JP2016196903A - Control valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce a size of a control valve.SOLUTION: A sequence valve 100 is a control valve which operates accompanied by an elongation-contraction operation of a base-end side cylinder, and controls a flow of an operation fluid which is fed and discharged to/from a tip-side cylinder. The sequence valve comprises: a valve body 1 having a bottom part; a spool 20 which is movably arranged in the valve body 1, and permits the flow of the working fluid which is fed and discharged to/from the tip-side cylinder accompanied by the elongation/contraction operation of the base-end side cylinder; a coil spring 40 which energizes the spool 20 to a direction in which the flow of the working fluid which is fed and discharged to/from the tip-side cylinder is blocked; and a support member 30 which slidably supports the spool 20. The support member 30 is energized toward the bottom part 5 of the valve body 1 by the coil spring 40, and accommodated in the valve body 1.SELECTED DRAWING: Figure 5

Description

  The present invention relates to a control valve.

  Patent Document 1 discloses a control valve that includes a valve body that can partially protrude into an oil chamber of a fluid pressure cylinder, and that is provided via a cap member in a mounting hole formed in an upper end wall member of the cylinder member. Yes. In the control valve in Patent Document 1, the base end portion of the valve body is slidably fitted in the concave hole of the cap member, and the cap member is fixed to the cylinder body by screwing to close the mounting hole.

JP 2013-248732 A

  In the control valve disclosed in Patent Document 1, the valve element urged in the valve closing direction by the fluid pressure and the coil spring is opened by being pushed by the piston rod member. In the control valve disclosed in Patent Document 1, the valve body is slidably supported by the cylinder body and a cap member that closes the mounting hole of the cylinder body.

  Here, generally, in screw fastening for fixing members together, a radial gap (backlash) is generated between the male screw and the female screw. When such a gap in the radial direction occurs, it is difficult to perform screw fastening by aligning the coaxiality of the male screw and the female screw, so the members may be displaced from each other in the radial direction of the screw and fastened together. .

  For this reason, in the control valve as disclosed in Patent Document 1, the cylinder body and the cap member may be displaced in the radial direction of the screw and fastened to each other. When a displacement occurs between the cylinder body and the cap member, an axial displacement occurs between the mounting hole of the cylinder body into which the valve body is slidably inserted and the recessed hole of the cap member.

  If a shaft misalignment occurs in the hole into which the valve element is inserted, the frictional force between the valve element and the support part that supports the valve element increases, so that it is necessary to act on the valve element in order to ensure that the valve is closed. It is necessary to increase the power. However, if the urging force acting on the valve body is increased by a method such as increasing the wire diameter of the coil spring, the control valve may be increased in size.

  The present invention has been made in view of the above problems, and an object thereof is to reduce the size of a control valve.

  1st invention is a control valve which controls the flow of the working fluid which is operated with expansion and contraction operation of the 1st fluid pressure cylinder, and is supplied and discharged to the 2nd fluid pressure cylinder different from the 1st fluid pressure cylinder, A valve body that is movably provided in the valve body, allows a flow of the working fluid supplied to and discharged from the second fluid pressure cylinder as the first fluid pressure cylinder expands and contracts, and a second fluid pressure An urging member that urges the valve body in a direction that blocks the flow of the working fluid supplied to and discharged from the cylinder; and a support member that slidably supports the valve body. It is biased toward the bottom of the valve body and is housed in the valve body.

  In the first invention, the support member that supports the valve body is urged toward the bottom of the valve body by the urging member and is accommodated in the valve body, and is fixed to the valve body by screwing. It is not something. That is, since the outer periphery of the support member is not constrained by the valve body, the valve body can be supported by the support member accommodated so as to align the axis with the other support portions. Therefore, an increase in the frictional force between the valve body and the support portion that supports the valve body is prevented, and there is no need to increase the urging force.

  According to a second aspect of the present invention, a back pressure is provided between an entry portion provided in a fluid pressure chamber of a first fluid pressure cylinder so as to advance and retract, and a support member slidably supported and a bottom portion of the valve body. A base end section that defines the chamber, and an introduction passage that guides the working fluid in the fluid pressure chamber to the back pressure chamber. The pressure of the working fluid in the back pressure chamber acting in the same direction as the urging force of the urging member is reduced. The pressure receiving area of the valve body to be received is formed to be larger than the pressure receiving area of the valve body that receives the pressure of the working fluid in the fluid pressure chamber acting on the valve body against the biasing force of the biasing member.

  In the second invention, in the valve body, a pressure receiving area difference is provided such that the pressure receiving area that receives the pressure of the working fluid in the back pressure chamber is larger than the pressure receiving area that receives the pressure of the working fluid in the fluid pressure chamber. For this reason, a force in the same direction as the urging force of the urging member acts on the valve body under the pressure of the back pressure chamber based on the pressure receiving area difference. Therefore, the biasing force of the biasing member can be supplemented by the pressure in the back pressure chamber.

  According to a third aspect of the present invention, the support member is provided in the valve body so as to be movable in a direction in which the biasing member is compressed under the pressure of the working fluid in the back pressure chamber.

  In the third invention, since the urging member is compressed by the support member moving by the pressure of the working fluid in the back pressure chamber, the urging force acting on the valve body by the urging member can be increased.

  According to a fourth aspect of the invention, the valve body has a first port and a second port through which the working fluid supplied to and discharged from the second fluid pressure cylinder passes, and the urging member includes a first port and a second port. The valve body is urged in the direction that cuts off the communication, and the valve body allows the flow of working fluid from the first port to the second port as the first fluid pressure cylinder expands and contracts. And a check mechanism that allows the flow of the working fluid from the first port to the second port and that blocks the flow of the working fluid from the second port to the first port.

  In the fourth invention, by providing the check mechanism in the valve body, the flow of the working fluid supplied to and discharged from the second fluid pressure cylinder can be controlled by a single control valve.

  According to the present invention, the control valve can be reduced in size.

It is a circuit diagram of the crane drive unit provided with the control valve concerning the embodiment of the present invention, and shows the state where both the base end side cylinder and the tip end side cylinder contracted. It is a circuit diagram of the crane drive unit provided with the control valve concerning the embodiment of the present invention, and shows the state where only the base end side cylinder extended from the contracted state. It is a circuit diagram of the crane drive unit provided with the control valve concerning the embodiment of the present invention, and shows the state where both the base end side cylinder and the tip end side cylinder extended. It is a circuit diagram of the crane drive unit provided with the control valve concerning the embodiment of the present invention, and shows the state where only the tip side cylinder contracted from the extension state. It is sectional drawing which shows the control valve which concerns on embodiment of this invention, and shows the state which is not attached to the front end side cylinder. It is sectional drawing which shows the control valve which concerns on embodiment of this invention, and shows the state in a check position. It is sectional drawing which shows the control valve which concerns on embodiment of this invention, and shows the state which exists in a communicating position. It is sectional drawing which shows the control valve which concerns on embodiment of this invention, and is the state of a check position, and shows the state by which the working fluid was guide | induced to the back pressure chamber.

