece 22, which was in the normal position, changes its position to a breaking position (as shown in FIG. 13, FIG. 15, etc.) in which the tongue 26 is tilted backward against the biasing force of the tension spring 24 and the attracted piece 25 approaches or comes into contact with the upper end of the coil part 23. With this change in position of the movable electromagnetic piece 22, the action protrusion 28 moves backward and collides with a first collision part 37 described later, thereby changing the position of the rotating member 31. As described in the background art, in the AC circuit breaker 1, the attracted piece 25 is intermittently attracted multiple times when an excessive current flows through the electric circuit. Therefore, the movable electromagnetic piece 22 repeatedly changes its position between the normal position and the interrupted position, and as a result, the action protrusion 28 repeatedly collides with the first collision target portion 37.

[0019] Next, the common mechanism 30 will be described. The common mechanism 30 includes a rotating member 31 that changes its position by rotating about an axis in the left-right direction, and a hook plate 41 that changes its position by tilting about an axis in the left-right direction as the rotating member 31 changes its position. The main body of the rotating member 31 is formed in a plate shape that is long in the left-right direction, and the rotating member 31 is disposed across two electric circuits disposed in the main body case. In addition, the front surface of the rotating member 31 is provided with rotating shaft support parts 33, 33 and a shaft hole 34 for supporting a rotating shaft 32 (shown in FIG. 3, etc.) extending in the left-right direction. Furthermore, a holding piece 35 formed in a plate shape with a thickness direction in the left-right direction is provided on the front surface of the rotating member 31 so as to protrude forward. Furthermore, the lower part of the rotating member 31 is provided with collision receiving pieces 36, 36 protruding downward, and the right collision receiving piece 36 can be inserted from above into the insertion hole 27 of the electromagnetic tripping device 20 arranged on the first electric circuit connecting the power supply side terminal 4A and the load side terminal 5A, and the left collision receiving piece 36 can be inserted from above into the insertion hole 27 of the electromagnetic tripping device 20 arranged on the second electric circuit connecting the power supply side terminal 4B and the load side terminal 5B. In addition, a first collision receiving part 37 and a second collision receiving part 38 that collide with the action protrusion 28 are arranged side by side on the left and right on the front surface of each collision receiving piece 36. The second collision receiving part 38 is provided adjacent to the right side of the first collision receiving part 37 and is a recess recessed further rearward than the first collision receiving part 37.

[0020] The above-mentioned rotating member 31 is assembled in a state in which the rotating shaft 32 is supported by the rotating shaft support portion 33 and the shaft hole 34, and each collision receiving piece 36 is inserted from above into the corresponding insertion hole 27 of the electromagnetic tripping device 20. In the AC circuit breaker 1, the first collision receiving part 37 is positioned behind the action protrusion 28 in each insertion hole 27, that is, on the movement path of the action protrusion 28 during the interruption operation of the electromagnetic tripping device 20, as shown in FIG. 11. The rotating member 31 is urged toward the normal position by a spring 39 (shown in FIG. 2, FIG. 6, etc.) in a normal position in which the holding piece 35 protrudes substantially horizontally forward with a substantially vertical standing posture. When an excessive current flows in the electric circuit and the electromagnetic tripping device 20 performs an interruption operation, the action protrusion 28 repeatedly collides with the first collision receiving part 37 as shown in FIG. 16. Therefore, the rotating member 31 rotates about the rotating shaft 32 against the biasing force of the spring 39, and changes its posture to a blocking posture in which the collision receiving pieces 36, 36 extend diagonally downward toward the rear and the holding piece 35 is inclined diagonally downward toward the front. After the posture is changed to the blocking posture, the holding piece 35 is hooked into a hooking hole 44 of a hooking plate 41 described later, and the rotating member 31 is held in the blocking posture.

[0021] On the other hand, the hook plate 41 is formed in a plate shape with the thickness direction being in the front-rear direction, and the lower end is provided with tilting shaft support parts 43, 43 for supporting the tilting shaft 42 extending in the left-right direction. A hook hole 44 is opened in the upper part of the hook plate 41. The upper edge of the hook hole 44 is formed in a straight line extending substantially horizontally. The upper part of the right end of the hook hole 44 on the rear surface of the hook plate 41 is an AC working surface 45 with which the tip of the holding piece 35 abuts when the hook plate 41 is configured as an AC circuit breaker 1. A notch 46 is cut upward at a position on the upper side of the hook hole 44, adjacent to the AC working surface 45 on the left. The left-right width of the notch 46 is sufficiently wider than the left-right width of the holding piece 35. The upper part of the notch 46 on the rear surface of the hooking plate 41 is the DC action surface 47 on which the tip of the holding piece 35 abuts when the hooking plate 41 is configured as a DC circuit breaker as described later. Therefore, the vertical width of the AC action surface 45 is wider than the vertical width of the DC action surface 47. That is, when the rotating member 31 is changed to the interrupting position as described above, the holding piece 35 enters the hooking hole 44 more quickly and more easily when the tip of the holding piece 35 abuts the DC action surface 47, and the holding of the hooking plate 41 by the holding piece 35 is released. In addition, the part on the left side of the notch 46 on the upper side of the hooking hole 44 functions as a hooked part 48 on which the hooking piece 13, which is a component of the handle side mechanism 12, is hooked under normal conditions, as shown in FIG. 2 and FIG. 5.

