JP2004342359A - Vacuum switching device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vacuum switching device reduced in required operation force in closing it by reducing load variation of the operation force. <P>SOLUTION: This vacuum switching device is equipped with an insulation lever supported to an insulation mold frame, connected to a moving electrode of a vacuum valve at one end, and connectable to an operation mechanism at the other end; a contact pressure spring is installed between the insulation lever and the moving electrode to provide contact pressure; a release spring is installed between the moving electrode and the vacuum valve to keep the moving electrode opened; and spring action force of the release spring provided for the moving electrode is set smaller than that of the contact pressure spring. The release spring is so structured as to be extended and contracted only between opening dimensions, and closing operation force after contact touch in closing can be reduced. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vacuum switchgear used for, for example, a high-voltage power transmission and distribution line for electric power.
[0002]
[Prior art]
A vacuum switchgear represented by a VCB (high-pressure vacuum circuit breaker) has a tendency to increase the switching operation force with a higher voltage and a larger current. There is a demand for smaller powers. A conventional vacuum switching device includes a vacuum valve having a movable electrode which is separated from and connected to a fixed electrode in a vacuum vessel supported by an insulating frame and extends movably through the vacuum vessel. The movable electrode is opened and closed by being driven via a wipe spring by a conversion lever connected to an operation mechanism. The wipe spring is provided between the conversion lever and the movable electrode, and applies a contact pressure between the electrodes. The vacuum switching device also includes an opening spring that is provided between the conversion lever and the insulating frame and holds the electrode in an open state. (For example, see Patent Document 1)
[0003]
In such a conventional vacuum switchgear, when closing the electrode from the open position, the opening spring is expanded by the driving operation force of the operation mechanism while accumulating the energy, and is stored together with the wipe spring through a link such as a conversion lever. The movable electrode is driven in the closing direction. Even after the movable electrode comes into contact with the fixed electrode and the contact is touched, the operation mechanism is further activated.However, this driving force is accumulated as compression of the wipe spring and applies contact pressure between the contacts of the electrode to close the electrode. Complete. When the electrode is opened from the closed position, the movable electrode is separated from the fixed electrode via a link such as a conversion lever by an operating mechanism, and is held at the opened position by an open spring. Accordingly, in such a link mechanism, the movable electrode is driven to the closed position via the opening spring and the wipe spring and is held at that position. And the force of the release spring.
[0004]
In a link mechanism of a conventional vacuum switch, the movable electrode is driven to a closed position via both an open spring and a wipe spring and is held at that position. Therefore, the total stroke required to drive the movable electrode to the closed position by the operating mechanism is a stroke for compressing the open spring to bring the contact into a contact state and a stroke for bringing the contact pressure into a closed state. The driving force required at this time is the sum of the force for compressing only the release spring by the total stroke and the force for compressing the wipe spring by the wipe distance. In other words, after the contact touch state is reached, in addition to the force required to compress the release spring, a force required to compress the wipe spring is also required, and the operating mechanism requires a relatively large driving force corresponding to this force. Is required.
[0005]
[Patent Document 1]
JP-A-9-198976 (FIG. 1)
[0006]
[Problems to be solved by the invention]
In the structure of the main circuit single pole part in the conventional vacuum switchgear, the opening spring holds the movable electrode open via the insulating lever, so that it is necessary to keep being compressed over the entire area when the vacuum switchgear is closed, The driving force at the time of closing required from the contact position to the closing position is a load obtained by adding the opening spring load and the contact pressure spring load, and a large driving operation force is required. For this reason, the operation mechanism becomes large and it is necessary to make it robust. In addition, there is an inflection point of the load characteristic where the spring load increases rapidly from the time of contact touch, so that when configuring the operating mechanism, output efficiency is good and there are few components and it becomes an obstacle to configure a small, lightweight and inexpensive operating mechanism. It has been difficult to manufacture the vacuum switchgear itself in a small, lightweight and inexpensive manner.
