A control system configured to control movement of a hydraulically operated crane assembly and a crane tool of a work vehicle with a primary power source and a hydraulic working system. The control system configured to calculate a deviation between an actual value and a predetermined target value of a lifting movement of the crane assembly, and configured to control the crane assembly to fulfill the predetermined target value.

A manipulator for concrete pumps having an articulated boom with at least two boom arms and a hydraulic drive that pivots one or more of the boom arms. A hydraulic cylinder has piston and rod side working volumes. A hydraulic circuit has a first switching state in which the hydraulic circuit connects a first working port for feed or discharge of hydraulic fluid to the rod-side working volume and connects a second working port for feed or discharge of hydraulic fluid to the piston-side working volume. In a second switching state, the hydraulic circuit separates the first working port from the first fluid channel and thereby connects the first fluid channel to the second fluid channel for the feed of hydraulic fluid from the rod-side to the piston side working volume. A sensor acquires an operating state variable based upon which an activation assembly sets the switching state.

A crane is disclosed, the crane includes detachable hydraulic cylinder including a head side oil chamber and a rod side oil chamber both to be connected to a control valve through a joint, in which a head side hydraulic detecting section and a rod side hydraulic detecting section are each provided to the hydraulic cylinder, and a connection state between the hydraulic cylinder and the control valve is determined based on a head side hydraulic pressure and a rod side hydraulic pressure in a period until a predetermined time elapses after supply of electric power to the head side hydraulic detecting section and the rod side hydraulic detecting section is started and an operation tool for hydraulic cylinder switches the control valve to a state of supplying hydraulic fluid to the hydraulic cylinder.

A crane is disclosed, the crane includes detachable hydraulic cylinder including a head side oil chamber and a rod side oil chamber both to be connected to a control valve through a joint, in which a head side hydraulic detecting section and a rod side hydraulic detecting section are each provided to the hydraulic cylinder, and a connection state between the hydraulic cylinder and the control valve is determined based on a head side hydraulic pressure and a rod side hydraulic pressure in a period until a predetermined time elapses after supply of electric power to the head side hydraulic detecting section and the rod side hydraulic detecting section is started and an operation tool for hydraulic cylinder switches the control valve to a state of supplying hydraulic fluid to the hydraulic cylinder.

There is provided a crane winch device allowing a suspended load to freely fall due to a load thereof. The crane winch device includes a winch drum around which a rope for suspending the suspended load is wound, braking brake unit that brakes the winch drum, speed-increasing unit that performs speed-increasing assist of the winch drum in a direction of free fall acceleration when a braking force of the brake unit is smaller than a first threshold, and an adjustment unit that adjusts the first threshold.

The present invention relates to a hydraulic unit with a housing in which a hydraulic converter is accommodated, which is coupled with a drive shaft that includes a connecting shaft piece located outside the housing for connection to a mechanical drive element The invention furthermore relates to a hydraulic driving device with such hydraulic unit and to a drive train connecting piece to which the hydraulic unit is connected. It is proposed to integrate a clutch for connecting and disconnecting the hydraulic unit into the hydraulic unit itself, so that a mechanical drive train, to which the hydraulic unit is connected, can remain unchanged or need not especially be adapted to the clutch. In accordance with the invention, a clutch for coupling and uncoupling the connecting shaft piece of the hydraulic unit to and from the hydraulic converter of the hydraulic unit is accommodated in the housing of the hydraulic unit.

The present invention relates to a hydraulic unit with a housing in which a hydraulic converter is accommodated, which is coupled with a drive shaft that includes a connecting shaft piece located outside the housing for connection to a mechanical drive element The invention furthermore relates to a hydraulic driving device with such hydraulic unit and to a drive train connecting piece to which the hydraulic unit is connected. It is proposed to integrate a clutch for connecting and disconnecting the hydraulic unit into the hydraulic unit itself, so that a mechanical drive train, to which the hydraulic unit is connected, can remain unchanged or need not especially be adapted to the clutch. In accordance with the invention, a clutch for coupling and uncoupling the connecting shaft piece of the hydraulic unit to and from the hydraulic converter of the hydraulic unit is accommodated in the housing of the hydraulic unit.

A working machine includes a lower body, a turning body, a turning manipulating member which turns the turning body, a hydraulic motor which rotationally drives the turning body, a brake device which brakes the hydraulic motor, a main hydraulic source which supplies hydraulic oil to the hydraulic motor, and a direction control valve which controls a flow direction of the hydraulic oil according to the manipulated variable of the turning manipulating member, in which in a state where the hydraulic motor is braked by the brake device based on a manipulation of a brake manipulating member, when the turning manipulation is performed by the turning manipulating member, a brake applied to the hydraulic motor by the brake device is released with respect to turning in an indication direction indicated by the turning manipulation such that the turning body turns in the indication direction.

A working machine includes a lower body, a turning body, a turning manipulating member which turns the turning body, a hydraulic motor which rotationally drives the turning body, a brake device which brakes the hydraulic motor, a main hydraulic source which supplies hydraulic oil to the hydraulic motor, and a direction control valve which controls a flow direction of the hydraulic oil according to the manipulated variable of the turning manipulating member, in which in a state where the hydraulic motor is braked by the brake device based on a manipulation of a brake manipulating member, when the turning manipulation is performed by the turning manipulating member, a brake applied to the hydraulic motor by the brake device is released with respect to turning in an indication direction indicated by the turning manipulation such that the turning body turns in the indication direction.

A hydraulic driving apparatus that drives a plurality of driving subjects and regenerates energy thereof. This hydraulic driving apparatus includes: a first pump motor; a second pump motor that is switchable between a state of moving a first driving subject by hydraulic oil discharged from the first pump motor and a state of being operated as a pump by means of energy of the first driving subject; a first pump motor line that couples the first and second pump motors with each other; a first accumulator connected to the first pump motor line; a regeneration subject hydraulic actuator that moves a second driving subject; a second accumulator that receives hydraulic oil from the regeneration subject hydraulic actuator; a second pump motor line that couples the second accumulator with the first pump motor; and a pressure release changeover valve that opens/closes the second pump motor line.