FIELD OF INVENTION:
[001] The present subject matter described herein, relates to a vehicle construction and more particularly, relates to purpose of lowering noise level 5 within a vehicle passenger compartment.
BACKGROUND AND PRIOR ART:
[002] In passenger cars/vehicles, low frequency (30 Hz to 150 Hz) booming noise is a common problem. The reason for booming noise is structural panel resonances which cause the passenger cabin air cavity/volume to 10 compress/decompress and cause pressure differences leading to booming noise. For a vehicle equipped with such structural panels, it has been known that booming noise is generated at the time of low-speed running. When vibrations of an engine rotating at a low speed close to the resonance frequency of structural panels are transmitted to the vehicle body, the structural panels vibrate, and 15 periodic changes in volume take place in the passenger cabin, whereby booming noise is generated.
[003] Booming noise is mostly generated in low speed high gear combination wherein the driver gives full throttle by completely pressing the accelerator pedal. The high engine vibrations in such a situation are transmitted to the body through 20 the engine mounting paths. When frequency of this excitation matches the natural frequency of structural panels, panels come under resonance. This leads to compression/decompression of air cavity which leads to booming noise generation.
[004] In cases where backdoor assembly (attached to the body-rear side quarter 25 panel through hinges and balancer) resonance is responsible for the booming noise, conventional methods like increasing thickness of the panels, addition of mass blocks or dead weights on panels, are employed. In both these cases, i.e. addition of mass block or by increasing the panel thickness, changes the stiffness
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to mass ratio, which changes the natural frequency of the system. This decouples the natural frequency of the backdoor assembly from the problem frequency and reduces the booming noise. However, such conventional methods increase weight of the vehicle, are cost inclusive, and also deteriorates fuel efficiency of the vehicle. 5
[005] United States Patent publication US6254174B1 provides a reinforcement structure for a rear pillar of automobiles. In this structure, a reinforcing panel, forming the upper portion of the rear pillar, is integrated with the welded junction between an inside upper quarter panel and a rear lower roof rail, thus forming a closed cavity within the rear pillar while maximizing the structural strength of rear 10 roof rails. This structure thus allows the top edge of the body's rear portion, formed by the rear roof rails, to effectively and stably support a rear hatch and effectively intercepts noise transmitted from tires of wheels into the passenger compartment through the rear pillars during operation of the automobile. The reinforcing panel extends in a space defined between the inside upper quarter 15 panel and a side panel and is integrated with the lower end of the inside upper quarter panel at its lower end. This reinforcing panel is also integrated with the upper end of the side panel at its upper end portion. The upper end portion of the reinforcing panel further extends to a position around an upper end of the inside upper quarter panel and is integrated with the upper end of the inside upper 20 quarter panel while forming a closed cavity within the rear pillar.
[006] The US prior art provides a conventional solution for preventing tire noise to enter inside passenger cabin. Further, the assembly, shape, operation and location of the parts mentioned in the prior art are not similar to the present disclosure. 25
OBJECTS OF THE INVENTION:
[007] The principal objective of the present invention is to reduce booming noise in passenger compartment of automobiles.
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[008] Another object of the present subject matter is to provide a simple, cost effective, and efficiently designed brace bracket in the rear body structure for effectively reducing the booming noise.
SUMMARY OF THE INVENTION:
[009] The present invention relates to a reinforced rear body structure for 5 reducing booming noise in passenger compartment of automobiles. The rear body structure includes a plurality of quarter panel sections, each quarter panel section includes a quarter panel inner, and a quarter panel outer secured to the quarter panel inner, the quarter panel inner and the quarter panel outer defining a space therebetween; and a brace bracket provided within the space, the brace bracket 10 defining a substantial D shaped base with a straight edge, an arcuate edge, and a plurality of flanges extending from the straight edge and the arcuate edge, the plurality of flanges being secured to the quarter panel inner and the quarter panel outer.
[0010] In order to further understand the characteristics and technical contents of 15 the present subject matter, a description relating thereto will be made with reference to the accompanying drawings. However, the drawings are illustrative only but not used to limit scope of the present subject matter.
