[001] The present subject matter described herein, relates to a reinforcement structure for rear floor of automobiles. More particularly, the present subject matter relates to a reinforcement structure for rear floor of the automobile for reduction of booming noise generated due to compression and decompression of cabin air because of removal of a spare tyre from rear floor of the automobile.
BACKGROUND AND PRIOR ART AND PROBLEM IN PRIOR ART:
[002] In general, booming noise is generated in automobiles due to compression and decompression of cabin air. At rear floor of the automobile a spare tyre is kept in a well area of the rear floor. Upon removal of the spare tyre from the well area, there is no counter weight available that acts in downward direction and air inside the vehicle is compressed and de-compressed during driving of the automobile and generate booming noise in the vehicle cabin.
[003] Weight of the spare tyre, (for example, in the range of 12kg – 15kg), acts as a mass damper and avoids generation of booming noise. Further, the well area of the rear floor is reinforced to avoid sagging of the well area due to weight of the spare tyre. When the spare tyre is placed in the well area, weight of the spare tyre damps the compression and decompression of air.
[004] In gas fuel operated automobiles, a gas cylinder is provided on the rear floor of the automobile. For easy accessibility, compactness, and variability of the spare tyre, the spare tyre is mounted in a vertical orientation such that the spare tyre no longer comes in contact with the well area of rear floor. In such cases, in the absence of spare tyre, which was earlier acting as a damper to damp the compression and decompression of cabin air, the amplitude of compression and de-compression increases. With high energy content, the high amplitude bending mode excites the air inside the cabin of the automobile and creates a disturbance in the air pressure to generate booming noise.
[005] In the existing rear floor portion of the automobile, reinforced structures are usually integrated with inner and outer walls of the well area of rear floor to avoid sagging of the well area due to weight and pressure of the spare tyre. For example, in prior art publication number KR20110032501A a Y-shaped structure is provided for reinforcing the rear floor of an automobile such that it is integrally connected to the rear floor upper cross member and connects the well area to the rear floor upper cross member. These reinforcement structures are provided to avoid sagging of the well area due to weight of the spare tyre. However, even with the reinforcement structures, when spare tyre is removed from the well area, air inside the vehicle compress and de-compress with upward and downward movement of the well area of the rear floor to generate booming noise.
[006] Further, prior art publication number KR20110085563A discloses an under frame structure for a rear floor of an automobile. The under frame structure is provided for improving the rigidity against collision, for reducing the tremors caused during the running of the vehicle, for reducing the repair costs if a vehicle suffers damage and to secure the safety of passengers by ensuring rigidity of the vehicle’s body. However, this under frame structure is limited in its application to an end portion of rear floor of a vehicle body used for mounting of spare tyres and to avoid sagging of a well section due to weight of the spare tyre. Even with the reinforcement, when spare tyre is removed, the well area bends due to which booming noise is generated.
[007] In addition to the above described prior arts, the existing technology provides for addition of blocks that weigh roughly equal to the weight of the spare tyre (~15kg) removed from well area or provision of big cross reinforcements which can restrict the bending motion of the rear floor. But, certain disadvantages are associated with the existing solutions like additional cost due to additional weight, problems associated with handling and assembly of such heavy weights, reduction of fuel efficiency, big, and complicated reinforcements.
[008] There is requirement of commonization of parts in the automobile industry to avoid high manufacturing cost. In the automobile industry, same rear floor is used for both gas operated vehicles where gas cylinders are mounted at the rear floor of the vehicle and liquefied fuel operated vehicles where the spare tyre is mounted in the well area of the rear floor. When the same rear floor is used in gas operated vehicles where spare tyre is mounted apart from the well area of the rear floor, a technical problem of bending of the well area increases due to which booming noise in generated in the rear floor of the automobile.
[009] However, no such structure exists which is designed to reduce the booming noise caused due to the removal of spare tyre in automobiles and is capable of being fit into the rear floor of an automobile vehicle.
