JPH0334820Y2 - - Google Patents

Description

[Detailed description of the invention] (Industrial application field) This invention relates to a current limiting fuse air switch.
Specifically, the present invention relates to an air switch with a current-limiting fuse that allows grounding work to be easily and safely performed during maintenance and inspection.

(Prior art) In general, in high-voltage power receiving equipment that uses this type of switch as the main breaker, when performing maintenance and inspection on various circuits lower than the main breaker, safety is taken into account and the load-side bus bar is The work was carried out by installing grounding devices for each phase.

(Problems that the invention aims to solve) However, this grounding device is expensive, and the workers are required to install and remove it during the above-mentioned work, which is not only very troublesome but also makes it easy to forget to ground There was also a fear that

This invention solves the above-mentioned problems and allows the above-mentioned maintenance and inspection to be carried out safely and easily.It also prevents the switch, which is the main disconnection device of the high-voltage power receiving equipment, from closing once it becomes grounded, and prevents the work from being carried out due to erroneous operation. An object of the present invention is to provide a current-limiting fuse equipped air switch which can prevent electric shock accidents.

Structure of the device (means for solving the problem) This device fixes a pair of upper and lower support insulators to the mounting base that constitutes the machine frame, and provides a fixed electrode on the upper support insulator, and a limited number of support insulators on the lower support insulator. A fuse support stand is provided with upper and lower fuse clamping fittings that clamp both ends of the current-limiting fuse, and a movable contact blade electrically connected to the current-limiting fuse is adapted to be able to approach and separate from the fixed electrode. In a pneumatic switch with a current-limiting fuse, a fixed electrode for grounding is provided on the load side connection terminal connected to the lower fuse clamping fitting, and the grounding switch is connected to an insulating support plate provided at the bottom of the machine frame. A grounding rotating shaft that is driven to open and close by a drive mechanism is rotatably installed, and the grounding rotating shaft is provided with a movable grounding electrode that comes into contact with and separates from the grounding fixed electrode, while the grounding opening and closing drive The earthing opening/closing drive mechanism is provided with a closing prevention member that engages with the mechanism by an engagement means and restricts the driving of the grounding opening/closing drive mechanism in the opening direction and restricts the closing operation of the switch serving as the main disconnection device. The gist is that they were installed side by side.

(Function) With the above configuration, the switch with current limiting fuse of the present invention, which is the main interrupting device of the power receiving equipment, opens the switch, and then closes the grounding rotation shaft via the grounding switching drive mechanism. Then, the grounding movable electrodes of each phase are connected to the grounding fixed electrode all at once. As a result, various circuits below the switch of the present application are automatically grounded. After being grounded, the circuit will not be driven in the opposite direction due to the engagement between the closing prevention member and the grounding opening/closing drive mechanism.

(Embodiment) An embodiment embodying this invention will be described below with reference to FIGS. 1 to 8.

The machine frame K is composed of a mounting base 1 which is bent so that the front surface thereof protrudes into a mountain shape, and a pair of fixed frames 2 and 3 having an L-shaped cross section and fixed to the left and right sides of the mounting base 1. ing. An upper support insulator 4 for each phase is attached to the upwardly inclined surface of the mountain-shaped portion of the mounting base 1, and a bolt 5 is attached at the base end.
At the same time, lower support insulators 6 for each phase are arranged in a V-shape with respect to each of the upper support insulators 4 on the downwardly inclined surface of the mountain-shaped portion at the base end. It is fixed with bolts 7.

An arc extinguishing chamber 8 is fixed at the tip of the upper support insulator 4, and a fixed interposed electrode 9 is fixedly installed inside the arc extinguishing chamber 8. Power supply side terminal 10 led out upward from arc chamber 8
is connected.

As shown in FIG. 2, a vertically extending fuse support 11 is integrally formed at the tip of the lower support insulator 6 in an oblique shape so that its lower end is inclined toward the support insulator 6 from its upper end. Upper and lower fuse clamping fittings 12 and 13 are fixed to the upper and lower ends of the fuse support stand 11, respectively.

A load-side connection terminal 14 led out downward is connected and fixed to the lower fuse holding fitting 13. A fixed grounding electrode 15 having an L-shaped cross section is fixed on the rear surface of the load side connection terminal 14, and as shown in FIG. It has been extended.

As shown in FIG. 1, a projection 11a is provided on one side of the fuse support base 11 from the center to the upper end.
A lower end portion of a movable contact blade 16, which corresponds to the protrusion portion 11a so as to be able to approach and separate from the fixed insertion electrode 9, is rotatably supported by a shaft 16a. The upper end portion of a conductive plate 17, which also constitutes a terminal plate, is connected to the upper surface of the base end of the upper fuse holding fitting 12 in an overlapping manner.

Further, from one side of the lower end of the conductive plate 17, a connecting portion 17a is connected.
is bent and extended to a position where it is inserted into the shaft 16a, and is fixed between the lower end of the movable contact blade 16 and the protrusion 11a, and is electrically connected to the movable contact blade 16.

