JPH09200911A - Locking device for the back cover of a closed switchboard - Google Patents

Abstract

(57) [Abstract] [PROBLEMS] When the main circuit in a closed type switchboard is inspected, the back cover can be removed only when the main circuit is grounded by a ground switch and there is no voltage. A possible structure is to provide a locking device for the back cover that prevents a dangerous condition during inspection. SOLUTION: A fixing jig 11 having a rectangular through hole 11a attached to an inner surface of a back cover 1a and an operating shaft 5a for driving a ground blade 5d of a ground switch 5 are provided on the fixing jig 11 side. And a holding jig 10 having a protruding portion 10a that is inserted into and locked in the through hole 11a of the fixing jig 11 provided at the tip of the holding jig 10, and drives the operating shaft 5a to ground the switch 5. The ground contactor 5e and the blade 5d are fixed in contact with each other, and when the main circuit is in the grounded state, the locking state between the fastening jig 10 and the fixing jig 11 is released.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of a lock device for preventing removal of a back cover which constitutes a metal container of a closed type switchboard for storing power distribution equipment by an interlock mechanism with an operation shaft of a ground switch.

[0002]

7 to 9 show the structure of a conventional closed type switchboard, and FIG. 7 is a sectional view of the closed type switchboard, and FIG.
Is a partial front view of the back cover installed on the closed switchboard,
FIG. 9 is an enlarged view of the arrow P in FIG. The metal container that constitutes the closed type switchboard is required to have a structure having sufficient strength for accommodating devices and the like and ensuring the safety of the human body.
Therefore, as shown in FIGS. 7 and 8, a cover 1 made of a steel plate is attached to a frame 2 which constitutes a framework of a metal container and bolts 3
It is configured to be fixed by such as. The cover 1 that constitutes this metal container is used for normal operation such as control operation of the circuit breaker 4 and the grounding switch 5 for the purpose of preventing the main circuit of the stored device or the like from approaching the charging part. When it is necessary to open the door occasionally, a door 7 with a hinge 6 provided on the front side of the closed type switchboard on the right side of FIG. On the other hand, in the case of the rear cover 1a on the side where the power supply wiring 8 such as the main bus bar 8a and the main circuit cable 8b, which need not be opened during normal operation, is located, so that it cannot be opened or removed without using tools, The bolt 3 as shown in FIG. 8 and FIG.
The structure is fixed by screwing on.

The maintenance inspection of the closed type switchboard includes a daily inspection and a regular inspection. In this daily inspection, an abnormality from the outside is visually inspected. Therefore, the cover 1 constituting the metal container is removed. Done without. On the other hand, when it is necessary to perform detailed inspections at the time of regular inspections and the above-mentioned daily inspection inspections, the back cover 1a is removed and the inside of the closed type switchboard (panel) is inserted into the above-mentioned equipment and power supply wiring. Perform an internal inspection of the main circuit of. In the case of this internal inspection, the closed type switchboard is completely cut off for safety, and the circuit breaker 4 is cut off to put the main circuit in a non-voltage state, and the ground switch 5 is turned on to be grounded. When the ground switch 5 is turned on, the operating shaft 5a is rotated, and the rod end 5b connected to the operating shaft 5a is vertically moved to move the movable lever 5c.
Through the ground blade 5d to the ground contactor 5e
It is carried out by contacting and fixing.

[0004]

By the way, in the structure for fixing and fixing the back cover of the rear portion of the conventional closed type switchboard by the bolts, the bolts can be removed from the back cover at any time. Therefore, the above-mentioned inspection work of the closed type switchboard is usually done after the safety inspection according to the inspection manual, but at the time of inspection in the case of an abnormal situation, etc., the main switch by the earthing switch after the circuit breaker is cut off. Since it is possible to enter the panel without waiting for the circuit to be grounded and to go into a no-voltage state, there is a risk of encountering a dangerous state where the main circuit is in a charged state or has a residual charge. There is a problem that there is. An object of the present invention is to remove the rear cover only when the main circuit is grounded by a grounding switch and there is no voltage during inspection of the conventional closed type switchboard as described above, and it is impossible to remove it during charging. Another object of the present invention is to provide a lock device for the back cover that prevents a dangerous state during inspection.

[0005]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention relates to a fixing jig attached to the inner surface of a back cover, and a fixing jig fitted to the fixing jig to fix the back cover. The holding jig is connected to an operation shaft for driving the ground blade of the ground switch, and the main circuit is driven by the operation shaft so that the main circuit includes a ground contactor of the ground switch and a blade. It is configured such that the fitting between the fastening jig and the fixing jig is released when the contact fixing and grounding state are achieved. This makes it possible to remove the back cover only when the main circuit is grounded by the grounding switch and there is no voltage when entering the panel for power supply and equipment inspection work. It is possible to perform the inspection work in a safe state without the risk of such as.

