Method for producing a sound-dampened automotive enclosure

• US 5,271,142 A
• Filed: 11/30/1992
• Issued: 12/21/1993
• Est. Priority Date: 05/09/1991
• Status: Expired due to Fees

• Current Assignee: Soundwich, Inc. (Dan T. Moore Co., Inc.)
• Original Assignee: Soundwich, Inc. (Dan T. Moore Co., Inc.)
• Inventors: Moore, Austin W., Moore, Dan T. III
• Primary Examiner(s): Rosenbaum, Mark
• Assistant Examiner(s): VO, PETER DUNG BA
• Application Number:
  US07/983,269
• Time in Patent Office: 386 Days
• Field of Search: 29/163.6, 29/163.7, 29/169.5, 29/421.1, 29/432, 29/460, 29/506, 29/773, 29/469.5, 29/897.2, 72/347-351, 72/363, 72/379.2, 72/379.4, 181/204, 181/208, 428/34.1, 428/323, 428/425.8, 428/461, 524/418
• US Class Current: 29/469.5
• CPC Class Codes: B21D 22/205 Hydro-mechanical deep-drawing
• CPC Class Codes: B29C 51/14 using multilayered preforms or sheets
• CPC Class Codes: B29K 2995/0002 insulating
• CPC Class Codes: B32B 15/06 of natural rubber or synthetic rubber
• CPC Class Codes: F01M 11/0004 Oilsumps
• CPC Class Codes: F01M 2011/0008 with means for reducing vibrations
• CPC Class Codes: F02B 77/13 Acoustic insulation
• CPC Class Codes: F05C 2225/02 Rubber
• CPC Class Codes: G10K 11/168 Plural layers of different materials, e.g. sandwiches
• CPC Class Codes: Y10T 29/49622 Vehicular structural member making
• CPC Class Codes: Y10T 29/49906 Metal deforming with nonmetallic bonding

Abstract

A method for making a sound-dampened automotive enclosure, such as an oil pan, having a metal constraining layer, a metal housing layer, and a viscoelastic layer sandwiched therebetween. In a preferred embodiment, the constraining layer and viscoelastic layer are between the housing layer and the die while the housing layer is being drawn. This results in a very close and snug fit between the layers, leading to enhanced sound-dampening effectiveness. The article thus produced is also disclosed.

Claims

1. A method of producing a stamped three-dimensional sound-damped automotive enclosure having a metal housing layer, a metal constraining layer, and a viscoelastic layer disposed therebetween, said method comprising the steps of:

a) providing a metal housing layer, a metal constraining layer, and a viscoelastic layer, said metal housing layer having a marginal single layer metal flange portion;

b) disposing said metal housing layer, said viscoelastic layer, and said metal constraining layer in press means;

c) urging said metal constraining layer into deforming contact with said metal housing layer by said press means while said viscoelastic layer is disposed between said metal constraining layer and said metal housing layer to deform at least a significant portion of at least one of said metal layers into a three-dimensional shape;

d) providing from said metal flange portion a single layer metal flange on the enclosure;

thereby producing a sound-damped automotive enclosure having a single layer metal flange extending from said metal housing layer, said metal constraining layer and said viscoelastic layer closely conforming to the shape of those portions of the metal housing layer to which they are adjacent, the viscoelastic layer being capable, through effective solid contact with areas of said metal layers, of providing effective sound-dampening of noise associated with the enclosure.

2. The method of claim 1, further comprising the step of affixing a second metal constraining layer to said metal housing layer with a second viscoelastic layer disposed therebetween.

3. The method of claim 1, wherein said metal housing layer and said metal constraining layer disposed in said press means are sheets.

4. The method of claim 1, wherein said viscoelastic layer is comprised of a urethane polymer and an olefin polymer.

5. The method of claim 1, further comprising the step of providing a pattern of ridges or raised portions in said metal constraining layer to stiffen said metal constraining layer.

6. The method of claim 1, wherein a portion of said press means comprises fluid-forming press means.

7. The method of claim 1, wherein said metal constraining layer and said viscoelastic layer each have a corresponding cutout.

8. The method of claim 1, said metal constraining layer and said metal housing layer being deformed simultaneously by said press means.

9. The method of claim 1, said metal constraining layer and said metal housing layer being, prior to stamping, different in thickness.

10. The method of claim 1, wherein said metal layers are mechanically attached after said deforming operation.

11. The method of claim 1, wherein the single layer metal flange is adapted for mounting the enclosure to an engine block.

12. A method according to claim 1, said viscoelastic layer containing a blowing agent prior to said urging step, further comprising a step of heating the viscoelastic layer to activate the blowing agent therein.

13. A method according to claim 1, the viscoelastic layer being provided with supplemental holding means to assist in holding the metal layers together after said deforming operation.

14. The method of claim 1, wherein said viscoelastic layer is disposed in step (b) without a blowing agent.

15. The method of claim 14, further comprising a step of heating the enclosure to permit the viscoelastic layer to flow into and fill open space between the metal layers.

16. The method of claim 9, said metal constraining layer being steel from 0.010 to 0.032 inches thick before stamping, and said metal housing layer being steel from 0.030 to 0.060 inches thick before stamping.

17. The method of claim 1, wherein said metal constraining layer is formed with said press means.

18. A method according to claim 17, said metal housing layer having previously been deformed into the shape of an oil pan before said metal constraining layer is deformed during said urging step.

19. The method of claim 17, wherein in step (c), said metal housing layer is drawn with said press means.

20. The method of claim 19, wherein a substantial portion of said metal constraining layer is formed while said metal housing layer is drawn.

21. The method of claim 17, wherein said viscoelastic layer is adhered to said metal constraining layer when said metal constraining layer is formed with said press means.

22. The method of claim 21, wherein said adherence is by tabs.

23. The method of claim 21, wherein said adherence is by gluing means.

24. The method of claim 21, wherein said adherence is by heat-bonding.

25. The method of claim 1, wherein the sound-dampened automotive enclosure thus produced is an oil pan which has an inside and an outside and said metal constraining layer and said viscoelastic layer are on the inside of said oil pan.

26. The method of claim 25, wherein the metal constraining layer and viscoelastic layer closely conform to the shape of those portions of the metal housing layer to which they are adjacent, said portions being preselected as those subject to the most vibration when said enclosure is utilized as an automobile oil pan.

27. The method of claim 25, wherein the single layer metal flange is adapted for mounting the oil pan to an engine block.

28. The method of claim 10, wherein said visco-elastic layer is comprised of a urethane polymer and an olefin polymer.

29. The method of claim 28, wherein said viscoelastic layer is disposed in step (b) without a blowing agent.