A driven lever 18 is pivotally supported at the center of the upper end of the fuse support base 11 so as to be rotatable. One end of a connecting rod 19 constituting a part of an open-phase prevention mechanism is fixed to the upper end of the driven lever 18, and a blowout display device Fa for a current-limiting fuse F connected between the fuse clamping fittings 12 and 13 is attached. When the driven lever 18 is rotated in response to the protruding operation, the movable contact blades 16 of each phase are simultaneously opened via the open-phase prevention mechanism.

Furthermore, one end of a push-up rod 20 made of an insulating material such as synthetic resin and constituting a part of the opening/closing mechanism is rotatably attached to the center of the movable contact blade 16. The opening/closing mechanism including the push-up rod 20 is opened and closed by operating an operating handle 22 fixed to the right end of an operating shaft 21 rotatably installed between the lower portions 2 and 3 of both fixed frames. The movable contact blade 16 is rotated to open and close through the movable contact blade 16, and the operating handle 22 is inserted against the tensile force of a release spring (not shown) suspended between the operating shaft 21 and the inner surface of the mounting base 1. 50 to configure the closed state.

A pair of left and right support plates 23 and 24 made of an insulating material such as glass fiber reinforced plastic are fixed to the lower inner surfaces of the fixed frames 2 and 3 by bolts 25 and 26. A bearing groove 23a and a bearing hole 24a are formed in mutually corresponding positions of both the support plates 23 and 24, respectively.
A grounding rotation shaft 27 is installed in 4a so as to be parallel to the operating shaft 21.

An auxiliary plate 28 made of an insulating material such as glass fiber reinforced plastic is fixed to the inner surface of the support plate 23 with bolts 29, and a bearing groove (not shown) formed at the rear side of the lower end of the auxiliary plate 28 is secured to the inner surface of the support plate 23. The grounding rotation shaft 27 is rotatably engaged, and the grounding rotation shaft 27 is inserted into the bearing groove 2 of the support plate 23.
It has become impossible to get out of 3a.

A movable grounding electrode 30 is fixed to the grounding rotation shaft 27 in correspondence with the grounding fixed electrode 15,
When the grounding rotation shaft 27 is reciprocated, it comes into contact with and separates from the grounding fixed electrode 15 by means of a clamping electrode 30a provided at the tip. When the grounding movable electrode 30 is opened, the grounding movable electrode 30 is connected between the fixed frames 2 and 3, and between the operation shaft 21 and the grounding rotating shaft 27.
It is placed in between.

The grounding rotation shaft 27 and the grounding movable electrode 30 except for the sandwiched electrode 30a are molded with insulating resin, so that the switch can be made more compact and its electrical characteristics can be maintained. There is.

An operating lever 31 is fixed to a protruding end of the grounding rotation shaft 27 that protrudes leftward from the support plate 23, and an operating lever 31 is fixed to a protruding end of the operating shaft 21 that protrudes leftward from the fixed frame 2. A drive lever 32 is fixed, and a pair of links 33 made of an insulating material such as reinforced plastic are rotatably articulated between the front end of the drive lever 32 and the front end of the operating lever 31.

The drive lever 32, the link 33, the operating lever 31, and the grounding rotating shaft 27 constitute a grounding opening/closing drive mechanism A. Then, the grounding opening/closing drive mechanism A operates the operation handle 22,
Alternatively, when one of the current limiting fuses F is blown and the open/close prevention mechanism causes the movable contact blade 16 to open from the closed state via the opening/closing mechanism, the grounding movable electrode may be removed after the opening is completed. 30 is designed to close the circuit to the grounding fixed electrode 15.

A locking pin 34 protruding toward the fixed frame 2 is provided at the upper part of the base end of the drive lever 32 . Further, in the fixed frame 2, the operating shaft 21
A closing prevention lever 35 is rotatably supported at a position above the pivot point, and a stopper 35a is protruded from the outer surface of the fixed frame 2 slightly above the pivot point. 3
The amount of rotation in the Q arrow direction and the anti-Q arrow direction of No. 5 is regulated.

Further, a spring latching piece 36 is fixedly attached to the outer surface of the fixed frame 2 slightly below the pivot point of the closing prevention lever 35, and the tip of the spring latching piece 36 and the center portion of the closing prevention lever 35 are fixedly connected to each other. A tension spring 37 is hung between them. The tension spring 37 causes the stopper 35a to lock the closing prevention lever 35 at the line X connecting the latching position of the tension spring 37 to the spring locking piece 36 and the pivot point of the closing prevention lever 35. It is adapted to be selectively positioned between a locked position and an unlocked position.

