Vehicle Soundproofing Part with Fibrous Insert and Foam Layer
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Solution Overview
Problem
Existing motor vehicle soundproofing components face challenges in maintaining acoustic performance and structural integrity, particularly around openings for components like the steering column, due to issues such as loss of thickness, deformation, and manufacturing complexities.
Innovation Solution
A soundproofing part comprising a layer of heavy mass with a fibrous material insert and a foam layer, where the insert is bonded without adhesive and the foam penetrates into the fibrous material to form a stiffened reinforcement interface, ensuring consistent thickness and improved rigidity around openings.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the heavy mass layer is strongly stretched during thermoforming to create openings for the steering column, then the opening is formed, but the local thickness is reduced causing loss of acoustic performance
Solution Approach 1:
The insert is placed in the mold cavity before the heavy mass layer is thermoformed. This preliminary placement allows the insert to serve as a support structure during the stretching process, preventing excessive thinning of the heavy mass layer at critical locations while still allowing the opening to be formed.
Solution Approach 2:
The insert acts as an intermediary element between the mold cavity and the heavy mass layer. It provides mechanical support during thermoforming, distributing the stretching forces and preventing localized thinning that would occur if the heavy mass layer were stretched directly against the mold without support.
2Ease of operation
If the heavy mass layer is strongly stretched during thermoforming, then the opening is formed, but the structure becomes deformed and generates rejects
Solution Approach 1:
The insert is pre-placed in the mold to provide structural support before the heavy mass layer undergoes stretching. This prevents deformation and structural failure during the thermoforming process, reducing rejects and improving reliability.
Solution Approach 2:
The insert serves as a cushioning support structure placed beforehand in the mold cavity. It absorbs and distributes the mechanical stresses during stretching, preventing excessive deformation and structural damage to the heavy mass layer that would lead to rejects.
3Manufacturing precision
If a complementary piece of heavy mass is used to reinforce the critical zone, then acoustic behavior improves, but air is trapped creating bubbles during heating
Solution Approach 1:
Instead of adding a complementary piece of heavy mass that creates manufacturing issues, the invention extracts the reinforcement function and transfers it to a separate insert made of different material (such as metal or rigid plastic) that does not trap air during the thermoforming process.
Solution Approach 2:
The invention changes the material parameter of the reinforcement element from heavy mass material to a different material type (insert) that has different thermal and physical properties, allowing it to be placed in the mold without trapping air during heating while still providing the necessary acoustic reinforcement.
4Reliability
If a complementary piece of heavy mass is used, then robustness improves, but heating is not homogeneous and the two heavy masses are not entirely glued
Solution Approach 1:
The reinforcement function is extracted from the heavy mass layer and implemented through a separate insert with different material properties. This insert does not interfere with the thermal homogeneity of the heavy mass layer during heating, eliminating the bonding and heating uniformity problems associated with using multiple heavy mass pieces.
5Reliability
If a complementary piece of heavy mass is used, then robustness improves, but time is lost due to the need for a gripper to place it on the heater
Solution Approach 1:
The insert placement is merged with the heavy mass layer forming process. The insert is placed in the mold cavity before the heavy mass layer is applied, allowing both components to be formed and assembled in a single thermoforming operation, eliminating the need for separate handling and placement steps that reduce productivity.
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 enhances acoustic insulation and absorption while simplifying manufacturing and storage, reducing deformation and maintaining acoustic performance around critical areas like the steering column.
Implementation Method 1
A soundproofing component works by 'acoustic absorption' (in the medium and high frequency range), when the energy of the acoustic waves is dissipated in an absorbent material.
Implementation Method 2
A soundproofing component provides 'insulation' within the meaning of the present invention, when it prevents the entry of medium and high frequency acoustic waves into the soundproofed space, essentially by reflection of the waves towards the noise sources or outside the soundproof space.
Implementation Method 3
In the field of low frequencies, the acoustic waves generated by the aforementioned noise sources are damped by materials in the form of single or double sheets, having a viscoelastic behavior
Implementation Method 4
In the field of low frequencies, the acoustic waves generated by the aforementioned noise sources are damped by materials in the form of single or double sheets, having a viscoelastic behavior, or by acoustic attenuation of a porous mass-spring system and elastic.
Data Source
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AI summary
The part (12) comprises: - a heavy mass layer (14); - an insert (16) applied to a first region of a first face (20) of the heavy mass layer (14); - a foam layer (18) applied to a second region of the first face (20) of the heavy mass layer (14). The insert (16) is made of a fibrous material.