JP6423754B2 - Flow control valve - Google Patents

Description

  The present invention relates to a flow control valve.

  Patent Document 1 discloses a control device including a first circuit system connected to a first pump and provided with a plurality of switching valves, and a second circuit system connected to a second pump and provided with a plurality of switching valves. The invention is described. In the control device described in Patent Document 1, the first circuit system is provided with a switching valve having a regeneration function for regenerating the return fluid from a specific actuator to the supply side of the specific actuator. When the switching valve is switched to the regeneration position, the switching valve is provided with a regeneration throttle in the return passage, and returns with a pressure corresponding to the pressure loss when the fluid passes through the regeneration throttle. The fluid is regenerated.

JP 2009-41616 A

  In the control device of Patent Document 1, the regeneration throttle in the return side passage is configured as a fixed throttle, and thus the regeneration flow rate cannot be adjusted. For this reason, there is a type in which the regeneration throttle is a variable flow control valve so that the regeneration flow rate can be adjusted. In such a flow rate control valve, an external pilot type that controls the flow rate using a signal supplied from the outside as a pilot signal, and an internal pilot type that controls the flow rate using the supply pressure supplied from the pump to the switching valve as a pilot signal, Exists. In manufacturing the flow control valve, there is a demand to share the valve block in the external pilot type and the internal pilot type.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a flow control valve having a valve block that can be used in common in an internal pilot type and an external pilot type.

  In the first invention, the fluid pressure control device is connected to a pump and controls the supply and discharge of the working fluid to and from one and the other pressure chambers of the actuator, and the working fluid discharged from the one pressure chamber to the other. A control valve having a regeneration passage for regenerating to the pressure chamber, a neutral passage for returning the working fluid of the pump to the tank when the control valve is in the neutral position, and supplying the working fluid to the control valve by branching from the neutral passage A supply passage, a first tank passage provided between the control valve and the tank for discharging the working fluid from one pressure chamber of the actuator to the tank, and the other pressure chamber of the actuator provided between the control valve and the tank A second tank passage for discharging the working fluid from the tank to the tank, and a flow rate control for controlling the flow rate of the working fluid provided in the first tank passage and passing through the first tank passage according to the pilot pressure. And the flow control valve includes a valve block having a bottomed cylindrical accommodation hole and a valve body inserted into the accommodation hole, and the valve block intersects the accommodation hole. A tank port provided on the downstream side of the valve body in the first tank passage from the opening side of the housing hole and communicating with the tank, and an actuator discharge provided on the upstream side of the valve body in the first tank passage and communicated with the control valve A port and an internal pilot port communicating with the supply passage are formed. The valve block further includes an intra-block supply passage to which the working fluid discharged from the pump is supplied. A part of the supply hole in the block and the internal pilot are formed on a part of the axis of the receiving hole and spaced from the bottom of the receiving hole to the opposite side of the opening. The distance between the over bets may be greater than the distance between the internal pilot ports and actuator exhaust port on the axis of the accommodation hole.

  In the first invention, in the valve block of the flow control valve, the distance between the supply passage in the block and the internal pilot port on the axis of the receiving hole is based on the distance between the internal pilot port and the actuator discharge port on the axis of the receiving hole. Is also formed to be large. Thereby, a space for adding a drain port for using the flow control valve as an external pilot type can be secured.

  According to a second aspect of the present invention, the internal pilot port is provided at a substantially intermediate position between the tank port and the in-block supply passage on the axis of the accommodation hole.

  According to a third aspect of the present invention, the pilot pressure is a pressure of the working fluid supplied to the internal pilot port, and an internal pilot pressure chamber communicating with the internal pilot port is provided between the bottom of the accommodation hole and one end face of the valve body. The flow rate of the working fluid passing through the first tank passage is controlled by moving the valve body according to the pilot pressure.

  In the third invention, the flow control valve can be used as an internal pilot type controlled by a working fluid supplied to the internal pilot port.

  According to a fourth aspect of the present invention, the valve block is further formed with a drain port facing one end face of the valve body between the intra-block supply passage and the internal pilot port on the axis of the receiving hole. An external pilot pressure chamber facing the other end face of the valve body is formed between the cap member provided outside and the pilot pressure is the pressure of the working fluid supplied to the external pilot pressure chamber. The flow rate of the working fluid passing through the first tank passage is controlled by moving according to the pressure.

  In the fourth invention, the flow control valve can be used as an external pilot type controlled by the working fluid supplied to the external pilot pressure chamber.

  The fifth invention is characterized in that the internal pilot port is always closed by the valve body.

  In the fifth invention, even if the internal pilot port is present in the valve block, the internal pilot port is always closed by the valve body, so that only a simple additional process is required for the internal pilot type valve block. Can be used for external pilot type flow control valves.

  The sixth invention is characterized in that the in-block supply passage is a part of the neutral passage.

  ADVANTAGE OF THE INVENTION According to this invention, the flow control valve which has a valve block which can be used in common with an internal pilot type | mold and an external pilot type | mold can be provided.

It is a circuit diagram showing a fluid pressure control device provided with an internal pilot type flow control valve concerning an embodiment of the present invention. It is the figure which expanded a part of fluid pressure control device provided with the flow control valve concerning the embodiment of the present invention. It is a structure sectional view of an internal pilot type flow control valve concerning an embodiment of the present invention. It is a circuit diagram showing a fluid pressure control device provided with an external pilot type flow control valve concerning an embodiment of the present invention. 1 is a structural cross-sectional view of an external pilot type flow control valve according to an embodiment of the present invention.

  Hereinafter, a flow control valve 50 according to an embodiment of the present invention will be described with reference to the drawings.

  First, with reference to FIG. 1, the fluid pressure control apparatus 100 to which the flow control valve 50 in this embodiment is applied will be described.

