JP6506597B2 - Hydraulic control system and construction machine - Google Patents

Description

  The present invention relates to a hydraulic control system and a construction machine, and more particularly to a hydraulic control system for driving a work device by a hydraulic actuator and a construction machine provided with the hydraulic control system.

  As a prior art of this type, for example, the technology disclosed in Patent Document 1 is known. This known technology includes an arm cloud, a bucket directional control valve parallel-parallel connected to a first hydraulic pump, a second arm directional control valve, and a second hydraulic pressure to improve operability at the time of combined operation of the bucket and the bucket. In a hydraulic drive system of a hydraulic shovel including a first arm direction control valve connected to a pump, a flow rate control device for suppressing a flow rate of pressure oil supplied to a second arm direction control valve when operating a bucket It is characterized by having. This flow control device is provided in a bypass bypass connected to the supply port of the second arm direction control valve, and is a variable throttle controlled so that the opening amount becomes smaller as the bucket operating device is operated to the cloud side. Contains.

  By configuring in this way, at the time of combined operation of the arm cloud or arm dump and the bucket cloud, the pilot pressure supplied from the pilot pump along with the operation to the cloud side of the bucket operating device that instructs the operation of the bucket Oil is supplied to the control unit of the variable throttle via an oil passage. When the hydraulic pressure by the pilot pressure oil becomes larger than the force of the spring of the variable throttle, the switching operation of the variable throttle reduces the flow rate of the hydraulic oil supplied to the second arm directional control valve, so the opening amount is small. To be controlled. The oil pressure in the bypass bypass channel connected to the supply port of the second arm direction control valve becomes high, and the pressure oil discharged from the first hydraulic pump is mainly supplied to the bucket cylinder via the bucket direction control valve. Further, the pressure oil discharged from the second hydraulic pump is supplied to the arm cylinder via the first arm direction control valve. As a result, both the bucket and the arm can be driven to perform a good combined operation of the arm cloud or arm dump and the bucket cloud.

JP, 2011-163030, A

  In the known technology, as described above, the operability at the time of combined operation of the arm cloud or the arm dump and the bucket cloud can be improved. However, since the flow rate is reduced by the variable throttle, the flow rate supplied from the pump becomes excessive to the flow rate required by the bucket operating device, and the excess flow rate is discharged to the hydraulic oil tank. Therefore, the hydraulic energy loss will increase accordingly.

  An object of the present invention is to provide a hydraulic control system capable of suppressing wasteful energy loss while securing operability of combined operation.

In order to solve the above-mentioned subject, the 1st means is a variable displacement hydraulic pump which supplies pressure oil which drives the 1st and 2nd hydraulic actuator which drives a work device, and the 1st and 2nd hydraulic actuator. A direction control device for controlling the direction and flow rate of pressure oil supplied from the variable displacement hydraulic pump to drive the first and second hydraulic actuators; and driving the first and second hydraulic actuators A hydraulic control system having first and second control levers for generating an operation signal for adjusting the amount of operation according to the amount of operation, wherein a flow rate disposed in a conduit from the variable displacement hydraulic pump to the direction control device A control device, an input device for inputting a flow rate adjustment value of the flow rate control device, and a flow rate of pressure oil passing through the flow rate control device are adjusted, and the first and second corresponding to the adjustment amount. A controller for controlling the discharge flow rate of the variable displacement hydraulic pump so as to supply the excess flow rate generated by the suppression to the larger load when the flow rate to the smaller load of the hydraulic actuators is suppressed; A load pressure sensing unit that senses a load pressure of the variable displacement hydraulic pump; an engine rotational speed sensing unit that senses a rotational speed of an engine that drives the variable displacement hydraulic pump; The first and second operation levers, the load pressure detected by the load pressure detection unit, the engine rotation speed detected by the engine rotation speed detection unit, and the flow rate adjustment value input from the input device And a controller configured to set a flow rate .

  According to the first means, the pressure oil supplied from the variable displacement hydraulic pump drives the first and second hydraulic actuators in accordance with the amount of operation of the first and second control levers, so that the combined operation is operated Sex is guaranteed. At this time, since the excess flow rate of the flow rate of the pressure oil to the smaller load is supplied to the larger load, the pressure oil discharged from the variable displacement hydraulic pump can be used without waste.

