Control system for a working machine, working machine and method for controlling a working machine

Abstract

Control system (10) for a working machine (100), comprising: a control device (9); a plurality of hydraulic pumps (32) that deliver hydraulic oil; a hydraulic cylinder (2) that moves a working tool element (11, 12, 13); a plurality of flow rate control valves (40), each connected to the plurality of hydraulic pumps (32) and adjusting a flow rate of the hydraulic oil supplied to the hydraulic cylinder (2); a plurality of supply flow paths (37), each connected to the plurality of flow rate control valves (40); a counter input flow path (72) that connects a collecting part (37S) of the plurality of supply flow paths (37) and an inlet (2D) of the hydraulic oil into the hydraulic cylinder (2); a plurality of discharge flow paths (36), each connected to the plurality of flow rate control valves (40); a counter output flow path (71) that connects a collecting part (36S) of the plurality of delivery flow paths (36) and an outlet (2C) of the hydraulic oil into the hydraulic cylinder (21); and a choke (51) arranged in the counter output flow path, an actuating device (5) that generates an operation command with an operation; wherein the control device (9) contains: a correlation data storage unit (9A) that stores correlation data between an actuation amount of the actuating device (5) and a target counter input flow rate, which indicates a target flow rate of the hydraulic oil flowing into the inlet (2D); an operations order capture unit (9B) that captures the operations order; a target counter output flow rate calculation unit (9G) which, based on the correlation data and the operation instruction, calculates a counter output flow rate that indicates a target flow rate of the hydraulic oil flowing out of the outlet (2C); a control valve opening area calculation unit (9I) that calculates a target opening area of ​​the flow rate control valves (40) based on the target counter output flow rate; and a control valve control unit (9L) that issues a control command to cause the flow rate control valves (40) to have the target opening area of ​​the flow rate control valves (40).

Description

Area

[0001] The present invention relates to a control system for a working machine, a working machine and a method for controlling a working machine. background

[0002] In a technical field relating to a working machine, a hydraulic control device is known as disclosed in JP 2018-028 358 A. In JP 2018-028 358 A, the hydraulic control device includes a control valve that adjusts the flow rate of the hydraulic oil supplied to a hydraulic cylinder and a variable throttle located in the flow path of the hydraulic cylinder. The flow rate of the hydraulic oil discharged from the hydraulic cylinder into a tank is adjusted by the variable throttle located in the flow path. The cylinder speed is adjusted by changing the flow rate of the hydraulic oil. Patent literature

[0003] US 2018 / 0 251 960 A1; US 2019 / 0 024 343 A1; JP 2018 - 028 358 A.

[0004] US Patent 2018 / 0 251 960 A1 discloses a working machine comprising a control device and a plurality of hydraulic pumps that deliver hydraulic oil, and a plurality of hydraulic cylinders that move working machine elements. The machine also includes a plurality of flow rate control valves connected to the hydraulic pumps that regulate the flow rate of the hydraulic oil supplied to the hydraulic cylinders. Furthermore, the machine comprises supply flow paths connected to the flow rate control valves, a counter inlet flow path connecting a manifold of the plurality of supply flow paths to an inlet of the hydraulic oil in the hydraulic cylinder, and discharge flow paths, each connected to the plurality of flow rate control valves. Finally, the machine includes a counter outlet flow path connecting a manifold of the plurality of discharge flow paths to an outlet of the hydraulic oil in the hydraulic cylinder. Summary Technical Problem

[0005] In a setup where multiple control valves are connected to a hydraulic cylinder, the hydraulic oil discharged from the cylinder is returned to the reservoir via the meter outlet flow path. If the variable throttle is not properly positioned, the hydraulic oil flow rate may be excessively restricted. When the hydraulic oil flow rate is excessively restricted, the cylinder speed decreases excessively, potentially leading to reduced work efficiency.

[0006] One object of the present invention is to suppress a decrease in work efficiency. Solution to the problem

[0007] This problem is solved according to the invention by a control system for a working machine with the features of claim 6. Advantageous embodiments are specified in dependent claims 2 to 5. Furthermore, the problem is solved by a working machine with the features of claim 6 and by a method for controlling a working machine with the features of claim 7.

[0008] According to one aspect of the present invention and according to claim 1, a control system for a working machine therefore comprises the following: a control device, a plurality of hydraulic pumps that supply hydraulic oil; a hydraulic cylinder that moves a working element; a plurality of flow rate control valves, each connected to the plurality of hydraulic pumps and which adjust a flow rate of the hydraulic oil supplied to the hydraulic cylinder; a plurality of supply flow paths, each connected to the plurality of flow rate control valves; a counter inlet flow path that connects a manifold of the plurality of supply flow paths and an inlet of the hydraulic oil to the hydraulic cylinder; a plurality of discharge flow paths, each connected to the plurality of flow rate control valves;A counter output flow path connecting a manifold of the multiple delivery flow paths and an outlet of the hydraulic oil into the hydraulic cylinder; and a throttle arranged in the counter output flow path. Furthermore, an actuating device is provided, which generates an operation command with an operation. The control device further comprises: a correlation data storage unit, which stores correlation data between an actuation amount of the actuating device and a target counter input flow rate, indicating a target flow rate of the hydraulic oil flowing into the inlet; an operation command acquisition unit, which acquires the operation command; and a target counter output flow rate calculation unit, which, based on the correlation data and the operation command, calculates a counter output flow rate indicating a target flow rate of the hydraulic oil flowing out of the outlet.a control valve opening area calculation unit that calculates a target opening area of ​​the flow rate control valves based on the target counter output flow rate; and a control valve control unit that issues a control command to cause the flow rate control valves to have the target opening area of ​​the flow rate control valves. Advantageous effects of the invention

[0009] According to the present invention, it is possible to suppress a decrease in work efficiency. Brief description of the drawings. Fig. Figure 1 is a perspective view depicting a working machine. Fig. Figure 2 is a schematic diagram describing the movements of a working device. Fig. Figure 3 is a schematic diagram representing a control system for the working machine according to the embodiment. Fig. Figure 4 is a schematic diagram representing a control system for the working machine according to the embodiment. Fig. Figure 5 is a functional block diagram representing a control device according to the embodiment. Fig. Figure 6 is a diagram describing the correlation data according to the implementation. Fig. Figure 7 is a flowchart illustrating a control procedure for an excavator according to this embodiment. Fig. Figure 8 is a schematic diagram representing a control system for the working machine according to the embodiment. Fig. Figure 9 is a block diagram representing a computer system according to this embodiment. Description of the embodiments

[0010] Embodiments of the present invention are described below with reference to the drawings, but the present invention is not limited thereto. The components of the embodiments described below can be combined in a suitable manner. Some components are not used in some cases. [Working machine]

[0011] Fig. 1 and Fig. Figure 2 shows a conventionally designed working machine. The embodiment described below is an example where the working machine 100 is an excavator. In the following description, the working machine 100 will expediently be referred to as excavator 100.

[0012] As in Fig. As shown in Figure 1, the excavator 100 includes a working tool 1, a hydraulic cylinder 2, a vibrating body 3, a drive body 4 and an actuating device 5.

[0013] The vibrating body 3 supports the working implement 1. The vibrating body 3 oscillates about an oscillation axis RX. The vibrating body 3 oscillates with the force generated by an oscillating motor (not shown). The vibrating body 3 contains an operating chamber 6 and a machine chamber 7. An operator of the excavator 100 enters the operating chamber 6. An operator's seat 6S is provided in the operating chamber 6, on which the operator sits.

[0014] The undercarriage 4 supports the vibrating body 3. The undercarriage 4 contains a pair of crawler tracks 4C. The crawler tracks 4C are rotated by the power generated by a drive motor (not shown). The excavator 100 moves with the rotation of the crawler tracks 4C. The undercarriage 4 may include a tire attached to an axle.

[0015] The working device 1 is supported by the vibrating body 3. The working device 1 comprises a plurality of relatively movable working device elements. The working device elements of the working device 1 include a boom 11 connected to the vibrating body 3, an arm 12 connected to the boom 11, and a bucket 13 connected to the arm 12.

[0016] The boom 11 and the vibrating body 3 are coupled via a boom bolt. The boom 11 is rotatably supported on the vibrating body 3 about a pivot axis AX1.

[0017] The boom 11 and the arm 12 are coupled via a pivot pin. The arm 12 is rotatably supported by the boom 11 about a pivot axis AX2.

[0018] The arm 12 and the bucket 13 are coupled via a bucket pin. The bucket 13 is rotatably supported by the arm 12 about a pivot axis AX3.

[0019] The axes of rotation AX1, AX2, and AX3 are parallel to each other. The axis of rotation AX1 and an axis parallel to the oscillation axis RX are orthogonal to each other. In the following description, a direction parallel to the oscillation axis RX is referred to as the vertical direction of the oscillating body 3, a direction parallel to the axis of rotation AX1 is conveniently referred to as the vehicle width direction or horizontal direction of the oscillating body 3, and a direction orthogonal to both the axis of rotation AX1 and the oscillation axis RX is conveniently referred to as the front-to-rear direction of the oscillating body 3. The direction in which the implement 1 is located with respect to the oscillation axis RX is a front direction. The direction in which the engine compartment 7 is located with respect to the oscillation axis RX is a rear direction.

[0020] The hydraulic cylinder 2 moves the working equipment elements using hydraulic oil. A number of hydraulic cylinders 2 are provided to move the respective working equipment elements. The hydraulic cylinders 2 include a boom cylinder 21, which moves the boom 11, an arm cylinder 22, which moves the arm 12, and a bucket cylinder 23, which moves the bucket 13.

