| 摘要 |
The present invention relates to a gear for an automotive automatic transmission and a manufacturing method thereof and, more specifically, to a gear for an automotive automatic transmission and a manufacturing method thereof, wherein the manufacturing method is capable of largely reducing machine equipment costs for manufacturing the gear (an inner race and an annulus gear) and is capable of improving the durability of the gear and reducing the manufacturing costs of the gear. According to the present invention, the gear for an automotive automatic transmission is formed as follows: forming a tube by cutting a seamless pipe; forming a gear part on the tube by pressing the tube using a die and a press; forming groove parts on the tube through a first and a second turning process; and forming oil flow holes on predetermined positions on the tube through a piercing process. The manufacturing method of the gear comprises: a step of arranging the tube by cutting the seamless pipe at a calculated length, and completing to process the tube through a shot process and a conversion coating chemical treatment process; and a step of molding the gear part on the tube by pressing the tube using the die and the press, and completing the gear part through the turning processes and the piercing process. According to the present invention, the gear (the inner race and the annulus gear) for an automotive automatic transmission can be provided by the seamless pipe, so the machine equipment costs and work processes can be reduced to improve productivity. In particular, a product with a high quality can be produced regardless of the skill level of a worker because the gear for an automotive automatic transmission can be manufactured by the die and the press, so labor costs for the production of the product can be reduced, thereby obtaining an economic gain. |