A hook portion 35b is formed at the distal end of the closing prevention lever 35 so as to curve upward, and a latching projection 38 and an engaging projection 39 are provided downwardly at the lower part of the base end and the lower part of the approximately central part. . The latching protrusion 3
8. When the closing prevention lever 35 is in the locked position and the lock plate 40 (described later) is normally located in the released position due to its own weight, the operating shaft 21 moves from the closing state to the opening direction (in the direction of arrow P), as shown in FIG. ), the latching pin 34 of the drive lever 32 comes into contact with the inner surface 38a of the latching protrusion 38, and the closing prevention lever 35 is rotated in the direction of arrow Q against the biasing force of the tension spring 37. Before the tension spring 37 crosses the line X, the latch pin 34 rides on the upper surface of the latch protrusion 38,
When the closing prevention lever 35 is disengaged from the latching pin 34, it is rotated by the biasing force of the tension spring 37.
Rotated in the direction of the arrow.

The latching protrusion 38 engages the latching pin 34 of the drive lever 32 when the operation shaft 21 is rotated from the open state in the closing direction as shown in FIG. 6 when the closing prevention lever 35 is in the locked position. is latched to prevent the operating shaft 21 from being rotated.

A lock plate 40 is provided at a position below the input prevention lever 35 on the outer surface of the side wall of the fixed frame 2.
is provided. That is, the lock plate 40 has a vertically extending long hole 40a formed therethrough, and is inserted into the long hole 40 and slidably attached to a screw 41 that is screwed onto the fixed frame 2. Therefore, it is possible to move up and down within the range allowed by the elongated hole 40a.

The upper end of the lock plate 40 is formed with an abutting part 42 that engages with the front part of the engagement protrusion 39 of the closing prevention lever 35 in the lock position to hold the lock plate 40 in the upper position (i.e., in the non-lock position). Q of the closing prevention lever 35 when held in the release position)
It is designed to prevent rotation in the direction of the arrow.
Further, when the lock plate 40 is held at the lower position (that is, the release position), the abutment portion 42 is separated from the engagement protrusion 39 and positioned at the lower side, and the closing prevention lever 35 is rotated in the counterclockwise direction. It is in an unlocked state that allows.

At the lower ends of the lock plate 40 and the support plate 23, locking holes 43, 44 are formed in correspondence with each other, and by locking a lock 45 in the locking holes 43, 44, the lock plate 40 is placed in the upper position (i.e. When the lock 45 is not engaged, it always falls to the lower position due to its own weight. The central part of the lock plate 40 is extended forward, and a display plate 46 is integrally provided at the tip of the extended part so as to be perpendicular to it, and a "grounding lock" and a "ground lock" are provided at the top and bottom of the front surface. "Unlocked" is displayed.

The display plate 46 is formed by a cover plate 2a bent into an L-shape at the front end of the lower end of the fixed frame 2, so that the display plate 46 can be opened in the upper and lower portions according to the locked state and unlocked state of the closing prevention lever 35 by the lock plate 40. Either one of them is covered and the display of the other is displayed.

A lock mechanism D is constituted by the closing prevention lever 35, the tension spring 37, and the lock plate 40.

As shown in FIG. 1, a support fitting 47 having a channel-shaped cross section is fixed to the lower end of the support plate 24 by a pair of bolts 47a, and a hook hole is provided at the tip of one end of the fixed frame 3 facing one side. A contact blade 48 having a diameter 48a is rotatably supported.
Further, a contact fixing plate 49 is fixedly installed at the lower part of the outer surface of the fixed frame 3, and its lower end protrudes laterally perpendicularly to the upper end thereof, and the contact blade 48 comes into contact with and separates from the contact blade 48. A fixed contact 50 is fixed.

One end of the grounding wire L is connected to the side portion of the support member 47 on the fixed frame side by one bolt 47a, and the other end of the grounding wire L is connected to the side portion of the supporting member 47 on the fixed frame side. It is connected to a connecting plate 27a fixed to the shaft 27. The contact blade 48 is in a normal state, that is, when a megger test is not performed, it is held in contact with the fixed contact 50, and when a megger test is performed, it is released from the fixed contact 50. Note that the fixed frame 3
is grounded by a grounding wire (not shown).

The operation of the switch configured as described above will be explained.

Now, in FIG. 3, the switch is in the closing state, and the locking plate 40 has its abutting portion 42 separated from the front part of the engagement protrusion 39 of the closing prevention lever 35, as shown by the solid line, and the closing prevention lever 35 is in the locked position. Located in At this time, as shown in FIG. 4, on the display board 46 of the lock plate 40, the "Earth Lock" display on the upper front surface is hidden by the cover plate 2a, and the "Unlock" display on the lower front surface is exposed. Further, as shown in FIG. 7, the contact blade 48 is in narrow contact with the fixed contact 50.

When the closing lock release lever 51 is rotated clockwise from this state, it is disengaged from the operating handle 22, and the operating shaft 21 is rotated in the direction of the arrow P by the tensile force of the release spring (not shown). This drives the opening/closing mechanism and opens the movable contact blade 16 which is in the closed state. When the movable contact blade 16 rotates to open, the operating shaft 21 is also rotated in the direction of the arrow P, so the drive lever 32 is rotated in the same direction, and the grounding rotation shaft is rotated through the link 33 and the operating lever 31. 2
7 is rotated. As a result, the grounding movable electrode 30
After the opening of the movable contact blade 16 is completed, all phases are brought into narrow contact with the grounding fixed electrode 15 at the same time, and the lower circuit of this switch is automatically grounded (see FIG. 6).

