Movable Parts

     The term movable parts refers to body macro-components which have the task ofopening and closing the body compartments，i. e. doors (passenger compartment)，hood(engine compartment)，deck-lid (luggage compartment)，liftgate (passenger and luggagecompartments) and sunroof.

    Side Doors

    On average，car doors are operated between 10，000 and 50，000 times during itslifetime. In this operation, the customer applies a load，registering either a pleasant orunpleasant sensation associated with a perceived noise timbre（ soft, smooth or hard,metallic closing，silent or squeaking opening and so on) depending on the interactionbetween the different constituent components，namely: the door frame，the weatherstrips，the locking devices，the handles，all door-fitted components featuring specificfunction (glass, window regulators，electric actuators，rear mirrors，loudspeakers，innertrim) and interface.

    Sliding Doors

    Sliding doors have nearly rectilinear rails, in which trolleys with one or more roller(depending on the specified constraints) slides. The rails can be on the roofs or sills or onthe body sides (in which case the trolleys are fitted to the doors) or on the doors (in whichcase the trolleys are hinged to the bodies)．

    In order to establish a statically determined overall constraint condition，threeconnecting, non-aligned devices should be designed which can be located on three or twoindependent rails（each of them leaving only one freedom degree，along the principalaxis)．

    Doors of this type are usually adopted on commercial and industrial vehicles bodysides with straight side surfaces which enable three rails at different heights to be located：low (sills)，middle (belt line) and up (roof).