Further, by providing a fastening jig which is fitted and fixed to the fixing jig provided on the back cover, directly on the other end portion of the operation shaft extended in the direction of the fixing jig, It is possible to obtain the target back cover locking device with a simpler structure.

Further, in addition to the above-described locking device, a structure is provided in which protrusions having groove portions which fit into a frame for supporting the back cover are provided on both upper and lower surfaces of the inner surface of the back cover. Therefore, even after the lock of the back cover is released, a work process that can be removed only by lifting the back cover up and down and moving it from the back cover groove is added, so safety when removing the back cover is added. Can be further improved.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 3 show a structure of a closed type switchboard according to an embodiment of the present invention, FIG. 1 is a partial sectional view of the closed type switchboard, FIG. 2 is an enlarged sectional view of a Q portion of FIG.
FIG. 3 is a view on arrow R of FIG. As shown in FIG. 1, the lock portion 9 for preventing the rear cover 1a from being removed is provided with the ground blade 5 of the ground switch 5 for making the main circuit non-voltage.
The operation shaft 5a for rotating d is extended to the back cover 1a side, and the fastening jig 10 shown in FIGS. 2 and 3 provided at the end thereof, and the back cover at a position facing the fastening jig 10. It is composed of a fixing jig 11 fixed to the side surface of 1a by welding or screws. And the above-mentioned fastening jig 1
Reference numeral 0 denotes a flat plate-shaped projecting plate 10a projecting in the radial direction of the operation shaft 5a. The fixing jig 11 has a rectangular through hole 11a on the surface facing the fastening jig 10.
Is provided. 2 and 3, 12 is aligned for fixing the back cover 1a to the frames 2 positioned on the left and right of the back cover 1a, and is supported by the frame 1 in the up and down directions described later. It is a side plate having a function.

The back cover 1 including the above-mentioned lock portion 9
In the lock device of a, the grounding blade 5d shown in FIG. 1 in which the closed switchboard is in operation or the grounding switch 5 is not turned on after the breaker 4 is cut off is grounded at the position A ₁ shown by the dotted line. When not connected to the child 5e, the projecting plate 10a of the fastening jig 10 connected to the operation shaft 5a of the grounding switch 5 is at the position B ₁ in FIGS. It is in a locked state in which it is inserted and fitted in the through hole 11. Therefore, in such a locked state, even when the bolt 3 to which the back cover 1a is attached to the frame 2 is removed, the through hole 11 of the fixing jig 11 described above is used.
The protruding plate 10a of the fastening jig 10 attached to the a serves as a stopper, and the state in which the back cover 1a is fixed to the frame 2 can be held.

Next, at the time of inspection, the circuit breaker 4 is turned off, and
As shown in Fig. 4, the operation shaft 5a of the grounding switch 5 is rotated to fix the grounding blade 5d to the grounding contact 5c at the position A ₂ , and the grounding switch 5 is closed to ground the main circuit of the closed switchboard. When no voltage is applied, the projecting plate 10a of the fastening jig 10 moves to the state of B ₂ in FIG. 3, that is, as shown in FIG. Since the locking jig 10 is unlocked at the position opened from the through hole 11a, the back cover 1a can be moved after the bolt 3 is removed.

Further, the rear cover 1a of the present invention is provided on the left and right sides of the rear cover 1a so as to prevent the rear cover 1a from being immediately removed even if the interlock mechanism with the ground switch 5 is released. The side plate 12 made of a steel plate is fixedly provided by bolts or welding.
That is, as shown in FIG. 3, the side plate 12 has an inner side of the rear cover 1a so that when the rear cover 1a is fixed to the frame 2, the left and right frames 2 can be positioned with a space of about 2 mm. 4 is provided so as to project into
As shown in FIG. 2, the frames 2a, 2a positioned in the vertical direction are configured to be inserted into and supported by the groove portions 12a, 12a formed by cutting out a part of the both ends of the side plate 12 on the side of the back cover 1a. There is.

By providing the side plates 12 on the left and right end surfaces of the inner surface of the back cover 1a, the lock state of the lock portion 9 including the fastening jig 10 and the fixing jig 11 is released. Also in the state of 4, the back cover 1a cannot be removed from the frame 2 because of the protrusions 12b adjacent to the grooves 12a at both ends of the side plate 12. At the time of removal, as shown in FIG.
The rear cover 2a is lifted in the direction from O to O ₁ indicated by an arrow so that a is located above the end of the frame 2a, and then moved in the direction from O ₁ to O ₂ so that the rear cover 2a is moved from the frame 2a to the back. The cover 1a can be removed.