  Hereinafter, a control valve according to an embodiment of the present invention will be described with reference to the drawings.

  Below, the case where the control valve is sequence valve 100, 200 used for crane drive unit 300 which carries out expansion and contraction operation of the jib of a jib crane is explained.

  First, with reference to FIG. 1, the structure of the crane drive unit 300 in which the sequence valves 100 and 200 are used will be described.

  The crane drive unit 300 expands and contracts the jib crane by sequentially expanding and contracting the plurality of fluid pressure cylinders.

  As shown in FIG. 1, the crane drive unit 300 includes a base end side cylinder 210 and a front end side cylinder 220 that are hydraulic cylinders for expanding and contracting the jib crane, a pump 230 that discharges hydraulic oil as a working fluid, and a base end side cylinder. 210 and the switching valve 231 for switching the flow of hydraulic oil supplied to and discharged from the distal end side cylinder 220, the tank 232 to which hydraulic fluid discharged from the proximal end side cylinder 210 and the distal end side cylinder 220 is guided, and the proximal end side cylinder 210. The first sequence valve 100 that operates in accordance with the expansion / contraction operation of the cylinder and controls the flow of hydraulic oil supplied to the distal end side cylinder 220, and the operation that operates in accordance with the expansion / contraction operation of the distal end side cylinder 220 and is discharged from the proximal end side cylinder 210. And a second sequence valve 200 for controlling the flow of oil.

  The proximal cylinder 210 and the distal cylinder 220 are provided at cylindrical cylinder tubes 211 and 221, piston rods 212 and 222 inserted into the cylinder tubes 211 and 221, and end portions of the piston rods 212 and 222. Pistons 213 and 223 that slide along the inner peripheral surfaces of the cylinder tubes 211 and 221, respectively.

  The inside of each cylinder tube 211, 221 is partitioned into rod side chambers 214, 224 and bottom side chambers 215, 225 by pistons 213, 223. The base end side cylinder 210 and the front end side cylinder 220 are expanded and contracted by the pressure difference between the hydraulic oil supplied to and discharged from the rod side chambers 214 and 224 and the bottom side chambers 215 and 225, respectively.

  The first sequence valve 100 is a 2-port 2-position control valve. The first sequence valve 100 allows a communication position 100A that allows communication between the first port 1A and the second port 1B, allows flow of hydraulic oil from the first port 1A to the second port 1B, and allows the second port 1B. And a check position 100B for shutting off the flow of hydraulic oil from the first port 1A.

  The first sequence valve 100 includes a spool 20 as a valve body that can advance and retreat in the rod side chamber 214 of the base end side cylinder 210. The position of the first sequence valve 100 is switched to the communication position 100 </ b> A when the spool 20 that has entered the rod-side chamber 214 is pressed by the piston 213 and retracts from the rod-side chamber 214 as the proximal end cylinder 210 is extended.

  The second sequence valve 200 is a 2-port 2-position control valve. The second sequence valve 200 allows a communication position 200A that allows communication between the first port 101A and the second port 101B, allows flow of hydraulic oil from the first port 101A to the second port 101B, and allows the second port 101B. And a check position 200B for cutting off the flow of hydraulic oil from the first port 101A to the first port 101A.

  The second sequence valve 200 includes a spool 120 as a valve body that can advance and retreat in the bottom side chamber 225 of the front end side cylinder 220. The position of the second sequence valve 200 is switched to the communication position 200 </ b> A when the spool 120 that has entered the bottom side chamber 225 is pressed by the piston 223 and retracts from the bottom side chamber 225 as the tip side cylinder 220 contracts.

  The switching valve 231 is a 4-port 3-position electromagnetic switching valve whose position is switched by excitation of a solenoid. The switching valve 231 has a first position 231A shown on the right side in FIG. 1, a second position 231B shown on the left side, and a cutoff position 231C shown in the center. A discharge passage 250 through which the hydraulic oil discharged from the pump 230 passes and a discharge passage 251 through which the hydraulic oil guided to the tank 232 passes are connected to one port of the switching valve 231. A first main passage 252 and a second main passage 253 are connected to the other port of the switching valve 231.

  When the switching valve 231 is switched to the first position 231A, the discharge passage 250 and the first main passage 252 communicate with each other, and the discharge passage 251 and the second main passage 253 communicate with each other.

  When the switching valve 231 is switched to the second position 231B, the discharge passage 250 and the second main passage 253 communicate with each other, and the discharge passage 251 and the first main passage 252 communicate with each other.

  When the switching valve 231 is switched to the cutoff position 231C, the communication between the discharge passage 250 and the discharge passage 251 and the first main passage 252 and the second main passage 253 is cut off.

  The first main passage 252 branches into a first valve passage 252A and a second valve passage 252B. The first valve passage 252A is connected to the second port 1B of the first sequence valve 100, and the second valve passage 252B is connected to the first port 101A of the second sequence valve 200.

  The first main passage 252 is provided with a first counter balance valve 233 that guides the pressure of hydraulic oil passing through the second main passage 253 as a pilot pressure. The first counter balance valve 233 is provided between the branch point of the first main passage 252 and the switching valve 231. The second main passage 253 is provided with a second counter balance valve 234 that guides the pressure of the hydraulic oil passing through the first main passage 252 as a pilot pressure. By providing the first and second counter balance valves 233 and 234 in the first and second main passages 252 and 253, respectively, the speed of expansion and contraction operation of the jib crane is controlled to be constant, and a sudden drop due to its own weight is prevented.

  The second port 101B of the second sequence valve 200 is connected to the bottom chamber 215 of the proximal cylinder 210 through the first bottom passage 254. The second sequence valve 200 controls the flow of hydraulic oil discharged from the bottom side chamber 215 of the base end side cylinder 210.

  The first port 1 </ b> A of the first sequence valve 100 is connected to the bottom chamber 225 of the front end side cylinder 220 through the second bottom passage 255. The first sequence valve 100 controls the flow of hydraulic oil supplied to the bottom side chamber 225 of the front end side cylinder 220.

  The second main passage 253 is connected to the rod side chamber 214 of the base end side cylinder 210. Further, the rod side chamber 214 of the proximal end side cylinder 210 and the rod side chamber 224 of the distal end side cylinder 220 are connected by a rod passage 256.

  Next, the operation of the crane drive unit 300 will be described.

  When both the base end side cylinder 210 and the front end side cylinder 220 of the crane drive unit 300 are extended from a contracted state, the switching valve 231 is switched to the first position 231A as shown in FIG. When the switching valve 231 is switched to the first position 231A, the discharge passage 250 and the first main passage 252 communicate with each other, and the discharge passage 251 and the second main passage 253 communicate with each other.

