Considerations for  high frequency Welded Steel Pipe Machine

These are somethings need to consider when designing the a new Welded Steel Pipe Machine:

　　　1, enlarge the middle extension of tube billet In the molding operation, increase the pressure of the opening hole type, so that the roll gap between the upper and lower rollers is slightly smaller than the thickness of the tube billet, the middle part of the tube billet is compressed by the micro-pressure, so that the middle produces a slightly larger extension to reduce the relative elongation of the edge. If the middle extension is greater than the edge extension, the outlet appears to bend upwards, if less than the edge extension, it bends downward,

　　　Adjust the operation should be straight as well.

　The extension of the middle part of the molding machine to increase the deformation, so that the increase in power consumption, roller wear and tear, equipment is easy to damage, when the tube billet and roll surface has relatively sliding, easy to produce roller printing and scratches.

　　　2, increase the deformation zone length

　If possible, the increase in the number of deformation racks, that is, the increase of deformation zone length, the relative reduction of two adjacent racks of deformation, due to the edge extension and the formation of highly democratic square proportional to the shape, can significantly reduce the edge elongation.

　　　3, increase the roller diameter

　Increasing the roll diameter is to increase the deformation zone length of the frame, and the length of the edge extension and the hole shape deformation area is inversely proportional to, under the possible conditions, as far as possible increase the roll diameter, can make the edge extension reduce.

　　　4, reduce the distance between the racks The edge of the billet is compressed between the racks.

　When the distance is larger, the edge extension must be compressed and absorbed by the last several frames. Easy to cause drum kit. Shorten the distance, in essence, increase the number of racks, can be at any time by the edge of the extension of the compression and absorption, and improve the molding conditions. But the distance cannot be too small, you must set aside enough operating space.

　　　5, improve the arrangement of rollers, set up roll group.

　In the forming unit, the horizontal frame is the rack that produces the edge extension, vertical roller frame In addition to guide and prevent rebound, there are compression and absorption edge extension of the role of the pre-forming a large number of the edge of the extension, the need to be in the closure of the hole before compression and absorption, using three or four sets of vertical roll group layout.

　　　6, adjust the speed between the racks,

　In the forming of each frame, so that the next speed is slightly greater than the speed of the last one, given a number of tension, can prevent the edge of the extension of the wave generated. On the unit of the collective drive, the bottom diameter of the lower roller can be increased by frame, (0.6-1.0 mm).

　　　7, increase the pressure of the closed hole

　The Tube billet has no longer a relative edge extension in the closed hole. The closed hole is compressed to the edge of the tube through the guide ring and the two sides of the roll. Appropriate increase in the pressure of the closed hole to absorb part of the edge extension, can prevent waves and drum.

　       8, a small vertical roll group is added between the horizontal racks as an auxiliary device to compress the edges. In fact, it absorbs the edge extension to prevent waves and drum kits.

          9, the use of lower roller drive on the passive transmission mode