The side plate 12 also constitutes the positioning when the back cover 2a is fixed to the left and right frames 2 and 2 (see FIGS. 3 and 8) as described above, and thus is described above. It also has a function of preventing the rear cover 2a from moving in the left and right directions and being removed unless the locked state by the groove 12a is released.

The side plate 12 having the groove portion 12a held between the frames 2 does not have to be an integral body which is vertically continuous with the back cover 2a shown in FIG.
As shown in FIG. 6, the side plate 121 having a length dimension that allows positioning between the frames 2 and 2 is provided on the frames 2a and 2
The structure may be such that the back cover 1a where a is located is attached to the upper and lower positions and the left and right ends of the back cover 1a.

[0015]

As described above, according to the present invention, the fixing jig attached to the inner surface of the back cover and the fastening jig provided in connection with the operating shaft for driving the ground blade of the ground switch. When the main circuit is brought into contact with and fixed to the ground contactor of the ground switch and the blade by the drive of the operation shaft, the fitting between the fastening jig and the fixing jig is released. The locking device is configured as an interlock with the grounding switch configured as described above. As a result, the back cover can be removed only when the main circuit is grounded by the grounding switch and is in a non-voltage state, so that the inspection work can always be performed in a safe state in the panel.

In addition to the above-described locking device, a structure is also provided in which protrusions having groove portions that fit into a frame supporting the back cover are provided on both sides of the top and bottom ends of the back cover inside the closed type switchboard. By doing so, after the lock of the back cover is released, a work step of moving and removing the back cover from the upper and lower groove portions is required, so that the safety at the time of removing the back cover can be further improved. Furthermore, by configuring the above-mentioned protruding portion from the side plates that are inserted and positioned between the left and right frames that fix the rear cover, it is possible to prevent the rear cover from moving and removing in the left and right directions. The safety can be improved.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional view of a closed switchboard according to an embodiment of the present invention.

FIG. 2 is an enlarged sectional view of a Q portion of FIG.

FIG. 3 is a view on arrow R in FIG.

FIG. 4 is a partial perspective view of the inside of the back cover in which the locked state is released by the lock device.

FIG. 5 is a partial cross-sectional view showing a state where the back cover is removed from the frame.

FIG. 6 is a partial perspective view of the inside of a back cover having a configuration different from that of FIG.

FIG. 7 is a cross-sectional view of a conventional closed switchboard.

FIG. 8 is a front view of a rear cover of the closed switchboard.

9 is an enlarged view of the arrow P view of FIG. 7. FIG.

[Explanation of symbols]

 1 Cover 2a Rear Cover 2 Frame 2a Frame 5 Grounding Switch 5a Operation Axis 5b Rod End 5e Grounding Contact 9 Locking Part 10 Locking Jig 10a Projecting Plate 11 Fixing Tool 12 Side Plate 12a Groove 12b Projecting 121 Side Plate

Claims (4)

[Claims] 1. A lock device for preventing removal of a rear cover fixed to a frame of a closed type switchboard, the fixing device being attached to an inner surface of the rear cover, and the fixing jig. And a fastening jig for fixing the back cover, the fastening jig being provided in connection with an operating shaft for driving the ground blade of the grounding switch, the grounding blade being grounded by the driving of the operating shaft. A lock device for a rear cover of a closed type switchboard, wherein the fastening jig and the fixing jig are disengaged from each other when the main circuit is brought into a grounded state by being fixed in contact with the contactor. 2. The locking device according to claim 1, wherein a fastening jig that is connected to and driven by the operating shaft of the grounding switch is provided at an end of the operating shaft extending in the direction of the fixing jig. A locking device for a rear cover of a closed type switchboard, which is characterized in that 3. The lock device according to claim 1 or 2, wherein the upper and lower ends of the inner surface of the back cover are each provided with a protrusion having a groove for fitting and supporting the back cover in a frame. Provided, and after the fitting between the fastening jig and the fixing jig is released, the back cover is lifted up and down,
A lock device for a rear cover of a closed type switchboard, wherein the rear cover is removable by moving it from the upper and lower grooves. 4. The lock device according to claim 3, wherein the protrusions having the groove portions are provided so as to protrude inwardly on the left and right end sides of the inner surface of the back cover and are inserted between the frames located on the left and right sides. A lock device for a rear cover of a closed type switchboard, which comprises a side plate for wearing and positioning the rear cover, and notches provided at both upper and lower ends of the side plate.