U.S. patent application number 11/565872 was filed with the patent office on 2008-06-05 for engine head cover assembly having an integrated oil separator.
This patent application is currently assigned to Toyota Engineering & Manufacturing North America, Inc.. Invention is credited to Wei Liu, Naveen Rajan, Teng-Hua Shieh.
Application Number | 20080127953 11/565872 |
Document ID | / |
Family ID | 39474312 |
Filed Date | 2008-06-05 |
United States Patent
Application |
20080127953 |
Kind Code |
A1 |
Shieh; Teng-Hua ; et
al. |
June 5, 2008 |
Engine Head Cover Assembly Having An Integrated Oil Separator
Abstract
A head cover assembly for covering a crankcase of an internal
combustion engine includes a head cover and an integral oil
separator. The oil separator includes a housing that defines a flow
path that separates oil from crankcase gases passing therethrough.
At least a portion of the housing is integrally formed along an
inner surface of the head cover.
Inventors: |
Shieh; Teng-Hua; (Ann Arbor,
MI) ; Rajan; Naveen; (Ann Arbor, MI) ; Liu;
Wei; (Canton, MI) |
Correspondence
Address: |
GIFFORD, KRASS, SPRINKLE,;ANDERSON & CITKOWSKI, P.C.
P.O. BOX 7021
TROY
MI
48007-7021
US
|
Assignee: |
Toyota Engineering &
Manufacturing North America, Inc.
Erlanger
KY
|
Family ID: |
39474312 |
Appl. No.: |
11/565872 |
Filed: |
December 1, 2006 |
Current U.S.
Class: |
123/573 ;
123/41.86 |
Current CPC
Class: |
F01M 2013/0461 20130101;
F01M 13/0416 20130101; F01M 13/0405 20130101 |
Class at
Publication: |
123/573 ;
123/41.86 |
International
Class: |
F01M 13/04 20060101
F01M013/04 |
Claims
1. A head cover assembly for covering a crankcase of an internal
combustion engine, said head cover assembly comprising: a head
cover having opposite outer and inner surfaces; and an oil
separator for separating oil from crankcase gases passing
therethrough, the oil separator having a housing disposed along an
inner surface of the head cover, the housing having at least one
side wall integral with the head cover, which together with the
head cover define an interior space of the oil separator.
2. A head cover assembly as set forth in claim 1, wherein the
housing is formed by a plurality of side walls, one of the side
walls extending along the inner surface of the head cover.
3. A head cover assembly as set forth in claim 2 including a plate
releasably attached to the side walls to enclose the interior space
of the oil separator.
4. A head cover assembly as set forth in claim 3, wherein the oil
separator includes a plurality of guide walls that are integral
with the head cover and extend between the inner surface and the
plate to define a labyrinth path that causes separation of oil from
crankcase gases passing therethrough.
5. A head cover assembly as set forth in claim 1, wherein the at
least one side wall is cylindrically shaped to define a cylindrical
recess in the head cover.
6. A head cover assembly as set forth in claim 5 including a cap
releasably attachable to the at least one side wall to define the
interior space of the oil separator.
7. A head cover assembly as set forth in claim 6, wherein the cap
includes threads for engaging mating threads on the at least one
side wall.
8. A head cover assembly as set forth in claim 7 including a cover
plate disposed between the cap and the head cover to enclose the
interior space of the oil separator.
9. A head cover assembly as set forth in claim 8 including guide
walls extending from the cover plate toward the cap to define an
oil path for separating oil from crankcase gases passing
therethrough.
10. A head cover assembly as set forth in claim 6, wherein the cap
and the at least one side wall are coupled to each other by a tab
and slot arrangement, wherein the cap is rotated relative to the at
least one side wall to cause locking engagement between a tab and a
key slot.
11. A head cover assembly as set fort in claim 10, wherein the tab
extends outwardly from the cap and the key slot is formed in the at
least one side wall.
12. A head cover assembly as set forth in claim 11, wherein the at
least one side wall is generally cylindrical and forms a recess for
receiving the cap therein.
13. A head cover assembly as set forth in claim 12, wherein the at
least one side wall includes a guide slot that receives the tab
from the cap as the cap is inserted into the recess.
14. A head cover assembly as set forth in claim 13, wherein the key
slot extends orthogonally from an end of the guide slot so that
rotation of the cap within the recess causes locking engagement
between the tab and the key slot.
Description
FIELD OF THE INVENTION
[0001] The invention relates to an engine head cover for an
internal combustion engine. More particularly, the invention
relates to an engine head cover having an integrated oil separator
for separating oil from crankcase gases during operation of the
engine.