BRIEF DESCRIPTION OF THE DRAWINGS 20
[0011] 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, the left-most digit(s) of a reference number 25 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 in accordance with
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embodiments of the present subject matter are now described, by way of example, and with reference to the accompanying figures, in which:
[0012] Fig. 1a illustrates a back view of a reinforced rear body structure for reducing booming noise in passenger compartment of automobiles in accordance with an embodiment of the present disclosure; 5
[0013] Fig. 1b illustrates an enlarged view of a portion of the reinforced rear body structure of Fig. 1a;
[0014] Fig. 2a illustrates a side view of the reinforced rear body structure, and Fig. 2b illustrates an enlarged view of a portion of the reinforced rear body structure of Fig. 2a; 10
[0015] Fig. 3 illustrates a perspective view of brace bracket in accordance with an embodiment of the present disclosure;
[0016] Fig. 4 illustrates cross-sectional views, about a plane A-A’, of quarter panel section, with and without the brace bracket, of Fig. 1a; and
[0017] Fig. 5 illustrates a graphical simulation result depicting booming noise 15 profiles.
[0018] 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 20 of the disclosure described herein.
DESCRIPTION OF THE PREFERRED EMBODIMENTS:
[0019] The present disclosure presents embodiments for a reinforced rear body structure for reducing booming noise in passenger compartment of automobiles. The rear body structure includes a plurality of quarter panel sections, each quarter 25 panel section includes a quarter panel inner, and a quarter panel outer secured to the quarter panel inner, the quarter panel inner and the quarter panel outer defining a space therebetween; and a brace bracket provided within the space, the
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brace bracket defining a substantial D shaped base with a straight edge, an arcuate edge, and a plurality of flanges extending from the straight edge and the arcuate edge, the plurality of flanges being secured to the quarter panel inner and the quarter panel outer.
[0020] It should be noted that the description and figures merely illustrate the 5 principles of the present subject matter. It should be appreciated by those skilled in the art that conception and specific embodiment disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present subject matter. It should also be appreciated by those skilled in the art that by devising various arrangements that, although not 10 explicitly described or shown herein, embody the principles of the present subject matter and are included within its spirit and scope. Furthermore, all examples recited herein are principally intended expressly to be for pedagogical purposes to aid the reader in understanding the principles of the present subject matter and the concepts contributed by the inventor(s) to furthering the art, and are to be 15 construed as being without limitation to such specifically recited examples and conditions. The novel features which are believed to be characteristic of the present subject matter, both as to its organization and method of operation, together with further objects and advantages will be better understood from the following description when considered in connection with the accompanying 20 figures.
[0021] 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 25 various arrangements that, although not explicitly described herein, embody the principles of the present subject matter and are included within its scope.
[0022] Fig. 1a illustrates a back view of a reinforced rear body structure (100) for reducing booming noise in passenger compartment of automobiles in accordance with an embodiment of the present disclosure. Fig. 1b illustrates an enlarged view 30
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of a portion of the reinforced rear body structure (100). In an embodiment, the reinforced rear body structure (100) includes a plurality of quarter panel sections (102). Each quarter panel section (102) of the plurality of quarter panel sections (102) includes a quarter panel inner (104), and a quarter panel outer (106) secured to the quarter panel inner (104). In an example, the quarter panel inner (104) and 5 the quarter panel outer (106) defining a space (108) therebetween.
[0023] Fig. 2a illustrates a side view of the reinforced rear body structure (100), and Fig. 2b illustrates an enlarged view of a portion of the reinforced rear body structure (100). Referring to Figs. 1a, 1b, 2a, 2b, the reinforced rear body structure (100) further includes a brace bracket (110) provided within the space (108). Fig. 10 3 illustrates a perspective view of the brace bracket (110) in accordance with an embodiment of the present disclosure.
[0024] In an embodiment, the brace bracket (110) defines a substantial D shaped base (112) with a straight edge (114), an arcuate edge (116), and a plurality of flanges (118) extending from the straight edge (114) and the arcuate edge (116). 15 In an example, the plurality of flanges (118) are configured to be secured to the quarter panel inner (104) and the quarter panel outer (106). Further, the brace bracket (110) is configured to be welded with the quarter panel section (102), such that the plurality of flanges (118) of the brace bracket (110) are spot welded to the quarter panel inner (104) and the quarter panel outer (106) of the quarter panel 20 section (102). Further, the straight edge (114) of the brace bracket (110) is towards the quarter panel outer (106), and the arcuate edge (116) is towards the quarter panel inner (104). Alternatively, the brace bracket (110) may be secured to the quarter panel section (102) through state of the art joining techniques.
