Disassembly of top slewing self elevating tower cr

Disassembly of the upper slewing jack up tower crane

① turn the boom to the front and swing the brake. Drive the trolley outward to balance the backward tilt torque, so that the center of gravity of the jacking part roughly coincides with the axis of the jacking oil cylinder, and if necessary, additional weight of the lifting point

② remove the upper and lower connecting bolts of the uppermost standard section, put the introduction roller frame at the lower end of its four main chords, and align the roller with the introduction beam; Start the pump station, extend the piston rod of the jacking oil cylinder, and accurately insert the shoulder pole beam into the next jacking support plate groove; The operating procedures and functional characteristics of the simply supported beam impact tester jack up the upper part of the tower crane, drive the introduction beam to rise, embed the introduction roller on the introduction beam, and then slightly lift it to completely separate the top standard section from the lower standard section. At this time, pull out the standard section

③ retract the oil cylinder, and at the same time, use the rope to pull the tail with the same effect as that in manual operation, stand up, avoid the top jacking support plate, and continue to descend, so that the movable climbing claw rests on the top surface of the next jacking support plate

④ the oil cylinder is slightly retracted again, and the shoulder pole beam is extracted from the jacking support plate groove; Then, the oil cylinder extends again, so that the shoulder pole beam is built into the next jacking support plate groove. Extend the oil cylinder slightly, jack up the upper part of the tower crane, turn over the movable crawling claw, and avoid the just overlapped support padeye. The oil cylinder retracts, and the upper part of the tower crane continues to fall until the lower support of the slewing machine contacts the top of a standard section such as graphene based high-density porous carbon material

⑤ connect the lower slewing support with the top standard section with connecting bolts. At this time, only one nut can be installed, but it is not easy to lift without installing connecting bolts. Use the lifting hook to remove the standard section just pulled out

⑥ repeat the steps ① ~ ⑤, continue to remove the standard section and reduce the height of the tower crane. When the lower part of the jacking jacket is less than a standard section height from the attachment frame, the attachment frame should be removed first, and then the standard section. When the lower part of the jacket is about to touch the brace of the base frame, remove the brace first, and then continue to remove the standard section until the jacking jacket is completely lowered, and install the top connecting bolt

(2) remove the counterweight with a truck crane. For the large and long boom, 1 ~ 2 counterweights can be reserved to balance the excessive forward tilt torque of the boom. For fixed tower cranes with a length of less than 50m, the balance weight can be completely removed, but the balance arm must not be removed before the boom is removed

(3) lift the boom with a truck crane, slightly tilt it up, remove the boom tie rod, put it in the fixed clamp slot on the upper chord of the boom frame, and then remove the connecting pin at the root of the boom. Note that before removing the counterweight, never disassemble the jib or the jib rod when the sample is stretched to the yield point, otherwise there is a danger of tower collapse

(4) remove the remaining balance weight, and then remove the balance arm

(5) remove the assembly of the rotating tower body and tower cap

(6) remove the assembly of the rotating part

(7) remove the jacking jacket

(8) remove the bottom section and underframe