WO2018207268A1

WO2018207268A1 - Work machine

Info

Publication number: WO2018207268A1
Application number: PCT/JP2017/017600
Authority: WO
Inventors: 裕昭天野; 井村　進也; 真司西川; 真史日田
Original assignee: 日立建機株式会社
Priority date: 2017-05-09
Filing date: 2017-05-09
Publication date: 2018-11-15
Also published as: JPWO2018207268A1; JP6788733B2

Abstract

A work machine provided with: a regulator (42) for controlling the pump capacity of a variable capacity hydraulic pump (41) on the basis of a pump control signal generated according to the operation amount of an operation lever device (52) for a bucket (35); a proportional electromagnetic valve (45) that is capable of adjusting the pump control signal input to the regulator; and a controller for controlling the proportional electromagnetic valve (45) on the basis of the operation amount of the operation lever device (52). The controller is able to switch to either a normal mode in which adjustment of the pump control signal is performed by the signal adjustment valve or a responsiveness-priority mode in which adjustment of the pump control signal by the signal adjustment valve is not performed. As a result, it is possible to achieve both reduction of pressure loss and flow loss, which result from control of the flow discharged from the hydraulic pump, and responsiveness of a hydraulic actuator with intermittent, sudden lever operations.

Description

Work machine

The present invention relates to a work machine.

In a working machine such as a hydraulic excavator, a hydraulic pump is generally driven by a prime mover, and a hydraulic actuator such as a hydraulic cylinder is driven by pressure oil discharged from the hydraulic pump. The speed and direction of operation of the hydraulic actuator are performed by controlling the direction and flow rate of the pressure oil supplied from the hydraulic pump to the hydraulic actuator by a direction control valve that operates in conjunction with an operation lever device provided in the cab. .

In recent years, there has been an increasing need for lower fuel consumption of work machines from the viewpoint of energy saving and protection of the global environment, and the loss of hydraulic energy from the hydraulic pump to the hydraulic actuator has been minimized. Since the hydraulic energy is the product of the pressure and volume of the pressure oil used, in order to reduce energy loss, the pressure loss from the pump discharge pressure to the hydraulic actuator inlet pressure, or the hydraulic pump discharge flow rate and the hydraulic actuator It is conceivable to reduce the flow rate loss, which is the difference in the inlet flow rate.

As a method of reducing the flow rate loss, for example, in a fine operation region of a lever operation amount where a large amount of flow rate is not required for the hydraulic actuator, an unnecessary pump discharge flow rate is reduced by reducing the discharge flow rate of the hydraulic pump. It is known to reduce the loss of bleed-off flow that is discarded. Further, as an example of further reducing the flow loss, for example, in Patent Document 1, the pump reference flow rate according to the lever operation amount is adjusted to the minimum necessary pump discharge flow rate according to the opening of the bleed-off valve. A technique for minimizing pressure loss and bleed-off flow loss without deteriorating operability is disclosed.

Patent No. 5886976

However, the above prior art has the following problems.

The response of increase / decrease in the discharge flow rate in the variable displacement hydraulic pump tends to be slower than the response of the directional control valve or electronically controlled bleed-off valve. Therefore, since it takes time until the discharge flow rate of the hydraulic pump reaches an appropriate discharge flow rate with respect to the opening of the directional control valve and the bleed-off valve, the discharge pressure of the hydraulic pump does not increase until it overcomes the load pressure of the hydraulic actuator. There is a problem that the operation of the hydraulic actuator is delayed. In other words, when the operation lever is operated intermittently and quickly, the operation lever is returned before the pump flow rate finishes increasing, so the pump flow rate is less than in the steady operation, and the operation of the hydraulic actuator becomes extremely worse. There is concern. In particular, when the flow control signal pressure of a hydraulic pump is generated by a solenoid valve, the pump control signal pressure changes suddenly due to a delay in control of the solenoid valve or a decrease in signal pressure due to pressure loss when passing through the solenoid valve. There was a case that could not be done.

The present invention has been made in view of the above, and is an operation capable of achieving both reduction in pressure loss and flow loss by controlling the discharge flow rate of the hydraulic pump and responsiveness of the hydraulic actuator in intermittent sudden lever operation. The purpose is to provide a machine.

The present application includes a plurality of means for solving the above-described problems. For example, a variable displacement hydraulic pump driven by a prime mover and a plurality of driven members are rotatably connected. A multi-joint type front working machine, a plurality of hydraulic actuators driven by pressure oil discharged from the hydraulic pump and respectively driving the plurality of driven members, and from the hydraulic pump to the plurality of hydraulic actuators, respectively. A plurality of directional control valves for controlling the direction and flow rate of the supplied pressure oil, a plurality of operating devices for controlling the plurality of directional switching valves, and an operation amount of at least one operating device among the plurality of operating devices. Based on one or more operation amount detection devices to be detected and a pump control signal generated according to an operation amount of at least one operation device among the plurality of operation devices. The regulator that controls the pump volume of the hydraulic pump, the signal adjustment valve that can adjust the pump control signal input to the regulator, and the operation that detects the operation amount of the operating device related to the generation of the pump control signal A controller that controls the signal adjustment valve based on a detection result of an operation amount from at least one operation amount detection device of the amount detection devices, and the controller adjusts the pump control signal by the signal adjustment valve. It is possible to switch between the normal mode in which the control is performed and the response priority mode in which the pump control signal is not adjusted by the signal adjustment valve.

According to the present invention, it is possible to achieve both reduction in pressure loss and flow rate loss by controlling the discharge flow rate of the hydraulic pump, and responsiveness of the hydraulic actuator in intermittent sudden lever operation.

It is a side view which shows typically the appearance of a hydraulic excavator which is an example of the working machine concerning a 1st embodiment. It is a figure which extracts and shows typically the principal part of the hydraulic circuit system which concerns on 1st Embodiment. It is a functional block diagram which shows the calculation content of the pump target volume in a controller. It is a functional block diagram which shows the detail of the processing content of a pump target volume calculating part. It is a flowchart explaining the processing content in the responsiveness priority mode switching part. It is a functional block diagram which shows the calculation content of the pump target volume in the controller of the modification of 1st Embodiment. It is a figure which shows an example of the setting menu structure displayed on the monitor (display apparatus) of the input / output device in the modification of 1st Embodiment. It is a figure which shows an example of the validity / invalidity determination table for determining the possibility of switching to the responsiveness priority mode for every work mode in the modification of 1st Embodiment. It is a figure which extracts and shows typically the principal part of the hydraulic circuit system which concerns on 2nd Embodiment. It is a functional block diagram which shows the calculation content of the pump target volume in the controller of 2nd Embodiment.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In this embodiment, as an example of a working machine, a hydraulic excavator provided with a bucket as a work tool at the tip of a front device (front working machine) will be described as an example. However, the present invention is applied to a hydraulic excavator provided with an attachment other than a bucket. The invention can also be applied.

