JPH0646046Y2 - Hydraulic operating device pilot valve - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial field of application) The present invention relates to a pilot valve in a hydraulic pressure control device for shutting off and closing a circuit breaker.

(Prior Art) In recent years, the performance of a circuit breaker provided in a circuit has been remarkably improved due to the realization of a large capacity and an ultra-high voltage of a power transmission system, but further improvement in performance has been strongly demanded. As a circuit breaker that meets these demands, many gas circuit breakers that use SF ₆ insulating gas as an arc extinguishing medium have been put to practical use in various fields.

In addition, one of the factors to improve the performance of these gas circuit breakers,
The improvement of the drive source for instructing the circuit breaker to perform a breaking operation or a closing operation can be mentioned. Generally, a gas pressure system is generally used as a drive source of a gas circuit breaker. However, as the capacity of the power transmission system is increased and the ultra-high pressure is increased, an extremely large driving force is required, and equipment such as a pneumatic cylinder and an air tank becomes large. In an operating device using such an air pressure, noise generated by air supply / exhaust generated during the shutoff operation becomes large, and therefore a muffling device is required.

On the other hand, there is a hydraulic operating device as a drive source of the circuit breaker. Since this hydraulic pressure control device can easily increase the pressure as compared with the pneumatic pressure, it is possible to reduce the size of the entire device, and the noise during the shutoff operation is significantly reduced. Further, since the liquid is incompressible as compared with air, there is an advantage that the response is excellent.

However, in order to use the hydraulic operating device as an operating device for a power circuit breaker, since the circuit breaker is a safety model against accidents in the power system, operation errors due to inoperability or malfunction of the operating device cannot be tolerated. There is a demand for reliable products.

The liquid operation device of the circuit breaker as described above is constructed as shown in FIG. That is, the operating part consisting of the piston P and the cylinder S for opening and closing the circuit breaker CB is the pilot valve P ・ V.
It is driven by the hydraulic pressure from the main valves M and V controlled by.
The pilot valves P and V have two pilot valves, a closing pilot valve and a shut-off pilot valve, and the main valves M and
The operation part is controlled by supplying / discharging the pressure liquid by the accumulator AL of the piping system and the pump into V.

An electromagnetic pilot valve is generally used as the pilot valves P and V described above, and is configured as shown in FIG. That is, the ball 22 is disposed so as to contact the valve seat 21a of the block 21, and the spring 23 is biased to push the ball 22 upward.

Further, the pressurized liquid is supplied to the first liquid chamber 24a from the high pressure side port 24b, and the second liquid chamber 24c partitioned by the first liquid chamber 24a and the ball 22 is communicated with the low pressure side port 24d. , Can be drained. Further, a plunger 25 is disposed above the ball 22 and is movable downward by an electromagnetic solenoid 26.

In the conventional hydraulic operation device having such a configuration, the plunger 25 is pressed downward by the excitation of the electromagnetic solenoid 26, the ball 22 moves downward, and the first liquid chamber 24a and the second liquid chamber 24c are moved. And are communicated. Then, the pressurized liquid in the first liquid chamber 24a is discharged through the second liquid chamber 24c to the low-pressure side port 24d which is a drain port.

When the electromagnetic solenoid 26 is de-energized, the plunger 25
The downward pressure of the ball disappears and the restoring force of the spring 23 causes the ball 22
Abuts on the valve seat 21a and shuts off the flow path between the first liquid chamber 24a and the second liquid chamber 24c.

(Problem to be Solved by the Invention) By the way, a drawback of the conventional pilot valve as described above is that a very large electromagnetic force is required as its driving force. That is, open the ball 22 (push down)
As the force, a force equal to or larger than the sum of the spring force of the spring 23 and the liquid pressure corresponding to the aperture area of the valve seat 21a is required. In particular, the higher the fluid pressure, the greater the electromagnetic force required to open and close the pilot valve.

The present invention has been proposed to eliminate the above drawbacks, and an object thereof is to provide a highly reliable pilot valve for a hydraulic operating device that can be driven by a small electromagnetic force.

