WO2018020642A1 - Flow control valve - Google Patents

Flow control valve Download PDF

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Publication number
WO2018020642A1
WO2018020642A1 PCT/JP2016/072190 JP2016072190W WO2018020642A1 WO 2018020642 A1 WO2018020642 A1 WO 2018020642A1 JP 2016072190 W JP2016072190 W JP 2016072190W WO 2018020642 A1 WO2018020642 A1 WO 2018020642A1
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WO
WIPO (PCT)
Prior art keywords
spool
port
spring
neutral position
control valve
Prior art date
Application number
PCT/JP2016/072190
Other languages
French (fr)
Japanese (ja)
Inventor
経博 竹内
Original Assignee
住友精密工業株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 住友精密工業株式会社 filed Critical 住友精密工業株式会社
Priority to PCT/JP2016/072190 priority Critical patent/WO2018020642A1/en
Priority to JP2016567886A priority patent/JP6067953B1/en
Publication of WO2018020642A1 publication Critical patent/WO2018020642A1/en

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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16K—VALVES; TAPS; COCKS; ACTUATING-FLOATS; DEVICES FOR VENTING OR AERATING
    • F16K3/00—Gate valves or sliding valves, i.e. cut-off apparatus with closing members having a sliding movement along the seat for opening and closing
    • F16K3/22—Gate valves or sliding valves, i.e. cut-off apparatus with closing members having a sliding movement along the seat for opening and closing with sealing faces shaped as surfaces of solids of revolution
    • F16K3/24—Gate valves or sliding valves, i.e. cut-off apparatus with closing members having a sliding movement along the seat for opening and closing with sealing faces shaped as surfaces of solids of revolution with cylindrical valve members
    • F16K3/26—Gate valves or sliding valves, i.e. cut-off apparatus with closing members having a sliding movement along the seat for opening and closing with sealing faces shaped as surfaces of solids of revolution with cylindrical valve members with fluid passages in the valve member
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16K—VALVES; TAPS; COCKS; ACTUATING-FLOATS; DEVICES FOR VENTING OR AERATING
    • F16K11/00—Multiple-way valves, e.g. mixing valves; Pipe fittings incorporating such valves
    • F16K11/02—Multiple-way valves, e.g. mixing valves; Pipe fittings incorporating such valves with all movable sealing faces moving as one unit
    • F16K11/06—Multiple-way valves, e.g. mixing valves; Pipe fittings incorporating such valves with all movable sealing faces moving as one unit comprising only sliding valves, i.e. sliding closure elements
    • F16K11/065—Multiple-way valves, e.g. mixing valves; Pipe fittings incorporating such valves with all movable sealing faces moving as one unit comprising only sliding valves, i.e. sliding closure elements with linearly sliding closure members
    • F16K11/07—Multiple-way valves, e.g. mixing valves; Pipe fittings incorporating such valves with all movable sealing faces moving as one unit comprising only sliding valves, i.e. sliding closure elements with linearly sliding closure members with cylindrical slides