<First Embodiment>
A first embodiment of the present invention will be described with reference to FIGS.

FIG. 1 is a side view schematically showing the appearance of a hydraulic excavator that is an example of a working machine according to the present embodiment.

In FIG. 1, a hydraulic excavator 100 is a multi-joint type front device (front) that is configured by connecting a plurality of driven members (boom 31, arm 33, bucket (work implement) 35) that rotate in the vertical direction. Working machine) 30 and an upper swing body 20 and a lower traveling body 10 constituting the vehicle body, and the upper swing body 20 is provided so as to be rotatable with respect to the lower traveling body 10. The upper swing body 20 is configured by disposing each member on a swing frame 21 serving as a base, and the swing frame 21 constituting the upper swing body 20 can swing with respect to the lower traveling body 10. Further, the base end of the boom 31 of the front device 30 is supported by the front portion of the upper swing body 20 so as to be rotatable in the vertical direction, and one end of the arm 33 is an end (tip) different from the base end of the boom 31. The bucket 35 is supported at the other end of the arm 33 so as to be rotatable in the vertical direction.

The lower traveling body 10 includes a pair of crawlers 11a (11b) wound around a pair of left and right crawler frames 12a (12b), and traveling hydraulic motors 13a (13b) that respectively drive the crawlers 11a (11b). ing. In addition, about each structure of the lower traveling body 10, only one structure of right-and-left pair is illustrated and attached | subjected and a code | symbol is attached | subjected about the other structure, and only the code | symbol in brackets is attached in the figure, and illustration is abbreviate | omitted To do.

The boom 31, the arm 33, the bucket 35, and the lower traveling body 10 are driven by a boom cylinder 32, an arm cylinder 34, a bucket cylinder 36, and left and right traveling hydraulic motors 13a (13b), which are hydraulic actuators. Similarly, the upper swing body 20 is also driven by a swing hydraulic motor 27 that is a hydraulic actuator via a speed reduction mechanism 26 and performs a swing operation on the lower traveling body 10.

On the revolving frame 21 constituting the upper revolving structure 20, the engine 22 as a prime mover, the boom cylinder 32, the arm cylinder 34, the bucket cylinder 36, the revolving hydraulic motor 27, the left and right traveling hydraulic motors 13a (13b), etc. A hydraulic circuit system 40 for driving the hydraulic actuator is mounted.

FIG. 2 is a diagram schematically showing an essential part of the hydraulic circuit system according to the present embodiment. In FIG. 2, only the bucket cylinder 36 and its related configuration are shown as representatives among the plurality of hydraulic actuators, and the other hydraulic actuators and their related configurations are not shown for simplicity of explanation.

In FIG. 2, a hydraulic circuit system 40 includes a variable displacement hydraulic pump 41 and a fixed displacement pilot pump (pilot hydraulic source) 49 driven by the engine 22, and a hydraulic oil tank that is a hydraulic oil supply source of the hydraulic pump. 48 and an operation pilot pressure (operation signal) guided from the operation lever device 52 for operating the bucket through the pilot lines L1 and L2, is supplied from the hydraulic pump 41 to the hydraulic actuator (bucket cylinder) 36 through the discharge line L4. A control valve (direction switching valve) 44 for controlling the direction and flow rate of the hydraulic oil and an operation pilot pressure sensor (operation) for detecting the operation amount of the operation lever device 52 by detecting the operation pilot pressure of the pilot lines L1 and L2. (Quantity detection device) SE1, SE2 and operation lever device 52 operation The regulator 42 that controls the pump volume (tilt angle) of the hydraulic pump 41 based on the pilot pressure (pump control signal) generated according to the pressure, and the pump control signal that is input from the operation lever device 52 to the regulator 42 is reduced. The proportional electromagnetic valve 45 (signal adjusting valve) that can be adjusted by the operation, and the controller 60 that controls the proportional electromagnetic valve 45 based on the detection result of the operation amount from the operation pilot pressure sensors SE1 and SE2. . In the discharge line L4 from the hydraulic pump 41, a relief valve 41a that defines the upper limit of the discharge pressure of the hydraulic pump 41 is installed.

A driver's cab 23 (cabinet: see FIG. 1) in which an operator is boarded is provided with a plurality of operation lever devices (operation devices) that output operation signals for operating the

hydraulic actuators

27, 32, 34, and 36. . Among these, the operation lever device 52 for operating the bucket generates an operation signal output to the pilot lines L1 and L2 based on the operation lever 52a tilted by the operator and the lever operation amount and operation direction of the operation lever 52a. And an operation signal generation unit 52b. When the operation lever 52a is operated, the operation signal generation unit 52b operates one of a pair of pressure reducing valves (not shown) according to the operation direction and the operation amount, and sets the pilot primary pressure of the pilot pump 49 to the operation amount. The pressure is reduced to the corresponding pilot pressure and output as an operation signal (operation pilot pressure) to one of the pilot lines L1 and L2. The pilot lines L1 and L2 include an operation pilot pressure sensor (operation amount detection device) SE1, which detects an operation amount of the operation lever 52a (hereinafter also referred to as an operation amount of the operation lever device 52) by detecting an operation pilot pressure. SE2 is arranged, the operation signal of the bucket cloud by the operation lever 52a is detected by the operation pilot pressure sensor SE1, and the operation signal of the bucket dump by the operation lever 52a is detected by the operation pilot pressure sensor SE2, and each is sent to the controller 60. Sent. The operation lever device may be an electric signal system, and the lever tilt amount corresponding to the operation signal from the operation lever device 52 operated by the operator (that is, the lever operation amount) is electrically output to the controller 60. The pilot pressure for driving the

hydraulic actuators

27, 32, 34, 36 may be controlled by controlling the electromagnetic proportional valve or the like with the controller 60 based on the detected lever operation amount.

An operation of the bucket 35 is assigned to the operation lever device 52, and when the bucket cloud is operated by the operation lever device 52, the control valve 44 is moved to the right side in FIG. 2 (that is, as shown in FIG. 2) according to the operation amount. ) And the pressure oil discharged from the hydraulic pump 41 is supplied to the bottom chamber (bucket cylinder bottom chamber) 36a of the bucket cylinder 36 via the control valve 44 and the rod chamber (bucket cylinder) of the bucket cylinder 36. The pressure oil in the rod chamber 36 b flows into the hydraulic oil tank 48 through the control valve 44, whereby the bucket cylinder 36 is extended and the bucket cloud operation is performed. Similarly, when the bucket dump is operated by the operation lever device 52, the control valve 44 is driven to the left in FIG. 2 according to the operation amount, and the pressure oil discharged from the hydraulic pump 41 passes through the control valve 44. While being supplied to the bucket cylinder rod chamber 36b, the pressure oil in the bucket cylinder bottom chamber 36a flows to the hydraulic oil tank 48 via the control valve 44, whereby the bucket cylinder 36 is shortened and the bucket dump operation is performed. When the operation by the operation lever device 52 is not performed, the control valve 44 is in the neutral position, and the pressure oil discharged from the hydraulic pump 41 returns to the hydraulic oil tank 48 via the center bypass line L5.

