Kobe Steel, Ltd.

Kobelco Construction Machinery Co., Ltd.

Kobelco Cranes Co., Ltd.

Mamoru Uejima

Naoki Sugano

Koji Inoue

Hideaki Yoshimatsu

Hirotsugu Sawai

Satoshi Mimura

A combination crane A is formed by connecting two crawler cranesL andR. Each crawler crane is provided with at least a lower propelling bodywhich can be propelled by crawlers, an upper revolving bodyrotatably mounted on the lower propelling bodyby a swing unitprovided between them, a boomwhose base section is tiltably supported on the upper revolving body, a tilting mechanismthat raises and lowers the boom and a hoist mechanism that hoists and lowers the lifting membershung by a hoist ropefrom the top of the boom. Both upper swing bodies of two cranes are connected together with a connecting beam. Swing motion is performed by driving the one crawler crane to move around the other crawler crane which is free to rotate and is locked against propulsion.

Combination crane

In a neutral range preset, there are set a zone for stopping and holding a rotating body only by a mechanical brake, a zone for holding the body only by performing position holding control, and a zone for simultaneously exerting both effects, i.e., the effect of the mechanical brake and the effect of the holding control. On-the-spot holding torque generated when the position holding control is performed is stored. The higher of the on-the-spot holding torque stored and accelerating torque according to an operation amount of the body at a rotation starting time is set as electric motor torque for acceleration. When performing a pressing work including pressing a bucket against an object for work, torque control is carried out according to the operation amount.

Rotation control device of working machine

Growing community of inventors

Akashi, Japan

Mamoru Uejima