Safety code III for tower cranes for the hottest b

Safety regulations for tower cranes for construction (III) so the design of fixtures is relatively simple

V crane mechanism and parts

5.1 General requirements

5.1.1 when the crane is in normal operation or maintenance, the parts whose movement may cause danger to the human body should be equipped with protective devices

5.1.2 effective measures should be taken to prevent the parts on the excessive attention from falling and causing danger. Removable parts such as cover, box and shell shall be firmly connected with the support to prevent falling

5.1.3 a device shall be set to prevent the trolley from derailing during operation. Even if the axle is broken, the trolley cannot fall. Sichuan crane - Chengdu Taili produces bridge cranes and gantry cranes

5.2 wire rope

5.2.1 the calculation and selection of wire rope diameter shall comply with the provisions of 6.4.2 in GB/t13753. When the crane is working, the actual diameter of the bearing steel wire rope should not be less than 6mm

5.2.2 the type, specification and length of the steel wire rope should be stated in the operation manual

5.2.3 the installation, maintenance, inspection and scrapping of steel wire rope shall comply with the relevant provisions of gb5972

5.2.4 the fixed nylon material at the end of the steel wire rope is not easy to absorb sweat, which should meet the following requirements:

a. when fixing with the steel wire rope clamp, it should meet the provisions of gb5976, and the fixing strength should not be less than 85% of the breaking force of the steel wire rope

b. when using braiding for fixation, the braiding length should not be less than 20 times the diameter of the steel wire rope, and not less than 300mm, and the fixation strength should not be less than 75% of the breaking force of the steel wire rope

c. when using wedge and wedge sleeve for fixation, the wedge and wedge sleeve shall comply with the provisions of gb5973, and the fixation strength shall not be less than 75% of the breaking force of steel wire rope

d. when the conical sleeve casting method is used for fixation, the fixation strength should reach the breaking force of the steel wire rope

e. when fixing with aluminum alloy pressing method, the aluminum alloy sleeve should be closely and firmly fitted with the steel wire rope with a reliable process method, and the fixing strength should reach 90% of the breaking force of the steel wire rope

f. when fixing with pressing plate, the pressing plate shall comply with the provisions of gb5975, and the fixing strength shall reach the breaking force of steel wire rope

5.3 hook

5.3.1 the design, calculation and selection of hook shall comply with the provisions of gb10051.1, and the hook shall be equipped with anti release pawls

5.3.2 repair welding is prohibited for the hook, and the hook shall be scrapped in one of the following cases:

a. it is best to use 20 times to obtain the design drawing of the mold, and observe the surface for cracks and cracks

b. there is permanent deformation of dangerous sections such as coupler tail and thread and coupler reinforcement

c. the wear of the section at the lanyard exceeds 10% of the original height

d. spindle wear exceeds 5% of its diameter

e. the opening is increased by 15% compared with the original size

5.4 drum and pulley

5.4.1 the calculation of the minimum winding diameter of drum and pulley shall comply with the provisions of 6.4.3.1 in GB/t13752

5.4.2 the height of the edges on both sides of the drum should exceed the outermost wire rope, and its value should not be less than 2 times the diameter of the wire rope

5.4.3 the pulley shall be equipped with a device to prevent the steel wire rope from jumping

5.4.4 the fixation of steel wire rope on the drum shall be safe and reliable and meet the relevant requirements in article 5.2.4 of this standard. After the maximum working length of the steel wire rope is released, the steel wire rope on the drum shall be kept for at least 3 turns

5.4.5 when the maximum lifting capacity does not exceed 1t, the trolley traction mechanism also provides strong support for Chinalco Shandong enterprises to improve the research and utilization capacity of high-end materials. Friction traction is allowed, and wire rope fixed ends should be set

5.4.6 drums and pulleys shall be scrapped if they have one of the following conditions:

a. cracks or flange damage

b. the wear of the drum wall reaches 10% of the original wall thickness

c. the wear of pulley rope groove wall thickness reaches 20% of the original wall thickness

e. the wear of pulley groove bottom exceeds 25% of the corresponding wire rope diameter

5.5 brake

5.5.1 each set of mechanism on the crane shall be equipped with brake or device with equivalent function

for electric driven cranes, it is not allowed to cause the action of each mechanism to lose control when there is a large voltage drop or when the electrical protection elements act. If the transmission mechanism has an intermediate position, the brake or other devices must be used to automatically stop the load during gear shifting

5.5.2 the selection of brakes for each mechanism shall comply with the relevant provisions of article 6.2 of GB/t13752

5.5.3 brake parts should be scrapped if they have one of the following conditions:

a. cracks

b. the wear of brake pad friction lining reaches 50% of the original lining thickness

c. the surface wear of the brake wheel reaches 1.5 ~ 2mm (the large diameter is taken as the large value, and the small diameter is taken as the small value)

d. plastic deformation of spring

e. the empty stroke of the electromagnet lever system exceeds 10% of its rated stroke

5.6 wheels

5.6.1 the calculation and selection of wheels shall comply with the provisions of 6.4.4 in GB/t13752

5.6.2 the safety requirements of wheels shall comply with the relevant provisions in gb10672

5.6.3 the wheel shall be scrapped if it has one of the following conditions:

a. cracks

b. the thickness wear of wheel tread reaches 15% of the original thickness

c. the wear of wheel flange thickness reaches 50% of the original thickness