Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
  • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
  • F15B11/00—Servomotor systems without provision for follow-up action; Circuits therefor
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
  • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
  • F15B11/00—Servomotor systems without provision for follow-up action; Circuits therefor
  • F15B11/02—Systems essentially incorporating special features for controlling the speed or actuating force of an output 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
  • F16K27/00—Construction of housing; Use of materials therefor

Definitions

• Construction machinery such as excavators that are equipped with multiple actuators are equipped with a hydraulic drive device that controls the flow of hydraulic fluid to the actuators.
• a hydraulic drive device is the hydraulic drive system of Patent Document 1.
• a meter-in control valve and a meter-out control valve are connected to one actuator.
• the meter-in control valve controls the flow rate of hydraulic fluid that flows from the pump to the actuator, i.e., the meter-in flow rate
• the meter-out flow rate controls the flow rate of hydraulic fluid that is discharged from the actuator to a tank, i.e., the meter-out flow rate.
• the hydraulic drive system of Patent Document 1 controls the flow of hydraulic fluid to an actuator having two ports. That is, in the hydraulic drive system, when the meter-in control valve supplies hydraulic fluid to one of the two ports, the meter-out control valve discharges hydraulic fluid from the other port. Also, when the meter-in control valve supplies hydraulic fluid to the other port, the meter-out control valve discharges hydraulic fluid from the other port. Therefore, both the meter-in control valve and the meter-out control valve need to be connected to two ports of the actuator.
• the hydraulic drive system is equipped with, for example, a multi-control valve, and if the meter-in control valve and the meter-out control valve are connected to two ports, respectively, the configuration of the passages formed in the multi-control valve becomes complex. This causes the multi-control valve to become larger.
• the multi-control valve of the first disclosure is a multi-control valve that controls the flow of hydraulic fluid to two ports of a first actuator, and includes a first control spool that is connected to a first hydraulic pump, a tank, and one of the two ports and controls the flow of hydraulic fluid to the one port, and a second control spool that is connected to the first hydraulic pump, the tank, and the other of the two ports and controls the flow of hydraulic fluid to the other port, and the first and second control spools control the flow rate of hydraulic fluid independently of each other.
• the hydraulic drive device of the present disclosure includes a third control spool connected to one of two ports of the second actuator, the second hydraulic pump, and the tank, and controls the flow of hydraulic fluid to one port of the second actuator, and a fourth control spool connected to the other port of the second actuator, the second hydraulic pump, and the tank, and controls the flow of hydraulic fluid to the other port of the second actuator, the third and fourth control spools controlling the flow rate of hydraulic fluid independently of each other, the multi-control valve as described above, and a control device, and the multi-control valve includes a first travel spool connected to a first travel motor and the first hydraulic pump, and controls the flow rate of hydraulic fluid supplied to the first travel motor, and a second travel motor and the second hydraulic pump, and controls the flow rate of hydraulic fluid supplied to the second travel motor.
• the control device further includes a second travel spool that controls the flow rate of hydraulic fluid supplied to the travel motor, and a plurality of pressure sensors that detect the supply pressure of the hydraulic fluid supplied to the first actuator, the first travel motor, and the second travel motor, respectively.
• the control device controls the openings of the first and second control spools and the first and second travel spools based on the input command and the hydraulic pressure detected by each pressure sensor.
• the control device narrows the openings of the first to fourth control spools, and if the supply pressure of the first and second travel motors is lower than the supply pressure of the first actuator in the hydraulic pressure detected by each pressure sensor, the control device narrows the openings of the first and second travel spools.
• the second spool 24 is connected to the second supply/discharge port 4b via the second supply/discharge passage 53.
• the second spool 24 receives pilot pressures output from the solenoid valves 24a and 24b in opposing directions, and strokes to a position according to the pilot pressures of the solenoid valves 24a and 24b.
• the second spool 24 switches the connection of the second supply/discharge port 4b to either the second main passage 32 or the tank passage 33 by stroking.
