DESC:TECHNICAL FIELD
[001] The present invention relates to a diesel exhaust fluid (DEF) tank assembly having a tank shell body and a mounting structure that results in an increased storage capacity of the diesel exhaust fluid (DEF) tank in complex body-on-frame vehicle packaging environment.

BACKGROUND
[002] Generally, in order to comply with modern emission norms, diesel engine powered vehicles employ systems wherein exhaust treatment fluids are furnished to treat engine exhaust gases to considerably reduce nitrogen oxide (NOx) levels. Selective catalytic reduction (SCR) is one such system wherein a reducing agent such as an aqueous urea solution (generically termed as diesel exhaust fluid (DEF)) is dosed into an engine exhaust prior to exposure to a catalyst, to reduce NOx emissions by converting NOx gases into less toxic byproducts such as ammonia.
[003] In SCR system, a controlled amount of DEF is supplied from the DEF storage tank to a stream of exhaust emissions by means of a feed pump and dosing injector. Due to space constraints, especially in vehicles using body-on-frame structure, DEF storage tanks conventionally with limited size / capacity are used. In such cases, conventionally, DEF storage tanks are mounted in-board of the ladder frame using plurality of horizontal mounting brackets welded over frame long rails and cross members. Such conventional DEF storage tank shell body has plurality of integrated mounting surfaces which are fastened with corresponding mating frame brackets using fasteners. Shape of such conventional DEF storage tanks are boxy wherein length and width of the tank are much larger than height of the tank. Height of these conventional tanks are limited at the top by body floor and ground clearance planes in bottom. Capacity of such conventional DEF storage tanks are limited due to space constraints on vehicle. To mitigate the limitation of storage capacity, conventionally DEF storage tanks having larger length has been developed but unusable fluid volume increases, while vehicle is negotiating gradients, there by defeating the purpose. Also, such larger conventional tanks required higher investments to develop. Additionally, such larger conventional tanks are more susceptible to fluid slosh noise requiring plurality of internal baffles, inflating the component cost. Limited capacity of conventional DEF Storage Tank leads to vehicle requiring frequent DEF filling making vehicle usage inconvenient especially considering limited availability of DEF as against availability of diesel fuel or gasoline fuel.
[004] Therefore, there is a need to provide a diesel exhaust fluid (DEF) tank assembly to overcome one or more of the aforementioned problems.

SUMMARY
[005] Accordingly, an exemplary aspect of the present invention discloses a diesel exhaust fluid (DEF) storage tank assembly for a body-on-frame vehicle comprising a tank shell body mounted outwardly, extending beyond ladder frame structure of the vehicle ensuring an increased storage capacity of the diesel exhaust fluid (DEF) storage tank. The vertical space available in vehicle out-board of ladder frame is utilized to design DEF storage tank in L-shape wherein height of the tank is considerably larger than length and width of the tank. The tank shell body has a plurality of parallel recessed zones with parallel inclined mounting surfaces and a plurality of parallel horizontal mounting surfaces. To appropriately support overhung weight of the DEF storage tank, mounting structure is provided extending beyond vehicle frame’s long rail. The mounting structure welded on frame has a plurality of cantilever mounting brackets mating with inclined mounting surfaces of the tank shell body and a plurality of horizontal mounting brackets mating with horizontal mounting surfaces of the tank shell body. DEF storage tank is mounted over frame mounting brackets using fasteners. All the mounting surfaces are integrated with blow moulded tank shell body, and they are located and oriented along the parting line in such a way that peak blow depth on either side of tank shell body are well balanced to ensure adequate wall thicknesses.

BRIEF DESCRIPTION OF ACCOMPANYING DRAWINGS
[006] The above and other aspects, features, and advantages of certain exemplary embodiments of the present invention will be more apparent from the following description taken in conjunction with the accompanying drawings in which:
[007] Figure 1 illustrates a bottom view of a vehicle with a diesel exhaust fluid (DEF) tank assembly, according to an aspect of the present invention;
[008] Figure 2 illustrates a side view of the diesel exhaust fluid (DEF) tank assembly at a lower rear end of the vehicle off board and extending beyond ladder frame chassis, according to an embodiment of the present invention;
[009] Figure 3 illustrates an isometric view of the diesel exhaust fluid (DEF) tank assembly, according to the embodiment of the present invention;
[010] Figure 4 illustrates a detailed rear view of the diesel exhaust fluid (DEF) tank assembly, according to the embodiment of the present invention; and
[011] Figure 5 illustrates a detailed front view of the diesel exhaust fluid (DEF) tank assembly, according to the embodiment of the present invention.
[012] Persons skilled in the art will appreciate that elements in the figures are illustrated for simplicity and clarity and may have not been drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to the other elements to help to improve understanding of various exemplary embodiments of the present disclosure. Throughout the drawings, it should be noted that like reference signs are used to depict the same or similar elements, features, and structures.

