DESC:TECHNICAL FIELD
[0001] The present subject matter relates generally to a vehicle, and more particularly but not exclusively relates to a step through type vehicle.
BACKGROUND
[0002] Conventionally, a frame is the main supporting structure of a vehicle, including step through-type vehicles and serves to support different parts of the 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 vehicle.
[0003] The structure and construction of the frame also plays a critical role for the packaging of components of the step through-type vehicle. Challenges especially lie in redesigning an existing frame to accommodate additional, more sophisticated parts that may develop over a period with development in relevant technologies. With rapidly developing technologies, competition, and 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 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 and 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.
[0004] Further, any major change to the 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 and especially step through type vehicles, which are compact and have not much room for flexibility. Such challenges are further amplified if one has to re-design the frame or the vehicle layout to cater to different powertrains like gasoline fuel, hybrid, EV, Fuel cell, etc.


BRIEF DESCRIPTION OF THE DRAWINGS
[0005] 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. The same numbers are used throughout the drawings to reference like features and components.
[0006] Figure 1 illustrates a right side of a step through-type vehicle, in accordance with an embodiment of the present subject matter.
[0007] Figure 2 illustrates a side perspective view of the frame structure of the step through-type vehicle as per an embodiment of the present subject matter and designed to be powered by the energy storage unit.
[0008] Figure 3 illustrates a detailed exploded view depicting the mounting of the sub-frame member as per one embodiment.
[0009] Figure 4A illustrates a side view of the frame structure of the step through-type vehicle as per an embodiment of the present subject matter and designed to be powered by the energy storage unit.
[00010] Figure 4B to Figure 4D illustrates a sectional side view of the frame structure of the step through-type vehicle as per an embodiment of the present subject matter and designed to be powered by the energy storage unit.
[00011] Figure 5A to Figure 5B illustrates a sectional side view of the frame structure of the step through-type vehicle, when the energy storage unit is being accessed from a space underneath the utility unit, as per an embodiment of the present subject matter.
DETAILED DESCRIPTION
[00012] During the recent decades the customers attraction and expectation towards two wheeled vehicles have increased. Such two wheeled vehicle are expected to meet the customer requirements with respect to providing convenient leg space, improved utility space and comfortable riding without compromising with the two wheeled vehicle being light weighted. Such requirements become imperative especially for a step through type vehicle having storage space underneath the seat. Generally, such step through type vehicle driven by electrical power train has an energy storage device mounted at the rear portion of vehicle. Specifically in such step through type vehicles, the energy storage device is mounted under the seat, and more specifically below the utility unit.
[00013] Several known arts disclose about the location of the energy storage device either in rear portion of the step through type vehicle or directly under the utility unit of the step through type vehicles. Some other known arts disclose about one or more energy storage device being held within an energy storage case. Subsequently the energy storage case, also called as energy storage unit case, along with the one or more energy storage device is placed on a sub frame connecting the front and rear frame of the step through type vehicle.
[00014] The one or more energy storage devices include one or more batteries. The energy storage device such as a battery is an imperative part of the step through type vehicle, especially when the vehicle is an electric or hybrid vehicle. Further, known arts suggest usage of swappable batteries or off board charging of the batteries. This is because parts related to on board charger of the battery requires significant space, which is usually undesired, owing to maintain the compactness of the vehicle. Some known arts also disclose about on-board charger that can be packed and carried with the vehicle. Some other known arts disclose about placement of the on-board charger within the utility unit. For instance, the offboard charger can be secured using mountings provided on the periphery of the utility unit. Therefore, regular maintenance, serviceability, and in some cases regular removal of the battery becomes imperative for the user.
[00015] Considering the known arrangement of the energy storage unit underneath the seat and the utility unit, usually the energy storage unit placed underneath the utility unit, can only be accessed from vehicle top, after dismantling the utility unit. Mostly, the energy storage unit cannot be accessed from the sides, front, rear, or bottom portion of the step through type vehicle, owing to the rigidness of the frame assembly, and lack of clearance due to tight packaging of the step through type vehicle to maintain compactness. For instance, the access of the energy storage unit from the sides is hindered by the pair of bottom members disposed between the sub-frame and a rear wheel hub. Similarly, the access of the energy storage unit from the front and bottom and the bottom is significantly hindered by the sub frame and the pair of step-through frame members. Further, the access of the energy storage unit from the rear is hindered by the rear interferences such as wheel and rear suspension. Thereby, to access the energy storage unit from the top of the vehicle, ideally one must dismantle the seat and the utility unit; and remove the energy storage unit from the space exposed after the removal of the utility unit and the seat.
