Conceptual Design of Seat Belt Installation for Rear-facing Child Car Seat

Sammanfattning: Children are more vulnerable in vehicles compared to adults in collisions. Two main reasons are the different body structure between these two and vehicles are more designed to fit adults. Children’s head is larger relative to their body mass and their neck muscle ligaments are still not fully developed. Children are therefore in need of a restraint system that match their anatomy to make them protected during transportation in vehicles. Crash tests have shown that if children up to the age of five use rear-facing child car seats are the chances reduced of injuries by five times compared to front-facing. This report describes the development project of a concept which enables to fasten a rear-facing child car seat with the car seat belt. The objective was to design the fastening components for a rear-facing child car seat that suits children up to five years and considering the regulations, ECE R44, and the Swedish Plus test. This is a Master thesis that has been in collaboration with Company Xand Havd Group in Gothenburg. The project aimed to deliver a digital concept of the fastening components with information about the material, manufacturing methods, product costs, and design form. Also, was the aim to gather information through the project on what it takes to develop a rear-facing child car seat. The project consisted of five phases: planning, pre-study, ideation, detailed design and at last presentation of the result. The first phase was to plan and coordinate the project. A pre-study was then made investigating the products on the market, interviews with both users and experts regarding safety for children in vehicles, relevant literature for developing a child car seat was also collected and regulations were studied. The ideation phase developed ideas and three concepts were taken forward for development. One concept was chosen after decision making and the concept was more detailed designed in CAD.The result is presented through a CAD model which illustrates the design form and chosen material. The result is a concept that fastens the car seat belt with two hooks which can be connected to the child car seat base. In the base is two buckles designed to connect with the hooks, which uses the same fastening way used in the vehicles to fasten passengers. This is supposed to increase the usability of the installation. Material, manufacturing methods and product costs have been considered and are presented with the result.