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 for a working machine includes a hydraulic actuator having a first fluid chamber and a second fluid chamber, an accumulator, an outputting fluid tube to output an operation fluid, and a switching valve to be switched between a first position and a second position. The first position allows the first fluid chamber and the second fluid chamber to be communicated with the outputting fluid tube and thereby allowing a floating operation. The second position allows the first fluid chamber and the accumulator to be communicated with each other, allows the second fluid chamber and the outputting fluid tube to be communicated with each other, and thereby allows an anti-vibration operation.

A method of controlling hydraulic fluid flow to a material handling vehicle implement 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 a first actuator, coupling an attachment to the boom arm for rotation with respect to the boom arm, rotating the attachment with respect to the boom arm with a second actuator, sensing a velocity of the attachment, communicating the sensed velocity to a control system, sensing a weight of the attachment, communicating the sensed weight to the control system, calculating a kinetic energy of the attachment based upon the sensed velocity and the sensed weight of the attachment, and adjusting fluid flow through the control valve to limit a range of movement of the attachment in response to the calculated kinetic energy of the attachment exceeding a pre-determined kinetic energy.

A system for enabling an upper swing body of construction equipment to swing freely. A working device is attached to the upper swing body to lift and move an object. A swing motor is connected to a power unit to swing the upper swing body. A controller is electrically connected to the working device and the swing motor to detect forces applied to the working device, and based on the detected forces, generating a control signal to control the swing motor so that the upper swing body swings freely. The system enables the upper swing body to swing freely to reduce energy consumption while ensuring safety when the upper swing body lifts a load.

A hydraulic lifting mechanism suspension has a main valve in the activation position whereof at least one hydraulic accumulator is connected to a connection line of the lifting mechanism suspension acting in the lifting direction or to working line of the lifting mechanism suspension acting in the lifting direction. The lifting mechanism suspension is deactivated via a deactivation position of the main valve, while at the same time a connection for recharging or filling the hydraulic accumulator is opened.

A hydraulic system for a working machine includes a hydraulic actuator having a first fluid chamber and a second fluid chamber, an accumulator, an outputting fluid tube to output an operation fluid, and a switching valve to be switched between a first position and a second position. The first position allows the first fluid chamber and the second fluid chamber to be communicated with the outputting fluid tube and thereby allowing a floating operation. The second position allows the first fluid chamber and the accumulator to be communicated with each other, allows the second fluid chamber and the outputting fluid tube to be communicated with each other, and thereby allows an anti-vibration operation.

Provided is a swing-back preventing apparatus capable of preventing a hydraulic actuator in a stop state from operating by undesired load. The swing-back preventing apparatus includes a housing, a piston, and a pair of biasing members. First and second spaces are formed between the piston and the housing, and the piston includes a pair of communication passages that are communicable with first and second spaces. When the piston is located at a first offset position, the first space is blocked from a first port. When the piston separates from the first offset position, the first space is connected to the first port. When the piston is located at a second offset position, the second space is blocked from a second port. When the piston separates from the second offset position, the second space is connected to the second port. When the piston is located at a position on the first offset position side of a neutral position, a first communication passage is connected to the first space. When the piston is located in a range from the neutral position to the second offset position, the first communication passage is blocked from the first space. When the piston is located at a position on the second offset position side of the neutral position, a second communication passage is connected to the second space. When the piston is located in a range from the neutral position to the first offset position, the second communication passage is blocked from the second space.

In a vibration suppression control OFF state, a signal pressure supply control valve stops supplying a first signal pressure, a pressure-regulating valve is in first position where a supply/discharge port connects to a pump port, and an open/close signal pressure is not supplied to an open/close control valve, so an open/close valve is closed. When the OFF state switches to ON state, the signal pressure supply control valve allows supplying the first signal pressure, and the pressure-regulating valve is in second position where the supply/discharge port connects to a tank port, so the pressure of a pressure accumulator decreases. In the ON state, when the pressure of the pressure accumulator is equal to pressure of a pressure chamber, the pressure-regulating valve is in third position where the supply/discharge port is blocked, and the open/close signal pressure is supplied to the open/close control valve, so the open/close valve is opened.

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), first and second control valves (700, 800), and a selection valve set (850). The selection valve set is adapted to self-configure to a first configuration and to a second configuration when a net load (90) is supported by a first chamber (116, 118) and a second chamber (118, 116) of the hydraulic cylinder, respectively. When the selection valve set is enabled in the first and second configurations, the second and first control valve may fluctuate hydraulic fluid flow to the second and first chamber, respectively, to produce a vibratory response (950) that counters environmental vibrations (960) of the boom. When the selection valve set is not enabled, the first and second counter-balance valves are adapted to provide the hydraulic cylinder with conventional counter-balance valve protection.

A shovel includes a hydraulic actuator, an operating apparatus used to operate the hydraulic actuator, an obtaining device configured to obtain information concerning the vibration of the body of a shovel, and a hardware processor. The hardware processor is configured to perform such control as to reduce the responsiveness of the hydraulic actuator to the operation of the operating apparatus when the body of the shovel is vibrating or the vibration is likely to occur in the body of the shovel, based on the output of the obtaining device.