Split engine control system

A cylinder cut-out system including an intake manifold having first passage means communicating with one half of the engine combustion chambers; second passage means communicating with the other half of the engine combustion chambers; an air metering mechanism having passage means for respectively supplying a combustible air-fuel mixture or metered air to the first and second manifold passage means; and a control device having first and second valves that prevent mixture flow to the manifold passage to be inactivated, and open the manifold passage to either atmosphere or the exhaust manifold, respectively.

BACKGROUND OF THE INVENTION 
The present invention relates to a control system for an internal 
combustion spark ignition engine which permits the engine to be run on 
less than all of its cylinders in order to achieve substantial economies 
in engine operation. Such a capability is sometimes referred to as 
"split-engine" operation through which it is possible to operate on 
one-half of the cylinders. 
Engine operation is more econommical if each cylinder of the engine is run 
under relatively high loads. However, under a large percentage of vehicle 
operating conditions the engine is operating under relatively light loads 
resulting in uneconomical fuel consumption. Accordingly, it is desirable 
to operate the engine on half of the cylinders during normal or light load 
operation with the remaining cylinders being brought into operation only 
after the load on the engine exceeds a given value. In this way it is 
possible to increase the load on each of the active cylinders and in that 
way achieve greater overall economies for the engine. 
More specifically, to operate an engine at part load it has to be throttled 
and thus produces a manifold vacuum the production of which wastes a 
significant portion of the engine power. This is referred to as 
"throttling losses". On the other hand, operating an engine on one-half of 
its cylinders requires less throttling thereby reducing the vacuum 
produced and, in turn, greatly reducing "throttling losses". Also, during 
reduced number of cylinders-operation combustion takes place in only the 
"active" cylinders as a result of which considerably less heat radiating 
surfaces are dissipating the combustion energy. 
PRIOR ART DEVICES 
In the past it has been extremely difficult to achieve split engine 
operation in such a manner as to make the transition between all- and 
half-cylinders-operation smooth enough to be acceptable to an operator. It 
has also been difficult in practice to achieve the theoretically expected 
fuel economy and particularly in view of the now mandated emission control 
requirements. 
In my prior U.S. Pat. No. 2,878,798 entitled "Split Engine" there is shown 
a mechanism for achieving engine operation utilizing either all or half of 
the engine cylinders, and in my U.S. Pat. No. 4,080,948 an improved method 
is described. This invention is a more general solution to the Split 
Engine than No. 4,080,948 and combines the split engine operation with the 
catalytic converter and exhaust gas recirculation system used for exhaust 
emission reduction of CO--(CH).sub.n --NOX (carbon monoxide, hydrocarbon, 
and nitrogen oxides). 
SUMMARY OF INVENTION 
It is to be understood that the present invention is applicable to all 
types of carburetted, fuel injected and the like types of engines so long 
as there are at least two cylinder combustion chambers. Not only is the 
invention applicable to a conventional piston engine but it may also be 
applied to a so-called "rotary" or Wankel type engine utilizing at least 
two rotors supplied by separate intake manifolds. Thus, the hereinafter 
use in the specification and claims of words such as "internal combustion 
engine", "cylinders", "pistons" and the like, is meant to comprehend 
rotary type engines and their functionally equivalent or related 
components such as "combustion chambers", "rotors" and the like. Likewise, 
reference to an "air metering mechanism" shall include carburetors, fuel 
injection systems or the like wherein the flow of combustion air is 
throttled or metered by suitable throttle valve means to control engine 
power output. 
In my invention U.S. Pat. No. 4,080,948 I described and claimed that for 
the smooth transition from all cylinder operation (ACO) to half cylinder 
operation (HCO) it was necessary to have a common metering air or fuel 
system for both manifolds, incorporating throttle or throttles. To achieve 
H.C.O. one intake manifold should first be intercepted from the Meter. 
Then the same intake manifold opened to atmospheric air. The example of 
device described in invention U.S. Pat. No. 4,080,948 consisted of a 
shuttle that performed the two operations in succession. 
