| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a hollow coil spring which can prevent inner surface corrosion and improving product appearance, and to provide a method for manufacturing the same. <P>SOLUTION: In an end sealing step, the material of an end Wa of a spring material W is gathered by machining to seal the end Wa. Spinning is preferably carried out as the form of machining. While pressing the end of the spring material W with a squeezing roller R, for example, toward the inside in the radial direction, the squeezing roller R is appropriately moved in the axial direction as necessary. The end Wa of the spring material W is thus blocked, as shown in Fig.3, eliminating the need to use a separate member such as a lid member. Such an end sealing step can be carried out immediately after an inner surface processing step, for example. In a coil forming step performed after the end sealing step, even when the end Wa of the spring material W is gripped and the spring material W is wound around a rod, the formation of a gap at the end Wa can be prevented. <P>COPYRIGHT: (C)2012,JPO&INPIT |
