Note: Descriptions are shown in the official language in which they were submitted.
W~ 94/02?1? ~. -' ~; ~ ~~ ~ ~~ PCT/US93/06952
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BACRGROBRD
1.. ~'aeld of Ir~~ent3:on .
This invention pertains to valves and valve
timing for a cylinder of an. internal combustion engine.
2. Rel ted art end ~ther ~oa~siderations
~pening and closing of valve holes, as well as
the sizes of valve holes, are ~nportant considerations in
a four-stroke internal combustion engine.
Four valve heads are traditionally arranged
w~.th teao suctipn or intake valves on one side of the
head, and two exhaust valves an the other side of the
head. ~here h~.ve been attempts to alter the placement of
the valves~ asgs, pl.ac.l.ng exhaust valves diagonally
across from one another. These altered valve placement
I5 attempts appear to ~nh~n~e volumetric efficiency, to
lowed interference, and to offer certain thermodynama.c
advantages:
~Ct eras generally believed that four valves in
each cylinder mould optimally assure maximuz~ quantity of
air intake. But recently some technicians have taken
issue with the 'nothing better than four" credo. For
example, Yamaha developed a five-valve FZ ?50 head.
., .
~le~andro De Tommaso developed a six valve head having
._
three suction valves and three cachaust valves inside a 90
mm circu~trference.
With the conventional ~aultiple valve
arrangeanents very little of the valve head real estate is
actually devoted to induction of combustible mixture,
particularly since the valve head must also acco~odate
exhaust valves (and in a manner without interference).
A~VO 94/02717 PCT/U593/U~952
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_2_
Moreover, the exhaust valves protrude into the cylinder
and thereby have a tendency to oppose the outflowing'of
exhaust gases. Moreover, the exhaust valves (including
the valve stems) are subjected to intense heat as the
exhaust gas escapes.
There have been unsuccessful attempts (for
example, the "Knight°' engine] to eliminate valves on the
cylinder head, for example by reciprocating sleeves up
and down within a cylinder lining for the purpose of
1,0 selectively opening and closing radial induction and
exhaust ports.
Accordingly, it is an object of the present
invention to provide a valuing arrangement that enhances
volumetric efficiency and improves fuel consumption in an
internal combustion engine.
An advantage of the present invention is the
provision of a variable and efficient timing system for
operating the ~ralving arrangement of the present
invention.
S 'Y
The invention pertains.to a four stroke
internal combust~.oz~ engine, and provides a single
induction valve and a single exhaust valve, each of which
are two times bigger than the valves of a typical four
valve cylinder. Also included is a timing system with
only one spring and two bearing-like gears with caaiing
lobes for actuating movement of the valves.
The exhaust valve is part of an exhaust valve
assembly selectively covers an exhaust port
~eircumferentially located about a top wall of a cylinder
without interfering with segments of a piston, The
exhaust valve assembly includes a ring-shaped portion of , '
a cylinder lining which is configured to selectively
obstruct air from escaping radially from the top of the
cylinder. The exhaust port is opened an~i closed by the
i
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dVt'~ 94/02717 ;~ ? v. __ ~_ i~ a PCT/US93/06952
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lifting of the exhaust valve assembly (30) by a vertical
guillotine-type motion. " . .
The induction valve is included in an intake a
val~cre assembly and is provided on a cylinder head. The
intake valve assembly has a ring or washer shape. The
ring shaped induction valve thus provides a single, large
opening in a cylinder head for induction of a combustible
mixture.
The ti~:ng of both valves is faciliated by a
single spring and induction a:nd exhaust gear-like, planar
timing bearings. Each of the induction timing bearing
and the exhaust timing bearing have a carving surface
provided thereon to face the other bearing. The
induction timing bearing and the exhaust timing bearing
are followed by respective roller tappets. The valuing
and timing arrangement faciliate the flexibility in the
design of a combustion chamber.
Thus, the dynamics of the induction and exhaust
timing systems are inverted with respect to one another,
2U but both systems share a co~cunon biasing spring and a
common variable driving shaft.
~RI~F DESCRIpTI~N C,1F TEE DRAwII~GS
The foregoing and other objects, features, and
advantages of the invention will be apparent from the
following more particular description of preferred
embodiments as illustrated in the accompanying drawings
i~a which reference characters refer to the same parts
throughout the various views. The drawings are not
necessarily to scale, emphasis instead being placed upon
illustrating the principles of the invention.
Fig. 1 is a partially sectioned, partially
exploded front view of an exhaust valve assembly
according to an embodiment of the invention.
Fig. 2 is a sectioned front view of an internal
combustion engine showing an exhaust valve assembly and a
'AaV~ 94/02717 PCT/L1593/06952
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timing control system for use therewith in accordance
with an embodiment
of the invention.
Fig. 3 is a sectioned side view of the engine
of the embodiment
of Fig. 2.
Fig. 4 is a sectioned view taken along line ~
-
4 of Fig . 2 .
Fig. 5 is a sectioned view taken along line 5
-
5 of Fig . 2 .
Fig. 6 is a sectioned view taken along line 6
-
C of Fig . 2 .
Fig. 7 is a sectioned view taken along line 7
7 of Fig. 3.
Fig. 8 is a partial front view,of an induction
valve assembly according to an embodiment of the
invention.
Fig. 9 is an isometric view of an exhaust valve
assembly and a cylinder lining according to an embodiment
of the invention.
Fig. 10 is a sectioned, .isometric view of a
seal included in an exhaust valve assembly of an
embodiment of the inventions
Fig. 3l is an enlarged detailed sectioned view
of a portion of
the exhaust valve
assembly of the
embodiment of Fig. 1.
I?FTl~II~D IaE~GF~PTIG~3 ~F SEE DR~~1II~GS
Fig. 1 shows a cylinder assembly 20 for an
internal combustion engine. the cylinder assembly 20
includes a cylinder lining 22 having a major cylindrical
axis 23. Cylinder lining 22 is comprised of two segments :.
