Method and apparatus for forging gear
AssigneeToyota Jidosha Kabushiki Kaisha
InventorsToshitaka Suzuki, Takeshi Kimura
Life of this patent
Estimating the term…
Abstract
The present disclosure provides a method for forging a gear capable of preventing burrs from being formed at an edge of the surface opposite to a direction in which a material in external teeth of the material is pushed. A first exemplary aspect is a method for moving the second punch along a tooth profile groove of the guide die to stack the material and the second punch in this order; and pushing the material and the second punch into a tooth profile groove of the tooth profile die in a stacked state to pass them therethrough, in which a tooth pressing part of the second punch covers at least an edge of a region where external teeth are formed on a surface of the material on the first punch side.
Claims8
A method for forging a gear comprising:
- pushing a material into a through hole of a tooth profile die from one side of the tooth profile die by a first punch and then discharging a gear having external teeth formed thereon from the other side of the tooth profile die by the first punch;
- disposing, on the one side of the tooth profile die, a guide die that includes a through hole having an inside diameter size smaller than an outside diameter size of one end of the through hole of the tooth profile die so that a tooth profile groove formed on an inner peripheral surface of the guide die and a tooth profile groove formed on an inner peripheral surface of the tooth profile die are continuously connected with each other;
- pushing the material into the through hole of the guide die;
- pushing a second punch into the through hole of the guide die subsequently to the material, thereby inserting a tooth pressing part composed of a tooth part formed on an outer peripheral part of the second punch into the tooth profile groove of the guide die to move the second punch along the tooth profile groove of the guide die, and stacking the material and the second punch in this order so as to be in a stacked state;
- and
- pushing the material and the second punch into the tooth profile groove of the tooth profile die in the stacked state to pass them therethrough, wherein
- the tooth pressing part of the second punch covers, when the material passes through the tooth profile groove of the tooth profile die, at least an edge of a region where the external teeth are formed on a surface of the material that faces the first punch.
An apparatus for forging a gear comprising:
- a first punch that pushes a first material into a through hole of a tooth profile die from one side of the tooth profile die and then discharges a gear having external teeth formed thereon from the other side of the tooth profile die;
- a second punch configured to be stacked with the first material;
- and
- a guide die configured to be disposed on one side of the tooth profile die and inserted with the first material and the second punch in this order, wherein
- the guide die comprises a through hole having an inside diameter size smaller than an outside diameter size of one end of the through hole of the tooth profile die,
- a tooth profile groove is formed on an inner peripheral surface of the guide die, and the tooth profile groove and a tooth profile groove that is formed on the tooth profile die are continuously connected with each other while the guide die is disposed on the one side of the tooth profile die,
- the first punch pushes the first material and the second punch into the tooth profile groove of the tooth profile die in a stacked state so that the first material and the second punch pass therethrough, and
- the second punch includes a tooth part serving as a tooth pressing part configured to press at least an edge of a region where external teeth are formed on a surface of the first material facing the first punch, and the tooth pressing part is inserted into the tooth profile groove of the guide die and the tooth profile groove of the tooth profile die.
Dependencies are inferred from the claim text.