Description:FIELD OF THE INVENTION
[001] The present invention relates to a frame structure of a vehicle. More particularly, rear frame structure mounted on a side tube of the frame structure.

BACKGROUND OF THE INVENTION
[002] Apart from performance and mileage requirements of a user in a vehicle for example a scooter vehicle, expectation on a larger leg space, improved utility space and improved ride quality has also been paramount. Typically, in the scooter vehicle, internal parts such as a frame member, an energy storage device and the like are covered through style panels. Such scooter vehicles also include a utility box which is configured to accommodate personal belongings of the user.
[003] In order to meet the requirement of the larger utility space, vehicle manufacturers may increase size of the utility box. However, increasing size of the utility box creates a problem for functioning of interface parts such as frame numbering, style panel mountings and seat lock mountings surrounding the utility box.
[004] To overcome the problem associated with functioning of interface parts, the style panels have to be extended in a rear direction of the vehicle. However, such an extension of style panels, increases overall size and weight of the vehicle which is undesirable. Additionally, the frame member of the conventional scooter vehicles may be characterized with lesser rigidity to support vertical loads. Moreover, the vehicle numbering position or a frame number (or chassis number) of the vehicle is typically provided on an outside portion of the vehicle. Such a location of the frame number is prone to accessibility of mud or muddy water, which makes it difficult to trace the frame number.
[005] In view of the above, there is a need for a frame structure of a vehicle, which addresses one or more limitations stated above.

SUMMARY OF THE INVENTION
[006] In one aspect, a rear frame structure for a vehicle is disclosed. The rear frame structure comprises a top structural part extending in a lateral direction of the vehicle and a bottom structural part also extending in the lateral direction of the vehicle. The bottom structural part is positioned below the top structural part and is coupled to the top structural part in an upward-downward direction to form an enclosure, wherein the top structural part and the bottom structural part are connected to side tubes of the vehicle for enhancing rigidity of the rear frame structure.
[007] In an embodiment, the top structural part is provided with a plurality of top flanges for mounting onto a top portion of the side tubes. The plurality of top flanges comprises a first top flange extending along the lateral direction of the vehicle, a second top flange extending along the lateral direction of the vehicle and positioned parallelly to the first top flange and a third top flange adapted to engage top portions of the first top flange and the second top flange. Further, a fourth top flange extends along a longitudinal direction of the vehicle and is adapted to tangentially engage a right side portion of the first top flange, the second top flange and the third top flange. A fifth top flange extends along the longitudinal direction of the vehicle and is adapted to tangentially engage a left side portion of the first top flange, the second top flange and the third top flange.
[008] In an embodiment, the fourth top flange is adapted to diverge angularly from the right side portion of the first top flange, the second top flange and the third top flange. The fourth top flange upon engagement with the right side portion provides a right side projection to the top structural part, wherein the right side projection is adapted to engage on the top portion of the side tube for mounting of the top structural part on the top portion of the side tube.
[009] In an embodiment, the fifth top flange is adapted to diverge angularly from the left side portion of the first top flange, the second top flange and the third top flange. The fifth top flange upon engagement with the left side portion provides a left side projection to the top structural part, wherein the left side projection is adapted to engage on the top portion of the side tube for enabling mounting of the top structural part on the top portion of the side tube.
[010] In an embodiment, the third top flange is provided with a frame number of the vehicle.
[011] In an embodiment, the third top flange is provided with a provision for enabling mounting of a pillion handle of the vehicle.
[012] In an embodiment, the bottom structural part is provided with a plurality of bottom flanges for mounting onto a side portion of the side tubes. The plurality of bottom flanges comprises a first bottom flange extending along the lateral direction of the vehicle, a second bottom flange extends along the lateral direction of the vehicle and is positioned parallelly to the first bottom flange. A third bottom flange is adapted to tangentially engage bottom portions of the first bottom flange and the second bottom flange.
[013] In an embodiment, the first bottom flange engages with the first top flange and the second bottom flange engages with the second top flange for enabling mounting of the bottom structural part with the top structural part.
[014] In an embodiment, the first bottom flange and the second bottom flange are defined to with a Z-shaped profile for facilitating mounting with the first top flange and the second bottom flange.
[015] In an embodiment, the third bottom flange is defined with a curved profile such that ends of the third bottom flange are curved to engage the side portion of the side tubes and a central portion of the third bottom flange is positioned above a top portion of the side tubes.
[016] In an embodiment, a height of the top structural part is greater than a width of the top structural part.
[017] In an embodiment, a width of the bottom structural part is greater than a height of the bottom structural part.
[018] In another aspect, the frame structure for a vehicle is disclosed. The frame structure comprises a head pipe and a main tube that extends downwardly from the head pipe and terminates at a rear cross tube. Side tubes extend rearwardly from the rear cross tube and the rear frame structure is mounted onto the side tubes. The rear frame structure comprises the top structural part extending in the lateral direction of the vehicle and the bottom structural part extending in the lateral direction of the vehicle. The bottom structural part is positioned below the top structural part and is coupled to the top structural part in an upward-downward direction to form the enclosure, wherein the top structural part and the bottom structural part are connected to side tubes of the vehicle for enhancing rigidity of the rear frame structure.