E.~.:
-- a lower lining segment 22a and an upper lining segment _ ''
22b. Cylinder lining segment 22a is accommodated in an
appropriately sized hole 24 in an engine block 25. ,
Cylinder lining segment 22b is discussed in greater
detail hereinafter.
Engine block 25 has mated thereover an engine
head 26. Are upper inner peripheral edge of the hole 24
WC~ 94/02717 r. .; ~ y ,~ ~ j PCf/US93/06952
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is peripherally recessed for receiving an annular seal
28. Annular seal 28 has a top interior surface which is
beveled at an angle on the order of about 45 degrees (see
Fig. 11). Annual seal 28 has a lower lip which protrudes
into hole 24 and covers the axial top of cylinder lining
segment 22a.
The cylinder lining 22 has a piston
(unillustrated in Fig. 1, but illustrated as element 21
in Figs. 2 and 3) reciprocating therein in customary
fashion. An ignition plug 29 a.s threadingly received in
plug channel 29A of head 25, centrally above the cylinder
lining 22. A spark end of the plug 29 depends into an
annular combustion chamber 21a provided between a squish
band 21b of piston 21 (see Figs. 2 and 3).
ST~tU~TUR.E : EXHAUST VALVE ASSEMBLY
As shown in Figs. 1 and 9, cylinder assembly 20
further includes an exhaust valve assembly 30. Exhaust
valve assembly 30 .includes the cylinder lining segment
22b, also known as an exhaust valve ring member. As
shown in more detail in Fig. 9, the exhaust valve ring
member includes both a.lawer exhaust ring 32 and an upper
exhaust ring 33. Both rings 32~and 33 are centered about ,
axis 23. Zower ring 32 has inner and outer diameters
substantially eq~xal to the respective inner and outer
dia~aeters of the cylinder lining lower segment 22a.
Upper ring segment 33 has a smaller inner diameter than
the lower ring 32, thereby forming an overhanging ledge
34 which, as explained below, facilitates a sealing
function. K::.
In the illustrated embodiment, the upper
exhaust ring segment 33 has three valve stems 40 formed .
a'
(preferably soldered) on an axial end thereof. Valve ~.
r
stems 40 are provided at 120 degree angles about axis 23.
It should be understood that fewer or more than the
illustrated number of valve stems 40 can be employed in
other embodiments.
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As explained subsequently, exhaust valve
assembly 30 reciprocates parallel to axis 23 (up andwdown
in Fig. lj. During an exhaust stroke, lining segment 22b
is lifted above seal 28, allowing exhaust gases to escape
radially through exhaust channels or manifold 42 formed
. in engine block 25 and head 26. During other strokes,
cylinder lining segment 22b sits tightly on seal 28,
blocking exhaust manifold 42.
Fig. Z1 shows in detail, among other things,
the sealing of the exhaust valve assembly 30, including
annular seal 28 mentioned before as fitting over the
cylinder lining 22. In addition to annular seal 28, Fig.
11 shows an access ring 44 and a fishtailing seal 46.
Access ring 44 is threadingly fastened about
the periphery of the ay~inder head portion which is
directly above the cylinder. Removal of access ring 44
faciliates engre~s and egress of the exhaust valve
assembly 30 during fabrication and repair.
The seal 46, shown partially in cross section
2p in Figo 10, has an annular shape as seen from above but
an lateral teardrop shape in cross section. The outer
peripheral edge of seal 46 has a series of small radial
cuts or notches 47, which enhances its elasticity. deal
46, not being under high temperature, may be fabricated
from normal steel.
The inner peripheral edge of seal 46 is
positioned between access ring 44 and head 26 as shown in
Fig. 11. The outer peripheral edge of seal 46 is ,
vertically flexible but vertically limited by the ledge
44 provided on exhaust upper ring segment 33.
The shape of seal 46 assures an airtight
closure variable in height, as it is not possible to have
a precise connection between the head 26 and the rest of , -.
the block 25. Then the connection of head and block is
not perfect, the exhaust valve assembly 30 may be seated
too high and (without the benefit o~ seal 46) gases may
escape. But with the provision of the seal 46, the
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vertical amplitude of the segment flexures will be higher
E
than the amplitude of the tolerance of combining head and
r
block.
L
It is thus seen that the exhaust valve assembly
30 is provided only along the wall of the cylinder and on
the highest part of the cylinder assembly 20. In this
manner, the exhaust valve assembly 30 does not interfere
with the surface that concerns the piston rings. By
providing an exhaust valve assembly 30 that opens 360
~,0 degrees around axis 23, an exhaust area is provided with
comparable area with a desirably large induction hole but
without extending. the exhaust area undesirably deeper
into the cylinder (e. g., along the axis 23j, and thereby
increasing the likelihood of interfering with the piston
and ring structure. In t~se illustrated embodiment, the
cylinder assembly 20 has a bore of approximately 90 mm,
but the fissure created by the opening of exhaust valve
assembly 30 (projected on axis 23~ is only about 10 mm.
It should be noted that the valve assembly 30
of the present invention overcomes a great disadvantage
of prior art exhaust valves. Prior art exhaust valves
open toward the inside of a cylinder and accordingly
oppose the outflow of combustion gases and further heat
the valve stem. In contrast, the exhaust valve assembly
30 of the present invention does not, when opened,
protrude into the interior of the cylinder, and does not
expose its valve stem to hot exhaust gases. therefore,
there is substantially less danger of preignition.
the exhaust valve assembly 30 of the present
invention is well protected in its seat over the exhaust 3y...
fissure, and accordingly is not significantly exposed to
exhaust gases escaging fr~m the cylinder assembly 20, nor
does it obstruct flow of exhaust gases. Any heat that is y
absorbed by the exhaust valve assembly 30 is dissipated
3a through stems 40 and its lower edge (which is near the
cooling liquid).
