There are three types of metal springs for automobile suspensions, namely coil springs, leaf springs and torsion bar springs. The spiral spring is named after its shape like a spiral. It has the advantages of small weight and less space. When the impact of the road on the wheel is transmitted, the spiral spring deforms, absorbing the kinetic energy of the wheel and converting it into the potential energy (potential energy) of the spiral spring , Thereby alleviating the impact of ground impact on the body. The middle part of the leaf spring is fixed to the axle by U-shaped bolts (also called riding bolts), and the lugs at both ends are hinged on the bracket of the frame with pins. The axle and the body are connected by the leaf springs. When the impact force of the wheel is transmitted, the steel plate deforms, which acts as a buffer and vibration reduction. One end of the torsion bar spring is fixedly connected with the frame, and the other end is connected with the suspension control arm. The torsion bar spring achieves a buffer effect through the torsional deformation of the torsion bar. Among the three kinds of springs, coil springs and leaf springs are common automobile springs, and their functions are better understood. Many people are not quite clear about the shape and function of torsion bar springs.
Viewed from the cross section, torsion bar springs have round, tubular, rectangular, laminated and combined types. The most used is a round torsion bar, which is a long rod, and the two ends can be processed into splines, hexagons, etc., so that one end is fixed to the frame and the other end is fixed to the wheel through the control arm.
The torsion bar is made of alloy spring steel, which has high elasticity, can be twisted and deformed, and can be restored. In fact, it plays the same role as a coil spring, but the form of expression is different. When the car is running, the wheels move up and down under the influence of the unevenness of the ground, and the control arm will rise or fall accordingly. When the wheel is up, the control arm rises, so that the torsion bar is forced to twist and deform and absorb the impact energy. When the impact is weakened, the natural reduction ability of the rod can quickly return to its original position, so that the wheels return to the ground and avoid bumps in the frame.
Torsion bar springs can store larger energy, much larger than coil springs and leaf springs of equal stress. The shorter and thicker the rod, the greater the stiffness. Generally speaking, compared with the three springs, the torsion bar spring has a larger energy storage per unit weight, and takes up the smallest space position, is easy to arrange, and can moderately adjust the height of the body. Therefore, many passenger car suspensions use torsion bar springs.
The manufacturer applies prestress when manufacturing the torsion bar spring to increase the fatigue strength. Since the prestress is directional, the torsion bar spring is also directional. The torsion bar spring is marked on the left or right to identify which side it is installed on.