Diamet Corporation

Yoshiki Tamura

Tsuneo Maruyama

Yoshinari Ishii

Hideo Sakai

Shinichi Takezoe

Osamu Sakai

The molding die of the invention includes: a first die having a through-hole; a second die inserted into the through-hole and capable of moving relative to the first die; and a first punch and a second punch each insertable into the through-hole. A cavity surrounded by the second die, the first punch, and the second punch to compression-mold a molding object is formed in the through-hole. An undercut molding part is formed in the surface of the second die facing the cavity. The second die is formed so as to be splittable into two or more split bodies.

Molding die and molding method

An oil-impregnated sintered bearing in which a Fe&#x2014;Cu-based sintered body is impregnated with a lubricant and which has a bearing hole that is configured to support a rotary shaft inserted therethrough, in which an inner circumferential surface of the bearing hole includes at least a first region including a central portion in a shaft direction and a second region forming a portion from a first end portion of the first region to a first opening of the bearing hole, and, in a friction surface of the second region, an area of a Fe phase is larger and an area of a Cu phase formed of Cu powder including Cu-based flat raw material powder is smaller than those in a friction surface of the first region.

Oil-impregnated sintered bearing

A molding die includes a first die having a through-hole; a second die inserted into the through-hole and configured to be movable relative to the first die; and first and second punches configured to be insertable into the through-hole, wherein an undercut molding part is provided on the second die, and a molding target is compression-molded in a cavity surrounded by inner side walls of the through-hole, the second die, the first punch, and the second punch.

The oil-impregnated sintered bearing of the present invention is an oil-impregnated sintered bearing having a Fe&#x2014;Cu-based sintered body being impregnated with, a bearing hole being formed in the Fe&#x2014;Cu-based sintered body and configured to be penetrated by and support a rotating shaft, in which an inner circumferential surface of the bearing hole includes a first region forming a central portion in a shaft direction, a second region from a first end portion of the first region to a first opening of the bearing hole, and a third region from a second end portion of the first region to a second opening of the bearing hole, and an area ratio of the Cu phase of the second region in a center along the shaft direction is 80% or more and 100% or less of an area ratio of the Cu phase of the third region in a center along the shaft direction.

Oil-impregnated sintered bearing and production method therefor

A Cu-based sintered sliding member that can be used under high-load conditions. The sliding member is age-hardened, including 5 to 30 mass % Ni, 5 to 20 mass % Sn, 0.1 to 1.2 mass % P, and the rest including Cu and unavoidable impurities. In the sliding member, an alloy phase containing higher concentrations of Ni, P and Sn than their average concentrations in the whole part of the sliding member, is allowed to be present in a grain boundary of a metallic texture, thereby achieving excellent wear resistance. Hence, without needing expensive hard particles, there can be obtained, at low cost, a Cu-based sintered sliding member usable under high-load conditions. Even more excellent wear resistance is achieved by containing 0.3 to 10 mass % of at least one solid lubricant selected from among graphite, graphite fluoride, molybdenum disulfide, tungsten disulfide, boron nitride, calcium fluoride, talc and magnesium silicate mineral powders.

Method of producing a Cu-based sintered sliding member

There is provided a bearing for motor-powered fuel injection pumps, made from Cu&#x2014;Ni-based sintered alloy, which is able to be obtained at a low cost, having excellent corrosion and abrasion resistances. The bearing contains 10 to 20% by mass of Ni, 5 to 13% by mass of Sn, 0.1 to 0.8% by mass of P, 1 to 6% by mass of C, and a remainder containing Cu and inevitable impurities, and is formed with a Ni&#x2014;Sn&#x2014;Cu&#x2014;P phase containing at least 30% by mass of Sn in a grain boundary, and has a 8 to 18% porosity. The Ni&#x2014;Sn&#x2014;Cu&#x2014;P phase contains 30 to 49% by mass of Ni, 10 to 30% by mass of Cu, 0.5 to 1.5% by mass of P, and a remainder containing Sn and inevitable impurities.

Sintered bearing for motor-powered fuel injection pumps

There is provided a novel sintered sliding member superior in thermal resistance, corrosion resistance and wear resistance. The sintered sliding member of the present invention includes 7.7-30.3% Cu, 2.0-20.0% Sn and 0.3-7.0% boron nitride by mass, with a remainder composed of Ni and unavoidable impurities. The sintered sliding member may further include 0.1-3.0% C or 0.1-0.7% P. A porosity of the sintered sliding member is 5-25%.

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Niigata, Japan

Yoshiki Tamura