[Structure of the Invention] (Means for Solving the Problem) In the present invention, a ball as a valve body is housed in a first liquid chamber formed in a block, and the first liquid chamber is opened to the low pressure side. A push rod that presses the sphere is provided in the second liquid chamber on the low-pressure side, which is configured to open and close with the second liquid chamber, and the upper end portion thereof is attached so as to be rotatable about an axis. Of the hydraulic operating device, which is arranged so as to abut one end of the link, and the other end of the link is abutted against the plunger of the electromagnetic solenoid attached to the base fixed to the block. In the valve, third and fourth liquid chambers are formed in the block, and a piston is slidably arranged in the third liquid chamber so as to communicate with the first liquid chamber. The fourth liquid chamber formed above the liquid chamber of No. 3 is connected to the piston. Rod disposed were, at the upper end of the rod which is characterized by being configured to abut on the link.

(Operation) According to the pilot valve of the hydraulic operating device of the present invention, the push rod for opening and closing the first liquid chamber and the second liquid chamber, and the rod provided on the piston sliding in the third liquid chamber By abutting both sides of the link that rotates around the axis, the driving force required to open and close the first liquid chamber and the second liquid chamber can be significantly reduced.

(Embodiment) An embodiment of the present invention will be specifically described below with reference to FIG.

* Structure of Embodiment * In this embodiment, as shown in FIG.
The ball 2 is disposed so as to abut on the valve seat 1a, and the spring 3 disposed below the valve seat 1a is biased to push the ball 2 upward.

Further, the first liquid chamber 4a in which the ball 2 and the spring 3 are arranged is communicated with the high-pressure side port 5a, while the first liquid chamber 4a and the second liquid chamber 4b opened and closed by the ball 2 are discharged. Liquid low pressure side port
It is in communication with 5b.

Further, a third liquid chamber 4c formed by the block 1 and a piston 6 sliding inside the block 1 is formed in communication with the first liquid chamber 4a, and is formed above the third liquid chamber 4c. The fourth liquid chamber 4d is connected to the atmosphere. Further, in the fourth liquid chamber 4d, a rod 6a for taking out the vertical movement of the piston 6 is provided so as to penetrate therethrough, and the piston 6 is
Is provided with a spring 3a for suppressing the upward movement of the. The third liquid chamber 4c and the fourth liquid chamber 4d are sealed by a packing 7a provided on the side portion of the piston 6.

On the other hand, in the second liquid chamber 4b above the sphere 2, a push rod 8 for pressing the sphere 2 is arranged so as to be vertically movable, and the lower end portion thereof is in contact with the sphere 2. Further, the second liquid chamber 4b is provided with a packing 7 attached to the outer peripheral portion of the push rod 8.
Sealed from the atmosphere by.

Further, above the push rod 8, a link 9 is attached rotatably around a shaft 10, one end of the link 9 is attached to the upper end of the push rod 8, and the other end is attached to a base 11 of an electromagnetic solenoid. It is arranged so as to come into contact with twelve plungers 13.

The upper end of the rod 6a is also configured to abut the link 9.

In addition, the diameter of the valve seat 1a of the block 1 is D ₁ and the diameter of the piston 6 is
D ₂ , the distance between axis 10 and push rod 8 is L ₁ , axis 10 and rod
If the distance of 6a is L ₂ , then D ₁ ² · L ₁ ≧ D ₂ ² · L ₂ .

* Operation of the Embodiment * In the pilot valve of the hydraulic operating device of the present embodiment having the above-mentioned configuration, the pilot valve is opened and closed as described below.

That is, when the coil of the electromagnetic solenoid 12 is excited and the plunger 13 is pushed up, the link 9 rotates in the clockwise direction in the figure and pushes down the push rod 8. As a result, sphere 2
Is pushed downward from the valve seat 1a, and the pressurized liquid from the high pressure side port 5a is discharged to the low pressure side port 5b through the first liquid chamber 4a and the second liquid chamber 4b.