A check valve 44 a is provided on the upstream side of the supply flow path of the control valve 44 (that is, on the hydraulic pump 41 side). The check valve 44a permits the supply of hydraulic oil to the hydraulic actuator 36 side only when the discharge pressure (pump pressure) of the hydraulic pump 41 is higher than the pressure (actuator pressure) on the hydraulic actuator 36 side. When the pressure is lower than the actuator pressure, the flow of the pressure oil from the hydraulic actuator 36 side to the hydraulic pump 41 side is blocked.

The pilot pilot pressures in the pilot lines L1 and L2 are respectively guided to the shuttle valve 43, and the larger pilot pilot pressure is selectively output to the pilot line L3 (hereinafter referred to as the pump control signal primary pressure). The primary pressure of the pump control signal output to the pilot line L3 is reduced by the proportional solenoid valve 45 and output to the regulator 42 (hereinafter referred to as the pump control signal secondary pressure). The regulator 42 is a positive control system that increases the pump volume (discharge flow rate) of the hydraulic pump 41 as the input operation pilot pressure (pump control signal secondary pressure) increases.

The controller 60 calculates the pump target volume of the hydraulic pump 41 based on the detection results of the operation pilot pressure sensors SE1, SE2, and controls the proportional solenoid valve 45 based on the pump target volume. That is, the proportional solenoid valve 45 changes the opening area based on the control signal from the controller 60, so that the pump control signal (operation pilot pressure) input to the regulator 42 via the shuttle valve 43 is supplied as the pump control signal. This is a signal adjustment valve that can be adjusted by reducing the primary pressure to the pump control signal secondary pressure. The proportional electromagnetic valve 45 is held at the position shown in FIG. 2 (maximum opening area) when there is no pump control signal from the controller 60, and moves upward in FIG. Decrease. The proportional solenoid valve 45 reduces the pump control signal input to the regulator 42 and restricts it in a fine operation region of the lever operation amount that does not require a large flow rate for the hydraulic actuator, so that the discharge flow rate of the hydraulic pump This reduces the loss of the bleed-off flow that throws away unnecessary pump discharge flow into the tank.

FIG. 3 is a functional block diagram showing the calculation content of the pump target volume in the controller.

In FIG. 3, the controller 60 includes a pump target volume calculation unit C1, a pump control signal pressure target value calculation unit C2, a response priority mode switching unit C3, a pump flow rate control proportional solenoid valve valid / invalid switching unit C4, and proportional electromagnetics. A valve current calculation unit C5 is provided.

The pump target volume calculation unit C1 calculates the pump target volume based on the lever operation amount (operation pilot pressure) of the operation lever device 52 detected by the operation pilot pressure sensors SE1 and SE2 and a predetermined table.

The pump control signal pressure target value calculation unit C2 calculates a pump control signal secondary pressure target value based on the pump target volume calculated by the pump target volume calculation unit C1 and a predetermined table. The table used to calculate the pump control signal secondary pressure target value from the pump target volume is the change in the pump volume of the hydraulic pump 41 by the pump control signal (pilot pressure) that is set in hardware by the positive control regulator 42. Set from characteristics.

The responsiveness priority mode switching unit C3 determines whether or not the operation that requires the responsiveness of the bucket operation is performed based on the lever operation amount of the operation lever device 52 detected by the operation pilot pressure sensors SE1 and SE2. If it is determined that an operation requiring responsiveness is being performed, the operation mode is switched to the responsiveness priority mode, and if not, the operation mode is switched to the normal mode.

Here, the responsiveness priority mode refers to, for example, a case where the operation lever device 52 is repeatedly tilted in the bucket dump direction and returned to the bucket dump in a short time, such as gravel operation using a bucket for excavation, or on the bottom surface. Like the sieving operation using a skeleton bucket (not shown) having a mesh-like hole, the operation lever device 52 is repeatedly moved and returned in the bucket dump direction and bucket cloud direction in a short time to vibrate the bucket. In other words, in other words, this is an operation mode that is switched in an operation that requires responsiveness, such as when the operation amount of the operation lever device 52 changes intermittently and frequently in a short time. When switched to the priority mode, the opening area of the proportional solenoid valve 45 is widened to increase the responsiveness. The normal mode is an operation mode that is switched during an operation other than the response priority mode. When the normal mode is switched in this embodiment, the opening area of the proportional solenoid valve 45 is narrowed and input to the regulator 42. By reducing the primary pressure of the pump control signal to the secondary pressure of the pump control signal, the loss of the bleed-off flow for discarding unnecessary pump discharge flow to the tank is reduced by reducing the pump volume of the hydraulic pump.

The pump flow control proportional solenoid valve valid / invalid switching unit C4 calculates the calculation result (pump control signal secondary pressure target) of the pump control signal pressure target value calculation unit C2 according to the operation mode switched by the response priority mode switching unit C3. When the operation mode is switched to the normal mode, the output of the pump control signal pressure target value calculation unit C2 is used as it is in the subsequent processing block (proportional solenoid valve current calculation unit C5). When the operation mode is switched to the response priority mode, the pump control signal secondary pressure target value is replaced with the maximum pilot pressure (for example, 4 MPa) of the hydraulic circuit system 40, and the processing block ( Output to the proportional solenoid valve current calculation unit C5).

The proportional solenoid valve current calculation unit C5 generates a control signal for the proportional solenoid valve 45 based on the target pressure of the proportional solenoid valve 45 input from the pump flow control proportional solenoid valve valid / invalid switching unit C4 and a predetermined table. The proportional electromagnetic valve 45 is driven by calculating and outputting. That is, when the response priority mode switching unit C3 is switched to the normal mode, the pump control signal primary pressure is changed to the pump control signal secondary pressure based on the calculation result of the pump control signal pressure target value calculation unit C2. The proportional solenoid valve 45 is driven so that the pressure is reduced. When the operation mode is switched to the response priority mode, the proportional solenoid valve 45 is driven so that the pressure reduction in the proportional solenoid valve 45 becomes invalid.

FIG. 4 is a functional block diagram showing details of processing contents of the pump target volume calculation unit.

