FIELD OF INVENTION:
[001] The present subject matter described herein, relates to roof rear end tailgate mounting region in vehicle, and, in particularly, to a bracket structure which is mounted over hinge reinforcement at tailgate hinge mounting location to provide strength by distributing stress across tailgate hinge bolt location in vehicle.
BACKGROUND AND PRIOR ART:
[002] In hatch back and SUV vehicles, tailgates open and close along rear roof panel. Generally, the tailgate is hinged at two locations on the roof panel to perform open and close operations. During the movement, all stress or load of the tailgate is transferred on the tailgate hinge bolt location through tailgate hinge. In order to provide strength at the tailgate hinge bolt location at rear end of the vehicle, a reinforcement is provided.. The reinforcement at the tailgate hinge bolt location may not uniformly distribute stress in all direction due to which there are cracks on the roof panel. In order to provide more strength to the tailgate hinge bolt location, a bracket is provided over the hinge reinforcement to distribute the stress.
[003] Fig. 1 and Fig. 2 illustrate location of tailgate hinge bolt location in the vehicle. Loads at tailgate hinge bolt location are shared using brace supports provided in the tailgate hinge bolt location. The bracket 200 is connected to the roof panel 198 and hinge reinforcement 199 by bolt at the center and spots welds at the periphery as shown in Figure 2. The bracket 200 is spot welded near the center bolt location. Figure 3a and 3b illustrate the cross section of the tailgate hinge mounting location. The existing brackets have several disadvantages which are:
[004] Due to inertia of tailgate and other vehicle loads, there is stress concentration near the bolt location which causes panel failure near the bolt.
[005] Spot welds close to the bolt location also experience high stress, making them prone to failure in physical testing. Therefore, the relative displacement between the panels, such as hinge reinforcement and the roof panel at hinge bolt location is high which further deteriorates the performance.
[006] In view of the above, it is beneficial to have a bracket structure that distributes the load and stress uniformly over the hinge reinforcement and the roof panel to improve the strength and durability at tailgate hinge bolt location. Therefore, there is a need in the art to provide a bracket structure for the tailgate hinge bolt location that is more simple and inexpensive, and which can be placed in the existing vehicle to reduce the existing above mentioned problems.
SUMMARY OF THE INVENTION:
[007] The present subject matter herein relates to a structure of the vehicle rear body where tailgate hinge is mounted. The tailgate hinge is mounted at roof panel of the vehicle at rear end. The vehicle rear body structure has a hinge reinforcement which is welded on the roof panel for providing strength to the tailgate hinge. Further, a brace member structure or a bracket structure (hereinafter called as bracket structure) is spot welded on the hinge reinforcement to provide additional strength and durability at hinge bolt location. The present bracket structure distributes the stress of the tailgate hinge uniformly across the hinge reinforcement and the roof panel of the vehicle. The bracket structure is in rectangular shape which has rectangular base where long side of the rectangular base is mounted in the direction of the vehicle. The bracket structure has at least three legs which extend from the rectangular base in three different planes. Each leg from the at least three legs is spot welded on the hinge reinforcement in three different directions or planes to uniformly distribute the stress of the tailgate hinge. Further, the bracket structure has a flange which extends rearwardly away from the rectangular base and towards front end of the vehicle. The flange is spot welded to the roof panel of the vehicle. Accordingly, the bracket structure is mounted on at least four locations where three are on the hinge reinforcement to distribute stress and one on the roof panel to prevent relative motion of the bracket structure with the hinge reinforcement to avoid cracks in the roof panel. The bracket structure has a dumbbell shaped bead structure at center of the rectangular base to cover stress concentrated hinge bolt location where stress level is maximum. The dumbbell shaped bead structure provides additional stiffness to the bracket structure and reduces the stress on the hinge reinforcement.
[008] In order to further understand the characteristics and technical contents of the present subject matter, a description relating thereto will be made with reference to the accompanying drawings. However, the drawings are illustrative only but not used to limit scope of the present subject matter.
BRIEF DESCRIPTION OF THE DRAWINGS
[009] It is to be noted, however, that the appended drawings illustrate only typical embodiments of the present subject matter and are therefore not to be considered for limiting of its scope, for the invention may admit to other equally effective embodiments. The detailed description is described with reference to the accompanying figures. In the figures, the left-most digit(s) of a reference number identifies the figure in which the reference number first appears. The same numbers are used throughout the figures to reference like features and components. Some embodiments of system or methods in accordance with embodiments of the present subject matter are now described, by way of example, and with reference to the accompanying figures, in which:
[0010] Fig. 1 illustrates location of the brace member in tailgate hinge mounting location in vehicles;
[0011] Fig. 2 illustrates structure of existing brace member as known in the art;
[0012] Fig. 3a and 3b illustrate structure of existing brace member and cross section view of the mounted brace member at tailgate hinge mounting location, respectively of the figure 2;
[0013] Fig. 4 illustrates structure and mounting of brace member or bracket structure, in accordance with an embodiment of the present subject matter;
[0014] Fig. 5 illustrates mounting of the brace member structure (bracket structure) at four locations, in accordance with an embodiment of the present subject matter; and
[0015] Fig. 6 illustrates cross section of the mounted brace member at the tailgate hinge mounting location, in accordance with an embodiment of the present subject matter.
[0016] The figures depict embodiments of the present subject matter for the purposes of illustration only. A person skilled in the art will easily recognize from the following description that alternative embodiments of the structures and methods illustrated herein may be employed without departing from the principles of the disclosure described herein.
DESCRIPTION OF THE PREFERRED EMBODIMENTS:
