JP2005251545A - Hydraulic driving device of circuit breaker - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To miniaturize a hydraulic drive device of a circuit breaker and improve reliability. <P>SOLUTION: The hydraulic drive device 3 comprises a hydraulic cylinder 7 for opening and closing a contact part 70, a control valve for opening a flow passage making the hydraulic cylinder open by a liquid force of the operating liquid, and a control valve for closing the flow passage making the hydraulic cylinder close. The control valve for opening the flow passage has a main control valve 30 for opening the flow passage and a pilot valve 50 for driving the opening main control valve. The control valve for closing the flow passage has has a main control valve 20 for closing the floe passage and a pilot valve 60 for driving the closing main control valve. Each main control valve has a valve seat 25, 35 and valve elements 21, 31 for contacting this valve seat. Each valve is arranged in opposition to each other and the length between the contact sections of the valve element with the valve seat is made longer than the distance between the valve seat sections where each valve element contacts with each valve seat. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a circuit breaker fluid pressure drive device, and more particularly to a fluid pressure drive device suitable for a power circuit breaker.

  An example of a conventional fluid pressure drive device for a circuit breaker is described in Patent Document 1. In the drive device described in this publication, an open valve and a close valve are provided separately on the same shaft. Then, the opening valve is once opened and opened, and then returned to the small opening to keep the opening, and the opening valve is quickly closed during the closing operation. Another example of a conventional hydraulic drive device for a circuit breaker is described in Patent Document 2. This publication describes a fluid pressure drive device that is downsized by disposing a main operation valve portion and a pilot valve portion in an integral case. In the prior art section of this publication or in Patent Document 3, in a two-stage fluid pressure drive device having a pilot valve and a main operation valve, the shut-off main operation valve and the open main operation valve are separated. Is described.

Japanese Patent Laid-Open No. 11-96859 Japanese Patent Laid-Open No. 2003-45296 JP-A-11-353983

  In the fluid pressure driving device described in Patent Document 1, a large flow rate is required to operate the control valve, and the pilot valve capacity for driving the control valve increases. Further, it is necessary to keep the closed valve open after the closing operation, and the closing valve cannot be quickly closed during the opening operation. As a result, the control valve operates during the closing operation, and the amount of working fluid flowing from the high pressure supply side to the low pressure return side increases, which may cause pressure fluctuations. Since this pressure fluctuation adversely affects the operation of the circuit breaker, it is desired to reduce it.

  In the fluid pressure driving device described in Patent Document 2, since the main operation valve and the pilot valve are housed in an integrated case, the flow path configuration inside the case is complicated, and the valve configuration is also complicated. Therefore, the device is complicated. Moreover, although the thing of the flow path structure is simpler than the invention of patent document 2 as for the thing described in the prior art section of patent document 2, or the thing described in patent document 3, a liquid supply port, a drainage port, and a control port Since the required ports are closed both when shut-off and when the open circuit is held, the main operation valve part must be three valve members, and the flow path structure is also complicated. Become.

  The present invention has been made in view of the above-mentioned problems of the prior art, and an object thereof is to downsize and simplify the fluid pressure driving device of the circuit breaker. Another object of the present invention is to improve the reliability of a fluid pressure drive device for a circuit breaker.

  A feature of the present invention that achieves the above object includes a fluid pressure cylinder that opens and closes a contact portion, a circuit control valve that opens the fluid pressure cylinder by a fluid force of a working fluid, and a circuit control valve that performs a circuit close operation. In the circuit breaker fluid pressure drive device, the open circuit control valve includes an open circuit main control valve and an open circuit pilot valve that drives the open circuit main control valve, and the close circuit control valve includes the close circuit main control valve and A closed-circuit pilot valve that drives the closed-circuit main control valve, each main control valve has a valve seat and a valve body that can come into contact with the valve seat, The length between the contact portions of the valve body with respect to the valve seat is made longer than the distance between the valve seat portions with which the valve body and each valve seat abut.

  In this feature, the valve body of the open circuit main control valve and the valve body of the close circuit main control valve are preferably arranged so that the valve opening directions are opposite to each other. The body and the valve body of the closing main control valve are separate and coaxial, and are preferably arranged so as not to contact each other during the operation of the fluid pressure drive device.

  In addition, an opening control chamber is formed in the opening main control valve, the opening control chamber is set to a low pressure to open the valve body of the opening control valve, and a closing control chamber is formed in the closing main control valve. The valve body of the main control valve for closing is preferably opened by making the control chamber for high pressure open, and the valve body of the main control valve for opening and the valve body of the main control valve for closing contact with each other in the open circuit holding state. At the same time, the main control valve for opening is slightly opened, and the main control valve for opening is further opened from the open circuit holding state during the opening operation, and the main control valve for opening circuit is opened slightly during the closing operation, and is closed during the closing operation. It is preferable to arrange each valve body so that the main control valve for use opens more than the closed circuit holding state.

  Further, in the closed circuit holding state, the resultant force due to the pressure applied to the valve body of the closed circuit main control valve is set to almost zero, and the fluid force of the working fluid in the high-pressure section is operated on the valve body of the open circuit main control valve. The force is applied in the direction of closing the body, and in the open circuit holding state, the resultant force of the pressure of the working fluid applied to the valve body of the open circuit main control valve is almost zero, and the valve body of the closed circuit main control valve is It is preferable to apply a force in the direction in which the valve body is closed by the fluid force of the working fluid in the high pressure section.

