US2658489A - Internal-combustion engine - Google Patents

Description

Nov. 10, 1953 1 J -r 2,658,489

INTERNAL-COMBUSTION ENGINE Filed March 14, 1952 2 Sheets-Sheet 1 INVENTOR. J. Laws PUTTY FITTORIYEY 2 Sheets-Sheet, 2

flTTORNEY NOV. 10, 1953 J 1 PUTT INTERNAL-COMBUSTION ENGINE Filed March 14, 1952 Patented Nov. 10, 1953 UNITED STATES @ATENT OFFICE INTERNAL-COMBUSTION ENGINE J Lewis Putt, Huntington Station, N. Y.

Application March 14, 1952, Serial No. 276,500

13 Claims. 3

The present invention relates to internal combustion engines, and more particularly to vaporization systems for the volatile liquid fuel supplied to such engines.

The engine of the present invention is similar in certain respects to the engine shown in my copending application, Ser. No. 214,257 filed March 7, 1951 for an Internal Combustion Engine and now Patent No. 2,598,300 issued May 27, 1952.

An object of the invention is to provide a fuel supply system in which a mixture of air and vaporized fuel is maintained under pressure in immediate proximity to the fuel intake valve of an internal combustion engine.

Another object of the invention is to provide improved vaporization means for mixing the fuel with compressed air to form the combustible mixture used by the internal combustion engme.

A further object of the invention is the provision of improved throttling means for controlling the engine speed.

Still another object of the invention is the provision of means for vaporizing the volatile liquid fuel and admitting the mixture of air and vapor into the intake manifold in synchronism with the reciprocating action of the engine piston, so that the amount of mixture available to the engine will increase as the engine speed increases.

Other and further objects will become apparent upon reading the following specification together with the accompanying drawing forming a part thereof.

Referring to the drawing:

Fig. l is an end view, partly in section, of an internal combustion engine embodying the invention;

Fig. 2 is an enlarged vertical sectional view of a fuel control and vaporization apparatus in accordance with the invention;

Fig. 3 is a vertical sectional view taken along the line 33 of Fig. 2, looking in the direction of the arrows;

Fig. 4 is a vertical sectional view taken along the line 4-4 of Fig. 2, looking in the direction of the arrows;

Fig. 5 is an unrolled view of a cylindrical control member forming a part of the throttle valve.

Fig. 6 is an enlarged fragmentary sectional View taken along the line 6-6 of Fig. 1, looking in the direction of the arrows;

Fig. 7 is a diagrammatic representation of a modified form of the invention.

Referring to Fig. 1, an internal combustio engine, designated generally as I0, is shown comprising a cylinder II having a piston I2 slidably mounted therein, the piston I2 being provided with the usual piston rings I 3. The piston I2 is provided with a wrist pin l4 which is connected by a connecting rod I5 with a crank arm I6 of a crankshaft H.

The engine i9 is of the four cycle type, and the cylinder Il may be one of a plurality of cylinders. The engine is shown provided with an intake manifold I8 which communicates with the upper end of the cylinder II through an intake valve I9 disposed in the engine head 29. Intake valve I9 is operated in conventional manner, usually by a camshaft (not shown) which revolves at one-half the speed of the crankshaft II. Similarly disposed in the engine head is an exhaust valve 2| which operates in synchronism with intake valve I 9 in the usual manner, and which communicates with an exhaust manifold 22. The fuel charge is ignited in conventional manner by a spark plug 23.

A cam 24 is carried by crankshaft H to rotate therewith, and alternately engages the cam followers 25 and 26 with its rounded end portion.

The crankcase 21 of engine I9 is airtight, and air intake and outlet valves 28 and 29, respectively, cooperate therewith and'with the lower end of piston I2 to form an air compressor. Air intake valve 28 comprises a horizontally extending valve stem 28a which carries a valve member 30 arranged to seat in closing relationship in a valve seat 3| at one side of crankcase '21. Valve member 21 is yieldingly urged into closing relationship with valve seat 3| by a helical compression spring 32 which surrounds valve stem 29, and is forced open by engagement cam 24 with the cam follower 25 which is disposed at one end of valve stem 29.

The air outlet valve 29 similarly comprises a valve stem 33 which extends horizontally in the same direction as air intake valve stem 29, but at the opposite side of crankcase 21. The air outlet valve stem carries a valve member 34 arranged to seat in closing relationship in a valve seat 35, being yieldingly urged into closing relationship by a helical compression spring 35. Valve 29 is forced open by engagement of cam 24 with cam follower 25 which is disposed at one end of valve stem 33.

