Abstract: A work machine (1) having a controller (40) that can perform area limiting control, the work machine further includes a machine control ON/OFF switch (17) that alternatively selects an ON position permitting execution of the area limiting control and an OFF position prohibiting execution of the area limiting control. The controller (40) has an engine control section (63) that performs automatic idling control when a predetermined period of time (T1) has elapsed after a point in time when all of operation levers (1, 23) have attained a neutral state. The engine control section (63) is configured to execute the automatic idling control during when the switch (17) is in the OFF position and not to execute the automatic idling control during when the switch (17) is in the ON position.

Abstract: Provided is a work machine that is equipped with a control unit that executes area limiting control with respect to a work device. The control unit includes: a position computing section that calculates the position, on an operation plane, of the forward end (first reference point) of a bucket and the rear end (second reference point) of the bucket; and a first distance computing section that calculates the distances in the operating plane from the first reference point and the second reference point to the target face A to be controlled. When the smaller one of the two distances is equal to or lower than a threshold during area limiting control, the control unit corrects an operation signal output from an operation lever device so as to reduce the operating speed of a hydraulic actuator that is a control target of the operation signal.

Abstract: A work machine includes: a multi-joint type work implement; a plurality of hydraulic actuators driving the work implement; an operation device outputting an operation signal to the plurality of hydraulic actuators; a storage section storing a target configuration defined by connecting a plurality of target surfaces; a control object surface selection section that in the case where a control point set at a claw tip of a bucket is under the target configuration, uses a target surface closest to the control point on the target configuration as a control object surface; and a target operation control section that controls the plurality of hydraulic actuators such that the operational range of the control point is limited to the control object surface and a region above the same in the case where an excavation operation is input from an operator via the operation device.

Abstract: A hydraulic excavator includes a controller having an actuator control section that executes machine control of operating a work implement in accordance with a predetermined condition in a case in which a work implement is positioned in a deceleration area, and that does not execute machine control in a case in which the work implement is positioned in a non-deceleration area. The controller further includes an operation deciding section that decides operation of the work implement on the basis of an operation amount of an operation device, and a display control section that displays, on a display device, a positional relationship among the work implement, a target surface and a boundary line between the deceleration area and the non-deceleration area.

Abstract: A controller (40) of a hydraulic excavator (1) includes: a first distance calculation section (43f) calculating a first distance D1 that is a distance between a bucket toe and a target surface on a virtual straight line Lv extended vertically from the bucket toe, based on position information on the bucket toe and position information on the target surface (700); and a second distance calculation section (43g) calculating a second distance D2 that is a distance between the target surface and a current landform on the virtual straight line Lv, based on the position information on the bucket toe and the position information on the target surface and position information on the current landform 800. A display device (53a) displays the first distance D1 and the second distance D2.

Abstract: A controller outputs a first velocity (first limiting velocity) as a limiting velocity for a boom cylinder when a boom lowering operation amount is smaller than a first operation amount, and outputs a second velocity when the boom lowering operation amount is equal to or larger than the first operation amount. The first velocity is set to decrease according to a decrease in a target surface distance. The second velocity is defined by a weighted average of the first velocity and a third velocity (second limiting velocity) set to change according to one of the target surface distance and the boom lowering operation amount of the operation device, and is set such that an increase in the boom lowering operation amount reduces a weight for the first velocity while increasing a weight for the third velocity.

Abstract: A work machine (1) includes a controller (40) having a notification control section (374) that exercises control as to whether to notify an operator of operation support information in accordance with a distance between a predetermined target surface, out of a plurality of discretionally set target surfaces, and a work implement (1A), the work machine including a current terrain profile acquisition device (96) that acquires a position of a current terrain profile, the controller including a target surface comparison section (62) that compares the position of the current terrain profile (800) with a position of the predetermined target surface (700) to determine a vertical position relationship between the current terrain profile and the predetermined target surface. The notification control section (374) changes content of the operation support information in accordance with a result of determination by the target surface comparison section.