[0021] The operating device 5 is operated by the operator of the excavator 100. The operating device 5 is operated to move the working tool 1 and the vibrating body 3. The operating device 5 is located in the operating compartment 6. The operating device 5 contains a plurality of operating levers. The working tool 1 and the vibrating body 3 are moved by actuating the operating device 5. [Movement of the work equipment]

[0022] Fig. Figure 2 is a schematic diagram describing the movements of the working device 1 according to the embodiment. The actuating device 5 is actuated to move the working device 1 and the vibrating body 3. The hydraulic cylinder 2 or the vibrating motor (not shown) is driven by the actuating device 5. The drive of the hydraulic cylinder 2 causes the movement of the working device 1. The drive of the vibrating motor causes the movement of the vibrating body 3. A lifting movement of the boom 11, a lowering movement of the boom 11, a digging movement of the boom 12, a discharge movement of the boom 12, a discharge movement of the bucket 13, and a digging movement of the bucket 13 are carried out by the actuating device 5. A vibrating movement of the vibrating body 3 is carried out by the actuating device 5.

[0023] Extending the boom cylinder 21 causes the boom 11 to perform the lifting movement. Retracting the boom cylinder 21 causes the boom 11 to perform the lowering movement.

[0024] Extending the arm cylinder 22 causes the arm 12 to perform the digging movement. Retracting the arm cylinder 22 causes the arm 12 to perform the unloading movement.

[0025] Extending the bucket cylinder 23 causes the bucket 13 to perform the digging motion. Retracting the bucket cylinder 23 causes the bucket 13 to perform the unloading motion.

[0026] The drive of the oscillating motor causes the oscillating body 3 to perform the oscillating movement. [Tax system]

[0027] Fig. Figure 3 is a schematic diagram representing a control system 10 for the excavator 100 according to the embodiment. As in Fig. As shown in Figure 3, the control system 10 comprises a control device 9, a motor 30, a power transmission mechanism 31, a hydraulic pump 32, a first flow path 33, a second flow path 34, a tank 35, the hydraulic cylinder 2, a flow rate control valve 40, a vent valve 50, a throttle 51, and a regeneration valve 52. Each of the motor 30, the power transmission mechanism 31, the hydraulic pump 32, and the tank 35 is arranged in the engine room 7 of the vibrating body 3.

[0028] The engine 30 is a power source for the excavator 100. For example, a diesel engine is intended to be used as engine 30.

[0029] The power transmission mechanism 31 transmits the power generated by the motor 30 to the hydraulic pump 32. In this embodiment, a plurality of hydraulic pumps 32 are provided. In the Fig. In the example shown, six hydraulic pumps 32 are provided. The power transmission mechanism 31 distributes the power generated by the motor 30 to the multiple hydraulic pumps 32.

[0030] The hydraulic pump 32 is driven by the power transmitted by the power transmission mechanism 31. The hydraulic pump 32 pumps hydraulic oil. In this embodiment, the hydraulic pump 32 is a variable displacement hydraulic pump.

[0031] The hydraulic cylinders 2 move the working equipment elements within a movable range using hydraulic oil supplied by the hydraulic pumps 32. As described above, the hydraulic cylinders 2 include the boom cylinder 21, which moves the boom 11, the arm cylinder 22, which moves the arm 12, and the bucket cylinder 23, which moves the bucket 13.

[0032] Each hydraulic cylinder 2 contains a bottom chamber 2A and a rod chamber 2B. When hydraulic oil is supplied to the bottom chamber 2A, the hydraulic cylinder 2 extends. When hydraulic oil is supplied to the rod chamber 2B, the hydraulic cylinder 2 retracts.

[0033] The first flow path 33 is connected to an outlet port of the hydraulic pump 32. In the Fig. In the example shown in Figure 3, the first flow path 33 is connected to each of the discharge ports of two of the hydraulic pumps 32. The hydraulic oil discharged from the outlet port of the hydraulic pump 32 can flow through the first flow path 33. The hydraulic oil pumped by the hydraulic pump 32 and flowing through the first flow path 33 is supplied to the hydraulic cylinder 2.

[0034] The second flow path 34 is designed to branch off from the first flow path 33. The hydraulic oil discharged from the outlet port of the hydraulic pump 32 can flow through the second flow path 34. The hydraulic oil discharged by the hydraulic pump 32 and flowing through the second flow path 34 is discharged into the tank 35.

[0035] The flow rate control valve 40 adjusts the flow rate of the hydraulic oil supplied to the hydraulic cylinder 2 via the first flow path 33. The bottom chamber 2A of the hydraulic cylinder 2 is connected to the flow rate control valve 40 via a bottom flow path 36 and a manifold flow path 71. The rod chamber 2B of the hydraulic cylinder 2 is connected to the flow rate control valve 40 via a manifold flow path 72 and a rod flow path 37.

[0036] A plurality of flow rate control valves 40 are provided. The flow rate control valves 40 include a boom flow rate control valve 41, which adjusts the flow rate of the hydraulic oil supplied to the boom cylinder 21; an arm flow rate control valve 42, which adjusts the flow rate of the hydraulic oil supplied to the arm cylinder 22; and a bucket flow rate control valve 43, which adjusts the flow rate of the hydraulic oil supplied to the bucket cylinder 23. The hydraulic oil delivered by the hydraulic pump 32 into the first flow path 33 is supplied to the corresponding boom flow rate control valve 41, arm flow rate control valve 42, and bucket flow rate control valve 43.

[0037] In this embodiment, a plurality of boom flow rate control valves 41, a plurality of arm flow rate control valves 42, and a plurality of blade flow rate control valves 43 are provided. In the Fig. In the example shown, three boom flow rate control valves 41 are provided. Three arm flow rate control valves 42 are provided. Three blade flow rate control valves 43 are provided.

[0038] The flow rate control valves 40 are each connected to the plurality of hydraulic pumps 32. The three boom flow rate control valves 41 are each connected to the plurality of hydraulic pumps 32. The three arm flow rate control valves 42 are each connected to the plurality of hydraulic pumps 32. The three blade flow control valves 43 are each connected to the plurality of hydraulic pumps 32.

[0039] Three collecting flow paths 71 are provided, which are connected to the bottom chamber 2A of the boom cylinder 21, the bottom chamber 2A of the arm cylinder 22 and the bottom chamber 2A of the bucket cylinder 23 respectively.

[0040] Three collecting flow paths 72 are provided, which are connected to the rod chamber 2B of the boom cylinder 21, the rod chamber 2B of the arm cylinder 22 and the rod chamber 2B of the bucket cylinder 23 respectively.

[0041] Nine bottom flow paths 36 are provided, which are connected to the three boom flow rate control valves 41, the three arm flow rate control valves 42 and the three bucket flow rate control valves 43 respectively.

[0042] The bottom flow paths 36, each connected to the three boom flow rate control valves 41, are connected to the collecting flow path 71, which is connected to the bottom chamber 2A of the boom cylinder 21 via a collecting part 36S.

[0043] The bottom flow paths 36, each connected to the three arm flow rate control valves 42, are connected via a collector 36S to the collector flow path 71, which is connected to the bottom chamber 2A of the arm cylinder 22.

[0044] The bottom flow paths 36, each connected to the three blade flow rate control valves 43, are connected via a collector 36S to the collector flow path 71, which is connected to the bottom chamber 2A of the blade cylinder 23.

[0045] Nine rod flow paths 37 are provided, which are connected to the three boom flow rate control valves 41, the three arm flow rate control valves 42 and the three blade flow rate control valves 43 respectively.

[0046] The rod flow paths 37, each connected to the three boom flow rate control valves 41, are connected via a collecting part 37S to the collecting flow path 72 connected to the rod chamber 2B of the boom cylinder 21.

[0047] The rod flow paths 37, each connected to the three arm flow rate control valves 42, are connected via a collector 37S to the collector flow path 72 connected to the rod chamber 2B of the arm cylinder 22.

[0048] The rod flow paths 37, each connected to the three blade flow rate control valves 43, are connected via a collector 37S to the collector flow path 72 connected to the rod chamber 2B of the blade cylinder 23.

[0049] This means that the bottom chamber 2A of the boom cylinder 21 is connected to each of the three boom flow rate control valves 41 via the manifold flow path 71 and the bottom flow path 36. The rod chamber 2B of the boom cylinder 21 is connected to each of the three boom flow rate control valves 41 via the manifold flow path 72 and the rod flow path 37.

[0050] The bottom chamber 2A of the arm cylinder 22 is connected to each of the three arm flow rate control valves 42 via the manifold flow path 71 and the bottom flow path 36. The rod chamber 2B of the arm cylinder 22 is connected to each of the three arm flow rate control valves 42 via the manifold flow path 72 and the rod flow path 37.

[0051] The bottom chamber 2A of the blade cylinder 23 is connected to each of the three blade flow rate control valves 43 via the collecting flow path 71 and the bottom flow path 36. The rod chamber 2B of the blade cylinder 23 is connected to each of the three blade flow rate control valves 43 via the collecting flow path 72 and the rod flow path 37.

[0052] The hydraulic pump 32 can supply hydraulic oil to the corresponding boom flow rate control valve 41, arm flow rate control valve 42, and blade flow rate control valve 43 via the first flow path 33. A supply flow path 33A is connected to the corresponding boom flow rate control valve 41, arm flow rate control valve 42, and blade flow rate control valve 43. The first flow path 33 is connected to each of the three supply flow paths 33A. The hydraulic oil delivered by the hydraulic pump 32 into the first flow path 33 is supplied via the supply flow path 33A to the corresponding boom flow rate control valve 41, arm flow rate control valve 42, and blade flow rate control valve 43.