Definitions

  • the present invention relates to a flow rate control valve, and more particularly to a flow rate control valve that controls the flow rate by opening and closing an oil passage by moving a spool in the body.
  • a flow rate control valve that opens and closes an oil passage by moving a spool in the body to control the flow rate.
  • Such a flow control valve is disclosed in, for example, Japanese Patent Application Laid-Open No. 11-280705.
  • JP-A-11-280705 discloses a flow control valve having a body provided with an oil passage through which hydraulic oil enters and exits and a spool that moves within the body to open and close the oil passage.
  • the oil passage is closed by the seal portion where the outer peripheral surface of the spool and the valve seat portion which is the inner peripheral surface of the body face each other.
  • a gap (opening) is formed between the spool and the valve seat portion, and the oil passage is opened.
  • the flow control valve disclosed in Japanese Patent Application Laid-Open No. 11-280705 is a proportional control valve that outputs hydraulic oil at a flow rate proportional to the amount of movement of the spool by expanding a gap (opening) according to the amount of movement of the spool. .
  • the length of the seal portion between the outer peripheral surface of the spool and the valve seat in the neutral position is such that the flow control is started after the spool starts to move. This corresponds to the dead zone until (until a gap is formed).
  • the flow control valve is formed so that the length of the seal portion is as small as possible.
  • the present invention has been made to solve the above-described problems, and an object of the present invention is a spool system capable of suppressing leakage of hydraulic oil to an oil passage without impairing responsiveness. Is to provide a flow control valve.
  • a flow control valve includes a body provided with an oil passage through which hydraulic oil enters and exits, and a spool that is movably held in the body and opens and closes the oil passage.
  • the body is provided on the inner peripheral surface of the body, and when the spool is in the neutral position and the standby position, a valve seat portion that blocks the oil passage by the outer peripheral surface of the spool, and an attachment for holding the spool in the neutral position.
  • an actuating force for moving the spool is supplied in a magnitude between a first threshold that is an upper limit for holding the spool in a neutral position and a second threshold that is greater than the first threshold.
  • the spool moves from the neutral position to the standby position against the urging force of the urging means, and an operating force larger than the second threshold is supplied, so that the spool resists the urging force of the urging means.
  • Samba From the position, and is configured to move the control area to change the valve opening in accordance with the movement amount of the spool.
  • the valve seat portion that blocks the oil passage with the outer peripheral surface of the spool is provided on the inner peripheral surface of the body.
  • the valve seat portion can be provided over a range between the neutral position of the spool and the standby position, so that the length of the seal portion between the spool and the valve seat portion in the neutral position can be sufficiently secured.
  • the leakage of hydraulic oil to the oil passage can be suppressed.
  • the operating force for moving the spool is supplied in a magnitude between the first threshold value that is the upper limit for holding the spool in the neutral position and the second threshold value that is larger than the first threshold value.
  • the spool moves from the neutral position to the standby position against the urging force of the urging means, and an operating force larger than the second threshold is supplied, so that the spool resists the urging force of the urging means.
  • the flow rate control valve is configured to move from the standby position to a control region in which the valve opening is changed according to the amount of movement of the spool.
  • the spool can quickly move to the standby position and start flow rate control.
  • the flow rate control can be started immediately from the time when the operating force exceeds the second threshold.
  • the biasing means generates a biasing force equal to the first threshold value when the spool is in the neutral position, and applies a pressure equal to the second threshold value when the spool is in the standby position. It is configured to generate power. If comprised in this way, a spool can be hold
  • the urging means further includes a first spring that is compressed to the spool at least between the neutral position and the standby position, and a second spring that is compressed to the spool in the control region.
  • a first spring that is compressed to the spool at least between the neutral position and the standby position
  • a second spring that is compressed to the spool in the control region.
  • the spring constant of the first spring is preferably smaller than the spring constant of the second spring.
  • the body preferably has a first stopper that restricts movement of the spool in the neutral position and a second stopper that restricts movement of the spool in the standby position.
  • the first spring biases the first stopper against the body with an initial biasing force equal to the first threshold
  • the second spring biases the second stopper against the body with an initial biasing force equal to the second threshold. Is energized against. If comprised in this way, a spool can be hold
  • the spool does not move even if a force below the first threshold is applied to the spool due to disturbance or the like, so the spool can be stably brought to the neutral position. Can be held.
  • the second threshold value can be set by the second spring independently of the first spring. Therefore, compared with the case where the second threshold value is set by the combined spring of the first spring and the second spring, the second threshold value can be easily set and the operating force required to operate the spool in the control region is large. It can be suppressed.
  • the oil passage includes a supply port to which the hydraulic oil is supplied, a discharge port from which the hydraulic oil is discharged, and a first port that allows the hydraulic oil to flow in or out alternately.
  • the second port, and in the neutral position, the spool is provided so as to communicate with the discharge port from the outer peripheral surface of the spool through the inside of the spool, and allows the hydraulic oil to pass between the valve seat portion and the spool.
  • a passage portion for discharging is provided, and the passage portion is disposed at a position facing at least the first valve seat portion between the first port and the supply port in the neutral position of the spool.
  • the passage portion only needs to be disposed at least in the first valve seat portion between the first port and the supply port, and not only the first valve seat portion but also the second port and the supply port.
  • a passage portion may be further arranged in the valve seat portion between the two.
  • the passage portion is disposed at a position closer to the other end portion of the first valve seat portion on the first port side than the one end portion of the first valve seat portion on the supply port side in the neutral position of the spool.
  • path part is arrange
  • the passage portion In the configuration in which the passage portion is disposed at a position close to the other end portion on the first port side of the first valve seat portion in the neutral position of the spool, preferably, the passage portion has the spool from the neutral position to the first port.
  • the first valve passes through the first port and moves to a position facing the second valve seat between the first port and the discharge port. If comprised in this way, a channel
  • the passage portion is always the valve seat portion (the first valve seat portion and the second valve portion at the neutral position and the standby position) without making the first valve seat portion longer than necessary. It is possible to prevent the first seat from communicating with the first port.
  • the length between the passage portion in the neutral position of the spool and the one end portion of the first valve seat portion is movable from the neutral position to the second port side. More than the distance.
  • the passage portion preferably has an inner diameter smaller than the inner diameter of the supply port.
  • the flow control valve 100 is a hydraulic valve that controls the supply of hydraulic oil to a hydraulic machine such as a hydraulic actuator.
  • the flow control valve 100 of the first embodiment is configured as a proportional flow control valve of a spool type (slide spool type).
  • the proportional flow rate control valve is a control valve configured so that the flow rate of the output hydraulic oil is proportional to the spool position (stroke amount).
  • the flow control valve 100 is required to maintain a control position in a neutral state (neutral position of the spool), such as an elevating hydraulic cylinder (lift cylinder) that moves up and down along the gravity action direction (vertical direction). It is suitably used for controlling the flow rate of hydraulic oil to a hydraulic machine.
  • a neutral state neutral position of the spool
  • elevating hydraulic cylinder lift cylinder
  • gravity action direction vertical direction
  • the flow control valve 100 is connected to a lifting hydraulic cylinder (lift cylinder) of a forklift and the flow control valve 100 is used for supply control of hydraulic oil for raising and lowering the cylinder.
  • the flow control valve 100 is connected to a hydraulic cylinder 101, a hydraulic pump 102, and an oil tank 103, respectively.
  • the flow control valve 100 includes four oil passages: a first port A, a second port B, a supply port P, and a discharge port T.
  • the hydraulic cylinder 101 has a structure in which a piston 111 and a rod 112 connected to the piston 111 are slidably provided in the tube 113.
  • the hydraulic cylinder 101 is, for example, a single rod cylinder, and the rod 112 protrudes from one end side of the tube 113 to the outside.
  • the inside of the tube 113 is partitioned by a piston 111 into a rod side oil chamber 114 and a head side oil chamber 115.
  • the first port A of the flow control valve 100 is connected to the head side oil chamber 115 via the check valve 104.
  • a second port B of the flow control valve 100 is connected to the rod side oil chamber 114.
  • the first port A may be connected to the rod side oil chamber 114 and the second port B may be connected to the head side oil chamber 115.
  • the check valve 104 allows the hydraulic oil to flow from the first port A toward the head-side oil chamber 115 and prevents the hydraulic oil from flowing from the head-side oil chamber 115 toward the first port A.
  • the check valve 104 is a pilot check valve, and the pilot port is connected to the flow path between the rod side oil chamber 114 and the second port B.
  • the check valve 104 operates in the direction from the head-side oil chamber 115 toward the first port A. Allow distribution.
  • the supply port P of the flow control valve 100 is connected to the discharge side of the hydraulic pump 102.
  • the hydraulic pump 102 is driven by a pump motor 121 and supplies the hydraulic oil in the oil tank 103 on the suction side to the flow control valve 100 with a predetermined pressure.
  • a discharge port T of the flow control valve 100 is connected to the oil tank 103.
  • the order of supply port P> first port A and second port B >> discharge port T is obtained.
  • the pressure relationship between the first port A and the second port B may be such that the first port A> the second port B or the first port A> the second port B.
  • the pressure of the supply port P on which the discharge pressure of the hydraulic pump 102 acts is the highest, and the pressure of the discharge port T released in the oil tank 103 is the lowest.
  • the flow control valve 100 performs flow path switching and flow control by the operating force supplied from the external operating force supply means 105. That is, the flow control valve 100 connects the supply port P and the first port A to the neutral state in which both the first port A and the second port B are blocked with respect to the supply port P, and the second port B. Functions as a directional control valve capable of switching between a PA control state in which the discharge port T is connected and a PB control state in which the supply port P and the second port B are connected and the first port A and the discharge port T are connected To do.
  • the flow control valve 100 In the neutral state, all of the supply port P, the first port A, and the second port B are blocked by the flow control valve 100. That is, the flow control valve 100 is configured to be fully closed in a neutral state. In the neutral state, since the hydraulic oil in the hydraulic cylinder 101 does not flow, the position of the rod 112 is maintained.
  • the flow rate control valve 100 controls the flow rate of the hydraulic oil from the port according to the position (stroke amount) of the spool 2 (see FIG. 2) moved by the operating force. Is done.
  • the position of the spool 2 corresponds to the magnitude of the operating force supplied from the operating force supply means 105.
  • the operating force supply means 105 supplies an operating force to the flow control valve 100 in accordance with a control signal from the controller 106.
  • the operating force supply means 105 is not particularly limited as long as it can apply an operating force to the spool.
  • the operating force supply means 105 for example, a method of supplying an operating force by electromagnetic force such as a solenoid method, a method of supplying an operating force by hydraulic pressure using a hydraulic pilot valve, or the like can be adopted.
  • the hydraulic pressure of the hydraulic pump 102 is supplied to the pilot port 15 of the flow control valve 100 via the operating force supply means 105 including a hydraulic pilot valve, so that the operating force is supplied.
  • the flow control valve 100 includes a body 1 provided with an oil passage through which hydraulic oil enters and exits, and a spool 2 that is movably held in the body 1 and opens and closes the oil passage.
  • the oil passage includes the supply port P to which the hydraulic oil is supplied, the discharge port T from which the hydraulic oil is discharged, and the first port A and the second port that allow the hydraulic oil to flow in or out alternately.
  • the body 1 has a spool chamber 11 in which the spool 2 is disposed, and a pair of pilot chambers 12 disposed on both sides of the spool chamber 11.
  • the spool chamber 11 is a linear cylindrical internal space, and the spool 2 is slidably disposed along the axial direction (X direction).
  • Each pilot chamber 12 is arranged on both sides of the spool chamber 11 in the axial direction of the spool 2.
  • the oil passages of the supply port P, the discharge port T, the first port A and the second port B pass through the body 1 from the outer periphery of the body 1 and communicate with the spool chamber 11.
  • the supply port P is disposed at the center of the spool chamber 11, and the first port A and the second port B are disposed on both sides of the supply port P, respectively.
  • the discharge port T is disposed outside the first port A and the second port B, respectively.
  • a valve seat portion 13 formed of the inner peripheral surface of the spool chamber 11 (body 1) is provided.
  • the valve seat portion 13 is oiled by an outer peripheral surface (sliding surface) 21 of the spool 2. It is configured to block the road. That is, the valve seat portion 13 blocks the oil passages by facing the outer peripheral surface 21 of the spool 2 with a very small interval for the spool 2 to slide.
  • the valve seat 13 is supplied with the first valve seat 13a between the first port A and the supply port P, the second valve seat 13b between the first port A and the discharge port T, and the second port B.
  • a third valve seat 13c between the port P and a fourth valve seat 13d between the second port B and the discharge port T are included.
  • the length of the facing portion (seal portion 14) between the outer peripheral surface 21 of the spool 2 and the valve seat portion 13 at the neutral position S0 is longer than that of a general proportional flow control valve.
  • the lengths of the facing portions (seal portions 14) of the first valve seat portion 13a, the second valve seat portion 13b, the third valve seat portion 13c, and the fourth valve seat portion 13d in the neutral position S0 are as follows. , L1, L2, L3 and L4.
  • the lengths L1 to L4 of each facing portion are larger than the inner diameter d1 (see FIG. 8) of each port.
  • the pilot chambers 12 on both sides in the axial direction are provided with pilot ports 15 for connection to the operating force supply means 105, respectively.
  • the pilot hydraulic pressure from the operating force supply means 105 is input to the pilot chamber 12 and acts as an operating force that moves the spool 2 in the spool chamber 11 in the axial direction (X direction).
  • the spool 2 is a roughly cylindrical shaft member.
  • the spool 2 is provided with an outer peripheral surface 21 that is a sliding surface and a groove portion 22 for switching between the oil passages to a communication state.
  • the groove portion 22 is formed with a predetermined depth over the entire circumference in the circumferential direction of the spool 2, and is disposed corresponding to the position of the supply port P and each discharge port T at the neutral position S0.
  • the groove portion 22 constitutes an oil passage that allows the first port A or the second port B to communicate with the supply port P or the discharge port T as the spool 2 moves.
  • the two outer peripheral surfaces 21 between the groove portions 22 are formed so as to block the first port A and the second port B at the neutral position S0, respectively.
  • the outer peripheral surfaces 21 at both ends of the spool 2 are provided so as to close the space between the pilot chamber 12 and the spool chamber 11.
  • the notch part 23 is provided in the boundary part (step part) of the three groove parts 22 and the two outer peripheral surfaces 21 between them.
  • a plurality of notches 23 are provided at equal angular intervals in the circumferential direction of the spool 2.
  • each notch 23 has a semicircular shape whose width (width in the circumferential direction) increases as it approaches the groove 22 side.
  • the shape of the notch part 23 is not restricted to what was shown in FIG. 3, It is arbitrary.
  • the notch 23 makes the flow rate of the hydraulic oil proportional to the amount of movement of the spool 2 when the first port A or the second port B communicates with the supply port P or the discharge port T as the spool 2 moves in the axial direction. It has a function.
  • a bypass passage 24 is formed inside the spool 2.
  • the bypass passage 24 is provided so as to connect the groove portions 22 on both sides in the axial direction (X direction).
  • the bypass passage 24 opens in the surface of the spool 2 (the bottom of the groove 22) at a position that coincides with each discharge port T at the neutral position S0 in the X direction.
  • the body 1 includes urging means 30 for holding the spool 2 in the neutral position S0.
  • the urging means 30 holds the spool 2 in the neutral position S0 by the urging force.
  • the flow control valve 100 is maintained in the neutral state (fully closed state) when the operating force is not supplied.
  • the urging means 30 associates the operating force supplied from the operating force supply means 105 with the movement amount of the spool 2 by the urging force.
  • the spool 2 enters a control region S2 (see FIGS. 5 and 7) in which the notch portion 23 and the groove portion 22 are communicated with each other so as to straddle the ports. To reach.
  • the notch 23 changes the opening area (flow channel cross-sectional area) between each port and the groove 22 according to the amount of overlap with each port in the axial direction (X direction).
  • the flow area of the hydraulic oil is proportional to the amount of movement of the spool 2 by increasing the opening area between the notch 23 (groove portion 22) and the port as the amount of movement of the spool 2 increases.
  • the urging means 30 is configured to hold the spool 2 in the standby position S1 (see FIGS. 4 and 6) by the urging force. That is, the flow control valve 100 is provided with a state in which the spool 2 is held at the standby position S1 in addition to a state in which the spool 2 is held at the neutral position S0 and a state in which the spool 2 moves in the control region S2.
  • the flow control valve 100 has a first threshold value TH1 that is an upper limit for holding the spool 2 at the neutral position S0 and a second threshold value TH2 that is larger than the first threshold value TH1.
  • the spool 2 is configured to move from the neutral position S0 to the standby position S1 against the urging force of the urging means 30.
  • the flow rate control valve 100 is supplied with an operating force larger than the second threshold value TH2, so that the spool 2 resists the urging force of the urging means 30 from the standby position S1 to the moving amount of the spool 2. Accordingly, the valve travels to the control region S2 in which the valve opening is changed.
  • the standby position S1 is a position between the neutral position S0 and the control area S2, and is a position immediately before the control by the control area S2 is started. That is, the standby position S1 is a boundary position of the control region S2 where the length of the seal portion 14 between the ports by the outer peripheral surface 21 of the spool 2 and the valve seat portion 13 is minimized. It is set for each port B side. For example, as shown in FIGS. 4 and 5, when the spool 2 moves even slightly from the standby position S1 on the first port A side to the first port A side, the spool 2 enters the control area S2 on the first port A side. Thus, the first port A and the supply port P communicate with each other.
  • the biasing means 30 generates a biasing force equal to the first threshold TH1 when the spool 2 is in the neutral position S0, and the second threshold TH2 when the spool 2 is in the standby position S1. It is comprised so that equal urging
  • the biasing means 30 is compressed to the spool 2 in the control region S2 and the first spring 31 compressed to the spool 2 at least between the neutral position S0 and the standby position S1.
  • the first spring 31 and the second spring 32 are respectively disposed in the pair of pilot chambers 12.
  • the first spring 31 and the second spring 32 are both compression coil springs, and are arranged so as to generate an initial urging force at the neutral position S0 by being arranged in a predetermined compression state.
  • the body 1 further includes a first stopper 33 that restricts the movement of the spool 2 at the neutral position S0 and a second stopper 34 that restricts the movement of the spool 2 at the standby position S1.
  • the first spring 31 biases the first stopper 33 against the body 1 with an initial biasing force equal to the first threshold TH1
  • the second spring 32 biases the second stopper 34 with an initial biasing force equal to the second threshold TH2. Is urged against the body 1.
  • the first stopper 33 and the second stopper 34 are respectively disposed in the pair of pilot chambers 12. These springs and stoppers are arranged side by side in the order of the first stopper 33, the first spring 31, the second stopper 34, and the second spring 32 from the center side where the spool 2 is disposed to the outside.
  • the pilot chamber 12 is provided with a first positioning portion 16 corresponding to the neutral position S0 and a second positioning portion 17 corresponding to the standby position S1.
  • the first positioning portion 16 and the second positioning portion 17 are stepped portions provided so as to reduce the inner diameter of the pilot chamber 12.
  • the first stopper 33 is urged toward the spool 2 by the first spring 31 and is pressed against the first positioning portion 16 which is a part of the body 1.
  • the first stopper 33 is disposed by the first positioning portion 16 at a position substantially equal to the axial end surface of the spool 2 at the neutral position S0.
  • the spool 2 is held at the neutral position S0.
  • the first spring 31 When applied, the first spring 31 is compressed together with the first stopper 33. Conversely, even if a force equal to or less than the first threshold value TH1 acts on the spool 2 due to disturbance or the like, the first stopper 33 does not move. Since the first stopper 33 is pressed by the first positioning portion 16, no pressing force acts on the spool 2 at the neutral position S0.
  • the first stopper 33 functions as a wall surface that moves only when an operating force larger than the first threshold value TH1 is applied to the spool 2.
  • the first spring 31 is held in a state where one end side is in contact with the first stopper 33 and the other end side is in contact with the second stopper 34.
  • the other end side of the first spring 31 is supported by the second spring 32 via the second stopper 34.
  • the second stopper 34 is urged toward the spool 2 by the second spring 32 and is pressed against the second positioning portion 17 which is a part of the body 1.
  • the second stopper 34 is disposed by the second positioning portion 17 so as to hold the spool 2 at the standby position S1. That is, when the spool 2 moves and compresses the first spring 31, the first stopper 33 and the second stopper 34 come into contact with each other, so that the movement of the spool 2 is restricted (see FIGS. 4 and 6). ).
  • the second spring 32 is held in a state where one end is in contact with the second stopper 34 and the other end is in contact with the inner surface of the body 1. As shown in FIGS. 5 and 7, when an operating force larger than the second threshold value TH2 is applied to the spool 2, the spool 2, the first stopper 33, and the second stopper 34 come into contact with each other, and the second The control region S2 for compressing the spring 32 is reached. In the control region S2, the amount of compression of the second spring 32 (that is, the amount of movement of the spool 2) is proportional to the operating force that is greater than the second threshold value TH2.
  • the first spring 31 and the second spring 32 are configured to be compressed by the spool 2 independently of each other. That is, only the urging force of the first spring 31 acts on the spool 2 as a reaction force between the neutral position S0 and the standby position S1, and only the urging force of the second spring 32 acts on the spool 2 as a reaction force in the control region S2. Therefore, the urging force of each spring acts separately.
  • the spring constant K1 of the first spring 31 is smaller than the spring constant K2 of the second spring 32.
  • the first spring 31 is configured such that the generated urging force is less than the second threshold value TH2 even when it is compressed to the maximum extent (see FIGS. 4 to 7).
  • Each of the first stopper 33 and the second stopper 34 is provided with a through hole 35 for allowing hydraulic oil to pass therethrough. For this reason, when hydraulic fluid is supplied to the pilot chamber 12 in order to apply the operational force, the hydraulic fluid acts on the spool 2 through the through hole 35.
  • the operating force F can be increased immediately (in a step function) to a predetermined first operating force F1 (see FIG. 10).
  • the first operating force F1 is preferably set to a magnitude as close as possible to the second threshold TH2 between the first threshold TH1 and the second threshold TH2.
  • the spool 2 compresses the first spring 31 and quickly moves from the neutral position S0 to the standby position S1.
  • the movement of the spool 2 is stopped by the second stopper 34 and the second spring 32 at the standby position S1.
  • the second port B and the discharge port T communicate with each other via the notch portion 23, the groove portion 22 and the bypass passage 24 of the spool 2, and the hydraulic oil (return oil) flowing into the second port B from the hydraulic cylinder 101. Is discharged from the discharge port T.
  • the spool 2 has a passage portion 25 for discharging hydraulic oil that passes between the valve seat portion 13 and the spool 2.
  • the passage portion 25 discharges hydraulic fluid that leaks through a minute gap between the valve seat portion 13 and the outer peripheral surface 21 of the spool 2, so that the hydraulic fluid between the ports in the neutral position S ⁇ b> 0 (fully closed state). Has a function of preventing leakage.
  • the passage portion 25 is disposed at a position facing at least the first valve seat portion 13a between the first port A and the supply port P in the neutral position S0 of the spool 2.
  • a passage portion 26 is provided.
  • the passage portion 25 (passage portion 26) is provided so as to communicate with the discharge port T from the outer peripheral surface 21 of the spool 2 through the inside of the spool 2 at the neutral position S0.
  • the passage portion 25 (passage portion 26) is formed so as to open to the outer peripheral surface 21 between the adjacent groove portions 22, and penetrates through the spool 2 and is connected to the bypass passage 24. Accordingly, the passage portion 25 (passage portion 26) communicates with the discharge port T through a route that is partially in common with the bypass passage 24.
  • the passage portion 25 is a fine hole having an inner diameter d2 smaller than the inner diameter d1 of the supply port P.
  • the passage portion 25 (passage portion 26) discharges a very small amount of hydraulic oil that leaks through the passage between the valve seat portion 13 and the outer peripheral surface 21 of the spool 2 to the discharge port T.
  • a fine annular groove (not shown) is provided on the outer peripheral surface 21 of the spool 2 to reduce sliding resistance, and the passage portion 25 (passage portion 26) is formed at the bottom of the annular groove. Is open.
  • the passage portion 25 is positioned closer to the other end portion on the first port A side of the first valve seat portion 13a than one end portion on the supply port P side of the first valve seat portion 13a. Has been placed.
  • the passage portion 26 is located closer to the other end portion on the second port B side of the third valve seat portion 13c than to one end portion on the supply port P side of the third valve seat portion 13c. It is arranged at a close position. For this reason, the hydraulic oil that leaks into the gap from the high-pressure supply port P is discharged to the discharge port T only after reaching the vicinity of the first port A (second port B).
  • the length L11 between the passage portion 25 and the one end portion of the first valve seat portion 13a at the neutral position S0 of the spool 2 is the spool from the neutral position S0 to the second port B side. It is 2 or more movable distance L21.
  • a length L12 between the passage portion 26 and the one end portion of the third valve seat portion 13c at the neutral position S0 of the spool 2 is a movable distance L22 of the spool 2 from the neutral position S0 to the second port B side. That's it.
  • the lengths L11 and L12 are equal, and the distances L21 and L22 are equal.
  • the distance L21 (L22) is approximately equal to the sum of the distance D1 between the first stopper 33 and the second stopper 34 at the neutral position S0 and the distance D2 between the second stopper 34 and the inner surface of the body 1.
  • the passage portion 25 is blocked by the second valve seat portion 13b, and the passage portion 26 is supplied by the third valve seat portion 13c. Maintain a closed state without communication with P.
  • the passage portion 25 is kept closed by the first valve seat portion 13a so as not to communicate with the supply port P. The state closed by the fourth valve seat portion 13d is maintained.
  • the valve seat portion 13 that blocks the oil passage with the outer peripheral surface 21 of the spool 2 is provided.
  • the valve seat portion 13 can be provided over a range between the neutral position S0 and the standby position S1, and therefore the length (L1 to L4) of the seal portion 14 between the spool 2 and the valve seat portion 13 in the neutral position S0. ) Can be secured sufficiently. As a result, the leakage of hydraulic oil to the oil passage can be suppressed.
  • the operating force F that moves the spool 2 is between the first threshold TH1 that is the upper limit for holding the spool 2 in the neutral position S0 and the second threshold TH2 that is greater than the first threshold TH1.
  • the flow rate control valve 100 is configured so that the spool 2 moves from the standby position S1 to the control region S2 in which the valve opening is changed according to the amount of movement of the spool 2 against the urging force of the urging means 30. .
  • the flow rate control when the flow rate control is performed, if the operating force (first operating force F1) having a magnitude between the first threshold value TH1 and the second threshold value TH2 is supplied in advance, the spool 2 quickly moves to the standby position S1.
  • the flow rate control can be started, and the flow rate control can be started immediately from the time when the operating force F exceeds the second threshold value TH2. That is, since the responsiveness can be improved by moving the spool 2 from the neutral position S0 to the standby position S1 immediately before the flow rate control, the valve seat portion 13 is lengthened and the length of the seal portion 14 ( Even when L1 to L4) are sufficiently secured, high responsiveness can be secured.
  • the flow control device 100 of the first embodiment it is possible to suppress leakage of hydraulic oil to the oil passage without impairing responsiveness.
  • the length of the seal portion is made as small as possible in order to reduce the dead zone (the region where flow control does not start even when the spool is moved) to ensure proportional control responsiveness. For this reason, it is not possible to suppress leakage through a minute gap for sliding the spool, and the sealing performance between the ports in the neutral position is not high.
  • the comparative example of FIG. 10 there is a constant leak flow rate from the supply port P to the first port A or the second port B in the neutral position, although the responsiveness from the flow control start time t2 is ensured. Will continue to do.
  • the lengths L1 to L4 of the seal portion 14 are sufficiently secured. For this reason, the sealing performance between the ports at the neutral position S0 is improved, and a leak flow rate is not substantially generated at the neutral position S0.
  • the dead zone usually increases by the lengths L1 to L4.
  • the seal portion 14 The spool 2 can be moved to the standby position S1 where is as small as possible. In the standby position S1, since the seal portion 14 is small, a leak (so-called pre-leakage) may occur between the supply port P and the first port A or the second port B depending on the moving direction.
  • the movement to the standby position S1 can be completed in a very short time by setting the first operating force F1 in the vicinity of the second threshold value TH2 (the time interval between the times t1 and t2 is reduced). Therefore, the time (leakage flow rate) during which leakage occurs at the standby position S1 can be minimized.
  • the same responsiveness as that of the proportional flow control valve of the comparative example can be ensured.
  • the biasing means 30 when the spool 2 is in the neutral position S0, the biasing means 30 generates a biasing force equal to the first threshold value TH1, and the spool 2 is in the standby position S1. In addition, an urging force equal to the second threshold value TH2 is generated. Accordingly, the spool 2 can be held at the standby position S1 by using the biasing means 30 for holding the spool 2 at the neutral position S0. As a result, it is possible to easily realize the configuration in which the spool 2 is moved stepwise to the neutral position S0, the standby position S1, and the control region S2 by the biasing means 30.
  • the urging means 30 includes at least the first spring 31 compressed by the spool 2 between the neutral position S0 and the standby position S1, and the spool 2 in the control region S2.
  • an initial biasing force equal to the first threshold value TH1 is generated in the first spring 31
  • an initial biasing force equal to the second threshold value TH2 is generated in the second spring 32.
  • Each spring constant can be determined freely. Therefore, it is possible to more easily configure the urging means 30 that generates the urging force equal to the first threshold value TH1 at the neutral position S0 and generates the urging force equal to the second threshold value TH2 at the standby position S1.
  • the spring constant K1 of the first spring 31 is set smaller than the spring constant K2 of the second spring 32 as described above.
  • the magnitude of the operating force required to compress the first spring 31 from the first threshold TH1 to the standby position S1 (K1 ⁇ travel distance) can be reduced.
  • the difference between the operating force (TH1 + K1 ⁇ movement distance) required to move the spool 2 to the standby position S1 and the second threshold value TH2 can be increased, so that the spool 2 is moved to the standby position S1. Can be done quickly.
  • the first stopper 33 for restricting the movement of the spool 2 at the neutral position S0 and the second stopper 34 for restricting the movement of the spool 2 at the standby position S1 are provided on the body 1.
  • the first spring 31 biases the first stopper 33 against the body 1 with an initial biasing force equal to the first threshold value TH1
  • the second spring 32 biases the second stopper 34 with an initial biasing force equal to the second threshold value TH2. Is urged against the body 1.
  • the spool 2 since the spool 2 does not move even if a force of the first threshold value TH1 or less is applied to the spool 2 due to disturbance or the like, the spool 2 can be stably held at the neutral position S0. Further, by providing the second stopper 34, the second threshold value TH 2 can be set by the second spring 32 independently of the first spring 31. Therefore, compared with the case where the second threshold value TH2 is set by the combined spring of the first spring 31 and the second spring 32, the second threshold value TH2 can be set easily, and the spool 2 is operated in the control region S2. It is possible to suppress an increase in necessary operating force.
  • the spool 2 is provided with the passage portion 25 that communicates from the outer peripheral surface 21 of the spool 2 through the inside of the spool 2 to the discharge port T. Is disposed at a position facing at least the first valve seat 13a between the first port A and the supply port P in the neutral position S0 of the spool 2.
  • a slight leakage of hydraulic oil between the spool 2 and the first valve seat portion 13 a can be sent out to the discharge port T by the passage portion 25.
  • the flow rate control valve 100 is used for raising / lowering control of the hydraulic cylinder 101 or the like, it is possible to prevent leakage of hydraulic oil at the neutral position S0 and to prevent displacement.
  • the passage portion 26 is provided not only in the first valve seat portion 13a but also in the valve seat portion 13 between the second port B and the supply port P, the first port A and It is possible to prevent the hydraulic oil from leaking to both of the second ports B.
  • the passage portion 25 is arranged at the neutral position S0 of the spool 2 at the neutral position S0 of the first valve seat portion 13a rather than the one end portion on the supply port P side of the first valve seat portion 13a. It arrange
  • the passage portion 25 passes through the first port A and It is provided so as to move to a position facing the second valve seat 13b between the 1 port A and the discharge port T.
  • the passage portion 25 is moved from the first valve seat portion 13a to the second valve seat portion 13b. 25 can be prevented from being arranged at a position communicating with the first port A.
  • the passage portion 25 is always in the neutral position S0 and the standby position S1 without making the first valve seat portion 13a longer than necessary. It is possible to prevent the first valve seat portion 13a and the second valve seat portion 13b) from communicating with the first port A.
  • the length L11 between the passage portion 25 and the one end portion of the first valve seat portion 13a at the neutral position S0 of the spool 2 is set to the second port B from the neutral position S0. More than the movable distance L21 of the spool 2 to the side. Accordingly, even when the spool 2 is moved to the control region S2 on the second port B side and the flow rate control to the second port B is performed, the passage portion 25 moves to the outside of the first valve seat portion 13a and is supplied. It is possible to prevent communication with the port P.
  • the passage portion 25 having the inner diameter d2 smaller than the inner diameter d1 of the supply port P is provided.
  • the passage portion 25 having a small inner diameter in this way, a small amount of hydraulic oil that leaks from the supply port P to the first port A at the neutral position S0 is reliably discharged, and no hydraulic oil is required due to a pressure difference. Inflow to the passage portion 25 can be suppressed as much as possible.
  • the first spring 31 is configured to urge the spool 2 directly.
  • the spool 2 is held at the neutral position S0 by the biasing force of the first springs 31 on both sides.
  • the first spring 31 is provided such that one end is in contact with the spool 2 and the other end is in contact with the stopper 201.
  • the stopper 201 is biased toward the body 1 by the second spring 32. That is, the stopper 201 is pressed against the positioning portion 202 formed of the step portion of the body 1.
  • the positioning unit 202 defines the standby position S1. As shown in FIG. 12, when the operating force F between the first threshold value TH1 and the second threshold value TH2 is applied to the spool 2, the spool 2 moves until it compresses the first spring 31 and contacts the stopper 201. To do.
  • the stopper 201 is urged by the positioning portion 202 with the urging force equal to the second threshold value TH2 by the second spring 32. Therefore, when the operating force is less than or equal to the second threshold value TH2, the stopper 2 is not moved and is put on standby. Hold at position S1.
  • the second spring 32 is provided such that one end is in contact with the stopper 201 and the other end is in contact with the inner surface of the body 1.
  • the spool 2 compresses the second spring 32 and moves to the control region S2 together with the stopper 201.
  • the port (first port A or second port B) corresponding to the moving direction of the spool 2 is communicated with the supply port P, and the hydraulic oil is circulated at a flow rate proportional to the moving amount.
  • the first spring 31 In the standby position S1, the first spring 31 is compressed and the end surface of the spool 2 comes into contact with the stopper 201. Therefore, the first spring 31 does not function during the movement of the spool 2 in the control region S2. That is, the first spring 31 and the second spring 32 are configured to be compressed by the spool 2 independently of each other. The urging force of each spring acts separately.
  • the spool 2 is held at the neutral position S0 by the balance of the first spring 31. Therefore, in order to stably hold the spool 2 at the neutral position S0, it is preferable to increase the spring constant of the first spring 31.
  • the first spring 31 is provided such that one end contacts the end surface of the spool 2 and the other end contacts the inner surface of the body 1. .
  • the spool 2 is held at the neutral position S0 by the biasing force of the first springs 31 on both sides.
  • the second spring 32 is provided such that one end is in contact with the stopper 301 and the other end is in contact with the inner surface of the body 1.
  • the stopper 301 is biased toward the body 1 by the second spring 32. That is, the stopper 301 is pressed against the positioning portion 302 formed of the step portion of the body 1.
  • the positioning unit 302 defines the standby position S1.
  • the spool 2 compresses the first spring 31, and the step portion 303 of the spool 2 comes into contact with the stopper 301.
  • the stopper 301 is biased to the positioning portion 302 by the second spring 32, and the spool 2 is biased by the first spring 31.
  • the second threshold value TH2 shown in FIG. 14 is the resultant force of the urging force of the first spring 31 and the urging force of the second spring 32 when the spool 2 is moved to the standby position S1.
  • the operating force F is equal to or less than the second threshold value TH2 (greater than the first threshold value TH1), the spool 2 is not moved and is held at the standby position S1.
  • the spool 2 when an operating force F greater than the second threshold value TH2 is applied to the spool 2, the spool 2 compresses the second spring 32 and the first spring 31 and moves to the control region S2 together with the stopper 301. . Therefore, in the control region S2, the position control of the spool 2 is performed by the balance with the combined spring of the first spring 31 and the second spring 32. Even in this case, when the spool 2 moves to the control region S2 by the operating force F larger than the second threshold TH2, the port (first port A or second port B) corresponding to the moving direction of the spool 2 is set as the supply port P. Communicate and distribute the hydraulic oil at a flow rate proportional to the amount of movement.
  • the spool 2 is held at the neutral position S0 by the balance of the first spring 31 as in the second embodiment. Therefore, in order to stably hold the spool 2 at the neutral position S0, it is preferable to increase the spring constant of the first spring 31.
  • the effect of the third embodiment is the same as that of the first embodiment.
  • the passage portion 25 is provided in the spool 2
  • the present invention is not limited to this.
  • the passage portion 25 (26) may not be provided in the spool 2.
  • the lengths L1 to L4 of the seal portion 14 between the outer peripheral surface 21 of the spool 2 and the valve seat portion 13 can be sufficiently secured, It is possible to effectively suppress leakage between hydraulic oil ports caused by passing between 21 and the valve seat portion 13.
  • the passage portion 25 it is possible to more reliably prevent leakage between the ports. Therefore, it is preferable to provide the passage portion 25 in an application in which leakage between the ports is not allowed.
  • the passage portion 25 and the passage portion 26 are provided in the spool 2
  • the present invention is not limited to this.
  • the passage portion when the passage portion is provided, the passage portion may be only between the first port A and the supply port P (only the passage portion 25), or the passage portion 26 may not be provided.
  • the urging means 30 is configured by the first spring 31 and the second spring 32.
  • the present invention is not limited to this.
  • the urging means may be constituted by three or more springs.
  • the biasing means may be configured using a single spring and a variable spring whose spring constant varies.
  • the present invention is not limited to this.
  • the spring constant of the first spring 31 and the spring constant of the second spring 32 may be equal, or the spring constant of the first spring 31 may be larger than the spring constant of the second spring 32.
  • the passage portion 25 is connected to the first valve seat portion 13a at the neutral position S0 of the spool 2 rather than the one end portion on the supply port P side of the first valve seat portion 13a.
  • the passage portion 25 may be disposed at the center of the first valve seat portion 13a or on the supply port P side at the neutral position S0 of the spool 2.
  • the passage portion 26, and it may be arranged at the center of the second valve seat portion 13c or on the supply port P side at the neutral position S0.
  • the passage portion 25 passes through the first port A and faces the second valve seat portion 13b.
  • the passage portion 25 may be disposed at a position facing the first valve seat portion 13a in both the neutral position S0 and the standby position S1.
  • the passage portion 26 may be disposed at a position facing the third valve seat portion 13c in both the neutral position S0 and the standby position S1.
  • the length L11 between the passage portion 25 and the one end portion of the first valve seat portion 13a at the neutral position S0 is the spool from the neutral position S0 to the second port B side.
  • the structural example which becomes 2 or more movable distance L21 was shown, this invention is not limited to this.
  • the length L11 may be smaller than the movable distance L21. In that case, when the spool 2 moves to the standby position S1 of the second port B, the passage portion 25 passes over the supply port P and moves to a position facing the third valve seat portion 13c. May be.

