A low-friction sliding mechanism includes first and second sliding members having respective sliding surfaces slidable relative to each other and a lubricant applied to the sliding surfaces of the first and second sliding members. At least the sliding surface of the first sliding member is made of a diamond-like carbon material, and at least the sliding surface of the second sliding member is made of either an aluminum-based alloy material, a magnesium-based alloy material or a diamond-like carbon material. The lubricant contains a base oil and at least one of an ashless fatty-ester friction modifier and an ashless aliphatic-amine friction modifier.

Low-friction sliding mechanism

A fuel injection valve for an automotive internal combustion engine comprises a needle valve and an opposite member which are in slidable contact with each other in presence of fuel. A hard carbon thin film is coated on at least one of the sliding sections of the base materials of the needle valve and the opposite member. The hard carbon thin film has a surface hardness ranging from 1500 to 4500 kg/mm in Knoop hardness, a film thickness ranging from 0.3 to 2.0 mu m, and a surface roughness (Ry) ( mu m) which satisfies a relationship represented by the following formula (A):   Ry ) of the hard carbon thin film.

Fuel injection valve

A sliding structure for an automotive engine includes a sliding member with a sliding portion and a lubricant applied to the sliding portion so that the sliding portion can make sliding contact with a counterpart member via the lubricant. The sliding member is either of a piston ring, a piston pin, a cam lobe, a cam journal, a plain bearing, a rotary vane and a timing chain. The sliding portion has a base made of a steel or aluminum material and a hard carbon film formed on the base to coat the sliding portion. The hard carbon film has a thickness of 0.3 to 2.0 μm, a Knoop hardness of 1500 to 4500 kg/mm2, a surface roughness Ry (μm) satisfying the following equation: Ry<{(0.75−Hk/8000)×h+0.07/0.8}, where h is the thickness (μm) of the film; and Hk is the Knoop hardness (kg/mm2) of the film.

Sliding structure for automotive engine

A sliding structure for a reciprocating internal combustion engine, including sliding elements (100;104:120;124;128) relatively slidable via lubricating oil therebetween, the sliding elements including sliding surfaces (102;106:122;126;130) opposed to each other and lubricated with a laminar flow of the lubricating oil. The sliding surfaces (102;106:122;126;130) each have base surfaces (10;20) and microscopic dimples (11) or grooves (21) which are so constructed as to prevent reduction of flow resistance to the lubricating oil passing through a clearance between the sliding surfaces (102;106:122;126;130) and assure a lubricating oil film thickness required for reducing friction loss between the sliding elements (100;104:120;124;128).

A sliding structure for a reciprocating internal combustion engine and a reciprocating internal combustion engine using the sliding structure

A piston for an internal combustion engine of an automotive vehicle. The piston has a piston ring and a piston skirt section each of which has a sliding section in slidable contact with a cylinder bore section of a cylinder block in presence of a lubricating oil. The cylinder bore section is formed of eutectic or hyper-eutectic aluminum alloy. Additionally, a hard carbon thin film is coated on the sliding section of the piston and contains hydrogen atom in an amount of not more than 1 atomic %. Here, the lubricating oil contains at least one selected from the group consisting of ashless fatty acid ester friction modifier, ashless aliphatic amine friction modifier, polybutenyl succinimide, derivative of polybutenyl succinimide, zinc dithiophosphate, and derivative of zinc dithiophosphate.

Piston for internal combustion engine

A sliding structure including first and second sliding elements made of metal and including first and second sliding surfaces relatively slidable via a lubricating oil film therebetween, in which at least one of the first and second sliding surfaces having a microscopic surface structure including a base portion, dimples inward recessed from the base portion and separated from one another, and a peripheral portion defining the opening area of each of the dimples and extending along a periphery of each of the dimples. A ratio of a sum of opening areas of the dimples to an area of the at least one of the first and second surfaces is in a range of 5% to 60%. The peripheral portion has a height smaller than a thickness of the lubricating oil film.