  Furthermore, the closing main control valve includes a closing control chamber, a supply port communicating with the high pressure portion of the working fluid, and a closing cylinder port connected to the fluid pressure cylinder. Open the control valve, connect the supply port and the closing cylinder port, supply the working fluid to the fluid pressure cylinder and close the contact part, and open the main control valve to the opening control chamber and the low pressure part of the working fluid The discharge port and the open cylinder port communicating with the fluid pressure cylinder are opened, the open control chamber is set to low pressure, the open main control valve is opened, and the open cylinder port and the discharge port are communicated to operate from the fluid pressure cylinder. It is preferable to discharge the fluid and open the contact portion.

  In this configuration, the valve body of the closing main control valve has a shaft portion protruding toward the closing control chamber, and is disposed so as to be able to contact the valve element of the opening main control valve in the discharge port. There is a cylindrical part opened to the low pressure part of the working fluid on the back side of the valve body of the closing main control valve, and the valve element of the opening main control valve is opened to the low pressure part of the working fluid on the opening control chamber side. The open main control valve is provided with a spring that generates force in the closing direction of the open main control valve, and the close main control valve closes the open main control valve. It is preferable to provide a spring for generating a force, and the cylinder port of the opening main control valve and the opening control chamber may be connected via a throttle.

  Further, the closing main control valve includes a closing control chamber, a supply port communicating with the high pressure portion of the working fluid, and a closing cylinder port communicating with the fluid pressure cylinder. The control valve is opened, the supply port and the closing cylinder port are connected, the working fluid is supplied to the fluid pressure cylinder to close the contact, and the opening main control valve is the opening control chamber and the working fluid low pressure part. A discharge port communicating with the fluid pressure cylinder and an opening cylinder port communicating with the fluid pressure cylinder, the opening control chamber is set to a low pressure to open the main control valve, and the opening cylinder port communicates with the discharge port. It is desirable to discharge the working fluid from the fluid pressure cylinder to open the contact portion.

  In this configuration, the valve body of the closing main control valve has a shaft portion that protrudes toward the closing control chamber, and is disposed in the discharge port so as to be in contact with the valve element of the opening main control valve. A cylindrical part is provided on the back side of the valve body of the valve, a back pressure chamber communicating with the closing cylinder port is formed on the back side of the cylindrical part, and the valve body of the main control valve for opening is the cylindrical part on the side of the opening control chamber A back pressure chamber communicating with the opening cylinder port is formed on the back surface of the cylindrical portion, and the opening main control valve has a spring that generates a force in the direction of closing the valve element of the opening main control valve. The closing main control valve preferably has a spring that generates a force in the direction of closing the valve body of the closing main control valve.

  In the present invention, the opening control valve is fully opened during the opening operation, and is held at an opening smaller than that when fully opening after the operation is completed. Further, the closing control valve is fully opened during the closing operation, and is held in an opening smaller than the full opening after the operation is completed. Thereby, the flow rate required to operate the opening control valve and the closing control valve can be reduced. As a result, the fluid pressure driving device of the circuit breaker can be reduced in size and simplified and the reliability can be improved.

  Hereinafter, several embodiments of a fluid pressure driving device for a circuit breaker according to the present invention will be described with reference to the drawings.

  FIG. 1 to FIG. 6 are longitudinal sectional views of an embodiment of a fluid pressure driving device for a circuit breaker. FIG. 1 is a diagram showing a closed state of a circuit breaker, and shows a state during energization. FIG. 2 shows an initial state of the opening operation, and FIG. 3 shows a later state of the opening operation. FIG. 4 is a diagram of an open circuit state where the circuit is shut off. FIG. 5 shows an initial state of the closing operation, and FIG. 6 shows a later state of the closing operation.

  The circuit breaker fluid pressure drive device 3 includes a fluid pressure cylinder portion 4 that opens and closes the contact portion 70, an opening main control valve 30 that switches the pressure of the fluid pressure cylinder portion 4, and a closing main control valve 20. An opening pilot valve 50 and a closing pilot valve 60 for driving the valves 30 and 20, and an opening solenoid 51 and a closing solenoid 61 for driving the pilot valves 50 and 60 are provided. That is, it has a two-stage valve configuration.

  The fluid pressure cylinder portion 4 has a piston 5 that slides in the cylinder 7, and the cylinder 7 divides the inside of the cylinder 7 into a small pressure receiving area side 6 and a cylinder control chamber (large pressure receiving area side) 7a. The small pressure receiving area side 6 has a smaller pressure receiving area than the large pressure receiving area side 7 a by the cross-sectional integral of the rod 11. The other end of the rod 11 with the piston 5 attached to the tip is connected to the movable contact 2. The movable contact 2 cuts off or puts in power with the fixed contact 1 by reciprocating movement of the rod.

  On the small pressure receiving area side 6, the supply pressure of the working fluid discharged from the pump 8 and accumulated in the accumulator 9 always acts via the communication path 102. The large pressure receiving area side 7a forming the cylinder control chamber is connected to the open main control valve 30 and the close main control valve 20, and by opening and closing these main control valves 30, 20, a high pressure supply pressure side and a reservoir are connected. The communication is switched to the return side of the low pressure communicating with 10. The reservoir 10 collects and stores the fluid discharged from the fluid pressure cylinder unit 4.

  The open circuit main control valve 30 includes a valve seat 35 in which an opening is formed, and a valve body 31 having a trapezoidal cross section that comes into contact with the valve seat 35. In the vicinity of the opening of the valve seat 35, a cylinder port 33 having a diameter larger than that of the valve body 31 is formed, and the cylinder port 33 communicates with the cylinder control chamber 7a through a communication passage 10. A discharge port 38 having a smaller diameter than the valve body 31 is formed adjacent to the cylinder port 33. The discharge port 38 is always in communication with the low-pressure reservoir 10 through the communication path 105. In the state of FIG. 1, the valve body 31 closes the opening of the valve seat 35, and the cylinder port 33 and the discharge port 38 are partitioned.

