JPH0213407B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a hydraulic operating circuit for a shingle breaker equipped with a pumping operation prevention mechanism.

[Prior Art] Conventionally, breaker circuits have been used to cut off and turn on and off high voltages and high currents. Since the high-voltage contact must be moved at high speed in this shingle disconnector, the recent trend is to use hydraulic pressure for its operation. This hydraulic operation circuit consists of a main valve that sends operating pressure oil to the hydraulic cylinder;
It consists of an operating valve that sends operating pressure oil to the main valve, a closing solenoid valve that drives the operating valve, and a shearing solenoid valve.

[Problem that the invention seeks to solve]

In conventional hydraulic circuits of this type, abnormal operation of the hydraulic cylinder called pumping has been viewed as a problem. This is a phenomenon that occurs because the shrunken command is given the highest priority from a safety perspective, and if the shrunken command is issued while the closing command is continuing, the hydraulic cylinder performs the shrunken operation, but the closing command is not received. Because it remains, the closing operation is automatically performed after the shrinking operation is completed.
This is repeated until one of the commands is released, causing damage to the breaker and its hydraulic operating circuit.

In addition, in a buffer-type gas tank or disconnector, the arc-extinguishing fluid (SF ₆ gas, etc.) in the buffer cylinder is compressed by moving the buffer cylinder or piston to increase the pressure. When pumping occurs, the pressure in the buffer cylinder may not rise sufficiently, and as a result, the pressure in the buffer cylinder may not rise sufficiently due to the previous action. There is a risk that the generated arc cannot be extinguished, leading to a serious accident resulting in inoperability.

An object of the present invention is to provide a hydraulic operating circuit for a shingle breaker that can reliably prevent pumping by a safety device using a spool valve.

[Means for solving problems]

The hydraulic operation circuit of the present invention includes a hydraulic cylinder that operates a shear cutter, an operation valve that sends pressure oil for operation to the hydraulic cylinder, a closing solenoid valve that drives the operation valve, and a shear cut-off solenoid valve. The operation valve has a first hydraulic operation switching valve for direct control of the main valve having two operation chambers A and B, and one operation chamber A of the hydraulic operation switching valve and the closing solenoid valve. In the meantime, the pressure oil that has flowed into the operation chamber A is released by the ON operation of the closing solenoid valve, and the spool moves in conjunction with the ON operation, and in this state, the closing solenoid valve is turned ON by the hydraulic balance of the spool. A second hydraulically operated switching valve of the spool valve type that is held during the operation, a third hydraulically operated switching valve that sends operating pressure oil to the hydraulically operated switching valve, and the other of the first hydraulically operated switching valve. A fourth hydraulic switching valve is located between chamber B and the shear cut-off solenoid valve, and is responsible for self-holding of the first hydraulically operated switching valve, and releases the self-holding when the shear cut-off solenoid valve is turned on.
It is characterized by having a hydraulically operated switching valve.

Hereinafter, the present invention will be explained in detail with reference to embodiments shown in the drawings.

〔Example〕

In Fig. 1, 1 is a hydraulic cylinder that operates the bridge and disconnector 1, 3 is the main valve that sends pressure oil for operation to the hydraulic cylinder 2, and 4 is the main valve that supplies the operating pressure oil to the main valve 3. Operation valves 5 and 6 are operation valves 4 for sending pressure oil.
The closing solenoid valve and the closing solenoid valve that drive the valve are respectively shown.

The main valve 3 is a type of 3-port 2-position switching valve having a P port, an A port, and an R port, including a poppet valve 31 that controls opening and closing between P and A, a spring 35 that applies pilot pressure to the poppet valve 31, and a poppet valve 31 that controls opening and closing between P and A. an operation piston 37, an operation chamber 38 of the piston 37, a poppet valve 32 that controls opening and closing between A and R independently of the poppet valve 31, and a poppet valve 3.
A spring 36 is provided for applying a pilot pressure to the air conditioner 2, and a housing chamber for the spring 36 is connected to the operation chamber 38.

The P port of the main valve 3 is connected to the rod side of the hydraulic cylinder 2 and the accumulator 7 which is the supply source of pressure oil.
The A port is connected to the bore side of the hydraulic cylinder 2.

