JPS624989Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an interlock device for a gas switch, and more particularly to a device that can interlock both during depressurization and manual operation.

In a gas switch, when the insulating gas pressure is low, the insulation is reduced and opening/closing is dangerous, so a pressure sensor must be used to detect the drop in gas pressure and disable electrical opening/closing operations. When depressurizing, it is necessary to interlock the electrical operating circuit. Also, manual opening/closing operations are dangerous during depressurization, so the manual operation mechanism must also be interlocked when depressurizing.

On the other hand, even if the gas pressure is normal, when performing manual opening/closing operations for inspection, etc., if electrical opening/closing operations are performed by mistake, abnormal situations such as flash shorts or electric shocks may occur, or during manual operation. Since it is dangerous to apply sudden force due to electrical operation, it is necessary to interlock the electrical operation circuit even during manual operation.

Conventionally, devices for each of the above-mentioned interlocks were provided separately, which not only required a large installation space but also required a large number of parts and a large amount of time and effort for installation and wiring.

SUMMARY OF THE INVENTION It is an object of the present invention to overcome the above-mentioned drawbacks and to provide a simple interlock device that can perform the conventionally separate interlocks at once.

In order to achieve such an object, the feature of the present invention is to provide a limit switch as an interlock switch for a gas switch, which is fixed to one of the rotary lever and the operating lever and is opened and closed by being brought into contact with and separated from the other. The rotary lever is biased by a spring and is locked in a normal position by a stopper, and this locking is released by the operation of a pressure reduction operating rod when the pressure is reduced. The contact point of the limit switch is held in a constant state by the rotary lever only in the normal position, and the contact point is moved in the opposite direction by attaching a manual operation handle to the gas switch to release the holding of the contact point. An interlock plate is provided which rotates together with the rotary lever to prevent the manual operation handle from operating.

The present invention will be described below with reference to an embodiment shown in the drawings. FIG. 1 is a plan view of the main parts of the interlock device according to the embodiment, and FIG. 2 is a front view showing the main parts of FIG. 1, both of which are shown with the wall plate of the operation box 1 cut away. FIG. 3 is a schematic perspective view of the vicinity of the rotary lever 4, and FIG. 4 is a schematic perspective view of the vicinity of the operating lever 10. Note that the main body of the gas switch including the operating mechanism is not shown. Further, the arrows in the figure indicate the direction of movement of each member during interlock.

In these figures, 2 is a limit switch,
Reference numeral 2a designates the operating lever, which is a switch for performing electrical interlock such as opening and closing of the contacts to open the control circuit of the motor of the electrical opening/closing operation mechanism to prevent automatic closing. This limit switch 2 is fixed to one end of a rotatable lever 4 fixed to the upper end of a rotating shaft 3. A projection plate 5 is fixed to the other end of the rotary lever 4. The rotary lever 4 is always urged to rotate counterclockwise by a helical spring 6, and the protrusion plate 5 is pressed against the stopper 7.
By locking the stopper 7, it is set and held at the normal position, and by releasing the locking of the stopper 7, it is removed from the normal position by the force of the spring. Further, an interlock plate 8 for preventing manual operation is integrally fixed to the lower end of the rotating shaft 3, and rotates together with the rotating lever 4 to lock the up and down movement of the manual operation handle 9 which will be described later. A concave cutout 8a is formed.

In contrast to the operating lever 2a of the limit switch 2, an operating lever 10 is fixed to a rotating shaft 11 and is arranged to rotate up and down. The operating lever 10 is brought into contact with the operating lever 2a of the limit switch 2 by a helical spring 12 to maintain the contact in a normally closed state. Further, an engagement lever 13 for the manual operation handle 9 is fixed to the rotating shaft 11 to which the operation lever 10 is individually attached so as to rotate together, and the manual operation handle 9 is attached to the joint shaft 14 of the closing/opening operation shaft 23. As a result, it is pushed up by its upper end and rotated. The manual operation handle 9 has an insertion hole and a notch at its upper end, and the joint shaft 14 is rotated by fitting the insertion hole into the lower end of the joint shaft 14 and engaging the pin 14a with the notch.

On the other hand, the stopper 7 that is engaged with the protrusion plate 5 of the rotary lever 4 is fixed to an arm 16 that is supported by a fixed shaft 15 and rotates around this, and is constantly detached from the protrusion plate 5 via a spring 17. is urged to do so. On the other hand, arm 16 is
A pressure reduction actuation rod 2 that is pulled in by a spring 19 when the gas pressure in the gas chamber 18 drops below a set value.
0 and is normally held in the set state as shown in the figure. The gas chamber 18 is connected to the main body of the gas switch (not shown) via a gas pipe 21, and when the gas pressure of the gas switch decreases, the gas pressure of the gas chamber 18 decreases and the spring 1
The pressure reducing rod 20 is pulled in by the spring force 9, and the arm 16 rotates clockwise to release the stopper 7.