Further , according to the first means, the control device is configured based on the load pressure detection unit, the engine rotation speed detection unit, the operation amount, the load pressure, the engine rotation speed, and the flow rate adjustment value. And a controller for setting the flow rate, and the flow rate passing through the flow rate adjusting device is set electrically based on the flow rate adjustment value, so that operability can be ensured and unnecessary energy loss can be suppressed.

The second means is, in the first means, provided with a plurality of the variable displacement hydraulic pumps, and the controller is for the pressure oil passing through the flow control device corresponding to the flow adjustment value inputted from the input device. Torque distribution ratio for calculating the torque distribution ratio of the variable displacement hydraulic pump corresponding to the inflow rate adjustment unit that changes the passage flow rate, the adjustment amount of the flow rate control unit set by the inflow rate adjustment unit, and the operation amount of the operation lever Maximum torque setting that outputs the maximum value of the total torque of the plurality of hydraulic pumps corresponding to the ratio calculation unit, the operation amount of the first and second operation levers, and the engine rotational speed detected by the engine rotational speed detection unit A plurality of the variable units based on the torque distribution ratio calculated by the torque distribution ratio calculation unit and the maximum value of the total torque output from the maximum torque setting unit. From the torque distribution unit for calculating the torque of each of the quantitative hydraulic pumps, the pump load pressure of each of the plurality of variable displacement hydraulic pumps detected by the load pressure detection unit, and the torque calculated by the torque distribution unit And a pump volume calculator for calculating a pump volume of each of the plurality of variable displacement hydraulic pumps.

A third means is characterized in that, in the second means, the torque distribution ratio calculation unit corrects the torque distribution ratio of the plurality of variable displacement hydraulic pumps in accordance with the adjustment amount of the inflow rate adjustment unit. I assume.

A fourth means according to the third means, wherein the torque distribution ratio calculator sets the pressure inflow to any one of the first and second hydraulic actuators in a direction to reduce the inflow rate of the pressure oil. The adjustment amount is set such that the torque distributed to the variable displacement hydraulic pump connected with the hydraulic actuator set in the direction in which the inflow rate of oil decreases is reduced.

According to the second to fourth means, good operability can be realized by correcting the pump discharge flow rate determined in accordance with the operation amount of the operation lever in accordance with the adjustment amount of the flow rate control means. The increase in energy loss can be suppressed. At that time, since the torque distribution ratio of the plurality of variable displacement hydraulic pumps is corrected according to the adjustment amount of the flow control device, it is possible to realize a good speed balance among the plurality of hydraulic actuators.

A fifth means features a construction machine provided with the hydraulic control system according to any one of the first to fourth means.

According to the fifth means, it is possible to provide a construction machine having the effects of the first to fourth means, and to improve the operability and the energy saving property of the construction machine.

A sixth means is characterized in that in the fifth means, the input device is attached to a monitoring device provided in the construction machine.

According to the sixth means, the operator of the construction machine can operate the input device while looking at the monitor device attached, for example, in the cabin of the construction machine, so that the adjustment value can be easily adjusted without putting a burden on the operator. You can enter

  In the embodiment described later, the working device is denoted by reference numeral 30b, the first hydraulic actuator is attached to the first hydraulic actuator 16 (arm cylinder 36), and the second hydraulic actuator is attached to the second hydraulic actuator 17 (attachment drive actuator [bucket In the cylinder 37], the variable displacement hydraulic pump is the second hydraulic pump 3, the direction control device is the second direction control valve 13, the first operating lever is the first operating lever 18, and the second operating lever is In the second control lever 19, the flow control device is the flow control valve 15, the input device is the code 21b, the load pressure detector is the second pump load pressure detector 11, the engine speed detector is the controller 1a, the controller Is the second pump load pressure detection unit 11, the engine speed detection unit 1a and the controller 20, The displacement type hydraulic pump is used for the first variable displacement type hydraulic pump 2 and the second variable displacement type hydraulic pump 3, the inflow rate adjustment unit is denoted by 20a, the torque distribution ratio operation unit is denoted by 20b, and the maximum torque setting unit is denoted by 20c The torque distribution unit corresponds to the code 20 d, the pump volume calculation unit to the code 20 e, and the monitor device to the monitor unit 21, respectively.

