Research On Hydraulic Pressure System In Six Rollers Straightening Machine Based On PLC

During the press-working process of steel, mill bar is affected by rolling, cooling, transportation and many factors in heat treatment and warps to influence quality. In order to removal of warp defects mill bar need to be straightened on straightening machine. Based on the device structural features flattening machine can be divided into four types including gag straightener, roller straightener, cross roll straightener and stretcher machine.The present paper introduced layout status of production line, control appliance, function and flow of work of six roller hydraulic straightener. Cross roll straightener is the important equipment in the production of steel tube and hydraulic control system is the core of the pipe straightener. The project focused on the study of hydraulic control system of the pipe straightening machine and achieved a hydraulic control system of straightener based on programmable logic controller (PLC) on the basis of theoretical analysis. The working principle of the hydraulic control system was made out through the study of the straightening principle of cross roll straightener, Based on this, lectotype design calculation was done and the substance of the hydraulic control system was made out and installed and debugged. Finally Siemens PLC was used to achieve the entire automatic control process. PIC performed straightening quantity statistics.The paper put emphasis upon the design of quick-open type oilchannel. The machine was equipped with three groups of straightening rolls up and down. The lower roll was drive roll and the upper roll was underdriven roll. The elevation direction movements of the inlet upper and lower roll, outlet upper and lower roll and middle upper roll were drove by hydraulic cylinder respectively. The rotation of three drive rolls were drove by electric machine. It was equipped with photoelectric switch in front of every group of straightening roll in order to instantly induce if there was pipe clamp or pipe thread passed. When tubular products were transported to the entrance of complete machine by transfer chain, hydraulic power drove the inlet upper and lower roll, middle upper roll and outlet upper and lower roll to turn on rapidly in turn. The upper and lower rolls were both clamped to implement the purpose of straightening after pipe clamp or pipe thread passed. The study conclusion of this paper was verified in the production field. It provided reliable technical base for the enterprises to achieve good economic benefit.