Maintenance of Working Device of Electriclifter Truck

Maintenance of Working Device of Electric lifter Truck
 When chains and pulleys are repaired, the chains must not be cracked or deformed, so they need to rotate flexibly. The elongation of each 20 segments of the chain shall not exceed the specified value (8mm). The wear of the chain pin shall not exceed 5% of the original diameter, and there shall be no severe bending, fatigue cracking and corrosion. If it exceeds the allowable condition, it should be replaced. If uneven wear occurs on the surface of the pulley, the difference of outer diameter between the two pulleys is greater than 0.2 mm, and the step or indentation on the surface of the pulley affects the normal operation of the chain. It should be replaced.           
 When the main and side rollers are repaired, the wear marks of the main and side rollers should be checked evenly. The wear limit is 1.Omm for the main roller and 0.5mm for the side roller. Otherwise, it should be replaced. When repairing  the inner and outer portal frames, the inner and outer portal frames should be straight. The non-linearity in the whole length should not exceed 1mm, and the use limit should be 3mm. Otherwise, it should be repaired. The cracks were checked by magnetic flaw detection and percussion method. If so, it should be repaired. Check for distortion or distortion. When the bending deformation is more than 1.5mm in the whole length range, the difference of transverse width is more than 1.5mm, and the bending deformation of the roof of the inner portal frame is more than 2.Omm, it should be corrected. When the overall deformation is serious and the inner diameter of the guide exceeds the wear limit, it should be scrapped. When the wear of inner and outer gantry guide rails reaches 2 mm on each side, the guide rails should be replaced or repaired and used.           
 When working device assembly is checked and adjusted, the front and rear clearances of the inner and outer portal frames are checked and adjusted first. Rollers with clearance less than 1 mm are selected for assembly. When assembling, after obtaining the suitable clearance, the lifting handle is operated to make the inner gantry run smoothly, and the rollers rotate freely and evenly. The second is to check and adjust the left and right clearance of the inner and outer gantry. According to the required size, the installation position of the lateral roller is adjusted by adding or reducing gaskets to ensure that the clearance between the roller and the inner and outer wall of the channel steel  of the inner and outer portal frames is satisfied (0.1-1.Omm at the highest position of the inner portal frame and 0.1-1.5mm at the lowest position of the inner portal frame); and the third is the adjustment of the clearance between the left and right sides of the fork frame, and between the inner and outer portal frames. The clearance adjustment is the same except that the clearance  values are 0.1-1.Omm everywhere. After all adjustments, lift fork and inner door frame to see if the movement is smooth. The lowering from the maximum height requires the inner portal frame to fall freely with the empty fork. Otherwise, it should be readjusted; fourth, the adjustment of lifting chain. Lifting chain is too long to meet the requirements of lifting height; too short  will cause serious accidents of fork rack running out of the channel steel of  the inner portal frame; two chains are loose and tight, resulting in overload  and unbalanced load of a chain, resulting in unstable movement and inflexibility of fork rack and inner portal frame. Therefore, the two chains must be adjusted. The method is that the electric lifter truck is parked on a flat ground, the portal frame is in a vertical state, the fork is lowered to the ground, and the piston (plunger) of the lifting cylinder is lowered to the bottom stop. Install the chain, one end of the two chains is connected with the  fork and locked. The other end of the chain is connected with the flange of the lifting cylinder block or the cross beam of the external portal frame, and the  length of the chain is adjusted by hinged bolts. Use your finger at 1000 mm from the ground, 49N as the quasi-chain, the chain movement distance is less than 20 mm, in the same way, adjust another chain. After the two chains are adjusted, the lifting fork should check the tightness and length of the two chains.