JP6949254B2 - Circuit breaker - Google Patents

Description

The present invention relates to a circuit breaker provided with a crossbar to prevent malfunction of the mechanical unit.

In the conventional inexpensive circuit breaker, the mechanism part linearly operates the crossbar engaged with the movable contact conductor to separate the fixed contact and the movable contact in the arc extinguishing chamber from each other. It was configured to perform an opening / closing operation (see, for example, Patent Document 1).

Jikkai Sho 61-104956

However, in such a conventional method, the metal melt generated between the fixed contact and the movable contact in the arc extinguishing chamber when the arc is extinguished and adhering to the crossbar scatters to the mechanical portion as the crossbar operates. Invaded, and sometimes hindered the operation of the mechanical part.

The present invention has been made to solve the above-mentioned problems, and the metal melt generated in the arc extinguishing chamber at the time of shutting off and adhering to the crossbar scatters to the mechanism unit during the operation of the crossbar during the duty of shutting off. It is an object of the present invention to provide a circuit breaker capable of preventing malfunction of the mechanical unit and realizing stable operation by reducing the number of operations.

In the circuit breaker according to the present invention, when the fixed contact conductor to which the fixed contact is fixed, the movable contact conductor to which the movable contact that can be separated from the fixed contact is fixed, and the fixed contact and the movable contact are separated from each other. It is provided with an arc extinguishing chamber for extinguishing the arc generated in the arc, a crossbar having a groove on the surface facing the arc extinguishing chamber, and a mechanism for driving the crossbar so that the fixed contact and the movable contact are separated from each other. It is a feature.

In the circuit breaker according to the present invention, the metal melt adhering to the crossbar at the time of interrupting is adhered to and held in the groove of the crossbar even during the operation of the crossbar during the duty of interrupting, and the adhesion position in the groove. Since the distance from the mechanism to the mechanism is long, the amount of scattering to the mechanism side is reduced, and malfunction of the mechanism can be prevented and stable operation can be realized.

It is sectional drawing of the circuit breaker in the ON state of Embodiment 1. FIG. It is a front view of the crossbar of Embodiment 1. FIG. 5 is a cross-sectional view taken along the line AA viewed from the direction of the arrow A of the crossbar of the first embodiment. It is sectional drawing of the circuit breaker in the OFF state of Embodiment 1. FIG. It is sectional drawing of the circuit breaker in the trip state of Embodiment 1. FIG. It is a front view of the crossbar of Embodiment 2. FIG. 5 is a cross-sectional view taken along the line CC of the crossbar according to the second embodiment as viewed from the direction of the arrow C.

Embodiment 1.
The circuit breaker according to this embodiment will be described. FIG. 1 shows a cross-sectional view of the circuit breaker 100 in the ON state. FIG. 2 shows a front view of the crossbar 81, and FIG. 3 shows a cross-sectional view of the crossbar 81. FIG. 4 shows a cross-sectional view of the circuit breaker 100 in the OFF state, and FIG. 5 shows a cross-sectional view of the circuit breaker 100 in the trip state.
First, the structure of the circuit breaker 100 will be described with reference to FIGS. 1 to 3. At the same time, the operation of the circuit breaker 100 will be described with reference to FIGS. 1, 4 and 5.

As shown in FIG. 1, the circuit breaker 100 includes a housing 3 including a cover 1 and a base 2 formed of an insulating material such as plastic. The housing 3 is provided with a load-side terminal 18 to which an external electric wire on the load side is connected at a position viewed from the arrow side of L in FIG. 1, and an external electric wire on the supply side is provided at a position viewed from the arrow side of K. A fixed contact conductor 5 to be connected is provided.
The fixed contact conductor 5 includes a fixed contact 4 that is fixed. Further, the movable contact conductor 7 includes a fixed movable contact 6. The fixed contact conductor 5 and the movable contact conductor 7 are provided so that the fixed contact 4 and the movable contact 6 are located in the arc extinguishing chamber 17. When the circuit breaker 100 is in the ON state, the circuit breaker 100 becomes conductive when the fixed contact 4 and the movable contact 6 come into contact with each other in the arc extinguishing chamber 17.
In the arc extinguishing chamber 17, when the arc is extinguished, the grid, the movable contact 6 and the fixed contact 4 in the arc extinguishing chamber 17 are melted to generate a metal melt and scatter. The metal melt generated when the arc is extinguished is a powder of a metal such as silver alloy, copper, or iron having a size of about several tens of μ.
Further, the trip bar 9, the link pin 10, the handle 11, the frame 12, the roller 13, the lever 14, and the release spring 16 which is a compression spring constitute a mechanical portion for driving the crossbar 81. Further, the crossbar 81 is engaged with the movable contact conductor 7.
When an overcurrent or a short-circuit current flows through the circuit breaker 100, in order to cut off the overcurrent or the short-circuit current, the mechanism unit uses the urging force of the release spring 16 to move the crossbar 81 in the direction of the arrow M in FIG. Drive to move linearly. When the crossbar 81 moves, the movable contact 6 is separated from the fixed contact 4, and the circuit breaker 100 is turned off in FIG.

