MASS DAMPER MOUNTING ASSEMBLY AT BACK DOOR FOR DAMPING BOOMING NOISE
FIELD OF INVENTION:
[001] The present subject matter described herein, relates to a mass damper at back door in vehicles, and, in particular, to mass damper at back door for damping 5 booming noise and to achieve manufacturability in vehicle. More particularly, the present subject matter relates to a mass damper in T shape which is provided at centre of the back door of the vehicle to damp booming noise in the vehicle at the back door.
BACKGROUND AND PRIOR ART: 10
[002] In vehicles various vibrations are generated by vehicle speed, engine speed, mounting of parts, window opening conditions. When vehicle is in moving condition, the vehicle creates vibrations inside the vehicle cabin. Further, forward and backward movement or compression and decompression of the back door create vibrations in the vehicle cabin. Natural frequency of the back door matches 15 with the natural frequency of the vehicle hence resonance occurs and booming noise in cabin gets created due to increased amplitude of vibration.
[003] To prevent generation of booming noise in the vehicle cabin, dynamic damper or mass dampers are provided in the vehicle to damp vibrations by altering the natural frequency of the back door to avoid resonance with vehicle 20 body. Various locations are identified where mass dampers or dead mass can be provided to damp the booming noise.
[004] Conventionally, mass dampers are bolted onto the reinforcement of the back door garnish. Further, the reinforcement is welded onto the back door. Further, weight of the mass damper is defined based on the CAE analysis of the 25 booming noise. This concept of providing mass damper on the reinforcement is not feasible as there are packaging constraints to assemble mass damper on back door reinforcement, complete new design and tool of reinforcement back door garnish was required.
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[005] The technical problem exist in the prior art is that there is no mass damper at the centre of the back door. Further, it is not feasible to optimize the space and achieve manufacturability of mass damper at the centre of the back door with existing concept. In the existing technologies, the mass dampers are bolted on the reinforcement of back door garnish reinforcement. Further, there is no 5 reinforcement available at the center of the back door for mounting of the mass damper.
[006] US patent US9527370B2 titled, “Damping and stiffening of a vehicle body panel” discloses damping and stiffening assembly for a body panel. The assembly includes a first damping patch and a second damping patch that are 10 attached to the body panel. The assembly also includes a stiffening lamination that has a first end, a middle portion, and a second end. The first end of the stiffening lamination attaches to and overlaps the first damping patch. The middle portion of the stiffening lamination attaches to the body panel. The second end of the stiffening lamination attaches to and overlaps the second damping patch. This US 15 patent publication is associated with damping of vibration generated during NVH and closing time vibrations. It does not reduce booming noise in the vehicle.
[007] In order to damp booming noise in the back door of the vehicle, a mass damper is required at the center of the door. Further, mounting of the mass damper should be inexpensive, reliable, simple in manufacturing, and can be 20 implemented on existing back door panels of the vehicle. Therefore, the present invention does provide a solution by satisfying all the requirements which suited best for the automobile industry.
OBJECTS OF THE INVENTION:
[008] The principal objective of the present invention is to provide a mass 25 damper at back door panel of vehicle to damp booming noise.
[009] Another object of the present subject matter is to provide a mass damper at center of the back door panel with space optimization and mass optimization to effectively damp vibrations and the booming noise.
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[0010] Another object of the present subject matter is to provide a mass damper in T shape with a reinforcement which is mounted in between reinforcement of the back door garnish and door latch.
[0011] Yet another object of the present subject matter is to provide a reinforcement in between the reinforcement of the back door garnish and door 5 latch to receive mass damper for damping the booming noise.
[0012] Yet another object of the present subject matter is to provide a simple, effective, and cost efficient mass damper to damp booming noise in the vehicle cabin.
