JPS6340338B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in the opening/closing mechanism of a vacuum valve using a vacuum valve as a current cutting element.

The elements of the opening/closing mechanism of a vacuum valve can be broadly divided into a transmission mechanism that transmits the power from the power source, a tripping mechanism that generally uses a coil spring to generate a predetermined speed when opening, and a buffer that cushions the shock when opening. It consists of a device. Among these, mitigation of the impact at the time of contact opening has a great influence on the mechanical life of the bellows of the vacuum valve, and is therefore considered to be the most important, and various methods have been adopted. Oil dampers are considered to be the most likely type of shock absorbing device, and are widely used. In particular, the opening/closing mechanism of vacuum valves used in on-load tap changers used in insulating oil has a simple structure and can be manufactured at low cost, and is required to have a long life. I have it too.

By the way, the biggest drawback of this shock absorber using an oil damper is that when it is used in insulating oil, it functions as an oil damper, but during the adjustment stage during assembly, it is in air, so the difference between oil and air is The problem is that it is unable to perform its buffering function.

As a result, the operation of the vacuum valve cannot be sufficiently tested during the adjustment stage during assembly. This is because the function of this oil damper is to reduce the impact when opening and to prevent overstroke of the movable shaft, but because it cannot perform this function, it is at the heart of the mechanical life of the vacuum valve in the early stages of assembly. There is a high possibility that it will support a large amount of damage to a certain bellows. For this reason, the adjustment work had to be done in insulating oil, which was time-consuming and expensive.

An object of the present invention is to provide a vacuum valve opening/closing mechanism that solves this problem.

Hereinafter, one embodiment of the present invention will be described in detail using FIGS. 1 to 7. Reference numeral 1 designates a first lever which is connected to a pin 1a through a suitable mechanism by the power of a drive source (not shown) and rotates about a fixed shaft 2 fixed to a bearing 4 as a rotational fulcrum. A second lever (α
A boss 1b is provided so as to provide a gap of +β). Like the first lever 1, the second lever 3 also rotates about the fixed shaft 2 as a rotational fulcrum, and is arranged with the first lever 1 as shown in the figure. The arm end of the second lever 3 has a groove 3a, and contacts a pin 5 attached to the operating shaft 7 and a rotatably held roller 6 to transmit power. The operating shaft 7 is provided with a semicircular groove 7a, allowing a plurality of balls 8 to enter and exit. The operating shaft 7 is connected to the opening shaft 9 by a ball 8 that fits into a hole 9a of the opening shaft 9, and the other end is supported by the bearing 4 so as to be slidable. The opening shaft 9 has a bush 28 fixed to the hole 4c of the bearing 4 and having a semicircular groove 28a on the inner periphery.
The operating shaft 7 is fitted into the inner diameter of the shaft 7 and is slidably supported.
Responds to upward and downward movements. Also, the large diameter portion 9 of the opening shaft 9
C is fitted with the cylinder 4a of the bearing 4 at a minute interval, and has the role of performing a doss-hot action by the control valve 40 provided in the opening operation bearing 4 and closing the hole 9b communicating with the sealed cylinder chamber 9b. The function of the control valve 40 will be described in detail later. 11 is an opening spring that comes into contact with the flange surface of the opening shaft 9 and generates a predetermined opening speed;
Reference numeral 2 denotes a wipe spring that applies the necessary contact force to the contact point of the vacuum valve 22 via the closing rod 15 after the closing operation. The input rod 15 has a flange 15a that comes into contact with the shoulder of the sealed cylinder chamber 9d of the opening shaft 9, and this flange 15a acts as a piston between it and the sealed cylinder chamber 9d and performs the opening operation. This is provided to prevent the movable shaft 22a of the vacuum valve 22 from overstroke. The upper end of the opening shaft 9 is supported by a bearing in a hole 14a of a bearing 14 fixed to a bearing 13 by a mounting bolt 14b, so that the opening shaft 9 can be smoothly moved up and down. The bearing 14 has a hole 14c, which serves as a communication hole when the opening shaft 9 moves downward. The upper part of the input rod 15 is integrated with the movable shaft 22a of the vacuum valve 22 by means of a nut 16, so that it operates integrally with the movable shaft 22a.
A terminal 17 fixed to the movable shaft 22a with a bolt and nut 19 is a terminal necessary for flowing current to the movable shaft 17. The movable shaft 22a is supported by a bushing 19 provided on the bearing 20 so that upward and downward movement can be performed smoothly.
A movable contact 22b provided at the upper end of the vacuum valve 2a and a bellows 22c provided to maintain the degree of vacuum within the vacuum valve 22 provide smooth movement. The fixed contact 2 faces the movable contact 22b.
2e is fixed to a fixed shaft 22d, and the fixed shaft 22d is further attached to a connecting conductor 27, and the movable shaft 22d is attached to a connecting conductor 27.
A current is drawn from the terminal 17 provided at the end of 2a. The vacuum valve 22 is provided with a bearing 20 at its lower part, a mounting flange 25 at its upper part, and an insulating cylinder 23 provided in both cylindrical parts to completely cover the outer periphery. This is to prevent unexpected external force from being applied to the insulator tube part of the vacuum valve 22 when installing the vacuum valve 22, and to prevent the vacuum valve 22 from suddenly cutting off an accidental current due to a short circuit in an external circuit. This was established to minimize the spread of accidents to others. The vacuum valve opening/closing mechanism constructed in this manner is entirely fixed to the mounting base 10, and is generally housed in insulating oil.

