Construction Machinery

Abstract

The speed compensation unit (54) of the engineering machinery (100) of the present invention performs feedback control as follows: when a composite operation is performed and a preset load judgment condition is satisfied, a larger correction amount is calculated as the speed difference between the target speed of the first actuator determined based on the operation amount of the first command operation, i.e., the first target speed, and the actual speed of the first actuator, i.e., the first actual speed, is greater, and the opening of the second control valve is adjusted to an opening obtained by subtracting the correction amount from the second target opening of the second control valve.

Description

Technical Field

[0001] The present invention relates to engineering machinery such as hydraulic excavators. Background Art

[0002] Engineering machinery such as hydraulic excavators usually include: a lower traveling body; an upper rotating body rotatably mounted on the lower traveling body; a working device including a boom mounted on the upper rotating body; a rotating motor, which is a hydraulic motor for rotating the upper rotating body; a boom cylinder, which is a hydraulic cylinder for driving the boom; a first hydraulic pump, which discharges working oil to be supplied to the rotating motor; a second hydraulic pump, which discharges working oil to be supplied to the boom cylinder; a rotating control valve, which is located between the first hydraulic pump and the rotating motor; and a boom control valve, which is located between the second hydraulic pump and the boom cylinder. In most cases, the working oil discharged from the first hydraulic pump is supplied not only to the rotating motor but also to other actuators (such as the boom cylinder). In this case, the engineering machinery also includes a confluence valve, which is located between the first hydraulic pump and the boom cylinder and performs an opening and closing action to allow a part of the working oil discharged from the first hydraulic pump to merge with the working oil discharged from the second hydraulic pump and be supplied to the boom cylinder. In such a construction machine, in order to maintain a balance between the swinging motion of the upper swing body and the raising and lowering motion of the boom, it is necessary to appropriately distribute the hydraulic oil to the swing motor and the boom cylinder through the above-mentioned combining valve.

[0003] Patent document 1 discloses a rotary hydraulic engineering machine having a confluence valve as described above (a boom 2-speed control valve in patent document 1). In the rotary hydraulic engineering machine, when the first command operation is applied to the swing lever and the boom raising command operation is applied to the boom raising lever, that is, when a combined operation is performed, the controller controls the flow rate of the working oil discharged from the hydraulic pump to be distributed to the swing motor and the boom cylinder. Specifically, when the possibility of being required to accelerate the swing is high, the controller limits the actuator flow rate with a larger restriction, thereby maintaining the working pressure of the swing motor at a higher level to ensure the operation of the swing torque required for acceleration.

[0004] The rotary hydraulic engineering machinery of Patent Document 1, when performing the above-mentioned combined operation and being required to accelerate the rotation with a high possibility, ensures the rotation torque required for accelerated rotation by performing the flow distribution control of the working oil as described above, thereby increasing the actual speed of the rotary motor (the rotation speed of the rotary motor). However, it does not take into account the actual speed of the rotary motor being adjusted to the target speed with good accuracy.

[0005] The above-mentioned problem occurs not only in the combination of the swing motor and the boom cylinder but also in the combination of two hydraulic actuators in which at least one of the swing motor and the boom cylinder is replaced by another hydraulic actuator.

[0006] Prior art literature

[0007] Patent Literature

[0008] Patent Document 1: Japanese Patent Publication No. 2019-27261 Summary of the invention

[0009] An object of the present invention is to provide a construction machine capable of adjusting the actual speed of a first actuator to a target speed with good accuracy even when the load on the first actuator is larger than the load on the second actuator during combined operation.

[0010] The engineering machinery provided includes: a first pump, which is a variable displacement hydraulic pump for discharging working oil; a second pump, which is a variable displacement hydraulic pump for discharging working oil; a first actuator, which is operated by receiving the supply of working oil discharged from the first pump; a second actuator, which is operated by receiving the supply of working oil discharged from the second pump; a first control valve, which is located between the first pump and the first actuator, and is opened and closed in a manner that changes the flow rate of the working oil supplied from the first pump to the first actuator; and a second control valve, which is located between the first pump and the second actuator, and is operated by changing the flow rate of the working oil supplied from the first pump to the first actuator. The pump control unit is configured to adjust the discharge volume of the first pump and the discharge volume of the second pump so that the sum of the first target flow rate and the second target flow rate, that is, the total target flow rate, is equal to the sum of the first target flow rate and the second target flow rate. a first control valve having a first target opening and a second control valve having a first target opening and a second target opening; and a valve control unit for adjusting the opening of the first control valve to a first target opening determined based on the first target flow rate, adjusting the opening of the second control valve to a second target opening determined based on the second control valve target flow rate, and adjusting the opening of the third control valve to a first target opening determined based on the second control valve target flow rate. The valve opening is adjusted to a third target opening determined based on a third control valve target flow rate, wherein the second control valve target flow rate is a target flow rate of the working oil to the second actuator via the second control valve in the second target flow rate, and the third control valve target flow rate is a target flow rate of the working oil to the second actuator via the third control valve in the second target flow rate; a condition determination unit determines whether a preset load determination condition is satisfied, the load determination condition being a condition for determining that the load of the first actuator, i.e., the first load, is greater than the load of the second actuator, i.e., the second load;and a speed compensation unit that performs feedback control such that, when a composite operation is performed and the condition determination unit determines that the load determination condition is satisfied, a larger correction amount is calculated as the speed difference between a first target speed of the first actuator determined based on the operation amount of the first command operation and an actual speed of the first actuator, that is, a first actual speed, is larger, and the opening of the second control valve is adjusted to an opening obtained by subtracting the correction amount from the second target opening. ; BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 It is a side view showing a construction machine according to an embodiment of the present invention.

[0012] Figure 2 It is a diagram showing a hydraulic circuit of a construction machine according to the first embodiment.

[0013] Figure 3 This is a flowchart showing processing performed by the controller of the construction machine according to the first embodiment.

[0014] Figure 4 This is a flowchart showing processing performed by the controller of the construction machine according to the first embodiment.

[0015] Figure 5 It is a diagram showing a hydraulic circuit of a construction machine according to a second embodiment.

[0016] Figure 6 This is a flowchart showing processing performed by the controller of the construction machine according to Modification 1.

[0017] Figure 7 This is a flowchart showing processing performed by the controller of the construction machine according to Modification 2.

[0018] Figure 8 This is a flowchart showing processing performed by the controller of the construction machine according to Modification 3.

[0019] Fig. 9 This is a flowchart showing processing performed by the controller of the construction machine according to Modification 3.

[0020] Fig.10 This is an example of a map showing the relationship between the operation amount of the first command operation and the pump flow rate command value.

[0021] Fig.11 This is an example of a map showing the relationship between the operation amount of the second command operation and the pump flow rate command value.

[0022] Fig.12 This is an example of a map showing the relationship between the pump flow rate command value and the control valve opening command value.

[0023] Fig.13 This is an example of a map showing the relationship between the operation amount of the first command operation and the first target speed. DETAILED DESCRIPTION

[0024] Preferred embodiments of the present invention will be described with reference to the accompanying drawings. Figure 1 It is a side view showing a hydraulic excavator as an example of the construction machine 100 according to the embodiment of the present invention.

[0025] The construction machine 100 comprises: a lower traveling body 1 capable of traveling on the ground; an upper revolving body 2 mounted on the lower traveling body 1 in a manner capable of rotating around an axis Z in the vertical direction; a working device 3 mounted on the upper revolving body 2; and a plurality of hydraulic actuators. A cab serving as a control room is provided at the front side portion of the upper revolving body 2 in the front-to-back direction and the working device 3 is mounted. An engine room is provided at the rear side portion of the upper revolving body 2 and a counterweight is mounted. The working device 3 includes a boom 4, an arm 5, and a bucket 6. The plurality of hydraulic actuators include a boom cylinder 7, an arm cylinder 8, a bucket cylinder 9, and a revolving motor 10.

[0026] The boom 4 is supported at the front side of the upper rotating body 2 so as to be able to rise and fall. The boom 4 has a base end portion which is mounted on the upper rotating body 2 so as to be able to swing in the vertical direction relative to the upper rotating body 2 about a horizontal axis, and a distal end portion which is located on the opposite side of the base end portion. The arm 5 has a base end portion which is connected to the distal end portion of the boom 4 so as to be able to swing around a horizontal axis, and a distal end portion which is located on the opposite side of the base end portion. The bucket 6 has a base end portion which is connected to the distal end portion of the arm 5 so as to be able to swing around a horizontal axis.

[0027] The boom 4 performs a boom-raising action in which the boom is swung in the erection direction with its base end as the center, and a boom-lowering action in which the boom is swung in the lying direction with the base end as the center. The erection direction is the direction in which the distal end of the boom 4 is away from the ground, and the lying direction is the direction in which the distal end of the boom 4 is close to the ground. The dipper arm 5 performs an arm-extending action in which the dipper arm is swung forward with its base end as the center, and an arm-retracting action in which the dipper arm is swung backward with the base end as the center. The bucket 6 performs a bucket-extending action in which the bucket is swung with its base end as the center, and a bucket-retracting action.

[0028] The boom cylinder 7 has one end connected to the upper rotating body 2 and the other end connected to the boom 4. The boom cylinder 7 is extended to swing the boom 4 in the uprighting direction to cause the boom 4 to perform a boom raising action, and the boom cylinder 7 is contracted to swing the boom 4 in the crouching direction to cause the boom 4 to perform a boom lowering action.

[0029] The arm cylinder 8 has one end connected to the boom 4 and the other end connected to the arm 5 . The arm 5 is retracted by extending the arm cylinder 8 , and is extended by contracting the arm cylinder 8 .

[0030] The bucket cylinder 9 has one end connected to the arm 5 and the other end connected to the bucket 6 . The bucket 6 is retracted when the bucket cylinder 9 is extended, and is extended when the bucket cylinder 9 is contracted.