[00016] Usually, the shape of a standard 3.2 to 3.5 KW/hour energy storage unit used in a vehicle is rectangular in shape and weighs around 11.5 kilograms to 12 kilograms. Thereby, owing to shape, size and weight of the energy storage unit, in order to access the energy storage unit from the top, on need to slightly rotate the energy storage unit and then remove from the top. However, the access of the energy storage unit from the top of the vehicle, also becomes challenging, owing to shape of the energy storage unit and the restricted space through which it can be accessed.
[00017] Conventionally, to solve such problems, known art suggest repositioning of surrounding interface parts with more than adequate clearances and thereby increase the size of vehicle around the energy storage unit for enabling easy access. However, packaging of new additional components within existing vehicle layout is already cumbersome. Therefore, not enough flexibility is there to create needed adequate clearances.
[00018] Further, such repositioning of parts and changes in layout and dimensions of the vehicle are not desirable. This is because with increase in vehicular dimensions, for instances increase in size of the vehicle width wise, the vehicle becomes bulkier and thereby maneuverability of the vehicle is negatively impacted. Further in certain instances, the changes in the vehicular dimensions and layout shifts the Centre of gravity of the vehicle, sometimes leading to vehicle imbalance. Further such increased clearances around the energy storage unit, increases the chances of disorientation of the interface parts around the periphery of the energy storage unit, which is undesirable.
[00019] Hence, it is desired to have a frame structure, which enables easy access of the energy storage device, without majorly changing the dimensions of the vehicle and the without increasing the clearance with respect to surrounding interface parts.
[00020] Hence, there is a need of addressing the above circumstances and problems of the known arts.
[00021] The present subject matter has been devised in view of the above circumstances as well as solving other problems of the known art.
[00022] The present subject matter discloses about a step-through vehicle having a provision to enable easy access of one or more energy storage unit, without doing major changes in the dimensions of the vehicle and the without increasing the clearance with respect to surrounding interface parts.
[00023] In the present embodiment, frame structure is designed to support the energy storage unit used for powering the step through-type vehicle. In the present embodiment, the frame structure comprises a connecting frame member that is designed to support the energy storage unit but also connect a rear portion of the vehicle to the pair of main frame members. In the present embodiment, the connecting frame member is a sub-frame. For example, in an embodiment where a hub mounted electric machine is used, swingarm assembly extending from a rear wheel hub, is connected to the sub-frame. The sub-frame is in turn mounted to a pair of first mounting members. Each of the first mounting member are provided at a junction formed between each step-through frame member and rear frame member on both sides of the frame structure. 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 mounts the rear suspension to the pair of rear frames and supports the rear wheel.
[00024] The sub-frame has two mounting locations, one at the junction between the pair of step-through frame members and the rear frame members and the second on the pair of rear frame members. In the present embodiment, the sub-frame has a front base member to be mounted to a pair of first mounting members provided at the junction between the left and right step-through frame members and the pair of rear frame members. The front base member of the sub-frame is secured to the pair of first mounting members by means of an axle. Each of the one or more bush member is provided on each mounting member of the pair of first mounting members. The axle is inserted through each of the bush member. Further, the sub-frame has a pair of upper frame members to be mounted to a pair of second mounting members. In the present embodiment, the pair of upper frame members extend forwardly and upwardly from a rear base member. The pair of second mounting members are provided in an upward extending portion of the pair of rear frame members. Particularly, the pair of second mounting members are disposed at a position just above the pair of first mounting members. By securing the pair of upper frame members of the sub-frame to the pair of second mounting members disposed on the upward extending portion of the pair of rear frame members, it is ensured that no portion of the sub-frame comes in contact with other components of the vehicle.
[00025] In an embodiment, one or more energy storage unit is held within an energy storage unit case having a base member. The base member of the energy storage unit case is disposed on a case supporting member of the sub-frame. In the present embodiment, the case supporting member extends rearwarly inclinedly from the pair of upper frame members of the sub-frame. This provides additional support and stability to the energy storage unit case. More particularly, the case supporting member extends slightly beyond a rear base member of the sub-frame, when viewed from either a sideward direction or a rearward direction of the frame structure. The case supporting member is also supported by a first supporting member extending centrally rearwardly from the first base member up to a rear portion of the supporting case member.