In FIG. 4, the pump target volume calculation unit C1 calculates the pump target volume of the hydraulic pump 41 based on the operation pilot pressure corresponding to the bucket cloud operation, that is, the detection result of the operation pilot pressure sensor SE1 and a predetermined table. Calculate the pump target volume of the hydraulic pump 41 based on the bucket cloud target volume calculation unit T1 to be calculated, the operation pilot pressure corresponding to the bucket dump operation, that is, the detection result of the operation pilot pressure sensor SE2, and a predetermined table. The larger one of the calculation results of the bucket dump target volume calculation unit T2, the bucket cloud target volume calculation unit T1, and the bucket dump target volume calculation unit T2 is output as the pump target volume calculation result of the pump target volume calculation unit C1. And a maximum value selection unit T3.

The table set in the bucket cloud target volume calculation unit T1, for example, as shown in FIG. 4, sets the input value (operation amount on the bucket cloud side of the operating lever device 52) on the horizontal axis and the pump target volume on the vertical axis. The graph target table is set so that the pump target volume increases as the operation amount on the bucket cloud side of the operation lever device 52 increases. In the table set in the bucket cloud target volume calculation unit T1, the target volume (shown by a solid line) of the hydraulic pump 41 is set so as to minimize pressure loss and flow rate loss according to the opening area of the control valve 44. Therefore, it is set to be smaller than the reference volume (indicated by a dotted line) of the hydraulic pump 41. Here, the reference volume of the hydraulic pump 41 corresponds to the relationship between the pilot pressure (pump control signal) input to the regulator 42 and the pump volume.

Similarly, the table set in the bucket dump target volume calculation unit T2, for example, as shown in FIG. 4, the horizontal axis represents the input value (the operation amount on the bucket dump side of the operation lever device 52), and the vertical axis represents the pump target. It is a graph-like table in which the volume is set, and is set so that the pump target volume increases as the operation amount on the bucket dump side of the operation lever device 52 increases. In the table set in the bucket dump target volume calculation unit T2, the target volume (shown by a solid line) of the hydraulic pump 41 is set so as to minimize pressure loss and flow rate loss according to the opening area of the control valve 44. Therefore, it is set to be smaller than the reference volume (indicated by a dotted line) of the hydraulic pump 41.

The maximum value selection unit T3 outputs the larger one of the calculation results of the bucket cloud target volume calculation unit T1 and the bucket dump target volume calculation unit T2 as the calculation result of the pump target volume of the pump target volume calculation unit C1.

FIG. 5 is a flowchart for explaining processing contents in the responsiveness priority mode switching unit.

In FIG. 5, the responsiveness priority mode switching unit C3 repeatedly performs the mode determination process (steps S100 to S161) at intervals of time Δt. That is, the time Δt is a cycle in which the mode determination process is repeatedly performed, and is a sampling cycle of the operation pilot pressure sensors SE1 and SE2, and for example, a unit time (for example, 10 ms) of internal calculation in the controller 60 is used.

The responsiveness priority mode switching unit C3 first detects the pilot pressure detection value corresponding to the bucket operation at the time of the previous mode determination process (time t−Δt), that is, the previous time of the operation pilot pressure sensors SE1 and SE2. Whether the current detection result (current value) is equal to or greater than the threshold value PI_ON (step S100). The threshold value PI_ON is a reference for determining whether or not the operation of the bucket 35 (bucket cloud operation or bucket dump operation) has been performed by the operation lever device 52, and the detection results of the operation pilot pressure sensors SE1 and SE2 are the threshold values. If it is less than PI_ON, it is determined that the operation lever device 52 is not operated (is in the neutral position), and if it is less than the threshold value PI_ON, it is determined that the operation lever device 52 is operated. If the previous value does not exist for the reason that the process in step S100 is the first mode determination process, the determination in step S100 is performed assuming that the previous value is less than the threshold value PI_ON.

If the determination result in step S100 is YES, that is, if the bucket 35 is operated by the operation lever device 52 during the time Δt, the timer T, which is a variable for counting time, is reset and T (T) = 0 is set (step S110), and 1 is added to a count N that is a variable for counting the number of times that the bucket 35 has been operated by the operating lever device 52 (number of times of operation) (step S120). If the determination result in step S100 is NO, that is, if the bucket 35 is not operated by the operation lever device 52 during the time Δt, the time Δt is added to the timer T (step S111).

Subsequently, it is determined whether or not the timer T is smaller than a predetermined reference time Tmax (for example, 0.5 seconds) (step S130). When the determination result in step S100 is NO (in other words, when the operation of the bucket 35 is not performed by the operation lever device 52 during the reference time Tmax), the count N is reset and N (t) = 0. (Step S140).

Subsequently, if the determination result in step S130 is YES, or if the process in step S140 ends, it is determined whether the count N is equal to or greater than a predetermined reference number Nmax (for example, 2 times). (Step S150). If the determination result in step S150 is YES, in other words, the number of times the bucket 35 is operated by the operation lever device 52 within a certain time (here, the reference time Tmax) is a certain number (here, the reference number Nmax). If it is above, the mode is switched to the response priority mode (step S160). If the determination result in step S150 is NO, the mode is switched to the normal mode (step S161), and the mode determination process (steps S100 to S161) is performed. repeat.

The operation of the present embodiment configured as described above will be described.

In the work machine 100 according to the present embodiment, when an operation in which the operation amount of the operation lever device 52 is intermittently and frequently changed in a short time, that is, for example, an operation like a gravel rolling operation or a concrete gravel screening operation is performed. When the operation of returning the lever device 52 in the bucket dump direction (or the cloud direction) and the operation of returning the lever device 52 are repeatedly performed in a short time, the response priority mode is switched. When switched to the response priority mode, the pressure reduction of the control signal of the regulator 42 by the proportional solenoid valve 45 is invalidated. As a result, the pump volume can be increased in an operation in which the operation amount of the operation lever device 52 changes intermittently and frequently in a short time, so that the responsiveness of the bucket operation can be increased.

Also, the normal mode is set when a normal operation other than the operation that sets the responsiveness priority mode is performed. When the mode is switched to the normal mode, the control signal input to the regulator 42 is reduced and limited (adjusted) by the proportional solenoid valve 45 in accordance with the operation amount of the operation lever device 52. The adjustment of the control signal at this time uses an optimized table (see bucket dump target volume calculation units T1 and T2) that can minimize excessive pressure loss at the control valve 44 and flow rate loss from the center bypass passage. , Fuel consumption can be reduced.

The effect of the present embodiment configured as described above will be described.

As a conventional technique for reducing the flow loss in the flow of hydraulic energy from the hydraulic pump to the hydraulic actuator, for example, in the region of fine operation of the lever operation amount that does not require a large flow rate in the hydraulic actuator, the pump of the hydraulic pump It is known to reduce the loss of the bleed-off flow rate by discarding unnecessary pump discharge flow rate into the tank by reducing the volume. In addition, by adjusting the pump reference flow rate according to the lever operation amount to the minimum required pump discharge flow rate according to the opening of the bleed-off valve, pressure loss and bleed-off flow loss are minimized without deteriorating operability. Some of them are known to be suppressed.

