CA1163154A - Internal combustion engine - Google Patents
Internal combustion engineInfo
- Publication number
- CA1163154A CA1163154A CA000392653A CA392653A CA1163154A CA 1163154 A CA1163154 A CA 1163154A CA 000392653 A CA000392653 A CA 000392653A CA 392653 A CA392653 A CA 392653A CA 1163154 A CA1163154 A CA 1163154A
- Authority
- CA
- Canada
- Prior art keywords
- flow
- intake
- intake valve
- passage
- tubular member
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
- F02M29/00—Apparatus for re-atomising condensed fuel or homogenising fuel-air mixture
- F02M29/04—Apparatus for re-atomising condensed fuel or homogenising fuel-air mixture having screens, gratings, baffles or the like
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
- F02B17/00—Engines characterised by means for effecting stratification of charge in cylinders
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
- F02B2275/00—Other engines, components or details, not provided for in other groups of this subclass
- F02B2275/18—DOHC [Double overhead camshaft]
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Characterised By The Charging Evacuation (AREA)
Abstract
Abstract of the Disclosure An internal combustion engine comprises a carbure-tor, which precedes an intake passage, at least one cylinder, a piston movable in said cylinder, intake and exhaust valves and igniting means. A flow-guiding element extends in said intake passage and defines therein a flow passage which tapers along said intake passage toward the intake valve so that the velocity of flow of the fuel-air mixture flowing in said flow passage will be progressively increased. The flow-guiding element may consist of a funnel-shaped tubular member or of a flow-guiding strip. The smaller end of the tubular member is disposed close to the intake valve and near that side of the intake passage on which said igniting means are disposed relative to the intake valve. Near its end opposite to the intake valve, the tubular member has a projection, which constricts another flow passage, which surrounds the tubular member in said intake passage. The flow-guiding strip gradually approaches the boundary wall defining the intake passage on that side thereof on which said igniting means are disposed relative to said intake valve.
Description
1 ~63~
This invention relates to an internal combus-tion engine comprising a carburetor, which precedes an intake passage, at least one cylinder, a piston movable in said cylinder, intake and exhaust valves and ignit-ing means.
In such an internal combustion engine, a fuel-air mixture is sucked from the carburetor into the intake passage and flows past the valve member of the intake valve into the working chamber of the cylinder during the intake stroke. The mixture is uniformly- -distributed in the working chamber and is then com-pressed and ignited.
It is known that the conditions in the work-ing chamber can be altered in that a supply duct extends in the intake passage and terminates close to the inlet valve as far as possible from the igniting means. Air can be supplied through said supply duct so that the mixture will be depleted in a region which is remotè
from the igniting electrodes.
In connection with an internal combustion engine which has fuel-injecting means and in which air is sucked into the intake passage, it has already been suggested to inject fuel into the intake passage and to guide the injected fuel along a fuel-guiding element to the valve seat of the intake valve on the side on which ; the igniting means are disposed.
Fuel-injecting means are required in such an engine and in the proposed design the fuel~guiding element may consist of a sheet element which extends at least from the region in front of the fuel-injecting nozzle to the valve seat of the intake valve at a por-tion of the periphery of the intake passage which is disposed on the same side as the igniting means.
t S'~.y~l~'~ ~
1 1~3~4 Whereas this arrangement will also increase the concen-tration of fuel în the central region of the working chamber, the fuel-injecting means involve a certain expendi-ture and effect a locally restricted supply of fuelO
~ ost existing motor vehicles comprise carburetor engines, which will be required also in uture and should be improved to have a higher power capacity and to carry out a combustion process which produces purer exhaust gases.
It is an object of the invention so to improve an internal combustion engine which is of the kind described first hereinbefore that the operating conditions of the engine and the composition of the exhaust gases produced by it are improved; this should be accomplished without substantial structural alterations only by measures adopted in the intake passage~
This object is accomplished according to the invention by the provision of a flow-guiding element~ which extends in the intake passage and defines a flow passage which terminates above the intake valve near the igniting means and decreases iD cross-section toward said intake valve SQ that the velocity of flow of the fuel-air mixture, which is supplied to the intake passage in a uniform distri-bution over the cross-section thereof, is increased as it flows along said flow passageO
It has surprisingly been found that when the mixture is supplied to said intake paCsage in a uniform distribution over the cross-section thereof and the velocity Gf flow of the mixture is increased in a tapering flow passage, which terminates near the igniting electrodes, the resulting higher velocity of flow will result in a } 1~31~4 higher fuel concent~atîon of the fuel-air mixture in the middle of the working chamber7 near the igniting electrodes.
That higher concentration will be maintained during the intake and compression strokes so that the combustion will be lmproved. The taper of the flow passage terminatiDg as close as possible to the igniting means has necessarily the result that the other flow passage defined in the intake passage flares toward the intake valve.
As a result of that arraDgement, the mixture flows relatively slowly in said other flow passage near the intake valve so that the desired result produced by the first-mentioned flow passage is augmented. It has sur-prisingly been found that an improved com~ustion of the fuel is obtained and the engine has a higher elasticity than kno~n carburetor engines. A higher torque will be obtained even at lower speeds so that the elasticity of the internal combustion engine is improved. This result ~nay be explained by the fact that at lower speeds the concentration of the fuel-air mixture supplied at a higher velocity near the igniting means is maintained and has special effects because the inertias in the flow conditions are taken up in an improved mannerO
In a preferred embodiment, a funnel-shaped tubular member is arranged in the intake passage and khe smaller end of said tubular member is disposed at the inkake valve.