[0010] Therefore, there is a need in the art to provide a structure for reinforcing well area of the rear floor such that it restricts the bending of the rear floor and avoids generation of booming noise caused due to the removal of a spare tyre from the well area of the rear floor and overcomes the aforementioned limitations.
OBJECTS OF THE INVENTION:
[0011] It is therefore the object of the subject matter to overcome the aforementioned and other drawbacks in prior structure.
[0012] The principal objective of the present subject matter is to provide a reinforcement structure for reduction of booming noise caused due to removal of spare tyre from the well area of the rear floor of an automobile.
[0013] Another object of the present subject matter is to restrict the bending of the well area of the rear floor caused due to removal of the spare tyre.
[0014] Yet another object of the present subject matter is to design the reinforcement structure in such a way that the design is in sync with the shape of the well area of the rear floor of an automobile.
[0015] These and other objects and advantages of the present subject matter will be apparent to a person skilled in the art after consideration of the following detailed description taken into consideration with accompanying drawings in which preferred embodiments of the present subject matter are illustrated.
SUMMARY OF THE INVENTION:
[0016] One or more drawbacks of existing reinforcement structures of rear floor of an automobile are overcome, and additional advantages are provided through a reinforcement structure as claimed in the present disclosure. Additional features and advantages are realized through the technicalities of the present disclosure. Other embodiments and aspects of the disclosure are described in detail herein and are considered to be a part of the claimed disclosure.
[0017] The present subject matter relates to a reinforcement structure for reduction of booming noise caused due to removal of a spare tyre from a well area of a rear floor of an automobile. The reinforcement structure has been designed on the basis of a study of the mode shape of the well area of the rear floor at different amplitudes with and without spare tyre.
[0018] In an embodiment, the present subject matter relates to a reinforcement structure for rear floor of an automobile having well area. The reinforcement structure comprising a first frame and a second supporting frame. The first frame comprises a base portion attached with a base plate; an inclined portion extended at an angle (a) from both ends of the base portion; and a mounting portion extended at an angle (ß) from end portion of each of the inclined portions; and the second supporting frame joined at each of the inclined portions of the first frame.
[0019] In an aspect, the mounting portion is attached with vertical surface of the well area by means of a mounting plate, the mounting plate having two vertical beads to receive the mounting portion.
[0020] In an aspect, the base plate is attached with bottom surface of the well area.
[0021] In an aspect, the second supporting frame defines bending portions at both ends to facilitate joining of the second supporting frame on each of the inclined portions.
[0022] In an aspect, the base plate and the mounting plate are joined by means of welding including CO2 welding or spot welding.
[0023] In an aspect, cross-sectional shape of the first frame and the second supporting frame is selected from circular, square, L shape, channel shape, triangular shape, cylindrical shape rod, cylindrical shape pipe and any poly-angular shape.
[0024] In an aspect, the first frame defines boat shaped profile or bow shaped profile.
[0025] In another embodiment of the present subject matter, a reinforcement structure is provided for rear floor of an automobile having well area. The reinforcement structure comprising: a base mounting flange configured to join with bottom surface of the well area; an inclined portion extended away at an angle (a) from both ends of the base mounting flange; and a mounting portion extended in vertical upward direction from end portion of the inclined portion at both ends, the mounting portion defines a mounting flange extending perpendicularly from the mounting portion to mount the reinforcement structure with vertical surface of the well area.
[0026] In an aspect, the reinforcement structure defines boat shaped profile or bow shaped profile.
[0027] In an aspect, the reinforcement structure is made of L shape channel.
[0028] It is to be understood that the aspects and embodiments of the disclosure described above may be used in any combination with each other. Several of the aspects and embodiments may be combined to form a further embodiment of the disclosure.
