JPH07192583A - Hydraulic drive - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a hydraulic drive device capable of downsizing the device and increasing the output, and ensuring good response and excellent reliability. [Structure] A main piston 31 and a sub piston A31 are connected to a main contact 2 and a resistance contact A2 of a circuit breaker. Main piston 3
1, sub-piston A31 to main cylinder 30, sub-cylinder A
30. The main operation valve unit 10 and the auxiliary control valve unit A5 are connected to the main cylinder 30 and the auxiliary cylinder A30. The main cylinder and the sub control valve portion are connected by the connection flow path 107. A check valve A71 and a throttle A72 are provided in the connection channel 107. A high pressure port A53 and a drainage port A54 are formed in the sub control valve portion A5. The cross-sectional area for connecting the high-pressure port is made larger than the cross-sectional area for connecting the drainage port. Auxiliary closing valve A51b for opening and closing the high pressure port A5 and the drainage port A54, an auxiliary shutoff valve A5
1a is provided. The sliding body A51c is provided on the auxiliary cutoff valve A51a. All parts are hydraulically linked.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a circuit breaker hydraulic drive device having a resistance contact for suppressing a surge voltage generated when a circuit breaker is opened and closed.

[0002]

2. Description of the Related Art At present, a circuit breaker for a line of 550 kV class uses a circuit breaker with a closing resistor provided with a resistance closing contact in parallel with the main contact in order to suppress a surge voltage when the main contact is closed. ing. That is, the resistance contact is turned on before the main contact is turned on to energize the resistor, and the resistance contact is turned off prior to the main contact when turning off. In order to obtain this function with a simple structure, by directly connecting each movable contactor of the main contact and the resistance contact, it is possible to drive them simultaneously by the same driving device, while the timing of disconnecting and closing both contacts depends on the structure of the contactor. It corresponds by the difference in shape.

However, in an even higher voltage system of 1100 kV class, it is necessary to suppress the surge voltage generated at the time of interruption in order to reduce the insulation level. In this case, the circuit breaker has a configuration in which a breaking resistance contact is provided in parallel with the main contact.
Here, with reference to the electric circuit of FIG. 4, the operation concept of the circuit breaker with resistance in which the breaking resistance contact is also used as the closing resistance contact will be described.

In the closed state of the circuit breaker of FIG. 4 (a),
The current i flows through the main contact 2 having a small energization resistance value. Now, assume that an accident has occurred on the right terminal side of the circuit breaker. In this case, as shown in FIG. 4B, the drive device 1 opens the main contact 2 to interrupt the current i, but at this moment, a high transient recovery voltage (surge voltage) is present on the left terminal side of the circuit breaker. Occur. However, since the closed state of the resistance contact A2 is maintained, the surge voltage is mitigated by the resistance A2a provided in series with this. At this time, the current ir flowing through the resistance contact A2 and the resistance A2a is determined by the system voltage and the value of the resistance A2a.

Subsequently, as shown in FIG. 4C, the resistance contact A2
The current ir is also cut off when the circuit is opened, and the circuit breaker is opened. At this time, in order to sufficiently suppress the surge voltage, the resistance contact A2 needs to be opened 20 to 30 ms later than the main contact 2. On the other hand, when closing the circuit breaker,
From the state of (c), the resistance contact A2 is closed prior to the main contact 2, and the main contact 2 is closed when the surge voltage is sufficiently suppressed by the resistance A2a (after about 10 ms).

[0006]

As described above, 1100 is used.
The kV class circuit breaker with resistance must have a function of opening the resistance contact before the closing operation of the main contact and opening the resistance contact after a predetermined time elapses from the breaking operation of the main contact.
However, it is extremely difficult to realize such a function only by the difference in the structure of both contacts, as seen in the circuit breaker with a closing resistance of the conventional 550 kV system.

Therefore, it is necessary to operate each movable contactor of the main contact and the resistance contact with another driving device, and to secure the operation timing by a mechanical interlocking device or the like. Generally, the main contact is driven by a hydraulic pressure that can easily obtain a large output,
A method in which the resistance contact is driven by the compressive force of a spring and both are linked by a link mechanism can be considered. However, during the shutoff operation,
It is necessary to operate the resistance contact at the same speed as the main contact, and a drive spring having a large output must be used to obtain a high speed operation.

Further, like the main contact, the resistance contact also requires an arc extinguishing function, and when the widely used puffer type arc extinguishing method is applied, a driving force for compressing the insulating gas is further added. Must. Therefore, the drive spring for the resistance contact must be upsized. Moreover, as the size of the drive spring increases, the weight of the spring increases, which may cause a decrease in responsiveness. Of course, the driving force can be reduced by reducing the weight of the movable portion such as the movable contact of the resistance contact, but there is a practical limit.

It is also conceivable to rely on the hydraulic drive device for driving the main contact for the energy storage action of the drive spring. In this case, however, the energy storage force is applied as a load, so that the hydraulic drive device is made larger. Connect As described above, the structure in which the resistance contact is driven by the compression spring requires the provision of an interlocking mechanism with the main contact such as a link, which is not a good idea from a practical point of view such as miniaturization and responsiveness.

Further, in the circuit breaker with resistance, when only the resistance contact is energized independently for a long time, there is a problem that the resistance burns out. Therefore, when an abnormality occurs in a part of the driving device and the opening of the resistance contact is significantly delayed, it is necessary to add an emergency protection device that detects this and drives the contact at high speed. However, such emergency protection devices usually
There is a problem in that the structure is complicated and the hydraulic drive device is increased in size.