The wider end of such a funnel-shaped tubular member is remote from the intake valve and disposed in khe central region of the intake passage and the smaller end is disposed near -that boundary surface of the intake passage which is disposed on khe same side as the igniking 1 ~3~5~
means. ~ithin the scope of the invention the outlet end of the ~unnel-shaped tubular member is bevelled and arranged in such a manner that the accelerated and more highly con-centrated mixture is fed to that portion of the periphery of the valve seat of the intake valve which is Oll the same side as the igniting meansO Within the scope of the inveDtion the funnel-shaped tubular member may extend around the stem of the intake valve.
In accordance with another desirable émbodiment the inlet opening of the funnel-shaped tubular member is secured in the intake passage by radial arms. These radial arms and the outer end portion of the funnel-shaped tubular member define a constriction which influences the flow in the intake passage in a favorable manner and during the period from the beginni~g of the compression stroke to the closing of the intake valve and the period from the opening of the intake valve to the end of the exhaust stroke obstructs the blowback of the exhaust gases and tends to produce smookher flow conditions in the intake passage and to limit any reactions into the latter.
That embodiment is desirable also because the mixture which is initially uniformly distribute~ over the cross-section of the intake passage is influenced only in part of the cross~sectio~ of the intake passage in the manner described.
ln a preferred embodimen~, the funDel-shaped tubular member has near its inlet end an external boss, which constricts said other flow passage so that the pressure of the mixture is increased on the outside of the funnel-shaped tubular member adjacent to the inlet end thereof _ 4 _ l 1631~4 an~ the velocity difference iD the flowing mixture at theoutlet end of the funnel-shaped tubular member near the inlet valve is increased~
In another desirable embodiment, a strip-shaped flow-guiding element is provided in the intake passage and in the direction toward the inlet valve said flow-guiding element progressively approaches that boundary surface of the intake passage which is disposed on the same side as the igniting ~eansO
It has surprisingly been found that by such strip-shaped flow-guiding element which is arranged in a special manner and preferably has a curvature which differs from that of the intake passage, the fuel~air mixture flowing to the intake valve in a flow passage on the side on which the spark plug is disposed will be accelerated and compressed.
If a strip-shaped flow-guiding element is used, the latter will suitably be fonmed with a slot at its end that is disposed near the intake valve and the stem of the intake valve will extend through said slotO
In that embodiment, the flow passage which te~ni-nates at the intake valve on the side opposite to the igniting means is constricted near the inlet end of the intake passage by means which are carried by the strip-shaped flow-guiding elemen~ so that smoother and improved flow conditions will be obtained~
Such strip-shaped flow-guiding element may have a predetermined resiliency so that the taper of the flow : passage on one side of the strip is so influenced in de-pendence on the speed of the internal-combustion engine that the inner end of the strip-shaped flow-guiding element 1 ~3~54 will be deflected toward the middle of the intake passage or toward that side which is opposite to the igniting means at higher s-peeds of the engine and the taper of said flow passage will be increased at lower speeds~ In this way the more desirable torque characteristic of the internal combustion engine can be improved further at lower speedsO
Constricting means may also be provided on the outside of the funnel-shaped tubular member near the inlet end thereof and have preferably a radially symmetrical configurationO The diameter of the inlet opening of the funnel-shaped tubular member is suitably about 60% of the diameter of the intake passage.
The features described hereinbefore result in surprising improvements and afford the advantage that the area of the outlet opening of the funnel-shaped tubular member is about one~half the area of the inlet opening of said tubular member.
Surprisingly it has been found that the arrangement which has been described hereinbefore and in conjunctioD with an internal combustion engine affords the advantages set forth can be subsequently installed in existing carburetor engines in that a properly designed ~low-guiding element is secured to the flanged joint between the intake duct and the intake manifold. Existlng engines can easily be altered in that manner.
The invention will now be explained with reference to illustrative embodiments, which are shown in the drawing in diagrammatic and detail views. In the drawings, Figure 1 is a fragmentary elevation showing a c~linder head with the intake valve and igniting means shown in section, ~ ~63~54 Figure 2 is a view that is similar to Figure 1 and shows a modification7 Figure 3 is a view that is similar to Figure 1 and shows another modification, Figure 4 is a top plan view showing a detail of Figure 3 and Figure 5 is a sectional view showing an internal combustion engine viewed on a plane extending through a cylinder; the internal combustion engine may comprise a plurality of in-line cylinders, the associated elements are shown only diagrammatically.
