JP2002367494A - Breaker - Google Patents

Abstract

PROBLEM TO BE SOLVED: To miniaturize a making spring by improving a breaking spring. SOLUTION: This breaker is structured so that the breaking spring 20 is composed by serially connecting two coil springs 20A and 20B, having spring constants different from each other between a fixed end 2C and a movable end 2B, and the movable end 2B is made to drive a moving contact.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a circuit breaker in which the opening and closing of a contact is driven by a spring, and more particularly to a circuit breaker in which excess energy is removed by optimizing the output of the spring to reduce the size.

[0002]

2. Description of the Related Art FIG. 5 is a principle diagram for explaining the operation of a conventional circuit breaker. The circuit breaker includes a contact 1 including a fixed contact 1A and a movable contact 1B, and includes a breaking spring 2 and a closing spring 3 for driving the movable contact 1B of the contact 1. The cut-off spring 2 has a coiled compression spring 2A interposed between a fixed end 2C and a movable end 2B. The closing spring 3 also has a coiled compression spring between the fixed end 3C and the movable end 3B. 3A is interposed. Movable end 2B of blocking spring 2
Is connected to the movable contact 1B and the lever 10, and the lever 10 is integral with the opening / closing shaft 8 and is rotatable around the opening / closing shaft 8. On the other hand, the movable end 3B of the closing spring 3
Is connected via a transmission mechanism 7 to the input cam 6, and the input cam 6 is in contact with the lever 9, which is integral with the opening and closing shaft 8, on the side opposite to the opening and closing shaft 8. The input cam 6 is integral with a disk 5C having irregularities formed on the outer periphery, and a claw 18 is engaged with the irregularities. The disk 5C rotates in conjunction with the gear 5B, and the gear 5B obtains a rotational driving force from the electric motor 4 via the gear 5A. The input cam 6 is provided with a locking portion 6A, which can be locked with the input latch portion 11 provided with the input coil 12. Further, a cam 19 integrated with the opening / closing shaft 8 can be locked with the cut-off latch 13 provided with the cut-off coil 14.

FIG. 5 shows a state in which the contact 1 is cut off and the cut-off spring 2 and the closing spring 3 are not charged (compressed). In the state of FIG. 5, when the electric motor 4 is driven, the rotational driving force in the direction of the arrow is changed to the gears 5A, 5B.
Is transmitted to the disk 5C via the. As a result, the input cam 6 rotates counterclockwise, so that the transmission mechanism 7 is pulled to the left, and the input spring 3 is charged. The claw 18 is locked only by clockwise rotation of the disk 5C. When the closing cam 6 rotates a half turn from the state shown in FIG. 5, the locking portion 6A is locked by the closing latch portion 11, and the charging of the closing spring 3 is completed. When a closing command is issued, the closing coil 12 is excited and the closing latch unit 11 opens the closing cam 6. As a result, the closing cam 6 starts to rotate counterclockwise by the return force of the closing spring 3, and the opening / closing shaft 8 rotates clockwise via the lever 9 in the direction of the arrow. By the rotation of the opening / closing shaft 8, the lever 10 rotates clockwise, the contact 1 is turned on, and the blocking spring 2 is charged. When the lever 10 makes a half turn from the state shown in FIG. 5, the lever 19 is locked by the cut-off latch portion 13, and the energy storage of the cut-off spring 2 is completed. When a cutoff command is issued, the cutoff coil 14 is excited and the cutoff latch 13 opens the lever 19, so that the opening / closing shaft 8 becomes free, the contact 1 is cut off by the return force of the cutoff spring 3, and the state returns to the state shown in FIG. . Hereinafter, a similar operation is repeated.

[0004]

However, the conventional circuit breaker as described above has a problem that the size of the entire circuit breaker becomes large due to the large closing spring. That is, since the closing spring compresses the breaking spring during the closing operation of the circuit breaker, the characteristics to be provided depend on the characteristics of the breaking spring. The shut-off spring activates a movable mechanism, such as a movable contact or an opening / closing shaft, which has been stopped at the time of the shut-off operation. Along with that,
It is necessary to increase the energy stored in the closing spring, which has increased the closing spring and increased the size of the entire circuit breaker. An object of the present invention is to reduce the closing spring by improving the shut-off spring.

