Induction system for engine

An induction system and control arrangement for a three valve per cylinder engine, wherein the induction passages are tuned to provide different effective lengths for different engine running conditions. In addition, a control valve arrangement is provided for controlling the flow to the combustion chambers through the valve seats to generate unrestricted flow under high-speed, high-load conditions and tumble and/or tumble and swirl for promoting turbulence under low-speed, low-load conditions.

BACKGROUND OF THE INVENTION 
This invention relates to an induction system for an internal combustion 
engine and more particularly to an improved control valve arrangement for 
an engine intake control system. 
It has been known that the performance of an engine and particularly its 
power output can be substantially increased by employing multiple intake 
valves. Therefore, it is a common practice with many engines, particularly 
of the automotive type, to employ two intake valves per cylinder. However, 
the advantages of employing even more, and specifically three intake 
valves for each cylinder, are becoming recognized. 
Although the use of multiple intake valves can be effective in increasing 
the power output of an engine, the use of such free-breathing induction 
systems can deteriorate the performance at low speeds and mid-range. The 
reason for this is that the intake charge flows relatively slowly into the 
combustion chambers under these conditions with the free-breathing intake 
passages. As a result, there is low turbulence in the combustion chamber 
and flame propagation under these low speed, low load conditions 
deteriorates. 
In order to further improve the performance of three valve per cylinder 
engines, particularly under low speed running, it has been proposed to 
employe various tuning devices for the induction system. Although these 
tuning devices can improve volumetric efficiency, they still may not 
totally solve the problems under all conditions. 
It is, therefore, a principal object of this invention to provide an 
improved control valve arrangement for a multi-valve engine wherein the 
control valve can be employed to generate turbulence in the combustion 
chamber without restricting the output at high-load and high-speed 
conditions. 
It is a further object of this invention to provide an improved control 
valve assembly for a multi-valve engine wherein the desired types of 
turbulence can be generated in the combustion chamber under varying 
running conditions. 
It has also been acknowledged that turbulence in the combustion chamber is 
effective under some running conditions so as to improve engine 
performance. Turbulence helps to increase the rate of flame propagation 
and ensures complete burning. However, the type of turbulence which is 
generated can be significant in controlling and improving engine 
performance. One type of turbulence, called "swirl," is by a rotary motion 
around the cylinder bore axis. This type of turbulence is relatively easy 
to generate, particularly with three-valve-per-cylinder engines. However, 
a different type of turbulence known as tumble has been found to give 
better performance under some running conditions. Tumble is a type of 
swirling motion, but the motion occurs about an axis that extends 
generally transversely to the cylinder bore axis. This type of motion is 
more difficult to generate, particularly with three-valve-per-cylinder 
engines. 
It is, therefore, a still further object of this invention to provide an 
improved three-intake-valve-per-cylinder engine having a control valve 
that is usable to generate tumble in the combustion chamber under some 
running conditions. 
In my aforenoted copending application Ser. No. 08/378,532, under low-speed 
and low-load conditions, the control valve directs the intake charge into 
the combustion chamber primarily to two of the three intake valve seats. 
Embodiments are shown wherein the flow through the remaining valve seat is 
restricted under this condition and the flow is directed either to both of 
the side intake valves or one of the side intake valves and the center 
intake valve. Although this arrangement is particularly useful, in some 
instances it may be desirable to direct the flow through primarily one of 
the valve seats under certain running conditions. 
It is, therefore, a still further object of this invention to provide an 
induction system for a multi-valve engine wherein under some running 
conditions the flow is directed primarily into the combustion chamber 
through one of three or more intake valve seats. 
It is a further object of this invention to provide an improved control 
valve arrangement for a multi-valve engine wherein the control valve 
directs the flow primarily to one of three or more intake valve seats 
under some running conditions and the flow to this one valve seat is in a 
different direction than when the control valve is in its opened position. 
As is noted in my aforenoted copending application Ser. No. 08/378,532, the 
control valve arrangement can be simplified if the intake valve seats all 
are served by a flow passage that has a common section in which the 
control valve is positioned. This simplifies the number and placement of 
the control valves in the engine. However, if it is desired to shut off 
the flow or substantially restrict the flow through one or more of the 
valve seats, then the overall body of the control valve becomes quite 
large, particularly in diameter. Of course, it is desirable to maintain 
the control valve position as close as possible to the combustion chamber 
so that the optimum flow effects in the combustion chamber can be 
obtained. However, where large control valves are employed, this becomes 
difficult. 
It is, therefore, a still further object of this invention to provide an 
improved and simplified control valve arrangement for a multi-valve 
engine. 
It is a further object of this invention to provide a control valve for a 
multi-valve engine wherein the control valve is capable of controlling the 
flow through all of the intake valve seats and yet has a compact 
construction and one which permits the control valve to be positioned 
close to the combustion chamber. 
One way in which the control valve may be kept compact is by having it as a 
cylindrical body but which has a larger diameter portion that 
substantially restricts the flow through some of the intake valve seats 
when in its closed position and a smaller diameter portion that controls 
the flow to the remaining valve seat or seats when in its flow controlling 
position. However, such stepped diameter control valves can present 
problems in assembly, particularly when a single control valve assembly 
controls the flow to a plurality of combustion chambers that are in line 
with each other. If a single control valve bore supports the entire 
control valve assembly then it obviously must have the same diameter as 
the largest portion of the control valve and this means that the overall 
size tends to become large. 
