Vehicular Headlamp Heat Sink Extraction for Airtightness

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

In vehicular headlamps, the heat sink tilts with the lens unit during aiming adjustments, compromising the internal airtightness of the external case and allowing dust or moisture to penetrate, which degrades light intensity and operational smoothness.

Innovation Solution

The light source unit is fixed to the lamp housing with the heat sink positioned outside the external case, ensuring that the heat sink does not move during aiming adjustments, thus maintaining airtightness while enhancing heat dissipation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the heat sink is attached to the frame inside the external case and tilts with the lens unit during aiming adjustments, then the aiming adjustment function is achieved, but the internal airtightness of the external case deteriorates and dust or moisture penetrates inside

Engineering Contradiction:
Improveaiming adjustment functionVSAvoidinternal airtightness
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The heat sink is extracted from the internal space of the external case and positioned outside, through a heat sink installation hole in the lamp housing. This separation allows the heat sink to remain stationary during aiming adjustments while the lens unit tilts, thereby maintaining the internal airtightness of the external case while still achieving the aiming adjustment function.

Inventive Principle:
Principle #2Taking out (Extraction)

2Temperature

If the heat sink protrudes rearward from the lamp housing to ensure excellent heat dissipating performance, then the heat dissipation performance is improved, but the internal airtightness of the external case is compromised

Engineering Contradiction:
Improveheat dissipation performanceVSAvoidinternal airtightness
Core Design Contradiction:
TemperatureVSReliability

Solution Approach 1:

The heat sink is extracted from the sealed internal environment and positioned outside the external case through the heat sink installation hole. This allows the heat sink to protrude rearward from the lamp housing for effective heat dissipation while preventing it from compromising the internal airtightness, as it is no longer part of the sealed internal structure.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The heat sink installation hole serves as an intermediary structure that allows the heat sink to pass through the lamp housing and extend outside the external case. This intermediary opening enables thermal management functionality while maintaining the airtight seal of the internal case structure.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Reliability

If the heat sink is positioned outside the external case of a lamp, then the internal airtightness is maintained, but the heat dissipation performance may be reduced

Engineering Contradiction:
Improveinternal airtightnessVSAvoidheat dissipation performance
Core Design Contradiction:
ReliabilityVSTemperature

Solution Approach 1:

By extracting the heat sink to the external position, the invention maintains the airtight seal of the internal case while still achieving effective heat dissipation. The heat sink's position outside allows it to operate in an unsealed environment optimized for thermal management, compensating for any potential reduction in heat dissipation efficiency.

Inventive Principle:
Principle #2Taking out (Extraction)

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 improves heat dissipation performance while maintaining internal airtightness, ensuring consistent light output and reliable operation by preventing the heat sink from tilting with the lens unit during adjustments.

Implementation Method 1

a heat sink that dissipates heat generated when the light source is driven

Methodology Applied
Scientific EffectHeat dissipation: Convection

Implementation Method 2

a heat sink that dissipates heat generated when the light source is driven

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Data Source

PatentEP2508795B1Vehicular headlamp
Publication Date: 2020.02.26 KOITO MFG CO LTD
  • EP2508795B1 patent drawingFigure 1
  • EP2508795B1 patent drawingFigure 2
  • EP2508795B1 patent drawingFigure 3

AI summary

Provided is a vehicular headlamp that includes a light source unit (6), a reflector (50), a heat sink (49), a fixation frame (9) fixed inside an external case (4) of a lamp, a movable frame (8) supported on the fixation frame (9) to be movable in a vertical direction, a lens unit (7) including a projection lens (14) and a lens holder (13) and supported on the movable frame to be movable in a horizontal direction, a first aiming operating shaft (10) that performs optical axis adjustment, and a second aiming operating shaft (11) that performs the optical axis adjustment. In particular, the lens unit (7) moves in the horizontal direction and the vertical direction with respect to the fixation frame (9) while a distance from a focus of light reflected by the reflector to the projection lens is constant, and the light source unit is fixed to the lamp housing (2) while the heat sink (49) is positioned outside the external case (4).