[0031] [First embodiment]

[0032] Figure 2 1 is a diagram showing a hydraulic circuit of a construction machine 100 according to the first embodiment. Figure 2 As shown, the construction machine 100 includes a first pump 21, a second pump 22, an engine 23, a plurality of control valves, a plurality of operating devices, a plurality of electromagnetic proportional pressure reducing valves, a pilot hydraulic source 24, a plurality of detectors, a box, and a controller 50. Figure 2 In the hydraulic circuit, only the components related to the boom cylinder 7 and the swing motor 10 are shown, and the other components are omitted.

[0033] The first pump 21 and the second pump 22 are variable capacity hydraulic pumps, respectively, and are connected to the output shaft of the engine 23. The first pump 21 and the second pump 22 are driven by the engine 23 to discharge the hydraulic oil in the tank. The first pump 21 and the second pump 22 each have a regulator, and are configured to change the deflection angle according to the discharge amount instruction input to the regulator from the controller 50, thereby changing the motor capacity and changing the discharge amount of the hydraulic oil.

[0034] The swing motor 10 is a hydraulic motor that rotates the upper swing body 2 by receiving the supply of the working oil discharged from the first pump 21. The swing motor 10 has an output shaft (not shown) that rotates by receiving the supply of the working oil, and the output shaft is connected to the upper swing body 2 in such a way that the upper swing body 2 rotates in both left and right directions. Specifically, the swing motor 10 has a pair of ports, and the output shaft rotates in the direction corresponding to the port of one of the ports by receiving the supply of the working oil to the port of the one of the ports, and the working oil is discharged from the port of the other port. The swing motor 10 is an example of a first actuator.

[0035] The boom cylinder 7 is extended or contracted by receiving the supply of at least one of the hydraulic oil discharged from the first pump 21 and the hydraulic oil discharged from the second pump 22, thereby swinging the boom 4 in the raising direction or the lowering direction. The boom cylinder 7 is an example of a second actuator.

[0036] The plurality of control valves include a first control valve 31 , a second control valve 32 , and a third control valve 33 .

[0037] The first control valve 31 is located between the first pump 21 and the rotary motor 10, and performs an opening and closing operation in a manner that changes the direction and flow rate of the working oil supplied from the first pump 21 to the rotary motor 10. The first control valve 31 is a three-position reversing valve having a pair of pilot ports, and has a flow rate regulating function of changing the flow rate of the working oil by adjusting the opening (opening amount) of the first control valve 31 according to the displacement of the valve core (position of the valve core).

[0038] The second control valve 32 is located between the first pump 21 and the boom cylinder 7, and performs an opening and closing operation in a manner that changes the direction and flow rate of the working oil supplied from the first pump 21 to the boom cylinder 7. The second control valve 32 is a three-position reversing valve having a pair of pilot ports, and has a flow rate regulating function of varying the flow rate of the working oil by adjusting the opening (opening amount) of the second control valve 32 according to the displacement of the valve core (position of the valve core).

[0039] The third control valve 33 is located between the second pump 22 and the boom cylinder 7, and performs an opening and closing operation in a manner that changes the direction and flow rate of the working oil supplied from the second pump 22 to the boom cylinder 7. The third control valve 33 is a three-position reversing valve having a pair of pilot ports, and has a flow rate regulating function of changing the flow rate of the working oil by adjusting the opening (opening amount) of the third control valve 33 according to the displacement of the valve core (position of the valve core).

[0040] The plurality of operating devices include a first operating device 41 and a second operating device 42 .

[0041] The first operating device 41 has a first operating lever 41A to which a first command operation for instructing the movement of the swing motor 10 is applied. The first operating device 41 is an electric lever device that receives a first command operation and outputs a first command signal, which is an electric signal corresponding to the first command operation. The first command signal output from the first operating device 41 is input to the controller 50.

[0042] The second operating device 42 has a second operating lever 42A to which a second command operation for instructing the movement of the boom cylinder 7 is applied. The second operating device 42 is an electric lever device that receives the second command operation and outputs a second command signal that is an electric signal corresponding to the second command operation. The second command signal output from the second operating device 42 is input to the controller 50.

[0043] The plurality of electromagnetic proportional pressure reducing valves include a pair of electromagnetic proportional pressure reducing valves 34 , 34 , a pair of electromagnetic proportional pressure reducing valves 35 , 35 , and a pair of electromagnetic proportional pressure reducing valves 36 , 36 .

[0044] The pair of electromagnetic proportional pressure reducing valves 34, 34 are respectively provided in a pair of pilot lines connecting the pilot hydraulic source 24 and a pair of pilot ports of the first control valve 31. The pair of electromagnetic proportional pressure reducing valves 35, 35 are respectively provided in a pair of pilot lines connecting the pilot hydraulic source 24 and a pair of pilot ports of the second control valve 32. The pair of electromagnetic proportional pressure reducing valves 36, 36 are respectively provided in a pair of pilot lines connecting the pilot hydraulic source 24 and a pair of pilot ports of the third control valve 33.

[0045] The controller 50 receives the input of the first command signal so that the pilot pressure corresponding to the first command signal is input to the pilot port on one side of the first control valve 31 (the pilot port in a pair of pilot ports corresponding to the direction of the first command operation), thereby causing the electromagnetic proportional pressure reducing valve 34 on one side (the electromagnetic proportional pressure reducing valve 34 in a pair of electromagnetic proportional pressure reducing valves 34, 34 corresponding to the direction of the first command operation) to open and close.

[0046] The controller 50 receives the input of the second command signal so that the pilot pressure corresponding to the second command signal is input to the pilot port on one side of the second control valve 32 (the pilot port in a pair of pilot ports corresponding to the direction of the second command operation), thereby causing the electromagnetic proportional pressure reducing valve 35 on one side (the electromagnetic proportional pressure reducing valve 35 in a pair of electromagnetic proportional pressure reducing valves 35, 35 corresponding to the direction of the second command operation) to open and close.

[0047] The controller 50 receives the input of the second command signal so that the pilot pressure corresponding to the second command signal is input to the pilot port on one side of the third control valve 33 (the pilot port in a pair of pilot ports corresponding to the direction of the second command operation), thereby causing the electromagnetic proportional pressure reducing valves 36, 36 on one side (the electromagnetic proportional pressure reducing valves 36 in a pair of electromagnetic proportional pressure reducing valves 36 corresponding to the direction of the second command operation) to open and close.

[0048] The first control valve 31, the second control valve 32, and the third control valve 33 each have a valve core, and when the pilot pressure is not supplied to any one of the pair of pilot ports, the valve core is in a neutral position. The first control valve 31 when the valve core is in the neutral position cuts off the supply of the working oil from the first pump 21 to the swing motor 10, thereby stopping the rotation of the swing motor 10. The second control valve 32 when the valve core is in the neutral position cuts off the supply of the working oil from the first pump 21 to the boom cylinder 7, and the third control valve 33 when the valve core is in the neutral position cuts off the supply of the working oil from the second pump 22 to the boom cylinder 7. When the valve cores of the second control valve 32 and the third control valve 33 are both in the neutral position, since the working oil is not supplied to the boom cylinder 7 from either the first pump 21 or the second pump 22, the boom cylinder 7 stops.

[0049] When the pilot pressure is supplied to one of the pair of pilot ports of the first control valve 31, the valve core moves from the neutral position to the direction corresponding to the pilot port of the first control valve 31 by a displacement amount corresponding to the pilot pressure. Thus, the first control valve 31 is adjusted to an opening (opening amount) corresponding to the displacement amount, and the working oil is allowed to be supplied from the first pump 21 to one port of the rotary motor 10 at a flow rate corresponding to the displacement amount, while the working oil is allowed to return to the tank from the other port.

[0050] When the pilot pressure is supplied to one of the pair of pilot ports of the second control valve 32, the valve core moves from the neutral position to the direction corresponding to the pilot port by a displacement amount corresponding to the pilot pressure. Thus, the second control valve 32 is adjusted to an opening (opening amount) corresponding to the displacement amount, and the working oil is allowed to be supplied from the first pump 21 to one of the head side chamber and the connecting rod side chamber of the boom cylinder 7 at a flow rate corresponding to the displacement amount, while the working oil is allowed to return to the tank from the other of the head side chamber and the connecting rod side chamber.

[0051] When the pilot pressure is supplied to one of the pair of pilot ports of the third control valve 33, the valve core moves from the neutral position to the direction corresponding to the pilot port by a displacement amount corresponding to the pilot pressure. Thus, the third control valve 33 is adjusted to an opening (opening amount) corresponding to the displacement amount, and the working oil is allowed to be supplied from the second pump 22 to one of the head side chamber and the connecting rod side chamber of the boom cylinder 7 at a flow rate corresponding to the displacement amount, while the working oil is allowed to return to the tank from the other of the head side chamber and the connecting rod side chamber.

[0052] The plurality of detectors include a first speed detector 61, a second speed detector 62, a first discharge pressure detector 63, and a second discharge pressure detector 64. The first speed detector 61 is a sensor that detects the rotation speed of the rotary motor 10. As such a sensor, for example, a rotary encoder, a phase resolver, etc. can be used. The second speed detector 62 is a sensor that detects the extension and retraction speed of the boom cylinder 7. The first discharge pressure detector 63 is a pressure sensor that detects the discharge pressure of the working oil of the first pump 21, that is, the first discharge pressure. The second discharge pressure detector 64 is a pressure sensor that detects the discharge pressure of the working oil of the second pump 22, that is, the second discharge pressure. The first speed detector 61 is an example of a first detector.

[0053] The controller 50 is composed of a computer having a central processing unit, a memory, etc., and includes a valve control unit 51, a pump control unit 52, a condition determination unit 53, a speed compensation unit 54, and an output determination unit 55. Figure 2 In the figure, for convenience, two blocks representing the controller 50 are depicted on the left and right, but these two blocks are actually a single controller 50.