BRIEF DESCRIPTION OF THE DRAWINGS
[019] Reference will be made to embodiments of the invention, examples of which may be illustrated in accompanying figures. These figures are intended to be illustrative, not limiting. Although the invention is generally described in context of these embodiments, it should be understood that it is not intended to limit the scope of the invention to these particular embodiments.
Figure 1 is a schematic view of a vehicle without outer panels, in accordance with an exemplary embodiment of the present disclosure.
Figure 2 is a schematic view of the vehicle without the outer panels and wheels, in accordance with an exemplary embodiment of the present disclosure.
Figure 3 is a schematic view of the vehicle without the wheels, in accordance with an exemplary embodiment of the present disclosure.
Figure 4 is a perspective view of a frame structure of the vehicle including a utility box, in accordance with an exemplary embodiment of the present disclosure.
Figure 5 is a left side view of the frame structure of the vehicle including the utility box, in accordance with an exemplary embodiment of the present disclosure.
Figure 6 is a perspective view of the frame structure of the vehicle, in accordance with an exemplary embodiment of the present disclosure.
Figure 7 is a perspective view of a rear frame structure mounted on the frame member, in accordance with an exemplary embodiment of the present disclosure.
Figure 8 is a perspective view of the rear frame structure, in accordance with an exemplary embodiment of the present disclosure.
Figure 9 is a sectional view of the rear frame structure, in accordance with an exemplary embodiment of the present disclosure.
Figure 10 is a perspective view of the frame structure including an outer panel and a wiring harness looping around the rear frame structure, in accordance with an exemplary embodiment of the present disclosure.
Figure 11 is a perspective view of the wiring harness provided between the frame member and the outer panel, and looping around the rear frame structure, in accordance with an exemplary embodiment of the present disclosure.
Figure 12 is a rear sectional view of the frame member including the outer panels, in accordance with an exemplary embodiment of the present disclosure.
Figure 13 is a schematic view of the rear frame structure mounted to the frame structure of the vehicle, in accordance with an exemplary embodiment of the present disclosure.