DETAILED DESCRIPTION
[013] While this invention is susceptible of embodiments in many different forms, there is shown in the drawings and will herein be described in detail, a preferred embodiment of the invention with the understanding that the present disclosure is to be considered as an exemplification of the principles of the invention and is not intended to limit the broad aspects of the invention to the embodiment illustrated. Other aspects, advantages, and salient features of the invention will become apparent to those skilled in the art from the following detailed description, which, taken in conjunction with the annexed drawings, discloses exemplary embodiments of the invention. Embodiments of the present disclosure will now be described with reference to the accompanying drawings. Embodiments are provided so as to thoroughly and fully convey the scope of the present disclosure to a person skilled in the art. Numerous details are set forth relating to specific components to provide a complete understanding of embodiments of the present disclosure. It will be apparent to the person skilled in the art that the details provided in the embodiments should not be construed to limit the scope of the present disclosure. In some embodiments, well-known processes, well-known apparatus structures, and well-known techniques are not described in detail.
[014] In general, the present invention claims a diesel exhaust fluid (DEF) tank assembly coupled to a mounting structure of the body-on-frame vehicle, comprising a tank shell body mounted outwardly, extending beyond ladder frame structure of the vehicle ensuring an increased storage capacity of the diesel exhaust fluid (DEF) storage tank. The tank shell body has a plurality of parallel recessed zones with parallel inclined mounting surfaces and a plurality of parallel horizontal mounting surfaces. To appropriately support overhung weight of the DEF storage tank, mounting structure is provided extending beyond vehicle frame’s long rail. The mounting structure welded on frame has a plurality of cantilever mounting brackets mating with inclined mounting surfaces of the tank shell body and a plurality of horizontal mounting brackets mating with horizontal mounting surfaces of the tank shell body.
[015] The terminology used, in the present disclosure, is only for the purpose of explaining a particular embodiment and such terminology shall not be considered to limit the scope of the present disclosure. The use of the expression “at least” or “at least one” suggests the use of one or more elements or ingredients or quantities, as the use may be in the embodiment of the disclosure to achieve one or more of the desired objects or results. As used in the present disclosure, the forms “a,” “an,” and “the” may be intended to include the plural forms as well, unless the context clearly suggests otherwise. The terms “comprises,” “comprising,” “including,” “made of” and “having,” are open ended transitional phrases and therefore specify the presence of stated elements, units and/or components, but do not forbid the presence or addition of one or more other elements, components, and/or groups thereof.
[016] The terms and words used in the following description and claims are not limited to the bibliographical meanings, but, are merely used by the inventor to enable a clear and consistent understanding of the invention. Accordingly, it should be apparent to those skilled in the art that the following description of exemplary embodiments of the present invention are provided for illustration purpose only and not for the purpose of limiting the invention as defined by the appended claims and their equivalents. Accordingly, it should be apparent to those skilled in the art that the following description of DEF tank assembly referred in the description for the purpose of the understanding and nowhere limit the invention. The skilled person will be able to devise various structures, shapes of the DEF tank assembly that, although not explicitly described herein, embody the principles of the present invention. All the terms and expressions in the description are only for the purpose of the understanding and nowhere limit the invention. Terms plurality, top, bottom, front end, rear end, first, second, parallel, inner, outer, perpendicular, primary, secondary, and the like are used to differentiate between objects having the same terminology and are in no way intended to represent a chronological order, unless where explicitly stated otherwise. Moreover, all statements herein reciting principles, aspects, and embodiments of the invention, as well as specific examples thereof, are intended to encompass equivalents thereof. Thus, while particular type of structure of the DEF tank assembly, shell body, with desired configuration, volume, depth, shape, material, heights, lengths, widths, diameters, thickness, distances, angles, inclination, mounting surfaces, mounting structures, manufacturing processes, have been disclosed, nowhere limit the invention and are provided for understanding of the invention. It will be appreciated those of ordinary skill in the art that various changes and modifications of the embodiments manufactured with other design parameters and configurations as well and are not limited to those described herein above may be as per operational requirements by making necessary changes without departing from the scope of the invention.
