Embodiments of the present invention relate to a switchgear and a switchgear operating mechanism.
In general, there are available, as an operating mechanism of a switchgear, one using a hydraulic operating force for high power and one using a spring operating force for middle/small output power. The former is referred to as “hydraulic operating mechanism” and the latter as “spring operating mechanism”. In recent years, the advancement of miniaturization of an arc-extinguishing chamber of a gas circuit breaker which is a type of a switchgear allows fault current to be broken with a smaller operating force, so that application of the spring operating mechanism becomes popular. However, a gas circuit breaker of extra high-voltage class requires high-speed operating capability called “two-cycle cutoff” that is capability of achieving cutoff within a time length corresponding to two-cycle time periods of alternating current. A conventional spring operating mechanism typically has operating capability equivalent to about three-cycle operation, and it is not easy to realize the two-cycle cutoff capability due to poor responsiveness of a retention mechanism or retention control mechanism of a spring force.
The above and other features and advantages of the present invention will become apparent from the discussion hereinbelow of specific, illustrative embodiments thereof presented in conjunction with the accompanying drawings, in which:
The embodiments described here have been made to solve the above problem, and an object thereof is to reduce a time period for the cutoff spring force to be released so as to reduce the entire contact opening time period in a switchgear for opening/closing an electrical circuit and its operating mechanism.
According to one embodiment, a switchgear operating mechanism for reciprocatively driving a movable contact of a switchgear so as to shift the switchgear between a cutoff state and a closed state, the operating mechanism including: a frame; a closing shaft rotatably disposed relative to the frame; a main lever fixed to the closing shaft and capable of being swung in conjunction with the movable contact; a cutoff spring disposed such that it accumulates energy when the switchgear operating state is shifted from the cutoff state to the closed state in accordance with rotation of the closing shaft while it discharges its accumulated energy when the switchgear operating state is shifted from the closed state to the cutoff state; a sub-shaft disposed so as to be rotatable relative to the frame around a rotation axis substantially parallel to a rotation axis of the closing shaft; a sub-lever swingably fixed to the sub-shaft; a main-sub connection link rotatably connecting a leading end of the sub-lever and the main lever; a cam mechanism swinging the sub-shaft in accordance with the rotation of the closing shaft; a latch lever swingably fixed to the sub-shaft; a latch roller pin rotatably mounted to a leading end of the latch lever; a trigger lever disposed so as to be rotatable relative to the frame around a rotation axis substantially parallel to the rotation axis of the closing shaft; a trigger roller pin rotatably mounted to a leading end of the trigger lever; a trigger lever return spring biasing the trigger lever so as to rotate the trigger lever in a predetermined direction; a latch fixed to the trigger lever at a position different from a rotation axis of the trigger lever so as to be rotatable around a rotation axis substantially parallel to the rotation axis of the closing shaft and having a leading end engageable with the latch roller pin; a latch return spring biasing the latch so as to rotate the latch in a predetermined direction; a solenoid lever disposed relative to the frame so as to be rotatable around a rotation axis substantially parallel to the rotation axis of the closing shaft and having a leading end engageable with the trigger roller pin; a solenoid lever return spring biasing the solenoid lever so as to rotate the solenoid lever in a predetermined direction; and an electromagnetic solenoid for cutoff which acts against a biasing force of the solenoid lever return spring to push the solenoid lever so as to shift the switchgear operating state from the closed state to the cutoff state, wherein in a state where the switchgear operating state is shifted from the closed state to the cutoff state, the solenoid lever is pushed by the electromagnetic solenoid for cutoff so as to be rotated in an opposite direction to the biasing direction of the solenoid lever return spring to release an engagement between the trigger roller pin and the solenoid lever, and the trigger lever and an eccentric pin are rotated by the biasing force of the latch roller pin to release an engagement between the latch roller pin and the leading end of the latch, which causes the cutoff spring to discharge its energy to rotate the latch lever.