[0007]
SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and an operation mechanism that can be reduced in size and cost by reducing a load after a contact is touched when closing a pole and reducing an operation force of the operation mechanism. It is an object of the present invention to obtain a vacuum switchgear provided with:
[0008]
[Means for Solving the Problems]
The vacuum switchgear of the present invention is an insulating mold frame, a vacuum vessel supported by the insulating mold frame, a vacuum vessel, a fixed electrode provided in the vacuum vessel, and a contact with the fixed electrode in the vacuum vessel, and penetrates the vacuum vessel. A vacuum valve having a movable electrode movably extended, an insulating lever pivotally attached to the insulating mold frame, connected to the movable electrode at one end, and connected to an operating mechanism at the other end, and the insulating lever and the insulating lever. A contact pressure spring that is provided between the movable electrodes and applies a contact pressure between the fixed and movable electrodes; and an open spring that is provided between the movable electrode and the mold frame and holds the fixed and movable electrodes open. A spring acting force applied to the movable electrode by the release spring is smaller than a spring acting force applied to the movable electrode by the contact pressure spring. A switchgear.
[0009]
BEST MODE FOR CARRYING OUT THE INVENTION
FIG. 1 is a sectional view of a single pole portion of a main circuit showing an open state of a vacuum switchgear according to an embodiment of the present invention.
[0010]
The vacuum switchgear of the present invention includes an insulating mold frame 1 and a vacuum valve 2 supported by the insulating mold frame 1. The vacuum valve 2 includes a vacuum vessel 3, a fixed electrode 4 provided in the vacuum vessel 3, and a movable electrode movably extending through the vacuum vessel 3 so that the fixed electrode 4 can be separated from and connected to the vacuum vessel 3. 5 is provided. The outer end of the fixed electrode 4 is supported on the mold frame 1 together with the upper terminal 7 by bolts 6, and the outer end 8 of the movable electrode 5, which is outside the vacuum vessel 3, is an intermediate part. It is connected to a lower terminal 10 attached to the mold frame 1 via a flexible conductor 9.
[0011]
In the vacuum switchgear of the present invention, a connecting rod 12 is screwed into the lower end of the outer end 8 of the movable electrode 5 projecting outside from an electrode guide which is a part of the end plate 11 of the vacuum vessel 3. Thus, an extended portion of the movable electrode 5 is formed. The flexible conductor 9 is fixedly connected between the outer end 8 of the movable electrode 5 and the connecting rod 12 by a nut 13 fitted to the connecting rod 12, and is connected to the flexible conductor 9 and the lower end. 8, a spring seat 14 is provided.
[0012]
An open spring 15 which is a compression coil spring is provided between the spring seat 14 and the end plate 11 of the vacuum vessel 3. The upper end of the opening spring 15 is received and supported in an annular groove 11 a formed on the lower surface of the end plate 11 so as to surround the movable electrode 5, and the opening spring 15 moves in the radial direction with respect to the movable electrode 5. To prevent it from becoming stable. In this sense, the annular groove 11a is a means for preventing the opening spring 15 from moving in the radial direction with respect to the movable electrode, and providing a concave portion or a convex portion in place of the annular groove, or connecting the outer peripheral portion of the movable electrode guide to the opening spring 15. An equivalent side slip prevention function can be provided by contacting the inner circumference.
[0013]
The open spring 15 has one end in contact with the end plate 11 of the vacuum vessel 3 fixed to the mold frame 1 and the other end in contact with the spring seat 14 provided in the movable electrode 5. It can be said that it is provided between the movable electrode 5 and the release spring 15 is provided on the mold frame 1 via a vacuum container. One end of the opening spring 15 can be supported not by the vacuum container 3 but by another appropriate fixing member or directly by the mold frame 1. The spring seat 14 does not move with respect to the movable electrode 5. The opening spring 15, which is a compression coil spring, is for releasing the movable electrode 5 with respect to the fixed electrode 4 at the time of the opening operation and holding the electrode at the opening position shown in FIG.
