Title of Invention

AN EXHAUST MANIFOLD ASSEMBLY AND A METHOD OF COUPLING AN EXHAUST MANIFOLD TO AN ENGINE

Abstract An exhaust manifold may include a manifold body and a flange. The manifold body may include a first tube that forms an exhaust gas inlet. The flange may be coupled to the manifold body and may fix the manifold body to an engine. The flange may include a first aperture having first and second portions located along an axial extent of the first aperture. The first portion may extend to a first end surface of the flange and the second portion may extend to a second end surface of the flange. The first portion may have a first radial width that is less than a second radial width of the second portion. The second portion may receive an end of the first tube therein. The first tube may be fixed to the flange at a location within the first aperture between the first portion and the second end surface.
Full Text EXHAUST MANIFOLD ASSEMBLY
FIELD
[0001] The present disclosure relates to exhaust manifolds, and more
specifically to engagement between a mounting flange and a manifold body of an
exhaust manifold.
BACKGROUND
[0002] The statements in this section merely provide background
information related to the present disclosure and may not constitute prior art.
[0003] An engine assembly typically includes an exhaust manifold
coupled to an engine to direct an exhaust gas flow therefrom. The exhaust
manifold may include a manifold body fixed to a flange that couples the exhaust
manifold to the engine. The manifold body may be welded to the flange
generally at an end surface thereof that generally abuts the engine after
assembly. The manifold body and flange are typically formed from similar
materials to account for the thermal expansion experienced during the welding
process.
SUMMARY
[0004] An exhaust manifold may include a manifold body and a flange.
The manifold body may include a first tube that forms an exhaust gas inlet. The
flange may be coupled to the manifold body and may fix the manifold body to an

engine and place the manifold body in communication with an exhaust gas from
the engine. The flange may include a first aperture having first and second
portions located along an axial extent of the first aperture. The first portion may
extend to a first end surface of the flange and the second portion may extend to a
second end surface of the flange. The first portion may have a first radial width
that is less than a second radial width of the second portion. The second portion
may receive an end of the first tube therein. The first tube may be fixed to the
flange at a location within the first aperture between the first portion and the
second end surface.
[0005] A method may include inserting an end of a first tube that forms
an exhaust gas inlet to an exhaust manifold into a first aperture of a flange that
mounts the exhaust manifold to an engine. The first aperture may include first
and second portions located along an axial extent of the first aperture. The first
portion may extend to a first end surface of the flange and the second portion
may extend to a second end surface of the flange. The first portion may have a
first radial width that is less than a second radial width of the second portion.
The method may further include aligning the end axially within the first aperture
at a location between the first portion and the second end surface and fixing the
end of the first tube to an inner surface of the first aperture.
[0006] Further areas of applicability will become apparent from the
description provided herein. It should be understood that the description and
specific examples are intended for purposes of illustration only and are not
intended to limit the scope of the present disclosure.

DRAWINGS
[0007] The drawings described herein are for illustration purposes only
and are not intended to limit the scope of the present disclosure in any way.
[0008] Figure 1 is a schematic illustration of an engine assembly
according to the present disclosure;
[0009] Figure 2 is a perspective view of an exhaust manifold according
to the present disclosure;
[0010] Figure 3 is a fragmentary sectional view of the exhaust manifold
of Figure 2;
[0011] Figure 4 is a fragmentary plan view of an end of a tube of the
cjxhaust manifold of Figure 2; and
[0012] Figure 5 is a bottom plan view of a flange of the exhaust
manifold of Figure 2.
DETAILED DESCRIPTION
[0013] The following description is merely exemplary in nature and is
not intended to limit the present disclosure, application, or uses. It should be
understood that throughout the drawings, corresponding reference numerals
indicate like or corresponding parts and features.
[0014] Referring to Figure 1, an exemplary engine assembly 10 is
schematically illustrated. Engine assembly 10 may include an engine 12 in
communication with an intake system 14, an exhaust system 16, and a fuel
system 18. In the example shown, intake system 14 may include an intake

manifold 20 and a throttle 22. However, it is understood that alternate
applications may not include throttle 22. Throttle 22 may control an air flow
(indicated by arrow 23) into engine 12 and fuel system 18 may control a fuel flow
into engine 12. Exhaust system 16 may include an exhaust manifold 24 fixed to
engine 12 and in communication with exhaust gas created by combustion of the
air/fuel mixture. Exhaust manifold 24 may direct an exhaust gas flow (indicated
by arrow 25) from engine 12.
[0015] With reference to Figure 2, exhaust manifold 24 may include a
manifold body 26 and a flange 28. Manifold body 26 may include, but is not
limited to, a series of tubes 30, 32, 34, 36 having a jacket 38 fixed thereto.
Tubes 30, 32, 34, 36 may be fixed relative to one another by engagement with
jacket 38. More specifically, each of tubes 30, 32, 34, 36 may be welded to
jacket 38. Tubes 30, 32, 34, 36 may be formed from a variety of materials
including steel, such as wrought low-carbon and stainless steels. Ends 40, 42,
44, 46 of each of tubes 30, 32, 34, 36 may extend beyond jacket 38. Due to
manufacturing variation, the extent of ends 40, 42, 44, 46 beyond jacket 38 may
vary among tubes 30, 32, 34, 36.
[0016] Flange 28 may be formed, for example, from a powdered metal.
In this example, tubes 30, 32, 34, 36 and flange 28 may be formed from different
materials. Tubes 30, 32, 34, 36 may therefore have a different coefficient of
thermal expansion than flange 28. The powdered metal of flange 28 may have a
density of at least 6.8 g/cm3. Flange 28 may include a series of apertures 48, 50,
52, 54 extending between first and second end surfaces 56, 58 thereof. First end

