Information
-
Patent Grant
-
6758175
-
Patent Number
6,758,175
-
Date Filed
Friday, October 25, 200222 years ago
-
Date Issued
Tuesday, July 6, 200420 years ago
-
Inventors
-
Original Assignees
-
Examiners
- Denion; Thomas
- Corrigan; Jaime
Agents
-
CPC
-
US Classifications
Field of Search
US
- 123 9012
- 123 9015
- 123 9016
- 123 9017
- 123 320
- 123 321
- 123 322
- 251 12901
- 251 12902
- 251 12903
- 251 12904
- 251 12905
-
International Classifications
-
Abstract
A hydraulic manifold assembly for variable actuation of engine valves in accordance with the invention includes oil flow galleries. Engine oil under pressure communicates with a global supply gallery in the manifold assembly, from which pressurized oil is supplied selectively via individual supply galleries to each variable actuator for each valve through the action of solenoid valves. At engine startup, all galleries may be empty of oil, or partially filled. A global relief valve at the end of the global supply gallery causes air to be purged immediately upon startup of the engine. Each solenoid and individual gallery is provided with a low pressure relief valve leading back to the crankcase when the solenoid supply valve is closed. A bleed orifice between the global supply gallery and each individual gallery continually bleeds oil under low pressure into the individual gallery, which purges initial air therein. Anti-draining means in each individual gallery keeps the gallery filled when the valve deactivation mechanism is deactuated.
Description
TECHNICAL FIELD
The present invention relates to internal combustion engines; more particularly, to devices for controlling systems in an internal combustion engine; and most particularly, to an improved hydraulic manifold assembly for controlling the flow of engine oil in variable activation and deactivation of valve lifters in an internal combustion engine, wherein air is automatically purged from the supply gallery and individual control galleries, and oil drainage there from is prevented.
BACKGROUND OF THE INVENTION
In conventional prior art four-stroke internal combustion engines, the mutual angular relationships of the crankshaft, camshaft, and valves are mechanically fixed; that is, the valves are opened and closed fully and identically with every two revolutions of the crankshaft, fuel/air mixture is drawn into each cylinder in a predetermined sequence, ignited by the sparking plug, and the burned residue discharged. This sequence occurs irrespective of the rotational speed of the engine or the load being placed on the engine at any given time.
It is known that for much of the operating life of a multiple-cylinder engine, the load might be met by a functionally smaller engine having fewer firing cylinders, and that at low-demand times fuel efficiency could be improves if one or more cylinders of a larger engine could be withdrawn from firing service. It is known in the art to accomplish this by de-activating the valve train leading to pre-selected cylinders in any of various ways, such as providing special valve lifters having internal locks which may be switched off either electrically or hydraulically. Such switching conveniently performed via a hydraulic manifold that utilizes electric solenoid valves to selectively pass oil to the lifters on command from an engine control module (ECM). Such a manifold is referred to in the art as a Lifter Oil Manifold Assembly (LOMA).
A serious problem exists in adapting hydraulic control to valve deactivation. Such systems require hydraulic rigidity for proper operation and as such are highly intolerant of air in either the main gallery or the individual control galleries. Air in these galleries can increase the deactivation response time and also cause variation in response time. Both of these conditions can cause inaccurate activation or deactivation timing, resulting in loss of function and potentially catastrophic engine failure.
It is a principal object of the present invention to provide an improved solenoid-actuated hydraulic manifold assembly for controlling the hydraulic locking and unlocking of deactivatable valve lifters in an internal combustion engine, wherein any air present in the supply or control oil galleries at engine startup is automatically purged from the circuits and is actively prevented from re-entry during the periods of inactivity.
SUMMARY OF THE INVENTION
Briefly described, a hydraulic manifold assembly for variable actuation of engine valves in accordance with the invention includes oil flow passages, or galleries, formed therein. Typically, a riser providing engine oil under pressure communicates with a global supply gallery in the manifold assembly, from which pressurized oil is supplied selectively via an individual supply gallery to each variable actuator for each valve through the action of a solenoid valve disposed between the global supply gallery and each individual supply gallery. At engine startup, all galleries may be empty of oil, or partially filled. A global relief valve at the end of the global supply gallery opposite the oil riser leads back to the crankcase and is set to open at a pressure below the normal operation engine oil pressure. Air in the global supply gallery is thus purged immediately upon startup of the engine, and oil continues to be flowed actively throughout the global gallery at all times, the pressure therein being equal to the opening pressure of the relief valve. Further, each solenoid and gallery is provided with a low pressure relief valve leading back to the crankcase. When the solenoid valve is open, the pressure relief valve is closed; when the solenoid valve is closed, the pressure relief valve is open. A bleed orifice between the global supply gallery and each individual gallery continually bleeds oil under low pressure into each individual gallery, which purges initial air therein but is insufficient to actuate the deactivation mechanism. Further, each individual gallery is provided with anti-draining means to keep the gallery filled while the valve deactivation mechanism is inactive.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will now be described, by way of example, with reference to the accompanying drawings, in which:
FIG. 1
is a schematic drawing of an oil system for an internal combustion engine showing the relationship of a valve deactivation control system to a prior art pressurized oil system;
FIG. 2
is an enlarged schematic drawing of a portion of the drawing shown in
FIG. 1
, showing addition and rearrangement of valving and oil galleries in accordance with the invention;
FIG. 3
is a cross-sectional schematic view, not to scale, of a first embodiment of a portion of a hydraulic manifold control system in accordance with the invention;
FIG. 4
is a cross-sectional schematic view, not to scale, of a second embodiment of a portion embodiment of a portion of a hydraulic manifold control system in accordance with the invention;
FIG. 5
is an enlarged cross-sectional view of the valve head portion of the hydraulic manifold system shown in
FIGS. 3 and 4
, showing an oil bleed configuration alternative to that shown in
FIGS. 3 and 4
.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to
FIG. 1
, the prior art engine oil circuits for an internal combustion engine are provided with a valve deactivation apparatus. While only a single control valve and lifter are shown in the schematic drawing, it should be understood that valve deactivation is useful only in multiple-cylinder engines for selectively reducing the number of combusting cylinders.