SUMMARY OF THE INVENTION: 10
[0013] The subject matter disclosed herein relates to a mass damper mounting assembly for damping booming noise and vibrations of a vehicle. The mass damper mounting assembly is mounted in between reinforcement of back door garnish and door latch where amplitude of vibrations is maximum. To damp all vibrations, the present subject matter provides mass damper at center of the back 15 door panel to damp booming noise and vibrations. The mass damper mounting assembly includes a reinforcement, a mass damper, and a plurality of bolts. The reinforcement has a rectangular base portion and two legs projected away from the rectangular base portion in upward direction and define a U shape in between the two legs. The two legs of the reinforcement are spot welded with the 20 reinforcement of back door garnish. Further, the rectangular base portion has at least two locations for spot welding with back door panel of the vehicle. The rectangular base portion has spot welding locations at corner. The rectangular base portion is spot welded at spot welding location by a weld gun. Further, the rectangular base portion has at least three mounting holes to receive mass damper. 25 The mass damper mounting assembly has a T shaped mass damper which has at least three mounting holes corresponding to at least three mounting holes of the reinforcement. The T- shaped mass damper is bolted onto the reinforcement with the inline mounting holes with at least three bolts to damp the booming noise and vibrations in the vehicle. The weight of the mass damper can be optimized based 30
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on the dimensions of the vehicle. In the present subject matter, mass damper is provided at the center where it is effective to avoid the resonance frequency with minimum possible weight.
[0014] In order to further understand the characteristics and technical contents of the present subject matter, a description relating thereto will be made with 5 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
[0015] 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 10 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 identifies the figure in which the reference number first appears. The same numbers are used throughout the figures to reference like features and 15 components. Some embodiments of system or methods 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:
[0016] Fig. 1 illustrates structure of back door panel, in accordance with an embodiment of the present subject matter; 20
[0017] Fig. 2 illustrates structure of back door panel with latch and location for mass damper, in accordance with an embodiment of the present subject matter;
[0018] Fig. 3 illustrates structure of reinforcement for mass damper, in accordance with an embodiment of the present subject matter;
[0019] Fig. 4 illustrates structure of mass damper, in accordance with an 25 embodiment of the present subject matter; and
[0020] Fig. 5 illustrates exploded view of assembly of reinforcement and mass damper with the bolts, in accordance with an embodiment of the present subject matter.
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[0021] 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. 5
DESCRIPTION OF THE PREFERRED EMBODIMENTS:
[0022] The subject matter disclosed herein relates to a mass damper mounting assembly for damping booming noise and vibrations of a vehicle. The mass damper mounting assembly is mounted in between reinforcement of back door garnish and door latch where it is effective to avoid the resonance frequency with 10 minimum possible weight addition based on CAE and actual trial. To damp all vibrations, the present subject matter provides mass damper at center of the back door panel to damp booming noise and vibrations. The mass damper mounting assembly includes reinforcement, a mass damper, and a plurality of bolts. The reinforcement has a rectangular base portion and two legs projected away from 15 the rectangular base portion in upward direction and define a U shape in between the two legs. The two legs of the reinforcement are spot welded with the reinforcement of back door garnish. Further, the rectangular base portion has at least two locations for spot welding with back door panel of the vehicle. The rectangular base portion has spot welding locations at corner. The rectangular 20 base portion is spot welded at spot welding location by a weld gun. Further, the rectangular base portion has at least three mounting holes to receive mass damper. The mass damper mounting assembly has a T shaped mass damper which has at least three mounting holes corresponding to at least three mounting holes of the reinforcement. The T- shaped mass damper is bolted onto the reinforcement with 25 the inline mounting holes with at least three bolts to damp the booming noise and vibrations in the vehicle. The weight of the mass damper can be optimized based on the dimensions of the vehicle. In the present subject matter, mass damper is provided at the center where it is most effective to avoid the resonance frequency
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with minimum possible weight based on CAE result and actual trial done on vehicle.
[0023] It should be noted that the description and figures merely illustrate the 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 5 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 assembly that, although not 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 10 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 construed as being without limitation to such specifically recited examples and conditions. The novel features which are believed to be characteristic of the 15 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 figures.