On the other hand, when the drive lever 32 rotates in the direction of arrow P, the latch pin 34
By pressing into contact with the lower surface of the latching protrusion 38, the closing prevention lever 35 is rotated in the direction of the arrow Q against the biasing force of the tension spring 37. Since the latch pin 34 gets over the latch protrusion 38 before the tension spring 37 crosses the line
5 is rotated in the direction opposite to the arrow Q by the biasing force of the tension spring 37, and the drive lever 32 is locked so that it cannot be rotated in the direction opposite to the arrow P.

Next, the lock plate 40 is moved upward, and its abutting portion 42
When the lock 45 is brought into contact with the engagement protrusion 39 of the closing prevention lever 35, the lock plate 40 and the support plate 23 are locked.
It is held in the locked state by hooking it to the latching holes 43 and 44. At this time, on the display board 46 of the lock plate 40, the "unlock" display at the lower front of the display board 46 is hidden by the cover plate 2a, and the "ground lock" display at the upper front of the display board 46 appears.

Therefore, when performing maintenance and inspection work in this state, the closing prevention lever 35 cannot be freely released as shown in FIG. , drive lever 3
The latch pin 34 of No. 2 is hooked to the latch protrusion 38 of the closing prevention lever 35, making it impossible for the operating shaft 21 to rotate for loading, and even if the operating handle 22 is operated by mistake, loading will not be possible. and safe.

Next, to return to the normal state after maintenance and inspection, remove the lock 45 from the latching hole 44 of the support plate 23 and insert the lock plate 40 so that the upper end of the elongated hole 40a is connected to the screw 41.
It moves down to the release position where it locks. Then, the contact portion 42 of the lock plate 40 separates from the engagement protrusion 39 and becomes unlocked, and the display plate 46 of the lock plate 40 has the "Earth Lock" display on the upper front side hidden by the cover plate 2a, and the front surface The "Unlock" message will appear at the bottom.

Next, to explain the switch closing operation, operate the hook part 35b and move the closing prevention lever 35 to Q.
Rotate it in the direction of the arrow to cross the line X and position the closing prevention lever 35 to the unlocked position (see FIG. 5). From this state, the operating handle 22 is operated to drive the opening/closing mechanism and the movable contact blade 16 in the open state is turned on.

When the movable contact blade 16 rotates to close, the operating shaft 21 is rotated in the opposite direction of the arrow P, so the drive lever 32 is rotated in the same direction, and the grounding rotation is rotated via the link 33 and the operating lever 31. The moving shaft 27 is rotated in the direction of the R arrow. As a result, as shown in FIG. 2, the grounding movable electrode 30 is opened from the grounding fixed electrode 15 in all phases at once, and then the movable contact blade 16 is inserted into the fixed narrow electrode 9.

On the other hand, when the drive lever 32 rotates in the opposite direction of the arrow P, the latching pin 34
By pressing against the upper surface of the engaging protrusion 39 of No. 5, the closing prevention lever 35 is rotated in the opposite direction of the arrow Q, and is moved beyond the line X and held at the closing prevention locking position (see FIG. 3).

In addition, when carrying out the megger test of this switch, the contact blade 48 is separated from the fixed contact 50, and it is made into an open state as shown in FIG. After this,
When the contact blade 48 is inserted into the fixed contact 50 and the circuit is closed as shown in FIG. 7, the initial state is returned.

In this way, after the grounding of the machine frame side of the fixed frames 2, 3, etc. is released by the contact blade 48, a megger test can be easily performed.

Next, a second embodiment will be explained with reference to FIGS. 9 and 10.

In the following embodiments, the same or corresponding configurations as those in the first embodiment will be denoted by the same reference numerals, and the explanation thereof will be omitted. Also, in this second embodiment, for convenience of explanation, the lock plate 40 and the lock 45 are not shown in the drawings.
etc. are omitted, but these structures are provided in the same manner as in the previous embodiment.

In this embodiment, a grounding opening/closing drive mechanism B is provided on the outside of the fixed frame 2 and between the phases. Since the grounding opening/closing drive mechanisms between the phases have substantially the same configuration, the grounding opening/closing drive mechanism B provided in the fixed frame 2 will be described.

A two-pronged drive lever 32 is fixed at the center of the operating shaft 21, and a locking pin 34 is provided on the inner surface of the front end thereof to perform the same function as in the previous embodiment. Further, one end of a link 52 made of an insulating material such as reinforced plastic is rotatably supported at the rear end of the drive lever 32.

On the other hand, an elongated engagement hole 53 is provided in the base end portion of each grounding movable electrode 30 in the width direction thereof.
A drive rod 54 common to each phase is slidably inserted into the engagement hole 53 of each movable grounding electrode 30, and one end of the drive rod 54 is connected to the grounding opening/closing drive mechanism provided on the fixed frame 2. Links 52 configuring B
A portion thereof is fixed to one end of a link 52 in the grounding opening/closing drive mechanism B provided between the phases.