  The fluid pressure control device 100 is used for a working machine such as a power shovel. Here, although the case where the working machine is a power shovel will be described, the fluid pressure control device 100 can also be applied to other working machines such as a wheel loader. In the fluid pressure control device 100, hydraulic oil is used as the working fluid, but other fluids such as hydraulic water may be used as the working fluid.

  As shown in FIG. 1, the fluid pressure control apparatus 100 includes a first circuit system 10 connected to the first pump P1 and supplied with hydraulic oil from the first pump P1, and a second pump P2 connected to the second pump P2. And a second circuit system 20 to which hydraulic oil is supplied.

  The first circuit system 10 includes a first neutral passage 11 that guides hydraulic oil supplied from the first pump P1 to the tank T, a plurality of control valves 121 to 125 that are connected in series to the first neutral passage 11, and control. And a first parallel passage 13 branched from the first neutral passage 11 on the upstream side of the valves 121 to 125. The control valves 121 to 125 are connected in series by the first neutral passage 11 and are connected in parallel by the first parallel passage 13.

  The hydraulic oil discharged from the first pump P1 is, in order from the upstream side, the first traveling control valve 121, the spare control valve 122, the turning control valve 123, the first boom control valve 124, and the first arm. Guided to the control valve 125. The first travel control valve 121 controls supply and discharge of hydraulic oil to and from a travel motor provided on the left side of the vehicle body of a power shovel (not shown). The spare control valve 122 controls supply / discharge of hydraulic oil to / from an actuator that drives an attachment such as a breaker or a crusher attached instead of the bucket. The turning control valve 123 controls the supply and discharge of the hydraulic oil to and from the turning motor that turns the turning body disposed at the upper part of the vehicle body. The first boom control valve 124 controls supply / discharge of hydraulic oil to / from an actuator that drives the boom. The first arm control valve 125 controls supply / discharge of hydraulic oil to / from an actuator that drives the arm.

  In the first circuit system 10, when all the control valves 121 to 125 are in the neutral position, the hydraulic oil supplied from the first pump P <b> 1 is returned to the tank T through the first neutral passage 11. On the other hand, when at least one of the control valves 121 to 125 is in the operating position, the connection between the first pump P1 and the tank T in the first neutral passage 11 is cut off.

  Further, in the first circuit system 10, even when any one of the control valves 121 to 124 is switched to the operating position and the connection between the first pump P1 and the tank T in the first neutral passage 11 is interrupted, the first pump The hydraulic oil supplied from P <b> 1 can be supplied to the control valves 122 to 125 through the first parallel passage 13.

  The fluid pressure control device 100 forms a main body by stacking a plurality of valve blocks and fastening them with bolts or the like. The fluid pressure control device 100 may be formed by a single valve block.

  The first circuit system 10 further includes a neutral cut valve 40 that is provided downstream of the control valves 121 to 125 in the first neutral passage 11 and communicates or blocks connection between the first neutral passage 11 and the tank T. The neutral cut valve 40 communicates the connection between the first neutral passage 11 and the tank T when in the G position (normal position) in FIG. 1, and when in the H position (blocking position), The connection with the tank T is cut off.

  Next, a specific structure of the neutral cut valve 40 will be described with reference to FIG. FIG. 3 is a cross-sectional view showing a cross section when the neutral cut valve 40 is in the G position (normal position).

  As shown in FIG. 3, the neutral cut valve 40 cuts off or communicates the connection between the valve block 60 having the bottomed cylindrical accommodation hole 61 and the first neutral passage 11 and the tank T accommodated in the accommodation hole 61. A spool 41 as a valve body, a drain chamber 48 defined between one end of the spool 41 and the bottom of the accommodation hole 61 and communicating with the tank T, a valve block 60 and a cap member 43 provided on the other end side of the spool 41 And a return spring 44 that is provided in the pilot pressure chamber 49 and biases the spool 41 in the direction in which the first neutral passage 11 and the tank T communicate with each other (the left direction in FIG. 2). And comprising. The cap member 43 is provided with a pilot port 42 for supplying and discharging pilot pressure to and from the pilot pressure chamber 49.

  The spool 41 includes a first land portion 45 and a second land portion 46 that slide along the inner peripheral surface of the accommodation hole 61, and an annular groove formed between the first land portion 45 and the second land portion 46. 47.

  The valve block 60 includes a neutral passage portion 66 that passes through the valve block 60 in a direction perpendicular to the axis of the receiving hole 61 and communicates with the downstream side of the first arm control valve 125, and the spool 41 is surrounded by the receiving hole 61. An inlet port portion 62 formed to communicate with the neutral passage portion 66 and an outlet port portion 63 formed so as to surround the spool 41 in the accommodation hole 61 and communicated with the tank T are formed. A flow path from the neutral passage portion 66 in the valve block 60 to the outlet port portion 63 through the inlet port portion 62 constitutes a part of the first neutral passage 11. The flow path from the neutral passage portion 66 to the outlet port portion 63 through the inlet port portion 62 corresponds to the in-block supply passage.

  Next, the operation of the neutral cut valve 40 will be described.

  In the state where the hydraulic oil in the pilot pressure chamber 49 is not supplied, the neutral cut valve 40 is located in the state shown in FIG. 3, that is, in the G position (normal position) in FIG. In this state, the inlet port portion 62 and the outlet port portion 63 communicate with each other through an annular groove 47 formed in the spool 41. Therefore, the hydraulic oil that has flowed into the inlet port portion 62 from the neutral passage portion 66 communicating with the downstream of the first arm control valve 125 in the first neutral passage 11 passes through the annular groove 47 and the outlet port portion 63 to the tank T. Refluxed. That is, the first neutral passage 11 and the tank T communicate with each other by switching the neutral cut valve 40 to the G position (normal position).