Next, the trip bar 9, the link pin 10, the handle 11, the frame 12, the roller 13, the lever 14, and the release spring 16 constituting the mechanical portion will be described.
The trip bar 9 has a T-shape when viewed from the arrow side of K in FIG. 1, and includes a trip bar pressure receiving portion 9a, a trip bar engaging portion 9b, and a trip bar shaft 9c.
The link pin 10 has a U shape when viewed from the arrow side of K in FIG. 1, and includes a link pin pivoting portion 10a and a link pin connecting portion 10b.
The handle 11 includes a handle shaft 11a, a handle hole 11b, and a lever pressing portion 11c.
The frame 12 is fixed to the housing 3 and supports the link pin 10, the handle 11, and the lever 14. Further, the frame 12 includes a handle stopper 12a.
The lever 14 includes a lever guide surface 14a, a lever engaging portion 14b, and a lever shaft 14c.

One of the levers 14 is the lever shaft 14c, and the other is the lever engaging portion 14b.
The lever shaft 14c is formed by making a hole in the plate thickness direction of the lever 14 and bending it so as to have a square parenthesis shape when viewed from the arrow side of K in FIG. By pivotally attaching the hole provided in the frame 12 to the lever shaft 14c, the lever 14 can rotate about the lever shaft 14c.
The lever engaging portion 14b is urged counterclockwise on FIG. 1 by a twisting spring (not shown) to engage the trip bar engaging portion 9b. The opposite surface of the lever 14 with respect to the lever engaging portion 14b is a lever guide surface 14a which is a guide when the roller 13 operates.

In the link pin 10, the side that is open in a U shape is the link pin pivoting portion 10a, and the side that is closed in a U shape is the link pin coupling portion 10b.
Further, the handle 11 can rotate about the handle shaft 11a by pivotally mounting the hole provided in the frame 12 and the handle shaft 11a. When the handle 11 is operated in the direction of the arrow L, the handle stopper 12a controls the handle 11 so that it does not turn too much in the direction of the arrow L.
The cylindrical roller 13 is rotatably pivotally attached to the link pin pivoting portion 10a. The link pin coupling portion 10b is rotatably coupled to the handle hole 11b. The roller 13 moves in the direction of the arrow M and the direction of the arrow N along the lever guide surface 14a via the link pin 10 in conjunction with the operation of the handle 11.
Further, the roller 13 is in contact with the crossbar 81. In the crossbar 81, when the roller 13 moves in the direction of the arrow M in conjunction with the movement of the roller 13, the crossbar 81 also moves in the direction of the arrow M. Similarly, when the roller 13 moves in the direction of the N arrow, the crossbar 81 also moves in the direction of the N arrow. Further, the crossbar 81 is controlled by the frame 12 so as not to move too much in the direction of the arrow M.

Next, the relay unit 15 which is a contact peeling mechanism for interrupting the current at the time of trip will be described.
The relay unit 15 includes a coil 15a, an iron core 15b, and an armature 15c.
The operation of the relay unit 15 when an overcurrent or a short-circuit current flows through the coil 15a will be described.
The iron core 15b is attracted to the inside of the coil 15a due to an overcurrent or a short-circuit current flowing through the coil 15a. By attracting the iron core 15b to the inside of the coil 15a, the magnetic force generated in the coil 15a increases.
When an overcurrent or a short-circuit current flows through the coil 15a, the armature 15c is attracted in the direction of the arrow N by the magnetic force of the coil 15a increased to the iron core 15b.

