Description:TECHNICAL FIELD
[0001] The present disclosure generally relates to underbody structures of vehicles and more particularly, relates to an inflatable underbody structure integrated to a Body In white (BIW) of an electric vehicle for reducing aerodynamic drag and to prevent/ mitigate thermal runaway of batteries of the electric vehicle.
BACKGROUND
[0002] In vehicles, particularly electric vehicles, aerodynamics play a crucial role in determining a range of the vehicle. The range of the vehicle increases with decrease in aerodynamic drag experienced by the vehicle. The energy used to overcome air resistance cannot be recovered with vehicle acceleration and therefore, good aerodynamics and low air resistance are more important for extending the range of the vehicles. Essentially, batteries of the electric vehicle have less capacity available to power electric vehicles as compared to vehicles powered by an internal combustion engine. So, optimization of efficiency in every area including aerodynamics of the vehicle is vital.
[0003] Generally, the aerodynamic drag is dependent on the design configuration of the vehicle. A tear drop shape of the vehicle optimizes the aerodynamics of the vehicle. The upper portion of the vehicle is designed to achieve the tear drop shape, however, due to packaging and ground clearance constraints, generally the vehicle underbody is designed to be flat and does not have any curvatures to reduce the aerodynamic drag.
[0004] In a conventional vehicle, the underbody houses a large number of parts such as the exhaust pipes, mufflers, fuel tank and in some vehicle configurations, a gearbox and a propeller shaft. These parts contribute to a large number of the total drag due to the disruption of the airflow passing along the underbody of a vehicle. In order to reduce airflow disturbance, some modifications have been made on the design of the underbody panels.
[0005] In a typical electric vehicle, either an all-electric or hybrid vehicle, the battery pack is mounted to the vehicle's floor (i.e., underbody) in a location intended to be as unobtrusive as possible. This placement of the battery not only improves the handling, stability and ride comfort due to the lower center of gravity but also aids aerodynamic performance. Although a flat underbody contributes to the great aerodynamic performance of vehicles, there is scope in optimization of aerodynamic performance by optimizing the design of the underbody of the vehicle.
[0006] In some prior arts, modifications have been made to the underbody of the vehicle to improve the aerodynamics of the vehicle by reducing the drag experienced by the vehicle. The existing solutions include providing a suspension system which facilitates varying a height of the underbody from a ground surface to improve aerodynamics of the vehicle. An alternative solution is providing a plastic underbody with a curved shape. However, providing an additional suspension system and a plastic underbody increases the manufacturing cost and affects the maintenance of the vehicle. Also providing a curved plastic underbody affects the ground clearance of the vehicle.
[0007] Another issue which affects the performance of the electric vehicle is the possibility of a thermal runaway in the battery, leading to failure of the vehicle. Additional measures have to be taken to prevent and mitigate thermal runaway in the battery of the electric vehicle. If the thermal runaway is not restricted in its initial stage, it can cause damage to the entire vehicle and endanger lives of the passengers of the vehicle. Generally, the thermal runaway in battery is addressed by providing extra thermal barriers in the battery pack. However, these thermal barriers have the limitation of spreading the thermal runaway of cells for some time and it can still spread if the runaway continues. Therefore, there is a requirement of providing additional measures in the electric vehicle for mitigating thermal runaway in the battery.
[0008] Thus, there is a need for providing an underbody of the vehicle which improves the aerodynamics of the vehicle, does not affect the performance of the vehicle by providing varying ground clearance in the vehicle, and also functions as an additional kit for mitigating thermal runaway in the battery of the electric vehicle.
OBJECTS
[0009] The principal object of an embodiment of this invention is to provide an inflatable underbody structure for an electric vehicle which reduces an aerodynamic drag experienced by the vehicle.
[0010] Another object of an embodiment of this invention is to provide the inflatable underbody structure for the electric vehicle which is adapted to be inflated for reducing aerodynamic drag and deflated to increase a ground clearance of the vehicle.
[0011] Still another object of an embodiment of this invention is to provide the inflatable underbody structure which is inflatable with any one of an atmospheric air or nitrogen.
[0012] Yet another object of an embodiment of this invention is to provide the inflatable underbody structure which aids in mitigating thermal runaway in a battery pack of the electric vehicle by discharging nitrogen from the inflated underbody structure to the battery pack via an air pump provided in communication with the inflatable underbody structure.
[0013] Another object of an embodiment of this invention is to provide the inflatable underbody structure which protects the vehicle in a flood condition by enabling the vehicle to float on water.
[0014] Yet another object of an embodiment of this invention is to provide a method for controlling inflation and deflation of the inflatable underbody structure of a vehicle.
[0015] These and other objects of the embodiments herein will be better appreciated and understood when considered in conjunction with the following description and the accompanying drawings. It should be understood, however, that the following descriptions, while indicating embodiments and numerous specific details thereof, are given by way of illustration and not of limitation. Many changes and modifications may be made within the scope of the embodiments herein without departing from the spirit thereof, and the embodiments herein include all such modifications.