  In a state where the base end side cylinder 210 is contracted, the first sequence valve 100 is in the check position 100B. In the state where the front end side cylinder 220 is contracted, the second sequence valve 200 is in the communication position 200 </ b> A with the spool 120 pushed by the piston 223 of the front end side cylinder 220.

  Therefore, the hydraulic fluid guided to the second valve passage 252B passes through the second sequence valve 200 at the communication position 200A, and is guided to the bottom side chamber 215 of the base end side cylinder 210 through the first bottom passage 254. For this reason, the hydraulic oil discharged from the pump 230 is supplied to the bottom side chamber 215 of the base end side cylinder 210, the base end side cylinder 210 extends, and the hydraulic oil from the rod side chamber 214 of the base end side cylinder 210 receives the first oil. The two main passages 253 and the discharge passage 251 are discharged to the tank 232.

  On the other hand, since the first sequence valve 100 is at the check position 100B, the flow of hydraulic oil from the first valve passage 252A to the second bottom passage 255 is blocked. Therefore, at this stage, the hydraulic oil is not supplied to or discharged from the front end side cylinder 220, and the front end side cylinder 220 does not extend.

  When the proximal end side cylinder 210 is extended until reaching a predetermined stroke amount, the spool 20 of the first sequence valve 100 is pushed by the piston 213 of the proximal end side cylinder 210 as shown in FIG. Switches to the communication position 100A. Accordingly, the flow of hydraulic oil from the first valve passage 252A to the second bottom passage 255 is allowed, so that the hydraulic oil is supplied to the bottom side chamber 225 of the tip side cylinder 220. Accordingly, the front end side cylinder 220 starts the extension operation, and the hydraulic oil in the rod side chamber 224 is tanked through the rod passage 256, the rod side chamber 214 of the base end side cylinder 210, the second main passage 253, and the discharge passage 251 along with the extension operation. 232 is discharged.

  When the distal end side cylinder 220 is extended until it reaches a predetermined stroke amount, the spool 120 of the second sequence valve 200 is not pushed by the piston 223 of the distal end side cylinder 220, so the second sequence valve 200 is switched to the check position 200B. (See FIG. 3). However, since the second valve passage 252B is connected to the first port 1A of the second sequence valve 200, even if the second sequence valve 200 is switched to the check position 100B, the second valve passage 252B is switched to the first bottom passage 254. The flow of hydraulic fluid to is not blocked. Therefore, the extension operation of the base end side cylinder 210 is continued.

  Thus, at the time of the extension operation, only the base end side cylinder 210 is first extended, and the first sequence valve 100 is switched to the communication position 100A along with the extension operation of the base end side cylinder 210. The hydraulic oil is guided to 220, and the front end side cylinder 220 starts to extend.

  When both the proximal end side cylinder 210 and the distal end side cylinder 220 of the crane drive unit 300 are contracted from the extended state, the switching valve 231 is switched to the second position 231B as shown in FIG. When the switching valve 231 is switched to the second position 231B, the discharge passage 250 and the second main passage 253 communicate with each other, and the discharge passage 251 and the first main passage 252 communicate with each other.

  In the state where the base end side cylinder 210 is extended, the spool 20 of the first sequence valve 100 is pushed by the piston 213 of the base end side cylinder 210 and is in the communication position 100A. In a state where the front end side cylinder 220 is extended, the second sequence valve 200 is in the check position 200B.

  Accordingly, since the flow of hydraulic oil from the first bottom passage 254 to the second valve passage 252B is blocked by the second sequence valve 200, the hydraulic oil is not discharged from the bottom chamber 215 of the proximal cylinder 210, and the proximal end The side cylinder 210 is not contracted. The hydraulic fluid guided to the second main passage 253 is guided to the rod side chamber 224 of the distal end side cylinder 220 through the rod side chamber 214 and the rod passage 256 of the proximal end side cylinder 210.

  Since the first sequence valve 100 is in the communication position 100A, the flow of hydraulic oil from the second bottom passage 255 to the first valve passage 252A is allowed. For this reason, the front end side cylinder 220 is contracted, and hydraulic oil from the bottom side chamber 225 is transferred to the tank 232 through the second bottom passage 255, the first valve passage 252A, the first main passage 252 and the discharge passage 251 in accordance with the contraction operation. Discharged.

  When the distal end side cylinder 220 contracts until reaching a predetermined stroke amount, as shown in FIG. 4, the spool 120 of the second sequence valve 200 is pushed by the piston 223 of the distal end side cylinder 220, and the second sequence valve 200 communicates. Switch to position 200A. As a result, the flow of hydraulic oil from the first bottom passage 254 to the second valve passage 252B is allowed, so that the hydraulic oil in the bottom side chamber 215 of the base end side cylinder 210 becomes the first bottom passage 254 and the second valve passage 252B. The first main passage 252 and the discharge passage 251 are discharged to the tank 232. Therefore, the base end side cylinder 210 starts the contraction operation.

  When the proximal end side cylinder 210 is contracted until reaching a predetermined stroke amount, the spool 20 of the first sequence valve 100 is not pushed by the piston 213 of the proximal end side cylinder 210, so the first sequence valve 100 is moved to the check position 100B. Switch. However, since the second bottom passage 255 is connected to the first port 1A of the first sequence valve 100, even if the first sequence valve 100 is switched to the check position 100B, the second bottom passage 255 to the first valve passage 252A. The flow of hydraulic fluid to is not blocked. Therefore, the contraction operation of the front end side cylinder 220 is continued. Therefore, both the proximal end side cylinder 210 and the distal end side cylinder 220 are contracted to return to the contracted state shown in FIG.

  Thus, during the contraction operation, only the distal end side cylinder 220 is contracted first, and the second sequence valve 200 is switched to the communication position 200A along with the contraction operation of the distal end side cylinder 220. The hydraulic oil is guided to the base end side cylinder 210 to start the contraction operation.

  As described above, in the crane drive unit 300, the flow of hydraulic oil supplied to the distal end side cylinder 220 is controlled by the first sequence valve 100 that operates in accordance with the expansion and contraction operation of the proximal end side cylinder 210. The flow of the hydraulic oil discharged from the base end side cylinder 210 is controlled by the second sequence valve 200 that is operated in accordance with the expansion / contraction operation. Thereby, at the time of extending | stretching operation | movement, after extending only the base end side cylinder 210, the front end side cylinder 220 can be extended | stretched. Further, at the time of contraction operation, only the distal end side cylinder 220 can be contracted and then the proximal end side cylinder 210 can be contracted.