The driving rod 54 is connected to the grounding movable electrode 30.
is located on one end side of the engagement hole 53 when it is in an open state. Although not shown in the drawings, the support plate 23 is provided with an insertion hole through which the driving rod 54 is inserted to permit movement of the driving rod 54.

The drive lever 32, the link 52, the drive rod 54, the tension spring 57, and the engagement hole 53 constitute a grounding opening/closing drive mechanism B. Note that in the grounding opening/closing drive mechanism B provided between the phases, the latching pin 34 of the drive lever 32 is omitted.

Further, the protruding end of the grounding rotation shaft 27 protruding outward from the support plate 23 is protruded to a position where it does not interfere with the operation of the link link 52, and a spring retaining plate is attached to the end surface of the protruding end. 55 is fixed. The fixed frame 2 corresponds to the spring hanging plate 55.
One lower side extends outward, and a spring hook 56 is fixed to the extended portion.

One end of a tension spring 57 is hung on the tip of the spring hook piece 56, and the other end of the tension spring 57 is hooked on the spring hook plate 55. Due to its biasing force, the tension spring 57 moves the movable grounding electrode 30 between the open circuit position and the closed circuit at a line Y connecting the latching position of the tension spring 57 with respect to the spring latching piece 56 and the axis of the grounding rotation shaft 27. It is designed to be selectively located at the position.

When the movable contact blade 16 is in the closed state, the grounding opening/closing drive mechanism B is in the operating handle 2 in the state shown in FIG.
When the opening/closing mechanism is driven to open by operating 2 or by blowing out the current limiting fuse, the operating shaft 21 is rotated in the direction of the arrow P, and therefore the drive lever 32 is also rotated in the same direction. At this time, the linked link 52
The drive rod 54 moves the engagement hole 53 to the other end side via the .

After the movable contact blade 16 is driven via the opening/closing mechanism to complete the cutoff, the drive lever 3
2 is rotated in the direction of arrow P, the drive rod 54 is engaged with the other end of the engagement hole 53 via the drive lever 32 and link 52, and the movable grounding electrode 30 is rotated in the direction of closing the circuit. move. And the grounding rotation shaft 27
When the spring hook plate 55 is rotated in the same direction and the tension spring 57 crosses the line Y, the biasing force of the tension spring 57 causes the spring hook plate 55 to rotate vigorously in the same direction to close the circuit.

In addition, as shown in FIG. 10, a grounding movable electrode 30
is in the closed state and the movable contact blade 16 is in the open state, the drive lever 32 is moved to the opposite position via the operating handle 22.
When rotated in the direction of the arrow, the drive rod 54 moves toward one end of the engagement hole 53 via the link 52. When the drive rod 54 is locked to one end of the engagement hole 53, the movable grounding electrode 30 is driven in the opening direction.

Further, a grounding rotation shaft 27 and a spring retaining plate 55
is rotated in the same direction so that the tension spring 57 crosses the line Y, the grounding movable electrode 30 is vigorously rotated in the same direction by the biasing force of the tension spring 57, and all phases are opened simultaneously.

Then, when the operating shaft 21 is further rotated in the opposite direction of the arrow P, the movable contact blade 16 is inserted via the opening/closing mechanism.

Therefore, in this embodiment, a time difference is provided so that when the load current is flowing through the switch, the grounding movable electrode 30 is driven to close the circuit vigorously by the biasing force of the grounding switching drive B and the tension spring 57. It will be done.

11 and 12 show a third embodiment, in which the grounding opening/closing drive mechanism C is provided on the outside of the fixed frame 3. That is, the grounding rotation shaft 27 is arranged at a closer distance to the operating shaft 21 than the grounding rotation shaft 27 of the first and second embodiments, and is fixed to the grounding rotation shaft 27. The grounding movable electrode 30 is fixed so as to be located on the side opposite to the mounting base 1 when the circuit is open.

An operating lever 58 is fixed to the end of the grounding rotation shaft 27 protruding outward from the fixed frame 3, and the tip thereof is connected to the operating handle 22.
It is arranged so as to correspond to the proximal end. In addition, a stopper 59 is fixedly provided on the outer surface of the support plate 24 at a position slightly below the grounding rotation shaft 27, and is engaged with a latch piece 58a provided at the base end of the operating lever 58 to lock the operating lever. The amount of rotation of 58 in the opening direction is restricted.

A spring locking piece 60 with a spring locking hole 60a is formed in the support plate 24 at a position slightly below the grounding rotation shaft 27 and extends laterally. One end of the tension spring 61 is hooked to the tip of the operating lever 58, and the other end of the tension spring 61 is hooked to the tip. The tension spring 61 selectively positions the grounding movable electrode 30 in an open position and a closed position with a line Z connecting the spring locking hole 60a and the axis of the grounding rotation shaft 27 as a boundary. It's becoming like that.