BRIEF DESCRIPTION OF DRAWINGS
[0016] The embodiments herein are illustrated in the accompanying drawings, throughout which like reference letters indicate corresponding parts in the various figures. The embodiments herein will be better understood from the following description with reference to the drawings, in which:
[0017] Fig. 1 depict a front view of an inflatable underbody structure assembled to a vehicle underbody, according to an embodiment of the invention as disclosed herein;
[0018] Fig. 2 is a top-perspective view of the inflatable underbody structure, according to an embodiment of the invention as disclosed herein;
[0019] Figs. 3a and 3b depict a front view of the inflatable underbody structure, according to an embodiment of the invention as disclosed herein;
[0020] Fig. 4 is a block diagram depicting an air pump provided in communication with the inflatable underbody structure, a battery pack of the vehicle, and a controller for use of the inflatable structure in mitigating thermal runaway in the vehicle, according to an embodiment of the invention as disclosed herein;
[0021] Fig. 5 is a flowchart depicting a process flow of a method of inflating and deflating an inflatable underbody structure of a vehicle, according to an embodiment of the invention as disclosed herein; and
[0022] Fig. 6 is a flowchart depicting a method of controlling a thermal runaway within a battery pack of a vehicle, according to an embodiment of the invention as disclosed herein.
DETAILED DESCRIPTION
[0023] The embodiments herein and the various features and advantageous details thereof are explained more fully with reference to the non-limiting embodiments that are illustrated in the accompanying drawings and detailed in the following description. Descriptions of well-known components and processing techniques are omitted so as to not unnecessarily obscure the embodiments herein. The examples used herein are intended merely to facilitate an understanding of ways in which the embodiments herein may be practiced and to further enable those of skill in the art to practice the embodiments herein. Accordingly, the examples should not be construed as limiting the scope of the embodiments herein.
[0024] The embodiments herein achieve an inflatable underbody structure for an electric vehicle which reduces an aerodynamic drag experienced by the vehicle. Further, the embodiments herein achieve the inflatable underbody structure for the electric vehicle which is adapted to be inflated for reducing aerodynamic drag and deflated to increase a ground clearance of the vehicle. Furthermore, the embodiments herein achieve the inflatable underbody structure which is inflatable with any one of an atmospheric air and nitrogen. Moreover, the embodiments herein achieve the inflatable underbody structure which aids in mitigating thermal runaway in the battery pack of the electric vehicle by discharging nitrogen from the inflated underbody structure to the battery pack via an air pump provided in communication with the inflatable underbody structure. The embodiments herein achieve the inflatable underbody structure which protects the vehicle in a flood condition by enabling the vehicle to float on water. Additionally, the embodiments herein achieve a method for controlling inflation and deflation of the inflatable underbody structure of a vehicle. Referring now to the drawings, and more particularly to FIGS. 1 through 5, where similar reference characters denote corresponding features consistently throughout the figures, there are shown embodiments.
[0025] Fig. 1 depicts a front view of an inflatable underbody structure assembled to a vehicle underbody, according to an embodiment of the invention as disclosed herein. The inflatable underbody structure (100) (hereafter referred to as inflatable structure in this description) comprises a body (101) made of vinyl polymer. In an embodiment, the inflatable structure (100) comprises a rubber body (101) which is inflatable. Further, the inflatable structure (100) is glued to an underbody panel of the vehicle (200), according to an embodiment of the invention. In another embodiment, the inflatable structure (100) is mounted on a chassis of the vehicle (200) using a sealant.