[0014]
A second nut 16 is fixed on the distal end side (downward in the figure) of the nut 13 on the connecting rod 12 on the movable electrode 5, and supports a fixed washer 17. One end of a contact pressure spring 18, which is a compression coil spring, is in contact with the fixed washer 17, and the other end of the contact pressure spring 18 is in contact with a movable washer 19 that can slide on the movable electrode 5 in the axial direction. A flange-shaped end plate 20 is fixed to the distal end of the connecting rod 12 which is a part of the movable electrode 5, and a space is formed between the end plate 20 and the movable washer 19. An operating end 23 of an insulating lever 22 rotatably supported by the shaft 21 on the insulating mold frame 1 is movably received and connected to this portion of the movable electrode 5. An operation lever 24 is integrally connected to the insulating lever 22 via a shaft 21, and a link 26 of an operation mechanism 25 can be connected to a distal end of the operation lever 24.
[0015]
As described above, the contact pressure spring 18 is a compression coil spring that is provided between the movable electrode 5 and the insulating lever 22 and applies a contact pressure between the fixed electrode 4 and the movable electrode 5. It is a lever that is pivotally attached to the insulating mold frame 1, connected at one end to the movable electrode 5, and at the other end to an operation mechanism 25 described later. The release spring 15 is a compression coil spring fitted on the outer periphery of the movable electrode 5, and is axially aligned with the contact pressure spring 18. The release spring 15 and the contact pressure spring 18 may be tension springs depending on the operation mechanism 25 or a link mechanism that transmits the driving force of the operation mechanism 25 to the movable electrode 5.
[0016]
The opening spring 15 and the contact pressure spring 18 are set such that the spring acting force applied to the movable electrode 5 by the opening spring 15 is smaller than the spring acting force applied to the movable electrode 5 by the contact pressure spring 18. In, the spring constants of the release spring 15 and the contact pressure spring 18 are set so as to satisfy this relationship.
[0017]
In the illustrated open state, the insulating lever 22 connected to the connecting rod 12 is held at the illustrated position by the operating mechanism 25, and the movable electrode 5 is at the open position. At this time, the release spring 15 and the contact pressure spring 18 are both in an initial compression state (initial load), but both are in their maximum expansion state.
[0018]
When the pole is closed, the driving operation force from the operation mechanism 25 pushes down the lever 24 via the link 26, and the insulating lever 22 rotates clockwise about the shaft 21 to push the movable washer 19 upward in the figure. The force applied to the movable washer 19 is transmitted to the movable electrode 5 via the contact pressure spring 18 and the fixed washer 17 and the nut 16 to push the movable electrode 5 to the closed position. When the movable electrode 5 is pushed up, the opening spring 15 provided between the spring seat 14 fixed to the movable electrode 5 and the end plate 11 of the vacuum valve 2 is compressed (energized), and is fixed to the movable electrode 5 soon. The electrode 4 comes into contact with the electrode 4 and a contact state is established. In this state, the compression state of the contact pressure spring 18 stronger than the release spring 15 has not changed.
[0019]
After the compressed contact state, the movable electrode 5 does not move upward any more, and the open spring 15 is not further compressed. Thereafter, the insulating lever 22 is further rotated clockwise by the operating mechanism 25 to push up the movable washer 19, and the contact pressure spring 18, which has not been compressed, is compressed (energized), and the contact at the closed position is closed. A contact pressure is applied in between to complete the closing operation. When an appropriate contact pressure (wipe) dimension is reached, the driving operation force from the operation mechanism 25 is stopped, and the closing operation is completed by holding the closing completion position by a latch mechanism (not shown) in the operation mechanism 25.
[0020]
FIG. 2 is a graph showing a load characteristic representing a change in driving force required for the operation mechanism 25. FIG. 2 is a graph showing a load characteristic of the operation mechanism 25 when the vacuum switchgear of the present invention is closed. FIG. 2 shows a comparison with the load characteristic of the operating mechanism at the time of closing according to the conventional technique. In the graph of FIG. 2, the horizontal axis indicates the position of the movable electrode from the opening position to the closing position, and the vertical axis indicates the load force (spring load generated) which is the driving force required for the operating mechanism. It represents.