  A cylindrical portion 36a having a diameter smaller than that of the discharge port and substantially the same as the outer diameter of the valve body is formed on the back surface side of the valve body 31, and the sliding portion 37 of the valve body 31 slides on the cylindrical portion 36a. A sliding ring is interposed in the sliding portion 37. A shaft portion 32 is formed on the back side of the valve body 31, and a control chamber 36b is formed by the shaft portion 32 and the cylindrical portion 36a. A spring 34 is attached to the outer peripheral portion of the shaft portion 32. One end of the spring 34 is in contact with the wall surface of the control chamber 36b.

  The closing control valve 20 has substantially the same configuration as the opening control valve 30 and is arranged symmetrically with the opening control valve 30. In other words, the closing control valve 20 includes a valve body 21 having a trapezoidal cross section and a valve seat 25 in which an opening is formed. A supply port 23 having a larger diameter than that of the valve body 21 is formed adjacent to the opening of the valve seat 25, and the main control valve for opening the circuit is smaller than a small diameter portion that is a contact portion (opening) between the valve body 21 and the valve seat. A cylinder port 27 is formed on the 30 side.

  The cylinder port 27 is always in communication with the cylinder control chamber 7a through the communication path 103. The supply port 23 is always in communication with the small pressure receiving area portion 6 of the fluid pressure cylinder portion 4 via the communication path 100. In the state of FIG. 1, the valve body 21 is not in contact with the valve seat 25, so that the cylinder port 27 communicates with the supply port 23. A spring 24 is attached to the outer periphery of the valve body 21 on the back side of the valve body 21. One end of the spring 24 is in contact with the main control valve block 19.

  The opening main control valve 30 side extends from the cross-sectional trapezoidal portion of the valve element 21 of the closing main control valve 20 in the direction of the opening main control valve 30, and a cylinder port is located in the middle of the extending portion. A cylindrical sliding portion 28 a that slides on the inner circumference of the 27 is formed. The cylinder port 27 is divided into two upper and lower rooms, that is, a cylinder port chamber 26a and a closing main valve control chamber 26b by the sliding portion 28a.

  The valve element 21 of the closing main control valve 20 is in contact with the valve element 31 of the opening main control valve 30 and has a cylindrical part (shaft part) 28b having a smaller diameter than the sliding part 28a. The shaft portion 28b extends to the discharge port 38 of the open circuit main control valve 30. When the shaft portion 28b comes into contact with the valve body 31, it is located between the valve seat 25 and the valve body 21 or between the valve seat 35 and the valve body. Any one between the bodies 31 opens minutely.

  Each of the closing main control valve 20 and the opening main control valve 30 is driven by a pilot valve. That is, a closing pilot valve 60 that drives the closing main control valve 20 and a circuit pilot valve 50 that drives the opening main control valve 30 are attached to the main control valve block 19. A closing solenoid 61 is attached to the closing pilot valve 60. Similarly, an opening solenoid 51 is attached to the opening pilot valve 50. The opening pilot valve 50 opens when the opening solenoid 51 is excited, and closes by the spring force of the built-in spring when the excitation is released. The same applies to the closing pilot valve 60.

  The secondary side of the closing pilot valve 60 is always in communication with the cylinder port 20 of the closing main control valve 20 through the communication path 101. The secondary side of the opening pilot valve 50 is always in communication with the control chamber 36 b of the opening main control valve 30 through the communication path 108. The primary side of the closing pilot valve 60 is always in communication with the control chamber 26 b of the closing main control valve 20 and the control chamber 36 b of the opening main control valve 30 through the communication path 106. The primary side of the closing pilot valve 60 is always in communication with the cylinder port 33 of the closing main control valve 30 via the throttle 40. The primary side of the opening pilot valve 51 is always in communication with the low-pressure reservoir 10 through the communication passage 107.

  The closing main control valve 20 and the opening main control valve 30 are disposed on the same axis. When one valve is closed, the other valve is set to be open. Shaft portions (cylindrical portions) 22 and 32 are formed at the rear end portions of the valve bodies 21 and 31, and the shaft portions 22 and 32 are formed in the main control valve block 19 and communicate with the low-pressure reservoir 10. Slide in the hole. In order to prevent the hydraulic oil from leaking during the sliding, a sliding ring is interposed in the shaft portion. Similarly, a sliding ring is interposed in the sliding portion 28a of the valve body 21 that slides on the cylinder port 27 of the closing main control valve 20, and seals the cylinder port chamber 26a and the control chamber 26b.

  When the open circuit main control valve 30 is opened and the cylinder port 33 communicates with the discharge port 38, both the ports 33 and 38 are in a low pressure state, and the working fluid is discharged from the contact portion drive cylinder portion 4. As a result, the piston 5 opens. When the contact portion 70 is opened, the spring force of the spring 34 acting on the valve body 31 closes the open circuit main control valve 30. On the other hand, when the closing main control valve 20 is opened and the supply port 23 and the cylinder port 27 of the closing main control valve 20 communicate with each other, both ports become high pressure and both sides of the piston 5 are filled with high pressure hydraulic oil. However, since the large pressure receiving area side 7a has a large area by the cross-sectional integral of the rod, the piston 5 is closed. When the contact part 70 is closed, the spring force of the spring 24 acting on the valve body 21 closes the closing main control valve 20.

