A method of manufacturing a lift-gate of a vehicle

Abstract

A method of manufacturing a lift-gate (110) of a vehicle comprising the following steps: • locating and positioning a first panel (12) on a machining station (50); • locating and positioning a second panel (22) adjacent to and abutting the first panel with the help of supports (21, 23); • hemming an edge (13) of the first panel and an edge of the second panel (33) to enable interlocking of the first panel and the second panel (22), and form interlocked hemmed edges; • welding along the interlocked hemmed edges of the first panel and the second panel at predetermined locations (11), to join the first panel and the second panel; • locating and positioning a third panel (32) adjacent to and abutting a free edge (34) of the second panel; and • welding along the free edge (34) of the second panel and the third panel (32) at predetermined locations.

Description

[0001]A METHOD OF MANUFACTURING A LIFT-GATE OF A VEHICLE FIELD The present disclosure relates to a method of manufacturing a lift-gate of a vehicle for providing access to an operative rear of the vehicle. DEFINITION As used in the present disclosure, the following terms are generally intended to have the meaning as set forth below, except to the extent that the context in which they are used indicate otherwise. Lift-gate – The term ‘lift-gate’ refers to means configured on the vehicle for accessing the interior of the vehicle and one that has provision for attachment of tail lamps or indicators or combination thereof. The lift-gate is typically in the form of a door, a hatchback, that is opened by lifting. It comprises a plurality of panels, generally brazed or welded together to form the lift-gate. Interlocking – The term ‘interlocking’ refers to fitment of panels that constrains any relative movement between the panels. BACKGROUND The background information herein below relates to the present disclosure but is not necessarily prior art. A lift-gate provides access through an operative rear of a vehicle. The lift-gate assembly is attached to the structure of the vehicle. The lift-gate assembly includes a plurality of panels configured to be attached to each other. For example, the edges of the panels are configured to be welded together. To accommodate styling constraints on the lift-gate, the conventional lift-gate teaches a method of attachment of separate plastic panel of a desired profile to the panels to improve the aesthetics of the lift-gate assembly. However, the use of plastic cover results in visible parting lines that deteriorate the aesthetic appeal of the vehicle. Moreover, the panels are joined at their ends by brazing which requires significant capital investment. Therefore, there is a need for method of manufacturing a lift-gate of a vehicle, that alleviates the aforementioned drawbacks. OBJECTS Some of the objects of the present disclosure, which at least one embodiment herein satisfies are as follows: An object of the present invention is to provide a method of manufacturing a lift-gate of a vehicle. Another object of the present invention is to provide a method of manufacturing a lift-gate of a vehicle that offers an improved aesthetics of the vehicle. Still another object of the present invention is to provide a method of manufacturing a lift- gate of a vehicle that eliminates the use of plastic parts used for improving styling constraints. Yet another object of the present invention is to provide a method of manufacturing a lift-gate of a vehicle that offers an economical manufacturing solution by performing the hemming operation and spot-welding operation at a single stage location on the assembly line. Yet another object of the present invention is to provide a method of manufacturing a lift-gate of a vehicle that incorporates one sided spot welding operation to prevent visibility of welding marks on the outer surface of the vehicle. Still another object of the present invention is to provide a lift-gate assembly of a vehicle that allows easy access to tools during joining of the panels of the lift-gate assembly. Other objects and advantages of the present disclosure will be more apparent from the following description, which is not intended to limit the scope of the present disclosure. SUMMARY The present disclosure discloses a method of manufacturing a lift-gate of a vehicle comprising the following steps: locating and positioning a first panel on a machining station; locating and positioning a second panel adjacent to and abutting the first panel with the help of supports; hemming an edge of the first panel and an edge of the second panel to enable interlocking of the first panel and the second panel, and form interlocked hemmed edges; welding along the interlocked hemmed edges, of the first panel and the second panel at a plurality of predetermined locations, to join the first panel and the second panel; locating and positioning a third panel adjacent to and abutting a free edge of the second panel; and welding along the free edge of the second panel and the third panel at a plurality of predetermined locations, to form the lift-gate. In a preferred embodiment, the step of welding the interlocked hemmed edges, includes welding from a first side of the first panel to prevent visibility of welding marks when viewed from an operative outside rear of the vehicle. In a preferred embodiment, the step of welding the interlocked hemmed edges includes welding from a first side of the first panel by a single sided welding tool to prevent visibility of welding marks when viewed from an operative outside rear of the vehicle. In a preferred embodiment, the step of welding along the free edge of the second panel and the third panel includes welding from both sides of the third panel. In a preferred embodiment, the step of welding along the free edge of the second panel and the third panel includes welding by a two-sided welding tool from both sides of the third panel. In a preferred embodiment, the step of placing and positioning a second panel on the first panel includes applying an adhesive on the edges, of the first panel and the second panel. In a preferred embodiment, the step of hemming an edge of the first panel and an edge of the second panel includes the steps of: performing a first pass of hemming on the edge of the first panel by a tapered roller, to