  When the hydraulic oil in the pilot pressure chamber 49 is supplied from this state, the spool 41 moves toward the right side in FIG. 3 against the urging force of the return spring 44 by the pressure of the hydraulic oil supplied to the pilot pressure chamber 49. Moving. As a result, the inlet port portion 62 and the outlet port portion 63 are blocked by the first land portion 45 of the spool 41. That is, it switches to the H position (blocking position) in FIG. Therefore, the hydraulic oil that has flowed into the inlet port portion 62 from the neutral passage portion 66 communicating with the downstream of the first arm control valve 125 in the first neutral passage 11 flows into the outlet port portion 63 by the first land portion 45. Is blocked. That is, the connection between the first neutral passage 11 and the tank T is cut off by switching the neutral cut valve 40 to the H position (cutoff position).

  Next, the first arm control valve 125 will be described with reference to FIGS. 1 and 2.

  As shown in FIGS. 1 and 2, the first arm control valve 125 is supplied with hydraulic fluid for driving the arm cylinder 90 by branching from the first neutral passage 11 and the first neutral passage 11. A passage 12, a first cylinder passage 91 a communicating with the high load side pressure chamber 90 a in the arm cylinder 90, a second cylinder passage 91 b communicating with the low load side pressure chamber 90 b in the arm cylinder 90, and the pressure chamber 90 a The first tank passage 14 for discharging the hydraulic oil to the tank T and the second tank passage 15 for discharging the hydraulic oil in the pressure chamber 90b to the tank T are connected. A first parallel downstream passage 13b joins the supply passage 12. A check valve 17 for preventing the backflow of hydraulic oil is provided on the upstream side of the joining portion of the supply passage 12 and the first parallel passage 13. The first tank passage 14 is provided with a flow rate control valve 50 that controls the flow rate of the hydraulic oil passing through the first tank passage 14 in accordance with the pilot pressure.

  The first arm control valve 125 includes a neutral position A, a high load side operation position B shown on the right side of FIGS. 1 and 2, a low load side operation position C shown on the left side of FIGS. The three positions are switched. The positions A, B, and C of the first arm control valve 125 are switched according to the pilot pressure supplied to the pilot chambers 125 a and 125 b provided at both ends of the first arm control valve 125. When the pilot pressure does not act on any of the pilot chambers 125a and 125b, the first arm control valve 125 is moved to the neutral position A by the urging force of the springs 125c provided on both sides of the first arm control valve 125. Become. When the pilot pressure is supplied to the pilot chamber 125b, the first arm control valve 125 is switched to the high load side operating position B. When the pilot pressure is supplied to the pilot chamber 125a, the first arm control valve 125 is Switches to the low load side operating position C.

  In the neutral position A, the first neutral passage 11 is connected to the tank T, and the other passages are blocked. As a result, the hydraulic oil is not supplied to or discharged from the pressure chambers 90a and 90b of the arm cylinder 90, and the arm cylinder 90 is held at that position.

  In the high load side operation position B, the first neutral passage 11 is blocked, the supply passage 12 is connected to the first cylinder passage 91a, and the second cylinder passage 91b is connected to the second tank passage 15. Accordingly, the hydraulic oil discharged from the first pump P1 is supplied from the first neutral passage 11 and the first parallel downstream passage 13b to the pressure chamber 90a through the supply passage 12 and the first cylinder passage 91a. Further, the hydraulic oil in the pressure chamber 90 b is discharged to the tank T through the second cylinder passage 91 b and the second tank passage 15.

  At the low load side position C, the first neutral passage 11 is blocked, the supply passage 12 is connected to the second cylinder passage 91b, and the first cylinder passage 91a is connected to the first tank passage 14. As a result, the hydraulic oil discharged from the first pump P1 is supplied from the first neutral passage 11 and the first parallel passage 13 to the pressure chamber 90b through the supply passage 12 and the second cylinder passage 91b. The hydraulic oil in the pressure chamber 90 a is discharged to the tank T through the first cylinder passage 91 a and the first tank passage 14. At this time, the flow rate of the hydraulic oil discharged to the tank T through the first tank passage 14 is controlled by the flow rate control valve 50.

  Further, in the first arm control valve 125, the first internal passage 126 that connects the first cylinder passage 91a and the first tank passage 14 at the low load side position C, the supply passage 12, and the second cylinder passage 91b. Are formed, and a regeneration passage 128 that connects the first internal passage 126 and the second internal passage 127 is formed (see FIG. 2). The regeneration passage 128 is provided with a check valve 129 that allows only the flow from the first internal passage 126 to the second internal passage 127. Therefore, the hydraulic oil discharged from the pressure chamber 90a can be regenerated into the pressure chamber 90b through the regeneration passage 128. The first internal passage 126 is provided with a throttle 130 that regulates the flow rate of the hydraulic oil discharged from the pressure chamber 90a.

  Next, a specific structure of the flow control valve 50 will be described with reference to FIGS. 1, 2, and 3.

  As described above, the flow control valve 50 is provided in the first tank passage 14. A flow control valve 50 shown in FIGS. 1, 2, and 3 is an internal pilot type flow control valve that is controlled by using hydraulic oil supplied through a pilot passage 16 branched from the supply passage 12 as a pilot pressure.

 As shown in FIG. 3, the flow control valve 50 includes a valve block 60 in which a bottomed cylindrical accommodation hole 51 is formed, a sleeve 70 inserted into the accommodation hole 51, and the accommodation hole 51 via the sleeve 70. And a spool 80 as a valve body to be inserted. The neutral cut valve 40 and the flow rate control valve 50 use the valve block 60 as a common one, but each may have an individual valve block.

