Why do we need kingpin inclination?

The kingpin angle has an important effect on steering, making it tend to return to the straight ahead or centre position because the straight ahead position is where the suspended body of the vehicle is at its lowest point.

What is the importance of kingpin inclination?

On current suspension systems, the kingpin is set at an angle to the vertical plane when viewed from the front or rear of the vehicle. This angle is known as the king pin inclination. The purpose of the KPI is to produce vertical displacement of the vehicle in during steering in an upward direction.

What is the value of kingpin inclination angle?

King pin inclination value for vehicles

In general Kingpin angle should be in between 6 to 14 degrees for effective performance. Most of the formula cars have kingpin angle more than 10 degree as it reduces the scrub radius.

What is the kingpin offset and what is it used for?

The kingpin offset is the “lever arm” of the longitudinal forces at the wheel center. It produces a self-centering action of steering, mainly sensitive at low speed. At high speed, it is usually minimal compared to other effects such as the caster angle effect.

What is the main reason for steering axis inclination?

Steering axis inclination (SAI) causes both front wheels to gain positive camber as they steer away from center. This acts with caster to provide self-centering of the front wheels. This gives the car straight line stability.

How King Pin Inclination Angle (KPI/KPA) Works

What is kingpin inclination?

Swivel pin or kingpin inclination is the lateral inward tilt (inclination) from the top between the upper and lower swivel ball joints or the kingpin to the vertical (Figure 10.3).

What is the effect of incorrect steering axis inclination angle?

Yes, incorrect S.A.I leads to pull the vehicle to the side of higher inclination(not in lesser side), and take time to get back.

How is kingpin inclination determined?

Kingpin angle is measured in Degrees and is positive when the top of the steering axis points towards the centre of the car. Scrub radius is the distance from the steer axis to the centre of the tyre contact patch at ground level and wheel centre offset is the distance from the kingpin axis to the wheel centre.

How does Castor affect steering?

Caster angle settings allow the vehicle manufacturer to balance steering effort, high speed stability and front end cornering effectiveness. Increasing the amount of positive caster will increase steering effort and straight line tracking, as well as improve high speed stability and cornering effectiveness.

What is toe in and out?

First, let's define what we mean by toe. It is the difference in the distance between the front and rear edges of the rims on one axle. If the distance at the front is larger than the rear, then the alignment is said to be toed-out, and if the distance at the rear is larger than the front, that's toe-in.

What is castor adjustment?

Caster is an alignment adjustment that occurs on the turning wheels only, i.e., the front wheels of a vehicle.

What is KPI and camber?

Camber compliance (the inverse of camber stiffness) is a measure of the compliance of a suspension system when subject to a cornering (lateral) force at the contact patch. It is expressed as the camber change in degrees per kilo Newton of lateral force, Deg/kN.

What is camber caster and kingpin inclination?

Caster is the angle of the steering axis from the vertical as viewed from the side and is shown in Fig. Positive caster is defined as the steering axis inclined toward the rear of the vehicle. b. Camber is the angle of the tire/wheel with respect to the vertical as viewed from the front of the vehicle, as shown in Fig.

What does toe mean in alignment?

Toe is a measurement that determines how much the front and/or rear wheels are turned in or out from a straight-ahead position. The amount of toe, whether it's toe-in or toe-out, is expressed as the difference between the track widths as they are measured at the leading and trailing edges of the tires.

What's a kingpin mean?

Definition of kingpin

1 : the chief person in a group or undertaking. 2 : any of several bowling pins: such as. a : headpin. b : the pin that stands in the middle of a triangular arrangement of bowling pins.

What is the difference between kingpin and ball joint?

A ball joint is a metal case that is crimped around a ball that has a threaded shaft protruding from it, while a kingpin is a solid pin that either a bushing or bearing rotates around.

How many positions are there in King Pin?

A Two-Position King Pin allows the operator to have the choice between two swing clearance lengths on the same gooseneck. This assembly consists of a special length fifth wheel plate, two king pin mounting sleeves, and a drop-in style kingpin.

What is castor and camber angle?

1] While viewing from the side of a vehicle, the caster is the angle between the steering axis and a vertical axis of the wheel. While viewing from the front of a vehicle, the camber is the angle made by an axis of the wheel with an axis perpendicular to the road.

What is the most important alignment angle in terms of TYRE wear?

Toe is the most critical tire-wearing angle. Tires that “toe-in” point toward one another. Tires that “toe-out” point away from each other.

How do you increase steering Returnability?

In order to improve steering returnability, it is possible to increase the total steering rack force in both road wheels through adjustments to the kingpin axis and steering angle. This approach is useful for setting up a proper suspension geometry during conceptual chassis design.

What are the three basic steering angles?

There are three main wheel alignment angles, which determine how each wheel is positioned relative to the car, the ground and each other. These are camber, caster and toe.

What is kingpin torque?

Step One: Kingpin Torque

W = Vehicle Weight supported by the steered axle. f = Coefficient of friction (dimensionless). Based on 0.7 as a Maximum. Determine from chart at left.

What is tire slip angle?

In vehicle dynamics, slip angle or sideslip angle is the angle between the direction in which a wheel is pointing and the direction in which it is actually traveling (i.e., the angle between the forward velocity vector and the vector sum of wheel forward velocity and lateral velocity.

What is positive scrub radius?

The distance between the center of the tire's contact patch and the point where that line touches the road is the scrub radius. If the line touches the road inboard of the contact patch, scrub radius is positive. If the line touches the road outboard of the contact patch, scrub radius is negative (see Figure 2).