Assembly method and assembly device for suspension device of vehicle and mixed model production line

An assembly method for a suspension device of a vehicle, the suspension device comprising a suspension member which is elastically and swingably supported by a vehicle body and supports a wheel;

• and a coil spring which is interposed between the vehicle body and the suspension member and receives a compression load, the assembly method being characterized by:
• bringing a fastening member into a distorted state, and connecting the suspension member, which is elastically and swingably supported by the vehicle body, and the vehicle body or a vehicle part attached to the vehicle body, by the fastening member, the fastening member being stretchable to a stretched state wherein the fastening member extends to a certain length when tension is applied;
• forcibly changing orientation of the suspension member with respect to the vehicle body so as to increase a distance between the vehicle body and the suspension member at an interposition portion of the coil spring;
• restricting a change in the orientation of the suspension member relative to the vehicle body by the fastening member which stretches to the stretched state wherein the fastening member extends to the certain length with the increase in the distance caused by the change in the orientation of the suspension member, and inserting the coil spring between the vehicle body and the suspension member;
• in a state in which the orientation of the suspension member is changed until the fastening member is in the stretched state, the coil spring is inserted between the vehicle body and the suspension member;
• the suspension member is elastically and swingably supported by the vehicle body through a rubber bushing, and the vehicle body or the vehicle part and the suspension member are connected by the fastening member, on an opposite side of the interposition portion of the coil spring from the rubber bushing on the suspension member;
• the suspension member is a torsion beam suspension member, and a spring seat for disposing the coil spring is provided on a swing arm of the suspension member;
• a damper for connecting the vehicle body and the swing arm is provided as the vehicle part;
• the orientation of the swing arm is forcibly changed in a state in which the damper is coupled to the vehicle body and is not coupled to the swing arm;
• and
• the fastening member is connected to a coupling portion of the damper with respect to the swing arm.