In the present invention the shuttle function is divided into two valves, 
one shutting the flow from the meters to the manifold to be inactivated. 
In series with it a second valve opens said intake manifold either to 
atmospheric air or to the exhaust manifold. Means shall be described that 
recirculate the air or exhaust of the inactive cylinder, thus preventing 
exhaust dilution of active cylinder exhaust and lowering it and catalytic 
converter temperatures. Also means have been inverted to convey to the 
active cylinders (A.C.) the exhaust gas recirculation used for the 
reduction of the nitrogen oxides (NOX) generated by the active cylinders.

In the summary of invention U.S. Pat. No. 4,080,948 a single member called 
shuttle performed the function of: 
a. sensing the manifold vacuum and at pre-selected values 
b. changing engine operation from all cylinders to part of them by: 
deviating the mixture from the inactive cylinders to the active cylinders 
and 
simultaneously shutting off the flow to the inactive cylinder manifold then 
c. opening to atmosphere the inactive cylinders manifold. 
In the present invention the inactive cylinders gaseous operating fluid is 
either: 
d. if air is discharged to atmosphere instead to exhaust catalytic 
cvonverter or 
e. recirculated if air or exhaust thus facilitating the warm up of the 
catalytic converter after an engine cold start. 
To achieve this result and/ or to use the split engine cycle with 4 barrel 
carburetors additional valves must be used. Thus an external valve 
activator is desirable as it will be described later. Furthermore this new 
invention permits to reduce the space required between the intake manifold 
and air cleaner, thus permitting its use as a retrofit of existing 
vehicles where the vertical clearance between air cleaner and hood is 
critical. Means have been added to lock the device so it operates only 
some of the engine cylinders until the accelerator pedal is depressed to 
engine high power, thus achieving greater fuel economy. The manufacturing 
of the device has been simplified to reduce its weight and cost. 
FIG. 1 is a vertical section DD of FIG. 2 of a mixture metering device 114 
with throttle or throttles 115-116 mounted on a common shaft 118. A 
thermal barrier 120 prevents heat from boiling the fuel of metering device 
114. Spacer 122 provides a gradual enlargement 119 from throat 117 to 
valve plate 123 with pierced fenestrations 121 (see also FIG. 4) it has 
also the large cross passage 124 to handle flow from 117 to 128. Pin 125 
is secured to plate 123 by press fit into hole 125p and valve 127 can 
freely rotate around said pin and under plate 123. Thrust bearing 129 
supports the downward pressure upon valve 127. 
The upper face 127 of the above valve is flat as is the lower face 131 of 
plate 123. The clearance between pin 125 and valve hole 125h is large 
enough so the valve is free to lay flat against the plate when upward 
pressures are present. 
Lower body 132 has a passage 128 feeding the active cylinders (A.C.) 
connected with branch 130 of engine intake manifold. Said body has a 
gradual flow section reducer 119' to facilitate flow from fenestrations 
121 to manifold branch 133 when the inactive cylinders are operating 
because valve 127 is open. When valve 127 is closed, as shown in FIGS. 1-2 
flow originates from 135 which receives either air and/or recirculating 
exhaust which shall be called gaseous fluids (GF) and it will be described 
later. 
The G.F. enters fenestrations 137' when valve is open as in FIGS. 1-2-3-4 . 
Both valves 127 and 137 have a peripheral groove 139, FIG. 3AA-FIG. 3E. 
Within the groove are two cables or music wires 141-143 for valve 127 and 
145-147 for valve 137. The mounting of said cables and the way the valves 
are rotated shall be described for valve 127 only since 137 operates in 
the same way. 
Cable 141 and 143 are secured to their valve respectively at 141' and 145' 
FIG. 3b, thus they pass along each other at X-. Since the valve operates 
in the induction system, air leaks from the outside must be minimal. Thus 
said cables are led outwardly through orifices 141", 143", FIGS. 3C-3D 
within plastic blocks 150. Said blocks have a slot 151 through which the 
cable or wire is inserted prior to the assembly of the blocks into the 
body 132. End 141s is secured to spring cup 149 which receives the 
returning force from spring 151. 