  According to the present invention, wasteful energy loss can be suppressed while securing a combined operation.

BRIEF DESCRIPTION OF THE DRAWINGS It is a perspective view which shows the whole structure of the hydraulic shovel which concerns on embodiment of this invention. It is a figure showing the system configuration of the hydraulic control system of the hydraulic shovel concerning this embodiment. It is a figure which shows the flow of control of the hydraulic control system shown in FIG. It is a flowchart which shows the processing procedure of the controller shown in FIG. It is a figure which shows the processing content of the 1st step in FIG. It is a figure which shows the processing content of the 2nd step in FIG.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a perspective view showing an entire configuration of a hydraulic shovel according to an embodiment of the present invention. In FIG. 1, the hydraulic shovel according to the present embodiment includes a traveling body 31 and a swing body 30. The revolving unit 30 is disposed on the traveling unit 31 and constitutes a vehicle body. The swing body 30 includes an operation chamber 30a, a work device 30b, a motor (not shown), a control valve, and a swing device. The working device 30 b includes a boom 32, a boom cylinder 35, an arm 33, an arm cylinder 36, a bucket (attachment 34) and a bucket cylinder 37.

  The boom 32 is rotatably attached to the revolving unit 30 in the vertical direction, and is driven by the boom cylinder 35. The arm 33 is vertically rotatably attached to the tip of the boom 32 and driven by an arm cylinder 36. Further, at the tip of the arm 33, for example, a bucket (not shown) is attached so as to be rotatable in the vertical direction, and a bucket cylinder 37 for controlling the posture of the bucket is attached. The bucket is replaced with an attachment 34 according to the work content. FIG. 1 shows an example in which the bucket is replaced by, for example, a small crusher. In addition, inside the small crusher, an actuator (not shown) for driving the small crusher is provided. In addition to the bucket or small crusher, the attachment 34 may be, for example, a large crusher, a breaker, or a grapple.

  FIG. 2 is a diagram showing a system configuration of a hydraulic control system of the hydraulic shovel according to the present embodiment. The hydraulic control system according to the present embodiment includes an engine 1, first and second hydraulic pumps 2 and 3, a pilot pump 4, first and second hydraulic actuators 16 and 17, first and second operation levers 18 and 19, and First, second and third directional control valves 12, 13 and 14 are provided.

  The first and second hydraulic pumps 2 and 3 are variable displacement hydraulic pumps and are connected to the engine 1. The pilot pump 4 is a fixed displacement hydraulic pump that is connected to the engine 1 and generates pressure oil for control signals. The first and second hydraulic actuators 16 and 17 are driven by pressure oil discharged from the first and second hydraulic pumps 2 and 3 respectively. The first and second control levers 18 and 19 generate operation signal pressure corresponding to the amount of operation so as to drive the first and second hydraulic actuators 16 and 17, respectively. The first to third directional control valves 12, 13, 14 correspond to pressure oil to the first and second hydraulic actuators 16, 17 in response to the operation signal pressure outputted from the first and second control levers 18, 19. Control the flow rate and direction of the In FIG. 2, the first hydraulic actuator 16 is, for example, the arm cylinder 36 in FIG. 1, and the second hydraulic actuator 17 is, for example, a bucket cylinder 37 as an attachment driving actuator.

  The displacements of the first and second hydraulic pumps 2 and 3 are controlled by first and second pump regulators 5 and 6, respectively. The first and second pump regulators 5 and 6 are driven according to the outputs from the first and second regulator control devices 7 and 8, respectively. The flow of pressure oil flowing from the first hydraulic pump 2 into the first hydraulic actuator 16 is controlled by the first direction control valve 12, and the flow of pressure oil flowing from the second hydraulic pump 3 into the first hydraulic actuator 16 is It is controlled by the second direction control valve 13. A flow control valve 15 is disposed between the second hydraulic pump 3 and the second direction control valve 13 to limit the flow of pressure oil flowing from the second hydraulic pump 3 into the first hydraulic actuator 16. The flow control valve 15 is driven by a flow control valve controller 9.

