Abstract: A coil spring includes a helically formed wire having end turn portions at ends thereof, a plurality of first rough surfaces, each including first shot peening indentations formed on a part of a surface of the end turn portions, and a second rough surface including second shot peening indentations formed on the entire surface of the wire except for the first rough surface. The second rough surface has a surface roughness different from that of the first rough surface.

Abstract: A coil spring processing device includes an end positioning device, shot peening device, and controller. The end positioning device positions ends of a coil spring. The shot peening device includes a turntable mechanism, pressure mechanism, rotation mechanism which rotates the coil spring, and projection mechanism which projects shots. Holding mechanisms each include a lower shifting prevention jig and an upper shifting prevention jig. The controller stops a first holding mechanism and a second holding mechanism in rotation stop positions corresponding to end turn portions of the coil spring.

Abstract: A coil spring includes a helically formed wire having end turn portions at ends thereof, a plurality of first rough surfaces, each including first shot peening indentations formed on a part of a surface of the end turn portions, and a second rough surface including second shot peening indentations formed on the entire surface of the wire except for the first rough surface. The second rough surface has a surface roughness different from that of the first rough surface.

Abstract: A vertical motion impeller-type shot peening device performs a second shot peening to a coil spring including first shot peening indentations. The vertical motion impeller-type shot peening device includes a workpiece holding mechanism including a lower end turn support and an upper end turn support, a stress applying mechanism which compresses the coil spring, a rotation mechanism, and a projection mechanism which includes a pair of vertically movable impeller units. A first rough surface including first shot peening indentations is formed on a part of end turn portions of the coil spring. A second rough surface including second shot peening indentations is formed on the entire surface of wire except for the first rough surface.

Abstract: A shot peening device includes a turntable which rotates about a revolution axis, holding mechanism which moves with the turntable, pressure mechanism which compresses a coil spring, rotation mechanism which rotates the coil spring, projection mechanism which projects shots to the compressed coil spring, load cell which detects a load applied to the coil spring, and controller. A signal output from the load cell is input to the controller, and the controller detects a chronological change of the load applied to the coil spring during the shot peening.

Abstract: A coil spring processing device includes an end positioning device, shot peening device, and controller. The end positioning device positions ends of a coil spring. The shot peening device includes a turntable mechanism, pressure mechanism, rotation mechanism which rotates the coil spring, and projection mechanism which projects shots. Holding mechanisms each include a lower shifting prevention jig and an upper shifting prevention jig. The controller stops a first holding mechanism and a second holding mechanism in rotation stop positions corresponding to end turn portions of the coil spring.

Abstract: A vertical motion impeller-type shot peening device performs a second shot peening to a coil spring including first shot peening indentations. The vertical motion impeller-type shot peening device includes a workpiece holding mechanism including a lower end turn support and an upper end turn support, a stress applying mechanism which compresses the coil spring, a rotation mechanism, and a projection mechanism which includes a pair of vertically movable impeller units. A first rough surface including first shot peening indentations is formed on a part of end turn portions of the coil spring. A second rough surface including second shot peening indentations is formed on the entire surface of wire except for the first rough surface.