PURPOSE: To improve the accuracy of a diametral size by setting the length in the reeling part of each cone type roll of a cross helical rolling mill by a mathematical expression thereby executing rolling while bringing each part of the axial direction of a rolling material into contact with the reeling part at a prescribed number of times or above.
CONSTITUTION: The rolls 1, 2, 3 are rotated in arrow directions and while the rolling material 4 engaged between these rolls is rotated around the axial center thereof at hot, the material is moved in the axial longitudinal direction. The walking size l at the axial length of the reeling parts 1c, 2c, 3c of the rolls 1, 2, 3 is set under the conditions of the equation in such a manner that the respective parts of the material 4 in the longitudinal direction thereof contacts ≥7 times in total with the reeling parts 1c, 2c, 3c of the rolls 1, 2, 3 in the process of passing between the rolls 1, 2, 3. In the equation, (d) is the set outside diameter, B is an angle of inclination and (m) is the number of the disposed rolls. The equation is set by determining the number of contacts at ≥7 times and may be set by taking production efficiency into consideration as the accuracy of the diametral accuracy is improved up to the specified level but not above the same.
NAKASUJI KAZUYUKI
HAYASHI CHIHIRO
| JPS594902A | 1984-01-11 | |||
| JPS59147702A | 1984-08-24 |
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