An engagement groove 64 having engagement protrusions 62 and 63 on both sides is formed in the lower part of the base end of the operating handle 22 so that it can be engaged with and detached from the tip of the operating lever 58 . The engagement protrusion 62 on the front side is formed longer than the engagement protrusion 63 on the rear side, and when the operating lever 58 is in the open position as shown in FIG. When the lever 58 is rotated in the opening direction, the tip of the engagement protrusion 62 comes into contact and rotates the operating lever 58 in the closing direction.

Then, before the operating lever 58 is rotated by the engagement of the engagement protrusion 62 and the tension spring 61 crosses the Z line, the movable contact blade 1 is rotated by the rotation of the operating shaft 21.
6 completes the shutoff via the opening/closing mechanism.

Further, the operating lever 58 is in the closed circuit position (the 12th
(state in the figure), that is, when the operating lever 58 is engaged in the engagement groove 64, when the operating handle 22 is rotated in the closing direction, the other engagement protrusion 63 The distal end of the lever 58 is brought into contact with the lever 58 to rotate the actuating lever 58 in the opening direction. Then, the operation lever 58 is rotated by the engagement of the engagement protrusion 63, and before the tension spring 61 crosses the Z line, the movable contact blade 16 completes the loading via the opening/closing mechanism by the rotation of the operating shaft 21. I'm starting to do that.

The operating lever 58, the engagement protrusions 62, 63, and the tension spring 61 constitute a grounding opening/closing drive mechanism C.

When the movable contact blade 16 is in the closed state, when the operating handle 22 is operated or the current limiting fuse is blown to open the opening/closing mechanism C, the base end of the grounding opening/closing drive mechanism C opens as shown in FIG. S from the state of
Move in the direction of the arrow. Then, when the engaging protrusion 62 is locked to the tip of the operating lever 58, the operating lever 58 is rotated in the circuit closing direction T. Then, before the operating lever 58 is rotated and the tension spring 61 crosses the line Z, the movable contact blade 16 completes the interruption via the opening/closing mechanism. When the operating lever 58 is further rotated and the tension spring 61 crosses the line Z, the biasing force of the tension spring 61 causes it to rotate vigorously in the same direction and close the circuit.

Furthermore, when the operating handle 22 is rotated in the closing direction when the grounding movable electrode 30 is in a closed state and the movable contact blade 6 is in an open state, its base end moves from the state shown in FIG. 12 in the direction of the arrow S. . Then, when the engaging protrusion 63 is locked to the tip of the operating lever 58,
The operating lever 58 is rotated in the opposite direction of the T arrow. Then, the operating lever 58 is rotated and the tension spring 6
1 crosses the line Z, the movable contact blade 16 completes the injection via the opening/closing mechanism. Furthermore, the operating lever 58
is rotated and the tension spring 61 crosses the line Z,
Due to the biasing force of the tension spring 61, it is vigorously rotated in the same direction to open the circuit.

Therefore, in this embodiment as well, when the load current is flowing through the switch, the grounding movable electrode 3
A time difference is provided so that the circuit is closed after the circuit 0 is vigorously driven to close by the biasing force of the grounding opening/closing drive mechanism C and the tension spring 61, and is completely cut off.

Note that this invention is not limited to the above-described embodiment, and for example, the grounding opening/closing drive mechanism A of the first embodiment may be arranged between any of the phases, or the
The engaging protrusions 62 and 63 in the embodiment are connected to the operating shaft 21.
It may also be provided between the fixed frames 2 and 3.

Next, a fourth embodiment will be described with reference to FIGS. 13 and 14.

In the first embodiment, the grounding rotation shaft 27 and the portion of the grounding movable electrode 30 excluding the narrowing electrode 30a are molded with insulating resin. An L-shaped insulating plate 66 is fixed with screws 65, and the insulating plate 66 is arranged so as to cover the grounding rotation shaft 27 and the grounding movable electrode 30 except for the sandwiched electrode 30a. The difference is that the characteristics are maintained.

Other effects of this embodiment are similar to those of the first embodiment.

Next, a fifth embodiment will be explained with reference to FIGS. 15 to 17.

In this embodiment, an elongated sliding hole 68 is provided from the end of the link 33 on the operating lever 31 side to the center thereof, and the sliding hole 68 has a sliding shaft 69 projecting from the tip of the operating lever 31. is slidably inserted and attached. In addition, the auxiliary plate 28 is attached to the grounding rotation shaft 27.
A twist spring 70 is wound between the grounding movable electrode 30 and the auxiliary plate 28 which are close to each other, and its both ends are respectively attached to the grounding movable electrode 30 and the auxiliary plate 28 to prevent the grounding rotation. The shaft 27 is always biased in the direction of closing the circuit. Further, as shown in FIG. 17, the grounding movable electrode 30 is connected to the grounding fixed electrode 15.
When the drive lever 32 is rotated in the opposite direction of the arrow P while in contact with the lower end 68 of the sliding hole 68,
At a point a, the operating lever 31 is rotated in the direction of the arrow R.

