Tadano Ltd.

Satoshi Tanii

Daiki Karashima

Kazuaki Tsuda

A controller calculates a theoretical payout length X1(θ) of a wire in a posture in which a hook block is raised, a theoretical payout length X2(θ) of the wire in a posture in which the hook block is lying, dX1(θ)/dt, and dX2(θ)/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 θ of the boom. The controller makes the boom stand and lie at a constant speed of F=dθ/dt, and makes a winch drive at a wind-up speed of J×{dX1(θ)/dt+dX2(θ)/dt}/2 taking J×{X1(θ)+X2(θ)}/2 as a target value.

Controller, boom device, and truck crane

Provided is a controller with high versatility that can automatically store or raise a boom and can be commonly used for various boom devices. The controller generates a function based on a length of a boom and a distance from a derrick fulcrum of the boom to an engaging member stored in a memory, and a depression angle of the engaging member with respect to the fulcrum. Then, the controller substitutes a derrick angle of the boom detected by a derrick angle sensor into the generated function to calculate a displacement distance from a distal end of the boom to the engaging member. The controller rotates a winch while raising and lowering the boom between a lowered position and a raised position such that the calculated displacement distance is a distance corresponding to an unwinding length of a wire detected by a length sensor.

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Kagawa, Japan

Satoshi Tanii