• the merging spool 25 is disposed in a merging passage 54 connecting the two main passages 31, 32, and opens and closes the merging passage 54.
• the merging spool 25 receives pilot pressure output from the solenoid valve 25b in a direction against the biasing force of a spring mechanism 25d, which will be described in detail later, and strokes to a position according to the pilot pressure of the solenoid valve 25b.
• the merging spool 25 opens and closes the merging passage 54 by stroking, and adjusts the opening degree of the merging spool 25. In this way, the merging spool 25 merges the hydraulic fluid from the second main passage 32 to the first main passage 31 and in the opposite direction, and also controls the flow rate of the hydraulic fluid to be merged.
• the boom regenerative valve element 26 is connected to the head side passage 41 and the first arm passage 44. More specifically, the boom regenerative valve element 26 is connected to the head side passage 41 so as to be parallel to the spools 14 and 15. The boom regenerative valve element 26 is also connected to the downstream side of the check valve 44a in the first arm passage 44 so as to be parallel to the spools 17 and 19.
• the boom regenerative valve element 26 regenerates hydraulic fluid discharged from the head side port 5a of the boom cylinder 5 to the arm cylinder 6. More specifically, the boom regenerative valve element 26 opens and closes in response to the pilot pressure output from the solenoid valve 26a, and adjusts the opening degree of the boom regenerative valve element 26. As a result, the boom regenerative valve element 26 regenerates hydraulic fluid from the head side port 5a of the boom cylinder 5 to the head side port 6a or the rod side port 6b of the arm cylinder 6, and controls the regenerated flow rate.
• the pressure sensors 61a to 67a, 61b to 67b correspond to the ports 2a to 7a, 2b to 7b of the hydraulic pumps 8, 9 and the actuators 2 to 7.
• the pressure sensors 61a, 61b are connected to the main passages 31, 32, and detect the discharge pressures of the corresponding hydraulic pumps 8, 9.
• the pressure sensors 62a to 67a, 62b to 67b are connected to the passages 35, 36, 38, 39, 41, 43, 45, 47, 49, 50, 52, 53 that are connected to the corresponding ports 2a to 7a, 2b to 7b.
• the control device 70 controls the operation of each of the spools 12 to 25 and the boom regeneration valve element 26.
• the control device 70 controls the operation of each of the spools 12 to 25 and the boom regeneration valve element 26 in response to a command signal input from, for example, an operating device 71.
• the operating device 71 includes a plurality of operating levers and operating pedals (both not shown), and outputs a command signal to the control device 70 in response to the operation of the operating levers and operating pedals.
• the control device 70 also acquires the discharge pressures of the hydraulic pumps 8 and 9 from the pressure sensors 61a and 61b, and acquires the port pressures of the ports 2a to 7a and 2b to 7b from the pressure sensors 62a to 67a and 62b to 67b.
• the control device 70 controls the operation of each of the spools 12 to 25 and the boom regeneration valve element 26 based on the input command signal and the acquired hydraulic pressures of the ports 2a to 7a and 2b to 7b.
• the block body 11a is formed, for example, in a roughly rectangular parallelepiped shape.
• the block body 11a is formed in a rectangular shape in a plan view seen from one side in the height direction.
• the block body 11a includes a first block member 11d and a second block member 11e.
• the block body 11a can be divided into the first block member 11d and the second block member 11e in the height direction.
• the block body 11a does not necessarily need to be divided into the first block member 11d and the second block member 11e.
• the block body 11a has a plurality of first spool holes 11b and a plurality of second spool holes 11c formed as follows.
• the second spool holes 11c are formed on the other widthwise side of the block body 11a as shown in FIG. 4. More specifically, the second spool holes 11c are arranged in two rows on the other widthwise side of the block body 11a. In this embodiment, eight second spool holes 11c are formed on the other widthwise side of the block body 11a. The eight second spool holes 11c are arranged in two rows in the depth direction, four each in the height direction. In each row, the second spool holes 11c are aligned so that they are aligned in a row in the height direction. In this embodiment, four second spool holes 11c are formed in each of the block members 11d and 11e so arranged.