In
FIG. 1
, an oil pump
10
feeds oil from sump
12
to a juncture
14
where the flow is split three ways. A first portion
16
provides general lubrication the engine. A second portion
18
provides oil conventionally to the hydraulic lifter gallery
19
, which support valve deactivation lifters
20
. A third portion
22
provides oil to a valve deactivation control system
24
. An optional pressure relief valve
26
at the entrance to the system is openable to the sump to maintain pressure in system
24
at a predetermined maximum level. Oil is filtered by strainer
28
and then is supplied via a global supply gallery
38
to a solenoid control valve
30
wherein it is either diverted to the sump
12
of the control valve
30
is not energized, or is diverted to deactivation lifter
20
if the control valve
30
is energized, to cause the associated engine intake and exhaust valves to be deactivated. An engine control module (ECM)
32
receives input signals
33
from a pressure transducer
34
in the control system
24
and integrates via an algorithm such signals with other input operating data such as oil temperature and engine speed to provide output signals
36
to energize or de-energize solenoid control valve
30
.
Referring to
FIGS. 2 through 4
, oil circuits in accordance with the invention are similar to those shown in
FIG. 1
, with the following implement changes.
First, pressure relief valve
26
leading to drain
29
is moved from the entrance to the global supply gallery
38
to an end thereof adjacent solenoid control valve
30
to permit purging of air from all of the gallery up to the entry to the solenoid control valve. As in the prior art, relief valve
26
is set to establish a desired pressure in the global supply gallery.
Second, a gallery
40
is provided through the seat
42
of solenoid valve
30
in communication with drain line
44
, which is provided with a second pressure relief valve
46
, and in communication behind valve head
43
with individual gallery
48
when valve
30
is closed to gallery
38
, as shown in FIG.
3
.
Third, an oil bleed port
50
disposed between global gallery
38
and individual gallery
48
, as shown in
FIGS. 3 and 4
, permits a low volume of oil to fill and then flow through these galleries at all times when the engine is running to purge air therefrom. Preferably, bleed port
50
has a diameter between about 0.25 mm and 0.50 mm. Valve
46
is set to open at a relatively low pressure, for example, 2 psig. Valve
46
thus functions as an anti-draining valve to prevent gallery
40
from draining by gravity when the engine is not running.
Fourth, two different anti-draining means are provided in individual gallery
48
, as shown in
FIGS. 3 and 4
, respectively.
Referring to
FIG. 3
, in a first arrangement
51
, manifold body
52
is mated to engine tower
54
with contains a bore
56
in communication with individual gallery
48
and leading to deactivation valve lifer
20
. Tower
54
may be sealed to body
52
as by an O-ring
58
in known fashion. Bore
56
houses an extension
60
of gallery
48
which may comprise, for example, a length of flexible hose attached to body
52
as by a nipple
62
. At the distal end of extension
60
is a third pressure relief valve
64
having a very low opening pressure, preferably about 1 psig. Thus, when galleries
40
,
48
, and
60
have been filled with oil, valves
46
and
64
prevent them from draining by gravity when the engine is shut off. Because drain valve
46
has a higher opening pressure than does valve
64
, oil admitted to individual gallery
48
when solenoid valve
30
is opened during operation will open valve
64
preferentially to actuate lifter
20
as intended. When the solenoid valve is closed, pressure capacitance in galleries
40
and
48
is dissipated immediately through valves
46
and
64
, but the galleries do not drain and thus are ready for the next demand of lifter
20
.
Referring to
FIG. 4
, an alternate arrangement
59
is shown which is similar to that shown in FIG.