[017] Figures 1-5 disclose a diesel exhaust fluid (DEF) tank assembly (100), a diesel exhaust fluid (DEF) storage tank shell body (105), at least an orifice (106), at least a horizontal mounting surface (110), at least an inclined mounting surface (120), a filler and venting unit (130), a plurality of horizontal mounting brackets (140), a plurality of cantilever mounting brackets (150), a rear left / right wheel (160), a parting line (PL),
a height (h) of tank shell body, a width (w) of the tank shell body, a length (l) of the tank shell body, a feed pump protective cover (170) and a peak blow depth (BD).
[018] According to an exemplary aspect, the present invention, Referring Figures 1-5, discloses a diesel exhaust fluid (DEF) tank assembly (100) for a body-on-frame vehicle. The diesel exhaust fluid (DEF) tank assembly (100) comprises a L-shaped tank shell body (105) mounted outwardly, extending beyond ladder frame structure of the vehicle ensuring an increased storage capacity of the diesel exhaust fluid (DEF) storage tank. The tank shell body (105) has a plurality of parallel recessed zones with parallel inclined mounting surfaces (120) and a plurality of parallel horizontal mounting surfaces (110).
[019] According to an exemplary embodiment, the diesel exhaust fluid (DEF) tank assembly (100) includes a mounting structure for mounting said tank shell body (105).
The mounting structure welded on frame has a plurality of cantilever mounting brackets (150) mating with inclined mounting surfaces (120) of the tank shell body (105) and a plurality of horizontal mounting brackets (140) mating with horizontal mounting surfaces (110) of the tank shell body.
[020] According to the exemplary embodiment, each said cantilever mounting bracket (150) is coupled to each said inclined mounting surface (120) and each said horizontal mounting bracket (140) is coupled to each said horizontal mounting surface (110). According to the exemplary embodiment of the present invention, each inclined mounting surface (120) is at 45° with respect to each horizontal mounting surface (110). However, the inclination angle is not limited to 45° and may be as per design and operational requirements. The plurality of parallel recessed zones aid in easy coupling of the plurality of cantilever mounting brackets (150) with the parallel inclined mounting surfaces (120).
[021] According to the exemplary embodiment of the present invention, each said horizontal mounting bracket (140) and each said cantilever mounting bracket (150) aid in connecting said shell body (105) of said diesel exhaust fluid (DEF) storage tank to chassis via not limited to but includes a plurality of fasteners or the like. The fasteners may include but are not limited to nuts and bolts, screws or a combination thereof. The DEF storage tank may be made of materials that include but not limited to, for example a high-density polyethylene (HDPE). The mounting of DEF storage tank may include but not limited to mounting DEF storage tank outwardly off-board extending beyond chassis frame at a bottom left / right rear end of the chassis of the vehicle adjacent to a rear left / right wheel (160) of the vehicle. The plurality of cantilever mounting brackets (150) and the plurality of horizontal mounting brackets (140) are coupled to a chassis of the vehicle. According to the exemplary embodiment of the present invention, each said inclined mounting surface (120) and each said horizontal mounting surface (110)
is located and oriented along the parting line (PL) of said tank shell body (105).
[022] According to the exemplary embodiment of the present invention, the tank shell body (105) has orifices (106) for coupling with a diesel exhaust fluid (DEF) filler and venting unit (130) and a diesel exhaust fluid (DEF) supply unit. The filler and venting unit (130) include inlet tubes with a filler port with integrated inlet control valve and another tube with vent port connecting the orifices (106) located on the top surface of the shell body (105) to facilitate controlled filling and refilling of said diesel exhaust fluid (DEF). Vent tube is shown in figure 3. The diesel exhaust fluid (DEF) tank further includes a feed pump connected to an orifice located at bottom surface for supplying a controlled amount of said diesel exhaust fluid (DEF) from said diesel exhaust fluid (DEF) storage tank. The feed pump is encapsulated by a protection cover (170).
