Foam Duct with Inner Projections for Rigidity and Secure Attachment
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Solution Overview
Problem
Existing foam ducts face issues with reduced rigidity and ease of detachment when wall thickness is minimized, leading to deflection and vibration during fluid flow, and difficulty in secure attachment to vehicle components due to smooth inner surfaces.
Innovation Solution
Incorporating projections on the inner surface of the foam duct's cylindrical portion with varying wall thickness, which increases rigidity and enhances secure engagement with other members by deforming to match the outer surface contour, and using a molding process that forms these projections during the blow molding of foam resin.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Weight of moving object
If wall thickness of foam duct is reduced to lower weight, then weight decreases, but rigidity decreases and duct becomes easily deflected
Solution Approach 1:
The patent applies local quality by creating projections on the inner surface of the foam duct that locally increase wall thickness in specific regions. These projections are positioned at locations where rigidity is needed to prevent deflection during fluid flow, while other regions maintain reduced wall thickness for weight reduction. This allows different parts of the duct to have different thickness characteristics optimized for their specific functional requirements.
2Weight of moving object
If inner walls of foam duct are smoothed to reduce weight, then weight decreases, but attachment to members becomes difficult
Solution Approach 1:
The patent applies local quality by creating projections on the inner surface of the foam duct that locally increase wall thickness in specific regions. These projections are positioned at locations where rigidity is needed to prevent deflection during fluid flow, while other regions maintain reduced wall thickness for weight reduction. This allows different parts of the duct to have different thickness characteristics optimized for their specific functional requirements.
3Weight of moving object
If wall portions become thin to reduce weight, then weight decreases, but vibration occurs during fluid flow
Solution Approach 1:
The patent applies local quality by creating projections on the inner surface of the foam duct that locally increase wall thickness in specific regions. These projections are positioned at locations where rigidity is needed to prevent deflection during fluid flow, while other regions maintain reduced wall thickness for weight reduction. This allows different parts of the duct to have different thickness characteristics optimized for their specific functional requirements.
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 solution significantly improves the rigidity of the foam duct, prevents easy removal from vehicle components, and reduces vibration during fluid flow by maintaining structural integrity and secure attachment.
Implementation Method 1
air is blown into the foam parison in the metallic mold to push the foam parison against a cavity of the metallic mold to thereby shape the foam parison. The foam parison is then extended to be molded in a contour of the cavity.
Implementation Method 2
The molded item having the cavity contour is cooled. The mold is then opened. The molded item is removed
Data Source
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Figure 5
AI summary
A foam duct (200) in which rigidity is improbable includes a cylindrical portion (206) having an external contour of a polygonal shape and a projection (204) in an inner surface side of the cylindrical portion, and thickness of wall portions of the cylindrical portion is larger in a portion in which the projection is formed than in a portion in which the projection is not formed.