| 摘要 |
PURPOSE:To elevate the shape accuracy of a gear, by executing forgemolding by means of double-acting extrusion, and reducing burr removed marks remaining on a tooth surface of the gear, when executing plastic-working of the gear. CONSTITUTION:A tooth part is formed by setting a gear work 1 into a die 3, depressing a product takeout punch 4, and executing double-acting extrusion by an outer punch 5 and the inner punch 6. Lower surfaces of the outer punch 5 and the inner punch 6 which have a tooth are formed as one boty, the work 1 is pushed into the die 3 having a tooth, and the tooth part of the work 1 is extruded. In this case, the thickness of a burr 2 becomes small by being pushed, and when its rigidity becomes smaller than cushion force of a counter sunk spring 9, the inner punch 6 projects from the lower face of the outer punch 5 by cushion force of the counter sunk spring 9, the work 1 is extruded to the lower part of the die 3, double-acting extrusion is completed, and a gear having high accuracy is formed. |
