US20080136110A1

US20080136110A1 - Acoustic Perimeter Seal for Vehicle Energy Storage Module

Info

Publication number: US20080136110A1
Application number: US11/567,790
Authority: US
Inventors: Hua He
Original assignee: GM Global Technology Operations LLC
Current assignee: GM Global Technology Operations LLC
Priority date: 2006-12-07
Filing date: 2006-12-07
Publication date: 2008-06-12
Also published as: DE102007058250B4; CN101195362A; DE102007058250A1; CN101195362B

Abstract

An acoustic seal arrangement is provided for a motor vehicle. The vehicle has a floor pan defining the floor of a passenger compartment. The vehicle also has an energy storage module. The energy storage module has a top wall with an outer perimeter portion and the energy storage module is suspended in spaced relation beneath the floor pan. A ring-shaped seal of compressible material is positioned between the outer perimeter portion of the energy storage module and the floor pan and in compression therebetween to form a sealed space and impede the transmission of noise into the sealed space between the top wall of the energy storage module and the floor pan. Accordingly, that portion of the vehicle floor pan that lies above the sealed space is protected from exposure to road noise, thereby quieting the passenger compartment.

Description

FIELD OF THE INVENTION

The present invention relates to the reduction of noise within the passenger compartment of a motor vehicle body and more particularly to reducing the transmission of road noise through the floor pan in the region of an energy storage module such as a fuel tank or a battery pack.

BACKGROUND OF THE INVENTION

It is known in motor vehicles that a vehicle body includes a sheet metal floor pan that defines the floor of the passenger compartment. The floor pan is typically covered with a layer of carpeting to provide an aesthetically pleasing environment for the passenger. An energy storage module, such as a fuel tank or a battery pack, is mounted on the vehicle body beneath the floor pan.
It is also known that the comfort of the passenger is enhanced by limiting the intrusion of road noise into the passenger compartment. Because noise can be transmitted through the floor pan, it is well known to place a layer of sound insulating material beneath the carpet to reduce the transmission of road noise.
It would be desirable to provide new and improved techniques for minimizing the transmission of road noise through the floor pan in the region of the energy storage module, particularly when it may be desirable to minimize the space that is needed for packaging the insulation material beneath the carpeting.

SUMMARY OF THE INVENTION

An acoustic seal arrangement is provided for a motor vehicle. The vehicle has a floor pan defining the floor of a passenger compartment. The vehicle also has an energy storage module, such as a fuel tank or a battery pack. The energy storage module has a top wall with an outer perimeter portion and the energy storage module is suspended in spaced relation beneath the floor pan. A ring-shaped seal of compressible material is positioned between the outer perimeter portion of the energy storage module and the floor pan and in compression therebetween to form a sealed space and impede the transmission of noise into the sealed space between the top wall of the energy storage module and the floor pan. Accordingly, that portion of the vehicle floor pan that lies above the sealed space is protected from exposure to road noise, thereby quieting the passenger compartment.
Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating exemplary embodiments of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will become more fully understood from the detailed description and the accompanying drawings, wherein:

FIG. 1 is a schematic elevation view showing a fuel tank suspended beneath a vehicle floor pan;

FIG. 2 is a plan view of the fuel tank of FIG. 1 taken in the direction of arrows 2-2 of FIG. 1; and

FIG. 3 is a view similar to FIG. 1 but showing another embodiment of the invention.

DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS

The following description of certain exemplary embodiments is exemplary in nature and is not intended to limit the invention, its application, or uses.
Referring to FIG. 1, a vehicle body 8 includes a floor pan 10 of stamped steel sheet that forms the floor of a passenger compartment. A carpet 12 covers the floor. A sound insulating pad 14 underlies the carpet 12 and rests upon the floor pan 10.
A fuel tank 18 is mounted on the vehicle body beneath the floor pan 10. The fuel tank 18 is of conventional design and may be of steel construction, blow molded plastic, or other conventional construction. Fuel tank 18 has a top wall 22 and the top wall 22 has an outer perimeter portion 24. The fuel tank 18 is attached to the vehicle body 8 by hanger straps or hanger brackets, not shown in the drawing. The top wall 22 of fuel tank 18 is positioned a distance from the floor pan 10 so that a space 26 remains between the top wall 22 of the fuel tank 18 and the floor pan 10.
An acoustic seal 30 is installed between the top wall 22 of the fuel tank 18 and the floor pan 10 to impede the transmission of road noise into the space 26 between the fuel tank 18 and the floor pan 10. In particular, as seen in FIGS. 1 and 2, the acoustic seal 30 is a ring-shaped seal of compressible material such as closed cell foams EPDM, nitrile, cellular urethane, or neoprene, etc.
As seen in FIG. 1, the acoustic seal 30 is dimensioned in relation to the distance between the fuel tank and the floor pan to assure that the acoustic seal 30 is maintained in a compressed condition so that the acoustic seal 30 acts as a dam to impede the transmission of noise into the sealed empty space 26 that exists within the confines of the ring-shape and between the top wall 22 of the fuel tank 18 and the floor pan 10. Because the road noise cannot reach the sealed space 26, that region of the floor pan 10 that overlies the fuel tank is not subjected to road noise and therefore the extent of noise intrusion into the passenger compartment is reduced.
If desired, the assembly of the acoustic seal 30 into the vehicle body 8 can be facilitated by adhesively securing the acoustic seal 30 to the outer perimeter portion 24 of the fuel tank 10 prior to mounting the fuel tank 10 on the vehicle 8. Accordingly, when the fuel tank 10 is installed, the acoustic seal 30 is automatically compressed between the floor pan 10 and the fuel tank 10. If desired, the acoustic seal 30 can be manufactured with a bead of adhesive or an adhesive tape formed on the acoustic seal 30 for ready attachment of the acoustic seal 30 to the fuel tank 18.
FIG. 3 shows a second embodiment of the invention. In FIG. 3, a ring-shaped acoustic seal 130 is compressed between the floor pan 110 and the outer perimeter portion 124 of the top wall 122 of the fuel tank 118. However, the ring-shaped acoustic seal 130 also includes an additional pad 132 that fills the sealed space 126, partially or completely, that resides within the inside of the ring shape of the ring-shape acoustic seal 130. The additional pad 132 of material may be formed integrally with the acoustic seal 130 or may be a separately manufactured and installed pad. The additional pad 132 may be of sufficient thickness to fill the entire height of the space 126 between the top wall 122 and the floor pan 10, or the additional pad 132 may be of thickness less than the height of the space 126. Notwithstanding the use of the additional pad 132, the ring-shaped acoustic seal 130 will act as a perimeter seal to impede the entry of noise into the space 126, while the presence of the additional pad 130 will provide additional benefit by absorbing noise that might transmit through the tank 118. Thus, in one form the acoustic seal may simply be a sheet of material that is generally coextensive in size with the top wall 122 of the fuel tank 118 and has at least the outer perimeter portion of the sheet of material compressed between the floor pan and the top wall of the fuel tank at the outer perimeter to form a perimeter seal.
The foregoing description of the invention is merely exemplary in nature and, thus, variations thereof are intended to be within the scope of the invention. For example, although it is desirable that the shape of the ring-shape acoustic seal 30 should follow the outer edge of the fuel tank 10 as close as possible in order to seal the largest possible space beneath the floor pan, it may be necessary for the seal to take a path that that is further from the fuel tank edge, for example to accommodate fuel lines or other vehicle components and structures. The ring-shaped seal may have varying thickness around its perimeter in order to accommodate the fact that both the fuel tank and the floor pan commonly have complex shapes and indentations and reinforcements that lend strength to these stamped or molded structures. It will be understood that the ring-shaped seal 30 may be manufactured from any of the wide range of commercially available materials that exhibit acceptable performance in relation to sound absorption, resistance to exposure to water and other foreign matter, physical strength and compression, and chemical stability and durability. Although the drawings herein show the example of a conventional fuel tank, it will be appreciated that the seal arrangement may be used with any fuel storage tank, whether the tank is for storage of gasoline, diesel fuel, hydrogen, bio fuels, or other fuels or liquids for supply to internal combustion, hybrid, or fuel cell power systems. In addition, the seal arrangement can be used with a battery pack that is located beneath the floor pan.

