A work machine according an aspect includes a work implement, an operation apparatus for operating the work implement, and a controller for controlling the work implement. The controller performs intervention control for lowering the work implement based on an operation command from the operation apparatus, and reduces a speed of the work implement during the intervention control to stop the work implement before completion of the intervention control.

A shovel that performs excavation in accordance with an arm excavation operation including an arm closing operation includes an excavation operation detection part, a position detection part, a maximum allowable pressure calculation part, and an arm cylinder pressure control part. The excavation operation detection part detects that the arm excavation operation has been performed. The position detection part detects the position of the shovel. The maximum allowable pressure calculation part calculates the pressure of the expansion-side oil chamber of an arm cylinder corresponding to an excavation reaction force at a time when the shovel is dragged by the excavation reaction force as a maximum allowable pressure, based on the position of the shovel. The arm cylinder pressure control part controls the pressure of the expansion-side oil chamber not to exceed the maximum allowable pressure when the arm excavation operation is performed.

Problems: Provided is a drive control device for a fluid pressure cylinder that has good operability for expanding and contracting the fluid pressure cylinder in the vicinity of a stroke end. Solutions: A drive control device includes an expansion and contraction unit configured to expand and contract a fluid pressure cylinder in response to an operation of an operating body; a position detection unit configured to detect an expansion and contraction position of the fluid pressure cylinder; a speed detection unit configured to detect an expansion and contraction speed of the fluid pressure cylinder; a limiting unit configured to limit, according to the expansion and contraction position of the fluid pressure cylinder within a predetermined range from a stroke end and the expansion and contraction speed in a stroke end direction, the expansion and contraction speed of the fluid pressure cylinder in the stroke end direction by the expansion and contraction unit; and a stopping unit configured to stop expansion and contraction of the fluid pressure cylinder at a predetermined position by reducing an amount of a working fluid supplied to the fluid pressure cylinder as a distance of the fluid pressure cylinder from the predetermined position in the vicinity of the stroke end is shorter.

A drive control system for a work machine. A gradual stoppage command and an operation speed limitation command are calculated and output. A pilot pressure is corrected such that, upon a stoppage operation of a control lever, a drive actuator is stopped gradually; and the pilot pressure is corrected such that an operation speed of the drive actuator is limited. A supply of the pilot hydraulic fluid to the speed increasing unit is interrupted when a failure of a speed increasing solenoid proportional valve of the speed increasing unit is detected.

The invention relates to a device for generating oscillations for a construction machine, comprising a housing, a piston which is movable back and forth in a working chamber in the housing between a first return point and a second return point, a pressurized fluid supply through which in each case pressurized fluid can be fed into and discharged from the working chamber via at least one actuatable control valve in the region of the first return point and the second return point, wherein the piston can be induced into a reciprocating motion in order to generate the oscillations, and a control unit which is configured to actuate the at least one control valve and by means of which the movement of the piston in the working chamber is controllable and variable. According to the invention, it is provided that the control unit is configured to control the piston in a first operating mode for generating oscillations and in a second operating mode for generating impact pulses, wherein a strike surface is formed on at least one end side of the working chamber, onto which surface the piston strikes when it reaches at least one return point in order to generate an impact pulse.

A wheel loader includes a vehicular body, a work implement, a front wheel, and a control unit. The work implement is disposed in front of the vehicular body. The work implement has a boom. The front wheel has a tire made of an elastic material. The control unit starts to raise the boom while the tire compressed in a vertical direction rebounds and vertically stretches.

A control method for a work machine, includes: detecting a posture of a working unit driven by a hydraulic cylinder in a movable range; determining whether the working unit at a stop position of the movable range has started moving based on an operation of the working unit; setting a deceleration section including an end position of the movable range and a deceleration ratio of the working unit in the deceleration section, based on the posture of the working unit in a stopped state at the stop position, and a threshold determined in advance; and outputting a command signal to a control valve, which is capable of adjusting an amount of a working oil supplied to the hydraulic cylinder, such that the working unit moves from the stop position to the end position based on the deceleration section and the deceleration ratio.

Provided is construction equipment including: an undercarriage; an upper swing body rotatably supported on the undercarriage; a work device supported by the upper swing body and comprising a boom, an arm and a bucket, which operate by means of respective hydraulic cylinders; a control valve for controlling the boom cylinder; an electronic proportional pressure reducing valve for controlling a spool of the control valve; a control lever for outputting a control signal corresponding to the amount of control of a driver; a work setting unit for providing a work mode and target work surface setting function; a location information providing unit for, according to a work mode setting of the work setting unit, collecting and/or calculating location information of the work device and location information of a work surface that has been set; and an electronic control unit.

In controlling a work vehicle including a boom supported by a vehicle body and configured to turn, and a bucket supported by a side, away from the vehicle body, of the boom and configured to turn according to an operation of an actuator, an operation amount for raising the boom or a rising speed of the boom, and an operable amount that the actuator is able to operate before the bucket reaches the stopper based on the posture of the boom and the posture of the bucket, are obtained, and an operating speed of the actuator is limited according to the operable amount of the actuator before the bucket reaches the stopper, and based on the operation amount for raising the boom or the rising speed of the boom obtained, a limit amount of the operating speed of the actuator is changed.

A control method for a work machine, includes: detecting a posture of a working unit driven by a hydraulic cylinder in a movable range; determining whether the working unit at a stop position of the movable range has started moving based on an operation of the working unit; setting a deceleration section including an end position of the movable range and a deceleration ratio of the working unit in the deceleration section, based on the posture of the working unit in a stopped state at the stop position, and a threshold determined in advance; and outputting a command signal to a control valve, which is capable of adjusting an amount of a working oil supplied to the hydraulic cylinder, such that the working unit moves from the stop position to the end position based on the deceleration section and the deceleration ratio.