Subsequently, the structure of the crossbar 81 for preventing the malfunction of the mechanical portion of the circuit breaker 100 will be described.
FIG. 2 is a front view of the crossbar 81. Further, FIG. 3 is a cross-sectional view taken along the line AA as seen from the direction of the arrow A in FIG.
The crossbar 81 is formed of an insulating material such as plastic, and a crossbar groove 8a is provided on the surface facing the arc extinguishing chamber 17.
The metal melt generated and scattered at the time of extinguishing the arc adheres to the surface of the crossbar 81 facing the arc extinguishing chamber 17. Since the surface of the crossbar 81 facing the arc extinguishing chamber 17 has the crossbar groove 8a, the metal melt also adheres to the inner surface of the crossbar groove 8a.

In the present embodiment, the crossbar groove 8a is provided on the central surface portion of the surface of the crossbar 81 facing the arc extinguishing chamber 17 as seen in FIG. This is because the crossbar 81 also functions as a shielding wall for preventing the metal melt scattered from the arc extinguishing chamber 17 from scattering to the mechanical portion. However, when the structure is such that the crossbar 81 of the circuit breaker 100 does not function as a shielding wall, in addition to the crossbar groove 8a, the surface of the crossbar 81 facing the arc extinguishing chamber 17 A groove similar to the crossbar groove 8a may be provided at the portion 8a2 and the surface portion 8a3.

In the present embodiment, the shape of the crossbar groove 8a is as shown in FIGS. 3 and 4. However, the crossbar groove 8a may be tapered or may have a tapered shape. Alternatively, the shape may have a rounded back.

Next, the operation of the circuit breaker 100 of the present embodiment will be described in order for each of the cases of the OFF state to the ON state, the ON state to the OFF state, and the ON state to the trip state.
First, the operation of the circuit breaker 100 from the OFF state of FIG. 4 to the ON state of FIG. 1 will be described with reference to FIGS. 1 and 4.

When the handle 11 is operated in the direction of the arrow L in the OFF state of FIG. 4, the handle 11 rotates about the handle shaft 11a. Then, the link pin coupling portion 10b moves in the direction of the arrow B. As the link pin 10 moves, the roller 13 moves along the lever guide surface 14a in the direction of the arrow N while countering the urging force of the release spring 16.

As the roller 13 moves, the handle shaft 11a, the link pin connecting portion 10b, and the link pin pivoting portion 10a exceed the positions where they are aligned horizontally on the paper surface, and the handle 11 rotates to the handle stopper 12a. Is turned on.
Since the handle 11 receives a counterclockwise urging force by the force in the direction of the arrow M of the crossbar 81 via the link pin 10, the handle 11 can hold the position in the ON state.

Next, the operation of the circuit breaker 100 from the ON state of FIG. 1 to the OFF state of FIG. 4 will be described with reference to FIGS. 1 and 4 in the same manner. The operation is completely opposite to the operation from the OFF state to the ON state.

When the handle 11 is operated in the direction of the arrow K in the ON state of FIG. 1, the handle 11 rotates, and the handle shaft 11a, the link pin coupling portion 10b, and the link pin pivot portion 10a are horizontal on the paper surface of FIG. Line up in a straight line in the direction.
When the link pin coupling portions 10b are moved in the direction of the arrow L from the state where they are aligned in a straight line, the crossbar 81 receiving the urging force of the release spring 16 moves the handle 11 through the link pin 10 with the arrow K. Move in the direction of.

When the roller 13 moves in the direction of the arrow M with the movement of the link pin 10, the crossbar 81 also moves in the direction of the arrow M. Further, as the crossbar 81 moves, the movable contact conductor 7 also moves in the direction of the arrow M, and the fixed contact 4 and the movable contact 6 are separated to be in the OFF state of FIG.

Next, the operation in which an overcurrent flows through the circuit breaker 100 in the ON state of FIG. 1 and the trip state of FIG. 5 is obtained will be described with reference to FIGS. 1 and 5.

