REAR SUSPENSION SYSTEM


  1. OUTLINE


    1. A torsion-beam type suspension is used.

    2. Through the optimal specification of components, the rear suspension offers excellent riding comfort and stability.

    3. A rear axle carrier bush is obliquely mounted to obtain a toe-correct function, thus providing excellent driving stability and ride comfort.

      A01UWF3E02
      Text in Illustration
      *A For Drum Brake *B For Disk Brake
      *1 Rear Suspension Support *2 Rear Coil Spring
      *3 Rear Shock Absorber Assembly *4 Axle Beam (Rear Axle Beam Assembly)
      *5 Trailing Arm (Rear Axle Beam Assembly) *6 Rear Axle Carrier Bush

      Note

      Be sure to use the jack-up points that are provided on the body when raising the vehicle on the jack. Never apply a jack under the axle beam (rear axle beam assembly), spring seat, trailing arm (rear axle beam assembly), or bushing of the rear suspension.

  2. MAIN FEATURES


    1. Camber Change


      1. In a torsion-beam type suspension, the camber angle and the toe change differ between the bouncing case and the tramping case, offering both straight-line stability and excellent cornering stability.

      2. The same as the full-trailing arm type suspension, the axis that joins the center of the right and left bushings in the trailing arms (rear axle beam assembly) is the center of movement during any same direction travel.

      3. During opposite direction travel, or if any difference in the suspension travel is created between the right and left wheels, the axle beam (rear axle beam assembly) twists with its shearing center as the center of its rotation. Also, camber changes in relation to the suspension travel are determined by the ratio of the distance between the bushing in the trailing arm (rear axle beam assembly), the axle center and the shearing center ("α" in the figure below) and distance between the bushing in the trailing arm (rear axle beam assembly) and the axle center ("L" in the figure below). Consequently, through the optimal allocation of the axle beam (rear axle beam assembly), the changes in the camber angle in relation to the suspension travel have been optimized, thus ensuring excellent cornering performance.

        A01UWDZE05
        Text in Illustration
        *a Bound *b Rebound
        *c Shearing Center *d Center of Bushing
        *e Instantaneous Rotational Axis of Right Axle *f Camber Change Rate α/L

    2. Anti-lift Geometry


      1. The lifting of the rear end of the vehicle during braking occurs due to the shifting of the center of gravity caused by inertia. The intersecting point (OR) supports the braking force (BF), and generates a force (BF1) in the direction of the intersecting point (OR) and a component force (BF2) in the direction of the ground contact. The force (BF1) can change the height of the intersecting point (OR). When the intersecting point (OR) is set high, it acts in the opposite direction (-▲W) of the load fluctuation (W) in order to restrain the lift.

        A01UW3LE02
        *1 OR

    3. Toe-correct Function


      1. The longitudinal and lateral forces that are created in the vehicle during cornering cause the bushings in the trailing arms (rear axle beam assembly) to deform. On a right turn, the right trailing arm (rear axle beam assembly) moves forward and the left trailing arm (rear axle beam assembly) moves rearward, creating a tendency for the left wheel to toe-out. In this situation, the bushings that are installed in the trailing arms (rear axle beam assembly) are designed to utilize the lateral force, which is applied to the bushings during cornering, to correct the left trailing arm (rear axle beam assembly) towards the toe-in direction.

        A01UWOME09
        Text in Illustration
        *A Without Toe-correct Function *B With Toe-correct Function
        *1 Bushing *2 Left Wheel
        A01UWJU Bushing Movement A01UWQJ Lateral Force
        A01UWNT Lengthwise Force A01UW2C Lateral Force Applied to the Bushing