Decoupling Suspension Kinematics and Isolation via Segmented Control Arm

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Solution Overview

Problem

Vehicle suspension systems face a trade-off between providing stiffness for safety and stability, and softness for comfort, as existing designs often fail to effectively decouple kinematics from isolation, leading to suboptimal vibration and noise isolation.

Innovation Solution

A two-piece lower control arm assembly with a base member coupled to the vehicle via elastomeric isolators and a control arm pivotally connected via ball joint assemblies, decoupling kinematics from isolation, allowing for adjustable elastic axes and reduced deflection steer, steering feedback, and ride harshness.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a stiff suspension is provided to enhance vehicle safety and stability, then vehicle safety and stability are improved, but passenger comfort deteriorates due to inability to absorb road roughness

Engineering Contradiction:

Improvevehicle safety and stabilityVSAvoidroad roughness transmission

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The control arm assembly is divided into two separate pieces: a base member and a control arm. This segmentation allows the base member to provide structural stiffness for safety and stability, while the control arm with isolators absorbs road roughness, thus resolving the contradiction between stiffness and comfort.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The isolators are extracted from the traditional integrated control arm design and placed specifically on the control arm portion that couples to the steering knuckle. This extraction allows the isolators to specifically address road roughness without compromising the structural integrity provided by the base member.

Inventive Principle:

Principle #2Taking out (Extraction)

2Device complexity

If traditional integrated control arm design is used, then structural simplicity is maintained, but vibration and noise isolation is insufficient

Engineering Contradiction:

Improvecontrol arm structureVSAvoidvibration and noise

Core Design Contradiction:

Device complexityVSObject-affected harmful factors

Solution Approach 1:

The control arm assembly is segmented into a base member and a control arm, allowing the isolators to be strategically positioned on the control arm. This segmentation enables effective vibration and noise isolation without excessive complexity, as the isolators are concentrated at the optimal location.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The isolators act as intermediaries between the control arm and the steering knuckle, absorbing vibrations and noises before they can be transmitted to the vehicle interior. This intermediary function effectively reduces harmful vibrations and noises without requiring complex active control systems.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Object-affected harmful factors

If isolators are positioned on the control arm rather than the base member, then kinematics are decoupled from isolation, but manufacturing complexity increases

Engineering Contradiction:

Improveisolation effectivenessVSAvoidassembly manufacturing

Core Design Contradiction:

Object-affected harmful factorsVSEase of manufacture

Solution Approach 1:

By segmenting the control arm assembly into base member and control arm components, the isolators can be manufactured and positioned on the control arm separately. This segmentation allows for specialized manufacturing of each component with its specific function, potentially simplifying the overall manufacturing process despite the additional component.

Inventive Principle:

Principle #1Segmentation

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 improves vibration and noise isolation, reduces peak forces on isolators, and enhances passenger comfort by allowing independent adjustment of elastic axes and reducing deflection steer, resulting in improved ride quality and control.

Implementation Method 1

a base member configured to couple to a structural member of the vehicle via at least one isolator

Methodology Applied

Scientific EffectElasticity: Elasticity

Implementation Method 2

improves vibration and noise isolation

Methodology Applied

Scientific EffectVibration absorption: Damping

Implementation Method 3

a control arm pivotally coupled to the base member and configured to couple to a steering knuckle of the vehicle

Methodology Applied

Scientific EffectSpherical joint mechanism: Ball

Data Source

PatentUS10675933B2Suspension control arm assembly

Publication Date: 2020.06.09 FCA US LLC

AI summary

A control arm assembly for a suspension system of a vehicle includes a base member configured to couple to a structural member of the vehicle via at least one isolator, and a control arm pivotally coupled to the base member and configured to couple to a steering knuckle of the vehicle, such that kinematics acting on the control arm are decoupled from an isolation provided by the coupling between the base member and the vehicle structural member.