Like parts are designated with like reference characters in all Figures. This is due to the fact that the drawings show only those parts of an internal combustion engine which are essential for the invention whereas the engine ls not shown in its entirety~ The internal combustion engine is designed as usual except for the features embodying the invention~ The engine block comprises a crankcase, which contains a crankshaft, and cylinders mounted on the crank-case. Pistons are movable in said cylinders and are connectedto the crankshaft by connectiDg rodsO The engine block comprises a cylinder head member, which comprises the cylider heads4 Each cylinder head contains an intake port and an exhaust port, ~ich extend iDto and out of the working chamber of the cylind~r, and igniting means. Each of the intake and exhaust ports is provided at that end which faces the working cham~er with a valve seat for an intake valve or an exhaust valve, respectively. The stems of said valves extend throwgh the walls which define the intake and exhaust valves a~d are provided with actuators~ The latter ~ 1631~4 may consist of rocker levers and tappets, which are actuated by the crankshaft of the engineO
Igniting means are electrically connected to an electric power source via a distributor which is driven by the engi~eO
A carburetor of conventional type precedes the inlet end of the intake passage and may be connected to the intake passage by an intake manifold, through w~ich a plurality of cylinders are suppliedO
Fîgure 1 shows th~ upper portion of the cylinder 1 with the working chamber 2 9 in which a piston 3 having a piston head is reciprocableO A cylinder head 4 is mounted on the cylinder wallO An intake passage 5 extends in the cylinder head 4 on one side thereof and terminates at an intake valve seat 7. An exhaust passage 6 extends in the cylinder head 4 on the other side thereof and terminates at the exha~st valve seat 80 Igniting means ~ consisting of a spark plug are disposed centrally between the valve seats 7, 80 An intake valve member 10 is associated with the intake valve seat 7 and connected to a valve stem 11, which can be actuated in a conventional manner by a cam 14 and a bucket tappet 13, which is biased by a spring 120 The cam 14 is driven in conventional manner. An exhaust valve member 15 is associated with the exhaust valve seat 8 and carried by a va-lve stem 16, which is actuated by a cam 19 through the intermediary of a bucket tappet 18, which is biased by a spring 170 The cam 19 is also driven by the crankshaft of the engine.
~n intake ~anifold 20 is connected to the lntake passage 5 by a flanged joint 21, which is only diagrammati-cally indicated~ The intake manifold 20 is of known type and terminates at a carburetor 22, which is known per se and has inlets for fuel and air so tha~ a fuel-air mixture flows through the intake manifold 20 and is uniformly distributed over the cross-section thereofO
Figure 1 shows a funnel-shaped tu~ular member 23?
which is disposed in the central region of the intake passage 5. That end of said tubular member which faces the intake manifold 20 is connected to the flanged joint 21 by a plurality of radial arms, e.`g., three radial arms 24, 25, which protrude outwardly from the tubular member 23. The radial arms 24, 25 are integrally formed with a ring 26, which exte~ds between the flanges 21 by which the intake passage 5 and the intake manifold 20 are connected. In the embodiment shown by way of example, the inlet opening 27 of the funnel-shaped tubular member 23 is approximately cen-trally disposed in the in~ake passage 5. The outlet opening 28 of the funnel-shaped tubular member 23 is smaller than the inlet opening 27 and disposed close to or directly over the intake valve seat 7 adjacent to the center of the cylinder head 4, as close as possible to the igniting means 9O Adja-cent to its outlet opening 28, the funnel-shaped tubular member 23 is curved to extend around part of the periphery of the valve stem llo As is indicated by dotted lines iD
Figure 1, the tubular member may have a beveled end face 29 surrounding the outlet opening 28 so that the latter Eaces the igniting means 9~
In this arrangement, the mixture is accelerated and compressed in the interior of the funnel-shaped tubular _ g _ l ~31~
member 23 and is enriched at the igniting electrodes 30 of the igniting means whereas the velocity of flow of the mixture is decreased outside the funnel-shaped tubular memberO
The area oE the outlet opening 28 may be about one-third of the area of the inlet opening 27.
The embodiment shown iD Figure 2 differs from the one show~ in Figure 1 by the design of the funnel-shaped tubular member 23, which near its inlet opening 27 has an external annular boss 319 which constricts the outer 10w passage 32 of the intake passage 5. This results in a build-up of dynamic pressure at the inlet opening 27 and iD an increase of the differential velocity of flow adjacent to the outlet opening 28 so that the concentratio~ of the mixture in the working chamber is increased at the igniting electrodes. The fun~el-shaped tubular member 23 contains a smooth-surfaced tubular i~sert 33 ex-tending through the annular boss 31.
The design described hereinbefore, in which a funnel-shaped tubular member 23 is provided which has a centrally disposed inlet opening 27, is preferred. In a different embodiment,. shown in Figures 3 and 4, the intake passage 5 contains a tapered flow passage 34, which leads to the intake valve seat 7 and is defined by a flow-guiding strip 36, which terminates near that boundary surface 35 of the intake passage which is disposed on the same side as the igniting electrodes 30 o~ the igniting means 90 That flow-guiding strip 36 may be secured to the flanged joint 21 by spider arms 37, 380 An eccentric arrangement of said arms, as shown in Figure 3, is preferredO Alternatively, a ~etaining 1 1$3~
plate may be provided, which extends through the flanged joints 21 and has openings which are flush with the respective intake passages 5, and holding means 46 may be provided, which extend through said openings preferably eccentrically and connect the flow-guiding s~rips 36 to said retaining plate The flow-guiding strip is secured only at the inlet end of the intake passage 5 and is self-supporting.
Because the flow-guiding strip 36 is eccentrically disposed, the flow passage 34 on one side of said strip 36 is larger in cross-section at its inlet end 39 than the flow passage 40, which is disposed on the o-ther side of the strip 36 and which near the intake valve seat 7 is larger in cross-section than the flow passage 34 at its outlet end 42.
