U.S. patent number 3,738,337 [Application Number 05/213,881] was granted by the patent office on 1973-06-12 for electrically operated hydraulic valve particularly adapted for pollution-free electronically controlled internal combustion engine.
Invention is credited to Philip E. Massie.
United States Patent |
3,738,337 |
Massie |
June 12, 1973 |
ELECTRICALLY OPERATED HYDRAULIC VALVE PARTICULARLY ADAPTED FOR
POLLUTION-FREE ELECTRONICALLY CONTROLLED INTERNAL COMBUSTION
ENGINE
Abstract
An electrically operated hydraulically driven valve driven by
internal combustion engine lubricating oil. A ported valve sleeve
is positioned between inner and outer cylinders, the inner of which
is the hydraulic valve operating cylinder. All concentric members
have radial ports. The electrically operated sleeve member controls
the porting controlling the inflow and outflow of hydraulic liquid.
The control sleeve is moved electromagnetically by way of
electromagnetic windings combined with a permanent magnet adapting
the operation to pulse type of digital control adapting the valve
to electronic digital control from multiple variable inputs.
Inventors: |
Massie; Philip E. (Culver City,
CA) |
Family
ID: |
22796866 |
Appl.
No.: |
05/213,881 |
Filed: |
December 30, 1971 |
Current U.S.
Class: |
123/90.12;
123/90.11; 251/30.05 |
Current CPC
Class: |
F01L
9/10 (20210101) |
Current International
Class: |
F01L
9/02 (20060101); F01L 9/00 (20060101); F01l
009/02 (); F01l 009/04 () |
Field of
Search: |
;123/90.12,90.11,90.14 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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|
|
|
|
|
1,916,167 |
|
Oct 1970 |
|
DT |
|
1,944,177 |
|
Mar 1971 |
|
DT |
|
1,962,916 |
|
Jun 1971 |
|
DT |
|
Primary Examiner: Smith; Al Lawrence
Claims
What is claimed is:
1. In an hydraulically operated valve positioned to control flow of
fluid with respect to an internal combustion engine cylinder in
combination: a cylinder having a piston therein connected to a
valve member and movable between open and closed positions of the
valve member; means comprising a valve sleeve member cooperable
with said cylinder, said valve sleeve member and cylinder having
mutually cooperable porting providing for flow of hydraulic fluid
to and from opposite sides of said piston for moving said valve
member through its stroke in opposite directions, control means for
controlling the position of opening and closing of the valve with
respect to crankshaft angle comprising means responsive to
crankshaft position and means responsive to at least one variable
which is related to an engine operating condition.
2. A device as in claim 1, including means to reciprocate said
sleeve member relative to said cylinder, to cause said piston to
reciprocate.
3. A device as in claim 2, wherein said cylinder has ports for
admitting hydraulic fluid to one side of said piston for moving it
in one direction and ports for relieving pressure from one side of
said piston, said cylinder having ports for admitting fluid to the
opposite side of said piston and ports for withdrawing fluid from
the opposite side of said piston, said sleeve member being
operative to control all of said ports for causing said piston to
reciprocate.
4. A device as in claim 3, wherein said sleeve member has ports
positioned to be moved into alignment with ports in said cylinder
and to moved out of alignment with ports in said cylinder for
controlling the flows.
5. A device as in claim 3, wherein said ports include a port in an
end wall of said cylinder and said sleeve member having a part
cooperating with said end wall port.
6. A device as in claim 1, including an electro-magnetic winding
associated with said sleeve member for causing said sleeve member
to reciprocate relative to said cylinder.
7. A device as in claim 6, including a further cylinder spaced
outwardly from said sleeve member and adapted to accommodate a flux
circuit for flux from said electro-magnetic winding.
8. A device as in claim 7, wherein said electro-magnetic winding is
of ring shape and is positioned around a part of said further
cylinder.
9. A device as in claim 6, including spring means for urging said
sleeve member in one direction.
10. A device as in claim 7, including a pair of electro-magnetic
windings and a permanent magnet associated with said sleeve whereby
reciprocation of said sleeve may be produced by energization of
said windings.
