Analysis and Optimization of Automotive Self-Priming Door Lock Closing Sound

With higher customer expectations and advances in vehicular technology, automotive functions and operations are becoming more intelligent. Electric self-priming door locks fulfil the automatic closing and locking of side doors, hatchback doors, sliding doors, liftgates, decklids, etc. They are widely implemented into high-end models for the elegance of soft closing. In the list of perceived vehicle qualities, door-closing sound quality has been one of the important customer concerns in the market. In comparison to conventional door locks, electric self-priming door locks add another dimension to the development of sound quality for noise, vibration, and harshness (NVH) efforts. In this article, the characteristics of door-closing sound involving self-priming door lock mechanisms are analyzed and illustrated. Human perception of different sounds from the self-priming door lock working process is ranked by subjective evaluations. For typical door closing sounds associated with the self-priming lock mechanisms, i.e., the motor sound and rebound sound, real-case examples are discussed. A case of the buzzing noise issue due to the self-priming lock on a hatchback door is also presented. In these cases, the correlation between the sounds and the structure of the self-priming door locks is investigated and the root causes of the encountered issues are identified. The door closing sound quality associated with the self-priming door locks is improved in each case to meet the program requirements. In the particular cases presented in this work, the analysis involves psychoacoustic metrics for sound quality study originally. It is found later that sound pressure level can address the encountered issues, and thus only sound pressure level results are included.