Abstract: An oil ring for an internal combustion engine is provided that can prevent adhesion and deposition of oil sludge even during long-time operation of the engine, can thereby prevent the occurrence of sticking of the oil ring components to each other, and can maintain a good oil control function. At least part of the surface of the oil ring for an internal combustion engine is coated with a metal coating having a surface free energy of 40 mJ/m2 or less and a hydrogen bonding strength of 1.0 mJ/m2 or less. A coating of Ni, Cu, or an alloy containing Ni or Cu is used as the metal coating.

Abstract: A multi-piece oil ring is provided in which, even after long-term operation of an engine, adhesion and deposition of oil sludge are prevented, sticking of components does not occur, and a high oil control function can be maintained. The multi-piece oil ring includes a spacer expander and a pair of upper and lower side rails supported by the spacer expander. To achieve the above features, at least side faces of the side rails that face the spacer expander are coated with a fluorine-containing coating, and the spacer expander is coated with a metal coating. The angle of contact (?1) of a paraffin-based lubricating oil with the portions of the side rails at 150° C. that are coated with the fluorine-containing coating is 50° or larger, and the angle of contact (?2) of the paraffin-based lubricating oil with the portion of the spacer expander at 150° C. that is coated with the metal coating is 10 to 50°. The difference between ?1 and ?2 (?1??2) is 30° or larger.

Abstract: A multi-piece oil ring is provided in which, even after long-term operation of an engine, adhesion and deposition of oil sludge are prevented, sticking of components does not occur, and a high oil control function can be maintained. The multi-piece oil ring includes a spacer expander and a pair of upper and lower side rails supported by the spacer expander. To achieve the above features, at least side faces of the side rails that face the spacer expander are coated with a fluorine-containing coating, and the spacer expander is coated with a metal coating. The angle of contact (?1) of a paraffin-based lubricating oil with the portions of the side rails at 150° C. that are coated with the fluorine-containing coating is 50° or larger, and the angle of contact (?2) of the paraffin-based lubricating oil with the portion of the spacer expander at 150° C. that is coated with the metal coating is 10 to 50°. The difference between ?1 and ?2 (?1-?2) is 30° or larger.

Abstract: An oil ring for an internal combustion engine is provided that can prevent adhesion and deposition of oil sludge even during long-time operation of the engine, can thereby prevent the occurrence of sticking of the oil ring components to each other, and can maintain a good oil control function. At least part of the surface of the oil ring for an internal combustion engine is coated with a metal coating having a surface free energy of 40 mJ/m2 or less and a hydrogen bonding strength of 1.0 mJ/m2 or less. A coating of Ni, Cu, or an alloy containing Ni or Cu is used as the metal coating.

Abstract: A piston ring mounted in the ring groove of an aluminum alloy piston does not cause aluminum adhesion during the long-term use. The piston ring includes a resin film deposited on at least one of an upper face and a lower face. The resin film contains from 0.5 to 20% by volume of carbon black particles and from 3 to 30% by volume of solid lubricant particles with respect to the total volume of the resin film. The carbon black particles preferably contain one or both of graphitized carbon black particles and composite graphite black particles.

Abstract: A three-piece combined oil-control ring comprises a pair of upper and lower side rails 222 in the axial direction and a spacer expander 224. The spacer expander is located between the side rails 222, and pushes the side rails from their inner peripheral side to generates the tension of the side rails 222. The ears of the spacer expander made of austenitic stainless steel in contact with inner peripheral surfaces of the side rails, are subjected to gas-nitriding at a temperature of 470° C. or higher to form a 10 to 60 ?m thick gas-nitriding surface-layer comprising a phase having peaks at 2?=40° and 2?=46° by Cu—K ? X-ray diffraction. In addition or alternatively, a resin coating film (31) is formed on at least surfaces of the spacer expander (7) faced to the side surfaces of the side rails or on at least surfaces of the side rails (5,6) faced to the spacer expander (7).

