| 摘要 |
<p>PURPOSE: To improve the quality and reliability of the weld zone by welding a tube by means of a ultrasonic welding wheel and driving the wheel at the peripheral speed identical to that of drawing the overlapping tube. CONSTITUTION: A strip 20 is drawn out of a roll 10 and formed into a cross- sectionally U-shaped strip 22 by means of a forming block 21. It becomes an overlapping tube with a forming bush 24 attached on a mandrel 23 and passes a positioning sleeve 30. The positioning sleeve 30 is provided with a welding slot 31, through which an ultrasonic welding wheel 32 descends and welds the overlap of the tube. At this time, the mandrel 23 serves as an anvil, while the wheel 32 is driven at the same peripheral speed as the speed of the tube. Then, the inside and the outside surface is coated with plastic at the inner and outer coating stations 14, 15, and cooled at the cooling station to form the product.</p> |