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~'C~ 9/02717 PCTlUS93l06952
~~~.~a.~.~l~~~~
_8_
Moreover, the exhaust valve assembly 30 of the
present invention permits the entire exhaust manifold 42
to be opened so that the depression therein increases the
effective volumentric efficiency of the cylinder during
induction. Prior art valuing arrangements employing
exhaust valves on the cylinder head permitted only
limited opening of the exhaust valves in view of the
proximity of the piston. Hawever, piston proximity is
not a problem for the exhaust valve assembly 30 of the
I,0 present invention. Accordingly, full opening of the
exhaust manifold 42 provides a total suction
substantially equivalent tn increasing the suction
created by the piston by about 1.5 times. .
~5 STRUCTURE: II~IDUCTI~N ASSEMBLY
Although unillustrated, cylinder assembly 20 of
the embodiment of Fig. 5, has one or more .induction valves
provided above lining 22 and in head 26 around plug 29.
The number and positioning of the induction valves is not
20 critical for an understanding of the operation of the
exhaust valve assembly 30 of the present invention. A
currently preferred embodiment having one induction valve
is illustrated, for example, in Figs. 2 and 3.
Figs. 2 ~ 3 and 7 illustrate an embodiment of a
25 timing system for controlling the operation of exhaust
valve assembly 30 of Fig. 1. In addition, Figs. 2 and 3 '
(as well as Fig. 8) illustrate an induction valve
assembly 50 for introducing combustible gases into
combustion chamber 21a through induction channels 52.
30 Induction valve assembly 50 includes a flat
valve ring member 54 concentric about cylinder axis 23.
Fling member 54 is thus also concentric with ignition plug,
2
29. Ring member~54 has a surface area approximately .
equal to half the surface area of the roof of the
35 cylinder. Advantageously, the single ring member 54
provides a passage area on the order of about twice as
large as a conventional arrangement employing four
VV~ 94/02717 " i (° j ~~ pCTlUS93106952
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valves, and approximately two and one half times as much
passage area as a conventional two valve arrangement.
The top edges of ring member 54 are beveled for
seating against annular seals 56, 58. Seal 56 is shown v
in Fig. 8; both seals 5G and 58 are shown in Fig. 2. ,
Induction valve ring member 50 has three stems
60 extending upwardly on an axial tap surface of ring 50 r
(e. g., extending in a direction garallel to cylindrical
axis 23). Induction valve stems 60 are positioned about
axis 23 at 120 degree angular intervals, and are
preferably soldered to the axial top surface of ring 50.
STRUCTURES TINTING SYSTEM
The timing system of the embodiment of Figs. 2,
3 and 7 includes both an induction tuning sub-system and
an exhaust timing sub-system. Induction timing sub~
system includes an induction timing gear 70; two
induction rollers 72; and, an induction tuning linkage to
which the tops of the induction valve stems 60 are
20' connected.
Induction tiaxing gear 70 is disk-shaped bearing
(the terms '°gear°° and °'bearing" being used
interchangeably for this element) and lies in a plane
perpendicular to cylinder axis 23. Gear 70 has its
center on axis 23. Gear 70 is rotatable (via bearings or
the like) about the head wall portion which forms plug
channel 29A. Gear 70 has gear teeth 74 forrnned on its
outer periphery. .
On its axial underside surface 76, induction
timing gear 70 has three annular surface segments,
including inner surface segment 76a; outer surface .
segment 76b; and, intermediate surface segment 76c (see '
Fig. 2). Outer surface segment 76b rides on shoulders
80, which in turn rest on head support surfaces 82 (see
3~ Fig. 2). ~r portion of intermediate surface segment 76c
forms an integral carving surface against which rollers 72
ride. The carving surface includes lobes 78 (see Fig. 3).
~~;:
i~~ 941027 ~ 7 PCT/ US93/06952
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Induction rollers 72 are provided at 180 degree
intervals about cylinder axis 23. Each of the two M
induction rollers 72 are concentrically mounted about a
roller pin 84. 1~ proximal end of each roller pin 84 is
anchored in a roller post 86. Each roller post 86 is
mounted on head support surface 88. Pd guide roller 90 is
mounted intermediate roller post 86 and induction roller
72.
A distal end of each roller pin 84 is engaged
by a reciprocating circular collar member 94. Collar 94
serves as part of the induction linkage. Collar 94
reciprocates about head wall 26 in a direction parallel
to cylinder axis 23, and is concentric with cylinder axis
23. At its top collar 94 has the two corresponding
roller pins 84 soldered or otherwise affixed thereto.
At three goints, an underside surface of collar
94 has attached thereto, near its outer periphery, the
upper ends of induction valve stems 60. The underside
surface of collar 94, at a diameter intermediate those of
the valve stems 60 and head wall 26, is fitted with a
spring 100. Spring 100 is concentric with and extends
around the portion of head wall 26 which forms plug
channel 29.A. A strength of spring 100 at rest on the
ordeg of 65 Rg. is sufficient to seal the exhaust valves.
gn the crossing lift existing between the exhaust valve
end the suction valve, the spring 100 will never exceed
the highest compression established, in which case one
h,as to pay attention that the valves are both partially
opened and the sum of the two lifts must-be lower car
equal to the maximum lift of each exhaust or suction
!, _
valve.
The exhaust timing sub-system includes an
exhaust timing gear 110 (see Fig. 3); three exhaust
rollers 1I2; and, an exhaust timing linl~age to which tops
of exhaust valve stems 40 are connected. Exhaust timing
gear 110 is a ring-shaped bearing (the terms "gear" and
"bearing" being used interchangeably for this element ,
CVO 96/02717 ~ ~ ; ~ ~' ' ~ PCT/US93/Ob952
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and lies in a plane perpendicular to cylinder axis 23.
Gear 110 rotates (via interior peripheral bearings or the
like) on support surface 114 provided by engine head 26.
Gear 110 has gear teeth formed on its outer periphery.
At its outer periphery, the upper surface of~gear 110 ,
provides a carving surface, having carving lobes such as
lobes 116 provided thereon (see Fig. 3).
