Dual-Material Engine Bracket for Resonance and NVH Damping

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Solution Overview

Problem

Existing engine brackets exhibit poor resonance behavior, leading to noise, vibration, and potential material weakening due to resonant frequencies, which affects vehicle dynamics and fuel economy.

Innovation Solution

An engine bracket with a dual-material structure, featuring a first material for the main body and a second, overmolded plastic material with lower stiffness and higher attenuation coefficient, specifically designed to eliminate or shift eigenmodes by converting kinetic energy into thermal energy, thereby improving resonance behavior and reducing weight.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If a single-material bracket body is used, then the structure is simple and manufacturing is easy, but the resonance behavior is poor and noise vibration harshness increases

Engineering Contradiction:
Improvemanufacturing simplicityVSAvoidnoise vibration harshness
Core Design Contradiction:
Ease of manufactureVSObject-generated harmful factors

Solution Approach 1:

The patent applies composite materials by combining a first material (e.g., metal or rigid plastic) for the bracket body with a second plastic material having different material properties for the attenuation structure. This composite construction enables the bracket to simultaneously achieve structural integrity and effective vibration attenuation, resolving the contradiction between manufacturing simplicity and NVH performance.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The attenuation structure is designed to cover specific vibration zones rather than the entire bracket body. This local application of the second material targets areas with high vibration amplitudes, effectively reducing noise and vibration while maintaining manufacturing efficiency and avoiding unnecessary complexity in non-critical areas.

Inventive Principle:
Principle #3Local quality

2Strength

If the bracket body is made of metal, then strength and temperature resistance are improved, but weight increases

Engineering Contradiction:
Improvestrength and temperature resistanceVSAvoidbracket weight
Core Design Contradiction:
StrengthVSWeight of moving object

Solution Approach 1:

The patent employs composite materials by combining metal or rigid plastic for the structural bracket body with a plastic attenuation material. This composite approach maintains the strength and temperature resistance of the first material while the plastic component provides vibration attenuation, enabling weight reduction compared to a fully metallic construction.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent changes material parameters by selecting a second material with different properties (lower density, higher attenuation coefficient) than the first material. This parameter change allows the attenuation structure to provide vibration damping functionality while reducing the overall weight of the bracket assembly.

Inventive Principle:
Principle #35Parameter changes

3Weight of moving object

If the bracket body is made of plastic, then weight is reduced, but resistance to extreme temperatures and durability decrease

Engineering Contradiction:
Improvebracket weightVSAvoidtemperature resistance and durability
Core Design Contradiction:
Weight of moving objectVSReliability

Solution Approach 1:

The patent uses composite materials where the first material (metal or rigid plastic) provides the structural framework with high strength and temperature resistance, while the second plastic material is added specifically for vibration attenuation. This composite construction enables the bracket to achieve lightweight design without compromising reliability under extreme conditions.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The attenuation structure made of second plastic material is applied locally to vibration zones rather than throughout the entire bracket. This local quality approach ensures that critical structural areas maintain the high temperature resistance and durability of the first material, while still achieving weight reduction and vibration attenuation where needed.

Inventive Principle:
Principle #3Local quality

4Object-generated harmful factors

If an attenuation structure with different material properties is added, then resonance behavior and NVH properties are improved, but device complexity increases

Engineering Contradiction:
Improveresonance behavior and NVH propertiesVSAvoidstructural complexity
Core Design Contradiction:
Object-generated harmful factorsVSDevice complexity

Solution Approach 1:

The patent applies composite materials by integrating the attenuation structure made of second plastic material with the bracket body made of first material. This composite construction improves resonance behavior and NVH properties through the inherent damping characteristics of the plastic material, while the integration process maintains manufacturing efficiency.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The attenuation structure is strategically positioned to cover only the vibration zones identified through analysis, rather than covering the entire bracket body. This local quality approach improves NVH properties effectively while minimizing the added complexity and material usage, as the attenuation structure is applied only where vibration amplitudes are highest.

Inventive Principle:
Principle #3Local quality

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

The dual-material engine bracket significantly reduces eigenmode amplitudes and shifts resonant frequencies to uncritical ranges, enhancing noise vibration harshness (NVH) properties and maintaining a lightweight design, thus improving vehicle dynamics and fuel efficiency.

Implementation Method 1

the second, plastic material with a second material stiffness and a second attenuation coefficient, wherein the second material stiffness is lower than the first material stiffness and/or the second attenuation coefficient is higher than the first attenuation coefficient

Methodology Applied
Scientific EffectVibration attenuation: Damping

Implementation Method 2

converting kinetic energy into thermal energy

Methodology Applied
Scientific EffectEnergy conversion: Viscous Heating

Data Source

PatentEP4272986A1Engine bracket and method of constructing an engine bracket
Publication Date: 2023.11.08 VIBRACOUSTIC SE
  • EP4272986A1 patent drawingFigure 1~2
  • EP4272986A1 patent drawingFigure 3~5
  • EP4272986A1 patent drawingFigure 6

AI summary

Disclosed is an engine bracket (2), with a bracket body (4), which consists of a first material with a first material stiffness and first attenuation coefficient, wherein the bracket body (4) has at least a first connection surface (16) and at least a first fastening structure (9) for arrangement on a body of a vehicle (52), at least a second connection surface (8) and at least a second fastening structure (6) for arrangement on a drive unit of the vehicle, wherein the bracket body (4) is at least partially provided with an attenuation structure (24) consisting of a second, plastic material with a second material stiffness and a second attenuation coefficient, wherein the second, plastic material is overmolded, wherein the second material stiffness is lower than the first material stiffness and/or the second attenuation coefficient is higher than the first attenuation coefficient.