According to another embodiment, a switchgear having a movable contact that can be moved in a reciprocating mariner and an operating mechanism that drives the movable contact and configured to be shifted between a cutoff state and a closed state by the movement of movable contact, the operating mechanism including: a frame; a closing shaft rotatably disposed relative to the frame; a main lever fixed to the closing shaft and capable of being swung in conjunction with the movable contact; a cutoff spring disposed such that it accumulates energy when the switchgear operating state is shifted from the cutoff state to the closed state in accordance with rotation of the closing shaft while it discharges its accumulated energy when the switchgear operating state is shifted from the closed state to the cutoff state; a sub-shaft disposed so as to be rotatable relative to the frame around a rotation axis substantially parallel to a rotation axis of the closing shaft; a sub-lever swingably fixed to the sub-shaft; a main-sub connection link rotatably connecting a leading end of the sub-lever and the main lever; a cam mechanism swinging the sub-shaft in accordance with the rotation of the closing shaft; a latch lever swingably fixed to the sub-shaft; a latch roller pin rotatably mounted to a leading end of the latch lever; a trigger lever disposed so as to be rotatable relative to the frame around a rotation axis substantially parallel to the rotation axis of the closing shaft; a trigger roller pin rotatably mounted to a leading end of the trigger lever; a trigger lever return spring biasing the trigger lever so as to rotate the trigger lever in a predetermined direction; a latch fixed to the trigger lever at a position different from a rotation axis of the trigger lever so as to be rotatable around a rotation axis substantially parallel to the rotation axis of the closing shaft and having a leading end engageable with the latch roller pin; a latch return spring biasing the latch so as to rotate the latch in a predetermined direction; a solenoid lever disposed relative to the frame so as to be rotatable around a rotation axis substantially parallel to the rotation axis of the closing shaft and having a leading end engageable with the trigger roller pin; a solenoid lever return spring biasing the solenoid lever so as to rotate the solenoid lever in a predetermined direction; and an electromagnetic solenoid for cutoff which acts against a biasing force of the solenoid lever return spring to push the solenoid lever so as to shift the switchgear operating state from the closed state to the cutoff state, wherein in a state where the switchgear operating state is shifted from the closed state to the cutoff state, the solenoid lever is pushed by the electromagnetic solenoid for cutoff so as to be rotated in an opposite direction to the biasing direction of the solenoid lever return spring to release an engagement between the trigger roller pin and the solenoid lever, and the trigger lever and an eccentric pin are rotated by the biasing force of the latch roller pin to release an engagement between the latch roller pin and the leading end of the latch, which causes the cutoff spring to discharge its energy to rotate the latch lever.
Embodiments of an operating mechanism of a switchgear according to the present invention will be described below with reference to the accompanying drawings.
First, with reference to
In
A cutoff spring 6 has one end fixed to an attachment surface 5a of the frame 5 and the other end fitted to a cutoff spring receiver 7. A damper 8 is fixed to the cutoff spring receiver 7. In the damper 8, a fluid is encapsulated and a piston 8a is provided so as to translationally slide. One end of the damper 8 is fixed to a cutoff spring link 9, which is rotatably attached to a pin 3a of the main lever 3.
A sub-shaft 10 is rotatably disposed relative to the frame 5, and a sub-lever 11 is fixed to the sub-shaft 10. A pin 11a is disposed at a leading end of the sub-lever 11. A pin 3b disposed in the main lever 3 and the pin 11a are connected by a main-sub connection link 20. A latch lever 12 is fixed to the sub-shaft 10, and a latch roller pin 12a is rotatably fitted to a leading end of the latch lever 12. Further, a cam lever 13 is fixed to the sub-shaft 10, and a cam roller 13a is rotatably fitted to a leading end of the cam lever 13.