The commanding force is applied to cable 143 engaged through spring 173 to 
pin 153" of differential lever 155. Similarily cable 147 is engaged 
through spring 177 to pin 157 at the other end of lever 155. As previously 
stated, the kinematic operation of valve 137 and its attachment, is 
similar to 127, but spring 161 is approximately 4 times stronger than 
spring 151. 
At midway of differential lever 155 is pin 163 that in FIG. 2 engages with 
pull rod 165 manually operable by handle 167. 
Stops 169 defines the closed and open positions of valve 127 which is shown 
closed. Similarly stop 171 defines the open and closed positions of valve 
137 shown open. The above valve setting being performed by pulling handle 
and lever 155 against stops 169' and 171' at which position detent 170 
locks 165 in place. 
As shown in FIGS. 1 and 2, the device is in the position causing all the 
metered air or fuel air to go to the cylinders of manifold 130 and air or 
recirculating self-cooled exhaust to return from 135, valve 137, passage 
way 132' to manifold 133 and to the inactive cylinders. 
To obtain all cylinder operation, handle must be pushed inwards causing the 
following: 
Pin 163 will thus move to 163", 
Lever 155 will swing to 155" because spring 161 minus rotating friction of 
valve 137 is stronger than spring 151 minus rotating friction of valve 
137. Thus spring 161 acting on cable 145 will rotate valve 137 until its 
corner 137" hits stop 171. Said rotation will cause cable 147 to wind into 
groove of valve periphery. 
Thus, the flow of air or recirculating exhaust to manifold 133 is stopped. 
Spring 151 thru cable 141, valve 127, cable 143 will keep retracting pin 
153" to 153' lever and handle connected to it. 
Thus, fenestrations 121 becomes open and the metered air and fuel reach the 
I.C. and powers them. 
The described sequence prevents intercommunication of 135 manifold, 133 and 
130, when 135 pressure within it is greater than 130 internal pressure. 
The above condition would cause engine misfiring if enough dilution of 
incoming mixture is caused by the air or exhaust from 135. 
To restore split engine operation, the driver should pull handle all the 
way out. Because spring 151 plus friction from rotating valve 137 is 
approximately less than one-fourth of spring 161 and friction of rotating 
valve 137, it will let pin 153' and its cable 143, valve 127, be the first 
to rotate to stop 169 and shut fenestrations 121 and intercept the mixture 
to the inactive cylinders. The completion of tfhe pull will open the other 
valve and establish the air flow or recirculating exhaust flow to the I.C. 
This manual arrangement permits the continuous operation of the engine in 
the economy range until the throttle 181 FIGS. 1-1A, is depressed to a 
preselected value; for example, to 50% opening, when tab 230 engages end 
182 of cable 180 secured at the other end to interlock 170, thus releasing 
the system which through the action of spring 151 and 161, will restore 
all cylinder operation. 
Another way to operate the "split engine" control consists of using the 
vacuum from interconnecting passage 124 by means of conduit 124', FIG. 1, 
ending at passage 194, FIG. 12, intercommunicating through groove 195, 
passage 196 to vacuum reservoir 190 within which a cylinder 191 with 
piston 192 receives the vacuum action at its lower face, and atmospheric 
pressure at its upper face because of atmospheric vent 193. 
Magnet 196 and vacuum on the piston and friction balance the pull of spring 
151-161 until vacuum drops to a predetermined value; for example, 2 in Hg, 
then the springs restore all cylinder operation as previously described 
for the manual control. Wire hook 202 by momentarily lifting 203 from 
opening 204, eliminates the residual vacuum; facilitating the upward 
piston movement. Thus, groove 197 will line up with passages 194 and 196 
to receive next vacuum activation from cross over 124, FIG. 1. The system 
is held to the A.C.O. by the springs 151 and 161 and magnet 198 until 
vacuum at engine manifolds is: for example, 12 in. Hg, or more and half 
cylinder operation is more economical. Then the vacuum on piston 192 will 
reverse the previous cycle. 
