| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To prevent defects such as deformation into an odd shape and crack of a die in a hollow steel pipe even when the hollow steel pipe is pressed with a punch in order to form a flat part on the hollow steel pipe. <P>SOLUTION: An apparatus includes: right and left dies 31, 32 which are opened in the horizontal direction and also with which the hollow steel pipe is held between them; tapered surfaces 31b, 32b and 41a, 41b which are arranged above the right and left dies 31, 32 and by which pressurizing force from above is converted into pressurizing force in a direction in which the right and left dies are closed; a punch 43 with which a flat part 11a is formed in the upper part of a hollow rack bar 10 held with the right and left dies 31, 32; a pressurizing mechanism 52 by which the punch 43 is moved vertically; and fixed pressing mechanisms 51 which are moved vertically and independently from the pressurizing mechanism 52 and with which pressurization is performed through the tapered surfaces 31b, 32b and 41a, 41b. <P>COPYRIGHT: (C)2013,JPO&INPIT</p> |
