Motor Vehicle Lens Welding Tolerance Compensation

Solution Overview

Problem

Existing methods for joining a lens to a housing in motor vehicle lighting devices fail to ensure dimensional accuracy due to tolerances in fasteners and housing components, leading to inconsistent protrusion or indentation of lighting devices from the vehicle's outer skin.

Innovation Solution

A method that involves positioning the housing with a fastener in a holding device, measuring the fastener's position using a sensor element, calculating a correction value for the lens's travel distance, and adjusting the welding process to achieve a defined target height, ensuring consistent alignment and flush installation of lighting devices.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If a relative welding process is used to join the lens to the housing, then uniform welding depth is achieved, but dimensional accuracy is compromised due to uncorrected tolerances in fasteners and housing

Engineering Contradiction:

Improvewelding depth uniformityVSAvoiddimensional accuracy

Core Design Contradiction:

Manufacturing precisionVSMeasurement precision

Solution Approach 1:

The method performs preliminary measurement of the fastener position and housing dimensions before the welding process. Based on these measurements, correction values are calculated and stored in advance to adjust the lens travel distance, ensuring dimensional accuracy is compensated before welding occurs.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system implements a feedback mechanism where the actual position of the fastener and housing dimensions are measured, compared against target values, and correction values are generated based on the deviations. This feedback loop ensures that tolerance variations are detected and compensated for in the welding process.

Inventive Principle:

Principle #23Feedback

2Manufacturing precision

If an absolute welding process is used to join the lens to the housing, then consistent lens height above welding contour is achieved, but dimensional accuracy is compromised due to uncorrected tolerances in fasteners and housing

Engineering Contradiction:

Improvelens height consistencyVSAvoiddimensional accuracy

Core Design Contradiction:

Manufacturing precisionVSMeasurement precision

Solution Approach 1:

The method performs preliminary measurement of the fastener position and housing dimensions before the welding process. Based on these measurements, correction values are calculated and stored in advance to adjust the lens travel distance, ensuring dimensional accuracy is compensated before welding occurs.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system implements a feedback mechanism where the actual position of the fastener and housing dimensions are measured, compared against target values, and correction values are generated based on the deviations. This feedback loop ensures that tolerance variations are detected and compensated for in the welding process.

Inventive Principle:

Principle #23Feedback

3Ease of manufacture

If fixed travel distance welding is used, then welding process simplicity is maintained, but dimensional accuracy deteriorates due to uncorrected tolerances

Engineering Contradiction:

Improvewelding process simplicityVSAvoiddimensional accuracy

Core Design Contradiction:

Ease of manufactureVSManufacturing precision

Solution Approach 1:

The method performs preliminary measurement of the fastener position and housing dimensions before the welding process. Based on these measurements, correction values are calculated and stored in advance to adjust the lens travel distance, ensuring dimensional accuracy is compensated before welding occurs.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system dynamically changes the travel distance parameter of the lens based on measured tolerance deviations. Instead of using a fixed travel distance, the system adjusts this parameter within a defined range to compensate for variations in fastener and housing dimensions, achieving both simplicity and precision.

Inventive Principle:

Principle #35Parameter changes

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 approach ensures high dimensional accuracy and reliability by compensating for tolerances in fasteners and housing components, ensuring all lighting devices align flush with the vehicle's outer skin during installation.

Implementation Method 1

identifying the position of the at least one fastener relative to the receiving device

Methodology Applied

Scientific EffectPosition measurement:

Implementation Method 2

welding the lens to the housing by means of welding

Methodology Applied

Scientific EffectWelding: Welding

Data Source

PatentUS11104083B2Method and device for joining a lens with a housing of a lighting device for a motor vehicle

Publication Date: 2021.08.31 HELLA GMBH & CO KGAA

AI summary

A method for joining a lens with a housing of a lighting device for a motor vehicle, having the steps: positioning the housing in a receiving device of a welding device, said housing having on its underside at least one fastener for attaching the lighting device in the motor vehicle, identifying the position of the at least one fastener relative to the receiving device, calculating a correction value on the basis of the identified position of the at least one fastener, and moving the lens held in a holding device of the welding device in the direction of the housing along a travel distance and welding the lens to the housing.