  The flow of pressure oil flowing from the second hydraulic pump 3 into the second hydraulic actuator 17 is controlled by the third direction control valve 14. The second direction control valve 13 and the third direction valve 14 are connected in parallel via the second pump line 3a. The first to third directional control valves 12, 13, 14 are open center type spool valves. When the first and second control levers 18 and 19 are not operated, pressure oil discharged from the first hydraulic pump 2 is led to the hydraulic oil tank 22 through the center bypass line of the first direction control valve 12. The pressure oil discharged from the second hydraulic pump 3 passes through the center bypass line of the second direction control valve 13 to the hydraulic oil tank 22 or the center bypass line of the second and third direction control valves 13 and 14. It is led to the hydraulic oil tank 22 through it, and the consumption of unnecessary energy is suppressed. Further, between the first and second hydraulic pumps 2 and 3 and the first to third directional control valves 12, 13 and 14, in order to prevent the backflow of pressure oil from the first and second hydraulic actuators 16 and 17. Check valves 23 are provided respectively.

  The first and second hydraulic pumps 2, 3 are provided with first and second pump load pressure detection units 10, 11, respectively, and the engine 1 is provided with an engine rotational speed detection unit 1a. The first and second operation levers 18 and 19 are provided with first to fourth lever operation amount detectors 18a, 18b, 19a, 19b for detecting the operation amount of the lever. The signal lines from the detection units 10, 11, 1a, 18a, 18b, 19a and 19b are connected to the controller 20, and the detection output is input to the controller 20. The monitor unit 21 includes a display device 21 a for displaying a screen and an input device 21 b in which a plurality of operation keys are arranged, and the input device 21 b is connected to the controller 20.

  FIG. 3 is a diagram showing a control flow of the hydraulic control system shown in FIG. In the figure, the controller 20 includes an inflow rate adjustment unit 20a, a torque distribution ratio calculation unit 20b, a maximum torque setting unit 20c, a torque distribution unit 20d, and a pump volume calculation unit 20e. Each of the functional units 20a, 20b, 20c, 20d, and 20e is set in the software of the controller 20, and implements the functions of the respective functional units by executing the software. The controller 20 includes a central processing unit (CPU), a random access memory (RAM), and a read only memory (ROM). The CPU reads software from the ROM, or reads it from a server via the HDD or the Internet, and expands it in the RAM. The function is realized by executing an operation defined by software while using the RAM as a data buffer.

  In the controller 20, the pump pressure load from the first and second pump load pressure detectors 10, 11 and the first to fourth lever operation amount detectors 18a, 18b, 19a, 19b from the first and second operation levers 18 respectively. , 19 are input from the engine speed detector 1a to the engine speed. In response to this input, the above-described units of the controller 20 function to instruct the first and second regulator control units 7 and 8 to output according to the displacements of the first and second hydraulic pumps 2 and 3.

  Here, the inflow rate adjustment unit 20a changes the flow rate of the flow control valve 15 in accordance with the adjustment value input from the input device 21b. The torque distribution ratio calculation unit 20b uses the adjustment amount of the flow control valve 15 set by the inflow rate adjustment unit 20a and the lever operation amount sensed by the first to fourth lever operation amount detectors 18a, 18b, 19a, 19b. The torque distribution ratio of the corresponding first and second hydraulic pumps 2 and 3 is calculated and output.

  The maximum torque setting unit 20c is a first corresponding to the lever operation amount detected by the first to fourth lever operation amount detectors 18a, 18b, 19a, 19b and the engine rotational speed detected by the engine rotational speed detector 1a. And the maximum value of the total torque of the second hydraulic pumps 2 and 3 is output. The torque distribution unit 20d calculates the torques of the first and second hydraulic pumps 2 and 3 from the torque distribution ratio output by the torque distribution ratio calculation unit 20b and the maximum torque output by the maximum torque setting unit 20c. The pump volume calculator 20e calculates a pump volume from the pump load pressure sensed by the first and second pump load pressure sensors 10 and 11 and the torque calculated by the torque distributor 20d. Here, the torque is the product of flow rate and pressure.