  Next, a specific configuration of the first and second sequence valves 100 and 200 will be described in detail with reference to FIG. The first and second sequence valves 100 and 200 differ from each other only in the cylinders to which they are attached and the fluid pressure chambers into which the spools 20 and 120 enter, and have the same configuration. For this reason, below, the structure of the 1st sequence valve 100 is demonstrated and the detailed description of the 2nd sequence valve 200 is abbreviate | omitted. Hereinafter, the first sequence valve 100 is simply referred to as “sequence valve 100”.

  The sequence valve 100 is operated as a working fluid supplied to a distal end side cylinder 220 as a second fluid pressure cylinder that operates in accordance with the expansion and contraction operation of the proximal end side cylinder 210 as a first fluid pressure cylinder. Controls the flow of hydraulic oil. In the second sequence valve 200, the distal end side cylinder 220 corresponds to a first fluid pressure cylinder, and the proximal end side cylinder 210 corresponds to a second fluid pressure cylinder. The second sequence valve 200 controls the flow of hydraulic oil discharged from the base end side cylinder 210.

  FIG. 5 is a cross-sectional view of the sequence valve 100 showing a state before being attached to the proximal cylinder 210. As shown in FIG. 5, the sequence valve 100 has a check position 100 </ b> B in a position before being attached. The sequence valve 100 includes a cylindrical valve body 1 having a first port 1A and a second port 1B through which hydraulic oil passes, a spool 20 as a valve body movably provided in the valve body 1, and a spool 20 A support member 30 that is slidably inserted to support the spool 20, and a coil spring 40 as an urging member that urges the spool 20 in a direction that blocks the flow of hydraulic oil supplied to the tip side cylinder 220; Is provided.

  The valve body 1 includes a cylindrical portion 10 having openings at both ends, a sealing portion 2 that seals an opening on one end side of the cylindrical portion 10, and a cap that seals an opening on the other end side of the cylindrical portion 10. And 5.

  The cylinder part 10 is formed between the main body part 11 in which the first and second ports 1 </ b> A and 1 </ b> B are formed, the accommodating part 12 in which the support member 30 is accommodated, and the intermediate part formed between the main body part 11 and the accommodating part 12. Part 13.

  First and second ports 1 </ b> A and 1 </ b> B are formed in the main body 11 side by side in the axial direction. The first and second ports 1 </ b> A and 1 </ b> B are formed to penetrate the main body portion 11 in the radial direction and communicate with the inner and outer peripheral surfaces of the main body portion 11. An annular seat portion 14 formed between the first port 1A and the second port 1B and protruding radially inward is formed on the inner periphery of the main body portion 11. A check valve body 71, which will be described later, abuts the seat portion 14.

  The inner diameter of the intermediate part 13 is larger than the inner diameter of the main body part 11 and smaller than the inner diameter of the housing part 12. Thereby, a first step portion 15 is formed between the inner periphery of the main body 11 and the inner periphery of the intermediate portion 13. In addition, a second step portion 16 is formed between the inner periphery of the intermediate portion 13 and the inner periphery of the accommodating portion 12.

  The cylinder portion 10 further includes a first screwing portion 17 in which the sealing portion 2 is screwed onto the inner peripheral surface, and a second screwing portion 18 in which the cap 5 is screwed into the inner peripheral surface.

  The sealing portion 2 includes a first flange portion 3 that is in contact with an end surface of the first screwing portion 17, that is, an end surface on one end side of the cylindrical portion 10, and a first boss portion 4 that is inserted into the first screwing portion 17. Have. The first screw part 17 and the first boss part 4 of the sealing part 2 are screwed together by the first screw part 4A. Thereby, the sealing portion 2 is fixed to the cylindrical portion 10 by sealing the opening of the first screwing portion 17, that is, the opening on one end side of the cylindrical portion 10.

  The sealing part 2 has an insertion hole 2A into which the spool 20 is slidably inserted. The spool 20 is slidably supported by the sealing portion 2.

  The cap 5 includes a second flange portion 6 that comes into contact with an end surface of the second screwing portion 18, that is, an end surface on the other end side of the main end portion, a second boss portion 7 that is inserted into the second screwing portion 18, and Have The second screw portion 18 and the second boss portion 7 of the cap 5 are screwed together by the second screw portion 7A. Thereby, the cap 5 is fixed to the cylinder part 10 by sealing the opening of the accommodating part 12, that is, the opening on the other end side of the cylinder part 10.

  The cap 5 is provided with a recess 6 </ b> A formed on an end surface facing the spool 20. The recess 6A is formed so that the spool 20 and the cap 5 do not come into contact with each other when the spool 20 moves in accordance with the extension operation of the base end side cylinder 210.

  Sealing materials (not shown) are provided between the first threaded portion 17 and the sealing portion 2 and between the second threaded portion 18 and the cap 5 to prevent leakage of hydraulic oil to the outside.

  The spool 20 includes an entry portion 21 provided in the rod side chamber 214 of the proximal end side cylinder 210 so as to be able to advance and retreat, a proximal end portion 22 slidably supported by the support member 30, and a second port 1B to a first port. A blocking portion 23 for blocking the flow of hydraulic oil toward 1A, a small diameter portion 24 formed between the blocking portion 23 and the entry portion 21 and having an outer diameter smaller than the outer diameter of the entry portion 21, and a blocking portion. And an annular portion 25 that is formed between the base end portion 22 and the first step portion 15 of the valve body 1.

  The entry portion 21 is slidably inserted into the insertion hole 2A of the sealing portion 2. A part of the entry portion 21 is provided so as to protrude axially outward from one end surface of the valve body 1 (end surface of the sealing portion 2). Thus, when the sequence valve 100 is attached to the proximal cylinder 210, a part of the entry portion 21 enters the rod side chamber 214 of the proximal cylinder 210 (see FIG. 6).

  Since the entry portion 21 enters the rod side chamber 214 of the base end side cylinder 210, the pressure of the rod side chamber 214 acts on the end surface of the entry portion 21. Therefore, a force in the right direction in FIG. 5 acts on the spool 20 against the biasing force of the biasing spring due to the pressure of the hydraulic oil in the rod side chamber 214.

  The blocking part 23 is formed with an outer diameter larger than the outer diameter of the entry part 21 and smaller than the inner diameter of the seat part 14 of the valve body 1. The blocking portion 23 blocks communication between the first port 1A and the second port 1B by contacting a contact portion 72 of the check valve body 71 described later. The blocking part 23 is provided so as to face the first port 1 </ b> A, and has an outer diameter smaller than the inner diameter of the main body part 11 of the valve body 1. For this reason, an annular passage 26 communicating with the first port 1 </ b> A is formed between the inner periphery of the main body 11 and the outer periphery of the blocking portion 23.

  Since the small diameter portion 24 is formed with an outer diameter smaller than the outer diameter of the entry portion 21, an annular groove 27 is formed on the outer periphery of the small diameter portion 24.

