Coupled torsion beam axle type suspension system

A coupled torsion beam axle type suspension system (CTBA), in which opposite ends of a torsion beam are coupled to left and right trailing arms and the left and right trailing arms are coupled to vehicle body-engaging units for being mounted on the vehicle body at front end portions thereof, wherein each vehicle body-engaging unit includes:

• a trailing arm bush connected to the front end portion of the trailing arm;
• a rotation link disposed in front of the trailing arm bush and engaged to the trailing arm bush in a width direction of the vehicle;
• a slider rotatably connected to a front end portion of the rotation link, and slidably mounted within a guide hole formed to the vehicle body;
• and
• a connection link configured to couple an outer end portion of the rotation link to the vehicle body,
• wherein an instantaneous rotational center point of the CTBA, of which an intersection of extending lines that pass an instantaneous rotational center points of the rotation links and centers of the trailing arm bushes forms, is positioned behind wheel centers.