DETAILED DESCRIPTION OF THE INVENTION
[020] Various features and embodiments of the present invention here will be discernible from the following further description thereof, set out hereunder.
[021] Figure 1 illustrates a schematic view of a two-wheeled vehicle 200, in accordance with an embodiment of the present disclosure. As an example, the two-wheeled vehicle 200 is a scooter-type vehicle. The vehicle 200 may include an engine (not shown) and a transmission assembly (not shown) that is disposed behind a floorboard 218 and below a seat assembly (not shown) and/or a storage box 220 (shown in Figure 4). In an embodiment, the vehicle 200 may include an electric motor (not shown) for providing motive force required for movement of the vehicle 200. The vehicle 200 has a front wheel 222, a rear wheel 224 and a frame structure 210.
[022] The frame structure 210 comprises a head pipe 212 for supporting a steering shaft (not shown). A main tube 214 extends downwardly from the head pipe 212 and terminates at a rear cross tube 216 (shown in Figures 2, 3, 4, 5 and 6). In an embodiment, the main tube 214 extends downwardly upto a front cross tube 226 and thereafter extends longitudinally along a longitudinal direction X-X’ of the vehicle 200 upto the rear cross tube 216. The portion between the front cross tube 226 and the rear cross tube 216 is provided with the floorboard 218. The floorboard 218 may be adapted to support a battery module 230a, 230b of the vehicle 200, which is adapted to power the electric motor for driving the vehicle 200. In an embodiment, the battery module 230a is supported on the floorboard 218, while the battery module 230b is supported at a rear end of the floorboard 210 or over the rear cross tube 216. In an embodiment, the longitudinal direction X-X’ refers to the direction about the front wheel 222 and the rear wheel 224 of the vehicle 200.
[023] Further, side tubes 202a, 202b extend rearwardly from the rear cross tube 216. The side tubes 202a, 202b act as a support structure for the storage box 220 (as shown in Figures 4 and 5) and other ancillary components of the vehicle 200. The side tubes 202a, 202b also support the seat assembly of the vehicle 200. In an embodiment, the side tube 202a is a right side tube extending rearwardly from a right side of the rear cross tube 216, while the side tube 202b is a left side tube extending rearwardly from a left side of the rear cross tube 216. In an embodiment, the side towards the direction Y in Figure 1 is the right side of the vehicle 200, while the side towards the direction Y’ in Figure 1 is the left side of the vehicle 200. To the side tubes 202a, 202b, a rear frame structure 100 is mounted. The rear frame structure 100 will be described in detail in description pertaining to Figures 7-13.
[024] A front suspension 228 is attached to the steering shaft through a lower bracket (not shown). The front suspension 228 supports the front wheel 222. An upper portion of the front wheel 222 is covered by a front fender (not shown) mounted to the front suspension 228. In an embodiment, the front fender is movable along with the front wheel 222, during travel over undulations on a road surface. A handlebar 232 is fixed to upper bracket (not shown) and can rotate about the steering shaft for turning the vehicle 200. A headlight (not shown) and an instrument cluster (not shown) may be arranged on an upper portion of the head pipe 212.
[025] Further, a rear suspension 234 is provided to the rear wheel 224 for dampening the vibrations induced during travel of the vehicle 200 over undulations on the road surface. A taillight unit (not shown) is disposed at the end of the vehicle 200 and at the rear of the seat assembly. A grab rail (not shown) is also provided for facilitating grip and/or balance to a rider (not shown) on the vehicle 200 during movement. The rear wheel 224 is arranged below the seat assembly and is adapted to receive motive force from the engine or the electric motor. A rear fender (not shown) may be disposed above the rear wheel 224.
[026] In an embodiment, the frame structure 210 is also adapted to support outer panels 236 (as shown in Figures 3, 10, 11 and 12), which are provided to conceal components of the vehicle 200. As an example, the outer panels 236 typically provided behind the floorboard 218 are provided. As such, the outer panels 236 depicted in the Figures should not be considered as the only outer panels 236 provided to the vehicle 200.
[027] Referring to Figures 7-9 in conjunction with Figures 1-6, the rear frame structure 100 of the vehicle 200 is depicted. The rear frame structure 100 is mounted at a rear side (not shown) of the side tubes 202a, 202b and is adapted to improve overall strength of the frame structure 210 or rear side of the frame structure 210. The rear frame structure 100 is adapted to enhance packaging space in the vehicle 200 for accommodating the ancillary components along with a larger storage box 220, without increasing the size of the vehicle 200.
[028] The rear frame structure 100 comprises a top structural part 102 extending in a lateral direction Y-Y’ of the vehicle 200. In an embodiment, the lateral direction Y-Y’ is perpendicular to the longitudinal direction X-X’. The top structural part 102 is adapted to be mounted onto a top portion 204a, 204b of the side tubes 202a, 202b. The top structural part 102 comprises a plurality of top flanges (106, 108, 110, 112, 114) for enabling mounting of the top structural part 102 onto the top portion 204a, 204b of the side tubes 202a, 202b. In the present embodiment, the plurality of top flanges is five in number.