It is, therefore, a still further object of this invention to provide an 
improved control valve assembly for a multi-cylinder engine wherein 
stepped diameter portions can be utilized and the supporting bore for the 
control valve need not be of a uniform diameter large enough to 
accommodate the largest portion of the control valve. 
SUMMARY OF THE INVENTION 
A first feature of this invention is adapted to be embodied in an induction 
system for an internal combustion engine having a combustion chamber 
served by at least three valve seats. An intake passage arrangement 
comprised of at least a common section serves each of the valve seats. A 
control valve is supported in the common section for controlling the flow 
therethrough and is movable between a first position wherein the flow 
through each of the valve seats is substantially unrestricted and without 
significantly affecting the flow direction issuing from the valve seats 
into the combustion chamber. In a second position, the control valve 
substantially restricts the flow through one of the valve seats, and the 
flow through another one of the valve seats is directed into the 
combustion chamber in a different direction than when the control valve is 
in its first position. 
Another feature of the invention is also adapted to be embodied in an 
induction system for an internal combustion engine having a combustion 
chamber served by at least three valve seats. The valve seats are served 
by an intake passage arrangement that includes a common section in which a 
control valve is rotatably journalled. A control valve has a first, larger 
diameter portion that is journalled in a housing having a corresponding 
larger diameter portion. The control valve further includes a second 
smaller diameter portion which is rotatably journalled in a smaller 
diameter portion of the housing.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS OF THE INVENTION 
Referring now in detail to the drawings and initially to FIG. 1, an 
internal combustion engine constructed in accordance with an embodiment of 
the invention is indicated generally by the reference numeral 21. As will 
become apparent, the engine 21 is of the V-8 type and operates on a 
four-stroke principle. Although the invention is described in conjunction 
with such an engine, it will be readily apparent to those skilled in the 
art that certain facets of the invention may be employed with engines 
having other cylinder numbers and other cylinder configurations. It is 
believed well within the scope of those skilled in the art to understand 
how the features of the invention may be employed with such other engines. 
The engine 21 is comprised of a cylinder block, indicated generally by the 
reference numeral 22, having two angularly inclined cylinder banks 23 and 
24, each of which is formed with four respective cylinder bores 25. In the 
illustrated embodiment, the angle between the cylinder banks 23 and 24 is 
90.degree.. 
Pistons 26 are slidably supported within each of the cylinder bores 25. 
These pistons 26 are connected by means of piston pins 27 to the upper or 
small ends of respective connecting rods 28. As is typical with V-type 
engine practice, the cylinder bank 23 is staggered slightly in an axial 
direction relative to the cylinder bank 24 so that the connecting rods 28 
of respective cylinders of the banks 23 and 24 can be journalled on common 
throws 29 of a crankshaft 31. The crankshaft 31 is rotatably journalled in 
a well-known manner within a crankcase chamber formed by a skirt 32 of the 
cylinder block 22 and a crankcase member 33 that is detachably affixed 
thereto in a known manner. 
The construction of the cylinder block 22 and those components which are 
contained within it and the crankcase member 33 may be considered to be 
conventional. Since the invention deals primarily with the induction 
system, to be described later, further details of the construction of the 
lower portion of the engine is not believed to be necessary to permit 
those skilled in the art to practice the invention. For that reason, 
further description of these conventional components will not be made. 
Cylinder heads 34 are affixed to each of the cylinder banks 23 and 24 in a 
manner which will be described. Also, the detailed construction of the 
cylinder heads 34 and the mechanisms contained therein will be described 
by reference to FIG. 2 and related, copending applications. Cam covers 35 
are affixed to the cylinder heads 34 in a suitable manner. 
It should be noted that the cylinder banks 23 and 24 and the attached 
cylinder heads 34 and attached cam covers 35 define a valley between them, 
which valley is indicated generally by the reference numeral 36. An 
induction system, indicated generally by the reference numeral 37 and 
which also will be described later in more detail by reference to the 
remaining figures, since it embodies the invention, is disposed in this 
valley 36 for supplying a fuel-air charge to the individual combustion 
chambers of the engine 21. 
Exhaust manifolds 38 are affixed to the outer sides of the cylinder heads 
34 and discharge the exhaust gases to the atmosphere through any 
conventional type of exhaust system (not shown). 
The configuration of the combustion chambers for the engine will now be 
described by primary reference to FIGS. 2-4. It should be initially noted 
that the cylinder heads 34 for each of the cylinder banks 23 and 24 are 
substantially identical in construction, with the cylinder head 34 for the 
bank 23 being placed onto the bank 23 in the one direction. When the same 
cylinder head 34 is attached to the cylinder bank 24, the head 34 will be 
reversed from this position. This permits the use of a single casting for 
both sides of the engine 21 with obvious cost advantages. 
