OPERATING DEVICE |
|||||||
申请号 | EP09843975.5 | 申请日 | 2009-04-27 | 公开(公告)号 | EP2426686A1 | 公开(公告)日 | 2012-03-07 |
申请人 | Mitsubishi Electric Corporation; | 发明人 | MORI, Tsuyoshi; FUJITA, Daisuke; KAWAHIGASHI, Masato; | ||||
摘要 | To prevent generation of an unexpected load between a main body of a switch 1 and an operating device 2, to prevent breakage of a power transmission mechanism 3, and to match an open/close state of the operating device 2 with an open/close state of the main body of the switch 1. A torque limiter 10 is provided between a motor 7 and a speed reduction mechanism 11 in the operating device 2. Further, the operating device has a circuit configuration such that, after completing an open/close operation, a circuit configuration of a motor control circuit 8 is switched, and a braking current flows to resistors R1 and R2. By reducing a torque generated by the motor 7, an application load to the power transmission mechanism 3 is reduced. | ||||||
权利要求 | |||||||
说明书全文 | The present invention relates to an operating device of a switch. In a conventional switch, a window that enables visual confirmation of a switch main body is provided, to prepare for a case when mismatch occurs between an open/close state of the switch main body and a display state of a switch display that is provided in an operating device. According to Patent Literature 1, in an electric-spring operating device, there is provided a torque limiter that generates slide when a load torque becomes equal to or larger than a predetermined value between a motor that accumulates energy of a spring and gears, thereby preventing breakage of a power transmission mechanism itself by an excessive load torque. Patent Literature 1: Japanese Utility Model Laid-open Publication No. In a power transmission mechanism of a conventional switch, when a load equal to or larger than that assumed in designing occurs, for example, when a frictional resistance of a sliding unit in the mechanism increases or when a parts fastening bolt becomes loose, there is a possibility that a part in the power transmission mechanism is broken, that a switch at a main circuit side does not operate although an open/close operation is completed at an operating device side, and that an open/close state of the operating device and an open/close state of a switch main body do not match each other. At an electric power substation, for example, a portion to be monitored is grounded by turning on a separate switch after a circuit is separated from a system in an operation of maintenance and monitoring. In this case, if the state of the switch cannot be correctly confirmed, it is possible that a high voltage portion is erroneously turned on. Furthermore, in an operating device having a torque limiter incorporated therein described in Patent Literature 1, the device has an object of preventing generation of an excessive load by controlling not to transmit an excessive torque equal to or larger than an assumed value. However, when the torque limiter operates immediately before completing an open/close operation, the mechanism continues operating based on inertia of a rotation shaft at a power transmission mechanism side immediately after a torque limiter operation. As a result, there is a possibility that other parts are broken due to a collision between parts in the mechanism. The present invention has been achieved in view of the above problems, and an object of the present invention is to provide an operating device that can prevent generation of an unexpected load between a switch main body and the operating device, prevent breakage of a power transmission mechanism, and match an open/close state of the operating device with an open/close state of the switch main body. In order to solve above-mentioned problems and to achieve the object, an operating device according to the present invention including a motor, a motor control circuit that controls the motor, an operating circuit that controls the motor control circuit, and a torque limiter that does not output a torque equal to or larger than a predetermined value by the motor, and that performs an open/close operation by transmitting a torque by the motor to a switch via a power transmission mechanism, wherein during a turn-on operation or a turn-off operation of the switch, the operating circuit controls the motor control circuit in a circuit configuration including a first series circuit in which a motor armature of the motor and a motor field element are connected in series and in which a motor current flows, and during a certain time after completing a turn-on operation or a turn-off operation, the operating circuit controls the motor control circuit in a circuit configuration including a closed loop circuit in which the motor armature and a first resistor are connected in series and a second series circuit in which the motor armature and a second resistor are connected in series. According to the present invention, by converting the energy of an inertia motion of a motor into heat energy via first and second resistors immediately after completing a turn-on operation or an open operation, a torque generated by the inertia motion of the motor after disconnecting a motor current can be reduced, and a load that is applied to a motor transmission mechanism is reduced. Therefore, generation of a torque equal to or larger than that assumed in designing can be prevented even after completing a turn-on operation or an open operation. Therefore, according to the present invention, it is possible to prevent generation of an unexpected load between a switch main body and an operating device, to prevent breakage of a power transmission mechanism, and to match an open/close state of the operating device with an open/close state of the switch main body.
