| 摘要 |
PURPOSE:To form interval of bellows with high accuracy in forming bellows in a cylinder usig liquid pressure by limiting the direction of drawing of the cylinder to one direction. CONSTITUTION:A cylinder 5 is inserted into a clearance between a forming die and a mandrel 3, and one of O-rings 7 is positioned at the edge of one side of a recessed part 2 of the forming die 1. Pressure liquid is fed to a liquid pressure applying part 8 through a liquid pressure supplying passage 9. The liquid is sealed by two O-rings, accumulated in the liquid pressure applying part 8, and pressing force is applied on the inner face of the cylinder 5. The cylinder 5 is closely stuck to the forming die 1 by the pressing force, and formed along the recessed part 2. Since liquid pressure is not applied on the cylinder 5 that does not correspond to the liquid pressure applying part 8, the cylinder 5 is pulled into the forming die 1 only from the direction shown by the arrow. When the second bellows is to be made at an intervel, the part of the cylinder that is drawn in is made opposite to above-mentioned bellows, and liquid pressure is applied to the recessed part 2 of the forming die in the same way as the above. |
