Description and Analysis of Structural Design Improvement of Liftgate Hinge Reinforcement Plate_Hing

In recent years, the rapid development of my country's automobile industry has been remarkable, particularly with the addition of self-owned and joint venture brands. This growth has led to a gradual reduction in automobile prices, flooding the consumer market with tens of thousands of vehicles being produced annually. As the times progress and people's income improves, owning a car has become a common means of transportation to enhance both production efficiency and quality of life.

However, with the expansion of the automotive industry, there has been an increase in car recalls due to design problems. These incidents serve as a reminder that when developing new products, it is crucial to not only consider the development cycle and cost, but also pay close attention to product quality and user needs. To ensure better quality control, stricter regulations have been introduced, such as the "Three Guarantees Act" for automotive products. This act stipulates that the warranty period should not be less than 2 years or 40,000 km, or 3 years or 60,000 km, depending on the product. Therefore, it is vital to focus on the early stages of product development, optimize the structure, and avoid the need for later fixes.

One specific area of concern in the automotive industry is the design of the liftgate hinge reinforcement plate. This component is welded to the inner and outer panels of the liftgate to provide a mounting point for the hinge and ensure the strength of the installation point. However, the hinge area often experiences stress concentration and excessive loading, which has been a persistent challenge. The goal is to reduce the stress value in this area through proper design and optimization of the hinge reinforcement plate structure.

This article focuses on addressing the issue of cracking in the inner panel at the hinge of the liftgate hinge reinforcement plate during vehicle road tests. The study aims to find ways to reduce the stress values experienced by the sheet metal in the hinge area. By optimizing the structure of the hinge reinforcement plate, the goal is to achieve an optimal state that reduces stress and improves the performance of the liftgate system. Computer-aided engineering (CAE) tools are utilized in the process of structural optimization to improve the quality of design, shorten the design cycle, and save costs associated with testing and production.

The cracking problem in the inner panel at the hinge is analyzed and attributed to two factors. Firstly, the staggered boundaries of the hinge installation surface and the upper boundary of the hinge reinforcement plate result in the inner panel being exposed to greater stress. Secondly, stress concentration occurs at the lower end of the hinge mounting surface, exceeding the yield limit of the plate and leading to cracking.

Based on these insights, several optimization schemes are proposed to address the cracking issue. These schemes involve modifying the structure of the hinge reinforcement plate and extending its boundaries to eliminate stress concentration points. After conducting CAE calculations for each scheme, it is determined that Scheme 4, which involves extending the reinforcement plate to the corner of the window frame and welding it to the inner and outer plates, shows the most significant reduction in stress value. Although this scheme requires changes in the manufacturing process, it is deemed the most feasible and advantageous option.

To validate the effectiveness of the optimization schemes, manual samples of the modified parts are created. These samples are then incorporated into the vehicle manufacturing process, and a reliability road test is conducted. The results show that Scheme 1 fails to address the cracking problem, while Schemes 2, 3, and 4 successfully resolve the issue.

In conclusion, through the analysis, optimization, CAE calculations, and road test verification of the hinge reinforcement plate, an optimal structural design scheme is developed to reduce stress values and enhance the performance of the liftgate system. This improved design will guide the future development of the hinge reinforcement plate structure in vehicle projects. However, it is important to consider the practicality and cost-effectiveness of implementing these optimization measures, as they may require adjustments to the manufacturing process and incur additional expenses. Nonetheless, by prioritizing product quality and user needs in the early stages of development, the automotive industry can continue to innovate and deliver safe and reliable vehicles to consumers.