Abstract: In a flare fitting structure in which a flared portion that is formed in an end of a flared tube and faces a connected member is pressed by a flared nut to connect the flared tube to the connected member, the flared tube is formed by flaring a cylindrical tube including an original tube and a coating layer that coats a surface of the original tube, the flared portion includes a flare inclined plane that faces the connected member, and the flare inclined plane is formed with a machining portion in which the original tube is exposed by a machining operation.

Abstract: Provided is a terminal structure of a high-pressure fuel pipe for a direct injection engine which can prevent stress concentration to a brazed portion between a pipe and a connection part effectively. In the terminal structure of a high-pressure fuel pipe for a direct injection engine where a connection head is brazed to an end of a fuel pipe, the end of the fuel pipe continued to a fuel pipe insertion portion of the connection head is provided with a drawn portion, an outer diameter D1 of the drawn portion to a fuel pipe diameter D satisfies 0.8D?D1?0.9D, and a length L1 of the drawn portion having the outer diameter D1 in a pipe-axial direction from an end of the fuel pipe insertion portion satisfies L1?0.06D.

Abstract: Provided is a terminal structure of a high-pressure fuel pipe for a direct injection engine which can prevent stress concentration to a brazed portion between a pipe and a connection part effectively. In the terminal structure of a high-pressure fuel pipe for a direct injection engine where a connection head is brazed to an end of a fuel pipe, the end of the fuel pipe continued to a fuel pipe insertion portion of the connection head is provided with a drawn portion, an outer diameter D1 of the drawn portion to a fuel pipe diameter D satisfies 0.8D?D1?0.9D, and a length L1 of the drawn portion having the outer diameter D1 in a pipe-axial direction from an end of the fuel pipe insertion portion satisfies L1?0.06D.

Abstract: Provided is a terminal structure of a high-pressure fuel pipe for a direct injection engine which can prevent stress concentration to a brazed portion between a pipe and a connection part effectively. In the terminal structure of a high-pressure fuel pipe for a direct injection engine where a connection head is brazed to an end of a fuel pipe, the end of the fuel pipe continued to a fuel pipe insertion portion of the connection head is provided with a drawn portion, an outer diameter D1 of the drawn portion to a fuel pipe diameter D satisfies 0.8D?D1?0.9D, and a length L1 of the drawn portion having the outer diameter D1 in a pipe-axial direction from an end of the fuel pipe insertion portion satisfies L1?0.06D.

Abstract: Provided is a terminal structure of a high-pressure fuel pipe for a direct injection engine which can prevent stress concentration to a brazed portion between a pipe and a connection part effectively. In the terminal structure of a high-pressure fuel pipe for a direct injection engine where a connection head is brazed to an end of a fuel pipe, the end of the fuel pipe continued to a fuel pipe insertion portion of the connection head is provided with a drawn portion, an outer diameter D1 of the drawn portion to a fuel pipe diameter D satisfies 0.8D?D1?0.9D, and a length L1 of the drawn portion having the outer diameter D1 in a pipe-axial direction from an end of the fuel pipe insertion portion satisfies L1?0.06D.

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 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.