[0026] In an embodiment of the invention, the inflatable structure (100) is attached to an underbody panel of an electric vehicle. However, it is also within the scope of the invention to provide the inflatable structure in any other kind of vehicle, without deterring from the intended purpose of the invention.
[0027] As shown in Figs. 3a and 3b, the inflatable structure (100) has a tear drop shape when the inflatable structure is inflated to aid reduction of the aerodynamic drag experienced by the vehicle (200) in motion. The inflatable structure (100) is disposed across a length of the vehicle (200), wherein a fore portion (100F) of the inflatable structure (100) is disposed towards a front end of the vehicle (200) and an aft portion (100R) of the inflatable structure (100) is disposed towards a rear end of the vehicle (200). In an inflated condition, the inflated structure (100) takes a convex shape, wherein the inflatable structure (100) bulges outwards in a middle portion and tapers in the fore portion (100F) and aft portion (100R). In a deflated condition, the inflatable structure (100) remains flat against the underbody panel, as shown on Fig. 2.
[0028] Further, a valve (102) is provided in communication with the inflatable structure (100), wherein the valve (102) allows the ingress of one of air and nitrogen gas into the inflatable structure (100) and egress of one of air and nitrogen gas from the inflatable structure (100). In an embodiment of the invention, the inflatable structure (100) is adapted to be filled with atmospheric air. In another embodiment, the inflatable structure (100) is adapted to be filled with nitrogen gas.
[0029] In an embodiment of the invention, an air pump (202) is provided in communication with the inflatable structure (100) via the valve (102). The air pump (202) is configured to pump air into the inflatable structure (100) for inflating the inflatable structure (100) and deflating the inflatable structure (100) by drawing out air from the inflatable structure (100) via the valve (102). In an embodiment, the inflatable structure (100) is inflated with an external source of air/gas.
[0030] In an embodiment of the invention, a controller (206) is provided in communication with the air pump (202). The controller (206) is programmed to actuate the air pump (202) to inflate and/or deflate the inflatable structure (100) in accordance with a set of predetermined conditions. The inflatable structure (100) is inflated by actuating the air pump (202) when the controller (206) determines that a speed of the vehicle (200) is above a predetermined threshold speed and the road condition is smooth so that the vehicle (200) is operable with a lower ground clearance on the road. The determination of speed of the vehicle and the road condition can be based on the mode in which the vehicle (200) is being driven. As a non-limiting example, if the vehicle (200) is being operated in a highway mode, the controller (206) will actuate the air pump (202) disposed within the vehicle (200) to fill the inflatable structure (100) with atmospheric air.
[0031] The inflatable structure (100) is deflated when the controller (206) receives an over-riding signal from the driver of the vehicle (200) to deflate the inflatable structure (100). In an embodiment, a user interface of the vehicle (200) is provided in communication with the controller (206) to provide an input signal to deflate and/or inflate the inflatable structure (100). Alternatively, the air pump (202) is actuated to deflate the inflatable structure (100) by the controller (206) when the controller (206) determines that the speed of the vehicle (200) is below a threshold speed, or the road condition is such that a high ground clearance is required for the vehicle (200) to operate on the road. As a non-limiting example, if the vehicle (200) is being operated in a city mode, the controller (206) will actuate the air pump (202) to draw out air from the inflatable structure (100).
