Separable U-Shaped Damper Mass for Wheel Hop Reduction

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Solution Overview

Problem

Current vibration absorption systems in vehicles, such as tuned mass dampers, face challenges in effectively reducing wheel hop and other unwanted vibrations due to limitations in design and material distribution, which affect the efficiency of vibration reduction and stability during impacts.

Innovation Solution

A vibration absorption system featuring a damper mass with a U-shaped configuration, comprising first and second mass portions connected by a third mass portion, which separates under stress to allow relative motion and includes stress concentration points for efficient force distribution, along with fluid-operated damper assemblies to regulate motion, is integrated into the vehicle suspension system.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If a traditional solid damper mass is used, then the structure is simple and manufacturing is easy, but the ability to absorb and dissipate vibration energy is limited

Engineering Contradiction:
Improvevibration energy dissipationVSAvoiddamper mass structure
Core Design Contradiction:
Loss of energyVSDevice complexity

Solution Approach 1:

The damper mass is divided into multiple separable portions (first mass portion, second mass portion, and third mass portion) connected by a frangible section. This segmentation allows the mass portions to move relative to each other during vibration, increasing energy dissipation through internal friction and motion, while maintaining a relatively simple overall structure that is easy to manufacture.

Inventive Principle:
Principle #1Segmentation

2Strength

If the damper mass is made uniformly thick, then manufacturing is simple, but stress distribution is inefficient and separation capability is reduced

Engineering Contradiction:
Improvestress concentration and separation capabilityVSAvoiddamper mass fabrication
Core Design Contradiction:
StrengthVSEase of manufacture

Solution Approach 1:

The damper mass features non-uniform thickness with a thinner third mass portion and frangible section located at specific locations. This local variation in geometry creates targeted stress concentration zones that facilitate controlled separation under high stress conditions, while the overall design remains compatible with standard manufacturing processes.

Inventive Principle:
Principle #3Local quality

3Reliability

If the damper mass is designed to remain rigid, then structural stability is maintained, but relative motion between mass portions is restricted reducing vibration absorption

Engineering Contradiction:
Improvestructural stabilityVSAvoidrelative motion capability
Core Design Contradiction:
ReliabilityVSStability of the object's composition

Solution Approach 1:

The damper mass transitions from a rigid structure to a dynamic system with a frangible section that allows controlled separation. The frangible section remains intact under normal conditions maintaining structural stability, but separates under high stress to enable relative motion between mass portions for enhanced vibration absorption, thus adapting its properties based on loading conditions.

Inventive Principle:
Principle #15Dynamics

4Ease of manufacture

If stress concentration points are not incorporated, then the structure is more uniform and easier to manufacture, but controlled separation under stress is not achieved

Engineering Contradiction:
Improvedamper mass fabricationVSAvoidstress concentration location and separation control
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

Stress concentration features are pre-designed and incorporated into the damper mass geometry during manufacturing. These pre-planned stress concentration locations ensure that separation occurs at predetermined points when stress thresholds are reached, providing controlled and predictable separation behavior without requiring complex post-manufacturing adjustments.

Inventive Principle:
Principle #10Preliminary action

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 configuration enhances the vehicle's ability to absorb and dissipate vibrations, reducing wheel hop and improving stability during impacts by allowing relative motion between mass portions and utilizing fluid-operated dampers for controlled motion regulation.

Implementation Method 1

the damper mass includes a portion of stress concentration within the third mass portion such that the third mass portion is configured to separate within the portion of stress concentration in response to the force transferred to the damper mass

Methodology Applied
Scientific EffectStress concentration:

Implementation Method 2

the third mass portion is configured to separate within the portion of stress concentration

Methodology Applied
Scientific EffectFracture: Fracture Mechanics

Implementation Method 3

a first spring and fluid-operated damper assembly that is configured to regulate motion of the damper mass with respect to an external portion and a second spring and fluid-operated damper assembly that is configured to regulate motion of the damper mass with respect to the external portion

Methodology Applied
Scientific EffectFluid damping: Viscous Damping

Implementation Method 4

a first spring and fluid-operated damper assembly that is configured to regulate motion of the damper mass with respect to an external portion

Methodology Applied
Scientific EffectElastic potential energy: Elasticity

Implementation Method 5

the first mass portion has a first curved surface defined at a first end of the damper mass facing a first direction away from the second mass portion and the second mass portion has a second curved surface defined at a second end of the damper mass facing in a second and opposite direction away from the first mass portion, and the force transferred to the damper mass is applied at the first curved surface of the first mass portion and causes rotation of the damper mass

Methodology Applied
Scientific EffectTorque: Torque

Data Source

PatentEP4289641A1Vibration absorber
Publication Date: 2023.12.13 APPLE INC
  • EP4289641A1 patent drawingFigure 1
  • EP4289641A1 patent drawingFigure 2A
  • EP4289641A1 patent drawingFigure 2B

AI summary

A tuned mass damper includes a damper mass having a first mass portion and a second mass portion connected by a third mass portion. The first mass portion, the second mass portion, and the third mass portion form a U-shaped configuration of the damper mass. The damper mass is configured to separate within the third mass portion in response to a force transferred to the damper mass of the tuned mass damper to allow relative motion between the first mass portion and the second mass portion. The damper mass may include geometric features that promote rotation of the tuned mass damper relative to the vehicle longitudinal axis, when subjected to impact loads.