Claims:1. A frame structure (200) for a saddle-type vehicle (100) comprising:
a head tube (205);
a down frame member (210) extending rearwardly and downwardly from the head tube (205);
a left and right step-through frame members (220) extending sidewardly and rearwardly from the down frame member (210);
a pair of rear frame members (255) extending upwardly and rearwardly from the left and right step-through frame members (220);
a connecting frame member (225) detachably attached to the left and right step-through frame members (220); and
a carrier frame member (700) detachably attached to the connecting frame member (225) and extending rearwardly towards a rear end of the saddle-type vehicle (100), wherein the carrier frame member (700) is designed to mount a rear suspension (250) of the saddle-type vehicle to the pair of rear frame members (255), and wherein the carrier frame member (700) is configured to support one of an internal combustion engine (102) and an electric machine (920).
2. The frame structure (200) as claimed in claim 1, wherein the connecting frame member (225) is a sub-frame (225a).
3. The frame structure (200) as claimed in claim 2, wherein the sub-frame (225a) is detachably attached to the left and right step-through frame members (220) and to the pair of rear frame members (255).
4. The frame structure (200) as claimed in claim 3, wherein the sub-frame (225a) is detachably attached to the left and right step-through frame members (220) by getting mounted to a pair of first mounting members (230) provided on the left and right step-through frame members (220).
5. The frame structure (200) as claimed in claim 3, wherein the sub-frame (225a) is detachably attached to the pair of rear frame members (255) by being mounted to a pair of second mounting members (340) provided on an upward extending portion (255a) of the pair of rear frame members (255).
6. The frame structure (200) as claimed in claim 3, wherein the sub-frame (225a) is detachably attached to the pair of rear frame members (255) by getting mounted to a pair of second mounting members (340) provided on a rearward extending portion (255b) of the pair of rear frame members (255).
7. The frame structure (200) as claimed in claim 4, wherein the sub-frame (225a) comprises a front base member (375) for mounting to the pair of first mounting members (230).
8. The frame structure (200) as claimed in claim 5, wherein the sub-frame (225a) comprises a pair of upper frame members (365) for mounting to pair of second mounting members (340).
9. The frame structure (200) as claimed in claim 2, wherein the sub-frame (225a) accommodates an energy storage unit (505).
10. The frame structure (200) as claimed in claim 9, wherein the sub-frame (225a) comprises a case supporting member (385) for supporting a battery case (510) of the energy storage unit (505).
11. The frame structure (200) as claimed in claim 10, wherein the case supporting member (385) extends rearwardly inclinedly from a pair of upper frame members 365 of the sub-frame (225a).
12. The frame structure (200) as claimed in claim 2, wherein the carrier frame member (700) is detachably attached to a rear base member (380) of the sub-frame (225a).
13. The frame structure (200) as claimed in claim 12, wherein the carrier frame member (700) comprises a left and right mounting members (720) for attachment with the rear base member (380).
14. The frame structure (200) as claimed in claim 1, wherein the carrier frame member (700) comprises an inverted U-shaped mounting member (715) for supporting the electric machine (920).
15. The frame structure (200) as claimed in claim 14, wherein the inverted U-shaped mounting member (715) is secured at its two ends to a multi-functional brackets (705), each provided at a rear end of each of the left and right mounting members (720).
16. The frame structure (200) as claimed in claim 15, wherein the multi-functional bracket (705) comprises a pair of mounting arms (745) to mount the rear suspension (250), and a slot (740) to receive an axle of a rear wheel (190).
17. The frame structure (200) as claimed in claim 1, wherein the connecting frame member (225) is a toggle link (225b).
18. The frame structure (200) as claimed in claim 17, wherein the carrier frame member (700) is detachably attached to the toggle link (225b).
19. The frame structure (200) as claimed in claim 18, wherein the carrier frame member (700) comprises the left and right mounting members (720) for attachment to the toggle link (225b).
20. The frame structure (200) as claimed in claim 1, wherein the carrier frame member (700) comprises a first engine mounting bracket (900) and a pair of engine mounting bushes (905) to support the internal combustion engine (102).