On the other hand, when the electromagnetic solenoid 12 is de-excited, the ball 2 moves upward due to the restoring force of the spring 3, and at the same time, the action of the link 9 and the spring 3a pushes the piston 6 downward. As a result, the sphere 2 is pushed upward by a large pressure and comes into contact with the valve seat 1a to shield between the first liquid chamber 4a and the second liquid chamber 4b.

In this way, the forces acting upward (closed direction) of the ball 2 in the blocked state of the ball 2 are the liquid pressure corresponding to the area of the diameter D ₁ of the valve seat 1a and the upward biasing force of the spring 3. . On the other hand, the liquid pressure corresponding to the area of the outer diameter D ₂ of the piston 6 in the third liquid chamber 4c acts on the lower side (opening direction) of the sphere 2 via the link 9 from the principle of leverage. The force of the spring 3a is considerably smaller than the liquid pressure.

Therefore, in order to open the ball 2, if the hydraulic pressure is P, then π
/ 4 {D ₁ ² − (L ₂ / L ₁ ) D ₂ ² } xP, which is larger than the sum of the hydraulic force and the spring force. That is, compared with the conventional pilot valve shown in FIG.
Amount corresponding resistance of the liquid pressure corresponding to the area multiplied by L ₂ / L ₁ is reduced. Especially when D ₁ ² · L ₁ = D ₂ ² · L ₂ ,
Only the force that resists the spring 3 and the spring 3a is sufficient, and the electromagnetic force required for the opening / closing operation is small, and the electromagnetic solenoid can be downsized.

Further, since a small electromagnetic solenoid generally has a small inductance, it also has an advantage that it becomes an electromagnetic pilot valve with good response.

Further, as the valve element, it is possible to use a poppet valve having a conical contact portion with the valve seat 1a, but the poppet valve needs to be increased in hardness in order to prevent wear of the seal portion. Is also relatively difficult. On the other hand, when the ball as shown in the present embodiment is used, it has a sealing effect even when the valve body is tilted, has a better sealing property, and is inexpensive because it is used for a ball bearing or the like. .

[Advantages of the Invention] As described above, according to the present invention, it is possible to provide a highly reliable pilot valve for a hydraulic pressure control device capable of opening the valve body with a small electromagnetic force.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of a pilot valve of a hydraulic pressure control device of the present invention, FIG. 2 is a schematic view showing a general configuration of the hydraulic pressure control device, and FIG. 3 is a conventional pilot valve. It is sectional drawing which shows a structure. 1 ... Block, 1a ... Valve seat, 2 ... Ball, 3,3a ... Spring, 4a, 4b, 4c, 4d ... Liquid chamber, 5a ... High pressure side port, 5b ...
… Low pressure side port, 6 …… Piston, 6a …… Rod, 7,7a
...... Packing, 8 ... Push rod, 9 ... Link,
10 ... Axis, 11 ... Base, 12 ... Electromagnetic solenoid, 13 ...
… Plunger, 21 …… Block, 21a …… Valent seat, 22 ……
Ball, 23 ... Spring, 24a, 24c ... Liquid chamber, 24b ... High pressure side port, 24d ... Low pressure side port, 25 ... Plunger, 26 ...
Electromagnetic solenoid.

Claims (1)

[Scope of utility model registration request] 1. A ball as a valve body is housed in a first liquid chamber formed in a block, and the first liquid chamber is configured to open and close with a second liquid chamber opened to a low pressure side, A push rod for pressing the sphere is provided in the second liquid chamber on the low pressure side, and an upper end portion of the push rod is arranged so as to come into contact with one end of a link rotatably mounted around an axis. In a pilot valve of a hydraulic operating device configured to abut the other end of the link with a plunger of an electromagnetic solenoid attached to a base fixed on the block, a third and a fourth pilot valve are provided in the block. A liquid chamber is formed, a piston is slidably disposed in the third liquid chamber, communicates with the first liquid chamber, and a fourth chamber is formed on the upper side of the third liquid chamber. A rod connected to the piston is installed in the liquid chamber, and the upper end of the rod is attached to the A pilot valve for a hydraulic pressure control device, characterized in that the pilot valve is configured to come into contact with a fuel tank.