[0029] The foregoing summary is illustrative only and is not intended to be in any way limiting. In addition to the illustrative aspects, embodiments, and features described above, further aspects, embodiments, and features will become apparent by reference to the drawings and the following detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
[0030] It is to be noted, however, that the appended drawings illustrate only typical embodiments of the present subject matter and are therefore not to be considered for limiting of its scope, for the invention may admit to other equally effective embodiments. The detailed description is described with reference to the accompanying figures. In the figures, a reference number identifies the figure in which the reference number first appears. The same numbers are used throughout the figures to reference like features and components. Some embodiments of system or methods or structure in accordance with embodiments of the present subject matter are now described, by way of example, and with reference to the accompanying figures, in which:
[0031] Fig. 1a, 1b, and 1c illustrate a top view, a side view, and a perspective view, respectively of a rear floor defining a well area for a spare tyre, in accordance with the existing state of the art.
[0032] Fig. 2a illustrates a perspective view of an assembled reinforcement structure with the well area of the rear floor, in accordance with an embodiment of the present subject matter.
[0033] Fig. 2b illustrates a top view of an assembled reinforcement structure with the well area of the rear floor, in accordance with an embodiment of the present subject matter.
[0034] Fig. 3a illustrates a perspective view of an assembled reinforcement structure with the well area of the rear floor, in accordance with another embodiment of the present subject matter.
[0035] Fig. 3b illustrates a top view of an assembled reinforcement structure with the well area of the rear floor, in accordance with another embodiment of the present subject matter.
[0036] Fig. 4a, 4b, and 4c illustrate an un-assembled view of the reinforcement structure of Fig. 2a, in accordance with an embodiment of the present subject matter.
[0037] Fig. 4d illustrates an assembled view of the reinforcement structure of Fig. 2a, in accordance with an embodiment of the present subject matter.
[0038] Fig. 5 illustrates a perspective view of the reinforcement structure of Fig. 3a, in accordance with another embodiment of the present subject matter.
[0039] Fig. 6 illustrates the bending pattern of the well area of rear floor as per existing state of the art and the bending pattern of the well area of rear floor in accordance with an embodiment of the present subject matter, without the spare tyre.
[0040] Fig. 7 illustrates the graph depicting the booming noise performance of the well area with a spare tyre, without a spare tyre, and with any embodiment of the present subject matter.
[0041] The figures depict embodiments of the present subject matter for the purposes of illustration only. A person skilled in the art will easily recognize from the following description that alternative embodiments of the structures and methods illustrated herein may be employed without departing from the principles of the disclosure described herein.
DETAILED DESCRIPTION:
[0042] The detailed description of various exemplary embodiments of the disclosure is described herein with reference to the accompanying drawings. It should be noted that the embodiments are described herein in such details as to clearly communicate the disclosure. However, the amount of details provided herein is not intended to limit the anticipated variations of embodiments; on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the scope of the present disclosure as defined by the appended claims.
[0043] It is also to be understood that various arrangements may be devised that, although not explicitly described or shown herein, embody the principles of the present disclosure. Moreover, all statements herein reciting principles, aspects, and embodiments of the present disclosure, as well as specific examples, are intended to encompass equivalents thereof.
[0044] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments. As used herein, the singular forms “a",” “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the tennis “comprises,” “comprising,” “includes” and/or “including,” when used herein, specify the presence of stated features, integers, steps, operations, elements and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components and/or groups thereof.
[0045] It should also be noted that in some alternative implementations, the functions/acts noted may occur out of the order noted in the figures. For example, two figures shown in succession may, in fact, be executed concurrently or may sometimes be executed in the reverse order, depending upon the functionality/acts involved.
[0046] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which example embodiments belong. It will be further understood that terms, e.g., those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.
[0047] These and other advantages of the present subject matter would be described in greater detail with reference to the following figures. It should be noted that the description merely illustrates the principles of the present subject matter. It will thus be appreciated that those skilled in the art will be able to devise various arrangements that, although not explicitly described herein, embody the principles of the present subject matter and are included within its scope.
[0048] The present subject matter describes structure of reinforcement in rear floor of automobiles for reduction of booming noise. The present reinforcement structure can be referred as boat shaped or bow shaped structure that has been designed to restrict bending of the well area of the rear floor of the automobile in the absence of a spare tyre. The reinforcement structure has a high stiffness and is strong enough to resist the bending of the well area of the rear floor when the spare tyre is not placed inside the well area of the rear floor.
