In the casting and rolling process of seamless steel pipe, one of the important technical indicators to measure the processing quality of seamless steel pipe is straightness. Most seamless pipes need to be straightened, and the oblique roller straightening has high work efficiency and is in the main position. However, for the bending deformation of steel pipe ends and large-diameter steel pipes, the pressure straightening method is often used. The structure of the pressure leveler is simple and flexible.
Due to the lack of theoretical research on the pressure correction technology, for a long time, the workers have tried and tested the correction according to their experience, and the pressure correction accuracy is poor, the efficiency is low, and the labor intensity is high. Therefore, analyzing the deformation behavior of the steel pipe during the straightening process and accurately calculating the straightening stroke are the prerequisites for ensuring the straightening quality of the steel pipe, improving the straightening efficiency, and designing and manufacturing an automatic straightening machine.
Calculating the straightening stroke of the steel pipe is the key technology of the automatic steel pipe straightening machine. In view of the problems of low stroke accuracy of the current pressure correction thick-walled steel pipe, repeated corrections are usually required, and the efficiency is low.
According to the theory of elasticity, the mathematical model of load-deflection in the process of pressure correction of thick-walled steel pipe is established, and the correction stroke of stainless steel seamless pipe can be simply calculated by using this model. The flat deformation of the section is a common problem in the process of pressure straightening of the steel pipe, which seriously affects the processing quality of the steel pipe. Establishing an accurate cross-sectional flat mathematical model can effectively guide engineering practice and realize processing, which has important practical significance for improving yield.
Straightening process of seamless steel pipe:
1. The seamless steel pipe enters the roller table at the entrance of the leveler from the upstream roller table.
2. When the head of the seamless steel pipe is sensed by the sensor element in the middle of the entrance roller table, the roller table will decelerate.
3. When the head of the seamless steel pipe is sensed by the sensor element at the end of the entrance roller table, the first stage of the entrance roller table falls, and the closing delay of the inlet quick-opening cylinder starts to count.
4. When the pipe head enters the middle position of the inlet straightening roller, the inlet quick opening cylinder is closed, the seamless steel pipe is bitten in, and at the same time the second roller table of the inlet falls.
5. Through the setting of the delay time of the quick-opening cylinder, when the pipe head enters the middle position of the intermediate roll and the exit roll, the quick-opening cylinders of the intermediate roll and the exit roll are closed successively, and the seamless steel pipe enters the straightening process.
6. When the tube tail leaves the sensor element in the middle of the entrance roller, the first section of the entrance roller rises.
7. When the tube tail leaves the sensor element at the end of the inlet roller table, the second section of the inlet roller table rises. At the same time, through the setting of the quick-open cylinder delay, when the tube tail reaches the middle position of the inlet roller, the middle roller and the outlet roller, The quick-opening cylinders of the inlet roller, the middle roller and the outlet roller are opened successively.
8. The outlet roller table rises, and the seamless steel pipe is transported to the baffle at the end of the outlet roller table.
9. The exit roller table is lowered, the side door of the channel is opened, and the seamless steel pipe rolls onto the L-shaped splicing hook by gravity.
10. When the receiving hook falls, the seamless steel pipe rolls onto the soot-blowing stand, and the iron oxide scale on the inner surface of the seamless steel pipe is purged.