Buzz Avoidance on Sunroof Light Sunshades: Design and Validation

摘要

Sunroof is placed in certain high-end vehicles to give user a better driving experience. All automakers are searching alternatives to reduce weight and cost in the vehicle, in which sunroofs are also impacted. Some alternatives are already applied, as a honeycomb paper used in some sunshades that presents benefits, as less weight and with a good cost reduction. Although, due the reduced weight for this part produced in this material, it shows more susceptibility to reproduce the vibration that vehicle propagates in movement, especially in bad condition roads. The sunroof assembly is dependent of the roof reinforcement and roof skin, but in this special case, the validation could be done in the components itself because the interaction of the sunshades is directly dependent of the other sunroof parts, as rails and front frame. These buzz noise in lights sunshades is perceptible when it is almost or totally close, since lighter material vibrates freely without rail anchorage, then clashing against the front frame surface. Considering the package, the key point is to design the sunshade to have always an interference against the front frame, ensuring the effort to open and close are not excessive. In addition, the material that covers the sunshade must not have degraded appearance after user normal lifetime. If cost is not a project roadblock, the component could be designed using different material and shape. To summarize, to complete design validation, specific test must be performed to evaluate wear and effort. To summarize, vehicle driving tests must be performed to guarantee the complete functionality for this part, with no generation of disadvantage for users.