Common problems and safe use methods of the three

Common problems and safe use methods of the three components of the crane

the three components of the crane refer to the hook, steel wire rope and brake. Once these three components have problems, it is very easy to cause the lifting objects to fall, and even cause serious casualties

the common problem of the hook is that the jack rope is unhooked, that is, when the object is not tied well, the included angle between the jack ropes exceeds 120 degrees, or the hook is hit laterally during lifting, and the bottom of the weight is placed, the jack rope will be pulled out of the hook. In addition, because the hook is made of gray cast iron or steel castings, it is brittle, not resistant to collision, and easy to crack. Therefore, during the lifting process, if the site is narrow or the operator is careless, the pulley will be damaged due to collision. Once the pulley is damaged, the rim break will cause the cutting of the steel wire rope, and even cut the steel wire rope, causing accidents. If the operator fails to refuel the hook pulley in time, the pulley may cause excessive wear at the groove bottom due to inflexible rotation. For a long time, the pulley will be half cracked, and the hook will cause accidents during operation. Moreover, when the wear amount at the bottom of the groove increases, it will make the embedding amount of the steel wire rope medium deep and increase the friction resistance, which will lead to the deepening of the embedding amount of the steel wire rope and increase the resistance, which will lead to the galling of the steel wire and accelerated scrapping

the common problems of steel wire rope are generally caused by human factors. For example, when the operator is operating, the steel wire rope often rubs and scrapes with some equipment and buildings, resulting in local wire breakage and deformation of the outer layer of the steel wire rope; When operating the drum, the steel wire rope is wound on the drum in multiple layers in disorder; The hook often spins in the air, and the steel wire rope is twisted; Until the steel wire rope at point E is short of oil for a long time, causing its surface to rust; The steel wire rope is often burned by high temperature, and the steel wire rope is burned by touching the high-voltage power line, which is also the cause of accidents

the common problems of the brake are: the main spring of the brake is damaged or adjusted too loosely, and the braking torque is insufficient; The brake shoe is excessively worn, exposing the cap nail, resulting in insufficient friction, and the brake cannot brake the heavy objects; The locking nut of the brake lever is loose, the lever moves, or the joints of the lever system are stuck, which affects the holding brake; The opening clearance of brake shoe is abnormal. When some brakes are opened, the clearance of brake shoe on one side is as high as 2 to 3mm, while the additional brake shoe on the other side is still attached to the brake wheel, which accelerates the wear of brake shoe and brake wheel, and the car cannot be braked under heavy load. In addition, it is also disadvantageous to brake too tightly, because when the brake is deduced according to the relaxation coefficient of the first 100 hours and the stress relaxation coefficient of the anchor bolt after 1000h, the brake opening clearance is less than the normal value, the resistance of the brake wheel rotation will increase, often smelling the smell of scorched skin. When the friction has thermal expansion, it will not stop the car and cause accidents

to ensure the safe use of the three major components of the crane and prevent accidents, each crane user and operator must do:

first, ensure that the anti unhooking device of the hook is intact, and the hook should be anti-collision during use; Refuel the lubricating points frequently; In case of cracks, breaches or wear exceeding the standard, the pulley shall be replaced in time. Check the hook body frequently. If cracks and wear of the hook mouth exceed 10% of the thickness and the opening changes, they should be rectified in time. It is worth noting that the hook defects shall not be repaired by welding

second, when using the steel wire rope, sharp corners and twists should be avoided. The hoisting (braking) and acceleration (deceleration) speed of the crane shall be slow to prevent the steel wire rope from being subjected to excessive force and breaking. When the crane is working next to the power line, pay attention to ensure a sufficient safety distance from the power line to prevent the steel wire rope from touching the power line and burning. When the steel wire rope contacts with the sharp corners of buildings and equipment, wooden blocks shall be padded. The steel wire rope shall be neatly arranged on the drum without confusion to avoid pressure damage. As the greatest invention in the 21st century, steel wire plastic should not be burned at the rope edge to prevent high-temperature arc and welding slag from burning the steel wire rope. When the steel wire rope is too short, it is not allowed to take a long method to reuse it. It is necessary to strengthen the maintenance of the steel wire rope, often wash the dirt on the steel wire rope with kerosene and other cleaning agents, and pay attention to dip the lubricating oil into the steel wire rope. During operation, the operator shall check the steel wire rope once a day, pay attention to whether the steel wire rope is worn, broken, corroded, changes in diameter and other physical and chemical changes, and pay attention to the fixation of the rope end

III. during crane operation, the operator should carefully check whether the brake parts operate normally, whether they are jammed, whether the brake shoe clearance is appropriate, whether the brake Lun surface is good, and whether the adjusting nut is fastened. The brake should be lubricated twice a week, but pay attention not to stick the lubricating friction coefficient and low-noise oil on the friction parts. If the wear of brake shoe, brake wheel, small shaft, spindle, etc. exceeds the standard; The main spring and auxiliary spring are broken or plastically deformed; Cracks appear at the brake, etc; In case of failure of brake electromagnet, electric hydraulic stacking rod, etc., due to timely repair, it is not allowed to operate with disease to ensure safety