 The valve block 60 has a tank port 52 provided on the downstream side of the spool 80 in the first tank passage 14 from the opening side of the accommodation hole 51 so as to intersect the accommodation hole 51, and a first tank passage that communicates with the tank T. 14, an actuator discharge port 53 provided on the upstream side of the spool 80 and communicating with the first arm control valve 125, and an internal pilot port 54 communicating with the supply passage 12 through the pilot passage 16 are formed.

 In the valve block 60, a space 65 is formed on a flow path connecting the neutral passage portion 66 and the inlet port portion 62. The space 65 is formed at a position on the axis of the receiving hole 51 and spaced from the bottom of the receiving hole 51 to the side opposite to the opening. Instead of providing the space 65, the neutral passage portion 66 may be formed at a position where the space 65 is provided.

  The sleeve 70 is formed in a hollow cylindrical shape. The sleeve 70 has a plurality of first through holes 71 that communicate with the tank port 52, a plurality of second through holes 72 that communicate with the actuator discharge port 53, and a plurality of slits formed on the end surface that contacts the receiving hole 51. 73 is formed. The sleeve 70 is accommodated in the accommodation hole 51 and fixed so as to be pressed against the bottom surface of the accommodation hole 51 by a plug 77 screwed into the valve block 60.

  The spool 80 includes a first land portion 81 and a second land portion 82 that slide along the inner peripheral surface of the sleeve 70, and an annular groove 83 formed between the first land portion 81 and the second land portion 82. And a piston 84 provided so as to be in contact with the end surface of the second land portion 82 opposite to the annular groove 83. The piston 84 may be formed integrally with the spool 80.

  An inner pilot pressure chamber 55 is defined at the bottom of the accommodation hole 51 by the inner peripheral surface of the sleeve 70 and the end surface of the piston 84. The internal pilot pressure chamber 55 communicates with the internal pilot port 54 through a slit 73.

  Inside the plug 77, a spring accommodating space 74 is formed in which a spool spring 75 that urges the spool 80 toward the bottom surface side of the accommodating hole 51 is accommodated. The spring accommodating space 74 communicates with the tank port 52 through the through hole 76.

  Next, the second circuit system 20 will be described with reference to FIG.

  The second circuit system 20 includes a second neutral passage 21 that guides hydraulic oil supplied from the second pump P2 to the tank T, a plurality of control valves 221 to 224 connected in series to the second neutral passage 21, And a second parallel passage 23 branched from the second neutral passage 21 upstream of the valves 221 to 224. The control valves 221 to 224 are connected in series by the second neutral passage 21 and are connected in parallel by the second parallel passage 23.

  The hydraulic oil discharged from the second pump P2 is guided to the second traveling control valve 221, the bucket control valve 222, the second boom control valve 223, and the second arm control valve 224 in order from the upstream side. . The second travel control valve 221 controls supply and discharge of hydraulic oil to and from a travel motor provided on the right side of the vehicle body of a power shovel (not shown). The bucket control valve 222 controls supply and discharge of hydraulic oil to and from an actuator that drives the bucket. The second boom control valve 223 controls the supply and discharge of hydraulic oil to and from the actuator that drives the boom. The second arm control valve 224 controls supply and discharge of hydraulic oil to and from an actuator that drives the arm. Note that the control valves 221 to 224 correspond to second control valves.

  In the second circuit system 20, when all the control valves 221 to 224 are in the neutral position, the hydraulic oil supplied from the second pump P <b> 2 is returned to the tank T through the second neutral passage 21. On the other hand, when at least one of the control valves 221 to 224 is in the operating position, the connection between the second pump P2 and the tank T in the second neutral passage 21 is cut off.

  Further, in the second circuit system 20, even when any one of the control valves 221 to 223 is switched to the operating position and the connection between the second pump P2 and the tank T in the second neutral passage 21 is interrupted, the second pump The hydraulic oil supplied from P <b> 2 can be supplied to the control valves 222 to 224 through the second parallel passage 23.

  The second circuit system 20 further includes a neutral cut valve 24 that is provided downstream of the second arm control valve 224 in the second neutral passage 21 and communicates or blocks the connection between the second neutral passage 21 and the tank T. The neutral cut valve 24 has the same configuration as the neutral cut valve 40.

  The second circuit system 20 communicates in the second neutral passage 21 downstream of the second arm control valve 224 and upstream of the neutral cut valve 24, and supplies hydraulic oil discharged from the second pump P2 to the outside. A possible branch passage 29 is further provided.

  The second circuit system 20 further includes a straight travel control valve 25 that is connected downstream of the branch point of the second neutral passage 21 with the second parallel passage 23 and upstream of the second travel control valve 221. The first parallel passage 13 is connected to the straight travel control valve 25. The first parallel passage 13 is connected to the first parallel upstream passage 13a that connects the first pump P1 and the straight travel control valve 25, and the first parallel passage that connects the straight travel control valve 25 and the control valves 122 to 125. And a downstream passage 13b.

  The straight travel control valve 25 is switched to a normal position D shown in the center of FIG. 1, a straight travel position E shown on the left side of FIG. 1, and a merging position F shown on the right side of FIG. The positions D, E, and F of the straight travel control valve 25 are switched according to the pilot pressure supplied to the pilot chambers 25a and 25b provided at both ends of the straight travel control valve 25. When the pilot pressure is not acting on any of the pilot chambers 25a and 25b, the straight travel control valve 25 assumes the normal position D by the biasing force of the springs 25c provided on both sides of the straight travel control valve 25. When the pilot pressure is supplied to the pilot chamber 25a, the travel rectilinear control valve 25 is switched to the travel rectilinear position E, and when the pilot pressure is supplied to the pilot chamber 25b, the travel rectilinear control valve 25 is set to the joining position F. Switch.