[00026] In an embodiment, the at least one mounting at the front is called as front mounting for brevity, and the at least one mounting at the rear are called as the rear mounting. The mountings provided in the locations stated provide stability to the energy storage units.
[00027] In an embodiment, the front mounting is positioned lower than the rear mounting, thereby the energy storage unit will be placed inclined with the front face towards ground and rear face towards upward direction. Such placement of the energy storage unit ensures making the center of gravity of the energy storage unit closer to the center of the gravity of the vehicle, thereby ensuring better stability for the vehicle and makes it easier to remove and replace the energy storage units.
In accordance with an embodiment, a relief is provided within the energy storage unit case itself, wherein the energy storage unit case is mounted to the sub-frame of the vehicle. frame assembly of the vehicle.
In an embodiment the relief is provided is in inverted trapezoidal shape.
In an embodiment the inverted trapezoidal shaped relief is provided at front bottom portion of the energy storage unit case.
[00028] The sub-frame and relief designed and positioned in the configuration stated in the embodiments of the application provide a stable platform for the energy storage units while allowing easy access and removal for maintenance or replacement. Further, the relief enables the smooth transition of the energy storage units to a position which minimizes the risk of damage to the energy storage units during installation and removal.
[00029] As per an aspect of the present embodiment, the at least one front mounting between the energy storage unit case and the sub-frame is provided near the periphery of the inverted trapezoidal shaped relief to mount the energy storage unit case with the sub-frame. This positioning of the front mounting provides additional support to the energy storage units.
[00030] In another embodiment, the inverted trapezoidal shaped relief in the energy storage unit case is positioned between the sub-frame mountings with frame structure and swingarm assembly, providing additional stability to the vehicle.
[00031] In another embodiment, the inverted trapezoidal shaped relief of the energy storage unit case is positioned near to vehicle Centre of gravity, providing stability, and enabling better handling of vehicle.
[00032] The inverted trapezoidal shaped relief includes at least two parallel bases, and at least two connecting legs. The at least two parallel bases include a top base and a bottom base; the at least two connecting legs include a right connecting leg and a left connecting leg. In embodiment, the bottom base of the inverted trapezoidal shaped relief of the energy storage unit case is positioned higher at vertical distance of ‘d’ from a fastener outermost edge when viewed in a side view of the vehicle. The fastener is used to hold the energy storage unit case with the sub-frame when viewed in vehicle longitudinal direction. Such distance ‘d’ ensures that the head of the fastener does not come in contact with the energy storage unit, when the energy storage unit is being removed from the energy storage unit case while servicing or replacing the energy storage unit.
[00033] In another embodiment, the parallel base corresponds to base member of energy storage unit case, right connecting leg corresponds to a rearwardly inclined surface of the energy storage unit case, starting at the base member of energy storage unit case to the first mounting left connecting leg corresponds to a forwardly inclined surface of the energy storage unit case, starting at the base member of energy storage unit case to the first mounting and parallel base corresponds to an imaginary line joining the lower edge of right connecting leg and left connecting leg.
[00034] In another embodiment, the vertical distance ‘d’ should be less than or equal to or twice the size of the fastener diameter.
[00035] In general, the energy storage unit will be in rectangular shape, when positioned in the vehicle. To access either to assemble or service the energy storage unit, the energy storage unit must be tilted which creates trapezoidal shape. This perimeter of trapezoidal shape is usually higher than perimeter of the original rectangular shape of the energy storage unit during assembled condition.
[00036] Hence, while removing the energy storage unit from the vehicle, the energy storage unit needs more space for accessibility. In an embodiment, the inverted trapezoidal shaped relief ensures smooth transition of the position of the energy storage unit into a position enabling access and removal of the energy storage unit, tangentially to the rear wheel of the vehicle.
[00037] Thereby, the inverted trapezoidal shaped relief of the energy storage unit case enhances ease of accessibility for the energy storage unit.
[00038] In another embodiment, the inverted trapezoidal shaped relief of the energy storage unit case enhances the accessibility of the energy storage unit with adequate clearances around interface parts thus providing compact vehicle layout.