The cylinder head 34 has a lower sealing surface 38 that is affixed to the 
upper end of the respective cylinder block 23 or 24 by fasteners 40 so as 
to effect a tight gas seal therewith. The cylinder head surface 38 is 
provided with individual recesses 39 which cooperate with the cylinder 
bores 25 and the heads of the pistons 26 to form the combustion chambers 
for the engine 21. In a preferred form, the combustion chambers have a 
generally lens-shaped configuration, as described in the copending 
application of Masaaki Yoshikawa, entitled "Engine Combustion Chamber and 
Air Intake Device," Ser. No. 08/354,539, filed Dec. 13, 1994, and assigned 
to the assignee hereof. Where any details of the combustion chamber 
configuration are not described herein, reference may be had to that 
copending application, the disclosure of which is incorporated herein by 
reference, for such details. 
The axes of the individual cylinder bores 25 are indicated in FIG. 2 and 
identified by the reference numeral 41 for orientation purposes. On one 
side of a plane containing the cylinder bore axis 41 there is provided a 
center intake valve seat 42. This intake valve seat 42 is disposed 
generally on the outer periphery of the cylinder bore 25 and is spaced the 
greatest distance from the cylinder bore axis 41. 
A further pair of side intake valve seats 43 are disposed closer to the 
cylinder bore axis 41, but are positioned so as to extend in part across 
the aforenoted plane containing the cylinder bore axis 41. 
Respective poppet-type intake valves 44 are slidably supported in the 
cylinder head 34 by pressed or cast-in guides 45 and control the flow 
through the valve seats 42 and 43. The reciprocal axis of the intake valve 
44 associated with the center valve seat 42 is disposed at an acute angle 
.theta..sub.c to a plane which is parallel to the cylinder bore axis 41 
and to the aforenoted plane containing it. This plane is offset from the 
plane containing the cylinder bore axis 41 toward the valley 36 between 
the cylinder banks 23 and 24. 
The intake valves 44 associated with the side intake valve seats 42 have 
their reciprocal axes lying in a common plane. This plane is also disposed 
at an acute angle to the plane containing the axis 41. This acute angle, 
indicated by the dimension .theta..sub.s, is greater than the acute angle 
.theta..sub.c. 
An intake passage arrangement, indicated generally by the reference numeral 
46, extends from an outer surfaces 47 of the cylinder heads 34 on the side 
adjacent the valley 36 and is served by the intake system 37 in a manner 
which will be described. The intake passage arrangement 46 in this 
embodiment is of a Siamesed-type intake passage that serves all of the 
valve seats 42 and 43. However, other arrangements are possible. The 
invention, however, has particular use with Siamesed passages having a 
common portion, for a reason as will become apparent. 
Referring again to FIG. 2, coil compression springs 51 encircle the stems 
of the intake valves 44 and bear against machined surfaces on the cylinder 
head 34 and keeper retainer assemblies 52 fixed to the upper ends of the 
stems of the valves 44 for urging the valves 44 to their closed positions. 
Thimble tappets 53 are slidably supported in tappet-receiving bores 54 
formed in the cylinder head 34 for actuating the valves 44. The bores 54 
are disposed at the same angle as the reciprocal axes of their respective 
valve stems 44. 
An intake camshaft, indicated generally by the reference numeral 57, is 
rotatably supported in the cylinder head 34 in a manner which will be 
described. This intake camshaft 57 is driven in a manner which will also 
be described at one-half crankshaft speed. The intake camshaft 57 is 
provided with three cam lobes 58 for each cylinder which it serves and 
which are spaced apart by bearing surfaces. These bearing surfaces are, in 
turn, journalled in the cylinder head 54 in bearings formed integrally in 
the cylinder head. 
The intake camshaft 57 is supported for rotation by bearing caps 59 that 
are affixed to the cylinder head 34 in the manner described in the 
copending application of Tateo Aoyoma and Masahiro Uchida, entitled 
"Cylinder Head Arrangement for Multi-Valve Engine," Ser. No. 08/363,412, 
filed Dec. 23, 1994 (attorney docket no. YAMAH2.847A), and assigned to the 
assignee hereof. In fact, that copending application discloses further 
details of the construction of the cylinder head 34, the way in which the 
tappet-receiving bores 54 are formed, and other details of the cylinder 
head arrangement. That disclosure is incorporated herein by reference. 
Since this invention deals primarily with the induction system for the 
engine, it is believed that the details of the construction of the 
cylinder heads except for what are given herein are not necessary for 
those skilled in the art to practice the invention. 
Continuing to refer to FIGS. 2-4, a pair of exhaust valve seats 61 are 
formed in the cylinder head recesses 39 on the side of the plane 41 
opposite to the center intake valve seat 42. These exhaust valve seats 61 
are formed at the beginning of exhaust passages 62, which extend through 
the exhaust side of the cylinder heads 34 and which terminate at the 
exhaust manifolds 38 previously referred to and illustrated in FIG. 1. The 
exhaust passages 62 may be of the Siamesed type, or if preferred, 
individual passages may be employed for each exhaust valve seat 61. 
