Convertible Top Rivet Noise Damping via Composite Materials

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

The existing folding top arrangements in convertibles generate unwanted noise due to metal-on-metal contact between rivet bolts or rivet nuts and bows or links, leading to uncomfortable cracking sounds for vehicle occupants.

Innovation Solution

The implementation of a hybrid component system where rivet bolts or rivet nuts, made of metallic material, are permanently connected to non-metallic components with noise-damping properties, such as plastic, to reduce noise during contact, and are produced using methods like cold extrusion or thixomolding for cost-effectiveness and improved mechanical properties.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If metal rivet bolts or rivet nuts are used to connect metallic bows and links, then the structural strength and reliability are ensured, but unwanted noise is generated due to metal-on-metal contact

Engineering Contradiction:
Improvestructural strengthVSAvoidnoise
Core Design Contradiction:
StrengthVSObject-generated harmful factors

Solution Approach 1:

The patent applies composite materials by combining metallic and non-metallic components in the rivet assembly. The rivet bolt or rivet nut is equipped with a non-metallic element (plastic coating, overmold, or insert) that contacts the metallic bow or link, creating a composite structure that maintains structural strength while reducing noise through the noise-damping properties of the non-metallic material.

Inventive Principle:
Principle #40Composite materials

2Object-generated harmful factors

If a non-metallic component is added to the rivet bolt or rivet nut to reduce noise, then noise damping is improved, but the device complexity increases

Engineering Contradiction:
ImprovenoiseVSAvoiddevice complexity
Core Design Contradiction:
Object-generated harmful factorsVSDevice complexity

Solution Approach 1:

The patent merges the rivet fastening function with the noise-damping function into a single integrated component. The non-metallic element is combined with the metallic rivet body through methods such as coating, overmolding, or inserting, creating a unified rivet assembly that performs both structural connection and noise reduction without requiring separate noise-damping components.

Inventive Principle:
Principle #5Merging (Combining)

3Object-generated harmful factors

If a non-metallic component is added to reduce noise, then noise damping is improved, but manufacturing costs increase

Engineering Contradiction:
ImprovenoiseVSAvoidmanufacturing costs
Core Design Contradiction:
Object-generated harmful factorsVSEase of manufacture

Solution Approach 1:

The non-metallic noise-damping element is integrated into the rivet manufacturing process itself, rather than being added as a separate assembly step. Through methods like coating during forming, overmolding in the same mold, or inserting pre-formed inserts, the noise-reduction feature is built into the rivet during primary manufacturing, avoiding additional assembly operations and reducing overall manufacturing costs.

Inventive Principle:
Principle #10Preliminary action

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 solution effectively reduces noise pollution inside the vehicle by utilizing the damping properties of non-metallic materials while maintaining the strength and cost-effectiveness of metallic components, thereby enhancing the overall user experience and reducing production costs.

Implementation Method 1

a non-metallic material which has noise-damping properties is arranged at the contact point between the rivet bolt or rivet nut and the bow or link

Methodology Applied
Scientific EffectNoise damping: Damping

Data Source

PatentEP2853427B1Roof assembly
Publication Date: 2019.08.14 MAGNA CAR TOP SYSTEMS GMBH(DE)
  • EP2853427B1 patent drawingFigure 1~2
  • EP2853427B1 patent drawingFigure 3~4
  • EP2853427B1 patent drawingFigure 5

AI summary

Convertible top assembly for a convertible, wherein a convertible top can be moved into an open position and into a closed position, comprising a plurality of bows and links (11), wherein the bows and links (11) are movable relative to each other by means of a driven convertible top kinematics, and wherein a rivet bolt (1, 3) or a rivet nut (2) is arranged in at least one convertible top component, wherein the convertible top component is a first bow or a first link (11) or a body-fixed bearing point, which is designed as a mechanical stop for a second bow or a second link (11) which is movable relative to the convertible top component, wherein the rivet bolt (1, 3) or the rivet nut (2) and/or the second bow or the second link (11) are made of a metallic material, wherein the rivet bolt (1,3) or the rivet nut (2) and/or the second bow or the second link (11) has a non-metallic material at least at the contact point between the rivet bolt (1, 3) or the rivet nut (2) and the second bow or the second link (11).