[0021]
At the opening position, the opening spring 15 is compressed (energized) as shown in FIG. 1, and an initial load of, for example, 5 kg is generated. When the closing operation is started, the opening spring 15 is gradually compressed during the opening dimension, and a final load of, for example, 10 kg is reached at the contact point. Even if the closing operation is further advanced, the load of the opening spring 15 does not increase any more during the contact pressure (wipe) dimension, and is constant until the closing completion position.
[0022]
On the other hand, the contact pressure spring 18 is generated as a contact pressure spring initial load of, for example, 20 kg only at the contact touch position. The initial load (for example, 20 kg) of the contact pressure spring is added to the final load of the open spring (for example, 10 kg), and acts on the operation mechanism 25 as a load (spring load) of, for example, 30 kg. The contact pressure spring load gradually increases during the contact pressure (wipe) dimension from the contact contact position to the closing position, and at the closing position the contact pressure spring final load becomes, for example, 30 kg. The total load force (spring load) on the operating mechanism 25 is, for example, 40 kg. As described above, the maximum load force required for the operation mechanism 25 is the total load of the final load of the release spring and the final load of the contact pressure spring, and is 40 kg in this example.
[0023]
In the graph of FIG. 2, a portion shown by a broken line is a graph showing a load in a conventional vacuum switchgear. That is, in the conventional vacuum switchgear, as described above, in order to apply the necessary contact pressure between the contacts, even after the contact pressure position is passed and the period of the contact pressure (wipe) is entered, The opening spring 15 needs to be kept compressed. For this reason, the load of the opening spring 15 continues to increase gradually as indicated by the broken line A, and at the closing position, becomes X kg in proportion to the wipe size and the spring constant, and the final load of the opening spring is (10 + X) in this example. kg. Accordingly, the load force (spring load) in the operation mechanism of such a conventional vacuum switchgear is (40 + X) kg obtained by adding the final load (10 + X) kg of the release spring 15 to the final load of the contact pressure spring 30 kg. is there.
[0024]
As described above, in the vacuum switchgear of the present invention, the compression of the release spring 15 is performed only in the section of the opening size, and in the section of the wipe size in which the contact pressure spring 18 is compressed, a further increase is performed. No compression is done. For this purpose, a contact pressure spring 18 for applying a contact pressure between the fixed electrode 4 and the movable electrode 5 is provided between the insulating lever 22 and the movable electrode 5, and the movable electrode 5 is held open with respect to the fixed electrode 4. An opening spring 15 is provided between the movable electrode 5 and the mold frame 1. The spring action force (opening holding force) applied to the movable electrode 5 by the opening spring 15 is smaller than the spring action force (contact pressure) applied to the movable electrode 5 by the contact pressure spring 18.
[0025]
By disposing the open spring 15 coaxially with the movable electrode 5 and moving the same displacement as the movable electrode 5, that is, compressing (spring energy storage) only in the opening dimension section, from the contact position to the closing position. In the contact pressure dimension section, the load of the release spring 10 does not increase and only the load of the contact pressure spring 18 increases, so that the maximum spring load does not increase unnecessarily. Therefore, the operation driving force of the operation mechanism 25 can be reduced, and the operation mechanism 12 can be reduced in size and weight. In addition, since the change in the load characteristic at which the contact pressure spring load starts to be applied from the time of touching the contact is reduced and the operation mechanism 25 is configured, it is possible to configure the operation mechanism 25 with high output efficiency of the driving operation force, small size, light weight, and low cost.
