| 摘要 |
PURPOSE:To form a small-load effective seal surface of a designated width by bending one end of a cylindrical member inwards in the radial direction to form a seal portion, and expanding the other end thereof outwards in the radial direction to form an O-ring receive portion. CONSTITUTION:The lower side 3 of a cylindrical member 2 is throttled, and then the upper side 4 is throttled. The upper side 4 is bent a little inwards in the radial direction. The portion 4 bent a little inwards is further bent inwards in the radial direction by hemming, and at this time, a plane seal portion 5 is formed. After that, the lower end portion is expanded a little outwards in the radial direction to form an O-ring receive portion 6. Thus, the manufacturing of a seal base A having the seal portion 5 and the O-ring receive portion is completed. |
