| 摘要 |
PROBLEM TO BE SOLVED: To reduce the lowering of a remaining axial force to an inner cylinder by suppressing the axial elongation of an outer tube accompanied by the press-insertion of a spring sheet. SOLUTION: After inserting an element tube W between a ring-shaped outer mold 21 and an expandable/contractible inner mold 31, a pair of wedge members 41, 42 are relatively moved while imparting a prescribed axial force F1 to the element tube W, a segment 32 of the inner mold 31 is moved to the outside in the radial direction, and the element tube W is gradually expanded to the outside (A). The element tube W is concentrically bent at two points P1, P2 at both end sides of a first molding recess 51 of the outer mold 21 and a first molding protrusion 53 of the inner mold 31, and the axial force is increased to F2 in this stage (B). The element tube W is finally adhered between the molding recesses 51, 52 of the outer mold 21 and the molding protrusions 53, 54 of the inner mold 31, and a small-diameter salient 12 and a large-diameter salient 13 are continuously formed (C). The rigidity of the small-diameter salient 12 which is fit with the spring sheet is increased by this mechanical-type bulge processing, and the elongation of the outer tube at the press-insertion of the spring sheet can be suppressed. COPYRIGHT: (C)2009,JPO&INPIT
|
