A stabilizer system includes a first object that moves relative to a second object and includes a first actuator coupled to a first wear pad. The first actuator drives the first wear pad to contact a first side of the second object to control motion of the first object relative to the second object. The first actuator operates in a first mode and in a second mode. While operating in the first mode, the first actuator applies a first force to the first wear pad to block the motion of first object relative to the second object. While the first actuator is operating in the second mode, the first actuator applies a second force, lower than the first force, to the first wear pad to enable the motion of the first object relative to the second object.

A hydraulic system (600) and method for reducing boom dynamics of a boom (30), while providing counter-balance valve protection, includes a hydraulic cylinder (110), first and second counter-balance valves (300, 400), and first and second control valves (700, 800). A net load (90) is supported by a first chamber (116, 118) of the hydraulic cylinder, and a second chamber (118, 116) of the hydraulic cylinder may receive fluctuating hydraulic fluid flow from the second control valve to produce a vibratory response (950) that counters environmental vibrations (960) on the boom. The first control valve may apply a holding pressure and thereby hold the first counter-balance valve closed and the second counter-balance valve open.

It is determined whether a velocity estimation model is established from an actual operating velocity Vr and a target operating velocity Vt of each of actuators 20A, 21A, and 22A; in a case in which the velocity estimation model is established, a dynamic center-of-gravity position of a hydraulic excavator 1 in a case in which each of the actuators 20A, 21A, and 22A is suddenly stopped from a driven state is predicted from an estimated operating velocity Ve; in a case in which the velocity estimation model is not established, the dynamic center-of-gravity position is predicted from the actual operating velocity Vr and it is determined whether to execute control intervention using the predicted dynamic center-of-gravity position; and in a case in which it is determined to execute the control intervention, the target operating velocity Vt is corrected in such a manner that each of the actuators 20A, 21A, and 22A slowly decelerate. It is thereby possible to appropriately carry out operating velocity limiting on a front work implement 2 and slow deceleration of the front work implement 2 and to suppress reductions in workability and operability, a deterioration in a ride quality, and the like even in a case of work involving an abrupt change in disturbance or a change in the lever operation amount within minute time.

Provided is a work vehicle which is capable of appropriately setting the height of a work tool as a control threshold value for a ride control device or an automatic transmission control device, and which is excellent in operability, travel stability, and work efficiency. A value detected by an angle sensor (39) when a signal import switch (46) is operated by an operator is stored in a height position storage unit (35b) of a main controller (35) as height position information about a bucket (13) for excavation work. In the height position storage unit (35b), the height position of the bucket (13) for hauling work and the height position of the bucket (13) for loading work are stored in advance as offset values from the height position information about the bucket (13) for excavation work. In this way, the ride control device or the automatic transmission control device can be appropriately controlled regardless of the preference or habit of the operator.

A controller for a hydraulic excavator includes a first speed computation section that calculates a first speed of an arm cylinder from a value detected by an operation amount sensor; a second speed computation section that calculates a second speed from a value detected by a posture sensor and a third speed computation section calculates a third speed that is used as the speed of the arm cylinder in an actuator control section adapted to execute MC. The third speed computation section calculates the first speed as the third speed during the period between the detection of an input of operation for an arm by the operation amount sensor and predetermined time to, the third speed as a speed calculated from the first speed and the second speed during the period between t0 and time t1, and the second speed as the third speed at and after time t1.

A hydraulic system for moving an implement of a working machine includes a hydraulic cylinder with a cylinder and a piston which is adapted to move in the cylinder to thereby move the implement relative to a body structure of the working machine, and an actuator pump arranged to provide hydraulic fluid to the hydraulic cylinder, the hydraulic cylinder having a first port and a second port adapted to be in fluid communication with the actuator pump, the hydraulic cylinder and the actuator pump being arranged so that the hydraulic cylinder is directly controlled by the actuator pump so that the rate of movement of the piston of the hydraulic cylinder is purely pump controlled, the hydraulic system further including a hydraulic accumulator for suspension of the implement, which hydraulic accumulator is arranged to be selectively connectable to the first port, the hydraulic system further including a further pump in addition to the actuator pump, the hydraulic accumulator being arranged to be pressurised by the further pump.

A hydraulic system includes a hydraulic mechanism that includes a first and a second chamber. The hydraulic system includes a control valve fluidly connected to the first chamber and a pressure sensor that is configured to measure the fluid pressure in the first chamber. The hydraulic system includes a processing unit connected to the control valve. The processing unit is configured to control a hydraulic fluid flow rate to and from the first chamber of the hydraulic mechanism via the control valve to provide a shock absorption response. The hydraulic fluid flow rate is based at least in part on a pressure measurement received from the pressure sensor. The shock absorption response is based on a simulated hydraulic accumulator.

A hydraulic system of construction machinery includes: a boom cylinder divided; a first boom hydraulic line serving to supply a hydraulic oil to the boom cylinder during an ascending operation of a boom; a second boom hydraulic line serving to supply the hydraulic oil to the boom cylinder during a descending operation of the boom; a regeneration line serving so that the hydraulic oil discharged from the head side of the boom cylinder flows during the descending operation of the boom; a circulation line connected to the second boom hydraulic line; an accumulator connected to the regeneration line and serving to accumulate the hydraulic oil discharged from the boom cylinder; a boom regeneration valve including a first regeneration spool and a second regeneration spool; and a control unit serving to adjust opening areas of the first regeneration spool and the second regeneration spool during the descending operation of the boom.

A system for damping mass-induced vibrations in a machine having a long boom or elongate member, the movement of which causes mass-induced vibration in such boom or elongate member. The system comprises at least one motion sensor operable to measure movement of such boom or elongate member resulting from mass-induced vibration, and a processing unit operable to control a first control valve spool in a pressure control mode and a second control valve spool in a flow control mode in order to adjust the hydraulic fluid flow to the load holding chamber of an actuator attached to the boom or elongate member to dampen the mass-induced vibration. The system further comprises a control manifold fluidically interposed between the actuator and control valve spools that causes the first and second control valve spools to operate, respectively, in pressure and flow control modes.

Systems and methods for mast stabilization on a material handling vehicle are provided. In one aspect, the present disclosure provides systems and methods for a hydraulic circuit configured to stabilize a mast of a material handling vehicle in dynamic and static events. The hydraulic circuit is integrated into a typical hydraulic system used to raise and lower the mast and thereby a load supported by the mast.