11. A device as in claim 10, including a second pair of
electro-magnetic windings coupled with said first pair whereby said
device is adapted to pulse type digital control from a driving
circuit having connections to all four windings.
12. A device as in claim 6, wherein said sleeve member is
constructed of material so as to constitute an armature.
13. A device as in claim 6, wherein said sleeve member has an end
closure which is constructed of material so as to constitute an
armature.
14. A device as in claim 10, wherein said first pair of
electro-magnetic windings are spaced axially from each other with a
permanent magnet positioned between them.
15. A device as in claim 11, wherein said second pair of windings
is positioned to surround the first pair of windings respectively
to provie magnetic coupling therewith.
16. A valve as in claim 1, said valve being positioned and
constructed to receive engine lubricating oil to drive the piston
and to discharge lubricating oil into the engine crankcase.
Description
SUMMARY OF THE INVENTION
This valve is an electric/hydraulic Servo Valve designed to be
installed as either the intake or exhaust valve on an internal
combustion engine.
This valve is designed to enable the timing of the opening and
closing of the intake and exhaust valves of an I.C. engine to be
operated and varied by a digital processor (computer). Such
operation will permit changing the four significant valve operating
points to match the operating conditions of the engine. It will
serve as a replacement for "full race" cam, three-fourths race cam,
"normal" cam and low speed cam shaft. By varying the operating
times of the four valve points (in conjunction with fuel injection
and ignition) the I.C. engine can be operated at the optimum
(smog-free) timing, regardless of engine speed, torque, temperature
or acceleration demand. It should enable a single I.C. engine to
idle at 300 to 500 rpm without excessive pollutants or at maximum
engine speed, under low speed and high torque (drag race) or high
speed acceleration (freeway passing).
The assembly opens and closes the valve to allow for fuel/exhaust
between the intake/exhaust manifold in the engine cylinder head to
the combustion chamber. Since I.C. engines may operate at
rotational speed to 11,000 rpm, valve operation time must be in the
fractions of millisecond time.
The particular, unique design of the valve described herein
involves some further considerations. As stated above, the valve
may be installed as either the intake or the exhaust valve on an
internal combustion engine. All parts of the valve are cylindrical,
positioned about a common axis which is the axis of the valve stem.
These considerations are significant to the installation of the
valve. Space considerations are another factor, the space required
by the porting arrangement of the valve being such as to optimize
it from the standpoint of space required. The valve is operated
directly by the lubricating oil system of the internal combustion
engine and its construction is such as to eliminate need for
plumbing connections inasmuch as inlet ports to the oil operated
valve and vent ports may in effect be built-in, having direct
connection to the pressurized side of the lubricating system and
back to the crankcase. Another factor is that all of the parts of
the valve being cylindrical, their fabrication and that of the
porting is simplified inasmuch as it can be accomplished by
unsophisticated machine operations.
The primary object of the invention is to make available a valve
which is adapted for hydraulic operation by lubricating oil of an
internal combustion engine and which is electrically controlled,
being adapted for pulse-type digital control. The particular
construction of the valve is such as to realize a number of
particular objects as follows.
An object is to provide a valve of appropriate size adapting it to
be installed as either the intake or the exhaust valve of the
internal combustion engine and characterized in that the valve is
movable between fully opened and closed positions in response to a
single electromagnetically operated control valve member in the
form of a ported sleeve.
Another object is to realize a valve of the type operated by a
hydraulic piston in a cylinder wherein the cylinder has side ports
for admission and exhaust of hydraulic fluid which are controlled
by a ported sleeve reciprocatable with respect to the cylinder.
Another object is to realize a valve of the type referred to in the
previous object wherein the control sleeve is positioned between
the inner cylinder and an outer cylinder and constitutes the
armature of an electromagnetic system adapted to move it so as to
produce valve operation between fully open and fully closed
positions.
Another object is to realize a valve of the type referred to
wherein all of the parts are cylindrical having a common axis
thereby facilitating fabrication of its parts.