The operation valve 4 includes four hydraulically operated switching valves 41, 42,
43 and 44.

The first hydraulically operated switching valve 41 that directly controls the main valve 3 is composed of a ball valve type 3-port 2-position switching valve, and the ball valve 4 controls opening and closing between P and A.
11. A ball valve 412 that is connected to the ball valve 411 and controls opening and closing between A and R, a spring 415 that applies pilot pressure to the ball valves 411 and 412, an operation piston 417 of the ball valves 411 and 412, two operation chambers 418, and A. and 419,B.

The pressure oil supply source 8 is connected to the P port of this valve 41, and the A port is connected to the operation chamber 38 of the main valve 3, the operation chamber 429 of the second hydraulically operated switching valve 42, which will be described later,
Each is connected to the P port of the fourth hydraulically operated switching valve 44.

The second hydraulically operated switching valve 42 that controls the first hydraulically operated switching valve 41 is a spool type valve having five ports P ₁ , P ₂ , P ₃ , A and R, and the pressure oil is supplied from the P ₁ port. spool 421 that controls opening and closing between A and R, spool 422 that controls opening and closing between P ₂ and A and receives pressure oil from port P ₃ , spring 425 that applies pilot pressure to spools 421 and 422, and spool 421. , 422 operating pistons 427 and two operating chambers 428, 429.

A pressure oil supply source 8 is connected to each port of P ₁ , P ₂ , and P ₃ of this valve 42 via a closing solenoid valve 5 , and the A port is connected to the operation chamber 418 of the first hydraulically operated switching valve 41 . It is connected to the.

The spools 421 and 422 have different diameters on the left and right sides, and if the cross-sectional area of 421 is S ₁ and the cross-sectional area of 422 is S ₂ , then at the position shown in FIG. 1, P ₁ , P ₂ ,
When pressure oil is received from each port of P ₃ , the spring 425 keeps pushing it to the right for hydraulic balance, and the operating piston 427
In the state where it is forcibly pushed to the left (the state shown in Figure 2), it is balanced in the state where it is pushed to the left due to the force setting of (S ₂ - S ₁ ) x oil pressure > spring (425). It is designed like this.

The operating chambers 428 and 429 drive the operating piston 427 in different directions, and are configured to balance the operating piston 427 when pressure oil is received in both chambers.

A third hydraulically operated switching valve 43 that controls the second hydraulically operated switching valve 42 is a ball valve type 3-port 2
Consists of a position switching valve, opening/closing between P-A and A-
Ball valve 431 and ball valve 43 that control opening and closing between R
1 through a plunger 434, an operation piston 437 of a ball valve 431, and an operation chamber 438.

The pressure oil supply source 8 is connected to the P port of this valve 43, and the A port is connected to the operation chamber 428 of the second hydraulically operated switching valve 42. Further, a pressure oil supply source 8 is connected to the operation chamber 438 via a closing solenoid valve 5.

The fourth hydraulically operated switching valve 44, which is responsible for self-maintenance of the first hydraulically operated switching valve 41, is structurally substantially the same as the third hydraulically operated switching valve 43 described above, and includes a ball valve 441, It has a spring 445, an operating piston 447, and an operating chamber 448.

The A port of the first hydraulically operated switching valve 41 is connected to the P port of this valve 44, and the A port is also connected to the operation chamber 419 of the first hydraulically operated switching valve 41. Further, a pressure oil supply source 8 is connected to an operation chamber 448 of this valve 44 via a solenoid valve 6 for shutting off the pressure.

The operation of the hydraulic operation circuit having the above configuration is as follows.

FIG. 1 shows a state in which the closing solenoid valve 5 is OFF and the cutting solenoid valve 6 is also OFF.
In this state, the ball valve 411 of the first hydraulically actuated switching valve 41 is pushed by the spring 415 and closes the P port, blocking the pressure oil from the supply source 8, and at the same time closes the gap between A and R and closes the main valve 3. The pressure oil in the operation chamber 38 is released to the tank, and the pressure oil in the accumulator 7 is prevented from going to the bore side of the hydraulic cylinder 2. Therefore, the shingle breaker 1 is in the shingled state.

