Foamed Polyolefin Duct Structure for Lightweight Noise Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current vehicle ducts fail to adequately reduce noise, particularly from air conditioner compressors and whistling sounds, and do not meet the demands for lightweight, compact designs with enhanced sound deadening properties, especially in vehicles with idling stop technology and hybrid or electric vehicles.
Innovation Solution
A duct made from a foamed blow-molded article using a polyolefin-based resin with specific properties, including a bending elastic modulus of 800-1300 MPa, average apparent density of 0.1-0.4 g/cm³, and a unique density ratio between inner and outer surfaces, which provides improved sound absorption and blocking capabilities.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Weight of moving object
If a non-foam resin blow-molded article is used for ducts, then structural strength and rigidity are maintained, but weight reduction and sound deadening properties are insufficient
Solution Approach 1:
The patent applies parameter changes by controlling the foam density within a specific range (0.05-0.5 g/cm³ apparent density) and specifying the base resin bending elastic modulus (800-1300 MPa) to achieve the optimal balance between weight reduction and structural strength. This quantitative parameter control allows the foamed resin to provide sufficient strength while significantly reducing weight compared to non-foam alternatives.
Solution Approach 2:
The patent uses composite materials by combining foamed resin with enhanced cellular structure characteristics. The specific foam density range and bending elastic modulus requirements indicate a composite approach that integrates the lightweight benefits of foaming with the structural integrity of high-modulus resin, creating a material that simultaneously achieves weight reduction and maintains strength.
2Weight of moving object
If a foamed blow-molded article is used to reduce weight, then weight reduction is achieved, but sound deadening properties are insufficient for modern vehicle noise requirements
Solution Approach 1:
The patent applies parameter changes by optimizing the foam density within a specific range (0.05-0.5 g/cm³) and controlling the base resin bending elastic modulus (800-1300 MPa). This quantitative control creates a cellular structure that provides both weight reduction and improved sound deadening properties, addressing modern vehicle noise requirements while maintaining lightweight characteristics.
Solution Approach 2:
The patent utilizes porous materials by employing a foamed resin with controlled cellular structure. The specific apparent density range (0.05-0.5 g/cm³) indicates a porous material approach where the foam cells provide sound absorption and damping characteristics, enhancing sound deadening properties while maintaining weight reduction benefits.
3Weight of moving object
If the foam density is reduced to lighten weight, then weight reduction increases, but structural rigidity and strength deteriorate
Solution Approach 1:
The patent applies parameter changes by defining a specific foam density range (0.05-0.5 g/cm³ apparent density) and base resin bending elastic modulus (800-1300 MPa). This quantitative parameter control prevents excessive weight reduction that would compromise rigidity, instead achieving an optimal balance where the foamed structure provides sufficient strength while maintaining lightweight characteristics.
Solution Approach 2:
The patent uses composite materials by combining foamed resin with enhanced cellular structure. The specific density and modulus requirements indicate a composite approach that integrates lightweight foaming with high-modulus resin characteristics, creating a material that simultaneously achieves weight reduction and maintains structural rigidity.
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 duct achieves significant sound deadening properties, reducing noise levels effectively across the audible frequency range, making it suitable for various vehicle applications, including air conditioning systems and electric vehicle cooling systems.
Implementation Method 1
a duct that is light in weight and has excellent sound deadening properties
Implementation Method 2
the ability to absorb sound and the ability to block the transmission of sound
Data Source
Figure 1
Figure 2A~2B
Figure 2C~2D
AI summary
A duct (1) of a foamed blow-molded article that is constituted of a polyolefin-based resin with a bending elastic modulus of 800-1,300 MPa, that has an average apparent density (D) of 0.1 to 0.4 g/cm3 and an average thickness (T) [cm] providing D×T2 of 0.005 to 0.04 g/cm, and that has an outer surface side region (18) and an inner surface side region (19) having an average apparent density lower than that of the outer surface region.