Micro-perforated Acoustic Assembly for Broad Frequency Absorption

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Solution Overview

Problem

Existing sound-absorbing assemblies for enclosures have limitations in terms of size, weight, and efficiency, particularly in absorbing sound vibrations across a wide frequency spectrum, with prior solutions being ineffective for frequencies between 4000 and 8000 Hz.

Innovation Solution

An acoustic assembly comprising at least two superimposed supports with micro-perforations, where one support lacks micro-perforations and is visible, allowing for enhanced aesthetic appeal, and multiple series of micro-perforations with varying diameters and densities to optimize sound absorption across a broader frequency range.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If porous materials are used for sound absorption, then sound absorption capability is improved, but size and weight increase

Engineering Contradiction:
Improvesound absorption capabilityVSAvoidweight
Core Design Contradiction:
ReliabilityVSWeight of stationary object

Solution Approach 1:

The patent uses micro-perforated supports with孔径 (perforation diameters) of 0.5-2mm arranged in series, creating an equivalent porous structure without requiring traditional thick porous materials. The series arrangement of multiple supports with different perforation sizes creates a cumulative sound absorption effect across different frequency ranges, achieving high sound absorption capability with reduced weight and thickness compared to conventional porous absorbers.

Inventive Principle:
Principle #31Porous materials

2Reliability

If micro-perforations with diameter less than 2mm are used, then absorption is improved for frequencies between 300-4000 Hz, but absorption effectiveness decreases for frequencies between 4000-8000 Hz

Engineering Contradiction:
Improvesound absorption efficiencyVSAvoidfrequency range coverage
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent divides the sound absorption function across multiple supports, each with different micro-perforation diameters (0.5-2mm). Each support segment handles specific frequency ranges, and the series arrangement ensures that high frequencies (4000-8000 Hz) are absorbed by the cumulative effect of multiple segments, overcoming the limitation of single-diameter micro-perforations.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent varies the perforation diameter parameter across different supports (from 0.5mm to 2mm) to optimize absorption across different frequency ranges. This parameter variation allows the assembly to maintain high absorption efficiency across the entire 300-8000 Hz spectrum, with smaller perforations handling lower frequencies and larger perforations contributing to higher frequency absorption.

Inventive Principle:
Principle #35Parameter changes

3Adaptability or versatility

If multiple supports with micro-perforations are superimposed, then sound absorption across broader frequency range is improved, but device complexity increases

Engineering Contradiction:
Improvefrequency range coverageVSAvoidassembly complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

Each support in the series serves multiple functions: it acts as a structural element, a sound absorption element for its specific frequency range, and a spacer maintaining the series arrangement. This multi-functionality reduces the need for additional components and simplifies the overall assembly process despite the presence of multiple supports.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The supports are arranged in a compact series configuration where each support is positioned close to the others, creating a nested-like structure. This compact arrangement minimizes the overall thickness of the assembly while maintaining the series configuration necessary for broad frequency coverage, thereby reducing spatial complexity.

Inventive Principle:
Principle #7Nested doll (Nesting)

4Shape

If a support without micro-perforations is added for aesthetic purposes, then appearance is improved, but device complexity increases

Engineering Contradiction:
Improveaesthetic appearanceVSAvoidassembly complexity
Core Design Contradiction:
ShapeVSDevice complexity

Solution Approach 1:

The non-perforated support serves dual functions: it provides the desired aesthetic appearance as a visible facade, and it acts as a structural support element maintaining the series arrangement of the micro-perforated supports behind it. This eliminates the need for separate aesthetic cladding, reducing overall assembly complexity.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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 proposed assembly achieves improved sound absorption efficiency across a wider frequency range, including frequencies above 2000 Hz, matching or exceeding the performance of prior systems while allowing for aesthetic benefits and flexibility in material choice.

Implementation Method 1

porous materials having the property of transforming into heat the sound vibrations which they receive due to the phenomena friction to which these materials were subjected due to these vibrations

Methodology Applied
Scientific EffectFriction: Friction

Implementation Method 2

the control of the absorption of sounds by walls has called upon various devices comprising passive absorption elements

Methodology Applied
Scientific EffectAcoustic absorption: Acoustic Absorption

Data Source

PatentEP2472018B1Acoustically absorbing assembly
Publication Date: 2020.03.25 NORMALU
  • EP2472018B1 patent drawingFigure 1~2
  • EP2472018B1 patent drawingFigure 3~4
  • EP2472018B1 patent drawingFigure 5~6

AI summary

The assembly (1) has two supports (3) formed with micro-perforations, and a support (2) formed without micro-perforations. The support without micro-perforations is not enclosed by the supports with micro-perforations. The supports with micro-perforations are superimposed with each other. The supports are formed of tensed layers constituted of films made of PVC. The supports consist of textile materials or any other flexible or rigid materials, where distance between the supports with micro-perforations is comprised between 10 and 90 mm.