Toda Corporation has developed a swing control device that can handle large loads such as precast prestressed concrete (PCaPC) floor slabs and girders. Equipped with two parts (flywheels) that use centrifugal force to counteract unevenness in rotational motion. Control the lifted load by changing the rotation direction and tilt. The control capacity was 3.3 times (250 tons), which was previously limited to 75 tons per square meter.
Application to replace the first floor slab on the Yubarigawa Bridge on the Hokkaido Expressway (access road) (Provided by Toda Construction)
At worksites, there was the problem of the load swinging against the will of the operator due to the inertia of strong winds and crane movement. The control device of the lifted load uses the gyro effect obtained by rotating the internal flywheel at high speed to control the turning.
The developed large-sized load turning control device "Hypergien" is characterized by two flywheels. The tilting of the flywheel produces a turning moment to turn the load, and the passive control maintains the turning position of the load by generating resistance against wind pressure and inertial force.
Active control to rotate in any direction by remote control makes the installation work much more efficient than the installation positioning of PCaPC floor slabs using intermediary ropes. Since it can maintain a fixed posture even in strong winds, it prevents contact between the lifted load and workers, and prevents the lifted load from jumping out of the road regulation range.
First time for removal of existing floor slabs and erection of PCaPC floor slabs for "Douou Expressway Yubari River Bridge (In-bound Line) Floor Slab Replacement Work" (ordered by East Japan Expressway Company), which the company is constructing between Ebetsu City and Iwamizawa City, Hokkaido. Application. It was confirmed that work efficiency and safety were improved. In the future, we will continue to reduce the weight and improve the operation method, and will actively apply it to construction work that handles long and heavy loads.