The present invention has been proposed in order to solve the problems of the prior art as described above, and its purpose is to control the operation of each movable contact of the main contact and the resistance contact and the time difference between them. The purpose of the present invention is to provide a hydraulic drive device that achieves downsizing and high output of the drive device by using pressure, and ensures good response and excellent reliability.

[0012]

In order to achieve the above object, the invention according to claim 1 provides a main cylinder and a sub-cylinder provided with a liquid chamber in which a pressurized fluid is stored, and a liquid chamber of the main cylinder. The main piston connected to the main contact of the circuit breaker is provided movably according to the pressure change in the liquid chamber, and the liquid chamber of the sub-cylinder is movably provided according to the pressure change in the liquid chamber, A sub-piston connected to the resistance contact of the circuit breaker, a main operation valve portion connected to the liquid chamber of the main cylinder, and provided with a valve chamber accommodating pressurized fluid, and a liquid chamber of the sub-cylinder. A liquid pressure drive device having a sub-control valve portion provided with a valve chamber accommodating a pressure fluid, wherein the liquid chamber of the main cylinder and the valve chamber of the sub-control valve portion are connected by a connection flow path. Connect to the sub-control from the liquid chamber of the main cylinder A check valve is provided in the connection flow passage so that the flow rate of the pressure fluid to the valve chamber of the sub-chamber is larger than the flow rate in the opposite direction, and the check valve is provided in the connection flow passage. From the liquid chamber of the sub-cylinder to the pressure chamber for adjusting the flow rate of the pressure fluid from the liquid chamber of the main cylinder to the valve chamber of the sub-control valve section. A discharge port that discharges a pressure fluid is formed, and a cross-sectional area for connecting a supply port that connects the liquid chamber of the sub cylinder and the supply port in the valve chamber of the sub control valve unit is defined as the sub control valve. In the valve chamber on the side of the connection flow path of the sub-control valve portion, the cross-sectional area for connecting the discharge port connecting the liquid chamber of the sub-cylinder and the discharge port in the valve chamber Moves in response to pressure changes, said supply port and front A supply valve body and a discharge valve body that open and close the discharge port are movably provided in the valve chamber of the sub-control valve unit, and a slide body that closes the discharge port is provided until the discharge valve body moves a predetermined distance. The discharge valve element is provided.

According to a second aspect of the present invention, in the hydraulic drive system according to the first aspect, the valve on the side of the connection flow passage in the sub control valve portion is larger than the cross-sectional area for connecting the supply port in the sub control valve portion. It is characterized by forming a large cross-sectional area in the room.

According to a third aspect of the present invention, in the hydraulic drive system according to the first aspect, the opening time difference between the main contact and the resistance contact is td, the pressure of the pressure fluid is P, and the density of the pressure fluid is ρ. , L1 is the length of the slide body of the discharge valve, Sx is the flow passage cross-sectional area of the throttle, Sv is the cross-sectional area of the valve passage on the side of the connection flow passage in the sub-control valve portion, and the valve of the sub-control valve portion is If the cross-sectional area for connecting the supply port in the chamber is So, then t
The relationship of 0 <(L1 / td) (ρ / 2P) ^1/2 ≦ (Sx / Sv) (So / Sv) ^1/2 is established between d, P, ρ, L1, Sx, Sv, and So. It is characterized in that it is configured to hold.

[0015]

The operation of the present invention having the above construction is as follows. That is, according to the first aspect of the invention, first, when the main contact and the resistance contact are in the closed state, the main piston and the sub-piston are connected to each other by the pressure fluid contained in the liquid chambers of the main cylinder and the sub-cylinder. It is maintained in a position that keeps the resistance contact closed.
From this state, adjust the pressure in the valve chamber of the main operating valve,
The pressure in the liquid chamber of the main cylinder connected to the valve chamber is reduced. Then, the main piston moves and the main contact connected to the main piston is disconnected.

On the other hand, when the main contact and the resistance contact are in the closed state, the discharge valve body in the valve chamber of the sub control valve portion closes the discharge port, so that the pressure fluid is not discharged from the valve chamber. Here, when the main contact is shut off as described above, the pressure in the main cylinder decreases, so the pressure in the valve chamber on the connection flow path side of the sub control valve portion also decreases. However, since the connection passage that connects the liquid chamber of the main cylinder and the valve chamber of the sub control valve section is provided with a throttle for adjusting the flow rate of the pressure fluid, this throttle reduces the pressure drop in the main cylinder. Than the pressure drop in the valve chamber of the sub-control valve portion is delayed.
When the pressure in the valve chamber on the side of the connection flow path of the sub-control valve portion decreases in this way, the discharge valve body starts to move to the position where the discharge port is opened, and when it moves a predetermined distance, the sliding body opens the discharge port. Then, the pressure fluid in the liquid chamber of the sub cylinder passes through the cross section for connecting the exhaust port in the valve chamber of the sub control valve unit,
Since the liquid is discharged from the discharge port, the pressure in the liquid chamber of the sub cylinder decreases. Since the cross-sectional area for connecting the supply port is formed to be larger than the cross-sectional area for connecting the discharge port, the discharge valve after the discharge port is opened is larger than when the discharge port is closed. The speed of the body becomes faster. Therefore, after the sliding body opens the discharge port, the pressure in the liquid chamber of the sub cylinder is rapidly lowered, so that the sub piston moves quickly and the resistance contact connected to the sub piston is cut off.