In a comparison with the embodimen-ts shown in Figures 1 and 2, the flow passage 34 can be compared to the interior of the funnel-shaped tubular member 23 and the other flow passage 40 can be compared to that flow passage 41 which surrounds the funnel-shaped tubular memberO
Because the latter is closed throughout its periphery, it has.
special flow-guiding properties and results in a particularly desirable concentration adjacent to the outlet opening 28~
On the other hand, the design with the flow-guiding strip 36 affords the advantage that the strip 36 may be made from lightweight resilient material, such as plastic material and may be so curved that it will be deflected by the intake ~flow in dependence on the speed of the engine9 as is indi-cated by the arrow 45. The flow-guiding strip is deflected to have a curvature or if initially curved is deflected to l~ ~8315~
have a steeper curvature, as is indicated by the arrow 45, when the engine is operating at high speeds. This will auto~atically result in an adjustment by which the operation will be improved.
As is apparent from Figure 4, the flow-guiding strip 36 has a slot 43 at that end which is near the inlet ~alve 7, 10. The valve stem 11 extends through that slot 43 so that the end 44 of the strip 36 can be disposed very close to the intake valve seat 7 adjacent to the wall 35 that is disposed on the same side as the igniting means 9O
Figure 5 and its context disclose additional parts of an internal combustion engine including a cylinder 1 having a working chamber 2.
Cylinders 1 are ~ounted in line on a crankcase 50.
The cylinder walls are designatecl by the same reference characters. A cranksha~t 51 is disposed in the crankcase and is rotatably mounted in the crankcase end walls, which extend parallel to the plane of the drawing. Under each cylinder wall 1, the cran~shaft has a crankpin 52, which is connected to the ~ainshaft by crankwebs 53. The flight circle of the crankpin 52 is designated 540 The piston 3 is movable in the cylinder 1 and sealed in the latter by piston rings 57 and is connected to the associated crankpin 52 by a connectlng rod 55, which is pivoted at one end to the piston 3 by the piston pin 56 and at the other end to the associated crankpin 52. In ~igure 5 the crankpin 52 is shown in the position corresponding to the bottom dead center position oF the associated piStoD 3O The cylinder 1 is closed at its top by the cylinder head, which is only dia-grammatically indicated and contains the intake valve 10 and l 1~3 ~ ~4 an exhaus~ valve 15, which controls the communication between the cylinder 1 and the exhaust passage 6~ The intake valve 10 is represented by its valve member, which is carried by the valve stem 11~ Rather than by a tappet, the valve SteM 11 in Figure 5 is actuated by a rocker lever 59, Another rocker lever 60 serves to actuate the valve stem 16 of the exhaust valve~ Both rocker levers 59, 60 are pivoted on respective pivot pins 61, 62, which are mounted in the engine blockO
The two rocker levers are actuated by a common cam 63, which is rotated by a camshaft 64. The latter is driven from the crankshaft 51 via a reduction gear, which consists, e.g., of a cogged belt drive.
The igniting means 9 are electrically connected by a lead 66 to a distributor 67, which is mechanically connected to the camshaft 64 by a transmission 68 and is electrically connected to a battery, The valve stems are urged against the respective rocker levers 59, 60 by respeckive springs 12 an~ 17.
The valve member 10 of the intake valve cooperates with a valve seat 7 and the valve member 15 of the exhaust valve cooperates with a valve seat 8D
Air and fuel are supplied to the carburetor in conventional manner. The fuel supply means include a known fuel tank. A starter motor is connected to the crankshaft 51 in conventional mannerO
This invention relates to an internal combus-tion engine comprising a carburetor, which precedes an intake passage, at least one cylinder, a piston movable in said cylinder, intake and exhaust valves and ignit-ing means.
In such an internal combustion engine, a fuel-air mixture is sucked from the carburetor into the intake passage and flows past the valve member of the intake valve into the working chamber of the cylinder during the intake stroke. The mixture is uniformly- -distributed in the working chamber and is then com-pressed and ignited.
It is known that the conditions in the work-ing chamber can be altered in that a supply duct extends in the intake passage and terminates close to the inlet valve as far as possible from the igniting means. Air can be supplied through said supply duct so that the mixture will be depleted in a region which is remotè
from the igniting electrodes.
In connection with an internal combustion engine which has fuel-injecting means and in which air is sucked into the intake passage, it has already been suggested to inject fuel into the intake passage and to guide the injected fuel along a fuel-guiding element to the valve seat of the intake valve on the side on which ; the igniting means are disposed.
Fuel-injecting means are required in such an engine and in the proposed design the fuel~guiding element may consist of a sheet element which extends at least from the region in front of the fuel-injecting nozzle to the valve seat of the intake valve at a por-tion of the periphery of the intake passage which is disposed on the same side as the igniting means.
t S'~.y~l~'~ ~
1 1~3~4 Whereas this arrangement will also increase the concen-tration of fuel în the central region of the working chamber, the fuel-injecting means involve a certain expendi-ture and effect a locally restricted supply of fuelO
~ ost existing motor vehicles comprise carburetor engines, which will be required also in uture and should be improved to have a higher power capacity and to carry out a combustion process which produces purer exhaust gases.
It is an object of the invention so to improve an internal combustion engine which is of the kind described first hereinbefore that the operating conditions of the engine and the composition of the exhaust gases produced by it are improved; this should be accomplished without substantial structural alterations only by measures adopted in the intake passage~
This object is accomplished according to the invention by the provision of a flow-guiding element~ which extends in the intake passage and defines a flow passage which terminates above the intake valve near the igniting means and decreases iD cross-section toward said intake valve SQ that the velocity of flow of the fuel-air mixture, which is supplied to the intake passage in a uniform distri-bution over the cross-section thereof, is increased as it flows along said flow passageO
It has surprisingly been found that when the mixture is supplied to said intake paCsage in a uniform distribution over the cross-section thereof and the velocity Gf flow of the mixture is increased in a tapering flow passage, which terminates near the igniting electrodes, the resulting higher velocity of flow will result in a } 1~31~4 higher fuel concent~atîon of the fuel-air mixture in the middle of the working chamber7 near the igniting electrodes.