A closing spring 21 has one end fixed to the attachment surface 5a of the frame 5 and the other end fixed to a closing spring receiver 22. A pin 22a is disposed in the closing spring receiver 22. The pin 22a is connected to a pin 23a of a closing lever 23 which is fixed to an end portion of the closing shaft 4 through a closing link 24. A closing cam 25 is fixed to the closing shaft 4 and releasably engaged with the cam roller 13a in accordance with rotation of the closing shaft 4.
A tab 23b is disposed at one end of the closing lever 23 and is releasably engaged with a half-column portion 26a provided in an anchoring lever 26 for closing which is rotatably disposed relative to the frame 5. Further, a return spring 27 is disposed at one end of the anchoring lever 26 for closing. The other end of the return spring 27 is fixed to the frame 5. The return spring 27 is a compression spring and spring force thereof always acts on the anchoring lever 26 for closing as a clockwise torque. However, the rotation of the anchoring lever 26 for closing is restricted by an engagement between a plunger 28a of an electromagnetic solenoid 28 for closing which is fixed to the frame 5 and the anchoring lever 26 for closing.
In a cutoff state illustrated in
As illustrated in
A trigger lever 31 is fixed to an eccentric pin 32 rotatably disposed relative to an end portion of the anchoring lever 30, and a trigger roller pin 31a is rotatably fitted to a leading end of the trigger lever 31. A trigger lever return spring 33 is disposed between the frame 5 and the trigger lever 31. An end portion of the trigger lever return spring 33 is engaged with a pin 5b fixed to the frame 5. The trigger lever return spring 33 always generates a clockwise torque for the trigger lever 31. The clockwise rotation of the trigger lever return spring 33 is restricted by an abutment between a stopper pin 5c disposed on the frame 5 and the trigger lever 31.
A latch 34 is rotatably disposed around the eccentric pin 32 so as to have a rotation axis center 34a at a position eccentric from a rotation axis center 31b of the trigger lever 31. The latch 34 has a protrusion 34b. A latch return spring 35 is disposed between the anchoring lever 30 and the latch 34. An end portion of the latch return spring 35 is engaged with a pin 30b fixed to the anchoring lever 30. The latch return spring 35 always generates a clockwise torque for the latch 34. The clockwise rotation of the latch 34 is restricted by an abutment between a stopper pin 30c disposed on the anchoring lever 30 and the protrusion 34b of the latch 34. A leading end 34c of the latch 34 is formed by a plane normal to a line connecting a rotation axis center of the latch roller pin 12a, the rotation axis center 34a of the latch 34 and a rotation axis center 36b of a solenoid lever 36.
The latch 34 has a leading end protrusion 34d which protrudes from a one side surface of the leading end 34c. In a closed state illustrated in
The solenoid lever 36 is configure to be rotatable around the rotation axis center 36b fixed to the frame 5 and has a first side 36c extending in one direction from the rotation axis center 36b and a second side 36d extending in a direction perpendicular to the first side 36c from the rotation axis center 36b. A solenoid lever return spring 37 is disposed at one end of the first side 36c of the solenoid lever 36, and the other end of the solenoid lever return spring 37 is fixed to the frame 5. The solenoid lever return spring 37 is a tension spring, and a spring force that rotates the solenoid lever 36 in the clockwise direction is always applied to the solenoid lever 36. However, the rotation of the solenoid lever 36 is restricted by an engagement between a stopper pin 5d fixed to the frame 5 and the first side 36c of the solenoid lever 36.
As illustrated in
A leading end of a plunger 38a of an electromagnetic solenoid 38 for cutoff which is fixed to the frame 5 is releasably engaged with the solenoid lever 36, which causes the solenoid lever 36 to be rotated in the counterclockwise direction upon input of an cutoff command.
In the closed state illustrated in
In the closed state, the main lever 3 always receives a clockwise torque by a tensile spring force of the cutoff spring 6. The force transmitted to the main lever 3 is then transmitted to the sub-lever 11 through the main-sub connection link 20. The transmitted force becomes a torque for always rotating the sub-lever 11 in the counterclockwise direction. This counterclockwise torque is supplied also to the latch lever 12.