Next, the closing operation of the main contact and the resistance contact which are cut off as described above will be described. That is, the pressure in the valve chamber of the main operation valve unit is adjusted to increase the pressure in the liquid chamber of the main cylinder connected to the valve chamber. Then, the check valve opens due to the pressure, and the pressure fluid flows from the liquid chamber of the main cylinder to the valve chamber of the sub control valve portion, so that the pressure in the valve chamber of the sub control valve portion on the connection flow path side rises. When the pressure in the valve chamber on the connection flow path side in the sub control valve portion rises in this way, the discharge valve body closes the discharge port and the supply valve body moves to a position where the supply port opens. Then, the pressure fluid flows from the supply port into the liquid chamber of the sub cylinder, and the pressure in the liquid chamber rises. Therefore, the auxiliary piston moves and the resistance contact is closed. Furthermore, if the pressure in the main cylinder rises to the extent that the pressure at the time of breaking the main contact cannot be maintained due to the flow to the sub control valve section side via the check valve in the connection flow path, the main piston moves. The main contact is turned on.

According to the second aspect of the invention, as described above,
When the check valve opens and pressure fluid flows from the liquid chamber of the main cylinder to the valve chamber of the sub control valve, the cross sectional area of the valve chamber on the connection flow path side of the sub control valve is smaller than the cross sectional area for connecting the supply port. Is also large, a sufficient force for driving the supply valve body and the discharge valve body can be obtained. Therefore, the movement of the supply valve body and the discharge valve body, the movement of the sub-piston and the closing operation of the resistance contact can be performed quickly and surely.

According to the third aspect of the invention, the opening time difference between the main contact and the resistance contact can be determined by the length of the sliding body, which is advantageous in designing the device.

[0020]

The first embodiment of the hydraulic drive system of the present invention is as follows.
An embodiment and a second embodiment will be described below with reference to FIGS. The same members as those in the conventional example shown in FIG. 4 are designated by the same reference numerals and the description thereof will be omitted. Also, in each of the embodiments, the same members are designated by the same reference numerals.

(1) Configuration of the First Embodiment The configuration of the first embodiment of the present invention will be described below with reference to FIGS. 1 and 2. The first embodiment corresponds to the hydraulic drive system according to the first and second aspects. In addition, claim 1
The supply valve element described is the sub-closing valve, the discharge valve element is the sub-blocking valve, the supply port is the high pressure port of the sub-control valve section, the discharge port is the drain port of the sub-control valve section, and the sliding body is the sliding body of the sub-blocking valve. And

In the present embodiment, the main operating portion 3 and the sub operating portion A3 for opening and closing the main contact 2 and the resistance contact A2 of the circuit breaker, respectively.
It has and. These main operating section 3 and sub operating section A3
Is driven by the pressure fluid controlled by the main control valve unit 5 and the sub control valve unit A5. The main operation valve portion 10 is provided in the liquid chamber 34 at the back of the main piston 31, and the pressure fluid is supplied and discharged through the main operation valve portion 10.

The main operating section 3 comprises a main cylinder 30, a main piston 31, and a main piston rod 32.
Both are connected by a main piston rod 32 so that the main contact 2 is opened and closed by the operation of 1. Liquid chamber 3 of main cylinder 30
3 is communicated with an accumulator 6 that constantly stores pressure fluid via a pipe 4, and pressure fluid is supplied to and discharged from a liquid chamber 34 at the back of the main piston 31 via a main control valve portion 5.

The main control valve portion 5 is composed of a manifold 50 and a main switching valve 51 that operates inside thereof, and has a main valve port 52a, a high pressure port 53, and a drainage port 54. The main valve port 52a is the valve chamber 1 of the main operation valve unit 10.
06, the high pressure port 53 is connected to the liquid chamber 33 and the flow path 35.
The drainage port 54 is communicated with the low-pressure tank 9. Further, between the main valve port 52a and the high pressure port 53, or between the main valve port 52a and the drainage port 54, opening / closing can be switched by moving the main switching valve 51. In addition, the manifold 50 and the main switching valve 51
The valve chambers 55 and 56 formed by the high pressure port 53
And throttle fluids 57 and 58, respectively, to which pressure fluid is constantly supplied.

Further, the shutoff solenoid valve 7 and closing solenoid valve 8 are connected to the main switching valve 51 via the valve chambers 55 and 56 and the flow passages 55a and 56a, respectively.

The shutoff solenoid valve 7 and the closing solenoid valve 8 operate the main switching valve 51.
1, 81 and pilot valve bodies 72, 82, and the pilot valve body 7 is operated by the operation of the electromagnetic solenoids 71, 81.
2,82 are designed to open. In addition, drainage flow passages 73 and 83 are formed in the shutoff solenoid valve 7 and the closing solenoid valve 8, and when the pilot valve bodies 72 and 82 are opened, the valves are discharged via the drainage passages 73 and 83. The pressure fluid in the chamber 55 or 56 is collected in the low pressure tank 9.

