An upper rail is located along an upper edge of a boarding opening. A center rail extends from a side edge of the boarding opening in a direction away from the boarding opening. A lower rail is located along a lower edge of a sliding door. An upper hinge that is guided by the upper rail and a center hinge that is guided by the center rail slide with the sliding door. A lower hinge that is guided by the lower rail is located at each of front and rear side edges of the boarding opening, and does not slide. A lower edge lock mechanism fixes the lower edge of the sliding door to a vehicle body side structure.

A vehicle side structure includes: a vehicle body side structure including a boarding opening through which an occupant gets into and out of a vehicle; a sliding door configured to slide to open and close the boarding opening; an upper support structure; a middle support structure; a lower support structure; and a drive unit located in an upper portion of the vehicle body side structure and configured to drive the sliding door to open and close via at least a part of the upper support structure. The upper support structure, the middle support structure, and the lower support structure are configured to support the sliding door in upper, middle, and lower portions of the vehicle body side structure in a vertical direction of a vehicle such that the sliding door slides, respectively.

A vehicular slide door apparatus includes a guide rail forming a sliding path. A cutout portion in a side wall portion of the sliding path forms an insertion opening for a guide roller. The apparatus includes a fixing portion at a first end portion in the cutout portion, a positioning portion at a second end portion in the cutout portion, a closing member that includes a fixed end fixed to the fixing portion and a free end positioned by the positioning portion and that closes the insertion opening, and a fulcrum forming portion forming a rotation fulcrum for the closing member. The fulcrum forming portion generates biasing force of displacing the free end outward. The free end is positioned in contact against the positioning portion located on an outer side of the sliding path. Thereby, the free end and the side wall portion form a continuous sliding contact surface.

A hold lock mechanism for a vehicle door, the hold lock mechanism including a grip assembly configured to be mounted on a vehicle body, the grip assembly including a pair of grip members configured to releasably grip a door component and a hook provided on at least one of grip members, and a release assembly mounted on the door component, the release assembly including a release member configured to releasably engage with the hook.

A sliding door system for a vehicle includes a sliding door including an upper edge and a lower edge; a lower roller coupled to the lower edge of the sliding door, the lower roller defining a groove; a lower guide coupled to the lower edge of the sliding door adjacent to the lower roller, the lower guide defining a groove; an upper roller coupled to the upper edge of the sliding door, the upper roller defining a groove; an upper guide coupled to the upper edge of the sliding door adjacent to the upper roller, the upper guide defining a groove; a lower rail affixed to a frame of the vehicle and disposed vertically below the lower edge of the sliding door, wherein the groove of the lower roller is engaged with the lower rail and wherein the groove of the lower guide partially surrounds the lower rail; and an upper rail affixed to a frame of the vehicle and disposed vertically above the upper edge of the sliding door, wherein the groove of the upper roller is engaged with the upper rail and wherein the groove of the upper guide partially surrounds the upper rail.

A guide rail includes: a first rail that has a bottom wall on which a load roller rolls and supports the weight of a sliding door; a second rail that has side walls on which two guide rollers roll and defines a moving direction of the sliding door; and a first restriction part that restricts the motion of the load roller in an axial direction.

A door opening assembly is provided for moving a door of a vehicle between an open position and a closed position. The assembly includes a frame member coupled to the vehicle, a link is coupled to the frame member, and a link arm pivotally coupled to the link. A pivot arm is pivotally coupled to the frame member and a pivot bracket is pivotally coupled to the door and the pivot arm. The pivot bracket includes a slot such that a pin on the link arm slides therethrough. The assembly includes a gear rack and a gear operably coupled to the gear rack. The gear is driven by a motor as the door moves between its open and closed positions. The assembly further includes a guide track coupled to the vehicle and a roller rotatably driven along the guide track as the door moves between its open and closed positions.

A sliding/swing complex door for a vehicle includes a sliding door configured to be opened upon a first operation of an outside handle positioned on an outside of the sliding door, a swing door configured to be integrated and opened with the sliding door upon a second operation of the outside handle, and a fixing unit configured to be opened in such a way to be integrated and rotated with the swing door in a state in which the sliding door is fully opened.

A door roller includes a carriage member comprising a plurality of bores, and a plurality of roller assemblies connected to the carriage member, each roller assembly of the plurality of roller assemblies including a pivot bearing rotatably disposed within a bore of the plurality of bores and a pair of rollers coupled to the pivot bearing. Each wheel assembly is configured to pivot relative to the carriage member.

A link mechanism for a vehicle door is provided. The link mechanism includes a body having a first end portion facing a vehicle body and a second end portion facing a vehicle door and a first mounting member that is mounted on the vehicle body, and rotatably connected to the first end portion of the body through a first shaft. A second mounting member is mounted on the vehicle door, and is rotatably connected to the second end portion of the body through a second shaft. A rotation restricting unit selectively restricts a rotation of the second mounting member.