[0049] Referring to fig. 7, when there is no spare tyre in the well area of the rear floor, the rear floor has resonance at 72Hz, whereas when the spare tyre is placed in the well area, the well area of the rear floor has resonance at 26Hz. So difference of vibration amplitude between the well area without spare tyre and well area with spare tyre is approx. 31.7dB. Thus, a high amplitude of bending mode is observed when spare tyre is removed from the well area which causes the compression and decompression of cabin air thus causing booming noise in automobiles.
[0050] In such circumstances, the solution lies in either providing a replacement for the weight as provided by the spare tyre in the well area or providing big reinforcements which can hold the bending of the well area of the rear floor. It is important to note that providing a replacement of the spare tyre weight may not be a possibility due to cost constraints and strength requirements. Further, it will increase total weight of the vehicle as spare tyre may be mounted at different location. Further, big and complicated reinforcements lead to changes in the platform design. Since, platform development takes a lot of time, effort and cost, a common platform design becomes important to automobile manufacturers to reduce cost by using the same rear floor and eliminate the tests required to validate the platform again.
[0051] Fig. 1a, 1b, and 1c illustrate a top view, a side view, and a perspective view, respectively of the rear floor along with a provision for a spare tyre in a well area 101 of the rear floor 100.
[0052] Fig. 2a and 2b illustrate structure of a reinforcement for well area of the rear floor in accordance with an embodiment of the present subject matter. The reinforcement structure 200 defines a closed section profile to reinforce the well area when spare tyre is removed. The reinforcement structure 200 is attached with bottom surface 101a (i.e., horizontal plane) and vertical surface 101b (i.e., vertical plane) of the well area 101 to strengthen the well area 101 and restrict bending of the bottom surface 101a.
[0053] As shown in figs. 4a, 4b, 4c, and 4d, the reinforcement structure 200 comprises of a base plate 201 having a plurality of flange 202, 203, 204 that extend in upward direction from edges of the base plate 201. The base plate 201 is attached with the bottom surface 101a of the well area 101 by means of known attaching method, such as arc welding or spot welding.
[0054] The reinforcement structure 200 comprises a bow shaped or boat shaped first frame 205. The first frame 205 defines a base portion 205a that joins with the base plate 201. From both ends, i.e., left hand side and right hand side of the base portion 205a, an inclined portion 205b extend at an angle ‘a’ towards the vertical surface 101b of the well area 101. A mounting portion 205c extends at an angle ‘ß’ from end portion of the inclined portion 205b to mount with a mounting plate 210. The mounting plate 210 is mounted with both the mounting portion 205c of the first frame 205 by means of known mounting method, such as arc welding, spot welding, or bolting. Further, the angle ‘ß’ is in range 75o to 90o. A supporting frame 207 that acts as counter frame is joined with the first frame 205 by means of known joining method, such as arc welding, spot welding, or bolting. The supporting frame 207 joins both the inclined portions 205b of the first frame 205 provided on left hand side and right hand side to define a closed profile, for example, A-shaped closed profile. The supporting frame 207 provides support and strength to the inclined portions 205b to avoid bending of the same. The supporting frame 207 may be bend in upward direction to define bending portions 207a, 207b at both ends to join with the inclined portion 205b of the first frame 205. In an embodiment, the bending portions 207a, 207b of the supporting frame 207 are joined at middle of each side of the inclined portion 205b. In an alternative embodiment, the bending portions 207a, 207b of the supporting frame 207 are joined at end of each side of the inclined portion 205b. In another embodiment, the bending portions 207a, 207b of the supporting frame 207 are joined at any location on each side of the inclined portion 205b based on improvement required in vibration amplitude of the well area.
[0055] As shown in fig. 4b, the mounting plate 210 may define a plurality of beads 210a, 210b to act as base for mounting of the mounting portion 205c of the first frame 205. The plurality of beads 210a, 210b extend toward the mounting portion 205c.