• the eight second spool holes 11c extend in one width direction from the other widthwise side of the block body 11a. Of the eight second spool holes 11c, six second spool holes 11c are arranged to correspond to the first spool holes 11b, and extend toward the corresponding first spool holes 11b. A pair of spool holes 11b, 11c, which are the first spool hole 11b and the second spool hole 11c corresponding to each other, are arranged in a line in the width direction. In this embodiment, the pair of spool holes 11b, 11c are arranged in a line in the width direction so that their axes coincide with each other. In the valve block 11, a partition wall 11f is formed between the pair of spool holes 11b, 11c to isolate them.
• each of the spools 12 to 25 are inserted into the valve block 11 as follows. That is, each of the spools 12 to 25 is slidably inserted into the first spool hole 11b and the second spool hole 11c of the valve block 11 as shown in Figures 6 to 9.
• each of the spools 16, 19, 20, 22, 24, and 25, which are an example of a first spool, is slidably inserted into the first spool hole 11b.
• Each of the spools 16, 19, 20, 22, and 24 forms an inner pilot chamber 16e, 19e, 20e, 22e, and 24e between the partition wall 11f and the first spool hole 11b.
• Each of the spools 12 and 13 forms an inner pilot chamber 12e, 13e at the bottom of the second spool hole 11c.
• Each of the spools 14, 15, 17, 18, 21, and 23 forms an inner pilot chamber 14e, 15e, 17e, 18e, 21e, and 23e between the second spool hole 11c and the partition wall 11f.
• Pilot pressure is introduced to each of the inner pilot chambers 12e to 24e, and each of the spools 12 to 24 receives the pilot pressure of the inner pilot chambers 12e to 24e in a direction away from the partition wall 11f (hereinafter referred to as "axially outward").
• the boom rod side spool 16, the second arm rod side spool 20, and the bucket rod side spool 22 are slidably inserted into the first spool holes 11b in the row on one side in the depth direction, starting from one side in the height direction.
• the junction spool 25, the first arm rod side spool 19, and the second swivel spool 24 are slidably inserted into the first spool holes 11b in the row on the other side in the depth direction, starting from one side in the height direction.
• the spools 14 to 25 are arranged in the valve block 11 as follows. That is, the first boom head side spool 14 and the boom rod side spool 16 are slidably inserted into a pair of spool holes 11b, 11c arranged in a row. Also, the first arm head side spool 17 and the first arm rod side spool 19 are slidably inserted into a pair of first spool holes 11b, 11c different from the pair of spool holes 11b, 11c through which the spools 14, 16 are inserted.
• the spool covers 12c to 25c are provided on the block body 11a so as to cover the openings of the spool holes 11b and 11c. That is, the spool covers 12c to 25c are provided on the block body 11a so as to cover the corresponding spools 12 to 25.
• the spool covers 16c, 19c, 20c, 22c, 24c, and 25c are provided on one widthwise side of the block body 11a, and the spool covers 12c to 15c, 17c, 18c, 21c, and 23c are provided on the underside of the block body 11a.
• the spool covers 12c to 25c are formed integrally with two adjacent spool covers 12c to 25c to form a double cover.
• outer pilot chambers 12f to 25f are formed within the spool covers 12c to 25c.
• the outer pilot chambers 12f to 25f correspond to the respective spools 12 to 25. Pilot pressure is introduced into the outer pilot chambers 12f to 25f, and the pilot pressure of each of the outer pilot chambers 12f to 24f acts on the corresponding spools 12 to 25 in a direction against the pilot pressure of the inner pilot chambers 12e to 24e (hereinafter referred to as "axially inward").