As shown in Fig. 3, exhaust rollers 112 ride on
the carving surface provided by the outer periphery of the
upper surface of gear 110. Each of the three exhaust
rollers 112 is centrally and rotatably mounted on an
outer end of a roller pin 120. An inner end of each
roller gin 120 is anchored in a plate 122. A lower
surface of platy 122 lies in a plane perpendicular to
axis 23. Plate 122 has its outer edges shaped t~ form a
triangle. Flate 122 is thicker towards its center, and .
has a central aperture (for fitting about the portion of
head wall 26 wh~.ch forms the plug channel 29Ay.
At i.ts top inner edge, plate 122 supports
20~ spring 100, and many even have the bottom of spring 100
soldered or otherwise anchored thereagainst. The top of .
plate 122 may even have an annular groove for
. accommodating the bottom of 'the spring. Thus, after
exhaust rollers 112 are lifted upwardly by lobes 116,
spring 100 applies a return forr:e to urge plate 122 and
rolhers 112 downwardly.
Intermediate the triangular plate 122 and each
f
exhaust roller 112, each roller pin 124 carries a guide
f
roller 126 and a clamp 128 (see Figs. 3 and 7). Clamp
t.
128 receives the upper end of a respective one of the
~... : .
exhaust valve stases AO aligned therebeneath.
Guide rollers 126 are each confined by a pair
of upstanding guide walls 127. As shown in Fig. 3,
spacer guide walls have the shape of a right triangle.
Guide rollers 90 for the induction rollers 70 likewise
are confined by guide walls 129 (see Fig. 7j.
1
V~'~ 94/02717 PCT/US93/05952
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Fig. 3 further shows means for driving the
timing system. In particular, the driving means includes
a driving shaft assembly 150 having a dra.ving shaft axis
152. Driving shaft axis 152 is parallel to cylinder axis
23 but displaced to a side thereof. Driving shaft
assembly 150 includes three driving shaft segments,
particularly lower segment 150x, middle segment 150b, and
upper segment 150c. Each segment has an axial bore for
receiving a center spline 153. Spline I53 has two
IO helically threaded segments, particularly spline segment
153a at its bottom and segment 153b at its top.
Driving. shaft segment 150b includes a toothed
gear 154 radially mounted thereon so that its peripheral
teeth mesh with teeth 74 provided on induction gear 70.
similarly, driving shaft segment 150c includes a toothed
gear 156 radially maunted thereon so that its peripheral
teeth mesh with teeth provided on exhaust gear 110.
At its base, as seen in Fig. 3, driving shaft
assembly I50 has a driving shaft gear I58 which meshes
with a crass shaft gear 160. As also shown in Fig. 3,
crass shaft gear 160 also meshes with a comparable
driving shaft gear 162 for another side of head 26.
At its top, driving shaft assembly 150 includes
a ball bearing I64 having an engagement Or connection
handle 166. Handle 166 is mechanically linked to an
unillustrated rotating drive actuator, which in turn is
governed in accordance with motor RPM and other
parameters. In accordance with sensed RPM and other
parameters, the rotating drive actuator rotationally
3fl displaces the spline I53, thereby causing the spline I53 i~.. .
#,:.~
to adjust the positioning of the gears 154, 156 in
accordance with all requireanents. Adjustment of gears ,
154, 156 in turn performs an RPM-dependent adjustment for _ w
induction gear 70 and exhaust gear 110, respectively.
Head 26 is also provided with oil passageways
170 for the induction timing gear 70. 5imi.larly, head 26
is provided with oil passageways 172 for the exhaust
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%V~ 94!02717
r.~ a .E ~_ .!_ ~..) ~ PCTlUS93/OS952 '.
_13_
t.ixn:ing gear 110. These oil passageways are used only
with the particular type bearing shown, but would not be
i
used should roller bearings instead be employed.
Thus, it is seen that the timing system of the
present invention comprises two gears 70, 110, both
rotating about cylinder axis 23, but lying in spaced
apart parallel planes (perpendicular to cylinder axis
23). Surfaces of the gears 70, 110 facing each other
form carving surfaces operative for timing the opening and
closing of valves. Bobh valve assemblies 30 and 50 move
parallel, rather than at an angle to, cylinder axis 23.
7Ct will be observed that Fig. 3 illustrates
portions of a timing system for an adjacent cylinder
assembly, it being well understood that the cylinders are
laterally aligned in conventional manner and commonly
driven by intermeshed gearing.
As seen in Fig. 7, screws 180 are provided for
securing head 26 to block 25. Screw holes I82 are also
provided for a cover to attach to head 26.
Although not specifically discussed therein, it
will be further understood that the internal combustion
engine of the present invention includes other
conventional features well known by those skilled in the
art. For example, engine block 25 and engine head 26 are
provided with passageways for the circulation of a
coolant fluidv Similar, the cylinder lining 22 has a
piston reciprocating therein.
~~~~T~O~ s ~~~U~T~~~ ~~~ AS~
In operation, it is understood that the
induction valve assembly 50 is to be opened during an
intake stroke of the engine; that the induction valve
assen~bly 50 and the exhaust valve assembly are both to be
closed during both the compression and combustion strokes _
of the engine; and, that the induction valve assembly ~0
is to be closed and the exhaust valve assembly 30 op~e:.ad
during an exhaust stroke of the engine. As indicated
i'"~ ~y
~~ 94/02717 P~CTIUS93/06952
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-14-
above, the timing of the opening and closing of the
induction valve assembly 50 and the exhaust valve
assembly 30 is governed by the carving surfaces provided
on the respective gears 70, 110, as more fully described
belaw.
The timing of the actuation of the induction
valve assembly 50 is governed by the carving surface
provided in the inner surface segment 76a on the,
underside of induction timing gear 70. Tn particule.r,
induction rollers 72 follow the carving surface on inner
surface segment 76a. When the induction valve assembly
50 is to alloy fluid communication between induction
channel 52 and the interior of cylinder assembly 20
(i.e., during an intake stroke), lobes 78 on, the carving
surface on inner surface segment 76a cause induction
rollers 72 to descend ~i.e., travel in a direction
parallel to axis 23 toward the cylinder assembly 20).
Descent of the induction rollers 72 pushes down the
circular collar member 94, which in turn gushes down the
valve stems 60 and hence the flat valve ring member 54.