[0053] The vent valve 50 regulates the flow rate of the hydraulic oil that is discharged into the tank 35 via the second flow path 34. The vent valve 50 is located in the second flow path 34. The hydraulic pump 32 can supply the vent valve 50 with hydraulic oil via the second flow path 34. The second flow path 34 branches off from the first flow path 33 between the hydraulic pump 32 and the flow rate control valve 40. The hydraulic oil discharged by the hydraulic pump 32 into the second flow path 34 is fed to the vent valve 50 without being fed to the flow rate control valve 40.

[0054] The vent valve 50 has an inlet port Pe and an outlet port Pf.

[0055] The inlet port Pe is connected to the hydraulic pump 32 via the second flow path 34. The hydraulic oil delivered by the hydraulic pump 32 can flow from the inlet port Pe into the vent valve 50 after passing through the second flow path 34.

[0056] The outlet port Pf is connected to the tank 35 via a tank flow path 39. The hydraulic oil flowing out of the outlet port Pf flows through the tank flow path 39 and is then discharged into the tank 35.

[0057] A slide of the vent valve 50 moves between a discharge position P4 to discharge the hydraulic oil into the tank 35 and a stop position P5 in which the hydraulic oil cannot flow.

[0058] When the slide of the vent valve 50 is in the discharge position P4, the hydraulic oil delivered by the hydraulic pump 32 flows through the second flow path 34, then flows through the inlet port Pe into the vent valve 50 and flows out through the outlet port Pf. The hydraulic oil flowing out of the outlet port Pf flows through the tank flow path 39 and is then discharged into the tank 35.

[0059] If the slide of the vent valve 50 is in the stop position P5, the hydraulic oil cannot flow through the vent valve 50.

[0060] The vent valve 50 controls the flow rate of the hydraulic oil discharged into the tank 35 depending on the movement of the spool. The opening area of ​​the port through which the hydraulic oil flows in the vent valve 50 is adjusted according to the movement of the spool. The flow rate of the hydraulic oil discharged into the tank 35 is set by adjusting the opening area of ​​the vent valve 50.

[0061] The throttle 51 is arranged in the collecting flow path 71 or in the collecting flow path 72. In this embodiment, the throttle 51 is arranged in the collecting flow path 71, which is connected to the bottom chamber 2A of the boom cylinder 21. The throttle 51 can be arranged in the collecting flow path 72, which is connected to the rod chamber 2B of the arm cylinder 22. The throttle 51 can be arranged in the collecting flow path 72, which is connected to the rod chamber 2B of the bucket cylinder 23. The throttle 51 regulates the flow rate of the hydraulic oil flowing through the collecting flow path 71 or the collecting flow path 72. The throttle 51 is located in a collecting flow path that is influenced by the weight (gravity) of the working equipment components.

[0062] The regeneration valve 52 sets a regeneration flow rate of the hydraulic oil that is regenerated from the manifold flow path 71 into the manifold flow path 72, or a regeneration flow rate of the hydraulic oil that is regenerated from the manifold flow path 72 into the manifold flow path 71. In the embodiment, the regeneration valve 52 is arranged such that it sets the regeneration flow rate of the hydraulic oil that is regenerated from the manifold flow path 71 connected to the bottom chamber 2A of the boom cylinder 21 to the manifold flow path 72 connected to the rod chamber 2B of the boom cylinder 21. The regeneration valve 52 can be arranged to adjust the regeneration flow rate of the hydraulic oil regenerated from the collecting flow path 72 connected to the rod chamber 2B of the boom cylinder 22 to the collecting flow path 71 connected to the bottom chamber 2A of the boom cylinder 22.

[0063] Fig. Figure 4 is a schematic diagram illustrating the control system 10 for the excavator 100 according to the embodiment. Fig. Figure 4 corresponds to a diagram obtained by pulling out the boom cylinder 21 and the boom flow rate control valve 41 into Fig. 3 was received. In which in Fig. In the example shown in Figure 3, the hydraulic oil from the two hydraulic pumps 32 arranged in series is combined and supplied to the plurality of parallel flow rate control valves 40 (41, 42, 43), but in the Fig. In example 4, the number of hydraulic pumps is 32. The number of hydraulic pumps can be arbitrarily high. In the example shown in Fig. In the example shown in Figure 3, a plurality of hydraulic pumps 32 are connected to the power transmission mechanism 31. The hydraulic oil pumped by the hydraulic pumps 32 arranged in series flows through a flow rate control valve 40 and is then combined and supplied to a hydraulic cylinder 2. A plurality of hydraulic circuits are provided through which the hydraulic oil supplied to a hydraulic cylinder 2 flows. In the Fig. In the example shown in Figure 3, the hydraulic oil is combined by the three flow rate control valves 40 (e.g., 41, 41, 41) provided in the respective hydraulic circuits and supplied to a hydraulic cylinder 2 (e.g., the boom cylinder 21), but the present invention is not limited to this. The number of flow rate control valves 40 that supply a hydraulic cylinder 2 with hydraulic oil can be arbitrary.

[0064] As in Fig. As shown in Figure 4, the control system 10 comprises a plurality of hydraulic pumps 32 that deliver hydraulic oil, the hydraulic cylinder 2 which moves a working device element, the plurality of flow rate control valves 40, each connected to the plurality of hydraulic pumps 32 and which adjust a flow rate of the hydraulic oil supplied to the hydraulic cylinder 2, the plurality of rod flow paths 37, each connected to the plurality of flow rate control valves 40, the collecting flow path 72, which connects the collecting part 37S of the plurality of rod flow paths 37 and an opening 2D of the rod chamber 2B of the hydraulic cylinder 2, a plurality of bottom flow paths 36, each connected to the plurality of flow rate control valves 40, and the collecting flow path 71, which connects the collecting part 36S of the plurality of bottom flow paths 36 and an opening 2C of the bottom chamber 2A of the hydraulic cylinder 2.and the throttle 51 arranged in the collecting flow path 71.

[0065] The boom 11 performs the lifting and lowering movement with the boom cylinder 21. Fig. Figure 4 represents a state in which the boom cylinder 21 retracts and the boom 11 performs the lowering movement. When the boom 11 performs the lowering movement, the hydraulic oil flows into the rod chamber 2B of the boom cylinder 21 and flows out of the bottom chamber 2A of the boom cylinder 21. That is, the hydraulic oil delivered by the hydraulic pump 32 flows through the boom flow rate control valve 41 into the rod flow path 37, flows through the manifold flow path 72, and then flows through the opening 2D into the rod chamber 2B. The hydraulic oil flowing out of the opening 2C of the bottom chamber 2A of the hydraulic cylinder 2 flows through the manifold flow path 71 and the bottom flow path 36 and is then discharged into the tank 35 via the boom flow rate control valve 41.

[0066] In the following description, the rod flow path 37 is conveniently referred to as the supply flow path 37, the opening 2D of the rod chamber 2B is conveniently referred to as the inlet 2D, the collecting flow path 72 is conveniently referred to as the counter inlet flow path 72, the opening 2C of the bottom chamber 2A is conveniently referred to as the outlet 2C, the collecting flow path 71 is conveniently referred to as the counter outlet flow path 71, and the bottom flow path 36 is conveniently referred to as the discharge flow path 36.

[0067] The hydraulic pump 32 pumps hydraulic oil. A variety of hydraulic pumps 32 are available. In the Fig. In the example shown in Figure 4, three hydraulic pumps 32 are provided. One hydraulic pump 32 is connected to a boom flow rate control valve 41. As shown in Fig. As shown in Figure 3, two hydraulic pumps 32 can be connected to a boom flow rate control valve 41.

[0068] The boom cylinder 21 moves the boom 11. The boom 11 performs the lifting and lowering movements with the boom cylinder 21. During the lowering movement of the boom 11, the hydraulic oil flows from the inlet 2D into the rod chamber 2B, and the hydraulic oil in the bottom chamber 2A flows out of the outlet 2C.

[0069] The boom flow rate control valve 41 adjusts the flow rate of the hydraulic oil supplied to the boom cylinder 21. A plurality of boom flow rate control valves 41 are provided. In the Fig. In the example shown, three boom flow rate control valves 41 are provided. The three flow rate control valves 41 are each connected to the three hydraulic pumps 32. The boom flow rate control valve 41 and the hydraulic pump 32 are in a one-to-one relationship with each other.

[0070] The supply flow path 37 is connected to the boom flow rate control valve 41. A plurality of supply flow paths 37 are provided. In the Fig. In the example shown in Figure 4, three supply flow paths 37 are provided. Each of the three supply flow paths 37 is connected to one of the three boom flow rate control valves 41. The supply flow path 37 and the boom flow rate control valve 41 are in a one-to-one relationship.

[0071] One end section of the supply flow paths 37 is each connected to the boom flow rate control valves 41. The other end sections of the supply flow paths 37 are collected at the manifold 37S. The other end sections of the supply flow paths 37 are connected via the manifold 37S to the counter input flow path 72. The hydraulic oil flowing through each of the multiple supply flow paths 37 discharges into the counter input flow path 72.

[0072] The counter inlet flow path 72 is connected to the inlet 2D, into which the hydraulic oil flows during the lowering movement of the boom 11. The counter inlet flow path 72 connects the manifold 37S of the three supply flow paths 37 and the inlet 2D of the hydraulic oil of the boom cylinder 21. The hydraulic oil flowing through each of the multiple supply flow paths 37 and merging in the counter inlet flow path 72 flows through the counter inlet flow path 72 and then flows from the inlet 2D into the rod chamber 2B.

[0073] The discharge flow path 36 is connected to the boom flow rate control valve 41. A plurality of discharge flow paths 36 are provided. In the Fig. In the example shown in Figure 4, three discharge flow paths 36 are provided. Each of the three discharge flow paths 36 is connected to one of the three boom flow rate control valves 41. The discharge flow path 36 and the boom flow rate control valve 41 have a one-to-one relationship.

