Abstract: A raw material of aluminum base alloy is extruded and formed by using a forming pattern comprising an upper pattern having plural through-holes for supplying the raw material into diaphragms of equal angles on the circumference and circular cylindrical protrusions positioned in the center of plural through-holes so as to be surrounded by plural through-holes at the exit side of the through-holes, and a lower pattern positioned in the concave portions commonly penetrating at the exit of the plural through-holes of the upper pattern, having through-holes for inserting the protrusions of circular circumference of the upper pattern by providing a tube forming gap, positioned in the center of concave portions of the concave portions in the circular columnar shape of the upper pattern.

Abstract: A manufacturing method and apparatus for gears for a speed change device. The gears having a large end and a small end forming a reverse-tapered tooth part on an outer circumference thereof, spline teeth of an intermediate material having the small end provided in a rim of the large end thereof, a plurality of dies having a radial shape and an inclination angle to a gear axial line and slidably holding to an inclined axial line on a holding member are slid from outside of the radiation direction toward the center by a pushing cam mechanism, thereby pushing the reverse-tapered blade part formed at the leading end of the die, the spline teeth are formed in the reverse-tapered tooth part, and the die is slid by an extracting mechanism from the center of the radiation direction toward the outside along the inclined axial line.

Abstract: [Problem] To present a manufacturing apparatus of a plate-like tooth profile member capable of forging and forming in one process by using a closed type die, being hardly accompanied by burrs due to plastic changes in the circumferential direction and in the axial direction of the material of the plate-like tooth profile member.

Abstract: The objective of the present invention is to provide a forging method that improves workability in machining, by turning the metallographical structure of products subject to impact load to a fine ferrite-perlite structure, without adopting the method of quenching and tempering, to obtain, as strength, a yield point (YP value) exceeding that obtained by the method of quenching and tempering, and making the tensile strength (TS) smaller compared with the method of quenching and tempering. A material to be forged has at least one kind of group 5 metal added thereto and is heated to a temperature suitable for hot forging. After forging to prescribed shape, cooling, and holding for a prescribed set time in a furnace at a tempering temperature, the material is further cooled to normal temperature by natural cooling.

Abstract: For the purpose of providing a speed-changing gear manufacturing apparatus capable of forming back-tapered spline teeth having a chamfer at the tip with high accuracy, by forming both side faces of spline teeth in back-tapered shape and forming the tip in chamfered shape at a time, the present invention is a speed-changing gear manufacturing apparatus comprising dies formed at regular intervals on a circumference, to enable to move a plural number of spline teeth forming units for forming back-tapered spline teeth on lines extending radially from the center axis of the gear material, and a pressing member for moving the spline teeth forming units toward the center axis of the gear material, by pressing the outer circumferential face of the spline teeth forming units of the dies, wherein said spline teeth forming units are constructed in a way to form an open space in which to form both side faces of spline teeth in back-tapered shape and form the tip in chamfered shape at a time, in contact with the adjacent

Abstract: A cold deep hole forming device is capable of forming, by cold forging a deep hole for an involute spline, etc. with high accuracy and in a simple way, even in a member to be formed that is partially different in thickness. A supporting base 1A supports the member W to be formed and a punch 1B forms the deep hole H in the member W. A clamp holder 3 is provided on the outer circumference of the punch 1B. A clamp 2 is composed of split clamping pieces 21 disposed in the clamp holder 3. When forming deep hole H in the member W with the punch 1B, the clamping pieces 21 are made to move in the direction of the center under fluid pressure so as to constrain the member W to be formed at its outer circumference having a small diameter portion WT.