[0054] The pump control unit 52 adjusts the discharge volume of the first pump 21 and the discharge volume of the second pump 22 so that the sum of the first target flow rate and the second target flow rate, that is, the total target flow rate of working oil is discharged from at least one of the first pump 21 and the second pump 22, wherein the first target flow rate is a target flow rate of the working oil for the rotary motor 10 determined based on the operation amount of the first instruction operation, and the second target flow rate is a target flow rate of the working oil for the boom cylinder 7 determined based on the operation amount of the second instruction operation.

[0055] The controller 50 stores in advance a map for adjusting the discharge amount of the first pump 21 and the discharge amount of the second pump 22 by the pump control unit 52 .

[0056] The pump control unit 52 controls the pump according to, for example, Fig.10 The pump control unit 52 obtains the pump flow rate command value (first command value) corresponding to the operation amount of the first command operation, and outputs the first command value. Similarly, the pump control unit 52 controls the pump flow rate command value according to, for example, the operation amount of the first command operation applied to the first operating device 41. Fig.11 A map showing the relationship between the operation amount of the second command operation applied to the second operating device 42 and the pump flow rate command value is obtained, and the pump flow rate command value (second command value) corresponding to the operation amount of the second command operation is output.

[0057] Fig.11 The mapping diagram shown represents the following form: among the first pump 21 and the second pump 22, only the first pump 21 is used until the capacity of the first pump 21 reaches the maximum capacity, and after the capacity of the first pump 21 reaches the maximum capacity, the second pump 22 starts to be used. In this form, until the capacity of the first pump 21 reaches the maximum capacity, the capacity of the first pump 21 is adjusted to the capacity corresponding to the first instruction value and the capacity corresponding to the second instruction value. As a result, the first pump 21 discharges the working oil in an amount equal to the sum of the first target flow rate and the second target flow rate. In addition, after the capacity of the first pump 21 reaches the maximum capacity, the capacity of the first pump 21 is adjusted to the maximum capacity, and the capacity of the second pump 22 is adjusted to the capacity corresponding to the second instruction value ( Fig.11 As a result, the first pump 21 discharges the hydraulic oil of the discharge amount corresponding to the maximum capacity, and the second pump 22 discharges the hydraulic oil of the discharge amount corresponding to the second instruction. The discharge amount corresponding to the second instruction discharged by the second pump 22 is the amount obtained by subtracting the discharge amount corresponding to the maximum capacity of the first pump 21 from the total target flow rate, which is the sum of the first target flow rate and the second target flow rate.

[0058] However, the map showing the relationship between the operation amount of the second command operation and the pump flow rate command value is not limited to Fig.11 The form shown. The mapping diagram representing the relationship between the operation amount of the second instruction operation and the pump flow rate instruction value can also represent, for example, a form in which the first pump 21 and the second pump 22 are started to be used at the same time. In addition, the mapping diagram representing the relationship between the operation amount of the second instruction operation and the pump flow rate instruction value can also represent, for example, the following form: among the first pump 21 and the second pump 22, until the capacity of the second pump 22 reaches the maximum capacity, only the second pump 22 is used for the second target flow rate, and after the capacity of the second pump 22 reaches the maximum capacity, the first pump 21 is also used for the second target flow rate. In addition, in the latter case, even before the capacity of the second pump 22 reaches the maximum capacity, when the first instruction operation is applied to the first operating device 41, the first pump 21 is also used.

[0059] The valve control unit 51 adjusts the opening of the first control valve 31 to the target opening of the first control valve 31, i.e., the first target opening; adjusts the opening of the second control valve 32 to the target opening of the second control valve 32, i.e., the second target opening; and adjusts the opening of the third control valve 33 to the target opening of the third control valve 33, i.e., the third target opening.

[0060] The first target opening is a target opening of the first control valve 31 determined based on the first target flow rate. The second target opening is an opening determined based on the second control valve target flow rate, and the second control valve target flow rate is a target flow rate of the working oil to the boom cylinder 7 through the second control valve 32 in the second target flow rate. The third target opening is an opening determined based on the third control valve target flow rate, and the third control valve target flow rate is a target flow rate of the working oil to the boom cylinder 7 through the third control valve 33 in the second target flow rate.

[0061] The controller 50 stores in advance a map for adjusting the opening degree of the first control valve 31 , the opening degree of the second control valve 32 , and the opening degree of the third control valve 33 by the valve control unit 51 .

[0062] The valve control unit 51 is based on the expression, for example, Fig.12 A map showing the relationship between the pump flow rate command value and the control valve opening command value (control valve opening command value) is used to obtain the control valve opening command value corresponding to the pump flow rate command value and output the control valve opening command value.

[0063] Specifically, the valve control unit 51 is based on Fig.10 The pump flow rate command value (first command value) obtained by the map shown in FIG. 1 , that is, the pump flow rate command value corresponding to the operation amount of the first command operation and Fig.12The mapping diagram shown in FIG. 1 is used to obtain the opening command value of the first control valve and output the opening command value. When the opening command value is input to the electromagnetic proportional pressure reducing valve 34 corresponding to the direction of the first command operation among the pair of electromagnetic proportional pressure reducing valves 34, 34, the electromagnetic proportional pressure reducing valve 34 performs an opening and closing operation so that the pilot pressure corresponding to the opening command value is input to the pilot port of the first control valve 31. As a result, the first control valve 31 is adjusted to the first target opening determined based on the first target flow rate.

[0064] After the capacity of the first pump 21 reaches the maximum capacity, the valve control unit 51 controls the Fig.11 The pump flow rate command value (second command value) obtained by the map shown in FIG. 1 , that is, the pump flow rate command value corresponding to the operation amount of the second command operation and the pump flow rate command value corresponding to the operation amount of the second command operation and the pump flow rate command value corresponding to the operation amount of the second control valve 32 set Fig.12 Similarly, the mapping diagram (not shown) is used to obtain the opening command value of the second control valve and output the opening command value. When the opening command value is input to the electromagnetic proportional pressure reducing valve 35 corresponding to the direction of the second command operation among the pair of electromagnetic proportional pressure reducing valves 35, 35, the electromagnetic proportional pressure reducing valve 35 performs an opening and closing action so that the pilot pressure corresponding to the opening command value is input to the pilot port of the second control valve 32. As a result, the second control valve 32 is adjusted to the second target opening determined based on the second control valve target flow rate, which is the target flow rate of the working oil to the boom cylinder 7 through the second control valve 32 in the second target flow rate.

[0065] The valve control unit 51 is based on Fig.11 The pump flow rate command value (second command value) obtained by the map shown in FIG. 1 , that is, the pump flow rate command value corresponding to the operation amount of the second command operation and the pump flow rate command value corresponding to the operation amount of the second command operation and the pump flow rate command value corresponding to the operation amount of the third control valve 33 set Fig.12 The same mapping diagram is used to obtain the opening command value of the third control valve and output the opening command value. When the opening command value is input to the electromagnetic proportional pressure reducing valve 36 corresponding to the direction of the second command operation among the pair of electromagnetic proportional pressure reducing valves 36, 36, the electromagnetic proportional pressure reducing valve 36 performs an opening and closing action so that the pilot pressure corresponding to the opening command value is input to the pilot port of the third control valve 33. As a result, the third control valve 33 is adjusted to a third target opening degree determined based on the third control valve target flow rate, which is the target flow rate of the working oil to the boom cylinder 7 through the third control valve 33 in the second target flow rate.

[0066] The condition determination unit 53 determines whether a preset load determination condition is satisfied. The load determination condition is a condition for determining that the load of the first actuator, i.e., the first load, is greater than the load of the second actuator, i.e., the second load. In the first embodiment, the load determination condition is a condition that the rotation speed of the swing motor 10 detected by the first speed detector 61 is less than the target rotation speed of the swing motor 10. The condition determination unit 53 determines that the load determination condition is satisfied when the rotation speed is less than the target rotation speed.

[0067] When a combined operation in which the first command operation is applied to the first operating device 41 and the second command operation is applied to the second operating device 42 is performed and the condition determination unit 53 determines that the load determination condition is satisfied, the speed compensation unit 54 performs speed compensation control.

[0068] The speed compensation control includes the following feedback control (second control valve feedback control): the greater the speed difference between the target speed of the rotary motor 10 determined based on the operation amount of the first instruction operation and the actual speed, that is, the speed of the rotary motor 10, the larger the correction amount is calculated, and the opening of the second control valve 32 is adjusted to the opening obtained by subtracting the correction amount from the second target opening.

[0069] In the feedback control of the second control valve, the speed compensation unit 54 can actually calculate the speed difference between the first target speed and the first actual speed. The larger the calculated speed difference, the larger the calculated correction amount. In addition, the deviation between the first target flow corresponding to the first target speed and the first actual flow corresponding to the first actual speed can also be calculated. The larger the calculated deviation, the larger the calculated correction amount.

[0070] The rotation speed of the swing motor 10 is an example of the first actual speed, and the target rotation speed of the swing motor 10 is an example of the first target speed.

[0071] The first target speed is a target speed determined based on the operation amount of the first instruction operation, and the second target speed is a target speed determined based on the operation amount of the second instruction operation. The first target speed is a value that is highly correlated with the first target flow rate, and the second target speed is a value that is highly correlated with the second target flow rate. Therefore, the controller 50 can calculate the first target speed using a preset conversion formula based on the first target flow rate, and can calculate the second target speed using a preset conversion formula based on the second target flow rate. Similarly, the controller 50 can calculate the first target flow rate using a preset conversion formula based on the first target speed, and can calculate the second target flow rate using a preset conversion formula based on the second target speed. In addition, the controller 50 can also calculate the first target flow rate using a preset conversion formula based on, for example, Fig.13The first target speed is calculated based on a mapping diagram in which the relationship between the operation amount of the first command operation and the first target speed is pre-set as shown, and a first command signal output from the first operating device 41 and input to the controller 50. Similarly, the controller 50 can also calculate the second target speed based on a mapping diagram (not shown) in which the relationship between the operation amount of the second command operation and the second target speed is pre-set, and a second command signal output from the second operating device 42 and input to the controller 50.

