| 摘要 |
PURPOSE:To caulk and fix a double pipe into a boss aperture simply by inserting the double pipe into a boss aperture of arm member and by buckling and deforming the outer pipes of both sides of the boss aperture with pressurizing the outer pipe only in an axial direction. CONSTITUTION:A double pipe 7 overlapping an outer pipe 6 on the outside of an inner pipe 5 is prepared. A steel pipe, etc. which are easily deformable are used for the outer pipe 6 and for the inner pipe 5 a carbon steel pipe, Cr-Mo steel pipe, etc. having big mechanical intensity are used. When the double pipe 7 is inserted into a boss aperture 3 of a fork part 4 and only the outer pipe 6 is pressurized in axial direction, a flange 9 is formed with the buckling of the part of the part of the outer pipe 6 exposed on the upper side and lower side of the boss aperture. The fork part 4 and the inner pipe 6 are joined via the flange 9. |