[0022] The above-mentioned hook plate 41 is assembled in a state where the tilt shaft 42 is supported by the tilt shaft support part 43 at the front side of the rotating member 31, particularly at the front side of the holding piece 35. The hook plate 41 is in a normal position in which it stands up substantially vertically, and is biased toward the interrupting position, which will be described later, by a torsion spring 49 (shown in FIG. 6, etc.). In the AC circuit breaker 1, as shown in FIG. 12, the tip of the holding piece 35 abuts against the AC working surface 45 of the hook plate 41 in the normal position, and the hook plate 41 is held in the normal position with the tip of the holding piece 35 pressing the AC working surface 45 by the biasing force of the spring 39 which biases the rotating member 31 toward the normal position and the torsion spring 49 which biases the hook plate 41 toward the interrupting position. When an excessive current flows through the electric circuit and the rotating member 31 changes its position to the cut-off position, the tip of the holding piece 35 moves downward on the AC action surface 45, and finally moves away from the AC action surface 45 and into the hook hole 44. Therefore, the hook plate 41 tilts rearward around the tilt shaft 42 due to the urging force of the torsion spring 49, and changes its position to the cut-off position, which is a backward tilted position tilted toward the rotating member 31. In addition, as the hook plate 41 changes its position, the hooking piece 13 and the hook plate 41 are released, so the handle side mechanism 12 performs a cut-off operation and the electric circuit is turned off. In addition, as the hook plate 41 changes its position to the cut-off position, the holding piece 35 penetrates the hook hole 44, and the upper surface of the holding piece 35 and the upper edge of the hook hole 44 are hooked as shown in FIG. 17.

[0023] Here, a series of operations of the electromagnetic tripping device 20 and the common mechanism section 30 when an excessive current flows through the electric circuit in the AC circuit breaker 1 will be described. When an excessive current flows through the electric circuit, the electromagnetic tripping device 20 performs an interruption operation. That is, the attracted piece 25 is intermittently attracted to the coil portion 23, and the movable electromagnetic piece 22 repeatedly changes its position between the normal position and the interruption position. Therefore, the action projection 28 repeatedly collides with the first collision portion 37, and as a result, the rotating member 31 changes its position from the normal position to the interruption position. With this change in position of the rotating member 31, the tip of the holding piece 35 moves downward on the AC action surface 45, and finally moves away from the AC action surface 45 into the hook hole 44, and as a result, the hooking plate 41 changes its position from the normal position to the interruption position. With this change in position of the hooking plate 41, the hooking piece 13 and the hooking plate 41 are released from the hooking, and the handle side mechanism portion 12 performs an interruption operation to turn off the electric circuit.

[0024] (DC Circuit Breaker Description) Next, a case where the circuit breaker is configured as a DC circuit breaker will be described. Fig. 18 is an explanatory diagram showing the state of linkage between the electromagnetic tripping device 20 and the rotating member 31 in a DC circuit breaker in normal operation. Fig. 19 is an explanatory diagram showing the state of linkage between the rotating member 31 and the hook plate 41 in a DC circuit breaker in normal operation. Fig. 20 is an explanatory diagram showing the state of linkage between the electromagnetic tripping device 20 and the rotating member 31 during an interruption operation in a DC circuit breaker. Fig. 21 is an explanatory diagram showing the state of linkage between the rotating member 31 and the hook plate 41 during an interruption operation in a DC circuit breaker.

[0025] The DC circuit breaker is composed of substantially the same components as the AC circuit breaker 1, and also includes an electromagnetic tripping device 20 and a common mechanism 30 as a breaking mechanism section. However, the DC circuit breaker and the AC circuit breaker 1 differ from each other in the positional relationship between the electromagnetic tripping device 20 and the rotating member 31, and the positional relationship between the rotating member 31 and the hook plate 41.

