| 摘要 |
PURPOSE:To enhance the spring stiffness in the last period of load input and sufficiently secure a stroke for providing low spring stiffness in the first period of load input. CONSTITUTION:A stiffness ring 11 is attached to the large-diameter part 2 of a bellows cylindrical bumper base body 1. The stiffness ring 11 is composed of an embedded part 12 to the bumper base body 1 and a cylinder part 13 axially extended along the outer peripheral surface of the large-diameter part 2 from this embedded part 12. The cylinder part 13 as well as the embedded part 12 of the stiffness ring 11 restrain the expansion in the outer diametral direction of the bumper base body 1 in the last period of load input, so as to rapidly enhance the spring stiffness. Since only embedded part 12 of the stiffness ring 11 is embedded in the bumper base body 1, the bellows shaped part of the bumper base body 1 is not shortened by the stiffness ring 11, so that low spring stiffness in the first period of load input may secure a sufficient stroke. |