[0032] According to an embodiment of the invention as shown in Fig. 4, the inflatable structure (100) is filled with nitrogen gas and the air pump (202) is provided in fluid communication with the inflatable structure (100) via the valve (102). The air pump (202) is also in fluid communication with a battery pack (204) of the vehicle (200). When a thermal runaway condition of the battery pack (204) is detected by a sensor (not shown) disposed within the battery pack (204), the air pump (202) is actuated by the controller (206) and the nitrogen gas from the inflatable structure (100) is drawn out and delivered to the battery pack (204) via a channel (not shown). As a result, the battery pack (204) is flushed with an inert gas such as nitrogen gas which helps in mitigating thermal runaway. Flushing the battery pack (204) with nitrogen gas delays the process of thermal runaway and therefore increases evacuation time available for the driver and the passengers before any fire hazard is caused.
[0033] In an embodiment, the controller (206) is a controller of the battery management system of the electric vehicle.
[0034] Further, in an embodiment of the invention, the inflatable structure (100) is adapted to be inflated across a length of the vehicle (200) and across a width of the vehicle (200) such that the inflatable structure (100) enables the floating of the vehicle (200) on water, upon a water flood condition. In the flood condition, the inflatable structure (100) protects the vehicle from being submerged into the water by enabling the body of the vehicle (200) to float over the water via the inflatable structure (100).
[0035] Fig. 5 is a flowchart depicting a process flow of a method of controlling inflation and deflation of an inflatable structure (100) attached to an underbody panel of an electric vehicle (200). The method (300) includes providing a controller (206) in communication with an air pump (202) disposed in fluid communication with a valve (102) attached to the inflatable structure (100). The method (300) further includes determining by the controller (206), whether a speed of the vehicle (200) is above a predetermined threshold speed and the vehicle (200) is operable with a low ground clearance on a road. Furthermore, the method (300) includes actuating the air pump (202) to inflate the inflatable structure (100) by the controller (206) when the speed of the vehicle (200) is above the threshold speed and the vehicle (200) is operable with a low ground clearance. The method (300) also includes actuating the air pump (202) to deflate the inflatable structure (100) by the controller (206), on determining any one of condition comprising receiving an input signal from a driver of the vehicle (200) for deflating the inflatable structure (100), the speed of the vehicle (200) reaching below a predetermined threshold speed, and a high ground clearance is required for operation of the vehicle (200), is satisfied.
[0036] Fig.6 is a flowchart depicting a method (400) of controlling a thermal run-away within a battery pack (204) of the vehicle (200). According to an embodiment, the method (400) includes providing the controller (206) in communication with the air pump (202) disposed in fluid communication with the valve (102) attached to the inflatable structure (100) (at step 402). Further, the method (400) for controlling the thermal run-away includes detecting and communicating a thermal run-away condition by a sensor disposed within the battery pack (204) to the controller (206) (at step 404). Furthermore, the method (400) includes actuating the air pump (202) to deflate the inflatable structure (100) and discharge nitrogen into the battery pack (204) by the controller (206) based on an input signal received from the sensor (at step 406).
[0037] The technical advantages achieved by the embodiments disclosed herein includes reducing the aerodynamic drag experienced by the vehicle in motion, aiding in mitigating thermal runaway of the battery pack, protecting the vehicle in a flood condition by inflating the inflatable structure to enable the vehicle to float on water, inexpensive and easy for maintenance.
[0038] The foregoing description of the specific embodiments will so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the spirit and scope of the embodiments as described herein.
, Claims:1. An inflatable structure (100) for a vehicle (200), comprising:
a body (101) attached to an outer surface of an underbody panel of the vehicle (200), said body (101) defining an aerodynamic convex shape in an inflated condition; and
a valve (102) provided in communication with the inflatable structure (100).