  In the normal position D, the first parallel upstream passage 13a of the first parallel passage 13 is connected to the first parallel downstream passage 13b of the first parallel passage 13, and the second neutral passage 21 is connected to the second pump P2. Is done. As a result, the hydraulic oil discharged from the first pump P1 is supplied to the control valves 121 to 125 through the first neutral passage 11 and the first parallel passage 13. The hydraulic oil discharged from the second pump P <b> 2 is supplied to the control valves 221 to 224 through the second neutral passage 21 and the second parallel passage 23. That is, when only the traveling motor is operated, the hydraulic oil discharged from the first pump P1 is supplied to the first traveling control valve 121, and the second pump P2 is supplied to the second traveling control valve 221. The hydraulic oil discharged from is supplied.

  In the straight travel position E, the first parallel upstream passage 13a of the first parallel passage 13 is connected to the second neutral passage 21 downstream of the travel straight travel control valve 25, and the first parallel downstream passage 13b is the first parallel passage 13b. Two pumps P2 are connected. That is, when the travel motor and the actuator other than the travel motor are operated simultaneously, the hydraulic oil discharged from the first pump P1 is supplied to the first travel control valve 121 and the second travel control valve 221. The other control valves 122 to 125 and the other control valves 222 to 224 are supplied with hydraulic oil discharged from the second pump P2. Therefore, at the straight travel position E, even if the travel motor and the actuator other than the travel motor are operated simultaneously, the circuit for the travel motor and the circuit of the actuator other than the travel motor are independent. The traveling straightness of the vehicle is ensured.

  At the merge position F in the straight travel control valve 25, the second neutral passage 21 upstream from the straight travel control valve 25 is connected to the second neutral passage 21 downstream, and the first parallel upstream passage 13a It is connected to the second neutral passage 21 through a merge passage 26 formed inside the straight travel control valve 25. As a result, the hydraulic oil of the first pump P1 and the hydraulic oil of the second pump P2 merge and are supplied to the second control valve, and more hydraulic oil can be supplied to the actuator connected to the second control valve. it can.

  The junction passage 26 formed inside the straight travel control valve 25 includes a check valve 27 that allows only the flow from the first parallel upstream passage 13a to the second neutral passage 21, and the operation in the junction passage 26. A throttle 28 for restricting the flow of oil is provided in this order from the upstream side. Accordingly, the hydraulic oil of the second pump P2 can be prevented from flowing to the first parallel upstream passage 13a side, and the first control valve and the second control are controlled by limiting the hydraulic oil of the first parallel upstream passage 13a. The combined flow rate from the first pump P1 to the second pump P2 can be adjusted and combined with the second neutral passage 21 during the combined operation with the valve.

  Here, for example, the case where the hydraulic oil discharged from the first pump P1 is merged with the second neutral passage 21 when the cylinder 22 that drives the bucket is driven will be described.

  A pilot pressure chamber of a bucket control valve 222 that controls the supply and discharge of hydraulic oil to and from the cylinder 22 that drives the bucket, a pilot pressure chamber 49 of the neutral cut valve 40, a pilot chamber 25b of the straight travel control valve 25, Supply hydraulic oil to As a result, when the bucket control valve 222 is operated, the operation discharged from the first pump P1 in addition to the hydraulic oil discharged from the second pump P2 to the second neutral passage 21 and the second parallel passage 23. Oil is supplied through the junction passage 26 of the straight travel control valve 25. Thereby, the cylinder 22 is driven in a state in which the hydraulic oil discharged from the first pump P1 joins the hydraulic oil discharged from the second pump P2. Therefore, the cylinder 22 can be driven at high speed.

  Next, the operation of the flow control valve 50 will be described with reference to FIGS. FIG. 3 is a diagram showing a state where the pilot pressure acting on the internal pilot pressure chamber 55 is low.

  When the first arm control valve 125 is switched to the low load side position C, the flow rate control valve 50 adjusts the flow rate of the hydraulic oil returned from the high load side pressure chamber 90a to the tank T through the first tank passage 14. To do. Specifically, when the pilot pressure is supplied to the pilot chamber 125 a of the first arm control valve 125, the first arm control valve 125 is switched to the low load side position C. As a result, the hydraulic oil in the pressure chamber 90a on the high load side of the arm cylinder 90 flows into the actuator discharge port 53 of the flow control valve 50 through the first cylinder passage 91a, the first internal passage 126, and the first tank passage 14. . The hydraulic fluid that has flowed into the actuator discharge port 53 flows into the annular groove 83 from the second through hole 72, and flows out to the tank port 52 through the first through hole 71.

  When the pilot pressure acting on the internal pilot pressure chamber 55 from the supply passage 12 through the pilot passage 16 is low, the spool 80 is urged toward the bottom surface side of the accommodation hole 51 by the spool spring 75. As a result, as shown in FIG. 3, the first land portion 81 of the spool 80 overlaps the first through hole 71 so that the flow passage area of the first through hole 71 is narrowed. In this state, the flow rate of the hydraulic oil that can pass through the first tank passage 14 is small. Therefore, most of the hydraulic oil discharged from the pressure chamber 90a is regenerated into the pressure chamber 90b through the regeneration passage 128.

  When the pilot pressure acting on the internal pilot pressure chamber 55 increases from this state, the spool 80 moves toward the plug 77 against the urging force of the spool spring 75. Thereby, the overlap of the 1st through-hole 71 and the 1st land part 81 becomes small, and the flow-path area of the 1st through-hole 71 spreads. Accordingly, the flow rate of the hydraulic oil that can pass through the first tank passage 14 increases, and the flow rate of the hydraulic oil that is regenerated from the pressure chamber 90a to the pressure chamber 90b through the regeneration passage 128 decreases. As the pilot pressure acting on the internal pilot pressure chamber 55 becomes higher, the spool 80 further moves toward the plug 77 side. Thereby, the flow rate of the hydraulic oil that can pass through the first tank passage 14 further increases. Therefore, the hydraulic oil is not regenerated from the pressure chamber 90 a to the pressure chamber 90 b through the regeneration passage 128, and the entire amount of hydraulic oil in the pressure chamber 90 a is discharged to the tank T.