Sliding element, sliding structure including the sliding element, and method for producing microscopic surface structure in the sliding element

PROBLEM TO BE SOLVED: To provide a method for manufacturing components for high-strength mechanical structure in which an improvement in bending fatigue strength and an improvement in pitting resistance are made compatible with each other. SOLUTION: The method for manufacturing the components for high-strength mechanical structure by subjecting a case hardening steel for mechanical structure as a raw material to a vacuum carburizing and nitriding treatment within a vacuum furnace includes a step S 1 of performing the nitriding treatment at the point of the time when the temperature in the vacuum furnace attains the prescribed temperature T 1 during the temperature-rising by heating of the vacuum furnace and further a carburizing step S 2 of performing the carburizing treatment by causing the temperature-rising by heating (temperature: T 2) in the vacuum furnace, then a step S 3 of performing the nitriding treatment again at the point of the time the temperature in the vacuum furnace falls down to the temperature (hardening holding temperature) T 3 higher than the hardenable temperature. COPYRIGHT: (C)2006,JPO&NCIPI

Method for manufacturing components for high-strength mechanical structure and components for high-strength mechanical structure

The present invention provides a method for surface hardening a maraging steel and a belt for a belt-type continuously variable transmission, the surface of which is hardened by the method, which can improve the fatigue strength and wear resistance of the maraging steel. A method for hardening the surface of a maraging steel through aging treatment and nitriding treatment, wherein first, as a pretreatment of the nitriding treatment, oxidation treatment at 330 ° C. to 450 ° C. in an oxidizing atmosphere is performed. Oxidation is performed at a temperature and for an oxidation treatment time of less than 15 minutes to form an oxide layer that is mainly a layer of Fe 3 O 4 . Thereafter, nitriding is performed at a nitriding temperature of 430 ° C. to 480 ° C. in a nitriding atmosphere to form a nitride layer. [Selection diagram] Fig. 1

Surface hardening treatment method for maraging steel and belt for belt type continuously variable transmission produced by the method

The high-strength race of the present invention comprises using A steel for a high-strength race comprising the following elements in percentage by weight: C: 0.30 to 0.60%, Si: 0.30 to 1.30%, Mn: 0.5 to 1.5%, B: 0.0050% or less, Cr: 0.1 to 0.5%, Mo: 0.1 to 0.5%, Si +Mo: 0.5 to 1.4%, Ni: 0.02 to 1.0%, the balance of Fe and unavoidable impurities, performing induction hardening to make the race have a surface hardness of 58 HRC or more and further a surface hardness of 52 HRC or more even after the surface is tempered at 300° C. The high-strength race is superior in rotating fatigue properties, anti-surface fatigue strength and productivity by a combination of composition control and induction hardening.

High-strength race and method of producing the same

PROBLEM TO BE SOLVED: To provide a bearing sliding member which can reduce sliding resistance and can greatly reduce sliding loss even when the oil film thickness is relatively small. SOLUTION: For example, after dimple-shaped recessed parts are formed by irradiating steel balls or ceramic balls of 10-200 μm on the sliding surface of the member by sandblasting or shot peening, the dimple-shaped recessed parts 2 are provided on at least one member surface of the bearing sliding member by grinding swelling to be formed in the vicinity of the recessed parts by lapping and barrelling, and moreover, the swelling 3 in the vicinity of the recessed parts is made so as to be sufficiently smaller compared with the oil film thickness of the sliding parts. COPYRIGHT: (C)2003,JPO

Shinji Asano

Papers

Sliding element, sliding structure including the sliding element, and method for producing microscopic surface structure in the sliding element

Method for manufacturing components for high-strength mechanical structure and components for high-strength mechanical structure

Surface hardening treatment method for maraging steel and belt for belt type continuously variable transmission produced by the method

High-strength race and method of producing the same

Bearing sliding member