When an overcurrent flows through the coil 15a in the ON state of FIG. 1, the iron core 15b is attracted to the inside of the coil 15a, that is, in the direction of the arrow M, and the magnetic force generated by the coil 15a increases. The increased magnetic force of the coil 15a attracts the armature 15c to the iron core 15b. When one of the armatures 15c touches the iron core 15b, the other kicks the trip bar 9 in the direction of the L arrow. By being kicked up, the trip bar 9 rotates clockwise around the trip bar shaft 9c, and the trip bar engaging portion 9b and the lever engaging portion 14b are disengaged.

As a result of the trip bar engaging portion 9b and the lever engaging portion 14b being disengaged, the lever 14 is rotated in the direction of the arrow K by a twisting spring (not shown).
The roller 13 rolls on the surface in contact with the crossbar 81 in the direction of the arrow K, and is disengaged from the crossbar 81.
When the crossbar 81 and the roller 13 are disengaged, the crossbar 81 and the movable contact conductor 7 move in the direction of the arrow M due to the urging force of the release spring 16 in the direction of the arrow M. As a result, the movable contact 6 is separated from the fixed contact 4.
When the movable contact 6 and the fixed contact 4 are released, the handle 11 is in a state of not receiving the force from the link pin 10. Therefore, the handle 11 is brought into a position between the ON state and the OFF state, that is, the trip state shown in FIG. 5, by a tension spring (not shown) attached to the handle 11.

Next, the operation of changing from the trip state of FIG. 5 to the OFF state of FIG. 4 will be described with reference to FIGS. 5 and 4.
When the handle 11 is operated in the direction of the arrow K in the trip state of FIG. 5, the lever pressing portion 11c rotates the lever 14 to the trip bar engaging portion 9b counterclockwise on the paper surface.
The trip bar 9 is urged counterclockwise by a twisting spring (not shown). When the lever 14 passes the trip bar engaging portion 9b, the trip bar 9 automatically rotates to the engaging position. By rotating, the trip bar engaging portion 9b and the lever engaging portion 14b are engaged.

The handle 11 is urged clockwise on the paper by a tension spring (not shown) attached. The roller 13 moves in the direction of the arrow M while in contact with the lever guide surface 14a. The roller 13 comes into contact with the surface of the crossbar 81 seen from the arrow side of M, and is in the OFF state of FIG.

Next, as an example of the number of times that the crossbar 81 operates in the direction of the arrow M and the direction of the arrow N in FIG. 1, consider the number of times in the operation duty.
Here, the operation duty is an operation of energizing the circuit breaker to cut off a short-circuit current equal to the rated breaking capacity, or a series of operations of energizing and cutting off at regular time intervals. The operational responsibilities in the circuit breaker breaking test are defined by Japanese Industrial Standards and international standards.
The O duty of the operation duty is an operation of energizing a short-circuit current when the circuit breaker is ON to shut off the circuit breaker. The CO duty of the operation duty is an operation of operating the circuit breaker from the OFF state to the ON state and energizing the circuit breaker with a short-circuit current to cut off the circuit breaker.

In the present embodiment, the O duty, then the CO duty, and finally the operation duty to perform the CO duty will be described as an example. That is, in the operation described below in the present embodiment, as an O duty, a short-circuit current is applied to the circuit breaker 100 in the ON state of FIG. 1, and the circuit breaker 100 is cut off to be in the trip state of FIG. Next, as a CO duty, after turning off the circuit breaker 100 in FIG. 4, the circuit breaker 100 is turned on in FIG. 1 to energize the short-circuit current, and the circuit breaker 100 is cut off to enter the trip state in FIG. Further, as a CO duty, the circuit breaker 100 is turned off again in FIG. 4 and then turned on to energize the short-circuit current, and the circuit breaker 100 is cut off to be in the trip state shown in FIG.
In the present embodiment, as an example, the operation duty of first the O duty, then the CO duty, and finally the CO duty is given, but there is also a case of an operation such that the operation duty is further turned off and then turned on again.

