| 摘要 |
PURPOSE:To obtain a precise groove section by providing the upper roller in which a cross sectional shape of a formed part has an inclined linear part of both end parts, an inclined linear part of the center and a curved part for coming into contact therewith, and two inclined linear parts are connected by a curve whose radius is different from a radius of said curved part. CONSTITUTION:In the upper roller of a hot forming roller, a cross sectional shape of its formed part has inclined linear parts A-A', B-B' which are positioned in both end parts and have an inclination angle theta1, inclined linear parts A'-A'', B'-B'' which are positioned in the center and have an inclination angle theta2 being different from said angle, and a curved part A''-B'' for coming into contact therewith. These two kinds of inclined linear parts are connected by a curve whose radius (r) is different from a radius R of the curved part. In such a way, it is prevented that a flaw is generated in a web part of a product, and also, deterioration of flatness of the product is prevented. |
