Unisia Jecs Corporation

Other

Jfe Steel Corporation

Kawasaki Steel Corporation

Unisa Jecs Corporation

Hitachi, Ltd.

Mitsumasa Iijima

Takashi Yoshimura

Yasuo Hatai

Satoshi Uenosono

Shigeru Unami

Masashi Fujinaga

Shin Koizumi

Masao Sakamoto

Naomichi Nakamura

Takayuki Matsumoto

Hiroyuki Amma

Hiroyuki Anma

Tadanori Baba

In a preliminary molding step, a metallic powder mixtureobtained by blending an iron-based metal powderwith graphitesuch that the graphite is present in an amount of preferably not less than 0.1% by weight, more preferably not less than 0.3% by weight, is compacted into a preformhaving a density of not less than 7.3 g/cm. In a provisional sintering step, the preformis provisionally sintered at a predetermined temperature to form a metallic powder-molded bodyhaving a structure in which the graphite remains along a grain boundary of the metal powder. In a re-compaction step, the metallic powder-molded bodyis re-compacted into a re-compacted body. In a re-sintering step, the re-compacted bodyis re-sintered to obtain a sintered body. In a heat treatment step, the sintered bodyis heat-treated to obtain a heat-treated sintered body Accordingly, in accordance with the present invention, there are provided a re-compacted body produced from a metallic powder-molded body having an excellent deformability which is suitably applied to the production of machine parts exhibiting high mechanical properties due to the use of sintered metal, and a sintered body produced from the re-compacted body as well as a process for the production thereof.

Metallic powder-molded body, re-compacted body of the molded body, sintered body produced from the re-compacted body, and processes for production thereof

A sintered iron-based powder metal body with lower re-compacting load and having a high density and a method of manufacturing an iron-based sintered component with fewer pores of a sharp shape and having high strength and high density.

Iron-based sintered powder metal body, manufacturing method thereof and manufacturing method of iron-based sintered component with high strength and high density

Metallic powder molding material and its re-compression molded body and sintered body obtained from the re-compression molded body and production methods thereof

A method of forging a raw material for sintering and forging. The method comprises the steps of: (a) compacting metallic powder containing iron as a main component and graphite to obtain a compact having a predetermined density; (b) sintering the compact at a temperature ranging from 700 to 1000&deg; C. to form a sintered compact having a texture in which graphite is retained at grain boundary of metal powder; (c) compressing the sintered compact from two directions to obtain a compressed sintered compact; and (d) extruding the compressed sintered compact upon pressing the compressed sintered compact from the two directions in a manner that a pressure in one of the two directions is reduced relative to a pressure in the other of the two directions to accomplish extrusion forging.

Method of forging raw material for sintering and forging

An outer joint part includes a cup-shaped body portion having a rotation axis. The cup-shaped body portion has an inner circumferential surface having a plurality of circumferentially spaced inner grooves, and an outer circumferential surface having a plurality of outer grooves circumferentially alternately disposed relative to the inner grooves. The wall thickness of the cup-shaped body portion at the outer grooves is smaller than the wall thickness of the cup-shaped body portion in the areas between the outer grooves. A preform formed into the outer joint part includes a bowl-shaped preform portion having a center axis and inner and outer circumferential surfaces similar in shape to each other. The inner circumferential surface defines inner recesses circumferentially spaced from each other. The outer circumferential surface defines outer recesses circumferentially alternately disposed relative to the inner recesses.

Outer joint part of a constant velocity ball joint

An apparatus for forming a cup-shaped cage, including a cup-shaped workpiece, an outer die having a center axis and a cavity about the center axis, an inner die coaxially disposed within the cavity of the outer die, and a mandrel adapted to move axially and radially the inner die relative to the outer die. The outer and inner dies have first and second control surfaces which are engaged with outer and inner surfaces of the workpiece, respectively, when the outer and inner dies are in the cooperative press position. The outer die includes a part allowed to be out of contact with the outer surface of the workpiece to permit the movement of the inner die relative to the outer die into the cooperative press position.

Apparatus for forming a cup-shaped cage

A universal joint constituted by a first joint, a second joint and a rolling element. The first joint is formed by friction-welding an outer race member and a connecting shaft member. The connecting shaft member has a ring-shaped connecting portion which is welded with a bottom portion of the outer race member. The connecting portion is formed to project from a recess portion of the connecting shaft member toward the outer race member. Therefore, burr generated by the friction welding between the connecting portion and the bottom surface of the outer race member is received in a space defined by the recess portion and the bottom surface of the outer race member. This facilitates removal of the burr.

Universal joint

Growing community of inventors

Kanagawa, Japan

Mitsumasa Iijima