[0072] In the present embodiment, the speed compensation control further includes first control valve feedback control, third control valve feedback control, and pump feedback control.

[0073] The first control valve feedback control is a feedback control in which a larger correction amount is calculated as the speed difference between the first target speed and the first actual speed increases, and the opening of the first control valve 31 is adjusted to an opening obtained by adding the correction amount to the first target opening.

[0074] In the first control valve feedback control, the speed compensation unit 54 can actually calculate the speed difference between the first target speed and the first actual speed. The larger the calculated speed difference, the larger the calculated correction amount. In addition, the deviation between the first target flow corresponding to the first target speed and the first actual flow corresponding to the first actual speed can also be calculated. The larger the calculated deviation, the larger the calculated correction amount.

[0075] The third control valve feedback control is a feedback control as follows: the greater the speed difference between the target speed of the boom cylinder 7 determined based on the operation amount of the second instruction operation, that is, the second target speed, and the actual speed of the boom cylinder 7, that is, the second actual speed, the larger the correction amount is calculated, and the opening of the third control valve 33 is adjusted to the opening obtained by adding the correction amount to the third target opening.

[0076] In the third control valve feedback control, the speed compensation unit 54 can actually calculate the speed difference between the second target speed and the second actual speed. The larger the calculated speed difference, the larger the calculated correction amount. In addition, the deviation between the second target flow corresponding to the second target speed and the second actual flow corresponding to the second actual speed can also be calculated. The larger the calculated deviation, the larger the calculated correction amount.

[0077] The pump feedback control is a feedback control as follows: the sum of the first target flow and the second target flow, that is, the total target flow, is calculated; the actual flow of the working oil supplied to the rotary motor 10, that is, the first actual flow, and the actual flow of the working oil supplied to the boom cylinder 7, that is, the second actual flow, that is, the total actual flow, are calculated; the greater the flow difference between the total target flow and the total actual flow, the greater the correction amount calculated; and the discharge amount of at least one of the first pump 21 and the second pump 22 is adjusted in such a way that the sum of the discharge amount of the first pump 21 and the discharge amount of the second pump 22, that is, the total discharge amount, is increased by the component of the correction amount.

[0078] The speed compensation control includes: making the opening of the first control valve 31 larger than the first target opening; making the opening of the second control valve 32 smaller than the second target opening; making the opening of the third control valve 33 larger than the third target opening; and increasing at least one of the discharge volume of the first pump 21 and the discharge volume of the second pump 22. The second control valve 32 may be closed when the opening of the second control valve 32 is made smaller than the second target opening.

[0079] The output determination unit 55 determines the maximum output of the engine 23. Specifically, the controller 50 stores in advance a map showing the characteristics of the engine speed and the engine output determined by the engine specifications. The output determination unit 55 determines the maximum output of the engine 23 based on the engine speed command output from the controller 50 to the engine 23 and the map.

[0080] Figure 3 and Figure 4 : is a flowchart showing the control operation executed by the controller 50 . Figure 3 and Figure 4 The flowchart shown is a flowchart showing a series of control actions, but for the sake of convenience is divided into Figure 3 and Figure 4 These 2 pictures.

[0081] First, signals corresponding to detection values ​​detected by the first speed detector 61 , the second speed detector 62 , the first discharge pressure detector 63 , and the second discharge pressure detector 64 are input to the controller 50 (step S1 ).

[0082] Next, the controller 50 determines the first target speed based on the preset mapping diagram and the first command signal corresponding to the first command operation applied to the first operating lever 41A of the first operating device 41. Similarly, the controller 50 determines the second target speed based on the preset mapping diagram and the second command signal corresponding to the second operating lever 42A of the second operating device 42 (step S2).

[0083] Next, the speed compensation unit 54 calculates the difference between the first target speed and the first actual speed, that is, the speed deviation of the rotary motor 10 (first target speed - first actual speed), and calculates the difference between the second target speed and the second actual speed, that is, the speed deviation of the boom cylinder 7 (second target speed - second actual speed) (step S3).

[0084] Next, the speed compensation unit 54 determines whether the composite operation is being performed based on the first command signal and the second command signal (step S4). When the composite operation is being performed ("yes" in step S4), the condition determination unit 53 determines whether the load determination condition is satisfied (step S5). In the first embodiment, when the rotation speed (first actual speed) is less than the target rotation speed (first target speed), that is, when the difference between the first actual speed and the first target speed (first target speed-first actual speed) is a positive value, the condition determination unit 53 determines that the load determination condition is satisfied.

[0085] When the load judgment condition is satisfied ("Yes" in step S5), the controller 50 executes the processing of steps S6a to S16a, S17, and S18 (first speed compensation control). The first speed compensation control is a control equivalent to the speed compensation control of the present invention. On the other hand, when the composite operation is not being performed ("No" in step S4) or when the load judgment condition is not satisfied ("No" in step S5), the controller 50 executes the processing of steps S6b to S16b, S17, and S18 (second speed compensation control).

[0086] In the first speed compensation control of steps S6a to S16a, S17, and S18, the speed compensation unit 54 performs feedback control to adjust the opening of the first control valve 31 so that the speed deviation of the swing motor 10 approaches zero, performs feedback control to adjust the opening of the second control valve 32 so that the speed deviation of the swing motor 10 approaches zero, and performs feedback control to adjust the opening of the third control valve 33 so that the speed deviation of the boom cylinder 7 approaches zero. The details are as follows.

[0087] The speed compensating unit 54 calculates a correction value (first correction value) of the opening (opening amount) of the first control valve 31 such that the speed deviation of the swing motor 10 is close to zero (first target speed-first actual speed) by using the speed deviation of the swing motor 10 (first target speed-first actual speed) and, for example, the following formula (1) (step S6a). The first correction value calculated in step S6a is a correction value for making the opening of the first control valve 31 larger than the first target opening. The speed compensating unit 54 calculates the first opening command value corrected by adding the first correction amount to the first target opening.

[0088] 1st correction value = proportional gain × speed deviation + integral gain × accumulated value of speed deviation + differential gain × speed deviation difference (1)

[0089] In addition, the speed compensation unit 54 calculates a correction value (third correction value) of the opening (opening amount) of the third control valve 33 such that the speed deviation of the boom cylinder 7 is close to zero (step S7a) by using the speed deviation of the boom cylinder 7 (second target speed-second actual speed) and, for example, the following formula (2). The third correction value calculated in step S7a is a correction value for making the opening of the third control valve 33 larger than the third target opening. The speed compensation unit 54 calculates the third opening command value corrected by adding the third correction amount to the third target opening.

[0090] Third correction value = proportional gain × speed deviation + integral gain × accumulated value of speed deviation + differential gain × speed deviation difference (2)

[0091] In addition, the speed compensation unit 54 calculates a correction value (second correction value) of the opening (opening amount) of the second control valve 32 such that the speed deviation of the swing motor 10 is close to zero (step S8a) by using the speed deviation of the swing motor 10 (first target speed-first actual speed) and, for example, the following formula (3). The second correction value calculated in step S8a is a correction value for making the opening of the second control valve 32 smaller than the second target opening. The speed compensation unit 54 calculates the second opening command value corrected by subtracting the second correction amount from the second target opening.

[0092] Second correction value = proportional gain × speed deviation + integral gain × accumulated value of speed deviation + differential gain × speed deviation difference (3)

[0093] Next, the speed compensating unit 54 calculates a target flow rate (first target flow rate) of hydraulic oil to be supplied to the swing motor 10 based on the first target speed, and calculates a target flow rate (second target flow rate) of hydraulic oil to be supplied to the boom cylinder 7 based on the second target speed (step S9a).

[0094] The speed compensating unit 54 calculates a total target flow rate which is the sum of the first target flow rate and the second target flow rate (step S10a). The total target flow rate is the flow rate of the hydraulic oil that must be discharged from the first pump 21 and the second pump 22.

[0095] Next, the speed compensating unit 54 calculates the total maximum discharge amount (maximum dischargeable flow rate) based on the first discharge pressure and the second discharge pressure detected by the first discharge pressure detector 63 and the second discharge pressure detector 64 and the maximum output of the engine 23 determined by the output determining unit 55 (step S11a). The total maximum discharge amount is the sum of the first maximum discharge amount, which is the maximum discharge amount of the hydraulic oil that can be discharged by the first pump 21, and the second maximum discharge amount, which is the maximum discharge amount of the hydraulic oil that can be discharged by the second pump 22.

[0096] The speed compensating unit 54 determines whether the total target flow rate is less than the total maximum discharge amount (step S12a). If the total target flow rate is greater than the total maximum discharge amount ("No" in step S12a), the speed compensating unit 54 corrects the first target flow rate and the second target flow rate so that the total target flow rate becomes less than the total maximum discharge amount while maintaining the ratio of the first target flow rate to the second target flow rate (step S18).

[0097] On the other hand, when the total target flow rate is less than the total maximum discharge volume ("Yes" in step S12a), the speed compensation unit 54 calculates the flow rate (first actual flow rate) of the working oil actually supplied to the rotary motor 10 based on the first actual speed, and calculates the flow rate (second actual flow rate) of the working oil actually supplied to the boom cylinder 7 based on the second actual speed (step S13a).

[0098] The speed compensating unit 54 calculates a total actual flow rate which is the sum of the first actual flow rate and the second actual flow rate (step S14a). The total actual flow rate is the total amount of hydraulic oil actually discharged by the first pump 21 and the second pump 22.

[0099] The speed compensating unit 54 performs feedback control to adjust the discharge amount of the second pump 22 in order to reduce the difference between the total actual flow rate and the total target flow rate, thereby bringing the total actual flow rate close to the total target flow rate.