That higher concentration will be maintained during the intake and compression strokes so that the combustion will be lmproved. The taper of the flow passage terminatiDg as close as possible to the igniting means has necessarily the result that the other flow passage defined in the intake passage flares toward the intake valve.
As a result of that arraDgement, the mixture flows relatively slowly in said other flow passage near the intake valve so that the desired result produced by the first-mentioned flow passage is augmented. It has sur-prisingly been found that an improved com~ustion of the fuel is obtained and the engine has a higher elasticity than kno~n carburetor engines. A higher torque will be obtained even at lower speeds so that the elasticity of the internal combustion engine is improved. This result ~nay be explained by the fact that at lower speeds the concentration of the fuel-air mixture supplied at a higher velocity near the igniting means is maintained and has special effects because the inertias in the flow conditions are taken up in an improved mannerO
In a preferred embodiment, a funnel-shaped tubular member is arranged in the intake passage and khe smaller end of said tubular member is disposed at the inkake valve.
The wider end of such a funnel-shaped tubular member is remote from the intake valve and disposed in khe central region of the intake passage and the smaller end is disposed near -that boundary surface of the intake passage which is disposed on khe same side as the igniking 1 ~3~5~
means. ~ithin the scope of the invention the outlet end of the ~unnel-shaped tubular member is bevelled and arranged in such a manner that the accelerated and more highly con-centrated mixture is fed to that portion of the periphery of the valve seat of the intake valve which is Oll the same side as the igniting meansO Within the scope of the inveDtion the funnel-shaped tubular member may extend around the stem of the intake valve.
In accordance with another desirable émbodiment the inlet opening of the funnel-shaped tubular member is secured in the intake passage by radial arms. These radial arms and the outer end portion of the funnel-shaped tubular member define a constriction which influences the flow in the intake passage in a favorable manner and during the period from the beginni~g of the compression stroke to the closing of the intake valve and the period from the opening of the intake valve to the end of the exhaust stroke obstructs the blowback of the exhaust gases and tends to produce smookher flow conditions in the intake passage and to limit any reactions into the latter.
That embodiment is desirable also because the mixture which is initially uniformly distribute~ over the cross-section of the intake passage is influenced only in part of the cross~sectio~ of the intake passage in the manner described.
ln a preferred embodimen~, the funDel-shaped tubular member has near its inlet end an external boss, which constricts said other flow passage so that the pressure of the mixture is increased on the outside of the funnel-shaped tubular member adjacent to the inlet end thereof _ 4 _ l 1631~4 an~ the velocity difference iD the flowing mixture at theoutlet end of the funnel-shaped tubular member near the inlet valve is increased~
In another desirable embodiment, a strip-shaped flow-guiding element is provided in the intake passage and in the direction toward the inlet valve said flow-guiding element progressively approaches that boundary surface of the intake passage which is disposed on the same side as the igniting ~eansO
It has surprisingly been found that by such strip-shaped flow-guiding element which is arranged in a special manner and preferably has a curvature which differs from that of the intake passage, the fuel~air mixture flowing to the intake valve in a flow passage on the side on which the spark plug is disposed will be accelerated and compressed.
If a strip-shaped flow-guiding element is used, the latter will suitably be fonmed with a slot at its end that is disposed near the intake valve and the stem of the intake valve will extend through said slotO
In that embodiment, the flow passage which te~ni-nates at the intake valve on the side opposite to the igniting means is constricted near the inlet end of the intake passage by means which are carried by the strip-shaped flow-guiding elemen~ so that smoother and improved flow conditions will be obtained~
Such strip-shaped flow-guiding element may have a predetermined resiliency so that the taper of the flow : passage on one side of the strip is so influenced in de-pendence on the speed of the internal-combustion engine that the inner end of the strip-shaped flow-guiding element 1 ~3~54 will be deflected toward the middle of the intake passage or toward that side which is opposite to the igniting means at higher s-peeds of the engine and the taper of said flow passage will be increased at lower speeds~ In this way the more desirable torque characteristic of the internal combustion engine can be improved further at lower speedsO
Constricting means may also be provided on the outside of the funnel-shaped tubular member near the inlet end thereof and have preferably a radially symmetrical configurationO The diameter of the inlet opening of the funnel-shaped tubular member is suitably about 60% of the diameter of the intake passage.
The features described hereinbefore result in surprising improvements and afford the advantage that the area of the outlet opening of the funnel-shaped tubular member is about one~half the area of the inlet opening of said tubular member.
Surprisingly it has been found that the arrangement which has been described hereinbefore and in conjunctioD with an internal combustion engine affords the advantages set forth can be subsequently installed in existing carburetor engines in that a properly designed ~low-guiding element is secured to the flanged joint between the intake duct and the intake manifold. Existlng engines can easily be altered in that manner.