[0026] First, the positional relationship between the electromagnetic tripping device 20 and the rotating member 31 will be described. In the DC circuit breaker, the rotating member 31 is assembled with each struck piece 36 inserted from above into the corresponding insertion hole 27 of the electromagnetic tripping device 20, but the pivot position in the direction of the rotation axis 32 of the rotating member 31 slides to the left, and the second struck part 38 is located behind the action protrusion 28 in each insertion hole 27, that is, on the movement path of the action protrusion 28 during the interruption operation of the electromagnetic tripping device 20, as shown in FIG. 18. Therefore, when an excessive current flows in the electric circuit and the electromagnetic tripping device 20 performs the interruption operation, the action protrusion 28 strikes the second struck part 38 as shown in FIG. 20. Unlike the AC circuit breaker 1, this strike of the action protrusion 28 occurs only once. However, since the second collision receiving portion 38 is a recess recessed further forward than the first collision receiving portion 37, the movement distance of the action projection 28 until it collides with the rotating member 31 is longer than that of the AC circuit breaker 1, and a strong load is applied to the rotating member 31 at the time of collision. Then, when the action projection 28 collides with the second collision receiving portion 38, the rotating member 31 changes its position from the normal position to the interrupting position. After the position is changed to the interrupting position, the holding piece 35 is engaged with the notch 46 of the hook plate 41, and the rotating member 31 is held in the interrupting position. The position of the rotating member 31 in the left-right direction relative to the rotation shaft 32 is determined before the rotating member 31 is assembled into the main body case, and the rotating member 31 does not slide after assembly.

[0027] Next, the positional relationship between the rotating member 31 and the hook plate 41 will be described. In the DC circuit breaker, as described above, the pivot position of the rotating member 31 slides to the left, so that the tip of the holding piece 35 abuts against the DC action surface 47 of the hook plate 41 in the normal position as shown in Fig. 19, and holds the hook plate 41 in the normal position. When an excessive current flows through the electric circuit and the rotating member 31 changes its position to the interruption position, the tip of the holding piece 35 moves downward on the DC action surface 47, and finally leaves the DC action surface 47 and moves into the notch 46 and into the hook hole 44. In this operation, the holding piece 35 enters the hook hole 44 more easily than in the AC circuit breaker 1, because the vertical width of the DC action surface 47 is narrower than the vertical width of the AC action surface 45. Therefore, similarly to the AC circuit breaker 1, the hook plate 41 tilts rearward about the tilting shaft 42 due to the biasing force of the torsion spring 49, changing its posture to the interrupting posture, which is a backward tilting posture inclined toward the rotating member 31. As the posture of the hook plate 41 changes, the hook between the hook piece 13 and the hook plate 41 is released, and the handle side mechanism unit 12 performs an interrupting operation to turn off the electric circuit. As the posture of the hook plate 41 changes to the interrupting posture, the retaining piece 35 penetrates the hook hole 44, and the upper surface of the retaining piece 35 is engaged with the notch 46 as shown in FIG.

[0028] Here, a series of operations of the electromagnetic tripping device 20 and the common mechanism section 30 when an excessive current flows through the electric circuit in the DC circuit breaker will be described. When an excessive current flows through the electric circuit, the electromagnetic tripping device 20 performs an interruption operation. That is, the attracted piece 25 is attracted to the coil portion 23, and the movable electromagnetic piece 22 changes its position from the normal position to the interruption position. Therefore, the action protrusion 28 collides with the second collision portion 38, albeit only once. However, as described above, the second collision portion 38 is recessed rearward from the first collision portion 37, and the tip of the holding piece 35 abuts against the DC action surface 47, which is narrower in vertical width than the AC action surface 45, and so on, so that the rotating member 31 reliably changes its position from the normal position to the interruption position. Then, as the position of the rotating member 31 changes, the hooking plate 41 changes its position from the normal position to the interruption position, so that the hooking piece 13 and the hooking plate 41 are released from the engagement, and the handle side mechanism portion 12 performs an interruption operation to turn off the electric circuit.

[0029] According to the interrupting mechanism of the circuit breaker having the electromagnetic tripping device 20 and the common mechanism 30 as described above, the common mechanism 30 is provided with the rotating member 31 which changes its position from the normal position to the interrupting position by rotating about an axis in the left-right direction, and the hooking plate 41 which changes its position from the normal position to the interrupting position in response to the change in position of the rotating member 31. The rotating member 31 is provided with the first collision receiving portion 37 and the second collision receiving portion 38 with which the action projection 28 collides when the movable electromagnetic piece 22 is actuated, and is also provided with the holding piece 35 which protrudes toward the hooking plate 41. Furthermore, the hanging plate 41 is provided with a hanging hole 44 through which the retaining piece 35 of the pivotable member 31 in the blocking position can be inserted, and a notch 46 is provided at the upper edge of the hanging hole 44, cut upward over an area wider than the left-right width of the retaining piece 35. On the rear surface of the hanging plate 41, the area to the right of the notch 46 above the hanging hole 44 is formed as an AC action surface 45, while the area above the notch 46 is formed as a DC action surface 47. The AC circuit breaker 1 can be configured by positioning the rotating member 31 at a first position where the first collision target portion 37 is located on the movement path of the action projection 28 during the interruption operation of the electromagnetic tripping device 20 and the tip of the holding piece 35 abuts against the AC action surface 45, while the DC circuit breaker can be configured by sliding the rotating member 31 to the left and positioning it at a second position where the second collision target portion 38 is located on the movement path of the action projection 28 during the interruption operation of the electromagnetic tripping device 20 and the tip of the holding piece 35 abuts against the DC action surface 47. Therefore, the AC circuit breaker 1 and the DC circuit breaker can share the same parts in the interruption mechanism, thereby reducing the number of parts and the associated costs related to manufacturing and management.