Exhaust valves 63 are slidably supported for reciprocation in the cylinder 
head 34 by valve guides 64 that are inserted into the cylinder head 34 in 
any suitable manner. The axes of reciprocation of the exhaust valves 63 
lie in a common plane that is disposed at an angle .theta..sub.e to the 
plane containing the cylinder bore axis 41. The angle .theta..sub.e is 
equal to or greater than the angle .theta..sub.s of the side intake valves 
and substantially greater than the angle .theta..sub.c of the center 
intake valve. 
Coil compression springs 65 encircle the stems of the exhaust valves 62 and 
act upon keeper retainer assemblies 66 for urging these valves to their 
closed position in seating engagement with the valve seats 61. 
The exhaust valves 63 are opened by thimble tappets 67 that are slidably 
supported in bores 68 formed in the cylinder head 34. The bores 68 extend 
parallel to the axes of reciprocation defined by the valve guides 64 and 
extend downwardly from the upper cylinder head surface, as described in 
the aforenoted copending application, Ser. No. 08/363,412. 
An exhaust cam shaft 69 is provided that has individual cam lobes 71 that 
engage each of the exhaust valve tappets 67 for operating them. The 
exhaust cam shaft 69 is journalled in the cylinder head 34 in the manner 
also described in copending application Ser. No. 08/363,412, which 
includes bearing caps 72. 
As has been noted, the intake and exhaust cam shafts 57 and 69 are driven 
from the engine crankshaft 31 at one-half crankshaft speed. Any of a wide 
variety of types of cam shaft drives may be employed, including that 
described in copending application Ser. No. 08/363,412. As seen in FIG. 2, 
the intake camshaft 57 rotates about a rotational axis that is disposed at 
a lesser distance L.sub.1 from the cylinder bore axis 41 than is the axis 
of rotation of the exhaust camshaft 69, this latter distance being 
indicated by the reference character L.sub.2. 
The area between the intake and exhaust camshafts 59 and 61 centered over 
each of the cylinder bores 25 is provided with a spark plug well that 
extends along an axis indicated at 73 and which is disposed at an acute 
angle .theta..sub.p relative to the plane containing the cylinder bore 
axis 41. A spark plug 74 is disposed at the lower end of this well for 
each cylinder bore 25 and extends into the cylinder head recess 39 for 
firing the charge which is introduced thereto through the induction system 
which will now be described. 
The induction system 37 of this embodiment will now be described by primary 
reference to FIGS. 1-12. As has been noted, this induction system 37 is 
positioned in the valley 36 between the cylinder banks 23 and 24 and 
cooperates with the cylinder head surfaces 47 for supplying a fuel air 
charge to the induction passage 46 of the cylinder heads 34. 
The induction system 37 is, except for the flow control valves, indicated 
generally by the reference numerals 75, the same as that disclosed in the 
copending application entitled "Intake Control System," Ser. No. 
08/363,746, filed Dec. 23, 1994, in the names of Kenichi Sakurai, Masami 
Wada, and Masato Nishigaki and assigned to the assignee hereof the 
disclosure of which is incorporated herein by reference. Therefore, the 
portion of the induction system 37 which is the same as that described in 
the noted copending application Ser. No. 08/363,746, and be described only 
briefly. 
This induction system includes a plenum chamber 76 that is disposed within 
the valley 36 between the cylinder banks 23 and 24, but which is spaced 
inwardly from it to provide a cooling air flow therearound. This plenum 
chamber 76 is provided with an atmospheric air inlet (not shown) in which 
a manually positioned throttle valve is contained for controlling the 
speed of the engine. 
The plenum chamber 76 supplies air to an intake manifold, indicated 
generally by the reference numeral 77, and which has individual runner 
sections 78 which terminate in respective passages (to be described) of 
the control valve assembly 75 for delivering the air to the cylinder head 
intake passages 46. 
In order to permit tuning of this induction system for a wide variety of 
engine speed and load ranges, each manifold runner 78 is served by a 
relatively short, high-speed intake passage 79 that communicates with the 
plenum chamber 76, and a second, relatively long primary intake passage 
81. The passages 81 also terminate within the plenum chamber 76. The 
orientation and formation of these passages is described in more detail in 
the incorporated copending application. 
The short, high-speed intake passages 79 all have sections that extend 
along the center of the engine and through which a throttle valve assembly 
82 extends. The valve assembly 82 controls the opening and closing of 
these short, high-speed intake passages 79. The throttle valve assembly 82 
is operated by any desired strategy, but primarily maintains the passages 
79 closed at the low speed and low mid-range performance. Thus, the 
combustion chambers of the engine are served by the longer intake passages 
81 which are tuned to provide optimum charging efficiency under their 
served running conditions. As the engine speed and load increases, the 
throttle valves 82 are opened automatically, and the effective length of 
the intake passages is shortened to provide better tuning and charging 
efficiency for high-speed running conditions. 
The manifold runners 78 each have flanges 83 at their cylinder head ends 
which are affixed in a suitable manner to a valve body 84 of the control 
valve assembly 75. This valve body 84 is provided with a through-flow 
passage 86 which has an inlet end 87 that is complementary to the 
configuration of the runners 78 and which is generally oval in 
configuration, as may be best seen in FIG. 5. In a like manner, the 
passage 86 has a correspondingly shaped outlet that corresponds with an 
inlet opening 88 which is also of complementary shape and which forms the 
inlet to the individual cylinder head induction passages 46. 
