| 摘要 |
A manufacturing method of a cold-drawn pipe for cam shaft is provided to manufacture the cold-drawn pipe simply by reducing the manufacturing time of the cold-drawn pipe and forming grooves with positions and depths on the cold-drawn pipe without post-processing and improve reliability of a product by preventing the generation of a mechanical tolerance. In a manufacturing method of a pipe for cam shaft by passing a pipe matrix(P) between a die and a plug to reduce outer diameter and inner diameter of the pipe matrix at the same time, and post-processing "V" shaped grooves on the pipe matrix, a manufacturing method of a cold-drawn pipe for cam shaft comprises: passing the pipe matrix between the die and the plug for twice or more to adjust thickness of the pipe matrix; and finally passing the pipe matrix between an ordinary plug(300) and a die(100) comprising a blade which has two or more "V" shaped grooves(110) integrally formed at an inner side thereof with the "V" shaped grooves being spaced apart from one other in a predetermined distance to form "V" shaped grooves with a depth of 0.4 mm or more at an outer side of the pipe matrix. The "V" shaped grooves are formed in one shape selected from a semicircular shape, a rectangular shape, a trapezoidal shape and a "U" character shape.
|