At this time, the third hydraulically operated switching valve 43
38 is released into the tank, the ball valve 431 closes the R port with the spring 435 via the plunger 434, and the pressure oil from the supply source 8 is transferred via the P port and the A port to the second hydraulically operated switching valve. 4
2 to the operation room 428. On the other hand, no pressure oil is sent to the operation chamber 429. Moreover, each port P ₁ , P ₂ , and P ₃ communicates with the tank. Therefore, the spools 421 and 422 are pressed to the right by the spring 425, causing communication between P ₂ and A.
The operation chamber 418 of the first hydraulically operated switching valve 41 is connected to the tank.

When the closing solenoid valve 5 is turned ON in this state, pressure oil from the supply source 8 is sent to the operation chamber 438 of the third hydraulically operated switching valve 43, and the ball valve 431 is moved to the left. As a result, the distance between P and A is closed, the distance between A and R is opened, and the second hydraulically operated switching valve 42
The operation room 428 of is connected to the tank.

At the same time, pressure oil from the supply source 8 is sent to each port P ₁ , P ₂ , P ₃ of the second hydraulically operated switching valve 42,
Pressure oil sent to P ₂ port passes through A port to
is sent to the operation chamber 418 of the hydraulically operated switching valve 41.

At this time, since the spools 421 and 422 are configured to maintain hydraulic balance as described above, they remain pushed to the right by the spring 425.

The pressure oil sent to the operation chamber 418 of the first hydraulically operated switching valve 41 moves the operation piston 417 to the left, opens the space between PA and closes the space between A and R. As a result, the pressure oil is sent to the operation chamber 38 of the main valve 3, moves the operation piston 37 to the left, and opens the gap between P and A. Since the pressure receiving area of the hydraulic cylinder 2 is larger on the bore side than on the rod side, by opening the gap between P and A, the pressure oil stored in the accumulator 7 enters the bore side of the hydraulic cylinder 2, causing the piston to move at high speed. , and the shaya breaker 1 is inserted.

The pressure oil sent from the A port of the first hydraulically operated switching valve 41 is also sent to the fourth hydraulically operated switching valve 44, and passes through its P and A ports to the operation chamber of the first hydraulically operated switching valve 41. 418 and hold the operating piston 417 at the left tail end.

The same pressure oil is also sent to the operating chamber 429 of the second hydraulically operated switching valve 42, and moves the operating piston 427 to the left. As a result, the spools 421 and 422, which were hydraulically balanced, moved to the left,
_P2 -A is closed, A-R is opened, and the operation chamber 418 of the first hydraulically operated switching valve 41 is connected to the tank via the A and R ports. Spool 421,4
As described above, the valve 22 is maintained in a state moved to the left by the pressure oil from the supply source 8, so it continues in this state as long as the closing solenoid valve 5 is ON. This state is shown in FIG.

Next, when the cut-off solenoid valve 6 is turned on in the state shown in FIG. , closes the gap between P and A, opens the gap between A and R, and closes the first hydraulically operated switching valve 4.
The operation room 419 of No. 1 is connected to the tank. Control room 4
18 is already connected to the tank via the second hydraulically actuated switching valve 42, the self-retention of the operation piston 417 is released at this stage, and the ball valves 411,
412 and the operating piston 417 move to the right, and at the same time the pressure oil from the supply source 8 is stopped from being sent to the main valve 3, the pressure oil that was being sent to the main valve 3 is switched to the first hydraulic operation. It is opened to the tank via the switching valve 41. That is, the shingle breaker 1 enters the shingling state.

At this time, the operation chamber 4 of the second hydraulically operated switching valve 42
The pressure oil of 29 is also A of the first hydraulically operated switching valve 41,
The spools 421 and 422 are opened to the tank via the R port, but as mentioned earlier, as long as the closing solenoid valve 5 is ON, the spools 421 and 422 continue to be moved to the left. The operation chamber 418 of the operation switching valve 41 is kept connected to the tank. Pressure oil will not be sent to the operation chamber 419 unless the breaker 1 is turned on again. Therefore, in this state, that is, in the state where the closing solenoid valve 5 is ON and the shrinking solenoid valve 6 is ON, even if the shrinking solenoid valve 6 is turned OFF, the closing operation will not be restored. do not have. In other words, pumping is prevented.

