Straddled Vehicle Headlight Cover Geometry for Heat and Rain Management

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Straddled vehicle headlight units face challenges in managing heat space volume due to varying thermal energy from sunlight, leading to increased size and rainwater accumulation, which affects light distribution and clarity.

Innovation Solution

The headlight unit design features a front cover portion extending obliquely downward and a transparent cover with inverse and forward inclined surfaces to reduce sunlight entry and rainwater clinging, while maintaining effective light irradiation and easy rainwater removal.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of stationary object

If the headlight unit size is increased to ensure sufficient heat space volume, then the heat space volume is improved, but the device complexity and overall size increase

Engineering Contradiction:
Improveheat space volumeVSAvoidheadlight unit size
Core Design Contradiction:
Volume of stationary objectVSVolume of moving object

Solution Approach 1:

The patent positions the transparent cover portion to protrude further forward than the front cover portion, creating a spatial arrangement where the heat space extends in the forward direction rather than uniformly in all directions. This dimensional adjustment allows sufficient heat space volume while controlling overall headlight unit size.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Volume of stationary object

If the transparent cover portion protrudes further forward than the front cover portion, then the heat space volume is reduced, but rainwater accumulation on the transparent cover portion increases

Engineering Contradiction:
Improveheat space volumeVSAvoidrainwater accumulation
Core Design Contradiction:
Volume of stationary objectVSObject-affected harmful factors

Solution Approach 1:

The transparent cover portion is designed with a curved surface that slopes downward from front to back. This curvature facilitates rainwater runoff by creating a gradient that directs water toward the rear, preventing accumulation on the protruding forward portion of the transparent cover.

Inventive Principle:
Principle #14Spheroidality (Curvature)

3Object-affected harmful factors

If the front cover portion extends further forward, then rainwater accumulation is reduced, but the amount of sunlight entering the headlight unit increases

Engineering Contradiction:
Improverainwater accumulationVSAvoidthermal energy from sunlight
Core Design Contradiction:
Object-affected harmful factorsVSTemperature

Solution Approach 1:

The front cover portion is designed to extend forward only at its lateral edges while leaving the central region open. This local differentiation allows rainwater to run off the extended edge portions while limiting sunlight entry through the covered lateral areas, whereas the central open region maintains adequate light transmission without excessive heat gain.

Inventive Principle:
Principle #3Local quality

4Illumination intensity

If the transparent cover portion is extended rearward and downward, then the incident angle of high beam light deviates from vertical, but light distribution is improved

Engineering Contradiction:
Improvelight distributionVSAvoidincident angle control
Core Design Contradiction:
Illumination intensityVSManufacturing precision

Solution Approach 1:

The transparent cover portion is designed with specific angular parameters - extending rearward and downward at controlled angles. By optimizing these geometric parameters, the design achieves improved light distribution across the road while maintaining sufficient vertical incident angle for effective high beam illumination. The specific angles are chosen to balance both requirements.

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 configuration minimizes heat space volume, ensures consistent light distribution, and facilitates easy removal of rainwater, preventing light diffusion and maintaining high beam irradiation efficiency.

Implementation Method 1

the incident angle of the high beam light HL tends to deviate from 0-degrees with respect to the transparent cover portion 4000 (that is, vertical incidence tends to be lost). As a result, there is a concern that an effect will occur in which the high beam light HL is refracted by the inverse inclined surface of the transparent cover portion 4000

Methodology Applied
Scientific EffectRefraction: Refraction

Implementation Method 2

a bulb 91 for emitting light

Methodology Applied
Scientific EffectLight emission: Light Emitting Diode

Implementation Method 3

a reflector portion 92 for reflecting the light from the bulb 91 in the forward direction of the vehicle

Methodology Applied
Scientific EffectReflection: Reflection

Data Source

PatentEP3782885B1Straddled vehicle
Publication Date: 2022.03.23 YAMAHA MOTOR CO LTD
  • EP3782885B1 patent drawingFigure 1
  • EP3782885B1 patent drawingFigure 2~3
  • EP3782885B1 patent drawingFigure 4

AI summary

A front edge portion of a front cover portion (421) is arranged further downward and forward than an upper edge portion of a reflector portion (92). The light-emitting surface includes a light-emitting surface upper portion (941) that extends rearward and downward of the vehicle from the front edge portion of the front cover portion, and a light-emitting surface lower portion (942) that extends forward and downward of the vehicle from the light-emitting surface upper portion, as seen in the cross-section at the center in the vehicle left-right direction. The reflector portion includes, at least, a reflector upper portion (921) that is positioned above a bulb (91) and extends rearward and downward of the vehicle and reflects the light from the bulb in the forward direction of the vehicle, and the reflector lower portion (922) that is positioned below the bulb and extends forward and downward of the vehicle and reflects the light from the bulb in the forward direction of the vehicle, as seen in the cross-section at the center in the vehicle left-right direction.