Thus, the valve ring member 54 is unseated from seals 56,
58, allowing induction fluid to enter from induction
channels 52 into combustion chamber 21a.
When the induction valve assembly 50 is to
preclude fluid communication between induction channel 52
and combustion chamber 2la (e.g., during compression, and
coBabustion strokes), the induction rollers 72 do not ride ;
on the lobes, but rather on a flat portion of the inner
surface segment 76a, thereby causing valve stems 60 to
rise and valve ring member 54 to seat against seals 56,
,.,.
58 in the manner shown in Fig. 2.
In analogous but inverted fashion, the timing
of the actuation of the exhaust valve assembly 30 is
governed by the carving surface provided on the outer
periphery of the togside of exhaust timing gear 110. In
particular, exhaust rollers 112 follow the gerighery of
gear 110. When the exhaust valve assembly 30 is to allow
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~'~ 94/02717 ~: .~ '~: ~. ~~ v) ~ PCl'lUS93/06952
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-15-
fluid communication between exhaust channel 52 and
a
combustion chamber 21a (i.e., during an exhaust stroke);
i
the lobes on the periphery of gear 110 exhaust rollers s
112 to rise (i.e., travel in a direction para~.~.el to axis
23 away from the cylinder assembly 20~. The rise of the
exhaust rollers I12 pulls up the exhaust linkage, which
in pulls up the valve stems 40 and hence the cylinder
lining segment 22b, causing the lining segment 22b to
reciprocate away in guillotine fashion from the cylinder
lining 22a and seal 28 fitted thereover. Thus, the
cylinder lining segment 22b is unseated from seal 28,
allowing exhaust fluid to escape radially at
substantially 360 degrees from cylinder assembly 20 into
exhaust manifold 42.
15' On the other hand, when the exhaust valve
assembly 30 is to preclude fluid communication between
exhaust channel 52 end cylinder assembly 20 (e. g., during
compression and combustion strokes), the exhaust rollers
112 do not ride on the elevated lobes, but rather on a
flat portion ~f the periphery of gear 110, thereby
causing valve stems 40 to fall and cylinder lining
segment 22b to seat against seal 28 in the manner shown
in Fig. 3.
The exhaust valve ring member of the present
invention has a height (projected on central axis 23)
which is only about 11 mm, which is less than 50$ of the
cylinder stroke and preferably less than 20~ of the '
cylinder stroke.
While the invention has been particularly shown
5 ' .'..:
and described with reference to the preferred embodiments
thereof. it will be understood by those skilled in the
2
art that various alterations in form and detail may be
aaade therein without departing from the spirit and scope
of the invention.
:: ~.
o'VV~ 94!02717 PCT/L1S93/06952
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-16-
".
Ig~ IAN
,~.s .said l~fara 3.f you try to inscribe in a circle se~rne
.~d~ant3cal c3rcumfer~:nces s you will nat:.ice~ that aalth ~i~c
~3.~c3~s y~u d~ nest cover the ma3or area. Inscrihang fcur
circles you can occupy a larger space, s~ith fivr.~- an aver
lars~r one.
Nor, 1~t's auppos~ apt the ~~chaust of .a c~l3nder could he
carried out raot thr~ugh the heed valves but ire another ww
and through a,nath~r plat~, ~tc~ get the maximum passing area
the 3,nducti~n, ~e cou3d use the exhaust l3gh°~ tao. v
'~i~ fiv~ ~a~ves sae ~rould have an excellent pass5.ng area. but
'~~cause ~f probls du~ to s~al3ng and fluid3~:y ~f air w
i,nta3seP ~.he ~p~.~3.ng oil the valv~s must h~ppe,n towards the
inside oaf the eyl finder and a very vast aurface~ cowered by the
va~sre,e ~.s not useful. ~b~cau~e, part c~f the same snrfacw,
cotal~ represent an ~bs~cla the .ira~ka ~f air a.nc~ pet..~°o3 ,
the sum ~f al°i the valve ax~as cann~t be hasher than hR~f the
area cf the cylinder aroaf top P otherw~,se if ~re~ occ~:py the
oth~r half the passing as ~r~.ll be reduced in a d3recy
pr~i~rtionai mann~r. ~ .
~n the above grounds, 3t ,ia therefore superfluous tn u:~e
four, f3~~ ~r even aj.~c valves °to cavgr a aurf~c~ that can
easily obstaruct~d bythr~e va~l~'ers. E~ut eve: w: tl: three _ ,
~alwee there remains the ,prable~a of th~r is~$.e:rf~rreaa~:~° W~a':
i
f.v
'l~l~~ 94/02717 P~C1'/US93/a6952
.~ ;n a ,~ ;,, ~~
,.. ! :e .L ... c.~ a
-17
occurs i.ri .those cones ~.rhere the circumferences of the valves
s
are tangent to themselves and tc~ the cvl indpr w.~l l , t:~~ f~~.;t
solution remains , then , that. of the s ingle ceW..°-aI v,.~lve :
h,.~t
has also the aclvant.~ge of a considerably reduced surface u'
contact with the seat; in f ct for a cert-.ain hc: ie the
overlapping edge of the valve represPrts ,~ 1 ~~:~r p.~s sags
surface
Adopting the solLataon of the singler v,.~IvP trse problem :°.f
functionally fitting the ignition pl~.ag remains aa:c~ , ~~: ~~: i;~
not possible to obtain an adequate pr~.~ximity for t:»c~ p'! aags .
the solution will be that of introducing sign.if.icant charges
to the big valve: a large hole will have to bR m~~de in the
~entr~ of the, halve, thin the s°fem gill have tt~ be el :urinated
and r~placed by throe having a smaller diameter, f~~~n they
~rlll be soldered to the valve am tend the hole fnr the pl;ag .