Air is drawn into crankcase 21 by piston I2 during its upstroke under control of air intake valve 28 through an air inlet duct 3'! shown provided at its upper end with an air filter 38.

i ture outlet passage 58 which passes through the interior thereof.

At one side thereof, body 54 has upper and lower air inlet passages 59 and 60 therein which communicate via upper and lower air ducts 6| and 62 with the upper and lower outlet passages and 52, respectively, of the throttle valve 40.

Disposed within body 54 and extending inwardly and downwardly from one wall thereof To facilitate an understanding of the'inven- 10 immediatelyabove the' lower air inlet passage 60, tion, the following chart illustrates the relative is a further baflie 63 which guides air entering conditions of the several valves. the body 54 through the lower air inlet passage Engine Engine Air Air Mixtfna Intake Exhaust" Intake 1 Outlet reap lied g Valve Valve Valve Valve to Intake to C 19 21 2s 29 Marigold i Downstroke Intake Open. Closed. Closed O pen Yes Yes. Upstroke Compression Glosed.. do Open Closed. No No. Downstroke Combustion; l do ,do jOlosedia 0pen. Yes No. Upstroke Exhaust .v -do Open Open. ,C1osed No No.

From theabove'table', it will be see'nthat dii'n- 60 downwardly and toward the center of the ing' the two downstroke's of each four cycle," the vaporizer 41. fuel mixture is supplied to intake manifold 8 volatile liquid fuel 64 within body 54 is under pressure; and during the single intake maintained at-constant level by a valve member downstroke of each four cycl'e's,'i't isajdmittedin'to 65 disposed to engage a valve: seat- 66 in closing the upper portion of cylinder being at the 30 relationship therewith when urged upwardly. A

same" time drawn in by pressure accompanying the'downstrokeof the piston 2'.

The throttle or control valve 40; which regulates the how of air to the pressure vaporizer 41, comprises a valve body 43 having an inlet passage 4-4 therein to which the air outlet duct 35 39' is shown threadedly connected. Rotatably di'sp'osed in valve" body 4'3 and coaxially with the inlet passage 44- isa hollow cylindrical" control niember 45 which is open: atone end communicating with inlet passage 44'; and is closed atthe other end by an operating member 46 to. which it is secured; Valve" operating member 48' carries" an upwardly projecting throttle lever 41 whose upper end may be connected to a' link 48, which in the case of an automobile, for example; would extend to theaccelerator pedal;

The cylindrical control member 45' is provided with upper' and lower control' apertures 48 and 50; respectively, which are movablelto' communicate with upper and lower outlet passages 5| and 52,.respectively.

As may best be seen in Fig. 5, which shows the hollow cylindrical control member 45- an unrolled or developed view, the upper control aperture 49- is of constant width, whereas the lower aperture-tapers to a point-at 53'. The'narrow, portion 53 is first-brought intogpos-ition to admit air through the lower controlaaperture into the lower outlet passage 5| as the valvecontrol member is rotated from its closed position to its position whereair is first permitted topass. Accordingly, for the initial portion of the rotation of valve control member 45',- a relatively slowly increasing amount ofair is permitted to pass into the lower outlet passage- 52, the rate of'rincrease becoming greater as the valve control member 45 rotates progressively toward its fully open position. v I l The pressure vaporizer 4|. comprises a body 54 having an upwardly projecting dome portion centrally disposed in the upper side thereof. Disposed directly beneath the dome 55 is a fuel mixture outlet pipe 56 which carries a downwardly extending conical, bafile 51. at its upper end, and the outlet pipe 56 provides a fuel mixhollow float 61 is carried by an arm 68 atone end thereof, the other end'of" arm 68* being pivo'tally" secured to a bracket '66 fixed to: the side wall 1-0 of body 54. A valve operating rod TI is pivotally connected to= arm 68' at 7-1 and its lower end isattachedto' valve member 65. Valve operating rod H is freely slid'able through a guide-bracket T3 fixed to the side wall HT of body 54 below the bracket 69. Fuel at: suitable pressure is supplied by a fuel supply line 14, and enters the body 54 until the fuel level rises to a point where flbat 61 raises" valve member 65 into closing engagement with the valve seat 64 When the level of fuel 64 drops, float- 61 moves dbwnwardly, moving rod TI and valve member 65 downwardly and thereby opening the passage between valve member 65 and valve seat 65, so that fuel may again enter body 54' rrom: the fuel supply'line 14.

