Hood Closing Characteristics in a Dual Hood Latch System

Certain sports utility vehicles (SUVs) utilize dual latches and gas struts in their hood design. This is primarily driven by the larger size of the hood and specific architectural requirements. These hoods can be securely latched either by a dynamic single stroke closing method or by quasistatic two stroke closing method. In dynamic method, the hood is closed with a single, high-velocity motion for the final primary latching, whereas in quasistatic method, force is initially applied for the secondary latching and then for the final primary latching. In this study, both the dynamic and quasistatic closing methods are compared in terms of closing force and velocity and hood over travel distance. A load cell is used for measuring the closing force, velocity meter is used for velocity measurement and a rope sensor is used for measuring the hood over travel distance. It is evident from the study that the velocity required for hood closing is higher in the dynamic method, than the quasi-static loading conditions. However, the closing force and hood over travel distance are higher in the quasi-static method compared to dynamic method. The hood overtravel distance in quasistatic method is twice that of the dynamic method. This excess hood overtravel in quasistatic method could potentially have a significant impact on the interface parts of the hood. The study clearly indicates that when dual hood latches and gas struts are employed, it is crucial for the structure of the hood system and its interface components to be robust enough to effectively handle both the quasistatic and dynamic closing conditions. This robustness is necessary to ensure the durability and reliable performance of the hood in varying operational scenarios.