surface 56 may be a mating surface for engagement with engine 12. With
additional reference to Figure 3, aperture 48 will be described with the
understanding that the description applies equally to apertures 50, 52, 54.
Aperture 48 may include first and second portions 60, 62 having a stepped
region 64 therebetween.
[0017] First portion 60 may extend to first end surface 56 and second
portion 62 may extend to second end surface 58. First portion 60 may have a
radial width that is less than a radial width of second portion 62. More
specifically, and with additional reference to Figure 5, second portion 62 may
extend radially outwardly relative to first portion 60 and may include major and
minor diameters (D1, D2) that are greater than major and minor diameters (D3,
D4) of first portion 60.
[0018] Stepped region 64 may extend at an angle relative to the
longitudinal axis of aperture 48. For example, stepped region 64 may extend at
an angle (θ) of between 10 and 90 degrees. Alternatively, stepped region 64
may extend at an angle of between 90 and 135 degrees to provide a generally
closed recess. Stepped region 64 may be located a distance (x) from first end
surface 56 of between 25 and 75 percent of the axial extent (y) of aperture 48.
More specifically, stepped region 64 may be located at approximately the
midpoint of the axial extent (y) of aperture 48. End 40 of tube 30 may extend into
aperture 48 at a location between first end surface 56 and second end surface
58. For example, an end face 41 of end 40 may be located axially between first
portion 60 and second end surface 58. It is understood that the description of

tube 30 and aperture 48 applies equally to tubes 32, 34, 36 and apertures 50, 52,
54.
[0019] With additional reference to Figure 4, end face 41 of tube 30
may have a major diameter (D5) that is less than D1 and greater than D3. End
face 41 of tube 30 may have a minor diameter (D6) that is less than D2 and
greater than D4. As such, stepped region 64 may extend radially over end 40 of
tube 30. A recess 66 may be formed between first portion 60 and end 40 of tube
30 and may have an axial extent defined by end face 41 and stepped region 64.
Recess 66 may extend radially outwardly relative to an inner surface of tube 30
at end 40 and first portion 60 of aperture 48. The radially outward extent of
recess 66 may be between 0.5 mm and 4.0 mm relative to first portion 60.
Recess 66 may be located a distance (x) from first end surface 56 of between 25
and 75 percent of the axial extent (y) of aperture 48 (seen in Figure 3). More
specifically, recess 66 may be located at approximately the midpoint of the axial
extent (y) of aperture 48.
[0020] End 40 of tube 30 may be fixed to an inner wall of aperture 48 at
a location between first and second end surfaces 56, 58. For example, end 40 of
tube 30 may be fixed to flange 28 at a location between first portion 60 and
second end surface 58, and more specifically at recess 66. Due to the fixation of
tube 30 within aperture 48 at a location between first and second end surfaces
56, 58, rather than at first end surface 56, the axial extent of tube 30 within
aperture 48 may vary without requiring additional machining operations. For
example, at least two of tubes 30, 32, 34, 36 may have different axial extents

within apertures 48, 50, 52, 54. One of tubes 30, 32, 34, 36 may have an axial
extent that is up to 2.0 mm greater than another of tubes 30, 32, 34, 36, and
more specifically between 1.0 and 2.0 mm greater than another of tubes 30, 32,
34, 36.
[0021] Tube 30 may be fixed to flange 28 by a weld bead 68. A weld
tip may be inserted into aperture 48 and may apply weld bead 68 within recess
66. The angular extent of stepped region 64 discussed above may generally
facilitate insertion of the weld tip for the welding operation. Weld bead 68 may
have a radially inward extent relative to first portion 60 that is, for example, less
than or equal to 1 mm. As such, weld bead 68 may provide little or no additional
flow restriction within aperture 48. The location of weld bead 68 within recess 66
at a location proximate the midpoint of the axial extent of aperture 48 may
generally limit warpage of first end surface 56 that is typically caused by the heat
generated during welding. More specifically, warpage of first end surface 56 may
be generally less than a warpage caused by welding directly on first end surface
56. The reduced warpage may eliminate or reduce the amount of machining
required on first end surface 56.