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  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Sliding Valves (AREA)
  • Multiple-Way Valves (AREA)

Abstract

This flow control valve is configured so that as a result of a spool (2)-moving operating force being supplied at a magnitude between a first threshold (TH1), which is the upper limit for holding the spool in a center position (S0), and a second threshold (TH2), which is greater than the first threshold, the spool moves from the center position to a standby position (S1), and as a result of an operating force greater than the second threshold being supplied, the spool moves from the standby position to a control range (S2).

Description

流量制御弁Flow control valve
　この発明は、流量制御弁に関し、特に、ボディ内でスプールを移動させることにより油路を開閉して流量を制御する流量制御弁に関する。 The present invention relates to a flow rate control valve, and more particularly to a flow rate control valve that controls the flow rate by opening and closing an oil passage by moving a spool in the body.
　従来、ボディ内でスプールを移動させることにより油路を開閉して流量を制御する流量制御弁が知られている。このような流量制御弁は、たとえば、特開平１１－２８０７０５号公報に開示されている。 Conventionally, a flow rate control valve that opens and closes an oil passage by moving a spool in the body to control the flow rate is known. Such a flow control valve is disclosed in, for example, Japanese Patent Application Laid-Open No. 11-280705.
　上記特開平１１－２８０７０５号公報には、作動油が出入りする油路が設けられたボディと、ボディ内で移動して油路を開閉させるスプールとを備えた流量制御弁が開示されている。スプールが中立位置にある状態では、スプールの外周面とボディの内周面である弁座部とが対向するシール部分によって、油路が閉鎖される。スプールに作動力が付与されてスプールが中立位置から移動すると、スプールと弁座部との間に隙間（開口）が形成されて油路が開かれる。上記特開平１１－２８０７０５号公報の流量制御弁は、スプールの移動量に応じて隙間（開口）が拡大することにより、スプールの移動量に比例した流量で作動油を出力する比例制御弁である。 JP-A-11-280705 discloses a flow control valve having a body provided with an oil passage through which hydraulic oil enters and exits and a spool that moves within the body to open and close the oil passage. In the state where the spool is in the neutral position, the oil passage is closed by the seal portion where the outer peripheral surface of the spool and the valve seat portion which is the inner peripheral surface of the body face each other. When an operating force is applied to the spool and the spool moves from the neutral position, a gap (opening) is formed between the spool and the valve seat portion, and the oil passage is opened. The flow control valve disclosed in Japanese Patent Application Laid-Open No. 11-280705 is a proportional control valve that outputs hydraulic oil at a flow rate proportional to the amount of movement of the spool by expanding a gap (opening) according to the amount of movement of the spool. .
　上記特開平１１－２８０７０５号公報のようなスプール方式の流量制御弁では、中立位置におけるスプールの外周面と弁座部とのシール部分の長さは、スプールが移動し始めてから流量制御が開始されるまで（隙間が形成されるまで）の不感帯に相当する。応答性を向上させるため、流量制御弁では、このシール部分の長さが極力小さくなるように形成される。 In the spool-type flow control valve as described in JP-A-11-280705, the length of the seal portion between the outer peripheral surface of the spool and the valve seat in the neutral position is such that the flow control is started after the spool starts to move. This corresponds to the dead zone until (until a gap is formed). In order to improve responsiveness, the flow control valve is formed so that the length of the seal portion is as small as possible.
特開平１１－２８０７０５号公報JP-A-11-280705
　しかしながら、中立位置でのシール部分の長さを小さくすると、応答性が向上する一方で、スプールと弁座部との間のシール性が低下するため、油路への作動油の漏れが発生し易いという問題点がある。たとえばフォークリフトの昇降用油圧シリンダ（リフトシリンダ）などの昇降制御に流量制御弁が用いられる場合、中立位置で作動油の漏れが発生すると、高さ位置が保持されずに僅かずつ変化することになる。そこで、スプール方式の流量制御弁において、応答性を損なうことなく、油路への作動油の漏れ（リーク）を抑制することが望まれている。 However, if the length of the seal portion at the neutral position is reduced, the responsiveness is improved, but the sealability between the spool and the valve seat portion is lowered, so that hydraulic oil leaks to the oil passage. There is a problem that it is easy. For example, when a flow control valve is used for raising / lowering control of a lifting cylinder for lifting / lowering a forklift, if hydraulic fluid leaks at a neutral position, the height position is changed little by little without being maintained. . In view of this, in a spool type flow control valve, it is desired to suppress leakage of hydraulic oil into the oil passage without impairing responsiveness.
　この発明は、上記のような課題を解決するためになされたものであり、この発明の目的は、応答性を損なうことなく、油路への作動油の漏れを抑制することが可能なスプール方式の流量制御弁を提供することである。 The present invention has been made to solve the above-described problems, and an object of the present invention is a spool system capable of suppressing leakage of hydraulic oil to an oil passage without impairing responsiveness. Is to provide a flow control valve.
　上記目的を達成するために、この発明による流量制御弁は、作動油が出入りする油路が設けられたボディと、ボディ内に移動可能に保持され、油路を開閉させるスプールと、を備え、ボディは、ボディの内周面に設けられ、スプールが中立位置およびスタンバイ位置にある場合に、スプールの外周面とによって油路を遮断する弁座部と、スプールを中立位置に保持するための付勢手段とを有し、スプールを移動させる作動力が、スプールを中立位置に保持する上限である第１閾値と、第１閾値よりも大きい第２閾値との間の大きさで供給されることにより、スプールが付勢手段の付勢力に抗して中立位置からスタンバイ位置に移動し、第２閾値よりも大きい作動力が供給されることにより、スプールが付勢手段の付勢力に抗して、スタンバイ位置から、スプールの移動量に応じて弁開度を変化させる制御領域に移動するように構成されている。 To achieve the above object, a flow control valve according to the present invention includes a body provided with an oil passage through which hydraulic oil enters and exits, and a spool that is movably held in the body and opens and closes the oil passage. The body is provided on the inner peripheral surface of the body, and when the spool is in the neutral position and the standby position, a valve seat portion that blocks the oil passage by the outer peripheral surface of the spool, and an attachment for holding the spool in the neutral position. And an actuating force for moving the spool is supplied in a magnitude between a first threshold that is an upper limit for holding the spool in a neutral position and a second threshold that is greater than the first threshold. Thus, the spool moves from the neutral position to the standby position against the urging force of the urging means, and an operating force larger than the second threshold is supplied, so that the spool resists the urging force of the urging means. , Samba From the position, and is configured to move the control area to change the valve opening in accordance with the movement amount of the spool.
　この発明による流量制御弁では、上記のように、スプールが中立位置およびスタンバイ位置にある場合に、スプールの外周面とによって油路を遮断する弁座部をボディの内周面に設ける。これにより、スプールの中立位置とスタンバイ位置との間の範囲にわたって弁座部を設けることができるので、中立位置におけるスプールと弁座部とのシール部分の長さを十分に確保することができる。その結果、油路への作動油の漏れを抑制することができる。また、上記のように、スプールを移動させる作動力が、スプールを中立位置に保持する上限である第１閾値と、第１閾値よりも大きい第２閾値との間の大きさで供給されることにより、スプールが付勢手段の付勢力に抗して中立位置からスタンバイ位置に移動し、第２閾値よりも大きい作動力が供給されることにより、スプールが付勢手段の付勢力に抗して、スタンバイ位置から、スプールの移動量に応じて弁開度を変化させる制御領域に移動するように流量制御弁を構成する。これにより、流量制御を行う場合に予め第１閾値と第２閾値との間の大きさの作動力を供給すれば、スプールが速やかにスタンバイ位置に移動して流量制御を開始可能な状態となり、作動力が第２閾値を越えた時点から速やかに流量制御を開始することができる。すなわち、流量制御の直前にスプールを中立位置からスタンバイ位置に移動させておくことにより、応答性を向上させることができるので、弁座部を長くしてシール部分の長さを十分に確保する場合でも、高い応答性を確保することができる。以上により、本発明によれば、応答性を損なうことなく、油路への作動油の漏れを抑制することができる。 In the flow control valve according to the present invention, as described above, when the spool is in the neutral position and the standby position, the valve seat portion that blocks the oil passage with the outer peripheral surface of the spool is provided on the inner peripheral surface of the body. As a result, the valve seat portion can be provided over a range between the neutral position of the spool and the standby position, so that the length of the seal portion between the spool and the valve seat portion in the neutral position can be sufficiently secured. As a result, the leakage of hydraulic oil to the oil passage can be suppressed. Further, as described above, the operating force for moving the spool is supplied in a magnitude between the first threshold value that is the upper limit for holding the spool in the neutral position and the second threshold value that is larger than the first threshold value. Thus, the spool moves from the neutral position to the standby position against the urging force of the urging means, and an operating force larger than the second threshold is supplied, so that the spool resists the urging force of the urging means. The flow rate control valve is configured to move from the standby position to a control region in which the valve opening is changed according to the amount of movement of the spool. As a result, if an operating force having a magnitude between the first threshold value and the second threshold value is supplied in advance when performing flow rate control, the spool can quickly move to the standby position and start flow rate control. The flow rate control can be started immediately from the time when the operating force exceeds the second threshold. In other words, since the responsiveness can be improved by moving the spool from the neutral position to the standby position immediately before the flow rate control, when the valve seat part is lengthened and the length of the seal part is sufficiently secured However, high responsiveness can be ensured. As described above, according to the present invention, it is possible to suppress leakage of hydraulic oil to the oil passage without impairing responsiveness.
　上記発明による流量制御弁において、好ましくは、付勢手段は、スプールが中立位置にある場合、第１閾値と等しい付勢力を発生させ、スプールがスタンバイ位置にある場合に、第２閾値と等しい付勢力を発生させるように構成されている。このように構成すれば、スプールを中立位置に保持するための付勢手段を用いて、スプールをスタンバイ位置に保持することができる。この結果、スプールを中立位置、スタンバイ位置および制御領域に段階的に移動させる構成を付勢手段により容易に実現することができる。 In the flow control valve according to the present invention, preferably, the biasing means generates a biasing force equal to the first threshold value when the spool is in the neutral position, and applies a pressure equal to the second threshold value when the spool is in the standby position. It is configured to generate power. If comprised in this way, a spool can be hold | maintained in a standby position using the biasing means for hold | maintaining a spool in a neutral position. As a result, a configuration in which the spool is moved stepwise to the neutral position, the standby position, and the control region can be easily realized by the biasing means.
　この場合、好ましくは、付勢手段は、少なくとも中立位置とスタンバイ位置との間でスプールに圧縮される第１ばねと、制御領域においてスプールに圧縮される第２ばねと、をさらに含む。このように構成すれば、第１ばねと第２ばねとを設けることにより、たとえば第１ばねに第１閾値と等しい初期付勢力を発生させ、第２ばねに第２閾値と等しい初期付勢力を発生させるなど、各々のばね定数を自由に決められる。そのため、中立位置において第１閾値と等しい付勢力を発生させ、スタンバイ位置において第２閾値と等しい付勢力を発生させる付勢手段を、より容易に構成することができる。 In this case, preferably, the urging means further includes a first spring that is compressed to the spool at least between the neutral position and the standby position, and a second spring that is compressed to the spool in the control region. According to this configuration, by providing the first spring and the second spring, for example, an initial biasing force equal to the first threshold value is generated in the first spring, and an initial biasing force equal to the second threshold value is generated in the second spring. Each spring constant can be freely determined, such as generating. Therefore, it is possible to more easily configure the urging means that generates the urging force equal to the first threshold value in the neutral position and generates the urging force equal to the second threshold value in the standby position.
　上記付勢手段が第１ばねと第２ばねとを含む構成において、好ましくは、第１ばねのばね定数は、第２ばねのばね定数よりも小さい。このように構成すれば、第１ばねのばね定数を相対的に小さくすることにより、第１閾値を越えてからスタンバイ位置まで第１ばねを圧縮するのに必要な作動力の大きさ（圧縮に伴う第１ばねの付勢力の増分）を小さくすることができる。その結果、スプールをスタンバイ位置に移動するのに必要な作動力と、作動力の第２閾値との差を大きくすることができるので、スタンバイ位置へのスプールの移動を迅速に行うことができる。 In the configuration in which the biasing means includes the first spring and the second spring, the spring constant of the first spring is preferably smaller than the spring constant of the second spring. With this configuration, by reducing the spring constant of the first spring relatively, the magnitude of the operating force required to compress the first spring from the first threshold value to the standby position (for compression) The accompanying increase in the biasing force of the first spring) can be reduced. As a result, the difference between the operating force required to move the spool to the standby position and the second threshold value of the operating force can be increased, so that the spool can be quickly moved to the standby position.
　上記付勢手段が第１ばねと第２ばねとを含む構成において、好ましくは、ボディは、中立位置におけるスプールの移動を規制する第１ストッパと、スタンバイ位置におけるスプールの移動を規制する第２ストッパとをさらに含み、第１ばねは、第１閾値と等しい初期付勢力で第１ストッパをボディに対して付勢し、第２ばねは、第２閾値と等しい初期付勢力で第２ストッパをボディに対して付勢している。このように構成すれば、第１ばねによりボディに付勢される第１ストッパにより、スプールを中立位置に保持することができる。この場合、スプールが付勢力の釣り合いによって中立位置に保持される構成と異なり、外乱などによってスプールに第１閾値以下の力が作用してもスプールが移動しないため、安定してスプールを中立位置に保持することができる。また、第２ストッパを設けることにより、第２閾値を第１ばねとは独立して第２ばねにより設定することができる。そのため、第２閾値を第１ばねおよび第２ばねの合成ばねにより設定する場合と比較して、第２閾値を容易に設定できるとともに、スプールを制御領域で動作させるために必要な作動力が大きくなることを抑制することができる。 In the configuration in which the urging means includes a first spring and a second spring, the body preferably has a first stopper that restricts movement of the spool in the neutral position and a second stopper that restricts movement of the spool in the standby position. The first spring biases the first stopper against the body with an initial biasing force equal to the first threshold, and the second spring biases the second stopper against the body with an initial biasing force equal to the second threshold. Is energized against. If comprised in this way, a spool can be hold | maintained in a neutral position with the 1st stopper urged | biased by the body with a 1st spring. In this case, unlike the configuration in which the spool is held at the neutral position by the balance of the urging force, the spool does not move even if a force below the first threshold is applied to the spool due to disturbance or the like, so the spool can be stably brought to the neutral position. Can be held. Further, by providing the second stopper, the second threshold value can be set by the second spring independently of the first spring. Therefore, compared with the case where the second threshold value is set by the combined spring of the first spring and the second spring, the second threshold value can be easily set and the operating force required to operate the spool in the control region is large. It can be suppressed.
　上記発明による流量制御弁において、好ましくは、油路は、作動油が供給される供給ポートと、作動油が排出される排出ポートと、互いに択一的に作動油を流入または流出させる第１ポートおよび第２ポートとを含み、スプールは、中立位置において、スプールの外周面からスプールの内部を通って排出ポートに連通するように設けられ、弁座部とスプールとの間を通過する作動油を排出するための通路部を有し、通路部は、スプールの中立位置において、少なくとも第１ポートと供給ポートとの間の第１弁座部と対向する位置に配置されている。このように構成すれば、スプールをボディ内で移動可能に構成することによって不可避的に発生するスプールと第１弁座部との間での作動油の僅かな漏れを、通路部によって排出ポートへ送り出すことが可能となる。このため、たとえば昇降用シリンダの昇降制御などに流量制御弁が用いられる場合でも、中立位置での作動油の漏れを防止して、位置ずれが生じることを確実に防止することができる。なお、本発明において、通路部は、少なくとも第１ポートと供給ポートとの間の第１弁座部に配置されていればよく、第１弁座部のみならず、第２ポートと供給ポートとの間の弁座部にも通路部がさらに配置されていてもよい。 In the flow control valve according to the present invention, preferably, the oil passage includes a supply port to which the hydraulic oil is supplied, a discharge port from which the hydraulic oil is discharged, and a first port that allows the hydraulic oil to flow in or out alternately. And the second port, and in the neutral position, the spool is provided so as to communicate with the discharge port from the outer peripheral surface of the spool through the inside of the spool, and allows the hydraulic oil to pass between the valve seat portion and the spool. A passage portion for discharging is provided, and the passage portion is disposed at a position facing at least the first valve seat portion between the first port and the supply port in the neutral position of the spool. If comprised in this way, the slight leakage of the hydraulic fluid between the spool and the 1st valve seat part which inevitably generate | occur | produces by comprising a spool so that a movement in a body is carried out to a discharge port by a channel | path part. It can be sent out. For this reason, even when a flow control valve is used for elevating control of the elevating cylinder, for example, it is possible to prevent leakage of hydraulic oil at the neutral position and reliably prevent displacement. In the present invention, the passage portion only needs to be disposed at least in the first valve seat portion between the first port and the supply port, and not only the first valve seat portion but also the second port and the supply port. A passage portion may be further arranged in the valve seat portion between the two.
　この場合、好ましくは、通路部は、スプールの中立位置において、第１弁座部の供給ポート側の一端部よりも、第１弁座部の第１ポート側の他端部に近い位置に配置されている。このように構成すれば、通路部が高圧側の供給ポートから離れた位置に配置されるので、第１ポートへの作動油の漏れを防止しつつ、圧力差によって作動油が供給ポートから通路部へ漏れ出ることを抑制することができる。 In this case, preferably, the passage portion is disposed at a position closer to the other end portion of the first valve seat portion on the first port side than the one end portion of the first valve seat portion on the supply port side in the neutral position of the spool. Has been. If comprised in this way, since a channel | path part is arrange | positioned in the position away from the supply port by the side of a high voltage | pressure, hydraulic oil is prevented from leaking from a supply port by a pressure difference, preventing the hydraulic fluid to leak to a 1st port. It is possible to suppress leakage into the water.
　上記スプールの中立位置において、通路部が第１弁座部の第１ポート側の他端部に近い位置に配置されている構成において、好ましくは、通路部は、スプールが中立位置から第１ポート側のスタンバイ位置に移動する際に、第１ポートを通過して、第１ポートと排出ポートとの間の第２弁座部と対向する位置に移動する。このように構成すれば、スプールを中立位置からスタンバイ位置へと移動させる構造を利用して、通路部を第１弁座部から第２弁座部へと移動させることにより、通路部が第１ポートと連通する位置に配置されることを防止することができる。すなわち、スプールの外周面に通路部を設ける場合でも、第１弁座部を必要以上に長くすることなく、中立位置およびスタンバイ位置で通路部が常に弁座部（第１弁座部および第２弁座部）と対向して第１ポートと連通することがないようにすることが可能となる。 In the configuration in which the passage portion is disposed at a position close to the other end portion on the first port side of the first valve seat portion in the neutral position of the spool, preferably, the passage portion has the spool from the neutral position to the first port. When moving to the standby position on the side, the first valve passes through the first port and moves to a position facing the second valve seat between the first port and the discharge port. If comprised in this way, a channel | path part will be 1st by moving a channel | path part from a 1st valve seat part to a 2nd valve seat part using the structure which moves a spool from a neutral position to a standby position. Arrangement at a position communicating with the port can be prevented. That is, even when the passage portion is provided on the outer peripheral surface of the spool, the passage portion is always the valve seat portion (the first valve seat portion and the second valve portion at the neutral position and the standby position) without making the first valve seat portion longer than necessary. It is possible to prevent the first seat from communicating with the first port.
　上記スプールに通路部を設ける構成において、好ましくは、スプールの中立位置における通路部と第１弁座部の一端部との間の長さは、中立位置から第２ポート側へのスプールの移動可能距離以上である。このように構成すれば、スプールを第２ポート側の制御領域へ移動させて第２ポートへの流量制御が行われる場合でも、通路部が第１弁座部の外部へ移動して供給ポートと連通してしまうことを防止することができる。 In the configuration in which the passage portion is provided in the spool, preferably, the length between the passage portion in the neutral position of the spool and the one end portion of the first valve seat portion is movable from the neutral position to the second port side. More than the distance. With this configuration, even when the spool is moved to the control region on the second port side and flow control to the second port is performed, the passage portion moves to the outside of the first valve seat portion and It is possible to prevent communication.
　上記スプールに通路部を設ける構成において、好ましくは、通路部は、供給ポートの内径よりも小さい内径を有する。このように内径の小さな通路部を設けることにより、中立位置において供給ポートから第１ポートへ漏れようとする僅かな作動油を確実に排出しつつ、圧力差によって作動油が不必要に通路部へ流入することを極力抑制することができる。 In the configuration in which the spool is provided with the passage portion, the passage portion preferably has an inner diameter smaller than the inner diameter of the supply port. By providing the passage portion having a small inner diameter in this way, the hydraulic oil is surely discharged from the supply port to the first port in the neutral position, and the hydraulic oil is unnecessarily moved to the passage portion due to the pressure difference. Inflow can be suppressed as much as possible.