[0074] One end section of the discharge flow paths 36 is each connected to the boom flow rate control valves 41. The other end sections of the discharge flow paths 36 are collected at the manifold 36S. The other end sections of the discharge flow paths 36 are connected via the manifold 36S to the counter output flow path 71. The hydraulic oil flowing through the counter output flow path 71 branches into the three discharge flow paths 36.

[0075] The counter output flow path 71 is connected to the outlet 2C, through which the hydraulic oil flows during the lowering movement of the boom 11. The counter output flow path 71 connects the manifold 36S of the three discharge flow paths 36 and the outlet 2C of the hydraulic oil of the boom cylinder 21. The hydraulic oil flowing from outlet 2C of the bottom chamber 2A flows through the counter output flow path 71, then flows through each of the plurality of discharge flow paths 36, and flows into each of the plurality of boom flow rate control valves 41.

[0076] The boom flow rate control valve 41 (flow rate control valve 40) has a pump port Pa, a bottom port Pb, a rod port Pc and a tank port Pd.

[0077] The supply flow path 33A is connected to the pump port Pa. The pump port Pa is connected to the hydraulic pump 32 via the supply flow path 33A. The hydraulic oil delivered by the hydraulic pump 32 can flow from the pump port Pa into the flow rate control valve 40 after passing through the supply flow path 33A.

[0078] The supply flow path 37 is connected to the rod connection Pc. The rod connection Pc is connected to the rod chamber 2B of the hydraulic cylinder 2 via the supply flow path 37 and the counter inlet flow path 72. The hydraulic oil flowing out of the rod connection Pc can flow into the rod chamber 2B of the hydraulic cylinder 2 after passing through the rod flow path 37 and the counter inlet flow path 72.

[0079] The discharge flow path 36 is connected to the lower port Pb. The bottom port Pb is connected to the bottom chamber 2A of the hydraulic cylinder 2 via the discharge flow path 36 and the counter output flow path 71. The hydraulic oil flowing out of the bottom chamber 2A of the hydraulic cylinder 2 can flow from the bottom port Pb into the flow rate control valve 40 after passing through the counter output flow path 71 and the discharge flow path 36.

[0080] Tank connection Pd is connected to tank 35 via a discharge flow path 38. The hydraulic oil flowing out of tank connection Pd flows through the discharge flow path 38 and is then discharged into tank 35.

[0081] The boom flow rate control valve 41 (flow rate control valve 40) is a spool-type flow rate control valve that switches the flow rate and direction of the hydraulic oil supplied to hydraulic cylinder 2 by moving a rod-shaped spool. As the spool moves axially, the supply of hydraulic oil to the bottom chamber 2A and the supply of hydraulic oil to the rod chamber 2B are switched. The flow rate of the hydraulic oil supplied to hydraulic cylinder 2 is also adjusted based on the amount of movement of the spool.

[0082] The slide of the boom flow rate control valve 41 moves between a first working position P1 for supplying hydraulic oil to the bottom chamber 2A of the hydraulic cylinder 2, a second working position P2 for supplying hydraulic oil to the rod chamber 2B of the hydraulic cylinder 2, and a stop position P3 in which no hydraulic oil can flow and which lies between the first working position P1 and the second working position P2. Fig. 4 the slide of the boom flow rate control valve 41 is arranged in the second working position P2.

[0083] When the slide of the boom flow rate control valve 41 is in the first working position P1, the hydraulic oil delivered by the hydraulic pump 32 flows through the supply flow path 33A, then flows into the boom flow rate control valve 41 from the pump port Pa and flows out of the bottom port Pb. The hydraulic oil flowing out of the lower port Pb flows through the lower flow path 36 and the collecting flow path 71 and then flows into the bottom chamber 2A of the hydraulic cylinder 2. This extends the boom cylinder 21. When the boom cylinder 21 extends, the hydraulic oil flows out of the rod chamber 2B. The hydraulic oil flowing out of the rod chamber 2B of the boom cylinder 21 flows through the collecting flow path 72 and the rod flow path 37, then flows via the rod connection Pc into the boom flow rate control valve 41 and flows out via the tank connection Pd.The hydraulic oil flowing from the tank connection Pd is discharged into the tank 35 via the discharge flow path 38.

[0084] When the slide of the boom flow rate control valve 41 is in the second working position P2, the hydraulic oil delivered by the hydraulic pump 32 flows through the supply flow path 33A, then flows into the boom flow rate control valve 41 from the pump port Pa and flows out of the rod port Pc. The hydraulic oil flowing out of the rod port Pc flows through the rod flow path 37 and the collecting flow path 72 and then flows into the rod chamber 2B of the boom cylinder 21. This causes the boom cylinder 21 to retract. When the boom cylinder 21 retracts, the hydraulic oil flows out of the bottom chamber 2A. The hydraulic oil flowing out of the bottom chamber 2A of the boom cylinder 21 flows through the collecting flow path 71 and the bottom flow path 36, then flows through the bottom connection Pb into the boom flow rate control valve 41 and flows out through the tank connection Pd.The hydraulic oil flowing from the tank connection Pd is discharged into the tank 35 via the discharge flow path 38.

[0085] When the slide of the boom flow rate control valve 41 is in the stop position P3, the hydraulic oil cannot flow through the boom flow rate control valve 41.

[0086] The boom flow rate control valve 41 adjusts the flow rate of the hydraulic oil supplied to the boom cylinder 21 as a function of the slide's movement. The opening area of ​​the port through which the hydraulic oil flows in the boom flow rate control valve 41 is adjusted according to the slide's movement. The flow rate of the hydraulic oil supplied to the boom cylinder 21 is set by adjusting the opening area of ​​the boom flow rate control valve 41.

[0087] The throttle 51 is located in the counter output flow path 71. Specifically, it is positioned between the outlet 2C and the manifold 36S. The throttle 51 regulates the flow rate of the hydraulic oil flowing through the counter output flow path 71. The opening area of ​​the throttle 51 is smaller than the opening area of ​​the outlet 2C and smaller than the maximum opening area of ​​the boom flow rate control valve 41. The throttle 51 defines the flow rate of the hydraulic oil flowing through the counter output flow path 71 during the lowering movement of the boom 11.

[0088] The control system 10 also includes the regeneration valve 52, which adjusts the regeneration flow rate of the hydraulic oil that is regenerated from the meter output flow path 71 to the meter input flow path 72 of the meter. The regeneration valve 52 is arranged in a regeneration flow path that connects a middle section of the meter output flow path 71 and a middle section of the meter input flow path 72.

[0089] The regeneration valve 52 has an inlet port Pg and an outlet port Ph.

[0090] The inlet port Pg is connected to the meter output flow path 71. The hydraulic oil flowing from outlet 2C can flow from the inlet port Pg into the regeneration valve 52 after it has flowed through at least part of the meter output flow path 71.

[0091] The outlet port Ph is connected to the meter inlet flow path 72. The hydraulic oil flowing out of the outlet port Ph flows through at least part of the meter inlet flow path 72 and then flows from the inlet 2D into the rod chamber 2B.

[0092] During the lowering movement of the boom 11, the hydraulic oil pressure may increase due to the boom's own weight (effect of gravity). The boom's movement speed can be increased by recirculating some of the hydraulic oil flowing from the bottom chamber 2A back into the rod chamber 2B, thereby utilizing the pressure exerted by the boom's own weight.

[0093] A slide of the regeneration valve 52 moves between a stop position P6, in which no hydraulic oil can flow, and a regeneration position P7, in which hydraulic oil is regenerated.

[0094] If the slide of the regeneration valve 52 is in the stop position P6, the hydraulic oil cannot flow through the regeneration valve 52.

[0095] When the slide of the regeneration valve 52 is in the regeneration position P7, at least some of the hydraulic oil in the counter output flow path 71 can flow via the regeneration valve 52 into the counter input flow path 72.

[0096] The regeneration valve 52 controls a regeneration flow rate, which specifies the flow rate of the hydraulic oil supplied from the meter output flow path 71 to the meter input flow path 72, depending on the movement of the spool. The opening area of ​​the port through which the hydraulic oil flows in the regeneration valve 52 is adjusted according to the amount of movement of the spool. The regeneration flow rate is set by adjusting the opening area of ​​the regeneration valve 52.

[0097] The control system 10 also includes a suction valve 53, which is arranged between the supply flow path 37 and the tank 35. The suction valve 53 causes hydraulic oil to flow from the tank 35 into the supply flow path 37 when a pressure difference between the supply flow path 37 and the tank 35 becomes equal to or greater than a predetermined value. An inlet port Pi of the suction valve 53 is connected to the tank 35. An outlet port Pj of the suction valve 53 is connected to the supply flow path 37.

[0098] The cylinder speed of the boom cylinder 21 is determined by the actuation force of the actuator 5. The cylinder speed increases when the actuation force of the actuator 5 increases, and the cylinder speed decreases when the actuation force of the actuator 5 decreases. During the lowering movement of the boom 11, it is possible that the cylinder speed of the boom cylinder 21 will be higher than the cylinder speed determined by the actuation force of the actuator 5 due to the dead weight (effect of gravity) of the boom 11. That is, during the lowering movement of the boom 11, the boom cylinder 21 can retract rapidly.If the boom cylinder 21 retracts rapidly due to the dead weight of the boom 11, the flow rate of the hydraulic oil supplied to the rod chamber 2B of the boom cylinder 21 is insufficient, even when hydraulic oil is being delivered from the hydraulic pump 32, and the pressure in the supply flow path 37 and in the counter inlet flow path 72 can drop rapidly. If the hydraulic oil supplied by the hydraulic pump 32 is insufficient, a cavitation phenomenon can occur, in which bubbles are generated in the hydraulic oil. By providing the suction valve 53, an opening of the suction valve 53 is opened, and the hydraulic oil is supplied from the tank 35 into the supply flow path 37 via the suction valve 53 when the pressure in the supply flow path 37 and in the counter input flow path 72 drops rapidly and the pressure difference between the supply flow path 37 and the tank 35 becomes equal to or greater than a certain value.Consequently, the hydraulic oil is supplied to the supply flow path 37 by both the hydraulic pump 32 and the suction valve 53. Therefore, a shortage of hydraulic oil is suppressed and the occurrence of a cavitation phenomenon is prevented.

