Information
-
Patent Grant
-
6679215
-
Patent Number
6,679,215
-
Date Filed
Friday, November 30, 200122 years ago
-
Date Issued
Tuesday, January 20, 200420 years ago
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Inventors
-
Original Assignees
-
Examiners
- Yuen; Henry C.
- Benton; Jason
Agents
-
CPC
-
US Classifications
Field of Search
US
- 123 18461
- 123 18434
- 123 18457
-
International Classifications
-
Abstract
An improved air intake manifold for a V-style internal combustion engine comprising three individual injection molded sections joined by friction welding of flanged mating elements. Each section is formed of a high-melting temperature composite polymer. The welds are all on the exterior of the manifold. The mating surfaces are formed to be directly accessible to welding apparatus and are so oriented that friction welding may be carried out by relative motion between the components in the axial direction. When joined, the lower and middle sections form the individual air distribution runners from the plenum to the intake ports in the engine heads. The lower and middle sections are so configured that each such runner crosses the valley of the engine, providing great strength and rigidity to the module. All runners are identical, so that air flows from the plenum to the individual cylinders are substantially identical. The middle and upper sections may be rotationally symmetrical about a vertical axis, preventing mis-orientation during assembly. Modifications may be made to any one of the sections without requiring retooling of molds for the other two sections, provided the configurations of the mating surfaces are unchanged.
Description
TECHNICAL FIELD
The present invention relates to intake manifolds for internal combustion engines; more particularly, to such manifolds formed of a polymer; and most particularly, to an intake manifold module formed by vibration welding of a plurality of injection-molded components.
BACKGROUND OF THE INVENTION
An internal combustion engine, powered by either diesel fuel or gasoline, includes generally an intake manifold assembly for collecting air from outside the engine and distributing the collected air to each of the combustion cylinders. In modern engines, the manifold typically is part of a relatively complex assembly known generally in the art as an integrated air/fuel module (IAFM). The IAFM may include a variety of sub-systems for performing a host of related functions, including, for example, a throttle body and valve for air flow control, a helmholz resonator for noise suppression, an exhaust gas recirculation valve for mixing exhaust gas into the fresh air stream, a fuel rail and fuel injectors for injecting fuel to the cylinders, and a purge valve for stripping fuel from a fuel tank cannister.
Historically, intake manifolds were formed of metal such as cast iron or aluminum by molding around a sand-cast core, a costly manufacturing technique wherein the integrity of the core was destroyed by the heat of the molten metal, allowing the sand to be poured from the interior of the cooled component. More recently, intake modules are known in the art to be formed of high-temperature thermoplastic composites such as glass-filled nylon or glass-filled polyphthalamide by “lost core” molding, a technique related to sand casting wherein a sacrificial internal core, formed typically of a tin/bismuth alloy having a relatively low melting temperature, is destroyed after the molding process.
It is highly desirable to form an intake module by less-expensive forming techniques such as injection molding, wherein a component is formed by filling a cavity between an inner and an outer mold. The shape of the component must be such that the inner mold can be released and extracted from the part upon solidification of the molding material, a requirement that heretofore has generally dictated use of a sacrificial inner mold.
Recently, it is known in the art to form an intake module for an in-line engine by injection molding matable components which may be assembled as by welding to form a finished module. However, injection molding has not been available heretofore for the formation of a satisfactory IAFM for a V-style engine because of 1) very tight tolerances required in bridging across the valley between the left- and right-bank cylinder heads, and 2) great difficulty in reliably welding mating surfaces of components within the module.
Further, in known intake manifolds, the runners carrying air from a central plenum to the individual cylinders may differ in length and/or geometry, which is undesirable because the various cylinders may experience differing air/fuel ratios. It is preferred that the runners be identical, so that each cylinder is supplied identically with air.
Therefore, there is a strong need for an improved integrated air/fuel module for a V-style engine wherein the intake manifold may be assembled from injection molded components.