　本発明によれば、上記のように、応答性を損なうことなく、油路への作動油の漏れを抑制することが可能なスプール方式の流量制御弁を提供することができる。 According to the present invention, as described above, it is possible to provide a spool-type flow rate control valve capable of suppressing the leakage of hydraulic oil to the oil passage without impairing responsiveness.
流量制御弁が適用される油圧回路の一例を示した図である。It is the figure which showed an example of the hydraulic circuit to which a flow control valve is applied. 第１実施形態による流量制御弁を示した断面図である。It is sectional drawing which showed the flow control valve by 1st Embodiment. スプールの構成例を示した斜視図である。It is the perspective view which showed the structural example of the spool. 第１ポート側のスタンバイ位置にスプールが移動した状態を示した図である。It is the figure which showed the state which the spool moved to the standby position by the side of the 1st port. 第１ポート側の制御領域にスプールが移動した状態を示した図である。It is the figure which showed the state which the spool moved to the control area of the 1st port side. 第２ポート側のスタンバイ位置にスプールが移動した状態を示した図である。It is the figure which showed the state which the spool moved to the standby position by the side of the 2nd port. 第２ポート側の制御領域にスプールが移動した状態を示した図である。It is the figure which showed the state which the spool moved to the control area of the 2nd port side. 第１ポート側のスタンバイ位置での通路部の位置を示した拡大断面図である。It is the expanded sectional view which showed the position of the channel | path part in the standby position by the side of a 1st port. 第２ポート側のスタンバイ位置での通路部の位置を示した拡大断面図である。It is the expanded sectional view which showed the position of the channel | path part in the standby position on the 2nd port side. 第１実施形態および比較例による流量制御弁の開閉動作の一例を示したグラフである。It is the graph which showed an example of the opening / closing operation | movement of the flow control valve by 1st Embodiment and a comparative example. 第２実施形態による流量制御弁を示した断面図である。It is sectional drawing which showed the flow control valve by 2nd Embodiment. 第１ポート側のスタンバイ位置にスプールが移動した状態を示した図である。It is the figure which showed the state which the spool moved to the standby position by the side of the 1st port. 第３実施形態による流量制御弁を示した断面図である。It is sectional drawing which showed the flow control valve by 3rd Embodiment. 第１ポート側のスタンバイ位置にスプールが移動した状態を示した図である。It is the figure which showed the state which the spool moved to the standby position by the side of the 1st port. 第１実施形態による流量制御弁の変形例を示した断面図である。It is sectional drawing which showed the modification of the flow control valve by 1st Embodiment.
　以下、本発明の実施形態を図面に基づいて説明する。 Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[第１実施形態]
　まず、図１～図１０を参照して、第１実施形態による流量制御弁について説明する。 [First embodiment]
First, the flow control valve according to the first embodiment will be described with reference to FIGS.
　第１実施形態による流量制御弁１００は、油圧アクチュエータなどの油圧機械への作動油の供給を制御する油圧弁である。第１実施形態の流量制御弁１００は、スプール形（スライドスプール形）の比例流量制御弁として構成されている。比例流量制御弁は、出力される作動油の流量が、スプールの位置（ストローク量）に比例するように構成された制御弁である。 The flow control valve 100 according to the first embodiment is a hydraulic valve that controls the supply of hydraulic oil to a hydraulic machine such as a hydraulic actuator. The flow control valve 100 of the first embodiment is configured as a proportional flow control valve of a spool type (slide spool type). The proportional flow rate control valve is a control valve configured so that the flow rate of the output hydraulic oil is proportional to the spool position (stroke amount).
（油圧回路の全体構成）
　第１実施形態による流量制御弁１００は、重力作用方向（鉛直方向）に沿って昇降する昇降用油圧シリンダ（リフトシリンダ）など、中立状態（スプールの中立位置）において制御位置を保持することが要求される油圧機械に対する作動油の流量制御に好適に用いられる。以下では、一例として、フォークリフトの昇降用油圧シリンダ（リフトシリンダ）に流量制御弁１００が接続され、シリンダを昇降させるための作動油の供給制御に流量制御弁１００が用いられる例について説明する。 (Whole structure of hydraulic circuit)
The flow control valve 100 according to the first embodiment is required to maintain a control position in a neutral state (neutral position of the spool), such as an elevating hydraulic cylinder (lift cylinder) that moves up and down along the gravity action direction (vertical direction). It is suitably used for controlling the flow rate of hydraulic oil to a hydraulic machine. In the following, an example will be described in which the flow control valve 100 is connected to a lifting hydraulic cylinder (lift cylinder) of a forklift and the flow control valve 100 is used for supply control of hydraulic oil for raising and lowering the cylinder.
　図１に示すように、流量制御弁１００は、油圧シリンダ１０１、油圧ポンプ１０２、およびオイルタンク１０３とそれぞれ接続されている。具体的には、流量制御弁１００は、第１ポートＡ、第２ポートＢ、供給ポートＰおよび排出ポートＴの４つの油路を備えている。 As shown in FIG. 1, the flow control valve 100 is connected to a hydraulic cylinder 101, a hydraulic pump 102, and an oil tank 103, respectively. Specifically, the flow control valve 100 includes four oil passages: a first port A, a second port B, a supply port P, and a discharge port T.
　油圧シリンダ１０１は、ピストン１１１と、ピストン１１１に接続されたロッド１１２とが、チューブ１１３内に摺動可能に設けられた構造を有する。油圧シリンダ１０１は、たとえば片ロッドシリンダであり、ロッド１１２がチューブ１１３の一端側から外部に突出している。チューブ１１３内は、ピストン１１１によって、ロッド側油室１１４と、ヘッド側油室１１５とに区画されている。流量制御弁１００の第１ポートＡが、チェック弁１０４を介してヘッド側油室１１５に接続されている。流量制御弁１００の第２ポートＢが、ロッド側油室１１４に接続されている。なお、第１ポートＡをロッド側油室１１４に接続し、第２ポートＢをヘッド側油室１１５に接続してもよい。チェック弁１０４は、第１ポートＡからヘッド側油室１１５へ向かう方向への作動油の流通を許容し、ヘッド側油室１１５から第１ポートＡへ向かう方向への作動油の流通を防止する。チェック弁１０４は、パイロットチェック弁であり、パイロットポートがロッド側油室１１４と第２ポートＢとの流路に接続されている。チェック弁１０４は、ロッド側油室１１４と第２ポートＢとの間の油圧（パイロットポートの油圧）が所定値を上回ると、ヘッド側油室１１５から第１ポートＡへ向かう方向への作動油の流通を許容する。 The hydraulic cylinder 101 has a structure in which a piston 111 and a rod 112 connected to the piston 111 are slidably provided in the tube 113. The hydraulic cylinder 101 is, for example, a single rod cylinder, and the rod 112 protrudes from one end side of the tube 113 to the outside. The inside of the tube 113 is partitioned by a piston 111 into a rod side oil chamber 114 and a head side oil chamber 115. The first port A of the flow control valve 100 is connected to the head side oil chamber 115 via the check valve 104. A second port B of the flow control valve 100 is connected to the rod side oil chamber 114. The first port A may be connected to the rod side oil chamber 114 and the second port B may be connected to the head side oil chamber 115. The check valve 104 allows the hydraulic oil to flow from the first port A toward the head-side oil chamber 115 and prevents the hydraulic oil from flowing from the head-side oil chamber 115 toward the first port A. . The check valve 104 is a pilot check valve, and the pilot port is connected to the flow path between the rod side oil chamber 114 and the second port B. When the hydraulic pressure between the rod-side oil chamber 114 and the second port B (pilot port hydraulic pressure) exceeds a predetermined value, the check valve 104 operates in the direction from the head-side oil chamber 115 toward the first port A. Allow distribution.
　流量制御弁１００の供給ポートＰが、油圧ポンプ１０２の吐出側に接続されている。油圧ポンプ１０２は、ポンプモータ１２１によって駆動され、吸込側のオイルタンク１０３中の作動油を所定の圧力で流量制御弁１００に供給する。流量制御弁１００の排出ポートＴが、オイルタンク１０３に接続されている。 The supply port P of the flow control valve 100 is connected to the discharge side of the hydraulic pump 102. The hydraulic pump 102 is driven by a pump motor 121 and supplies the hydraulic oil in the oil tank 103 on the suction side to the flow control valve 100 with a predetermined pressure. A discharge port T of the flow control valve 100 is connected to the oil tank 103.
　流量制御弁１００における作動油の圧力を比較すると、供給ポートＰ＞第１ポートＡおよび第２ポートＢ＞＞排出ポートＴという順番になる。なお、第１ポートＡおよび第２ポートＢの圧力の大小関係は、第１ポートＡ＞第２ポートＢとなる場合も、第１ポートＡ＞第２ポートＢとなる場合もあり得る。油圧ポンプ１０２の吐出圧が作用する供給ポートＰの圧力が最も高く、オイルタンク１０３内に解放された排出ポートＴの圧力が最も低い。 When the pressure of the hydraulic oil in the flow control valve 100 is compared, the order of supply port P> first port A and second port B >> discharge port T is obtained. Note that the pressure relationship between the first port A and the second port B may be such that the first port A> the second port B or the first port A> the second port B. The pressure of the supply port P on which the discharge pressure of the hydraulic pump 102 acts is the highest, and the pressure of the discharge port T released in the oil tank 103 is the lowest.
　流量制御弁１００は、外部の作動力供給手段１０５から供給される作動力によって、流路切替および流量制御を行う。すなわち、流量制御弁１００は、供給ポートＰに対して第１ポートＡおよび第２ポートＢのいずれも遮断する中立状態と、供給ポートＰと第１ポートＡとを接続させるとともに第２ポートＢと排出ポートＴとを接続させるＰＡ制御状態と、供給ポートＰと第２ポートＢとを接続させるとともに第１ポートＡと排出ポートＴとを接続させるＰＢ制御状態とを切り替え可能な方向切換弁として機能する。 The flow control valve 100 performs flow path switching and flow control by the operating force supplied from the external operating force supply means 105. That is, the flow control valve 100 connects the supply port P and the first port A to the neutral state in which both the first port A and the second port B are blocked with respect to the supply port P, and the second port B. Functions as a directional control valve capable of switching between a PA control state in which the discharge port T is connected and a PB control state in which the supply port P and the second port B are connected and the first port A and the discharge port T are connected To do.
　中立状態では、供給ポートＰ、第１ポートＡおよび第２ポートＢのいずれもが、流量制御弁１００によって遮断される。つまり、流量制御弁１００は、中立状態で全閉となるように構成されている。中立状態では、油圧シリンダ１０１内の作動油が流通しないため、ロッド１１２の位置が保持される。 In the neutral state, all of the supply port P, the first port A, and the second port B are blocked by the flow control valve 100. That is, the flow control valve 100 is configured to be fully closed in a neutral state. In the neutral state, since the hydraulic oil in the hydraulic cylinder 101 does not flow, the position of the rod 112 is maintained.
　ＰＡ制御状態では、油圧ポンプ１０２から供給される高圧の作動油が、流量制御弁１００の供給ポートＰおよび第１ポートＡを通過して油圧シリンダ１０１のヘッド側油室１１５に流入し、ロッド１１２を押し出す。ロッド側油室１１４から押し出された作動油が、流量制御弁１００の第２ポートＢおよび排出ポートＴを通過してオイルタンク１０３に戻される。昇降用油圧シリンダとしては、上昇方向（鉛直上方向）への動作となる。 In the PA control state, high-pressure hydraulic oil supplied from the hydraulic pump 102 passes through the supply port P and the first port A of the flow control valve 100 and flows into the head side oil chamber 115 of the hydraulic cylinder 101, and the rod 112. Extrude The hydraulic oil pushed out from the rod side oil chamber 114 passes through the second port B and the discharge port T of the flow control valve 100 and is returned to the oil tank 103. The lifting hydraulic cylinder operates in the upward direction (vertically upward).
　ＰＢ制御状態では、油圧ポンプ１０２から供給される高圧の作動油が、流量制御弁１００の供給ポートＰおよび第２ポートＢを通過して油圧シリンダ１０１のロッド側油室１１４に流入し、ロッド１１２を引き込む。ヘッド側油室１１５から押し出された作動油が、流量制御弁１００の第１ポートＡおよび排出ポートＴを通過してオイルタンク１０３に戻される。昇降用油圧シリンダとしては、下降方向（鉛直下方向）への動作となる。 In the PB control state, high-pressure hydraulic oil supplied from the hydraulic pump 102 passes through the supply port P and the second port B of the flow control valve 100 and flows into the rod-side oil chamber 114 of the hydraulic cylinder 101, and the rod 112. Pull in. The hydraulic oil pushed out from the head side oil chamber 115 passes through the first port A and the discharge port T of the flow control valve 100 and is returned to the oil tank 103. The lifting hydraulic cylinder operates in a descending direction (vertically downward).
　そして、ＰＡ制御状態およびＰＢ制御状態においては、流量制御弁１００は、作動力によって移動されるスプール２（図２参照）の位置（ストローク量）に応じて、ポートからの作動油の流量が制御される。スプール２の位置は、作動力供給手段１０５から供給される作動力の大きさに対応する。作動力供給手段１０５は、コントローラ１０６からの制御信号に従って、流量制御弁１００に作動力を供給する。作動力供給手段１０５は、スプールに作動力を付与できるものであれば特に限定されない。作動力供給手段１０５としては、たとえば、ソレノイド方式などの電磁力により作動力を供給する方式、油圧パイロット弁を用いて油圧により作動力を供給する方式などが採用できる。第１実施形態では、油圧ポンプ１０２の油圧が、油圧パイロット弁からなる作動力供給手段１０５を介して流量制御弁１００のパイロットポート１５に供給されることにより、作動力が供給される。 In the PA control state and the PB control state, the flow rate control valve 100 controls the flow rate of the hydraulic oil from the port according to the position (stroke amount) of the spool 2 (see FIG. 2) moved by the operating force. Is done. The position of the spool 2 corresponds to the magnitude of the operating force supplied from the operating force supply means 105. The operating force supply means 105 supplies an operating force to the flow control valve 100 in accordance with a control signal from the controller 106. The operating force supply means 105 is not particularly limited as long as it can apply an operating force to the spool. As the operating force supply means 105, for example, a method of supplying an operating force by electromagnetic force such as a solenoid method, a method of supplying an operating force by hydraulic pressure using a hydraulic pilot valve, or the like can be adopted. In the first embodiment, the hydraulic pressure of the hydraulic pump 102 is supplied to the pilot port 15 of the flow control valve 100 via the operating force supply means 105 including a hydraulic pilot valve, so that the operating force is supplied.
（流量制御弁の構造）
　次に、図２～図９を参照して、流量制御弁１００の具体的な構成例について説明する。 (Structure of flow control valve)
Next, a specific configuration example of the flow control valve 100 will be described with reference to FIGS.
　図２に示すように、流量制御弁１００は、作動油が出入りする油路が設けられたボディ１と、ボディ１内に移動可能に保持され、油路を開閉させるスプール２と、を備えている。油路は、上述の通り、作動油が供給される供給ポートＰと、作動油が排出される排出ポートＴと、互いに択一的に作動油を流入または流出させる第１ポートＡおよび第２ポートＢとを含む。 As shown in FIG. 2, the flow control valve 100 includes a body 1 provided with an oil passage through which hydraulic oil enters and exits, and a spool 2 that is movably held in the body 1 and opens and closes the oil passage. Yes. As described above, the oil passage includes the supply port P to which the hydraulic oil is supplied, the discharge port T from which the hydraulic oil is discharged, and the first port A and the second port that allow the hydraulic oil to flow in or out alternately. B.
　ボディ１は、スプール２が配置されるスプール室１１と、スプール室１１の両側に配置された一対のパイロット室１２とを有する。スプール室１１は、直線円筒状の内部空間であり、スプール２が軸方向（Ｘ方向）に沿って摺動可能に配置されている。各パイロット室１２は、スプール２の軸方向におけるスプール室１１の両側に配置されている。 The body 1 has a spool chamber 11 in which the spool 2 is disposed, and a pair of pilot chambers 12 disposed on both sides of the spool chamber 11. The spool chamber 11 is a linear cylindrical internal space, and the spool 2 is slidably disposed along the axial direction (X direction). Each pilot chamber 12 is arranged on both sides of the spool chamber 11 in the axial direction of the spool 2.
　供給ポートＰ、排出ポートＴ、第１ポートＡおよび第２ポートＢの各油路は、ボディ１の外周からボディ１を貫通してスプール室１１に連通している。スプール２の軸方向（Ｘ方向）において、供給ポートＰがスプール室１１の中央に配置され、供給ポートＰの両側にそれぞれ第１ポートＡおよび第２ポートＢが配置されている。スプール２の軸方向において、第１ポートＡおよび第２ポートＢの外側に、それぞれ排出ポートＴが配置されている。 The oil passages of the supply port P, the discharge port T, the first port A and the second port B pass through the body 1 from the outer periphery of the body 1 and communicate with the spool chamber 11. In the axial direction (X direction) of the spool 2, the supply port P is disposed at the center of the spool chamber 11, and the first port A and the second port B are disposed on both sides of the supply port P, respectively. In the axial direction of the spool 2, the discharge port T is disposed outside the first port A and the second port B, respectively.
　供給ポートＰ、排出ポートＴ、第１ポートＡおよび第２ポートＢの各油路の間には、スプール室１１（ボディ１）の内周面からなる弁座部１３が設けられている。弁座部１３は、スプール２が中立位置Ｓ０（図２参照）および後述するスタンバイ位置Ｓ１（図４、図６参照）にある場合に、スプール２の外周面（摺動面）２１とによって油路を遮断するように構成されている。すなわち、弁座部１３は、スプール２が摺動するための極小さな間隔を隔てて、スプール２の外周面２１と対向することにより、各油路の間を遮断する。弁座部１３は、第１ポートＡと供給ポートＰとの間の第１弁座部１３ａ、第１ポートＡと排出ポートＴとの間の第２弁座部１３ｂ、第２ポートＢと供給ポートＰとの間の第３弁座部１３ｃ、および、第２ポートＢと排出ポートＴとの間の第４弁座部１３ｄを含む。 Between the oil passages of the supply port P, the discharge port T, the first port A, and the second port B, a valve seat portion 13 formed of the inner peripheral surface of the spool chamber 11 (body 1) is provided. When the spool 2 is in a neutral position S0 (see FIG. 2) and a standby position S1 (see FIGS. 4 and 6), which will be described later, the valve seat portion 13 is oiled by an outer peripheral surface (sliding surface) 21 of the spool 2. It is configured to block the road. That is, the valve seat portion 13 blocks the oil passages by facing the outer peripheral surface 21 of the spool 2 with a very small interval for the spool 2 to slide. The valve seat 13 is supplied with the first valve seat 13a between the first port A and the supply port P, the second valve seat 13b between the first port A and the discharge port T, and the second port B. A third valve seat 13c between the port P and a fourth valve seat 13d between the second port B and the discharge port T are included.
　第１実施形態では、中立位置Ｓ０におけるスプール２の外周面２１と弁座部１３との対向部分（シール部分１４）の長さが、一般的な比例流量制御弁よりも長くなっている。具体的には、中立位置Ｓ０における第１弁座部１３ａ、第２弁座部１３ｂ、第３弁座部１３ｃおよび第４弁座部１３ｄの各々の対向部分（シール部分１４）の長さは、Ｌ１、Ｌ２、Ｌ３およびＬ４となっている。各対向部分の長さＬ１～Ｌ４は、各ポートの内径ｄ１（図８参照）よりも大きい。 In the first embodiment, the length of the facing portion (seal portion 14) between the outer peripheral surface 21 of the spool 2 and the valve seat portion 13 at the neutral position S0 is longer than that of a general proportional flow control valve. Specifically, the lengths of the facing portions (seal portions 14) of the first valve seat portion 13a, the second valve seat portion 13b, the third valve seat portion 13c, and the fourth valve seat portion 13d in the neutral position S0 are as follows. , L1, L2, L3 and L4. The lengths L1 to L4 of each facing portion are larger than the inner diameter d1 (see FIG. 8) of each port.
　軸方向両側のパイロット室１２には、それぞれ、作動力供給手段１０５と接続するためのパイロットポート１５が設けられている。作動力供給手段１０５からのパイロット油圧は、パイロット室１２に入力され、スプール室１１内のスプール２を軸方向（Ｘ方向）に移動させる作動力として作用する。 The pilot chambers 12 on both sides in the axial direction are provided with pilot ports 15 for connection to the operating force supply means 105, respectively. The pilot hydraulic pressure from the operating force supply means 105 is input to the pilot chamber 12 and acts as an operating force that moves the spool 2 in the spool chamber 11 in the axial direction (X direction).
　図３に示すように、スプール２は、概略で円柱状の軸部材である。スプール２には、摺動面である外周面２１と、各油路の間を連通状態に切り替えるための溝部２２とが設けられている。溝部２２は、スプール２の周方向に全周にわたって所定の深さで形成され、中立位置Ｓ０で供給ポートＰおよび各排出ポートＴの位置に対応して配置されている。溝部２２は、スプール２の移動に伴って第１ポートＡまたは第２ポートＢを供給ポートＰまたは排出ポートＴと連通させる油路を構成する。各溝部２２の間の２つの外周面２１は、それぞれ、中立位置Ｓ０で第１ポートＡおよび第２ポートＢを塞ぐように形成されている。スプール２の両端の外周面２１は、パイロット室１２とスプール室１１との間を塞ぐよう設けられている。 As shown in FIG. 3, the spool 2 is a roughly cylindrical shaft member. The spool 2 is provided with an outer peripheral surface 21 that is a sliding surface and a groove portion 22 for switching between the oil passages to a communication state. The groove portion 22 is formed with a predetermined depth over the entire circumference in the circumferential direction of the spool 2, and is disposed corresponding to the position of the supply port P and each discharge port T at the neutral position S0. The groove portion 22 constitutes an oil passage that allows the first port A or the second port B to communicate with the supply port P or the discharge port T as the spool 2 moves. The two outer peripheral surfaces 21 between the groove portions 22 are formed so as to block the first port A and the second port B at the neutral position S0, respectively. The outer peripheral surfaces 21 at both ends of the spool 2 are provided so as to close the space between the pilot chamber 12 and the spool chamber 11.
　３つの溝部２２と、それらの間の２つの外周面２１との境界部（段差部分）には、切欠部２３が設けられている。切欠部２３は、スプール２の周方向に等角度間隔で複数設けられている。図３の構成例では、各々の切欠部２３は、溝部２２側に近付くほど幅（周方向の幅）が大きくなる半円形状を有している。なお、切欠部２３の形状は、図３に示したものに限られず、任意である。切欠部２３は、スプール２の軸方向移動に伴って第１ポートＡまたは第２ポートＢを供給ポートＰまたは排出ポートＴと連通させる際に、作動油の流量をスプール２の移動量に比例させる機能を有する。 The notch part 23 is provided in the boundary part (step part) of the three groove parts 22 and the two outer peripheral surfaces 21 between them. A plurality of notches 23 are provided at equal angular intervals in the circumferential direction of the spool 2. In the configuration example of FIG. 3, each notch 23 has a semicircular shape whose width (width in the circumferential direction) increases as it approaches the groove 22 side. In addition, the shape of the notch part 23 is not restricted to what was shown in FIG. 3, It is arbitrary. The notch 23 makes the flow rate of the hydraulic oil proportional to the amount of movement of the spool 2 when the first port A or the second port B communicates with the supply port P or the discharge port T as the spool 2 moves in the axial direction. It has a function.