However, the response of increase / decrease in the discharge flow rate in the variable displacement hydraulic pump tends to be slower than the response of the directional control valve or the electronically controlled bleed-off valve. Therefore, since it takes time until the discharge flow rate of the hydraulic pump reaches an appropriate discharge flow rate with respect to the opening of the directional control valve and the bleed-off valve, the discharge pressure of the hydraulic pump does not increase until it overcomes the load pressure of the hydraulic actuator. There is a problem that the operation of the hydraulic actuator is delayed. In other words, when the operation lever is operated intermittently and quickly, the operation lever is returned before the pump flow rate finishes increasing, so the pump flow rate is less than in the steady operation, and the operation of the hydraulic actuator becomes extremely worse. There is concern. In particular, when the flow control signal pressure of a hydraulic pump is generated by a solenoid valve, the pump control signal pressure changes suddenly due to a delay in control of the solenoid valve or a decrease in signal pressure due to pressure loss when passing through the solenoid valve. There was a case that could not be done.

Specifically, as an operation that requires responsiveness in a hydraulic excavator, for example, a skeleton bucket (a bucket in which a mesh hole is opened on the bottom of the bucket and fine earth and sand falls) is attached. Concreed Gala sieving operation. In such a sieving operation, it is necessary to vibrate the bucket part by continually turning back the bucket operation (which may be accompanied by an arm operation) to screen the dust in the bucket. There is a concern that the actuator may not operate sufficiently due to a delay in the rise.

In contrast, in the present embodiment, a variable displacement hydraulic pump 41 driven by a prime mover (for example, the engine 22) and a plurality of driven members (for example, the boom 31, the arm 33, and the bucket 35) are rotated. A multi-joint type front work machine 30 configured to be movable and a plurality of hydraulic actuators (for example, boom cylinders 32) that are driven by pressure oil discharged from a hydraulic pump and respectively drive a plurality of driven members. Arm cylinder 34, bucket cylinder 36), a plurality of directional control valves (for example, control valve 44) for controlling the direction and flow rate of pressure oil respectively supplied from the hydraulic pump to the plurality of hydraulic actuators, and a plurality of directional switching. A plurality of operating devices (for example, operating lever device 52) for controlling the valve, and at least one of the plurality of operating devices; One or more operation amount detection devices (for example, operation pilot pressure sensors SE1, SE2) for detecting the operation amount of the operation device, and the operation amount of at least one operation device among the plurality of operation devices are generated. A regulator 42 for controlling the pump volume of the hydraulic pump based on the pump control signal, a signal adjusting valve (for example, a proportional solenoid valve 45) capable of adjusting the pump control signal input to the regulator, and generation of the pump control signal A controller that controls a signal adjustment valve based on a detection result of an operation amount from at least one operation amount detection device among the operation amount detection devices that detect an operation amount of the operation device related to the control device, Normal mode in which the pump control signal is adjusted by the adjustment valve, and responsiveness priority mode in which the pump control signal is not adjusted by the signal adjustment valve When switching the control lever intermittently and quickly to vibrate the bucket, such as gravel operation or sieving operation, in other words, operating the control lever device In an operation that requires responsiveness, such as when the amount changes intermittently and frequently in a short time, it is possible to switch to the responsiveness priority mode, so pressure loss and flow rate by controlling the pump volume (discharge flow rate) of the hydraulic pump It is possible to achieve both a reduction in loss and the response of the hydraulic actuator with intermittent sudden lever operation.

In the present embodiment, the bucket operation is switched between the normal mode and the response priority mode, and the pump volume control mode is changed according to the operation mode. For example, the same effect can be obtained when the arm operation is switched between the normal mode and the responsiveness priority mode instead of (or in addition to) the bucket operation.

<Modification of the first embodiment>
A modification of the first embodiment will be described with reference to FIGS.

In this modification, in the first embodiment, for each work mode set according to the work content to be performed on the front work machine, whether or not the operation mode can be switched from the normal mode to the responsive priority mode can be set. It is composed.

FIG. 6 is a functional block diagram showing the calculation contents of the pump target volume in the controller.

In FIG. 6, the controller 60A includes a pump target volume calculation unit C1, a pump control signal pressure target value calculation unit C2, a response priority mode switching unit C3, a pump flow rate control proportional solenoid valve valid / invalid switching unit C4, a proportional solenoid valve current. A calculation unit C5 and a responsiveness priority mode valid / invalid switching unit C6 are provided. Further, the controller 60A is disposed in the cabinet 23, and a monitor (display device) 63a for displaying various information and setting screens related to the excavator 100, and operations for operating various setting screens displayed on the monitor 63a. The input / output device 63 in which the switch group 63b is arranged is connected. Since the operation switch group 63b only needs to be able to operate the content displayed on the monitor 63a, for example, a configuration may be adopted in which selection and determination are performed by rotating and pressing the rotation switch.

The pump control signal pressure target value calculation unit C2 calculates a pump control signal secondary pressure target value based on the pump target volume calculated by the pump target volume calculation unit C1 and a predetermined table. The table used to calculate the pump control signal secondary pressure target value from the pump target volume is set from the change characteristic of the pump volume of the hydraulic pump 41 by the pump control signal pressure that is set in hardware by the positive control regulator 42. To do.

The responsiveness priority mode valid / invalid switching unit 6C responds based on a work mode signal from the input / output device (work mode setting device) 63 and a predetermined valid / invalid determination table 300 (see FIG. 8 later). The pump flow control proportional solenoid valve valid / invalid switching unit C4 in the operation mode switched by the power priority mode switching unit C3 is switched between valid / invalid.

The work mode signal input to the responsive priority mode valid / invalid switching unit 6C is output corresponding to the work mode set in the input / output device (work mode setting device) 63. It is set by the operator in accordance with the work contents to be performed. The responsiveness priority mode valid / invalid switching unit 6C selects the responsiveness priority mode among the operation modes switched by the responsiveness priority mode switching unit C3 based on the work mode signal and a predetermined valid / invalid determination table 300. Switch between valid and invalid. Specifically, the responsiveness priority mode valid / invalid switching unit 6C determines whether valid / invalid is set in the valid / invalid determination table 300 for the work mode based on the work mode signal, and is set to valid. If it is, the signal indicating the result of the operation mode (ie, “normal mode” or “responsiveness priority mode”) switched by the responsiveness priority mode valid / invalid switching unit 6C is used as it is. Output to the valid / invalid switching section C4. The responsiveness priority mode valid / invalid switching unit 6C determines that the responsiveness priority mode is invalid when the work mode based on the work mode signal is set to invalid, and the responsiveness priority mode valid / Regardless of the operation mode switched by the invalid switching unit 6C (that is, whether the operation mode is “normal mode” or “responsiveness priority mode”), a signal indicating the “normal mode” is sent to the pump flow rate. Output to control proportional solenoid valve valid / invalid switching section C4. The valid / invalid determination table may be set by the input / output device 63 and stored in the responsiveness priority mode valid / invalid switching unit 6C.

