Loading patent…
AssigneeNamiki Seimitsu Houseki Kabushiki Kaisha
InventorsXinmin Wang, Akihisa Inoue, Yukiharu Shimizu
Estimating the term…
An internal gear manufacturing method capable of manufacturing time reduction and easy core removal, and a metallic glass internal gear manufactured thereby. A carbon core formed into a shape of an external gear is arranged in a thin, long tubular mold of a length equal thereto with a space extending longitudinally therealong. A molten metal material is pressure-injected under a temperature higher than a melting point thereof into the space between the mold and the core. The molten metal material is resolidified by rapid cooling at or above a critical cooling rate thereof together with the mold and the core. After resolidification of the molten metal material, the core is removed by pulverization or dissolution. Along internal gear formed of the resolidified metal material is cut into a plurality of segments of a prescribed length.
An internal gear manufacturing method comprising:
Dependencies are inferred from the claim text.
Drawings are temporarily unavailable. Open the PDF at USPTO
From the US filing history. Foreign family members aren’t listed.
Treating the metal in the mould while it is molten or ductile ; Pressure or vacuum casting: by using vacuum
Removing castings from moulds, not restricted to casting processes covered by a single main group; Removing cores; Handling ingots: removing cores
Toothed members; Worms: use of materials; Use of treatments of toothed members or worms to affect their intrinsic material properties
Method of mechanical manufacture: gear making
About 2 years 11 months of term left · ends 3 Oct 2029 (estimated)
The present invention relates to an internal gear manufacturing method and a metallic glass internal gear manufactured thereby.
Included among the conventional internal gear manufacturing methods are those for cold-plastically forming gear teeth on an inner circumferential surface of a member press-formed into a cup shape by means of an internal gear forming die (for example, refer to Japanese Unexamined Patent Application Publication No. 1996-300083) and those for cutting gear teeth along an inner surface of a hollow member by press-inserting thereinto an internal gear tooth cutting chisel (for example, refer to Japanese Unexamined Patent Application Publication No. 2003-89015). Unfortunately, these conventional methods are not problem-free regarding precision and miniaturization. For example, when required to manufacture a miniaturized internal gear for use in precision devices, such as micro-geared motors that require high accuracy, the internal gear is manufactured from a resin capable of ensuring sufficient working accuracy but at the expense of hardness and strength.
To solve the above problem, proposals have been made for metallic glass internal gear manufacturing methods reliant on molten metal injection molding methods, such as die casting (Cf., e.g., International Publication Pamphlet No. 2005/024274).
FIG. 1(a) is a perspective view of an internal gear manufacturing method according to the present invention and a metallic glass internal gear manufactured thereby, wherein core 12 is arranged inside mold 11.
FIG. 1(b) is another perspective view of an internal gear manufacturing method, wherein metal material 1 is poured into the mold 11.
FIG. 1(c) is another perspective view of an internal gear manufacturing method, wherein the core 12 is removed.
Descriptions are made below of the best modes for carrying out the present invention with reference to drawings appended hereto.
FIG. 1 to FIG. 3 show embodiments of the internal gear manufacturing method according to the present invention and a metallic glass internal gear manufactured thereby.
As shown in FIG. 1, a mold 11 and a core 12 are used in the embodiment of the internal gear manufacturing method according to the present invention.