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 work machine includes a chassis, a boom coupled to the chassis, and a work implement coupled to the boom and movable relative to the chassis. In system may further include dynamic payload weighing system configured to measure the payload weight on the work implement. The system may also include an electrohydraulic system controller in communication with the dynamic payload weighing system and an electrohydraulic control valve electrically coupled to the electrohydraulic system controller and moveable to a plurality of weight-specific valve positions based on the measured payload weight on the implement.

This hydraulic drive device for a work vehicle includes a main pump (1) of a variable displacement type or a fixed displacement type discharging pressure oil, a main flow passage (F1) for supplying pressure oil of the main pump to an actuator, a sub-pump (5) of a fixed displacement type discharging pressure oil, a sub-flow passage (F2) for making pressure oil of the sub-pump merge with the main flow passage and supplying the pressure oil to the actuator (2), a merging directional valve (6A) for connecting or cutting off the main flow passage and the sub-flow passage, a controller (30) for controlling operation of the merging directional valve, and a relief valve (7A) arranged in the sub-flow passage, in which the relief valve has a pressure override characteristic having a tendency that the relief pressure increases from a cracking pressure to a set pressure as a relief flow rate increases.

Embodiments described herein provide for the control of an industrial machine dump operation by monitoring a position of the piston within a dump cylinder. The position of the piston is determined using a sensor within the dump cylinder. The sensor generates and provides an output signal to a controller. Based the output signal from the sensor, the controller is configured to limit the travel of the dump cylinder during the dump operation to reduce wear on the dump cylinder (e.g., by preventing damage caused when the dump cylinder is extending or retracting rapidly and the internal cylinder components make forceful contact with the rod or cap end).

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 work implement includes a breaker. Sensors detect an attitude of the work implement. A pilot valve controls the operation of the breaker. A controller controls the pilot valve. The controller detects, from the attitude of the work implement obtained by the sensors, a distance between a tip of the breaker and a striking limit. When it is determined that the tip of the breaker has reached the striking limit, the controller controls the pilot valve to stop the operation of the breaker.

A work vehicle includes a work implement operatively connected to a frame through an actuator having a cylinder and a piston rod. Control circuitry is operatively connected to the actuator and includes a processer and a memory, wherein the memory is configured to store program instructions and the processor is configured to execute the stored program instructions to: identify one of an initial retracted reference position of the piston rod based on an initial minimum retracted distance or an initial extended reference position of the piston rod based on an initial maximum extended distance; identifying an end of stroke position of the piston rod after identifying one of the initial retracted reference position of the piston rod or the initial extended reference position of the piston rod; and moving the work implement with respect to the work vehicle based on a work implement command modified by the identified end of stroke position.

A method of controlling hydraulic fluid flow to an implement of a material handling vehicle includes coupling a boom arm to a vehicle frame for rotation about the vehicle frame, rotating a boom arm with respect to the vehicle frame with an actuator, coupling an attachment to the boom arm for rotation with respect to the boom arm, sensing a pressure of fluid in the actuator, communicating the sensed pressure to a control system, determining a baseline pressure of the attachment based upon the sensed pressure of the fluid in the actuator, and limiting fluid flow to the actuator with a control valve in response to the sensed pressure of the fluid in the actuator being above the baseline pressure.

Provided is a work machine that, within the limit of not harming dynamic stability, can perform work utilizing the impact generated when a cylinder driving a front work implement collides with a stroke end. A drive control system 34 includes: a stroke end distance calculation and evaluation section 34c that determines whether or not it is possible for cylinders 20A and 21A to collide with a stroke end; a dynamic center of gravity position prediction section 34d that, when the stroke end distance calculation and evaluation section determines that it is possible for the cylinders to collided on the stroke end, predicts a trajectory of the dynamic center of gravity position of a hydraulic excavator 1 from a time when a decelerating operation of the cylinder starts to a time when the cylinder stops; and an allowable velocity changing section 34f that changes the allowable velocity of the cylinder according to a minimum distance from the trajectory of the dynamic center of gravity position predicted by the dynamic center of gravity position prediction section to a tipping line of the hydraulic excavator.

A work vehicle includes a vehicle body, a work implement including a boom attached to the vehicle body and an attachment attached to a tip end part of the boom, a first actuator configured to rotate the boom up and down, and a controller configured to execute an automatic lowering control in order to automatically rotate and lower the boom. The controller is further configured to set the first actuator to a floating state when it is detected that the attachment has reached a predetermined position during an execution of the automatic lowering control.