[0025] Referring back to Fig. 1a, the brace bracket (110) is positioned between a 25 back door hinge location (120) and a back door balancer location (122), such that during the backdoor assembly bending mode in vehicle longitudinal direction,, the brace bracket (110) resists a longitudinal bending of the reinforced rear body structure (100) based on an increase in torsional rigidity, as maximum amplitude of vibration and deformation takes place between the back door hinge location 30
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(120) and a back door balancer location (122). In an example, the brace bracket (110) leads to reduction in deformation of the quarter panel section (102) and in particular, the space (108) between the quarter panel inner (104) and the quarter panel outer (106), which in turn restrict the amplitude of vibration of back door assembly, thereby reducing the booming noise. 5
[0026] Fig. 4 illustrates a cross-sectional view 400, about a plane A-A’, of the quarter panel section (102) of Fig. 1a, wherein a deformation associated with the quarter panel section (102) is reduced due to presence of the brace bracket (110), based on an increased stiffness. Fig. 4 further illustrates an exemplary cross-sectional view 402 corresponding to the cross-sectional view 400, wherein an 10 increased deformation associated with the quarter panel section (102’) in an absence of the brace bracket (110) is noted. In an example, a width W1, in the view 400, between the quarter panel inner (104) and the quarter panel outer (106) is greater than a width W2 between components of view 402 due to less deformation of the reinforced rear body structure (100). Hence a region between 15 the back door hinge location (120) and a back door balancer location (122) is stiffened against collapse due to presence of the brace bracket (110), and further deformation of a back door associated with the vehicle is also reduced.
[0027] Further, due to presence of the brace bracket (110) with the reinforced rear body structure (100), longitudinal bending of backdoor assembly is reduced, due 20 to which compression-decompression of air inside the passenger compartment is reduced, in turn reducing the booming noise. Fig. 5 illustrates a graphical simulation result depicting a booming noise profile 502 associated with the reinforced rear body structure (100) in comparison to a booming noise profile 504 associated with the conventional structure without the brace bracket (110). It is 25 noted, in an example, that the booming noise profile 502 of the reinforced rear body structure (100) is improved by 0.5-3 dB(A). Hence the reinforced rear body structure (100) provides reduction in booming noise; improvement in the torsional rigidity and overall body stiffness; increase in passenger comfort level;
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improvement in handling performance; weight saving as compared to conventional solutions; increase in fuel efficiency; etc.
[0028] 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, 5 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. 10

We claim:
1. A reinforced rear body structure (100) for reducing booming noise in passenger compartment of automobiles, the rear body structure (100) comprising:
a plurality of quarter panel sections (102), each quarter panel section 5 (102) having:
a quarter panel inner (104), and
a quarter panel outer (106) secured to the quarter panel inner (104), the quarter panel inner (104) and the quarter panel outer (106) defining a space (108) therebetween; and 10
a brace bracket (110) provided within the space (108), the brace bracket (110) defining a substantial D shaped base (112) with a straight edge (114), an arcuate edge (116), and a plurality of flanges (118) extending from the straight edge (114) and the arcuate edge (116), the plurality of flanges (118) being secured to the quarter panel inner (104) and the quarter 15 panel outer (106).
2. The reinforced rear body structure (100) as claimed in claim 1, wherein the brace bracket (110) resists a longitudinal bending of the reinforced rear body structure (100).
3. The reinforced rear body structure (100) as claimed in claim 1, wherein the 20 brace bracket (110) is positioned between a back door hinge location (120) and a back door balancer location (122).
4. The reinforced rear body structure (100) as claimed in claim 1, wherein the brace bracket (110) is welded with the quarter panel section (102).
5. The reinforced rear body structure (100) as claimed in claim 4, wherein the 25 plurality of flanges (118) of the brace bracket (110) are spot welded to the quarter panel inner (104) and the quarter panel outer (106) of the quarter panel section (102).
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6. The reinforced rear body structure (100) as claimed in claim 5, wherein the straight edge (114) of the brace bracket (110) is towards the quarter panel outer (106), and the arcuate edge (116) is towards the quarter panel inner (104).