The main operation valve portion 10 is composed of a manifold 100, a shutoff main valve 101 and a closing main valve 102 which operate inside thereof, and a cylinder port 103 and a liquid chamber 33 which communicate with a liquid chamber 34 in the main cylinder 30. A high-pressure port 104 communicating with the flow path 35 and a drain port 105 communicating with the low-pressure tank 9 are formed. The cylinder port 103 and the drainage port 105 are shut off by the shutoff main valve 101.
On the other hand, the cylinder port 103 and the high pressure port 104 can be opened and closed by the closing main valve 102. Further, the shutoff main valve 101 and the closing main valve 102 are urged by elastic members in the direction of closing each port. In the main operation valve unit 10, the manifold 100
A valve chamber 106 is formed by the shutoff main valve 101 and the closing main valve 102, and the main valve port 52 is formed in the valve chamber 106.
a is communicated, and the pressure fluid is supplied and discharged via the main control valve portion 5.

The sub-operation portion A3 comprises a sub-cylinder A30, a sub-piston A31 and a sub-piston rod A32. The sub-piston rod A32 connects the two so that the resistance contact A2 is opened and closed by the operation of the sub-piston A31. The liquid chamber A33 of the sub cylinder A30 is communicated with the accumulator 6 that constantly stores the pressure fluid via the pipe A4, and the sub piston A30
The pressure fluid is supplied to and discharged from the liquid chamber A34 at the back of 31 through the sub-control valve portion A5.

The sub-control valve section A5 comprises a manifold A50 and a sub-switching valve A51 which operates inside.
The manifold A50 has a liquid chamber A in the auxiliary cylinder A30.
There are formed a cylinder port A52 communicating with 34, a high pressure port A53 communicating with the liquid chamber A33 through the flow path A35, and a drainage port A54 communicating with the low pressure tank 9. Then, between the cylinder port A52 and the high pressure port A53,
Alternatively, the opening / closing can be switched between the cylinder port A52 and the drainage port A54 by moving the auxiliary switching valve A51.

The sub switching valve A51 is a sub shutoff valve A51.
It is formed by a and the sub-charging valve A51b. Sub shutoff valve A5
1a and sub-charging valve A51b have sliding bodies A51c and A51d, respectively. When the auxiliary switching valve A51 moves leftward from the closed state of FIG. 2 (a) and the sliding body A51c communicates between the cylinder port A52 and the drainage port A54,
As shown in FIG. 2B, the sliding body A 51d is a high pressure port A.
The communication between 53 and the cylinder port A52 is blocked. During the shutoff operation, the sliding body A51c and the manifold A50 are superposed, so that the auxiliary cylinder A30
Delay the timing to remove the pressure fluid in the main contact 2
And the opening time difference between the resistance contact A2 and the resistance contact A2 are set. Further, during the period from (b) to (c) in FIG. 2, the sliding body A51d overlaps with the manifold A50, and the high pressure port A
A large amount of pressure fluid from 53 is prevented from flowing out to the drainage port A54 via the cylinder port A52.

In the sub control valve portion A5, the valve chambers A55 and A56 are provided by the manifold A50 and the sub shutoff valve A51a.
Are formed. Of these, the valve chamber A55 is communicated with the main operating portion 3 through the interlocking valve portion A7 by the cylinder port 103 of the main operating valve portion 10 and the connection flow passage 107. On the other hand, the valve chamber A56 is in communication with the high pressure port A53, and the pressure fluid is constantly supplied thereto.

Further, the cross-sectional area of the pressure fluid containing portion of the sub control valve portion A5 is set as follows. That is, as shown in FIG. 2A, the high pressure port A
The cross section of the seat portion that connects 53 and the cylinder port A52 so that the pressure fluid flows can be opened and closed by the sliding body A51d of the auxiliary closing valve A51b, and the cross section area of this seat portion is Sc. The cross section of the seat portion that connects the cylinder port A52 and the drainage port A54 so that the pressure fluid flows can be opened and closed by the sliding body A51c of the auxiliary cutoff valve A51a. To do. Sub shut-off valve A in sub control valve section A5
The area of the cross section to which the cross-sectional area connection channel 107 on the 51a side is connected is defined as the valve element cross-sectional area Sv. The relationship between the seat section cross-sectional areas Sc and So and the valve body cross-sectional area Sv is Sv> Sc
It is set so that ≧ So.

The interlocking valve portion A7 includes a check valve A71 and a throttle A7.
2, the sub-control valve section A5 functions in conjunction with the hydraulic pressure of the pressure fluid controlled by the main control valve section 10.
That is, from the main control valve unit 10 to the valve chamber A of the sub-control valve unit A5.
When the pressure fluid is supplied to 55, the check valve A71 is opened to allow a large flow rate of the pressure fluid to flow. Conversely, when the pressure fluid is removed from the valve chamber A55, the check valve A71 is closed. The flow rate is limited by the diaphragm A72. Aperture A72
Is configured as a variable throttle capable of adjusting the flow rate from the outside.

(2) Operation of the first embodiment The operation of the first embodiment having the above-described structure is divided into (A) contact breaking operation and (B) contact closing operation, and the operation of FIG.
A description will be given with reference to FIGS. 2 and 3.

(A) At the time of contact breaking operation That is, in the closed state of the main contact 2 and the resistance contact A2 shown in FIG. 1, the cylinder ports 103 and A52 of the main operation valve unit 10 and the auxiliary control valve unit A5 and the exhaust port are removed. Liquid port 105, A5
Since the space between 4 is closed, the main piston 31 and the sub piston A31 are held at the upper position by the pressure fluid in the liquid chambers 34 and A34.

