INSULATED TUBULAR EXHAUST APPARATUS AND METHODS

Abstract

A bent tube with a sleeve of insulation and a protective outer metallic layer and related methods of manufacturing.

Claims

1. A method for manufacturing an insulated vehicle exhaust tube, the method comprising the steps of: sliding an insulating sleeve over an exhaust tube; adjusting the insulating sleeve to a substantially uniform material thickness over the tube; and enclosing the insulating sleeve with a metal protective cover.

2. The method of claim 1, and further comprising the steps of: restraining an end portion of the insulating sleeve relative to the exhaust tube; and allowing a central portion of the insulating sleeve to remain unrestrained relative to the exhaust tube.

3. The method of claim 1, and further comprising the steps of: restraining a first portion of the insulating sleeve relative to the exhaust tube; and allowing a second portion of the insulating sleeve to remain unrestrained relative to the exhaust tube.

4. The method of claim 1, wherein the insulating sleeve comprises a braided material.

5. The method of claim 1, wherein the metal protective cover is texturized.

6. The method of claim 1, wherein the metal protective cover is thin foil.

7. The method of claim 3, wherein the step of restraining the first portion of the insulating sleeve comprises the step of: wrapping the first portion of the insulating sleeve with a restraining material.

8. The method of claim 2, wherein the step of restraining the end portion of the insulating sleeve comprises the steps of: wrapping the end portion of the insulating sleeve with a restraining material; and trimming excess end portions of the insulating sleeve that extend outwardly beyond the restraining material.

9. The method of claim 3, wherein the step of restraining the first portion of the insulating sleeve comprises the step of: wrapping the first portion of the insulating sleeve with tape.

10. The method of claim 3, wherein the step of restraining the first portion of the insulating sleeve comprises the step of: wrapping the first portion of the insulating sleeve with a restraining material free of adhesives.

11. The method of claim 1, and further comprising the steps of: attaching a collar to the exhaust tube; and attaching the metal protective cover to the collar.

12. The method of claim 1, and further comprising the steps of: attaching a pair of collars to the exhaust tube to define a space for the insulating sleeve; and attaching end portions of the metal protective cover to each collar.

13. The method of claim 1, and further comprising the steps of: sliding a second insulating sleeve over the insulating sleeve; and adjusting the second insulating sleeve to a substantially uniform thickness.

14. An insulated exhaust tube comprising: an exhaust tube; an insulating sleeve wrapped around at least a portion of the exhaust tube; and a protective metal cover disposed around the insulating sleeve.

15. The insulated exhaust tube of claim 14, and further comprising: a restraining material in restraining engagement with an end portion of the insulating sleeve.

16. The insulated exhaust tube of claim 14, and further comprising: a restraining material in restraining engagement with a portion of the insulating sleeve.

17. The insulated exhaust tube of claim 14, wherein the insulating sleeve is trimmed to substantially match an edge of the restraining material.

18. The insulated exhaust tube of claim 14, wherein the insulating sleeve comprises a braided material.

19. The insulated exhaust tube of claim 16, wherein: the restraining material comprises: flexible plastic.

20. The insulated exhaust tube of claim 14, wherein the protective metal cover is embossed.

21. The insulated exhaust tube of claim 14, and further comprising: a collar joined to the exhaust tube to define an end location for the insulating sleeve.

22. The insulated exhaust tube of claim 14, and further comprising: a collar joined to the exhaust tube to define an end location for the insulating sleeve; and a pair of collars joined to the exhaust tube and spaced apart to define a space in which the insulating sleeve is at least partially disposed.