It is a principal object of this invention to provide an improved intake manifold formed of components which may be readily molded by injection molding and assembled by friction welding.
It is a further object of this invention to provide an improved intake manifold wherein the air flow paths between a plenum and the individual cylinders are identical.
It is a still further object of this invention to provide an improved intake manifold formed of welded components wherein the weld integrity of each air flow runner may be readily tested.
It is a still further object of this invention to provide an improved intake manifold having superior mechanical rigidity for installation as a bridge across the heads of a V-style engine.
SUMMARY OF THE INVENTION
Briefly described, the present invention is directed to an improved air intake manifold for a V-style internal combustion engine. The manifold is assembled from three individual injection molded sections by friction welding of mating surfaces. Preferably, each section is formed of a high-melting temperature composite polymer, such as glass-filled nylon or glass-filled polyphthalamide. The mating surfaces are all on the exterior of the manifold and are so formed as to be directly accessible to welding apparatus, including clamping devices. Further, the mating surfaces are so oriented that friction welding may be carried out by relative motion between the components in the axial direction. When joined, the lower and middle sections form the individual distribution runners from the plenum to the intake ports in the engine heads. The lower and middle sections are so configured that each such runner crosses the valley of the engine, providing great strength and rigidity to the module. Further, all runners are identical, so that air flows from the plenum to the individual cylinders are substantially identical. Preferably, the middle and upper sections are rotationally symmetrical about a vertical axis orthogonal to the longitudinal axis of the module, such that each may be added to the module during assembly in either of two orientations 180° apart, making mis-orientation impossible. Modifications may be made to any of the sections, as may be required for example to adapt the manifold to a specific engine IAFM requirement, without requiring retooling of molds for the other two sections, provided the configurations of the mating surfaces are unchanged.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing and other objects, features, and advantages of the invention, as well as presently preferred embodiments thereof, will become more apparent from a reading of the following description in connection with the accompanying drawings in which:
FIG. 1
is an exploded isometric view from above of an improved air intake manifold in accordance with the invention, showing the relationship of the upper, middle, and lower sections;
FIG. 2
is a bottom plan view of the lower section, and hence of the manifold;
FIG. 3
is a top plan view of the lower section, showing the runners crossing the manifold;
FIG. 4
is a top plan view of the middle section, showing the zip tube, entrance to the plenum, and entrances to the individual runners;
FIG. 5
is a bottom plan view of the underside of the upper section;
FIG. 6
is an end view of the lower section shown in
FIGS. 1 through 3
; and
FIG. 7
is an exploded elevational view of the upper, middle, and lower sections shown in FIG.
1
.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to
FIGS. 1 through 3
and
6
, an improved air intake manifold
10
in accordance with the invention includes an upper section
12
, a middle section
14
, and a lower section
16
, which are assemblable as shown in
FIG. 7
to form manifold
10
. Each of sections
12
,
14
,
16
is configured to be formed by injection molding of a suitable thermally-liquefied polymer into an injection mold having inner and outer reusable molds. Formation of these sections does not require a lost-core inner mold, as in the prior art. Auxiliary side slides also may be required, as is known in the art of injection molding. Preferably, such molded sections are formed of a high-melting temperature composite polymer, such as glass-filled high-temperature nylon or glass-filled polyphthalamide which are readily available from commercial sources.