  The operation of the fluid pressure drive device 3 according to this embodiment configured as described above will be specifically described. The operation of opening the circuit breaker contact 70 from the closed state will be described first. FIG. 1 shows a closed state. In this state, the cylinder control chamber 7a, the control chamber 36b of the opening main control valve 30, the control chamber 26b of the closing main control valve 20, the primary side of the closing pilot valve, and the primary side of the opening pilot valve are high pressure. It has become.

Since the diameter d1 of the cylindrical portion 22 of the closing main control valve 20 and the diameter d4 of the opening-side main valve-side cylindrical portion 28b are the same, the hydraulic oil applied to both surfaces of the valve element 21 of the closing main control valve 20 The power is balanced. In addition to this balanced force, the force of the spring 24 acts on the valve body 21 to move the valve body 21 to the valve seat 25 side. That is, the closing main control valve 20 is closed. On the other hand, on one surface (upper surface) of the valve element 31 of the main control valve 30 for opening, an area difference π (d ₆ ²⁾ due to the difference between the diameter d ₆ of the sliding portion 37 and the diameter d ₇ of the cylindrical portion 32. Since -d ₇ ² ) / 4 is generated, a force is exerted on the hydraulic oil to move the valve body 31 downward. Against this force, the spring 34 tries to push the valve element 31 upward. Since the hydraulic oil pressure is set so as to overcome the force of the spring 24, a minute opening is maintained between the valve seat 25 and the valve body 21 in the closed-side main control valve 20.

  FIG. 2 shows a state where a circuit opening command is issued in the state of FIG. 1 in which the circuit closing state is maintained. When the opening command is issued, the opening solenoid 51 is excited to push open the opening pilot valve 50. The control chamber 36b of the opening main control valve 30 and the control chamber 26b of the closing control valve communicate with the return side of the low pressure. As a result, the pressure balance between the two cylinder port ports 26a of the cylinder port 27 of the closing main control valve 20 and the control chamber 26b is lost, and the valve body 21 of the closing main control valve 20 moves downward in the figure. The valve seat 25 is closed with the valve body 21.

When the valve element 21 of the closing main control valve 20 moves, the valve element 31 of the opening main control valve 30 in contact with the shaft portion 28b of the valve element 21 also moves downward. Further, a force that moves the valve body 31 downward is also generated. That is, since the large pressure receiving area side 7a of the cylinder part 4 is high pressure, the pressure of the cylinder port 33 communicating with the large pressure receiving area side 7a is high. Since only the pressure of the working fluid in the cylinder port 33 is high, a force obtained by integrating the pressure acting on the area of π (d ₆ ² -d ₅ ² ) / 4 is applied to the valve body 31 downward. Here, d6 is the outer diameter d6 of the valve body 31, and d5 is the outer diameter of the discharge port 38. As a result, the piston 5 operates at a higher speed.

When the open main control valve 30 is opened, the cylinder port 33 communicates with the low pressure discharge port 38, and the pressure on the large pressure receiving area side 7a of the cylinder portion 4 communicating with the cylinder port 33 decreases. As a result, the force on the small pressure receiving area side 6 that pushes the piston 5 becomes larger than the force on the large pressure receiving area side, and the piston 5 moves to the right. The movable contact connected to the piston 5 via the rod 11 also moves to the right, and the opening operation is started. At this time, the volume V of the fluid discharged from the control chamber 26 is V = L × π (d ₆ ² −d ₇ ² ) / 4, and L is a stroke. Accordingly, the flow rate processed by the pilot valve 50 is small.

  FIG. 3 shows a state where the valve element 31 of the open circuit main control valve 30 is opened. FIG. 3 shows a state in the latter half of the opening operation. When the piston 5 of the cylinder part 4 finishes moving to the right, the flow of hydraulic oil discharged from the cylinder 7 stops. At the same time, the discharge port 38 and the cylinder port 33 communicate with each other, and both communicate with the reservoir 11 and are kept at a low pressure. As a result, the force for opening the valve element 31 is canceled out by the fluid pressure (upward and downward differential pressure) in the open circuit main control valve 30. Since the fluid pressure is balanced, the valve body 31 moves in the closing direction (leftward) by the spring force of the spring 34.

However, the valve element 21 of the closing main control valve 20 has a pressure difference (the pressure of the accumulator 9 and the pressure of the reservoir 10) applied to the diameter difference portion between the opening diameter d ₂ of the valve seat 25 and the rear side cylindrical diameter d _1. The downward force is applied by the force due to the pressure due to the difference between the spring 24 and the spring force of the spring 24. The upward force of the spring 34 is made smaller than the downward force so that the opening main control valve 30 in which the cylindrical portion 28b slides on the main control valve block 19 maintains a minute opening. At this time, since the excitation of the opening solenoid 51 is released, the opening pilot valve 50 is closed by the spring force of the built-in spring. This state is the open circuit holding state shown in FIG. 4. Only the supply port 23 of the closing main control valve 20 becomes high pressure, and the portion below the cylinder port 27 becomes low pressure.

  FIG. 5 shows a state when a closing command is issued in the open circuit holding state shown in FIG. When a closing command is issued, the closing solenoid 61 is excited, and the closing pilot valve 60 is pushed open. The primary side and the secondary side of the pilot valve for closing 60 communicate with each other, and the pressure of the supply port that communicates with the secondary side, that is, the high pressure, becomes high. Since the primary side of the closing pilot valve 60 is always in communication with the control chamber 26b of the closing main control valve 20 and the control chamber 36b of the opening main control valve 30, both the control chambers 26b and 36b become high pressure.