As shown in FIG. 12 magnet 196 is spaced with a gap 199 from 155. This gap 
can be reduced by letting in cable 167' anchored to differential lever 167 
with fulcrum 168 so spring 167" rotates lever 200, its eccentric 201 to 
reduce gap 199. The intensified magnet pull will keep the system at H.C.O. 
even when vacuum drops to zero; thus, extending the best economy condition 
to the brief accelerator throttle fluctuation habitual with some drivers. 
As in the manual control previously described cable 180 momentarily returns 
magnet 196 to normal gap at substantial throttle openings. 
240 is an air cleaner since valve 204 allows air suction into the device. 
To preserve normal operation of exhaust gas recirculating systems (E.G.R.) 
the interconnection 210 of exhaust nozzles 211-212 must be shut off at 
H.C.O. This can be done by adding to rotary valve 127, pin 213, FIG. 1 and 
FIG. 15, which engages flat valve 214 pivoted at 215 and held against 218 
by spring 217. From nozzle closed as shown in FIGS. 1-15 and its plan view 
FIG. 15a, the rotations that opens valve 127 is communicated by pin 213 to 
214, opening nozzle 211. 
Another way is to provide nozzle 211 with a double acting disc valve 221 
held within 220. During the transient, the very high depression in 
manifold 133 when 127 is shut and 137 is not opening yet, disc 221 will 
shut 222. After valve 137 opens, pressure within 133 is greater than at 
130 and passage 210, disc valve 221 shuts 211. 
It is evident that this device operates only when E.G.R. at 210 stays below 
atmospheric pressure. 
FIG. 16 shows the arrangement for a four barrel carburetor in which each 
intake manifold of the engine is fed by a larger barrel and a small 
barrel; the latter supplies fuel at idle and low power; the large barrel 
comes in at higher power. 
Thus to inactivate the cylinders of one manifold, it requires two 
synchronized valves, both indicated by 127" and functioning exactly as the 
previously described valve 127 of FIGS. 1-2. Both valves are secured to a 
common cable at 143" and 141" respectively functioning as 141-143. 
The identical functioning of this system for the four barrel carburetor to 
the one previously described for the two barrel, does not require a 
duplicate description. To readily recognize the equivalent components, the 
double comma has been used in FIG. 16 for the identification numbers of 
FIGS. 1 and 2. 
Reduction of emission of CO, (CH)n, NOX is often achieved by catalytic 
converters whose effectiveness requires fairly high exhaust temperatures. 
This invention includes means to prevent the dilution of the exhaust from 
the A.C. with the air or exhaust from the I.C. 
One obvious way is to return the air from the I.C. to the air inlet of the 
I.C. FIG. 5 refers to power plant with any of the split engine controls 
previously described. 
The exhaust manifold 80i for the I.C. must be independent from the exhaust 
manifold of A.C. 80a. Exhaust manifold 80i has an intercepting valve 100 
closing after valve 127 is closed. Valve 100 is between exhaust manifold 
80i and exhaust pipe 70i. Valve 137 is opening or opened simultaneously to 
the closing of valve 100. Also air inlet 52 should open at the same time. 
Thus the various gases of this closed system of I.C. and their manifolds 
would mix together and recirculate. If exhaust intercepting valve 100 is 
closed after valve 127 and the opening of valve 137 and no communication 
with outside air is established, the pressure within the recirculating 
system and the gases in it would be momentarily that of the exhaust at the 
shut off of valve 100 followed by a decrease due to exhaust cooling. 
To illustrate the operation of this system, the 6 cylinder V-6 engine will 
be illustrated as an example. The commonly used firing order of the V-6 
is: 1-6-5-4-3-2. FIG. 6 shows the schematic arrangement of the V-6 engine 
whose cylinder numbers indicate the operation of the previously mentioned 
firing order. 
It is evident that exhaust manifold 80i accept only I.C. and exhaust 
manifold 80a accept only A.C. 
FIG. 7 is a diagram whose abscissa represents crankshaft angle and 
ordinates the piston displaced volume of the I.C. of a V-6 cylinder 
engine. One cylinder displacement being one. 
