Improvement Technology of Hinge Reinforcing Plate Structure for Increasing Vertical Rigidity of Auto1

1. Background:

The vertical stiffness of car side doors is a critical performance index that affects the overall performance of the door system. To meet durability test specifications and ensure proper closing and sealing, the design of the door system must adhere to specific performance requirements. The LSR (Length to Span Ratio) value plays a decisive role in the vertical stiffness of the door, with passenger cars typically requiring an LSR value ≤ 2.5 and commercial vehicles requiring ≤ 2.7. The design of the hinge reinforcement plate is crucial in increasing the vertical stiffness of the car side door. This research aims to address layout defects in the door system through the innovative design of the hinge reinforcement plate, achieving the required stiffness index and improving waterproof, dustproof, and rustproof performance.

2. Structural Defects of the Prior Art:

Traditional hinge reinforcement plate structures consist of a hinge nut plate welded with nuts, which is then overlapped with the door inner panel using two welding spots. However, this structure has certain disadvantages. When the hinge distribution is relatively small compared to the door length, the overlapping area between the inner panel and the hinge reinforcement plate is small, leading to stress concentration and potential damage to the inner panel. Consequently, inadequate vertical stiffness of the front door can cause sagging and misalignment of the entire door system. Installation space constraints also necessitate the addition of a limiter reinforcement plate, further increasing costs and complexity. The existing hinge reinforcement plate structure fails to address insufficient vertical rigidity, deformations, and cost concerns.

3. Solutions to Existing Structural Defects:

3.1 Technical problems to be solved by the new structure:

The new hinge reinforcement plate structure aims to overcome the following deficiencies: insufficient vertical stiffness leading to door sagging, deformation, and misalignment; deformations and cracks on the inner plate due to stress on the limiter installation surface; increased costs associated with part molds, development, transportation, and labor; dust and rust prevention at the limiter installation area.

3.2 Technical solution of the new structure:

To address these challenges, the new hinge reinforcement plate design integrates both the front door hinge reinforcement plate and the front door limiter reinforcement plate into a single design. It increases the overlapping area between the hinge reinforcement plate and the inner plate, enhances the material thickness of the hinge mounting surface to prevent stress concentration, and improves the rigidity of the hinge installation surface. Moreover, this design ensures the limiter installation surface fits precisely, prevents damage to the inner plate and reinforcement plate from electrophoretic fluid, and strengthens the waterproof, dustproof, and rustproof properties. By combining both reinforcement plates into one, the design streamlines part molds, reducing costs for development, packaging, transportation, and labor.

3.3 Application examples of the new structure:

In an example where the front door LSR ratio significantly exceeds the prescribed limits, the new hinge reinforcement plate structure effectively compensates for the initial layout defects. Through CAE calculation, it is shown that the overall vertical stiffness of the door system meets enterprise standards. These results confirm the efficacy of the improved hinge reinforcement plate structure in enhancing safety and overall performance.

4. Economic benefits of the new structure:

By integrating both the front door hinge reinforcement plate and the front door limiter reinforcement plate into a single design, the new structure eliminates stress concentration, prevents deformation and cracks, increases vertical rigidity, enhances waterproof and dustproof properties, and resists rust. Furthermore, reducing the number of parts and molds required for the limiter reinforcement plate saves on development costs, packaging, transportation, processing, and labor expenses. Consequently, the new hinge reinforcement plate design accomplishes both performance improvement and cost reduction.

5.

The research findings reveal that when the hinge distribution law of car side doors is relatively large compared to the length, addressing layout defects through innovative hinge reinforcement plate design can significantly enhance vertical stiffness and overall performance. The structural design integrates cost control measures while consistently meeting performance standards. The experiences gained from this study provide valuable insights for future structural designs in new car models.

In conclusion, achieving optimal vertical stiffness and performance in car side doors necessitates innovative designs, such as the integration of hinge reinforcement plates and limiter reinforcement plates. This approach not only solves existing structural defects but also improves crucial performance indices while reducing costs.