The pump flow rate control proportional solenoid valve valid / invalid switching unit C4 calculates the calculation result of the pump control signal pressure target value calculation unit C2 according to the operation mode switched by the response priority mode valid / invalid switching unit 6C (pump control signal 2 When the operation mode is switched to the normal mode, the output of the pump control signal pressure target value calculation unit C2 is used as it is in the subsequent processing block (proportional solenoid valve current calculation). When the operation mode is switched to the response priority mode, the pump control signal secondary pressure target value is replaced with the maximum pilot pressure (for example, 4 MPa) of the hydraulic circuit system 40, and the subsequent stage It outputs to a processing block (proportional solenoid valve current calculating part C5).

FIG. 7 is a diagram showing an example of a configuration menu configuration displayed on the monitor (display device) of the input / output device.

As shown in FIG. 7, information that can be displayed on the monitor 63 a of the input / output device 63 by operating the operation switch group 63 b by the operator includes an information menu 210 and a setting menu 220 that are displayed by selecting the main menu 200. In addition, there is a work mode setting menu 230 for setting the work mode in accordance with the work content performed by the front work machine 30. When the work mode setting menu 230 is selected, for example, an excavation mode 231, a crane mode 232, a breaker mode 233, a crusher mode 234, a crusher mode 235, a tilt bucket mode 236, and the like are displayed as work modes. A work mode is set by selecting a desired work mode. From the input / output device 63, a work mode signal indicating the set work mode is output to the response priority mode valid / invalid switching unit 6C of the controller 60A.

FIG. 8 is a diagram illustrating an example of a valid / invalid determination table for determining whether or not switching to the responsiveness priority mode for each work mode is possible.

In FIG. 8, the validity / invalidity determination table 300 indicates whether or not switching to a plurality of types of work modes 301 and the responsiveness priority mode set corresponding to each work mode, that is, valid or invalid. Setting state 302. In the valid / invalid determination table 300, for example, in the crane mode 232 in which a delicate operation is required and the breaker mode 233 in which a heavy attachment whose movement is likely to change suddenly is used, switching to the responsive priority mode is set to invalid. ing. On the other hand, in excavation mode 231, tilt bucket mode 236, etc., there is a possibility that operations requiring responsiveness such as sieving operation of gravel and graveling operation may be performed, so it is effective to switch to responsiveness priority mode It is set.

Other configurations are the same as those in the first embodiment.

Also in this modified example configured as described above, the same effects as those of the first embodiment can be obtained.

In addition, since the responsiveness priority mode can be disabled in a predetermined work mode, the responsiveness priority mode is switched to a work mode that requires delicate movements or a work mode that uses heavy attachments that tend to change suddenly. Can be set to be invalid, and operability can be improved.

<Second Embodiment>
A second embodiment of the present invention will be described with reference to FIGS. In this embodiment, only differences from the first embodiment will be described. In the drawings, the same members as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted.

This embodiment shows a case where a negative control method is adopted for the regulator of the first embodiment.

FIG. 9 is a diagram schematically showing an essential part of the hydraulic circuit system according to the present embodiment. In FIG. 9, only the bucket cylinder 36 and its related configuration are shown as representatives among the plurality of hydraulic actuators, and the other hydraulic actuators and their related configurations are not shown for the sake of simplicity.

In FIG. 9, a hydraulic circuit system 40B includes a variable displacement hydraulic pump 41 and a fixed displacement pilot pump (pilot hydraulic source) 49 driven by the engine 22, and a hydraulic oil tank that is a hydraulic oil supply source of the hydraulic pump. 48 and an operation pilot pressure (operation signal) guided from the operation lever device 52 for operating the bucket through the pilot lines L1 and L2, is supplied from the hydraulic pump 41 to the hydraulic actuator (bucket cylinder) 36 through the discharge line L4. A control valve (direction switching valve) 44 for controlling the direction and flow rate of the hydraulic oil and an operation pilot pressure sensor (operation) for detecting the operation amount of the operation lever device 52 by detecting the operation pilot pressure of the pilot lines L1 and L2. (Quantity detection device) SE1, SE2 and operation lever device 52 A regulator 42a that controls the pump volume (tilt angle) of the hydraulic pump 41 based on a pilot pressure (pump control signal) generated according to the operation, and a pump control signal that is input from the operation lever device 52 to the regulator 42a. The proportional electromagnetic valve 56 (signal adjustment valve) that can be adjusted and a controller 60B that controls the proportional electromagnetic valve 56 based on the operation amount detection results from the operation pilot pressure sensors SE1 and SE2 are schematically configured. In the discharge line L4 from the hydraulic pump 41, a relief valve 41a that defines the upper limit of the discharge pressure of the hydraulic pump 41 is installed.

At the most downstream of the center bypass line L5, which is a return line of pressure oil from the control valve 44 to the hydraulic oil tank 48, an upper limit of the pressure on the throttle 53 and the control valve 44 side (that is, the hydraulic pump 41 side) of the throttle 53. And a relief valve 54 is provided. The pressure (pump flow rate signal) generated by reducing the pressure on the control valve 44 side (that is, the hydraulic pump 41 side) of the throttle 53 (referred to as a pump flow rate control signal) and the discharge pressure of the pilot pump 49 by the proportional solenoid valve 56. The lower pressure is guided to the shuttle valve 55, and the larger pressure is selectively output to the pilot line L13 as a pump control signal (pilot pressure) and input to the regulator 42a. The regulator 42a is a negative control system that decreases the pump volume of the hydraulic pump 41 as the input pilot pressure (pump control signal) increases.

Controller 60B calculates the pump target volume of hydraulic pump 41 based on the detection results of operation pilot pressure sensors SE1, SE2, and controls proportional solenoid valve 56 based on the pump target volume. That is, the proportional solenoid valve 56 and the shuttle valve 55 generate a pump flow rate lowering signal by changing the opening area based on the control signal from the controller 60B, and supply the pump flow rate lowering signal to the pilot line L13 via the shuttle valve 55. Thus, a signal adjustment valve capable of adjusting the pump control signal input to the regulator 42a is configured. Since the proportional solenoid valve 56 is held at the position (opening area maximum) shown in FIG. 2 when there is no control signal from the controller 60B, the proportional solenoid valve 56 moves upward in FIG. Decrease. The proportional solenoid valve 56 is controlled to take a larger opening area when the hydraulic actuator does not require a large flow rate, that is, when the lever operation amount is in the fine operation region, and the pump flow rate reduction signal is output. By inputting to the regulator 42a as a pump control signal via the shuttle valve 55, by reducing the discharge flow rate of the pressure hydraulic pump of the pump control signal, the loss of the bleed-off flow rate that discards unnecessary pump discharge flow rate to the tank can be reduced. To reduce.

