Vehicle Belt Deflector Spring Fit to Prevent Rattling

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Solution Overview

Problem

Deflectors for guiding webbing in vehicles often experience rattling noises due to manufacturing-related surface defects and tolerance issues between metal and plastic components, leading to a poor fit and increased noise during operation.

Innovation Solution

Incorporating a spring element that rests on the inner surface of the receptacle, providing a biasing force to compensate for manufacturing-related defects and prevent uncontrolled movement between the metal body and the fitting piece, thus creating a positive connection and reducing rattling noises.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Weight of moving object

If a metal body with a plastic fitting piece is used to reduce weight and improve aesthetics, then weight is reduced and appearance is improved, but manufacturing tolerances cause surface defects and rattling noises between components

Engineering Contradiction:
ImproveweightVSAvoidrattling noises
Core Design Contradiction:
Weight of moving objectVSObject-generated harmful factors

Solution Approach 1:

A spring element is introduced between the metal body and the plastic fitting piece to compensate for manufacturing tolerances and prevent rattling noises before they occur during operation. The spring element acts as a cushioning component that absorbs dimensional deviations and prevents direct rigid contact between the two parts.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

Solution Approach 2:

The spring element changes the mechanical parameters of the connection between metal body and plastic fitting piece by introducing elasticity and compliance. This transforms the rigid connection into a flexible one that can adapt to manufacturing variations and eliminate rattling noises.

Inventive Principle:
Principle #35Parameter changes

2Ease of manufacture

If higher tolerances are applied during manufacturing of the metal body for production reasons, then manufacturing is easier and cost is reduced, but the metal part does not fit precisely causing defects and rattling noises

Engineering Contradiction:
Improvemanufacturing easeVSAvoidfit precision
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The spring element serves as an intermediary component between the metal body and the plastic fitting piece. It mediates the connection by absorbing the dimensional deviations caused by loose tolerances, allowing both parts to be manufactured more easily without compromising the final fit and eliminating rattling noises.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Strength

If a positive connection is formed through an engagement section between the fitting piece and metal body, then structural integrity is improved, but surface defects and tolerance issues cause rattling noises in the engagement area

Engineering Contradiction:
Improvestructural integrityVSAvoidrattling noises
Core Design Contradiction:
StrengthVSObject-generated harmful factors

Solution Approach 1:

The spring element is positioned to compensate for surface defects and tolerance issues in the engagement section before they can cause rattling noises during operation. It provides beforehand cushioning that prevents the development of harmful vibrations while maintaining the positive connection's structural integrity.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

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 spring element effectively compensates for manufacturing tolerances, prevents rattling noises, and ensures a secure connection between the metal body and the fitting piece, enhancing the restraint effect and reducing assembly defects.

Implementation Method 1

the engagement section having at least one spring element resting on the receiving inner surface

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

prevent rattling noises, especially between the two components

Methodology Applied
Scientific EffectVibration damping: Damping

Data Source

PatentEP3950438B1Deflector with spring element
Publication Date: 2023.10.04 AUTOLIV DEV AB
  • EP3950438B1 patent drawingFigure 1
  • EP3950438B1 patent drawingFigure 2
  • EP3950438B1 patent drawingFigure 3

AI summary

The present invention relates to a deflector 1 for guiding a belt in a vehicle, comprising at least a metal body 2 with a mounting opening 3 attachable to the vehicle and with a belt slot 4, and a plastic fitting 5 connected to the metal body 2, wherein the metal body 2 has a receptacle 6 and an engagement section 7 corresponding to the receptacle 6 is formed on the fitting 5, such that the engagement section 7 engages in the receptacle 6, and wherein the receptacle 6 has an inner receiving surface 8 facing the engagement section 7 and the engagement section 7 has an engagement surface 9 facing the receptacle 6.