From the inlet opening 88, the cylinder head intake passages 44 divide into 
three generally cylindrically shaped portions comprised of a center 
portion 89 that serves the center intake valve seat 42 and a pair of side 
portions 91 which serve the side intake valve seats 43. In this particular 
embodiment, these portions 89 and 91 have very little dividing area 
between them and that is only immediately adjacent the respective valve 
seats 42 and 43. 
Referring again to the control valve assembly 75, its main housing 84 is 
provided with a transversely extending bore 92 that extends through it, 
with the center of the bore 92 being disposed slightly inwardly of the 
intake passage 86 for a reason which will become apparent. A generally 
cylindrically shaped control valve element 93 has individual valving 
portions 94 which extend across each of the passages 86 associated with 
each of the cylinder head induction passages 46. Each of the valving 
portions 94 is separated from the others by means of a short, cylindrical 
portion 95 that extends between adjacent cylinders. 
It should be noted that the valve body 84 is provided on the side opposite 
that to which the bore 92 is formed with a plurality of recesses 96 that 
have an elliptical, segmental shape, for a reason which will become 
readily apparent. 
Each valve element portion 94 is formed with a first cutout 97 which has a 
configuration as best shown in FIG. 10 that cooperates with the recess 96 
so as to provide an unobstructed flow path 98 which has an elliptical 
shape complementary to the inlet opening 87 of the valve body 84 and to 
the inlet opening 88 of the cylinder head intake passage 46. Therefore, 
when the control valve element 93 is rotated to the position shown in 
FIGS. 3, 8, and 10, the flow from the intake manifold runner 78 to the 
valve seats 42 and 43 will be substantially unrestricted and unencumbered. 
Thus the charge enters the combustion chambers formed by the cylinder head 
recesses 39 in a generally unobstructed and free-flowing direction. This 
permits high volumetric efficiency and high engine outputs. However, and 
as has been noted, this configuration is such that the charge which enters 
the combustion chamber under low-speed, low-load conditions will be 
relatively unrestricted, and the flow direction will not cause any 
significant turbulence. This is undesirable for optimum low and mid-range 
performance. 
Therefore, the control valve elements 94 are provided with a further 
flow-controlling recess 99 that has a generally large inlet portion that 
is generally complementary to the manifold runners 78 and valve body inlet 
portion 87, but which tapers and curves to a discharge end 101 which is 
disposed on one side of the valve body 94 and disposed so as to direct the 
air flow as shown in FIG. 7 when in its second extreme position primarily 
toward the center intake valve seat 42 and one side intake valve seat 43. 
There will be some limited flow through a clearance area 102 also toward 
the other side intake valve seat 43. However, the resulting air flow into 
the cylinder is such as it will pass in the direction indicated by the 
arrow 102 in FIGS. 2 and 7 so as to generate both a swirl around the 
combustion chamber configuration and also a tumble action into the 
cylinders. This tumble action is caused because of the fact that the side 
intake passage 43 has the flow through it directed toward the side 
adjacent the plane containing the cylinder bore axis 41 so that there will 
be more flow on one side than the other, as shown in FIG. 2. In addition, 
the flow through the center intake valve seat 42 is also so directed, and 
this will further promote the tumble action. This gives rise to a high 
rate of turbulence in the combustion chamber, and also the restricted flow 
area increases the velocity. Thus, there will be good combustion and rapid 
flame propagation that will result in significantly improved performance. 
The control valve 93 is operated by means of a servomotor 103 (FIG. 7) that 
is mounted at one end of the respective cylinder head 34 and on which a 
gear 104 is supported. The gear 104 is enmeshed with a gear 105 that is 
formed on a portion 106 of the control valve shaft 93 at this end of the 
engine so as to permit servo control of the control valve. The control may 
be as described in the aforenoted copending application, Ser. No. 
08/363,746. 
The control valve body 84 is provided with a plurality of fuel injector 
receiving ports 107 which are disposed in generally parallel relationship 
along the side of their flow passages 87. Fuel injectors 108 are mounted 
with their discharge nozzles in registry with these passages 107 by a 
mounting assembly 109. A fuel rail 111 supplies fuel to the fuel injectors 
108. 
In this embodiment, the passages 107 are generally flared outwardly so as 
to have relatively large outlet openings 112 so that the fuel sprayed 
therefrom will be directed to all of the intake valve seats 42 and 43 
through their respective induction passage sections 89 and 91, as shown in 
FIGS. 7 and 8. 
The ends of the control valve 93 are provided with cylindrical portions 
that are journalled in the valve body 84 by means of a pair of 
spaced-apart anti-friction bearings 113 and associated seals. The manifold 
runners 78 and valve body 84 are affixed to the cylinder head assemblies 
54 by threaded fasteners 114 which pass either at the ends of the cylinder 
head or in the area of the reduced diameter interconnecting sections 95 of 
the control valve 93. 
FIG. 6 shows another embodiment of the invention wherein the individual 
valving segments 94, rather than being integrally connected to each other, 
are connected by means of a tongue and groove connection, indicated 
generally by the reference numeral 151. A pair of bearings 152 are 
disposed at opposite ends of this tongue and groove connection 151 and 
provide gas sealing and rotary support. This connection will permit some 
thermal expansion of the cylinder head 34 and valve body 84 relative to 
the control valve elements 94. 
