The Application And Optimization Of500T Cold Shear’s Upgrades

Cold shear is the one of the key equipments of light special steel bar line, which working efficiency is one of the critical factors that will effect the production output. The original400t cold shear which installed on the production line cannot meet the requirement of the productivity due to the increasing of the mill productivity. In additional, the external shell has some cracks during operation, which leads to cold shear working with damages and effect the production output. Now, the new500t cold shear will instead of the original400t shear and making improvement on the assembly of the high speed shaft of gearbox. The external shell will be casting one piece with ZG55, enlarging the casting arc in the region of stress concentration, optimizing casting processing, enlarging the section dimension of the region of stress concentration in order to ensure the rigidity of the stand. The dimension of lifting pin of the sliding frame of the shear head will be increased. The sliding frame will be redesigned that add four group Belleville springs to avoid big impact to make lifting pin to be deformation or broken when shear head go down to the extreme position.During the redesign the500t cold shear, considering the force structure is "C" structure in the original design, the shell will be beat with huge force when cutting bars. The casting shell will be cracked after long-term operation. After a certain time observed and argument, combining with the actual operation, the force structure of the shear body is decided to be modified from "C" structure to gantry frame structure which has been proven to rigidity increasing highly. Sealed gantry frame is distribute the cutting force to the two M100screw rod, the force of the split section is decreased; and a hole of f30is drilled in the crack tail of the shell to avoid enlarging cracks, consequently to increase the lift time of the cold shear.After the upgrading of400t cold shear, the maximum cutting force will be increased from400t to500t, the cutting range will be enlarged to f60mm, and the quantity of bars at every cutting will be increased30%. Thus, the capacity bottleneck constraints will be improved magnificently, simultaneously, the horseshoe shaped section when cutting bar with size over f30mm will be solved. Moreover, the outer quality of the product will be improved highly. Consequently, the market competitiveness of the products of the special steel plant of Laiwu Steel Group will be enhanced which will improve the economic performance.