L48A1 Mast Section the safety check of tower crane and construction elevator
Tower hoist and construction elevator are indispensable large lifting machinery in construction site. There are high risks in the installation, disassembly and use of such equipment, and safety accidents occur from time to time. It is therefore particularly important to carry out safety inspections of such equipment. How to do the security check work of tower crane and construction elevator, the following discuss with everyone!
1, tower lifting inspection points
(1) Torque limiter: When the starting weight reaches 110 % of the rated starting weight of the corresponding amplitude, the power supply that rises upwards and changes forward is automatically cut off.
(2) Weight limiter: When the lifting weight is greater than the corresponding file size and the rated value is less than 110 % of the rating value, the power supply in the ascending direction shall be cut off, but the mechanism may be used for the movement in the descending direction.
(3) Height limit: When the hook device of the tower crane rises to the limit position specified below, the action power supply of the lifting shall be automatically cut off:
& lt; 1 & GT; When the doubling rate of the lifting wire rope is 2 times, its limit position should be 1000mm.
& lt; 2 & GT; When the doubling rate of the lifting wire rope is 4 times, its limit position should be 700MM.
(4) Variable limiting device: The car slows down 1.5 meters from the buffer at both ends of the lifting arm, and automatically stops at a distance of 0.5 meters.
(5) Rotary limiter: The rotation angle in the left and right directions is not greater than ± 540 °.
(6) Hook insurance: When the angle of the lifting wire rope is too large or the hook is not appropriate, it is easy to cause the wire rope to be removed from the hook head and the hanging object falls and hurts. Gap less than 20 % of rope diameter
Car broken rope protection device: Car broken rope protection device is a safety device to prevent sliding when the car breaks the rope
(8) Steel wire rope anti-grooving device: It is to prevent the wire rope from beating out of the slot during rotating operation, resulting in the wire rope being stuck, pulled off, or grinding shaft, and there is a hook accident.
(9) Steel wire rope inspection: serious deformation: wavy deformation, cage-shaped distortion, rope extruding, wire extruding, local increase, partial reduction in diameter, partial compression, severe twisting, severe bending.
(10) Rope card: The splint should be on the side where the wire rope is carrying the force, and the "U" bolt should be at the end of the wire rope, and it must not be reversed.
(11) Standard section screw: The connection bolt is complete and firm
(12) Attachment wall: When installing the attached wall device, a theodolite must be used to check the vertical condition of the tower body. The vertical deviation of the tower crane below the attachment point is not more than 2/1000, and the vertical deviation above the attachment point is not greater than 4/1000.
2, the main points of inspection of construction lifts
(1) Before it is put into use, it must undergo a fall test. The lift shall be subjected to a fall test every three months during use. The test procedure shall be carried out in accordance with the specifications. When the ladder cage falls beyond 1.2 M braking distance in the test, the reason shall be ascertained, and the crash safety device shall be adjusted to ensure that the braking distance does not exceed 1.2 M.
(2) Drive mechanism: When the full load of the suspension cage drops, the braking distance shall not exceed 0.3 meters, and the braking disc shall not be less than 5mm thin, otherwise it shall be replaced.
(3) Upper and lower limit: The installation position of the upper limit switch should ensure that the upper safety distance left by the ladder cage should not be less than 1.8 M, and the lower limit should ensure that the ladder cage must not touch hard bottom.
(4) Limit switch: The distance between the upper limit and the upper limit switch is greater than or equal to 0.15 meters.
(5) Entry and exit gate limits, window door limits, wire rope safety, and weight limiters must all ensure normal work.