[0005]

According to the present invention, there is provided, in accordance with the present invention, a shut-off spring and a closing spring for driving the movable contact of a contact comprising a movable contact and a fixed contact. When the closing spring is charged by a motor in advance and a closing command is issued, the movable contact is driven toward the fixed contact by the release of the closing spring, and the contact is turned on and the cutoff is performed. When the spring is charged and a cutoff command is issued, the movable contact is driven toward the fixed contactor side by the release of the cutoff spring, and in the circuit breaker in which the contact point is cut off, the cutoff spring is Preferably, a plurality of springs having different spring constants are connected in series between the fixed end and the movable end, and the movable end drives the movable contact. When the contacts are interrupted, a large operating force is required in the initial stage of the interruption because a movable mechanism such as a movable contact or an opening / closing axis is activated as described above. On the other hand, in the latter half of the interruption, the movable mechanism has acceleration, so that the magnitude is not required as large as the initial operation force, but an operation force that does not stagnate the interruption operation is required. If a spring with a different spring constant is connected in series as a cutoff spring, if a cutoff command is issued,
When the stored spring is released, the spring with the larger spring constant first expands, and the spring with the smaller spring constant expands sequentially. Therefore, a large operating force is output from the spring having the larger spring constant at the beginning of the breaking operation,
In the latter half of the breaking operation, a stable operating force is output from the spring with the smaller spring constant. By matching the operating force of the isolation spring to the force required by the circuit breaker, the stored energy of the isolation spring can be minimized. Since the closing spring is charged by the closing spring, the stored energy of the closing spring can be reduced by the saved energy of the closing spring, and the closing spring can be reduced in size.

In addition, there is provided a cut-off spring and a closing spring for driving the movable contact, which is a contact composed of a movable contact and a fixed contact, and the closing spring is pre-energized by an electric motor and a closing command is issued. The movable contact is driven to the fixed contact by the release of the closing spring,
When the contact is turned on and the cut-off spring is charged, and a cut-off command is issued, the movable contact is driven toward the fixed contact by the release of the cut-off spring,
In the circuit breaker in which the contact points are in a cutoff state, the cutoff spring is provided with a spring in which a spring constant is continuously changed between a fixed end and a movable end in a position in the expansion and contraction direction,
Preferably, the movable end drives the movable contact. When the contacts are interrupted, a large operating force is required in the initial stage of the interruption because a movable mechanism such as a movable contact or an opening / closing axis is activated as described above. On the other hand, in the latter half of the interruption, the movable mechanism has acceleration, so that the magnitude is not necessary as large as the initial operation force, but an operation force that does not stagnate the interruption operation is required. When a spring whose spring constant changes continuously at a position in the expansion and contraction direction is used as the cutoff spring,
When a cutoff command is issued, the stored cutoff springs are extended from a portion having a large spring constant when being released, and portions having a small spring constant are sequentially extended. Therefore, a large operating force is output in the early stage of the shutoff operation, and a stable operating force is output in the latter half of the shutoff operation. By matching the operating force of the isolation spring to the force required by the circuit breaker, the stored energy of the isolation spring can be minimized. Since the closing spring is charged by the closing spring, the stored energy of the closing spring can be reduced by the saved energy of the closing spring, and the closing spring can be reduced in size.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to embodiments. FIG. 1 is a sectional view showing a configuration of a breaking spring 20 of a circuit breaker according to an embodiment of the present invention. Cut-off spring 2
0 is composed of two coil springs 20A and 20B having different spring constants connected in series between the fixed end 2C and the movable end 2B, so that the movable end 2B drives the movable contact. I do. The winding pitch of the coil spring 20B that advances to the left and right is formed larger than that of the coil spring 20A. The circuit breaker according to the present invention is the same as the conventional structure shown in FIG. In FIG. 1, the spring constant of the coil spring 20B is larger than that of the coil spring 20A, and the output energy of the coil spring 20B when it is discharged from the coil spring 20A is large. That is, the coil springs 20A and 20B of the cut-off spring 20 are energized until the turns come into close contact with each other, and when the energized state is released by the cut-off command, the coil spring 20A having a large spring constant is first used.
B starts to expand, and then the coil spring 2 having a small spring constant
0A begins to grow.

FIG. 6 is a characteristic diagram showing the output characteristics of the cut-off spring. The vertical axis is the operating force, and the horizontal axis is the movable end 2B of the blocking spring.
Position. X ₀ indicates the position in the charged state, and X ₂ indicates the position in the released state. A characteristic 15 is an output characteristic of the conventional cut-off spring 2 of FIG. 5, and a characteristic 16 is an output characteristic of the cut-off spring 20 of FIG. Since the conventional isolation spring 2 is composed of a single coil spring 2A (FIG. 5), the operating force of the isolation spring 2 decreases linearly with the stroke, as indicated by a characteristic 15. On the other hand, the operating force of the shut-off spring 20 (FIG. 1) becomes a characteristic of a broken line, that is, a non-linear characteristic together with the position of the movable end, as shown by a characteristic 16. That is, the cut-off spring 20
A large operating force is outputted feeling that early in the coil spring 20B of the operation, the operation force becomes from the position X ₁ of the way as the coil spring 20A is effective against decreases. By adjusting the operating force of the isolation spring 20 to the required force of the circuit breaker, the stored energy of the isolation spring 20 can be minimized. The stored energy of the closing spring can be reduced by the saved energy of the cut-off spring 20. In FIG. 6, the area 17 between the characteristics 15 and 16 corresponds to the energy saved. Cut-off spring 20
Can be saved, so that the stored energy of the closing spring 3 (FIG. 5) for storing the shut-off spring 20 can be reduced. For this reason, the closing spring 3 can be made smaller than before, and the size of the entire circuit breaker can be reduced, thereby reducing the cost.

