Gear Forging with Tooth-Pressing Punch for Burr-Free Edges
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Solution Overview
Problem
In gear forging, existing methods often result in burrs forming at the edge of the surface opposite to the direction in which the material is pushed, leading to inefficiencies and inaccuracies in the formation of external teeth.
Innovation Solution
A method and apparatus that incorporate a guide die and a second punch with a tooth pressing part to ensure continuous connection with the tooth profile groove, preventing burrs by pressing down on the edge where external teeth are formed and housing excess material to prevent adhesion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a material is pushed into a tooth profile die by a single punch to form external teeth, then the gear can be discharged from the other side, but burrs are formed at the edge of the surface opposite to the pushing direction
Solution Approach 1:
The single punch operation is segmented into two distinct punches: a first punch that pushes material into the tooth profile die, and a second punch with a tooth pressing part that presses down on the edge of the material during forging. This segmentation allows each punch to perform its specific function without interfering with the other, eliminating burr formation while maintaining continuous material flow.
Solution Approach 2:
The second punch acts as an intermediary element between the material and the die cavity. Its tooth pressing part contacts and constrains the edge of the material during the forging process, preventing material from escaping and forming burrs. This intermediary action resolves the contradiction by controlling material flow without stopping the overall forging process.
2Manufacturing precision
If a guide die with continuously connected tooth profile grooves is introduced, then burr formation is prevented, but the device complexity increases
Solution Approach 1:
The guide die and tooth profile die are merged into an integrated assembly where the guide die's through hole and tooth profile grooves are continuously connected with the tooth profile die's features. This merging ensures smooth material flow and eliminates gaps where burrs could form, while the continuous connection design minimizes the need for additional complex components.
Solution Approach 2:
The second punch serves multiple functions: it pushes material into the die cavity along with the first punch, and simultaneously presses down on the edge of the material through its tooth pressing part. This multi-functionality reduces the need for separate dedicated pressing mechanisms, thereby limiting the increase in device complexity.
3Manufacturing precision
If the tooth pressing part covers the edge region during material passage, then burrs are prevented, but excess material must be shed and housed
Solution Approach 1:
The excess material that is shed during the forging process is captured and housed by the tooth pressing part of the second punch. Instead of being lost or requiring separate collection systems, the excess material is contained within the structure of the second punch itself, minimizing waste and simplifying post-processing operations.
Data Source
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AI summary
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 (20,21,31) along a tooth profile groove (13a) of the guide die (13) to stack the material (M) and the second punch (20) in this order; and pushing the material (M) and the second punch (20,21,31) into a tooth profile groove (12a) of the tooth profile die (12) in a stacked state to pass them therethrough, in which a tooth pressing part (20a) of the second punch (20,21,31) covers at least an edge of a region where external teeth are formed on a surface of the material (M) on the first punch (14) side.