| 摘要 |
PURPOSE: To prevent an elastic sleeve from protruding and to efficiently forge tubular members of various dimensions by providing a protrusion preventing means consisting of expandable segmented pieces at the time of cold forging the tubular member in the inside of an annular member by an action of the elastic sleeve. CONSTITUTION: A pucker assembly 14 of a forging tool is attached to a mandrel in an enclosed state. Pressure is fed to the inside of the elastic sleeve 26 via a passage 28 in a state that the annular member 16 is positioned in the tubular member 18. The elastic sleeve 26 is expanded outward in the radial direction and brought into contact with the inside of the tubular member 18. The tubular member 18 is cold forged and engaged with the inside of a recessed part 20 of the annular member 16. At this time, the segmented pieces 38, 48, 58, 60 of the protrusion preventing means are moved outward in a supported state with respect to the outside of the sleeve 26 and kept in a contact state with the end of flanges 30, 34. A contact state between the outer surfaces of the segmented pieces 58, 60 and the inner surface of the tubular member 18 is kept and the sleeve 26 is continuously supported. Therefore, a space into which the sleeve 26 protrudes does not exist. Thus, the elastic sleeve 26 is supported over the wide range of dimensions. |