• the biasing force of the spring mechanisms 12d to 25d also acts against the first solenoid valves 12a to 24a and second solenoid valves 12b to 25b on the corresponding spools 12 to 25. Therefore, each spool 12 to 25 strokes to a position where the biasing forces of each solenoid valve 12a to 24a, 12b to 25b and each spring mechanism 12d to 25d are balanced.
• each spool 12 to 25 controls the flow of hydraulic fluid according to the signal input to each solenoid valve 12a to 24a, 12b to 25b.
• the various passages 31-54 and the pump ports 31a, 32a are formed in the block body 11a as follows. That is, the first main passage 31 and the second main passage 32 are arranged on one side and the other side in the depth direction, sandwiching the first spool hole 11b and the second spool hole 11c, as shown in FIG. 6.
• the first main passage 31 and the second main passage 32 extend in the height direction (see also FIGS. 7 to 9), and open on one side and the other side in the depth direction, respectively, via the pump ports 31a, 32a.
• the various passages 33-54 are formed in the block body 11a to realize the hydraulic circuit 10a described above. An example of the arrangement of the various passages 33-54 is described below.
• the first running passage 34 and the second running passage 37 are adjacent to the first running spool 12 and the second running spool 13, respectively, and are arranged away from each other on one side and the other side in the depth direction.
• the first running passage 34 is connected to the first main passage 31 and the first running spool 12
• the second running passage 37 is connected to the second main passage 32 and the second running spool 13.
• the first and second supply and exhaust passages 35, 36 are connected to both axial sides of the first running passage 34, and the tank passage 33 is further connected to the axial outside of these.
• the first boom passage 40 and the second boom passage 42 are arranged apart from each other on one side and the other side in the depth direction.
• the first boom passage 40 is arranged adjacent to the first boom head side spool 14 and the boom rod side spool 16.
• the first boom passage 40 is connected to the first main passage 31, and branches off from the first main passage 31 midway to connect to the first boom head side spool 14 and the boom rod side spool 16.
• a check valve 40a is interposed in the first boom passage 40 at the branching point.
• the first boom head side spool 14 is connected to the head side passage 41 and the tank passage 33 in this order axially outward from the first boom passage 40.
• the boom rod side spool 16 is connected to the rod side passage 43 and the tank passage 33 in this order axially outward from the first boom passage 40.
• the rod-side passage 43 is connected to the rod-side port 5b of the boom cylinder 5 via a rod-side connection port 43a that opens on one side in the depth direction.
• the head-side passage 41 extends across the second boom head-side spool 15 to the other side in the depth direction, and is connected to the head-side port 5a of the boom cylinder 5 via head-side connection ports 41a, 41b that open on both sides in the depth direction.
• the second boom passage 42 is disposed adjacent to the second boom head side spool 15.
• the second boom passage 42 is connected to the second main passage 32 and the second boom head side spool 15 with a check valve 42a interposed therebetween.
• the second boom head side spool 15 is also connected to the head side passage 41 and the tank passage 33 axially outward of the second boom passage 42.
• the junction passage 54 is disposed adjacent to the other side of the junction spool 25 in the depth direction.
• the junction passage 54 connects the first main passage 31 and the second main passage 32 with the junction spool 25 interposed in the middle.
• the first arm passage 44 and the second arm passage 46 are arranged apart on one side and the other side in the depth direction.
• the second arm passage 46 is arranged adjacent to the second arm head side spool 18 and the second arm rod side spool 20.
• the second arm passage 46 is connected to the first main passage 31, branches off from the first main passage 31 midway, and connects to the second arm head side spool 18 and the second arm rod side spool 20.
• a check valve 46a is interposed in the second arm passage 46 at the branching point.
• the head side passage 45 and the tank passage 33 are connected in this order to the second arm head side spool 18 axially outward from the second arm passage 46.
• the rod side passage 47 and the tank passage 33 are connected to the second arm rod side spool 20 axially outward from the second arm passage 46.
