What issues should be paid attention to during the safety inspection of tower cranes
Tower cranes and construction lifts are indispensable large lifting machinery for construction sites, especially high-rise buildings. At the same time, due to the high risks involved in the installation, disassembly and use of this type of equipment, safety accidents occur from time to time. This is a real problem that our construction companies have to face, and it also puts a lot of pressure on our safety managers. How to check at the construction site and what aspects to check?
Inspection points for tower cranes:
① Moment limiter: When the lifting weight reaches 110% of the rated lifting weight of the corresponding range, Automatically cut off the power supply for lifting upward and luffing forward.
Weight limiter: When the lifting weight is greater than the rated value of the corresponding gear and less than 110% of the rated value, the power supply in the upward direction should be cut off, but the mechanism can move in the downward direction.
Height limit: When the hook device of the tower crane is lifted to the limit position specified below, the lifting action power supply should be automatically cut off:
1) The magnification of the lifting wire rope When the magnification is 2, the limit position should be 1000mm.
2) When the lifting wire rope has a magnification of 4, its limit position should be 700mm.
Amplitude limiter: The trolley decelerates when it reaches a distance of 1.5 meters from the buffers at both ends of the boom, and automatically stops at a distance of 0.5 meters
Rotation limiter: left and right The rotation angle in both directions is no more than ±540°.
Hook insurance: To prevent the lifting angle of the wire rope from being too large or improper hook, it is easy to cause the wire rope to come out of the hook head and cause the hanging object to fall and cause injury. The gap is less than 20% of the rope diameter
Car rope breakage protection device: The car rope breakage protection device is a safety device to prevent the luffing car from rolling when the rope is broken
Wire rope anti-slotting device: It is to prevent the wire rope from jumping out of the groove during rotation, causing the wire rope to be stuck, broken or shaft grinding, resulting in a hook accident.
Inspection of the wire rope: severe deformation: wavy deformation, cage distortion, strand extrusion, steel wire extrusion, local enlargement, local reduction in diameter, partial flattening, severe kinking, severe bending .
Rope clamp: The splint should be on the side that receives the force when the wire rope is loaded, and the "U" bolt should be on the tail end of the wire rope, and must not be crosswise. Standard section screws: The connecting bolts are complete and the fastening is firm
Wall attachment: When installing the wall attachment device, a theodolite must be used to check the verticality of the tower. Below the attachment point, ensure that the verticality deviation of the tower crane is not greater than 2/ 1000, the vertical deviation above the attachment point is not greater than 4/1000;