Abstract: A work machine has a controller which has an area limiting control section correcting the pilot pressures of pilot lines, a regeneration control section adjusting the flow rate of the hydraulic fluid caused to flow from a tank side line of an arm cylinder into a pump side line thereof between zero and a predetermined upper limit value, and a regeneration control switching section that issues an order to the regeneration control section to set the predetermined upper limit value to a first set value when the function of the area limiting control section is invalid and that issues an order to the regeneration control section to set the predetermined upper limit value to a second set value that is smaller than the first set value when the function of the area limiting control section is effective.

Abstract: A work machine including a front control section configured to calculate a limit command value for restricting an operation of a front work implement includes: for example, a bypass line that bypasses, for example, the proportional solenoid valve in, for example, the pilot line; for example, a bypass valve disposed in, for example, the bypass line; a switch configured to output a signal to turn on or off control by the front control section; an on/off determining part configured to determine whether the signal from the switch is an on signal that brings front control into an on state or an off signal that brings the front control into an off state; an open/close command part configured to generate an open/close command signal to open the bypass valve when the signal is determined to be the off/off signal.

Abstract: A hydraulic system for a work machine includes a first hydraulic pump driving a swing hydraulic motor; a second hydraulic pumps driving a boom cylinder; a first pump displacement increase valve controlling a volume of the first hydraulic pump; a swing pilot pressure sensor detecting a swing operation amount; a boom raising pilot pressure sensor detecting a boom raising operation amount; and a controller controlling a control signal to the first pump displacement increase valve on the basis of the swing operation amount and the boom raising operation amount. The controller controls the control signal in such a manner that a delivery rate of the first hydraulic pump becomes higher as the swing operation amount is larger and an increasing rate of the delivery rate of the first hydraulic pump becomes lower as the boom raising operation amount is larger during a swing boom raising operation.

Abstract: Provided is a hydraulic excavator (1) that performs work by operating an arm (9) after moving a bucket (10) to a work start position. An operation determination section (81c) determines, based on an operation performed on an operation device, whether a front work device (1A) is engaged in a work preparation operation for moving the bucket to the work start position. When the operation determination section determines that the front work device is engaged in the work preparation operation at the time of operation of the operation device, an actuator control section (81) controls a bucket cylinder (7) such that the angle of a work tool with respect to a target surface coincides with a preset target angle (?TGT).

Abstract: A work machine includes: control valves that control flows of a hydraulic operating oil supplied to actuators; operation lever devices that generate hydraulic signals to be output to the corresponding control valves according to an operation; solenoid proportional valves that reduce pressure of the hydraulic signals generated by the corresponding operation lever devices; and a front implement control section that controls the solenoid proportional valves. The work machine further includes: operation signal lines connected to the operation lever devices; signal input lines connected to the control valves; pressure reducing lines provided with the solenoid proportional valves; and selector valves that have a first position that interrupts connection of the operation signal lines and the pressure reducing lines and directly connects the operation signal lines to the signal input lines, and a second position that connects the operation signal lines to the signal input lines via the pressure reducing lines.

Abstract: A hydraulic excavator 1 includes a computer-aided construction controller 60 for performing machine control to operate a front work implement based on detected results from posture sensors 63, 65 and 67 and predetermined conditions. The computer-aided construction controller 60 has a calibration posture storing section 60a that stores at least one predetermined calibration posture of the front work implement for calibrating the posture sensors, and a calibration posture controlling section 60b that carries out the machine control to inactivate the hydraulic actuators if detection target values of the posture sensors in the calibration posture and the detected results from the posture sensors are equal to each other. The time required for calibration can thus be shortened by increasing the operability for adjusting a calibration posture.

Abstract: A hydraulic excavator includes: a hydraulic pump driven by power generated by an engine; a work device that operates by a plurality of hydraulic cylinders driven by power generated by the hydraulic pump; an actuator control section that controls the boom cylinder in such a manner that a tip end of a bucket is located on or above a target surface; a control point position calculation section that calculates a bucket claw tip position on the basis of angle sensors; and a power generator control section that imposes more limitations on output power ranges of the engine and the hydraulic pump when a distance between the claw tip position and the target surface is equal to or smaller than a threshold D than those when the distance between the claw tip position and the target surface is larger than the threshold D.