[023] According to the exemplary embodiment of the present invention, said diesel exhaust fluid (DEF) storage tank shell body (105) is formed by a blow molding process. The blow molded tank shell body (105) is defined by a plurality of inclined mounting surfaces (120) and a plurality of said horizontal mounting surfaces (110) are located and oriented along the parting line (PL) of said tank shell body (105). According to the exemplary embodiment of the present invention, the tank shell body (105) is not limited to but includes a L-shaped structure having height (h) considerably greater than a width (w) and a length (l) of the said tank shell body (105). Due to proposed structure of tank shell body (105) present invention allows to have minimum un-useable DEF volume when vehicle is negotiating gradients and also helps in containing fluid slosh noise.
[024] According to the exemplary embodiment of the present invention, a peak blow depth (BD) is defined as a maximum distance between a point on the parting line (PL) to an outermost surface of the shell body (105). According to the embodiment, both horizontal mounting surfaces (110) and both inclined mounting surfaces (120) are located and oriented along the blow molding parting line (PL) in such a way that peak blow depth (BD) on either side of tank shell body are minimized and well balanced to ensure adequate wall thicknesses which helps in containing fluid slosh noise. Thus, the limitation of blow molding process in controlling wall thicknesses are contained. Additionally, with the teachings of the present invention, the capacity of the DEF tank shell body (105) can be maximized in challenging body-on-frame vehicle packaging environment, by virtue of using inclined mounting surfaces (120). Another advantage of the present invention is that, by locating and orienting both horizontal mounting surfaces (110) and both inclined mounting surfaces (120) along the blow molding parting line (PL), no separate or welded mounting feature needs to be added over the tank shell body (105) which makes design economical because of lower component development cost and lower manufacturing cycle time.
[025] There have been described and illustrated herein several embodiments of exemplary indicative implementation of a diesel exhaust fluid (DEF) tank assembly. It will be also apparent to a skilled person that the embodiments described above are specific examples of a single broader invention, which may have greater scope than any of the singular descriptions taught. There may be many alterations made in the description without departing from the scope of the invention. While particular embodiments of the invention have been described, it is not intended that the invention be limited to said configuration disclosed thereto, as it is intended that the invention be as broad in scope as the art will allow and that the specification be read likewise not restrictive to the terminology described herein above. Any discussion of embodiments included in this specification is solely for the purpose of providing a context for the disclosure. It is not to be taken as an admission that any or all of these matters form a part of the prior art base or were common general knowledge in the field relevant to the disclosure as it existed anywhere before the priority date of this application.
,CLAIMS:
1. A diesel exhaust fluid (DEF) tank assembly (100) for a body-on-frame vehicle, said diesel exhaust fluid (DEF) tank assembly (100) comprising:
a tank shell body (105) mounted outwardly, extending beyond a ladder frame structure of the body-on-frame vehicle defining an increased storage capacity of the diesel exhaust fluid (DEF) storage tank, said tank shell body (105) having a plurality of parallel recessed zones with parallel inclined mounting surfaces (120) and a plurality of parallel horizontal mounting surfaces (110); and
a mounting structure for supporting said tank shell body (105) having a plurality of cantilever mounting brackets (150) mating with inclined mounting surfaces (120) of the tank shell body (105) and a plurality of horizontal mounting brackets (140) mating with horizontal mounting surfaces (110) of the tank shell body (105).

2. The diesel exhaust fluid (DEF) tank assembly (100) as claimed in claim 1, wherein each said inclined mounting surface (120) and each said horizontal mounting surface (110) is located and oriented along the blow molding parting line (PL) to balance a peak blow depth (BD) on either side of tank shell body (105).

3. The diesel exhaust fluid (DEF) tank assembly (100) as claimed in claim 1 or 2, wherein said tank body shell (105) is a L-shaped structure having height (h) considerably greater than a width (w) and a length (l) of the said tank shell body (105).

4. The diesel exhaust fluid (DEF) tank assembly (100) as claimed in any one of the preceding claims 1-3, wherein said inclined mounting surfaces (120) and said horizontal mounting surfaces (110) are located and oriented to minimize peak blow depth (BD) for an outermost surface of the tank shell body (105).