　図２に示すように、スプール２の内部には、バイパス通路２４が形成されている。バイパス通路２４は、軸方向（Ｘ方向）両側の溝部２２同士を接続するように設けられている。バイパス通路２４は、Ｘ方向において、中立位置Ｓ０における各排出ポートＴと一致する位置で、スプール２の表面（溝部２２の底部）に開口している。 2, a bypass passage 24 is formed inside the spool 2. The bypass passage 24 is provided so as to connect the groove portions 22 on both sides in the axial direction (X direction). The bypass passage 24 opens in the surface of the spool 2 (the bottom of the groove 22) at a position that coincides with each discharge port T at the neutral position S0 in the X direction.
（付勢手段）
　ボディ１は、スプール２を中立位置Ｓ０に保持するための付勢手段３０を備えている。付勢手段３０は、付勢力によって、スプール２を中立位置Ｓ０に保持する。これにより、流量制御弁１００は、作動力が供給されない場合に中立状態（全閉状態）が維持される。また、付勢手段３０は、付勢力によって、作動力供給手段１０５から供給される作動力とスプール２の移動量とを対応付ける。入力される作動力が所定の閾値を越えると、スプール２は、切欠部２３および溝部２２がポート間に跨がるようにしてポート間を連通させる制御領域Ｓ２（図５、図７参照）に到達する。制御領域Ｓ２では、切欠部２３は、軸方向（Ｘ方向）における各ポートとのオーバラップ量に応じて、各ポートと溝部２２との間の開口面積（流路断面積）を変化させる。これにより、制御領域Ｓ２では、スプール２の移動量の増大に伴って切欠部２３（溝部２２）とポート間の開口面積が増大することにより、作動油の流量がスプール２の移動量に比例する。 (Biasing means)
The body 1 includes urging means 30 for holding the spool 2 in the neutral position S0. The urging means 30 holds the spool 2 in the neutral position S0 by the urging force. Thereby, the flow control valve 100 is maintained in the neutral state (fully closed state) when the operating force is not supplied. Further, the urging means 30 associates the operating force supplied from the operating force supply means 105 with the movement amount of the spool 2 by the urging force. When the input operating force exceeds a predetermined threshold value, the spool 2 enters a control region S2 (see FIGS. 5 and 7) in which the notch portion 23 and the groove portion 22 are communicated with each other so as to straddle the ports. To reach. In the control region S2, the notch 23 changes the opening area (flow channel cross-sectional area) between each port and the groove 22 according to the amount of overlap with each port in the axial direction (X direction). As a result, in the control region S2, the flow area of the hydraulic oil is proportional to the amount of movement of the spool 2 by increasing the opening area between the notch 23 (groove portion 22) and the port as the amount of movement of the spool 2 increases. .
　ここで、第１実施形態では、付勢手段３０は、付勢力によって、スプール２をスタンバイ位置Ｓ１（図４、図６参照）に保持するように構成されている。つまり、流量制御弁１００には、スプール２が中立位置Ｓ０に保持される状態と、制御領域Ｓ２を移動する状態とに加えて、さらにスタンバイ位置Ｓ１に保持される状態が設けられている。 Here, in the first embodiment, the urging means 30 is configured to hold the spool 2 in the standby position S1 (see FIGS. 4 and 6) by the urging force. That is, the flow control valve 100 is provided with a state in which the spool 2 is held at the standby position S1 in addition to a state in which the spool 2 is held at the neutral position S0 and a state in which the spool 2 moves in the control region S2.
　第１実施形態では、流量制御弁１００は、スプール２を移動させる作動力が、スプール２を中立位置Ｓ０に保持する上限である第１閾値ＴＨ１と、第１閾値ＴＨ１よりも大きい第２閾値ＴＨ２との間の大きさで供給されることにより、スプール２が付勢手段３０の付勢力に抗して中立位置Ｓ０からスタンバイ位置Ｓ１に移動するように構成されている。そして、流量制御弁１００は、第２閾値ＴＨ２よりも大きい作動力が供給されることにより、スプール２が付勢手段３０の付勢力に抗して、スタンバイ位置Ｓ１から、スプール２の移動量に応じて弁開度を変化させる制御領域Ｓ２に移動するように構成されている。 In the first embodiment, the flow control valve 100 has a first threshold value TH1 that is an upper limit for holding the spool 2 at the neutral position S0 and a second threshold value TH2 that is larger than the first threshold value TH1. The spool 2 is configured to move from the neutral position S0 to the standby position S1 against the urging force of the urging means 30. The flow rate control valve 100 is supplied with an operating force larger than the second threshold value TH2, so that the spool 2 resists the urging force of the urging means 30 from the standby position S1 to the moving amount of the spool 2. Accordingly, the valve travels to the control region S2 in which the valve opening is changed.
　スタンバイ位置Ｓ１は、中立位置Ｓ０と制御領域Ｓ２との間の位置であり、制御領域Ｓ２による制御が開始される直前の位置である。すなわち、スタンバイ位置Ｓ１は、スプール２の外周面２１と弁座部１３とによるポート間のシール部分１４の長さが極小となる制御領域Ｓ２の境界位置であり、第１ポートＡ側と第２ポートＢ側との各々に設定されている。たとえば図４および図５に示すように、第１ポートＡ側のスタンバイ位置Ｓ１から、スプール２が僅かでも第１ポートＡ側に移動すると、スプール２が第１ポートＡ側の制御領域Ｓ２に進入して第１ポートＡと供給ポートＰとが連通する。 The standby position S1 is a position between the neutral position S0 and the control area S2, and is a position immediately before the control by the control area S2 is started. That is, the standby position S1 is a boundary position of the control region S2 where the length of the seal portion 14 between the ports by the outer peripheral surface 21 of the spool 2 and the valve seat portion 13 is minimized. It is set for each port B side. For example, as shown in FIGS. 4 and 5, when the spool 2 moves even slightly from the standby position S1 on the first port A side to the first port A side, the spool 2 enters the control area S2 on the first port A side. Thus, the first port A and the supply port P communicate with each other.
　第１実施形態では、付勢手段３０は、スプール２が中立位置Ｓ０にある場合、第１閾値ＴＨ１と等しい付勢力を発生させ、スプール２がスタンバイ位置Ｓ１にある場合に、第２閾値ＴＨ２と等しい付勢力を発生させるように構成されている。 In the first embodiment, the biasing means 30 generates a biasing force equal to the first threshold TH1 when the spool 2 is in the neutral position S0, and the second threshold TH2 when the spool 2 is in the standby position S1. It is comprised so that equal urging | biasing force may be generated.
　具体的には、図２に示すように、付勢手段３０は、少なくとも中立位置Ｓ０とスタンバイ位置Ｓ１との間でスプール２に圧縮される第１ばね３１と、制御領域Ｓ２においてスプール２に圧縮される第２ばね３２と、を含む。第１ばね３１および第２ばね３２は、一対のパイロット室１２にそれぞれ配置されている。第１ばね３１および第２ばね３２は、共に圧縮コイルばねであり、所定の圧縮状態で配置されることにより、中立位置Ｓ０で初期付勢力を発生するように設けられている。 Specifically, as shown in FIG. 2, the biasing means 30 is compressed to the spool 2 in the control region S2 and the first spring 31 compressed to the spool 2 at least between the neutral position S0 and the standby position S1. A second spring 32. The first spring 31 and the second spring 32 are respectively disposed in the pair of pilot chambers 12. The first spring 31 and the second spring 32 are both compression coil springs, and are arranged so as to generate an initial urging force at the neutral position S0 by being arranged in a predetermined compression state.
　また、第１実施形態では、ボディ１は、中立位置Ｓ０におけるスプール２の移動を規制する第１ストッパ３３と、スタンバイ位置Ｓ１におけるスプール２の移動を規制する第２ストッパ３４とをさらに含んでいる。第１ばね３１は、第１閾値ＴＨ１と等しい初期付勢力で第１ストッパ３３をボディ１に対して付勢し、第２ばね３２は、第２閾値ＴＨ２と等しい初期付勢力で第２ストッパ３４をボディ１に対して付勢している。 In the first embodiment, the body 1 further includes a first stopper 33 that restricts the movement of the spool 2 at the neutral position S0 and a second stopper 34 that restricts the movement of the spool 2 at the standby position S1. . The first spring 31 biases the first stopper 33 against the body 1 with an initial biasing force equal to the first threshold TH1, and the second spring 32 biases the second stopper 34 with an initial biasing force equal to the second threshold TH2. Is urged against the body 1.
　第１ストッパ３３および第２ストッパ３４は、一対のパイロット室１２にそれぞれ配置されている。これらのばねおよびストッパは、スプール２が配置される中央側から外側に向かって、第１ストッパ３３、第１ばね３１、第２ストッパ３４、第２ばね３２の順で並んで配置されている。 The first stopper 33 and the second stopper 34 are respectively disposed in the pair of pilot chambers 12. These springs and stoppers are arranged side by side in the order of the first stopper 33, the first spring 31, the second stopper 34, and the second spring 32 from the center side where the spool 2 is disposed to the outside.
　パイロット室１２には、中立位置Ｓ０に対応する第１位置決め部１６と、スタンバイ位置Ｓ１に対応する第２位置決め部１７とが設けられている。第１位置決め部１６および第２位置決め部１７は、パイロット室１２の内径を減少させるように設けられた段差部である。 The pilot chamber 12 is provided with a first positioning portion 16 corresponding to the neutral position S0 and a second positioning portion 17 corresponding to the standby position S1. The first positioning portion 16 and the second positioning portion 17 are stepped portions provided so as to reduce the inner diameter of the pilot chamber 12.
　第１ストッパ３３は、第１ばね３１によってスプール２側に付勢され、ボディ１の一部である第１位置決め部１６に押圧されている。第１ストッパ３３は、第１位置決め部１６により、中立位置Ｓ０におけるスプール２の軸方向端面と略等しい位置に配置される。スプール２に対して軸方向の両側に第１ストッパ３３が配置されることにより、スプール２が中立位置Ｓ０に保持される。第１ストッパ３３が第１閾値ＴＨ１と等しい付勢力で押圧されることにより、スプール２に第１閾値ＴＨ１と等しい作動力が作用した場合に釣り合い状態となり、第１閾値ＴＨ１よりも大きい作動力が付与されると、第１ストッパ３３とともに第１ばね３１が圧縮される。逆に、外乱などによりスプール２に第１閾値ＴＨ１以下の力が作用しても、第１ストッパ３３は移動しない。第１ストッパ３３は、第１位置決め部１６に押圧されているので、中立位置Ｓ０のスプール２に押圧力が作用することはない。第１ストッパ３３は、スプール２に対しては、第１閾値ＴＨ１よりも大きい作動力が付与される場合にのみ移動する壁面として機能する。 The first stopper 33 is urged toward the spool 2 by the first spring 31 and is pressed against the first positioning portion 16 which is a part of the body 1. The first stopper 33 is disposed by the first positioning portion 16 at a position substantially equal to the axial end surface of the spool 2 at the neutral position S0. By disposing the first stoppers 33 on both sides of the spool 2 in the axial direction, the spool 2 is held at the neutral position S0. When the first stopper 33 is pressed with an urging force equal to the first threshold value TH1, an operating force equal to the first threshold value TH1 is applied to the spool 2, and a balanced state is obtained, and an operating force larger than the first threshold value TH1 is applied. When applied, the first spring 31 is compressed together with the first stopper 33. Conversely, even if a force equal to or less than the first threshold value TH1 acts on the spool 2 due to disturbance or the like, the first stopper 33 does not move. Since the first stopper 33 is pressed by the first positioning portion 16, no pressing force acts on the spool 2 at the neutral position S0. The first stopper 33 functions as a wall surface that moves only when an operating force larger than the first threshold value TH1 is applied to the spool 2.
　第１ばね３１は、一端側が第１ストッパ３３と当接し、他端側が第２ストッパ３４と当接した状態で保持されている。第１ばね３１の他端側は、第２ストッパ３４を介して、第２ばね３２によって支持されている。 The first spring 31 is held in a state where one end side is in contact with the first stopper 33 and the other end side is in contact with the second stopper 34. The other end side of the first spring 31 is supported by the second spring 32 via the second stopper 34.
　第２ストッパ３４は、第２ばね３２によってスプール２側に付勢され、ボディ１の一部である第２位置決め部１７に押圧されている。第２ストッパ３４は、第２位置決め部１７により、スタンバイ位置Ｓ１にスプール２を保持するように配置されている。つまり、スプール２が移動して第１ばね３１を圧縮すると、第１ストッパ３３と第２ストッパ３４とが当接することにより、スプール２の移動が規制されるスタンバイ位置Ｓ１（図４、図６参照）に達する。第２ストッパ３４が第２閾値ＴＨ２に等しい付勢力で押圧されることにより、スプール２に第２閾値ＴＨ２と等しい作動力が作用した場合に釣り合い状態となり、第２閾値ＴＨ２よりも大きい作動力が付与されると、第２ストッパ３４とともに第２ばね３２が圧縮される。逆に、スプール２に第２閾値ＴＨ２以下の力が作用している間は、第２ストッパ３４は移動しない。第２ストッパ３４は、第２位置決め部１７に押圧されているので、第１ばね３１に第２ばね３２の付勢力が作用することはない。 The second stopper 34 is urged toward the spool 2 by the second spring 32 and is pressed against the second positioning portion 17 which is a part of the body 1. The second stopper 34 is disposed by the second positioning portion 17 so as to hold the spool 2 at the standby position S1. That is, when the spool 2 moves and compresses the first spring 31, the first stopper 33 and the second stopper 34 come into contact with each other, so that the movement of the spool 2 is restricted (see FIGS. 4 and 6). ). When the second stopper 34 is pressed with an urging force equal to the second threshold value TH2, an operating force equal to the second threshold value TH2 is applied to the spool 2, and a balanced state is obtained, and an operating force larger than the second threshold value TH2 is applied. When applied, the second spring 32 is compressed together with the second stopper 34. On the contrary, the second stopper 34 does not move while a force equal to or less than the second threshold value TH2 is acting on the spool 2. Since the second stopper 34 is pressed by the second positioning portion 17, the urging force of the second spring 32 does not act on the first spring 31.
　第２ばね３２は、一端側が第２ストッパ３４と当接し、他端側がボディ１の内面と当接した状態で保持されている。図５および図７に示すように、スプール２に第２閾値ＴＨ２よりも大きい作動力が付与される場合、スプール２と第１ストッパ３３と第２ストッパ３４とが接触して一体となり、第２ばね３２を圧縮する制御領域Ｓ２に到達する。制御領域Ｓ２では、第２ばね３２の圧縮量（すなわち、スプール２の移動量）が、第２閾値ＴＨ２よりも大きい作動力に対して比例する。 The second spring 32 is held in a state where one end is in contact with the second stopper 34 and the other end is in contact with the inner surface of the body 1. As shown in FIGS. 5 and 7, when an operating force larger than the second threshold value TH2 is applied to the spool 2, the spool 2, the first stopper 33, and the second stopper 34 come into contact with each other, and the second The control region S2 for compressing the spring 32 is reached. In the control region S2, the amount of compression of the second spring 32 (that is, the amount of movement of the spool 2) is proportional to the operating force that is greater than the second threshold value TH2.
　第１実施形態では、第１ばね３１と第２ばね３２とが互いに独立してスプール２に圧縮されるように構成されている。つまり、中立位置Ｓ０－スタンバイ位置Ｓ１間では第１ばね３１の付勢力のみがスプール２に反力として作用し、制御領域Ｓ２では第２ばね３２の付勢力のみがスプール２に反力として作用するため、各ばねの付勢力は分離して作用する。第１実施形態では、第１ばね３１のばね定数Ｋ１は、第２ばね３２のばね定数Ｋ２よりも小さい。たとえば、中立位置Ｓ０における初期付勢力で比較すると、第２ばね３２の初期付勢力（＝第２閾値ＴＨ２）は、第１ばね３１の初期付勢力（＝第１閾値ＴＨ１）の２倍以上となるように構成されている。また、第１ばね３１は、最大限圧縮された状態（図４～図７参照）でも、発生する付勢力が第２閾値ＴＨ２未満となるように構成されている。 In the first embodiment, the first spring 31 and the second spring 32 are configured to be compressed by the spool 2 independently of each other. That is, only the urging force of the first spring 31 acts on the spool 2 as a reaction force between the neutral position S0 and the standby position S1, and only the urging force of the second spring 32 acts on the spool 2 as a reaction force in the control region S2. Therefore, the urging force of each spring acts separately. In the first embodiment, the spring constant K1 of the first spring 31 is smaller than the spring constant K2 of the second spring 32. For example, when compared with the initial biasing force at the neutral position S0, the initial biasing force (= second threshold value TH2) of the second spring 32 is at least twice the initial biasing force (= first threshold value TH1) of the first spring 31. It is comprised so that it may become. In addition, the first spring 31 is configured such that the generated urging force is less than the second threshold value TH2 even when it is compressed to the maximum extent (see FIGS. 4 to 7).
　なお、第１ストッパ３３および第２ストッパ３４の各々には、作動油を通過させるための貫通孔３５が設けられている。このため、作動力を付与するためにパイロット室１２に作動油が供給されると、作動油が貫通孔３５を介してスプール２に油圧を作用させる。 Each of the first stopper 33 and the second stopper 34 is provided with a through hole 35 for allowing hydraulic oil to pass therethrough. For this reason, when hydraulic fluid is supplied to the pilot chamber 12 in order to apply the operational force, the hydraulic fluid acts on the spool 2 through the through hole 35.
　このような構成により、スプール２が、中立位置Ｓ０、スタンバイ位置Ｓ１、および制御領域Ｓ２のそれぞれに移動する。 With this configuration, the spool 2 moves to each of the neutral position S0, the standby position S1, and the control area S2.
〈第１ポートの開放動作〉
　第１ポートＡを開く（供給ポートＰと連通させる）場合、まず、図４に示すように、スプール２が第１ポートＡ側のスタンバイ位置Ｓ１に移動される。具体的には、第２ポートＢ側のパイロット室１２に、作動力供給手段１０５から作動油が供給され、第１ポートＡ側に向かう作動力Ｆがスプール２に付与される。なお、スプール２をスタンバイ位置Ｓ１に移動させるには、第１閾値ＴＨ１と、中立位置Ｓ０とスタンバイ位置Ｓ１との間の移動距離分だけ第１ばね３１を圧縮することによる付勢力の増分（ばね定数Ｋ１×移動距離）との合計以上の作動力Ｆが必要となる。作動力Ｆは、所定の第１作動力Ｆ１（図１０参照）まで直ち（ステップ関数的に）に上昇させることができる。第１作動力Ｆ１は、第１閾値ＴＨ１と第２閾値ＴＨ２との間で、なるべく第２閾値ＴＨ２近傍の大きさとすることが好ましい。これにより、スプール２が第１ばね３１を圧縮して中立位置Ｓ０からスタンバイ位置Ｓ１に速やかに移動する。スプール２の移動は、スタンバイ位置Ｓ１で第２ストッパ３４および第２ばね３２によって停止される。 <Opening operation of the first port>
When opening the first port A (ie, communicating with the supply port P), first, as shown in FIG. 4, the spool 2 is moved to the standby position S1 on the first port A side. Specifically, the hydraulic oil is supplied from the operating force supply means 105 to the pilot chamber 12 on the second port B side, and the operating force F toward the first port A is applied to the spool 2. In order to move the spool 2 to the standby position S1, an increase in the urging force (spring) by compressing the first spring 31 by the first threshold TH1 and the movement distance between the neutral position S0 and the standby position S1. A working force F equal to or greater than the sum of (constant K1 × movement distance) is required. The operating force F can be increased immediately (in a step function) to a predetermined first operating force F1 (see FIG. 10). The first operating force F1 is preferably set to a magnitude as close as possible to the second threshold TH2 between the first threshold TH1 and the second threshold TH2. As a result, the spool 2 compresses the first spring 31 and quickly moves from the neutral position S0 to the standby position S1. The movement of the spool 2 is stopped by the second stopper 34 and the second spring 32 at the standby position S1.
　次に、第２閾値ＴＨ２を越える第２作動力Ｆ２（図１０参照）がスプール２へ付与されることにより、図５に示すように第２ばね３２が圧縮され、スプール２がスタンバイ位置Ｓ１から制御領域Ｓ２へ移動する。これにより、スプール２の切欠部２３および溝部２２を介して供給ポートＰと第１ポートＡとが連通するとともに、スプール２の移動量に応じて切欠部２３による連通箇所の開口面積が制御される比例流量制御が開始される。このとき、第２ポートＢと排出ポートＴとが、スプール２の切欠部２３、溝部２２およびバイパス通路２４を介して連通し、油圧シリンダ１０１から第２ポートＢに流入する作動油（戻り油）が排出ポートＴから排出される。 Next, when the second operating force F2 (see FIG. 10) exceeding the second threshold TH2 is applied to the spool 2, the second spring 32 is compressed as shown in FIG. 5, and the spool 2 is moved from the standby position S1. Move to control area S2. As a result, the supply port P and the first port A communicate with each other via the notch portion 23 and the groove portion 22 of the spool 2, and the opening area of the communicating portion by the notch portion 23 is controlled according to the amount of movement of the spool 2. Proportional flow control is started. At this time, the second port B and the discharge port T communicate with each other via the notch portion 23, the groove portion 22 and the bypass passage 24 of the spool 2, and the hydraulic oil (return oil) flowing into the second port B from the hydraulic cylinder 101. Is discharged from the discharge port T.
〈第２ポートの開放動作〉
　第２ポートＢを開く（供給ポートＰと連通させる）場合も同様である。図６に示すように、第１ポートＡ側のパイロット室１２に作動力供給手段１０５から作動油が供給され、第２ポートＢ側に向かう第１作動力Ｆ１がスプール２に付与されると、スプール２が第１ばね３１を圧縮して中立位置Ｓ０からスタンバイ位置Ｓ１に速やかに移動する。 <Second port opening operation>
The same applies to the case where the second port B is opened (in communication with the supply port P). As shown in FIG. 6, when hydraulic oil is supplied from the operating force supply means 105 to the pilot chamber 12 on the first port A side and the first operating force F1 toward the second port B is applied to the spool 2, The spool 2 compresses the first spring 31 and quickly moves from the neutral position S0 to the standby position S1.
　次に、第２閾値ＴＨ２を越える第２作動力Ｆ２がスプール２へ付与されることにより、図７に示すように第２ばね３２が圧縮され、スプール２がスタンバイ位置Ｓ１から制御領域Ｓ２へ移動する。これにより、スプール２の切欠部２３および溝部２２を介して供給ポートＰと第２ポートＢとが連通し、比例流量制御が開始される。このとき、第１ポートＡと排出ポートＴとが、スプール２の切欠部２３、溝部２２およびバイパス通路２４を介して連通し、油圧シリンダ１０１から第１ポートＡ側に流入する作動油（戻り油）が排出ポートＴから排出される。 Next, when the second operating force F2 exceeding the second threshold TH2 is applied to the spool 2, the second spring 32 is compressed as shown in FIG. 7, and the spool 2 moves from the standby position S1 to the control region S2. To do. As a result, the supply port P and the second port B communicate with each other via the notch portion 23 and the groove portion 22 of the spool 2, and proportional flow rate control is started. At this time, the first port A and the discharge port T communicate with each other via the notch 23, the groove 22, and the bypass passage 24 of the spool 2, and hydraulic oil (return oil) flowing from the hydraulic cylinder 101 to the first port A side. ) Is discharged from the discharge port T.
（通路部）
　次に、スプール２に設けられた通路部について説明する。 (Passage)
Next, the passage portion provided in the spool 2 will be described.
　図２に示すように、第１実施形態では、スプール２は、弁座部１３とスプール２との間を通過する作動油を排出するための通路部２５を有している。 As shown in FIG. 2, in the first embodiment, the spool 2 has a passage portion 25 for discharging hydraulic oil that passes between the valve seat portion 13 and the spool 2.