[0017] The present subject matter herein relates to a structure of the vehicle rear body where tailgate hinge is mounted. The tailgate hinge is mounted at roof panel of the vehicle at rear end. The vehicle rear body structure has a hinge reinforcement which is welded on the roof panel for providing strength to the tailgate hinge. Further, a brace member structure or a bracket structure (herein after called as bracket structure) is spot welded on the hinge reinforcement to provide additional strength and durability at hinge bolt location. The present bracket structure distributes the stress of the tailgate hinge uniformly across the hinge reinforcement and the roof panel of the vehicle. The bracket structure is in rectangular shape which has rectangular base where long side of the rectangular base is mounted in the direction of the vehicle. The bracket structure has at least three legs which extend from the rectangular base in three different planes. Each leg from the at least three legs is spot welded on the hinge reinforcement in three different directions or planes to uniformly distribute the stress of the tailgate hinge. Further, the bracket structure has a flange which extends rearwardly away from the rectangular base and towards front end of the vehicle. The flange is spot welded to the roof panel of the vehicle. Accordingly, the bracket structure is mounted on at least four locations where three are on the hinge reinforcement to distribute stress and one on the roof panel to prevent relative motion of the bracket structure with the hinge reinforcement to avoid cracks in the roof panel. The bracket structure has a dumbbell shaped bead structure at center of the rectangular base to cover stress concentrated hinge bolt location where stress level is maximum. The dumbbell shaped bead structure increases the stiffness of the bracket structure and reduces the stress on the hinge reinforcement. Further, mounting of the bracket structure with the hinge reinforcement and the roof panel at four different locations restrict the panels’ relative motion and distribute the stress uniformly on the roof panel.
[0018] It should be noted that the description and figures merely illustrate the principles of the present subject matter. It should be appreciated by those skilled in the art that conception and specific embodiment disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present subject matter. It should also be appreciated by those skilled in the art that by devising various arrangements that, although not explicitly described or shown herein, embody the principles of the present subject matter and are included within its spirit and scope. Furthermore, all examples recited herein are principally intended expressly to be for pedagogical purposes to aid the reader in understanding the principles of the present subject matter and the concepts contributed by the inventor(s) to furthering the art, and are to be construed as being without limitation to such specifically recited examples and conditions. The novel features which are believed to be characteristic of the present subject matter, both as to its organization and method of operation, together with further objects and advantages will be better understood from the following description when considered in connection with the accompanying figures.
[0019] These and other advantages of the present subject matter would be described in greater detail with reference to the following figures. It should be noted that the description merely illustrates the principles of the present subject matter. It will thus be appreciated that those skilled in the art will be able to devise various arrangements that, although not explicitly described herein, embody the principles of the present subject matter and are included within its scope
[0020] Figure 4 illustrates structure and mounting of brace member or bracket structure, in accordance with the present subject matter. The vehicle rear body structure has tailgate panel, roof panel, and side pillars. The vehicle rear body structure has mounting locations where tailgate hinge is mounted. The tailgate of the vehicle is opened and closed along the direction of the tailgate hinge. Therefore, all stress of the tailgate goes to tailgate hinge bolt location which is provided on the roof panel of the vehicle. The present structure uniformly distributes the stress of the tailgate around the tailgate hinge bolt location to avoid any damage on the roof panel. The present vehicle rear body structure has a roof panel 398 and a hinge reinforcement 399 which is mounted on the roof panel. Further, a brace member structure or a bracket structure 400 (hereinafter called as bracket structure) is mounted on the hinge reinforcement 399 to provide strength and durability at tailgate hinge bolt location 406.
[0021] The bracket structure 400 has a rectangular base 400a and at least three legs 401, 402, 403. The at least three legs 401, 402, 403 extends from the rectangular base 400a in three different planes or three different directions, such as X, Y, Z direction. Further, each leg from the at least three legs 401, 402, 403 is mounted at a distance away from hinge bolt location 406 on the hinge reinforcement 399 which is mounted on the rear roof panel 398. The bracket structure 400 further comprises a flange 405 which extends rearwardly away from the rectangular base 400a towards front end of the vehicle. The flange 405 is mounted on the rear roof panel 398 to prevent relative motion of the bracket 400 with the hinge reinforcement 399. The bracket structure 400 has a dumbbell shaped bead structure 404 at center of the rectangular base 400a to cover stress concentrated hinge bolt location 406 where stress level is maximum, as shown in the figure 4 and 5. The dumbbell shaped bead structure 404 provides additional stiffness to the bracket structure 400 and reduces the stress on the hinge reinforcement 399 applied by the tailgate hinge. The hinge bolt location 406 is concentric with the hinge bolt location of the hinge reinforcement 399 and the roof panel 398. The bracket structure 400 is mounted on the hinge reinforcement 399 and the roof panel 398 by means of spot welding.
[0022] As shown in the figure 5, the bracket structure 400 distributes the stress of the tailgate hinge across the hinge reinforcement 399 and the roof panel 398 of the vehicle. The bracket structure 400 is mounted on the hinge reinforcement 399 and roof panel 398 in vertical direction to arrest the relative motion between the hinge reinforcement, bracket structure and the roof panel for better stress distribution. The connections of the bracket structure 400 with the hinge reinforcement 399 and the roof panel 398 have been done with spot welding and bolting at the center. The bracket structure 400 is made of sheet metal which has less thickness and high strength.
[0023] Figure 6 illustrates cross section of the present bracket structure mounted in the tailgate hinge mounting location. Due to the novel and unique structure of the bracket structure, spot welds can be provided at a distance from hinge bolt location which helps in the better load distribution. Further, the dumbbell shaped bead structure increases the stiffness at the stress concentrated hinge bolt location. Further, at least three legs facilitate spot welding of the bracket structure with hinge reinforcement in multiple planes away from high stress hinge bolt location resulting in better load sharing across the panels.
[0024] The bracket structure 400 can be optimized with minimum required part thickness to achieve weight reduction along with minimizing the stress around the hinge reinforcement. The bracket structure 400 can be optimized with minimum flat area in flanges or legs required for spot welding to achieve weight reduction along with minimizing the stress around the hinge reinforcement. The present bracket structure can be adopted in different models of the vehicle for reduction of stresses in the tailgate hinge bolt location.
[0025] Although embodiments for the present subject matter have been described in language specific to structural features, it is to be understood that the present subject matter is not necessarily limited to the specific features described. Rather, the specific features and methods are disclosed as embodiments for the present subject matter. Numerous modifications and adaptations of the system/component of the present invention will be apparent to those skilled in the art, and thus it is intended by the appended claims to cover all such modifications and adaptations which fall within the scope of the present subject matter.