[0024] These and other advantages of the present subject matter would be 20 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. 25
[0025] Fig. 1 illustrates structure of back door panel, in accordance with an embodiment of the present subject matter. The problem associated with mounting of mass damper in middle of the back door panel is direct mounting of mass damper on back door panel. Further, due to constraint of the weld gun length, it is not possible to weld the mass damper after a certain length which is more than the 30
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length of the weld gun. Accordingly, technical problem of manufacturability of mass damper at exact centre of the back door panel exist. Referring to figure 1, the back door 100 has window area 101 for movement of weld gun, a reinforcement of back door garnish 102, lower portion of the back door 103, and a mass damper 104. In the back door designs of some vehicle, it is not possible to weld the mass 5 damper at centre of the back door with a weld gun due to distance X which is more than length of weld gun.
[0026] Fig. 2 illustrates structure of back door panel with latch and location for mass damper, in accordance with an embodiment of the present subject matter. As shown in the figure 2, a countermeasure weight or mass damper is to be given in 10 the center area of the back door panel for countermeasure of booming noise effectively. The back door panel 200 has window area 201, reinforcement of back door garnish 202, door latch 203, center area 204, and mass damper mounting assembly 204. The mass damper mounting assembly 204 is provided in between the reinforcement of back door garnish 202 and the door latch 203. Further, upper 15 area is covered with the reinforcement of back door garnish 202 and lower area is covered with the latch mechanism 203. The present mass damper mounting assembly 204 is optimized based on the dimensions of the vehicle.
[0027] Fig. 3 illustrates structure of reinforcement, in accordance with an embodiment of the present subject matter. The reinforcement 300 is mounted in 20 between reinforcement of back door garnish 202 and door latch 203 which is exact center of the back door panel to avoid resonance. The reinforcement 300 has a rectangular base portion 301 and two legs 302 projected away from the rectangular base portion 301 in upward direction. The two legs 302 define a U shape. The two legs 302 are spot welded with the reinforcement of back door 25 garnish 202 of the back door panel. The rectangular base portion 301 has at least two locations for spot welding with back door panel of the vehicle. The reinforcement 300 is spot welded with the reinforcement of back door garnish from upper end. Further, the reinforcement 300 is spot welded with back door panel from lower end by a weld gun. 30
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[0028] The rectangular base portion 301 has at least three mounting holes 304 to receive mass damper on the reinforcement. The at least three mounting holes 304 define a triangle when mounting holes 304 are joined with each other by a line. The reinforcement 300 is made of high tensile material which can bear load of the mass damper during running of vehicle. The reinforcement 300 is spot welded by 5 a weld gun from the door window area.
[0029] Fig. 4 illustrates structure of the mass damper, in accordance with an embodiment of the present subject matter. In order to make the mass damper feasible to mount on the reinforcement 300 and to ensure the same mass of the plate by mass optimization and manufacturability, T shape of the mass damper 10 plate is provided as shown in the figure. The T-shaped mass damper 400 is achieved by space optimization by solving all technical problem associated with the space and welding constraint. The T-shaped mass damper 400 has at least three mounting holes 401 corresponding to the at least three mounting holes 304 of the reinforcement 300. The T-shaped mass damper 400 is mounted on the 15 reinforcement 300 with at least three bolts as shown in the figure 5. The T-shaped mass damper 400 with the reinforcement 300 is mounted at the center of the back door panel to damp booming noise and vibrations. The T-shaped mass damper 400 is made of metal, such as iron, steel.
[0030] Fig. 5 illustrates assembly of the T-shaped mass damper on the 20 reinforcement with three bolts, in accordance with an embodiment of the present subject matter. The mass damper mounting assembly 500 has reinforcement 503, T-shaped mass damper or weight or dead mass or dead weight 502, and a plurality of bolts 501. The T-shaped mass damper 502 is bolted with the reinforcement 503 with at least three bolts 501. The mounting holes of the T-shaped mass damper 25 502 in line with the mounting holes of the reinforcement 503 and mounting bolts 501 are inserted into the inline mounting holes to fix/assemble the mass damper 502 on to the reinforcement 503.