However, in the closed state, the leading end 34c of the latch 34 and the latch roller pin 12a are engaged with each other to restrict the counterclockwise rotation of the latch lever 12. Accordingly, the subsequent members from the sub-lever 11 to the cutoff spring 6 maintain their static state.
In the present embodiment, the rotation shafts, such as the closing shaft 4 and the sub-shaft 10, and axes of the respective pins are parallel to each other and are normal to the paper surfaces of
In the present embodiment having the configuration described above, a cutoff operation causing the operation state to be shifted from the closed state illustrated in
First, in the closed state illustrated in
Since the solenoid lever 36 is engaged with the plunger 38a, it is rotated in the counterclockwise direction (direction denoted by an arrow B) to release the engagement between the leading end 36a of the solenoid lever 36 and the trigger roller pin 31a, thereby rotating the trigger lever 31 and the eccentric pin 32 in the counterclockwise direction (direction denoted by an arrow C). Then, the latch 34 starts to swing while maintaining the engagement state between the leading end 34c of the latch 34 and the latch roller pin 12a, and the latch lever 12 receives the counterclockwise (direction denoted by an arrow D) torque from the cutoff spring 6 to be rotated in the counterclockwise direction. This state is illustrated in
At this time, the latch roller pin 12a pushes the leading end 34c of the latch 34 toward the rotation axis center 34a (direction denoted by an arrow E) of the latch 34, and the rotation axis center 31b of the trigger lever 31 is disposed to the sub-shaft 10 side relative to the arrow E. Thus, a counterclockwise (direction denoted by the arrow C) torque is applied to the eccentric pin 32 and the trigger lever 31.
After the state illustrated in
After the state illustrated in
After the state illustrated in
When the engagement between the latch 34 and the latch roller pin 12a is released in the closed state illustrated in
When the cutoff spring 6 is displaced by a given distance, the piston 8a abuts against the stopper 5e fixed to the frame 5 to generate a braking power of the damper 8 to thereby stop the movement of the cutoff spring 6. The movements of the link levers connected to the cutoff spring 6 are accordingly stopped, thereby completing the cutoff operation. This state is illustrated in
Next, a cutoff operation causing the operation state to be shifted from the cutoff state illustrated in
The rotation of the sub-lever 11 is transmitted to the main lever 3 and, accordingly, the main lever 3 is rotated in the counterclockwise direction (direction denoted by an arrow Q). Then, the link mechanism 1 and the movable contact 2 connected to the link mechanism 1 are moved to the left to start the closing operation. In association with the rotation of the main lever 3, the cutoff spring link 9 is moved in a direction denoted by an arrow R, with the result that the cutoff spring 6 is compressed to accumulate energy.
In the closing operation, the cam lever 13 is rotated in the clockwise direction (direction denoted by the arrow O) in a state where the operation is shifted from the cutoff state illustrated in
After the state illustrated in
When the engagement between the closing cam 25 and the cam roller 13a is released, the latch roller pin 12a is returned to its closed-state position by a stretching force of the cutoff spring 6. Further, when the engagement between the latch roller pin 12a and the latch 34 is released, the latch 34 is returned to its closed state-position by a biasing force of the latch return spring 35, with the result that the leading end 34c of the latch 34 and the latch roller pin 12a are reengaged with each other (
At this reengagement operation, the latch roller pin 12a pushes the leading end 34c of the latch 34 toward the rotation axis center 34a of the latch 34 (direction denoted by the arrow E), so that the trigger lever 31 and the eccentric pin 32 are ready to be rotated in the counterclockwise direction (direction denoted by the arrow C). However, the rotation of the trigger lever 31 is restricted by the engagement between the trigger roller pin 31a and the leading end 36a of the solenoid lever 36. Further, the trigger roller pin 31a pushes the leading end 36a of the solenoid lever 36 toward the rotation axis center 36b of the solenoid lever 36 to restrict the counterclockwise rotation of the solenoid lever 36, and the movements of the link levers are accordingly stopped, thereby completing the cutoff operation. This state is illustrated in
According to the present embodiment, after the electromagnetic solenoid 38 for cutoff is excited upon input of a cutoff command, the cutoff operation is completed by two operation steps: a first operation step in which the latch 34 is directly driven through the solenoid lever 36 and the eccentric pin 32 to release the engagement between the latch 34 and the latch roller pin 12a; and a second operation step in which the cutoff spring 6 operates. As described above, the number of operation steps for completing the cutoff operation is reduced from three (in the case of conventional spring operating mechanism) to two, thereby significantly reducing the cutoff operation time period. This means that T2 is removed from the expression (1) representing the contact opening time period, so that it is possible to reduce the contact opening time period.