FIGS. 13 and 14 show another embodiment of the invention which is generally 
the same as the embodiment of FIGS. 1-12. Because of this, only two 
figures, those corresponding to FIGS. 7 and 8, are believed necessary to 
understand the construction and operation of this embodiment. This 
embodiment differs from that previously described in that the fuel 
injector discharge recess, indicated by the reference numeral 201, is 
offset toward the side of the cylinder in which the air flow passes 
primarily when the control valve 93 is positioned in the low-speed 
turbulence-generating position. As a result, the fuel mixture will be 
delivered primarily to the one side intake valve seat 43 and the center 
intake valve seat 42, as shown in FIGS. 13 and 14, regardless of the 
position of the control valve 93. Even though the mixture strength is 
greater on one side of the cylinder when inducted, a homogeneous mixture 
will result under high-speed, high-load performance. Aside from this 
difference, this embodiment is the same and operates the same as that 
previously described, and for this reason, further description of the 
construction of this embodiment is not believed to be necessary to enable 
those skilled in the art to practice the invention. 
In all of the embodiments as thus far described, the intake passage 46 of 
the cylinder head has been substantially open up until the area 
immediately adjacent the valve seats 42 and 43. FIGS. 15 and 16 show 
another embodiment of the invention wherein the passages to which the flow 
is directed when the control valve 93 is in its low-speed, low-load 
condition are somewhat isolated from the remaining passage. In this 
embodiment, it should be noted that the cylinder head intake passage 46 is 
divided into a first portion 251 and a second portion 252 by an integral 
wall 253 of the cylinder head 34. The wall 253 has a further portion 254 
that extends into and is formed by the control valve body 84 and which is 
disposed so as to be aligned with one side of the restricted portion 101 
of the control valve 93 when in its low-speed, low-load condition. 
Thus, the primary portion of the air charge will be delivered to the center 
intake valve seat and the side intake valve seat through the passages 88 
and 91. However, some flow is also permitted to the remaining side intake 
valve passage 91 through a flow-directing opening 255 that is formed in 
the wall 253 and which is inclined from its inlet end to its outlet end 
toward the remaining side intake passage 91, as seen best in FIGS. 15 and 
16. This arrangement employs the offset positioning of the fuel injector 
opening 201 as with the embodiments of FIGS. 13 and 14. It is to be 
understood, however, that a central fuel injector placement as with the 
embodiment of FIGS. 1-12 could also be employed in conjunction with this 
embodiment. 
In the embodiments as thus far described, the control valve assembly 75 has 
the function when in its closed low-speed, low-load condition so as to 
restrict the flow through one of the side intake valve seats. As has been 
noted, this promotes both tumble and swirl. FIGS. 17-20 show another 
embodiment of the invention which employs a cylinder head porting 
configuration as shown in FIGS. 1-12, but which employs a control valve 
that has its valving portions 301 configured so as to primarily restrict 
the flow to the center intake valve seat 42 under these low-speed, 
low-load conditions and promote a greater flow through the side intake 
valve seats 43 and redirect this flow. This action will increase the 
amount of tumble that is generated and reduce or eliminate the amount of 
swirl from that of the previously described embodiments. Since the only 
difference between this embodiment and that of FIGS. 1-12 is in the 
configuration of the valve control elements 301, all other components have 
been identified by the same reference numerals and will not be described 
again, except insofar as is necessary to understand the construction and 
operation of this embodiment. 
In this embodiment, the valve elements 301 have a generally cylindrical 
configuration and have a first cutout 97 which cooperates with the valve 
body recess 96 so as to provide an unobstructed flow passage 98 when the 
valve is in the position shown in FIGS. 18 and 20. In this regard, this 
embodiment is also the same as that previously described, and hence the 
same reference numerals have been applied. 
In this embodiment, however, the shape of the valve element 301 in its 
other position is defined by a pair of flow-directing portions 302, which 
are divided by a wall 303 and which extend from a common inlet opening 304 
which registers with the manifold runners 78 when in the position shown in 
FIGS. 17 and 19. The upstanding wall 303 will, however, in this position 
substantially obstruct any flow through the cylinder head passage portion 
89 to the center intake valve seat 42 and direct substantially all of the 
flow to the side intake valve seat portions 91. Thus, substantially all of 
the flow will pass to the cylinder through the side intake valve seats 43. 
As with the previously described embodiment, this configuration is also 
such that the flow will be directed primarily toward the sides of the 
valve seats 43 closest to the cylinder bore axis 41, and hence primarily a 
tumble action will be generated. This tumble action will be accompanied by 
little swirl in this embodiment, since the flow is generally symmetric 
into the combustion chamber. 
In all of the embodiments as thus far described, the control valve has 
embodied a cylindrical valve element having a configured outer surface. 
