Abstract: To provide a steel pipe as a fuel injection pipe with high material strength, high internal pressure limit free from fatigue failure, prolonged fatigue life, and high reliability. A steel pipe as a fuel injection pipe of 500 N/mm2 or higher tensile strength comprising, by mass, C: 0.12 to 0.27%, Si: 0.05 to 0.40%, and Mn: 0.8 to 2.0%, and the balance being Fe and impurities, the contents of Ca, P, and S in the impurities being Ca: 0.001% or less, P: 0.02% or less, and S: 0.01% or less, respectively, characterized in that the maximum diameter of nonmetallic inclusions present in at least in a region extending from the inner surface of the steel pipe to a depth of 20 ?m is 20 ?m or less. Further, this steel pipe may contain, in place of a portion of Fe, at least one selected from among Cr: 1% or less, Mo: 1% or less, Ti: 0.04% or less, Nb: 0.04% or less, and V: 0.1% or less.

Abstract: A joint structure of a branch connector for a common rail capable of securing axial force applied to a seal surface and a branch connector and increasing bending fatigue strength of the branch connector is provided. In the joint structure of the branch connector for the common rail which includes a screw sleeve concentric with a bearing surface of a main pipe rail and connects a branch connector to the main pipe rail via a sleeve washer which has been externally fixed to the branch connector in advance to be combined therewith as one piece, a clearance is provided between an inner surface of the sleeve washer at an external opening thereof and an outer surface of the branch connector.

Abstract: To provide a steel pipe as a fuel injection pipe with high material strength, high internal pressure limit free from fatigue failure, prolonged fatigue life, and high reliability. A steel pipe as a fuel injection pipe of 500 N/mm2 or higher tensile strength comprising, by mass, C: 0.12 to 0.27%, Si: 0.05 to 0.40%, and Mn: 0.8 to 2.0%, and the balance being Fe and impurities, the contents of Ca, P, and S in the impurities being Ca: 0.001% or less, P: 0.02% or less, and S: 0.01% or less, respectively, characterized in that the maximum diameter of nonmetallic inclusions present in at least in a region extending from the inner surface of the steel pipe to a depth of 20 ?m is 20 ?m or less. Further, this steel pipe may contain, in place of a portion of Fe, at least one selected from among Cr: 1% or less, Mo: 1% or less, Ti: 0.04% or less, Nb: 0.04% or less, and V: 0.1% or less.

Abstract: A common-rail injection system is provided for a diesel engine and has excellent internal pressure fatigue resisting characteristics, vibrational fatigue resisting characteristics and cavitation resisting property and sheet face flawing resisting property, and can be made thin and light in weight. A main pipe rail is manufactured by transformation induced plastic type strength steel. After the main pipe rail is processed, residual austenite is generated by heat treatment, and the reduction processing of stress concentration of a branch hole and a main pipe rail side flow passage crossing portion is performed. Further, it is preferable that an induced plastic transformation is generated on the inner surface of the main pipe rail by autofrettage processing, and compression residual stress is left.

Abstract: A joint structure connects a diverging branch pipe to a fuel rail for an internal combustion engine. The fuel rail is stainless steel or steel with rust prevention processing on at least the inner face. The diverging branch pipe is a double pipe with inner and outer pipes. The inner pipe has excellent rust preventing ability with respect to fuel on its inner face in comparison with the outer face of the outer pipe. The inner and outer pipes are connected by a nut for fastening through a joint fitting. A connecting seal portion of the diverging branch pipe and the joint fitting has rust preventing ability equal to that of the inner circumferential face of the diverging branch pipe. An entire liquid contact portion, including a seal face of the diverging branch pipe with respect to the fuel is covered with the inner pipe.

Abstract: A common-rail injection system is provided for a diesel engine and has excellent internal pressure fatigue resisting characteristics, vibrational fatigue resisting characteristics and cavitation resisting property and sheet face flawing resisting property, and can be made thin and light in weight. A main pipe rail is manufactured by transformation induced plastic type strength steel. After the main pipe rail is processed, residual austenite is generated by heat treatment, and the reduction processing of stress concentration of a branch hole and a main pipe rail side flow passage crossing portion is performed. Further, it is preferable that an induced plastic transformation is generated on the inner surface of the main pipe rail by autofrettage processing, and compression residual stress is left.

Abstract: A common-rail injection system is provided for a diesel engine and has excellent internal pressure fatigue resisting characteristics, vibrational fatigue resisting characteristics and cavitation resisting property and sheet face flawing resisting property, and can be made thin and light in weight. A main pipe rail is manufactured by transformation induced plastic type strength steel. After the main pipe rail is processed, residual austenite is generated by heat treatment, and the reduction processing of stress concentration of a branch hole and a main pipe rail side flow passage crossing portion is performed. Further, it is preferable that an induced plastic transformation is generated on the inner surface of the main pipe rail by autofrettage processing, and compression residual stress is left.

Abstract: A joint structure connects a diverging branch pipe to a fuel rail for an internal combustion engine. The fuel rail is stainless steel or steel with rust prevention processing on at least the inner face. The diverging branch pipe is a double pipe with inner and outer pipes. The inner pipe has excellent rust preventing ability with respect to fuel on its inner face in comparison with the outer face of the outer pipe. The inner and outer pipes are connected by a nut for fastening through a joint fitting. A connecting seal portion of the diverging branch pipe and the joint fitting has rust preventing ability equal to that of the inner circumferential face of the diverging branch pipe. An entire liquid contact portion, including a seal face of the diverging branch pipe with respect to the fuel is covered with the inner pipe.