[00039] In another embodiment, the inverted trapezoidal shaped relief of the energy storage unit case has overlap with sub-frame mountings with swingarm assembly to enable better serviceability of the energy storage unit.
[00040] In another embodiment, the starting region of the inverted trapezoidal shaped relief of the energy storage unit case is behind the sub-frame mountings with the frame structure, so that the energy storage unit may be placed rigidly with sub-frame during vehicle operating conditions.
[00041] Exemplary embodiments detailing features regarding the afore mentioned and other advantages of the present subject matter will be described hereunder with reference to the accompanying drawings. Various aspects of different embodiments of the present invention will become discernible from the following description set out hereunder. Rather, the following description provides a convenient illustration for implementing exemplary embodiments of the invention. It should be noted that the description and figures merely illustrate principles of the present subject matter. Various arrangements may be devised that, although not explicitly described or shown herein, encompass the principles of the present subject matter. Moreover, all statements herein reciting principles, aspects, and examples of the present subject matter, as well as specific examples thereof, are intended to encompass equivalents thereof. Further, it is to be noted that terms “upper”, “down”, “right”, “left”, “front”, “forward”, “rearward”, “downward”, “upward”, “top”, “bottom”, “exterior”, “interior” and like terms are used herein based on the illustrated state or in a standing state of the two wheeled straddle type vehicles with a user riding thereon. Furthermore, arrows wherever provided in the top right corner of figure(s) in the drawings depicts direction with respect to the vehicle, wherein an arrow F denotes front direction, an arrow R indicates rear direction, an arrow Up denotes upward direction, an arrow Dw denotes downward direction, an arrow RH denotes right side, and an arrow LH denotes left side. 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.
[00042] Figure 1 illustrates a right side of a step through-type vehicle 100, in accordance with an embodiment of the present subject matter. Different parts of the step through-type vehicle 100 are supported by a frame structure 200 (shown in Figure 2). 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 step through-type vehicle 100. A front fork 121 is rotatably supported to the steering shaft through an upper bracket (not shown) 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.
[00043] 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 a floorboard 145 towards a lower side of a seat 135.
[00044] In one embodiment, the under-seat cover 140 serves to protect an energy storage unit 505 (shown in Figure 2) disposed under the seat 135. In another embodiment, the under-seat cover 140 serves to protect an Internal Combustion (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.
[00045] 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 the vehicle 100, and tail lamp unit 170 is provided in a rear portion of the vehicle 100. Safety of the step through-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 the front brake device and the rear brake device respectively through one or more cables including a front brake cable (not shown) and a rear brake cable (not shown).
[00046] For comfortable riding, suspension systems are provided for comfortable steering of the vehicle 100 on the road. The front fork 121, which forms the front suspension system, serves as rigidity component like the frame structure 200. The front fork 121 clamped to the head tube 205 (shown in Figure 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 Figure 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.
[00047] To enhance the overall aesthetics of the vehicle 100 and to prevent undesired foreign particles from entering parts of the 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 190 from entering other parts of the vehicle 100.
[00048] As per one embodiment of the present subject matter and as may be seen in Figure 1, the step through-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 (not shown) connected to the IC engine 102 and a muffler 185 connected to the exhaust pipe. The muffler 185 extends rearwards along the right side of the rear wheel 190. Power from the IC engine 102 is transmitted to the rear wheel 190 through a transmission assembly (not shown), to drive and rotate the rear wheel 190. The transmission assembly includes a gear unit containing gear train and a drive mechanism connecting the gear unit to the rear wheel 190. Thus, power from the IC engine 102 is transmitted to the rear wheel 190.
[00049] As per a second embodiment of the present subject matter, the step through-type vehicle 100 is designed to be fully powered by the energy storage unit 505 (shown in Figure 2).
[00050] Figure 2 illustrates a side perspective view of the frame structure 200 of the step through-type vehicle as per an embodiment of the present subject matter and designed to be powered by the energy storage unit 505. As may be seen in Figure 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.
[00051] As may be seen in Figure 2, the frame structure 200 is designed to support the energy storage unit 505 used for powering the step through-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 portion of the vehicle 100 to the pair of main frame members 220. In the present embodiment, the connecting frame member 225 is a sub-frame. For example, in an embodiment where a hub mounted electric machine 245 is used, swingarm assembly 580 extending from a rear wheel hub, is connected to the sub-frame 225. The sub-frame 225 is in turn mounted to a pair of first mounting members 230. Each of the first mounting member 230 are 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 225 mounts the rear suspension 250 to the pair of rear frames 255 and supports the rear wheel 190.