engage the second panel with the first panel; and performing a second pass of hemming operation on the edge of the first panel by a cylindrical roller to interlock the second panel with the first panel. In a preferred embodiment, wherein the step of hemming and the step of welding are performed at a single machining location on an assembly line of a vehicle manufacturing facility. In a preferred embodiment, wherein the step of welding on the interlocked hemmed edges, of the first panel and the second panel, includes spot welding at the predetermined locations along the interlocked hemmed edges. In a preferred embodiment, the step of welding the free edge of the second panel and the third panel includes spot welding at predetermined locations along the free edge of the second panel and an edge of the third panel. In a preferred embodiment, the step of locating and positioning the first panel on the machining station includes locating and positioning an operative top side of the first panel on the machining station. In a preferred embodiment, a lift-gate is manufactured by the method steps for accessing the interior of a vehicle. BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWING A method of manufacturing a lift-gate of a vehicle, of the present disclosure, will now be described with the help of the accompanying drawings, in which: Figure 1 shows an isometric view of the conventional lift-gate of the prior art; Figure 2 shows an exploded view of figure 1; Figure 3 shows an exploded view of figure 1 of the present disclosure; Figure 4 shows an exploded view of the second panel and supports; Figures 5 shows an exploded view of the first panel and the second panel of the prior art; Figure 6 shows a bottom view of the second panel positioned on the first panel; Figure 7 shows a bottom view of figure 6; Figure 8 shows welding locations on the first panel and the second panel; Figure 9 shows a stage location on the assembly line where the hemming operation and the spot welding operation is carried out; Figure 10 shows an isometric view of the assembly of first panel, the second panel and the third panel; Figure 11 shows an isometric view of the assembly of first panel, the second panel and the third panel joined a plurality of predetermined locations; and Figure 12 shows a rear view of the tail-gate with the first panel, the second panel and the third panel joined together. LIST OF REFERENCE NUMERALS 10 – first panel of the prior art 11 – locations on first panel 12 – first panel 12a – first side of first panel 13 – edge of first panel 14 – inner side of first panel 20 – second panel of the prior art 21, 23 – supports 22 – second panel 25 – parting line of the prior art 32 – third panel 33 – edge of second panel 34 – free edge of second panel 35 – edge of the third panel 36,37,38 – predetermined locations for welding free edge 34 and the third panel 32 50 – machining station of an assembly line 100 – lift-gate of the prior art 110 – lift-gate 102 – operative front of the vehicle 104 – operative outside rear of the vehicle DETAILED DESCRIPTION Embodiments of the present disclosure, will now be described with reference to the accompanying drawing. Embodiments are provided to thoroughly and fully convey the scope of the present disclosure to the person skilled in the art. Numerous details are set forth, relating to specific components, and methods, 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. 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. 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”, and “having”, are open ended transitional phrases and therefore specify the presence of stated features, elements, modules, units and / or components, but do not forbid the presence or addition of one or more other features, elements, components, and / or groups thereof. The particular order of steps disclosed in the method and process of the present disclosure is not to be constructed as necessarily requiring their performance as described or illustrated. It is also to be understood that additional or alternative steps may be employed. When an element is referred to as being “mounted on”, “engaged to”, “connected to”, or “coupled to” another element, it may be directly on, engaged, connected or coupled to the other element. As used herein, the term “and / or” includes any and all combinations of one or more of the associated listed elements. The terms first, second, third, etc., should not be construed to limit the scope of the present disclosure as the aforementioned terms may be only used to distinguish one element, component, region, layer or section from another component, region, layer or section. Terms such as first, second, third etc., when used herein do not imply a specific sequence or order unless clearly suggested by the present disclosure. Terms such as “inner”, “outer”, “beneath”, “below”, “lower”, “above”, “upper”, and the like, may be used in the present disclosure to describe relationships between different elements as depicted from the figures. Referring to figures 1-2, a conventional method of manufacturing a lift-gate assembly 100 of a vehicle for providing access to an operative outside rear of the vehicle is shown, in an embodiment of the prior art. The lift-gate 100 is attached to the structure of the vehicle. The method of manufacturing of the lift-gate 100 comprises joining a plurality of panels 10, 20, 30. A first panel 10 is joined to a third panel 30 by welding operation. A third panel 20 made of plastic is attached to the first panel 10 to impart a desired styling profile to the first panel 10. The conventional method of manufacturing the lift-gate 100 teaches a separate plastic cover i.e. third panel 20. However, attachment of a separate plastic cover i.e. the third panel 20 results in visible parting lines 25 that in turn deteriorate the aesthetics of the vehicle. This situation is explained in the figures 1 and 2. Moreover, the conventional method of manufacturing the lift-gate 100 teaches joining the ends of the panels 10 and 30 by brazing process. However, the brazing process requires significant capital investment which is not an economical solution. Moreover, the brazing operation deteriorates the aesthetics of the tail- gate 100. The tool used in performing the brazing operation cannot be positioned for obtaining a welding joint as desired. The