[029] The plurality of top flanges 106, 108, 110, 112, 114 comprises a first top flange 106 extending along the lateral direction Y-Y’ of the vehicle 200. A second top flange 108 extends along the lateral direction Y-Y’ of the vehicle 200 and is positioned parallelly to the first top flange 106. A third top flange 110 is also provided which is adapted to engage top portions 106a, 108b (shown in Figure 9) of the first top flange 106 and the second top flange 108.
[030] Further, a fourth top flange 112 extends along the longitudinal direction X-X’ of the vehicle 200 and is adapted to tangentially engage a right side portion of the first top flange 106, the second top flange 108 and the third top flange 110. The fourth top flange 112 is adapted to diverge angularly from the right side portion of the first top flange 106, the second top flange 108 and the third top flange 110. Accordingly, length of the first top flange 106, the second top flange 108 and the third top flange 110 at the right side portion, is considered based on the angular divergence of the fourth top flange 112. The fourth top flange 112, is thus adapted to cover the right side portion of the first top flange 106, the second top flange 108 and the third top flange 110 while also providing a right side projection 116 to the top structural part 102. The right side projection 116 ensures that a length of the first top flange 106, the second top flange 108 and the third top flange 110 at the right side portion extends beyond the side portion 206a of the side tube 202a. As such, the right side projection 116 enables mounting of the top structural part 102 on the top portion 204a.
[031] In an embodiment, tangential engagement of the fourth top flange 112 with the right side portion of the first top flange 106, the second top flange 108 and the third top flange 110 pertains to engagement at right side terminal or peripheral surface of the first top flange 106, the second top flange 108 and the third top flange 110. In an embodiment, the angular divergence of the fourth top flange 112 is selected as per design feasibility and requirement of the top structural part 102.
[032] Also, a fifth top flange 114 extends along the longitudinal direction X-X’ of the vehicle 200 and is adapted to tangentially engage a left side portion of the first top flange 106, the second top flange 108 and the third top flange 110. The fifth top flange 114 is adapted to diverge angularly from the left side portion of the first top flange 106, the second top flange 108 and the third top flange 110. Accordingly, the length of the first top flange 106, the second top flange 108 and the third top flange 110 towards the left side portion is considered based on the angular divergence of the fifth top flange 114. The fifth top flange 114 is thus adapted to cover the left side portion of the first top flange 106, the second top flange 108 and the third top flange 110 while also providing a left side projection 118 to the top structural part 102. The left side projection 118 ensures that the length of the first top flange 106, the second top flange 108 and the third top flange 110 at the left side portion, extends beyond the side portion 206b of the side tube 202b. As such, the left side projection 118 is adapted to engage on the top portion 204b of the side tube 202b for enabling mounting of the top structural part 102 on the top portion 204b of the side tube 202b. In an embodiment, the angular divergence of the fifth top flange 114 is selected as per design feasibility and requirement of the top structural part 102.
[033] In an embodiment, the tangential engagement of the fourth top flange 112 and the fifth top flange 114 at the right and left side portions of the first top flange 106, the second top flange 108 pertains to seamless engagement at terminal or peripheral surfaces at the right and left side portions. Such an engagement ensures a seamless construction of the top structural part (for e.g., as shown in Figure 13).
[034] In an embodiment, the first top flange 106 is provided with a frame number 208 (or chassis number) of the vehicle 200. In an embodiment, the frame number 208 is engraved on the first top flange 106. Such a location of the frame number 208 enables a user of the vehicle 200 to view or access the frame number 208 through an opening (not shown) provided on the storage box 220, thereby mitigating the need for dismantling components of the vehicle 200.
[035] In another embodiment, a provision 120 is provided on the third top flange 110 for enabling mounting of a grab rail (not shown) of the vehicle 200. In the present embodiment, the provision 120 is a protrusion provided on the third top flange 110 that may be engaged with an opening in the grab rail for mounting. Alternatively, the provision 120 may be a projection or a slot on the third top flange 110 which may be engaged with a protrusion on the grab rail for mounting.
[036] In an embodiment, the top structural part 102 is defined with a height H1 (as shown in Figure 9) which is greater than a width W1 of the top structural part 102. Such a configuration ensures high vertical cross-sectional properties to the rear frame structure 100. In an embodiment, ratio of height H1 with width W1 is greater than 4:3 (or 1.3). In another embodiment, ratio of height H1 with width W1 is 5:3.
[037] Further, the rear frame structure 100 comprises a bottom structural part 104 extending in the lateral direction Y-Y’ of the vehicle 200. The bottom structural part 102 is located below the top structural part 102 and is coupled to the top structural part 102 in an upward-downward direction (as shown in Figure 9). The engagement between the bottom structural part 104 and the top structural part 102 forms an enclosure.