At this time, if a shut-off operation command is given to the shut-off solenoid valve 7, pressure fluid flows out from the valve chamber 55 of the main control valve portion 5 and the pressure drops. The main switching valve 51 moves to the right. Main valve port 52a
By opening between the drain port 54 and the drain port 54,
The hydraulic pressure in the valve chamber 106 of 0 decreases, and the shutoff main valve 101 opens between the cylinder port 103 and the drain port 105. Therefore, the pressure fluid flows out from the liquid chamber 34 in the main cylinder 30,
The main piston 31 moves downward due to the pressure drop. Along with this, the main contact 2 performs the shut-off operation, but at the same time, the hydraulic pressure of the valve chamber A55 communicating with the cylinder port 103 decreases, and the sub switching valve A51 becomes integrated due to the action of the pressure fluid such as the valve chamber A56. Start to the left.

However, as shown in FIG. 2B, the valve chamber A
When the pressure fluid flows out of 55, the check valve A71 of the communication valve portion A7 is closed, and the throttle A72 suppresses the pressure fluid outflow from the valve chamber A55, so that the auxiliary switching valve A51 operates gently. During this operation, the sliding body A5 of the auxiliary cutoff valve A51a
1c blocks communication between the cylinder port A52 and the drainage port A54. Therefore, the liquid chamber A of the auxiliary cylinder A30
A high pressure state is maintained inside 34, and the auxiliary piston A31 maintains the closed state of the resistance contact A2.

After the shut-off operation command is released, even if the pressure in the valve chamber 55 is restored by closing the pilot valve body 72, the main switching valve 5 is reduced due to the decrease in the hydraulic pressure in the cylinder port 52.
1 maintains the closed state of the high pressure port 53, and the main piston 3
1 keeps the main contact 2 in the disconnected state. On the other hand, the auxiliary shutoff valve A51
A small amount of pressure fluid flows from the cylinder port A52 to the drainage port A54 through the gap in the overlapping portion between the sliding body A51c of a and the manifold A50, and during this time, the pressure fluid flows from the high pressure port A53 to the liquid chamber A34. Because of the inflow, the auxiliary piston A31 securely holds the resistance contact A2 at the closing position.

As shown in FIG. 2 (c), the sub switching valve A51 further moves to the left, and when the sliding body A51c and the manifold A50 are separated from each other, the cylinder port A52 and the drain port A54 are separated from each other. When opened, the liquid pressure in the liquid chamber A34 drops rapidly. At this time, the auxiliary closing valve A51b closes between the high pressure port A53 and the cylinder port A52, and the auxiliary piston A31 moves downward, so that the resistance contact A2 is opened. In this way, the resistance contact A2 can be opened later than the main contact 2.

From the opening operation of the main contact 2, the resistance contact A
The delay time until 2 is opened depends on the throttle A of the interlocking valve section A7.
The flow passage cross-sectional area of 72 and the sliding body A51 of the auxiliary shutoff valve A51a
By adjusting the stacking distance corresponding to the length of c, the auxiliary cylinder A3
This can be ensured by appropriately delaying the timing of removing the pressure fluid in 0.

Next, the movement of the auxiliary switching valve A51 during the shutoff operation as described above will be described in detail with reference to the configuration diagram shown in FIG. 2 and the graph showing the displacement of the main part and the pressure response waveform shown in FIG.

That is, as described above, the shutoff solenoid valve 7
When a cutoff operation command is given to, as shown in FIG.
The main cylinder pressure Pm at the cylinder port 103 of the main operation valve unit 10 decreases from the operation pressure Pa to the atmospheric pressure. Then, as shown in FIG.
The main contact displacement Xm that causes the opening / closing operation occurs. Also,
As shown in FIG. 3D, the auxiliary switching valve valve chamber pressure P of the valve chamber A55 of the auxiliary control valve portion A5 is interlocked with the main cylinder pressure Pm.
Since v also decreases, as shown in FIG. 3B, a sub switching valve displacement Xv in which the sub switching valve A51 operates is generated.

Until the sliding body A51c of the auxiliary shutoff valve A51a opens the drainage port A54, the auxiliary switching valve valve chamber pressure Pv on the side of the connection flow passage 107 is determined by the flow rate of the throttle A72 and the valve body speed. As shown in 3 (d), the intermediate value between the atmospheric pressure and the operating pressure Pa is maintained. At this time, the sub-operation valve valve chamber pressure Pv acts as a counter-driving force for the sub-switching valve A51, and the valve bodies are interlocked at a substantially constant speed.

Here, the pressure of the cylinder port A52 of the sub-control valve portion A5 is set to the sub-cylinder pressure Ps, and as described above, the seat portion cross-sectional area between the cylinder port A52 and the drainage port A54 is So, and the operation valve valve chamber The cross-sectional area of the valve body on which the pressure Pv acts is defined as the valve body cross-sectional area Sv. Then, the auxiliary switching valve A
The equation of the balance of the driving force with respect to 51 is as follows when the inertial force of the valve element is omitted.

[0045]

## EQU00001 ## Ps.So = Pv.Sv (1) However, the relationship between the operating pressure Pa and the auxiliary cylinder pressure Ps is Ps = P as shown in the above description and FIG. 3 (c).
a.

