| 摘要 |
PROBLEM TO BE SOLVED: To provide a coil spring capable of restricting occurrence of separation among carbon fibers when a force for expanding a spring member outwardly is high or when its force is repeatedly applied.SOLUTION: This invention relates to a cylindrical coil spring made of carbon fiber reinforced carbon complex material provided with an axial hole and a helical groove characterized in that the carbon fiber reinforced carbon complex material comprises a first group of carbon fibers arranged to extend in one direction in a horizontal direction perpendicular to a direction of the axial hole and a second group of carbon fibers arranged to extend in one direction of a horizontal direction to form an angle of 30° or more and 90° or less with the extending direction of the first group of carbon fibers, the first group of carbon fibers and the second group of carbon fibers are laminated in plural layers and at the same time carbon matrix is arranged between the layers of the laminated group of carbon fibers. |