  The outer diameter of the annular portion 25 is smaller than the inner diameter of the intermediate portion 13 of the valve body 1 and larger than the inner diameter of the main body portion 11. Thereby, the annular portion 25 is provided so as to be able to contact the first step portion 15 of the valve body.

  The support member 30 is provided in the accommodating portion 12 of the valve body 1 and between the second step portion 16 of the valve body 1 and the second boss portion 7 of the cap 5. The outer diameter of the support member 30 is formed smaller than the inner diameter of the accommodating portion 12 of the valve body 1. For this reason, a radial gap is formed between the support member 30 and the accommodating portion 12.

  On the outer periphery of the support member 30, a seal member 31 that closes a gap between the inner periphery of the accommodating portion 12 of the valve body 1 is provided. The seal member 31 is an elastic seal member that can be elastically deformed by an external force. The sealing member 31 prevents hydraulic fluid from leaking outside through a gap between the support member 30 and the inner periphery of the accommodating portion 12 of the valve body 1.

  Since the seal member 31 is elastically deformed by an external force, the support member 30 can move in the radial direction without the outer peripheral surface being completely restrained. That is, the support member 30 is elastically supported in the radial direction by the accommodating portion 12 of the valve body 1 through the seal member 31.

  The axial length of the support member 30 is shorter than the axial length between the second step portion 16 of the valve body 1 and the end surface of the cap 5. For this reason, the support member 30 is provided in the valve body 1 so as to be movable in the axial direction within a range between the second stepped portion 16 and the cap 5. The second step portion 16 functions as a defining portion that defines the axial movement of the support member 30.

  The support member 30 includes a sliding hole 30A into which the base end portion 22 of the spool 20 is slidably inserted, and a large-diameter hole that is continuous from the sliding hole 30A and has a larger diameter than the sliding hole 30A. 30B. The large diameter hole 30 </ b> B opens in the end surface of the support member 30 that faces the cap 5. The spool 20 is supported by the support member 30 when the base end portion 22 is slidably inserted into the slide hole 30 </ b> A of the support member 30. A third step portion 30C is formed between the large diameter hole 30B and the sliding hole 30A.

  The coil spring 40 is interposed between the annular portion 25 of the spool 20 and the support member 30 in a compressed state. For this reason, the spool 20 is urged by the coil spring 40 in the direction in which the entry portion 21 enters the rod side chamber 214 (left direction in FIG. 5). The support member 30 is accommodated in the accommodating portion 12 between the coil spring 40 and the cap 5, and is urged by the coil spring 40 in a direction in which the support member 30 is pressed against the cap 5.

  As described above, the spool 20 is slidably supported by the sealing portion 2 and the support member 30. The support member 30 is elastically supported in the radial direction by the accommodating portion 12 of the valve body 1 through the seal member 31, and is not fixed to the valve body 1 by screwing like the cap 5. That is, the outer peripheral surface of the support member 30 is not completely restrained by the accommodating portion 12 of the valve body. For this reason, after inserting the entry portion 21 of the spool 20 into the insertion hole 2A in the sealing portion 2, the base end portion 22 of the spool 20 is inserted into the sliding hole 30A of the support member 30 so as to align the axis with the insertion hole 2A. Can be inserted. Further, even if the spool 20 is to be inserted in a state where the axes of the insertion hole 2A of the sealing portion 2 and the sliding hole 30A of the support member 30 are shifted, the support member 30 is aligned with the axis of each hole. The seal member 31 is deformed and moved in the radial direction within the accommodating portion 12. As a result, the axes of the insertion hole 2A of the sealing portion 2 and the sliding hole 30A of the support member 30 are aligned.

  Therefore, since the increase in the frictional force between the spool 20 and the support member 30 that is the support portion that supports the spool 20 and the sealing portion 2 is prevented, the sliding resistance of the spool 20 is reduced. Therefore, it is not necessary to increase the biasing force by using a coil spring having a large wire diameter or a coil spring having a long overall length. That is, it is not necessary to increase the size of the coil spring 40.

  In the valve body 1, a back pressure chamber 50 is defined by a base end portion 22 of the spool 20, a support member 30, and a cap 5 that is a bottom portion of the valve body 1. The back pressure chamber 50 receives hydraulic oil in the rod side chamber 214 of the base end side cylinder 210 through an introduction passage 60 formed in the spool 20 along the central axis and opening at the end surfaces of the entry portion 21 and the base end portion 22. Led. The pressure of the hydraulic oil in the back pressure chamber 50 acts on the end surface of the base end portion 22.

  The pressure receiving area of the axial end surface of the base end portion 22 that receives the pressure of the hydraulic oil in the back pressure chamber 50 is formed larger than the pressure receiving area of the axial end surface of the entry portion 21 that receives the pressure of the hydraulic oil in the rod side chamber 214. Is done. Specifically, the area corresponding to the difference between the area of the end face of the base end portion 22 and the area of the introduction passage 60 opening in the end face of the base end portion 22 (hereinafter referred to as “base end side area”) is as follows. It is formed to be larger than the area corresponding to the difference between the area of the end face of the entry portion 21 and the area of the introduction passage 60 opening in the end face of the entry portion 21 (hereinafter referred to as “entrance side area”). Thus, in the spool 20, the pressure receiving area of the spool 20 to which the hydraulic oil pressure of the back pressure chamber 50 acts is larger than the pressure receiving area of the spool 20 to which the pressure in the rod side chamber 214 of the base end side cylinder 210 acts. Thus, a pressure receiving area difference is provided.

  Since the hydraulic oil in the back pressure chamber 50 is guided from the rod side chamber 214 of the base end side cylinder 210, the pressures in the back pressure chamber 50 and the rod side chamber 214 are substantially the same. For this reason, the spool 20 is urged in the same direction as the urging force of the coil spring 40 (left direction in FIG. 5) due to the difference in force based on the pressure receiving area difference between the base end side area and the entry side area.

  Thus, the spool 20 has a pressure receiving area (base end area) of the spool 20 that receives the pressure of the hydraulic oil in the back pressure chamber 50 acting in the same direction as the urging force of the coil spring 40. It is formed larger than the pressure receiving area (entrance side area) of the spool 20 that receives the pressure of the hydraulic oil in the rod side chamber 214 that acts on the spool 20 against the force. Thereby, the spool 20 can be urged in the same direction as the urging force of the coil spring 40 by the pressure of the hydraulic oil guided to the back pressure chamber 50, and the urging force of the coil spring 40 can be compensated. Therefore, a smaller coil spring 40 can be used.

  The pressure in the back pressure chamber 50 also acts on the third step portion 30 </ b> C of the support member 30. For this reason, the support member 30 is urged so as to move in a direction in which the coil spring 40 is compressed by the pressure of the back pressure chamber 50.

