Virtual Steering Axle for Passive Toe Correction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing motor vehicle axles, particularly in small and very small cars, are costly due to complex designs and high material and maintenance costs, and they lack efficient toe correction mechanisms, leading to subcritical driving conditions and reduced driving comfort.
Innovation Solution
A torsion beam rear axle with a virtual steering axis is implemented, utilizing a pivot bearing and two rubber-metal bearings to create a spring center of gravity outside the vehicle, allowing for passive toe correction through braking and cornering forces, reducing the need for active actuators and sensors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a complex axle construction with active actuators and sensors is used for toe correction, then toe correction capability is improved, but production costs, initial assembly costs, and maintenance costs increase significantly
Solution Approach 1:
The patent extracts the active actuator and sensor systems from the toe correction mechanism, replacing them with a passive geometric design. The virtual steering axis is positioned outside the vehicle body, allowing toe correction to occur automatically through the suspension kinematics without requiring active components, thus simplifying the device while maintaining adaptability
Solution Approach 2:
The axle design enables self-service toe correction through its geometric configuration. The virtual steering axis position and link arm arrangement automatically produce the desired toe-in effect during compression and cornering without external control systems, eliminating the need for active actuators and sensors
2Adaptability or versatility
If a complex axle construction with active actuators is used for toe correction, then toe correction capability is improved, but the weight of the axle increases
Solution Approach 1:
The patent removes the heavy active actuator components from the axle assembly, replacing them with a lightweight passive geometric design. The virtual steering axis configuration achieves toe correction through the existing suspension components' arrangement, eliminating the need for additional heavy machinery while maintaining correction capability
Solution Approach 2:
The design uses simple, lightweight geometric arrangements instead of complex, heavy active systems. The virtual steering axis and link arm configuration provide durable, maintenance-free toe correction without the weight penalty of active components, effectively replacing expensive and heavy systems with simpler alternatives
3Adaptability or versatility
If the virtual steering axis is positioned outside the vehicle, then toe correction effect is improved, but the axle construction becomes more complex
Solution Approach 1:
The patent positions the virtual steering axis in a different spatial dimension - outside the vehicle body rather than within the axle assembly. This external positioning is achieved through the geometric arrangement of link arms and pivot points, creating a virtual axis that extends beyond the physical components. This dimensional shift allows the steering axis to be effectively relocated without adding physical complexity to the axle construction
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This design results in a cost-effective, low-weight axle with improved driving characteristics and longer service life, maintaining suspension kinematics while providing effective toe correction without increasing maintenance needs.
Implementation Method 1
two rubber-metal bearings (7a, 7b), which form a spring center of gravity (9), based on the motor vehicle coordinate system outside of the motor vehicle
Data Source
Figure 1~2
Figure 3~4
Figure 5
AI summary
The axle (1) has a torsion profile (2) comprising longitudinal rocker arms (3), and a wheel suspension (5) coupled to a free end of the rocker arms and pivotable around a virtual steering axle (10). A wheel carrier is screwed at the wheel suspension. The wheel suspension is coupled with the rocker arms over two rubber-metal bearings (7a, 7b). The metal bearings form a spring balance point (9) that lies on a motor vehicle coordinate system at an outer side of a motor vehicle, where the steering axle intersects the spring balance point and a pivot bearing (6) i.e. spherical joint.