Hitachi Metals, Ltd.

Hino Motors, Ltd.

Masanori Hara

Koki Otsuka

Seiichi Endo

Masahide Kawabata

Susumu Katsuragi

Takashi Hattori

Kazuyuki Kurakake

Akira Mikami

Naoki Maruyama

Akitoshi Nakamura

Naoto Watanabe

Makoto Ohuchi

Shuuji Yamada

Yoshitaka Ito

Precipitation-hardened, martensitic, cast stainless steel having a composition comprising, by mass, 0.08-0.18% of C, 1.5% or less of Si, 2.0% or less of Mn, 0.005-0.4% of S, 13.5-16.5% of Cr, 3.0-5.5% of Ni, 0.5-2.8% of Cu, 1.0-2.0% of Nb, and 0.12% or less of N, the amounts of C, N and Nb meeting the condition of &#x2212;0.2&#x2266;9 (C %+0.86N %)&#x2212;Nb %&#x2266;1.0, the rest being Fe and inevitable impurities, and having a structure in which Cu precipitates having an average particle size of 0.1-0.4 &#x3bc;m are dispersed in a tempered-martensite-based matrix.

Precipitation-hardened, martensitic, cast stainless steel having excellent machinability and its production method

An integrally cast steel piston for internal engines, the cast steel having (a) a composition comprising 0.8% or less of C, 3% or less of Si, 3% or less of Mn,0.2% or less of S, 3% or less of Ni, 6% or less of Cr, 6% or less of Cu, and 0.01-3% of Nb, the balance being substantially Fe and inevitable impurities, or (b) a composition comprising 0.1-0.8% of C, 3% or less of Si, 3% or less of Mn, 0.2% or less of S, 10% or less of Ni, 30% or less of Cr, 6 % or less of Cu, and 0.05-8% of Nb, the balance being substantially Fe and inevitable impurities, by mass.

Internal engine piston and its production method

The differential apparatus comprises (a) a casing rotated by a driving force from outside; (b) a pair of opposing disc plates coaxially disposed in the casing, an opposing surface of each disc plate being formed with a circumferentially continuous groove winding such that a radial position changes at a constant period; (c) a plurality of balls rolling in opposing winding continuous grooves of both disc plates; and (d) a ball holder rotating integrally with the casing and having a plurality of radially extending guide holes, each guide hole movably receiving each ball, wherein the winding continuous groove of each disc plate circumferentially continuously has first guide regions each extending from a radially outer position to a radially inner position of each disc plate and second guide regions each extending from a radially inner position to a radially outer position, inflected regions each connecting each first guide region and each second guide region being larger in width and/or depth than the first guide regions and the second guide regions, whereby a contact stress between the balls and the winding continuous groove is decreased in the inflected regions.

Differential device and method of manufacturing the device

Growing community of inventors

Tochigi-ken, Japan

Masanori Hara