Abstract: A joint structure of a branch connector for a common rail capable of securing axial force applied to a seal surface and a branch connector and increasing bending fatigue strength of the branch connector is provided. In the joint structure of the branch connector for the common rail which includes a screw sleeve concentric with a bearing surface of a main pipe rail and connects a branch connector to the main pipe rail via a sleeve washer which has been externally fixed to the branch connector in advance to be combined therewith as one piece, a clearance is provided between an inner surface of the sleeve washer at an external opening thereof and an outer surface of the branch connector.

Abstract: In a high pressure fuel injection pipe, pipe extension and heat treatment are repeated by using a header manufactured by transformation induced plastic type strength steel. A process for depositing residual austenite is then performed, after which a final pipe extension process is performed, and the joint portion is molded and bending processing is performed without performing perfect annealing at the size of a product.

Abstract: There is provided a high-pressure fuel pipe for diesel engines, which is excellent in inner-pressure fatigue resistant property, vibrational fatigue resistant property, cavitation-resistant property, seat surface crack resistant property, and bending shape stability, and capable of thinning and lightening. A high-pressure fuel pipe for diesel engines, composed of a low alloy transformation inducing plastic type strength steel containing residual austenite of 5 to 40 wt %, and wherein an inner surface of a flow passage has a crack depth of 20 ?m or less, and plastic working is applied to an inner surface of a flow passage.

Abstract: A common-rail injection system is provided for a diesel engine and has excellent internal pressure fatigue resisting characteristics, vibrational fatigue resisting characteristics and cavitation resisting property and sheet face flawing resisting property, and can be made thin and light in weight. A main pipe rail is manufactured by transformation induced plastic type strength steel. After the main pipe rail is processed, residual austenite is generated by heat treatment, and the reduction processing of stress concentration of a branch hole and a main pipe rail side flow passage crossing portion is performed. Further, it is preferable that an induced plastic transformation is generated on the inner surface of the main pipe rail by autofrettage processing, and compression residual stress is left.

Abstract: A high pressure fuel injection pipe is provided for a diesel engine and has excellent internal pressure fatigue resisting characteristics, vibrational fatigue resisting characteristics and cavitation resisting property and sheet face flawing resisting property, and can be made thin and light in weight. In the high pressure fuel injection pipe, pipe extension and heat treatment are repeated by using a header manufactured by transformation induced plastic type strength steel, and processing for depositing residual austenite is then performed and final pipe extension processing is performed, and a joint portion is molded and bending processing is performed without performing perfect annealing at the size of a product.

Abstract: An expansible and retractable protective cover is provided for umbrellas. The cover is mountable to align with the shaft of the umbrella and can be expanded parallel to the shaft of the umbrella to cover the umbrella after the umbrella has been folded into a closed condition. Thus, the cover contains moisture accumulated on the wet umbrella cloth from scattering.

Abstract: A fan comprising resin blades which prevents the generation of cracks due to stress generated by the concentration of stress during rotation and heat contraction of the material, and which has improved fan durability and cooling performance, is provided.

Abstract: A hot worked steel material, such as a bar, or tube, has a surface layer improving its fatigue strength despite the non-metallic inclusions which it may contain, or the cracks which it may have. The surface layer is formed by heating a nickel layer on the steel surface to cause the diffusion of nickel therethrough.

Abstract: An expansible and retractable protective cover is provided for umbrellas. The cover is mountable to align with the shaft of the umbrella and can be expanded parallel to the shaft of the umbrella to cover the umbrella after the umbrella has been folded into a closed condition. Thus, the cover contains moisture accumulated on the wet umbrella cloth from scattering.

Abstract: A common rail includes a main pipe rail having a circulating passage extending in its inside in the axial direction thereof, branch holes formed in an axial peripheral wall portion of the main pipe rail, and branch connectors connected to the respective branch holes integrally or via separate connecting members. A Ni-diffused fatigue strength reinforcing layer is formed by heating a Ni layer plated in advance on at least a portion of an inner circumferential surface of the common rail. The increased strength and the action of the fatigue strength reinforcing layer lowers the degree of fatigue concentration to increase fatigue strength against inner pressure.

Abstract: A common rail has a main pipe rail with a peripheral wall. A boss is provided on the peripheral wall, and a branch hole extends through the boss and into the main pipe rail. The branch hole has a pressure receiving seat face. A branch pipe has a pressing seat face that is urged into the pressure receiving seat face by a fastening nut. An orifice pipe is mounted in the branch hole and abuts against an end of the branch pipe without effecting sealing performance between the pressing seat face and the pressure receiving seat face.

Abstract: There is provided a common rail which can effectively restrict a generation of a stress in a lower end inner peripheral edge portion of a branch hole and can improve an internal pressure fatigue strength in a branch pipe connecting portion, so that a secure and stable function can be obtained by having an excellent durability and preventing a fluid leakage due to a generation of the crack generation and a method of manufacturing a common rail in which a pressure application process by the press is only added to a normal manufacturing process, no complex equipment is required, a common rail having a high quality can be manufactured by a low cost without generating problems that an equipment cost is increased by an increase of the process and a productivity is reduced.