Abstract: A piston ring for internal combustion engines has a coating film comprising a heat-resistant material and a solid lubricant dispersed therein on at least one side surface, the heat-resistant material comprising at least one of a polyamideimide-silicon dioxide hybrid material and a polyimide-silicon dioxide hybrid material having high heat resistance and mechanical strength and low hygroscopicity.

Abstract: An exhaust gas cleaner consisting essentially of a first catalyst consisting essentially of a first porous inorganic oxide supporting 1.6-8.7 weight percent of an Ag component, on a metal basis, and a second catalyst consisting essentially of a second porous inorganic oxide supporting 0.1-3.8 weight percent of a Pt component and 1-9.9 weight percent of a W component, each weight percent on a metal basis. The Ag component includes Ag or a compound thereof. The Pt component includes Pt, Pd, Ru, Rh, Ir, and Au. The W component includes W, V, Mn, Mo, Nb, and Ta.

Abstract: An exhaust gas cleaner being constituted by a first catalyst of a first porous inorganic oxide supporting a silver component in combination with a W component and a second catalyst of a second porous inorganic oxide supporting a Pt component and optionally a W component. The Ag component may include Ag and compounds thereof, the Pt component may include Pt, Pd, Ru, Rh, Ir, and Au, and the W component may include W, V, Mn, Mo, Nb, and Ta. The W component effectively catalyzes the reduction of nitrogen oxides by ammonia to enhance the removal efficiency of the exhaust gas cleaner.

Abstract: Nitrogen oxides are removed from an exhaust gas containing nitrogen oxides and oxygen in an amount larger than its stoichiometric amount relative to unburned components in the exhaust gas, by using an exhaust gas cleaner having Ag supported by a porous inorganic oxide body and second catalyst containing second catalytically active components supported by a porous inorganic oxide body. The second catalytically active components consist essentially of Cu and/or other metals such as alkali metal elements, rare earth elements, etc.

Abstract: Nitrogen oxides are removed from an exhaust gas containing nitrogen oxides and oxygen in an amount larger than its stoichiometric amount relative to unburned components in the exhaust gas, by using an exhaust gas cleaner having Ag supported by a porous inorganic oxide body and second catalyst containing second catalytically active components supported by a porous inorganic oxide body. The second catalytically active components consist essentially of Cu and/or other metals such as alkali metal elements, rare earth elements, etc.

Abstract: Nitrogen oxides are efficiently removed from an exhaust gas containing nitrogen oxides and an excess amount of oxygen, by (i) disposing an exhaust gas cleaner in a flow path of the exhaust gas, the exhaust gas cleaner comprising a first catalyst comprising 0.2-15 weight % (on a metal basis) of at least one silver salt selected from the group consisting of silver halides, silver sulfate and silver phosphate supported on a porous inorganic oxide on an inlet side and a second catalyst comprising (a) 0.

Abstract: Nitrogen oxides are efficiently removed from an exhaust gas containing nitrogen oxides and an excess amount of oxygen, by (i) disposing an exhaust gas cleaner in a flow path of the exhaust gas, the exhaust gas cleaner comprising a first catalyst comprising 0.2-15 weight % (on a metal basis) of at least one silver salt selected from the group consisting of silver halides, silver sulfate and silver phosphate supported on a porous inorganic oxide on an inlet side and a second catalyst comprising (a) 0.

Abstract: Nitrogen oxides are efficiently removed frown an exhaust gas containing nitrogen oxides and an excess amount of oxygen, by (i) disposing an exhaust gas cleaner in a flow path of the exhaust gas, the exhaust gas cleaner comprising a first catalyst comprising 0.2-15 weight % (on a metal basis) of silver or silver oxide supported on a porous inorganic oxide on the inlet side and a second catalyst comprising 0.2-15 weight % (on a metal basis) of silver or silver oxide and 2 weight % or less (on a metal basis) of copper or copper oxide supported on a porous inorganic oxide on the outlet side; (ii) introducing hydrocarbons and/or oxygen-containing organic compounds into the exhaust gas on the upstream side of the exhaust gas cleaner; and (iii) bringing the exhaust gas into contact with the exhaust gas cleaner at a temperature of 200.degree.-600.degree. C.

