JPH06196047A - Liquid pressure operating device for power switch - Google Patents

Abstract

PURPOSE:To obtain a liquid pressure operating device wherein reboosting can be automatically performed while maintaining the same condition as at the time of dropping a liquid pressure. CONSTITUTION:An oil path 22 is formed so as to pass through a switching valve 11 in its inside. A hollow part 20 is formed in one end part of the switching valve 11, to store a piston 23 moved by a liquid pressure, first ball 24 pressed by this piston 23 and a spring 18 energized to a side of this first ball 24, in the inside of the hollow part, and an end part of the spring is sealed by a stop screw 19. A through hole 20a is formed in a radial direction in the switching valve 11, and the second ball 21 is stored in this through hole 20a. Further in a valve block 2, two grooves 30a, 30b, to which the second ball 21 is fitted, are formed in a surface slid with the switching valve 11.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hydraulic pressure control device for controlling the breaking / closing operation of a power switch.

[0002]

2. Description of the Related Art In recent years, among switchgear used in power transmission systems of ultra high voltage or higher, a hydraulic operating device has come to be used mainly because a circuit breaker performs a switching operation at high speed. In this hydraulic operation device, it is possible to reduce the size of the device by using high-pressure liquid pressure, noise during operation is significantly reduced, and there are advantages such as excellent response due to incompressibility of the liquid. . In addition, when using this hydraulic operating device for a circuit breaker for electric power, since it has the purpose of an emergency device that performs the operation of interrupting the fault current of the power system, abnormal operation is not allowed and high reliability is achieved. Is required.

FIG. 5 shows a typical construction of a hydraulic operating device which has been conventionally used. In addition, this hydraulic operation device operates three contacts with one hydraulic operation device in three-phase batch operation, and operates one contact with one hydraulic operation device in three-phase each phase operation. Is configured to.

That is, a piston rod 1 is arranged inside a cylinder capable of withstanding high pressure, and an electric contact 8 is connected to the tip thereof. An accumulator 7 is connected to the upstream side of the piston rod 1, and a hydraulic pump 5 is connected via a high pressure pipe 6. On the other hand, on the downstream side of the piston rod 1, a valve block 2 is provided via a high pressure pipe 3.
Is provided. The high pressure pipe 3 is for guiding the pressure of the accumulator 7 to the valve block 2. Further, a switching valve (not shown) is built in the valve block 2, and a closing pilot valve 9 and a closing pilot valve 9 for driving the switching valve are further provided. Further, the liquid discharged during the operation of the hydraulic cylinder is configured to be recovered by the hydraulic pump 5 via the low pressure tank 4.

FIG. 6 shows a more specific structure of the hydraulic pressure operating device. That is, a connecting portion 16 for connecting electrical contacts is provided at the tip of the piston rod 1, and a cylinder head 17 is provided at the upstream end of the cylinder.
On the other hand, the valve block 2 is fixed to the downstream end of the cylinder. A high pressure pipe 3 is connected between the cylinder head 17 and the valve block 2 in parallel with the cylinder. Further, the valve block 2 has a built-in switching valve 11, and a closing pilot valve 9 and a closing pilot valve 9 for driving the switching valve 11 are respectively provided with solenoids 13a and 1a.
It is configured to be operated by 3b.

The liquid pressure operating device is sealed by a low pressure tank 4. Further, a charging device composed of a spring 15 and a pin 14 is arranged on a part of the side surface of the low pressure tank 4. By pressing the pin 14 of the charging device, the switching valve 11 is moved leftward in the drawing, and the metal seat portion "A" of the switching valve 11 is seated, so that the hydraulic pressure in the hydraulic circuit is reduced. It is configured to be able to boost the voltage.

[0007]

In the conventional hydraulic operating device as described above, if the predetermined hydraulic pressure is applied, the switching valve 11 is operated.
Regardless of whether it is switched to the blocking side or the closing side, the metal sheet is held by the force generated by the hydraulic pressure, so that the hydraulic pressure can be maintained. However, when it is necessary to reduce the hydraulic pressure during inspection or as a countermeasure against accidents, once the hydraulic pressure is reduced, the sheet force of the metal sheet portion “A” cannot be maintained. Sometimes you can't. Therefore, as described above, the manual charging device is provided, and the metal sheet portion "A" in the shut-off state is pressed by the pin 14 so that the re-pressurization can be reliably performed.