Abstract: When a work implement is actuated in such a manner that a work point is located at each of a plurality of positions on a datum line, a first work point position computing section calculates a position of the work point at each of the plurality of positions. A calibration value computing section calculates calibration values of angle conversion parameters (?bm, ?bm, ?am, ?am, ?bk, ?bk), dimension parameters (Lbm, Lam, Lbk), and line parameters (tilt tan ?, intercept Zline) using the fact that the positions of the work point at each of the plurality of positions calculated by the first work point position computing section can satisfy a linear equation indicating a datum line. A parameter update section reflects the calibration values calculated by the calibration value computing section in computation by a corresponding computing section that is one of the angle computing section and the first work point position computing section.

Abstract: A motor-generator (27) is connected mechanically to an engine (21) and a hydraulic pump (23). The hydraulic pump (23) delivers pressurized oil to cylinders (12D) to (12F) in a working mechanism (12), a traveling hydraulic motor (25) and a revolving hydraulic motor (26). The revolving hydraulic motor (26) drives a revolving device (3) in cooperation with a revolving electric motor (33). An HCU (36) reduces outputs of the revolving electric motor (33), the revolving hydraulic motor (26), the boom cylinder (12D) and the like such that a ratio of a revolving speed of an upper revolving structure (4) and a movement speed of raising a boom (12A) is held to a ratio in a normal mode (NMODE) at the time of performing a compound movement of a revolving movement and a boom-raising movement in a low speed mode (LSMODE).

Abstract: A hydraulic excavator acquires operation content frequency data in a designated period based on output values output from a plurality of sensors sensing parameters that serve as indicators of operation contents performed via an operation device. A storage section stores a plurality of guide screens each corresponding to one of a plurality of work patterns of the hydraulic excavator. A work identifying section searches actual result data in the storage section for actual result data that matches or is similar to the operation content frequency data acquired by the data acquiring section in terms of operation contents and frequency thereof, and that identifies a current work pattern based on a work pattern allocated to actual result data related to a result of the search. A display device displays a guide screen corresponding to the work pattern identified by the work identifying section among the plurality of guide screens.

Abstract: A display system for a construction machine includes: a moving direction computing section for computing a predictive moving direction of a bucket; a work-tool display control section that, if the moving direction computing section predicts a movement of the bucket, changes the display position of a bucket image based on the predictive moving direction such that the area of a region located on the predictive moving direction side from the bucket image on the display screen of a monitor is displayed wider than when the bucket image is displayed at a reference position and that displays the bucket image at the reference position if a movement of the bucket cannot be predicted. A target-surface display control section displays on the display screen an image of a target surface when the bucket image is displayed at the display position determined by the work-tool display control section.

Abstract: A hydraulic excavator includes a controller (40) that executes region limiting control to forcibly raise a boom (8) in such a manner that a position of a tip end of a bucket (10) is kept on a target excavation surface and within a region above the target excavation surface if an operation device (45b, 46a) issues an action direction to an arm (9) or the bucket. The controller determines which is selected as a control mode over a raising speed of the boom at a time of executing region limiting control, a first mode or a second mode specified by a raising speed lower than a raising speed of the first mode if the tip end of the bucket is located below the target excavation surface, and controls the raising speed of the boom based on a result of determination.

Abstract: A work machine that can prevent restarting of an engine against a will of an operator from an idle stop state is provided. A hydraulic excavator includes a display device that displays a confirmation screen image for allowing an operator to confirm whether or not an engine is to be restarted from an idle stop state, and an inputting device that allows the operator to input a restart instruction for the engine in an interlocked relationship with the display of the confirmation screen image. A machine controller includes a restart controlling section that restarts the engine based on the restart instruction for the engine inputted by the inputting device.