[0099] The control system 10 also includes a pressure sensor 61 that detects the pressure of the hydraulic oil discharged from the boom cylinder 21, a pressure sensor 62 that detects the pressure of the hydraulic oil flowing into the boom cylinder 21, and a pressure sensor 63 that detects the pressure of the hydraulic oil after passing the throttle 51.

[0100] The pressure sensor 61 detects the pressure of the hydraulic oil flowing through the meter output flow path 71. The pressure sensor 61 detects the pressure of the hydraulic oil in the meter output flow path 71 between the outlet 2C and the throttle 51. In this embodiment, the pressure sensor 61 detects the pressure of the hydraulic oil in the meter output flow path 71 between the outlet 2C and the inlet port Pg of the regeneration valve 52.

[0101] Pressure sensor 62 detects the pressure of the hydraulic oil flowing through the counter inlet flow path 72. Pressure sensor 62 detects the pressure of the hydraulic oil between the outlet port Ph of the regeneration valve 52 and the inlet 2D.

[0102] The pressure sensor 63 detects the pressure of the hydraulic oil flowing through the counter output flow path 71. The pressure sensor 63 detects the pressure of the hydraulic oil in the counter output flow path 71 between the throttle 51 and the manifold 36S. [Control device]

[0103] Fig. Figure 5 is a functional block diagram illustrating the control device 9 according to the embodiment. The control device 9 includes a computer system. The control device 9 is connected to the actuating device 5, the pressure sensor 61, the pressure sensor 62, and the pressure sensor 63 via a communication line. The control device 9 is connected via a control line to the hydraulic pump 32, the flow rate control valve 40, and the regeneration valve 52, respectively.

[0104] The control device 9 includes a correlation data storage unit 9A, an operation command acquisition unit 9B, a pressure data acquisition unit 9C, a setpoint counter input flow rate calculation unit 9D, a setpoint regeneration flow rate calculation unit 9E, a setpoint pump flow rate calculation unit 9F, a setpoint counter output flow rate calculation unit 9G, a setpoint pump capacity calculation unit 9H, a control valve opening area calculation unit 9I, a regeneration valve opening area calculation unit 9J, a pump control unit 9K, a control valve control unit 9L and a regeneration valve control unit 9M.

[0105] The correlation data storage unit 9A stores correlation data between an actuation amount of the actuating device 5 and a target counter input flow rate, which indicates a target flow rate of the hydraulic oil flowing into the inlet 2D of the hydraulic cylinder 2.

[0106] The operation command detection unit 9B detects an operation command from the actuator 5. The operation command from the actuator 5 contains an actuation value for the actuator 5. The actuation value for the actuator 5 includes the tilt angle of the actuating lever. If the actuation value for the actuator 5 indicates the maximum value, the actuation value is 100%. If the actuator 5 is not actuated, the actuation value is 0%.

[0107] Fig. Figure 6 is a diagram describing correlation data according to the implementation. As in Fig. Figure 6 shows correlation data that predetermines the relationship between the actuation amount of the actuating device 5 and a target counter input flow rate Qcyl flowing into the inlet 2D of the flow rate control valve 40. The correlation data is stored in the correlation data storage unit 9A.

[0108] As in Fig. As shown in Figure 6, the correlation data are determined such that the target counter input flow rate Qcyl decreases when the actuation amount of the actuating device 5 decreases, and the target counter input flow rate Qcyl increases when the actuation amount of the actuating device 5 increases.

[0109] In this embodiment, the target meter input flow rate Qcyl is defined by a target pump flow rate Qp, a suction flow rate, and a target regeneration flow rate Qr. The target pump flow rate Qp is the target flow rate of the hydraulic oil delivered by the hydraulic pump 32. The suction flow rate is the flow rate of the hydraulic oil drawn from the tank 35 into the supply flow path 37 via the suction valve 53. The target regeneration flow rate Qr specifies the target flow rate of the hydraulic oil regenerated from the meter output flow path 71 into the meter input flow path 72 via the regeneration valve 52.

[0110] If the actuation amount of the actuator 5 is less than a predetermined value Ms, the target meter input flow rate Qcyl is defined by the sum of the target pump flow rate Qp and the intake flow rate. If the actuation amount of the actuator 5 is equal to or greater than the value Ms, the target meter input flow rate Qcyl is defined by the sum of the target pump flow rate Qp, the intake flow rate, and the target regeneration flow rate Qr.

[0111] The correlation data are determined such that the target pump flow rate Qp decreases when the actuation amount of the actuating device 5 decreases, and the target pump flow rate Qp increases when the actuation amount of the actuating device 5 increases.

[0112] If the actuation amount of the actuating device 5 is equal to or greater than the value Ms, the correlation data are determined such that the target regeneration flow rate Qr decreases when the actuation amount of the actuating device 5 decreases, and the target regeneration flow rate Qr increases when the actuation amount of the actuating device 5 increases.

[0113] The pressure data acquisition unit 9C acquires data from pressure sensor 61, pressure sensor 62, and pressure sensor 63. Pressure sensor 61 detects the pressure of the hydraulic oil flowing out of outlet 2C of the boom cylinder 21. In this embodiment, pressure sensor 61 detects the pressure of the hydraulic oil in the counter output flow path 71 between outlet 2C and inlet port Pg of the regeneration valve 52. Pressure sensor 62 detects the pressure of the hydraulic oil flowing into inlet 2D of the hydraulic cylinder 2. In this embodiment, pressure sensor 62 detects the pressure of the hydraulic oil between outlet port Ph of the regeneration valve 52 and inlet 2D. Pressure sensor 63 detects the pressure of the hydraulic oil flowing through the counter output flow path 71.In this embodiment, the pressure sensor 63 detects the pressure of the hydraulic oil in the counter output flow path 71 between the throttle 51 and the manifold 36S. The pressure data acquisition unit 9C acquires the acquisition data of the pressure sensor 61, the acquisition data of the pressure sensor 62, and the acquisition data of the pressure sensor 63, respectively.

[0114] The target counter input flow rate calculation unit 9D calculates the target counter input flow rate Qcyl [l / min] based on the correlation data stored in the correlation data storage unit 9A and the operation command (actuation amount) of the actuating device 5 detected by the operation command acquisition unit 9B.

[0115] The target regeneration flow rate calculation unit 9E calculates the target regeneration flow rate Qr [l / min] of the hydraulic oil based on the target meter input flow rate Qcyl, which was calculated by the target meter input flow rate calculation unit 9D. The target regeneration flow rate calculation unit 9E calculates the target regeneration flow rate Qr based on equation (1). Qr=(Qcyl−Qstart)×Kr

[0116] In equation (1), Qstart is a regeneration start flow rate and a threshold value related to the target counter input flow rate Qcyl. As in Fig. As shown in Figure 6, the regeneration start flow rate Qstart corresponds to the target counter input flow rate Qcyl when the actuation amount of the actuating device 5 is the value Ms. The value Ms and the regeneration start flow rate Qstart are freely determined. Kr represents a regeneration flow rate. The regeneration flow rate Kr is a unique value that relates to the regeneration valve 52 and is a known value.

[0117] The target pump flow rate calculation unit 9F calculates the target pump flow rate Qp [l / min] based on the target meter input flow rate Qcyl, calculated by the target meter input flow rate calculation unit 9D, and the target regeneration flow rate Qr, calculated by the target regeneration flow rate calculation unit 9E. The target pump flow rate calculation unit 9F calculates the target pump flow rate Qp based on equation (2). Qp=(Qcyl−Qr)×(1−Ks)

[0118] In equation (2), Ks represents an intake valve flow rate ratio. The intake valve flow rate ratio Kw is a unique value that relates to intake valve 53 and is a known value.

[0119] The target flow rate calculation unit 9G calculates a target flow rate Qo [l / min] based on the correlation data stored in the correlation data storage unit 9A and the operation command (actuation amount) of the actuating device 5 detected by the operation command acquisition unit 9B. This target flow rate represents the target flow rate of the hydraulic oil flowing out of the outlet 2C of the hydraulic cylinder 2. The target flow rate calculation unit 9G calculates the target flow rate Qo based on equation (3). Qo=Qcyl×(Ao / Ai)−Qr

[0120] In equation (3), Ao / Ai represents a pressure absorption area ratio of the hydraulic cylinder 2. The pressure absorption area ratio Ao / Ai is a unique value that relates to the hydraulic cylinder 2 and is a known value.

[0121] The target pump capacity calculation unit 9H calculates a target capacity q [cm³]. 3 The target pump flow rate Qp of hydraulic pump 32 is calculated by the target pump flow rate calculation unit 9F. The target pump capacity calculation unit 9H calculates the target capacity q of hydraulic pump 32 based on equation (4). q=Qp×1000Ne×h

[0122] In equation (4) Ne is the rotational speed [rpm] of the motor 30 and h is the gear ratio of the power transmission mechanism 31.