[0031] The present mass damper mounting assembly damps booming noise of the vehicle. Further, the mass damper mounting assembly ensures space optimization 30
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at center of the back door panel and mass optimization based on dimensions of the vehicle. The mass damper mounting assembly is easy to manufacture using the present reinforcement and T-shaped mass damper. The present mass damper mounting assembly does not deteriorate the aesthetic appearance by spot of welding on outer surface. 5
[0032] The term “vehicle” as used throughout this detailed description and in the claims refers to any moving vehicle that is capable of carrying one or more human occupants and is powered by any form of energy. The term “vehicle” is a motor vehicle which includes, but is not limited to: cars, trucks, vans, minivans, hatchback, sedan, MUVs, and SUVs. 10
[0033] It will be further appreciated that functions or structures of a plurality of components or steps may be combined into a single component or step, or the functions or structures of one-step or component may be split among plural steps or components. The present invention contemplates all of these combinations. Unless stated otherwise, dimensions and geometries of the various structures 15 depicted herein are not intended to be restrictive of the invention, and other dimensions or geometries are possible. In addition, while a feature of the present invention may have been described in the context of only one of the illustrated embodiments, such feature may be combined with one or more other features of other embodiments, for any given application. It will also be appreciated from the 20 above that the fabrication of the unique structures herein and the operation thereof also constitute methods in accordance with the present invention. The present invention also encompasses intermediate and end products resulting from the practice of the methods herein. The use of “comprising” or “including” also contemplates embodiments that “consist essentially of” or “consist of” the recited 25 feature.
[0034] 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 30
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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.

We claim:
1. A mass damper mounting assembly (500) for damping booming noise and vibrations of a vehicle, the mass damper mounting assembly (500) comprising:
a reinforcement (300, 503) being mounted in between 5 reinforcement of back door garnish (202) and door latch (203), the reinforcement (300, 503) comprising:
a rectangular base portion (301);
two legs (302) projected away from the rectangular base portion (301) in upward direction and define a U shape in between the two 10 legs (302); and
wherein the rectangular base portion (301) has at least two locations for spot welding with back door panel of the vehicle;
at least three mounting holes (304) provided on the rectangular base portion (301) to define a triangle; 15
a mass damper (400, 502) having at least three mounting holes (401) corresponding to at least three mounting holes (304) on the reinfrocement; and
wherein the mass damper (400, 502) bolted onto the reinforcement (300, 503) with at least three bolts (501) to damp the booming noise 20 and vibrations in the vehicle.
2. The mass damper mounting assembly (500) as claimed in claim 1, wherein the two legs (302) of the reinforcement (300) are spot welded with the reinforcement of back door garnish (202). 25
3. The mass damper mounting assembly (500) as claimed in claim 1, wherein the reinforcement (300, 503) is mounted in between the reinforcement of back door garnish (202) and the door latch (203) by spot welding.
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4. The mass damper mounting assembly (500) as claimed in claim 1, wherein mass damper mounting assembly (500) is mounted at center of the back door panel.
5. The mass damper mounting assembly (500) as claimed in claim 1, wherein 5 the mass damper (400, 502) is in T-shape.
6. The mass damper mounting assembly (500) as claimed in claim 1, wherein the at least three mounting holes (304) defines a triangle when mounting holes are joined with each other by a line. 10
7. The mass damper mounting assembly (500) as claimed in claim 1, wherein mass of the mass damper (400, 502) is optimized based on the vehicle.
8. The mass damper mounting assembly (500) as claimed in claim 1, wherein 15 the mass damper (400) is made of metal.
9. The mass damper mounting assembly (500) as claimed in claim 1, wherein the reinforcement (300) is spot welded by weld gun.
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10. The mass damper mounting assembly (500) as claimed in claim 1, wherein the rectangular base portion (301) of the reinforcement (300) is spot welded on the back door panel with weld gun.