[00052] Figure 3 illustrates a detailed exploded view depicting the mounting of the sub-frame member 225 as per one embodiment. As illustrated, the sub-frame 225 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 225 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. Each of the one or more bush member 335 is provided on each mounting member of the pair of first mounting members 230. The axle 330 is inserted through each of the bush member 335. Further, the sub-frame 225 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 255 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 225 to the pair of second mounting members 340 disposed on the upward extending portion of the pair of rear frame members 255, it is ensured that no portion of the sub-frame 225 comes in contact with other components of the vehicle 100.
[00053] Figure 4A illustrates a side view of the frame structure 200 of the step through-type vehicle as per an embodiment of the present subject matter and designed to be powered by the energy storage unit 505. Herein one or more energy storage unit 505 is held within an energy storage unit case 510 having a base member 520 (shown in Figure 4B). The base member 520 of the energy storage unit case 510 is disposed on a case supporting member 385 of the sub-frame 225. In the present embodiment, the case supporting member 385 extends rearwarly inclinedly from the pair of upper frame members 365 of the sub-frame 225. This, provides additional support and stability to the energy storage unit case 510. More particularly, the case supporting member 385 extends slightly beyond a rear base member 380 (shown in Figure 3) of the sub-frame 225, 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 (shown in Figure 3) extending centrally rearwardly from the first base member 375 up to a rear portion of the supporting case member 385.
[00054] Figure 4B to Figure 4D illustrates a sectional side view of the frame structure 200 of the step through-type vehicle as per an embodiment of the present subject matter and designed to be powered by the energy storage unit 505. Figure 4C and Figure 4D are zoomed view of at least a portion of the vehicle 100 in accordance with an embodiment of the present subject matter. As depicted in Figure 4C the sub-frame 225 mounted on the frame structure 200 has at least one mounting at the front and at least one mounting at rear to support energy storage unit 505 along with the energy storage unit case 510. Herein, the at least one mounting at the front is called as front mounting 605a for brevity, and the at least one mounting at the rear are called as the rear mounting 605b. The mountings provided in the locations stated provide stability to the energy storage units 505.
[00055] In an embodiment, the front mounting 605a is positioned lower than the rear mounting 605b, thereby the energy storage unit 505 will be placed inclined with the front face towards ground and rear face towards upward direction. Such placement of the energy storage unit 505 ensures making the center of gravity of the energy storage unit 505 closer to the center of the gravity of the vehicle 100, thereby ensuring better stability for the vehicle 100 and also makes it easier to remove and replace the energy storage units 505.
In accordance with an embodiment, a relief 600 is provided within the energy storage unit case 510 itself, wherein the energy storage unit case 510 is mounted to the sub-frame 225 of the vehicle 100.
[00056] In an embodiment the inverted trapezoidal shaped relief 600 is provided at front bottom portion of the energy storage unit case 510.
[00057] In an embodiment the relief 600 is inverted trapezoidal shaped.
[00058] The sub-frame 225 and relief 600 designed and positioned in the configuration stated in the embodiments of the application provide a stable platform for the energy storage units 505 while allowing easy access and removal for maintenance or replacement. Further, the relief 600 enables the smooth transition of the energy storage units 505 from position A to position C which minimizes the risk of damage to the energy storage units during installation and removal.
[00059] As per an aspect of the present embodiment, the at least one front mounting 605a between the energy storage unit case 510 and the sub-frame 225 is provided near the periphery of the inverted trapezoidal shaped relief 600 to mount the energy storage unit case 510 with the sub-frame 225. This positioning of the front mounting 605a provides additional support to the energy storage units 505.
[00060] In another embodiment, the inverted trapezoidal shaped relief 600 in the energy storage unit case 510 is positioned between the sub-frame 225 mountings with frame structure 200 and swingarm assembly 580, providing additional stability to the vehicle 100.
[00061] In another embodiment, the inverted trapezoidal shaped relief 600 of the energy storage unit case 510 is positioned near to vehicle Centre of gravity, providing stability and enabling better handling of vehicle 100.
