PURPOSE: To obtain high quality steel pipe, both the inner and the outer surfaces of which are simultaneously lined with polyvinyl chloride by a method wherein the end of the steel pipe is shifted to its predetermined rough cutting position so as to cut off the extensions over the end of steel pipe of the inner surface and outer surface polyvinyl chloride pipes leaving the predetermined excess lengths in order to cut off said excess lengths under the condition that the steel pipe is aligned.
CONSTITUTION: With a pusher 28, which is driven by means of a pusher driving circuit 29 connected to a CPU, steel pipe 21 is pushed leftwards so as to bring its end below a grindstone saw 27. The aligning of the steel pipe 21 is performed under the condition that outer surface polyvinyl chloride pipe 22 and inner surface polyvinyl chloride pipe 23 respectively have somewhat excess lengths. After the aligning, the grindstone saw 27 is lowered by means of a grindstone saw driving circuit 30 connected to the CPU so as to rough-cut the outer surface polyvinyl chloride pipe 22 and the inner surface polyvinyl chloride pipe 23. Next, the steel pipe 21 is fed to a pipe end polishing section 31 so as to be placed on alignment rollers 32. The excess length parts of the outer surface polyvinyl chloride pipe 22 and of the inner surface polyvinyl chloride pipe 23 are shifted leftwards as being aligned so as to polish the excess length parts until the end of the steel pipe 21 abuts against a belt sander 33.
ADACHI TAKEO
SUZUKI MASAYUKI
| JPH02225023A | 1990-09-07 | |||
| JPS60210428A | 1985-10-22 |