Nippon Piston Ring Co., Ltd.

Motonobu Onoda

Katsuaki Ogawa

Takeji Tsuchiya

Kazuo Shimizu

Keiichi Kanemitsu

Takeshi Tsuchiya

Makoto Murata

Tohru Watanabe

Yukio Tateishi

Etsuo Tamegai

Takao Sakai

According to an embodiment of the present invention a piston ring for internal combustion engines for use with a piston and a cylinder, is provided that has an external circumferential sliding surface adapted to slid against the internal wall of the cylinder. The piston ring has an ion-plating deposition layer formed over the externtal circumferential sliding surface, the deposition layer having pores and being made of a mixture of a first chromium nitride of CrN type and a second chromium nitride of Cr N type. The mixing ratios in the mixture are more than 45.5 and less than 98.0 weight percent for the first chromium nitride and the balance portion for the second chromium nitride. According to another embodiment of the present invention, a piston ring for internal combustion engines for use with a piston and a cylinder, is provided that has an external circumferential sliding surface adapted to slid against the internal wall of the cylinder. The piston ring having an ion-plating deposition layer formed over the external circumferential sliding surface thereof, the deposition layer having pores and being made of a mixture of a first chromium nitride of CrN type, a second chromium nitride of Cr N type, and metallic chromium. The mixing ratios in the mixture are more than 45.0 and less than 98.0 weight percent for the first chromium nitride, more than 0.5 and not more than 15.0 weight percent for the metallic chromium, and the balance portion for the second chromium nitride. According to a further embodiment of the present invention, the ion-plating deposition layer formed over the external circumferential sliding surface of the piston ring, made of the mixture described in the above embodiments, is formed to have porosity of more than 0.5 and not more than 20.0 percent.

Nitride-plated piston ring for internal combustion engines

An object of the present invention is to provide a sliding member which is coated a film having superior wear resistance, superior scuffing resistance and a superior property not to increase an amount of wear on an opponent material (an opponent attacking property). This object can be achieved by providing a sliding member coated by a Cr&mdash;B&mdash;N alloy film,on an outer surface,thereof. In this case, it is preferable that the Cr&mdash;B&mdash;N alloy film is formed through a physical vapor deposition, particularly ion plating, vacuum deposition, or sputtering. Further, it is preferable that the boron (B) content is within the range of 0.05-20 wt.%. Since the Cr&mdash;B&mdash;N alloy film,formed on the outer surface,of the sliding member has superior wear resistance, superior scuffing resistance and a superior opponent attacking property, it is possible to provide the sliding member which satisfies demand characteristics even when the sliding member are subjected to the harsh operating environments. Further, it is preferable that nitriding layer,is formed on a whole surface or at least an outer surface,of the sliding member, and the Cr&mdash;B&mdash;N alloy film,is covered on the nitriding layer

Sliding member

A laminated chromium plating layers providing improved wear resistance and fatigue strength for use in mechanical parts of an internal combustion engine. The lamination is formed on a base body and contains a plurality of high hardness chromium plating layer and a plurality of low hardness chromium plating layer, and each high hardness chromium plating layer is formed upon each low hardness chromium plating layer to provide the lamination of alternating high hardness chromium plating layer and low hardness chromium plating layer.

Laminated chromium plating layers having superior wear resistance and fatigue strength

A piston ring combination including at least one compression ring and at least one oil ring. If a plurality of compression rings are provided, an outer peripheral surface of at least a top ring is formed with a first ion plating layer. The oil ring has a pair of side rails whose outer peripheral surfaces are formed with second ion plating layers. These layers are formed of Cr&mdash;N mixture. The first ion plating layer has a porous structure with a porosity ranging from 3 to 10% and a hardness ranging from 1000 to 1500 Hv. The second ion plating layer has a dense structure with a porosity ranging from 0 to 3% and a hardness ranging from 1800 to 2200 Hv.

Combination of piston ring for use in internal combustion engine

An object of the present invention is to provide a sliding member which is coated a film having superior wear resistance, superior scuffing resistance and a superior property not to increase an amount of wear on an opponent material (an opponent attacking property). This object can be achieved by providing a sliding member coated by a Cr--V--B--N alloy film 4 on an outer surface 3 thereof. In this case, it is preferable that the Cr--V--B--N alloy film is formed through a physical vapor deposition, particularly ion plating, vacuum deposition, or sputtering. Further, it is preferable that V (Vanadium) content is within the range of 0.1-30 wt. % and the boron (B) content is within the range of 0.05-20 wt. %. Since the Cr--V--B--N alloy film 4 formed on the outer surface 3 of the sliding member has superior wear resistance, superior scuffing resistance and a superior opponent attacking property, it is possible to provide the sliding member which satisfies demand characteristics even when the sliding member are subjected to the harsh operating environments. Further, it is preferable that nitriding layer 5 is formed on a whole surface or at least an outer surface 3 of the sliding member, and the Cr--V--B--N alloy film 4 is covered on the nitriding layer 5.

Method of making a magnetic material in the form of a multilayer film by

A piston ring developed to prevent aluminum deposition and adhesion thereon is disclosed. The piston ring includes a ring-shaped piston ring main body including upper, lower, outer circumferential surfaces. An anti-abrasion surface treatment layer is formed on at least the lower surface of the main body, and a polybenzimidazole resin coating film including a solid lubricant, is formed on a surface of the anti-abrasion surface treatment layer.

Piston ring

A composite plating bath prepared by adding an agent of boron compounds, such as trimethylamine-borane, dimethylamine-borane and sodium borohydride, by an amount of 0.1 to 10 grams/liter, preferably 1 to 8 grams/liter to a usual nickel electroplating bath having an aqueous acidic solution of at least one nickel salt and micron size particles of at least one water-insoluble material.

Composite plating bath

A piston ring for use in an internal combustion engine. The piston ring includes a base body, a nitriding layer formed at an outer peripheral surface portion of the base body, and a composite Ni-B diffusion plating layer formed over the nitriding layer. The composite Ni-B diffusion plating layer has a thickness ranging from 0.5 to 20 micron meters. Since the nitriding layer is provided on at least the sliding surface of the piston ring, high durability of the piston ring can be attained because of the high wear resistivity of the nitriding layer. Further, since a Ni-Bi composite dispersion plating layer is formed over the nitriding layer, abnormal wearing due to scuffing is avoidable at an initial working phase because of the high scuffing resistance of the composite plating layer.

Growing community of inventors

Yono, Japan

Motonobu Onoda