Motor Vehicle Front Suspension Decoupling Steering and Springing
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Solution Overview
Problem
Three-wheeled motor vehicles face challenges in balancing stability and handling due to the coupling of steering motion with springing motion, leading to divergent wheel planes and poor steering precision, which affects dynamic behavior and safety.
Innovation Solution
A motor vehicle forecarriage design featuring an articulated quadrilateral kinematic mechanism with strategically positioned hinges and steering tie-rods that decouples steering motion from springing motion, ensuring parallelism of wheel planes and improved stiffness, thereby enhancing stability and handling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If steering motion is coupled with springing motion in three-wheeled vehicles, then the structure is simpler, but the wheel planes diverge and steering precision deteriorates
Solution Approach 1:
The invention segments the steering and springing motions by introducing an intermediate truss structure that decouples the wheel assembly from direct steering control. The wheel assembly can spring independently while the steering tie rod maintains precise control through the rigid truss, preventing the coupling problems of prior art.
Solution Approach 2:
The rigid truss acts as an intermediary between the steering tie rod and the wheel assembly. It transmits steering forces precisely while isolating the springing motion from the steering mechanism, thereby maintaining steering precision despite the presence of independent wheel springing.
2Stability of the object's composition
If additional elements are added to ensure stability like four-wheeled vehicles, then stability improves, but vehicle weight increases
Solution Approach 1:
The front wheel assembly performs multiple functions: it provides steering capability, independent springing for comfort, and contributes to vehicle stability through its kinematic configuration. The articulated quadrilateral mechanism enables the wheels to tilt and roll while maintaining directional control, achieving stability without additional support wheels.
Solution Approach 2:
The invention introduces dynamic capabilities to the front wheel assembly through the articulated quadrilateral mechanism, allowing the wheels to tilt and roll actively. This dynamic behavior provides stability during cornering and maneuvering, replacing the need for static additional support structures.
3Adaptability or versatility
If wheel planes are allowed to diverge due to asymmetric springing, then each wheel can respond independently to obstacles, but vehicle directionality control deteriorates
Solution Approach 1:
The rigid truss serves as an intermediary that maintains the parallelism of wheel planes while allowing independent springing. It transmits steering forces uniformly to both wheels, ensuring that asymmetric springing does not cause the wheel planes to diverge and compromising directionality control.
4Ease of operation
If steering reactions are transmitted to the handlebar during symmetrical springing, then the driver feels vehicle response, but unwanted steering and swerving occur
Solution Approach 1:
The rigid truss acts as a mediator that isolates the steering mechanism from springing reactions. It allows the driver to feel legitimate steering responses while blocking the transmission of unwanted steering reactions caused by symmetrical springing, thereby improving steering control reliability.
Data Source
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AI summary
A motor vehicle forecarriage (8) comprising a forecarriage frame (16), a pair of front wheels (10', 10") kinematically connected to the forecarriage frame (16) by means of an articulated quadrilateral comprising a pair of cross members, hinged to the forecarriage frame (16) in correspondence of middle hinges, said cross members being connected together, in correspondence of opposite transverse ends, by means of uprights pivoted to said transverse ends in correspondence of side hinges, wherein each of the uprights guides and supports a stub axle which is mechanically connected to a rotation pin of a front wheel (10', 10"), and the forecarriage (8) further comprises, in correspondence with each stub axle, a steering tie-rod mechanically connected to the related stub axle to allow the steering of the stub axle and the related front wheel (10', 10") about a respective steering axis ( S'-S', S"-S").