The invention will now be explained with reference to illustrative embodiments, which are shown in the drawing in diagrammatic and detail views. In the drawings, Figure 1 is a fragmentary elevation showing a c~linder head with the intake valve and igniting means shown in section, ~ ~63~54 Figure 2 is a view that is similar to Figure 1 and shows a modification7 Figure 3 is a view that is similar to Figure 1 and shows another modification, Figure 4 is a top plan view showing a detail of Figure 3 and Figure 5 is a sectional view showing an internal combustion engine viewed on a plane extending through a cylinder; the internal combustion engine may comprise a plurality of in-line cylinders, the associated elements are shown only diagrammatically.
Like parts are designated with like reference characters in all Figures. This is due to the fact that the drawings show only those parts of an internal combustion engine which are essential for the invention whereas the engine ls not shown in its entirety~ The internal combustion engine is designed as usual except for the features embodying the invention~ The engine block comprises a crankcase, which contains a crankshaft, and cylinders mounted on the crank-case. Pistons are movable in said cylinders and are connectedto the crankshaft by connectiDg rodsO The engine block comprises a cylinder head member, which comprises the cylider heads4 Each cylinder head contains an intake port and an exhaust port, ~ich extend iDto and out of the working chamber of the cylind~r, and igniting means. Each of the intake and exhaust ports is provided at that end which faces the working cham~er with a valve seat for an intake valve or an exhaust valve, respectively. The stems of said valves extend throwgh the walls which define the intake and exhaust valves a~d are provided with actuators~ The latter ~ 1631~4 may consist of rocker levers and tappets, which are actuated by the crankshaft of the engineO
Igniting means are electrically connected to an electric power source via a distributor which is driven by the engi~eO
A carburetor of conventional type precedes the inlet end of the intake passage and may be connected to the intake passage by an intake manifold, through w~ich a plurality of cylinders are suppliedO
Fîgure 1 shows th~ upper portion of the cylinder 1 with the working chamber 2 9 in which a piston 3 having a piston head is reciprocableO A cylinder head 4 is mounted on the cylinder wallO An intake passage 5 extends in the cylinder head 4 on one side thereof and terminates at an intake valve seat 7. An exhaust passage 6 extends in the cylinder head 4 on the other side thereof and terminates at the exha~st valve seat 80 Igniting means ~ consisting of a spark plug are disposed centrally between the valve seats 7, 80 An intake valve member 10 is associated with the intake valve seat 7 and connected to a valve stem 11, which can be actuated in a conventional manner by a cam 14 and a bucket tappet 13, which is biased by a spring 120 The cam 14 is driven in conventional manner. An exhaust valve member 15 is associated with the exhaust valve seat 8 and carried by a va-lve stem 16, which is actuated by a cam 19 through the intermediary of a bucket tappet 18, which is biased by a spring 170 The cam 19 is also driven by the crankshaft of the engine.
~n intake ~anifold 20 is connected to the lntake passage 5 by a flanged joint 21, which is only diagrammati-cally indicated~ The intake manifold 20 is of known type and terminates at a carburetor 22, which is known per se and has inlets for fuel and air so tha~ a fuel-air mixture flows through the intake manifold 20 and is uniformly distributed over the cross-section thereofO
Figure 1 shows a funnel-shaped tu~ular member 23?
which is disposed in the central region of the intake passage 5. That end of said tubular member which faces the intake manifold 20 is connected to the flanged joint 21 by a plurality of radial arms, e.`g., three radial arms 24, 25, which protrude outwardly from the tubular member 23. The radial arms 24, 25 are integrally formed with a ring 26, which exte~ds between the flanges 21 by which the intake passage 5 and the intake manifold 20 are connected. In the embodiment shown by way of example, the inlet opening 27 of the funnel-shaped tubular member 23 is approximately cen-trally disposed in the in~ake passage 5. The outlet opening 28 of the funnel-shaped tubular member 23 is smaller than the inlet opening 27 and disposed close to or directly over the intake valve seat 7 adjacent to the center of the cylinder head 4, as close as possible to the igniting means 9O Adja-cent to its outlet opening 28, the funnel-shaped tubular member 23 is curved to extend around part of the periphery of the valve stem llo As is indicated by dotted lines iD
Figure 1, the tubular member may have a beveled end face 29 surrounding the outlet opening 28 so that the latter Eaces the igniting means 9~
In this arrangement, the mixture is accelerated and compressed in the interior of the funnel-shaped tubular _ g _ l ~31~
member 23 and is enriched at the igniting electrodes 30 of the igniting means whereas the velocity of flow of the mixture is decreased outside the funnel-shaped tubular memberO
The area oE the outlet opening 28 may be about one-third of the area of the inlet opening 27.
The embodiment shown iD Figure 2 differs from the one show~ in Figure 1 by the design of the funnel-shaped tubular member 23, which near its inlet opening 27 has an external annular boss 319 which constricts the outer 10w passage 32 of the intake passage 5. This results in a build-up of dynamic pressure at the inlet opening 27 and iD an increase of the differential velocity of flow adjacent to the outlet opening 28 so that the concentratio~ of the mixture in the working chamber is increased at the igniting electrodes. The fun~el-shaped tubular member 23 contains a smooth-surfaced tubular i~sert 33 ex-tending through the annular boss 31.
