Suspension Link Undercut Geometry for Impact Load Release

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Solution Overview

Problem

Existing vehicle suspension systems face challenges in minimizing the effects of impact loads and ensuring predictable wheel kinematics during small frontal overlap impacts, requiring a solution that balances structural integrity with economical and fast response characteristics.

Innovation Solution

A suspension system with a link coupled to the engine cradle and wheel assembly, featuring a flange with an opening and undercut, designed to release the wheel assembly under specific load thresholds, allowing for controlled kinematics and minimizing vehicle body deformation by directing the wheel assembly through a trajectory that absorbs impacts effectively.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If the suspension system is designed to release the wheel assembly under impact loads to minimize vehicle body deformation, then the protective effect is improved, but the structural integrity and stability during normal operation may be compromised

Engineering Contradiction:

Improveimpact load effectsVSAvoidstructural integrity

Core Design Contradiction:

Object-affected harmful factorsVSReliability

Solution Approach 1:

The suspension link incorporates a dynamic release mechanism with an undercut geometry that allows the joint to transition from a locked state during normal operation to a released state under impact loads. The undercut creates a stress concentration point that enables controlled fracture when the applied moment exceeds a threshold, allowing the system to adapt its structural behavior based on load conditions.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The link is designed as a segmented structure where the flange with the undercut creates a predetermined weak point. This segmentation allows the link to remain intact during normal operation but separate into distinct segments (flange and remaining link body) when subjected to excessive impact loads, enabling the wheel assembly to release and redirect forces away from the vehicle body.

Inventive Principle:

Principle #1Segmentation

2Reliability

If a traditional rigid suspension link is used to maintain structural integrity, then the reliability is improved, but the ability to minimize deformation during impact loads is reduced

Engineering Contradiction:

Improvestructural integrityVSAvoidvehicle body deformation

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The undercut geometry is pre-formed in the flange during manufacturing, creating a predetermined fracture path before any impact occurs. This preliminary action ensures that when impact loads are applied, the link will fail in a controlled manner along the undercut, directing the wheel assembly through a specific trajectory that minimizes vehicle body deformation rather than causing unpredictable structural failure.

Inventive Principle:

Principle #10Preliminary action

3Adaptability or versatility

If the joint is designed to release under load to provide select kinematics, then the wheel kinematics control is improved, but the device complexity increases due to the undercut geometry and release mechanism

Engineering Contradiction:

Improvewheel kinematicsVSAvoidjoint structure

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The release mechanism is designed to be self-activating, requiring no external control systems, sensors, or actuators. The undercut geometry automatically detects when the applied moment exceeds the release threshold and initiates the fracture and release process on its own. This self-service approach provides adaptive wheel kinematics control while avoiding the complexity of active control systems.

Inventive Principle:

Principle #25Self-service

4Object-affected harmful factors

If the link is designed with release capability to redirect wheel trajectory, then the protective function is improved, but the manufacturing complexity increases due to the undercut feature

Engineering Contradiction:

Improveimpact effectsVSAvoidlink fabrication

Core Design Contradiction:

Object-affected harmful factorsVSEase of manufacture

Solution Approach 1:

The undercut geometry is defined by specific dimensional parameters (depth, width, location relative to the joint center) that can be optimized to achieve the desired release moment threshold and wheel trajectory. By carefully controlling these geometric parameters, the link provides effective impact protection while maintaining compatibility with standard manufacturing processes for metal forming and machining.

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS11633997B2Suspension system providing desired wheel kinematics at prescribed conditions

Publication Date: 2023.04.25 GM GLOBAL TECHNOLOGY OPERATIONS LLC

AI summary

Systems are provided for suspensions that deliver desirable wheel kinematics at prescribed conditions. A system includes a vehicle body structure with an engine cradle, and an associated wheel assembly. A suspension system links the wheel assembly with the engine cradle, and includes a link coupled with the engine cradle and coupled with the wheel assembly. A joint at the link includes a flange that has an opening, an edge, and at least one undercut defined in edge of the flange. The joint allows release of the wheel assembly from the engine cradle by designed tearing between the opening and the at least one undercut. The release is initiated only under loads above a select threshold at the joint, to provide select kinematics of the wheel assembly for specific operational cases.