FIG. 21 shows an embodiment wherein the valve element is of the plate 
type, and the valve element is indicated in this figure by the reference 
numeral 351. There is provided a valve element 351 for each control valve 
body passage 87, and these are all affixed on a common control valve shaft 
352 that is driven in the manner previously described. The control valve 
element 351 is of the butterfly type and has along one edge a cutout 353 
that terminates adjacent one of the side intake valve seats 42 in a 
tapered portion 354. As a result, the flow will be directed into the 
cylinder similar to that of the embodiment of FIGS. 1-12 when the valve 
element 351 is in its closed position. Hence, a swirl and tumble will be 
generated. When the valve element 351 is opened, however, there will be no 
flow resistance, and the normal flow will result. 
In the embodiments of the invention as thus far described, when the flow 
controlling control valve has been positioned in its low-speed, low-load 
condition, the flow to primarily one of the intake valve seats has been 
substantially restricted and the flow has been directed primarily to the 
remaining intake valve seats. In some instances it may be desirable to 
restrict the flow to two of the intake valve seats in a three-intake-valve 
arrangement so that the flow primarily flows into the combustion chamber 
through one of the intake valve seats. If this is done and that one intake 
valve seat is a side intake valve seat, then turbulence can be 
substantially increased; and both swirl and tumble, creating an action 
which may be referred to as slant tumble, can be achieved. Next will be 
described a number of embodiments wherein this type of flow arrangement is 
accomplished. 
The first of these embodiments is illustrated in FIGS. 22-28 and is 
generally the same as the embodiment of FIGS. 1-12. In fact, this 
embodiment varies from that embodiment only in two regards. The first is 
the shape of the cutout of the flow control valve, and the other is the 
shape of the intake passage in the valve body and in the cylinder head 34. 
Because of the fact that these are the only differences, the components of 
this embodiment which are the same or substantially the same have been 
identified by the same reference numerals and will not be described again, 
except insofar as it relates to these differences and the effect which 
they create. 
As best seen in FIGS. 23-26, the body 94 of the control valve 93 is 
provided with a first slot or cutout, indicated generally by the reference 
numeral 401, which has a generally tapered configuration starting out with 
a wide inlet end 402 that tapers to a throat and then expands and 
terminates in a discharge end 403 that is directed at an angle so that the 
air flow when the valve 93 is in its closed low-speed condition, as shown 
in FIGS. 23 and 25, will be directed primarily toward the one side intake 
passage 91 that serves one of the side intake valve seats 43. Hence, the 
intake charge that is inducted will flow primarily in the direction of the 
arrow 404, which appears in FIGS. 22 and 23, and creates both a tumble 
action and a swirling motion. As may be seen clearly in FIG. 25, the 
cutout 401 is disposed on the upper side of the valve member 94 when in 
this position so as to direct the charge primarily toward the side of the 
side intake valve seat 43 closest to the cylinder bore axis 41 so as to 
promote tumble. In addition, the side disposition creates a swirling 
motion. 
To further assist in this action, the passageway 96 in the valve body 84 
and the corresponding side wall of the cylinder head 34 which defines the 
intake passageway 46 are formed with a cut-out area 405 that is disposed 
on the upper side of the intake passage 91, and thus further direct and 
restrict the flow in this area so as to ensure a high velocity of the 
charge and flow in the desired direction. 
It should also be noted that the outer diameter of the valve element 93, 
and specifically the valving portion 94, is configured so as to provide a 
small gap G from the upper surface 406 of the valve body passage 96 so as 
to permit some flow, as shown by the arrows in FIG. 23 through the 
remaining valve seats 42 and 43. 
When in its open high-speed flow condition, as seen in FIGS. 24 and 26, a 
further slotted portion 407 in the outer periphery of the valving member 
portion 94 will be in registry with the flow passage 96 of the valve body 
84, and the flow will enter the combustion chamber and cylinder head 
intake passage 46 in a substantially unrestricted form, as shown by the 
arrows in FIG. 24. This promotes high volumetric efficiency and permit the 
attainment of large power outputs as with the earlier described 
embodiments. 
FIGS. 29-36 show another embodiment of the invention which is generally the 
same as the embodiment of FIGS. 22-28 in function. That is, this 
embodiment, like that embodiment, is constructed so that under the 
low-speed, low-load condition, the bulk of the air charge will be inducted 
through one of the side intake valve seats 43. There will be only 
restricted flow permitted through the remaining valve seats, including the 
other side valve seat 43 and the center intake valve seat 42. 
However, the actual construction of the valve element is different, and 
because of this difference the control valve assembly is identified by a 
new reference numeral, the numeral 451, and all reference numerals applied 
to the valve assembly 451 will be new, even though some of the components 
are the same as or similar to those of the previously described 
embodiments. In addition, the installation of the control valve 451 is 
similar, and the fasteners which hold it in place are identified by the 
reference numeral 452. As will also become apparent, the actual assembly 
of the valve 451 is different for reasons which will become obvious. 
In the embodiment of FIGS. 22-28 and some of the earlier embodiments, a 
generally cylindrical valve body or the valving element portions 94 have 
been employed. This results in the formation of a relatively large bore in 
the housing assembly and provides larger areas where leakage might occur. 
However, this has been utilized for ease of assembly, particularly where 
multiple cylinders are served by the same valve body. 