BRIEF DESCRIPTION OF THE DRAWINGS
Further objects and additional advantages of the invention will
become apparent from the following detailed description and annexed
drawings wherein:
FIG. 1 is a cross sectional view of one form of the valve of the
invention illustrating the fluid flows and magnetic flux flows;
FIG 2 is a cross sectional view of the valve of FIG. 1 showing the
valve in a closed position;
FIG. 3 is a cross sectional view of another form of the valve of
the invention using a different electromagnetic system, this figure
showing the electromagnetic flux flow;
FIG. 4 is a cross sectional view of the form of the invention shown
in FIG. 3 with the valve in closed position; and
FIG. 5 is a diagrammatic view of an internal combustion engine
controlled by a digital processor.
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIGS. 1 and 2 show one form of the invention, and these figures are
schematic in order to clearly illustrate the structure and
operation. The valve head is designated at 1. The valve has a stem
2 and seat. The valve assembly comprises an upper body 4 having a
bore 5 in it and a tapered counterbore 6 which forms the seat for
the valve. Body 4 is fitted into the cylinder head by way of the
upper cylindrical part 7 of the body 4 being fitted into conical
bore or opening 8. Body 4 has an extending flange 11 and has
downwardly or depending extending circular rib or flange 13 which
is internally and externally threaded as shown at 14 and 15.
Numeral 17 designates a ring member which has a bottom flange 19
formed as a hexagonal nut and which is externally threaded as shown
at 21. Body 4 seals to bore 8. Ring 17 seals to 11 and 27. The
valve is rotatable into position. Cylinder head 34 has an extending
flange 27 which is internally threaded. Ring member 17 is threaded
into the internal diameter of this flange. The upper cylindrical
portion of the body member 4 has bores or channels 29 and 30
communicating with the axial bore 5. These channels communicate
with channels 32 and 33 within head 34. These channels are for
admission of combustible materials when the valve is installed as
an inlet valve, or for products of combustion if the valve is
installed as an exhaust valve.
Part 7 seals against surface 8. Flange 11 seals against nut 27. The
valve itself must be free to rotate to the correct installation
position. Member 17 is a nut, and it creates the seal at these
points. A high pressure seal is formed at conical surface 8. A
clearance is provided at 35, this area being subjected to manifold
pressure only, which is usually negative. To realize the wedging
action seal between part 7 and 8, clearance 35 must be provided so
that all of the pressure of the installation nut 17 will be at the
joint between parts 7 and 8. This same pressure is exerted between
parts 17 and 11. Sealing between nut 17 and cylinder head flange 27
is obtained by the same pressure exerted by nut 17 made possible by
clearance 35. Installation clearance 13 is provided between flange
11 and nut 17. The assembled valve is inserted through the bore in
the cylinder head and into the conical area 8. Nut 17 is tightened
by means of hexangonal flange 19 to press part 7 against remaining
surface 8. This forms one seal. The internal shoulder of nut 17
bears on the flange 11 to exert pressure and to form a seal at the
internal annular shoulder of the nut. Clearance 35 is necessary to
assure that all the pressure of nut 17 is exerted on flange 11 and
the seal at 8. Threads between nut 17 and flange 27 form the other
seal surface between head 34 and upper valve body 4 to seal the
manifold against outside pressure. All O-ring seals are in annular
grooves, as shown.
The valve is hydraulically operated as previously pointed out by
the lubricating oil of the engine. On the end of the stem 2, is the
piston member 36 which operates within cylinder 38. The upper end
of it is externally threaded and threads into the inside threaded
surface of the depending flange 13. Piston 36 is sealed to the
interior of cylinder 38 by appropriate seals diagrammatically
designated at 40. These seals may be of a conventional type.
Numeral 50 designates another cylinder which is coaxial with
cylinder 38 and is spaced therefrom. Its upper end is internally
threaded into depending flange 13. Numeral 52 designates a bottom
wall. Numeral 54 designates a further cylinder having a bottom
horizontal wall extending outwardly from the walls of cylinder 50
so that an annular chamber is formed between the cylinders 50 and
54. As will be pointed out, an electromagnetic operating coil 58 is
received in this annular chamber, the top of which is formed by
flange 56.
