Arm triangle is a balanced supporting function.

When the car runs on uneven road surface, the tire will swing up and down, that is, by swinging the triangle arm to complete, the tire is installed on the axle head, the axle head is connected by the ball head and the triangle arm. The triangular arm is actually a universal joint, which can still be related when the relative position of the active and driven sides changes. For example, the shock absorber is compressed to make the A-arm rocking up while steering.

The triangular arm is connected with the sub-frame through the articulated sleeve of the front connecting point of the sub-frame, and the force and impact on the wheel are transmitted to the body through the articulated sleeve of the front connecting point of the sub-frame. The articulated sleeve of the front connecting point of the sub-frame is the place where cracking may occur, that is, if the accident of "axle breaking" occurs, the high probability is in the position of the articulated sleeve of the front connecting point of the sub-frame. Place.