Upper rail structure for vehicle

1 . A vehicle-body-integrated upper rail structure, which is provided at an upper side of a door opening portion formed in a vehicle body, the vehicle-body-integrated upper rail structure comprising:

a rail portion including a rail opening that provides a sliding route for a door and is formed in a longitudinal direction of the vehicle body;

a pillar connection portion extending from the rail portion toward a lower side of the vehicle body and connected to a pillar; and

a roof rail connection portion extending from an upper end portion of the rail portion toward a center portion of the vehicle body and connected to a roof rail of the vehicle body,

wherein the rail opening is formed through the rail portion in an upward and downward direction, and

wherein the rail opening is formed convex toward an outside of the vehicle body in the longitudinal direction of the vehicle body.

2 . The upper rail structure of claim 1 , further including a vehicle body connection portion extending from the upper end portion of the rail portion in the longitudinal direction of the vehicle body and connected to the vehicle body.

3 . The upper rail structure of claim 1 ,

wherein the pillar includes a B-pillar and a C-pillar,

wherein the pillar connection portion includes:

a B-pillar connection portion extending from a lower end portion of the rail portion toward the lower side of the vehicle body and connected to the B-pillar; and

a C-pillar connection portion extending from the lower end portion of the rail portion toward the lower side of the vehicle body and connected to the C-pillar.

4 . The upper rail structure of claim 1 , wherein a protrusion is formed to protrude toward an inside of the rail opening so that a bearing connected to a door arm is mounted on the protrusion and rolls on the protrusion.

5 . The upper rail structure of claim 1 , wherein the roof rail connection portion is formed concave toward the lower side of the vehicle body to be connected to and overlap an end portion of the roof rail.

6 . The upper rail structure of claim 5 , wherein an end portion of the roof rail connection portion is connected to the end portion of the roof rail by a blind rivet.

7 . The upper rail structure of claim 2 , wherein the vehicle body connection portion includes a stepped tunnel portion to be connected to and overlap an end portion of the vehicle body.

8 . The upper rail structure of claim 7 ,

wherein the vehicle body is inserted into and connected to the stepped tunnel portion of the vehicle body connection portion.

9 . The upper rail structure of claim 8 ,

wherein an upper side of the vehicle body is coupled to an upper side of the vehicle body connection portion by a self-piercing rivet (SPR), and a lower side of the vehicle body is coupled to a lower side of the vehicle body connection portion by a blind rivet.

10 . The upper rail structure of claim 3 , wherein the B-pillar connection portion and the C-pillar connection portion respectively include stepped tunnel portions to be connected to and overlap an end portion of the B-pillar and an end portion of the C-pillar.

11 . The upper rail structure of claim 10 ,

wherein the B-pillar is inserted into and connected to the stepped tunnel portion of the B-pillar connection portion.

12 . The upper rail structure of claim 11 ,

wherein an external side of the B-pillar is coupled to an external side of the B-pillar connection portion by a flow drill screw (FDS) and an internal side of the B-pillar is coupled to an internal side of the B-pillar connection portion by a blind rivet.

13 . The upper rail structure of claim 10 , wherein the C-pillar is inserted into and connected to the stepped tunnel portion of the C-pillar connection portion.

14 . The upper rail structure of claim 10 , wherein the C-pillar is connected to the stepped tunnel portion of the C-pillar connection portion by an FDS.

15 . The upper rail structure of claim 10 , wherein a guard bracket is coupled to cover an external surface of the B-pillar connection portion and an external surface of the C-pillar connection portion.

16 . The upper rail structure of claim 14 , wherein the guard bracket is coupled to the external surface of the B-pillar connection portion and the external surface of the C-pillar connection portion by FDSs.