However, in the conventional hydraulic operating device,
If you need to reduce the fluid pressure as described above,
The shut-off condition must be met by the charging device. Further, if the hydraulic pressure drops in the closed state due to an unexpected situation, if the pressure is re-pressurized, only the pressure on the cutoff side can be increased, and the hydraulic pressure is increased and the piston rod 1 moves from the closed position to the closed position. However, there was a problem that the electrical contacts were opened. Further, since the charging device is manual, when the circuit breaker operates each phase, different charging devices must be used. Therefore, in the case of a gas circuit breaker of a three-phase one-tank type for each phase operation, three hydraulic operating devices are arranged inside one mechanical box, so depending on the installation location, the use of the charging device is not recommended. It was difficult.

Further, as can be seen in the BBC / GCB catalog and the reference of the HKA hydraulically operated cylinder, there has been proposed a hydraulic operating device in which the position of the switching valve is held by balls and springs. However, in this configuration, when the switching valve operates, the ball pressed by the spring force always moves while in contact with the sliding surface of the valve block. There was a risk of biting.

The present invention has been proposed in order to solve the above-mentioned drawbacks of the prior art, and the purpose thereof is to automatically re-pressurize while maintaining the same state as when the hydraulic pressure drops. It is to provide a hydraulic operating device that can be used.

[0011]

According to the present invention, a switching valve for driving a piston rod that opens and closes an electric contact of a power switch is arranged in a valve block provided at an end of a hydraulic cylinder for power. In the hydraulic operating device for a switch, an oil passage is formed inside the switching valve so as to penetrate the switching valve, and a hollow portion is formed at one end of the switching valve. , A piston that is moved by hydraulic pressure, a first ball that is pressed by this piston, and a spring that is biased toward the first ball are housed, and the switching valve is formed with a through hole in the radial direction. A second ball is housed in the through hole, while two grooves into which the second ball fits are formed on the sliding surface of the valve block on which the switching valve slides. It is characterized by being.

[0012]

In the hydraulic operating device for a power switch according to the present invention, when the switching valve is at the shut-off side or at the closing side, the hydraulic pressure is lowered. There is no pressure in the oil passage, and the piston is pushed back into the hollow back by the biasing force of the spring, whereby the second ball is pressed by the first ball and is formed in the radial direction of the switching valve. It moves in the through hole and fits into the groove formed in the valve block. As a result, the position of the switching valve can be maintained and the seat force of the metal seat portion can be maintained.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be specifically described below with reference to FIGS. The same members as those of the conventional type shown in FIG. 6 are designated by the same reference numerals, and the description thereof will be omitted.

In this embodiment, as shown in FIG.
An oil passage 22 that guides high pressure is provided inside the switching valve 11.
It is formed so as to penetrate 1. In addition, the switching valve 11
A hollow portion 20 is formed at one end of the piston, and a piston 23 that moves by hydraulic pressure is provided inside the hollow portion 20.
The first ball 24 pressed by 3 and the spring 18 biased in the direction (right direction in the figure) against the movement of the first ball 24 are housed, and the end thereof is sealed by the set screw 19. ing. A stopper 19 a for limiting the movement of the first ball 24 is formed on the set screw 19 so as to project into the hollow portion 20.

A through hole 20a is formed in the switching valve 11 in the radial direction, and a second ball 21 is housed in the through hole 20a. In addition, this second ball 2
1 is configured to move up and down in the through hole 20a depending on the position of the first ball 24.

Further, the switching block 1 is provided in the valve block 2.
The surface on which 1 slides is fitted with the second ball 21 2
Two grooves 30a and 30b are formed. Here, the two grooves are formed so as to correspond to the shut-off side position and the closing-side position of the switching valve 11.

The fluid pressure operating device of this embodiment having such a structure operates as described below. That is, as shown in FIG. 2, when there is a pressure in the oil passage 22 formed in the switching valve 11, that is, when the hydraulic operating device is constantly pressurized, the piston 23 is not Pressed in the center left direction,
The first ball 24 is pressed against the biasing force of the spring 18 to the left in the drawing. When the first ball 24 is pressed by the piston 23 in this way, the second ball 21 is in the free state in the through hole 20a, and does not affect the operation of the switching valve 11 at all.

However, once the pressure drops, there is no pressure in the oil passage 22, so that the piston 23 is driven by the urging force of the spring 18 as shown in FIG.
It is pushed back to the inner part (right side in the figure) of the hollow part 20 via. Then, the second ball 21 is pressed by the first ball 24 and moves upward in the drawing in the through hole 20a formed in the radial direction of the switching valve 11. As a result, the second ball 2
1 fits in the groove 30 a formed in the valve block 2.