[0100] The speed compensation unit 54 uses the flow deviation between the total target flow rate and the total actual flow rate (total target flow rate-total actual flow rate) and, for example, the following formula (4) to calculate a correction value (discharge amount correction value) for the discharge amount of the second pump 22 so that the flow deviation is close to zero (step S15a).

[0101] Discharge correction value = proportional gain × flow deviation + integral gain × cumulative value of flow deviation + differential gain × difference of flow deviation (4)

[0102] The speed compensating unit 54 calculates a discharge amount instruction value by adding the discharge amount correction value to the total target discharge amount before the discharge amount correction value is calculated.

[0103] The speed compensation unit 54 outputs the discharge volume command value (discharge volume command) to the regulator of the second pump 22, and the regulator changes the deflection angle of the second pump 22 so that the discharge volume of the second pump 22 becomes the discharge volume corresponding to the discharge volume command value. As a result, the discharge volume of the second pump 22 increases to the discharge volume corresponding to the discharge volume command value (step S16a).

[0104] The speed compensation unit 54 outputs the first opening command value to the electromagnetic proportional pressure reducing valve 34, and the electromagnetic proportional pressure reducing valve 34 outputs a pilot pressure to the pilot port of the first control valve 31 so that the opening of the first control valve 31 is adjusted to the opening corresponding to the first opening command value. In addition, the speed compensation unit 54 outputs the second opening command value to the electromagnetic proportional pressure reducing valve 35, and the electromagnetic proportional pressure reducing valve 35 outputs a pilot pressure to the pilot port of the second control valve 32 so that the opening of the second control valve 32 is adjusted to the opening corresponding to the second opening command value. Furthermore, the speed compensation unit 54 outputs the third opening command value to the electromagnetic proportional pressure reducing valve 36, and the electromagnetic proportional pressure reducing valve 36 outputs a pilot pressure to the pilot port of the third control valve 33 so that the opening of the third control valve 33 is adjusted to the opening corresponding to the third opening command value (step S17).

[0105] Next, the processing of steps S6b to S16b, S17, and S18 will be described. As described above, when the composite operation is not being performed ("No" in step S4) or when the load determination condition is not satisfied ("No" in step S5), the controller 50 executes the processing of steps S6b to S16b, S17, and S18 (second speed compensation control).

[0106] In the processing of steps S6b to S16b, S17, and S18, the processing of the second speed compensation control different from the first speed compensation control is step S7b, step S8b, and step S16b. That is, step 6b is the same as the above-mentioned step 6a, steps S9b to S15b are the same as the above-mentioned steps S9a to S15a, and step S17 is the same as the above-mentioned step 17.

[0107] In step S7b, the speed compensating unit 54 calculates a correction value of the opening (opening amount) of the third control valve 33 such that the speed deviation of the boom cylinder 7 approaches zero by using the speed deviation (second target speed-second actual speed) of the boom cylinder 7 and a preset relationship. The correction value calculated in step S7b is a correction value such that the opening of the third control valve 33 is smaller or larger than the third target opening.

[0108] In step S8b, the speed compensating unit 54 calculates a correction value of the opening (opening amount) of the second control valve 32 such that the speed deviation of the boom cylinder 7 approaches zero, using the speed deviation (second target speed-second actual speed) of the boom cylinder 7 and a preset relationship. The correction value calculated in step S8b is a correction value such that the opening of the second control valve 32 is smaller or larger than the second target opening.

[0109] In step 16b, the speed compensation unit 54 outputs the discharge volume command value (discharge volume command) to the regulator of the first pump 21, and the regulator changes the deflection angle of the first pump 21 so that the discharge volume of the first pump 21 becomes the discharge volume corresponding to the discharge volume command value. As a result, the discharge volume of the first pump 21 increases to the discharge volume corresponding to the discharge volume command value (step S16b).

[0110] As described above, in the engineering machinery 100 involved in the first embodiment, the speed compensation unit 54 performs feedback control as follows, that is, the larger the speed difference (first target speed-first actual speed) between the first target speed determined based on the operation amount of the first command operation and the first actual speed is, the larger the second correction amount is calculated, and the opening of the second control valve 32 is adjusted to an opening obtained by subtracting the calculated second correction amount from the second target opening. Therefore, when performing a composite operation, even if the first load of the swing motor 10 is greater than the second load of the boom cylinder 7, the rotation speed of the swing motor 10 can be accurately adjusted to the target speed corresponding to the operation amount of the first command operation.

[0111] In the first embodiment, the second actual speed of the boom cylinder 7 can be accurately adjusted to the second target speed by further performing the third control valve feedback control for adjusting the opening of the third control valve 33 according to the speed difference between the second target speed and the second actual speed.

[0112] In the first embodiment, the first actual speed of the swing motor 10 can be more quickly adjusted to the first target speed by further performing the first control valve feedback control for adjusting the opening of the first control valve 31 according to the speed difference between the first target speed and the first actual speed.

[0113] [Second embodiment]

[0114] Figure 5 2 is a diagram showing a hydraulic circuit of a construction machine 100 according to a second embodiment. Figure 5As shown in FIG. 1 , in the second embodiment, the combination of the two hydraulic actuators for performing speed compensation control is different from that in the first embodiment, but the other structures are the same as those in the first embodiment. Therefore, the structure of the second embodiment that is different from the first embodiment is mainly described below, and the structure that is the same as the first embodiment is described below. Figure 5 The same reference numerals as those in the first embodiment are used and descriptions thereof are omitted.

[0115] In the first embodiment, speed compensation control is performed on the combination of the swing motor 10 (first actuator) and the boom cylinder 7 (second actuator), but in the second embodiment, speed compensation control is performed on the combination of the boom cylinder 8 (first actuator) and the boom cylinder 7 (second actuator).

[0116] like Figure 5 As shown, the arm cylinder 8 is extended or contracted by being supplied with hydraulic oil discharged from the first pump 21, thereby swinging the arm 5 forward or backward. The arm cylinder 8 is an example of a first actuator.

[0117] The first control valve 31 is located between the first pump 21 and the boom cylinder 8, and is opened and closed in such a manner that the direction and flow rate of the working oil supplied from the first pump 21 to the boom cylinder 8 are changed. The first control valve 31 is a three-position reversing valve having a pair of pilot ports, and has a flow rate regulating function of varying the flow rate of the working oil by adjusting the opening (opening amount) of the first control valve 31 in accordance with the displacement of the valve core (position of the valve core).

[0118] The first speed detector 67 is a sensor that detects the extension and retraction speed of the arm cylinder 8 .

[0119] In the second embodiment, the load determination condition is a condition that the first actual speed (extension speed) of the boom cylinder 8 detected by the first speed detector 67 is less than the first target speed of the boom cylinder 8. When the first actual speed is less than the first target speed, the condition determination unit 53 determines that the load determination condition is satisfied.

[0120] In the second embodiment, the control operation executed by the controller 50 may be performed along the same lines as in the first embodiment. Figure 3 and Figure 4 That is, the control action involved in the second embodiment is Figure 3 and Figure 4 In the flowchart of , except that the first actuator is the arm cylinder 8 , the control operation is the same as that of the first embodiment.

[0121] [Third embodiment]

[0122] The construction machine 100 according to the third embodiment is different from the first and second embodiments in that it includes detectors for actually detecting the first load of the first actuator and the second load of the second actuator. The other configurations in the third embodiment are the same as those in the first and second embodiments.

[0123] Therefore, the construction machine 100 involved in the third embodiment further includes a first load detection unit for detecting a first load and a second load detection unit for detecting a second load. The load determination condition is that the first load detected by the first load detector is greater than the second load detected by the second load detector. The first load detector is a pressure sensor for detecting the pressure of the working oil discharged from the first pump 21, and the second load detector is a pressure sensor for detecting the pressure of the working oil discharged from the second pump 22. The first load detector is, for example, Figure 2 The hydraulic circuit shown may include a pressure sensor 63 provided in the hydraulic piping connecting the first pump 21 and the first control valve 31. The first load detector may include, for example, a pressure difference sensor 65 (a pair of pressure sensors 65A, 65B) capable of detecting the pressure difference of the swing motor 10. The second load detector may include, for example, a pressure sensor 64 provided in the hydraulic piping connecting the second pump 22 and the third control valve 33. The second load detector may include, for example, a pressure sensor 66 provided in the piping connecting the third control valve 33 and the head side chamber of the boom cylinder 7. In addition, in the engineering machinery 100 involved in the first embodiment and the second embodiment, the first load detector and the second load detector may also be omitted.

[0124] In the third embodiment, the condition determination unit 53 can determine whether the load determination condition is satisfied by comparing the first load and the second load actually detected by the first load detector and the second load detector.

[0125] [Modifications]

[0126] also, Figure 3 and Figure 4 Among the multiple processes shown in the flowchart, steps S6a to S8a and steps S6b to S8b are processes for controlling the first to third control valves 31 to 33 (valve processes), and steps S9a to S16a and steps 9b to 16b are processes for controlling the first and second pumps 21 and 22 (pump processes). Figure 3 In the embodiment, the pump process is performed after the valve process, but the present invention is not limited to this form.

[0127] For example, you can also Figure 6 As in the first modification shown in FIG. 1 , the pump control is performed before the valve control, or as in Figure 7 As in the modified example 2 shown in the figure, valve control and pump control are performed in parallel.

[0128] Figure 8 and Fig. 9 This is a flowchart showing the processing performed by the controller 50 of the construction machine 100 according to the third modification. Figure 8 and Fig. 9 The flowchart shown is a flowchart showing a series of control actions, but for the sake of convenience is divided into Figure 8 and Fig. 9 These 2 pictures.

