EV Suspension Geometry for Stable Pitch During Blended Braking
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The use of regenerative brakes in electric vehicles, in conjunction with traditional friction brakes, can cause a difference in anti-lift and anti-dive angles, leading to unstable pitching behavior and discomfort for occupants due to differing points of braking force application.
Innovation Solution
A suspension device for electric vehicles with parallel and oblique swinging axes for front and rear wheels, incorporating front and rear dampers perpendicular to the wheel axes, ensuring coordinated control of regenerative and friction brakes to stabilize vehicle behavior.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If regenerative brakes and friction brakes are used together in electric vehicles, then braking efficiency and energy recovery are improved, but pitching behavior becomes unstable due to different anti-lift and anti-dive angles
Solution Approach 1:
The patent changes the geometric parameters of the suspension system by setting specific relationships between swinging axes and damper directions. The front wheel swinging axis is made parallel to the line perpendicular to the front damper extension direction, and the rear wheel swinging axis is made parallel to the line perpendicular to the rear damper extension direction. This parameter adjustment ensures that both regenerative and friction brakes produce the same anti-lift and anti-dive angles, stabilizing pitching behavior while maintaining high braking efficiency.
2Productivity
If different braking forces are applied to friction brakes and regenerative brakes during coordinated control, then braking performance is optimized, but uncomfortable pitching movements occur due to angle differences
Solution Approach 1:
The patent modifies the suspension geometry parameters so that the front wheel swinging axis parallels the line perpendicular to the front damper extension direction, and the rear wheel swinging axis parallels the line perpendicular to the rear damper extension direction. This ensures uniform anti-lift and anti-dive angles for both brake types, allowing optimized braking force distribution without causing uncomfortable pitching movements.
3Device complexity
If conventional suspension geometry is used without considering regenerative braking, then suspension design is simplified, but pitching behavior becomes unstable during brake coordination
Solution Approach 1:
The patent introduces specific geometric parameter relationships into the suspension design: the front wheel swinging axis is made parallel to the line perpendicular to the front damper extension direction, and the rear wheel swinging axis is made parallel to the line perpendicular to the rear damper extension direction. These parameter changes ensure stable pitching behavior during coordinated braking of friction and regenerative brakes, while maintaining relatively simple suspension design.
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
Prevents changes in pitching behavior and reduces occupant discomfort by maintaining consistent wheel movements during braking, enhancing support rigidity and reducing response delays.
Implementation Method 1
a front damper which extends in a direction perpendicular to the front wheel swinging axis in a side view; a rear damper which extends in a direction perpendicular to the rear wheel swinging axis in a side view
Data Source
AI summary
A suspension device for an electric vehicle prevents change in pitching behavior of the vehicle during regenerative and friction braking. The suspension device includes a front suspension arm that swings in a vehicle up-down direction with reference to a front wheel swinging axis; a front damper approximately perpendicular to the front wheel swinging axis in a side view; a rear suspension arm that swings in the vehicle up-down direction with reference to a rear wheel swinging axis; and a rear damper approximately perpendicular to the rear wheel swinging axis in a side view. The front wheel swinging axis and a first imaginary line perpendicular to a direction of extension of the front damper are approximately parallel to each other. The rear wheel swinging axis and a second imaginary line perpendicular to a direction of extension of the rear damper are approximately parallel to each other in a side view.