2. The inflatable structure (100) as claimed in claim 1, wherein the valve (102) is adapted to allow ingress of one of air and nitrogen gas into the inflatable structure (100) and egress of said air and nitrogen gas from the inflatable structure (100).

3. The inflatable structure (100) as claimed in claim 2, wherein an air pump (202) is provided in fluid communication with the inflatable structure (100), the air pump (202) is configured to fill the inflatable structure (100) with one of said atmospheric air and nitrogen, and collapse the inflatable structure (100) by discharging said one of atmospheric air and nitrogen from the inflatable structure (100).

4. The inflatable structure (100) as claimed in claim 3, wherein said air pump (202) is provided in communication with a controller (206), the controller (206) is configured to control said inflation and deflation of the inflatable structure (100) by actuating the air pump (202), wherein the controller (206) is a controller of the battery management system of the vehicle (200).

5. The inflatable structure (100) as claimed in claim 4, wherein the controller (206) is configured to:
actuate the air pump (202) to inflate the inflatable structure (100), when a speed of the vehicle (200) is above a predetermined threshold speed and the vehicle (200) is operable with a low ground clearance on a road; and
actuate the air pump (202) to deflate the inflatable structure (100) in any one of a condition comprising:
a driver of the vehicle (200) providing an input signal to the controller (206) to deflate the inflatable structure (100);
the vehicle (200) requiring a high ground clearance to operate on the road; and
the speed of the vehicle (200) reaches below a predetermined threshold speed.

6. The inflatable structure (100) as claimed in claim 4, wherein the air pump (202) is provided in fluid communication with the valve (102) of the inflatable structure (100) and a battery pack (204) of the vehicle (200), wherein the air pump (202) is configured to draw the nitrogen gas from the inflatable structure (100) via the valve (102) and supply the nitrogen gas to the battery pack (204) via a channel, during a thermal runaway of the battery pack (204).

7. The inflatable structure (100) as claimed in claim 6, wherein a sensor is positioned within the battery pack (204) of the vehicle (200) to measure/detect and communicate an input signal to said controller (206), when said battery pack (204) is under said thermal run-away.

8. The inflatable structure (100) as claimed in claim 1, wherein the inflatable structure (100) is adapted to be inflated across a length of the vehicle (200) and across a width of the vehicle (200) such that the inflatable structure (100) enables floating of the vehicle (200) on water in a flood condition.

9. The inflatable structure (100) as claimed in claim 1, wherein the inflatable structure (100) comprises a body made of vinyl polymer.

10. The inflatable structure (100) as claimed in claim 1, wherein the inflatable structure (100) is mounted on the underbody panel of the vehicle by a fastening means, glue and/or a sealant.

11. The inflatable structure (100) as claimed in claim 1, wherein, said inflatable structure (100) defines said convex shape in the inflated condition and retains a flat shape on the underbody panel of the vehicle (200), in a deflated condition and, wherein,
a fore portion (100F) of the inflatable structure (100) is defined towards a front end of the vehicle (200); and
an aft portion (100R) of the inflatable structure (100) is defined towards a rear end of the vehicle (200), said aft portion (100R) is narrower than a bulging convex middle portion of the inflatable structure (100).

12. A method (300) of controlling inflation and deflation of an inflatable structure (100) attached to an underbody panel of a vehicle (200), the method comprising:
providing a controller (206) in communication with an air pump (202) disposed in fluid communication with a valve (102) attached to the inflatable structure (100);
determining, by the controller (206), whether a speed of the vehicle (200) is above a predetermined threshold speed and the vehicle (200) is operable with a low ground clearance on a road;
actuating, the air pump (202) to inflate the inflatable structure (100) by the controller (206), when the speed of the vehicle (200) is above the predetermined threshold speed and the vehicle (200) is operable with said low ground clearance; and
actuating, the air pump (202) to deflate the inflatable structure (100), by the controller (206), on a satisfaction of at least one of a condition comprising receiving an input signal from a driver of the vehicle (200) for deflating the inflatable structure (100), the speed of the vehicle (200) reaching below the predetermined threshold speed, and a high ground clearance is required for operation of the vehicle (200).

13. A method (400) of controlling a thermal run-away within a battery pack (204) of a vehicle (200), the method (400) comprising:
providing, a controller (206) in communication with an air pump (202) disposed in fluid communication with a valve (102) attached to an inflatable structure (100);
detecting and communicating, a thermal run-away condition, by a sensor, disposed within said battery pack (204) to said controller (206); and
actuating, the air pump (202) to deflate the inflatable structure (100) and discharge nitrogen into the battery pack (204), by the controller (206) based on an input signal received from the sensor.