Automotive Compressor Acoustic Cover Noise Reduction

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

The challenge is to reduce noise in automobile air conditioning compressors while achieving weight saving and downsizing of the acoustic cover, as traditional heavy soundproofing materials are not suitable and gaps between the cover and pipes can lead to sound leakage.

Innovation Solution

A compressor design featuring an acoustic cover with an inner surface that closely follows the compressor body's outer surface, using a porous foam material and divided portions with overlap and locking features to minimize gaps and sound leakage, and optionally incorporating a honeycomb sandwich panel for enhanced noise absorption.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If a heavy sound absorption material such as rubber is used for the acoustic cover, then soundproofing performance is enhanced, but weight increases and downsizing becomes difficult

Engineering Contradiction:

Improvesoundproofing performanceVSAvoidweight of acoustic cover

Core Design Contradiction:

Object-affected harmful factorsVSWeight of stationary object

Solution Approach 1:

The patent applies porous foam material for the acoustic cover, which provides effective sound absorption through its porous structure while maintaining lightweight properties. The porous structure allows sound waves to enter and be absorbed through friction and viscous losses, achieving good soundproofing performance without requiring heavy materials like rubber.

Inventive Principle:

Principle #31Porous materials

Solution Approach 2:

The patent employs composite material construction by combining foam material with a hollow cylindrical structure. This composite approach integrates the sound absorption capabilities of foam with the structural support and weight reduction benefits of the hollow configuration, optimizing both acoustic performance and weight characteristics.

Inventive Principle:

Principle #40Composite materials

2Device complexity

If the acoustic cover is designed with a simple structure for weight saving, then manufacturing is easier, but gaps may form between the cover and pipe leading to sound leakage

Engineering Contradiction:

Improvestructure of acoustic coverVSAvoidsound leakage

Core Design Contradiction:

Device complexityVSObject-affected harmful factors

Solution Approach 1:

The patent applies local quality by creating an insertion hole portion with a specific tapered shape that provides a tight fit around the pipe. This localized geometric feature ensures acoustic sealing at the critical interface between the cover and pipe without requiring complex overall structure or additional sealing components throughout the entire cover.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent introduces a damping sheet as an intermediary component between the acoustic cover and the pipe. This thin intermediate layer fills and seals the gap between the cover's insertion hole and the pipe surface, effectively preventing sound leakage while adding minimal complexity to the overall structure.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Stability of the object's composition

If cushioning material is added around the discharge pipe to suppress vibration, then vibration is reduced, but the structure becomes complicated

Engineering Contradiction:

Improvevibration suppressionVSAvoidstructure of acoustic cover

Core Design Contradiction:

Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The patent merges the vibration suppression function into the existing acoustic cover structure by incorporating a damping sheet as an integrated component. This damping sheet is positioned within the hollow cylindrical structure, combining acoustic insulation and vibration damping functions in a single unified component rather than adding separate cushioning elements.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The patent employs a thin damping sheet as a flexible film structure that provides vibration suppression functionality. This thin film approach achieves the desired vibration damping effect while maintaining structural simplicity and avoiding the need for bulky cushioning materials or complex mechanical damping mechanisms.

Inventive Principle:

Principle #30Flexible shells and thin films

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 effectively reduces noise emissions by eliminating gaps and optimizing the structure for weight reduction and improved assembly, while maintaining effective soundproofing performance.

Implementation Method 1

the acoustic cover is a porous foam material. With this configuration, it is possible to absorb noise that is emitted from the compressor body by the porous foam material

Methodology Applied

Scientific EffectAcoustic absorption: Acoustic Absorption

Data Source

PatentUS12110910B2Compressor for automobile air conditioning device

Publication Date: 2024.10.08 MITSUBISHI HEAVY IND THERMAL SYST

AI summary

A compressor (100) comprises a compressor body (10), a pipe (20) connected to the compressor body (10), and an acoustic cover disposed so as to surround the compressor body (10). The acoustic cover (30) has an insertion hole (31) through which the pipe (20) is inserted while being in close contact with the pipe (20), and an inner surface (30A) of the acoustic cover has a shape that traces an outer surface (10A) of the compressor body (10). Due to this configuration, it is possible to reduce the size and the weight of the acoustic cover (30), and by using the acoustic cover (30) with a simpler structure, it is possible to reduce the noise of the compressor (100) of this automobile air conditioning device.