  As described above, the flow rate control valve 50 adjusts the flow rate of the hydraulic oil passing through the first tank passage 14 in accordance with the pilot pressure acting on the internal pilot pressure chamber 55, so that the pressure from the pressure chamber 90 a through the regeneration passage 128 The flow rate regenerated in the chamber 90b is adjusted.

  In the fluid pressure control apparatus 100 including the internal pilot type flow control valve 50 configured as described above, when the pressure of the hydraulic oil in the supply passage 12 is reduced due to the combined operation of the cylinder, that is, the pilot pressure. As described above, the flow rate control valve 50 can regenerate the hydraulic oil in the pressure chamber 90a to the pressure chamber 90b by restricting the first tank passage 14 as described above. On the other hand, when the pressure of the hydraulic oil in the supply passage 12 is high (not lowered), such as when the arm cylinder 90 is operated alone, that is, when the pilot pressure is high, the flow control valve 50 is set as described above. By opening the first tank passage 14, the hydraulic oil in the pressure chamber 90a is discharged to the tank T without being regenerated into the pressure chamber 90b.

  Next, the external pilot type flow control valve 150 will be described with reference to FIGS.

  The flow control valve 150 shown in FIG. 4 is different from the fluid pressure control device 100 shown in FIG. 1 in that the pilot pressure is supplied from the outside of the fluid pressure control device.

  A specific configuration of the flow control valve 150 will be described with reference to FIG. In addition, about the flow control valve 150, the same code | symbol is attached | subjected to the structure same as the flow control valve 50 in a figure, and description is abbreviate | omitted.

  The flow control valve 150 includes a valve block 160 having a bottomed cylindrical accommodation hole 151, a spool 180 as a valve body inserted into the accommodation hole 151, and one end of the spool 180 and the bottom of the accommodation hole 151. A drain port 156 that communicates with the tank T, an external pilot pressure chamber 155 that is provided on the other end side of the spool 180 and is defined by the valve block 160 and the cap member 173, and an external pilot pressure chamber 155. And a spool spring 175 that urges the spool 180 in the direction of the cap member 173 (left direction in FIG. 5). The cap member 173 is provided with a pilot port 174 for supplying and discharging pilot pressure to and from the external pilot pressure chamber 155.

  The valve block 160 of the flow control valve 150 shown in FIG. 5 and the valve block 60 of the flow control valve 50 shown in FIG. 3 are obtained by processing a valve block manufactured by a common mold. The accommodation hole 151 of the valve block 160 is deeper than the accommodation hole 51 in the valve block 60 and is processed so as to intersect the drain port 156.

  As described above, the valve block 160 is provided with the drain port 156 at a position between the internal pilot port 54 and the space 65. For this reason, in the valve block manufactured by the mold, a space in which the drain port 156 can be provided between the internal pilot port 54 and the space 65 is secured in advance. Specifically, the distance L1 between the space 65 on the axis of the receiving holes 51 and 151 and the internal pilot port 54 is greater than the distance L2 between the internal pilot port 54 and the actuator discharge port 53 on the axial lines of the receiving holes 51 and 151. Each port is arranged to be larger.

  The spool 180 is formed between the first land portion 181 and the second land portion 182 that slide along the inner peripheral surface of the receiving hole 151 of the valve block 160, and between the first land portion 181 and the second land portion 182. And a plurality of notches 184 provided at the end of the second land portion 182 on the annular groove 183 side. The flow control valve 150 may be provided with a sleeve between the valve block 160 and the spool 180.

  Next, the operation of the flow control valve 150 will be described with reference to FIGS. FIG. 5 is a diagram showing a state where the pilot pressure acting on the external pilot pressure chamber 155 is low.

 When the first arm control valve 125 is switched to the low load side position C, the flow rate control valve 150 adjusts the flow rate of the hydraulic oil returned from the high load side pressure chamber 90a to the tank T through the first tank passage 14. To do. Specifically, when the pilot pressure is supplied to the pilot chamber 125 a of the first arm control valve 125, the first arm control valve 125 is switched to the low load side position C. As a result, the hydraulic oil in the pressure chamber 90 a on the high load side of the arm cylinder 90 flows into the actuator discharge port 53 through the first cylinder passage 91 a, the first internal passage 126, and the first tank passage 14. The hydraulic fluid that has flowed into the actuator discharge port 53 flows out to the tank port 52 through the notch 184. At this time, the hydraulic oil acts on the internal pilot port 54 from the supply passage 12 through the pilot passage 16, but the internal pilot port 54 is always closed by the second land portion 182.

 When the pilot pressure is low, the spool 180 is urged toward the bottom surface of the accommodation hole 151 by the spool spring 175. As a result, as shown in FIG. 5, the notch 184 of the second land portion 182 is in a state where the flow path area is narrowed. In this state, the flow rate of hydraulic oil that can pass through the notch 184 is small. Therefore, most of the hydraulic oil discharged from the pressure chamber 90a is regenerated into the pressure chamber 90b through the regeneration passage 128.