A pressure reduction display plate 22 is integrally provided on the manual operation prevention interlock plate 8, and the pressure reduction operating rod 20 is activated to rotate the rotary lever 4 counterclockwise, and accordingly, the limit switch 2 is activated. When the actuating lever 2a is disengaged from the operating lever 10, the pressure reduction display plate 22 also rotates together to indicate that the pressure reduction interlock has been established. At the same time, the concave notch 8a of the interlock plate 8 for preventing manual operation engages with the lower part of the pin 14a of the joint shaft 14, so that the manual operation handle 9 cannot be operated.

Next, the operation of the interlock device of the present invention constructed as described above will be explained. First, when performing manual operation to inspect or adjust the gas switch, push up the manual operation handle 9 and engage it with the pin 14a of the joint shaft 14.
As a result, the operating lever 10 is rotated counterclockwise against the helical spring 12,
The normally closed state of limit switch 2 is released. Therefore, electric circuits etc. are turned off, and circuits such as motors (not shown) are opened to prevent automatic closing.

Further, when the pressure of the sealed gas in a gas switch (not shown) drops below a set value, the pressure reducing rod 20 is pulled in by the spring 19 and detached from the arm 16. As a result, the stopper 7 is lifted by the spring 17 and released from the engagement with the projection plate 5 of the rotary lever 4, so the rotary lever 4 is rotated counterclockwise by the helical spring 6, and the limit switch 2 fixed to the tip is activated. The lever 2a is separated from the operating lever 10 and the normally closed state is released.

Further, at the same time that the stopper 7 is separated from the projection plate 5 and the normally closed state of the limit switch 2 is released, the notch 8a of the interlock plate 8 for preventing manual operation is moved to the _A0 point as the rotary lever 4 rotates. from
A It rotates to _one point and engages the joint shaft 14 below the pin 14a, so even if you try to push up the manual operation handle 9 to operate the opening/closing operation shaft 23 of the gas switch, the manual operation handle 9 will not connect to the joint shaft. 14, and manual operation becomes impossible. Note that the rotary lever 4 stops at point B when the interlock plate 8 engages with the joint shaft 14.

As explained in detail above, according to the present invention,
When the gas pressure in the gas switch drops, the rotary lever to which the limit switch is attached rotates to release the contact and prevent the motor from operating, so the circuit breaker, etc. will not be operated due to poor gas insulation. do not have. Furthermore, during manual operation, the operating lever releases the contact of the limit switch in conjunction with the mounting operation of the manual operating handle, thereby preventing electrical operation and allowing inspection and adjustment work to be performed safely. Further, when the gas pressure in the gas switch drops below a set value, the gas switch can be automatically electrically interlocked and the manual operation handle can be prevented from operating.

In this way, the interlock device of the present invention can perform various interlocks at once, requiring less installation space, and requires only one limit switch, which simplifies installation and wiring. The effect is extremely noticeable.

In the embodiment, the limit switch 2 is fixed to the rotary lever 4, but the same effect can be obtained even if the limit switch 2 is fixed to the operating lever 10 and the rotating lever 4 is moved toward and away from the operating lever 2a.

[Brief explanation of the drawing]

Fig. 1 is a plan view showing one embodiment of the interlock device according to the present invention, Fig. 2 is a front view showing the main parts of Fig. 1, Fig. 3 is a schematic perspective view of the vicinity of the rotary lever, and Fig. 4 is FIG. 3 is a schematic perspective view of the vicinity of the operating lever. In the drawing, 1 is the operation box, 2 is the limit switch, 2
a is its operating lever, 3 is a rotation shaft, 4 is a rotation lever, 5 is a projection plate, 6 is a spiral spring, 7 is a stopper, 8 is an interlock plate, 9 is a manual operation handle, 10 is an operation lever, 11 is Rotation shaft, 12 spiral spring, 13 engagement lever, 14 joint shaft, 15 fixed shaft, 16 arm, 17 spring, 18 gas chamber, 19 spring, 20
21 is a gas pipe, 22 is a reduced pressure display plate, and 23 is an opening/closing operation shaft.

Claims (1)

[Scope of utility model registration request] As an interlock switch for the gas switch, a limit switch is fixed to one of the rotary lever and the operating lever, and is opened and closed by moving toward and away from the other.The rotary lever is biased by a spring and held in a normal position by a stopper. and the locking is released by the operation of a pressure reduction operating rod when the pressure is reduced, and the operating lever is biased by a spring to maintain the contact point of the limit switch in a constant state with the rotating lever only in the normal position. At the same time, when the manual operation handle is attached to the gas switch, the gas switch is moved in a counter-biasing direction to release the holding of the contact, and further rotates together with the rotary lever to operate the manual operation handle. Gas switch interlock device equipped with an interlock plate to prevent