Infrared Reflective Bulb Shield

1. Infrared Reflective Bulb Shield • Com-Corp Industries • Tier 1-2 automotive metal stamping and manufacturing • Isatec Technical Center • Captive tooling, engineering and process design • Illume • Affiliated advanced research and development company

2. Introduction

3. Com-Corp’s Bulb Shield • Automotive headlamp requires light shielding • Bulb shield component • Metal stamping • Decorative nickel chrome plating • New light bulbs and lamp designs were causing bulb shield to overheat

4. Bulb shield orientation Figure 1 Cross section of a headlamp with bulb shield (2) installed in front of bulb (1) and reflector (3)

5. Bulb shield interior coating • High temperature black paint • Applied to shield interior surface to prevent unwanted reflections With paint Without paint

6. Bulb shield temperature • Mechanical Actions • Proximity to bulb • Lack of air flow • Thermodynamic Actions • Electromagnetic radiation absorbed by the shield • Interior coating reflectivity • Exterior coating low emissivity

7. Deleterious effects of elevated temperature • Oxidation of Ni-Cr at 315° Celsius • Yellow oxide reflects in lamp EDS graph of discolored area Video will turn black while downloading. May take several minutes depending on connection speed

8. Deleterious effects of elevated temperature • Bulb shield required to pass SAE vibration test • Tensile strength of steel reduced at elevated temperatures

9. Previous research efforts to reduce shield temperature • Sah and Park – Shape and Orientation • Geometry of the bulb shield – air flow • Geometry of the reflector • Location of shield with respect to the bulb • Reduced bulb shield temperature by 15-20%

10. Economic impact of those solutions • Alter geometry of the bulb shield • Changes to existing tooling • Mechanical integrity of the shield • Geometry of the reflector • Changes to existing tooling • Location of shield with respect to the bulb • Changes to one or both components

11. Paint removal as a solution • No Paint • Highly reflective nickel-Chrome surface • Affects photometry of lamp • Metallic Flake Paint • Increase in reflectivity – some preferential IR

12. Research new interior coating solution • Visible wavelengths must be absorbed • Infrared should be reflected Bulb output Ideal coating

13. Reflectivity profiles • Normal Paint • Designed for low reflectance for headlamp photometry • New coating • Pigmented to absorb visible radiation (490-720nm) • Highly reflective in near infrared

14. Comparison of coating based solutions • Headlamp used as test environment • Type K thermocouple • Computer data collectioninterface • Sample sets randomized

15. Statistical analysis of results • ANOVA – normal distribution

16. Performance • Only un-coated shield performed better • IR reflective sample 2 was best performer

17. Both show statistically significant reductions in temperature IR reflective was 5.7% cooler than metallic flake Comparison to metallic flake coating

18. Shield Proximity Factor • Eliminate variation in shield geometry as variable • No statistical significance in shield proximity to bulb between sample sets • IR 2 samples were actually closest to bulb

19. Conclusion • Infrared reflective bulb shield • Comparable reduction in temperature to altering lamp design • No special handling • No increase in cost • Maintain low visible reflectance • U.S. and foreign patents pending

20. Contact Information Isatec Tooling and Engineering Dr. Steven Sheng ssheng@ccioh.com 216-265-9449 Illume LLC Michael Strazzanti mstrazz@illumeco.com 216-299-3567