  FIG. 4 is a flowchart showing the processing procedure of the controller 20 shown in FIG. In this processing procedure, the processing of the first stage to the fifth stage described below is sequentially performed.

In this procedure,
In the first step (step S100), the maximum torque setting unit 20c obtains the maximum value of the total torque of the first and second hydraulic pumps 2 and 3.
In the second step (step S200), the torque distribution ratio calculation unit 20b determines the torque distribution ratio of the first and second hydraulic pumps 2 and 3.
In the third step (step S300), the torque distribution unit 20d determines the torque of the first and second hydraulic pumps 2 and 3.
In a fourth step (step S400), the volumes of the first and second hydraulic pumps 2 and 3 are determined by the pump volume calculator 20e.
In the fifth step (step S500), the outputs of the first and second regulator control units 7 and 8 are controlled to be the pump volume obtained in the fourth step S400.
Processing is executed.

  FIG. 5 is a diagram showing processing contents of the first step (procedure S100) in FIG. The first stage (procedure S100) includes first to fifth processes (procedure S101 to S105).

In the first to fifth processes,
In the first process (step S101), torque (vertical axis) not exceeding the allowable torque of the engine is calculated from the engine rotational speed (horizontal axis) detected by the engine rotational speed detection unit 1a.
In the second process (step S102), the required torque (vertical axis) is calculated from the arm operation amount (horizontal axis) sensed by the third and fourth lever operation amount detectors 19a and 19b.
In the third process (step S103), the required torque (vertical axis) is calculated from the attachment operation amount (horizontal axis) sensed by the first and second lever operation amount detectors 18a and 18b.
In the fourth process (step S104), the required torques output from the second process S102 and the third process S103 are compared to output the maximum value.
In the fifth process (step S105), the torques output in the first process S101 and the fourth process S104 are compared to output the minimum value.
Processing is executed.

  That is, by executing the first to fifth processes (steps S101 to S105), the maximum torque of the total torque of the first and second hydraulic pumps 2 and 3 is calculated from the engine speed, the arm operation amount and the attachment operation amount. Calculate

  FIG. 6 is a diagram showing processing contents of the second step (procedure S200) in FIG. The second stage (procedure S200) includes sixth to eleventh processes (procedure S201 to S206).

In the sixth to eleventh processes,
· In the sixth process (step S201), the required torque T1 (vertical axis) of the first hydraulic pump 2 from the arm operating amount (horizontal axis) 33a sensed by the first and second lever operation amount detecting units 18a and 18b Calculate The sixth process (step S201) is a process performed on the first hydraulic pump 2 side.
In the seventh process (step S202), the correction value dT of the required torque in the ninth process (step S202) described later is calculated from the inflow rate adjustment amount 21c of the flow control valve 15 input from the input device 21b.
In the eighth process (step S203), the required torque (vertical axis) of the second hydraulic pump 3 is calculated from the attachment operation amount (horizontal axis) 34a detected by the third and fourth lever operation amount detectors 19a and 19b. calculate.
In the ninth process (step S204), the required torque (vertical axis) of the second hydraulic pump 3 is calculated from the arm operation amount (horizontal axis) sensed by the first and second lever operation amount detectors 18a and 18b. Do.
In the tenth process (step S205), the torques output from the eighth process (step S203) and the ninth process (step S204) are summed to calculate the total required torque T2 of the second hydraulic pump 3 .
In an eleventh process (step S206), the ratio between the required torque T1 of the first hydraulic pump 2 and the required torque T2 of the second hydraulic pump 3 is calculated.
Processing is executed.
The seventh to tenth processes (procedures S202 to S205) are processes executed on the second hydraulic pump 3 side.

  In the case where the operation combining the first and second hydraulic actuators 16 and 17 according to the operation of the present embodiment configured as described above, that is, the operation combining the bucket cylinder (attachment drive actuator) 37 and the arm cylinder 36 is performed This will be described by taking as an example.