A latch 71 is provided on the outer surface of the auxiliary plate 28 slightly closer to the operating shaft 21 than the grounding rotation shaft 27.
is rotatably supported on a shaft 72. A hook 73 is formed at the lower end of the latch 71. The grounding rotation shaft 2 corresponds to the hook 73.
A locking hole 27a is recessed in the outer periphery of 7, so that the hook 73 can be locked when the movable grounding electrode 30 is in a completely open state. That is, in a state in which it is latched by this hook 73, the grounding rotation shaft 27 is unable to rotate.

A torsion spring 74 is wound around the shaft 72, and one end of the torsion spring 74 is locked to the latch 71, so that the latch 71 is biased to rotate clockwise. The upper end of the latch 71 is bent into an L-shape, and an operating member 75 made of an insulating material is fixed to the upper end. The upper end of the actuating member 75 extends upward, and the upper end has a contact portion 7.
5a is formed. When the switch is turned on, this latch 71 locks the engagement hole 27a of the grounding rotation shaft 27, which rotates in the direction of the counter-R arrow, before the movable contact blade 16 makes narrow contact with the fixed narrow electrode 9. 73, the hook 73 of the latch 71 is adapted to engage with the engagement hole 27a by the biasing force of the twist spring 74. An L-shaped mounting member 76 is provided on the lower side of the drive lever 32 corresponding to the contact portion 75a.
is fixedly installed, and an engagement release member 77 made of a bolt is screwed into the mounting member 76. The disengagement member 77 is activated when the drive lever 32 in the engaged state is rotated in the direction of the arrow P by the operation shaft 21, and the movable contact blade 16 is disengaged from the arc extinguishing chamber 8 and sufficiently opened. The engagement hole 27a is pressed into contact with the member 75.
The latch 71, which is in a latched state, is rotated in the opposite latching direction. Note that by adjusting the amount of screwing of the disengagement member 77 into the mounting member 76, the timing at which it comes into contact with the actuating member 75 can be adjusted.

Now, to explain the operation of this embodiment,
Figure 15 shows the grounding movable electrode 30 when the switch is closed.
is in a completely open state, and the hook 73 of the latch 71 is latched in the engagement hole 27a of the grounding rotation shaft 21 with the torsion spring 70 in a stored state, and the earthing rotation shaft 27 is rotated. It's becoming impossible.

When the lock plate 40 is in the unlocked state, when the operating shaft 21 is rotated in the direction of the arrow P as in the first embodiment, the operating lever 32 is rotated in the same direction. This rotation of the operating shaft 21 causes the movable contact blade 16 to separate from the fixed narrow electrode 9 and the arc extinguishing chamber 8, while the link 33 driven by the drive lever 32 moves as shown by the chain line in FIG. However, the operating lever 31 is not driven except that its sliding shaft 69 slides in the sliding hole 68 of the link 33.

After that, after the movable contact blade 16 is sufficiently opened,
The disengagement member 77 of the drive lever 32, which rotates in the direction of arrow P, presses into contact with the actuating member 75. Then, the actuating member 75 disengages from the engagement hole 27a against the urging force of the torsion spring 74 and rotates in the anti-latching direction, so that the grounding rotation shaft 27 is released. As a result, the movable grounding electrode 30 is brought into narrow contact with the fixed grounding electrode 15 for all phases at the same time due to the biasing force of the torsion spring 70, and the lower circuit of the switch is automatically grounded. Movable electrode 3 for grounding at this time
The timing of the narrow contact of 0 takes into consideration the slow initial velocity of the torsion spring 70.

Hereinafter, when the actuating lever 32 is rotated in the direction of arrow P, it operates in the same manner as in the first embodiment, so the latch pin 34 rides over the latch protrusion 38, and the actuating lever 32 is rotated in the direction opposite to the arrow P. It is locked against rotation (see Figure 17).

Also, to explain the switch closing operation which returns the state from the state shown in FIG. 17 to the normal state after the maintenance and inspection work is completed, the closing prevention lever 35 is moved in the direction of arrow Q by operating the hook portion 35b as in the first embodiment. to cross line X and position the closing prevention lever 35 to the unlocked position. From this state, the operating handle 22 is operated to drive the opening/closing mechanism and the movable contact blade 16 in the open state is turned on.

When the movable contact blade 16 is rotated to close, the operating shaft 21 is rotated in the opposite direction of the arrow P, so the operating lever 32 is rotated in the same direction. This drive lever 3
2 in the anti-P arrow direction, the pressure of the engagement release member 77 on the contact portion 75a is released;
Due to the biasing force of the torsion spring 74, the latch 71 comes into contact with the outer peripheral surface of the grounding rotation shaft 27 at the hook 73.

On the other hand, due to the rotation of the operating lever 32 in the opposite direction of the arrow P, the link 33 is rotated at its lower end 68a via the operating lever 31 against the biasing force of the torsion spring 70, so that the grounding rotation shaft 27 is rotated in the direction indicated by the arrow R. Rotate in the direction. As a result, the grounding movable electrode 30 is disconnected from the grounding fixed electrode 15 in all phases at once.