21. The frame structure (200) as claimed in claim 20, wherein the first engine mounting bracket (900) is provided on a connecting member (710) connecting a left and right mounting members (720) of the carrier frame member (700).
22. The frame structure (200) as claimed in claim 20, wherein the pair of engine mounting bushes (905) is provided on an inverted U-shaped mounting member (715) of the carrier frame member (700).
23. A saddle type vehicle (100) having a frame structure (200), said frame structure comprising:
a head tube (205);
a down frame member (210) extending rearwardly and downwardly from the head tube (205);
a left and right step-through frame members (220) extending sidewardly and rearwardly from the down frame member (210);
a pair of rear frame members (255) extending upwardly and rearwardly from the left and right step-through frame members (220);
a connecting frame member (225) detachably attached to the left and right step-through frame members (220); and
a carrier frame member (700) detachably attached to the connecting frame member (225) and extending rearwardly towards a rear end of the saddle-type vehicle (100), wherein the carrier frame member (700) is designed to mount a rear suspension (250) of the saddle-type vehicle to the pair of rear frame members (255), and wherein the carrier frame member (700) is configured to support one of an internal combustion engine (102) and an electric machine (920).
, Description:TECHNICAL FIELD
[0001] The present subject matter described herein generally relates to a saddle-type vehicle, and particularly but not exclusively relates to a frame structure for the saddle-type vehicle.

BACKGROUND
[0002] Typically, a frame is the main supporting structure of a motor vehicle, including saddle-type motor vehicles and serves to support different parts of the motor vehicle. Besides acting as the main supporting structure of the vehicle, the construction of the frame also defines the outward appeal and looks of the motor vehicle. For example, saddle-type motor vehicles are majorly classified as saddle-type vehicles of the step over kind, and saddle-type vehicles of the step through kind, based on the construction of the frame defining such vehicles.
[0003] The structure and construction of the frame also plays a critical role for the packaging of components of the saddle-type vehicle. Challenges especially lie in redesigning an existing frame to accommodate additional, more sophisticated parts that may develop over a period of time with development in relevant technologies.
[0004] With rapidly developing technologies, competition & demand from product users for better performance, durability & attractive features, a manufacturer is faced with a challenge of continuously upgrading the products to stay ahead of the competition. This necessitates anticipating future requirements & designing platform product architectures which can enable incorporating progressive technologies, scalable features so as to cater to wide range of markets, have longer product platform life as well as minimise frequent investments for the manufacturers in frequently designing new products from scratch. Depending on the market & customer requirements, manufacturer needs to have flexibility to offer products ranging from low cost to high as well as one country to other without significantly changing the base design of the product. Any major change in base design e.g. frame architecture, layout etc. will adversely impact the lead time of launch of the product, cost incurred as well as complexity in controlling production cum manufacturing variations. In road transportation & especially saddle type vehicles, which are compact & have not much room for flexibility, such challenge is further amplified if one has to re-design a frame or vehicle layout to cater to different powertrains like gasoline fuel, hybrid, EV, Fuel cell, etc. Modular frame structure have always had a challenge of trade-off with strength at joints & thus not an ordinarily preferred option for a design engineer attempting to design a saddle type vehicle intended for commutation & transport of goods rather than leisure travel.

BRIEF DESCRIPTION OF DRAWINGS

[0005] The detailed description of the present subject matter is described with reference to the accompanying figures. Same numbers are used throughout the drawings to reference like features and components.
[0006] Fig.1 illustrates a left side view of a saddle-type vehicle in accordance with an embodiment of the present subject matter.
[0007] Fig.2 illustrates a representative side view of a frame structure in accordance with a first embodiment of the present subject matter.
[0008] Fig.3a illustrates an exploded view depicting mounting of a connecting frame member to a main frame member of the frame structure in accordance with an embodiment of the present subject matter.
[0009] Fig.3b illustrates an exploded view depicting mounting of a connecting frame member to a main frame member of the frame structure in accordance with another embodiment of the present subject matter.