present disclosure offers a solution to the problems discussed above. Referring to figures 5-14, a method of manufacturing a lift-gate 110 of a vehicle, the method comprising the following steps: locating and positioning a first panel 12 on a machining station 50; locating and positioning a second panel 22 adjacent to and abutting the first panel 12 with the help of supports 21, 23; hemming an edge 13 of the first panel 12 and an edge of the second panel 33 to enable interlocking of the first panel 12 and the second panel 22, and form interlocked hemmed edges 13, 33; welding along the interlocked hemmed edges 13, 33 of the first panel 12 and the second panel 22 at a plurality of predetermined locations 11, to join the first panel 12 and the second panel 22; locating and positioning a third panel 32 adjacent to and abutting a free edge 34 of the second panel 12; and welding along the free edge 34 of the second panel 22 and the third panel 32 at a plurality of predetermined locations 36,37,38, to form the lift-gate 100. In a preferred embodiment, the step of welding the interlocked hemmed edges 13, 33 includes welding from a first side 12a of the first panel 12 to prevent visibility of welding marks when viewed from an operative outside rear 104 of the vehicle. The step of welding the interlocked hemmed edges 13, 33 includes welding from at least one side of the third panel 32. Thus, the first panel 12 and the second panel 22 are joined in a way to prevent visibility of welding marks from an operative outside rear 104 of the vehicle, as shown in figures 3 and 12. The step of locating and positioning a second panel 22 on the first panel 12 includes applying an adhesive on the edges 13, 33 of the first panel 12 and the second panel 22. The adhesive helps forming a bond between the first panel 12 and the second panel 22. Thus, the joint between the first panel 12 and the second panel 22 is imparted with augmented strength. The step of hemming an edge 13 of the first panel 12 and an edge of the second panel 33 includes the following steps: performing a first pass of hemming on the edge 13 of the first panel 12 by a tapered roller, to engage the second panel 22 with the first panel 12; and performing a second pass of hemming operation on the edge 13 of the first panel 12 by a cylindrical roller to interlock the second panel 22 with the first panel 12. The step of hemming and the step of welding are performed at a single machining location 50 on an assembly line of a vehicle manufacturing facility. The step of welding on the interlocked hemmed edges 13, 33 of the first panel 12 and the second panel 13, 33 includes spot welding at the predetermined locations 11 along the interlocked hemmed edges 13, 33. The step of welding the interlocked hemmed edges 13, 33 includes welding from a first side 12a of the first panel 12 by a single sided welding tool to prevent visibility of welding marks when viewed from an operative outside rear 104 of the vehicle. The step of welding the free edge 34 of the second panel 22 and the third panel 32 includes spot welding at predetermined locations along the free edge 34 of the second panel 12 and an edge of the third panel 32. The step of welding along the free edge 34 of the second panel 22 and the third panel 32 includes welding by a two-sided welding tool from both sides of the third panel 32. The step of locating and positioning the first panel 12 on the machining station 50 includes locating and positioning an operative top side of the first panel 12 on the machining station 50. The present disclosure discloses a lift-gate 110 manufactured by the method steps as discussed above. The lift-gate 110 manufactured by the method steps discussed above eliminates necessity of expensive brazing process. Moreover, spot welding operation results in improved aesthetics of the lift-gate 110 of the vehicle. The foregoing description of the embodiments has been provided for purposes of illustration and not intended to limit the scope of the present disclosure. Individual components of a particular embodiment are generally not limited to that particular embodiment, but, are interchangeable. Such variations are not to be regarded as a departure from the present disclosure, and all such modifications are considered to be within the scope of the present disclosure. TECHNICAL ADVANCEMENT The present disclosure described herein above has several technical advantages including, but not limited to, a method of manufacturing a lift-gate of a vehicle, which: • imparts improved aesthetics of the vehicle; and • eliminates costly brazing process by incorporating hemming and spot welding. The disclosure has been described with reference to the accompanying embodiments which do not limit the scope and ambit of the disclosure. The description provided is purely by way of example and illustration. The embodiments herein and the various features and advantageous details thereof are explained with reference to the non-limiting embodiments 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. The foregoing description of the specific embodiments so fully revealed 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. Throughout this specification the word “comprise”, or variations such as “comprises” or “comprising”, will be understood to imply the inclusion of a stated element or group of elements, but not the exclusion of any other element or group of elements. 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. Any discussion of articles or the like that has been 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 housing or were common general knowledge in the field relevant to the disclosure as it existed anywhere before the priority date of this application. While considerable emphasis has been placed herein on the components and component parts of the preferred embodiments, it will be appreciated that many embodiments can be made and that many changes can be made in the preferred embodiments without departing from the principles of the disclosure. These and other changes in the preferred embodiment as well as other embodiments of the disclosure will be apparent to those skilled in the art from the disclosure herein, whereby it is to be distinctly understood that the foregoing descriptive matter is to be interpreted merely as illustrative of the disclosure and not as a limitation.

