| 摘要 |
<p>PURPOSE:To improve the productivity as well as the accuracy, by unifying firmly an annular body and a molded body by spot-welding the opposing faces of them. CONSTITUTION:A molten body which consists essentially of aluminum and contains silicon is molded by an extruding process and then cut into upper and lower annular bodies 1a and 1b. The molten aluminum is pressed into the annular bodies to form molded bodies 2a and 2b. Spot welding is applied to the spaces formed between the bodies 2a/2b and the bodies 1a/1b and at four areas. Nuggets Na and Nb are formed at four areas on the opposing faces, and a medium is unified with the molded body. A thermal treatment is applied to upper and lower guide cylinders A and B. The outer circumference of the cylinder A is cut to be formed into a tape guide surface (g) having a low level of friction. In the same way, a guide surface (a) and a guide edge (e) are formed to the cylinder B. Thereafter the same procedure as conventional is carried out.</p> |