Although FIGS. 2 and 3 show the case where the switching valve 11 is in the shut-off side position, when the pressure disappears in the closing side position, the second ball 21 is placed in the valve block. It is fitted in the groove 30b formed in 2.

As described above, according to this embodiment, the switching valve 11
Whether the valve is on the shut-off side or on the closing-side position, when the hydraulic pressure disappears in the usage state, the groove 30a formed with the second ball 21 in the valve block 2 is formed. , 30b, the position of the switching valve can be maintained and the seat force of the metal seat portion A can be maintained. As a result, re-pressurization can be automatically performed while maintaining the same state as when the hydraulic pressure drops.

In the low pressure tank 4, a pilot valve 9,
All valve bodies other than 10 can be built in, and the sealing portion of the pin of the charging device is eliminated as in the conventional case, so that there is also an advantage that the number of liquid sealing locations can be reduced. Further, in order to hold the position of the switching valve by automatically seating the metal sheet portion “A” on the closing side and the closing side, conventionally, when the hydraulic pressure was lowered, the pressure was lowered after the operation on the closing side. Since the hydraulic pressure can be lowered even at the closing position, there is also an advantage that the operability is greatly improved in the operation test and the use in the actual system.

When the hydraulic pressure is applied, the second ball 21 is in a free state and no radial force is generated on the switching valve 11, so that a load is applied to the operation of the switching valve. And the operation of the switching valve becomes reliable. Furthermore, since no load is applied to the second ball 21, no foreign matter or scratch is generated on the sliding surface of the valve block 2 when the switching valve 11 slides.

The present invention is not limited to the above-described embodiment, but may be constructed as shown in FIG. That is, in the present embodiment, the second ball 21 is provided in the through hole 20a formed in the radial direction of the switching valve 11.
A displacement transmission member 25 is also provided. With this configuration, the pressing force of the first ball 24 can be transmitted to the second ball 21 via the displacement transmitting member 25, so that the diameter of the piston 23 can be reduced. As a result, the excessive force generated by the piston 23 when the hydraulic pressure is applied can be suppressed to be small, so that the set screw 19 of the switching valve can also be made small, and the hollow portion of the switching valve and the components housed therein can be downsized. be able to.

[0024]

As described above, according to the present invention, an oil passage is formed inside the switching valve so as to penetrate the switching valve, and a hollow portion is formed at one end of the switching valve. However, a piston that is moved by hydraulic pressure, a first ball that is pressed by this piston, and a spring that is biased toward the first ball are housed inside the piston. A through hole is formed in the through hole, and the second ball is housed in the through hole. On the other hand, the second ball is fitted to the sliding surface of the valve block in which the switching valve slides. By forming the two grooves, it is possible to provide a hydraulic operation device capable of automatically increasing the pressure again while maintaining the same state as when the hydraulic pressure is lowered.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of a hydraulic operating device of the present invention.

FIG. 2 is an operation explanatory diagram of the embodiment shown in FIG.

FIG. 3 is a diagram for explaining the operation of the embodiment shown in FIG. 1 (when the hydraulic pressure drops).

FIG. 4 is a sectional view showing another embodiment of the present invention.

FIG. 5 is a schematic view showing an example of a conventional hydraulic operation device.

FIG. 6 is a sectional view showing an example of a conventional hydraulic operation device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Piston rod 2 ... Valve block 3 ... High pressure pipe 4 ... Low pressure tank 5 ... Hydraulic pump 6 ... High pressure piping 7 ... Accumulator 8 ... Electrical contact 9 ... Make-up side pilot valve 10 ... Shut-off side pilot valve 11 ... Switching valve 14 ... Pin 15 ... Spring 17 ... Cylinder head 18 ... Spring 19 ... Set screw 20 ... Hollow part 20a ... Through hole 21 ... Second ball 22 ... Oil passage 23 ... Piston 24 ... First ball 25 ... Displacement transmission member 30a, 30b …groove

Claims (1)

[Claims] 1. A hydraulic operating device for a power switch, wherein a switching valve for driving a piston rod for opening and closing an electrical contact of the power switch is provided in a valve block provided at an end of a hydraulic cylinder. An oil passage is formed inside the switching valve so as to penetrate the switching valve, and a hollow portion is formed at one end of the switching valve, and a piston that moves by hydraulic pressure is provided inside the hollow portion. A first ball pressed by the piston and a spring biased toward the first ball are housed. Further, a radial through hole is formed in the switching valve, and a second through hole is formed in the through hole. 2 balls are accommodated, and on the other hand, two grooves into which the second balls are fitted are formed on the sliding surface of the valve block in which the switching valve slides. Hydraulic operating device for power switch.