The configuration has been described above, and next, the operation will be described. FIG. 1 shows the open state. The closing operation shown in FIG. 1 will be explained. In the open state shown in FIG. 1, the contact portion between the first lever 1 and the second lever 3 has a gap of α for rotation in the time direction, and a gap of β for rotation in the counterclockwise direction. Each has The first lever 1 begins to rotate clockwise (in the direction of the arrow) due to the operation of a power source (not shown), and comes into contact with the second lever 3 after performing an idle movement of α. As the rotation progresses, the second lever 3 pushes the actuating shaft 7 upward through the roller 6 and pin 5 due to the groove 3a. As a result, the opening shaft 9 is simultaneously pushed upward via the semicircular groove 7a of the actuating shaft 7 and the ball 8, and the opening spring 11 starts to store energy, and the opening rod 15 is connected to the opening rod 15 via the wipe spring 12. The shaft 22a is pushed upward to start the closing operation. As the rotation of the first lever 1 further progresses, an upward closing operation is performed, and the movable contact 22b at the end of the movable shaft 22a contacts the fixed contact 22e, thereby closing.
As the rotation progresses further, the semicircular groove 7a of the operating shaft 7 and the ball 8 reach the semicircular groove 28a of the bush 28. The wipe spring 12 is compressed by the upward movement during this time, and the contact pressure between the movable and fixed contacts is gradually increased. (See Fig. 2) When the first lever 1 further rotates, the operating shaft 7 also moves upward, pushing the ball 8 out of the semicircular groove 7a and pushing the bush 28.
to the semicircular groove 28a. Next, the operating shaft 7 moves upward, and the opening shaft 9 is completely locked by the cylindrical surface of the operating shaft 7 and the semicircular groove 28a of the bush 28, completing the closing operation. (See Figure 3) This third
Always used as shown.

Next, the closing operation to the opening operation will be explained.
In the opening operation, the drive source operates in the completely opposite direction to the closing operation, and the first lever 1 rotates counterclockwise. At the initial stage of this rotation, there is a gap of α+β between the first lever 1 and the second lever 3, so the first
Even if the second lever 1 rotates counterclockwise, the second lever 3 continues to idle during this period. Only when the gap α+β becomes zero does the first and third levers engage and the second lever starts rotating. As the second lever rotates, the actuating shaft 7 begins to move downward via the roller 6 and pin 5. Actuation axis 7
When the semicircular groove 7a of the button matches the semicircular groove 28a of the bush 28 (see FIG. 4), the ball 8 is pushed out of the semicircular groove 28a of the bush 28 by the load of the opening spring 11, and the ball 8 is pushed out of the semicircular groove 28a of the bush 28, Moving on to the circular groove 7a. As a result, the opening shaft 9 is unlocked, and the opening shaft 9 connects the operating shaft 7, roller 6, pin 5 and the second
It begins to fall downward at a rapid speed, accompanied by the lever 3. After a while after the opening shaft 9 starts falling, the shoulder of the cylinder chamber 9d provided at the top of the opening shaft 9 comes into contact with the shoulder 15a of the input rod 15, and the movable contact 22b of the vacuum valve 22 is fixed. Contact 22e
Start the opening operation from. The opening speed at this time is such that the opening shaft 9 is brought into contact with the vacuum valve 22 after reaching a suitable speed by the opening spring 11.
The purpose is to improve cutting and cutting ability. Coinciding with this operating point, the large diameter portion 9c of the opening shaft 9 fits into the cylinder 4a of the bearing 4, and closes the hole 9b communicating with the cylinder chamber 9d arranged radially in the large diameter portion 9e. When the opening shaft 9 further falls downward, its speed is controlled by the control valve 40 provided on the outer periphery of the cylinder 4a, and the falling progresses until it comes into contact with the bush 28 and stops. At this time, insert rod 15
tries to overstroke further downward by overcoming the spring force of the wipe spring 12 due to its own inertia force and the inertia force of the movable shaft 22 and the terminal 17, but
Liquid (insulating oil) contained in the cylinder chamber 9d
Since the hole 9b is blocked, movement is stopped due to the dart pot effect. As a result, all the opening operations are completed and the state shown in FIG. 5 is reached. Figure 5 is the first
Shows the same open state as in the figure.