[0129] Figure 8 and Fig. 9 The control operation according to the third modification shown in the figure is performed by converting the speed into the flow rate of the hydraulic oil. Figure 3 and Figure 4 The control action shown is different from the control action shown in the figure. The overall control action process is the same as Figure 3 and Figure 4 The control operation shown is the same. The control operation related to the modification example 3 can be applied to any of the first embodiment and the second embodiment. The modification example 3 will be described in detail below.

[0130] First, signals corresponding to detection values ​​detected by the first speed detector 61 , the second speed detector 62 , the first discharge pressure detector 63 , the second discharge pressure detector 64 , and the differential pressure detector 65 are input to the controller 50 (step S31 ).

[0131] Next, the controller 50 determines the first target speed and the second target speed in the same manner as in step S2 (step S32 ).

[0132] The speed compensating unit 54 calculates the target flow rate (first target flow rate) of the hydraulic oil to be supplied to the arm cylinder 8 based on the first target speed, and calculates the target flow rate (second target flow rate) of the hydraulic oil to be supplied to the boom cylinder 7 based on the second target speed (step S33).

[0133] The speed compensating unit 54 calculates the flow rate (first actual flow rate) of the hydraulic oil actually supplied to the arm cylinder 8 based on the first actual speed, and calculates the flow rate (second actual flow rate) of the hydraulic oil actually supplied to the boom cylinder 7 based on the second actual speed (step S34).

[0134] The speed compensation unit 54 calculates the difference between the first target flow and the first actual flow, that is, the flow deviation of the boom cylinder 8 (first target flow - first actual flow), and calculates the difference between the second target flow and the second actual flow, that is, the flow deviation of the boom cylinder 7 (second target flow - second actual flow) (step S35).

[0135] Next, the speed compensating unit 54 determines whether the composite operation is being performed based on the first command signal and the second command signal (step S36). If the composite operation is being performed ("Yes" in step S36), the condition determining unit 53 determines whether the load determining condition is satisfied (step S37).

[0136] When the load determination condition is satisfied ("Yes" in step S37), the controller 50 executes the processing of steps S38a to S40a and steps S41 to S49 (first speed compensation control). The first speed compensation control is a control equivalent to the speed compensation control of the present invention. On the other hand, when the composite operation is not being performed ("No" in step S36) or when the load determination condition is not satisfied ("No" in step S37), the controller 50 executes the processing of steps S38b to S40b and steps S41 to S49 (second speed compensation control).

[0137] In the first speed compensation control of the processing of steps S38a to S40a and steps S41 to S49, the speed compensation unit 54 performs feedback control of adjusting the opening of the first control valve 31 so that the speed deviation of the boom cylinder 8 approaches zero, performs feedback control of adjusting the opening of the second control valve 32 so that the speed deviation of the boom cylinder 8 approaches zero, and performs feedback control of adjusting the opening of the third control valve 33 so that the speed deviation of the boom cylinder 7 approaches zero. The details are as follows.

[0138] The speed compensating unit 54 uses the flow deviation of the boom cylinder 8 (first target flow - first actual flow) and, for example, the following formula (5) to calculate a correction value (first correction value) of the opening (opening amount) of the first control valve 31 so that the flow deviation of the boom cylinder 8 is close to zero (step S38a). The first correction value calculated in step S38a is a correction value for making the opening of the first control valve 31 larger than the first target opening. The speed compensating unit 54 calculates the flute 1 opening command value corrected by adding the first correction amount to the first target opening.

[0139] First correction value = proportional gain × flow rate deviation + integral gain × cumulative value of flow rate deviation + differential gain × difference of flow rate deviation (5)

[0140] In addition, the speed compensating unit 54 calculates a correction value (third correction value) of the opening (opening amount) of the third control valve 33 such that the flow deviation of the boom cylinder 7 is close to zero (step S39a) by using the flow deviation of the boom cylinder 7 (second target flow-second actual flow) and, for example, the following formula (6). The third correction value calculated in step S39a is a correction value for making the opening of the third control valve 33 larger than the third target opening. The speed compensating unit 54 calculates the third opening command value corrected by adding the third correction amount to the third target opening.

[0141] Third correction value = proportional gain × flow rate deviation + integral gain × cumulative value of flow rate deviation + differential gain × difference of flow rate deviation (6)

[0142] In addition, the speed compensation unit 54 calculates a correction value (second correction value) of the opening (opening amount) of the second control valve 32 so that the flow deviation of the boom cylinder 8 is close to zero (step S40a) by using the flow deviation of the boom cylinder 8 (first target flow-first actual flow) and, for example, the following formula (7). The second correction value calculated in step S40a is a correction value for making the opening of the second control valve 32 smaller than the second target opening. The speed compensation unit 54 calculates the second opening command value corrected by subtracting the second correction amount from the second target opening.

[0143] Second correction value = proportional gain × flow rate deviation + integral gain × cumulative value of flow rate deviation + differential gain × difference of flow rate deviation (7)

[0144] Next, the speed compensating unit 54 calculates a total target flow rate which is the sum of the first target flow rate and the second target flow rate (step S41 ). The total target flow rate is the flow rate of the hydraulic oil that must be discharged from the first pump 21 and the second pump 22 .

[0145] The speed compensating unit 54 calculates the total maximum discharge amount (maximum dischargeable flow rate) (step S42) based on the first discharge pressure and the second discharge pressure detected by the first discharge pressure detector 63 and the second discharge pressure detector 64, and the maximum output of the engine 23 determined by the output determining unit 55. The total maximum discharge amount is the sum of the first maximum discharge amount, which is the maximum discharge amount of the hydraulic oil that can be discharged by the first pump 21, and the second maximum discharge amount, which is the maximum discharge amount of the hydraulic oil that can be discharged by the second pump 22.

[0146] The speed compensating unit 54 determines whether the total target flow rate is less than the total maximum discharge amount (step S43). If the total target flow rate is greater than the total maximum discharge amount ("No" in step S43), the speed compensating unit 54 corrects the first target flow rate and the second target flow rate so that the total target flow rate becomes less than the total maximum discharge amount while maintaining the ratio of the first target flow rate to the second target flow rate (step S49).

[0147] On the other hand, when the total target flow rate is less than the total maximum discharge flow rate ("Yes" in step S43), the speed compensation unit 54 calculates the total actual flow rate which is the sum of the first actual flow rate and the second actual flow rate (step S44). The total actual flow rate is the total amount of hydraulic oil actually discharged by the first pump 21 and the second pump 22.

[0148] The speed compensating unit 54 performs feedback control to adjust the discharge amount of the first pump 21 or the second pump 22 to reduce the difference between the total actual flow rate and the total target flow rate so that the total target flow rate approaches the total actual flow rate.

[0149] The speed compensation unit 54 uses the flow deviation between the total target flow and the total actual flow (total target flow-total actual flow) and, for example, the following formula (8) to calculate a correction value (discharge volume correction value) for the discharge volume of the first pump 21 or the second pump 22 so that the flow deviation is close to zero (step S45).

[0150] Discharge correction value = proportional gain × flow deviation + integral gain × cumulative value of flow deviation + differential gain × difference of flow deviation (8)

[0151] The speed compensating unit 54 calculates a discharge amount instruction value by adding the discharge amount correction value to the total target discharge amount before the discharge amount correction value is calculated.

[0152] Next, the speed compensating unit 54 determines whether the discharge volume of the first pump 21 has reached the maximum discharge volume of the first pump 21 (step S46). When the discharge volume of the first pump 21 has reached the maximum discharge volume of the first pump 21 ("Yes" in step S46), the speed compensating unit 54 outputs the discharge volume instruction value (discharge volume instruction) to the regulator of the second pump 22, and the regulator changes the deflection angle of the second pump 22 so that the discharge volume of the second pump 22 becomes the discharge volume corresponding to the discharge volume instruction value. As a result, the discharge volume of the second pump 22 increases to the discharge volume corresponding to the discharge volume instruction value (step S47b).

[0153] On the other hand, when the discharge volume of the first pump 21 does not reach the maximum discharge volume of the first pump 21 ("No" in step S46), the speed compensation unit 54 outputs the discharge volume command value (discharge volume command) to the regulator of the first pump 21, and the regulator changes the deflection angle of the first pump 21 so that the discharge volume of the first pump 21 becomes the discharge volume corresponding to the discharge volume command value. Thus, the discharge volume of the first pump 21 increases to the discharge volume corresponding to the discharge volume command value (step S47a).

[0154] The speed compensation unit 54 outputs the first opening command value to the electromagnetic proportional pressure reducing valve 34, and the electromagnetic proportional pressure reducing valve 34 outputs a pilot pressure to the pilot port of the first control valve 31 so that the opening of the first control valve 31 is adjusted to the opening corresponding to the first opening command value. In addition, the speed compensation unit 54 outputs the second opening command value to the electromagnetic proportional pressure reducing valve 35, and the electromagnetic proportional pressure reducing valve 35 outputs a pilot pressure to the pilot port of the second control valve 32 so that the opening of the second control valve 32 is adjusted to the opening corresponding to the second opening command value. Furthermore, the speed compensation unit 54 outputs the third opening command value to the electromagnetic proportional pressure reducing valve 36, and the electromagnetic proportional pressure reducing valve 36 outputs a pilot pressure to the pilot port of the third control valve 33 so that the opening of the third control valve 33 is adjusted to the opening corresponding to the third opening command value (step S48).

[0155] Next, the second speed compensation control of performing the processing of steps S38b to S40b and steps S41 to S49 will be described. As described above, when the composite operation is not performed ("No" in step S36) or when the load determination condition is not satisfied ("No" in step S37), the controller 50 performs the processing of steps S38b to S40b and steps S41 to S49 (the second speed compensation control).

[0156] Of the processes of steps S38b to S40b, the processes of the second speed compensation control which is different from the first speed compensation control are steps 39b and S40b. The other steps of the second speed compensation control are the same as those of the first speed compensation control.