• the head side passage 45 extends in the depth direction so as to straddle the two arm head side spools 18, 17.
• the head side passage 45 is connected to the head side port 5a of the arm cylinder 6 via head side connection ports 45a, 45b that open on both sides in the depth direction.
• the rod side passage 43 extends in the other depth direction so as to straddle the first arm rod side spool 19.
• the rod side passage 47 is connected to the rod side port 5b of the arm cylinder 6 via a rod side connection port 47a that opens on the other side in the depth direction.
• the bucket passage 48 and the turning passage 51 are arranged apart on one side and the other side in the depth direction.
• the bucket passage 48 is arranged adjacent to the bucket head side spool 21 and the bucket rod side spool 22.
• the bucket passage 48 is connected to the first main passage 31, and branches off from the first main passage 31 midway to connect to the bucket head side spool 21 and the bucket rod side spool 22.
• a check valve 48a is interposed in the bucket passage 48 at the branching point.
• the head side passage 49 and the tank passage 33 are connected in turn to the bucket head side spool 21 axially outward from the bucket passage 48.
• the rod side passage 50 and the tank passage 33 are connected in turn to the bucket rod side spool 22 axially outward from the bucket passage 48.
• the head side passage 49 is connected to the head side port 7a of the bucket cylinder 7 via a head side connection port 49a that opens on one side surface in the depth direction.
• the rod-side passage 50 is connected to the rod-side port 7b of the bucket cylinder 7 via a rod-side connection port 50a that opens on one side in the depth direction.
• the swivel passage 51 is disposed adjacent to the first swivel spool 23 and the second swivel spool 24.
• the swivel passage 51 is connected to the second main passage 32, and branches off from the second main passage 32 midway to connect to the first swivel spool 23 and the second swivel spool 24.
• a check valve 51a is disposed in the swivel passage 51 at the branching point.
• the first supply and exhaust passage 52 and the tank passage 33 are connected in turn to the first swivel spool 23 on the axially outer side of the swivel passage 51.
• the second supply and exhaust passage 53 and the tank passage 33 are connected in turn to the second swivel spool 24 on the axially outer side of the swivel passage 51.
• the first supply and exhaust passage 52 is connected to the first supply and exhaust port 4a of the swivel motor 4 via a first supply and exhaust connection port 52a that opens on the other side surface in the depth direction.
• the second supply and exhaust passage 53 is connected to the second supply and exhaust port 4b of the rotation motor 4 via a second supply and exhaust connection port 53a that opens on the other side in the depth direction.
• control device 70 When the control device 70 outputs pilot pressure from the first solenoid valves 12a, 13a, it acquires the discharge pressures of the hydraulic pumps 8, 9 and the port pressures of the ports 2a, 3a detected by the pressure sensors 61a, 61b, 62a, 63a. The control device 70 then operates the solenoid valves 12a, 13a based on the input command signal and the acquired discharge pressures and port pressures. As a result, the control device 70 allows a flow rate according to the input command signal to flow to the travel motors 2, 3, and drives the travel motors 2, 3 at a speed according to the amount of operation of the operating device 71. The control device 70 also operates the solenoid valves 14a-24a, 14b-24b for the actuators 4-7 described below based on the acquired discharge pressures and port pressures and command signals. Therefore, the description of the actuators 4-7 will be omitted.
• the control device 70 also operates as follows when rotating the rotating body. That is, the control device 70 outputs pilot pressure from one of the solenoid valves 23a, 23b, 24a, and 24b. For example, when pilot pressure is output from the solenoid valves 23a and 24b, the pilot pressure is guided to the pilot chambers 23f and 24e, and the rotation motor 4 is operated. At this time, the hydraulic fluid is supplied from the hydraulic pump 8 to the first supply and discharge port 4a via the first rotation spool 23, and the hydraulic fluid is further discharged from the second supply and discharge port 4b to the tank 30 via the second rotation spool 24.
