| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a rolling die structure of a both-screw body with which both-screw bodies each having a right screw part and a left screw part on the same region can be highly accurately mass-produced using a cylindrical screw material without the occurrence of rolling failure such as slipping, in which chips hardly occur, and there is no clogging even when chips do occur; and to provide a rolling method of the both-screw body. <P>SOLUTION: The rolling die structure of the both-screw body includes a die member 10 having a rigid surface which comes in press-contact with the screw material and which is relatively displaced, and provided with a plurality of recessed parts 30 each forming a substantially parallelogramic shape when viewed in a normal direction of a virtual surface obtained by connecting each of outermost parts of the rigid surface, the recessed parts being recessed from the virtual surface, and which are independent. Two corner parts 31 of four corner corresponding portions of the substantially parallelogramic shape of each recessed part 30 are formed round. In a cross section along the normal direction, the peripheral edge of each recessed part 30 is formed round along the peripheral edge of the substantially parallelogramic shape, each recessed part 30 forms a substantially quadrangular pyramid shape, a ridge-corresponding portion thereof is formed round in a cross sectional view orthogonal to the ridge line, and a deepest portion 34 has a bottom part 35. <P>COPYRIGHT: (C)2013,JPO&INPIT |