[0157] In step S39b, the speed compensating unit 54 calculates a correction value of the opening (opening amount) of the third control valve 33 such that the flow deviation of the boom cylinder 7 approaches zero by using the flow deviation of the boom cylinder 7 (second target speed-second actual speed) and a preset relationship. The correction value calculated in step S39b is a correction value such that the opening of the third control valve 33 is smaller or larger than the third target opening.

[0158] In step S40b, the speed compensating unit 54 calculates a correction value of the opening (opening amount) of the second control valve 32 such that the flow deviation of the boom cylinder 7 approaches zero by using the flow deviation of the boom cylinder 7 (second target flow - second actual flow) and a preset relationship. The correction value calculated in step S40b is a correction value such that the opening of the second control valve 32 is smaller or larger than the second target opening.

[0159] As described above, in the construction machinery 100 involved in the second embodiment, the second correction amount for adjusting the opening of the second control valve 32 is calculated using the target flow rate and the actual flow rate having a high correlation with the target speed and the actual speed of the actuator. Even in such a second embodiment, the speed compensation unit 54 can perform feedback control as follows: the larger the speed difference between the first target speed determined based on the operation amount of the first command operation and the first actual speed, the larger the second correction amount is calculated, and the opening of the second control valve 32 is adjusted to the opening obtained by subtracting the calculated second correction amount from the second target opening. As a result, even when the first load of the boom cylinder 8 is greater than the second load of the boom cylinder 7 during the composite operation, the actual speed of the boom cylinder 8 can be adjusted to the first target speed corresponding to the operation amount of the first command operation with good accuracy.

[0160] Furthermore, in the second embodiment, as a case where the first load is larger than the second load when a combined operation is performed, for example, a combined operation is assumed in which an operation for a boom raising operation and an operation for an arm extending operation are performed simultaneously.

[0161] Furthermore, in the second embodiment, the third correction amount for adjusting the opening of the third control valve 33 is calculated using the second target flow rate and the second actual flow rate, and the first correction amount for adjusting the opening of the first control valve 31 is calculated using the first target flow rate and the first actual flow rate, and the third control valve feedback control and the first control valve feedback control are also performed. Thus, the second actual speed of the boom cylinder 7 can be adjusted to the second target speed with good accuracy, and the first actual speed of the arm cylinder 8 can be adjusted to the first target speed more quickly.

[0162] In the speed compensation control, when the discharge volume of the first pump 21 is entirely used by the first actuator, it is more desirable to close the second control valve 32 than to make the opening of the second control valve 32 smaller than the second target opening. If the second control valve 32 is closed, the connection between the first pump 21 and the second actuator is cut off, so that the working pressure of the first actuator is not affected by the working pressure of the second actuator. In addition, when the flow rate of the second actuator can be supplied by the second pump 22 and the first actuator is a hydraulic motor (swing motor), it becomes easier to ensure the working pressure of the hydraulic motor, so that the first actual speed can be made to approach the first target speed more quickly.

[0163] The present invention is not limited to the above-described embodiment, and includes, for example, the following aspects.

[0164] (A) Combination of two hydraulic actuators for speed compensation control

[0165] In the first embodiment, speed compensation control is performed on the combination of the swing motor and the boom cylinder, and in the second embodiment, speed compensation control is performed on the combination of the arm cylinder and the boom cylinder, but the present invention is not limited to these forms. The combination of two hydraulic actuators that are the object of speed compensation control may also be a combination of two hydraulic actuators other than the combination in the first and second embodiments.

[0166] (B) About hydraulic pumps

[0167] In the embodiment, the first pump 21 and the second pump 22 are respectively variable capacity hydraulic pumps, however, when the speed compensation control does not include making the opening of the first control valve 31 greater than the first target opening without adjusting the opening of the first control valve 31, the first pump 21 may also be a fixed capacity hydraulic pump.

[0168] As described above, according to the present invention, it is possible to provide a construction machine that can accurately adjust the actual speed of the first actuator to the target speed even when the load on the first actuator is larger than the load on the second actuator during combined operation.

[0169] The engineering machinery provided includes: a first pump, which is a variable displacement hydraulic pump for discharging working oil; a second pump, which is a variable displacement hydraulic pump for discharging working oil; a first actuator, which is operated by receiving the supply of working oil discharged from the first pump; a second actuator, which is operated by receiving the supply of working oil discharged from the second pump; a first control valve, which is located between the first pump and the first actuator, and is opened and closed in a manner that changes the flow rate of the working oil supplied from the first pump to the first actuator; and a second control valve, which is located between the first pump and the second actuator, and is operated by changing the flow rate of the working oil supplied from the first pump to the first actuator. The pump control unit is configured to adjust the discharge volume of the first pump and the discharge volume of the second pump so that the sum of the first target flow rate and the second target flow rate, that is, the total target flow rate, is equal to the sum of the first target flow rate and the second target flow rate. a first control valve having a first target opening and a second control valve having a first target opening and a second target opening; and a valve control unit for adjusting the opening of the first control valve to a first target opening determined based on the first target flow rate, adjusting the opening of the second control valve to a second target opening determined based on the second control valve target flow rate, and adjusting the opening of the third control valve to a first target opening determined based on the second control valve target flow rate. The valve opening is adjusted to a third target opening determined based on a third control valve target flow rate, wherein the second control valve target flow rate is a target flow rate of the working oil to the second actuator via the second control valve in the second target flow rate, and the third control valve target flow rate is a target flow rate of the working oil to the second actuator via the third control valve in the second target flow rate; a condition determination unit determines whether a preset load determination condition is satisfied, the load determination condition being a condition for determining that the load of the first actuator, i.e., the first load, is greater than the load of the second actuator, i.e., the second load;and a speed compensation unit that performs feedback control such that, when a composite operation is performed and the condition determination unit determines that the load determination condition is satisfied, a larger correction amount is calculated as the speed difference between a first target speed of the first actuator determined based on the operation amount of the first command operation and an actual speed of the first actuator, that is, a first actual speed, is larger, and the opening of the second control valve is adjusted to an opening obtained by subtracting the correction amount from the second target opening. ;

[0170] In the construction machinery, the speed compensation unit performs feedback control as follows, that is, the larger the speed difference (first target speed-first actual speed) between the first target speed determined based on the operation amount of the first command operation and the first actual speed is, the larger the correction amount is calculated, and the opening of the second control valve is adjusted to an opening obtained by subtracting the calculated correction amount from the second target opening. Therefore, when a composite operation is performed, even if the first load of the first actuator is greater than the second load of the second actuator, the first actual speed of the first actuator can be accurately adjusted to the first target speed corresponding to the operation amount of the first command operation.

[0171] In addition, in the feedback control, the speed compensation unit can actually calculate the speed difference between the first target speed and the first actual speed, and the larger the calculated speed difference is, the larger the correction amount is calculated. In addition, the deviation between the physical quantity corresponding to the first target speed and the physical quantity corresponding to the first actual speed can also be calculated, and the larger the calculated deviation is, the larger the correction amount is calculated. As a physical quantity corresponding to the first target speed, for example, the target flow rate of the working oil to the first actuator, that is, the first target flow rate, can be exemplified. The first target flow rate is determined based on the operation amount of the first instruction operation and is a value that is highly correlated with the first target speed. As a physical quantity corresponding to the first actual speed, for example, the actual flow rate of the working oil supplied to the first actuator, that is, the first actual flow rate, can be exemplified. The first actual flow rate is a value that is highly correlated with the first actual speed.

[0172] Preferably, the construction machine further comprises: a first detector for detecting the first actual speed or a physical quantity corresponding thereto; wherein the load determination condition is the following condition: the first actual speed or a physical quantity corresponding thereto detected by the first detector is less than the first target speed or a physical quantity corresponding thereto. In this case, even if the construction machine does not have a detector for actually detecting the first load and the second load, the condition determination unit can determine whether the load determination condition is satisfied. The specific situation is as follows.

[0173] When the combined operation is performed and the first load is greater than the second load, the working oil discharged from the first pump flows biased toward the second actuator, so the first actual speed of the first actuator is less than the first target speed. That is, the first load being greater than the second load is related to the first actual speed being less than the first target speed. Therefore, even if the construction machine does not have a detector for actually detecting the first load and the second load, the condition determination unit can determine whether the load determination condition is satisfied by determining whether the first actual speed detected by the first detector or a physical quantity corresponding thereto is less than the first target speed or a physical quantity corresponding thereto.

[0174] Specifically, in the case where the first detector is a speed detector that detects the first actual speed, the condition determination unit can determine whether the load determination condition is satisfied by determining whether the first actual speed detected by the first detector is less than the first target speed. In addition, in the case where the first detector is a detector that detects a physical quantity corresponding to the first actual speed, the condition determination unit can determine whether the load determination condition is satisfied by determining whether the physical quantity detected by the first detector is less than the physical quantity corresponding to the first target speed. In the case where the physical quantity corresponding to the first actual speed is, for example, the actual flow rate of the working oil to the first actuator, that is, the first actual flow rate, the first detector is a flow rate detector that detects the first actual flow rate.

[0175] It is more ideal that the first actuator is a rotary motor, which is a hydraulic motor for rotating the upper rotary body of the engineering machinery that is rotatably constructed, the first actual speed is the rotation speed of the rotary motor, and the first target speed is the target rotation speed of the rotary motor. In rotary engineering machinery such as hydraulic excavators, when accelerating the rotation of the rotary motor, especially when the rotary motor is started, the load of the rotary motor as the first actuator is greater than the load of the second actuator (such as a boom cylinder, a dipper cylinder, a bucket cylinder, etc.). At this time, the working oil discharged from the first pump flows biased toward the second actuator, so that the first actual speed is less than the first target speed. Therefore, the condition determination unit can determine that the load determination condition is satisfied when the rotation speed of the rotary motor as the first actual speed is less than the target rotation speed of the rotary motor as the first target speed, and the speed compensation unit can perform the feedback control according to the determination result of the condition determination unit.