Claims

CLAIMS:

1. A method of manufacturing a lift-gate (110) of a vehicle, said method comprising the following steps: • locating and positioning a first panel (12) on a machining station (50); • locating and positioning a second panel (22) adjacent to and abutting said first panel (12) with the help of supports (21, 23); • hemming an edge (13) of the first panel (12) and an edge of the second panel (33) to enable interlocking of said first panel (12) and said second panel (22) to form interlocked hemmed edges (13, 33); • welding along the interlocked hemmed edges (13, 33) of the first panel (12) and the second panel (22) at a plurality of predetermined locations (11), to join the first panel (12) and the second panel (22); • locating and positioning a third panel (32) adjacent to and abutting a free edge (34) of said second panel (12); and • welding along the free edge (34) of said second panel (22) and said third panel (32) at a plurality of predetermined locations (36,37,38), to form said lift-gate (110).

2. The method as claimed in claim 1, said step of welding the interlocked hemmed edges (13, 33) includes welding from a first side (12a) of the first panel (12) to prevent visibility of welding marks when viewed from an operative outside rear of the vehicle.

3. The method as claimed in claim 1, said step of welding the interlocked hemmed edges (13, 33) includes welding from a first side (12a) of the first panel (12) by a single sided welding tool to prevent visibility of welding marks when viewed from an operative outside rear of the vehicle.

4. The method as claimed in claim 1, said welding along the free edge (34) of said second panel (22) and said third panel (32) includes welding from both sides of the third panel (32).

5. The method as claimed in claim 1, the step of welding along the free edge (34) of said second panel (22) and said third panel (32) includes welding by a two-sided welding tool from both sides of the third panel (32).

6. The method as claimed in claim 1, said step of locating and positioning a second panel (22) on said first panel (12) includes applying an adhesive on the edges (13, 33) of the first panel (12) and the second panel (22).

7. The method as claimed in claim 1, the step of hemming an edge (13) of the first panel (12) and an edge of the second panel (33) includes the following steps: • performing a first pass of hemming on the edge (13) of the first panel (12) by a tapered roller, to engage said second panel (22) with said first panel (12); and • performing a second pass of the hemming operation on the edge (13) of the first panel (12) by a cylindrical roller to interlock said second panel (22) with said first panel (12).

8. The method as claimed in claim 1, wherein said step of hemming and said step of welding are performed at a single machining location (50) on an assembly line of a vehicle manufacturing facility.

9. The method as claimed in claim 1, wherein said step of welding on the interlocked hemmed edges (13, 33) of the first panel (12) and the second panel (13, 33) includes spot welding at the predetermined locations (11) along the interlocked hemmed edges (13, 33).

10. The method as claimed in claim 1, wherein said step of welding the free edge (34) of the second panel (22) and the third panel (32) includes spot welding at predetermined locations along the free edge (34) of the second panel (12) and an edge of the third panel (32).

11. The method as claimed in claim 1, wherein said step of locating and positioning said first panel (12) on the machining station (50) includes locating and positioning an operative top side of said first panel (12) on the machining station (50).

12. A lift-gate (110) manufactured by the method steps as claimed in anyone of claim 1 to 11 for accessing the interior of a vehicle.

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