[00062] As depicted in Figure 4D, the inverted trapezoidal shaped relief 600 includes at least two parallel bases 600a, 600c and at least two connecting legs 600b, 600d. The at least two parallel bases 600a, 600c include a top base 600a and a bottom base 600c; the at least two connecting legs 600b, 600d include a right connecting leg 600b and a left connecting leg 600d. In embodiment, the bottom base 600c of the inverted trapezoidal shaped relief 600 of the energy storage unit case 510 is positioned higher at vertical distance of ‘d’ from a fastener 620 outermost edge when viewed in side view of the vehicle. The fastener 620 is used to hold the energy storage unit case 510 with the sub-frame 225 when viewed in vehicle longitudinal direction. Such distance ‘d’ ensures that the head of the fastener 620 does not come in contact with the energy storage unit 505, when the energy storage unit 505 is being removed from the energy storage unit case 510 while servicing or replacing the energy storage unit 505.
[00063] In another embodiment, the parallel base (600a) corresponds to base member (520) of energy storage unit case (510), right connecting leg (600b) corresponds to a rearwardly inclined surface of the energy storage unit case (510), starting at the base member (520) of energy storage unit case (510) to the first mounting (605a), left connecting leg (600d) corresponds to a forwardly inclined surface of the energy storage unit case (510), starting at the base member (520) of energy storage unit case (510) to the first mounting (605a) and parallel base (600c) corresponds to an imaginary line joining the lower edge of right connecting leg (600b) and left connecting leg (600d).
[00064] In another embodiment, the vertical distance ‘d’ should be less than or equal to or twice the size of the fastener 620 diameter.
[00065] Figure 5A to Figure 5B illustrates a sectional side view of the frame structure 200 of the step through-type vehicle 100, when the energy storage unit 505 is being accessed from a space underneath the utility unit, as per an embodiment of the present subject matter.
[00066] In general, the energy storage unit 505 will be in rectangular shape, when positioned in the vehicle 100. To access either to assemble or service the energy storage unit 505, the energy storage unit 505 must be tilted which creates trapezoidal shape. This perimeter of trapezoidal shape is usually higher than perimeter of the original rectangular shape of the energy storage unit 505 during assembled condition.
[00067] Hence, while removing the energy storage unit 505 from the vehicle 100, the energy storage unit 505 needs more space for accessibility. Figure 5A shows positioning of the energy storage unit 505 when a user tries to access the energy storage unit 505. Herein, the different positions of the energy storage unit 505 are labelled as, position A, position B, position C. Thereby, the position of the energy storage unit 505 undergoes change from position A to position C, when the user tries to access the energy storage unit 505. The inverted trapezoidal shaped relief 600 ensures smooth transition of the position of the energy storage unit 505 from position A to position C. Once the transition is complete, the user is enabled to access and remove the energy storage unit 505, tangentially to the rear wheel 190 of the vehicle 100. Herein the XX’ axis defines the tangential axis.
[00068] Thereby, the inverted trapezoidal shaped relief 600 of the energy storage unit case 510 enhances ease of accessibility for the energy storage unit 505.
[00069] In another embodiment, the inverted trapezoidal shaped relief 600 of the energy storage unit case 510 enhances the accessibility of the energy storage unit 505 with adequate clearances around interface parts thus providing compact vehicle layout.
[00070] In another embodiment, the inverted trapezoidal shaped relief 600 of the energy storage unit case 510 has overlap with sub-frame 225 mountings with swingarm assembly 580 to enable better serviceability of the energy storage unit 505.
[00071] In another embodiment, the starting region of the inverted trapezoidal shaped relief 600 of the energy storage unit case 510 is behind the sub-frame 225 mountings with the frame structure 200, so that the energy storage unit 505 may be placed rigidly with sub-frame 225 during vehicle 100 operating conditions.
[00072] Many modifications and variations of the present subject matter are possible in the light of above disclosure. Therefore, within the scope of claims of the present subject matter, the present disclosure may be practiced other than as specifically described.