FIG. 2 is a sectional view showing the structure of a breaking spring 22 of a circuit breaker according to another embodiment of the present invention. The cut-off spring 22 is formed of a series spring in which a flat spring 22A and a coil spring 22B are connected in series, and is formed such that the spring constant of the flat spring 22A is larger than that of the coil spring 22B. The circuit breaker according to the present invention is the same as the conventional structure shown in FIG. In FIG. 2, when the shut-off spring 22 is charged and released by the cut-off command, first, the flat spring 22 having a large spring constant is released.
A starts to expand in the left and right axial directions, and thereafter, the coil spring 22B having a small spring constant starts to expand. As a result, the shut-off spring 22 has a non-linear characteristic in which a large operating force is output at the beginning of the operation and the operating force is reduced halfway. By adjusting the operating force of the cut-off spring 22 to the force required by the circuit breaker, the stored energy of the cut-off spring 22 can be minimized. The stored energy of the spring can also be reduced. Therefore, the closing spring can be made smaller, the size of the entire circuit breaker can be reduced, and the cost can be reduced.

FIG. 3 is a sectional view showing the structure of a breaking spring 23 of a circuit breaker according to a further different embodiment of the present invention. The cut-off spring 23 includes the coil spring 23A and the coil spring 2
3B and a series spring connected in series, and the wire diameter of the coil spring 23B is formed larger than that of the coil spring 23A. The circuit breaker according to the present invention includes a breaking spring 2
Other than 3 is the same as the conventional configuration of FIG. In FIG. 3, the spring constant of the coil spring 23B is larger than that of the coil spring 23A, and the coil spring 23B is
Greater output energy when de-energized. That is, the coil springs 23A and 23B of the shut-off spring 23 are energized until the turns are closely contacted, and when the energization is released by the shut-off command, the coil spring 23B having a large spring constant starts to expand, and then the spring The coil spring 23A having a small constant starts to expand. Thereby, the cut-off spring 23
Has a non-linear characteristic in which a large operating force is output at the beginning of the operation and the operating force is reduced halfway. By adjusting the operating force of the cut-off spring 23 to the force required by the circuit breaker, the stored energy of the cut-off spring 23 can be minimized. The stored energy of the spring can also be reduced. For this reason, the closing spring can be made smaller, the size of the entire circuit breaker can be reduced, and the cost is reduced.

The structure according to the present invention is not limited to the embodiment shown in FIGS. 1 to 3, but is interposed between the fixed end and the movable end of the cut-off spring in series. Two or more springs having different spring constants may be provided. As a result, the operating force of the shut-off spring has a non-linear characteristic, and a large operating force is output from the spring having the larger spring constant at the beginning of the shut-off operation, and the spring having the smaller spring constant is obtained in the latter half of the shut-off operation. , And a stable operating force is output. Therefore, in this case as well, the stored energy of the cut-off spring can be minimized, and the stored energy of the closing spring is reduced by the saved amount of stored energy of the cut-off spring, so that the closing spring can be made smaller. .

FIG. 4 is a cross-sectional view showing the structure of a breaking spring 24 of a circuit breaker according to still another embodiment of the present invention. The winding diameter of the coil spring 24 </ b> A constituting the blocking spring 24 is formed so as to be continuously different at left and right expansion and contraction positions. The circuit breaker according to the present invention is the same as the conventional structure shown in FIG. In FIG. 4, since the spring constant increases as the winding diameter of the coil spring 24A decreases, the spring constant of the coil spring 24A continuously changes at a position in the expansion and contraction direction. The shut-off spring 24 is charged until the turns of the coil spring 24A come into close contact with each other. When the charge is released by the cut-off command, the coil spring 24A first starts to expand from the portion having the largest spring constant and the smallest winding diameter. The part with the larger winding diameter of begins to elongate. Thus, the shut-off spring 24 has a non-linear characteristic in which a large operating force is output at the beginning of the operation and the operating force is sequentially reduced. By adjusting the operating force of the cut-off spring 24 to the force required by the circuit breaker, the stored energy of the cut-off spring 24 can be minimized. The stored energy of the spring can also be reduced. Therefore, the closing spring can be made smaller, the size of the entire circuit breaker can be reduced, and the cost can be reduced.