Abstract: The method of cleaning an exhaust gas containing nitrogen oxides including disposing an exhaust gas cleaner comprising a heat-resistant, porous body, which may support a catalyst consisting essentially of (a) at least one of alkali metal elements; (b) at least one of elements selected from the group consisting of Cu, Co, Mn and V, (c) at least one of rare earth elements, in a flow path of the exhaust gas, spraying a liquid hydrocarbon into a stream of the exhaust gas on the upstream side of the exhaust gas cleaner, thereby causing atomized and gasified hydrocarbon to function as a reducing agent for reducing the nitrogen oxides in the exhaust gas.

Abstract: Nitrogen oxides are efficiently removed from an exhaust gas containing nitrogen oxides and an excess amount of oxygen, by (i) disposing an exhaust gas cleaner in a flow path of the exhaust gas, the exhaust gas cleaner comprising a first catalyst comprising 0.2-15 weight % (on a metal basis) of silver or silver oxide supported on a porous inorganic oxide on the inlet side and a second catalyst comprising 0.2-15 weight % (on a metal basis) of silver or silver oxide and 2 weight % or less (on a metal basis) of copper or copper oxide supported on a porous inorganic oxide on the outlet side; (ii) introducing hydrocarbons and/or oxygen-containing organic compounds into the exhaust gas on the upstream side of the exhaust gas cleaner; and (iii) bringing the exhaust gas into contact with the exhaust gas cleaner at a temperature of 200.degree.-600.degree. C.

Abstract: The method of cleaning an exhaust gas containing nitrogen oxides and oxygen in an amount larger than its stoichiometric amount relative to unburned components in the exhaust gas which includes (a) disposing an exhaust gas cleaner comprising a heat-resistant, porous inorganic oxide body made of alumina or composite oxide thereof and impregnated with Ag or its oxide, in a flow path of the exhaust gas; (b) introducing a reducing agent selected from the group consisting of gaseous hydrocarbons, liquid hydrocarbons and aliphatic oxygen-containing organic compounds into the exhaust gas on the upstream side of the exhaust gas cleaner; and (c) bringing the exhaust gas into contact with the exhaust gas cleaner at a temperature of 200.degree.-600.degree. C., thereby removing the nitrogen oxides.

Abstract: The exhaust gas cleaner comprising a heat-resistant, porous body and a catalyst supported by the body for cleaning an exhaust gas containing substantially no fine carbonaceous particles, which is equivalent to an oxidizing atmosphere, the catalyst consisting essentially of (a) one or more alkali metal elements; (b) one or more transition metal elements in Group IB; Group IIB, Group VA, Group VIA, Group VIIA, and Group VIII of the Periodic Table (excluding platinum-group elements), and Sn; and (c) one or more rare earth elements. The second catalyst consisting essentially of at least one platinum-group element, may be supported by the heat-resistant porous body.

Abstract: An exhaust gas cleaner comprising a heat-resistant, porous filter, a porous ceramic layer formed on the filter, and a catalyst supported by the ceramic layer, the catalyst consisting essentially of:(a) at least one of alkali metal elements;(b) copper and vanadium; and(c) at least one of rare earth elements.By using this exhaust gas cleaner, particulate matter in the exhaust gas is oxidized by the catalyst supported by the filter, and nitrogen oxides are reduced by the particulate matter serving as a reducing agent.

Abstract: An exhaust gas containing nitrogen oxides and particulate matter is cleaned by using an exhaust gas cleaner including a heat-resistant, porous filter; a porous ceramic powder layer formed on the filter; and a catalyst supported by the ceramic powder layer, the catalyst consisting essentially of (a) at least one of alkali metal elements, (b) cobalt and/or manganese, (c) vanadium, and (d) at least one of rare earth elements, whereby the nitrogen oxides are reduced by the particulate matter in the exhaust gas serving as a reducing agent.