As stated, the valve is hydraulically operated and porting is
provided to admit oil under pressure to one side of the piston
while releasing or venting it from the opposite side to drive the
piston in one direction. On the other hand to drive the piston in
the opposite direction, porting is provided to admit oil under
pressure to that side of the piston and to release or vent it from
the first side. The opening and closing of all ports for operation
of the hydraulic valve is accomplished by a single valve member
which is the cup-shaped member 60 which has a bottom wall 62, the
side walls being identified by numeral 64.
The lower end of cylinder 38 is closed by a circular head 68 having
an extending flange 69, the head being threaded and being threaded
into the cylinder 38. The head is made of nonmagnetic material for
reasons which will be explained presently. This head has a tapered
or bevelled bore 70 as shown. The cup-shaped valve member 60 has a
tapered circular boss 72 upstanding from its bottom which forms a
valve head cooperable with the tapered bore or port in the head 68,
for controlling of admission of hydraulic fluid to the cylinder 38.
The cup-shaped valve member 60 is biased by spring 74. Oil pressure
can be admitted through the bottom member 52 through the port 80,
this port having connection to the high pressure side of the
lubricating oil system of the internal combustion engine, and
through ports 82 and 82' in the bottom or end of cup-shaped valve
member 60.
The valve 1 is normally operated between a fully opened or fully
closed position by means of the hydraulic piston 36. That is, this
piston is moved through a complete stroke in either one direction
or the other.
Porting is provided in the side walls of the cylinders 38 and 50
and the cup-shaped valve member which in cooperation with the ports
80, 82 and 70 control admission of a hydraulic oil (lubricating
oil) to the volume above the piston 36; for the release therefrom;
to the volume below the piston 36; and the release therefrom. The
cylinder 38 is provided with diametrically opposed side ports 90,
92 and 94; and 90', 92' and 94' positioned at levels as shown in
FIGS. 1 and 2. The side walls of the cup-shaped valve member 60 are
similarly provided with diametrically opposed ports as designated
at 96, 98 and 100, and 96', 98' and 100' situated at levels
cooperable with the ports in the cylinder 38. The cup-shaped valve
member of course is movable axially to control flow through the
ports. The cylinder 50 is provided with diametrically opposed
radial ports 104 and 104' and 106 and 106' cooperable with the
upper sets of ports in the valve member 60. As will be observed,
the cup-shaped valve member 60 is positioned between the cylinders
38 and 50. Its axial movement controls the alignment and
misalignment of ports to provide for the flows of hydraulic oil as
described above. The figures, which are schematic, show an
arrangement of seals to appropriately seal the porting. The seals
may be in the form of O-rings situated in appropriate O-ring
grooves. FIG. 2 shows the closed position of the valve. The upper
radial ports are aligned admitting pressure above piston 36 as will
be explained. Numeral 110 designates a seal between the cylinder 38
and valve member 60 and numeral 112 designates a similar seal
between the valve member 60 and the cylinder 38. Numerals 114 and
116 designate similar O-ring seals situated on the opposite side of
radial ports in the valve member 60. Numerals 120 and 122 designate
another pair of O-ring seals positioned on opposite sides of the
ports 92 and 92' between cylinder 38 and the valve member 60.
Numerals 124 and 126 designate another pair of seals on opposite
sides of the ports 94 and 94' in the cylinder 38, between this
cylinder and the valve member 60 and an additional seal member 130
is positioned between the valve member 60 and cylinder 50 adjacent
to the ports 100 and 100' in the valve member 60. All sealing rings
are in annular grooves, as shown.
As previously stated, an electromagnetic winding as designated at
58 is positioned in the annular space between the cylinders 50 and
54. Numeral 136 designates an insert of nonmagnetic material
forming the lower part of cylinder 50. Other parts are of magnetic
material except for the head 68 which is nonmagnetic. FIGS. 1 and 2
show the open and closed positions of the valve respectively; and
these figures by the arrows illustrate the oil flows for the
opening and closing movements of the valve and other arrows also
indicate the magnetic flux flow pattern. These flows are referred
to hereinafter more in detail in connection with the description of
the operation.