  The sequence valve 100 is provided in the valve body 1 to allow the flow of hydraulic oil from the first port 1A to the second port 1B and to block the flow of hydraulic oil from the second port 1B to the first port 1A. A check mechanism 70 is further provided.

  The check mechanism 70 is slidably provided in the main body 11 of the valve body 1 and is provided with a cylindrical check valve body 71 slidably provided on the outer periphery of the spool 20, and the second port 1B to the first port 1A. And a check spring 75 that urges the check valve body 71 in a direction that blocks the flow of hydraulic oil toward the front.

  The check valve body 71 includes a contact portion 72 that contacts the blocking portion 23 of the spool 20 and the seat portion 14 of the valve body 1, and a communication hole 73 that opens to the inner and outer peripheral surfaces thereof. The communication hole 73 communicates the annular groove 27 provided on the outer periphery of the small diameter portion 24 of the spool 20 and the second port 1B.

  The check spring 75 is interposed in a compressed state in a check spring chamber 75A formed between the check valve body 71 and the sealing portion 2. The check spring 75 biases the check valve body 71 in a direction that blocks communication between the first port 1A and the second port 1B, that is, in a direction toward the contact portion 72 of the spool 20. The check spring chamber 75 </ b> A communicates with the communication hole 73 of the check valve body 71 through a through passage 74 formed in the check valve body 71.

  In order to cause the proximal end side cylinder 210 and the distal end side cylinder 220 to expand and contract sequentially rather than simultaneously, the sequence valve 100 supplies and discharges hydraulic oil to and from the distal end side cylinder 220 as the proximal end side cylinder 210 expands and contracts. A function as a switching valve that switches between and a shut-off, a function as a check valve that stops the supply of hydraulic oil to the front end side cylinder 220 at the time of expansion, and allows discharge of the hydraulic oil from the front end side cylinder 220 at the time of contraction, It is necessary to have these two functions. In other words, the sequence valve 100 is configured to always allow one of supply and discharge of hydraulic oil to and from the front end side cylinder 220 and to switch between allowing and shutting off according to the position.

  By providing the check mechanism 70 in the valve body 1, the sequence valve 100 can exhibit both a function as a switching valve and a function as a check valve by a single control valve.

  Next, the operation of the sequence valve 100 will be described with reference to FIGS. FIG. 6 is a cross-sectional view showing the sequence valve 100 attached to the proximal cylinder 210. The sequence valve 100 is at the check position 100B, and the flow of hydraulic oil from the second port 1B to the first port 1A is cut off. Shows the state. 6 to 8, illustration of the second bottom passage 255 connected to the first port 1A and the first valve passage 252A connected to the second port 1B is omitted.

  In the check position 100 </ b> B, the spool 20 is pressed toward the check valve body 71 by the biasing force of the coil spring 40, and the check valve body 71 is pressed toward the blocking portion 23 of the spool 20 by the biasing force of the check spring 75. As a result, as shown in FIGS. 5 and 6, the shut-off portion 23 of the spool 20 and the contact portion 72 of the check valve body 71 contact each other.

  When the hydraulic oil is guided to the second port 1B in a state where the spool 20 and the check valve body 71 are in contact with each other, the hydraulic oil is guided to the check spring chamber 75A through the communication hole 73 and the through passage 74 of the check valve body 71. . The spool 20 and the check valve body 71 slightly move in the direction in which the coil spring 40 is compressed (the right direction in FIG. 5) due to the pressure of the hydraulic oil guided to the check spring chamber 75A. Further, as shown in FIG. 6, the check valve body 71 is pressed against the seat portion 14 of the valve body 1 while being in contact with the spool 20, and the contact portion 72 of the check valve body 71 is in contact with the seat portion 14. . By the contact between the check valve body 71 and the seat portion 14, the flow of hydraulic oil from the second port 1 </ b> B toward the first port 1 </ b> A through the outer periphery of the check valve body 71 is blocked. By the contact between the check valve body 71 and the spool 20, the flow of hydraulic oil from the second port 1 </ b> B toward the first port 1 </ b> A through the inner periphery of the check valve body 71 is blocked. In this way, the flow of hydraulic oil from the second port 1B toward the first port 1A is blocked by the spool 20 and the check valve body 71.

  On the other hand, when the hydraulic oil is guided from the first port 1A at the check position 100B, the check valve body 71 moves to the left in FIG. 5 against the urging force of the check spring 75 due to the pressure of the hydraulic oil. Thereby, the contact part 72 of the check valve body 71 and the blocking part 23 of the spool 20 are separated from each other, and the first port 1A communicates with the second port 1B through the annular passage 26, the annular groove 27, and the communication hole 73. By opening the check valve body 71, the flow of hydraulic oil from the first port 1A to the second port 1B is allowed.

  In this way, at the check position 100B, the contact portion 72 of the check valve body 71 and the seat portion 14 of the valve body 1 are in contact with each other by the pressure of the hydraulic fluid guided from the second port 1B, and the blocking portion 23 of the spool 20 When the contact portion 72 of the check valve body 71 contacts, the flow of hydraulic oil from the second port 1B toward the first port 1A is blocked. Further, the check valve element 71 moves against the urging force of the check spring 75 by the pressure of the hydraulic oil guided from the first port 1A, so that the flow of the hydraulic oil from the first port 1A to the second port 1B is performed. Permissible.

  When the base end side cylinder 210 is extended, the rod side chamber 214 communicates with the tank 232, so that almost no hydraulic oil pressure is introduced into the back pressure chamber 50. For this reason, the support member 30 does not move due to the pressure of the back pressure chamber 50, and is biased by the coil spring 40 and abuts against the cap 5.

  When the proximal cylinder 210 is extended until reaching a predetermined stroke amount, the entry portion 21 of the spool 20 is pushed into the valve body 1 by the piston 213, and the spool 20 is attached to the coil spring 40 as shown in FIG. Move against the power. As the spool 20 moves, the check valve body 71 moves until it abuts against the seat portion 14 of the valve body 1 by the urging force of the check spring 75.

  When the entry portion 21 of the spool 20 is further pushed by the piston 213 while the check valve body 71 is in contact with the seat portion 14, the shut-off portion 23 of the spool 20 and the contact portion 72 of the check valve body 71 are separated from each other. . Thus, the first port 1A and the second port 1B communicate with each other through the annular passage 26, the annular groove 27, and the communication hole 73. Therefore, the flow of hydraulic oil from the second port 1B toward the first port 1A is allowed. In this way, the sequence valve 100 is switched to the communication position 100 </ b> A, whereby the flow of hydraulic oil supplied to the distal end side cylinder 220 is allowed.