Further, the counterclockwise (direction denoted by the arrow C) torque is always applied to the eccentric pin 32 during a time from input of the cutoff command to the release of the engagement between the leading end 34c of the latch 34 and the latch roller pin 12a, thereby enabling further reduction in the contact opening time period.
Further, the latch 34 is not directly driven by the electromagnetic solenoid 38 for cutoff, so that influence of a restoring force of the latch return spring 35 on the contact opening time period is small. Thus, an increase in the restoring force of the latch return spring 35 allows acceleration of return of the latch 34 at the time of the closing operation without prolonging the contact opening time period, thereby allowing stability of the closing operation to be increased.
Further, the solenoid lever 36 retaining the restoring force of the cutoff spring 6 stays at a position where it should be situated at the closing operation completion time, thereby allowing stability of the closing operation to be increased.
Further, the engagement surface of the leading end 36a of the solenoid lever 36 is formed by a plane, and the trigger roller pin 31a pushes the leading end 36a of the solenoid lever 36 toward the rotation axis center 36b of the solenoid lever 36 at the time of the closing operation, so that no torque is applied from the trigger roller pin 31a to the solenoid lever 36 in the closed state. This allows a reduction in a size of the solenoid lever 36 to thereby minimize a force required for pulling out the solenoid lever 36, which in turn can minimize a size of the electromagnetic solenoid 38 for cutoff.
Further, the number of components is reduced as compared to the conventional example, material cost and the number of assembling steps can significantly be reduced.
According to the first embodiment described above, in the switchgear for opening/closing an electrical circuit and its operating mechanism, retention and release of a cutoff spring force is performed by a combination of a latch and its malfunction preventing mechanism. With this configuration, it is possible to reduce the time required for releasing the cutoff spring force to thereby reduce the entire contact opening time period. At the same time, stability and reliability of a retention state of the cutoff spring force can be improved.
In the present embodiment, the solenoid lever 36 is rotatably disposed relative to the anchoring lever 30. The solenoid lever return spring 37 is a tension spring and the spring force thereof always acts on the solenoid lever 36 as a clockwise torque. However, the rotation of the solenoid lever 36 is restricted by an engagement between a stopper pin 30d fixed to the anchoring lever 30 and the solenoid lever 36. Further, an end portion of the trigger lever return spring 33 is engaged with the pin 30b fixed to the anchoring lever 30.
In the present embodiment having the configuration as described above, the solenoid lever 36 can be disposed on the anchoring lever 30 like the latch 34 and the trigger lever 31, so that error in a positional relationship between the components can be reduced.
As illustrated in
Further, as illustrated in
In the present embodiment, a latch pin 34e is disposed on the latch 34, and a ring 42 is on the latch pin 34e so as to be movable in a radial direction of the latch pin 34e. An inner diameter of the ring 42 is larger than an outer diameter of the latch pin 34e.
A state immediately before completion of the closing operation of the present embodiment having the above configuration is illustrated in
When the latch 34 is returned to its closed-state position by the latch return spring 35, the leading end protrusion 34d of the latch 34 collides with the latch roller pin 12a and bounces off, so that the latch 34 is not stopped at its closed-state position but is rotated in the counterclockwise direction, which may release the engagement between the leading end 34c of the latch 34 and the latch roller pin 12a to cause malfunction.
