A Car Rear Seat Backrest Framework Of Lightweight Design Improvements

Nowdays, seat lightweighting has become a very important part of carlightweighting. Based on this background and in order to match up with weightreduction of oems, from the perspective of engineering practical research,this paperutilizes seat finite element analysis to do the lightweight improvement design for aninitial model of the tube-plate back frame of a car rear seat without the increasing ofcost and complexity of manufacturing process while ensure the safety and comfort ofthe seat.This paper firstly chooses the Chinese GB-15083standard which is the mostdemanding test as the data base of lightweight improvement design. Next itestablishes the boundary conditions, loading method, the model assumes andfinally FEA modol of rear impact by using CATIA on the basis of geometric modeland LS-DYNA code is used to run calculation.Then classified all the back parts intothree categories which are newly developed parts, borrow parts and direct Purchasingparts and analyze the stress and surplus situation for intensity according to thecharacteristics of the various parts. Analysis shows that the tube-plate frame havesignificant surplus for strength and stiffness and so the paper then do the followingtwo phases lightweight improvement.The first stage, It changes the structrue of the back from tube-panel totube-wire.It designs the diameter of the wire, shape, etc.and establishes the geometricmodel of the tube-wire tube-wire and then the cargo rentention FEA model based onthe matching condition of the tubes,wires,foam and trims of the back seat. Analysisshows that the backt tube and the rotating bracket remain abundant strength, still canbe further optimized. After the first stage optimization, seat weight reduce about29.4%;The second phase, It does further optimization for the thickness of the tube androtating bracket and finds the best thickness combination based on the actualproductionand builds corresponding cargo rentrntion FEA model. Then the authormakes lightweight seat sample and physical cago rentention test andthree-dimensional H point measurement for further verifying of the feasibility. Finallythe author achieves maximizing the use of the material and lightweight in guaranteeunder the premise of backrest frame stiffness and strength. After the second stageoptimization, seat weight reduce about43.6%.Research achievements of this paper provides the seat manufacturing enterpriseslightweight scheme of the rear seat frame which is suitable and feasible for theengineering practice and has certain practical significance and engineering value.