A control device for at least one hydraulic working section (A, B), which can be connected to a pressure supply source (P) and a return flow (T) via a hydraulic supply circuit and to a control valve (34) supplied with a pilot pressure. The device includes an emergency shutdown system (32) having a pilot solenoid valve (16) and an additional valve (14). Both the hydraulic energy flow from the pressure supply source (P) to at least one of the respective working sections (A, B) and the pilot pressure supply to the control valve (34) can be suppressed by the pilot solenoid valve (16) via the additional valve (14).

This crane is provided with: a operable functional unit; an actuator; a generation unit that generates a first control signal including a first deceleration signal section composed of a control signal for decelerating a speed of the operable functional unit from a first speed to a second speed and a first constant-speed signal section composed of a control signal for maintaining the speed of the operable functional unit at the second speed; a filter unit for filtering the first control signal to generate a second control signal; and a control unit that controls the actuator so as to decelerate the operable functional unit based on the second control signal, then controls the actuator so as to maintain the speed at the second speed, and controls the actuator so as to zero the speed when a load has been moved to a location satisfying a prescribed condition.

This crane is provided with: a operable functional unit; an actuator; a generation unit that generates a first control signal including a first deceleration signal section composed of a control signal for decelerating a speed of the operable functional unit from a first speed to a second speed and a first constant-speed signal section composed of a control signal for maintaining the speed of the operable functional unit at the second speed; a filter unit for filtering the first control signal to generate a second control signal; and a control unit that controls the actuator so as to decelerate the operable functional unit based on the second control signal, then controls the actuator so as to maintain the speed at the second speed, and controls the actuator so as to zero the speed when a load has been moved to a location satisfying a prescribed condition.

Provided is a construction machine including a hydraulic system having a hydraulic pump, and a first hydraulic actuator and a second hydraulic actuator which are driven by hydraulic oil supplied from the hydraulic pump. The construction machine includes a first flow rate detector that detects a flow rate of drain hydraulic oil discharged from the first hydraulic actuator, a second flow rate detector that detects a flow rate of drain hydraulic oil discharged from the second hydraulic actuator, and an abnormality determination unit that determines abnormality of the first hydraulic actuator, based on a detection signal from the first flow rate detector, and determines abnormality of the second hydraulic actuator, based on a detection signal from the second flow rate detector. The first flow rate detector and the second flow rate detector each have a moving body.

Provided is a construction machine including a hydraulic system having a hydraulic pump, and a first hydraulic actuator and a second hydraulic actuator which are driven by hydraulic oil supplied from the hydraulic pump. The construction machine includes a first flow rate detector that detects a flow rate of drain hydraulic oil discharged from the first hydraulic actuator, a second flow rate detector that detects a flow rate of drain hydraulic oil discharged from the second hydraulic actuator, and an abnormality determination unit that determines abnormality of the first hydraulic actuator, based on a detection signal from the first flow rate detector, and determines abnormality of the second hydraulic actuator, based on a detection signal from the second flow rate detector. The first flow rate detector and the second flow rate detector each have a moving body.

Provided is a crane (1) including: a boom (7); a wire rope (8); a winch (9); and a hook (10). The crane further includes: a spooling operation instrument (24) for enabling commanding an operation state of the winch (9); and switches (switch (41) or switch (42)) for enabling commanding a switch of a control mode with regard to the operation of the spooling operation instrument (24). When the boom (7) is in a flat travel orientation with the hook (10) loaded on a prescribed site (hook platform (12)), the switches ((41), (42)) being in an on state and the spooling operation instrument (24) being operated toward one side thereof cause the boom (7) to be raised to a work orientation while the wire rope (8) is unwound such that the hook (10) is not lifted.

A system and method of this disclosure control an on/off state of a power take-off by monitoring the power demand of a fluid power circuit that includes the power take-off and a piece of equipment connected to the power take-off. The power demand may be indicated by a pressure or temperature of a fluid power circuit, by a motion of the equipment or its hand-held controller, or by an engine torque of an engine driving the power take-off. When the equipment transitions between an off state and an on state, the controller automatically engages the power take-off. When the equipment is in the on-state for a predetermined amount of time and the power demand is at or below a predetermined threshold during the predetermined amount of timethereby indicating idle time or an inactive state of the equipmentthe controller automatically disengages the power take-off.

A system and method of this disclosure control an on/off state of a power take-off by monitoring the power demand of a fluid power circuit that includes the power take-off and a piece of equipment connected to the power take-off. The power demand may be indicated by a pressure or temperature of a fluid power circuit, by a motion of the equipment or its hand-held controller, or by an engine torque of an engine driving the power take-off. When the equipment transitions between an off state and an on state, the controller automatically engages the power take-off. When the equipment is in the on-state for a predetermined amount of time and the power demand is at or below a predetermined threshold during the predetermined amount of timethereby indicating idle time or an inactive state of the equipmentthe controller automatically disengages the power take-off.

The present invention is provided with: a manipulation unit; a winch device that operates with an actuation mode of either a high speed mode or a low speed mode, and winds in or reels out a wire rope; a selection unit for an operator to select either the high speed mode or the low speed mode; a load calculation unit calculating a suspended load; a tension calculation unit calculating the tension of the wire rope; and a control unit controlling the actuation of the winch device. If the mode selected by the selection unit is the high speed mode, the manipulation unit is manipulated from a neutral state to a non-neutral state, and the suspended load is smaller than a load threshold and the tension is smaller than a tension threshold, the control unit controls the winch device so as to operate in the high speed mode.

The present invention is provided with: a manipulation unit; a winch device that operates with an actuation mode of either a high speed mode or a low speed mode, and winds in or reels out a wire rope; a selection unit for an operator to select either the high speed mode or the low speed mode; a load calculation unit calculating a suspended load; a tension calculation unit calculating the tension of the wire rope; and a control unit controlling the actuation of the winch device. If the mode selected by the selection unit is the high speed mode, the manipulation unit is manipulated from a neutral state to a non-neutral state, and the suspended load is smaller than a load threshold and the tension is smaller than a tension threshold, the control unit controls the winch device so as to operate in the high speed mode.