[038] The bottom structural part 104 is provided with a plurality of bottom flanges for mounting onto the side portion 206a, 206b of the side tubes 202a, 202b. The plurality of bottom flanges 122, 124, 126 comprises a first bottom flange 122 extending along the lateral direction Y-Y’ of the vehicle 200. The first bottom flange 122 engages with the first top flange 106. A second bottom flange 124 extends along the lateral direction Y-Y’ of the vehicle 200 and is positioned parallelly to the first bottom flange 122. The second bottom flange 124 is adapted to engage with the second top flange 108 for enabling mounting of the bottom structural part 104 with the top structural part 102. In an embodiment, top portions 122a, 124a (as shown in Figure 9) of the first bottom flange 122 and second bottom flange 124 are engaged with the first top flange 106 and the second top flange 108. In an embodiment, the first bottom flange 122 and the second bottom flange 124 are defined with a Z-shaped profile (as shown in Figure 9) for ease of mounting with the first top flange 106 and the second bottom flange 108. The Z-shaped profile facilitates controlled manufacturability, while also controlling positional variation of the frame numbering 208 engraved on the first top flange 106. In an embodiment, the mounting between the bottom structural part 104 and the top structural part 102 is based on conventional mounting techniques such as welding, brazing, fastening and the like, as per design feasibility and requirement.
[039] Further, a third bottom flange 126 is also provided in the bottom structural part 104, which is adapted to tangentially engage bottom portions 122b, 124b (shown in Figure 9) of the first bottom flange 122 and the second bottom flange 124. The third bottom flange 126 is also defined with a curved profile (as shown in Figure 8) such that ends of the third bottom flange 126 are curved downwardly to engage the side portion 206a, 206b of the side tubes 202a, 202b, while a central portion of the third bottom flange 126 is positioned above the top portion 204a, 204b of the side tubes 202a, 202b. As such, an arch like profile (as shown in Figure 12) is formed for the third bottom flange 126. Such a configuration of the third bottom flange 126 provides additional space for routing a wiring harness of the vehicle 200. Thus, the third bottom flange 126 enables to route wiring harness below the rear frame structure 100 as well, thereby improving packaging of components in the vehicle 200.
[040] In an embodiment, a width W2 (as shown in Figure 9) of the bottom structural part 104 is greater than a height H2 of the bottom structural part 104. Such a configuration of the bottom structural part 104 ensures a greater horizontal stiffness of the rear frame structure 100.
[041] In an embodiment, the wiring harness of an external charging unit 238 (as shown in Figures 10, 11 and 12) is routed between side portion 206a, 206b and between the fourth top flange 112 and the fifth top flange 114. The routing of the wiring harness of the external charging unit 238 is ensured due to the angular divergence of the fourth top flange 112 and the fifth top flange 114. As such, packaging space for accommodating the wiring harness is enhanced considerably due to the rear frame structure 100.
[042] In an embodiment, the rear frame structure 100 (as shown in Figure 12) is surrounded by vertical wall 220a (shown in Figure 5) of the storage box 220 at a front side, a grab rail or pillion handle at a top side, the external charging unit 238 in a rear side and an electrical box unit (not shown) such as a motor unit at a bottom side.
[043] The claimed invention as disclosed above is not routine, conventional or well understood in the art, as the claimed aspects enable the following solutions to the existing problems in conventional technologies. Specifically, the claimed aspects of the rear frame structure 100 comprising the top structural part 102 and the bottom structural part 104 provides a sleeker and a lightweight design, while enabling the interface parts to be packaged within a style periphery or the outer panel 236 of the vehicle 200. Further, the tangential connections between the plurality of top flanges 106, 108, 110, 112, 114 and the plurality of bottom flanges 122, 124, 126 eases manufacturability of the rear frame structure 100. Also, the width W2 of the bottom structural part 104 is greater than the height H2 of the bottom structural part 104 which ensures a greater horizontal stiffness of the rear frame structure 100. Further, divergence angle of the fourth top flange 112 along with the fifth top flange 114, and the arch-like shape of the third bottom flange 126 enhances packaging space for routing wiring harness.
Reference numerals
100 Rear frame structure
102 Top structural part
104 Bottom structural part
106 First top flange
108 Second top flange
110 Third top flange
112 Fourth top flange
114 Fifth top flange
116 Right side projection
118 Left side projection
120 Provision
122 First bottom flange
124 Second bottom flange
126 Third bottom flange
200 Vehicle
202a, 202b Side tubes
204a, 204b Top portion of side tubes
206a, 206b Bottom portion of side tubes
208 Frame number
210 Frame structure
212 Head pipe
214 Main tube
216 Rear cross tube
218 Floorboard
220 Storage box
220a Vertical wall of storage box
222 Front wheel
224 Rear wheel
226 Front cross tube
228 Front suspension
230a, 230b Battery module
232 Handlebar
234 Rear suspension
236 Outer panels
238 External charging unit
 
