Patent ID: 11940031
Assignee: NHK SPRING CO., LTD.
Field: Mechanical elements (Mechanical engineering)
Classification: CPC F  B | IPC B  F

Claim 0:
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.