On the other hand, regarding the relationship between the inflow amount and the outflow amount in the valve chamber A55, the speed of the auxiliary switching valve A51 is V1, the flow passage sectional area of the throttle A72 is Sx, the flow coefficient of the throttle portion is C, and the density of the pressure fluid is If ρ is assumed and the fluid is regarded as incompressible, it is expressed by the following equation.

[0047]

[Equation 2] Sv · V1 = C · Sx · (2 · Pv / ρ) ^1/2 Equation (2) Until Pv is deleted from the above equations (1) and (2) and the drain port A54 is opened. When the valve body speed V1 is calculated as follows.

[0048]

[Formula 3] V1 = C · (Sx / Sv) · {(2 / ρ) (So / Sv) · Pa} ^1/2 ... Formula (3) Further, the auxiliary switching valve A51 has the length L1 of the sliding body A51c. When the drainage port A54 is opened after moving the distance corresponding to, the auxiliary cylinder pressure Ps decreases from the operating pressure Pa to the atmospheric pressure as shown in FIG. 3C, and is shown in FIG. As described above, the resistance contact displacement Xs occurs so that the auxiliary piston A31 performs the opening / closing operation.

At this time, the sliding body A5 of the auxiliary closing valve A51b
1d closes the high pressure port A53, and the state of operating pressure Pa is maintained together with the valve chamber A56. Here, assuming that the seat section cross-sectional area between the high pressure port A53 and the cylinder port A52 is Sc, the forces acting on the auxiliary switching valve A51 are balanced as shown in the following equation.

[0050]

## EQU00004 ## Pa.Sc = Pv.Sv Equation (4) As described above, the valve body speed V2 at this time is expressed by Equation (2),
From (4),

V2 = C · (Sx / Sv) · {(2 / ρ) (Sc / Sv) · Pa} ^1/2 ... Formula (5)

During operation of the sub switching valve A51, the throttle A
The flow path cross-sectional area Sx of 72 is constant. Therefore, from the equations (3) and (5), the seat section cross-sectional areas So, Sc
The valve body speeds V1 and V2 can be adjusted by changing the setting of.

By the way, in the circuit breaker with resistance as in this embodiment, it is desirable that the resistance contact A2, which opens after a certain time delay from the opening of the main contact 2, is driven as fast as possible. To this end, the auxiliary switching valve A51 that controls the auxiliary piston A31 is switched at high speed so that the flow passage area between the cylinder port A52 and the drainage port A54 becomes an appropriate size, and the inside of the liquid chamber A34 is It is necessary that the fluid be discharged in a short time. If the valve body speed V2
Is insufficient, the pressure in the liquid chamber A34 increases and the responsiveness of the sub piston A31 decreases, as shown by the broken line in FIG. 3 (a).

Therefore, it is desirable that the speed V2 after the sub switching valve A51 opens the drainage port A54 is equal to or higher than the speed V1 before opening (V1≤V2). In the present embodiment, the relationship between the seat portion cross-sectional areas Sc and So is Sc ≧ So.
As shown in FIG. 3B, the auxiliary switching valve A5 is set to be smaller than that when Sc <So is set.
1 moves quickly.

Furthermore, when the drainage port A54 is opened,
Since the sliding body A51d is configured to close the high-pressure port A53, if Sc ≧ So is set, then FIG.
As shown in, it is possible to continue maintaining the decrease of the sub cylinder pressure Ps to about the atmospheric pressure as compared with the case of setting Sc <So. Then, when Sc ≧ So is set, as shown in FIG.
As shown in (d), it is possible to prevent the sub switching valve valve chamber pressure from lowering as compared with the case where Sc <So is set. Therefore, it is possible to avoid a local decrease in the operating pressure Pa in the expression (5), and it is possible to obtain good switching characteristics of the sub switching valve A51.

(B) At the time of contact opening operation On the other hand, when the closing operation of the main contact 2 and the resistance contact A2 is given, a closing operation command is given to the closing solenoid valve 8, the hydraulic pressure in the valve chamber 56 decreases, and the valve chamber 55 is closed. Main switching valve 51 due to the pressure fluid inside
Switches to the left. At this time, the pressure fluid flows into the valve chamber 106, and the closing main valve 102 causes the cylinder port 103 to move.
Since the high pressure port 104 and the high pressure port 104 communicate with each other, the pressure in the high pressure port 104 becomes high. Then, the check valve A71 of the interlocking valve portion A7 opens and a large amount of pressure fluid flows into the valve chamber A55, so that the sub-switching valve A51 integrally switches rapidly to the right by the action of the pressure fluid. Therefore, the liquid chamber A3
The hydraulic pressure of No. 4 rises, and the auxiliary piston A31 and the resistance contact A2 start in the closing direction. Therefore, the resistance contact A2 is closed.

Further, when the pressure in the high pressure port 104 increases, the liquid chamber 34 also becomes high in pressure. Then, the main piston 31
Moves in the closing direction together with the main contact 2, so that the main contact 2 is closed. As described above, the resistance contact A2 is closed before the main contact 2 by a predetermined time.

(3) Effects of the First Embodiment The effects of the first embodiment described above are as follows.
That is, since the main contact 2 and the resistance contact A2 are both driven by hydraulic pressure, a strong driving force can be obtained without using a large spring or the like, which is advantageous for downsizing the device.