, Claims:WE CLAIM:
1. A rear frame structure (100) for a vehicle (200), the rear frame structure (100) comprising:
a top structural part (102) extending in a lateral direction (Y-Y’) of the vehicle (200); and
a bottom structural part (104) extending in a lateral direction (Y-Y’) of the vehicle (200) and positioned below the top structural part (102), the bottom structural part (104) being coupled to the top structural part (102) in an upward-downward direction to form an enclosure,
wherein the top structural part (102) and the bottom structural part (104) are connected to side tubes (202a, 202b) of the vehicle (200) for enhancing rigidity of the rear frame structure (100).

2. The rear frame structure (100) as claimed in claim 1, wherein the top structural part (102) is provided with a plurality of top flanges (106, 108, 110, 112, 114) for mounting onto a top portion (204a, 204b) of the side tubes (202a, 202b), the plurality of top flanges (106, 108, 110, 112, 114) comprising:
a first top flange (106) extending along the lateral direction (Y-Y’) of the vehicle (200);
a second top flange (108) extending along the lateral direction (Y-Y’) of the vehicle (200) and position parallelly to the first top flange (106);
a third top flange (110) adapted to engage top portions (106a, 108b) of the first top flange (106) and the second top flange (108);
a fourth top flange (112) extending along a longitudinal direction (X-X’) of the vehicle (200) and adapted to tangentially engage a right side portion of the first top flange (106), the second top flange (108) and the third top flange (110); and
a fifth top flange (114) extending along the longitudinal direction (X-X’) of the vehicle (200) and adapted to tangentially engage a left side portion of the first top flange (106), the second top flange (108) and the third top flange (110).