A.I~o this new °~r3ng°°shaped~ valve, will have to h,~ve
surface to close equal tc~ half the area of tape c,ylander roof;
it s~~.l bee then, possible to widen the extern~~l diameter in
such a way as to increase the: surface by a.n a.~n~~uazt e~na,.~l ro -
the suacfaee of the hole for the pl;ag, thrd~tagh wh:~r.~: tie
att~rture will theca be free ~ to en ter; in :his r. ase tc~c~ the ~:-
contact surface between th~ plug edge .end the valve
r~presents a .~ 3 ost surface to ba added to the e,~ter a~ai one ,
beat still r~neasuring Iess th,~n than three valves. ~ Maren~.~ew. i.f
the space aror.~nd the plug does no: allow el,~~ugh w.id~:;v ;-.r~
~~ 94102717 , P~'/US93/pb952
~18-
permit the passage of water around the plug itself, zt~wil:
then be possible to further ea.ic~8r, the "ring°shaped" :~.=~lve . .
~ covering the same surface ) , as much as thoug3'W. tn 'oe
~agcessary. dais special inlet valve so produced, c:~Pa::es
passage area twic~~as big if compared to the four valves .~:eL?
about two and a half times if compared to the c3 a:v-..ic r
valves; the present abiliti.e~s in constrmcting pece: o'
rr~3cromechani.cs can nr~~x reach such levels of anfinitesi.~na~l
tolerance as to make it possible fc~r teze tyro ec3gea of '~:r:e
valve, the interior end t~~ exterior one. tn f.it in ;:heir
r~spective seats without mutual interlEerences; the seats wi::
then consist of the usual material.
We o~an raoga proceed to examine hair the exhaust should be mar3P
in order to ana3ce the above-mentioned .anc~uctian feasible to
all intents anc3 purpcases
;;:;.;
CVO 9dl X2717 . ~. ~ ~ n ~')
P~f/US93/~6952
i.: ~. I L 3- -f '~ S
~7.9_
'T~i~ 1°I~LT~'r -- .
l~ first considcratic~n comes n..~tural : from wh~:ra ~ should t~
Faust gases come out, if the hole head is occupied by the
g.aWuction?
coherently to the philasophy of the pro?ect, to such a
generous induction must corre:~gond a really free exh.~us~. w~'. ~t'~
an adequately vast suacface of the hole.
By exclusion, the opening for the exhaus t gases can bR foun;?
only along tha wall of the cylinder and on the h~.~hea *' p,~rt.
of the c?a~ber in order rant to interfere wit..' tie surface
that concerns the ~istan rings, they have, tharef.r~re~ ~.o be
under t3~e exhaust hole. If we want to give the exhaust hale ,
an area progort3onal, to the induction hope,. we find some
. proble.~ns : the dimension of one o~° :yore: syde windows wo~al d
be, indeed, notable in he~.~ht and would impose the uap ag d~
piston ~ra.t~ rings ~t the base of the skirt . That would n:~~-.
bar fiuractional: we would have, then. problems with tl°:e sealing
of the valves. as it would b~ necessary to onc~n *-..nwatd: the
,.
outside and to drive radial valves is a mess.
~'he solution is to rs~ak~ only on~ hole of limited height b°at. ;~~_
f
oahich turns all around the highest p:~rt of the cylinder: in = .
:.
i..
this way, we c,~r~ obtain an area of passage a'~War~l2v, a~'al to
the induction nne, with a fiasure of only 1I mrr,, if to~.e
cylinder Haas .the considerahle be~re of l~tl mm. 'rhe ris»:: can
CA 02141187 2005-03-16
-20-
have, in this way, a natural position finding their spline
mm or even less under the top of the piston (according to
the compression ratio, the shape of the chamber and the
squish band) . In order to open and close, the chamber, the
5 hole has a special valve, obviously cylindrical, (Table 6)
that moves up and down like a guillotine from the head to
the chamber and viceversa.
What follows needs our particular attention. The sealing of
the valves must be assured at the top with an edge of the
10 valve, folded inward, which rests on an edge made in the
head, where a particular segment guarantees the necessary
sealing, thanks to its shape and vertical elasticity.
To make this piece it will be necessary to choose a kind of
material which preserves its elastic properties at fairly
high temperatures; even though it is protected inside by the
edge of the head, it could be reached by burning gases. As
you can see in figure 3, Table 6 the shape has to assure for
the valve an airtight closure variable in height, as it is
not impossible for it to have a precise connection between
the head and the rest of the block, being the valves part of
the head. Therefore, if the connection is not perfect, the
valve will be higher than it should be on the upper seat,
and will be no longer sealed, in the case in which the head
is to be lifted from the rest of the engine, we can have an
escape from the lower part of the valve, that will not be
CA 02141187 2005-03-16
-21-
able to close the whole spline, as it will have already
knocked against its upper seat.
With the above-mentioned segment, we can obviate
difficulties like these. considering that the vertical
amplitude of the segment flexures will be higher than the
amplitude of the tolerance of the combining of the head and
block. This tolerance is even greater in the case of multi-
cylindrical heads. In any case the segment is required to
make oscillations that are not very tall and it has to bear
a small mechanical effort and so, it can have a limited
thickness, which, with small appropriate cuts around the
external circumference, could have the required elasticity
without having to apply to it weight superior to 5 Kg. The
lower part of the valve does not present any particular
problem for airtight closure, since it may be considered as
a big valve with the diameter equal to the cylinder.
Therefore a joining will be created which is similar to that
one of traditional valves with an inclination of the edge of
contact of 30-45 degrees to the axis of the valve.
The pressing down of the valve will be assured by a spring
of a special distribution, as will be seen later. A
strength for the spring at rest of 65 Kg will be sufficient
(less than the two exhaust springs of a Fiat Fire 1000*) to
make it possible to overcome the internal pressures of the
cylinder Which tends to escape.
*trademarked
CA 02141187 2005-03-16
-22-
In fact, we can establish that the sealing surface in a
100 mm cylinder is given by 314 mm per 0:040, 0:040 being a
normal tolerance of joining between cylinder and piston and
between valve and head. As a result of this we have a
circumferential extension subject to the sealing which will
approximately be equal to 314 mm. Now, considering a point
of maximum internal pressure of 200 Kg per cm (Honda R.A 168
turbo, one of the most powerful has a limit of 167 Kg
per cm). In extreme cases the strength of sealing is surely
minor than 50 Kg as opposed to the 65 Kg of the spring,
which wastes other 5 Kg to push the elastic segment down.