A high supply pressure is applied to the back side of the valve body 21 of the closing control valve 20 except for the cylindrical portion (the position of the diameter d ₁ ), and an opening ( low pressure acts in the cylinder port 27 to the position of the diameter d _2), high-pressure supply port 23 acts also on the large-diameter portion than that. Therefore, by the spring force of the fluid pressure and spring 24 acting on the portion of the diameter d ₁ of the valve body 21 to the diameter d _2, a downward force acts on the valve element 21. Therefore, a force to overcome these forces to occur at the cylinder port 27 portion, sets the diameter d ₄ of diameter d ₃ and the shaft portion 28b of the cylinder port 27. The upper surface of the sliding portion 28a formed intermediate shaft portion 28b of the valve body 21 acts a low-pressure, high-pressure supply pressure to the large diameter portion than the diameter d ₄ of the shaft portion 28b in the lower surface Act.

  Since the diameter of each part of the closing main control valve 20 is set in this way, the valve element 21 of the closing main control valve 20 moves upward to open the valve seat 25. On the other hand, the pressure in the control chamber 36b formed on the back side of the valve element 31 of the open main control valve 30 has changed from the low pressure that is the pressure of the reservoir 10 to the high pressure in the supply port 23. The balance state is lost, and the upward force increases. Therefore, the valve body 31 moves upward and closes the valve seat 35.

Since the opening main control valve 30 is closed and the closing main control valve 20 is opened, the pressure in the cylinder port chamber 26a of the cylinder port 27 acts on the large pressure receiving area side 7a of the cylinder 7, and the piston 5, the rod 11 and The movable contact 2 is moved to the fixed contact 1 side. In order to move the closing main control valve 20, fluid must be supplied from the pilot valve 60 to the control chamber 26b. The area of the control chamber 26b is π (d ₃ ² -d ₄ ² ) / 4. As a result, less flow is required for the pilot valve.

  Since the valve seat 25 is opened, the pressure in the cylinder control chamber 7a formed in the cylinder port 27 of the closing main control valve 20 also increases. However, the supply pressure does not rise while the piston 5 is moving. The reason is as follows. In order for the piston 5 to move, the force that overcomes the load such as the supply pressure acting on the small pressure receiving area side 6 and the mass of the movable contact 2 and the frictional force of the piston ring provided around the piston 5 is applied to the large pressure receiving area side 7a. Must be generated. This force is generally determined by the ratio of the pressure receiving area between the small pressure receiving area side 6 and the large pressure receiving area side 7a. Since the pressure receiving area on the large pressure receiving area side 7a is wide by the cross-sectional integral of the rod 11, the pressure on the large pressure receiving area side 7a is lower than the supply pressure.

When the supply pressure is Ps and the pressure on the large pressure receiving area side 7a is Pc, a force of Ps × π (d ₂ ²⁻ d ₁ ² ) / 4 acts on the valve body 21 in the closing direction at the supply port 23 portion. In the control chamber 26b of the closing main control valve 20, a force of Ps × π (d ₃ ² −d ₄ ² ) / 4 works in the opening direction. If the cylindrical portion diameter d1 on the back surface of the valve body 21 and the shaft portion diameter d4 on the front surface of the valve body 21 are the same, the sum of two forces Ps × π (d ₃ ² −d ₂ ² ) / 4 is obtained. 21 acts in the direction of opening.

On the other hand, in the cylinder port chamber 26a of the cylinder port 27, a force of Pc × π (d ₃ ² −d ₂ ² ) / 4 works in the closing direction. Since the supply pressure Ps is larger than the pressure Pc of the cylinder port chamber 26a, a force acts in the direction of opening the valve body 21 in the entire valve body 21. If the force with which the spring 24 closes the valve body 21 is smaller than the resultant force, the valve body 21 can be further opened. Therefore, the spring force of the spring 24 is made smaller than the resultant force to operate the piston 5 at a higher speed.

  While the piston 5 is closing, the valve body 21 is held in an open state away from the valve seat 25 and continues the closing operation. When the closing operation is completed, the piston 5 stops. Since the valve body 21 is away from the valve seat 25, the cylinder port 27 communicates with the supply port 23 and becomes high pressure. After the communication between the cylinder port 27 and the supply port 23, the fluid pressure acting on the valve body 21 is balanced, and the valve body 21 moves in the closing direction only by the force of the spring 24.

  On the other hand, in the valve element 31 of the open circuit main control valve 30, the force due to the supply pressure and the upward force due to the spring force of the spring 34 are acting on the control chamber 36 b provided on the back side of the valve element 31. The downward force of the spring 24 is made slightly smaller than this upward force. As a result, the main control valve 30 for opening the circuit moves upward until it contacts the valve seat 35.

  Since the spring 24 force is smaller than the upward force acting on the valve body 31 even when abutting against the end face of the shaft portion 28b of the valve body 31 of the closing main control valve 30 that moves downward during the movement, the valve body 21 both move upward. When the valve body 31 is in contact with the valve seat, the closing main control valve 20 is in an open state having a minute opening (see FIG. 4). Since the valve bodies 21 and 31 return to their original positions only by the force of the springs 24 and 34, the impact at the time of collision between the valve bodies 21 and 31 is small. The closing solenoid 61 is de-energized, and the closing pilot valve 60 is closed by the spring force of a built-in spring.

  According to the present embodiment, in the closed state, the closing main control valve is in an open state having a minute opening. Therefore, when the opening operation is performed from this closed state, the closing main control valve is quickly closed. Further, since the open main control valve has a minute opening in the open state, the open main control valve is quickly closed when the close operation is performed from the open state.