　通路部２５は、弁座部１３とスプール２の外周面２１との間の微小な隙間を介して漏れ出る作動油を排出することにより、中立位置Ｓ０（全閉状態）におけるポート間の作動油のリークを防止する機能を有する。第１実施形態では、通路部２５は、スプール２の中立位置Ｓ０において、少なくとも第１ポートＡと供給ポートＰとの間の第１弁座部１３ａと対向する位置に配置されている。図２の例では、第１ポートＡと供給ポートＰとの間の第１弁座部１３ａのみならず、第２ポートＢと供給ポートＰとの間の第３弁座部１３ｃと対向する位置にも通路部２６が設けられている。 The passage portion 25 discharges hydraulic fluid that leaks through a minute gap between the valve seat portion 13 and the outer peripheral surface 21 of the spool 2, so that the hydraulic fluid between the ports in the neutral position S <b> 0 (fully closed state). Has a function of preventing leakage. In the first embodiment, the passage portion 25 is disposed at a position facing at least the first valve seat portion 13a between the first port A and the supply port P in the neutral position S0 of the spool 2. In the example of FIG. 2, not only the first valve seat portion 13 a between the first port A and the supply port P but also the position facing the third valve seat portion 13 c between the second port B and the supply port P. Also, a passage portion 26 is provided.
　通路部２５（通路部２６）は、中立位置Ｓ０において、スプール２の外周面２１からスプール２の内部を通って排出ポートＴに連通するように設けられている。具体的には、通路部２５（通路部２６）は、隣り合う溝部２２の間の外周面２１に開口するように形成され、スプール２内を貫通してバイパス通路２４に接続されている。これにより、通路部２５（通路部２６）は、バイパス通路２４と部分的に共通する経路で、排出ポートＴと連通する。 The passage portion 25 (passage portion 26) is provided so as to communicate with the discharge port T from the outer peripheral surface 21 of the spool 2 through the inside of the spool 2 at the neutral position S0. Specifically, the passage portion 25 (passage portion 26) is formed so as to open to the outer peripheral surface 21 between the adjacent groove portions 22, and penetrates through the spool 2 and is connected to the bypass passage 24. Accordingly, the passage portion 25 (passage portion 26) communicates with the discharge port T through a route that is partially in common with the bypass passage 24.
　図８に示すように、通路部２５（通路部２６）は、供給ポートＰの内径ｄ１よりも小さい内径ｄ２を有する細孔である。通路部２５（通路部２６）は、弁座部１３とスプール２の外周面２１との間を通過して漏れ出るごく僅かな作動油を排出ポートＴに排出する。より詳細には、スプール２の外周面２１には、摺動抵抗を低減するために微細な環状溝（図示せず）が設けられおり、通路部２５（通路部２６）は、環状溝の底部に開口している。 As shown in FIG. 8, the passage portion 25 (passage portion 26) is a fine hole having an inner diameter d2 smaller than the inner diameter d1 of the supply port P. The passage portion 25 (passage portion 26) discharges a very small amount of hydraulic oil that leaks through the passage between the valve seat portion 13 and the outer peripheral surface 21 of the spool 2 to the discharge port T. More specifically, a fine annular groove (not shown) is provided on the outer peripheral surface 21 of the spool 2 to reduce sliding resistance, and the passage portion 25 (passage portion 26) is formed at the bottom of the annular groove. Is open.
　通路部２５は、スプール２の中立位置Ｓ０において、第１弁座部１３ａの供給ポートＰ側の一端部よりも、第１弁座部１３ａの第１ポートＡ側の他端部に近い位置に配置されている。同様に、通路部２６は、スプール２の中立位置Ｓ０において、第３弁座部１３ｃの供給ポートＰ側の一端部よりも、第３弁座部１３ｃの第２ポートＢ側の他端部に近い位置に配置されている。このため、高圧の供給ポートＰから隙間に漏れ出る作動油は、第１ポートＡ（第２ポートＢ）の近傍に到達して初めて排出ポートＴへ排出される。 In the neutral position S0 of the spool 2, the passage portion 25 is positioned closer to the other end portion on the first port A side of the first valve seat portion 13a than one end portion on the supply port P side of the first valve seat portion 13a. Has been placed. Similarly, in the neutral position S0 of the spool 2, the passage portion 26 is located closer to the other end portion on the second port B side of the third valve seat portion 13c than to one end portion on the supply port P side of the third valve seat portion 13c. It is arranged at a close position. For this reason, the hydraulic oil that leaks into the gap from the high-pressure supply port P is discharged to the discharge port T only after reaching the vicinity of the first port A (second port B).
　図８に示すように、通路部２５は、スプール２が中立位置Ｓ０から第１ポートＡ側のスタンバイ位置Ｓ１に移動する際に、第１ポートＡを通過して、第１ポートＡと排出ポートＴとの間の第２弁座部１３ｂと対向する位置に移動する。同様に、図９に示すように、通路部２６は、スプール２が中立位置Ｓ０から第２ポートＢ側のスタンバイ位置Ｓ１に移動する際に、第２ポートＢを通過して、第２ポートＢと排出ポートＴとの間の第４弁座部１３ｄと対向する位置に移動する。したがって、スプール２が中立位置Ｓ０からスタンバイ位置Ｓ１に移動する際には、通路部２５（通路部２６）が第１ポートＡ（第２ポートＢ）と対向して連通する状態があるが、上記の通り中立位置Ｓ０からスタンバイ位置Ｓ１への移動が短時間で完了するため、移動中のリークは実質的には発生しないようになっている。スタンバイ位置Ｓ１では、対向する第２弁座部１３ｂ（第４弁座部１３ｄ）によって通路部２５（通路部２６）が塞がれた状態となるため、通路部２５（通路部２６）は排出ポートＴ以外とは連通しない。 As shown in FIG. 8, when the spool 2 moves from the neutral position S0 to the standby position S1 on the first port A side, the passage portion 25 passes through the first port A and passes through the first port A and the discharge port. It moves to a position opposite to the second valve seat 13b between T. Similarly, as shown in FIG. 9, when the spool 2 moves from the neutral position S0 to the standby position S1 on the second port B side, the passage portion 26 passes through the second port B and passes through the second port B. And a position opposite to the fourth valve seat portion 13d between the valve and the discharge port T. Therefore, when the spool 2 moves from the neutral position S0 to the standby position S1, there is a state where the passage portion 25 (passage portion 26) communicates with the first port A (second port B). As described above, since the movement from the neutral position S0 to the standby position S1 is completed in a short time, leakage during movement is substantially not generated. In the standby position S1, the passage portion 25 (passage portion 26) is blocked by the opposing second valve seat portion 13b (fourth valve seat portion 13d), and therefore the passage portion 25 (passage portion 26) is discharged. It does not communicate with anything other than port T.
　また、図２に示すように、スプール２の中立位置Ｓ０における通路部２５と第１弁座部１３ａの一端部との間の長さＬ１１は、中立位置Ｓ０から第２ポートＢ側へのスプール２の移動可能距離Ｌ２１以上である。同様に、スプール２の中立位置Ｓ０における通路部２６と第３弁座部１３ｃの一端部との間の長さＬ１２は、中立位置Ｓ０から第２ポートＢ側へのスプール２の移動可能距離Ｌ２２以上である。なお、図２の構成例では、長さＬ１１とＬ１２とは等しく、距離Ｌ２１とＬ２２とは等しい。距離Ｌ２１（Ｌ２２）は、中立位置Ｓ０における第１ストッパ３３と第２ストッパ３４との間の距離Ｄ１と、第２ストッパ３４とボディ１の内面との間の距離Ｄ２との和に概ね等しい。 Further, as shown in FIG. 2, the length L11 between the passage portion 25 and the one end portion of the first valve seat portion 13a at the neutral position S0 of the spool 2 is the spool from the neutral position S0 to the second port B side. It is 2 or more movable distance L21. Similarly, a length L12 between the passage portion 26 and the one end portion of the third valve seat portion 13c at the neutral position S0 of the spool 2 is a movable distance L22 of the spool 2 from the neutral position S0 to the second port B side. That's it. In the configuration example of FIG. 2, the lengths L11 and L12 are equal, and the distances L21 and L22 are equal. The distance L21 (L22) is approximately equal to the sum of the distance D1 between the first stopper 33 and the second stopper 34 at the neutral position S0 and the distance D2 between the second stopper 34 and the inner surface of the body 1.
　このため、スプール２が第１ポートＡ側へ最大開度となるまで移動した場合、通路部２５は第２弁座部１３ｂによって塞がれ、通路部２６が第３弁座部１３ｃによって供給ポートＰと非連通で塞がれた状態を維持する。スプール２が第２ポートＢ側へ最大開度となるまで移動した場合、通路部２５は第１弁座部１３ａによって供給ポートＰと非連通で塞がれた状態を維持し、通路部２６が第４弁座部１３ｄによって塞がれた状態を維持する。 Therefore, when the spool 2 moves to the first port A side until the maximum opening degree is reached, the passage portion 25 is blocked by the second valve seat portion 13b, and the passage portion 26 is supplied by the third valve seat portion 13c. Maintain a closed state without communication with P. When the spool 2 moves to the second port B side until the maximum opening degree is reached, the passage portion 25 is kept closed by the first valve seat portion 13a so as not to communicate with the supply port P. The state closed by the fourth valve seat portion 13d is maintained.
（第１実施形態の効果）
　第１実施形態では、以下のような効果を得ることができる。 (Effect of 1st Embodiment)
In the first embodiment, the following effects can be obtained.
　第１実施形態では、上記のように、スプール２が中立位置Ｓ０およびスタンバイ位置Ｓ１にある場合に、スプール２の外周面２１とにより油路を遮断する弁座部１３を設ける。これにより、中立位置Ｓ０とスタンバイ位置Ｓ１との間の範囲にわたって弁座部１３を設けることができるので、中立位置Ｓ０におけるスプール２と弁座部１３とのシール部分１４の長さ（Ｌ１～Ｌ４）を十分に確保することができる。その結果、油路への作動油の漏れを抑制することができる。また、上記のように、スプール２を移動させる作動力Ｆが、スプール２を中立位置Ｓ０に保持する上限である第１閾値ＴＨ１と、第１閾値ＴＨ１よりも大きい第２閾値ＴＨ２との間の大きさで供給されることにより、スプール２が付勢手段３０の付勢力に抗して中立位置Ｓ０からスタンバイ位置Ｓ１に移動し、第２閾値ＴＨ２よりも大きい作動力Ｆが供給されることにより、スプール２が付勢手段３０の付勢力に抗して、スタンバイ位置Ｓ１から、スプール２の移動量に応じて弁開度を変化させる制御領域Ｓ２に移動するように流量制御弁１００を構成する。これにより、流量制御を行う場合に予め第１閾値ＴＨ１と第２閾値ＴＨ２との間の大きさの作動力（第１作動力Ｆ１）を供給すれば、スプール２が速やかにスタンバイ位置Ｓ１に移動して流量制御を開始可能な状態となり、作動力Ｆが第２閾値ＴＨ２を越えた時点から速やかに流量制御を開始することができる。すなわち、流量制御の直前にスプール２を中立位置Ｓ０からスタンバイ位置Ｓ１に移動させておくことにより、応答性を向上させることができるので、弁座部１３を長くしてシール部分１４の長さ（Ｌ１～Ｌ４）を十分に確保する場合でも、高い応答性を確保することができる。以上により、第１実施形態の流量制御装置１００によれば、応答性を損なうことなく、油路への作動油の漏れを抑制することができる。 In the first embodiment, as described above, when the spool 2 is in the neutral position S0 and the standby position S1, the valve seat portion 13 that blocks the oil passage with the outer peripheral surface 21 of the spool 2 is provided. As a result, the valve seat portion 13 can be provided over a range between the neutral position S0 and the standby position S1, and therefore the length (L1 to L4) of the seal portion 14 between the spool 2 and the valve seat portion 13 in the neutral position S0. ) Can be secured sufficiently. As a result, the leakage of hydraulic oil to the oil passage can be suppressed. In addition, as described above, the operating force F that moves the spool 2 is between the first threshold TH1 that is the upper limit for holding the spool 2 in the neutral position S0 and the second threshold TH2 that is greater than the first threshold TH1. By being supplied in a magnitude, the spool 2 moves from the neutral position S0 to the standby position S1 against the urging force of the urging means 30, and an operating force F greater than the second threshold value TH2 is supplied. The flow rate control valve 100 is configured so that the spool 2 moves from the standby position S1 to the control region S2 in which the valve opening is changed according to the amount of movement of the spool 2 against the urging force of the urging means 30. . Thus, when the flow rate control is performed, if the operating force (first operating force F1) having a magnitude between the first threshold value TH1 and the second threshold value TH2 is supplied in advance, the spool 2 quickly moves to the standby position S1. Thus, the flow rate control can be started, and the flow rate control can be started immediately from the time when the operating force F exceeds the second threshold value TH2. That is, since the responsiveness can be improved by moving the spool 2 from the neutral position S0 to the standby position S1 immediately before the flow rate control, the valve seat portion 13 is lengthened and the length of the seal portion 14 ( Even when L1 to L4) are sufficiently secured, high responsiveness can be secured. As described above, according to the flow control device 100 of the first embodiment, it is possible to suppress leakage of hydraulic oil to the oil passage without impairing responsiveness.
　図１０に示す開閉制御の一例を用いてより具体的に説明する。一般の比例流量制御弁では、不感帯（スプールを移動させても流量制御が開始しない領域）を減少させて比例制御の応答性を確保するため、シール部分の長さを極力小さくしている。このため、スプールを摺動させるための微小隙間を介したリークを抑制することができず、中立位置におけるポート間のシール性が高くない。図１０の比較例に示すように、流量制御の開始時間ｔ２からの応答性は確保されているものの、中立位置において供給ポートＰから第１ポートＡまたは第２ポートＢへ一定のリーク流量が存在し続けることになる。 This will be described more specifically using an example of the opening / closing control shown in FIG. In a general proportional flow control valve, the length of the seal portion is made as small as possible in order to reduce the dead zone (the region where flow control does not start even when the spool is moved) to ensure proportional control responsiveness. For this reason, it is not possible to suppress leakage through a minute gap for sliding the spool, and the sealing performance between the ports in the neutral position is not high. As shown in the comparative example of FIG. 10, there is a constant leak flow rate from the supply port P to the first port A or the second port B in the neutral position, although the responsiveness from the flow control start time t2 is ensured. Will continue to do.
　これに対して、第１実施形態では、シール部分１４の長さＬ１～Ｌ４が十分に確保される。このため、中立位置Ｓ０における各ポート間のシール性が向上し、中立位置Ｓ０においてリーク流量は略発生しない。この場合、通常は長さＬ１～Ｌ４の分だけ不感帯が増大することになるが、流量制御の開始時間ｔ２の直前のタイミングｔ１において、予め第１作動力Ｆ１を供給することにより、シール部分１４が極力小さくなるスタンバイ位置Ｓ１までスプール２を移動させることができる。スタンバイ位置Ｓ１では、シール部分１４が小さくなるため、移動方向に応じて供給ポートＰと第１ポートＡまたは第２ポートＢとの間にリーク（いわゆる前漏れ）が発生し得る。しかし、スタンバイ位置Ｓ１への移動は、第１作動力Ｆ１を第２閾値ＴＨ２の近傍に設定することにより、ごく短時間で完了させることができる（時刻ｔ１とｔ２との間の時間間隔を小さくできる）ため、スタンバイ位置Ｓ１においてリークが発生する時間（リーク流量）は極力小さくすることが可能である。その結果、シール性を確保しつつ、時間ｔ２で第２閾値ＴＨ２を越える第２作動力Ｆ２を供給する際にも、比較例の比例流量制御弁と同等の応答性を確保することができる。 On the other hand, in the first embodiment, the lengths L1 to L4 of the seal portion 14 are sufficiently secured. For this reason, the sealing performance between the ports at the neutral position S0 is improved, and a leak flow rate is not substantially generated at the neutral position S0. In this case, the dead zone usually increases by the lengths L1 to L4. However, by supplying the first operating force F1 in advance at the timing t1 immediately before the start time t2 of the flow control, the seal portion 14 The spool 2 can be moved to the standby position S1 where is as small as possible. In the standby position S1, since the seal portion 14 is small, a leak (so-called pre-leakage) may occur between the supply port P and the first port A or the second port B depending on the moving direction. However, the movement to the standby position S1 can be completed in a very short time by setting the first operating force F1 in the vicinity of the second threshold value TH2 (the time interval between the times t1 and t2 is reduced). Therefore, the time (leakage flow rate) during which leakage occurs at the standby position S1 can be minimized. As a result, when supplying the second operating force F2 that exceeds the second threshold value TH2 at time t2 while ensuring the sealing performance, the same responsiveness as that of the proportional flow control valve of the comparative example can be ensured.
　また、第１実施形態では、上記のように、付勢手段３０を、スプール２が中立位置Ｓ０にある場合、第１閾値ＴＨ１と等しい付勢力を発生させ、スプール２がスタンバイ位置Ｓ１にある場合に、第２閾値ＴＨ２と等しい付勢力を発生させるように構成する。これにより、スプール２を中立位置Ｓ０に保持するための付勢手段３０を用いて、スプール２をスタンバイ位置Ｓ１に保持することができる。この結果、スプール２を中立位置Ｓ０、スタンバイ位置Ｓ１および制御領域Ｓ２に段階的に移動させる構成を付勢手段３０により容易に実現することができる。 In the first embodiment, as described above, when the spool 2 is in the neutral position S0, the biasing means 30 generates a biasing force equal to the first threshold value TH1, and the spool 2 is in the standby position S1. In addition, an urging force equal to the second threshold value TH2 is generated. Accordingly, the spool 2 can be held at the standby position S1 by using the biasing means 30 for holding the spool 2 at the neutral position S0. As a result, it is possible to easily realize the configuration in which the spool 2 is moved stepwise to the neutral position S0, the standby position S1, and the control region S2 by the biasing means 30.
　また、第１実施形態では、上記のように、付勢手段３０に、少なくとも中立位置Ｓ０とスタンバイ位置Ｓ１との間でスプール２に圧縮される第１ばね３１と、制御領域Ｓ２においてスプール２に圧縮される第２ばね３２と、を設ける。第１ばね３１と第２ばね３２とを設けることにより、たとえば第１ばね３１に第１閾値ＴＨ１と等しい初期付勢力を発生させ、第２ばね３２に第２閾値ＴＨ２と等しい初期付勢力を発生させるなど、各々のばね定数を自由に決められる。そのため、中立位置Ｓ０において第１閾値ＴＨ１と等しい付勢力を発生させ、スタンバイ位置Ｓ１において第２閾値ＴＨ２と等しい付勢力を発生させる付勢手段３０を、より容易に構成することができる。 In the first embodiment, as described above, the urging means 30 includes at least the first spring 31 compressed by the spool 2 between the neutral position S0 and the standby position S1, and the spool 2 in the control region S2. A second spring 32 to be compressed. By providing the first spring 31 and the second spring 32, for example, an initial biasing force equal to the first threshold value TH1 is generated in the first spring 31, and an initial biasing force equal to the second threshold value TH2 is generated in the second spring 32. Each spring constant can be determined freely. Therefore, it is possible to more easily configure the urging means 30 that generates the urging force equal to the first threshold value TH1 at the neutral position S0 and generates the urging force equal to the second threshold value TH2 at the standby position S1.
　また、第１実施形態では、上記のように、第１ばね３１のばね定数Ｋ１を、第２ばね３２のばね定数Ｋ２よりも小さくする。第１ばね３１のばね定数を相対的に小さくすることにより、第１閾値ＴＨ１を越えてからスタンバイ位置Ｓ１まで第１ばね３１を圧縮するのに必要な作動力の大きさ（Ｋ１×移動距離）を小さくすることができる。その結果、スプール２をスタンバイ位置Ｓ１に移動するのに必要な作動力（ＴＨ１＋Ｋ１×移動距離）と第２閾値ＴＨ２との差を大きくすることができるので、スタンバイ位置Ｓ１へのスプール２の移動を迅速に行うことができる。 In the first embodiment, the spring constant K1 of the first spring 31 is set smaller than the spring constant K2 of the second spring 32 as described above. By relatively reducing the spring constant of the first spring 31, the magnitude of the operating force required to compress the first spring 31 from the first threshold TH1 to the standby position S1 (K1 × travel distance) Can be reduced. As a result, the difference between the operating force (TH1 + K1 × movement distance) required to move the spool 2 to the standby position S1 and the second threshold value TH2 can be increased, so that the spool 2 is moved to the standby position S1. Can be done quickly.
　また、第１実施形態では、上記のように、中立位置Ｓ０におけるスプール２の移動を規制する第１ストッパ３３と、スタンバイ位置Ｓ１におけるスプール２の移動を規制する第２ストッパ３４とをボディ１に設ける。第１ばね３１により、第１閾値ＴＨ１と等しい初期付勢力で第１ストッパ３３をボディ１に対して付勢し、第２ばね３２により、第２閾値ＴＨ２と等しい初期付勢力で第２ストッパ３４をボディ１に対して付勢する。第１ストッパ３３を設けることにより、スプール２を中立位置Ｓ０に保持することができる。この場合、外乱などによってスプール２に第１閾値ＴＨ１以下の力が作用してもスプール２が移動しないため、安定してスプール２を中立位置Ｓ０に保持することができる。また、第２ストッパ３４を設けることにより、第２閾値ＴＨ２を第１ばね３１とは独立して第２ばね３２により設定することができる。そのため、第２閾値ＴＨ２を第１ばね３１および第２ばね３２の合成ばねにより設定する場合と比較して、第２閾値ＴＨ２を容易に設定できるとともに、スプール２を制御領域Ｓ２で動作させるために必要な作動力が大きくなることを抑制することができる。 In the first embodiment, as described above, the first stopper 33 for restricting the movement of the spool 2 at the neutral position S0 and the second stopper 34 for restricting the movement of the spool 2 at the standby position S1 are provided on the body 1. Provide. The first spring 31 biases the first stopper 33 against the body 1 with an initial biasing force equal to the first threshold value TH1, and the second spring 32 biases the second stopper 34 with an initial biasing force equal to the second threshold value TH2. Is urged against the body 1. By providing the first stopper 33, the spool 2 can be held at the neutral position S0. In this case, since the spool 2 does not move even if a force of the first threshold value TH1 or less is applied to the spool 2 due to disturbance or the like, the spool 2 can be stably held at the neutral position S0. Further, by providing the second stopper 34, the second threshold value TH 2 can be set by the second spring 32 independently of the first spring 31. Therefore, compared with the case where the second threshold value TH2 is set by the combined spring of the first spring 31 and the second spring 32, the second threshold value TH2 can be set easily, and the spool 2 is operated in the control region S2. It is possible to suppress an increase in necessary operating force.
　また、第１実施形態では、上記のように、中立位置Ｓ０において、スプール２の外周面２１からスプール２の内部を通って排出ポートＴに連通する通路部２５をスプール２に設け、通路部２５を、スプール２の中立位置Ｓ０において、少なくとも第１ポートＡと供給ポートＰとの間の第１弁座部１３ａと対向する位置に配置する。これにより、スプール２と第１弁座部１３ａとの間での作動油の僅かな漏れを、通路部２５によって排出ポートＴへ送り出すことが可能となる。このため、油圧シリンダ１０１の昇降制御などに流量制御弁１００が用いられる場合でも、中立位置Ｓ０での作動油の漏れを防止して、位置ずれが生じることを防止することができる。なお、第１実施形態では、第１弁座部１３ａのみならず、第２ポートＢと供給ポートＰとの間の弁座部１３にも通路部２６を設けているため、第１ポートＡおよび第２ポートＢの両方への作動油の漏れを防止することが可能である。 In the first embodiment, as described above, at the neutral position S0, the spool 2 is provided with the passage portion 25 that communicates from the outer peripheral surface 21 of the spool 2 through the inside of the spool 2 to the discharge port T. Is disposed at a position facing at least the first valve seat 13a between the first port A and the supply port P in the neutral position S0 of the spool 2. As a result, a slight leakage of hydraulic oil between the spool 2 and the first valve seat portion 13 a can be sent out to the discharge port T by the passage portion 25. For this reason, even when the flow rate control valve 100 is used for raising / lowering control of the hydraulic cylinder 101 or the like, it is possible to prevent leakage of hydraulic oil at the neutral position S0 and to prevent displacement. In the first embodiment, since the passage portion 26 is provided not only in the first valve seat portion 13a but also in the valve seat portion 13 between the second port B and the supply port P, the first port A and It is possible to prevent the hydraulic oil from leaking to both of the second ports B.