  A feature of the present embodiment is that a flow control valve 15 for limiting the inflowing flow rate to the first hydraulic actuator (arm cylinder 36) 16 is provided in a pipeline flowing from the second hydraulic pump 3 to the second direction control valve 13. The flow control of the flow control valve 15 is controlled by the controller 20 based on the adjustment value input from the input device 21 b. The operation according to this configuration is as follows.

  That is, when the first and second control levers 18 and 19 are operated in the left direction in FIG. 2, the first to third direction control valves 12, 13 and 14 stroke to the right and discharge from the first hydraulic pump 2 The pressurized oil passes through the first direction control valve 12 to the bottom side of the first hydraulic actuator 16, and the pressure oil discharged from the second hydraulic pump 3 passes through the second and third direction control valves 13 and 14. The flow is divided into the bottom side of the first hydraulic actuator 16 and the second hydraulic actuator 17. At this time, when the adjustment value in the direction to decrease the flow rate passing through the flow control valve 15 is input from the input device 21b, the controller 20 controls the output of the flow control valve control unit 9 to squeeze the flow control valve 15. . Therefore, the flow rate from the second hydraulic pump 3 to the first hydraulic actuator 16 through the second direction control valve 13 is restricted, and flows into the second hydraulic actuator 17 through the third direction control valve 14 relatively. Flow rate increases.

  The amount of operation of the first hydraulic actuator 16 and the second hydraulic actuator 17 sensed by the first lever operation amount sensing portion 18 a of the first operation lever 18 and the third lever operation amount sensing portion 19 a of the second operation lever 19 is the controller 20. The controller 20 calculates the maximum torques of the first and second hydraulic pumps 2 and 3 in the first step (step S100). Subsequently, the controller 20 calculates the torque distribution ratio (ratio) of the first and second hydraulic pumps 2 and 3 in the second step (procedure S200).

  When limiting the flow rate flowing from the second hydraulic pump 3 to the first hydraulic actuator 16 in the second step (step S200), the seventh process (corresponding to the inflow rate adjustment amount input from the input device 21b) The torque correction value dT is calculated in step S202), and the required torque of the second hydraulic pump 3 calculated corresponding to the arm operation amount 33a in the ninth process (step S204) is corrected in the decreasing direction. Therefore, the ratio of the torque distributed to the second hydraulic pump 3 decreases. Subsequently, the controller 20 calculates the torques of the first and second hydraulic pumps 2 and 3 in the third step (step S300), and calculates the torques of the first and second hydraulic pumps 2 and 3 in the fourth step (step S400). Calculate the volume. Thereafter, the controller 20 controls the outputs of the first and third regulator control means 7 and 8 so as to obtain the pump volume calculated in the fourth step (step S400) in the fifth step (step S500).

  Here, for comparison, the operation at the time of combined operation of the second hydraulic actuator 17 and the first hydraulic actuator 16 in the case where the flow control valve 15 and the control device thereof in the present embodiment are not provided will be described.

  That is, when the first and second control levers 18 and 19 are operated in the left direction in FIG. 2, the first to third direction control valves 12, 13 and 14 stroke to the right and discharge from the first hydraulic pump 2 The pressurized oil passes through the first direction control valve 12 to the bottom side of the first hydraulic actuator 16, and the pressure oil discharged from the second hydraulic pump 3 passes through the second and third direction control valves 13 and 14. The flow is divided between the bottom side of the first hydraulic actuator 16 and the second hydraulic actuator 17. At this time, the controller 20 flows into the first hydraulic actuator 16 from the second hydraulic pump 3 through the second direction control valve 13 in order to control the output of the flow control valve control unit 9 so as to open the flow control valve 15. The flow rate is not limited.

  When the operation amounts of the first hydraulic actuator 16 and the second hydraulic actuator 17 sensed by the first lever operation amount detection unit 18a and the third lever operation amount detection unit 19a of the first operation lever 18 are transmitted to the controller 20, The controller 20 calculates the maximum torques of the first and second hydraulic pumps 2 and 3 in the first step (procedure S100). Subsequently, the controller 20 calculates the torque distribution ratio (ratio) of the first and second hydraulic pumps 2 and 3 in the second step (procedure S200). In the second step (step S200), when the flow rate from the second hydraulic pump 3 to the first hydraulic actuator 16 is not limited, the torque correction value dT calculated by the seventh process (step S202) is "0". Thus, the required torque of the second hydraulic pump 3 calculated corresponding to the arm operation amount in the ninth process (step S204) is not corrected.