3. The rear frame structure (100) as claimed in claim 2, wherein the fourth top flange (112) is adapted to diverge angularly from the right side portion of the first top flange (106), the second top flange (108) and the third top flange (110), the fourth top flange (112) upon engagement with the right side portion provides a right side projection (116) to the top structural part (102), wherein the right side projection (116) is adapted to engage on the top portion (204a) of the side tube (202a) for mounting of the top structural part (102) on the top portion (204a) of the side tube (202a).

4. The rear frame structure (100) as claimed in claim 2, wherein the fifth top flange (114) is adapted to diverge angularly from the left side portion of the first top flange (106), the second top flange (108) and the third top flange (110), the fifth top flange (114) upon engagement with the left side portion provides a left side projection (118) to the top structural part, wherein the left side projection (118) is adapted to engage on the top portion (204b) of the side tube (202b) for enabling mounting of the top structural part (102) on the top portion (204b) of the side tube (202b).

5. The rear frame structure (100) as claimed in claim 2, wherein the first top flange (106) is provided with a frame number (208) of the vehicle (200).

6. The rear frame structure (100) as claimed in claim 2, wherein the third top flange (110) is provided with a provision (120) for enabling mounting of a pillion handle of the vehicle (200).

7. The rear frame structure (100) as claimed in claim 1, wherein the bottom structural part (104) is provided with a plurality of bottom flanges (122, 124, 126) for mounting onto a side portion (206a, 206b) of the side tubes (202a, 202b), the plurality of bottom flanges (122, 124, 126) comprising:
a first bottom flange (122) extending along the lateral direction (Y-Y’) of the vehicle (200);
a second bottom flange (124) extending along the lateral direction (Y-Y’) of the vehicle (200) and positioned parallelly to the first bottom flange (122); and
a third bottom flange (126) adapted to tangentially engage bottom portions (122b, 124b) of the first bottom flange (122) and the second bottom flange (124).

8. The rear frame structure (100) as claimed in claim 7, wherein the first bottom flange (122) engages with the first top flange (106) and the second bottom flange (124) engages with the second top flange (108), for enabling mounting of the bottom structural part (104) with the top structural part (102).

9. The rear frame structure (100) as claimed in claim 7, wherein the first bottom flange (122) and the second bottom flange (124) are defined to with a Z-shaped profile for facilitating mounting with the first top flange (106) and the second bottom flange (108).

10. The rear frame structure (100) as claimed in claim 7, wherein the third bottom flange (126) is defined with a curved profile such that ends of the third bottom flange (126) are curved to engage the side portion (206a, 206b) of the side tubes (202a, 202b) and a central portion of the third bottom flange (126) is positioned above a top portion (204a, 204b) of the side tubes (202a, 202b).

11. The rear frame structure (100) as claimed in claim 1, wherein height (H1) of the top structural part (102) is greater than width (W1) of the top structural part (102).

12. The rear frame structure (100) as claimed in claim 1, wherein width (W2) of the bottom structural part (104) is greater than height (H2) of the bottom structural part (104).

13. A frame structure (210) for a vehicle (200), the frame structure (210) comprising:
a head pipe (212);
a main tube (214) extending downwardly from the head pipe (212) and terminating at a rear cross tube (216);
side tubes (202a, 202b) extending rearwardly from the rear cross tube (216); and
a rear frame structure (100) mounted onto the side tubes (202a, 202b), the rear frame structure (100) comprising:
a top structural part (102) extending in a lateral direction (Y-Y’) of the vehicle (200); and
a bottom structural part (104) extending in a lateral direction (Y-Y’) of the vehicle (200) and positioned below the top structural part (102), the bottom structural part (104) being coupled to the top structural part (102) in an upward-downward direction to form an enclosure,
wherein the top structural part (102) and the bottom structural part (104) are connected to the side tubes (202a, 202b) of the vehicle (200) for enhancing rigidity of the rear frame structure (100).