[0056] Fig. 4c illustrates a base plate 201 that can be mounted on the well area 101 to restrict generation of booming noise. The base plate 201 of the reinforcement structure 200 is mounted with the bottom surface 101a of the well area 101 at one surface and on the other surface mounted with the base portion 205a of the first frame 205. The mounting plate 210 of the reinforcement structure 200 is mounted on the vertical surface 101b of the well area 101 at one surface and on the other surface mounted with mounting portion 205c of the first frame 205.
[0057] In an embodiment, the first frame 205 and the supporting frame 207 can be of any shape, such as circular, square, L shape, channel shape, triangular shape, cylindrical pipe, and cylindrical rod, and any other shape as known in the state of the art.
[0058] Another embodiment of the present subject matter:
[0059] Figs. 3a and 3b illustrate perspective and top view respectively of an assembled reinforcement structure 300 in well area 101 of the rear floor 100, in accordance with another embodiment of the present subject matter. The reinforcement structure 300 is mounted with the well area 101 by means of a known method, such as arc welding or spot welding. Referring to figs. 5 and 3a together, the reinforcement structure 300 is a single part reinforcement structure that defines a base mounting flange 302 at center to join the reinforcement structure 300 with the bottom surface or horizontal plane 101a of the well area 101. As illustrated in Figs. 3a and Fig. 5, the single part reinforcement structure 300 is formed in form of a boat shaped single reinforcement structure mounted on the inner horizontal and vertical walls of the well area 101 of the rear floor 100 of an automobile, such that the reinforcement structure 300 remains in a fixed position inside the well area 101, and provides reinforcement to the well area 101. The reinforcement structure 300, thereby prevents bending of the well area 101, specifically, the bottom surface or horizontal plane 101a of the rear floor 100 and inhibits the booming noise created in the rear floor of the automobile.
[0060] The reinforcement structure 300 is made of single part by means of stamping process. From the base mounting flange 302, at both left side end and right side end, an inclined portion 301, 303 extend away at angle ‘a’ towards the vertical surface 101b of the well area 101. At both the left side end and the right side end of the inclined portion 301, 303, a mounting portion 304 extend in vertical upward direction from the inclined portion 303. The mounting portion 304 defines a mounting flange 304a extending perpendicularly from the mounting portion 304 to mount the reinforcement structure 300 with the vertical surface 101b of the well area 101.
[0061] The reinforcement structure 300 is in L shape channel. However, the reinforcement structure 300 can have cross section of any shape, such as channel, rod, cylindrical, triangular, etc.
[0062] As shown in fig. 6, the bending pattern of the well area 101 of the rear floor 100 as per existing state of the art and the bending pattern of the well area 101 of the rear floor 100 in accordance with an embodiment of the present subject matter is illustrated, without the spare tyre. As can be seen in fig. 6, high amplitude bending of well area 101 of rear floor 100 is observed in state of the art while bending of well area 101 of rear floor 100 is reduced using the reinforcement structure of the current invention.
[0063] Fig. 7 illustrates a graph depicting the vibration performance of the well area 101 of the rear floor 100 with a spare tyre, without a spare tyre, and with an embodiment of the present subject matter obtained upon the study of the mode shape of the well area 101 of the rear floor 100.
[0064] With the present subject matter, a counter reinforcement is added in the well area 101 to avoid bending of the horizontal plane 101a of the well area 101. The present subject matter adds a small weight, i.e., approximately 3% of spare tyre weight to achieve the same dynamic stiffness of the well area 101 similar to the stiffness achieved when the spare tyre is placed in the well area of the rear floor.
[0065] As shown in the fig. 7, with the present reinforcement structure in the well area, the vibration amplitude is reduced by at least 22.2dB. Hence, improvement in booming noise is observed in the present invention.
[0066] The present subject matter has certain advantageous features, such as reduced amplitude of vibrations which leads to a reduction in booming noise with low weight addition, ease of manufacturing due to simpler reinforcements, ease of assembly due to compact design and less number of spot locations, improved customer comfort, no requirement of changes in platform which helps in maintaining profitability and saves time, effort and cost and lastly, feasibility of scrap utilization due to design simplicity.
