Two-sides Belt Grinding Technology For Sperial Seam Arc Welding Pipe

To ensure the girth weld auto-welding in pipeline construction, the standards of SSAW pipe ask to grind the end of the pipe both inside and outside weld less than 0.5mm.Presently,it is extensive using single belt grinding machine in domestic industry.There are some faults such as inefficient,low degree of automation and tediously long produce progress.There is no two side belt grinding machine in domestic,while the cost performance of the external machines is too low. So it is practical need to exploit a suit of two sides belt grinding machine.This paper is based on the Oula formula to deduce the expansion of Oula formula after considering the centrifugal force of belt.According the tensile test,Polynomial fitting can obtain the analysis formula of belt Tensile-Elongation curve.Based on the existing theory of grinding,we can obtain the mechanical model of abrasive belt grinding of spiral welded pipe,and the relationship of the coefficient of friction,grinding force and the pretightening force. We can obtain the three-dimensional image display model by MATLAB formula.According to the mechanical model of the abrasive belt grinding, on the premise of the allowable tension and no slip conditions, we can obtain the best optimizing grinding parameters speed and grinding force.Based on analysis and comparison of grinding structure modes of the wheel pressure/belt pressure, two or three wheels, active/passive grinding, rotation direction of grinding,grinding position, weld fitting,and the floating device,we can obtain the optimum structure of double side grinding.Based on the one side grinding machine, using the optimum structure and parameters,utilizing symmetric design,and considering the difference between one side and two sides machine,we design the grinding head structure of two side machine.Finally,we use simple structures to simulate the progress of two side grinding.And by the comparison of the grinding force, grinding speed, the friction coefficient and other parameters, verify the lifetime of abrasive belt,grinding quality, and grinding efficiency.