Curves 1'-3'-5' represent suctions, 
Curves 1"-3"-5" represent exhausts. The overlap of suction 1' and exhaust 
3" shows that only 50% of direct recirculation between cylinders takes 
place. The remaining exhaust from 3" will be compressed in the volume 
enclosed by the system 10-11-12-80a-13. These passages plus the cylinders 
with intake or exhaust valve open shall be called "the system". 
At FIG. 8 we assume the same abscissa as FIG. 7. The ordinate are system 
volume in which 10-11-12-80i-13 is assumed equal to the displacement of 
one cylinder. It follows: ei is the end of 1" exhaust and the beginning of 
its intake stroke 1' and the volume of this system is one. 
Sixty crankshaft degrees later, the intake piston swept volume being 0.25, 
the system volume will be 1.25. The next cylinder exhaust opens to the 
system, thus the volume will read 2.25 @ 120.degree., the volume is 1.5, 
etc. 
FIG. 9 has the same abscissa as FIGS. 7-8. The ordinate shows the 
approximate absolute pressure within 11-12-13-80i assuming the lowest 
pressure as unity. It is evident that if the lowest pressure is an 
atmosphere, then the end of the exhaust stroke and the beginning of the 
intake stroke by the same cylinder is equal to one atmosphere. 
To produce the best oil consumption, it is desirable the pressure within 
the I.C. be above atmosphere, thus an inlet check valve 51, FIG. 6, 
allowing air into 11-12-13-80i would be necessary or a valve 52 opening to 
atmosphere should be used. The check valve produces the higher 
thermodynamic efficiency. 
FIG. 10 shows a simplified recirculating cycle in which check valve 5 or 
atmospheric valve 52 and exhaust valve 100 are not required. Again 
cylinders 1-3-5 are inactivated by closing valve 127 and opening valve 
137, FIGS. 10-11. Thus the pressure within 10-11-12-13-80i-70i will 
approximate the exhaust pressure generated by the A.C. at 80a-70a- and T 
connection 71. 
At low speed the flow can be described as follows: 
When any of the cylinders 1-3-5, for example cylinder 1 start suction it 
will: FIG. 7 first 60.degree. draw from 11-12-13-80i-70i and thru elbow 71 
approximately 43% of cylinder displacement by causing exhaust from 70a to 
flow a volume V approximately equivalent to the one aspirated by cylinder 
1. 
Then cylinder 3 will exhaust in the I.C. manifold and supply approximately 
50% of the requirement for cylinder 1, the remaining 7% being provided by 
V augmenting to the same extent. 
Since cylinder 3 will complete its exhaust stroke and deliver the remaining 
50% indicated by V', FIG. 11 to the system, V will be returned to 70a. 
This reversal of pulsations at the intercommunication of the I.C. and A.C. 
exhaust systems can be propagated to the catalytic converter, thus 
increasing its efficiency by prolonging some of the exhaust residence in 
it. 
Except for the first 720.degree. of crankshaft rotation after valve 132 
opens, no further hot exhaust will enter the I.C. Thus, no further heat 
input to them. Thus, the reduction of engine cooling requirements at idle 
and off idle are still achieved. 
This reduction of cooling requirements is important to prevent boiling of 
the cooling systems on air conditioned cars with condenser ahead of 
radiator and also to reduce cooling fan size and their power consumption. 
It is advisable to make exhaust manifold 80i with low heat capacity. 
Exhaust pipe 70a and connector 12, passage 10, should be well cooled and 
capable to rapidly lowering the temperature of the live exhaust trapped 
within 70i and 80i at the beginning of the I.C. cycle. Portion 111 and 113 
where exhaust pulsates back and forth may be insulated by sleeves 112-115. 
If an interconnection 40 of the active and inactive cylinders through the 
intake manifold hot spot is used, FIG. 1 then a thermostatic valve 51 
closed after engine warm up by thermostat 52 or closed at H.C.O. by the 
split engine control would improve the engine cooling and the 
thermodynamic efficiency of the split engine at H.C.O. 
Other modifications and variations may be made within the intended scope of 
the invention as set forth in the hereinafter appended claims.