Dash Panel Sound Insulating Member for Vehicle Noise Suppression
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Solution Overview
Problem
Existing vehicle designs fail to effectively suppress noise transmitted from the power unit chamber to the passenger compartment through the opening portion formed by the dash panel and the lower wall portion of the instrument panel, leading to increased noise levels inside the vehicle.
Innovation Solution
A noise suppression structure incorporating a sound insulating member with a base portion mounted to the dash panel and a cover portion extending towards the lower wall, which disperses and absorbs noise energy, reducing its transmission to the passenger compartment by reflecting and expanding noise waves, and utilizing a high-density portion to damp vibrations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a densely-porous sound absorber is mounted to a dash panel via an air layer, then noise absorption is improved, but noise transmission through the opening portion between the dash panel and instrument panel lower wall remains insufficient
Solution Approach 1:
The sound insulating member is divided into a base portion mounted to the dash panel and a cover portion extending to cover the opening portion. This segmentation allows the noise suppression function to be distributed across two distinct structural elements, with the base portion providing foundational insulation and the cover portion specifically addressing the opening portion gap, thereby resolving the insufficient noise suppression at the opening.
Solution Approach 2:
The sound insulating member extends in the vehicle width direction (transverse dimension) to cover the opening portion, adding a dimensional approach to noise suppression. By extending the insulation coverage laterally across the opening portion rather than only depth-wise from the dash panel, the invention effectively blocks noise transmission paths that would otherwise bypass traditional dash panel mounting.
2Object-affected harmful factors
If the sound insulating member is made larger to cover the opening portion, then noise suppression is improved, but vehicle interior space is reduced
Solution Approach 1:
The sound insulating member is specifically positioned to cover only the opening portion between the dash panel and instrument panel lower wall, rather than uniformly insulating the entire passenger compartment. This localized approach concentrates noise suppression where it is most needed while preserving overall interior space, as the insulation is applied only to the specific gap area rather than adding bulk throughout the cabin.
Solution Approach 2:
The sound insulating member is nested within the existing structural configuration of the dash panel and instrument panel assembly. The base portion is mounted to the rear surface of the dash panel, and the cover portion extends forward to cover the opening, fitting within the existing spatial envelope rather than adding external bulk, thereby maintaining passenger compartment volume.
3Object-affected harmful factors
If a sound insulating member is added to cover the opening portion, then noise suppression is improved, but device complexity increases
Solution Approach 1:
The sound insulating member combines the base portion and cover portion into a single integrated component that performs multiple functions: mounting to the dash panel and covering the opening portion. This merging of functions into one piece rather than separate components reduces assembly complexity and the number of parts, despite the enhanced noise suppression capability.
Solution Approach 2:
The sound insulating member serves multiple functions simultaneously: it acts as a mounting surface for noise insulation material, provides structural coverage for the opening portion, and contributes to the overall noise suppression system. This multi-functionality reduces the need for additional separate components, thereby managing device complexity while achieving improved noise suppression.
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 solution significantly reduces noise transmission to the passenger compartment by dispersing and absorbing noise energy in two stages, effectively suppressing noise levels and maintaining the shape of the soundproofing cover portion without excessive mass addition.
Implementation Method 1
Some of the noise transmitted to this space portion is reflected at the instrument panel, and is transmitted toward the opening portion
Implementation Method 2
the noise that is transmitted toward the opening portion is, at the sound insulating member that covers the opening portion or at the sound insulating member that partitions the space portion, reduced by the dispersing effect that is due to reflection or the like, and by the expending effect by which the noise is expended as kinetic energy for vibrating the sound insulating member
Implementation Method 3
the high-density portion is mounted to the base portion from the vehicle rear side at further toward a vehicle lower side than the opening portion
Data Source
AI summary
A structure for suppressing noise into a vehicle passenger compartment includes: a dash panel that separates a vehicle passenger compartment and a power unit chamber that is disposed at a vehicle front side; an instrument panel that covers the dash panel from a vehicle rear side, and that has a lower wall portion which extends toward a vehicle front side and forms an opening portion with the dash panel; and a sound insulating member that is disposed so as to cover the opening portion or is disposed so as to partition a space portion, which is between the dash panel and the instrument panel, in a vehicle transverse direction.