With electric power off, the sleeve valve 60 is held "up" by spring
74. Oil pressure is admitted through ports (aligned) 90, 90', 96,
96', 104, and 104' to apply pressure to the top of the piston 36
and hold the valve assembly down, seating head 1 firmly in seat 6.
Oil vent ports 94, 100 and 94', 104' vent oil from below the piston
36 through circular vent grooves 101 and 101' and the oil vent flow
space 144-144' between the sleeve valve 60 and cylinder 50 and
ports 106 and 106'. This relieves any residual pressure below
piston 36 by venting the volume below it. Seals as described (of
any type, not necessarily O-rings) direct the flow in the proper
channels.
When electrical power is applied to coil 58, magnetic flux flows as
shown by the arrows in FIG. 1 to create a magnetic flux in the
working air gap 140. The nonmagnetic portions 68 and 136 (300
series stainless steel or brass) prevent flux flow from by-passing
the working gap 140. Parasitic air gaps 150 and 142 are made long
to reduce flux flow in these gaps. The magnetic flux in the working
air gap 140 creates a force between the sleeve valve 60 and the
cylinder body end cap 52. Since the end cap 52 is fixed, the sleeve
valve 60 is moved against the force of the spring 74. This movement
(FIG. 1) opens the valve 72 and admits oil pressure to the bottom
of the piston 36 through port 80, ports 82, 82', past valve seat
70. Movement of the sleeve valve puts vent ports 98, 98' of the
valve in alignment with vent ports 92, 92' in the operating
cylinder and opening into vent space between valve 60 and cylinder
50 to the vent ports 106 and 106' and back to the engine oil
system. This vents oil from above the piston to permit the piston
to rise and open the valve by action of valve stem 2. Movement of
the sleeve valve 60 cuts off pressure to the volume above piston 36
by moving ports 96, 96' in the sleeve valve 60 out of alignment
between ports 90, 90' in the cylinder 38 and ports 104, 104' in the
valve body or cylinder 50. The dead space in air gap 150, 150' is
allowed to fill with oil (as the sleeve valve moves down) since
seals 110, 112 move with the sleeve valve and exposes ports 90, 90'
to the dead space. This space may be vented as shown at 151.
The upward movement of piston 36 and valve head 1 may be limited in
several ways. One method is to let the piston seal 40 close the
vent port 92, 92' trapping oil in the volume above piston 36 and
preventing further movement of the valve. Mechanical means can also
be used.
When electrical power is removed from the coil 58, the spring 74
moves the sleeve valve 60 up and vents the volume under the piston
36 and applies oil pressure to the volume above the piston, closing
the valve 1. FIG. 2 shows the positions of the ports and the flows
as described above.
The limiting factors on the operatimg time of the valve are:
The inertia of the valve assembly 1, 2 and the oil in volume above
piston 36.
The inertia and friction of the sleeve valve assembly 60.
The force of the spring 74.
The time constant of the magnetic circuit.
The time constant of the magnetic circuit is kept small by keeping
the inductance of the magnetic circuit small. This requires the use
of long (relatively) length working air gap 140 at the expense of
added electrical power required to operate the sleeve valve 60. The
magnitude of the spring force must be balanced between the magnetic
force required to move the sleeve valves 60 and the mechanical
force required to close the sleeve valve rapidly. The inertia and
friction forces are subject to astute mechanical design.
A modest amount of oil leakage through the valve is probably
desirable to minimize oil stagnation and "silting" of the system.
Further, some flow of oil will aid in cooling the valve and
prolonging valve life.
The sealing area 8 and the mounting ring 17 provide a means of
installing the valve and valve seat in the cylinder head 34. The
threaded portions between the body 4, the cylinder 38 and the valve
body cylinder 50 and between the piston 36 and the valve stem 2
provide means for assembly of the complete unit prior to
installation in the cylinder head 34.