FIG. 10 is a functional block diagram showing the calculation contents of the pump target volume in the controller.

In FIG. 10, the controller 60B includes a pump target volume calculation unit C1, a pump flow rate decrease signal pressure target value calculation unit C12, a response priority mode switching unit C3, a pump flow rate decrease proportional solenoid valve valid / invalid switching unit C14, and a proportional An electromagnetic valve current calculation unit C5 is provided.

The pump flow rate reduction signal pressure target value calculation unit C12 calculates the pump flow rate reduction signal target pressure based on the pump target volume calculated by the pump target volume calculation unit C1 and a predetermined table. The table used to calculate the pump flow rate reduction signal target pressure from the pump target volume is based on the change characteristic of the pump volume of the hydraulic pump 41 by the pump control signal (pilot pressure) set in hardware by the negative control regulator 42a. Set.

The pump flow rate lowering proportional solenoid valve valid / invalid switching unit C14 calculates the calculation result (pump flow rate lowering signal) of the pump flow rate lowering signal pressure target value computing unit C12 according to the operation mode switched by the response priority mode switching unit C3. When the operation mode is switched to the normal mode, the output of the pump flow rate lowering signal pressure target value calculation unit C12 is directly output to the subsequent processing block (proportional solenoid valve current calculation unit C5). When the operation mode is switched to the response priority mode, the pump flow rate lowering signal is replaced with the minimum pilot pressure (for example, 0 (zero) MPa) of the hydraulic circuit system 40, and the subsequent processing block (proportional electromagnetic To the valve current calculation unit C5).

The proportional solenoid valve current calculation unit C5 outputs a control signal for the proportional solenoid valve 56 based on the target pressure of the proportional solenoid valve 56 input from the pump flow rate reduction proportional solenoid valve valid / invalid switching unit C14 and a predetermined table. The proportional electromagnetic valve 56 is driven by calculating and outputting. That is, when the response priority mode switching unit C3 is switched to the normal mode, the proportional solenoid valve is configured so that the pump flow rate reduction signal is generated based on the calculation result of the pump flow rate reduction signal pressure target value calculation unit C12. When the operation mode is switched to the response priority mode, the proportional solenoid valve 56 is driven so that the pressure reduction in the proportional solenoid valve 56 becomes invalid.

Other configurations are the same as those in the first embodiment.

The operation and effect of the present embodiment configured as described above will be described.

In the work machine 100 according to the present embodiment, when an operation in which the operation amount of the operation lever device 52 is intermittently and frequently changed in a short time, that is, for example, an operation like a gravel rolling operation or a concrete gravel screening operation is performed. When the operation of returning the lever device 52 in the bucket dump direction (or the cloud direction) and the operation of returning the lever device 52 are repeatedly performed in a short time, the response priority mode is switched. When switched to the responsiveness priority mode, the generation of the pump flow rate reduction signal by the proportional solenoid valve 56 and the input as the pump control signal to the regulator 42a via the shuttle valve 55 are invalidated. As a result, the pressure (pump flow rate control signal) on the hydraulic pump 41 side of the throttle 53 of the center bypass line L5 is always selected as the pump control signal by the shuttle valve 55, so that the operation amount of the operation lever device 52 is intermittently interrupted. In an operation that changes frequently and frequently, the pump volume can be increased and the responsiveness of the bucket operation can be increased.

Also, the normal mode is set when a normal operation other than the operation that sets the responsiveness priority mode is performed. When the mode is switched to the normal mode, the generation of the pump flow rate reduction signal by the proportional solenoid valve 56 is enabled according to the operation amount of the operation lever device 52, and is input to the regulator 42a as the pump control signal via the shuttle valve 55. The regulator 42a adjusts the input pump control signal. The adjustment of the control signal at this time uses an optimized table (see bucket dump target volume calculation units T1 and T2) that can minimize excessive pressure loss at the control valve 44 and flow rate loss from the center bypass passage. , Fuel consumption can be reduced.

Next, features of the above embodiments will be described.

(1) In the above embodiment, the variable displacement hydraulic pump 41 driven by the prime mover (for example, the engine 22) and the plurality of driven members (for example, the boom 31, the arm 33, and the bucket 35) rotate. A multi-joint type front work machine 30 configured to be connected to a plurality of hydraulic actuators (for example, boom cylinders) that are driven by pressure oil discharged from the hydraulic pump and respectively drive the plurality of driven members. 32, arm cylinder 34, bucket cylinder 36), a plurality of directional control valves (for example, control valve 44) for controlling the direction and flow rate of pressure oil respectively supplied from the hydraulic pump to the plurality of hydraulic actuators, A plurality of operating devices (for example, operating lever device 52) for controlling the plurality of directional control valves; One or more operation amount detection devices (for example, operation pilot pressure sensors SE1 and SE2) for detecting an operation amount of at least one operation device, and an operation amount of at least one operation device among a plurality of operation devices. A regulator 42 that controls the pump volume of the hydraulic pump based on the generated pump control signal, and a signal adjustment valve (for example, a proportional solenoid valve 45; a shuttle valve 55) that can adjust the pump control signal input to the regulator. , Based on a detection result of an operation amount from at least one operation amount detection device among the operation amount detection devices for detecting an operation amount of the operation device related to the generation of the pump control signal. A controller for controlling the signal adjustment valve, and the controller is configured to adjust the pump control signal by the signal adjustment valve. Mode and was assumed to be switched to one of the not adjusted responsive priority mode of the pump control signal by the signal control valve.

As a result, when the bucket is vibrated by operating the operation lever intermittently and quickly, such as gravel operation or sieving operation, in other words, when the operation amount of the operation lever device changes intermittently and frequently in a short time For operations that require responsiveness, such as responsiveness, it is possible to switch to responsiveness priority mode, so that the amount of operation of the operating lever changes frequently in a short time without degrading workability during normal operation. In an operation that requires high performance, responsiveness can be increased, and a reduction in work efficiency can be suppressed.

(2) In the above embodiment, in the work machine of (1), the regulator is a positive control system that increases the pump volume of the hydraulic pump as the pump control signal increases, and the signal The regulating valve is a proportional solenoid valve capable of reducing the pilot pressure input as a pump control signal to the regulator.

(3) In the above-described embodiment, in the work machine of (1), the controller determines that the number of times that the operation amount of the operating device has risen beyond a predetermined threshold value within a predetermined time period. When the predetermined number of times has been exceeded, switching to the response priority mode in which the pump control signal is not adjusted by the signal adjustment valve.