Of course, the surface of contact between valve and pipe
will be covered with material similar to that of traditional
valve seats. In the same way, the upper point of contact of
the valve on the segment will be protected. As has already
been said, there is no need for the lifts to be higher than
11 mm, cams of distribution will have normal and already
tested dimensions. The common exhaust valves have a very
great disadvantage, that of opening towards the inside of
the cylinder, opposing the normal outflow of the exhaust
gases which after having overcome them, continue to eat the
stem too. The temperatures reached, are very high in
comparison to the suction-valves.
(Fig. 7)
:,
1~'O 94I~D2?17 ~, -;. ', _y ~, , ,
PCT/LJS93/46952
-23-
7
6Je a~ obliged to use more resistant and rxpeaive .naterial s i
j
t chromium-plate steel , silicon :steel . artin3iur~ wi~:h a,~'high
rcentage of nickel chromiuan). often, one .is obliged tc,
ac~ complicated pieces such as hnllaw valves or part:.ailly .
filled with metallic sodiivn or lithiigm or pot~~s: iu,°r,'s al t:
which improve heat transmission from the h~r~d to tha stem.
~~I1 these probl~ms do not affect the n~w syste:~ for tnE
B~pulsion of gases.
~ctuaZlyA fnr ~e greater part of gas el.~~.natant~~ tg.m~:, "the:
guillotine" valve is well protePcted ir. its seat :~~rer the
e'chatast fissure. It ia, therefore, not exposed to exllataar
uses and it does not obs~°uct th~rir flow. any heat that ? t.
could absorb, when it is clos~d. soould tc~ $asi.:y ansoroen o~
the stems anc~ the le~wer edge that is near the cool ing 1 a.cuic?,
as happens with tae piston. Sesic~es the function of
aupportin~ distribution, also the task of sending exhaus
uses towards the t~ao sides e~f the block and then tc thei.r
respectiv~ exhaust manifolds is left t.o the sep,~ra~:ing ,ura;l:c
t strong and wel l ~ a~ol ~d ? b~tween th~ cylirc~ers . Ir, this gray
the entry and exit c~f gas is facilitated.
Sore limitations are due to the position of tie stems, hia ~e
can ~bviate this, by inclining the separatior. galls of the
~1 ind~rs , as is shown in tabl a dr.. s.
;:.:
<<
~Y~ 9102717 PCT/US93/06952
. ~'
r~ .I -~ (1 ''~
1..1 r t
(v: ~. . .n .
-24-
s
Y~IrY~~ 'rx~ilNO CO OZr
~a the top ~of they three stays of the intake va~.ve, we fiat the
~ppa~.~support,ing bas~ of the spring, better still if counter
~balancad and of considerable dimensions.. inside which there
i,s an alluminium cylinder where the plug can be inserted.
°~,~ spring is inside the three stems and has as lower .
supporting base, a small bo~rl of appropriate shape which lees
on the head; the opening ~f the valve oncurs r~h~n the upper
supporting base is pushed dowse.
. F'a,r corr~ct end precise nnovement, it is necessary to have two
poa~z~ts where pressure , should be applied, contemporaneous ly'
~.$n the opposite marg~s of the circular base. Where. it is
. . us~fuI to apply roll~r .~tappe~ on which the low of lifting
~s . .~nposad by m~ans ' of the .rotation of a thrust bal l bearing ,
bel~nging to~~he h~ad co~r and that presents ion its Iawer
aide and dir~ctly ~ in oontaot . ~a~.th the rollers ) two backs
~ahi~h, .during every revolution. push the tapc~ets with proper
accalara°t~on and decalaration~
a backs, ,in fact, . ~ar~ . nc~thin~ else but the ~ccantrics of ~
n~ranal ~ cams ~ f3at ~ d~veloped ~n ~ the plane of the lower part of
_ ,
'the baasing -that is .dent~d ~xternally and that receive:
. . . . . . . . . . . 4.'
mov~ment .from the driving shaft. through. gearing:. In the earns ~
~ay~ it is engaged .'s~ith the teeth of the bearangs . of :~e
iaata3c~ valves of chambers which night. pass~.t~ly be contyg.~o:a.
' > '~;.
1%Vr3 94/02717 %' ~> i:' ~ ' ~ ~ PCT/US93/06952
i.~ ..:, .r. ,:_ ~., CJ '~
..' I
i
fior dimension and rotation speed (equal t.o half a turn of the l
e3rivins shaft) of the bearing, the development of a very"~lor.g
yam is possible. A glass inside the spring which runs ,.
outside the cylinder containing the plug. will prevent.
undesiderabLe oscillations of the stems of the valve. In the ,
sarr~s way. the exhaust valve is con~xolled by thr ee bacla of a
a~~g which lies on the head and encloses the stems of the
val~re externally. ~ha backs act, this time on three rollers
rather than two, because of the vaster perimetrical s ize.
hollers are fixed with a foot on the stems of "the
~illotine" when the backs operate on rollers ianc~ ,they a°.~.t.
simultaneously), moving them up, 'the whole valve ~s Lifted,
vit .opens in ~ai~ way the exl~aauqt circular fissure; the three .
sues fiaced on the edge of the valv~ push c~o~an ~,"~e valve,
~s~aa, w3a~n it is ne~ess~ry for it to be closRd. Thus
happ~rns becaus~ the three storms belong to the small lo~.~er _
supporting bowl of the spring of the intake valve which,
b~i,r~~ partially at rest, during fhe exhaust phase , can be
used even for the exhaust valve. In the crc::~sing lift r
existing betwe~n th~ exhaust valve and the suction valve. they
sprin~~will never axes~d the highest compression establi:h~:d
'by th~ proigct, in which one has to pay attention that the
i:.:'
~,
valves ar~ both partial ly vopened and the s:un of the two lifts ''' ~~
must be lower or equal to the maximum lift of each e~:h,.~us:. rr
suction valve.