[0030] In addition, the second struck portion 38 is a recess recessed further rearward than the first struck portion 37, and in relation to the movement distance of the action protrusion 28 when the movable electromagnetic piece 22 is actuated, the movement distance until it strikes the second struck portion 38 is longer than the movement distance until it strikes the first struck portion 37. Therefore, when the rotating member 31 is positioned at the second position, a larger load is applied when the action protrusion 28 strikes, so that even in a DC circuit breaker in which the action protrusion 28 strikes only once, the rotating member 31 can be reliably changed to the breaking position.

[0031] The circuit breaker mechanism of the circuit breaker according to the present invention is not limited to the above-described embodiment, and the configurations of the electromagnetic tripping device, the control mechanism related to the common mechanism, etc. may be appropriately modified as necessary without departing from the spirit of the present invention.

[0032] For example, in the above embodiment, one rotating member and hanging plate are used to correspond to the left and right electrical circuits, but the rotating member may be composed of multiple parts, or a rotating member and hanging plate may be provided for each electrical circuit. In addition, although in the above embodiment the DC circuit breaker is configured by sliding the rotating member to the left, the DC circuit breaker may also be configured by sliding the rotating member to the right, and the positions of the first and second collided parts and the positions of the cutouts, etc. can be modified as appropriate. Furthermore, in the above embodiment, the second collided portion is made to be a recess that is recessed deeper than the first collided portion, but since the notch is provided in the first place to shorten the distance that the retaining piece travels until it is released from the engagement with the hanging plate, it is also possible to not make the second collided portion recessed deeper than the first collided portion. [Explanation of symbols]

[0033] 1··AC circuit breaker (circuit breaker), 11··handle, 12··handle side mechanism part (breaking mechanism part), 13··hooking piece (breaking mechanism part), 20··electromagnetic tripping device, 22··movable electromagnetic piece, 28··acting protrusion, 30··common mechanism part, 31··rotating member (first breaking member), 32··rotating shaft, 35··holding piece (contact part), 37··first struck part, 38··second struck part, 41··hooking plate (second breaking member), 44··hooking hole, 45··AC acting surface, 46··notch, 47··DC acting surface, 48··hooking part.

Claims

1. A circuit breaker having a power supply side terminal at the front of a main body case and a load side terminal at the rear of the main body case, the circuit breaker comprising: an electromagnetic tripping device which operates a movable electromagnetic contact when an excessive current flows in an electric path connecting the power supply side terminal and the load side terminal; and a common mechanism which performs an interruption operation in response to the operation of the movable electromagnetic contact, A circuit breaker mechanism for a circuit breaker that performs a break operation on a handle for turning on / off the electric circuit in response to a break operation of the common mechanism, the common mechanism includes a first blocking member that changes its position from a normal position to a blocking position by a rotational motion about an axis in the left-right direction, and a second blocking member that changes its position from the normal position to the blocking position in response to the change in position of the first blocking member, The first blocking member is provided with a plurality of collision portions with which the movable electromagnetic piece collides when the movable electromagnetic piece is actuated, and is also provided with a contact portion that protrudes toward the second blocking member. the second blocking member is provided with a hook hole into which the abutment portion of the first blocking member in the blocking posture can be inserted, and a notch is provided at an upper edge of the hook hole, the notch being cut upward over a range wider than a left-right width of the abutment portion; When the first blocking member in the normal position is in the first position, the actuated movable electromagnetic piece can collide with the first collision portion, and the abutment portion abuts on a position above the engagement hole of the second blocking member in the normal position and shifted to the left or right from the notch; A circuit breaker breaking mechanism portion characterized in that, when the first breaking member in a normal position is in a second position slid left and right from the first position, the activated movable electromagnetic piece is capable of colliding with a second collision portion, and the abutment portion abuts at a position that is above the notch of the second breaking member in the normal position.

2. The second collision portion is a recess that is recessed deeper than the first collision portion, 2. The circuit breaker according to claim 1, wherein the moving distance of the movable electromagnetic piece until it collides with the collision portion is longer than the moving distance until it collides with the second collision portion than the moving distance until it collides with the first collision portion.

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