In order to close the shield breaker 1 again, it is necessary to turn off the closing solenoid valve 5 once, create the state shown in FIG. 1, and then turn on the closing solenoid valve 5.

Next, the case of normal operation, that is, the case where the closing solenoid valve 5 is turned on, the shroud breaker 1 is turned on, and then the closing solenoid valve 5 is turned off will be described with reference to FIG.

Since pressure oil from the supply source 8 is fed back to the operation chamber 419 of the first hydraulically operated switching valve 41 via the fourth hydraulically operated switching valve 44, it is possible to turn off the closing solenoid valve 5. No disconnection occurs.

On the other hand, by turning off the closing solenoid valve 5,
The operation chamber 438 of the third hydraulically operated switching valve 43 is connected to the tank, and the ball valve 431 is connected to the spring 43.
5, the pressure oil from the supply source 8 is sent to the operation chamber 428 of the second hydraulic switching valve 42 via the P and A ports. Pressure oil from the supply source 8 is sent to the operation chamber 429 via the first hydraulically operated switching valve 41, but the operation piston 427 is designed to be balanced with pressure oil from both directions. , by turning off the closing solenoid valve 5, P ₁ ,
After the ports P ₂ and P ₃ communicate with the tank, the spools 421 and 422 are moved to the right by the spring 425, releasing the pressure oil in the operation chamber 418 of the first hydraulically operated switching valve 41 to the tank. .

Therefore, there is no problem even if the solenoid valve 6 is turned ON in this state.

〔Effect of the invention〕

As is clear from the above description, the present invention not only ensures safety by prioritizing the shrinking operation when the shrinking solenoid valve is turned ON while the closing solenoid valve is ON, but also Since the pressure oil used by the first hydraulic switching valve to trigger the injection of the equipment is released continuously when the injection solenoid valve is turned on, the injection solenoid valve is turned on.
Even if the drain solenoid valve changes from ON to OFF in this state, the closing operation will not be reproduced, and therefore pumping will be prevented.

Moreover, in the present invention, this series of pressure oil control is performed using the slight delay time when the spool moves, and there is no need for special mechanical devices to create the delay time, so the structure is simple. Moreover, reliable operation can be expected and sufficient durability is guaranteed.

[Brief explanation of drawings]

FIGS. 1 and 2 are circuit diagrams showing the structure of an example of the hydraulic operation circuit of a shield disconnector embodying the present invention. FIG.
The solenoid valve for cutting off the solenoid is shown in an OFF state, and FIG. 2 shows the solenoid valve for closing the valve in the ON state and the solenoid valve for cutting off the damping in the OFF state. In the figure, 1: breaker, 2: hydraulic cylinder,
3: Main valve, 4: Operation valve, 41 to 44: 1st to 4th
Hydraulic operated switching valve, 5: Closing solenoid valve,
6: Solenoid valve for shearing, 7: Accumulator, 8: Pressure oil supply source.

Claims (1)

[Claims] 1. A hydraulic cylinder that operates the shield breaker, a main valve that sends pressure oil for operation to the hydraulic cylinder, an operation valve that sends pressure oil for operation to the main valve, a closing solenoid valve that drives the operation valve, and It has a solenoid valve for shutting off the valve, and the operation valve includes a first hydraulically operated switching valve for direct control of the main valve having two operating chambers A and B, and one operating chamber A of the hydraulically operated switching valve. The closing solenoid valve is located between the closing solenoid valve and the closing solenoid valve.
The pressure oil that has flowed into the operation chamber A due to the ON operation is released by the movement of the spool in conjunction with the ON operation, and this state is maintained while the closing solenoid valve is ON due to the hydraulic balance of the spool. A second hydraulically operated switching valve, a third hydraulically operated switching valve that sends operating pressure oil to the hydraulically operated switching valve, and a solenoid valve for cutting off the sheath and the operating chamber B of the first hydraulically operated switching valve. first between
and a fourth hydraulically operated switching valve which is in charge of self-holding of the hydraulically operated switching valve and releases said self-holding by turning on the shear breaker solenoid valve. Operation circuit.