  As described above, when the open main control valve or the close main control valve is operated, the fluid flowing directly from the supply side to the low pressure return side can be reduced. Thereby, the reliability of the drive device of a circuit breaker can be improved. In addition, the flow rate of the hydraulic oil required for the pilot valve that drives the open circuit main control valve or the close circuit main control valve is only the amount required when the fluid in the control chamber of these main control valves is discharged or supplied. Therefore, the area of the pilot valve is reduced. As a result, the pilot valve can be reduced in size and the capacity of the drive device can be increased.

  Another embodiment of the present invention will be described with reference to FIG. In this embodiment, the back side of the valve bodies 21 and 31 of the closing main control valve 20 and the opening main control valve 20 is not opened to the reservoir 10 in the embodiment shown in FIG. Accordingly, the flow path structure formed in the main control valve block 19 is also different from the embodiment shown in FIG. Specifically, with respect to the closing main control valve 20 side, the back pressure chamber 29 formed on the back surface of the valve body 21 and the shaft portion 28b of the valve body 21, which is closer to the valve seat 25 than the sliding portion 28a. A flow path 106 communicating with the side surfaces of the valve body 21 is formed inside the valve body 21.

  On the other hand, on the side of the main control valve 30 for opening the circuit, the back pressure chamber 39 formed on the back side of the valve body 31 and the flow path 109 communicating the surface where the valve body 31 contacts the valve seat 35 are formed inside the valve body 31. Form. The positions of the cylinder port 33d and the discharge port 38d are opposite to those in the embodiment shown in FIG. 1, the front side of the valve seat 35 is the discharge port 33d, and the back side of the valve seat 35 is the cylinder port 38d. It has become. A flow path 110 having a throttle 40 communicating with the primary side of the closing pilot valve 60 and the secondary side of the opening pilot valve 50 opens in the back pressure chamber 39 instead of opening in the cylinder port. Other configurations are the same as those of the embodiment shown in FIG.

The operation of this embodiment configured as described above will be described below. In the closed state shown in FIG. 7, the large pressure receiving area side 7a of the cylinder 7, the control chamber 36b of the main control valve 30 for opening, the control chamber 26b of the main control valve 20 for closing, the primary side of the pilot valve 60 for closing, The primary side of the opening pilot valve 50 is at a high pressure. At this time, the force applied from the working fluid to the valve element 21 of the closing main control valve 20 is balanced. Therefore, a force in the closing direction by the spring 24 acts on the valve body 21. The diameter _{d 1} and the diameter _{d 4} of the shaft portion 28b of the cylindrical portion 22 of the valve body 21 may be different.

The valve element 31 of the open circuit main control valve 30 has a force in a direction in which the valve seat is closed by the fluid pressure applied to the diameter difference portion between the diameter d ₆ of the sliding portion 37 and the diameter d ₇ of the cylindrical portion 32 and the spring 34. Works. This force overcomes the force of the spring 24 applied to the valve element 21 of the closing main control valve 20, and holds the valve seat 25 of the closing main control valve 20 in a minute opening state.

  When an opening command is issued in this state, the opening solenoid 51 is excited and the opening pilot valve 50 is pushed open. The control chamber 36 b of the open circuit main control valve 30 and the control chamber 26 b of the close circuit control valve 20 communicate with the low pressure return side via the open pilot valve 50. The valve element 31 of the open circuit main control valve 30 starts to open due to the high pressure acting from the large pressure receiving area side 7 a of the cylinder portion 4. Since the cylinder port 33d communicates with the low pressure discharge port 38d, the working fluid flows into the cylinder port 33d from the large pressure receiving area side 7a, and the amount of working fluid in the large pressure receiving area side 7a decreases. As a result, the piston 5 moves to the right integrally with the movable contact 2, and the contact portion 70 starts to open. At the same time, the valve body 21 of the closing main control valve 20 loses the pressure balance between the upper and lower sides of the sliding portion 28a and moves downward to close the valve seat 25.

  Even after the closing main control valve 20 is closed, the working fluid on the large pressure receiving area side 7a is pushed out by the high pressure applied to the small pressure receiving area side 6 of the cylinder 7, and the valve element 31 of the opening main control valve 30 moves. to continue. That is, the hydraulic force of the working fluid acts on the difference between the outer diameter d6 of the valve element 31 of the main control valve 30 for opening and the cylindrical part diameter d7 on the back side of the valve element 31, and the valve seat 35 is further opened. Thereby, the piston 5 operates at higher speed. Thereafter, the valve seat 35 of the open circuit main control valve 30 is kept open.

  After the operation of the piston 5 of the cylinder part 4 is completed, the working fluid is not discharged from the large pressure receiving area side 7a, so the pressure in the cylinder port 33 and the back pressure chamber 39 of the open circuit main control valve 30 decreases. As a result, the valve body 31 is not opened by the fluid pressure acting on the valve body 31, and the valve body 31 moves in the direction to close the open circuit main control valve 30 by the spring force of the spring 34. However, the fluid force (depending on the supply pressure) applied to the difference between the opening diameter d2 of the closing main control valve 20 and the diameter d1 of the cylindrical portion 22 on the back side of the valve body 21 rather than the spring 32 force of the opening main control valve 30. Force) and the downward force by the spring 24 are larger.

  Therefore, the closing main control valve 20 is kept closed, and the valve element 31 of the opening main control valve 30 is applied to the end face of the cylindrical portion 28b provided on the front side of the valve element 21 of the closing main control valve 20. The minute opening is maintained at the valve seat 35 portion. At this time, the excitation of the opening solenoid 51 is released, and the opening pilot valve 50 is closed by a built-in spring force.