In accordance with this embodiment, the actual valve element, indicated in 
these embodiments by the reference numeral 453, is constructed in a 
different manner so that it can be assembled more easily, permits the use 
of smaller bore diameters, and also facilitates machining of the actual 
valving surfaces. Like certain of the previously described embodiments, 
the actual control valve element 453 is made up of individual valving 
segments 454 that are connected to each other by a tongue and groove 
connection, as best seen in FIGS. 32-36. This tongue and groove connection 
will also be described in more detail later. 
Each of the valving sections 454 is provided with a first, larger diameter 
portion 455 and a second, smaller diameter portion 456. The valve body, 
indicated generally by the reference numeral 457, is made up of two 
sections, 458 and 459. These two sections are affixed by the fasteners 452 
between the cylinder head 34 and the flanges 83 of the manifold runners 
78, and thus are fixed relative to each other. 
The outer ends of each of the sections 458 and 459 are formed with large 
diameter counter bores 461, each of which receives a respective 
large-diameter portion 455 of the respecting valving element 454. 
Extending between these larger diameter bores 461 in each of the housing 
sections 458 and 459 is a smaller diameter bore 462. The smaller diameter 
portion 456 of each of the valve elements 454 is received in this smaller 
diameter bore 462. A still further bore 463 extends between the inner ends 
of the bores 462 and receives a pair of seals 464 for sealing the area at 
the adjacent ends 456 of the valve elements 454. The smaller diameter ends 
456 of each of the valve elements 454 have a tongue and groove connection 
465, like the previously described embodiments so as to accommodate 
thermal expansion and also so as to permit the simultaneous rotation of 
all of the valve elements 454. 
When the valve elements 454 are in their flow restricting low-speed 
condition, as shown in FIGS. 33 and 35, the cylindrical outer periphery 
466 of the valve element portion 455 will be spaced inwardly from the 
upper wall 467 of the flow opening 468 in the valve body 457 so as to 
define a small gap G where flow may occur to the center and one of the 
side intake valve seats 42 and 43, respectively. The smaller diameter 
valving portion 456 has a somewhat tapered configuration, indicated at 
469, which, coupled with the end surface 471 of the larger diameter 
portion 455, defines a relatively narrow small window through which flow 
to the one side intake valve seat 43 may occur so as to generate the swirl 
and tumble action, as indicated by the arrow 404. 
When the valve elements 454 are rotated to their fully opened, non-flow 
restricting position, as shown in FIGS. 34 and 36, a cutout 472 that 
extends through the valve element portions 455 and 456 will provide an 
open, unrestricted flow area that permits flow to the combustion chamber 
through each of the valve seats 42 and 43 so as to achieve maximum power 
output. 
In all of the embodiments thus far described, the control valves of the 
various embodiments have been rotary valves. This has been true with 
respect to not only the three-dimensional-type valves of all embodiments 
of FIG. 21, but also that particular butterfly-type control valve 
arrangement. In some instances it may be possible to employ control valves 
that are other than rotary or which rotate about axes that do not extend 
through and thus obstruct the flow passage in the intake system. 
FIG. 37 shows one such embodiment that employs a sliding-type flow control 
valve 501 that has a curved valving surface 502 which is complementary 
when in the non-flow restricting position (phantom line view) to a flow 
passage 503 of a valve body 504 which, like the previous embodiments, is 
interposed between the manifold runner 78 and the cylinder head 34. This 
valve element 501 is operated by an actuating shaft 505 that is slidably 
supported in a slot formed in a cover piece 506 of the housing assembly 
504. 
In flow-restricting flow redirecting direction (solid line view), the valve 
surface 502 protrudes into the passageway 503 and obstructs the flow to 
one or two of the valve seats and redirects the flow in the remaining 
valve seat so as to generate a swirl or tumble, or both. 
Another embodiment employing a pivotally supported vane-type valve 551 is 
shown in FIG. 38. Again, this valve 551 has a valving surface 552 that 
cooperates with a flow passage 553 formed in a housing assembly 554. The 
valve element 551 is supported on an actuating shaft 556, which is pivotal 
about an axis that extends transverse to the axis of the flow passage 553, 
but does not extend into it. 
In the non-flow restricting position as shown in the phantom-line view of 
FIG. 38, it will be seen that the flow passage 553 is unobstructed. When 
the valve element 551 is moved to the flow controlling position as shown 
in the solid-line view of FIG. 38, then the flow will be restricted 
through one or two of the valve seats and redirected through the remaining 
valve seats in accordance with the flow patterns of any of the previously 
described embodiments. 
From the foregoing description it should be readily apparent to those 
skilled in the art that the invention is particularly adapted in providing 
a three-intake-valve-per-cylinder arrangement that ensures good and full 
flow to the combustion chambers without restriction and without turbulence 
under high-speed, high-load conditions. However, the embodiments are 
effective in not only increasing the velocity, but also redirecting the 
flow pattern under low-speed, low-load conditions so as to generate the 
type of motion and turbulence in the combustion chamber, be it either 
swirl and tumble or tumble alone. Of course, the foregoing description is 
that of preferred embodiments of the invention, and various changes and 
modifications may be made without departing from the spirit and scope of 
the invention as defined by the appended claims.