[0123] The control valve opening area calculation unit 9I calculates a target opening area of ​​the flow rate control valve 40 based on the target counter output flow rate Qo calculated by the target counter output flow rate calculation unit 9G. In the embodiment, the control valve opening area calculation unit 9I calculates a target opening area Ao of the flow rate control valve 40 based on the target counter output flow rate Qo calculated by the target counter output flow rate calculation unit 9G, an opening area As of the throttle 51, a pressure Po of the hydraulic oil flowing out of the hydraulic cylinder 2, a pressure Pa of the hydraulic oil between the throttle 51 and the flow rate control valve 40, and a pressure Pt of the tank 35.

[0124] If the flow rate coefficient of a throttle valve is Cs, the opening area of ​​the throttle 51 is As, the pressure of the hydraulic oil flowing out of the hydraulic cylinder 2 is Po, and the pressure of the hydraulic oil between the throttle 51 and the flow rate control valve is 40 Pa, the setpoint counter output flow rate Qo can be expressed by equation (5). Qo=CsAsPo−Pa

[0125] If the flow rate coefficient of the flow rate control valve 40 is equal to Co, the target opening area of ​​the flow rate control valve 40 is equal to Ao, the pressure of the hydraulic oil between the throttle 51 and the flow rate control valve 40 is equal to Pa, and the pressure of the hydraulic oil in the tank 35 is equal to Pt, the target counter output flow rate Qo can be expressed by equation (6). Qo=CoAoPa−Pt

[0126] The pressure Po is detected by pressure sensor 61 and recorded by pressure data acquisition unit 9C. The pressure Pa is detected by pressure sensor 63 and recorded by pressure data acquisition unit 9C. The pressure Pt can be considered atmospheric pressure. The flow rate coefficient Cs is a unique value relating to throttle 51 and is a known value. The flow rate coefficient Co is a unique value relating to flow rate control valve 40 and is a known value.

[0127] Equation (7) is derived by removing Pa from equations (5) and (6). The control valve opening area calculation unit 9I calculates the target opening area Ao of the flow rate control valve 40 based on equation (7). Ao=QoCsAsCo(CsAs)2(Po−Pt)−Qo2

[0128] The target opening area Ao specifies a total target opening area of ​​the three flow rate control valves 40. If the target opening area of ​​each of the three flow rate control valves 40 is Ao[i], the control valve opening area calculation unit 9I calculates the target opening area Ao[i] of each of the flow rate control valves 40 based on equation (8). Ao[i]=Qo[i]Qo×Ao

[0129] In equation (8), Qo[i] is the target counter output flow rate of the flow rate control valve 40[i]. In the embodiment, three flow rate control valves 40[1], 40[2], and 40[3] are provided for a hydraulic cylinder 2. Qo[1] is a target counter output flow rate of the first flow rate control valve 40[1]. Qo[2] is a target counter output flow rate of the second flow rate control valve 40[2]. Qo[3] is a target counter output flow rate of the third flow rate control valve 40[3].

[0130] The regeneration valve opening area calculation unit 9J calculates a target opening area Ar of the regeneration valve 52 based on the target regeneration flow rate Qr, calculated by the target regeneration flow rate calculation unit 9E, a pressure Pi of the hydraulic oil flowing into the inlet 2D, and the pressure Po of the hydraulic oil flowing out of the outlet 2C. The regeneration valve opening area calculation unit 9J calculates the target opening area Ar of the regeneration valve 52 based on equation (9). Ar=QrCrPo−Pi

[0131] In equation (9), Pi is the pressure of the hydraulic oil flowing into the hydraulic cylinder 2. The pressure Pi is detected by the pressure sensor 62 and recorded by the pressure data acquisition unit 9C. Cr is a flow rate coefficient of the regeneration valve 52. The flow rate coefficient Cr is a unique value specific to the regeneration valve 52 and is a known value.

[0132] The pump control unit 9K issues a control command to control the hydraulic pump 32, so that the capacity of the hydraulic pump 32 reaches the target capacity q calculated by the target pump capacity calculation unit 9H. The hydraulic pump 32 has a swashplate that changes the capacity. The pump control unit 9K issues a control command to control the angle of the swashplate so that the target capacity q is reached.

[0133] The control valve unit 9L issues a control command to control the flow rate control valve 40, such that the flow rate control valve 40 has the target opening area Ao of the flow rate control valve 40 calculated by the control valve opening area calculation unit 9I. The opening area of ​​the flow rate control valve 40 is adjusted according to the amount of movement of the spool. The control valve control unit 9L issues a control command to an electromagnetic proportional control valve, which adjusts the amount of movement of the spool so that the target opening area Ao is achieved.

[0134] The regeneration valve control unit 9M issues a control command to control the regeneration valve 52, so that the regeneration valve 52 has the target opening area Ar of the regeneration valve 52 calculated by the regeneration valve opening area calculation unit 9J. [Method for controlling the working machine]

[0135] Fig. Figure 7 is a flowchart illustrating a control procedure for the excavator 100 according to the embodiment. The description refers to... Fig. Section 7 mainly describes control procedures for the boom 11 and the boom cylinder 21.

[0136] The operator operates the actuating device 5 to drive the boom cylinder 21. The boom cylinder 21 moves the boom 11 in a movable range.

[0137] Actuator 5 issues an actuation command when it is actuated by the operator. The operation command contains an actuation amount for actuator 5. The operation command detection unit 9B detects the actuation amount of actuator 5 (step S10).

[0138] The target counter input flow rate calculation unit 9D calculates the target counter input flow rate Qcyl based on the correlation data stored in the correlation data storage unit 9A and the actuation amount of the actuating device 5 (step S20) detected by the operation command acquisition unit 9B.

[0139] As in Fig. As shown in Figure 6, the correlation data storage unit 9A stores correlation data that specifies the relationship between the actuation amount of the actuator 5 and the target flow rate Qcyl. The correlation data is predefined. As shown in Figure 6, the correlation data storage unit 9A stores correlation data that specifies the relationship between the actuation amount of the actuator 5 and the target flow rate Qcyl. The correlation data is predefined. Fig. As shown in Figure 6, the correlation data are determined such that the target counter input flow rate Qcyl increases when the actuation amount of the actuating device 5 increases.

[0140] The target regeneration flow rate calculation unit 9E calculates the target regeneration flow rate Qr based on the target meter input flow rate Qcyl. The target regeneration flow rate calculation unit 9E calculates the target regeneration flow rate Qr based on equation (1) described above (step S30).

[0141] The regeneration valve 52 is controlled to close when the target counter input flow rate Qcyl is less than the regeneration start flow rate Qstart, and to open when the target counter input flow rate Qcyl is equal to or greater than the regeneration start flow rate Qstart. That is, in Fig. 6 closes the opening of the regeneration valve 52 when the actuation value of the actuator 5 is between 0 [%] and Ms [%]. The regeneration valve 52 opens when the actuation value of the actuator 5 becomes equal to or greater than Ms [%] and the target counter input flow rate Qcyl becomes equal to or greater than the regeneration start flow rate Qstart.

[0142] The target pump flow rate calculation unit 9F calculates the target pump flow rate Qp based on the target meter input flow rate Qcyl and the target regeneration flow rate Qr. The target pump flow rate calculation unit 9F calculates the target pump flow rate Qp based on equation (2) described above (step S40).

[0143] The target meter output flow rate calculation unit 9G at the meter output calculates the target meter output flow rate Qo at the meter output based on the target meter output flow rate Qo of the meter and the target regeneration flow rate Qr. The target meter output flow rate calculation unit 9G calculates the target meter output flow rate Qo based on equation (3) described above (step S50).

[0144] The target pump capacity calculation unit 9H calculates the target capacity q [cm³]. 3 The hydraulic pump 32 is calculated based on the target pump flow rate Qp. The target pump capacity calculation unit 9H calculates the target capacity q of the hydraulic pump 32 based on equation (4) described above (step S60).

[0145] The control valve opening area calculation unit 9I calculates the target opening area Ao of the boom flow rate control valve 41 based on the target counter output flow rate Qo, the opening area As of the throttle valve, the pressure Po of the hydraulic oil flowing out of the hydraulic cylinder 2, the pressure Pa of the hydraulic oil between the throttle valve and the flow rate control valve 40, and the pressure Pt of the tank 35. The control valve opening area calculation unit 9I calculates the target opening area Ao of the boom flow rate control valve 41 based on equations (5), (6), and (7) described above (step S70).

[0146] The target opening area Ao specifies a total target opening area of ​​the three boom flow rate control valves 41. If the target opening area of ​​each of the three boom flow rate control valves 41 is Ao[i], the control valve opening area calculation unit 9I calculates the target opening area Ao[i] of each of the three boom flow rate control valves 41 based on equation (8) described above (step S80).

[0147] The regeneration valve opening area calculation unit 9J calculates the target opening area Ar of the regeneration valve 52 based on the target regeneration flow rate Qr. The regeneration valve opening area calculation unit 9J calculates the target opening area Ar of the regeneration valve 52 based on the equation (9) described above (step S90).

[0148] The pump control unit 9K issues a control command to control the hydraulic pump 32 so that the hydraulic pump 32 has the target capacity q calculated in step S60. The hydraulic pump 32 has a swashplate that changes the capacity. The pump control unit 9K issues a control command to adjust the angle of the swashplate so that the target capacity q is achieved (step S100).

[0149] The control valve unit 9L issues a control command to control the boom flow rate control valve 41[i], such that each of the plurality of boom flow rate control valves 41[i] has the target opening area Ao[i] calculated in step S80. The opening area of ​​the boom flow rate control valve 41 is adjusted according to the amount of movement of the slide. The control valve unit 9L issues a control command to the electromagnetic proportional control valve, which adjusts the amount of movement of the slide so that the target opening area Ao[i] is achieved (step S110).