14. The frame structure (210) as claimed in claim 13, wherein the top structural part (102) is provided with a plurality of top flanges (106, 108, 110, 112, 114) for mounting onto a top portion (204a, 204b) of the side tubes (202a, 202b), the plurality of top flanges (106, 108, 110, 112, 114) comprising:
a first top flange (106) extending along the lateral direction (Y-Y’) of the vehicle (200);
a second top flange (108) extending along the lateral direction (Y-Y’) of the vehicle (200) and position parallelly to the first top flange (106);
a third top flange (110) adapted to engage top portions (106a, 108b) of the first top flange (106) and the second top flange (108);
a fourth top flange (112) extending along a longitudinal direction (X-X’) of the vehicle (200) and adapted to tangentially engage a right side portion of the first top flange (106), the second top flange (108) and the third top flange (110); and
a fifth top flange (114) extending along the longitudinal direction (X-X’) of the vehicle (200) and adapted to tangentially engage a left side portion of the first top flange (106), the second top flange (108) and the third top flange (110).

15. The frame structure (210) as claimed in claim 14, wherein the fourth top flange (112) is adapted to diverge angularly from the right side portion of the first top flange (106), the second top flange (108) and the third top flange (110), the fourth top flange (112) upon engagement with the right side portion provides a right side projection (116) to the top structural part (102), wherein the right side projection (116) is adapted to engage on the top portion (204a) of the side tube (202a) for mounting of the top structural part (102) on the top portion (204a) of the side tube (202a).
16. The frame structure (210) as claimed in claim 14, wherein the fifth top flange (114) is adapted to diverge angularly from the left side portion of the first top flange (106), the second top flange (108) and the third top flange (110), the fifth top flange (114) upon engagement with the left side portion provides a left side projection (118) to the top structural part, wherein the left side projection (118) is adapted to engage on the top portion (204b) of the side tube (202b) for enabling mounting of the top structural part (102) on the top portion (204b) of the side tube (202b).

17. The frame structure (210) as claimed in claim 14, wherein the first top flange (106) is provided with a frame number (208) of the vehicle (200).

18. The frame structure (210) as claimed in claim 14, wherein the third top flange (110) is provided with a provision (120) for enabling mounting of a pillion handle of the vehicle (200).

19. The frame structure (210) as claimed in claim 13, wherein the bottom structural part (104) is provided with a plurality of bottom flanges (122, 124, 126) for mounting onto a side portion (206a, 206b) of the side tubes (202a, 202b), the plurality of bottom flanges (122, 124, 126) comprising:
a first bottom flange (122) extending along the lateral direction (Y-Y’) of the vehicle (200);
a second bottom flange (124) extending along the lateral direction (Y-Y’) of the vehicle (200) and positioned parallelly to the first bottom flange (122); and
a third bottom flange (126) adapted to tangentially engage bottom portions (122b, 124b) of the first bottom flange (122) and the second bottom flange (124).

20. The frame structure (210) as claimed in claim 19, wherein the first bottom flange (122) engages with the first top flange (106) and the second bottom flange (124) engages with the second top flange (108), for enabling mounting of the bottom structural part (104) with the top structural part (102).

21. The frame structure (210) as claimed in claim 19, wherein the first bottom flange (122) and the second bottom flange (124) are defined to with a Z-shaped profile for facilitating mounting with the first top flange (106) and the second bottom flange (108).

22. The frame structure (210) as claimed in claim 19, wherein the third bottom flange (126) is defined with a curved profile such that ends of the third bottom flange (126) are curved to engage the side portion (206a, 206b) of the side tubes (202a, 202b) and a central portion of the third bottom flange (126) is positioned above a top portion (204a, 204b) of the side tubes (202a, 202b).