Type, structure and use of strands The type, structure, raw material and production process of the wire rope depend on the use. Generally, carbon steel wire with a diameter of 0.1 to 6.0 mm in circular section is used for steel wire ropes. When twisting sealed and semi-sealed wire ropes, Z-shaped and other special-shaped steel wires are used. The types of steel wire ropes are divided according to their uses: there are ropes for suspension bridges and strands for mining, load-bearing ropes for overhead cableways, traction ropes for transmission devices, ropes for elevators, tie ropes for bundling and dragging goods, etc. The variety of wire ropes is increasing, and the structure is increasingly complex. In addition to various coated steel wires, stainless steel wires and bimetallic steel wires are also used. In order to ensure the safety and reliability of the use of steel wire ropes, the steel wire ropes are required to have sufficient strength, good flexibility, compactness of twisting, compression resistance, wear resistance, corrosion resistance and fatigue resistance, among which strength is the most important. .
The cross-sectional structure of the steel wire rope is in contact with round strands, line contact with round strands, surface contact with round strands, special-shaped strands, single-layer strands that do not rotate, sealed and flat. The surface contact round strand wire rope is made by drawing the wire contact strand through the wire drawing die or the roller die by the traction force of the stranding machine. Through the drawing die, there are two anti-corrosion measures, oiling and plating, before and after the deformation of the strand.
Oiled: All wire ropes must be oiled. The fiber core is immersed in oil, and the grease is required to protect the fiber core from rotting and rusting the steel wire, moisturizing the fiber, and lubricating the steel wire rope from the inside. The surface is oiled so that the surface of all the steel wires in the rope strand is evenly coated with a layer of anti-rust lubricating grease. For the mine ropes with high friction and high mineral water, black oil grease with increased wear and strong water resistance should be applied; It is coated with red oil grease with strong film-forming property and good anti-rust performance, and requires a thin oil layer, which is easy to keep clean during operation.
Coating: galvanized, aluminum, nylon or plastic, etc. Galvanized is divided into thin coating with steel wire first plated and then drawn and thick coating with steel wire drawn and then galvanized. Aluminized steel wire rope is more corrosion-resistant, wear-resistant and heat-resistant than galvanized steel wire rope. It is mainly used in fishing trawl ships and mines containing H2S, etc. Steel wire ropes coated with nylon or plastic are divided into two types: coated ropes and strand-coated ropes. The former is used for static cables and the latter is used for moving cables.
Wire winding process: rewind the wire reel on the I-shaped wheel of the twisting machine; the steel wire can also be directly rolled onto the I-shaped wheel from the wire drawing machine. Stranding twists the steel wire into strands. There are basket type, shaft tube type, tubeless type and double twister. Schematic diagram of the 12-axis tubular stranding machine, 1 is the I-shaped wheel with the lower strands, 2 is the rotating barrel, with 12 I-shaped wheels full of steel wire inside, 3 is the stranded pressing shoe, 4 is the Traction wheel, 5 is the take-up wheel of the upper strand, the barrel rotates once, and the length of the strand drawn by the traction wheel is the lay length of the strand.