Claims

1. An acoustic seal arrangement for a motor vehicle comprising:

a floor pan defining the floor of a passenger compartment;

an energy storage module having a top wall with an outer perimeter portion and being suspended in spaced relation beneath the floor pan;

a ring-shaped seal of compressible material positioned between the outer perimeter portion of the energy storage module and the floor pan and being compressed therebetween to form a sealed space and reduce the transmission of noise into the sealed space between the top wall of the energy storage module and the floor pan.

2. The acoustic seal arrangement of claim 1 in which the ring shaped seal is comprised of a closed cell foam material.

3. The acoustic seal arrangement of claim 2 in which the material of the ring-shaped seal is selected from one of EPDM, nitrile, cellular urethane and neoprene.

4. The acoustic seal arrangement of claim 1 in which the ring-shaped seal is adhered to the outer perimeter portion of the energy storage module top wall prior to the mounting of the energy storage module on the vehicle body.

5. The acoustic seal arrangement of claim 4 in which the ring-shaped seal is manufactured with an adhesive in-situ on the face of the seal that is adhered to the outer perimeter portion of the energy storage module.

6. The acoustic seal arrangement of claim 1 in which an additional pad of acoustic control material is placed into the space between the energy storage module top wall and the floor pan.

7. The acoustic seal arrangement of claim 6 in which the additional pad is formed integrally with the ring-shaped seal.

8. The acoustic seal arrangement of claim 6 in which the additional pad fills substantially the entire height of the space between the energy storage module top wall and the floor pan.

9. The acoustic seal arrangement of claim 6 in which the additional pad is integrally formed with the ring-shaped seal and fills all or part of the space between the ring-shaped seal and the floor pan and the top wall of the energy storage module.

10. An acoustic seal arrangement for a motor vehicle comprising:

a floor pan defining the floor of a passenger compartment;

an energy storage module having a top wall and being suspended in spaced relation beneath the floor pan;

a sheet of compressible material positioned between top wall of the energy storage module and the floor pan, at least the outer perimeter portion of the sheet of material being compressed between the energy storage module and the floor pan to seal against the transmission of noise into space inwardly of the compressed outer perimeter portion.

11. The acoustic seal arrangement of claim 10 in which the portion of the sheet of compressible material that is inboard the compressed outer perimeter portion is also compressed between the top wall of the energy storage module and the floor pan.

12. The acoustic seal arrangement of claim 10 in which the material of the ring-shaped seal is selected from one of EPDM, nitrile, cellular urethane and neoprene.

13. An acoustic seal for a motor vehicle of the type having a floor pan and an energy storage module that is mounted beneath the floor pan and has a top wall with an outer perimeter portion, comprising:

a ring-shaped seal of compressible material adapted to be positioned and compressed between the outer perimeter portion of the energy storage module and the floor pan to form a seal reducing the transmission of road noise into space between the top wall of the energy storage module and the floor pan.

14. The acoustic seal of claim 13 in which the ring-shaped seal is a closed cell foam material such as EPDM, nitrile, cellular urethane or neoprene.

15. The acoustic seal of claim 13 in which the ring-shaped seal is adhered to the outer perimeter portion of the energy storage module top wall prior to the mounting of the energy storage module on the vehicle body.

16. The acoustic seal claim 15 in which an adhesive is provided in-situ on the face of the seal that contacts the energy storage module top wall.

17. The acoustic seal of claim 13 in which the acoustic seal has an additional pad of acoustic control material located inboard of the outer peripheral portion of the energy storage module.

18. The acoustic seal of claim 17 in which the additional pad is formed integrally with the ring-shaped seal.

19. The acoustic seal arrangement of claim 18 in which the additional pad fills substantially the entire height of the space between the energy storage module top wall and the floor pan.

20. The acoustic seal arrangement of claim 17 in which the additional pad is integrally formed with the ring-shaped seal and fills all or part of the space between the ring-shaped seal and the floor pan and the top wall of the energy storage module.