• the first rotation spool 23 and the second rotation spool 24 can stroke independently, and the opening degree of each can be adjusted independently of each other. Therefore, in the multi-control valve 10, the flow rate flowing through the first supply and discharge port 4a and the second supply and discharge port 4b can be controlled independently, and more precise control can be performed on the rotation motor 4.
• the multi-control valve 10 of this embodiment is further provided with a second arm head side spool 18 that is connected to the head side port 6a of the arm cylinder 6 and the first hydraulic pump 8 and controls the flow of hydraulic fluid supplied to the head side port 6a of the arm cylinder 6. Therefore, a larger flow rate of hydraulic fluid can be supplied to the head side port 6a by the first arm head side spool 17 and the second arm head side spool 18.
• the second arm head side spool 18 controls the flow rate of hydraulic fluid independently of the first arm head side spool 17 and the first arm rod side spool 19.
• the flow rate of hydraulic fluid supplied to the head side port 6a via the second arm head side spool 18 can be controlled independently from the flow rate of hydraulic fluid discharged from the rod side port 6b.
• the flow rate of the supplied hydraulic fluid can be controlled with higher accuracy.
• the multi-control valve 10 of this embodiment is further provided with a second arm rod side spool 20 that is connected to the first hydraulic pump 8 and the rod side port 6b of the arm cylinder 6 and controls the flow of hydraulic fluid to the rod side port 6b. Therefore, a larger flow rate of hydraulic fluid can be supplied to and discharged from the rod side port 6b by the first arm rod side spool 19 and the second arm rod side spool 20.
• the second arm rod side spool 20 controls the flow rate of hydraulic fluid independently of the first arm head side spool 17, the first arm rod side spool 19, and the second arm head side spool 18.
• two spools 14, 16 that can independently control the flow rate of the hydraulic fluid supplied to and discharged from each port 5a, 5b of the boom cylinder 5 can be arranged side by side in the width direction
• two spools 17, 19 that can independently control the flow rate of the hydraulic fluid supplied to and discharged from each port 6a, 6b of the arm cylinder 6 can be arranged side by side in the width direction.
• the control device 70 when the control device 70 operates the first travel spool 12 and the second travel spool 13, it connects the first hydraulic pump 8 and the second hydraulic pump 9 by opening the merging spool 25.
• This makes it possible to make the supply pressures of the two travel motors 2, 3 connected to the first hydraulic pump 8 and the second hydraulic pump 9, respectively, the same, thereby improving straight-line running ability during straight-line running when the two travel motors 2, 3 are operated simultaneously.
• the multi-control valve 10 of this embodiment is further provided with a second arm head side spool 18 that controls the flow rate of the hydraulic fluid supplied from the first hydraulic pump 8 to the head side port 6a of the arm cylinder 6. Therefore, a larger flow rate of hydraulic fluid can be supplied to the head side port 6a of the arm cylinder 6 by the two arm head side spools 17, 18.
• the first arm head side spool 17, the second arm head side spool 18, and the first arm rod side spool 19 control the flow rate of the hydraulic fluid independently of each other. Therefore, the flow rate to the head side port 6a of the arm cylinder 6 can be controlled independently from the flow rate of the hydraulic fluid discharged from the rod side port 6b.
• a second arm rod side spool 20 is further provided, which discharges hydraulic fluid from the rod side port 6b together with the first arm rod side spool 19 and controls the flow rate of the hydraulic fluid discharged from the rod side port 6b. Therefore, a larger flow rate of hydraulic fluid can be discharged from the other port by the two arm rod side spools 19, 20.
• the second arm rod side spool 20 controls the flow rate of hydraulic fluid independently of the first arm head side spool 17, the second arm head side spool 18, and the first arm rod side spool 19. Therefore, the flow rate of hydraulic fluid discharged from the rod side port 6b can be controlled independently from the flow rate flowing to the head side port 6a. This allows the flow rate of hydraulic fluid to be controlled with higher accuracy when discharging hydraulic fluid from the arm cylinder 6 via the two arm rod side spools 19, 20.