[00010] Fig.4a illustrates an exploded view depicting mounting of a energy storage unit on the connecting frame member in accordance with an embodiment of the present subject matter.
[00011] Fig.4b illustrates an exploded view depicting installation of a battery in the energy storage unit in accordance with an embodiment of the present subject matter.
[00012] Fig.5 illustrates an exploded view depicting mounting of a carrier frame member in accordance with an embodiment of the present subject matter.
[00013] Fig.6a illustrates an exploded view depicting mounting of the rear wheel having a hub mounted electric machine to the carrier frame member in accordance with an embodiment of the present subject matter.
[00014] Fig.6b illustrates an exploded view depicting mounting of an electric machine to the carrier frame member in accordance with an embodiment of the present subject matter.
[00015] Fig.7 illustrates a side view of the frame structure in accordance with a second embodiment of the present subject matter.
[00016] Fig.8 illustrates an exploded view depicting mounting of an internal combustion engine and a rear suspension to the carrier frame member in accordance with an embodiment of the present subject matter.

DETAILED DESCRIPTION OF THE INVENTION
[00017] The frame forms the core structure of a saddle-type vehicle. It typically supports the engine, the front and rear suspensions, the fuel tank etc. and also defines the location of parts such as the battery, motor, controller etc. The structure of the frame is typically fixed and therefore it is difficult to accommodate/package additional new parts within the structure of the frame. Additionally, packaging of additional parts that may be required to be provided in the future becomes cumbersome, more so packaging within the structure of an existing frame. For example, an existing frame of a saddle-type vehicle powered by an internal combustion engine cannot be used as the frame for an electric saddle-type vehicle that requires a large sized energy storage unit and a large sized controller, bigger and heavier than the conventional battery and controller respectively used in a conventional saddle-type vehicle. In other words, a frame used for a conventional IC engine powered saddle-type vehicle cannot be used as the frame for an electric saddle-type. However, frame so designed to accommodate either an IC engine or a battery and a controller can aid in effectively lowering the cost of manufacturing of an electric vehicle. Some customers using an IC engine powered saddle-type vehicle would particularly be interested in transforming their existing IC engine vehicle to an EV vehicle in order to save on costs. Alternatively, the manufacturer would like to have a flexible design of frame to cater to different powertrain in different markets based on the economic factors in respective markets.
[00018] It is therefore desirable to provide a frame designed for use both in a saddle-type powered by an IC engine and in an electric vehicle.
[00019] In view of the above, it is an object of the present subject matter to provide a frame structure for a saddle-type vehicle, designed to package either an internal combustion engine of a saddle-type vehicle or a battery and an electric machine of an electric saddle-type vehicle.
[00020] It is another object of the present subject matter to provide a frame structure that enables transformation of a saddle-type vehicle powered by an IC engine into an electric saddle-type vehicle and vice versa without involving an excessive increase in number of components.
[00021] It is one more object of the present subject matter to provide a frame that enables ease of manufacturing of both a conventional saddle-type vehicle and an electric saddle-type vehicle.
[00022] It is still another object of the present subject matter to provide a frame that aids in reducing cost of manufacturing of both a conventional saddle-type vehicle and an electric saddle-type vehicle.
[00023] Accordingly, the above and other objects are achieved by providing a saddle-type vehicle having a frame structure comprising a head tube, a down frame member extending downwardly and rearwardly from the head tube, a pair of step-through frame members extending sidewardly and rearwardly from the down frame member, a pair of rear frame members extending upwardly and rearwardly from the pair of step-through frame members, a connecting frame member attached to the pair of step-through frame members and adapted to support a rear section of the frame structure, and a carrier frame member secured to a portion of the connecting frame member. The head tube, the down frame member, the pair of step-through frame members, and the rear frame members together form the main frame as per the present subject matter.
