A method of manufacturing a cylindrical ring member includes a step of forming a metal intermediate material having a cylindrical portion and a chamfering step by cold forging in which a normal chamfer portion is formed on an axial end peripheral edge of the cylindrical portion by pressing a radial end portion of an axial end surface of the cylindrical portion against an annular chamfering surface provided in a mold configuring a mold device. A chamfering step is performed by cold forging in a state where a preliminary chamfer portion, of which a width dimension in a radial direction is larger than a width dimension of the normal chamfer portion in a radial direction, is formed on the axial end peripheral edge of the cylindrical portion.

Provided are a pressure sensor device and method for making the same. A base member and a pressure sensor chip are joined so that a pressure receiving portion is aligned with a through hole. A pressure introduction unit and the base member are positioned and joined so that through holes thereof are continuous. The pressure introduction unit has a stepped portion in an end portion on an opened end side, and has a protruding portion protruding from the stepped portion to the base member side in an end portion.

Provided are a pressure sensor device and method for making the same. A base member and a pressure sensor chip are joined so that a pressure receiving portion is aligned with a through hole. A pressure introduction unit and the base member are positioned and joined so that through holes thereof are continuous. The pressure introduction unit has a stepped portion in an end portion on an opened end side, and has a protruding portion protruding from the stepped portion to the base member side in an end portion.

The subject invention, a collet receiver hitch, has a receiver tube with collet features, and a collet collar to eliminate the problem movement of the draw bar/mount inside the receiver. The first part is a collet receiver tube with an open end for accepting the ball mount shank. The second part is an outside collet collar. The outside collet collar is drawn onto the collet receiver tube, thereby causing the wedging action that, in turn, centers and holds the mount shank. The hitch pin is still required, and its use does not impair the subject invention.

Provided is a high-pressure fuel injection pipe with a connection head which achieves an improvement in outer-surface cleanliness and prevention of a decrease in axial force and fastening strength. The pipe having, at a connection end of a narrow-diameter thick-wall steel pipe having a rust-inhibiting coating applied to an outer surface of the pipe, the connection head composed of a spherically-shaped seat surface, an annular flange, and a conical surface and having an outside peripheral surface forming formed into seat surface in a truncated conical shape or truncated arc shape for a mating seat; and a washer fitting in a neck lower part of the connection head and having a rust-inhibiting coating applied to an outer surface of the washer, wherein a contact part between the neck lower part of the connection head and an end part of the washer has a metal-to-metal contact structure without having the rust-inhibiting coating.

A device is provided with a first die, a second die and a pressing machine. The second die is provided with a plastic processing hole where a core metal is disposed on a hole center line. On the inner peripheral surface of the plastic processing hole, three projecting portions are provided at regular intervals in the circumferential direction of the hole center line. By the approach of the first and second dies to each other, the core metal is inserted into a guide hole of a contact tip, and the projecting portions plastically deform the head end side of the contact tip by pressing it until it is in contact with the core metal.

A hollow shaft includes a cylindrical main body part and an extremity drawn part that is integrally connected to one end of the main body part on the same axis and whose diameter is made smaller than a diameter of the main body part by drawing processing, wherein an inner peripheral face of the main body part and an inner peripheral face of a base portion, which is continuous with one end side of the main body part, of the extremity drawn part are formed as cut faces that are subjected to cutting processing before the drawing processing, and an inner peripheral face of a tip portion, which is continuous with an extremity side of the base portion, of the extremity drawn part is a non-cut face. Accordingly, the hollow shaft can be molded with high shape precision while maintaining a low drawing ratio for an extremity drawn part.

A method of manufacturing a cylindrical ring member includes a step of forming a metal intermediate material having a cylindrical portion and a chamfering step by cold forging in which a normal chamfer portion is formed on an axial end peripheral edge of the cylindrical portion by pressing a radial end portion of an axial end surface of the cylindrical portion against an annular chamfering surface provided in a mold configuring a mold device. A chamfering step is performed by cold forging in a state where a preliminary chamfer portion, of which a width dimension in a radial direction is larger than a width dimension of the normal chamfer portion in a radial direction, is formed on the axial end peripheral edge of the cylindrical portion.

An annular reference surface is formed around a through-hole of an eye portion. A distal-end-side curved portion is formed at a first corner portion, on an outer side of the annular reference surface. The thickness of the distal-end-side curved portion is reduced in a range of a length from the first flat surface toward the distal end surface. A hole-side curved portion whose thickness is reduced toward an inner surface of the through-hole is formed at a second corner portion, on an inner side of the annular reference surface. The length of the hole-side curved portion is less than the length of the distal-end-side curved portion. The hole-side curved portion is curved with a greater curvature than that of the distal-end-side curved portion.

In a method for thickening a plastically deformable hollow body wall of a hollow body, with effective radial support of the unthickened hollow body wall on an outer supporting face of an outer mold and with effective radial support of the hollow body wall on an inner supporting face of an inner supporting body, the hollow body is acted on by a compressive force by two application members at application points by moving the application members towards one another in the axial direction with a compressing movement. The application points on the hollow body are distanced from one another in the axial direction. An expansion space of the outer mold is arranged between the application points. Due to the compressing movement of the application members, material of the hollow body wall between the application points is plasticised in the region of the expansion space of the outer mold, and plasticised material of the hollow body wall flows into the expansion space of the outer mold, thus thickening the hollow body wall.