  Next, the controller 20 proceeds to the third step (step S300), calculates the torques of the first and second hydraulic pumps 2, 3, and calculates the first and second hydraulic pumps 2, 2, and 4 in the fourth step (step S400). Calculate the volume of 3. Thereafter, the controller 20 controls the outputs of the first and second regulator control units 7 and 8 so as to obtain the pump volume calculated in the fourth step (step S400) in the fifth step (step S500).

  In the present invention, the second hydraulic pump 3, the second direction control valve 13, the arm cylinder 16, the attachment drive actuator 17, the flow control valve 15, the second pump load pressure sensing unit 11, the first and second operation levers 18, 19, the controller 20 and the input device 21b (see FIG. 2).

  Therefore, according to the present invention, for example, first and second hydraulic actuators (arm cylinder 36 and attachment driving actuator [bucket cylinder 37]) 16 and 17 for driving the working device 30b, and first and second hydraulic actuators 16 and 17 Control the direction of pressure oil sent from the second variable displacement hydraulic pump 3 for driving the second variable displacement hydraulic pump 3 and the second variable displacement hydraulic pump 16, and second direction control to be supplied to the first and second hydraulic actuators 16 and 17 Hydraulic pressure having a valve (direction control device) 13 and first and second control levers 18 and 19 generating operation signals for driving the first and second hydraulic actuators 16 and 17 according to the amount of operation. In the control system, a flow control valve (flow control device) disposed in a line from the second variable displacement hydraulic pump 3 to the second direction control valve 13 5 and the input device 21b for inputting the flow rate adjustment value of the flow control valve 15, and the passing flow rate of the flow control valve 15 are adjusted, and the load of the first and second hydraulic actuators 16, 17 is adjusted according to the adjustment amount. Control device for controlling the discharge flow rate of the second variable displacement hydraulic pump 3 to supply the excess flow rate generated by the suppression to the larger load when the flow rate to the smaller one is suppressed (second pump load pressure detection unit 11. It is also possible to implement as a hydraulic control system provided with an engine speed detector 1a and a controller 20).

  As described above, according to the present embodiment, when the passing flow rate of the flow control valve 15 is adjusted in accordance with the attachment to be used and the preference of the operating operator, the first corresponding to the adjustment amount of the flow control valve 15 By correcting the torque distribution ratio of the second hydraulic pump 2 and 3, it is possible to realize a good speed balance between the first and second hydraulic actuators 16 and 17. In addition, it is possible to suppress the generation of useless energy loss. At that time, the flow control valve 15 restricts the flow rate of the pressure oil sent to the second direction control valve 13, and as a result, the flow rate of the second hydraulic pump 3 can be reduced. Can also be planned.

  The present embodiment shows an example of a configuration for describing the present invention, and does not limit the configuration of the present invention. That is, in the present embodiment, the case where the first hydraulic actuator (arm cylinder 36) 16 and the second hydraulic actuator (attachment driving actuator [bucket cylinder 37]) 17 are operated in combination is described. The combination of actuators is not limited to this, and may be various depending on the construction of the construction machine.

  Further, in the present embodiment, the flow control valve 15 is provided only in front of a specific directional control valve (the second directional control valve 13), but it may also be provided in front of other directional control valves according to the target operation. A flow control valve may be provided to correct the torque distribution ratio of the pump.

  Furthermore, in the present embodiment, although the passing flow rate of the flow control valve 15 is manually adjusted, the passing flow rate of the flow control valve 15 is automatically adjusted according to the lever operation amount or the pump load pressure. It can be configured as

  As described above, the present invention is not limited to the above-described embodiment, and various modifications are possible without departing from the scope of the present invention, and the technical matters included in the technical concept described in the claims. All are the subject of the present invention. Although the above embodiment shows a preferred example, various alternatives, modifications, variations or improvements can be realized by those skilled in the art from the contents disclosed herein. These are included in the technical scope described in an attached claim.

