Integrated formwork carriage

I. Composition of the Integrated Strand-Threading Trolley and Its Construction Principle

1. Composition of the Integrated Strand-Threading Trolley

The prestressed whole-strand threading trolley consists of an electric control system, a hydraulic system, a scissor lift system, and a threading head system.

The electric control system consists of an industrial remote controller, a frequency inverter, a transformer, a phase-sequence protector, and AC contactors. The core controller adopts an RS485 controller specially designed for prestressed whole-strand threading, featuring high reliability and easy maintenance. The hydraulic system consists of a pump-station motor, a gear pump, solenoid relief valves, solenoid directional valves, stack-type pilot-operated check valves, stack-type bidirectional throttle valves, and direct-acting reducing valves, ensuring a stable and reliable system. The scissor lift system consists of a lifting platform, a lifting base, inner and outer lifting legs, and lift cylinders, providing smooth and reliable lifting. The threading head system consists of a threading reduction motor, strand pressure rollers, clamping cylinders, and longitudinal-shift cylinders. Through the rotational offset and clamping of the upper and lower strand pressure rollers, and via gears, sprockets, and chains, all strand rollers achieve synchronous rotation and continuous threading.

2. Construction Principle

After inspection and acceptance of the corrugated pipes in the box girder prestressing ducts, and once the threading machine is installed and positioned, one end of the prestressed strand is loaded from the rear side of the base. The prestressed strand sequentially passes through the rear-side positioning holes, the driving wheel, the belt groove between the driven wheel, the groove between the secondary driving and secondary driven wheels, and the front-side positioning hole, and then enters the corresponding corrugated pipe opening. Then, the remote control adjusts the nut to lower the screw, pressing the bearing seat and the secondary bearing seat until all rotating wheels clamp the prestressed strand as tightly as possible, and finally the motor is started.

The strand is passed through the trolley's positioning rollers to control the strand and its running direction; a motor is used as the power source, driving a gear-based reduction device to thread the strand into the corrugated pipe. Through the variable-frequency control system, the forward or backward speed of the strand can be flexibly controlled. If an obstruction is encountered during threading, the strand can be quickly retracted for inspection and adjustment, then re-threaded.

During threading, a strand retainer is used. The strand retainer is made by welding four 16# (No.16) reinforcing bars around an anchor at four positions, which effectively prevents the strand from tangling or twisting during threading.