  When the proximal cylinder 210 is contracted, the hydraulic oil discharged from the pump 230 is guided to the rod side chamber 214. Therefore, since a high pump pressure is guided to the back pressure chamber 50, the support member 30 moves against the biasing force of the coil spring 40 due to the pressure of the back pressure chamber 50. That is, as shown in FIG. 8, the support member 30 moves away from the cap 5 by the pressure of the back pressure chamber 50 and compresses the coil spring 40.

  By compressing the coil spring 40 in this way, the urging force of the coil spring 40 acting on the spool 20 increases. By increasing the urging force of the coil spring 40, the spool 20 is more reliably prevented from moving in the valve opening direction (right direction in FIG. 8) by the pressure of the rod side chamber 214. Further, since the biasing force of the coil spring 40 is increased by the support member 30 compressing the coil spring 40, the spool 20 can be reliably biased in the valve closing direction even with a smaller coil spring 40. Can do. That is, when the support member 30 compresses the coil spring 40, a smaller coil spring 40 can be used.

  When the proximal cylinder 210 contracts from the extended end until reaching a predetermined stroke amount, the piston 213 and the entry portion 21 do not come into contact with each other, so that the entry portion 21 enters the rod side chamber 214 by the biasing force of the coil spring 40. The spool 20 moves to the position. As a result, the shut-off portion 23 of the spool 20 and the abutting portion 72 of the check valve body 71 abut. At this time, the check valve body 71 moves against the urging force of the check spring 75. In this way, the sequence valve 100 switches again to the check position 100B shown in FIG.

  According to the above embodiment, there exist the effects shown below.

  In the sequence valve 100, a support member 30 that slidably supports the spool 20 is elastically supported in the radial direction by the accommodating portion 12 of the valve body via a seal member 31. It is not fixed to the accommodating portion 12 of the body 1. For this reason, in a state where the axes of the insertion hole 2A in the sealing portion 2 that supports the entry portion 21 of the spool 20 and the sliding hole 30A in the support member 30 that supports the base end portion 22 of the spool 20 are aligned, respectively. A spool 20 can be inserted. For this reason, an increase in the frictional force between the spool 20 and the support member 30 that is a support portion for supporting the spool 20 and the sealing portion 2 is prevented. Therefore, it is not necessary to increase the biasing force by increasing the size of the coil spring 40 by using a coil spring having a large wire diameter or a coil spring having a long overall length. Therefore, the sequence valve 100 can be reduced in size.

  Further, in the spool 20, the pressure receiving area of the spool 20 that receives the pressure of the hydraulic oil in the back pressure chamber 50 acting in the same direction as the urging force of the coil spring 40 has a resistance against the urging force of the coil spring 40. It is formed larger than the pressure receiving area of the spool 20 that receives the pressure of the working oil in the acting rod side chamber 214. Therefore, the urging force of the coil spring 40 can be compensated by urging the spool 20 in the same direction as the urging force of the coil spring 40 by the pressure of the hydraulic oil guided to the back pressure chamber 50. Therefore, since the coil spring 40 can be further downsized, the sequence valve 100 can be further downsized.

  Further, since the support member 30 is movably provided so as to compress the coil spring 40 by the pressure of the back pressure chamber 50, the support member 30 moves and the coil spring 40 is compressed, thereby acting on the spool 20. The biasing force of the coil spring 40 increases. Thus, since the biasing force of the coil spring 40 is increased, a smaller coil spring 40 can be used. Therefore, the sequence valve 100 can be further downsized.

  Hereinafter, the configuration, operation, and effect of the embodiment of the present invention will be described together.

  The sequence valves 100 and 200 operate in accordance with the expansion / contraction operation of the first fluid pressure cylinder (the base end side cylinder 210 and the tip end side cylinder 220), and are different from the first fluid pressure cylinder (the base end side cylinder 210 and the tip end side cylinder 220). A control valve for controlling the flow of hydraulic oil supplied to and discharged from different second fluid pressure cylinders (the front end side cylinder 220 and the base end side cylinder 210), and a valve body 1 having a bottom (cap 5); 1 is movably provided in the first fluid pressure cylinder (the base end side cylinder 210, the tip end side cylinder 220), and is supplied to and discharged from the second fluid pressure cylinder (the tip end side cylinder 220, the base end side cylinder 210). Are supplied to and discharged from the spools 20 and 120 that allow the flow of the hydraulic oil to be supplied and the second fluid pressure cylinder (the front end side cylinder 220 and the base end side cylinder 210). A coil spring 40 that urges the spools 20 and 120 in a direction to block the flow of dynamic oil; and a support member 30 that slidably supports the spools 20 and 120. The valve body 1 is urged toward the bottom (cap 5) and accommodated in the valve body 1.

  In this configuration, the support member 30 that supports the spools 20 and 120 is urged toward the bottom (cap 5) of the valve body 1 by the coil spring 40 and is accommodated in the valve body 1, and is screwed. It is not fixed to the valve body 1 by the combination. That is, since the outer peripheral surface of the support member 30 is not completely restrained by the valve body 1, the spool 20 can be supported by the support member 30 accommodated so as to align the axis with the sealing portion 2. . Therefore, since the increase of the frictional force between the spool 20 and the support member 30 that supports the spool 20 and the sealing portion 2 is prevented, it is not necessary to increase the urging force. According to this configuration, the sequence valves 100 and 200 can be reduced in size.

  In addition, the sequence valves 100 and 200 allow the spools 20 and 120 to advance and retract into the fluid pressure chambers (rod side chamber 214 and bottom side chamber 225) of the first fluid pressure cylinder (base end side cylinder 210 and tip end side cylinder 220). A base end portion 22 that is slidably supported by the entry portion 21 provided and the support member 30 and defines the back pressure chamber 50 between the bottom portion (cap 5) of the valve body 1, and a fluid pressure chamber (rod) Pressure passage of the hydraulic oil in the back pressure chamber 50 that has the introduction passage 60 for guiding the hydraulic oil in the side chamber 214 and the bottom side chamber 225) to the back pressure chamber 50 and acts in the same direction as the urging force of the spools 20 and 120. The pressure receiving area of the base end portion 22 of the spools 20 and 120 receiving the pressure of the hydraulic oil in the fluid pressure chambers (the rod side chamber 214 and the bottom side chamber 225) acting on the spool 20 against the biasing force of the coil spring 40. It is larger than the pressure receiving area of the entrance portion 21 of the spool 20, 120 undergoing.

  In this configuration, in the spools 20 and 120, the pressure receiving area that receives the pressure of the hydraulic oil in the back pressure chamber 50 is larger than the pressure receiving area that receives the pressure of the hydraulic oil in the fluid pressure chamber (rod side chamber 214, bottom side chamber 225). Such a pressure receiving area difference occurs. Therefore, a force in the same direction as the urging force of the coil spring 40 is applied to the spools 20 and 120 by receiving the pressure of the back pressure chamber 50 based on the pressure receiving area difference. Therefore, the biasing force of the coil spring 40 can be supplemented by the pressure of the back pressure chamber 50. According to this configuration, the sequence valves 100 and 200 can be further downsized.