23. The insulated exhaust tube of claim 14, and further comprising: a second insulating sleeve wrapped around the insulating sleeve.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0014] FIG. 1 is a perspective view of a bent tube with an insulating sleeve wrapped around a portion of the bent tube, in accordance with the present invention;

[0015] FIG. 2 is a perspective view of a bent tube partially wrapped in an insulating sleeve and a restraining sheet;

[0016] FIG. 3 is a perspective view of a bent tube with an insulating sleeve wrapped in a textured foil, in accordance with the present invention;

[0017] FIG. 4 is a partial perspective view of the bent tube of FIG. 3;

[0018] FIG. 5 is an end view of a bent tube wrapped in an insulating sleeve and a textured foil outer layer, in accordance with the present invention;

[0019] FIG. 6 is a perspective view with a partial cutaway of layers of a bent tube with two layers of insulating sleeve in accordance with the present invention; and

[0020] FIG. 7 is a cross-sectional view of the bent tube taken along line 7-7 of FIG. 6.

DETAILED DESCRIPTION OF THE INVENTION

[0021] FIGS. 1 through 4 depict an insulated tube 20 in a sequence of steps in a method of manufacturing of the insulated tube 20. The insulated tube 20 includes an exhaust tube 22 having a first end 26, a second end 28, and a central portion 30. The illustrated central portion 30 includes optional bends 32. The exhaust tube 22 defines a conduit through which exhaust gases flow from an engine to any type of downstream exhaust component. The exhaust tube 22 is preferably rigid, but flexible exhaust tubes 22 can also be used. Further, the exhaust tube 22 may have ends that are reinforced with rims that are formed in the exhaust tube 22 or added before the insulation is installed.

[0022] The insulated tube 20 can be used in any type of vehicle on which insulated exhaust tubes are desirable, including those applications where insulation was once considered too expensive because the present invention saves considerable expense in materials and manufacturing.

[0023] FIG. 1 illustrates an early stage of the manufacturing process in which the step of sliding an insulating sleeve 36 over the exhaust tube 22 has been performed. The insulating sleeve 36 described herein is a braided sleeve 36, which is preferred because it is relatively easy to manipulate and bring into position over the exhaust tube 22 to have a relatively uniform thickness even around the bends 32. Of course, the internal area 38 of the bend 32 will have a more condensed amount of the insulating sleeve 36 than an outer area 40 of the bend 32, but both areas 38 and 40 will have ample insulating coverage when the insulating sleeve 36 is used. This provides a substantially uniform material thickness for insulating the exhaust tube 22, even when using a tubular insulating sleeve 36. Further, sleeves of insulating material 36 can be pre-cut to match the shape of the exhaust tube 22. Preferably, the insulating sleeve 36 is made of a high temperature insulation fiber, ceramic glass, or other suitable materials, and is preferably braided, as described herein. Nonetheless, other sleeve constructions are possible, including woven, non-woven, extruded, or any other material that slides over the end of the tube 20 and is manipulated into the desired position.

[0024] Also seen in FIG. 1 is a restraining material 44 which is preferably wrapped around end portions 46 of the braided sleeve 36 and restrains the end portions 46 from excessive movement during the remainder of the manufacturing process. The restraining material 44 can also be wrapped around all portions of the braided sleeve 36, or just a central portion while the end portions 46 are left unrestrained. The restraining material 44 is preferably made of plastic wrap, zip tie, metal, clips, fabric, or other suitable material.

[0025] An extra portion 48 of the insulating sleeve 36 may result from cutting, installing, and positioning the insulating sleeve 36. The restraining material 44 can hold some of the extra portion 48 in place, while an unrestrained portion extends outwardly. The unrestrained extra portion 48 is illustrated as a frayed portion, but it can be any extra material that is not needed on the portion of the insulated tube 20, and is rolled over or tucked in, or is preferably trimmed off using a rotary cutter, scissors, knife, or other device. The ends of the insulating sleeve 36 can also be prepared in any suitable manner before installation to prevent or reduce fraying.

[0026] In the illustrated embodiment, a central portion 52 of the insulating sleeve 36 is not wrapped and is permitted to be unrestrained, at least temporarily, to allow for readjustment of the braided sleeve 36, for example, before further manufacturing steps are performed. Restraining only a portion of the insulating sleeve 36, such as the end portions 46, anchors the insulating sleeve 36 while the remaining portions, such as the central portion 52, are adjusted as necessary to accommodate the shape of the exhaust tube 22, and simplifies the production of the insulated tube 20.

