Since closure systems such as door, hood, and tailgate are moving parts, the performance required for engineering design is very diverse. For example, not only the performance of general body parts such as collision and stiffness, but also the opening and closing layout, wind noise, sagging stiffness, opening and closing durability must be satisfied. Such a closure system behaves based on a hinge axis, and without a hinge, it is just a fixed part. After all, the essence of the closure system is the hinge, and therefore the hinge is inevitably closely related to the aforementioned performance. Therefore, in order to design a high-quality and robust closure system, it is very important to design an optimized hinge layout considering basic required performance such as opening trajectory gap, hinge span, and axial angle. Accordingly, a lot of man-hours are put into the design of the hinge layout. However, since engineering designers also have to consider other performance such as design and package, they are often in a situation where they have to trade-off between opening trajectory gap, hinge span, and axial angle in hinge layout design. In other words, the span can be reduced to ensure a minimum opening trajectory gap. At this time, if the span can be maximized even with the same gap, that is, if it is possible to optimize by analyzing the factors related to the opening trajectory gap, the span reduction can be minimized and sometimes the span can be further increased. Accordingly, the sagging rigidity and the frame rigidity can be made more robust, and as a result, it is possible to prevent problems such as the claim of wind noise, gap step in advance. To realize this, in this study, geometrical analysis was performed on the opening and closing behavior of the closure system. For example, the opening trajectory was mathematically analyzed using trigonometric functions and differentiation, and as a result, the gap was formulated so that the gap could be known through calculation even without using a design tool such as CATIA. In addition, through this formula, not only the factors affecting the gap, but also which factors had the greater influence were investigated. Finally, an automatic gap calculation program was created to automatically calculate the gap for each part by inputting some input values, thereby reducing the engineering designer’s man-hours and enabling an optimized hinge layout design. By the way, the research target was a door, which is one of the representative closure systems, but the principle is the same for any closure system that be haves on one axis regardless of vehicle class, design, and measurement location. Therefore I hope the result obtained in this study will contribute to the early prevention of many problems related to the closure system such as snapping when opening, frame stiffness, sagging stiffness, wind noise, opening and closing durability, gap step claim, excessive opening and closing load, rebound problems by realizing hinge layout design optimization and man-hour reduction.
Mr. KYEONGKUK CHO, RESEARCHER, HYUNDAI MOTOR COMPANY