We Claim:
1. A vehicle rear body structure for tailgate hinge mounting to distribute stress, the vehicle rear body structure comprising:
the rear roof panel (398) at rear side of the vehicle; and
a hinge reinforcement (399) mounted on the rear roof panel (398) along with pillars of the vehicle at the tailgate hinge mounting location,
characterized in that:
a bracket structure (400) mounted over the hinge reinforcement (399) to distribute tailgate hinge stress on the rear roof panel (398), the bracket structure (400) comprising:
a rectangular base (400a);
at least three legs (401, 402, 403) extending in different planes from the rectangular base (400a), wherein each leg from the at least three legs (401, 402, 403) is mounted at a distance away from hinge bolt location on the hinge reinforcement (399) to distribute the tailgate hinge stress.

2. The vehicle rear body structure as claimed in claim 1, wherein the rear roof panel (398), the hinge reinforcement (399) and the bracket structure (400) has concentric hinge bolt location (406).

3. The vehicle rear body structure as claimed in claim 1, wherein the bracket structure (400) further comprises a flange (405) which extend rearwardly away from the rectangular base (400a) and mounted on the rear roof panel (398).
4. The vehicle rear body structure as claimed in claim 2, wherein the rectangular base (400a) has a dumbbell shaped bead structure (404) at center to cover stress concentrated on the hinge bolt location (406).

5. The vehicle rear body structure as claimed in claim 1, wherein the mounting means for the bracket structure (400) on the hinge reinforcement (399) and the rear roof panel (398) is spot welding.

6. The vehicle rear body structure as claimed in claim 1, wherein the at least three legs (401, 402, 403) of the bracket structure (400) extend in three different planes and spot welded on the hinge reinforcement (399) for load sharing across the rear roof panel (398) of the tailgate hinge.

7. A bracket structure (400) for distributing stress of tailgate hinge mounting location, the bracket structure (400) comprising:
a rectangular base (400a);
at least three legs (401, 402, 403) extending from the rectangular base (400a) in three different planes, wherein each leg of the at least three legs (401, 402, 403) mounted at a distance away from hinge bolt location (406) on a hinge reinforcement (399) which is mounted on rear roof panel (398);
a flange (405) extending rearwardly away from the rectangular base (400a) and mounted on the rear roof panel (398) to prevent relative motion of the bracket structure (400) with the hinge reinforcement (399).

8. The bracket structure (400) as claimed in the claim 7, wherein the rectangular base (400a) has a dumbbell shaped bead structure (404) at center to cover stress concentrated the hinge bolt location (406).
9. The bracket structure (400) as claimed in the claim 7, wherein the bracket structure (400) is made of sheet metal having high strength.

10. The bracket structure (400) as claimed in the claim 7, wherein the at least three legs (401, 402, 403) of the bracket structure (400) extend in three different planes and spot welded on the hinge reinforcement (399) for load sharing across the rear roof panel (398) of the tailgate hinge.