The interlock between the main contact 2 and the resistance contact A2 is realized by connecting the auxiliary control valve portion A5 to the cylinder port 103 of the main operation valve portion 10 through the interlocking valve portion A7, so that a spring or the like is used. Even when it is used, a simple mechanism can establish a solid master-slave relationship between the main operating portion 3 and the sub operating portion A3. Since the device is driven by hydraulic pressure, it is more resistant to load fluctuations such as frictional force and disturbance than when a spring or the like is used, and this may cause fluctuations in the interlocking characteristics of the main piston 31 and the auxiliary piston A31. Less is. Therefore, both contacts can be interlocked with a certain time difference and with a reliable and good responsiveness.

Since the operation of the resistance contact A2 is carried out by detecting the pressure change in the main operating portion 3 which does not depend on the displacement characteristic of the main contact 2, the resistance contact A2 is caused by the load fluctuation due to various interruption modes of the main contact 2. It is possible to prevent the delayed opening time of the resistance contact A2 from varying.

In the sub switching valve A51, one of the sliding bodies A51c and A51d is in each port A in the entire operating range.
Since the communication between the valves 52, A53 and A54 is blocked, it is possible to prevent the stall of the auxiliary switching valve A51 due to the decrease in the driving pressure. Therefore, the moving speed of the sub piston A31 can be maintained at a high speed. Therefore, it is possible to obtain a predetermined delayed opening time and a high-speed cutoff characteristic after opening for the resistance contact A2, and it is possible to secure good responsiveness and excellent reliability.

The cross-sectional area Sv of the valve chamber A55 of the auxiliary switching valve A51 communicating with the main operating portion 10 and the cross-sectional areas Sc and So of the opening / closing seats on the high-pressure port A52 and drainage port A54 side are S
Since the setting is such that v> Sc ≧ So, it is possible to obtain the high-speed cutoff characteristic after the resistance contact A2 is opened and the good closing characteristic as described above.

Further, since the interlocking valve section A7 for controlling the sub operation section A5 is connected to the cylinder port 103 of the main operation section 3, it is avoided that only the resistance contact A2 is closed for a long time, and the circuit breaker with resistance is connected. Good operational reliability can be secured as a hydraulic drive device.

(4) Structure and operation of the second embodiment The second embodiment of the present invention will be described below with reference to FIGS. The second embodiment corresponds to the hydraulic drive system according to the third aspect of the invention, and has substantially the same configuration as the first embodiment. However, in order to secure the delay opening time of the resistance contact A2 with respect to the main contact 2, the auxiliary switching valve A51 and the throttle A7 are provided.
The difference is that the size of 2 is specified. That is, FIG. 3 (a)
As shown in (c), the opening time difference td between the main contact 2 and the resistance contact A2 can be regarded as equal to the decrease start time difference td 'of the pressure Pm in the main cylinder 30 and the pressure Ps in the auxiliary cylinder A30. it can. At this time, the sub switching valve A51
The product of the valve body speed V1 and the time difference td until the opening of the drainage port A54 corresponds to the length L1 of the sliding body A51c. The velocity V1 is as in the equation (3) shown in the first embodiment, and since the flow coefficient C in the equation has a value of 0 <C ≦ 1, the following relational expression can be derived.

[0064]

[Equation 6] 0 <(L1 / td) (ρ / 2Pa) ^1/2 ≦ (Sx / Sv) (So / Sv) ^1/2 (6) Therefore, the pressure of the pressure fluid is Pa and the density is ρ Then, the sectional area So of the seat portion of the auxiliary switching valve A51 on the drain port A54 side, the sectional area Sv of the valve chamber A55, and the throttle A72.
A predetermined opening time difference td can be obtained by selecting the length L1 so as to satisfy the equation (6) with respect to the channel cross-sectional area Sx of. On the contrary, when the length L1 and the cross-sectional areas So and Sv are fixed, the flow passage area Sx can be adjusted by the diaphragm A72 so as to satisfy the expression (6).

As described above, according to the second embodiment, the sliding body A51c provided on the auxiliary shutoff valve A51a is involved in the setting of the delayed opening time of the resistance contact A2 during the shutoff operation. By adjusting the length L1, the opening time difference between the main contact 2 and the resistance contact A2 can be easily set to a desired value. Therefore, it is possible to manufacture a device having good device manufacturing efficiency and an appropriate and reliable delayed opening characteristic.

(4) Other Examples The present invention is not limited to the above examples, and the material, shape, size, etc. of each member can be appropriately changed. That is, in the first embodiment, the main piston 31 is driven by the main operation valve portion 10, but this can be omitted. Further, although the sub piston A31 is directly driven by the sub switching valve A51, a valve having a large opening flow passage area is provided between the liquid chamber A34 and the cylinder port A52, and a large amount of pressure fluid is supplied to the liquid chamber A34. The same action and effect can be obtained even with the structure for supplying and discharging.

Furthermore, if the throttle A72 of the interlocking valve portion A7 is a variable throttle capable of adjusting the flow rate from the outside, the switching speed of the sub switching valve A51 at the time of shutoff can be controlled, so that the opening / closing operation of both contacts can be performed. The delay time can be finely adjusted.

[0068]

As described above, according to the present invention,
The main contact and the resistance contact are shut off and turned on, and interlocking with a predetermined time difference required for both contacts is realized by the hydraulic drive device, so that the drive device can be downsized and the output can be increased. Furthermore, it is possible to provide a hydraulic drive device having good responsiveness and excellent reliability.