Exemplary embodiments of an operating device according to the present invention will be explained below in detail with reference to the accompanying drawings. The present invention is not limited to the embodiments. The switch 1 includes a switching unit 5 that includes a conductor that performs an open/close operation in a tank 4 that is sealed with a gas. A monitoring window 6 provided in the tank 4 is for visually confirming an open/close state. In the operating device 2, a motor 7 as a generation source of an operation force is provided. The motor 7 is controlled by a motor control circuit 8, and the motor control circuit 8 is controlled by an operating circuit 9. A power transmission shaft as a rotation shaft of the motor 7 is connected to a speed reduction mechanism 11. Rotation of the motor 7 is decelerated via the speed reduction mechanism 11, and thereafter is transmitted as rotation of an output shaft 13 of the speed reduction mechanism 11. The output shaft 13 is connected to the power transmission mechanism 3, and operates the switching unit 5 as a main body of the switch 1 via a shaft that is hermetically accommodated in the tank 4. The power transmission mechanism 3 is configured to include a shaft, for example. In the present embodiment, a torque limiter 10 is provided that stops transmission of a torque when a torque equal to or larger than a predetermined value is generated between the motor 7 and the speed reduction mechanism 11. In the operating device 2, an open/close state display mechanism 12 is provided that can display an open/close state by moving a display plate with a bar that is coordinated with the output shaft 13, for example. A circuit configuration of the operating circuit 9 is explained next. A relay CX22 represents a coil portion of a relay used for a turn-on operation (a close operation). The relay CX22 includes contacts CX23 and CX25. The limit switch H is connected between the relay CX22 and the contact CX23. An input signal voltage as a turn-on operation signal (a closed-path command signal) can be applied between the limit switch H and the contact CX23. When the turn-on operation signal is input in a closed state of the limit switch H like in an example shown in A relay TX20 indicates a coil portion of a relay used for a turn-off operation (an open operation). The relay TX20 includes contacts TX21 and TX24. The limit switch L is connected between the relay TX20 and the contact TX21. An input signal voltage as a turn-off operation signal (an open-path command signal) can be applied between the limit switch L and the contact TX21. The contacts TX21 and TX24 can be open/close controlled by exciting a coil of the relay TX20 or by cancelling excitation of the coil. An operating voltage is always applied to both ends of the contact TX21, the limit switch L, and the relay TX20 that are connected in series. A timer relay T has a contact Ta and a contact Tb. The contact Ta is opened when a coil incorporated in the relay T is excited, and closes when excitation is cancelled. In the example shown in The operating circuit 9 further includes relays AX and BX. The relay AX or BX is connected in series to the contact Tb and the contact Ta, and an operating voltage is applied to their both ends. A circuit configuration of the motor control circuit 8 is explained next. In The contacts CX26 and CX27 are those of the relay CX22, respectively. The contacts TX28 and TX29 are those of the relay TX20, respectively. In In Although the motor 7 and the motor control circuit 8 are shown separately in An operation in the present embodiment is explained next with reference to First, the switch 1 is in an open state, and in this case, the operating circuit 9 and the motor control circuit 8 are in an initial state (a switched-off state) of Next, when the switching unit 5 reaches a turn-on position, the limit switch H opens, and excitation of the relay CX22 is cancelled and the contacts CX23, CX25, CX26, and CX27 are opened, thereby disconnecting a motor current that flows to the motor armature M and the motor field element MF ( Further, in this case, a current that flows through a field winding of the motor field element MF is also reduced by the resistor R2 ( When a certain time set in advance by a timer passes after a coil of the timer relay T is excited, the contact Tb is opened ( An open-path operation can be also similarly explained. In this case, in As explained above, in the present embodiment, the operating device 2 includes the torque limiter 10 that causes the power transmission shaft of the motor 7 to slide when a torque exceeds a constant torque value. Further, because