[0067] Although embodiments for the present subject matter have been described in language specific to structural features, it is to be understood that the present subject matter is not necessarily limited to the specific features described. Rather, the specific features and methods are disclosed as embodiments for the present subject matter. Numerous modifications and adaptations of the system/component of the present invention will be apparent to those skilled in the art, and thus it is intended by the appended claims to cover all such modifications and adaptations which fall within the scope of the present subject matter.
[0068] Reference Numerals
Reference Numeral Description
101 Well area
101a Bottom surface or horizontal plane
101b Vertical walls or vertical plane
200 First embodiment, reinforcement structure
201 Base plate
202, 203, 204 First, second, and third flange of the base plate
205 First frame of the reinforcement structure
205a Base portion of the reinforcement structure
205b Inclined portion of the reinforcement structure
205c Mounting portion of the reinforcement structure
207 Supporting frame 207 of the reinforcement structure
207a, 207b Bending portions 207a, 207b of the supporting frame 207
210 Mounting plate of the reinforcement structure
210a, 210a Bead structure of the mounting plate
300 Second embodiment, reinforcement structure
301 Inclined portion of the reinforcement structure
302 Mounting base portion of the reinforcement structure
303 Inclined portion of the reinforcement structure
304 Mounting portion of the reinforcement structure
304a, 304b Mounting flange of the mounting portion

We claim:

1.A reinforcement structure (200) for rear floor of an automobile having well area (101), the reinforcement structure (200) comprising:
a first frame (205) and a second supporting frame (207), the first frame (205) comprises:
a base portion (205a) attached with a base plate (201);
an inclined portion (205b) extended at an angle (a) from both ends of the base portion (205a); and
a mounting portion (205c) extended at an angle (ß) from end portion of each of the inclined portions (205b); and
the second supporting frame (207) joined at each of the inclined portions (205b) of the first frame (205).

2. The reinforcement structure (200) as claimed in claim 1, wherein the mounting portion (205c) is attached with vertical surface (101b) of the well area (101) by means of a mounting plate (210), the mounting plate (210) having two vertical beads (210a, 210b) to receive the mounting portion (205c).
3. The reinforcement structure (200) as claimed in claim 1, wherein the base plate (201) is attached with bottom surface (101a) of the well area (101).
4. The reinforcement structure (200) as claimed in claim 1, wherein the second supporting frame (207) defines bending portions (207a, 207b) at both ends to facilitate joining of the second supporting frame (207) on each of the inclined portions (205c).
5. The reinforcement structure (200) as claimed in claim 2, wherein the base plate (201) and the mounting plate (210) are joined by means of welding including CO2 welding or spot welding.
6. The reinforcement structure (200) as claimed in claim 1, wherein shape of the first frame (205) and the second supporting frame (207) is selected from circular, square, L shape, channel shape, triangular shape, cylindrical shape rod, cylindrical shape pipe and any poly-angular shape.
7. The reinforcement structure (200) as claimed in claim 1, wherein the first frame (205) defines boat shaped profile or bow shaped profile.
8. A reinforcement structure (300) for rear floor of an automobile having well area (101), the reinforcement structure (300) comprising:
a base mounting flange (302) configured to join with bottom surface (101a) of the well area (101);
an inclined portion (301, 303) extended away at an angle (a) from both ends of the base mounting flange (302); and
a mounting portion (304) extended in vertical upward direction from end portion of the inclined portion (301, 303) at both ends, the mounting portion (304) defines a mounting flange (304a) extending perpendicularly from the mounting portion (304) to mount the reinforcement structure (300) with vertical surface (101b) of the well area (101).
9. The reinforcement structure (300) as claimed in claim 8, wherein the reinforcement structure (300) defines boat shaped profile or bow shaped profile.
10. The reinforcement structure (300) as claimed in claim 8, wherein the reinforcement structure (300) is made of L shape channel.