The operation of the crossbar 81 in the case of the operation duty in the present embodiment will be described.
First, at the time of O duty, the circuit breaker 100 is changed from the ON state of FIG. 1 to the trip state of FIG. Therefore, the crossbar 81 moves once in the direction of the arrow M in FIG.
Next, at the time of CO duty, the circuit breaker 100 is operated from the OFF state of FIG. 4 to the ON state of FIG. Then, in the ON state of FIG. 1, the short-circuit current is energized and cut off to bring the trip state of FIG. 5 into the trip state. Therefore, the crossbar 81 moves once in the direction of the arrow N in FIG. 1 during the operation from FIG. 4 to FIG. Further, during the operation from FIG. 1 to FIG. 5, it moves once in the direction of the arrow M.
When the CO is responsible again, the circuit breaker 100 is operated from the OFF state of FIG. 4 to the ON state of FIG. 1 in the same manner as described above. Then, in the ON state of FIG. 1, the short-circuit current is energized and cut off to bring the trip state of FIG. 5 into the trip state. Therefore, the crossbar 81 moves once in the direction of the arrow N in FIG. 1 during the operation from FIG. 4 to FIG. Then, during the operation from FIG. 1 to FIG. 5, it moves once in the direction of the arrow M.

Even if the crossbar 81 operates a plurality of times in the direction of the arrow M and the direction of the arrow N in FIG. Therefore, the amount of scattering to the mechanism side is reduced.
Therefore, stable operation of the mechanical unit is possible during the operation duty at the time of interruption.
In particular, when the crossbar 81 moves in the direction of the M arrow, it moves faster than when it moves in the direction of the N arrow, so that when it moves in the direction of the M arrow, the scattered metal melt The amount of is large. Therefore, when the crossbar 81 moves in the direction of the arrow M, it can be said that it is more effective to provide the crossbar groove 8a.

As shown in FIGS. 1, 4 and 5, when the circuit breaker 100 is attached to the switchboard, for example, so that the crossbar 81 is below the arc extinguishing chamber 17 on the paper surface, it adheres to the crossbar 81. Since the resulting metal melt falls toward the mechanism portion, the amount of scattering increases. Therefore, it can be said that the crossbar groove 8a on which the metal melt can be adhered and held is more effective in preventing malfunction of the mechanical portion and realizing stable operation.
However, for example, even when the circuit breaker 100 is attached so that the crossbar 81 is on the right side or the left side of the arc extinguishing chamber 17, by providing the crossbar groove 8a, the mechanism unit can be seen from the adhesion position of the metal melt. Since the distance to the mechanism is long, the amount of metal melt scattered to the mechanism is reduced, which prevents malfunction of the mechanism and leads to stable operation.

Embodiment 2.
In the first embodiment, the inside of the groove of the crossbar groove 8a is provided as a space.

The difference between the second embodiment and the first embodiment is that the crossbar grooves are in a grid pattern. In the following, only the differences from the first embodiment will be described, and the description of the same or corresponding parts will be omitted. Regarding the reference numerals, the same or corresponding parts as those in the first embodiment will be the same reference numerals, and the description thereof will be omitted.

FIG. 6 is a front view of the crossbar 82 according to the present embodiment, and FIG. 7 is a cross-sectional view taken along the line CC of FIG. 6 as viewed from the direction of the arrow C of FIG.
As shown in FIGS. 6 and 7, the crossbar grooves 8b of the present embodiment are provided in a grid pattern. By providing the crossbar grooves 8b in a grid pattern as shown in FIGS. 6 and 7, the distance from the adhesion position of the metal melt to the mechanical portion is further increased. Further, the metal melt that has popped out hits the lattice and enters the crossbar groove 8b again. Therefore, the crossbar groove 8b can further prevent the metal melt from scattering.

The shape of the grid of the crossbar groove 8b may be provided as shown in FIGS. 5 and 6, or may be tapered. Alternatively, the shape may be thin or round.

When the circuit breaker is attached so that the crossbar 82 is below the arc extinguishing chamber 17 on the paper surface, the metal melt falls to the mechanism portion side, so that the amount of scattering increases. Therefore, it can be said that the crossbar groove 8a on which the metal melt can be adhered and held is more effective in preventing malfunction of the mechanical portion and realizing stable operation.
However, for example, even when the circuit breaker is attached so that the crossbar 82 is on the right side or the left side of the arc extinguishing chamber 17, by providing the grid-like crossbar groove 8b, the adhesion position of the metal melt is provided. Since the distance from the mechanism to the mechanism is further increased, the amount of scattered metal melt is reduced, which prevents the mechanism from malfunctioning and leads to stable operation.

