The vehicle braking device includes a pilot pressure control portion which executes normal control in which the pilot pressure is controlled in response to the target value of the servo pressure and shortening control in which the change amount of the pilot pressure per unit time is greater than the change amount under the normal control in a mutually different timing, a state judging portion which judges the state of the master piston relating hysteresis of sliding resistance of the master piston based on the detection result of the servo pressure detecting portion or the liquid pressure co-relating with the servo premeasure and a control switching over portion which terminates the shortening control based on the detection result of the servo pressure detecting portion and the detection result of the state judging portion.

A piston accommodated in an internal space of a cylinder and forming a pair of pressure chambers together with the cylinder, the piston being configured to move relative to the cylinder; a first actuator connected to one pair of pressure chambers; a second actuator connected to the other of the pair of pressure chambers; a position detector configured to detect a position of the piston relative to the cylinder; a pressure detector configured to detect a pressure of one pair of pressure chambers; and a controller configured to control the first actuator and the second actuator. The controller controls one of the first actuator and the second actuator that the position detected by the position detector is made close to a target position and controls the other of the first actuator and the second actuator that the pressure detected by the pressure detector is made close to a target pressure.

A piston accommodated in an internal space of a cylinder and forming a pair of pressure chambers together with the cylinder, the piston being configured to move relative to the cylinder; a first actuator connected to one pair of pressure chambers; a second actuator connected to the other of the pair of pressure chambers; a position detector configured to detect a position of the piston relative to the cylinder; a pressure detector configured to detect a pressure of one pair of pressure chambers; and a controller configured to control the first actuator and the second actuator. The controller controls one of the first actuator and the second actuator that the position detected by the position detector is made close to a target position and controls the other of the first actuator and the second actuator that the pressure detected by the pressure detector is made close to a target pressure.

The invention relates to a crane comprising a base for attaching the crane to a harvester or similar work machine, a main boom having two ends, one end pivoted to the base, an articulated boom having two ends, one end pivoted to the said main boom , an actuator cylinder for moving the main boom relative to the base having a cylinder part, a second actuator cylinder for moving the articulated boom relative to the main boom, a pressure cylinder in connection with one actuator cylinder, arranged to follow this actuator cylinder in order to produce pressure for the second actuator cylinder, wherein the pressure cylinder is arranged to form an essentially coaxial multi-chamber cylinder with the actuator cylinder to be followed.

The invention relates to a crane comprising a base for attaching the crane to a harvester or similar work machine, a main boom having two ends, one end pivoted to the base, an articulated boom having two ends, one end pivoted to the said main boom , an actuator cylinder for moving the main boom relative to the base having a cylinder part, a second actuator cylinder for moving the articulated boom relative to the main boom, a pressure cylinder in connection with one actuator cylinder, arranged to follow this actuator cylinder in order to produce pressure for the second actuator cylinder, wherein the pressure cylinder is arranged to form an essentially coaxial multi-chamber cylinder with the actuator cylinder to be followed.