[00024] As per an aspect of the present subject matter, the connecting frame member is designed to connect a rear section of the frame structure including the rear wheel and the rear suspension with the main frame. Whereas in one embodiment of the present subject matter, the connecting frame member is designed to merely connect the rear section of the frame structure to the main frame, in another embodiment, the connecting frame member in addition to supporting the rear section of the saddle-type vehicle also packages a energy storage unit of the saddle-type vehicle.
[00025] The frame structure further comprises a carrier frame member designed to be connected to a rear bottom portion of the connecting frame member. In one embodiment, the carrier frame member is designed to support an electric machine, and the rear suspension of the saddle-type vehicle. In another embodiment, the carrier frame member is designed to support an internal combustion engine (hereinafter IC engine) of the saddle-type vehicle. Thus, the carrier frame member of the frame structure is designed for use both in a saddle-type vehicle to be powered by the IC engine and is also designed for use in saddle-type vehicle powered by a battery.
[00026] For example, if the saddle-type vehicle powered by the battery has to be transformed into one powered by the IC engine, then the connecting frame member is provided as a toggle link. Further, the toggle link is connected to the carrier frame member that supports the IC engine. However, if the saddle-type vehicle powered by the IC engine has to be transformed into one powered by the energy storage unit, the connecting frame member is provided as a sub-frame capable of supporting the energy storage unit. Further, the sub-frame is connected to the carrier frame member that supports the electric machine. In other words, whereas in one embodiment, the connecting frame member is designed to merely connect/support the carrier frame member; in another embodiment, the connecting frame member is used to not only support/connect the carrier frame member but also support the energy storage unit of the saddle-type vehicle.
[00027] Thus, construction of the frame structure as per the present subject matter aids in ensuring that a saddle-type vehicle typically powered by the IC engine can be easily transformed into a saddle-type vehicle that is to be powered by the energy storage unit and vice versa without involving the need for making any major layout changes in the vehicle. Thus, a saddle-type vehicle having a frame structure as per the present subject matter and powered by the IC engine can easily be transformed into an electric saddle-type vehicle and vice versa. The use of the frame structure as per the present subject matter, therefore proves to be a cost-effective means for addressing futuristic upgrades that may necessitate the use of an electric saddle-type vehicle instead of IC engine powered saddle-type vehicle.
[00028] Summary provided above explains the basic features of the invention and does not limit the scope of the invention. The nature and further characteristic features of the present invention will be made clearer from the following descriptions made with reference to the accompanying drawings.
[00029] Exemplary embodiments detailing features of the frame structure and its construction, in accordance with the present subject matter will be described hereunder with reference to the accompanying drawings. Various aspects of different embodiments of the present subject matter will become discernible from the following description set out hereunder. Rather, the following description provides a convenient illustration for implementing exemplary embodiments of the present subject matter. Further, it is to be noted that terms “upper”, “lower”, “right”, “left”, “front”, “forward”, “rearward”, “downward”, “upward”, “top”, “bottom” and like terms are used herein based on the illustrated state or in a standing state of the saddle-type vehicle with a driver sitting thereon unless otherwise elaborated. Furthermore, a longitudinal axis refers to a front to rear axis relative to the saddle-type vehicle, defining a vehicle longitudinal direction; while a lateral axis refers to a side to side, or left to right axis relative to said vehicle, defining a vehicle lateral direction. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting.
[00030] The present invention along with all the accompanying embodiments and their other advantages would be described in greater detail in conjunction with the figures in the following paragraphs
[00031] With reference to FIG.1, a description is made of an entire schematic structure of a saddle riding vehicle 100 having a frame structure 200. The frame structure 200 (shown in Fig.2) supports different parts of said vehicle 100. The frame structure 200 supports a steering assembly including a steering shaft (not shown), and a Handlebar assembly 105 in a front portion of the saddle-type vehicle 100. A front fork 121 is rotatably supported to the steering shaft through a upper bracket and a lower bracket (not shown). The handlebar assembly 105 provided above the front fork 121 allows steering of a front wheel 125. A headlamp assembly 110 is disposed in front of the handlebar assembly 105.