[Brief description of drawings]

FIG. 1 is a first embodiment and a second embodiment of a hydraulic drive system of the present invention.
It is a piping lineblock diagram showing an example, and is a sectional view showing the closed state of a main contact and a resistance contact.

FIG. 2 is a first embodiment and a second embodiment of the hydraulic drive system of the present invention.
It is a block diagram which shows the structure and operation | movement of the sub control valve part in an Example, (a) is a closing state, (b) is operation | movement,
(C) is sectional drawing which shows a cutoff state.

FIG. 3 is a first embodiment and a second embodiment of the hydraulic drive system of the present invention.
It is the graph which showed the operating characteristic at the time of interruption in an example, (a) shows displacement of a main contact and a resistance contact,
(B) shows the displacement of the sub switching valve, (c) shows the displacement of the pressure of the main cylinder and the sub cylinder, and (d) shows the displacement of the sub switching valve chamber pressure.

FIG. 4 is a circuit diagram illustrating the operation of a general circuit breaker with a resistor that uses both a breaking resistance contact and a closing resistance contact.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Hydraulic drive device 2 ... Main contact 3 ... Main operation part 4, A4 ... Piping 5 ... Main control valve part 6 ... Accumulator 7 ... Shut-off solenoid valve 8 ... Make-up solenoid valve 9 ... Low pressure tank 10 ... Main operation valve Part 30 ... Main cylinder 31 ... Main piston 32 ... Main piston rod 33, 34, A33, A34 ... Liquid chamber 35, 55a, 56a, 59, A35 ... Flow path 50, A50 ... Manifold 51 ... Main switching valve 52, 103, A52 ... Cylinder port 52a ... Main valve port 53, 104, A53 ... High pressure port 54, 105, A54 ... Drainage port 55, 56, 106, A55, A56 ... Valve chamber 57, 58, A72 ... Throttle 71, 81 ... Electromagnetic Solenoid 72, 82 ... Pilot valve body 100 ... Manifold 101 ... Shut-off main valve 102 ... Make-up main valve 107 ... Connection flow path A2 ... Resistance contact A2a ... Resistance A3 ... Sub-operation part A5 ... Sub-control valve part A7 ... Interlocking valve part A30 ... Sub-cylinder A31 ... Sub-piston A32 ... Sub-piston rod A51 ... Sub-switching valve A51a ... Sub-blocking valve A51b ... Sub-closing valve A51c, A51d ... Sliding body A71 ... Check valve

Claims (3)

[Claims] 1. A main cylinder and a sub-cylinder provided with a liquid chamber containing a pressurized fluid, and a liquid contact of the main cylinder, which is provided in the liquid chamber of the main cylinder so as to be movable in response to a change in pressure in the liquid chamber. A main piston connected to the sub-cylinder, a sub-piston movably provided in the liquid chamber of the sub-cylinder according to a pressure change in the liquid chamber, and connected to a resistance contact of the circuit breaker, and a liquid chamber of the main cylinder. And a sub-control valve portion provided with a valve chamber accommodating the pressure fluid, and a main operation valve portion provided with a valve chamber accommodating the pressure fluid, and a sub-control valve portion provided with a valve chamber accommodating the pressure fluid. In the hydraulic drive device characterized in that the liquid chamber of the main cylinder and the valve chamber of the sub-control valve portion are connected by a connection flow path, from the liquid chamber of the main cylinder to the valve chamber of the sub-control valve portion The flow rate of the pressure fluid is larger than the flow rate in the opposite direction. So that a check valve is provided in the connection flow passage, and a throttle for adjusting the flow rate of the pressure fluid from the valve chamber of the sub control valve portion to the liquid chamber of the main cylinder is provided in the connection flow passage, In the valve chamber of the sub-control valve portion, a supply port for supplying the pressure fluid into the liquid chamber of the sub-cylinder and a discharge port for discharging the pressure fluid from the liquid chamber are formed. A cross-sectional area for connecting a supply port connecting the liquid chamber of the sub cylinder and the supply port is connected between the liquid chamber of the sub cylinder and the discharge port in the valve chamber of the sub control valve portion. A supply that is formed to have a size larger than a cross-sectional area for connecting an exhaust port and that moves in response to a pressure change in the valve chamber on the side of the connection flow path in the sub-control valve unit to open and close the supply port and the exhaust port. The valve body and the discharge valve body are controlled by the sub-control. Movable in the valve chamber parts, until the discharge valve body is moved a predetermined distance, the sliding body for closing the exhaust port, a hydraulic drive device, characterized in that provided on the discharge valve body. 2. A cross-sectional area of a valve chamber on the side of the connection flow path of the sub-control valve portion is formed larger than a cross-sectional area of the sub-control valve portion for connecting a supply port. Hydraulic drive. 3. The opening time difference between the main contact and the resistance contact is td, the pressure of the pressure fluid is P, the density of the pressure fluid is ρ,
The length of the slide body of the discharge valve body is L1, the flow passage cross-sectional area of the throttle is Sx, the cross-sectional area of the valve passage chamber of the sub-control valve portion on the connection flow passage side is Sv, and the valve chamber of the sub-control valve portion is Sv. Let So be the cross-sectional area for connecting the exhaust port at td, P,
It is configured such that the relationship of 0 <(L1 / td) (ρ / 2P) ^1/2 ≦ (Sx / Sv) (So / Sv) ^1/2 is established between ρ, L1, Sx, Sv, and So. The hydraulic drive system according to claim 1, wherein: