Vehicle Headlight Shade Positioning via V-Groove Stopper

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Solution Overview

Problem

Conventional light amount control mechanisms for vehicle headlamps face challenges in maintaining high positional precision of the movable shade during rotation, leading to variations in light distribution due to backlash, and stability issues when the bracket and housing thermally expand without an axial gap.

Innovation Solution

A light amount control mechanism featuring a V-shaped convex portion on the movable shade or housing and a V-groove-shaped concave portion on the other, with engagement sets offset in the rotation axis direction to precisely position the movable shade at different positions, eliminating backlash and allowing stable rotation with a predetermined axial gap.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If an axial gap is formed between the bracket and housing to allow smooth rotation, then the movable shade can rotate stably even when thermally expanded, but backlash is generated in the rotational axis direction causing variation in light distribution

Engineering Contradiction:

Improverotation stabilityVSAvoidpositional precision

Core Design Contradiction:

ReliabilityVSManufacturing precision

Solution Approach 1:

A stopper mechanism acts as an intermediary element between the bracket and housing. The stopper includes a convex portion on the bracket and a concave portion on the housing that engage to limit rotation at specific positions. This intermediary structure provides precise positioning without requiring direct contact between the bracket and housing, eliminating backlash while maintaining rotation stability through thermal expansion.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The stopper mechanism is designed beforehand to compensate for thermal expansion effects. By pre-positioning the convex and concave portions at calculated locations, the system anticipates thermal growth and maintains proper clearance and positioning even when components expand, preventing both backlash and rotation instability.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

2Manufacturing precision

If no axial gap is provided between the bracket and housing to eliminate backlash, then positional precision is improved, but the movable shade cannot rotate smoothly when thermally expanded

Engineering Contradiction:

Improvepositional precisionVSAvoidrotation smoothness

Core Design Contradiction:

Manufacturing precisionVSEase of operation

Solution Approach 1:

The stopper serves as a mediator that provides positioning function without requiring the bracket and housing to be in direct contact. The convex portion on the bracket engages with the concave portion on the housing only at the limiting positions, allowing smooth rotation throughout the range while maintaining precision at the endpoints.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The positioning function is segmented from the structural support function. The stopper mechanism handles positioning at specific angular positions, while the axial gap maintains rotation smoothness. This segmentation allows each function to be optimized independently without compromising the other.

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

This configuration ensures precise positioning of the movable shade, suppressing variations in light distribution and enabling stable rotation, even with thermal expansion, by maintaining a predetermined axial gap between the movable shade and the housing.

Implementation Method 1

a stopper configured to position and hold the movable shade at the first position and the second position, the stopper being constituted by a V-shaped convex portion formed on any one of the movable shade and the housing and a V-groove-shaped concave portion formed on the other thereof as a pair

Methodology Applied

Scientific EffectMechanical engagement: Mechanical Fastener

Implementation Method 2

when the bracket 104 and the housing 106 are heated and thermally expanded

Methodology Applied

Scientific EffectThermal expansion: Thermal Expansion

Data Source

PatentUS10436411B2Light amount control mechanism for vehicle headlight

Publication Date: 2019.10.08 STANLEY ELECTRIC CO LTD

AI summary

A light amount control mechanism for a vehicle headlamp can maintain high positional precision of a movable shade in its rotation axis direction to suppress variation in light distribution while allowing stable rotation of the movable shade. The light amount control mechanism includes a movable shade configured to be rotatably supported by a housing and selectively pivots to a first position or a second position to switch a shielding amount of light emitted from a light source, and an actuator configured to drive the movable shade. The light amount control mechanism for a vehicle headlamp may further include a stopper configured to position and hold the movable shade at the first position and the second position, the stopper being constituted by a V-shaped convex portion formed on any one of the movable shade and the housing and a V-groove-shaped concave portion formed on the other thereof as a pair.