(4) In the above-described embodiment, the work machine of (1) includes a work mode setting device that sets a work mode according to the work content performed by the front work machine, and the controller includes the work mode. In the work mode set by the setting device, when the response priority mode is set in advance to be invalid, it is not switched to the response priority mode.

As a result, the responsiveness priority mode can be disabled in a predetermined work mode, so the responsiveness priority mode is required in work modes that require delicate movements or work modes that use heavy attachments that tend to change suddenly. Switching to can be set to be invalid, and operability can be improved.

(5) In the above embodiment, in the work machine of (1), the regulator is a negative control system that decreases the pump volume of the hydraulic pump as the pump control signal increases, and the signal The regulating valve is generated to limit the pump volume control pilot pressure generated so as to decrease as the operation amount of the operating device related to the generation of the pump control signal increases and the pump volume of the hydraulic pump. A shuttle valve that selectively guides the larger pump volume limiting pilot pressure as a pump control signal to the regulator, and a proportional solenoid valve that can reduce the pump volume limiting pilot pressure input to the shuttle valve. It was supposed to be.

<Appendix>
In the above embodiment, a general hydraulic excavator that drives a hydraulic pump with a prime mover such as an engine has been described as an example, but a hybrid hydraulic excavator that drives the hydraulic pump with an engine and a motor, Needless to say, the present invention can also be applied to an electric hydraulic excavator that drives a hydraulic pump only by a motor.

Further, the present invention is not limited to the above-described embodiment, and includes various modifications and combinations within the scope not departing from the gist thereof. That is, in each of the embodiments described above, the case where the pump control signal is generated according to the operation amount of the operation lever device 52 related to the bucket 35 has been described as an example. Depending on the operation amount of the hydraulic actuator (for example, the boom cylinder 32, the arm cylinder 34, the swing hydraulic motor 27, etc.), that is, when the pump control signal is generated by using the operation amounts of a plurality of hydraulic actuators in combination. The present invention may be applied. In each of the above-described embodiments, the case where the normal mode and the response priority mode are switched based on the operation amount of the operation lever device 52 related to the bucket 35 has been described as an example. The normal mode and response based on the amount of operation of the hydraulic actuator (for example, the arm cylinder 34 related to the arm 33 that may be operated quickly when the bucket is vibrated). The priority mode may be switched, or the operation amount may be used in combination to switch between the normal mode and the response priority mode.

Further, the present invention is not limited to the one having all the configurations described in the above embodiment, and includes a configuration in which a part of the configuration is deleted. Moreover, you may implement | achieve part or all of said each structure, function, etc., for example by designing with an integrated circuit. Each of the above-described configurations, functions, and the like may be realized by software by interpreting and executing a program that realizes each function by the processor.

DESCRIPTION OF SYMBOLS 10 ... Lower traveling body, 11a (11b) ... Crawler, 12a (12b) ... Crawler frame, 13a (13b) ... Traveling hydraulic motor, 13b ... Traveling hydraulic motor, 20 ... Upper turning body, 21 ... Turning frame, 22 ... Engine , 23 ... cab (cabinet), 26 ... deceleration mechanism, 27 ... turning hydraulic motor, 30 ... front device (front work machine), 31 ... boom, 32 ... boom cylinder, 33 ... arm, 35 ... bucket, 36 ... bucket Cylinder, 36a ... Bucket cylinder bottom chamber, 36b ... Bucket cylinder rod chamber, 40, 40B ... Hydraulic circuit system, 41 ... Hydraulic pump, 41a ... Relief valve, 42, 42a ... Regulator, 43 ... Shuttle valve, 44 ... Control valve ( Directional switching valve), 44a ... check valve, 45, 56 ... proportional solenoid valve, 48 ... Hydraulic oil tank 49 ... Pilot pump (pilot hydraulic power source) 52 ... Operation lever device (operation device) 52a ... Operation lever 52b ... Operation signal generator 52b ... Operation signal generator 53 ... Restriction 54 ... Relief Valve, 55 ... Shuttle valve, 60, 60A, 60B ... Controller, 63 ... I / O device (work mode setting device), 63a ... Monitor (display device), 63b ... Operation switch group, 100 ... Hydraulic excavator (work machine), 200 ... main menu, 210 ... information menu, 220 ... setting menu, 230 ... work mode setting menu, SE1, SE2 ... operation pilot pressure sensor (operation amount detection device)

Claims

A variable displacement hydraulic pump driven by a prime mover;
A multi-joint type front work machine configured such that a plurality of driven members are rotatably connected;
A plurality of hydraulic actuators that are driven by pressure oil discharged from the hydraulic pump and that respectively drive the plurality of driven members;
A plurality of directional control valves for controlling the direction and flow rate of pressure oil respectively supplied from the hydraulic pump to the plurality of hydraulic actuators;
A plurality of operating devices for controlling the plurality of directional control valves;
One or more operation amount detection devices for detecting an operation amount of at least one operation device among the plurality of operation devices;
A regulator for controlling a pump volume of the hydraulic pump based on a pump control signal generated according to an operation amount of at least one operation device among the plurality of operation devices;
A signal adjustment valve capable of adjusting the pump control signal input to the regulator;
A controller that controls the signal adjustment valve based on a detection result of an operation amount from at least one operation amount detection device among the operation amount detection devices that detect an operation amount of the operation device related to generation of the pump control signal. And
The controller can be switched between a normal mode in which the pump control signal is adjusted by the signal adjustment valve and a responsiveness priority mode in which the pump control signal is not adjusted by the signal adjustment valve. A working machine characterized by
The work machine according to claim 1,
The regulator is a positive control system that increases the pump volume of the hydraulic pump as the pump control signal increases,
The work machine according to claim 1, wherein the signal adjusting valve is a proportional electromagnetic valve capable of reducing a pilot pressure input as a pump control signal to the regulator.
The work machine according to claim 1,
The controller adjusts the pump control signal by the signal adjustment valve when the number of times that the operation amount of the operating device has increased beyond a predetermined threshold within a predetermined time exceeds a predetermined number. A work machine characterized by switching to a responsiveness priority mode in which no operation is performed.
The work machine according to claim 1,
A work mode setting device for setting a work mode according to the work content to be performed by the front work machine;
The controller does not switch to the responsiveness priority mode when the responsiveness priority mode is set in advance to be invalid for the work mode set by the work mode setting device. .
The work machine according to claim 1,
The regulator is a negative control system that decreases the pump volume of the hydraulic pump as the pump control signal increases,
The signal regulating valve is
Pump volume control pilot pressure generated so as to decrease as the operation amount of the operating device related to generation of the pump control signal increases, and pump volume limit generated to limit the pump volume of the hydraulic pump A shuttle valve that selectively guides the larger pilot pressure to the regulator as a pump control signal;
A work machine comprising: a proportional solenoid valve capable of reducing the pump volume limiting pilot pressure input to the shuttle valve.