Light Module Lens Positioning via Dowel Pin and Ball Socket

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Solution Overview

Problem

Existing light modules in motor vehicle headlights face challenges in achieving precise and reproducible light beam distributions due to dispersion effects from refractive materials, which cause unwanted color edges and fringes, and the difficulty in precise positioning and fastening of lens devices, especially when using plastic parts.

Innovation Solution

A light module design featuring a positioning device with a dowel pin and dowel bushing for precise axial adjustment and a fastening device with a fastening projection and recess for secure attachment, allowing for precise positioning and detachment of the lens device, even with plastic components, thereby separating the positioning and fastening functions and maintaining accuracy despite potential deformations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If a lens device is fastened using conventional screwing or clamping methods, then the lens device can be securely attached, but precise positioning is difficult to achieve and maintain, especially with plastic parts that deform under fastening forces

Engineering Contradiction:
Improvepositioning accuracyVSAvoidfastening mechanism complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The fastening mechanism is segmented into two distinct functional components: a positioning device with dowel pins and dowel bushings that establishes precise spatial relationships, and a fastening device with fastening projections and recesses that secures the connection. This segmentation allows each component to optimize its specific function without compromise.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The positioning device performs preliminary positioning action before the fastening device is engaged. The dowel pins are inserted into the dowel bushings to establish precise alignment and spatial relationships between the lens device and other optical components, and between the lens holder and holding frame, before the fastening projections and recesses secure the connection.

Inventive Principle:
Principle #10Preliminary action

2Ease of manufacture

If plastic parts are used for lens holders and frames, then manufacturing cost and design flexibility improve, but positional accuracy deteriorates due to material deformation under fastening forces

Engineering Contradiction:
Improvemanufacturing cost and design flexibilityVSAvoidpositioning accuracy
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The positioning device with dowel pins and dowel bushings provides beforehand cushioning against positional deviations. By establishing precise alignment before fastening forces are applied, the system compensates for the inherent deformation susceptibility of plastic materials, ensuring that even when plastic parts deform under load, the optical components remain accurately positioned.

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

3Stability of the object's composition

If the lens device is tightly fastened to prevent movement, then positioning stability improves, but the ability to detach and reattach with the same precision is lost

Engineering Contradiction:
Improvepositioning stabilityVSAvoiddetachability
Core Design Contradiction:
Stability of the object's compositionVSAdaptability or versatility

Solution Approach 1:

The connection system is divided into positioning and fastening functions, allowing the lens device to be securely attached when needed while maintaining the capability for precise repositioning upon detachment. The positioning device with dowel pins ensures that even after detachment and reattachment, the precise spatial relationships are restored.

Inventive Principle:
Principle #1Segmentation

4Strength

If conventional fastening methods are used, then secure attachment is achieved, but repeated attachment and detachment causes thread widening and loss of positioning accuracy

Engineering Contradiction:
Improvefastening strengthVSAvoidpositioning accuracy
Core Design Contradiction:
StrengthVSManufacturing precision

Solution Approach 1:

By separating positioning and fastening functions, the positioning device with dowel pins and dowel bushings is not subjected to the mechanical stresses of repeated attachment and detachment. The fastening device handles all mechanical loading, while the positioning device maintains its precision alignment capabilities intact even after multiple connection cycles.

Inventive Principle:
Principle #1Segmentation

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

Ensures precise and reproducible light beam distributions with minimal color effects and allows for multiple attachments and detachments without compromising positional accuracy, even when using plastic parts, which are prone to deformation.

Implementation Method 1

The positioning device (60) guides the lens device (18) into a desired position with a high degree of precision

Methodology Applied
Scientific EffectMechanical guidance and positioning:

Implementation Method 2

The fastening device (80) fastens the lens device (18) in the desired position

Methodology Applied
Scientific EffectMechanical fastening: Mechanical Fastener

Implementation Method 3

lens device (18), for example a converging lens, for forming a desired light distribution

Methodology Applied
Scientific EffectRefraction: Refraction

Implementation Method 4

lenses or other transparent optical elements are usually made of a refractive material. Such materials usually have dispersion properties, i.e. they show a dependence of the refractive index on the wavelength of the light

Methodology Applied
Scientific EffectDispersion: Dispersion (of waves)

Data Source

PatentEP2693109B1Light module
Publication Date: 2020.09.02 MARELLI GERMANY GMBH
  • EP2693109B1 patent drawingFigure 1
  • EP2693109B1 patent drawingFigure 2
  • EP2693109B1 patent drawingFigure 3

AI summary

The light module (10) has a lens device (18) for forming desired light distribution, where the lens device is exactly positioned in a desired spatial position by a positioning device. The positioning device has a dowel pin and a ball socket, where the dowel pin is engaged and guided in the ball socket for positioning the lens device. A fastening device has a fastening projection, fastening recess and a fastening unit. The fastening projection is engaged in the fastening recess and is fixed with the fastening unit for fastening the lens device. The dowel pin is extended along a guide direction.