Abstract: This work machine includes: a first hydraulic cylinder and a second hydraulic cylinder that telescope a telescopic boom on the basis of hydraulic oil supply and discharge, a switching valve that is disposed on a pressure relief circuit for connecting the first hydraulic cylinder and the second hydraulic cylinder to a tank, and a control unit that causes the switching valve to connect the first hydraulic cylinder to the tank and releases the pressure in the first hydraulic cylinder when contracting or extending the second hydraulic cylinder in a condition in which the first hydraulic cylinder is contracted.

Abstract: A dynamic lift-off control device that is mounted on a crane including a boom and a winch for winding a wire rope and that controls dynamic lift-off of a suspended load, wherein: the dynamic lift-off control device comprises a load detection unit that detects a load acting on the boom, and a control unit that controls a winding action of the winch and a hoisting action of the boom; and the control unit controls the hoisting of the boom by using a control signal, which is generated on the basis of the change over time in the value detected by the load detection unit and to which a filter for attenuating a frequency component in a prescribed range, to suppress swaying of the suspended load is applied.

Abstract: There is provided a loading type truck crane that includes an outrigger device including a right outrigger and a left outrigger that are mounted on a vehicle and are capable of extending and retracting in a vehicle width direction of the vehicle, and a crane device that includes a turnable boom and is mounted on the vehicle. A control device that is provided in the truck crane calculates a critical working radius of the crane device on a basis of a ground-contact reaction force of the outrigger device, and implements safety control related to at least one of a lowering operation and an extension operation of the boom by the crane device on a basis of the calculated critical working radius.

Abstract: This work machine comprises: a plurality of booms that extend and retract with the power of an actuator; a first pin that is moved by a first spring to connect adjacent booms and is moved by power of a motor to release a connection of the adjacent booms; a second pin that is moved by a second spring to connect the boom and the actuator and is moved by power of the motor to release a connection of the boom and the actuator; and a circuit that is configured so that when the first pin is moved by the first spring or when the second pin is moved by the second spring, a current based on motor idling caused by the movement of the first pin or second pin is not generated.

Abstract: This crane is capable of transporting cargo and includes: a feedback control unit for feedback control of the crane or an object to be controlled that is a component of the crane; a learning model that has a weighting factor and learns the characteristics of the object to be controlled in real time by adjusting the weighting factor on the basis of a teacher signal including a first signal generated by the feedback control unit; and a communication control unit that transmits the weighting factor to an external device that is communicatively connected to the crane.

Abstract: This crane, which has a revolving body that supports a boom, includes: a traveling vehicle body that has a main frame that supports the revolving body, and runs on electricity; a left outrigger support section and a right outrigger support section provided at the rear of the main frame so as to be shifted back and forth; and a power supply unit having a rechargeable battery that supplies the electricity to the traveling vehicle body, wherein the power supply unit includes a current conversion unit which is in a space above the right end of the left outrigger support section of the traveling vehicle body and on the right side of the main frame, and converts the alternating current supplied from the charging port into direct current and sends the direct current to the rechargeable battery.

Abstract: This crane control device controls the operation of a boom and a winch and transports a load from a start point to an end point, the control device comprising: an acquisition unit that acquires position information of the start point and position information of the end point; a horizontal trajectory generation unit that, by using an optimal control theory, generates a horizontal trajectory for a distal-end part of the boom as represented by a horizontal-direction component of a straight line linking the start point and the end point; a movement trajectory generation unit that generates a trajectory of movement of the boom for transporting the load so as to follow the horizontal trajectory, and a trajectory of rotational movement of the winch; and a movement control unit that controls the boom and the winch based on the trajectory of movement of the boom and the winch.

Abstract: The invention addresses the problem of providing a remote operation terminal that prevents erroneous operation while remotely operating a mobile crane and that can easily and simply remotely operate the mobile crane, and a work vehicle comprising the remote operation terminal. A remote operation terminal comprises: a terminal-side GNSS receiver; a suspended load movement manipulation tool; and a terminal-side control device. The terminal-side control device acquires the current position of a boom tip from the crane control device and the current position of the remote operation terminal from the terminal-side GNSS receiver of the remote operation terminal, and sets the reference for the operation direction on a line L connecting the current position of the boom tip and the current position of the remote operation terminal.

Abstract: Provided is an estimation apparatus for estimating a number of wound layers of a wire rope in a crane including a boom, a winch drum, and the wire rope wound around the winch drum, the estimation apparatus being mounted on the crane, the estimation apparatus including: a calculation unit that calculates a delivery length of the wire rope; a detection unit that detects a rotational amount of the winch drum; and a control unit that estimates the number of wound layers, based on a difference in the delivery length of the wire rope and a difference in the rotational amount of the winch drum between a first orientation and a second orientation of the boom.

Abstract: This crane has a turning body that supports a boom, the crane including: a travel body that has a frame for supporting a front-side axle and a rear-side axle; and a motor that is disposed below the frame and between the front-side axle and the rear-side axle, the motor being connected to the front-side axle and the rear-side axle.

Abstract: This crane comprises a traveling vehicle body that travels through use of a motor driven by a power supply unit, and a first cooling system for cooling the motor, the first cooling system having a plurality of cooling devices that are distributed in the traveling vehicle body and connected in parallel with each other, and that cool a fluid that flows through a circuit of the first cooling system.