The design described hereinbefore, in which a funnel-shaped tubular member 23 is provided which has a centrally disposed inlet opening 27, is preferred. In a different embodiment,. shown in Figures 3 and 4, the intake passage 5 contains a tapered flow passage 34, which leads to the intake valve seat 7 and is defined by a flow-guiding strip 36, which terminates near that boundary surface 35 of the intake passage which is disposed on the same side as the igniting electrodes 30 o~ the igniting means 90 That flow-guiding strip 36 may be secured to the flanged joint 21 by spider arms 37, 380 An eccentric arrangement of said arms, as shown in Figure 3, is preferredO Alternatively, a ~etaining 1 1$3~
plate may be provided, which extends through the flanged joints 21 and has openings which are flush with the respective intake passages 5, and holding means 46 may be provided, which extend through said openings preferably eccentrically and connect the flow-guiding s~rips 36 to said retaining plate The flow-guiding strip is secured only at the inlet end of the intake passage 5 and is self-supporting.
Because the flow-guiding strip 36 is eccentrically disposed, the flow passage 34 on one side of said strip 36 is larger in cross-section at its inlet end 39 than the flow passage 40, which is disposed on the o-ther side of the strip 36 and which near the intake valve seat 7 is larger in cross-section than the flow passage 34 at its outlet end 42.
In a comparison with the embodimen-ts shown in Figures 1 and 2, the flow passage 34 can be compared to the interior of the funnel-shaped tubular member 23 and the other flow passage 40 can be compared to that flow passage 41 which surrounds the funnel-shaped tubular memberO
Because the latter is closed throughout its periphery, it has.
special flow-guiding properties and results in a particularly desirable concentration adjacent to the outlet opening 28~
On the other hand, the design with the flow-guiding strip 36 affords the advantage that the strip 36 may be made from lightweight resilient material, such as plastic material and may be so curved that it will be deflected by the intake ~flow in dependence on the speed of the engine9 as is indi-cated by the arrow 45. The flow-guiding strip is deflected to have a curvature or if initially curved is deflected to l~ ~8315~
have a steeper curvature, as is indicated by the arrow 45, when the engine is operating at high speeds. This will auto~atically result in an adjustment by which the operation will be improved.
As is apparent from Figure 4, the flow-guiding strip 36 has a slot 43 at that end which is near the inlet ~alve 7, 10. The valve stem 11 extends through that slot 43 so that the end 44 of the strip 36 can be disposed very close to the intake valve seat 7 adjacent to the wall 35 that is disposed on the same side as the igniting means 9O
Figure 5 and its context disclose additional parts of an internal combustion engine including a cylinder 1 having a working chamber 2.
Cylinders 1 are ~ounted in line on a crankcase 50.
The cylinder walls are designatecl by the same reference characters. A cranksha~t 51 is disposed in the crankcase and is rotatably mounted in the crankcase end walls, which extend parallel to the plane of the drawing. Under each cylinder wall 1, the cran~shaft has a crankpin 52, which is connected to the ~ainshaft by crankwebs 53. The flight circle of the crankpin 52 is designated 540 The piston 3 is movable in the cylinder 1 and sealed in the latter by piston rings 57 and is connected to the associated crankpin 52 by a connectlng rod 55, which is pivoted at one end to the piston 3 by the piston pin 56 and at the other end to the associated crankpin 52. In ~igure 5 the crankpin 52 is shown in the position corresponding to the bottom dead center position oF the associated piStoD 3O The cylinder 1 is closed at its top by the cylinder head, which is only dia-grammatically indicated and contains the intake valve 10 and l 1~3 ~ ~4 an exhaus~ valve 15, which controls the communication between the cylinder 1 and the exhaust passage 6~ The intake valve 10 is represented by its valve member, which is carried by the valve stem 11~ Rather than by a tappet, the valve SteM 11 in Figure 5 is actuated by a rocker lever 59, Another rocker lever 60 serves to actuate the valve stem 16 of the exhaust valve~ Both rocker levers 59, 60 are pivoted on respective pivot pins 61, 62, which are mounted in the engine blockO
The two rocker levers are actuated by a common cam 63, which is rotated by a camshaft 64. The latter is driven from the crankshaft 51 via a reduction gear, which consists, e.g., of a cogged belt drive.
The igniting means 9 are electrically connected by a lead 66 to a distributor 67, which is mechanically connected to the camshaft 64 by a transmission 68 and is electrically connected to a battery, The valve stems are urged against the respective rocker levers 59, 60 by respeckive springs 12 an~ 17.
The valve member 10 of the intake valve cooperates with a valve seat 7 and the valve member 15 of the exhaust valve cooperates with a valve seat 8D
Air and fuel are supplied to the carburetor in conventional manner. The fuel supply means include a known fuel tank. A starter motor is connected to the crankshaft 51 in conventional mannerO
Claims (14)
1. In an internal combustion engine comprising at least one cylinder, a piston adapted to reciprocate in said cylinder:
and defining a working chamber therewith, an intake valve and an exhaust valve communicating with said working chamber, igniting means exposed to said working chamber on one side of said intake valve, a carburetor for delivering a fuel-air mixture, an intake passage which is directly connected at one end to said intake valve and at the other end communi-cates with said carburetor and is arranged to receive said mixture from said carburetor in a substantially uniform pressure and concentration distribution over the cross-section of said intake passage at said other end thereof, and a flow-guiding element extending in said intake passage generally in the logitudinal direction thereof and dividing said intake passage into first and second flow passages, the improvement residing in that said flow-guiding element terminates at said intake valve near that side of said intake passage on which said igniting means are disposed relative to said intake valve, said first flow passage terminates near that side of said intake passage on which said igniting means are disposed relative to said intake valve, and said first flow passage tapers toward said intake valve.