Lower section
16
, having a longitudinal axis
17
, includes the lower portions
18
of individual air distribution runners, each terminating distally in a port
20
matable with a corresponding intake port (not shown) in a left or right head
22
,
24
of a V-style engine
26
(
FIG. 6
) having an included angle 25 between the heads. Heads
22
,
24
are arranged longitudinally and generally symmetrically about an engine plane of symmetry
27
. Lower portions terminating in left-head ports are designated
18
-
22
, and lower portions terminating in right-head ports are designated
18
-
24
. Each of lower portions
18
-
22
and
18
-
24
terminates proximally in an opening fully surrounded by a flange
28
extending axially of portion
18
and having a respective mating surface
30
-
22
or
30
-
24
. Preferably, all of the mating surfaces
30
-
22
are coplanar and mating surfaces
30
-
24
are coplanar, and all are contained in planes or surfaces parallel to axis
17
. Adjacent ones of flanges
28
preferably are axially separated by at least about 2 mm. Preferably, all of lower portions
18
-
22
are identical in size and shape, as are all of lower portions
18
-
24
; and further, portions
18
-
22
are mirror image configurations of portions
18
-
24
(when reversed end-for-end).
Lower section
16
further includes a plurality of injector ports
32
, a one of each opening into each of runner ports
20
for receiving a fuel injector (not shown) during final assembly of a finished IAFM. Section
16
further includes towers
34
containing bores
36
for receiving mounting screws for fuel rails (not shown) incorporating the fuel injectors, and a plurality of bores
38
for receiving bolts (not shown) for securing section
16
to the engine heads
22
,
24
. Any of various known gasket types (not shown) may be incorporated as desired between section
16
and heads
22
,
24
.
Referring to
FIGS. 1
,
4
, and
7
, middle section
14
includes a first bank
40
a
and a second bank
40
b
of upper portions
42
of individual air distribution runners
44
disposed along opposite sides of a central zip tube
46
. Each upper portion
42
crosses beneath zip tube
46
and terminates distally in an opening (not visible in the drawings) and flange
48
. As in the lower element, there are left flanges
48
-
22
and right flanges
48
-
24
. Each flange has a surface substantially identical to and matable with respective lower portion surfaces
30
-
22
,
30
-
24
to form left- and right-runners
44
-
22
,
44
-
24
, respectively.
Each upper portion
42
in banks
40
a
,
40
b
terminates proximally in an opening
50
in a planar element
52
disposed longitudinally along zip tube
46
in a plane parallel to a plane containing axis
54
of middle section
14
. Openings
50
a
in planar element
52
a
lead to runners
44
-
24
, and openings
50
b
in planar element
52
b
lead to runners
44
-
22
, all runners crossing under tube
46
as previously described and passing through engine symmetry plane
27
. Preferably, elements
52
a
and
52
b
are not coplanar but rather are mutually inclined in order to properly shape the entrance regions of runners
44
. Preferably, middle section
14
is rotationally symmetrical about vertical axis
47
such that section
14
may be oriented either as shown in
FIG. 1
or upon 180° rotation about axis
47
, to equal effect, such that openings
50
a
then lead to runners
44
-
24
and openings
50
b
lead to runners
44
-
22
.
Zip tube
46
includes an air intake port
53
at a proximal end
55
and an air exhaust port
56
in a central region of the tube, and may include other ports for auxiliary systems, for example, port
58
for an EGR valve and port
60
for a purge valve in known fashion. Intake port
53
may receive a throttle valve body (not shown) in known fashion. Preferably, the distal end
57
of zip tube
46
is closed by a helmholz resonator
62
for damping resonant sonic frequencies in the air intake system.
Referring to
FIGS. 1 and 5
, upper section
12
is slightly dome-shaped both axially and radially and is provided with a flange
64
configured to mate conformably with zip tube
46
and planar elements
52
a,b
along the outer edges
66
a,b
thereof. When section
12
is thus sealably mated to middle section
14
, a plenum is created therebetween for receiving intake air from tube exhaust port
56
and distributing the air to runners
44
via openings
50
a,b.
Like middle section
14
, upper section
12
is also preferably rotationally symmetrical about vertical axis
47
and may be installed in either of two 180° opposed orientations.