CLAIMS
What is claimed is:
1. An exhaust manifold comprising:
a manifold body including a first tube that forms an exhaust gas
inlet; and
a flange coupled to said manifold body that fixes said manifold body
to an engine and places said manifold body in communication with an exhaust
gas from said engine, said flange including a first aperture having first and
second portions located along an axial extent of said first aperture, said first
portion extending to a first end surface of said flange and said second portion
extending to a second end surface of said flange, said first portion having a first
radial width that is less than a second radial width of said second portion, said
second portion receiving an end of said first tube therein, said first tube being
fixed to said flange at a location within said first aperture between said first
portion and said second end surface.
2. The exhaust manifold of claim 1, further comprising a weld bead
located on an inner surface of said first aperture and fixing said end of said first
tube to said flange.

3. The exhaust manifold of claim 2, wherein a recess is defined
between said end of said first tube and said first portion of said first aperture, said
recess having said weld bead disposed therein.
4. The exhaust manifold of claim 3, wherein said weld bead extends
radially inwardly beyond an inner surface of said first portion less than 1
millimeter.
5. The exhaust manifold of claim 2, wherein said weld bead is located
at approximately an axial midpoint of said first aperture.
6. The exhaust manifold of claim 1, wherein said end of said first tube
includes a third radial width that is greater than said first radial width.
7. The exhaust manifold of claim 6, wherein said end of said first tube
and said first portion define a recess therebetween.
8. The exhaust manifold of claim 1, wherein said flange includes a
stepped region between said first and second portions.
9. The exhaust manifold of claim 8, wherein said stepped region
extends at an angle of between 10 and 90 degrees relative to a longitudinal axis
of said first aperture.

10. The exhaust manifold of claim 8, wherein said stepped region
extends radially over said end of said first tube.
11. The exhaust manifold of claim 8, wherein said manifold body
includes a second tube and said flange includes a second aperture having first
and second portions along an axial extent thereof with an additional stepped
region therebetween, said second tube forming an additional exhaust gas inlet
and having an axial extent within said second aperture that is greater than an
axial extent of said first tube within said first aperture.
12. The exhaust manifold of claim 1, wherein said first tube and said
flange are formed from different materials.
13. The exhaust manifold of claim 12, wherein said flange is formed
from a powdered metal.

14. A method comprising:
inserting an end of a first tube that forms an exhaust gas inlet to an
exhaust manifold into a first aperture of a flange that mounts said exhaust
manifold to an engine, said first aperture including first and second portions
located along an axial extent thereof, said first portion extending to a first end
surface of said flange and said second portion extending to a second end surface
of said flange, said first portion having a first radial width that is less than a
second radial width of said second portion;
aligning said end axially within said first aperture at a location
between said first portion and said second end surface; and
fixing said end of said first tube to an inner surface of said first
aperture.
15. The method of claim 14, wherein said fixing includes welding.
16. The method of claim 15, wherein said welding includes forming a
weld bead on said inner surface of said first aperture at approximately an axial
midpoint of said first aperture.
17. The method of claim 14, wherein said first aperture includes a
stepped region located between said first and second portions, said aligning
providing a recess between said first portion and said end of said first tube.

18. The method of claim 17, wherein said fixing includes forming a weld
bead within said recess.
19. The method of claim 18, wherein said fixing includes inserting a
weld tip into said recess to form said weld bead.
20. The method of claim 14, further comprising forming said flange
from a powdered metal.

An exhaust manifold may include a manifold body and a flange. The
manifold body may include a first tube that forms an exhaust gas inlet. The
flange may be coupled to the manifold body and may fix the manifold body to an
engine. The flange may include a first aperture having first and second portions
located along an axial extent of the first aperture. The first portion may extend to
a first end surface of the flange and the second portion may extend to a second
end surface of the flange. The first portion may have a first radial width that is
less than a second radial width of the second portion. The second portion may
receive an end of the first tube therein. The first tube may be fixed to the flange
at a location within the first aperture between the first portion and the second end
surface.

Documents:

http://ipindiaonline.gov.in/patentsearch/GrantedSearch/viewdoc.aspx?id=my2zTb0uGEcoj4ofRmN0tw==&loc=wDBSZCsAt7zoiVrqcFJsRw==


Patent Number 279248
Indian Patent Application Number 1565/KOL/2008
PG Journal Number 03/2017
Publication Date 20-Jan-2017
Grant Date 16-Jan-2017
Date of Filing 10-Sep-2008
Name of Patentee GM GLOBAL TECHNOLOGY OPERATIONS, INC.
Applicant Address 300 GM RENAISSANCE CENTER, DETROIT, MICHIGAN
Inventors:
# Inventor's Name Inventor's Address
1 ROBERT H. BECK 537 MEISNER ROAD EAST CHINA, MICHIGAN 48054
2 KENNETH L. MAROTTA 16889 RENEE DRIVE MACOMB, MICHIGAN 48402
PCT International Classification Number F01N7/10
PCT International Application Number N/A
PCT International Filing date
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 11/869,812 2007-10-10 U.S.A.