  When a closing command is issued in the open circuit state, the closing solenoid 61 is excited and the closing pilot valve 60 is pushed open. The primary side and the secondary side of the closing pilot valve 60 communicate with each other to provide a high supply pressure, and the control chamber 26b of the closing main control valve 20 and the control chamber 36b of the opening main control valve 30 also have a high pressure. In the valve body 21 of the closing main control valve 20, when the pressure balance in the vertical direction of the sliding portion 28a in the cylinder port 27 collapses, the valve body 21 moves upward and starts to open the valve seat 25 portion. At the same time, in the open main control valve 30, the pressure in the control chamber 36b is increased, the balance of the fluid force acting on the valve body 31 is lost, the valve body 31 is moved upward, and the valve seat 35 is closed.

  Since the closing main control valve 20 starts to open, the cylinder port 23 and the cylinder port chamber 26a communicate with each other, the working fluid is supplied from the small pressure receiving area side 6 of the cylinder 7 to the large pressure receiving area side 7b, and the piston 5 Move to the left. When the piston moves to the left, the movable contact 2 attached to the rod 11 connected to the piston 5 also moves to the left, and the contact portion 70 begins to close. Since the valve seat 25 is opened, the pressure on the cylinder port 27 and the large pressure receiving area side 7b of the closing main control valve 20 also increases. However, while the piston 5 is moving, the pressure in these spaces 27 and 7b does not rise to the supply pressure.

Assuming that the supply pressure is Ps and the pressure on the large pressure receiving area side 7b is Pc, the valve element 21 of the closing main control valve 20 is positive in the direction of opening the valve element,
Ps × π (d ₃ ² −d ₄ ² ) / 4 + Pc × πd ₄ ² / 4−Pc × πd ₁ ² / 4−Ps × π (d ₂ ² −d ₁ ² ) / 4−Pc × πd ₄ ² / 4
The force of acts. That is, (Ps−Pc) × π {(d ₃ ² −d ₄ ² ) − (d ₂ ² −d ₁ ² )} / 4 in the direction to open the main control valve 20 for closing.
The force of acts.

  Therefore, the area of the diameter difference portion formed by the diameter d3 of the cylinder port 27 of the closing main control valve 20 and the diameter d4 of the shaft portion 28b of the valve body 21 is the opening diameter d2 of the valve seat 25 and the valve body 21. It is larger than the area of the diameter difference portion formed by the diameter d1 of the cylindrical portion 22 provided on the back side. Thereby, the fluid pressure of the working fluid which acts on the valve body 21 acts in the direction which opens the valve body 21. The force of the spring 24 is made smaller than the fluid force so that the valve body 21 is further opened. Since the moving amount of the valve body 21 is increased, the piston 5 operates at a higher speed.

  When the piston 5 is closing, the valve body 21 is kept open and the closing operation is continued. When the closing operation is completed and the piston 5 is stopped, the cylinder port 27 becomes high pressure. The fluid force of the working fluid is balanced, and the valve body 21 moves in the closing direction by the force of the spring 24. At this time, in the open circuit main control valve 30, the control chamber 36b has a supply pressure, and the fluid force of the working fluid in the control chamber 36b and the spring force of the spring 34 act upward on the valve body 31. As a result, the open circuit main control valve 30 is closed.

  The force of the spring 24 acts downward on the valve body 21 of the closing main control valve 20, but is set smaller than the upward force acting on the valve body 31 of the opening main control valve 30, so that the shaft portion The valve seat 25 portion of the closing main control valve 20 that is in contact with the end face 28b maintains a minute opening. According to the present embodiment, the closing main control valve 20 and the opening main control valve 30 are not provided with a portion opened to the low pressure reservoir 10 side, and the structure is simplified.

  In any of the above-described embodiments, the main control valve for opening and the main control valve for closing are made to face each other, and the length of the valve bodies in contact with the valve seats is larger than the axial length between the opening portions of the valve seats of the control valves. Since the axial length between the portions in contact with the valve seat is increased, both main control valves do not close at the same time. Thereby, the operation of each main control valve can be speeded up. Furthermore, since the main control valve for opening and the main control valve for closing are separated, when one valve body is operating, the time during which the other valve body does not operate can be secured. Can prevent pressure loss.

The longitudinal cross-sectional view of one Example of the circuit breaker which concerns on this invention. FIG. 3 is a plan view for explaining an opening operation of the circuit breaker shown in FIG. 1. The figure explaining the circuit opening operation | movement of the circuit breaker shown in FIG. The figure explaining the open circuit state of the circuit breaker shown in FIG. The figure explaining the closing operation of the circuit breaker shown in FIG. The figure explaining the closing operation of the circuit breaker shown in FIG. It is a longitudinal cross-sectional view of the other Example of the circuit breaker based on this invention, and is a figure corresponding to FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 4 ... Fluid pressure cylinder, 5 ... Piston, 20 ... Closing main control valve, 21 ... Valve body, 26b ... Closing control chamber, 30 ... Opening main control valve, 31 ... Valve body, 36b ... Opening control chamber, DESCRIPTION OF SYMBOLS 50 ... Pilot valve for circuit opening, 51 ... Solenoid for circuit opening, 60 ... Pilot valve for circuit closing, 61 ... Solenoid for circuit closing, 70 ... Contact part.

