Disclosed are an apparatus and a method for actively reducing an action impact of an excavator, and an excavator, which are related to the technical field of engineering vehicles. The method includes: collecting a boom inclination angle, a stick inclination angle, a bucket inclination angle, and state information of an operating lever, of the excavator; determining operation information of the operating lever, and judging whether the boom inclination angle, the stick inclination angle, and the bucket inclination angle are within set ranges; and controlling, based on a judgment result, operating states of an electronically controlled main valve and a main pump of the excavator. The method may reduce impact and vibration generated during operation of the excavator, thereby reducing a failure rate, and improving service life and work efficiency.

A pilot neutralizing system of a work vehicle may include a pilot neutralizer and a flow control apparatus. The work vehicle may include a frame assembly and an actuating assembly to pivot the frame assembly. The pilot neutralizer is hydraulically coupled between an operator control member and a steering valve to selectively direct a pilot signal to the steering valve and is hydraulically coupled to a reservoir via a reservoir line. The pilot signal is used to switch the steering valve to change a direction of a hydraulic fluid flowing from the steering valve to the actuating assembly. The flow control apparatus is hydraulically coupled to the reservoir line and used to change a draining rate of the pilot signal to the reservoir. When the articulation position reaches a cushion region during steering, the pilot signal drains back through the flow control apparatus to the reservoir.

A hydraulic cylinder includes a cylinder having axially spaced-apart first and second bores, and a piston having a piston rod and arranged in the cylinder for movement between two end positions and dividing the cylinder into a piston side and a piston-rod side. A hydraulic pump pumps hydraulic oil into the piston side to move the piston from one end position toward the other end position while hydraulic fluid is discharged from the piston-rod side via the first bore and a first outlet line. A throttling device is operably connected to the cylinder to throttle a flow of the hydraulic fluid as the piston moves past and seals the first bore so that hydraulic fluid is discharged via the second bore, thereby reducing a delivery amount of the hydraulic oil and thereby braking and damping a movement of the piston toward the other one of the end positions.

A vibrating ripper for demolition comprising a chassis, a vibrating assembly supported by the chassis so that it can move with an alternating translational motion along a work direction between a first stroke limit position and a second stroke limit position, and at least one demolition tool associated with the vibrating assembly.

In the second stroke limit position, the vibrating assembly is spaced further from the chassis with respect to the first stroke limit position.

The vibrating assembly comprises a main body associated with at least one pair of oppositely rotating eccentric masses actuated rotationally by at least one motor element.

The particularity of the invention resides in that it comprises means for detecting an abnormal movement of the vibrating assembly along the work direction beyond at least one of the stroke limit positions.

The disclosure relates to a method for controlling the crane of a working machine by using boom tip control, in which method the crane comprises at least two booms connected to the working machine and each other in an articulated manner, which booms are moved in relation to the working machine and to each other by means of actuators controlled by a control system of the working machine, and in which method the direction and speed of motion of the head of the crane, controlled by the driver applying controls in the working machine, is implemented by applying speeds of the different booms of the crane. In the method according to the disclosure the speeds of different booms of the crane are determined automatically on the basis of at least one of the following factors: positions of the different booms of the crane in relation to the extreme position of their range of motion; the maximum speed of the head of the crane achieved by the crane; maximum force achieved by the crane; location of the head of the crane in relation to the working machine; location of surrounding obstacles in relation to the crane. The disclosure also relates to a system for controlling the head of the crane of a working machine by boom tip control.

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.

A pilot neutralizing system of a work vehicle may include a pilot neutralizer and a flow control apparatus. The work vehicle may include a frame assembly and an actuating assembly to pivot the frame assembly. The pilot neutralizer is hydraulically coupled between an operator control member and a steering valve to selectively direct a pilot signal to the steering valve and is hydraulically coupled to a reservoir via a reservoir line. The pilot signal is used to switch the steering valve to change a direction of a hydraulic fluid flowing from the steering valve to the actuating assembly. The flow control apparatus is hydraulically coupled to the reservoir line and used to change a draining rate of the pilot signal to the reservoir. When the articulation position reaches a cushion region during steering, the pilot signal drains back through the flow control apparatus to the reservoir.

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.

In a work machine, a load information output part outputs a load calculated by a load calculation part as load information before a piston member shifting toward a stroke end reaches a specific position, and a load storage part stores the load calculated by the load calculation part as a specific load when the piston member shifting toward the stroke end reaches the specific position. The load information output part further outputs the specific load as the load information after the piston member shifting toward the stroke end enters a specific region.

A carrier comprising a hydraulic cylinder having a piston, a controller and a piston position sensor, wherein the carrier is arranged to carry an accessory through the use of the hydraulic cylinder and wherein the controller is configured to: receive piston position information; determine a direction of movement of the piston; and if the piston position equals a stop distance from an end wall of the hydraulic cylinder in the direction of movement, abort the movement.