Vehicle Door Adhesion Layout for Low-Frequency Closing Sound

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Solution Overview

Problem

Existing vehicle door designs with panel reinforcements fixed by adhesives result in increased natural vibration frequency and rigidity, shifting the sound generated during door closure to high frequencies and compromising the luxury feel.

Innovation Solution

The vehicle door design features a varying number of adhesion sections in different areas, with more sections in the upper area for increased rigidity and fewer in the lower area to maintain low natural vibration frequency, thereby generating low-frequency sound during door closure.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If the panel reinforcement is fixed by an adhesive with a clearance being provided therebetween, then the natural vibration frequency of the outer panel is increased and rigidity is increased, but the sound generated at the time of closing the door is shifted to the high-frequency side and the sense of luxury is lost

Engineering Contradiction:
Improverigidity of outer panelVSAvoiddoor closing sound quality
Core Design Contradiction:
StrengthVSObject-generated harmful factors

Solution Approach 1:

The patent applies different numbers of adhesion sections in different areas of the outer panel. Specifically, the number of adhesion sections in the upper area is larger than in the lower area, and the number in the front lower area is larger than in the rear lower area. This creates local variations in rigidity: the upper area has higher rigidity to prevent deformation when touched, while the lower area maintains lower rigidity to generate low-frequency sound during door closure, thus resolving the contradiction between overall rigidity and sound quality.

Inventive Principle:
Principle #3Local quality

2Stability of the object's composition

If the panel reinforcement is attached to prevent easy deformation of the outer panel, then the outer panel rigidity is improved, but the door closing sound shifts to high frequency and luxury feel is compromised

Engineering Contradiction:
Improvedeformation resistance of outer panelVSAvoiddoor closing sound frequency
Core Design Contradiction:
Stability of the object's compositionVSObject-generated harmful factors

Solution Approach 1:

The patent implements local quality by strategically distributing adhesion sections with varying densities across different areas. The upper area and front lower area have more adhesion sections for higher stability and deformation resistance, while the lower area and rear lower area have fewer adhesion sections to maintain lower natural vibration frequency for luxury sound quality. This localized differentiation resolves the contradiction between deformation resistance and sound frequency.

Inventive Principle:
Principle #3Local quality

3Ease of manufacture

If adhesion sections are uniformly distributed across the outer panel, then manufacturing is simplified, but the door closing sound quality and luxury feel deteriorate

Engineering Contradiction:
Improveadhesion section distributionVSAvoiddoor closing sound quality
Core Design Contradiction:
Ease of manufactureVSObject-generated harmful factors

Solution Approach 1:

The patent specifies that the number of adhesion sections varies by area: more sections in the upper area and front lower area, fewer sections in the lower area and rear lower area. This non-uniform distribution optimizes door closing sound quality by creating appropriate rigidity gradients, while still maintaining reasonable manufacturing complexity through clear regional specifications.

Inventive Principle:
Principle #3Local quality

4Strength

If the number of adhesion sections is increased in the lower area to improve rigidity, then deformation resistance is improved, but low-frequency sound generation capability is reduced

Engineering Contradiction:
Improverigidity of lower areaVSAvoidlow-frequency sound generation
Core Design Contradiction:
StrengthVSObject-generated harmful factors

Solution Approach 1:

The patent explicitly states that the number of adhesion sections in the lower area is smaller than in the upper area, and the number in the rear lower area is smaller than in the front lower area. This deliberate reduction in adhesion sections in the lower area maintains lower rigidity, enabling the lower area to vibrate at low frequencies and generate the desired low-frequency door closing sound, thus resolving the contradiction between rigidity and low-frequency sound generation.

Inventive Principle:
Principle #3Local quality

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 reinforces the outer panel while ensuring low-frequency sound generation during door closure, enhancing the luxury feel and sound quality of the vehicle.

Implementation Method 1

a panel reinforcement (40) on an inner side of the outer panel (20), and a plurality of adhesion sections (50) between the outer panel (20) and the panel reinforcement (40)

Methodology Applied
Scientific EffectAdhesion: Adhesive

Data Source

PatentEP4197836B1Vehicle door and vehicle
Publication Date: 2025.04.23 MAZDA MOTOR CORP
  • EP4197836B1 patent drawingFigure 1
  • EP4197836B1 patent drawingFigure 2~3
  • EP4197836B1 patent drawingFigure 4~5

AI summary

A vehicle door has: an outer panel openably/closably attached to a vehicle body by a front hinge; and a panel reinforcement extending in a vehicle front-rear direction on an inner side of the outer panel, and the outer panel and the panel reinforcement are fixed by plural adhesion sections. In the vehicle door, the number of the adhesion sections in an upper area of the outer panel is larger than the number of the adhesion sections in a lower area of the outer panel. The number of the adhesion sections provided in a front lower area near the front hinge in the lower area is larger than the number of the adhesion sections in a rear lower area 226 away from the front hinge in the lower area.