Method of net-forming an article and apparatus for same
AssigneeGM Global Technology Operations LLC
InventorYoung Sik Kim
Life of this patent
Estimating the term…
Abstract
A method of forming an article such as a helical gear and an apparatus for forming the article are provided. The method includes applying pulsating pressure downward to extruding the work piece and, while the pressure is applied downward, injecting fluid to surround the work piece in fluid. The method eliminates pickling processes and phosphate lube coatings typically required for extrusion and external machining steps subsequently required to remove the coating. Extrusion of a cold net-formed article is thus possible due. An apparatus for carrying out the method is also provided.
Claims19
A method comprising:
- positioning a work piece between upper and lower punches operatively connected to upper and lower dies;
- applying pulsating pressure downward on the upper punch via the upper die, thereby extruding the work piece;
- during said applying, injecting fluid between the dies to surround the work piece in fluid;
- inserting a core rod through an inner diameter of the work piece prior to said applying pulsating pressure downward;
- and
- extruding an inner surface of the work piece by moving the core rod upward, thereby forming an article from the work piece.
An apparatus for net-forming a gear from a work piece having an inner diameter and an outer diameter, the apparatus comprising:
- a die holder that at least partially forms a chamber in which the work piece is receivable;
- an upper die at least partially supported by said die holder and movable within said die holder toward the work piece;
- a lower die having cavity formations;
- an upper punch axially movable toward said chamber in response to hydraulic pressure on said die for extruding the work piece within the lower die such that the cavity formations contact the outer diameter to create external gear teeth on the work piece;
- wherein said die holder at least partially forms a fluid passage in fluid communication with said chamber such that the work piece is at least partially submerged in fluid when said upper punch extrudes the work piece;
- a core rod extending through the inner diameter and axially movable in an opposite direction as the upper punch;
- and wherein the core rod is configured to contact the inner diameter to create internal splines on the work piece.
A method of net-forming a gear comprising:
- applying pulsating pressure in a first direction on a work piece to extrude external gear teeth on the work piece;
- and
- further extruding the work piece by moving a punch in a second opposing direction to form internal splines on the work piece;
- said applying pulsating pressure and further extruding thereby forming the gear.
Dependencies are inferred from the claim text.