PURPOSE: To manufacture a hollow rack shaft with high efficiency and at a low cost by controlling, and wrapping and holding the outside diameter of a pipe material inserted and attached to a core die, by upper and lower dies, heating locally a rack forming part, and thereafter, pressing and forming it by a waveform part forming mold, and cutting and finish-working a transfer waveform part.
CONSTITUTION: The outside diameter of a pipe base material 2 inserted and attached to a die mold 7 is controlled, and wrapped and held by upper and lower dies 4, 5. A rack part 11 is heated locally by a heating electrode 10, and thereafter, pressed by a waveform part forming mold 8, and formed. By cutting and finish-working its transfer waveform part 11, a hollow finish rack shaft is obtained. In this way, the hollow rack shaft is manufactured with high efficiency and at a low cost.
KANUKI SEIJI
IIJIMA MAMORU
| JPS58218339A | 1983-12-19 | |||
| JPS59174244A | 1984-10-02 |