[00032] Further, a front cover 115 is provided to cover a forward-facing side of the frame structure 200. A front fender 120 is provided to cover an upper portion of the front wheel 125. A leg shield 130 is disposed to cover an inward facing side of the frame structure 200, below the Handlebar assembly 105. The leg shield 130 protects the rider’s legs rested on a floorboard 145 from running wind. An under-seat cover 140 is provided that extends upwards from the floorboard 145 towards a lower side of a seat 135. In one embodiment, the under-seat cover 140 serves to protect a energy storage unit 505 (shown in Fig.4b) disposed under the seat 135. In another embodiment, the under-seat cover 140 serves to protect an IC engine 102 disposed under the seat 135. The seat 135 is disposed above the left and right side covers 175. A pillion-handle 165 extending rearwardly behind the seat 135 is provided as a gripping means for a pillion rider seated on the seat 135.
[00033] For safety of the rider and in conformance with the traffic rules, the headlamp assembly 110 and a turn signal lamp unit 111 are provided in a front portion of said vehicle 100, and tail lamp unit 170 is provided in a rear portion of said vehicle 100. Safety of said saddle-type vehicle 100 is also improved by providing a braking system, for example a linked type braking system which controls braking operation of a front brake device (not shown) and a rear brake device (not shown) of the front wheel 125 and the rear wheel 190 respectively. The braking system includes a front brake lever 132 and a rear brake lever (not shown) to be operated by the rider and connected to said front brake device and said rear brake device respectively through one or more cables including a front brake cable (not shown) and a rear brake cable (not shown).
[00034] For comfortable riding, suspension systems are provided for comfortable steering of said vehicle 100 on the road. The front fork 121, which forms the front suspension system, serves as rigidity component just like the frame structure200. The front fork 121 clamped to the head tube 205 (shown in Fig.2) through an upper bracket (not shown) and a lower bracket (not shown) is capable of being moved/steered to the left and right. Further, at least one rear suspension 250 (shown in Fig.2), which is a hydraulic damped arrangement, is connected to the frame structure 200 at a rear portion thereof. Particularly, at the rear portion of the frame structure 200, the rear wheel 190 is suspended by the rear suspension 250.
[00035] To enhance the overall aesthetics of said vehicle 100 and to prevent undesired foreign particles from entering parts of said vehicle 100, left and right side covers 175 are disposed to cover left and right side surfaces of a rear portion of the frame structure 200. A rear fender 180 is also provided for preventing mud/water splashed by the rear wheel from entering other parts of said vehicle 100.
[00036] As per one embodiment of the present subject matter and as may be seen in Fig.1, the saddle-type vehicle 100 is designed to be powered by the IC engine 102 that is equipped with an exhaust system that includes an exhaust pipe 184 connected to the IC engine 102 and a muffler 185 connected to the exhaust pipe 184. The muffler 185 extends rearwards along the right side of the rear wheel 190.
[00037] Power from the IC engine 102 is transmitted to the rear wheel 190 through atransmission assembly (not shown), so as to drive and rotate the rear wheel 190. The transmission assembly includes a gear unit containing gear train and a drive mechanism connecting the gearunit to the rear wheel 190. Thus, power from the IC engine 102 is transmitted to the rear wheel 190.
[00038] As per a second embodiment of the present subject matter, the saddle-type vehicle 100 is designed to be fully powered by an energy storage unit 505 (shown in Fig.2).
[00039] Fig.2 illustrates a side view of the frame structure 200 of the saddle-type vehicle as per a first embodiment 200(a) of the present subject matter and designed to be powered by the energy storage unit 505. As may be seen in Fig.2, the frame structure 200 is of the step-through type. The frame structure 200 comprises a head tube 205, a down frame member 210 extending downwardly and rearwardly from the head tube 205, a pair of step-through frame members 220 extending sidewardly and rearwardly from both sides of the down frame member 210, and a pair of rear frame members 255 extending rearwardly and upwardly from a rear portion of the pair of step-through frame members 220.