At the bottom of body 54, and disposed beneath the fuel mixture outlet pipe 55 is a check valve 15. The check valve 15 is shown comprising a valve member 16 carried by a valve stem ('1 having a head 18 thereon and arranged to seat'in closing engagement with a valve seat 19. Valve member 16 is yieldingly urged into closing engagement with the valve seat" 19 by a helical compression spring 19 which surrounds valve stem 11. The upper end of compression spring 19a bears against head 18 of valve stem' 11 and the lower end presses against a bottom wall which extends transversely across fuel mixture outlet pipe 56, and has apertures 8| therein to permit the passage of fuel mixture therethrough. Check valve 15 thus permits fuel mixture to pass into the fuel mixture supply duct 42, but will not permit it to return into the vaporizer 4|, thus permitting the fuel mixture to build up' pressure in the fuel mixture supply duct 42 and in the engine intake manifold I8.

In operation, twice during each four cycles, air will pass from the air outlet valve 29 in crankcase 21 through air outlet duct 39 and throttle valve 40 to the pressure vaporizer 4|. Part of the air enters vaporizer 4| through the upper air inlet passage 59 and at the same time the remainder enters through the lower air inlet passage 553. The air in passing through the lower air duct 52 mixes with fuel which is present therein as a result of the level of the fuel 54 within the body 54 of vaporizer 4!.

At the same time air in the lower air duct 62, then enters the vaporizer 4| and is deflected downwardly by the bafiie 63 to prolong its travel in contact with the fuel 64. This air then bubbles upwardly through the fuel 64, and after passing around the conical bafiie 51, enters the fuel mixture outlet passage 58 along with air which has entered the body 54 of the vaporizer directly through the upper air inlet passage 59 without entering into contact with any fuel. The direct air from the upper air inlet passage 59 completes the vaporization of any minute droplets of fuel which may have been carried upward past the conical baifle 57 by the vaporizing air.

As the valve 49 is progressively opened, the H amount of vaporizing air entering through the lower inlet 59 is relatively small, while the direct air entering through the upper inlet 59 is relatively greater, because of the relative shapes of the control apertures 49 and 59 in the control member 45. The shapes shown are illustrative, and will be arranged in practice to provide the most efficient air to fuel ratio for the particular engine speed corresponding to each throttle position, the richness of the fuel mixture being appropriate for the operating characteristics of the particular internal combustion engine involved.

Twice during each four cycles of the engine, air will pass through vaporizer 4! into the supply duct 42 and thence to the engine intake manifold l3, where it may build up pressure by reason of the action of the check valve 15. Thus, an initial charge of fuel mixture enters the supply duct 42 during the first downstroke when the engine intake valve 19 is open, and passes directly into the cylinder H. During the next downstroke, which is the power or combustion stroke, the intake valve 19 remains closed, and the fuel mixture builds up pressure in the supply duct 42 and intake manifold 18, awaiting the opening of the intake valve l9 at the beginning of the next downstroke.

Fig. 7 illustrates a modified form of the invention in which air is supplied from an air storage tank 9| which is furnished with compressed air by a compressor 92 through a pipe 93. Compressor 92 may be of any desired type and may be driven by any desired source of power, the usual arrangements being provided to maintain the air pressure within the storage tank 9| at a substantially constant pressure.

Air from storage tank 9| passes through a pipe 94 to a control valve 95 which is provided with an actuating lever 98 which opens and closes the valve. Actuating lever 96 is connected by a connecting rod 9'! with a crank 98 carried by crankshaft ll. Crank 98 is so positioned on crankshaft ll as to cause the valve 95 to open during each of the two downstrokes of each four cycles in the same manner as the air outlet valve 29 of Fig. 1 described above. This admits air to the throttle valve 49 twice during each cycle, and the operation is thereafter the same as described above for Fig. 1, the air passing from throttle valve 4s into the pressure vaporizer 4|.

The volume of the space in the pressure vaporizer above the maximum liquid fuel level plus the volume of the space within tube 56 and in intake manifold 18 is preferably not substantially less than the volume of the space in the cylinder Ii above the piston l2 when the latter 6 is in its downmost position, to obtain best results.

I have shown what I believe to be the best embodiments of my invention. I do not wish, however, to be confined to the embodiments shown, but what I desire to secure by Letters Patent, is the invention as defined in the appended claims.

I claim:

1. In a fuel supply system for a four cycle engine having a crankshaft, an intake manifold adapted to receive a fuel mixture, and an intake valve controlled by said crankshaft and communicating with said manifold, said valve open ing once during a portion of alternate revolutions of said crankshaft, a pressure vaporizer communicating with said manifold for supplying said fuel mixture thereto, means operative once during each revolution of said crankshaft including said portion of alternate revolutions when said intake valve is open, for supplying air under pressure to said vaporizer, and check valve means interposed between said pressure vaporizer and said manifold for preventing flow of said fuel mixture from said manifold back into said vaporizer.