[0026]
By making the movable electrode 5 have a component configuration as shown in FIG. 3, it is possible to eliminate the difficulty of the spring mounting work of the tripping spring and the contact pressure spring (mounting the spring at a predetermined position while compressing the spring). Can be. That is, the movable washer 19 is fitted on the connecting rod 12 to its shoulder 12a, the contact pressure spring 18 is fitted on the movable washer 19, and then the fixed washer 17 and the nut 16 are fitted on the threaded portion 12c of the connecting rod 12 and fixed. The nut 16 is tightened on the threaded portion 12c until the washer 17 stops at the shoulder 12b. Such a spring mounting operation is relatively easy. The nut 13 and the washer 13a are further loosely fitted to the screw portion 12c of the connecting rod 12 outside the nut 16, and an intermediate assembly as a contact pressure spring rod is prepared and placed. Next, the open spring 15 and the open spring supporting washer 14 are attached to the movable electrode 5 of the vacuum valve 3 by a separately assembled jig (not shown), and the open spring 15 is compressed by the jig. Then, the flexible conductor 9 is placed on one end surface of the open spring support washer 14, and the screw portion 12c at one end of the contact pressure spring rod 12 is screwed into the screw portion 5a so as to urge it to one end of the vacuum valve electrode rod (movable electrode 5). Further, by fastening the flexible conductor 9 with the nut 13 via the washer 13a, it is possible to easily assemble a single pole.
[0027]
【The invention's effect】
The vacuum switchgear of the present invention is an insulating mold frame, a vacuum vessel supported by the insulating mold frame, a vacuum vessel, a fixed electrode provided in the vacuum vessel, and a contact with the fixed electrode in the vacuum vessel, and penetrates the vacuum vessel. A vacuum valve having a movable electrode movably extended, an insulating lever pivotally attached to the insulating mold frame, connected to the movable electrode at one end, and connected to an operating mechanism at the other end, and the insulating lever and the insulating lever. A contact pressure spring provided between the movable electrodes and applying a contact pressure between the fixed and movable electrodes; and an open spring provided between the movable electrode and the mold frame to hold the fixed and movable electrodes open. The spring acting force applied to the movable electrode by the opening spring is smaller than the spring acting force applied to the movable electrode by the contact pressure spring. Therefore, it is possible to reduce the load after the contact is touched at the time of closing the contact, to reduce the operation force by the operation mechanism, to reduce the size and weight of the operation mechanism, and to configure the entire vacuum switching device at low cost.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a vacuum switching device of the present invention in an opened state.
FIG. 2 is a graph showing a load characteristic representing a change in driving force required for an operation mechanism of the vacuum switching device according to the present invention, in comparison with a conventional one;
FIG. 3 is an exploded view of a connecting rod assembly of the vacuum switching device of the present invention.
[Explanation of symbols]
1 Insulation mold frame, 2 vacuum vessel, 4 fixed electrode, 5 movable electrode, 3 vacuum valve, 22 insulating lever, 18 contact pressure spring, 15 release spring, 11a Means for preventing radial movement (annular groove).

Claims (5)

An insulating mold frame,
A vacuum vessel supported by the insulating mold frame and having a vacuum vessel, a fixed electrode provided in the vacuum vessel, and a movable electrode which is separated from and connected to the fixed electrode in the vacuum vessel and extends movably through the vacuum vessel. When,
An insulating lever pivotally attached to the insulating mold frame, connected to the movable electrode at one end, and connected to an operating mechanism at the other end;
A contact pressure spring that is provided between the insulating lever and the movable electrode and applies a contact pressure between the fixed and movable electrodes;
An open spring that is provided between the movable electrode and the mold frame and holds the fixed and movable electrodes in an open state,
A vacuum opening and closing device, wherein a spring action force applied to the movable electrode by the opening spring is smaller than a spring action force applied to the movable electrode by the contact pressure spring. 2. The vacuum switchgear according to claim 1, wherein the opening spring is provided on the mold frame via the vacuum container. 3. The vacuum switchgear according to claim 1, wherein the release spring is axially aligned with the contact pressure spring. The vacuum switchgear according to any one of claims 1 to 3, wherein the opening spring is a compression coil spring fitted on an outer periphery of the movable electrode. The vacuum switchgear according to any one of claims 1 to 4, further comprising means for preventing the opening spring from moving in the radial direction with respect to the movable electrode.

Images