[0150] The regeneration valve control unit 9M issues a control command to control the regeneration valve 52, so that the regeneration valve 52 has the target opening area Ar calculated in step S90 (step S120). [Distribution of hydraulic oil to a large number of hydraulic cylinders]

[0151] As in Fig. As shown in Figure 3, the hydraulic oil delivered by the hydraulic pump 32 is distributed via the first flow path 33 to each of the boom flow rate control valves 41, the arm flow rate control valves 42, and the bucket flow rate control valves 43. The distribution of the hydraulic oil to the plurality of hydraulic cylinders 2 is described below.

[0152] Fig. Figure 8 is a schematic diagram illustrating the control system 10 for the excavator 100 according to the embodiment. Fig. Figure 8 corresponds to a diagram obtained by removing the boom cylinder 21, the arm cylinder 22, the boom flow rate control valve 41 and the arm flow rate control valve 42. Fig. 3 was received.

[0153] The working equipment elements include the boom 11 and the arm 12. The hydraulic cylinders 2 include the boom cylinder 21, which moves the boom 11, and the arm cylinder 22, which moves the arm 12.

[0154] The flow rate control valve 40 comprises flow rate control valves of the first group 410, including a plurality of (three) boom flow rate control valves 41 with predetermined priority, and flow rate control valves of the second group 420, including a plurality of (three) arm flow rate control valves 42 with predetermined priority. The flow rate control valves 410 of the first group control the flow rate of the hydraulic oil supplied to the boom cylinder 21. The flow rate control valves 420 of the second group control the flow rate of the hydraulic oil supplied to the arm cylinder 22. In each flow rate control valve 40, it is predetermined which hydraulic cylinder 2 is preferentially supplied with the hydraulic oil. Although the priority is predetermined in the present embodiment, the hydraulic oil can be supplied evenly by each flow rate control valve 40 without defining the priority.

[0155] The flow rate control valves of the first group 410 include a boom flow rate control valve 41[1], a boom flow rate control valve 41[2], and a boom flow rate control valve 41[3]. In the flow rate control valves of the first group 410, the priority of boom flow rate control valve 41[1] is the highest, the priority of boom flow rate control valve 41[2] is the second highest after boom flow rate control valve 41[1], and the priority of boom flow rate control valve 41[3] is the lowest.

[0156] The flow rate control valves 420 of the second group comprise an arm flow rate control valve 42[1], an arm flow rate control valve 42[2], and an arm flow rate control valve 42[3]. In the flow rate control valves 420 of the second group, the priority of the arm flow rate control valve 42[3] is the highest, the priority of the arm flow rate control valve 42[2] is the second highest after the arm flow rate control valve 42[1], and the priority of the arm flow rate control valve 42[1] is the lowest.

[0157] The control device 9 includes a distribution control unit 9N, which controls the opening area of ​​the flow rate control valves 410 of the first group on the basis of the priority of the flow rate control valves 410 of the first group and the required flow rate of the hydraulic oil in the boom cylinder 21.

[0158] In the Fig. In the example shown in Figure 8, the required flow rate of the hydraulic oil in the boom cylinder 21 is 1500 [L] per minute, the required flow rate of the hydraulic oil in the arm cylinder 22 is 1500 [L] per minute, and 1000 [L] of the hydraulic oil is delivered per minute by each of the three hydraulic pumps 32.

[0159] The distribution control unit 9N issues a control command to adjust the opening area of ​​the flow rate control valves 410 of the first group, so that 1000 [L] hydraulic oil per minute is supplied from the boom flow rate control valve 41[1] to the boom cylinder 21, 500 [L] hydraulic oil per minute is supplied from the boom flow rate control valve 41[2] to the boom cylinder 21, and no hydraulic oil is supplied from the boom flow rate control valve 41[3] to the boom cylinder 21 in the flow rate control valves 410 of the first group.This means that the distribution control unit 9N issues a control command to adjust the opening area of ​​the flow rate control valves 410 of the first group, such that the higher the priority in the flow rate control valves 410 of the first group, the higher the flow rate of the hydraulic oil supplied by the boom flow rate control valve 41[i] to the boom cylinder 21, and the lower the priority, the lower the flow rate of the hydraulic oil supplied by the boom flow rate control valve 41[i] to the boom cylinder 21.

[0160] Additionally, the distribution control unit 9N issues a control command to adjust the opening area of ​​the flow rate control valves 420 of the second group, so that 1000 [L] hydraulic oil per minute is supplied from the arm flow rate control valve 42[3] to the arm cylinder 22, 500 [L] hydraulic oil per minute is supplied from the arm flow rate control valve 42[2] to the arm cylinder 22, and no hydraulic oil is supplied from the arm flow rate control valve 42[1] to the arm cylinder 22 in the flow rate control valves 420 of the second group.This means that the distribution control unit 9N issues a control command to adjust the opening area of ​​the flow rate control valves 420 of the second group, such that the higher the priority in the flow rate control valves 420 of the second group, the higher the flow rate of the hydraulic oil supplied by the arm flow rate control valve 42[i] to the arm cylinder 22, and the lower the priority, the lower the flow rate of the hydraulic oil supplied by the arm flow rate control valve 42[i] to the arm cylinder 22. [Computer system]

[0161] Fig.Figure 9 is a block diagram illustrating a computer system 1000 according to the embodiment. The control device 9 described above contains the computer system 1000. The computer system 1000 includes a processor 1001, such as a central processing unit (CPU), a main memory 1002 containing non-volatile memory, such as read-only memory (ROM), and volatile memory, such as random-access memory (RAM), a memory 1003, and an interface 1004 containing an input / output circuit. The function of the control device 9 is stored in the memory 1003 as a computer program. The processor 1001 reads the computer program from the memory 1003, executes the computer program in the main memory 1002, and performs the processing described above according to the computer program. The computer program can be supplied to the computer system 1000 via a network.

[0162] According to the embodiment described above, the computer program can: detect an operation command issued by the actuating device 5, calculate, based on the operation command and correlation data between the actuation amount of the actuating device 5 and the target counter input flow rate Qcyl, which specifies the target flow rate of the hydraulic oil flowing into the inlet 2D of the hydraulic cylinder 2, the target counter output flow rate Qo, which specifies the target flow rate of the hydraulic oil flowing out of the outlet 2C of the hydraulic cylinder 2, calculate the target opening area of ​​the flow rate control valve 40, which sets the flow rate of the hydraulic oil supplied to the hydraulic cylinder 2 based on the target counter output flow rate Qo, and issue a control command to cause the flow rate control valve 40 to have the target opening area of ​​the flow rate control valve 40. [Effects]

[0163] As described above, the control system 10 according to the embodiment comprises the plurality of hydraulic pumps 32 that supply hydraulic oil, the boom cylinder 21 that moves the boom 11, the plurality of boom flow rate control valves 41, each connected to the plurality of hydraulic pumps 32 and which adjust a flow rate of the hydraulic oil supplied to the boom cylinder 21, the plurality of supply flow paths 37, each connected to the plurality of boom flow rate control valves 41, the counter inlet flow path 72, which connects the manifold 37S of the plurality of supply flow paths 37 and the inlet 2D of the hydraulic oil of the boom cylinder 21, the plurality of discharge flow paths 36, each connected to the plurality of boom flow rate control valves 41, and the counter outlet flow path 71.which connects the collecting part 36S of the plurality of discharge flow paths 36 and the outlet 2C of the hydraulic oil of the boom cylinder 21, and the throttle 51, which is arranged in the counter output flow path 71. In a case where a plurality of boom flow rate control valves 41 are connected to a boom cylinder 21, the hydraulic oil flowing from the boom cylinder 21 is discharged into the tank 35 via the counter output flow path 71. Excessive throttling of the flow rate of the hydraulic oil discharged from the boom cylinder 21 is suppressed by the arrangement of the throttle 51 in the counter output flow path 71. For example, in the case where the throttle 51 is arranged only in the counter output flow path 71, the flow rate of the hydraulic oil delivered by the boom cylinder 21 is not excessively limited, compared to the case where the throttle 51 is arranged in each of the plurality of output flow paths 36.Therefore, an excessive reduction in the cylinder speed of the boom cylinder 21 compared to the cylinder speed set by the actuating device 5 is suppressed. Therefore, a decrease in work efficiency is suppressed.

[0164] The control device 9 contains the correlation data storage unit 9A, which stores correlation data between the actuation amount of the actuating device 5 and the target counter input flow rate Qcyl flowing into the inlet 2D of the boom cylinder 21; the operation command acquisition unit 9B, which acquires the operation command of the actuating device 5; the target counter output flow rate calculation unit 9G, which calculates the target counter output flow rate Qo of the hydraulic oil flowing from the outlet 2C based on the correlation data and the operation command; the control valve opening area calculation unit 9I, which calculates the target opening area Ao of the boom flow rate control valve 41 based on the target counter output flow rate Qo; and the control valve control unit 9L, which issues a control command to operate the To cause boom flow rate control valve 41 to be activated,The target opening area Ao of the boom flow rate control valve 41 is determined. Since the target opening area Ao of the boom flow rate control valve 41 is controlled based on the target counter output flow rate Qo, an excessive reduction in the cylinder speed of the boom cylinder 21 compared to the cylinder speed predetermined by the actuating device 5 is suppressed. Therefore, a decrease in work efficiency is prevented.

[0165] The control device 9 contains the target regeneration flow rate calculation unit 9E, which calculates the target regeneration flow rate Qr of the hydraulic oil based on the target counter input flow rate Qcyl; the regeneration valve opening area calculation unit 9J, which calculates the target opening area Ar of the regeneration valve 52 based on the target regeneration flow rate Qr, the pressure Pi of the hydraulic oil flowing into the inlet 2D of the boom cylinder 21 and the pressure Po of the hydraulic oil flowing out of the outlet 2C of the boom cylinder 21; and the regeneration valve control unit 9M, which issues a control command to cause the regeneration valve 52 to have the target opening area Ar of the regeneration valve 52.Since the target opening area of ​​the regeneration valve 52 is controlled based on the target regeneration flow rate Qr, an excessive reduction in the cylinder speed of the boom cylinder 21 compared to the cylinder speed predetermined by the actuating device 5 is suppressed. Therefore, a decrease in work efficiency is prevented.