As explained above, in the liquid (insulating oil), the opening speed of the opening shaft 9 and the overstroke of the input rod 15 are decelerated by the action of the control valve 40, so that the desired purpose is achieved. However, since the assembly is carried out in air, the above-mentioned effect cannot be achieved, and the same problem as explained at the beginning occurs. This problem is solved by changing the structure of the control valve to the structure shown in FIGS. 6 and 7. Figure 6 shows the state in which it is used in liquid (insulating oil);
The figure shows the state in which it is used in air during assembly.

First, to explain the structure, a screw is provided on the inner circumference of a cylinder provided in a hole 35 that communicates with the cylinder chamber 4c in a boss provided in a part of the bearing 4,
Furthermore, a plurality of small holes 30 and large holes 31 are arranged in stages at appropriate intervals in the radial direction. Small hole 3 in hole 35
0 and the large hole 31 are arranged, and this valve body 34 has a stud 33 that connects with the screw of the hole 35, and by rotating the stud 33, the small hole and the large hole can be freely closed. Can be opened or closed. Numeral 32 is a lock nut, which is used to lock the stud 33 in the position when the position of the valve body 34 is determined by the rotation of the stud 33.

When used in the liquid shown in FIGS. 1 to 5, the state shown in FIG. 6 is used, that is, both the small hole 30 and the large hole 31 are opened, and a predetermined speed is applied to the opening shaft 9. On the other hand, in the adjustment work stage during assembly, the state shown in FIG. 7 is achieved, that is, by closing the large hole 31 and leaving only the small hole 30 open, the speed of the opening shaft 9 can be controlled to avoid applying impact to the bellows. can. Here, the area ratio of the small hole 30 and the large hole 31 is naturally determined in proportion to the difference in specific gravity between air and liquid.

As explained above, in the type of opening/closing mechanism that utilizes the damper effect of liquid (insulating oil), the control valve 40
is an indispensable device.

The use of the control valve of the present invention provides the following advantages.

(1) Since sufficient speed control is possible during assembly work, unnecessary impact force is not applied to the bellows of the vacuum valve, and overstroke can be prevented, completely preventing a decrease in the mechanical strength of the bellows due to handling. can.

(2) Adjustment work during assembly work can be carried out sufficiently, and the number of work hours can be greatly reduced. As a result, an inexpensive opening/closing mechanism can be provided.

(3) When vacuum valves are applied to equipment that requires frequent switching (more than ¹⁰ times), such as on-load tap changers, the lifespan of the vacuum valve can be extended, making the equipment highly reliable and inexpensive. It becomes possible to provide

(4) The control valve of the oil damper mechanism has multiple radial holes with different diameters in the cylindrical body.
The speed of the opening axis can be adjusted by appropriately sealing this with a stud connected to a screw. In this case, by appropriately selecting the number and diameter of the holes, it becomes possible to freely and finely adjust the speed, that is, the damper effect.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view of a vacuum valve opening/closing mechanism showing an embodiment of the present invention, and FIGS. 2 to 7 are explanatory views of the operation of the embodiment of the present invention. 4: Bearing, 4a: Cylinder, 9: Opening shaft, 9
c: large diameter part of opening shaft, 30: small hole, 31: large hole,
34: cylinder, 35: hole.

Claims (1)

[Claims] 1. A charging rod directly connected to the valve of the vacuum valve, a sealed cylinder chamber in which one end of the charging rod is engaged so as to act as a piston, a cylindrical portion connected to the sealed cylinder chamber, and a plurality of cylinders communicating with the sealed cylinder chamber. an opening shaft having a large diameter portion with holes radially provided therein, and the large diameter portion of this opening shaft is fitted with a slight interval, and the opening shaft is fitted inside with a cylindrical portion of the opening shaft. In a vacuum valve opening/closing mechanism comprising a cylinder part provided with a mating bush, and an actuating shaft that transmits an operating force to a cylindrical part of the opening shaft in the bush, the hole is provided in communication with the cylinder part. A cylindrical body is attached to the cylindrical body and has a screw provided on its inner circumferential surface, and a plurality of holes with different diameters are provided at appropriate intervals in the radial direction. A control valve is provided in the cylindrical part of the cylindrical body and has a stud having a valve body that opens or closes a plurality of holes in the radial direction of the cylindrical body depending on the insertion position thereof, and an oil damper is provided in the cylindrical part of the opening shaft. A vacuum valve opening/closing mechanism characterized in that the vacuum valve is configured to operate.