BACKGROUND OF THE INVENTION
[0002] An internal combustion engine typically includes a
combustion chamber, where a fuel air mixture is burned to cause
movement of a set of reciprocating pistons, and a crankcase, which
contains the crankshaft driven by the pistons. During operation, it
is normal for the engine to experience "blow-by," wherein
combustion gases leak past the piston-cylinder gap from the
combustion chamber and into the crankcase. These blow-by or
crankcase gases contain moisture, acids and other undesired
by-products of the combustion process.
[0003] An engine typically includes a Positive Crankcase
Ventilation (PCV) system for removing harmful gases from the engine
and prevents those gases from being expelled into the atmosphere.
The PCV system does this by using manifold vacuum to draw vapors
from the crankcase into the intake manifold. Vapor is then carried
with the fuel/air mixture into an intake manifold of the combustion
chambers where it is burned. Generally, the flow or circulation
within the system is controlled by the PCV valve, which acts as
both a crankcase ventilation system and as a pollution control
device.
[0004] It is normal for crankcase gases to also include a very fine
oil mist. The oil mist is carried by the PCV system to the
manifold. The oil mist is then burned in the combustion chamber
along with the fuel/air mixture. This results in an increase in oil
consumption. A known method of removing oil from the crankcase
gases is to use an oil separator. The crankcase gases flow through
the oil separator. Localized high pressure areas in the oil
separator promote separation of oil from the gases. The oil is
re-introduced back to a sump via a drain device. The sump generally
holds excess oil in the system.
[0005] It remains desirable to provide an improved oil separator
that is more efficient than conventional oil separator designs in
the removal of oil from crankcase gases. It also remains desirable
to provide an oil separator that is compact in size and integral
with a part of the engine housing, such as a head cover, in order
to reduce the packaging space occupied by the oil separator inside
of the engine.
SUMMARY OF THE INVENTION
[0006] According to one aspect of the invention, a head cover
assembly is provided for covering a crankcase of an internal
combustion engine. The head cover assembly includes a head cover
and an oil separator. The head cover has opposite outer and inner
surfaces. The oil separator separates oil from crankcase gases
passing therethrough. The oil separator has a housing disposed
along an inner surface of the head cover. The housing has at least
one side wall integral with the head cover, which together with the
head cover define an interior space of the oil separator.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] Advantages of the present invention will be readily
appreciated as the same becomes better understood by reference to
the following detailed description when considered in connection
with the accompanying drawings, wherein:
[0008] FIG. 1 is a bottom view of a head cover assembly having an
integral oil separator according to one embodiment of the
invention;
[0009] FIG. 2 is an enlarged bottom view of a portion of the head
cover assembly shown in FIG. 1;
[0010] FIG. 3 is an exploded perspective bottom view of the head
cover assembly of FIG. 1;
[0011] FIG. 4 is a bottom view of a head cover assembly according
to a second embodiment of the invention;
[0012] FIG. 5 is an enlarged bottom view of a portion of the head
cover assembly shown in FIG. 4;
[0013] FIG. 6 is a top perspective view of the head cover assembly
of FIG. 4;
[0014] FIG. 7 is an enlarged exploded top perspective view of a
portion of the head cover assembly of FIG. 4;
[0015] FIG. 8 is an enlarged exploded perspective view of a portion
of the head cover assembly according to a third embodiment of the
invention;
[0016] FIG. 9 is an enlarged perspective view of a portion of the
head cover assembly of FIG. 8 showing a side of an oil separator
cap with a tab for securing the cap to a head cover; and
[0017] FIG. 10 is a cross sectional view of the head cover assembly
of FIG. 8 illustrating the slot for lockingly receiving the tab for
securing the cap to the head cover.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0018] Referring to FIGS. 1-3, a head cover assembly for enclosing
a crankcase of an internal combustion engine is generally indicated
at 10. The head cover assembly 10 includes a head cover 12 having
opposite outer 14 and inner 16 surfaces. The head cover assembly 10
also includes an oil separator 20 for removing oil from crankcase
gases in the engine. The oil separator 20 includes a housing 30
disposed along the inner surface 16 of the head cover 12. The
housing 30 has a plurality of side walls 22, 24, 26, 28 integrally
formed with the head cover 12. At least one of the side walls 28
extends along the inner surface 16 of the head cover 12, while the
remaining side walls 22, 24, 26 extend outwardly from the inner
surface 16 of the head cover 12. Alternatively, all of the side
walls of the housing extend outwardly from the inner surface of the
head cover. The head cover may be formed from steel, aluminum or
any material or combination of materials known by those skilled in
the art, which are suitable for use in the heat and the environment
associated with the engine and which allows integral formation of
at least portions of the oil separator housing with the head
cover.