Claims (11)

  In the fluid pressure drive device for a circuit breaker, comprising: a fluid pressure cylinder that opens and closes a contact portion; a circuit control valve that opens the fluid pressure cylinder by a fluid force of a working fluid; and a circuit control valve that performs a circuit close operation. The opening control valve has an opening main control valve and an opening pilot valve that drives the opening main control valve, and the closing control valve drives the closing main control valve and the closing main control valve. Each of the main control valves has a valve seat and a valve body that can come into contact with the valve seat, the valve bodies are arranged opposite to each other, and each valve body and each valve seat are in contact with each other. A fluid pressure drive device for a circuit breaker, characterized in that the length between contact portions of the valve body to the valve seat is made longer than the distance between the valve seat portions in contact with each other.   2. The circuit breaker fluid according to claim 1, wherein the valve body of the opening main control valve and the valve body of the closing main control valve are arranged so that the valve opening directions are opposite to each other. Pressure drive device.   The valve body of the opening main control valve and the valve body of the closing main control valve are separate and coaxial, and are arranged not to contact each other during the operation of the fluid pressure drive device. The circuit breaker fluid pressure driving device according to claim 1, characterized in that:   An opening control chamber is formed in the opening main control valve, the opening control chamber is set to a low pressure to open a valve body of the opening control valve, and a closing control chamber is formed in the closing main control valve. 2. The circuit breaker fluid pressure driving device according to claim 1, wherein the closing control chamber is set to a high pressure to open the valve element of the closing main control valve.   In the open circuit holding state, the valve body of the open circuit main control valve and the valve body of the closed circuit main control valve are in contact with each other and the open circuit main control valve is slightly opened. During the open circuit operation, the open circuit main control valve is held open. Each valve element is arranged so that the main control valve for closing is slightly opened in the closed state and the main control valve for closing is further opened than the closed state during the closing operation. The fluid pressure drive device for a circuit breaker according to claim 1.   In the closed circuit holding state, the resultant force due to the pressure applied to the valve body of the closed circuit main control valve is made substantially zero, and the fluid force of the working fluid in the high pressure section is actuated on the valve body of the open circuit main control valve. A force is applied in the direction in which the body is closed, and in the open circuit holding state, the resultant force of the working fluid applied to the valve body of the open circuit main control valve is substantially zero, and the valve body of the closed circuit main control valve 2. The circuit breaker fluid pressure drive device according to claim 1, wherein a force due to the pressure of the working fluid in the high-pressure portion is applied to the valve body in a closing direction. 3.   The closing main control valve includes a closing control chamber, a supply port communicating with a high pressure portion of the working fluid, and a closing cylinder port connected to the fluid pressure cylinder, and the closing control chamber is set to a high pressure. The control valve is opened, the supply port and the closing cylinder port are communicated, the working fluid is supplied to the fluid pressure cylinder to close the contact portion, and the opening main control valve is connected to the opening control chamber and the working fluid low pressure. An opening port communicating with the fluid pressure cylinder and an opening cylinder port communicating with the fluid pressure cylinder, the opening control chamber is opened by opening the opening control chamber, and the opening cylinder port communicates with the discharging port. The fluid pressure drive device for a circuit breaker according to claim 1, wherein the working fluid is discharged from the fluid pressure cylinder to open the contact portion.   The valve body of the closing main control valve has a shaft portion that protrudes toward the closing control chamber, and is disposed so as to be in contact with the valve body of the opening main control valve in the discharge port, It has a cylindrical part opened to the low pressure part of the working fluid on the back side of the valve body of the main control valve for closing, and the valve element of the main control valve for opening is opened to the low pressure part of the working fluid on the side of the opening control chamber A spring that generates a force in a direction to close the valve body of the open circuit main control valve is provided in the open circuit main control valve, and the valve body of the open circuit main control valve is provided in the close circuit main control valve 8. The circuit breaker fluid pressure driving device according to claim 7, further comprising a spring that generates a force in a closing direction.   The closing main control valve includes a closing control chamber, a supply port communicating with the high pressure portion of the working fluid, and a closing cylinder port communicating with the fluid pressure cylinder, and the closing control chamber is set to a high pressure. The supply port and the closing cylinder port are connected, the working fluid is supplied to the fluid pressure cylinder to close the contact portion, and the opening main control valve is connected to the opening control chamber and the low pressure portion of the working fluid. A discharge port that communicates with the fluid pressure cylinder, and an opening cylinder port that communicates with the fluid pressure cylinder. The opening control chamber is set to a low pressure to open the main control valve for opening, and the opening cylinder port and the discharge port are connected to each other. 2. The circuit breaker fluid pressure drive device according to claim 1, wherein the fluid pressure cylinder communicates and discharges the working fluid from the fluid pressure cylinder to open the contact portion.   The valve body of the closing main control valve has a shaft portion that protrudes toward the closing chamber, and is disposed in the discharge port so as to be in contact with the valve element of the opening main control valve. A cylindrical portion is provided on the back side of the valve body of the valve, and a back pressure chamber communicating with the closing cylinder port is formed on the back surface of the cylindrical portion. The valve body of the opening main control valve is located on the opening control chamber side. A spring having a cylindrical portion and forming a back pressure chamber communicating with the opening cylinder port on the back surface of the cylindrical portion, wherein the opening main control valve generates a force in a direction to close the valve body of the opening main control valve 2. The circuit breaker fluid pressure drive device according to claim 1, wherein the closing main control valve has a spring that generates a force in a direction to close the valve body of the closing main control valve.   10. The circuit breaker fluid pressure drive device according to claim 8, wherein a cylinder port of the open circuit main control valve and the open circuit control chamber are connected via a throttle.

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