2. A system according to claim 1, further comprising throttle means disposed to regulate the amount of air under pressure admitted to the pressure vaporizer during each crankshaft revolution.

3. A system according to claim 2 wherein said pressure vaporizer comprises an inlet for vaporizing air which comes into direct contact with the fuel and an inlet for air which mixes with the vaporizing air after the contact between the vaporizing air and the fuel has been completed, and in which the throttle means comprises means for separately controlling the flow rates of the air supplied to said two inlets to control the richness of the fuel mixture simultaneously with the control of the total amount of air.

4. A system according to claim 1, wherein said means operative once during each revolution of said crankshaft comprises a source of compressed air, a control valve connected to said source, an air duct connecting said pressure vaporizer to said control valve, and means controlled by said crankshaft and operative once during each revolution thereof for opening said control valve.

5. In a fuel supply system for a four cycle engine, said engine having a crankshaft, an intake manifold adapted to receive a fuel mixture, and an intake valve controlled by said crankshaft and communicating with said manifold, said valve opening once during a portion of alternate revolutions of said crankshaft, a pressure vaporizer communicating with said manifold for supplying said fuel mixture thereto, an air valve controlled by said crankshaft and adapted to supply air under pressure to said vaporizer once during each revolution thereof, and check valve means interposed between said pressure vaporizer and said manifold for preventing flow of said fuel mixture from said manifold back into said vaporizer.

6. A system according to claim 5, further comprising throttle means disposed to regulate the amount of air under pressure admitted to the pressure vaporizer during each crankshaft revolution.

7. A system according to claim 6 wherein said pressure vaporizer comprises an inlet for vaporizing air which comes into direct contact with the fuel and an inlet for air which mixes with the vaporizing air after the contact between the for separately controlling the how rates of the .air suppliedvto said two inlets-to control the richness of the fuel mixture simultaneously with the control of the total amount of ir.

8. in a fuel supply system fora four cycleengine, said engine having a crankshaft, a reciproeating piston for driving said crankshaft,an airtight crankcase for said crankshaft, an intake manifold controlled by said crankshaft and com municating with said manifold, said valve opening once during a portion of alternate-revolutions .of said crankshaft, anair inlet valve communicating with the interior of said crankcase for ad- -mi tting air therein during each upstroke of said piston, and air outlet valve for releasing air under pressure from said crankcase during each .downstroke of said piston, a pressure vaporizer communicating with said outlet'valve to receive compressed air from the crankcase, and with said manifold for supplying said fuel mixture thereto,

and check valve means interposed between said pressure vaporizerand said-manifold for preventing flow of said fuel mixture from said-manifold back into said vaporizer.

9. A system according to claim 2 further comprisingcam actuable means for opening and closing said air valves, and a cam carried by said crankshaft and disposed to actuate said cam actuable means.

10. A system according to claim 9, further comprising throttle means disposed to regulate the amount of air under pressure admitted to the pressure vaporizer during each crankshaft revolution.

11. A system according to claim 10, wherein said pressure vaporizer comprises an inlet for vaporizing air which comes into direct contact with the fuel and an air inlet for air which mixes with the vaporizing air after thecontact between the vaporizing air and the fuel has been completed, and in which the throttle means comprises means forseparately controlling the flow rates ofthe air supplied to said :two inletsto control the richness of the :fuel mixture simultaneously with'the control of the'total amount of air.

12. A four cycle internal combustion engine comprising an engine body provided with-a cylinder and a crankcase extending therefrom, an air inletopening formed .in the crankcase, an outlet opening in said crankcase, a pressure vaporizer havingan inlet connected to said inlet opening,

an intake manifold connecting the outlet of :the pressure vaporizer to the head :of the cylinder, valves controlling the inlet opening .and outlet opening of the crankcase, a piston in said cylinder, a crankshaft in ,said crankcase connected "to said piston, means controlled by said crankshaft to alternately open and close said valves, the volume of the space within said vaporizer-and inlet manifold being substantially equal to the volume of the space inthe cylinder above the piston when the latteris in its downmost position.

13. A four cycle internal combustion engine comprisingan enginebody provided with azcylinderand a crankcase-extending from the cylinder, a piston in the cylinder, a crankshaft in said crankcase, means to connect the crankshaft to thepiston, a pressure vaporizer, means to admit liquid fuel to the vaporizer to a predetermined References Cited ;in the file of this patent UNITED STATES PATENTS Number Name Date 1,972,874 Dobbs Sept. 11, 1934 2,353,430 Arden July 11, 1944

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