  The sequence valves 100 and 200 are provided in the valve body 1 so that the support member 30 can move in a direction in which the coil spring 40 is compressed by receiving the pressure of the hydraulic oil in the back pressure chamber 50.

  In this configuration, the coil spring 40 is compressed when the support member 30 is moved by the pressure of the hydraulic oil in the back pressure chamber 50, so that the urging force acting on the spools 20 and 120 by the coil spring 40 is increased. Can do. According to this configuration, the sequence valves 100 and 200 can be further downsized.

  In the sequence valves 100 and 200, the valve body 1 includes the first ports 1A and 101A through which the hydraulic oil supplied to and discharged from the second fluid pressure cylinder (the front end side cylinder 220 and the base end side cylinder 210) passes and the second ports 1A and 101A. And the coil spring 40 urges the spools 20 and 120 in a direction to block communication between the first ports 1A and 101A and the second ports 1B and 101B. The first port 1A, 101A and the second port 1B, 101B are allowed to communicate with the expansion / contraction operation of the one fluid pressure cylinder (base end side cylinder 210, front end side cylinder 220), and the sequence valves 100, 200 are connected to the valve body. 1 and allows the flow of hydraulic oil from the first port 1A, 101A to the second port 1B, 101B, and the second port Further comprising B, the first port 1A from 101B, the check mechanism 70 for blocking a flow of the hydraulic fluid to 101A (the check valve 71, check spring 75).

  In this configuration, the check mechanism 70 (the check valve body 71 and the check spring 75) is provided in the valve body 1, so that the second fluid pressure cylinder (the front end side cylinder 220, the base cylinder) is formed by the single sequence valves 100 and 200. The flow of hydraulic oil supplied to and discharged from the end cylinder 210) can be controlled.

  The embodiment of the present invention has been described above. However, the above embodiment only shows a part of application examples of the present invention, and the technical scope of the present invention is limited to the specific configuration of the above embodiment. Absent.

  In the above embodiment, the sequence valves 100 and 200 include the check mechanism 70 provided in the valve body 1. Instead of this, the check mechanism 70 may not be provided in the valve body 1 but a check valve may be provided independently. In this case, the shut-off portion 23 of the spools 20 and 120 is provided so as to be separable from the seat portion 14, and the switching valve for switching the communication between the first port 1A, 101A and the second port 1B, 101B and the shut-off is switched. A sequence valve is constituted by a check valve provided in parallel with the valve.

  In the above embodiment, the crane drive unit 300 sequentially expands and contracts two hydraulic cylinders (the base end side cylinder 210 and the front end side cylinder 220). Instead, the crane drive unit 300 may have three or more fluid pressure cylinders. Hereinafter, the case where the crane drive unit 300 has the base end side cylinder 210, the front end side cylinder 220, and the most advanced cylinder (not shown) as three fluid pressure cylinders will be described. In this case, in addition to the same configuration as that of the above embodiment, the crane drive unit 300 is operated in accordance with the expansion and contraction operation of the front end side cylinder 220 and controls the flow of hydraulic oil supplied to and discharged from the front end side cylinder. And a sequence valve that controls the flow of hydraulic oil that operates in accordance with the expansion and contraction operation of the front-end cylinder and is supplied to and discharged from the front-end cylinder 220. According to this, the three fluid pressure cylinders of the base end side cylinder 210, the front end side cylinder 220, and the most advanced cylinder are sequentially expanded and contracted. As described above, the crane drive unit 300 includes three or more fluid pressure cylinders, and is operated in accordance with the operation of one of the three or more fluid pressure cylinders, and another one fluid pressure cylinder. By providing a sequence valve for controlling the flow of hydraulic oil supplied and discharged according to the number of hydraulic cylinders, three or more hydraulic cylinders may be sequentially expanded and contracted.

  DESCRIPTION OF SYMBOLS 100,200 ... Sequence valve (control valve), 1 ... Valve body, 1A, 101A ... 1st port, 1B, 101B ... 2nd port, 5 ... Cap (bottom part), 20, 120 ... Spool (valve body), 21 DESCRIPTION OF SYMBOLS ... Entry part, 22 ... Base end part, 30 ... Support member, 40 ... Coil spring (biasing member), 50 ... Back pressure chamber, 60 ... Introduction passage, 70 ... Check mechanism, 210 ... Base end side cylinder (1st) Fluid pressure cylinder, second fluid pressure cylinder), 214 ... rod side chamber (fluid pressure chamber), 220 ... tip side cylinder (first fluid pressure cylinder, second fluid pressure cylinder), 225 ... bottom side chamber (fluid pressure chamber)

Claims (4)

A control valve that controls the flow of working fluid supplied to and discharged from a second fluid pressure cylinder that is different from the first fluid pressure cylinder and that operates in accordance with the expansion and contraction operation of the first fluid pressure cylinder;
A valve body having a bottom,
A valve body that is movably provided in the valve body and allows a flow of the working fluid supplied to and discharged from the second fluid pressure cylinder as the first fluid pressure cylinder expands and contracts;
An urging member that urges the valve body in a direction to block the flow of the working fluid supplied to and discharged from the second fluid pressure cylinder;
A support member that slidably supports the valve body,
The control valve, wherein the support member is urged toward the bottom portion of the valve body by the urging member and is accommodated in the valve body. The valve body is
An entry portion provided in a fluid pressure chamber of the first fluid pressure cylinder so as to be capable of advancing and retreating;
A base end portion slidably supported by the support member and defining a back pressure chamber with the bottom of the valve body;
An introduction passage for guiding the working fluid in the fluid pressure chamber to the back pressure chamber,
The pressure receiving area of the valve body that receives the pressure of the working fluid in the back pressure chamber acting in the same direction as the biasing force of the biasing member acts on the valve body against the biasing force of the biasing member. The control valve according to claim 1, wherein the control valve is formed larger than a pressure receiving area of the valve body that receives the pressure of the working fluid in the fluid pressure chamber.   The control valve according to claim 2, wherein the support member is provided in the valve body so as to be movable in a direction in which the biasing member is compressed in response to the pressure of the working fluid in the back pressure chamber. The valve body has a first port and a second port through which a working fluid supplied to and discharged from the second fluid pressure cylinder passes.
The biasing member biases the valve body in a direction that blocks communication between the first port and the second port;
The valve body allows the flow of the working fluid from the first port toward the second port in accordance with the expansion and contraction operation of the first fluid pressure cylinder,
The control valve is provided in the valve body and allows the flow of the working fluid from the first port toward the second port, and blocks the flow of the working fluid from the second port toward the first port. The control valve according to claim 1, further comprising a check mechanism.

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