Mitsubishi Denki Kabushiki Kaisha

Mitsubishi Electric Corporation

Nobuya Nakajima

Kyouichi Ohtsuka

Kyoichi Ohtsuka

Hitoshi Sadakuni

Tomohito Mori

Toshiaki Yoshizumi

Masato Kawahigashi

Mikio Hidaka

Kyouichi Ohtuka

Ken Komatsu

Mitsuyoshi Imura

In a gas-insulated switchgear provided with three-phase main bus bars consisting of single-phase bus bars arranged in parallel with one another and three-phase circuit breakers that are arranged in parallel with one another in a direction perpendicular to the main bus bar and each have two connecting terminals that are spaced a predetermined distance apart from each other, the main bus bars are arranged between two connecting terminals of each of the circuit breakers.

Gas-insulated switchgear

A compact, lightweight and low-cost operating apparatus for a switchgear include a second cam ( ) turned counterclockwise by an electric motor begins to maintain contact with a closing lever ( ) at a first angular position (POS ), turns the closing lever ( ) counterclockwise to energize a circuit-making coil spring ( ), and causes a closing latch ( ) to lock the closing lever ( ). The second cam ( ) further turning counterclockwise becomes separated from the closing lever ( ) and actuates a cam switch ( ) at a second angular position (POS ) to interrupt an electric current supplied to the electric motor. The second cam ( ) further turns due to inertial turning of the electric motor and is braked by a elastic brake member ( ) at a third angular position (POS ), whereby the second cam ( ) stops within a specific angular range &Dgr;&thgr; of rotation. Despite its simple structure, the elastic brake member ( ) can halt the second cam ( ) in a reliable fashion.

Switchgear operating apparatuses

A make break switchgear includes a first breaking lever receiving a torque in a counterclockwise direction, a second breaking lever connected through a linkage to the first breaking lever, and a making lever receiving a torque in a clockwise direction. These elements are supported by a main shaft and are rotatable. When a circuit is completely opened by the switchgear, a guide guiding a rotor on an arched surface is engaged with a first releasing latch. It is unnecessary to wait for engagement between the first releasing latch and the guide after the circuit is closed for opening the switchgear, and a subsequent opening can be immediately started. Therefore, it is possible to reduce the time from the closing of a make break contact to starting of the next opening.

Control device for make break switch

A cylindrical insulating rod and a connecting rod are connected to each other by a metallic shield ring and a connecting pin . The metallic shield ring has second shield portions and for electrical field relaxation on the external surface, and in which an inserted end receiving portion of the insulating rod is inserted. The connecting pin is inserted through the metallic shield ring , the inserted end receiving portion of the insulating rod and an end portion of the connecting rod . The insulation-operating rod is capable of being small-sized, and has stable mechanical and electrical characteristics.

Insulation-operating rod

In a driving force storing device for a switch operating mechanism, a joint device has a first joint portion including a first opposing surface, a second joint portion including a second opposing surface, and a coupling portion. A first torsion bar is connected between the first joint portion and a driving shaft portion. A second torsion bar is connected between the second joint portion and a fixed member. A torque is applied to the joint device by the first and second torsion bars in a direction where the first and second opposing surfaces are separated from each other and the first and second joint portions are pushed toward the coupling portion.

Driving force storing device for a switch operating mechanism

A making operation preventing device has a releasing trigger for retaining, via a releasing latch , a breaking lever to which a torque in a counterclockwise direction is applied by an opening torsion bar ; a releasing electromagnet for opening an on-off contact by releasing the engagement between the releasing trigger and the releasing latch to rotate the breaking lever in a counterclockwise direction; a cam rotated as one body with a gear connected via a link to a making lever to which a torque in a counterclockwise direction is applied by a closing torsion bar ; a making trigger which retains a second pin attached to the cam via a making latch and maintains the closing torsion bar in a prestressing state; a releasing electromagnet for driving a trigger lever in a right direction to release the engagement between the making latch and the making trigger , and an interlocking electromagnet for rotating the trigger lever in a counterclockwise direction when a circuit opening instruction is generated to thereby prevent a circuit closing operation.

Control device for breaker

A device for controlling a breaker comprising a weight (,) provided in the vicinity of a releasing trigger (,) and an auxiliary spring (,)for urging the weight (,) so that the weight (,)is in contact with the releasing trigger (,). An equivalent mass of the weight (,)is about one-third of an equivalent mass of the releasing trigger. When the releasing trigger (,)is in contact with a pin (,) of a releasing latch (,), the weight (,)rebounds but the releasing trigger (,)is settled without rebounding. By such a structure, the rebound of releasing latch and the releasing trigger is prevented when these are engaged, whereby a time for closing a circuit is shortened.

Device for controlling a breaker

A switch control device includes a prestressing spring, a make-break contact, and at least one of a device for closing a circuit and a device for opening the circuit, wherein the device for closing the circuit includes a first elastic member, closing the make-break contact with a releasing force applied by the prestressing spring, and a second elastic member for aiding closing of the circuit and prestressed by the prestressing spring, and the device for opening the circuit includes a third elastic member for opening the circuit by opening the make-break contact with a releasing force and a fourth elastic member for aiding opening of the circuit, aiding the releasing force of the third elastic member.

Switch control device

In a stationary contact unit of a gas circuit breaker, an arc-quenching cylinder for passing an arc-quenching insulation gas is formed in a substantially semicircular shape, and the stationary contact unit is supported by an insulation frame which is disposed beneath the dent part of the semicircular portion of the arc-quenching cylinder. The insulation frame is prevented from the degradation of dielectric strength between the stationary contact unit and a grounded tank, and the size of the gas circuit breaker is decreased.

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Tokyo, Japan

Nobuya Nakajima