• the boom regeneration valve body 26 regenerates the hydraulic fluid discharged from the head side port 5a of the boom cylinder 5 to the first arm passage 44. Therefore, a portion of the passage connecting the boom regeneration valve body 26 and each port 6a, 6b of the arm cylinder 6 can be omitted, and the configuration of the passage formed in the multi-control valve 10 can be simplified. This allows the multi-control valve 10 to be made more compact.
• the bucket head side spool 21 controls the flow of hydraulic fluid to the head side port 7a of the bucket cylinder 7, and the bucket rod side spool 22 controls the flow of hydraulic fluid to the rod side port 7b of the bucket cylinder 7. Therefore, the passage connecting the bucket head side spool 21 and the rod side port 7b, and the passage connecting the bucket rod side spool 22 and the head side port 7a can be omitted. This simplifies the configuration of the passages formed in the multi-control valve 10, and the multi-control valve 10 can be made smaller.
• the bucket head side spool 21 and the bucket rod side spool 22 control the flow rate of hydraulic fluid independently of each other. Therefore, the multi-control valve 10 can independently control the flow rate of hydraulic fluid supplied to and discharged from each port 7a, 7b of the bucket cylinder 7, and can be made smaller.
• the valve block includes a plurality of spool holes extending in a first direction and arranged in a row in the first direction with corresponding spool holes sandwiching a partition wall between them.
• the first and second control spools and the third and fourth control spools are slidably inserted into each of the different pairs of spool holes. Therefore, two control spools capable of independently controlling the flow rate of the hydraulic fluid supplied to and discharged from each port of the first actuator can be arranged in a row, and two control spools capable of independently controlling the flow rate of the hydraulic fluid supplied to and discharged from each port of the second actuator can be arranged in a row in the first direction. This allows the valve block capable of independently controlling the flow rate of the hydraulic fluid supplied to and discharged from each port of the first and second actuators to be made smaller.
• the multi-control valve is the multi-control valve of the fourteenth aspect, further comprising a boom regenerative valve body that regenerates hydraulic fluid discharged from the head side port of the boom cylinder to the arm cylinder.
• the boom regeneration valve body regenerates the hydraulic fluid discharged from the head side port of the boom cylinder to the arm passage. Therefore, a portion of the passage connecting the boom regeneration valve body and each port of the arm cylinder can be omitted, simplifying the configuration of the passage formed in the hydraulic drive device. This allows the hydraulic drive device to be made more compact.
• the multi-control valve of the fourteenth aspect further includes a first rotation spool connected to the second hydraulic pump, the tank, and the first supply/discharge port of the rotation motor and controlling the flow of hydraulic fluid to the first supply/discharge port of the rotation motor, and a second rotation spool connected to the second hydraulic pump, the tank, and the second supply/discharge port of the rotation motor and controlling the flow of hydraulic fluid to the second supply/discharge port of the rotation motor, and the first and second rotation spools control the flow rate of hydraulic fluid independently of each other.
• the first rotation spool controls the flow of hydraulic fluid to the first supply/discharge port
• the second rotation spool controls the flow of hydraulic fluid to the second supply/discharge port. Therefore, the passage connecting the first rotation spool and the second supply/discharge port, and the passage connecting the second rotation spool and the first supply/discharge port can be omitted. This simplifies the configuration of the passages formed in the hydraulic drive device, allowing the hydraulic drive device to be made smaller.
• the first and second rotation spools control the flow rate of hydraulic fluid independently of each other. Therefore, the flow rate of hydraulic fluid supplied to and discharged from each port of the rotation motor can be controlled independently of each other, and the hydraulic drive device can be made smaller.

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  • 2025-01-09 WO PCT/JP2025/000564 patent/WO2025150544A1/ja active Pending
  • 2025-01-09 JP JP2025569424A patent/JPWO2025150544A1/ja active Pending

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