Further, the configuration according to the present invention is not limited to the embodiment of FIG. 4, but it is generally sufficient if the spring constant of the coil spring continuously changes at the position in the expansion and contraction direction. . Therefore, for example, the winding diameters of the coil springs are all the same at the expansion and contraction positions as shown in FIG. 1, but the winding pitch of the coil springs may be continuously different at the expansion and contraction positions. Since the spring constant increases as the winding pitch of the coil spring increases, the spring constant of the coil spring changes continuously at a position in the expansion and contraction direction. The cut-off spring is charged until the turns of the coil spring come into close contact with each other. When the charge is released by the cut-off command, the coil spring first starts to expand from the portion with the largest winding pitch having the largest spring constant, and then sequentially decreases in the spring constant. The portion with a small winding pitch starts to elongate. As a result, the shut-off spring has a non-linear characteristic in which a large operating force is output at the beginning of the operation and the operating force is gradually reduced. By adjusting the operating force of the cut-off spring to the required force of the circuit breaker, the stored energy of the cut-off spring can be minimized, and the stored energy of the cut-off spring can be saved by the saved energy. Energy can be reduced. Therefore, the closing spring can be made smaller, the size of the entire circuit breaker can be reduced, and the cost can be reduced.

1 to 4 according to the present invention is effective when applied to any type of circuit breaker such as a puffer type or a vacuum type. That is, in general, when a circuit breaker is shut off, a large operating force is required since a movable mechanism such as a movable contactor and an opening / closing shaft is activated in an initial stage of the interruption. On the other hand, in the latter half of the interruption, the movable mechanism has acceleration, so that the magnitude is not required as large as the initial operation force, but an operation force that does not stagnate the interruption operation is required. If a spring having a different spring constant is connected in series at the position in the expansion / contraction direction or a spring whose spring constant changes continuously at the position in the expansion / contraction direction is used, a cutoff command is issued. In this case, a large operating force is output at the beginning of the shut-off operation, and a stable operating force is output at the latter half of the shut-off operation. The spring can also be made smaller.

[0015]

According to the present invention, as described above, the shut-off spring
A plurality of springs having different spring constants are connected in series between the fixed end and the movable end, and the movable end drives the movable contact to reduce the closing spring. The size of the entire circuit breaker can be reduced, and the cost can be reduced.

[0016] Further, the blocking spring is provided with a spring interposed between the fixed end and the movable end, the spring constant varying continuously at a position in the expansion and contraction direction, and the movable end drives the movable contact. By doing so, the closing spring can be made smaller, and the overall size of the circuit breaker can be reduced, thereby reducing costs.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a configuration of a breaking spring of a circuit breaker according to an embodiment of the present invention.

FIG. 2 is a sectional view showing a configuration of a breaking spring of a circuit breaker according to another embodiment of the present invention.

FIG. 3 is a sectional view showing a configuration of a breaking spring of a circuit breaker according to still another embodiment of the present invention.

FIG. 4 is a sectional view showing a configuration of a breaking spring of a circuit breaker according to still another embodiment of the present invention.

FIG. 5 is a characteristic diagram showing an output characteristic of the cut-off spring.

FIG. 6 is a principle diagram illustrating the operation of a conventional circuit breaker.

[Explanation of symbols]

1: contact, 1A: fixed contact, 1B: movable contact, 2,
20, 22, 23, 24: blocking spring, 2B: movable end, 2
C: fixed end, 3: closing spring, 4: electric motor

Claims (2)

[Claims] A contact spring comprising a movable contact and a fixed contact for driving the movable contact; a closing spring and a closing spring, wherein the closing spring is charged by a motor in advance and a closing command is issued. The movable contact is driven toward the fixed contact by the release of the closing spring, the contact is brought into the closed state, the cutoff spring is charged, and when a cutoff command is issued, the release of the cutoff spring is performed. In the circuit breaker in which the movable contact is driven to the opposite side of the fixed contact by a force and the contact is cut off, the breaking spring has a plurality of springs having different spring constants between a fixed end and a movable end. Are connected in series, and the movable end drives the movable contact. And a closing spring and a closing spring for driving the movable contact, which is a contact composed of a movable contact and a fixed contact, wherein the closing spring is charged in advance by an electric motor and a closing command is issued. The movable contact is driven toward the fixed contact by the release of the closing spring, the contact is brought into the closed state, the cutoff spring is charged, and when a cutoff command is issued, the release of the cutoff spring is performed. In the circuit breaker in which the movable contact is driven to the fixed contact side by the force and the contact is turned off, the breaking spring has a spring constant between a fixed end and a movable end in a position extending and contracting. A circuit breaker characterized in that a continuously changing spring is interposed, and the movable end drives the movable contact.