  From this state, when the pilot pressure acting on the external pilot pressure chamber 155 gradually increases, the spool 180 moves toward the bottom surface side of the receiving hole 151 against the urging force of the spool spring 175. Thereby, the channel area of the notch 184 is expanded. Accordingly, the flow rate of the hydraulic oil that can pass through the first tank passage 14 increases, and the flow rate of the hydraulic oil that is regenerated from the pressure chamber 90a to the pressure chamber 90b through the regeneration passage 128 decreases. As the pilot pressure acting on the external pilot pressure chamber 155 further increases, the spool 180 further moves toward the bottom surface side of the accommodation hole 151. Thereby, the flow rate of the hydraulic oil that can pass through the first tank passage 14 further increases. Therefore, the hydraulic oil is not regenerated from the pressure chamber 90 a to the pressure chamber 90 b through the regeneration passage 128, and the entire amount of hydraulic oil in the pressure chamber 90 a is discharged to the tank T.

  As described above, the flow rate control valve 150 adjusts the flow rate of the hydraulic oil passing through the first tank passage 14 in accordance with the pilot pressure acting on the external pilot pressure chamber 155, thereby allowing the pressure from the pressure chamber 90 a to pass through the regeneration passage 128. The flow rate regenerated in the chamber 90b can be adjusted.

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

  In the valve block 60 of the flow control valve 50, the distance L1 between the space 65 on the axis of the accommodation hole 51 and the internal pilot port 54 is the distance L2 between the internal pilot port 54 and the actuator discharge port 53 on the axis of the accommodation hole 51. It is formed to be larger. Thereby, the space which adds the drain port 156 for using a flow control valve as an external pilot form is securable. Therefore, even if the internal pilot type valve block and the external pilot type valve block are made common, the internal pilot type valve block 60 can be used for the external pilot type flow control valve 150 only by a simple modification. Can do. That is, according to the flow control valves 50 and 150, the valve blocks used for the internal pilot type and the external pilot type flow control valves can be shared.

  In the flow control valve 50, the internal pilot port 54 is preferably provided at an approximately middle position between the tank port 52 and the space 65 on the axis line of the accommodation hole 51. An actuator discharge port 53 is provided between the internal pilot port 54 and the tank port 52. That is, a space for providing the actuator discharge port 53 is secured between the internal pilot port 54 and the tank port 52. Since the distance L1 between the internal pilot port 54 and the space 65 is substantially equal to the distance L3 between the internal pilot port 54 and the tank port 52, a drain port 156 is formed between the internal pilot port 54 and the space 65. Space will be reserved in advance.

  The configuration, operation, and effect of the embodiment of the present invention configured as described above will be described together.

  The fluid pressure control device 100 is connected to the first pump P1 and controls supply / discharge of the working fluid to / from one and the other pressure chambers 90a, 90b of the actuator (arm cylinder 90), and discharge from the one pressure chamber 90a. The first arm control valve 125 having a regeneration passage 128 for regenerating the working fluid to be returned to the other pressure chamber 90b, and the working fluid of the first pump P1 when the first arm control valve 125 is in the neutral position 1 to the tank T, a supply passage 12 that branches from the first neutral passage 11 and supplies hydraulic oil to the first arm control valve 125, the first arm control valve 125, and the tank T A first tank passage 14 for discharging hydraulic oil from one pressure chamber 90a of the actuator (arm cylinder 90) to the tank T, and a control valve 12 for the first arm. And a tank T, a second tank passage 15 for discharging hydraulic oil from the other pressure chamber 90b of the actuator (arm cylinder 90) to the tank T, and a first tank passage provided in the first tank passage 14. Flow control valves 50 and 150 for controlling the flow rate of the working fluid passing through 14 according to the pilot pressure, and the flow control valves 50 and 150 are valves in which bottomed cylindrical accommodating holes 51 and 151 are formed. The valve blocks 60 and 160 have valve bodies (spools 80 and 180) inserted into the receiving holes 51 and 151. The valve blocks 60 and 160 include the receiving holes 51 and 151 so as to intersect the receiving holes 51 and 151, respectively. The tank port 52 provided on the downstream side of the valve body (spools 80, 180) in the first tank passage 14 from the opening portion side of the first tank passage 14, and the first tank passage 4 is formed on the upstream side of the valve body (spools 80, 180) in FIG. 4 and communicates with the first arm control valve 125, and an internal pilot port 54 communicates with the supply passage 12. 60 and 160 are further formed with an in-block supply passage (neutral passage portion 66, space 65, inlet port portion 62, outlet port portion 63) to which the hydraulic oil discharged from the first pump P1 is supplied. The supply passage (neutral passage portion 66, space 65, inlet port portion 62, outlet port portion 63) is at least partially on the axis of the receiving holes 51, 151 and has an opening from the bottom of the receiving holes 51, 151. Is formed at a position spaced apart on the opposite side, and the in-block supply passage (neutral passage portion 66, space 65, inlet port portion 6 on the axis of the receiving holes 51, 151 is formed. 2, the distance L1 between the outlet port portion 63) and the internal pilot port 54 is characterized by being larger than the distance L2 between the internal pilot port 54 and the actuator discharge port 53 on the axis of the receiving holes 51 and 151.

  In this configuration, in the valve block of the flow control valve, the in-block supply passage (neutral passage portion 66, space 65, inlet port portion 62, outlet port portion 63) and the internal pilot port 54 on the axis of the receiving holes 51 and 151 The distance L1 is formed to be larger than the distance L2 between the internal pilot port 54 and the actuator discharge port 53 on the axis of the receiving holes 51 and 151. As a result, a space for adding a drain port 156 for using the flow control valve as an external pilot type can be secured. Therefore, the valve blocks 60 and 160 used for the flow control valves of the internal pilot type and the external pilot type can be shared.

  Further, the flow control valves 50 and 150 are characterized in that the internal pilot port 54 is provided at a substantially intermediate position between the tank port 52 and the in-block supply passage (space 65) on the axis of the receiving holes 51 and 151. To do.