[00040] As may be seen in Fig.2, the frame structure 200 is designed to support the energy storage unit 505 used for powering the saddle-type vehicle 100. In the present embodiment, the frame structure 200 comprises a connecting frame member 225 that is designed to support the energy storage unit 505 but also connect a rear section of said vehicle 100 to the pair of main frame members 220. In the present embodiment, the connecting frame member 225 is a sub-frame 225a. For example, in an embodiment where a hub mounted electric machine 245 is used, left and right mounting members 720 extending from a rear wheel hub is connected to the sub-frame 225a. The sub-frame 225a is in turn mounted to a pair of first mounting members 230; a first mounting member each provided at a junction formed between each step-through frame member and rear frame member on both sides of the frame structure 200. In the present embodiment, each first mounting member of the pair of first mounting members is a mounting bracket. A rear end of the sub-frame 225a mounts the rear suspension 250 to the pair of rear frames 255 and also supports the rear wheel 190.
[00041] Fig.3a illustrates a detailed exploded view depicting the mounting of the sub-frame member 225a as per one embodiment. As illustrated, the sub-frame 225a has two mounting locations, one at the junction between the pair of step-through frame members 220 and the rear frame members 255 and the second on the pair of rear frame members 255. In the present embodiment, the sub-frame 225a has a front base member 375 to be mounted to a pair of first mounting members 230 provided at the junction between the left and right step-through frame members 220 and the pair of rear frame members 255. The front base member 375 of the sub-frame 225a is secured to the pair of first mounting members 230 by means of an axle 330. A bush member 335 each is provided on each mounting member of said pair of first mounting members 230. The axle 330 is inserted through each of said bush member 335.
[00042] Further, the sub-frame 225a has a pair of upper frame members 365 to be mounted to a pair of second mounting members 340. In the present embodiment, the pair of upper frame members 365 extend forwardly and upwardly from a rear base member 380. The pair of second mounting members 340 are provided in an upward extending portion 255a of the pair of rear frame members 255. Particularly, the pair of second mounting members 340 are disposed at a position just above the pair of first mounting members 230. By securing the pair of upper frame members 365 of the sub- frame 225a to the pair of second mounting members 340 disposed on the upward extending portion 255a of the pair of rear frame members 255, it is ensured that no portion of the sub-frame member 225a comes in contact with other components of said vehicle.
[00043] As per another embodiment and as may be seen in Fig.3b illustrating another embodiment of the sub-frame 225a, the pair of upper frame members 365 of the sub-frame 225 is secured to the pair of second mounting members 340. In the present embodiment, the pair of second mounting members 340 is provided on a rearward extending portion 255a of the pair of rear frame members 255. Particularly, the pair of upper frame members 365 of the sub-frame 225a is extended so that it can be secured at a position substantially above the pair of first mounting members 230.
[00044] Fig.4a and Fig.4b illustrate exploded views depicting mounting of the energy storage unit 505 to the sub-frame 225a in accordance with a first embodiment 200(a) of the frame structure 200. In the present embodiment, the energy storage unit is a battery storage unit. As may be seen in Fig.4a, the energy storage unit 505 comprises a battery case 510 having a base member 520. The base member 520 of the battery case 510 is disposed on a case supporting member 385 of the sub-frame 225a. In the present embodiment, the case supporting member 385 extends rearwarly inclinedly from the pair of upper frame members 365 of the sub-frame 225a. More particularly, the case supporting member 385 extends slightly beyond a rear base member 380 of the sub-frame 225a, when viewed from either a sideward direction or a rearward direction of the frame structure 200. The case supporting member 385 is also supported by a first supporting member 370 extending centrally rearwardly from the first base member 375 up to a rear member 386 of the supporting case member 385. The sub-frame 225a also comprises a plurality of mounting gussets 371 extending sidewardly from the first supporting member 370. The base member 520 of the battery case 510 is mounted at the plurality of mounting gussets 371. Fasteners 515 fastened from an up-side of the battery case 510 are used to secure said base member 520 to the plurality of mounting gussets 371. The battery case 510 thus mounted on the sub-frame 225a receives a battery pack 605 as illustrated in Fig.4b. The battery pack 605 is inserted into the battery case 510 from a top side of the pair of rear frame members 255 and through the space between the pair of rear frame members 255. In the present embodiment, once the battery pack 605 is inserted, a case cover 610 is fitted to side walls of the battery case 510 to close the battery case 510 with the battery pack 605 inside said case 510.