　また、第１実施形態では、上記のように、通路部２５を、スプール２の中立位置Ｓ０において、第１弁座部１３ａの供給ポートＰ側の一端部よりも、第１弁座部１３ａの第１ポートＡ側の他端部に近い位置に配置する。これにより、通路部２５が高圧側の供給ポートＰから離れた位置に配置されるので、第１ポートＡへの作動油の漏れを防止しつつ、圧力差によって作動油が供給ポートＰから通路部２５へ漏れ出ることを抑制することができる。 Further, in the first embodiment, as described above, the passage portion 25 is arranged at the neutral position S0 of the spool 2 at the neutral position S0 of the first valve seat portion 13a rather than the one end portion on the supply port P side of the first valve seat portion 13a. It arrange | positions in the position near the other end part by the side of the 1st port A. As a result, the passage portion 25 is disposed at a position away from the supply port P on the high pressure side, so that the hydraulic oil is prevented from leaking from the supply port P by the pressure difference while preventing leakage of the hydraulic oil to the first port A. Leakage to 25 can be suppressed.
　また、第１実施形態では、上記のように、通路部２５を、スプール２が中立位置Ｓ０から第１ポートＡ側のスタンバイ位置Ｓ１に移動する際に、第１ポートＡを通過して、第１ポートＡと排出ポートＴとの間の第２弁座部１３ｂと対向する位置に移動するように設ける。このように、スプール２を中立位置Ｓ０からスタンバイ位置Ｓ１へと移動させる構造を利用して、通路部２５を第１弁座部１３ａから第２弁座部１３ｂへと移動させることにより、通路部２５が第１ポートＡと連通する位置に配置されることを防止することができる。すなわち、スプール２の外周面２１に通路部２５を設ける場合でも、第１弁座部１３ａを必要以上に長くすることなく、中立位置Ｓ０およびスタンバイ位置Ｓ１で通路部２５が常に弁座部１３（第１弁座部１３ａおよび第２弁座部１３ｂ）と対向して第１ポートＡと連通することがないようにすることが可能となる。 In the first embodiment, as described above, when the spool 2 moves from the neutral position S0 to the standby position S1 on the first port A side, the passage portion 25 passes through the first port A and It is provided so as to move to a position facing the second valve seat 13b between the 1 port A and the discharge port T. Thus, by using the structure in which the spool 2 is moved from the neutral position S0 to the standby position S1, the passage portion 25 is moved from the first valve seat portion 13a to the second valve seat portion 13b. 25 can be prevented from being arranged at a position communicating with the first port A. That is, even when the passage portion 25 is provided on the outer peripheral surface 21 of the spool 2, the passage portion 25 is always in the neutral position S0 and the standby position S1 without making the first valve seat portion 13a longer than necessary. It is possible to prevent the first valve seat portion 13a and the second valve seat portion 13b) from communicating with the first port A.
　また、第１実施形態では、上記のように、スプール２の中立位置Ｓ０における通路部２５と第１弁座部１３ａの一端部との間の長さＬ１１を、中立位置Ｓ０から第２ポートＢ側へのスプール２の移動可能距離Ｌ２１以上とする。これにより、スプール２を第２ポートＢ側の制御領域Ｓ２へ移動させて第２ポートＢへの流量制御が行われる場合でも、通路部２５が第１弁座部１３ａの外部へ移動して供給ポートＰと連通してしまうことを防止することができる。 In the first embodiment, as described above, the length L11 between the passage portion 25 and the one end portion of the first valve seat portion 13a at the neutral position S0 of the spool 2 is set to the second port B from the neutral position S0. More than the movable distance L21 of the spool 2 to the side. Accordingly, even when the spool 2 is moved to the control region S2 on the second port B side and the flow rate control to the second port B is performed, the passage portion 25 moves to the outside of the first valve seat portion 13a and is supplied. It is possible to prevent communication with the port P.
　また、第１実施形態では、上記のように、供給ポートＰの内径ｄ１よりも小さい内径ｄ２を有する通路部２５を設ける。このように内径の小さな通路部２５を設けることにより、中立位置Ｓ０において供給ポートＰから第１ポートＡへ漏れようとする僅かな作動油を確実に排出しつつ、圧力差によって作動油が不必要に通路部２５へ流入することを極力抑制することができる。 In the first embodiment, as described above, the passage portion 25 having the inner diameter d2 smaller than the inner diameter d1 of the supply port P is provided. By providing the passage portion 25 having a small inner diameter in this way, a small amount of hydraulic oil that leaks from the supply port P to the first port A at the neutral position S0 is reliably discharged, and no hydraulic oil is required due to a pressure difference. Inflow to the passage portion 25 can be suppressed as much as possible.
[第２実施形態]
　次に、図１１および図１２を参照して、本発明の第２実施形態による流量制御弁２００について説明する。第２実施形態では、第１ストッパ３３によってスプール２を中立位置Ｓ０に保持するように構成した上記第１実施形態とは異なり、第１ばね３１の釣り合いによってスプール２を中立位置Ｓ０に保持する例について説明する。なお、第２実施形態では、上記第１実施形態と同様の構成については、同一の符号を用いるとともに説明を省略する。 [Second Embodiment]
Next, with reference to FIG. 11 and FIG. 12, the flow control valve 200 by 2nd Embodiment of this invention is demonstrated. In the second embodiment, unlike the first embodiment in which the spool 2 is held at the neutral position S0 by the first stopper 33, the spool 2 is held at the neutral position S0 by the balance of the first spring 31. Will be described. In the second embodiment, the same components as those in the first embodiment are denoted by the same reference numerals and the description thereof is omitted.
　図１１に示すように、第２実施形態の流量制御弁２００では、第１ばね３１がスプール２を直接付勢するように構成されている。スプール２は、両側の第１ばね３１の付勢力によって、中立位置Ｓ０に保持される。第１ばね３１は、一端がスプール２に当接し、他端がストッパ２０１に当接するように設けられている。 As shown in FIG. 11, in the flow control valve 200 of the second embodiment, the first spring 31 is configured to urge the spool 2 directly. The spool 2 is held at the neutral position S0 by the biasing force of the first springs 31 on both sides. The first spring 31 is provided such that one end is in contact with the spool 2 and the other end is in contact with the stopper 201.
　ストッパ２０１は、第２ばね３２によってボディ１に向けて付勢されている。すなわち、ストッパ２０１は、ボディ１の段差部からなる位置決め部２０２に対して押圧されている。位置決め部２０２は、スタンバイ位置Ｓ１を規定する。図１２に示すように、スプール２に第１閾値ＴＨ１と第２閾値ＴＨ２との間の作動力Ｆが付与されると、スプール２が第１ばね３１を圧縮してストッパ２０１と当接するまで移動する。ストッパ２０１は、第２ばね３２により第２閾値ＴＨ２と等しい付勢力で、位置決め部２０２に付勢されているため、作動力が第２閾値ＴＨ２以下の場合には移動せずにスプール２をスタンバイ位置Ｓ１に保持する。 The stopper 201 is biased toward the body 1 by the second spring 32. That is, the stopper 201 is pressed against the positioning portion 202 formed of the step portion of the body 1. The positioning unit 202 defines the standby position S1. As shown in FIG. 12, when the operating force F between the first threshold value TH1 and the second threshold value TH2 is applied to the spool 2, the spool 2 moves until it compresses the first spring 31 and contacts the stopper 201. To do. The stopper 201 is urged by the positioning portion 202 with the urging force equal to the second threshold value TH2 by the second spring 32. Therefore, when the operating force is less than or equal to the second threshold value TH2, the stopper 2 is not moved and is put on standby. Hold at position S1.
　第２ばね３２は、一端がストッパ２０１に当接し、他端がボディ１の内面に当接するように設けられている。スプール２に第２閾値ＴＨ２よりも大きい作動力Ｆが付与されると、スプール２が第２ばね３２を圧縮してストッパ２０１とともに制御領域Ｓ２に移動する。その結果、スプール２の移動方向に応じたポート（第１ポートＡまたは第２ポートＢ）を供給ポートＰと連通させ、移動量と比例する流量で作動油を流通させる。なお、スタンバイ位置Ｓ１では、第１ばね３１が圧縮されてスプール２の端面とストッパ２０１とが当接する状態となるため、制御領域Ｓ２でのスプール２の移動中に第１ばね３１は機能しない。つまり、第１ばね３１と第２ばね３２とが互いに独立してスプール２に圧縮されるように構成されている。各ばねの付勢力は分離して作用する。 The second spring 32 is provided such that one end is in contact with the stopper 201 and the other end is in contact with the inner surface of the body 1. When an operating force F greater than the second threshold value TH2 is applied to the spool 2, the spool 2 compresses the second spring 32 and moves to the control region S2 together with the stopper 201. As a result, the port (first port A or second port B) corresponding to the moving direction of the spool 2 is communicated with the supply port P, and the hydraulic oil is circulated at a flow rate proportional to the moving amount. In the standby position S1, the first spring 31 is compressed and the end surface of the spool 2 comes into contact with the stopper 201. Therefore, the first spring 31 does not function during the movement of the spool 2 in the control region S2. That is, the first spring 31 and the second spring 32 are configured to be compressed by the spool 2 independently of each other. The urging force of each spring acts separately.
　第２実施形態の場合、スプール２は、第１ばね３１の釣り合いによって中立位置Ｓ０に保持される。そのため、スプール２を中立位置Ｓ０で安定して保持するためには、第１ばね３１のばね定数を大きくすることが好ましい。 In the case of the second embodiment, the spool 2 is held at the neutral position S0 by the balance of the first spring 31. Therefore, in order to stably hold the spool 2 at the neutral position S0, it is preferable to increase the spring constant of the first spring 31.
　第２実施形態のその他の構成は、上記第１実施形態と同様である。 Other configurations of the second embodiment are the same as those of the first embodiment.
　また、第２実施形態の効果は、上記第１実施形態と同様である。 The effect of the second embodiment is the same as that of the first embodiment.
[第３実施形態]
　次に、図１３および図１４を参照して、本発明の第３実施形態による流量制御弁３００について説明する。第３実施形態では、第１ばね３１と第２ばね３２とが独立して機能するように構成した上記第１および第２実施形態とは異なり、制御領域Ｓ２において第１ばね３１と第２ばね３２とが合成ばねとして機能する例について説明する。なお、第３実施形態では、上記第１実施形態と同様の構成については、同一の符号を用いるとともに説明を省略する。 [Third embodiment]
Next, with reference to FIG. 13 and FIG. 14, the flow control valve 300 by 3rd Embodiment of this invention is demonstrated. In the third embodiment, unlike the first and second embodiments configured such that the first spring 31 and the second spring 32 function independently, the first spring 31 and the second spring in the control region S2. An example in which 32 functions as a composite spring will be described. Note that in the third embodiment, the same components as those in the first embodiment are denoted by the same reference numerals and description thereof is omitted.
　図１３に示すように、第３実施形態の流量制御弁３００では、第１ばね３１は、一端がスプール２の端面に当接し、他端がボディ１の内面に当接するように設けられている。スプール２は、両側の第１ばね３１の付勢力によって、中立位置Ｓ０に保持される。また、第２ばね３２は、一端がストッパ３０１に当接し、他端がボディ１の内面に当接するように設けられている。 As shown in FIG. 13, in the flow control valve 300 of the third embodiment, the first spring 31 is provided such that one end contacts the end surface of the spool 2 and the other end contacts the inner surface of the body 1. . The spool 2 is held at the neutral position S0 by the biasing force of the first springs 31 on both sides. Further, the second spring 32 is provided such that one end is in contact with the stopper 301 and the other end is in contact with the inner surface of the body 1.
　ストッパ３０１は、第２ばね３２によってボディ１に向けて付勢されている。すなわち、ストッパ３０１は、ボディ１の段差部からなる位置決め部３０２に対して押圧されている。位置決め部３０２は、スタンバイ位置Ｓ１を規定する。 The stopper 301 is biased toward the body 1 by the second spring 32. That is, the stopper 301 is pressed against the positioning portion 302 formed of the step portion of the body 1. The positioning unit 302 defines the standby position S1.
　スプール２に第１閾値ＴＨ１と第２閾値ＴＨ２との間の作動力Ｆが付与されると、スプール２が第１ばね３１を圧縮して、スプール２の段差部３０３がストッパ３０１と当接するまで移動する。第３実施形態では、ストッパ３０１が第２ばね３２により位置決め部３０２に付勢され、スプール２が第１ばね３１により付勢されている。図１４に示す第２閾値ＴＨ２は、スプール２がスタンバイ位置Ｓ１に移動した状態における、第１ばね３１の付勢力と第２ばね３２の付勢力との合力となる。作動力Ｆが第２閾値ＴＨ２以下（第１閾値ＴＨ１よりも大きい）の場合にはスプール２は移動せずにスタンバイ位置Ｓ１に保持される。 When the operating force F between the first threshold value TH1 and the second threshold value TH2 is applied to the spool 2, the spool 2 compresses the first spring 31, and the step portion 303 of the spool 2 comes into contact with the stopper 301. Moving. In the third embodiment, the stopper 301 is biased to the positioning portion 302 by the second spring 32, and the spool 2 is biased by the first spring 31. The second threshold value TH2 shown in FIG. 14 is the resultant force of the urging force of the first spring 31 and the urging force of the second spring 32 when the spool 2 is moved to the standby position S1. When the operating force F is equal to or less than the second threshold value TH2 (greater than the first threshold value TH1), the spool 2 is not moved and is held at the standby position S1.
　第３実施形態では、スプール２に第２閾値ＴＨ２よりも大きい作動力Ｆが付与されると、スプール２が第２ばね３２および第１ばね３１を圧縮してストッパ３０１とともに制御領域Ｓ２に移動する。そのため、制御領域Ｓ２では、第１ばね３１と第２ばね３２との合成ばねとの釣り合いによりスプール２の位置制御が行われる。この場合でも、第２閾値ＴＨ２よりも大きい作動力Ｆによってスプール２が制御領域Ｓ２に移動すると、スプール２の移動方向に応じたポート（第１ポートＡまたは第２ポートＢ）を供給ポートＰと連通させ、移動量と比例する流量で作動油を流通させる。 In the third embodiment, when an operating force F greater than the second threshold value TH2 is applied to the spool 2, the spool 2 compresses the second spring 32 and the first spring 31 and moves to the control region S2 together with the stopper 301. . Therefore, in the control region S2, the position control of the spool 2 is performed by the balance with the combined spring of the first spring 31 and the second spring 32. Even in this case, when the spool 2 moves to the control region S2 by the operating force F larger than the second threshold TH2, the port (first port A or second port B) corresponding to the moving direction of the spool 2 is set as the supply port P. Communicate and distribute the hydraulic oil at a flow rate proportional to the amount of movement.
　第３実施形態の場合も、第２実施形態と同様、スプール２は、第１ばね３１の釣り合いによって中立位置Ｓ０に保持される。そのため、スプール２を中立位置Ｓ０で安定して保持するためには、第１ばね３１のばね定数を大きくすることが好ましい。 Also in the case of the third embodiment, the spool 2 is held at the neutral position S0 by the balance of the first spring 31 as in the second embodiment. Therefore, in order to stably hold the spool 2 at the neutral position S0, it is preferable to increase the spring constant of the first spring 31.
　第３実施形態のその他の構成は、上記第１実施形態と同様である。 Other configurations of the third embodiment are the same as those of the first embodiment.
　また、第３実施形態の効果は、上記第１実施形態と同様である。 The effect of the third embodiment is the same as that of the first embodiment.
［変形例］
　なお、今回開示された実施形態は、すべての点で例示であって制限的なものではないと考えられるべきである。本発明の範囲は、上記した実施形態の説明ではなく特許請求の範囲によって示され、さらに特許請求の範囲と均等の意味および範囲内でのすべての変更（変形例）が含まれる。 [Modification]
The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is shown not by the above description of the embodiment but by the scope of claims for patent, and further includes all modifications (modifications) within the meaning and scope equivalent to the scope of claims for patent.
　たとえば、上記第１～第３実施形態では、スプール２に通路部２５を設けた例を示したが、本発明はこれに限られない。本発明では、図１５に示す変形例による流量制御弁４００のように、スプール２に通路部２５（２６）を設けなくてもよい。この場合でも、上記の通り、スプール２の外周面２１と弁座部１３との間のシール部分１４の長さＬ１～Ｌ４を十分に確保することが可能な本発明では、スプール２の外周面２１と弁座部１３との間を通過することによる作動油のポート間のリークを効果的に抑制することが可能である。通路部２５を設ける場合には、ポート間のリークをより確実に防止できるので、ポート間のリークが許容されない用途においては、通路部２５を設けることが好ましい。 For example, in the first to third embodiments, the example in which the passage portion 25 is provided in the spool 2 is shown, but the present invention is not limited to this. In the present invention, unlike the flow control valve 400 according to the modification shown in FIG. 15, the passage portion 25 (26) may not be provided in the spool 2. Even in this case, as described above, in the present invention in which the lengths L1 to L4 of the seal portion 14 between the outer peripheral surface 21 of the spool 2 and the valve seat portion 13 can be sufficiently secured, It is possible to effectively suppress leakage between hydraulic oil ports caused by passing between 21 and the valve seat portion 13. In the case where the passage portion 25 is provided, it is possible to more reliably prevent leakage between the ports. Therefore, it is preferable to provide the passage portion 25 in an application in which leakage between the ports is not allowed.
　また、上記第１～第３実施形態では、スプール２に通路部２５および通路部２６を設けた例を示したが、本発明はこれに限られない。本発明では、通路部を設ける場合、通路部は、第１ポートＡと供給ポートＰとの間のみ（通路部２５のみ）でもよく、通路部２６を設けなくてもよい。 In the first to third embodiments, the example in which the passage portion 25 and the passage portion 26 are provided in the spool 2 has been shown, but the present invention is not limited to this. In the present invention, when the passage portion is provided, the passage portion may be only between the first port A and the supply port P (only the passage portion 25), or the passage portion 26 may not be provided.
　また、上記第１～第３実施形態では、第１ばね３１および第２ばね３２により付勢手段３０を構成した例を示したが、本発明はこれに限られない。本発明では、付勢手段が３つ以上のばねにより構成されてもよい。また、単一のばねで、ばね定数が変化する可変ばねを用いて付勢手段を構成してもよい。 In the first to third embodiments, the urging means 30 is configured by the first spring 31 and the second spring 32. However, the present invention is not limited to this. In the present invention, the urging means may be constituted by three or more springs. Further, the biasing means may be configured using a single spring and a variable spring whose spring constant varies.
　また、上記第１～第３実施形態では、第１ばね３１のばね定数を第２ばね３２のばね定数よりも小さくする構成例を示したが、本発明はこれに限られない。本発明では、第１ばね３１のばね定数と第２ばね３２のばね定数とが等しくてもよいし、第１ばね３１のばね定数が第２ばね３２のばね定数よりも大きくてもよい。 In the first to third embodiments, the configuration example in which the spring constant of the first spring 31 is made smaller than the spring constant of the second spring 32 is shown, but the present invention is not limited to this. In the present invention, the spring constant of the first spring 31 and the spring constant of the second spring 32 may be equal, or the spring constant of the first spring 31 may be larger than the spring constant of the second spring 32.
　また、上記第１～第３実施形態では、通路部２５を、スプール２の中立位置Ｓ０において、第１弁座部１３ａの供給ポートＰ側の一端部よりも、第１弁座部１３ａの第１ポートＡ側の他端部に近い位置に配置した例を示したが、本発明はこれに限られない。本発明では、通路部２５を、スプール２の中立位置Ｓ０において、第１弁座部１３ａの中央あるいは供給ポートＰ側に配置してもよい。通路部２６についても同様であり、中立位置Ｓ０において、第２弁座部１３ｃの中央あるいは供給ポートＰ側に配置してもよい。 Further, in the first to third embodiments, the passage portion 25 is connected to the first valve seat portion 13a at the neutral position S0 of the spool 2 rather than the one end portion on the supply port P side of the first valve seat portion 13a. Although the example arrange | positioned in the position close | similar to the other end part by the side of 1 port A was shown, this invention is not limited to this. In the present invention, the passage portion 25 may be disposed at the center of the first valve seat portion 13a or on the supply port P side at the neutral position S0 of the spool 2. The same applies to the passage portion 26, and it may be arranged at the center of the second valve seat portion 13c or on the supply port P side at the neutral position S0.
　また、上記第１～第３実施形態では、通路部２５を、スプール２が中立位置Ｓ０からスタンバイ位置Ｓ１に移動する際に、第１ポートＡを通過して第２弁座部１３ｂと対向する位置に移動する構成の例を示したが、本発明はこれに限られない。本発明では、中立位置Ｓ０およびスタンバイ位置Ｓ１の両方で、通路部２５が第１弁座部１３ａと対向する位置に配置されてもよい。通路部２６についても同様であり、中立位置Ｓ０およびスタンバイ位置Ｓ１の両方で、通路部２６が第３弁座部１３ｃと対向する位置に配置されてもよい。 In the first to third embodiments, when the spool 2 moves from the neutral position S0 to the standby position S1, the passage portion 25 passes through the first port A and faces the second valve seat portion 13b. Although the example of the structure which moves to a position was shown, this invention is not limited to this. In the present invention, the passage portion 25 may be disposed at a position facing the first valve seat portion 13a in both the neutral position S0 and the standby position S1. The same applies to the passage portion 26, and the passage portion 26 may be disposed at a position facing the third valve seat portion 13c in both the neutral position S0 and the standby position S1.
　また、上記第１～第３実施形態では、中立位置Ｓ０における通路部２５と第１弁座部１３ａの一端部との間の長さＬ１１が、中立位置Ｓ０から第２ポートＢ側へのスプール２の移動可能距離Ｌ２１以上となる構成例を示したが、本発明はこれに限られない。本発明では、長さＬ１１が、移動可能距離Ｌ２１よりも小さくてもよい。その場合、スプール２が第２ポートＢのスタンバイ位置Ｓ１に移動する時点で、通路部２５が供給ポートＰ上を通過して第３弁座部１３ｃと対向する位置に移動するような構成であってもよい。 In the first to third embodiments, the length L11 between the passage portion 25 and the one end portion of the first valve seat portion 13a at the neutral position S0 is the spool from the neutral position S0 to the second port B side. Although the structural example which becomes 2 or more movable distance L21 was shown, this invention is not limited to this. In the present invention, the length L11 may be smaller than the movable distance L21. In that case, when the spool 2 moves to the standby position S1 of the second port B, the passage portion 25 passes over the supply port P and moves to a position facing the third valve seat portion 13c. May be.
　１　ボディ
　２　スプール
　１３　弁座部
　１３ａ　第１弁座部
　１３ｂ　第２弁座部
　２１　外周面
　２５　通路部
　３０　付勢手段
　３１　第１ばね
　３２　第２ばね
　３３　第１ストッパ
　３４　第２ストッパ
　Ａ　第１ポート（油路）
　Ｂ　第２ポート（油路）
　Ｐ　供給ポート（油路）
　Ｔ　排出ポート（油路）
　Ｓ０　中立位置
　Ｓ１　スタンバイ位置
　Ｓ２　制御領域
　ＴＨ１　第１閾値
　ＴＨ２　第２閾値
　１００、２００、３００、４００　流量制御弁 DESCRIPTION OF SYMBOLS 1 Body 2 Spool 13 Valve seat part 13a 1st valve seat part 13b 2nd valve seat part 21 Outer peripheral surface 25 Passage part 30 Energizing means 31 1st spring 32 2nd spring 33 1st stopper 34 2nd stopper A 1st port (Oilway)
B 2nd port (oil passage)
P Supply port (oil passage)
T discharge port (oil passage)
S0 Neutral position S1 Standby position S2 Control region TH1 First threshold TH2 Second threshold 100, 200, 300, 400 Flow control valve