1a Engine rotational speed detector 2 first variable displacement hydraulic pump 3 second hydraulic pump 11 second pump load pressure detector 13 second direction control valve 15 flow control valve 16 first hydraulic actuator 17 second hydraulic actuator 18 first Control lever 19 second control lever 20 controller 20a inflow rate adjustment unit 20b torque distribution ratio calculation unit 20c maximum torque setting unit 20d torque distribution unit 20e pump volume calculation unit 21 monitor unit 21b input device 30b work device 36 arm cylinder 37 bucket cylinder ( Attachment drive actuator)

Claims (6)

First and second hydraulic actuators for driving the work device;
A variable displacement hydraulic pump for supplying pressure oil for driving the first and second hydraulic actuators;
A direction control device that controls the direction and flow rate of pressure oil supplied from the variable displacement hydraulic pump, and supplies the first and second hydraulic actuators;
A hydraulic control system comprising: first and second control levers for generating operation signals for driving the first and second hydraulic actuators in accordance with the amount of operation;
A flow control device disposed in a pipeline extending from the variable displacement hydraulic pump to the direction control device;
An input device for inputting a flow rate adjustment value of the flow rate control device;
An excess caused by the suppression when the flow rate of the hydraulic oil passing through the flow control device is adjusted and the flow rate to the smaller load of the first and second hydraulic actuators is suppressed according to the adjustment amount. comprising a control device for controlling the discharge flow rate of the variable displacement hydraulic pump to supply the flow rate to the larger of the load, and
The controller
A load pressure detection unit that detects a load pressure of the variable displacement hydraulic pump;
An engine rotational speed detection unit that detects the rotational speed of an engine that drives the variable displacement hydraulic pump;
Based on the operation amounts of the first and second operation levers, the load pressure detected by the load pressure detection unit, the engine rotation speed detected by the engine rotation speed detection unit, and the flow rate adjustment value input from the input device A controller for setting the flow rate;
Hydraulic control system, which comprises a. In the hydraulic control system according to claim 1 ,
A plurality of variable displacement hydraulic pumps;
The controller
An inflow rate adjustment unit that changes a flow rate of pressure oil passing through the flow rate control device according to the adjustment value input from the input device;
A torque distribution ratio calculation unit that calculates a torque distribution ratio of the variable displacement hydraulic pump corresponding to the adjustment amount of the flow control device set by the inflow rate adjustment unit and the operation amount of the operation lever;
A maximum torque setting unit that outputs the maximum value of the total torque of the plurality of variable displacement hydraulic pumps corresponding to the operation amounts of the first and second operation levers and the engine rotation speed detected by the engine rotation speed detection unit; ,
A torque distribution unit that calculates the torque of each of the plurality of variable displacement hydraulic pumps based on the torque distribution ratio calculated by the torque distribution ratio calculation unit and the maximum value of the total torque output from the maximum torque setting unit When,
The pump volume of each of the plurality of variable displacement hydraulic pumps is calculated from the pump load pressure of each of the plurality of variable displacement hydraulic pumps detected by the load pressure detection unit and the torque calculated by the torque distribution unit A pump volume calculator;
A hydraulic control system comprising: In the hydraulic control system according to claim 2 ,
The hydraulic control system, wherein the torque distribution ratio calculation unit corrects the torque distribution ratio of the plurality of variable displacement hydraulic pumps in accordance with the adjustment amount of the inflow rate adjustment unit. In the hydraulic control system according to claim 3 ,
When the torque distribution ratio calculation unit is set in a direction to reduce the inflow rate of the pressure oil to one of the first and second hydraulic actuators, the hydraulic pressure set in the direction to reduce the inflow rate of the pressure oil A hydraulic control system, wherein the adjustment amount is set such that a torque distributed to the variable displacement hydraulic pump to which an actuator is connected is reduced. A construction machine comprising the hydraulic control system according to any one of claims 1 to 4 . In the construction machine according to claim 5 ,
A construction machine characterized in that the input device is attached to a monitor device provided in the construction machine.