[00045] Fig.5 illustrates the mounting of a carrier frame member 700 to the connecting frame member 225 as per an embodiment of the present subject matter. The carrier frame member 700 as per an aspect of the present subject matter comprises left and right mounting members 720 extending horizontally and parallely with one another. The left and right mounting members 720 are connected to one another at a front portion by a connecting member 710. A front end of the left and right mounting members 720 is integrally provided with a mounting bush 725 each for mounting to the rear base member 380 of the sub-frame 225a. Thus, the front end of the left and right mounting members 720 is fastened to the carrier frame member 700. In other words, the carrier frame member 700 is detachably attached to the sub-frame 225a. A rear end of the left and right mounting members 720 is integrally formed with a multi-functional mounting bracket 705. The multi-functional bracket 705 is designed to mount both the rear wheel 190 of the saddle-type vehicle and the rear suspension 250 (shown in Fig.7). Particularly, the multi-functional bracket 705 comprises an axle mounting slot 740 for receiving a rear wheel axle 805 (shown in Fig.6a) and a pair of mounting arms 745 for receiving a lower end of each rear suspension 250. Further, the carrier frame member 700 comprises an inverted U-shaped mounting member 715. In the present embodiment, the inverted U- shaped mounting member 715 is welded at both its ends to the multi-functional mounting bracket 705 disposed on both the left and right mounting members 720. In order to support the inverted U-shaped mounting member 715, the carrier frame member 700 also comprises a pair of support tubes 735 extending from the left and right mounting members 720 to arms of the inverted U-shaped mounting member.
[00046] As per an embodiment of the present subject matter and as may be seen in Fig.6a, the carrier frame member 700 is detachably attached to the sub-frame 225a and receives the axle 805 of the rear wheel 190 in each axle mounting slot 740 of the multi-functional bracket 705. In the present embodiment, the rear wheel 190 houses a hub mounted electric machine 245. Thus, the frame structure 200 comprising the connecting frame member 225 and the carrier frame member 700 as per one embodiment serves to support the energy storage unit 505 and the hub mounted motor for powering an electric saddle-type vehicle.
[00047] Fig.6b illustrates another embodiment of the carrier frame member designed to support an independent electric machine. In this embodiment, the electric machine 920 is mounted to a pair of carrier frame mounting arms 925 extending from the inverted U-shaped mounting member 715. Further, as may be seen, the sub-frame 225a connected to the carrier frame member 700 accommodates the battery pack 605 in the battery case 510. The axle mounting slot 740 provided in each of the multi-functional bracket 705 of the carrier frame member 700 receives the axle of the rear wheel 190.Thus, the frame structure 200 comprising the connecting frame member 225 and the carrier frame member 700 as per another embodiment serves to support the energy storage unit 505 and the electric machine 920 (independent motor) for powering an electric saddle-type vehicle.
[00048] Fig.7 illustrates the frame structure 200 as per a second embodiment (200(b)) of the present subject matter. The frame structure 200 as per this embodiment is designed for a saddle-type vehicle powered by an internal combustion engine 102 (shown in Fig.8). Said frame structure 200 comprises the head tube 205, the down frame member 210, the left and right step through frame members 220 extending sidewardly and rearwardly from the down frame member 210, the pair of rear frame members 255, the connecting frame member 225 fixed to left and right step-through frame members 220, and the carrier frame member 700 connected to the connecting frame member 225. In the present embodiment and as may be seen in Fig.7 and Fig.8, the connecting frame member 225 is a toggle link 225b. In the present embodiment, the connecting frame member 225 is provided as a toggle link 225b since the saddle-type vehicle does not contain the energy storage unit 505 (shown in Fig.6a) and instead contains the IC engine 102. Therefore, in the present embodiment the carrier frame member 700 is connected to the toggle link 255b. The cylinder head of the IC engine 102 is accommodated in the space formed between the pair of rear frame members 255. Further, in the present embodiment, the carrier frame member 700 is configured to receive the mounting of the IC engine 102. For example, in the present embodiment, the connecting member 710 of the carrier frame member 700 is provided with a first engine mounting bracket 900. The first engine mounting bracket 900 has two mounting holes 930 to receive a pair of front end portions of the IC engine 102. Further, the inverted U-shaped mounting member 715 of the carrier frame member 700 is provided with a pair of engine mounting bushes 905 to receive a pair of rear end portions of the engine 102. The engine 102 is thus secured to the carrier frame member 700.