[0027] Once the insulating sleeve 36 is adjusted into a desired position of a substantially uniform thickness, the central portion 52 can be wrapped with a restraining wrap 54, as seen in FIG. 2, for example. Other types of restraining wraps 54 can be used, as can adhesives, as described above.

[0028] Depicted in FIG. 2, is a collar 58 on each end of the insulated central portion 30. One collar 52 can be used, but it is preferred to use two, as illustrated. The collars 58 are preferably attached directly to the exhaust tube 22 using any suitable method, such as welding, adhesives, mechanical fasteners, for example. Further, the collars 58 can be attached before or after the insulating sleeve 36 is installed on the exhaust tube 22. The collars 58 can also be positioned over the ends of the insulating sleeve 36 to restrain the ends of the insulating sleeve 36. The collars 58 can be ring-shaped and fitted over the exhaust tube 22 from the ends or the collars 58 can be formed of a number of segments that are hinged together or assembled on the exhaust tube 22.

[0029] The collars 58 extend outwardly from the exhaust tube 22 a distance that preferably matches the thickness of the insulating sleeve 36, but other collar dimensions are possible, particularly to accommodate the thickness of any restraining material 44 or additional insulation layers (see below) being used. Also preferably, the collars 58 are joined to the exhaust tube 22 to provide reinforcement for the exhaust tube 22.

[0030] After the insulating sleeve 36 is properly positioned, and any restraining material 44 is applied, a protective cover 60 is added around the outside. The protective cover 60 is preferably metal and is attached to the collars 58 when they are used, but the protective cover 60 can be tapered or stepped down and attached directly to the exhaust tube 22 at the ends. The attachment can be made with welds, adhesives, and mechanical fasteners, as examples.

[0031] FIGS. 6 and 7 illustrate an alternate embodiment having multiple layers of insulating sleeves. In this illustrated embodiment, a first layer of insulating sleeve 36 is illustrated adjacent to the exhaust tube 22. A second layer of insulating sleeve 37 is illustrated around the first layer of insulating sleeve 36 to improve heat retention in the exhaust tube 22. Additional layers of insulating sleeves can be added as well. This embodiment can also include a restraining wrap 44, as described above. Restraining wrap 44 can be used on each layer of insulating sleeves, if desired, or only around the outer most layer of insulating sleeve 37. Preferably, an outer metal protective cover 60 and collars 58 are also used in this embodiment.

[0032] The metal protective cover 60 can be a tubular sleeve or a sheet wrapped around and secured to itself at a crimp 62, as seen in FIG. 5. Preferably, the metal protective cover 60 is a thin foil that is easily wrapped and secured to form a sleeve to provide light weight protection for the insulating sleeve. Thin foil is defined herein as being 0.012 inches thick or less. Preferably, 0.004 inch thick or 0.008 inch thick foil is used in the present invention. Other metal covers could be thicker, including a metal sheet 0.057 inches thick. The metal covers 60 can also be bent tubes which are cut, placed over the insulating sleeve 36 and rewelded together. Stamped covers and cover segments can also be used.

[0033] Also, preferably the metal protective cover 60 is textured to provide increased rigidity and resistance to creases and wrinkles, for example, as well as any desired ornamental features. Any suitable texture can be employed. Optionally, the outer protective cover can include: insulated wire mesh sleeve; insulated wire mesh wrap; wrapped mesh screen; stamped foil; wrapped foil; duct tape; metal/foil tape; and wire braid, as well as those depicted in FIGS. 3 to 5, for example, and such as a waffle or elephant skin pattern. Combinations of various types of outer covers can also be used, either in layers or with different types of outer layers wrapped around different portions of the insulated tube 20.

[0034] The above detailed description is provided for understanding the depicted embodiments of the present invention, and no unnecessary limitations therefrom should be read into the following claims.