LIST OF REFERENCE NUMERALS

100: Step-through type vehicle, vehicle
102: IC engine
111: Turn signal lamp unit
105: Handlebar assembly
110: Headlamp assembly
121: Front fork
125: Front wheel
130: Leg shield
132: Front brake lever
135: Seat
140: Under-seat cover
145: Floorboard
165: Pillion-handle
170: Tail lamp unit
175: Left and right side covers
180: Rear fender
185: Muffler
190: Rear wheel
200: Frame structure
205: Head tube
210: Down frame member
220: Step-through frame members
225: Connecting frame member, sub-frame
230: First mounting member
245: Hub mounted electric machine
255: Rear frames
330: Axle
335: Bush member
340: Second mounting members
365: Upper frame members
375: Front base member
370: First supporting member
375: First base member
380: Rear base member
385: Case supporting member
505: Energy storage unit
510: Energy storage unit case
520: Bottom members
580: Swingarm assembly
600: Relief
600a: Top base
600b: Right connecting leg
600c: Bottom base
600d: Left connecting leg
605a: Front mounting
605b: Rear mounting
620: Fastener
,CLAIMS:We claim,
1. A vehicle (100) comprising:
a frame structure (200), the frame structure comprises,
a head tube (205),
a down frame member (210),
one or more step-through frame member (220),
one or more rear frame member (255) extending rearwardly and upwardly from a rear portion of the one or more step-through frame members (220),
a sub-frame (225) being connected to the one or more step-through frame member (220) and comprises a case supporting member (385);
an energy storage unit case (510), wherein the energy storage unit case (510) comprises a base member (520) being disposed on the case supporting member (385) of the sub-frame (225) and a relief (600) being provided within the energy storage unit case (510);
one or more energy storage unit (505) being held within the energy storage unit case (510);
2. The vehicle (100) as claimed in claim 1, wherein the relief (600) being configured to ensure smooth transition of the position of the one or more energy storage unit (505) from position A to position C, enabling access and removal of the one or more energy storage unit (505) from the vehicle (100).
3. The vehicle (100) as claimed in claim 1, wherein the case supporting member (385) extends rearwardly inclinedly from the pair of upper frame members (365) of the sub-frame (225).
4. The vehicle (100) as claimed in claim 1, wherein the energy storage unit (505) is supported by at least one front mounting (605a) and at least one rear mounting (605b) of the sub-frame (225).
5. The vehicle (100) as claimed in claim 4, wherein the front mounting (605a) is positioned lower than the rear mounting (605b) to place the energy storage unit (505) inclined with the front face towards ground and rear face towards upward direction.
6. The vehicle (100) as claimed in claim 4, wherein the at least one front mounting (605a) between the energy storage unit case (510) and the sub-frame (225) is provided near the periphery of the relief (600).
7. The vehicle (100) as claimed in claim 1, wherein the relief (600) is positioned between the sub-frame (225) mountings with frame structure (200) and swingarm assembly (580).
8. The vehicle (100) as claimed in claim 1, wherein the relief (600) of the energy storage unit case (510) is positioned near to vehicle centre of gravity.
9. The vehicle (100) as claimed in claim 1, wherein the relief (600) includes at least two parallel bases (600a, 600c) and at least two connecting legs (600b, 600d).
10. The vehicle (100) as claimed in claim 9, wherein the parallel base (600a) corresponds to base member (520) of energy storage unit case (510), right connecting leg (600b) corresponds to a rearwardly inclined surface of the energy storage unit case (510), starting at the base member (520) of energy storage unit case (510) to the first mounting (605a), left connecting leg (600d) corresponds to a forwardly inclined surface of the energy storage unit case (510), starting at the base member (520) of energy storage unit case (510) to the first mounting (605a) and parallel base (600c) corresponds to an imaginary line joining the lower edge of right connecting leg (600b) and left connecting leg (600d).
11. The vehicle (100) as claimed in claim 1, wherein the relief (600) being provided within the energy storage unit case (510) for mounting the energy storage unit case (510) with the sub-frame (225).
12. The vehicle (100) as claimed in claim 1, wherein relief (600) being inverted trapezoidal shaped.
13. The vehicle (100) as claimed in claim 9, wherein the base (600c) of the inverted trapezoidal shaped relief (600) is positioned higher at a vertical distance 'd' from a fastener (620) outermost edge when viewed from vehicle side view.
14. The vehicle (100) as claimed in claim 13, wherein vertical distance 'd' is less than or equal to or twice the size of the fastener (620) diameter.
15. The vehicle (100) as claimed in claim 1, wherein the energy storage unit (505) being removed along an axis tangential to the rear wheel (190) of the vehicle (100).