[00049] Thus, the frame structure 200 is designed to be used in a saddle-type vehicle that can be powered either by the internal combustion engine or the energy storage unit. The frame structure 200 used for a saddle-type vehicle powered by the engine can be easily transformed into an electric saddle-type vehicle by disconnecting the carrier frame member from the connecting frame member i.e the toggle link and by also disconnecting the toggle link coupled to the pair of left and right step-through frame members, followed by installing the connecting frame member in the form of sub-frame that is designed to accommodate the energy storage unit. The sub-frame is secured to the left and right step-through frame members. Further, the carrier frame member designed to rigidly secure either a hub mounted motor or an independent electric machine is coupled to the sub-frame. Finally, the motor is secured to the carrier frame member.
[00050] Similarly, the electric saddle-type vehicle can be easily transformed into one powered by the engine by disconnecting the carrier frame member from the sub-frame and replacing the sub-frame with the toggle link. Further, the carrier frame member designed to accommodate the engine is installed by connecting the same with the toggle link.
[00051] The construction of the frame structure as per the present subject matter therefore enables the use of a common main frame platform structure including the head tube, the down frame member, the left and right step-through frame members and the pair of rear frame members for both a saddle-type vehicle powered by the engine and an electric saddle-type vehicle. Thus, the platform structure of the common main frame member need not be changed for effecting the transformation. The present subject matter therefore additionally provides a cost-effective means for transforming a saddle-type vehicle powered by the engine into an electric saddle-type vehicle and vice versa. The customer can easily switch from using an engine powered vehicle into a battery powered vehicle without spending a significant amount.
[00052] Although the present subject matter has been embodied for a saddle-type vehicle of the step-through kind, the features of the present subject matter can be extended to a saddle-type vehicle of the step-over kind, wherein a frame structure is redesigned for transforming an IC engine powered step-over kind vehicle into an electric step-over kind vehicle and vice versa.

Reference Numerals:
100 – Saddle-type vehicle 225b – Toggle link
102 – Internal combustion engine 230 – Pair of first mounting members
105 – Handlebar assembly 330 - Axle
110 – Headlamp Assy 335 – Bush member
115 – Front cover 340 - Pair of second mounting members
120 – Front fender 365 - Pair of upper frame members
121 – Front fork 370 – First supporting member
125 – Front wheel 375 – Front base member
130 – Leg shield 380 – Rear base member
135 – Seat 385 – Case supporting member
140 – Under-seat cover 386 – Rear member
145 – Floorboard
165 – Pillion-handle 505 – Energy storage unit
170 – Tail lamp unit 510 – Battery case
175 – Left and right side covers 520 – Base member
180 – Rear fender 605 – Battery pack
185 – Muffler 610 – Case cover
190 – Rear wheel 700 – Carrier frame member
200 – Frame structure 715 – Inverted U-shaped mounting member
205 – Head tube 705 – Multi-functional bracket
210 – Down frame 720 – Left and right mounting members
220 – Left and right step-through frame members
225 - Connecting frame member 735 – Pair of support tubes
225a – Sub-frame 745 – Pair of mounting arms
245 – Hub mounted electric machine
250 – Rear suspension
805 – Rear wheel axle
900 - First engine mounting bracket
905 – Pair of engine mounting bushes
930 - Mounting holes