[0166] The flow rate control valves 40 comprise the flow rate control valves 410 of the first group, including a plurality of boom flow rate control valves 41 for which a priority is specified, and the flow rate control valves 420 of the second group, including a plurality of arm flow rate control valves 42 for which a priority is specified. The control device 9 comprises the distribution control unit 9N, which controls the opening area of ​​the flow rate control valves 410 of the first group based on the priority of the flow rate control valves 410 of the first group, a required flow rate of hydraulic oil in the boom cylinder 21, and a required flow rate of hydraulic oil in the arm cylinder 22. In this way, each of the plurality of hydraulic cylinders 2 can be supplied with a suitable flow rate of hydraulic oil. [Other embodiments]

[0167] In the embodiment described above, the working machine 100 is an excavator. The working machine 100 is not limited as long as it includes the working attachment 1 and can be a wheel loader or a bulldozer.

[0168] In the embodiment described above, each flow rate control valve 40 has priority in supplying hydraulic oil to the boom cylinder 21 and the arm cylinder 22, but the present invention is not limited thereto. The bucket cylinder 23 may have priority.

[0169] In the embodiment described above, three pressure sensors are provided to detect the pressure of the hydraulic oil, but the present invention is not limited thereto. It is sufficient that the flow rate can be calculated from the pressure of the hydraulic oil flowing in and out of a hydraulic cylinder 20. Reference symbol list 1 WORK TOOL 2 hydraulic cylinders 2A BOTTOM CHAMBER 2B ROD CHAMBER 2C OUTLET (OPENING) 2D ENTRY (OPENING) 3 oscillating bodies 4 chassis 4C Caterpillar Chainring 5 ACTUATOR 6 OPERATING ROOM 6S DRIVER'S SEAT 7 MACHINE ROOM 9 CONTROL DEVICE 9A Correlation Data Storage Unit 9B OPERATIONAL ORDER RECORDING UNIT 9C PRINT DATA COLLECTION DEVICE 9D Target Counter Input Flow Rate Calculation Unit 9E Target Regeneration Flow Rate Calculation Unit 9F Target Pump Flow Rate Calculation Unit 9G Target Counter Output Flow Rate Calculation Unit 9H Target Pump Capacity Calculation Unit 9I Control Valve Opening Area Calculation Unit 9J Regeneration Valve - Opening Area Calculation Unit 9K PUMP CONTROL UNIT 9L CONTROL VALVE UNIT 9M Regeneration Valve Control Unit 9N DISTRIBUTION CONTROL UNIT 10 CONTROL SYSTEM 11 EXTENSIONS 12 ARM 13 SHOVEL 21 boom cylinders 22 ARM CYLINDERS 23 SHOVEL CYLINDERS 30 ENGINE 31 POWER TRANSFER MECHANISM 32 HYDRAULIC PUMP 33 FIRST FLOW PATH 33A Supply Flow Path 34 SECOND FLOW PATH 35 TANK 36 Soil Flow Path (Discharge Flow Path) 36S COLLECTIBLE 37 Pole Flow Path (Supply Flow Path) 37S COLLECTIBLE ITEM 38 Exhaust Flow Path 39 TANK FLOW PATH 40 Flow Rate Control Valve 41 Outrigger Flow Rate Control Valve 42 ARM FLOW RATE CONTROL VALVE 43 BUCKET FLOW RATE CONTROL VALVE 50 Vent Valve 51 THRUSH 52 Regeneration Valve 53 INTAKE VALVE 61 PRESSURE SENSOR 62 PRESSURE SENSOR 63 PRESSURE SENSOR 71 Collective Flow Path (Meter Exit Flow Path) 72 Collective Flow Path (Meter Entrance Flow Path) 100 EXCAVATORS (WORK MACHINE) AX1 TURNTABLE AX2 TURNTABLE AXLE AX3 TURNTABLE AXLE P1 FIRST WORK POSITION P2 SECOND WORK POSITION P3 Stop Position P4 DELIVERY POSITION P5 Stop Position P6 Stop Position P7 REGENERATION POSITION Pa PUMP CONNECTION Pb FLOOR CONNECTION PC rod connector Pd fuel tank connection PE inlet connection Pf OUTLET CONNECTION Pg Inlet Connection Ph OUTLET CONNECTION Pi INLET CONNECTION Pj OUTLET CONNECTION RX Swingarm Axle

Claims

[1] Control system (10) for a working machine (100), comprising: a control device (9); a plurality of hydraulic pumps (32) that deliver hydraulic oil; a hydraulic cylinder (2) that moves a working tool element (11, 12, 13); a plurality of flow rate control valves (40), each connected to the plurality of hydraulic pumps (32) and adjusting a flow rate of the hydraulic oil supplied to the hydraulic cylinder (2); a plurality of supply flow paths (37), each connected to the plurality of flow rate control valves (40); a counter input flow path (72) that connects a collecting part (37S) of the plurality of supply flow paths (37) and an inlet (2D) of the hydraulic oil into the hydraulic cylinder (2); a plurality of discharge flow paths (36), each connected to the plurality of flow rate control valves (40); a counter output flow path (71) that connects a collecting part (36S) of the plurality of delivery flow paths (36) and an outlet (2C) of the hydraulic oil into the hydraulic cylinder (21); and a choke (51) arranged in the counter output flow path, an actuating device (5) that generates an operation command with an operation; wherein the control device (9) contains: a correlation data storage unit (9A) that stores correlation data between an actuation amount of the actuating device (5) and a target counter input flow rate, which indicates a target flow rate of the hydraulic oil flowing into the inlet (2D); an operations order capture unit (9B) that captures the operations order; a target counter output flow rate calculation unit (9G) which, based on the correlation data and the operation instruction, calculates a counter output flow rate that indicates a target flow rate of the hydraulic oil flowing out of the outlet (2C); a control valve opening area calculation unit (9I) that calculates a target opening area of ​​the flow rate control valves (40) based on the target counter output flow rate; and a control valve control unit (9L) that issues a control command to cause the flow rate control valves (40) to have the target opening area of ​​the flow rate control valves (40). [2] Control system (10) for the working machine (100) according to claim 1, wherein the working tool element (11) performs a lifting movement and a lowering movement with the hydraulic cylinder (21) and the counter output flow path (71) is connected to the outlet (2C) through which the hydraulic oil flows out during the lowering movement. [3] Control system (10) for the working machine (100) according to claim 2, wherein the throttle (51) has an opening area that is smaller than a maximum opening area of ​​the flow rate control valves (40). [4] Control system (10) for the working machine (100) according to one of claims 1 to 3, wherein the control system (10) comprises: a regeneration valve (52) that sets a regeneration flow rate of the hydraulic oil regenerated from the meter output flow path (71) to the meter input flow path (72), wherein the control device (9) contains: a target regeneration flow rate calculation unit (9E) that calculates a target regeneration flow rate of the hydraulic oil based on the target counter input flow rate; a regeneration valve opening area calculation unit (9J) which calculates a target opening area of ​​the regeneration valve (52) based on the target regeneration flow rate, a pressure of the hydraulic oil flowing into the inlet (2D) and a pressure of the hydraulic oil flowing out of the outlet (2C); and a regeneration valve control unit (9M) which issues a control command to cause the regeneration valve (52) to have the target opening area of ​​the regeneration valve (52). [5] Control system (10) for the working machine (100) according to one of claims 1 to 4, wherein the working tool element (11, 12, 13) contains a first working tool element (11) and a second working tool element (12), the hydraulic cylinder (2) includes a first hydraulic cylinder (21) that moves the first working tool element (11) and a second hydraulic cylinder (22) that moves the second working tool element (12), the flow rate control valves (40) include flow rate control valves of a first group (410) which contain a plurality of flow rate control valves (41) for which a priority is specified, and flow rate control valves of a second group (420) which contain a plurality of flow rate control valves (42) for which a priority is specified, The flow rate control valves of the first group (410) set a flow rate of the hydraulic oil supplied to the first hydraulic cylinder (21), The flow rate control valves of the second group (420) adjust a flow rate of the hydraulic oil supplied to the second hydraulic cylinder (22), and the control device (9) The distribution control unit (9N) contains an opening area of ​​the flow rate control valves of the first group (410) based on the priority of the flow rate control valves of the first group (410) and a required flow rate of the hydraulic oil in the first hydraulic cylinder (21). [6] Working machine (100), comprising: a work tool (10) which contains a variety of work tool elements (11, 12, 13); a plurality of hydraulic cylinders (2), each of which actuates the plurality of working device elements (11, 12, 13); and the control system (10) for the working machine (100) according to one of claims 1 to 5. [7] Method for controlling a working machine (100) with a control system according to at least one of claims 1 to 5, wherein the method comprises: Capturing an operation command issued by an actuating device (5); Calculate, based on the operation instruction and correlation data between an actuation amount of the actuating device (5) and a target counter input flow rate, which specifies a target flow rate of hydraulic oil flowing into an inlet (2D) of a hydraulic cylinder (2), and a target counter output flow rate, which specifies a target flow rate of hydraulic oil flowing out of an outlet (2C) of the hydraulic cylinder (2); Calculate based on the target counter output flow rate of a target opening area of ​​a flow rate control valve (40) that sets a flow rate of the hydraulic oil supplied to the hydraulic cylinder (2); and Output of a control command that causes the flow rate control valve (40) to have the target opening area of ​​the flow rate control valve (40).

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