breakage of the power transmission mechanism 3 due to collision of parts occurs at the end of the open/close operation, the operating circuit 9 is controlled in a circuit configuration such that after completing an open/close operation, a braking current flows to the resistors R1 and R2 by switching the motor control circuit 8. According to the present embodiment, in addition to providing the torque limiter 10, energy of an inertia motion of the motor 7 is converted to heat energy via the braking circuit that includes the resistors R1 and R2 that are configured in the motor control circuit 8, after completing a turn-on operation or an open operation. With this arrangement, a torque generated by the inertia motion of the motor 7 after disconnecting a motor current can be reduced, a torque generated in the output shaft 13 that is transmitted from the motor 7 becomes small, and a load that is added to the power transmission mechanism 3 and the main body of the switch 1 can be suppressed. Therefore, according to the present embodiment, it becomes possible to prevent occurrence of an unexpected load between the main body of the switch 1 and the operating device 2, prevent breakage of the power transmission mechanism 3, and match an open/close state of the operating device 2 with an open/close state of the main body of the switch 1. In the present embodiment, the open/close state display mechanism 12 is arranged nearer to a main body side of the switch 1 than to the torque limiter 10. That is, the torque limiter 10 is provided between the motor 7 and the speed reduction mechanism 11, and is mounted on the power transmission shaft of the motor 7. On the other hand, the open/close state display mechanism 12 is provided at the main body side of the switch 1, and displays an open/close state of the switch 1 that is coordinated with the output shaft 13. Accordingly, even when the torque limiter 10 operates due to generation of a torque equal to or larger than that assumed in designing, the open/close state display mechanism 12 can display a state of the main body of the switch 1 because the open/close state display mechanism 12 is coordinated with the output shaft 13. When the open/close state display mechanism 12 is provided between the motor 7 and the torque limiter 10, for example, the open/close state display mechanism 12 displays an open/close state of the switch 1 that is coordinated with the power transmission shaft of the motor 7. When the torque limiter 10 operates and when rotation of the motor 7 is not transmitted to the output shaft 13, a state of the main body of the switch 1 cannot be correctly displayed. There is also a merit that installation of the monitoring window 6 can be omitted by improving the reliability of the open/close state display mechanism 12. The operating device 2 accumulates energy of the spring 15 via the speed reduction mechanism 11 by rotation of the motor 7. When the energy-accumulated spring 15 reaches a predetermined point, energy accumulation is completed, and the spring 15 releases energy and rotates the output shaft 13. The operating circuit 9 according to the present embodiment is identical to that shown in Next, the limit switch H is opened simultaneously with the completion of energy accumulation of the spring 15, and the operating circuit 9 and the motor control circuit 8 operate as shown in As shown in According to the present embodiment, because a motor current is disconnected after completing accumulation of energy of the spring 15 by the motor 7, a subsequent torque by the motor 7 is based on inertia rotation, and a load that is applied to the power transmission mechanism 3 by the motor 7 is reduced. Because a circuit is configured such that a braking current is generated in the motor control circuit 8 simultaneously with the completion of energy accumulation of the spring 15, a torque by the inertia rotation of the motor 7 can be reduced. By superimposing a torque by the inertia rotation of the motor 7 on a torque by the spring 15, generation of a torque equal to or larger than that assumed in designing can be prevented. Other effects of the present embodiment are identical to those of the first embodiment. As explained above, in the operating devices 2 and 52 according to the present invention, there are effects that designing of the strength of a mechanism is optimized by suppressing an output and that an open/close state of the operating devices 2 and 52 can be matched with an open/close state of the main body of the switch 1. The present invention is useful as an operating device of a switch of a gas-insulating switch device. |