To provide a spring device capable of surely preventing slipping-out of a receiving part from a ball part constituting a ball joint, by applying relatively small tensile energizing force to both links while keeping the mutual links in a proper interval distance, and furthermore, by applying large tensile energizing force when the interval distance of the mutual links becomes large.

This spring device has a first compression spring 19 and a second compression spring 20 arranged in series to the first compression spring 19 as an energizing element. A spring constant k1 of these first compression spring 19 and a spring constant k2 of second compression spring 20 are made mutually different. Thus, as a synthetic spring constant k0 of the whole energizing element, its constant can be restrained more than the respective spring constants k1 and k2 of these first and second compression springs 19 and 20. When the compression spring 20 of a small spring constant reaches a compression limit, since only the other compression spring 19 of a large spring constant is compressed, the spring device 15 exhibits large tensile energizing force.