FIGS. 3 and 4 are a modification of the previous design of the
valve that adapts it to pulse-type digital control.
The advantages of this design are:
1. "Logical" operation.
2. Faster operation.
Logical operation simply means that the valve has two stable
states, a concept that fits in the pattern of logic design
generally. The problem was to fit in the two state coil design to
this package.
The design is adapted to use in an electronically controlled
Internal Combustion engine operated by a digital processor. The
concept is to vary intake valve open and close time. exhaust valve
open and close time, fuel injection time and quantity, ignition
time and possibly water injection quantity and time in response to
the change in input functions of rpm, torque, manifold pressure,
atmospheric pressure, water (and/or oil) temperature, air
temperature, gear shift position, throttle position and wheel slip.
Possible engine states under analysis include: cold start, cold
idle; negative, idle, low, medium and high torque at low, medium
and high engine rpm.
The ultimate goal is to provide optimum combustion efficiency at
all engine operating conditions for maximum efficiency and minimum
pollution. The design will eliminate completely: cam shaft, valve
train, distributor, carburetor, breaker points and possibly one
forward gear.
The embodiment described above has a basic operating characteristic
of a solenoid valve, i.e., power on/open and power off/close. The
modified version of the valve permits operation in a "logic mode",
i.e., pulse coil 166 to open, pulse 164 to close, with no power
consumed between operations.
FIGS. 3 and 4 each show a cross section of the valve. The valve is
identical to the previously described valve form (and numbered the
same) down to the sleeve valve, valve seat, and operating coils.
(Valve 1 is the intake/exhaust valve between manifold and
cylinder.) This is driven by the double-acting piston 36 by
pressuring the volume below the piston and venting volume above the
piston to open the valve and a reverse process to close the valve.
The operation of the valve ports in the sleeve valve 60 and
operating cylinder 38 is like that of FIGS. 1 and 2 and need not be
repeated. If sleeve valve 60 is moved down, valve 1 opens. If
sleeve valve 60 is moved up, valve 1 closes.
The modified electrical operating means consists of permanent
magnet 160, pole piece structure for said permanent magnet 162,
operating coils 164 and 166, and feedback coils 165 and 167. The
sleeve valve 60' is now made of a nonmagnetic cylinder 64' and a
magnetic armature 62 with a nonmagnetic valve poppet 72'. The
hydraulic operating cylinder 38' is all magnetic material,
including the element 68'. The magnetic circuit is divided into A
and B sections by the nonmagnetic inserts 169 and 170. Two magnetic
working gaps are used, closing gap 172A and opening gap 172B.
Magnetic flux flows 174A and 174B control the position of the
valve. The permanent magnet, windings, pole piece structure, and
nonmagnetic inserts as shown are all ring shaped. They may have
other shapes.
The armature 62' has two stable positions with either gap 172A or
172B closed. The permeance of a closed gap is designed to be
several times larger than the permeance of an open gap. Thus, the
major portion of the flux from the permanent magnet will flow
through the closed gap. Since force varies as the square of the
flux, the force will be many times larger in the closed gap than in
the open gap. The parasitic gap 176 between pole pieces 52 and
magnet shoe 162 is made large to reduce flux leakage. Similarly gap
176' is made large.
Flux 174A flows up through part 54, cylinder wall 50 and down
through cylinder wall 38' to the pole face 68' and through working
gap 172A to armature 62', across radial gap 177' to pole shoe 162
and back to the permanent magnet. Flux 174B flows down through
cylinder 54 to pole piece 52, through working gap 172A to armature
62', through radial gap 177' and pole shoe 162' to the permanent
magnet 160'. Since the length of the gap 172A is small relative to
gap 172B, most of the flux will flow through this gap, thus holding
the valve 1 closed. See FIG. 4.
