The Application Study On Optimizing Seat Belt Retractor Performance

This article introduces automobile seat belt retracting performance optimization with DFSS methodology in advanced design phase to reach the uniform of safety and fastening comfort.Design for Six Sigma (DFSS) is a methodical approach to robust design. It does not focus on improving the existing design or process but creating a new and improved design or process. It requires applying resources to find out what customers'real needs are and do robust design to new product and process. Then it devotes the entire project to meet customers'demand within cost constraint.Automotive seat belt system is one of major passive safety system. It is used to protect passengers in vehicle and to limit the moment moving of passengers. It avoids or weakens the damage to passengers in traffic accident or urgent brake and takes effect in weakening passengers'injured degree. Author will research how to balance the safety performance and fastening comfort performance in design period.This article is used a new vehicle development as a platform, based on rear seat belt. Combined with the safety belt issue collection of current production vehicle, identify the requirement from customers, summary the voice of customers, transfer it into engineering indexes. Then find the relationship between voice of customers and engineering indexes and define the engineering indexes: retraction force and extraction force. Complete the concept design and math model establish. Through the calculated analysis of S/N and slope, optimizing the design parameters and make the system robust, make it insensitive to noise. Finally the optimized design was verified in vehicle. It shows the advantages of six sigma in earlier prevent and issue resolve compare to traditional design approach.