[0019] A portion of the head cover 12 extends between the side
walls 22, 24, 26, 28 to form an interior space. A plate 40
cooperates with the side walls 22, 24, 26, 28 to enclose the
interior space of the oil separator 20. The head cover 12 has at
least one threaded bore 29 for securing the plate 40 to the side
walls 22, 24, 26, 28 using a bolt. A gasket (not shown) may be
disposed between the side walls 22, 24, 26, 28 and the plate 40 to
prevent gases from leaking from the interior space of the housing
30. Alternatively, the housing may have a generally cylindrical
side wall that extends from the inner surface of the head cover
instead of the straight side walls of the illustrated embodiment.
The plate would then have a generally circular shape to cooperate
with the generally cylindrical shape of the side wall.
[0020] The housing 30 of the oil separator 20 includes an inlet and
an outlet. A plurality of guide walls 43 extend from the head cover
12 toward the plate 40 to define a path 39 that directs crankcase
gases through the housing 30. The path 39 is shaped to promote
separation of oil from crankcase gases as the gases flow through
the path 39 between the inlet and outlet. The separated oil is
collected in the housing 30 and re-introduced to the oil sump (not
shown) for re-use in the engine.
[0021] A second embodiment of the head cover assembly 110 is shown
in FIGS. 4-7, wherein like parts are indicated by numerals offset
by 100. In this embodiment, the housing 130 is formed by a cap 41,
a cover plate 45 and a cylindrical side wall 50, which together
define the interior space of the oil separator 120. More
specifically, the cylindrical side wall 50 is formed integrally
with the head cover 112 and defines a recess for receiving the cap
therein. More specifically, the cap 41 includes an annular portion
40 with threads 42 for engaging mating threads 44 on the head cover
112.
[0022] During assembly, the cap 41 is inserted into the recess
formed by the cylindrical side wall 50. The cap 41 is then turned
about its longitudinal axis to cause threading engagement between
the threads 42 on the cap 41 and mating threads 44 formed in the
cylindrical side wall 50, thereby securing the cap 41 to the head
cover 112. The cap 41 is fully inserted when it contacts a locating
surface 52 formed head cover 112 adjacent a bottom end of the
cylindrical side wall 50. The cover plate 45 is disposed between
the cap 41 and the head cover 112. The plurality of guide walls 143
extend from the cover plate 45 to define the flow path for
crankcase gases passing through the oil separator 120.
[0023] A third embodiment of the head cover assembly 210 are shown
in FIGS. 8-11. In this embodiment, the threads from the second
embodiment are replaced with a tab and slot arrangement, wherein a
tab 60 extends outwardly from the annular portion 240 of the cap
241 and a guide slot 62 is formed in the cylindrical side wall 250.
The guide slot 62 extends in a generally longitudinal direction
along the cylindrical side wall 250. A key slot 68 extends
generally orthogonally from an end 66 of the guide slot 62. During
assembly, the cap 241 of the housing 230 is inserted into the
recess defined by the cylindrical side wall 250. The tab 60 slides
in the guide slot 62 toward the key slot 68. The cap 241 is fully
inserted when it contacts the locating surface 252 at the bottom of
the recess. The cap 241 is then turned so that the tab 60 slides
into the key slot 68, thereby securing the oil separator 220 to the
head cover 212. Alternatively, the tab and slot arrangement may be
reversed, wherein the tab extends from the head cover and the slot
is formed in the cap.
[0024] In the illustrated embodiments, the guide walls are arranged
in the form of a labyrinth, which promotes the separation of oil
from the crankcase gases as the gases flow therealong.
Alternatively, the oil separator may be a cyclone type oil
separator, wherein the guide wall is a coil that defines a
spiral-shape flow path that extends between the inlet and the
outlet of the housing. It should be appreciated by those having
ordinary skill in the art that other types of oil separators may be
packaged within the housing. Alternatively, the oil separator may
incorporate more than one type of oil separating arrangement within
the housing, such as a combination between labyrinth and cyclone
type oil separating arrangements.
[0025] The invention has been described in an illustrative manner.
It is, therefore, to be understood that the terminology used is
intended to be in the nature of words of description rather than of
limitation. Many modifications and variations of the invention are
possible in light of the above teachings. Thus, within the scope of
the appended claims, it is clear that the invention may be
practiced other than as specifically described.
* * * * *