Sections
12
,
14
,
16
may be joined by any suitable means, as by adhesives or clamps, but preferably by thermal welding of all mating surface, and most preferably by vibration (friction) welding. As described above, the mating surfaces all lie parallel to the axes of their respective sections. Thus each surface may be axially displaced by a small distance relative to its opposite mate. Vibration, or friction, welding requires such relative movement, on the order of +/−1 mm, which is permitted in the axial direction by the careful arrangement of the mating surfaces. Further, all mating flanges extend axially from their respective openings such that mating flanges may be captured over their entire lengths between a sonic horn and a back-up tool, thus ensuring highly reliable welding of all surfaces. It is an important advantage of an air intake manifold in accordance with the invention that all welds are on outer surfaces of the manifold and thus are readily visible for inspection; and further, that all flanges
28
and
48
are continuous around each runner and are not shared, so that leakage of air between runners is not possible; and further, that each runner may be individually tested for weld integrity (leaks) as desired.
In an alternative embodiment of manifold
10
, sections
12
,
14
,
16
may be die-cast of aluminum or other metal and welded along the outer edges of the respective flanges; however, the injection-molded polymeric embodiment is currently preferred.
While the invention has been described with reference to preferred embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the scope of the invention. Therefore, it is intended that the invention not be limited to the particular embodiments disclosed as the best mode contemplated for carrying out this invention, but that the invention include all embodiments falling within the scope and spirit of the appended claims.
Claims
- 1. An air intake manifold for collecting ambient air and distributing the air to individual cylinders of a V-style internal combustion engine, said intake manifold having injection-molded components joined by welding, wherein said intake manifold comprises:a) a lower section including lower portions of air distribution runners; b) a middle section including upper portions of said air distribution runners, said upper portions cooperating with said lower portions to form said runners to distribute air to said engine cylinders; and c) an upper section for cooperating with said middle section to form a plenum for distributing air to said runners, wherein said V-style engine has a plane of symmetry, and wherein said engine has left and right heads disposed on opposite sides of said plane, and wherein each of said runners passes through said plane in distributing air from said plenum to said engine cylinders.
- 2. An air intake manifold for collecting ambient air and distributing the air to individual cylinders of a V-style internal combustion engine, said intake manifold having injection-molded components joined by welding, wherein said intake manifold comprises:a) a lower section including lower portions of air distribution runners; b) a middle section including upper portions of said air distribution runners and a helmholz resonator, said upper portions cooperating with said lower portions to form said runners to distribute air to said engine cylinders; and c) an upper section for cooperating with said middle section to form a plenum for distributing air to said runners.
- 3. An air intake manifold for collecting ambient air and distributing the air to individual cylinders of a V-style internal combustion engine, said intake manifold having injection-molded components joined by welding, wherein said intake manifold comprises:a) a lower section including lower portions of air distribution runners; b) a middle section including upper portions of said air distribution runners, said middle section is rotationally symmetrical about an axis orthogonal to a longitudinal axis thereof, said upper portions cooperating with said lower portions to form said runners to distribute air to said engine cylinders; and c) an upper section for cooperating with said middle section to form a plenum for distributing air to said runners.
- 4. An air intake manifold for collecting ambient air and distributing the air to individual cylinders of a V-style internal combustion engine, said intake manifold having injection-molded components joined by welding, wherein said intake manifold comprises:a) a lower section including lower portions of air distribution runners; b) a middle section including upper portions of said air distribution runners, said upper portions cooperating with said lower portions to form said runners to distribute air to said engine cylinders; c) an upper section for cooperating with said middle section to form a plenum for distributing air to said runners; and d) a zip tube integrally molded into said middle section.
- 5. A V-style internal combustion engine having an air intake manifold, said intake manifold having injection-molded components joined by welding, wherein said intake manifold comprises:a) a lower section including lower portions of air distribution runners; b) a middle section including upper portions of said air distribution runners and a zip tube, said upper portions cooperating with said lower portions to form said runners to distribute air to said engine cylinders; and c) an upper section for cooperating with said middle section to form a plenum for distributing air from said zip tube to said runners.
US Referenced Citations (12)