| 摘要 |
PURPOSE:To improve the dimensional accuracy of an extruded parts by heating a billet to the specific temp. and also cooling a die to hold temp. difference between the die and the billet. CONSTITUTION:The billet 10 of metallic material is heated to 100-300 deg.C. After this billet 10 is charged into the die, the die is cooled and while holding the temp. difference between the die and the billet 10 to >=80 deg.C, the billet 10 is extruded by a punch to obtain an extruded product 11. The method for holding the temp. difference between the die and the billet 10 to >=80 deg.C, is executed by arranging a pipe or a case with groove around the die to circulate cooling water, etc. By the temp. difference between the billet 10 and the die, the risen temp. at the time of working is absorbed with conduction of the heat into the die, and by reducing the temp. difference in the forming part, the dimensional accuracy of the extruded part can be improved. |