and defining a working chamber therewith, an intake valve and an exhaust valve communicating with said working chamber, igniting means exposed to said working chamber on one side of said intake valve, a carburetor for delivering a fuel-air mixture, an intake passage which is directly connected at one end to said intake valve and at the other end communi-cates with said carburetor and is arranged to receive said mixture from said carburetor in a substantially uniform pressure and concentration distribution over the cross-section of said intake passage at said other end thereof, and a flow-guiding element extending in said intake passage generally in the logitudinal direction thereof and dividing said intake passage into first and second flow passages, the improvement residing in that said flow-guiding element terminates at said intake valve near that side of said intake passage on which said igniting means are disposed relative to said intake valve, said first flow passage terminates near that side of said intake passage on which said igniting means are disposed relative to said intake valve, and said first flow passage tapers toward said intake valve.
2. The improvement set forth in claim 1, wherein said second flow passage flares toward said intake valve.
3. The improvement set forth in claim 1, wherein said flow-guiding element consists of a tubular member, which tapers toward said intake valve and internally defines said first flow passage.
4. The improvement set forth in claim 3, wherein said tubular member has at said intake valve an end face which is oblique to the axis of said tubu-lar member and defines an outlet opening which faces said igniting means.
5. The improvement set forth in claim 3, as applied to an internal combustion engine in which said intake valve comprises a valve stem, wherein said tubular member extends past said valve stem.
6. The improvement set forth in claim 3, wherein said tubular member has an inlet end which is remote from said intake valve and is held in position in said intake passage by radial arms.
7. The improvement set forth in claim 3, wherein said tubular member has near its end opposite to said intake valve an external annular peripheral boss, which constricts said second flow passage.
8. The improvement set forth in claim 7, wherein said tubular member has adjacent to said boss an inside surface portion which is flush with the axially adjacent inside surface portions of said tubular member.
9. The improvement set forth in claim 3, wherein the inside cross-sectional area of said tubular member at said end that is disposed at said intake valve is about one-half the cross-sectional area of said tubular member at the opposite end.
10. The improvement set forth in claim 1, as applied to an internal combustion engine in which said flow-guiding element in said intake passage is strip-shaped, wherein said strip-shaped flow-guiding element progressively approaches the boundary surface of said intake passage on that side thereof on which said igniting means are disposed relative to said intake valve.
11. The improvement set forth in claim 10, as applied to an internal combustion engine in which said intake valve comprises a valve stem, wherein said strip-shaped flow-guiding element is formed with a slot at its end disposed at said intake valve and said valve stem extends through said slot.
12. The improvement set forth in claim 10, wherein said strip-shaped flow-guiding element is secured only at the inlet end of said intake passage and said strip-shaped flow-guiding element is self-supporting and resilient.
13. The improvement set forth in claim 12, wherein said strip-shaped flow-guiding element consists of a rela-tively stiff, flexible material.
14. The improvement set forth in claim 1, wherein the first and second flow passages are open to the carbu-rator and said flow guiding element is provided as means for increasing the velocity of flow of the fuel-air mix-ture, which is supplied to the intake passage in a uniform distribution over the cross-section thereof, which increas-ing the velocity of flow of fuel-air mixture is pro-vided in the first flow passage.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DEP3100343.5 | 1981-01-08 | ||
| DE19813100343 DE3100343A1 (en) | 1981-01-08 | 1981-01-08 | Combustion engine |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1163154A true CA1163154A (en) | 1984-03-06 |
Family
ID=6122313
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000392653A Expired CA1163154A (en) | 1981-01-08 | 1981-12-18 | Internal combustion engine |
Country Status (2)
| Country | Link |
|---|---|
| CA (1) | CA1163154A (en) |
| DE (1) | DE3100343A1 (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2319298A (en) * | 1996-11-19 | 1998-05-20 | Ford Motor Co | Intake system for a stratified charge i.c. engine |
| JP7204515B2 (en) * | 2019-02-15 | 2023-01-16 | 株式会社Subaru | engine intake system |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE146727C (en) * | ||||
| DE513439C (en) * | 1929-04-26 | 1930-11-27 | Kohlentechnik M B H Ges | Device for after-atomizing a heavy oil-air mixture which is used to operate internal combustion engines and is supplied by a carburetor |
| DE1259941B (en) * | 1963-10-31 | 1968-02-01 | Siemens Ag | Message transmission system for transmission of pulse-modulated signal voltages via cables |
| DE2135825A1 (en) * | 1971-07-17 | 1973-02-01 | Bosch Gmbh Robert | CONTROL OF INLET AND EXHAUST VALVES OF COMBUSTION MACHINES |
| JPS529713A (en) * | 1975-07-10 | 1977-01-25 | Ibbott Jack Kenneth | Method and apparatus for improvement of rate of evaporation of volatile fuel in internal combustion engine |
| DE3029436A1 (en) * | 1980-08-02 | 1982-03-04 | Walter 2105 Seevetal Franke | Spark ignition IC engine operation - involves fuel injection into inlet duct and deflected to produce rich mixt. at spark plug electrodes |
-
1981
- 1981-01-08 DE DE19813100343 patent/DE3100343A1/en not_active Withdrawn
- 1981-12-18 CA CA000392653A patent/CA1163154A/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| DE3100343A1 (en) | 1982-07-15 |
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