>:
W~ 94/~D2717 PCT/LJ~93/06952 s~ ~~
i. .
n
~.,n ~. ~.C .al. .~. ~
-26-
~~r the e~chaust too, we can use Iiftin~, laws with very atxor.g
acceleration, thanks to roller tappets aahich can no:~cn,~lly
stapport c3oubl~d weights and thar~.la to very Small climbing
angles.
this is possible because of the nr~table dimensis~n of the
bearing. as has been already explained. I~t wi.l1 then be
useful to apply some rol l era . driver. by aural l sz: i table , t.o
the six arms which. cone~ct the, stems of bath v,~Ives to t':n~-
small supporting bowl for the spring . 1':~ais is tr a~~:;.;~a
unc3esiderable torsions of the stems when the ba~c.ks attack the
~l.Iar tappets.
~~rs the sterns of both valcres are shatter anc~ ;..'~3nner Char.
usual and as a singly spring, even though thicker, has been
used, we can rightly hope to obtain aurall weight, than3ss t.c~
th~r mechanics of dastsibution which a~3opt neith~:r arm: nnx
balanc~. hut the large ~i~e of valsr~:s c.~oes not. m~~:e it
possible, in my opinion, to save greatly on the s~aeight. Thss
is th~ reason why an accurate plan of lifting Iaws raat b~:
studied which. swan though they are helpez~, as alxeavy
meantionee~, 1'y the roll~r tappefi~ and by th~r very small
climbing angles, musk however, tales into consic?eration the
. :'
possibility of a rotation sped faster than normal. In fact
»w
a prop~ller crude in this way can reach a rotation Speed
unthinkable till to nova, 'because liari::ed :nosily by pas: ive .
resistances wore than pump ing ones . (:arlse~Laentl :~, a ear, t;~e
~VaD 94102717 h .~_ ~k .:.. ~ ~:~ i PCTIU~93/06952
-27-
i
spring becomes important9 the choice of niunber and section of
its coils anust be carefully considered so as not to have
bx~a~ca due. to resonant~. It is possw.ble tc~ assure the
~luba~icataon of the distribution and of the thruJt. bearings in
psrtacular, arraaaging Borne Ganali~ations which 3oin in the
supporting seats of the various thrust bearings. So, t?~c~ tail
fall from upper bearings iaill aasur~ roller lvbricatdon. On
~aeh side of ~very liner bearing s~ril1 beg created a
coaznections to the lower-.. base a.n order to eliminate
adar;uately the exceeding oil, otherwise emulsified by the
dears of ;the bearings. the connections b~tween the head and
.the bas~rnt, of course, pass through the separation walls of
. a ~ va~ous cyl indess .
:...... ~ ..;~..., ~.:.,... .. '..., . ..,... :.. ~ . ..~; ~:..~,, - ,.. . ,
~,~....: ,.,~~~ y
f :.v
,..:,
W~? 94/02717 PCT/US93/06952
f i
!_ o -28-
c~~a~~ ~~~~a
~~b~ ~asiar from ~ampetition ~ngines but alao in propell~srs
with~ut variabl~ inductiozxs it is useful to adopts this kind
~f distribution for its particular prerogative: in fact t°~ae
~o~ss.ibility ~f ~keepirrg completely opened ~-he exhaust valve,
gv~n ~nen ;~.h~ piston is at its ~.D.C. gives t3~e npportunitv
' ~o use ~tha c3epressi~r~ which is in the .exhainst pipe to
incre~s~r filling P in ~ther words , a kind of overf~redang
~ng.ln~ without the ~ disadva.nt:ages of excess ive ~ gas
Gonsa~mpt$onP weight ~~.ncrementa and complications typical of
.a turbo compressor. ids. 'can count on the most complete
.~ '~sP~ssiorn of the r~sidual . combustion products which are
f~lloc3 by an aig mass ~ that had not to st~.agraate in the
gn~ak~ a~a~ifold and hive a dower temperature to advantage the
.~ volumetrical output arW th~ chacnbe~r temperatures that
(~:ogether with th~ th~rmic advantages of "the ~u.~llotine"
.v~ the possibility to use larger pistons which give almaa::
. qtaadrati~ power incr~ments . . ~l.c3ding all these t~ireg to vahat I .
about the reduction , of pumping friction ~ that has much .
~raor~ ~I$~np~a~tanc~ than the 'passive. friction, specially at high
~p~ed.? ,, ~ 'it .s~e~aas ~r.igrat to ~xpect a considerab2e increment of .
. ire . and power . , , . ~ . . . .
If .a vea°~ little extension of th~ blQc°~; fr,r arranging
v,~r:~ous _
i
wrings of the distribution is accepted and if al9 ac.~~rilrate
CA 02141187 2005-03-16
-29-
planning of the big springs and of the cams is realized in
order to eliminate noise and vibrations and reach high
speeds, a perfectly flat combustion-chamber can be achieved
together with anotable squish band for a better swirl. (De
Tomaso, even though he had the problem of cooling the head,
showed the importance of that with his six valves).
So in engine projects designed for an economic aim, we can be
sure to obtain interesting savings and pollution reduction.
Another interesting advantage is the possibility to easily
realize (Table 2) a variable law of the time lifting of the
valves so as to increase torque at the different speeds.
It is possible also to adopt a double turbine for the four
cylinders, as was done for FIAT Triflux*.
We can have fluid exhaust (greater efficiency for a turbo
engine) ; we can use a lighter cooling system; the head height
and breadth much reduced, to the advantage of the barycentre
and weight. We can employ two injectors per cylinder instead
of only one, for a better spraying; we can have the
elimination of possible crush of the exhaust valve on the
piston. We can inspect again the chamber through the exhaust
fissures without opening the head. Today the new technologies
are the only way to survive in this sector. Over all the
actual possibility that C.A.D. C.A.M. computers give us in
terms of quickly projecting engines should encourage further
that the right step to do is to build this engine.
*trademarked