Abstract: A crane for transporting a load from a transportation origin to a transportation destination, the crane being provided with: an operation function unit provided so as to be turnable; a hook suspended by a wire rope from a distal end part of the operation function unit; an information-reading unit provided to the hook or a member that moves with the hook, the information-reading unit acquiring information relating to a position of the transportation destination from an information storage unit provided to the load; a control unit for calculating, on the basis of the information relating to the position acquired from the information-reading unit, information relating to an operation of the crane for transporting the load to the transportation destination; and a display unit for displaying the information relating to the position and the information relating to the operation.

Abstract: This control system for controlling an actuator of a crane is provided with a signal processing unit for generating a signal related to a target operating amount of the actuator, a feedback control unit for controlling the actuator on the basis of the difference between the signal relating to the target operating amount, and a fed-back signal relating to the operating amount of the actuator, and a feed-forward control unit which controls the actuator on the basis of the signal relating to the target operating amount, in cooperation with the feedback control unit, and learns the characteristics of the actuator by adjusting a weighting factor on the basis of a teaching signal, wherein the signal processing unit converts an input signal into the signal relating to the target operating amount by removing a pulse-shaped component from the input signal.

Abstract: A controller calculates a theoretical payout length X1(?) of a wire in a posture in which a hook block is raised, a theoretical payout length X2(?) of the wire in a posture in which the hook block is lying, dX1(?)/dt, and dX2(?)/dt, using a length L of the boom, A and B (first specified values) indicating coordinates of a hook hardware, a length K (second specified value) being a sum of a length of the hook block and a length of a hook hardware, and a derricking angle ? of the boom. The controller makes the boom stand and lie at a constant speed of F=d?/dt, and makes a winch drive at a wind-up speed of J×{dX1(?)/dt+dX2(?)/dt}/2 taking J×{X1(?)+X2(?)}/2 as a target value.

Abstract: Provided is a crane including: an operable function part; an actuator; a generation part; a filter part filtering a first control signal and generating a second control signal; a control part controlling the actuator based on the second control signal; and a computation part computing information relating to a flow quantity estimated as the operable function part moving, if a stop signal has been inputted into the actuator at the present position of the operable function part, from when the stop signal has been inputted into the actuator to when the operation of the operable function part stops. The control part outputs the stop signal to the actuator if information relating to the present position of the operable function part, information relating to a target stop position whereat the operable function part is to be stopped, and the information relating to the flow quantity satisfy prescribed conditions.

Abstract: This work machine includes: a telescoping actuator that moves a first boom in the telescoping direction with respect to a second boom; an electrical drive source that is disposed in a movable portion of the telescoping actuator; a first connection mechanism that switches a connection state between the telescoping actuator and the first boom on the basis of the power of the electrical drive source; a second connection mechanism that switches a connection state between the first boom and the second boom on the basis of the power of the electrical drive source; and a control device that controls operation of the electrical drive source. The control device executes motor assist processing of operating the electrical drive source when the first fixing pin and/or the second fixing pin is restored by biasing force.

Abstract: This power supply circuit for work machine is provided with a first switch for switching connection and disconnection of a first electrical path provided between a battery and a load which is driven with the power of the battery, and a second switch for switching connection and disconnection of a second electrical path bypassing the first switch. The second switch, when the first switch is switched from a state in which the first electrical path is connected to a state in which the first electrical path is disconnected, places the second electrical path in a connected state for a certain period and then, after the period elapses, switches the state in which the second electrical path is connected to a state in which the second electrical path is disconnected.

Abstract: A lightweight and high-rigidity telescopic boom in which strain during manufacturing is suppressed is disclosed. In a telescopic boom, a plurality of booms forms a telescope structure, and the telescopic boom includes a boom fixing mechanism that fixes a top boom disposed relatively inside at a predetermined position with respect to a first intermediate boom disposed relatively outside. The boom fixing mechanism includes a boom fixing pin that is provided to the top boom and advances and retreats with respect to the first intermediate boom, a fixing boss that is provided to the first intermediate boom and into which the boom fixing pin is inserted and extracted, and a gap maintaining member that is provided to the fixing boss and protrudes outward to maintain a gap between the first intermediate boom and a second intermediate boom disposed further outside.

Abstract: The work machine includes: a telescoping actuator that moves a first boom in the telescoping direction with respect to a second boom; an electrical drive source that is disposed in a movable portion of the telescoping actuator; a first connection mechanism that switches a connection state between the telescoping actuator and the first boom on the basis of the power of the electrical drive source; a second connection mechanism that switches a connection state between the first boom and the second boom on the basis of the power of the electrical drive source; and a torque limiter that is disposed between the electrical drive source and the first connection mechanism or the second connection mechanism, the torque limiter maintaining, at a predetermined value or less, a load acting on a mechanical element constituting a power transmission path from the electrical drive source.

Abstract: A performance information server comprises: a request acquisition unit that acquires a request including machine-type information for a work machine, and a performance information request to indicate performance information for the work machine; a storage unit that stores specification data for the work machine in association with the type of the work machine; a control unit that acquires the machine type information included in the request and the performance information for the work machine, on the basis of the specification data corresponding to the machine type information; and a response presentation unit that presents a response including the performance information acquired by the control unit.