3
. However, extension
60
and valve
64
are replaced by a rod
66
connected to manifold body
52
and extending within bore
56
to create an annular space
68
therebetween. Preferably, the radial dimension of space
68
is small, for example, about 0.4 mm as may be achieved when the diameter of bore
56
is 9.0 mm and the diameter of rod
66
is 8.2 mm. A check valve such as valve
64
is obviated, in that oil can flow freely through annular space
68
as needed to actuate lifter
20
, but when solenoid valve
30
is closed, surface tension keeps the oil residual in space
68
from draining out.
In either of the embodiments shown in
FIGS. 3 and 4
, bleed port
50
can be omitted if it is acceptable to allow galleries
40
,
48
, and
60
to fill upon startup to the engine, for example, during a brief startup protocol the solenoids may all exercised briefly to fill the galleries. Alternatively, referring to
FIG. 5
, if a bleed is desired, a fixed bleed
50
a
may be formed simply by providing a small groove in the seat
42
of the solenoid valve such that a low volume of oil is continuously bypassed of the solenoid valve.
While the invention has been described by reference to various specific embodiments, it should be understood that changes may be made within the spirit and scope of the inventive concepts described. Accordingly, it is intended that the invention not be limited to the described embodiments, but will have full scope defined by the language of the following claims.
Claims
- 1. A hydraulic manifold: assembly 24 for control of a variable valve actuation device for an engine valve wherein air is automatically purged from the assembly and is prevented from re-entering, comprising:a) a global oil supply gallery 38 in said manifold assembly and having a proximal end for receiving oil from said engine; b) a first pressure relief valve 26 disposed at a distal end of said global supply gallery for allowing purging of air from said gallery; c) at least one individual oil supply gallery 48 in said manifold assembly for supplying oil control from said global supply gallery to said variable valve actuation device; d) a control valve 30 having a valve seat 42 disposed between said global supply gallery and said individual supply gallery for regulating flow of control oil; and e) means 64, 66 for preventing draining of oil from said individual supply gallery.
- 2. A hydraulic manifold assembly in accordance with claim 1 further compromising oil bleed means 50 between said global supply gallery and said individual supply gallery.
- 3. A hydraulic manifold assembly in accordance with claim 2 wherein said oil bleed means compromises a bleed orifice 50.
- 4. A hydraulic manifold assembly in accordance with claim 2 wherein said oil bleed means comprises a groove 50a in said valve seat.
- 5. A hydraulic manifold assembly in accordance with claim 1 further compromising a drain gallery 40 from said valve seat and a second pressure relief valve 46 disposed in said drain gallery.
- 6. A hydraulic manifold assembly in accordance with claim 1 wherein said individual supply gallery has a distal end adjacent said variable valve deactuation device and wherein said means for preventing draining includes a third pressure relief valve 64 at said distal end.
- 7. A hydraulic manifold assembly in accordance with claim 1 wherein said individual supply gallery has a bore terminating at said variable valve deactuation device and wherein said means for draining comprises a rod disposed in said bore to create an annular space therebetween for flow of oil to said variable valve deactuation device, wherein oil is retained by surface tension during periods of inactivity of said device.
- 8. A hydraulic manifold assembly in accordance with claim 7 wherein the radial thickness of said annular space of about 0.4 mm.
- 9. An internal combustion engine having a hydraulic manifold assembly for control of a variable valve actuation device for an engine valve wherein air is automatically purged from the assembly and is prevented from re-entering, comprising:a) a global oil supply gallery 38 in said manifold assembly and having a proximal end for receiving oil from said engine; b) a first pressure relief valve 26 disposed at a distal end of said global supply gallery for allowing purging of air from said gallery; c) at least one individual oil supply gallery 48 in said manifold assembly for supplying oil control from said global supply gallery to said variable valve actuation device; d) a control valve 30 having a valve seat 42 disposed between said global supply gallery and said individual supply gallery for regulating flow of control oil; and e) means 64, 66 for preventing draining of oil from said individual supply gallery.
- 10. A hydraulic manifold assembly 24 for control of a variable valve actuation device for an engine valve wherein air is automatically purged from the assembly and is prevented from re-entering, comprising:a) a global oil supply gallery 38 in said manifold assembly and having a proximal end for receiving oil from said engine; b) a first pressure relief valve 26 disposed at a distal end of said global supply gallery for allowing purging of air from said gallery; c) at least one individual oil supply gallery 48 in said manifold assembly for supplying oil control from said global supply gallery to said variable valve actuation device; d) a control valve 30 having a valve seat 42 disposed between said global supply gallery and said individual supply gallery for regulating flow of control oil; and e) means for preventing draining of oil from said individual supply gallery, wherein said individual supply gallery has a bore terminating at said variable valve deactuation device, wherein said means for draining comprises a rod disposed in said bore to create an annular space therebetween for flow of oil to said variable valve deactuation device, and wherein oil is retained by surface tension during periods of inactivity of said device.
- 11. A hydraulic manifold assembly in accordance with claim 10 wherein the radial thickness of said annular space of about 0.4 mm.
US Referenced Citations (10)
Foreign Referenced Citations (1)
Number |
Date |
Country |
3807699 |
Sep 1989 |
DE |