US 11,940,031 B2
Coil spring
Shinichi Nishizawa, Walled Lake, MI (US); Daisuke Ibano, Yokohama (JP); Tsuyoshi Matsuda, Yokohama (JP); Norifumi Arisaka, Yokohama (JP); Shun Muramatsu, Yokohama (JP); Chihiro Ito, Yokohama (JP); Takuto Suzuki, Yokohama (JP); Masatake Kinoshita, Yokohama (JP); and Asuka Kawasaki, Yokohama (JP)
Assigned to NHK SPRING CO., LTD., Kanagawa (JP)
Filed by NHK SPRING CO., LTD., Yokohama (JP)
Filed on Mar. 24, 2022, as Appl. No. 17/703,295.
Prior Publication US 2023/0304557 A1, Sep. 28, 2023
Int. Cl. F16F 1/04 (2006.01); F16F 1/06 (2006.01); B60G 11/14 (2006.01)
CPC F16F 1/043 (2013.01) [F16F 1/06 (2013.01); B60G 11/14 (2013.01); B60G 2202/12 (2013.01); B60G 2206/42 (2013.01); B60G 2600/44 (2013.01); B60G 2800/162 (2013.01); F16F 2230/00 (2013.01); F16F 2230/0023 (2013.01); F16F 2238/026 (2013.01)] 13 Claims
OG exemplary drawing
 
1. A coil spring including a wire rod with one end and another end and including a coil section comprising a plurality of coil portions,
the wire rod comprising:
a round cross-sectional portion whose cross-section perpendicular to a longitudinal direction of the wire rod is round;
a rectangular cross-sectional portion whose cross-section perpendicular to the longitudinal direction of the wire rod is rectangular, the rectangular cross-sectional portion including a first plane at an upper side thereof, a second plane at a lower side thereof, an outer side surface, an inner side surface, and arc-shaped corner portions formed on respective sides of the first plane, and the first plane and the second plane opposing each other in the coil section; and
a cross section varying portion formed between the round cross-sectional portion and the rectangular cross-sectional portion,
the coil spring comprising an elastic coat provided on at least one of the first plane and the second plane of the rectangular cross-sectional portion, and
the elastic coat comprising:
a first coat portion provided on the round cross-sectional portion;
a second coat portion provided on the cross section varying portion; and
a third coat portion provided on the rectangular cross-sectional portion,
wherein a width of the third coat portion is less than or equal to a width of the first plane, and
wherein the rectangular cross-sectional portion comprises a coat-protect portion provided between the outer side surface and the elastic coat.