Instrument Panel, new design of Tear Line on Scoring Passenger Airbag by dedicated technical injection moulding Instead Laser or milling. Development, prototype and validation about molded solution.

An airbag is a vehicle occupant-restraint system that consists of an inflatable bag which quickly opens and interferes between the passengers and the car’s dashboard during an impact, preventing driver and passengers from possible serious injuries. The most important factors influencing the deployment of a passenger dedicated airbag are the intensity of the collision, the electronic actuator and the geometry of the Tear Line of the PAB door on the dashboard. The last element is the one studied in this elaborate. In particular, the work is related to a new prototype of Instrumental Panel dedicated to the DS D85 model, for which the launch is estimated in 2026. The study involves the realization of the Tear Line of the frontal passenger-side airbag directly on the component during the Injection Molding, instead of the commonly used Laser and Milling procedures. After a deep investigation, both in terms of time and expenses, it comes out that the Injection Molding Tear Line is the perfect solution because it permits to save material and money, also relating to the number of machines required for the realization of the PAB door. The Door must open in the right way, allowing the deployment of the airbag following the guidelines and respecting the correct timing, estimated in milliseconds (ms). The main elements to be considered in the realization of a Tear Line are the thickness of the residual material on the Instrument Panel, the length of the holes, and the correct geometry of the edges. The final steps, before the validation of the project and the consequence start of production, are the tests to be performed and passed. The main tests are: •??The Strenght Load test, the better method to evaluate the correct opening of the door and the chute welded to it; •??The deployment of the airbag, the most investigated and treated in this work. It is performed in Pomigliano D’Arco site (NA) and involves the realization of a high number of tests, of course all of them must be passed; •??The Thermal cycles: Divided in climatic aging, Humidity, Heat aging test and Sun Insolation tests; •??Misuse test: A typical test is to determine whether airbags or other elements of passenger restraint systems are deployed in non-collision situations. Driving a vehicle into a sandbank, wooden beam or over a ramp is extremely arduous for human test drivers, and doing so repeatedly can cause injuries. Stress levels are also high due to the possible deployment of airbags. Thermal and misuse tests are the same performed for the other dashboards with the same materials, and so are not studied in detail. For the Load and Deployment tests, instead, after some modification of the geometry of the Tear Line, due to an incorrect opening of the PAB door and a consequent misposition of the bag during the deployment, the final shape is achieved, and the tests passed.