However, in the present embodiment, when the leading end protrusion 34d of the latch 34 and the latch roller pin 12a collide with each other, the ring 42 is moved in a direction denoted by an arrow U (
According to the present embodiment, coming off of the latch 34 which may caused when the leading end protrusion 34d of the latch 34 and the latch roller pin 12a collide with each other in the closing operation is prevented by means of the ring 42, thereby increasing operational reliability of the spring operating mechanism.
Further, the mounting position of the ring 42 is not limited to the position illustrated in
Further, by designing the ring 42 to be formed of metal having high hardness and high density, a high-polymer material having high elasticity, or a complex thereof, it is possible to enhance the effect of preventing coming off of the latch 34.
Although compression coil springs are used as the cutoff spring 6 and the closing spring 21 in the above embodiments, other elastic bodies, such as torsion coil springs, disc springs, spiral springs, plate springs, air springs, and tension springs may be used alternatively. Further, although a coil spring or torsion coil spring is used as the return springs 27, 33, 35, and 37 provided in the anchoring lever 26 for closing, the trigger lever 31, the latch 34, and the solenoid lever 36, other elastic bodies such as disc springs, spiral springs, or plate springs may be used alternatively.
The present invention can also be applied to an apparatus having a plurality of cutoff springs or plurality of the closing springs.
Although the pin 5b engaged with the end portion of the trigger lever return spring 33 and the pin 30b engaged with the end portion of the latch return spring 35 are separately disposed in the first embodiment, the functions of the above two pins may be provided by one pin Although the stopper pin 5c for restricting the rotation of the trigger lever 31 and the stopper pin 30c for restricting the rotation of the latch 34 are separately disposed in the first embodiment, the functions of the above two pins may be provided by one pin.
Further, since the anchoring lever 30 is fixed to the frame 5, it may be omitted. In this case, the pin 30b and the stopper pin 30c, etc., may be directly fixed to the frame 5. Further, the pin 30b and the stopper pin 30c may be integrated with the anchoring lever 30 or the frame 5.
Although the stopper pin 5d is used to restrict the clockwise rotation of the solenoid lever 36 by the solenoid lever return spring 37, the plunger 38a of the electromagnetic solenoid 38 for cutoff may be used in place of the stopper pin 5d.
Further, it is possible to provide a plurality of the rings 42 of the fourth embodiment (
Further, although the ring 42 of the fourth embodiment has a hollow doughnut-like shape, the shape of the ring 42 is not limited to that shape, but the same effect can be obtained even with a shape other than the hollow doughnut-like shape.
Further, although the latch pin 34e and the ring 42 are mounted to the latch 34 of the first embodiment in the fourth embodiment, the latch pin 34e and the ring 42 may be mounted to the latch 34 of the second, third, or fifth embodiment.
Further, although the vibration absorbing member 43 is attached to the latch 34 of the first embodiment in the fifth embodiment (
Although the preferred embodiments of the present invention have been described above, the embodiments are merely illustrative and do not limit the scope of the present invention. These novel embodiments can be practiced in other various forms, and various omissions, substitutions and changes may be made without departing from the scope of the invention. The embodiments and modifications thereof are included in the scope or spirit of the present invention and in the appended claims and their equivalents.
Number | Date | Country | Kind |
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2011-018481 | Jan 2011 | JP | national |
This application is a continuation-in-part (CIP) application based upon the International Application PCT/JP2011/007350, the International Filing Date of which is Dec. 28, 2011, the entire content of which is incorporated herein by reference, and is based upon and claims the benefits of priority from the prior Japanese Patent Application No. 2011-018481, filed in the Japanese Patent Office on Jan. 31, 2011, the entire content of which is incorporated herein by reference.
Number | Date | Country | |
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Parent | PCT/JP2011/007350 | Dec 2011 | US |
Child | 13953119 | US |