What is the purpose of the kingpin inclination angle?

[LaKatherine]

The kingpin inclination angle serves to enable the wheels to automatically return to the correct position after steering and to make steering easier. The size of the kingpin inclination angle value has a significant impact on the car's steering and handling performance. This parameter generally only appears on the steering wheels. It refers to the inward tilt of the wheel's kingpin when viewed from the front to the rear of the car. In the lateral plane of the car, the upper end of the kingpin axis is slightly inclined inward, a phenomenon known as kingpin inclination. In the lateral vertical plane, the angle between the kingpin axis and the vertical line is called the kingpin inclination angle. Both the kingpin caster and the kingpin inclination have the effect of automatically returning the steering wheels to the correct position. However, the kingpin caster's return effect is related to the vehicle speed, while the kingpin inclination's return effect is not related to the vehicle speed. Therefore, at high speeds, the effect is mainly due to the kingpin caster, while at low speeds, it is mainly due to the kingpin inclination. The kingpin inclination angle ensures the car's straight-line driving and the wheels' automatic return to the correct position through the front axle load. The kingpin inclination and wheel camber angles are mainly determined by the steering knuckle. The kingpin inclination angle cannot be adjusted; if the inclination angle error is too large, the steering knuckle should be replaced. Currently, many cars with independent suspensions no longer have the kingpin component. However, in wheel alignment, the term 'kingpin' is still used as a synonym for the steering wheel's steering axis, meaning that when the steering wheel turns, it rotates around the kingpin axis.