[0176] In addition, the construction machine may further include: a first load detector for detecting the first load; and a second load detector for detecting the second load; wherein the load determination condition is the following condition: the first load detected by the first load detector is greater than the second load detected by the second load detector. According to this configuration, the condition determination unit can determine whether the load determination condition is satisfied by comparing the first load and the second load actually detected.

[0177] In the construction machine, it is preferable that the speed compensation unit further performs feedback control as follows: when the composite operation is performed and the condition determination unit determines that the load determination condition is satisfied, a correction amount (third correction value) is calculated as the speed difference between the second target speed, which is the target speed of the second actuator determined based on the operation amount of the second command operation, and the second actual speed, which is the actual speed of the second actuator, is larger, and the opening of the third control valve is adjusted to an opening obtained by adding the correction amount (third correction value) to the third target opening. According to this configuration, the feedback control for adjusting the opening of the third control valve based on the speed difference between the second target speed and the second actual speed is also performed, so that the second actual speed of the second actuator can be adjusted to the second target speed with good accuracy.

[0178] In the construction machine, it is preferable that the speed compensation unit further performs feedback control such that, when the combined operation is performed and the condition determination unit determines that the load determination condition is satisfied, a larger correction amount (first correction value) is calculated as the speed difference between the first target speed and the first actual speed increases, and the opening of the first control valve is adjusted to an opening obtained by adding the correction amount (first correction value) to the first target opening. According to this configuration, the feedback control for adjusting the opening of the first control valve based on the speed difference between the first target speed and the first actual speed is also performed, so that the first actual speed of the first actuator can be adjusted to the first target speed more quickly.

[0179] In the construction machine, it is preferable that the speed compensation unit further performs feedback control as follows: when the composite operation is performed and the condition determination unit determines that the load determination condition is satisfied, the sum of the actual flow rate of the working oil supplied to the first actuator, i.e., the first actual flow rate, and the actual flow rate of the working oil supplied to the second actuator, i.e., the second actual flow rate, i.e., the total actual flow rate is calculated, and the larger the flow difference between the total target flow rate and the total actual flow rate is, the larger the correction amount (discharge amount correction value) is calculated, and the discharge amount of at least one of the first pump and the second pump is adjusted according to the correction amount (discharge amount correction value). According to this configuration, the feedback control for adjusting the discharge amount of at least one of the first pump and the second pump based on the flow difference between the total target flow rate and the total actual flow rate is performed, so that the total actual flow rate can be adjusted to the total target flow rate with good accuracy.

[0180] In the construction machine, it is preferable that when the total target flow calculated by the speed compensation unit is greater than the sum of the maximum discharge amount of the working oil that can be discharged by the first pump, i.e., the first maximum discharge amount, and the maximum discharge amount of the working oil that can be discharged by the second pump, i.e., the second maximum discharge amount, i.e., the total maximum discharge amount, the speed compensation unit corrects the first target flow and the second target flow in such a manner that the total target flow becomes less than the total maximum discharge amount while maintaining the ratio of the first target flow to the second target flow. According to this configuration, the total discharge amount of the discharge amount of the first pump and the discharge amount of the second pump can be set to less than the total maximum discharge amount while maintaining the balance of the speeds of the first actuator and the second actuator corresponding to the operation amount of the first instruction operation and the operation amount of the second instruction operation.

[0181] Preferably, the engineering machine further includes: a first discharge pressure detector for detecting the discharge pressure of the working oil of the first pump, i.e., the first discharge pressure; a second discharge pressure detector for detecting the discharge pressure of the working oil of the second pump, i.e., the second discharge pressure; an engine for driving the first pump and the second pump; and an output determination unit for determining the output of the engine; wherein the speed compensation unit calculates the total maximum discharge amount based on the output of the engine and the first discharge pressure and the second discharge pressure. According to this configuration, the discharge amount of the first pump and the second pump can be limited based on the output of the engine and the first discharge pressure and the second discharge pressure, thereby compensating the speed of the first actuator and the second actuator without overloading the engine.

Claims

1. A construction machinery, characterized in that include: The first pump is a variable displacement hydraulic pump that discharges hydraulic oil; The second pump is a variable displacement hydraulic pump that discharges hydraulic oil; a first actuator that operates by receiving the supply of hydraulic oil discharged from the first pump; a second actuator that is operated by receiving the supply of hydraulic oil discharged from the second pump; a first control valve located between the first pump and the first actuator and opening and closing the valve so as to change the flow rate of the hydraulic oil supplied from the first pump to the first actuator; a second control valve located between the first pump and the second actuator and opening and closing the valve so as to change the flow rate of the hydraulic oil supplied from the first pump to the second actuator; a third control valve located between the second pump and the second actuator and opening and closing the valve so as to change the flow rate of the hydraulic oil supplied from the second pump to the second actuator; a first operating device to which a first instruction operation for instructing the operation of the first actuator is applied; a second operating device to which a second instruction operation for instructing the movement of the second actuator is applied; a pump control unit that adjusts the discharge amount of the first pump and the discharge amount of the second pump so that the working oil of a total target flow rate, which is the sum of a first target flow rate and a second target flow rate, is discharged from at least one of the first pump and the second pump, the first target flow rate being a target flow rate of the working oil to the first actuator determined based on the operation amount of the first command operation, and the second target flow rate being a target flow rate of the working oil to the second actuator determined based on the operation amount of the second command operation; a valve control unit, adjusting the opening of the first control valve to a first target opening determined based on the first target flow rate, adjusting the opening of the second control valve to a second target opening determined based on the second control valve target flow rate, and adjusting the opening of the third control valve to a third target opening determined based on the third control valve target flow rate, wherein the second control valve target flow rate is a target flow rate of the working oil to the second actuator via the second control valve in the second target flow rate, and the third control valve target flow rate is a target flow rate of the working oil to the second actuator via the third control valve in the second target flow rate; a condition determination unit for determining whether a preset load determination condition is satisfied, the load determination condition being a condition for determining that a first load of the first actuator is greater than a second load of the second actuator; and The speed compensation unit performs feedback control as follows: when a composite operation is performed and the condition determination unit determines that the load determination condition is satisfied, a larger correction amount is calculated as the speed difference between a target speed of the first actuator determined based on the operation amount of the first command operation, i.e., a first target speed, and an actual speed of the first actuator, i.e., a first actual speed, is greater, and the opening of the second control valve is adjusted to an opening obtained by subtracting the correction amount from the second target opening, wherein the composite operation is an operation in which the first command operation is applied to the first operating device and the second command operation is applied to the second operating device.

2. The construction machine according to claim 1, characterized in that Also includes: The first detector detects the first actual speed or a physical quantity corresponding thereto; wherein, The load determination condition is a condition in which the first actual speed detected by the first detector or a physical quantity corresponding thereto is smaller than the first target speed or a physical quantity corresponding thereto.

3. The construction machinery according to claim 2, characterized in that: The first actuator is a rotary motor, and the rotary motor is a hydraulic motor for rotating an upper rotary body configured to be rotatable in the construction machine. The first actual speed is the rotation speed of the rotary motor. The first target speed is a target rotation speed of the swing motor.

4. The construction machine according to claim 1, characterized in that Also includes: a first load detector for detecting the first load; as well as, The second load detector detects the second load; wherein, The load determination condition is a condition that the first load detected by the first load detector is larger than the second load detected by the second load detector.

5. The construction machine according to any one of claims 1 to 4, characterized in that: The speed compensation unit also performs feedback control as follows: when the composite operation is performed and the condition judgment unit determines that the load judgment condition is satisfied, a larger correction amount is calculated as the speed difference between the target speed of the second actuator determined based on the operation amount of the second instruction operation, i.e., the second target speed, and the actual speed of the second actuator, i.e., the second actual speed, is greater, and the opening of the third control valve is adjusted to an opening obtained by adding the correction amount to the third target opening.

6. The construction machine according to any one of claims 1 to 5, characterized in that: The speed compensation unit also performs feedback control as follows: when the composite operation is performed and the condition determination unit determines that the load determination condition is satisfied, a larger correction amount is calculated as the speed difference between the first target speed and the first actual speed increases, and the opening of the first control valve is adjusted to an opening obtained by adding the correction amount to the first target opening.

7. The construction machine according to any one of claims 1 to 6, characterized in that: The speed compensation unit also performs feedback control as follows: when the composite operation is performed and the condition judgment unit determines that the load judgment condition is satisfied, the sum of the actual flow rate of the working oil supplied to the first actuator, i.e., the first actual flow rate, and the actual flow rate of the working oil supplied to the second actuator, i.e., the second actual flow rate, i.e., the total actual flow rate is calculated, and a larger correction amount is calculated as the flow difference between the total target flow rate and the total actual flow rate is greater, and the discharge amount of at least one of the first pump and the second pump is adjusted according to the correction amount.

8. The construction machine according to claim 7, characterized in that: In a case where the total target flow calculated by the speed compensation unit is greater than the sum of the maximum discharge volume of the working oil that can be discharged by the first pump, i.e., the first maximum discharge volume, and the maximum discharge volume of the working oil that can be discharged by the second pump, i.e., the second maximum discharge volume, i.e., the total maximum discharge volume, the speed compensation unit corrects the first target flow and the second target flow in such a manner that the total target flow becomes less than the total maximum discharge volume while maintaining the ratio of the first target flow to the second target flow.

9. The construction machine according to claim 8, characterized in that Also includes: a first discharge pressure detector for detecting a first discharge pressure which is a discharge pressure of the working oil of the first pump; a second discharge pressure detector for detecting a discharge pressure of the working oil of the second pump, that is, a second discharge pressure; An engine driving the first pump and the second pump; as well as, An output determination unit determines the output of the engine; wherein: The speed compensation unit calculates the total maximum discharge amount based on the output of the engine and the first discharge pressure and the second discharge pressure.

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