Nippon Piston Ring Co., Ltd.

Takeshi Hiraoka

Shigeru Urano

Shunsuke Takeguchi

Satoshi Kawai

Masajiro Takeshita

Yoshikatsu Nakamura

Kentaro Takahashi

Keiji Nakamura

Kiyoshi Yamamoto

Osamu Kawamura

Genkichi Umeha

A camshaft comprising a steel shaft and a plurality of cam pieces fitted on the shaft. The cam piece is made from a sintering alloy material and bonded to the shaft by sintering. The shaft has pin-receiving holes perpendicular to the axis of the shift. The cam piece is formed on its side surface with a pin-receiving groove. A positioning pin has a lower portion tightly fitted in the hole of the shaft and an upper portion fitted in the groove to position the cam piece with respect to the shaft during sintering.

Camshaft

A camshaft comprising a steel shaft and a plurality of cam pieces fitted on the shaft. The cam piece is made from a sintering alloy material and bonded to the shaft by sintering. The shaft has pin-receiving holes perpendicular to the axis of the shaft. The cam piece is formed on its side surface with a pin-receiving groove. A positioning pin has a lower portion tightly fitted in the hole of the shaft and an upper portion fitted in the groove to position the cam piece with respect to the shaft during sintering.

A camshaft having a steel shaft and cam pieces made from a sintering iron-base alloy material and fixed to the shaft by sintering. Prior to sintering, the green or pre-sintered cam piece is fitted on the shaft and positioned by a steel positioning pin, which is inserted both into a pin-receiving hole in the shaft and into a pin-receiving groove on the side surface of the cam piece. The positioning pin contains carbon less than the steel shaft. This results in that the carbon diffusion initiates at a predetermined position where the pin and the cam piece are in contact with each other and that the cam piece always shrinks about the position.

Assembled camshaft

A method of making a camshaft of the type having a cam piece composed of outer and inner layers which comprises the steps of molding a green cam piece in a manner that the outer and inner layers are respectively made from powders of outer-layer and inner-layer forming materials, fitting the green cam piece on a steel shaft to produce a green camshaft assembly, and sintering said green camshaft assembly at a temperature in which the materials shrink and yield a liquid phase to produce a camshaft having a cam piece diffusion-bonded to the outer periphery of the shaft. The outer-layer forming material is prepared to have an axial shrinkage of 4 to 10% and shrink more than said inner-layer forming material prepared to have an axial shrinkage of 2.5 to 6%.

Method of making camshaft

A wear-resistant member and method for producing the same which member may form a movable member in an internal combustion engine which is subjected to high pressure such as a rocker arm, tappet, cam, valve or valve seat. The member is formed as a combination of a ferrous sintered body and a ferrous base body having a common surface. The sintered body is formed from a compressed powder body disposed in contact with the ferrous base body. The powder body, in a preferred embodiment, consists of 0.5 to 7.0% by weight carbon, 0.1 to 5.0% phosphorus, the balance being iron, and having a porosity of 12 to 20% by volume at least 40% of which is pores having a pore size of not more than 300.mu.. The combined powder body and ferrous base body are heated to a temperature higher than the liquid-phase temperature of the powder body but lower than the melting point of the ferrous body to sinter the powder body.

Wear-resistant member for use in internal combustion engine and method

A wear-resistant member and method for producing the same which member may form a movable member in an internal combustion engine which is subjected to high pressure such as a rocker arm, tappet, cam, valve or valve seat. The member is formed as a combination of a ferrous sintered body and a ferrous base body having a common surface. The sintered body is formed from a compressed powder body disposed in contact with the ferrous base body. The powder body, in a preferred embodiment, consists of 0.5 to 7.0% by weight carbon, 0.1 to 5.0% phosphorus, the balance being iron, and having a porosity of 12 to 20% by volume at least 40% of which is pores having a pore size of not more than 300 .mu.. The combined powder body and ferrous base body are heated to a temperature higher than the liquid-phase temperature of the powder body but lower than the melting point of the ferrous body to sinter the powder body.

Wear-resistant member for use in an internal combustion engine

A wear resistant ferro-based sintered alloy comprising a base structure comprising a mixture of 20 to 50% by area ratio of pearlite, 15 to 40% by area ratio of bainite and 15 to 40% by area ratio of martensite, and 3 to 20% by area ratio of ferromolybdenum particles dispersed uniformly in the base structure is disclosed.

Wear resistant ferro-based sintered alloy

A floating seal provided at its seal face with a hardened portion, in which the body of the floating seal is made of steel, and in which the sealing member is provided at its seal face with a deposit-alloyed surface obtained by surface remelting.

Steel floating seal with remelted deposit-alloyed wear surfaces

A cylinder liner is provided with a white cast iron layer formed in its inner peripheral surface in an area surrounding the top dead center position of the piston, and a thermally created layer is formed underlying the white cast iron layer. The layers may be simultaneously formed by reheating portions of the substantially finished liner with a high density heat radiation source.

Cylinder liner

A cylinder liner for an internal combustion engine has a white case iron layer formed by remelting and cooling a part or whole of areas of an outer peripheral surface of the cylinder liner. A thermally affected layer is also formed between the white cast iron layer and the parent material. This cylinder liner has improved anti-cavitation properties.

A sliding member for use in an internal combustion engine having an improved wear resistance. The sliding member has a sliding surface composed of a mixture of 50 to 97% by weight of high carbon ferrochromium and 3 to 50% by weight of ferrous alloy applied thereto by spraying. In a preferred embodiment, the ferrous alloy is high carbon iron containing at least 0.6% by weight of carbon.

Sliding member for use in an internal combustion engine

An abrasion resistant ferro-based sintered alloy comprising 1.1 to 1.6% by weight of carbon, 1.5 to 3.5% by weight of chromium, 1.6 to 2.9% by weight of molybdenum, 1.0 to 3.0% by weight of nickel, 3.0 to 5.0% by weight of cobalt, 0.5 to 1.5% by weight of tungsten, 1.8 to 18.0% by weight of copper and the balance iron wherein said alloy contains particles of specific alloy comprising C-Cr-W-Co and ferromolybdenum particles are uniformly dispersed in the base structure comprising a mixture of pearlite, bainite and martensite and wherein nickel and cobalt are distributed around the particles of specific alloy and of ferromolybdenum alloy is disclosed.

Abrasion resistant ferro-based sintered alloy

An abrasion resistant ferro-based sintered alloy comprising 0.8 to 1.5% by weight of carbon, 0.5 to 2.5% by weight of chromium, 2.0 to 6.0% by weight of molybdenum, 1.5 to 5.0% by weight of nickel, 0.1 to 2.0% by weight of tungsten, 0.2 to 5.0% by weight of copper and the balance iron wherein said alloy contains molybdenum particles around which nickel is distributed and which are uniformly dispersed in the base structure comprising a mixture of pearlite, bainite and martensite and said alloy contains composite carbide of Fe-Cr-W-C dispersed in the base structure, is disclosed.

Relative sliding members comprising as materials in combination a nitrified sintered alloy and an alloy cast iron, chemical components of which are well selected in percentage so as to provide better wear resistance and machinability.

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Saitama, Japan

Takeshi Hiraoka