A method for manufacturing a hollow spring member having a hollow steel spring rod having terminal sealed portions at both ends thereof. Each terminal sealed portion has a rotationally symmetric shape in which an axis passing through a center of the spring rod is an axis of symmetry. Each terminal sealed portion has an end wall portion including an end face; an arc-shaped smoothly curved surface between an outer peripheral surface of the spring rod and the end face, and a hermetically closed distal-end-center closure portion on the axis passing through the center of the spring rod. The method includes forming each of the end portions of the spring rod by forming a chamfered portion on an inner or outer peripheral side of the end portion of a hollow wire, the end portion having an opening portion at a distal end, heating the end portion of the hollow wire having the chamfered portion, and spinning the heated end portion to be gathered toward the axis from the outer peripheral side by a jig. The end wall portion, which includes the distal-end-center closure portion, is formed by the distal end of the end portion being joined together on the axis.

A method of manufacturing a hollow coil spring which is made of a hollow wire in which a terminal sealed portion is formed on an end portion of the wire. The terminal sealed portion has a rotationally symmetric shape in which an axis passing through the center of the wire is the symmetric axis. The hollow coil spring includes an end wall portion, and an end face arc-shaped curved surface. The end wall portion includes an end face perpendicular to the axis. A distal-end-center closure portion is formed on the axis at the center of the end wall portion. A spring seat includes a base member and a sheet member. An end turn portion of the hollow coil spring is in contact with the sheet member. The end face of the end turn portion is opposed to a stopper wall of the spring seat.

A method of manufacturing a hollow coil spring which is made of a hollow wire in which a terminal sealed portion is formed on an end portion of the wire. The terminal sealed portion has a rotationally symmetric shape in which an axis passing through the center of the wire is the symmetric axis. The hollow coil spring includes an end wall portion, and an end face arc-shaped curved surface. The end wall portion includes an end face perpendicular to the axis. A distal-end-center closure portion is formed on the axis at the center of the end wall portion. A spring seat includes a base member and a sheet member. An end turn portion of the hollow coil spring is in contact with the sheet member. The end face of the end turn portion is opposed to a stopper wall of the spring seat.

A method for manufacturing a hollow spring member having a hollow steel spring rod having terminal sealed portions at both ends thereof. Each terminal sealed portion has a rotationally symmetric shape in which an axis passing through a center of the spring rod is an axis of symmetry. Each terminal sealed portion has an end wall portion including an end face; an arc-shaped smoothly curved surface between an outer peripheral surface of the spring rod and the end face, and a hermetically closed distal-end-center closure portion on the axis passing through the center of the spring rod. The method includes forming each of the end portions of the spring rod by forming a chamfered portion on an inner or outer peripheral side of the end portion of a hollow wire, the end portion having an opening portion at a distal end, heating the end portion of the hollow wire having the chamfered portion, and spinning the heated end portion to be gathered toward the axis from the outer peripheral side by a jig. The end wall portion, which includes the distal-end-center closure portion, is formed by the distal end of the end portion being joined together on the axis.

A terminal sealed portion is formed on an end portion of a hollow rod made of steel. An enclosed space is formed on an inner side of the hollow rod. At an end of the enclosed space, a terminal gap is formed. A volatile powdered rust inhibitor is supplied in the enclosed space. As the volatile powdered rust inhibitor is vaporized, the enclosed space is turned into a rust-inhibiting atmosphere. As the vaporized component of the volatile powdered rust inhibitor is adsorbed to an inner surface of the enclosed space, an inner surface rust-inhibiting film is formed. The vaporized component also enters inside the terminal gap, and forms a terminal rust-inhibiting film.

A hollow coil spring is made of a hollow wire in which a terminal sealed portion is formed on an end portion of the wire. The terminal sealed portion has a rotationally symmetric shape in which an axis passing through the center of the wire is the symmetric axis. The hollow coil spring includes an end wall portion, and an end face arc-shaped curved surface. The end wall portion includes an end face perpendicular to the axis. A distal-end-center closure portion is formed on the axis at the center of the end wall portion. A spring seat includes a base member and a sheet member. An end turn portion of the hollow coil spring is in contact with the sheet member. The end face of the end turn portion is opposed to a stopper wall of the spring seat.

A chassis component (1) for a wheel suspension having at least two pivot points (3, 4), at least one connecting structure (7) which interconnects the pivot points (3, 4) with one another, and at least one sensor (9). The at least one sensor (9) is embodied as a piezoresistive thin film (19) arranged on a section of a surface (8) of the connecting structure (7). A thin film interconnects contact points (15, 16), of at least two conductive sections (13, 14) which are integrated in the connecting structure (7), to one another.

A suspension arm includes a ball stud including a spherical ball; a bearing in which the spherical ball is accommodated; a housing having an inner peripheral portion and an outer peripheral portion; an arm body coupled to the outer peripheral portion of the housing; and an insert molding part which is injected to a lower portion of the bearing and the outer peripheral portion of the housing to be coupled to the bearing, the housing, and the arm body. The housing includes a matching portion having a matching surface formed to protrude in a radially outward direction from an upper portion of the outer peripheral portion and to be brought into contact with a mold. By forming the matching portion, it is possible to reduce the volume of the housing and to reduce the weight of the suspension arm while providing the matching surface with the mold.

A paint spraying apparatus includes a supporting structure, a lower nozzle unit, and an upper nozzle unit. The lower nozzle unit includes lower flexible tubes and nozzles, and ejects powder paint toward an eye portion on a lower side of a stabilizer. The upper nozzle unit includes a first frame and a second frame. First flexible tubes are arranged on the first frame. Second flexible tubes are arranged on the second frame. The upper nozzles eject the powder paint toward an eye portion on an upper side of the stabilizer.

A chassis component (1) for a wheel suspension having at least two pivot points (3, 4), at least one connecting structure (7) which interconnects the pivot points (3, 4) with one another, and at least one sensor (9). The at least one sensor (9) is embodied as a piezoresistive thin film (19) arranged on a section of a surface (8) of the connecting structure (7). A thin film interconnects contact points (15, 16), of at least two conductive sections (13, 14) which are integrated in the connecting structure (7), to one another.