Embodiment 3.
The difference between the third embodiment and the first and second embodiments is that the inner surface of the crossbar groove is covered with a lubricating substance such as grease. As the grease to be applied, grease whose viscosity has been increased by adding a binder material to prevent the movement of oil is used.

By covering the inner surface of the crossbar groove with grease, the metal melt easily adheres to the crossbar groove. In addition, the crossbar groove makes it easier to hold the attached metal melt, and even if the crossbar moves, it is possible to further prevent the metal melt from scattering to the mechanism portion.

When the circuit breaker is installed so that the crossbar is below the arc extinguishing chamber on the paper surface, the metal melt adhering to the crossbar falls to the mechanism portion side, so that the amount of scattering increases. Therefore, it can be said that the crossbar groove capable of adhering and holding the metal melt is more effective in preventing malfunction of the mechanical portion and realizing stable operation. However, for example, even when the circuit breaker is installed so that the crossbar is on the right side or the left side of the arc extinguishing chamber, by providing the crossbar groove, the metal melt adhered position to the mechanism portion. Since the distance is long, the amount of metal melt scattered to the mechanical part is reduced, which leads to stable operation of the mechanical part. Further, in the present embodiment, since grease is applied to the inner surface of the crossbar groove, the holding force of the metal melt in the crossbar groove is increased, and the amount of the metal melt scattered from the arc extinguishing chamber to the mechanism portion is increased. Less. Therefore, it leads to stable operation of the mechanism unit.

1 Cover 2 Base 3 Housing 4 Fixed contact 5 Fixed contact conductor 6 Movable contact 7 Movable contact conductor 81, 82 Crossbar 8a2, 8a3 Surface part 8a, 8b Crossbar groove 9 Trip bar 9a Trip bar Pressure receiving part 9b Trip bar engagement Part 9c Trip bar shaft 10 Link pin 10a Link pin pivot part 10b Link pin coupling part 11 Handle 11a Handle shaft 11b Handle hole 11c Lever pressing part 12 Frame 12a Handle stopper 13 Roller 14 Lever 14a Lever guide surface 14b Lever engaging part 14c Lever shaft 15 Relay part 15a Coil 15b Iron core 15c Armature 16 Opening spring 17 Arc extinguishing chamber 18 Load side terminal 100 Circuit breaker

Claims (9)

With fixed contact conductors to which fixed contacts are fixed,
A movable contact conductor to which a movable contact that can be separated from the fixed contact is fixed,
An arc extinguishing chamber that extinguishes an arc generated when the fixed contact and the movable contact are separated from each other.
A crossbar having a groove on the surface facing the arc extinguishing chamber,
A mechanical unit that drives the crossbar so that the fixed contact and the movable contact are separated from each other.
With
The groove of the crossbar is a circuit breaker having a grid pattern. The circuit breaker according to claim 1, wherein the crossbar is mounted so as to be below the arc extinguishing chamber. The circuit breaker according to claim 1 or 2, wherein the mechanism unit is driven so as to move linearly in an extended plane having the facing surfaces. The circuit breaker according to any one of claims 1 to 3, wherein the groove of the crossbar has a tapered shape. The circuit breaker according to any one of claims 1 to 3, wherein the groove of the crossbar has a narrow shape at the back. The circuit breaker according to any one of claims 1 to 3, wherein the groove of the crossbar has a rounded back shape. The circuit breaker according to any one of claims 1 to 6 , wherein the inner surface of the groove of the crossbar is covered with an adhesive material. The circuit breaker according to claim 7 , wherein the material of the adhesive material is a grease to which a binder material is added. With fixed contact conductors to which fixed contacts are fixed,
A movable contact conductor to which a movable contact that can be separated from the fixed contact is fixed,
An arc extinguishing chamber that extinguishes an arc generated when the fixed contact and the movable contact are separated from each other.
A crossbar having a groove on the surface facing the arc extinguishing chamber,
A mechanical unit that drives the crossbar so that the fixed contact and the movable contact are separated from each other.
With
A circuit breaker in which the inner surface of the groove of the crossbar is covered with an adhesive material.

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