To open engine valve 1, an electrical pulse is applied to operating
coil 166. This applies a magnetomotive force to the magnet circuit
"B" and increases the flux flow 174B. Since the total flux through
the permanent magnet 160' is limited by the rapid decrease in
permeance with increase of flux above the knee of the magnetization
curve, flux increase in circuit "B" will produce a flux decrease in
circuit "A". Since this is "flux switching" rather than flux
increase, the time constant is smaller and flux buildup in circuit
"B" can be more rapid than for a solenoid type valve. The increase
of flux in circuit "B" causes an increase of flux in working gap
172B and a decrease of flux in working gap 172A. The balance of
flux shifts to working gap 172B and causes the armature 62' and
sleeve valve assembly 60' to move down. This opens valve poppet 72'
and admits oil under pressure below piston 36'. Ports 92, 98, 106
and 92', 98', 106' are aligned and vent the volume above piston 36.
This combination produces a force on the piston that lifts the
engine valve 1 and: (a) admits fuel/air mixture to the engine
cylinder or (b) emits exhaust gas from the engine cylinder.
An electrical pulse applied to operating coil 164 reverses the flux
flow and closes the engine valve 1. The coil is stable in either
position and requires no sustaining electrical power due to the
magnetomotive force of the permanent magnet 160 maintaining a flux
in the working gap with the higher permeance, shorter air path.
Coils 165 and 167 are feed back coils that can be connected as such
adapting the valve to control by way of a logic circuit.
One form of logic circuit that can be used to operate the valve is
shown in U. S. Pat. Application Ser. No. 113,321 filed Feb. 8,
1971, of this inventor entitled SEALED PUMP AND DRIVE THEREFOR and
it is hereby incorporated herein by reference.
FIG. 5 is a diagrammatic illustration of the operation of an eight
cylinder engine under control of a digital processor with the valve
of FIGS. 3 and 4 installed in the inlet to and exhaust from each of
the eight cylinders. Six events should take place at each engine
cylinder as a function of crankshaft angle which controls piston
position; intake valve open, intake valve close, exhaust valve
open, exhaust valve close, fuel injection (which may be a two stage
process for minimum emission) and ignition.
The variables that determine the best piston position for each
event are: rpm, torque, water temperature (fuel quantity for cold
start), throttle position (demand), manifold pressure and
transmission gear position. The continuous variable (clock) is the
720.degree. of crankshaft rotation. All other variables are
algebraically summed to provide a reference against which
crankshaft position matches to command an event. The events number
6 .times. 8 (for an 8 cylinder engine) and each has an optimum time
as a function of the variables.
Atmospheric pressure is a significant variable in high altitude
operation. Air temperature may be required to supplement water
temperature in cold weather starts. Wheel slip is being implemented
on some cars now.
The CPU has the function of combining 6 variables, matching to
crankshaft angle and commanding 48 events. Much of the work of the
CPU is accomplished by making each of the seven input transducers
provide a variable digital output. This eliminates the requirement
for analog to digital conversion in the CPU.
The digital outputs of the transducers may be in Gray code and, the
preferred transducers used may be like that of U. S. Pat.
Application Ser. No. 64,029 filed on July 20, 1970, of the herein
inventor and hereby incorporated herein by reference. As stated,
these outputs are summed by the CPU which then controls the six
events shown in FIG. 5 with reference to crankshaft angle. Each of
the six events for each cylinder has a digital code number which is
set into a register or comparator, that is, the number peculiar to
that event for that cylinder. Currently, technology is readily
available to implement the CPU in the manner described.
The fuel injector is preferably a type of device referred to in U.
S. Pat. Application Ser. No. 113,321 filed on Feb. 8, 1971,
alreadly referred to in the foregoing. With respect to ignition in
the system described, preferably, a type of ignition is employed
wherein a single small ignition coil is used for each cylinder
using a closed iron magnetic circuit.
From the foregoing, those skilled in the art will readily
understand the nature and the construction of the invention and the
manner in which it achieves and realizes all of the objectives and
advantages as set forth in the foregoing.
The foregoing disclosure is representative of the preferred form of
the invention and is to be interpreted in an illustrative rather
than a limiting sense, the invention to be accorded the full scope
of the claims appended hereto.
* * * * *