  The flow control valve 50 has a pilot pressure of the working fluid supplied to the internal pilot port 54, and the internal pilot port is located between the bottom of the accommodation hole 51 and one end face of the valve body (spool 80). An internal pilot pressure chamber 55 communicating with the valve 54 is formed, and the flow rate of the working fluid passing through the first tank passage 14 is controlled by moving the valve body (spool 80) according to the pilot pressure. .

  In this configuration, the flow control valve 50 can be used as an internal pilot type controlled by the working fluid supplied to the internal pilot port 54.

  Further, in the flow control valve 150, one end face of the valve body (spool 180) is provided in the valve block 160 between the in-block supply passage (space 65) and the internal pilot port 54 on the axis of the accommodation hole 151. A drain port 156 that faces is further formed, and an external pilot pressure chamber 155 that faces the other end face of the valve body (spool 180) is formed between the valve block 160 and the cap member 173 provided outside the valve block 160, The pilot pressure is the pressure of the working fluid supplied to the external pilot pressure chamber 155. The pilot pressure acts on the other end surface of the valve body (spool 180), and the valve body (spool 180) is pilot pressure. The flow rate of the working fluid passing through the first tank passage 14 is controlled by moving according to

  In this configuration, the flow control valve can be used as an external pilot type controlled by the working fluid supplied to the external pilot pressure chamber.

  The flow control valve 150 is characterized in that the internal pilot port 54 is always closed by a valve body (spool 180).

  In this configuration, even if the internal pilot port 54 exists in the valve block 160, the internal pilot port 54 is always closed by the valve body (spool 180), so that a simple additional process is added to the internal pilot type valve block 60. It can be used for the flow control valve 150 of the external pilot type.

  The flow control valves 50 and 150 are characterized in that the supply passage in the block is a part of the neutral passage 11.

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

  For example, at least one of the control valves 121 to 125 may be provided. The second circuit system 20 may not be particularly provided. The in-block supply passage may be a part of the first parallel passage 13.

50, 150 ... flow control valve, P1 ... first pump, P2 ... second pump, 10 ... first circuit system, 11 ... first neutral passage, 12 ... supply passage , 13 ... 1st parallel passage, 14 ... 1st tank passage, 15 ... 2nd tank passage, 16 ... Pilot passage, 20 ... 2nd circuit system, 25 ... Straight running Control valve, 40 ... neutral cut valve, 51, 151 ... receiving hole, 52 ... tank port, 53 ... actuator discharge port, 54 ... internal pilot port, 55 ... internal pilot Pressure chamber, 60, 160 ... Valve block, 65 ... Space, 80, 180 ... Spool, 90 ... Arm cylinder, 90a, 90b ... Pressure chamber, 100 ... Fluid pressure control device 125, first arm control valve, 1 25a, 125b ... pilot chamber, 125c ... spring, 128 ... regeneration passage, 155 ... external pilot pressure chamber, 156 ... drain port

Claims (6)

A flow rate control valve used in a fluid pressure control device for controlling an actuator driven by a working fluid supplied from a pump,
The fluid pressure control device includes:
Regeneration for controlling the supply and discharge of the working fluid to one and the other pressure chambers of the actuator connected to the pump and for regenerating the working fluid discharged from the one pressure chamber to the other pressure chamber A control valve having a passage;
A neutral passage for returning the working fluid of the pump to the tank when the control valve is in a neutral position;
A supply passage that branches off from the neutral passage and supplies a working fluid to the control valve;
A first tank passage provided between the control valve and the tank for discharging a working fluid from one pressure chamber of the actuator to the tank;
A second tank passage provided between the control valve and the tank for discharging the working fluid from the other pressure chamber of the actuator to the tank;
A flow rate control valve that is provided in the first tank passage and controls the flow rate of the working fluid that passes through the first tank passage according to a pilot pressure;
The flow control valve is
A valve block having a bottomed cylindrical accommodation hole;
A valve body inserted into the receiving hole,
The valve block is provided on the downstream side of the valve body in the first tank passage from the opening side of the housing hole so as to intersect the housing hole, and a tank port communicating with the tank, and the first tank An actuator discharge port that is provided on the upstream side of the valve body in the passage and communicates with the control valve, and an internal pilot port that communicates with the supply passage;
The valve block further includes an in-block supply passage to which the working fluid discharged from the pump is supplied,
The in-block supply passage is formed at a position where at least a part thereof is on the axis of the accommodation hole and spaced from the bottom of the accommodation hole to the side opposite to the opening,
The distance between the in-block supply passage and the internal pilot port on the axis of the receiving hole is larger than the distance between the internal pilot port and the actuator discharge port on the axis of the receiving hole, Flow control valve to do.   2. The flow control valve according to claim 1, wherein the internal pilot port is provided at a substantially intermediate position between the tank port and the supply passage in the block on the axis of the accommodation hole. The pilot pressure is the pressure of the working fluid supplied to the internal pilot port;
An internal pilot pressure chamber communicating with the internal pilot port is formed between the bottom of the accommodation hole and one end face of the valve body,
3. The flow rate control valve according to claim 1, wherein the flow rate of the working fluid passing through the first tank passage is controlled by moving the valve body according to the pilot pressure. 4. The valve block is further formed with a drain port facing one end surface of the valve body at a position between the supply passage in the block and the internal pilot port on the axis of the accommodation hole,
An external pilot pressure chamber facing the other end surface of the valve body is formed between the valve block and a cap member provided outside the valve block,
The pilot pressure is the pressure of the working fluid supplied to the external pilot pressure chamber,
3. The flow rate control valve according to claim 1, wherein the flow rate of the working fluid passing through the first tank passage is controlled by moving the valve body according to the pilot pressure. 4.   The flow control valve according to claim 4, wherein the internal pilot port is always closed by the valve body.   The flow control valve according to any one of claims 1 to 5, wherein the in-block supply passage is a part of the neutral passage.