Claims (10)

  1. 　作動油が出入りする油路が設けられたボディと、
    　前記ボディ内に移動可能に保持され、前記油路を開閉させるスプールと、を備え、
    　前記ボディは、前記ボディの内周面に設けられ、前記スプールが中立位置およびスタンバイ位置にある場合に、前記スプールの外周面とによって前記油路を遮断する弁座部と、前記スプールを前記中立位置に保持するための付勢手段とを有し、
    　前記スプールを移動させる作動力が、前記スプールを前記中立位置に保持する上限である第１閾値と、前記第１閾値よりも大きい第２閾値との間の大きさで供給されることにより、前記スプールが前記付勢手段の付勢力に抗して前記中立位置から前記スタンバイ位置に移動し、
    　前記第２閾値よりも大きい作動力が供給されることにより、前記スプールが前記付勢手段の付勢力に抗して、前記スタンバイ位置から、前記スプールの移動量に応じて弁開度を変化させる制御領域に移動するように構成されている、流量制御弁。     A body provided with an oil passage through which hydraulic oil enters and exits;
    A spool that is movably held in the body and opens and closes the oil passage,
    The body is provided on an inner peripheral surface of the body, and when the spool is in a neutral position and a standby position, a valve seat portion that blocks the oil passage with an outer peripheral surface of the spool; Biasing means for holding in position,
    The operating force for moving the spool is supplied in a magnitude between a first threshold value that is an upper limit for holding the spool in the neutral position and a second threshold value that is larger than the first threshold value. The spool moves from the neutral position to the standby position against the biasing force of the biasing means;
    By supplying an operating force larger than the second threshold value, the spool changes the valve opening degree from the standby position according to the amount of movement of the spool against the urging force of the urging means. A flow control valve configured to move to the control region.
  2. 　前記付勢手段は、前記スプールが前記中立位置にある場合、前記第１閾値と等しい付勢力を発生させ、前記スプールが前記スタンバイ位置にある場合に、前記第２閾値と等しい付勢力を発生させるように構成されている、請求項１に記載の流量制御弁。 The biasing means generates a biasing force equal to the first threshold value when the spool is in the neutral position, and generates a biasing force equal to the second threshold value when the spool is in the standby position. The flow control valve according to claim 1, configured as described above.
  3. 　前記付勢手段は、
    　　少なくとも前記中立位置と前記スタンバイ位置との間で前記スプールに圧縮される第１ばねと、
    　　前記制御領域において前記スプールに圧縮される第２ばねと、をさらに含む、請求項２に記載の流量制御弁。     The biasing means is
    A first spring that is compressed into the spool at least between the neutral position and the standby position;
    The flow control valve according to claim 2, further comprising a second spring that is compressed by the spool in the control region.
  4. 　前記第１ばねのばね定数は、前記第２ばねのばね定数よりも小さい、請求項３に記載の流量制御弁。 The flow rate control valve according to claim 3, wherein a spring constant of the first spring is smaller than a spring constant of the second spring.
  5. 　前記ボディは、前記中立位置における前記スプールの移動を規制する第１ストッパと、前記スタンバイ位置における前記スプールの移動を規制する第２ストッパとをさらに含み、
    　前記第１ばねは、前記第１閾値と等しい初期付勢力で前記第１ストッパを前記ボディに対して付勢し、
    　前記第２ばねは、前記第２閾値と等しい初期付勢力で前記第２ストッパを前記ボディに対して付勢している、請求項３に記載の流量制御弁。     The body further includes a first stopper that restricts movement of the spool in the neutral position, and a second stopper that restricts movement of the spool in the standby position,
    The first spring biases the first stopper against the body with an initial biasing force equal to the first threshold,
    The flow control valve according to claim 3, wherein the second spring biases the second stopper with respect to the body with an initial biasing force equal to the second threshold.
  6. 　前記油路は、作動油が供給される供給ポートと、作動油が排出される排出ポートと、互いに択一的に作動油を流入または流出させる第１ポートおよび第２ポートとを含み、
    　前記スプールは、前記中立位置において、前記スプールの外周面から前記スプールの内部を通って前記排出ポートに連通するように設けられ、前記弁座部と前記スプールとの間を通過する作動油を排出するための通路部を有し、
    　前記通路部は、前記スプールの前記中立位置において、少なくとも前記第１ポートと前記供給ポートとの間の第１弁座部と対向する位置に配置されている、請求項１に記載の流量制御弁。     The oil passage includes a supply port to which hydraulic oil is supplied, a discharge port from which hydraulic oil is discharged, and a first port and a second port that allow the hydraulic oil to flow in or out alternately.
    In the neutral position, the spool is provided so as to communicate with the discharge port from the outer peripheral surface of the spool through the inside of the spool, and discharges hydraulic oil passing between the valve seat portion and the spool. Having a passage part for
    2. The flow control valve according to claim 1, wherein the passage portion is disposed at a position facing at least a first valve seat portion between the first port and the supply port in the neutral position of the spool. .
  7. 　前記通路部は、前記スプールの前記中立位置において、前記第１弁座部の前記供給ポート側の一端部よりも、前記第１弁座部の前記第１ポート側の他端部に近い位置に配置されている、請求項６に記載の流量制御弁。 The passage portion is closer to the other end portion of the first valve seat portion on the first port side than the one end portion of the first valve seat portion on the supply port side in the neutral position of the spool. The flow control valve according to claim 6, which is arranged.
  8. 　前記通路部は、前記スプールが前記中立位置から前記第１ポート側の前記スタンバイ位置に移動する際に、前記第１ポートを通過して、前記第１ポートと前記排出ポートとの間の第２弁座部と対向する位置に移動する、請求項７に記載の流量制御弁。 The passage portion passes through the first port when the spool moves from the neutral position to the standby position on the first port side, and a second portion between the first port and the discharge port. The flow control valve according to claim 7, wherein the flow control valve moves to a position facing the valve seat portion.
  9. 　前記スプールの前記中立位置における前記通路部と前記第１弁座部の前記一端部との間の長さは、前記中立位置から前記第２ポート側への前記スプールの移動可能距離以上である、請求項６に記載の流量制御弁。 The length between the passage portion in the neutral position of the spool and the one end portion of the first valve seat portion is equal to or longer than the movable distance of the spool from the neutral position to the second port side. The flow control valve according to claim 6.
  10. 　前記通路部は、前記供給ポートの内径よりも小さい内径を有する、請求項６に記載の流量制御弁。 The flow control valve according to claim 6, wherein the passage portion has an inner diameter smaller than an inner diameter of the supply port.
PCT/JP2016/072190 2016-07-28 2016-07-28 Flow control valve WO2018020642A1 (en)

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CN113251174A (en) * 2021-05-27 2021-08-13 徐州重型机械有限公司 Multi-way valve and crane
JP2022010725A (en) * 2020-06-29 2022-01-17 株式会社クボタ Control valve
TWI808544B (en) * 2020-12-10 2023-07-11 日商住友重機械工業股份有限公司 Spool type flow control valve and manufacturing method thereof

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US10927866B2 (en) * 2017-12-15 2021-02-23 Eaton Intelligent Power Limited Leakage modulation in hydraulic systems containing a three-way spool valve
CN110450099A (en) * 2019-09-16 2019-11-15 三一重机有限公司 Axle sleeve compact system and sleeve pressing machine

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Cited By (4)

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Publication number Priority date Publication date Assignee Title
JP2022010725A (en) * 2020-06-29 2022-01-17 株式会社クボタ Control valve
JP7386764B2 (en) 2020-06-29 2023-11-27 株式会社クボタ control valve
TWI808544B (en) * 2020-12-10 2023-07-11 日商住友重機械工業股份有限公司 Spool type flow control valve and manufacturing method thereof
CN113251174A (en) * 2021-05-27 2021-08-13 徐州重型机械有限公司 Multi-way valve and crane

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