Further thereafter, when the engagement hole 27a of the grounding rotation shaft 27 that rotates in the direction of the arrow R corresponds to the hook 73, the biasing force of the torsion spring 74 causes the engagement hole 27a to correspond to the hook 73.
Since the hook 73 of the latch 71 is engaged, the grounding rotation shaft 27 cannot be rotated in the counter-R arrow direction. Thereafter, when the operating shaft 21 is further rotated in the opposite direction of the arrow P, the movable contact blade 16 is inserted into the fixed narrow electrode 9.

As described above, in this embodiment, in the unlikely event that the arc generated between the movable contact blade 16 and the fixed narrow electrode 9 is not extinguished within the arc extinguishing chamber 8 when the switch is opened, the arc is connected outside the arc extinguishing chamber 8. , if there is a risk of disappearing in the air, link 33
Since the grounding rotating shaft 27 is not immediately driven through the sliding hole 68 and a time lag is maintained, there is no possibility of transition to a ground fault or short circuit, and there is no risk of causing an accident.

Effects of the invention As detailed above, in this invention, when the switch is not closed, the earthing rotating shaft is rotated to bring the movable earthing electrode into contact with the fixed earthing electrode, which makes it easier to ground during maintenance and inspection. The work can be done easily and safely, which saves a lot of time. Also, because a closing prevention member is installed, once the grounding occurs, the switch, which is the main disconnection device of the high-voltage power receiving equipment, cannot be closed, preventing erroneous operation. It has the excellent effect of preventing electric shock accidents during work.

[Brief explanation of drawings]

Figure 1 is a front view of the switch in the closed state with the current limiting fuse omitted according to the first embodiment embodying this invention, Figure 2 is a side view of the switch in the closed state with the current limiting fuse installed, and Figure 3 is a Similarly, FIG. 4 is a side view of the grounding switching drive mechanism in the closing state of the switch, FIG. 4 is a front view of the main parts, FIG. Similarly, a side view showing the closing prevention state, Fig. 7 is a side view of the main part showing the contact blade in the grounding state, Fig. 8 is a side view similarly showing the megger test state, and Fig. 9 is the grounding opening/closing of the second embodiment. A side view of the drive mechanism, FIG. 10 is a side view showing the same action, FIG. 11 is a side view of the main part of the grounding opening/closing drive mechanism of the third embodiment, FIG. 12 is a side view of the main part showing the action, Fig. 13 is a front view of the switch in the closed state without the current limiting fuse of the fourth embodiment, Fig. 14 is a side view of the switch in the closed state with the current limiting fuse attached, and Fig. 15 is an open/close switch of the fifth embodiment. Side view of the grounding opening/closing drive mechanism in the closed state of the device, 1st
6 is a front view of the main part, and FIG. 17 is a side view of the grounding opening/closing drive mechanism in the open state of the switch. 1... Mounting base, 2, 3... Fixed frame,
4... Upper support insulator, 6... Lower support insulator, 9...
... Fixed narrow electrode, 11 ... Fuse support, 12
...Upper fuse clamping fitting, 13...Lower fuse clamping fitting, 16...Movable contact blade, 19...Pushing rod, 21...Operation shaft, 22...Operation handle,
27... Rotating shaft for grounding, 30... Movable electrode for grounding, 31... Operating lever, 32... Drive lever,
33... Link, 35... Closing prevention lever, 37
... Tension spring, 40 ... Lock plate, 52 ... Interlocking link, 54 ... Drive rod, 55 ... Spring latching plate, 57 ... Tension spring, 58 ... Operation lever,
61... tension spring, 62, 63... engaging protrusion,
64...Engagement groove, 68...Sliding hole, 69...Sliding shaft, 71...Latch, 73...Hook, 77...
Disengagement member, A, B, C... Grounding opening/closing drive mechanism, K... Machine frame.

Claims (1)

[Scope of Claim for Utility Model Registration] 1. A pair of upper and lower support insulators is fixed to a mounting base constituting the machine frame, a fixed electrode is provided on the upper support insulator, and both ends of a current limiting fuse are provided on the lower support insulator. A fuse support stand is provided with upper and lower fuse clamping fittings to attach the upper and lower fuses, and a movable contact blade that is electrically connected to the current limiting fuse can be attached to and separated from the fixed electrode. In the machine, a fixed grounding electrode is provided on the load-side connection terminal connected to the lower fuse clamping fitting, and the grounding opening/closing drive mechanism drives the grounding opening/closing drive mechanism to open and close the grounding fixed electrode with respect to an insulating support plate provided at the bottom of the machine frame. A grounding rotating shaft is rotatably constructed, and the grounding rotating shaft is provided with a movable grounding electrode that comes into contact with and separates from the fixed grounding electrode, and the grounding opening/closing drive mechanism and the engagement means A current limiting fuse air switch, characterized in that a closing prevention member that engages with the grounding switching drive mechanism and restricts the drive of the grounding switching drive mechanism in the opening direction is provided in parallel with the grounding switching drive mechanism. 2. The air switch with current-limiting fuse according to claim 1, wherein the grounding opening/closing drive mechanism is linked to an operating shaft constituting the opening/closing mechanism of the switch.