Supercharged Engines

Abstract

A fuel-air mixture is supercharged by a stuffed crankcase of an engine and is forced into a large volume reservoir from which it is metered by a throttle to intake valves of the engine. The fuel-air mixture in a carburetor is adjusted automatically by vacuum and/or mechanical linkage in accordance with air flow through the carburetor. Oil is forced from a sump in the reservoir by the pressure of supercharged mixture in the reservoir, through small orifices in an oil line to lubricate the engine. A second engine has radically cammed intake valves in addition to conventionally cammed valves, and valving provided between a large volume reservoir and the radically cammed valves is closed at engine speeds below 4,500 r.p.m. and is opened at speeds above 4,500 r.p.m.

Parent Case Text

This is a continuation of application Ser. No. 135,627 filed Apr. 20, 1971, now abandoned.

Description

DESCRIPTION

This invention relates to supercharged engines, and more particularly to reservoired supercharged engines.

An object of the invention is to provide new and improved supercharged engines.

Another object of the invention is to provide reservoired supercharged engines.

A further object of the invention is to provide a supercharged engine having a supercharged fuel-air reservoir of a volume several times that of the displacement of the engine.

Another object of the invention is to provide a supercharged engine having a supercharged fuel-air reservoir and a throttle between the reservoir and intake valving of the engine.

Another object of the invention is to provide a supercharged engine having a reservoir mounted on and connecting a crankcase and a head of the engine.

Another object of the invention is to provide a supercharged engine having a check valve assembly attachable as a unit to a crankcase of the engine.

Another object of the invention is to provide a supercharged engine having a carburetor having a needle valve in its throat controlling the fuel-air mixture by flow of air through the throat via vacuum and/or mechanical linkage.

Another object of the invention is to provide a supercharged engine including a reservoir of a supercharged fuel-air mixture and a lubrication system wherein the pressure of the mixture is utilized to feed oil through the system.

Another object of the invention is to provide a supercharged engine having a first set of conventionally cammed intake valving and a second set of radically cammed intake valving paralleling the first set and closed at low engine speeds.

In the drawings:

FIG. 1 is a perspective view of a supercharged engine forming one embodiment of the invention;

FIG. 2 is a vertical sectional view taken along line 2--2 of FIG. 1;

FIG. 3 is a vertical sectional view taken along line 3--3 of FIG. 2;

FIG. 4 is a schematic view of the fuel and air mixture flow to the cylinder;

FIG. 5 is an elevational view taken along line 5--5 of FIG. 2;

FIG. 6 is a fragmentary horizontal sectional view taken along line 6--6 of FIG. 2;

FIG. 7 is a fragmentary vertical sectional view of a supercharged engine forming an alternate embodiment of the invention;

FIG. 8 is a fragmentary horizontal sectional view taken along line 8--8 of FIG. 7;

FIG. 9 is a vertical sectional view of a supercharged engine forming an alternate embodiment of the invention; and

FIG. 10 is a vertical sectional view of a supercharged engine forming an alternate embodiment of the invention.

Referring now in detail to the drawings, there is shown in FIGS. 1-6 a supercharged engine 10 of the four-stroke cycle type and forming one embodiment of the invention. The engine preferably has two pistons 12 and 14 reciprocated in phase in cylinders 16 and 18, and fired alternately by spark plugs 20 (FIG. 3) fired by a known ignition system (not shown) driven in synchronism with the pistons. One each upward stroke of the pistons 12 and 14, air is drawn into inlets 22 (FIGS. 2 and 4) through carburetors 24 where the air is mixed with fuel (gasoline) metered by needle valves 26 having vane or baffle portions 27 forming variable venturis and controlled by vacuum operated diaphragms 28 regulated by vacuum control lines 30 connected to throats 32 of the carburetors 24. If desired, the vane portions 27 may be omitted to leave only the needle valve portions of the valves 26. The fuel-air mixture is drawn through intake manifolds 36 provided with vanes 38 to distribute the mixture of reed-type check valves 40 and on into the crankcase 34.

Each of the valves 40 includes a flanged, V-shaped body or insert 42 that is retained between upper half 44 and lower half 46 of the crankcase 34 by the intake manifold 36. The body 42 is provided with passages 48 (FIG. 6) in each side through which the flow is controlled in one direction only by flexible reeds 50 anchored at their one end by rivets 52 with the free ends seating against tapered portion 54 of the body 42. This permits the mixture to enter the crankcase 34 but prevents the backward flow on the downward stroke of the piston.

The crankcase 34 differs from usual crankcases in that the volume has been reduced to a minimum (slightly greater than the piston displacement) by filling pistons 12 and 14 and providing counterweight stuffers 56 (FIG. 3) forming part of the crankshaft 58. The pistons 12 and 14 are attached to the crankshaft 58 by connecting rods 60 pivoting on wrist pins 62 (FIG. 2) and journals 64.

On each down stroke of the pistons, the fuel-air mixture is compressed and discharged from the crankcase 34 through reed-type check valves 66 similar to valves 40 except that valves 66 permit only flow out of the crankcase. Each of the reeds 68 is anchored at one end to a V-shaped body 70 (FIG. 6) by a rivet 72 with the free end of the reed seated against the flanged portions of the body 70 and normally closing off opening 74. The fuel-air mixture is discharged from the reed valves 66 into updraft passages 76 leading to a pressure tank or reservoir 78, which, with the passages 76 and outlets 82, define a supercharging chamber. The volume of the supercharging chamber is at least eight times the combined displacement of the pistons in their strokes. The ends of the reservoir 78 are closed by plates 79 (FIG. 5) held tightly in place by a through-bolt 81 and sealed by "0" rings 83. As can be seen from FIG. 2, a smooth, tangential flow of fuel-air mixture is had around portion of the periphery of the reservoir 78 and out of the outlet ports 82 to intake valve passages 84 of engine head 86. The intake passages 84 are provided with manually controlled butterfly-type throttle valves 88 (FIGS. 2 and 4) which provide easy starting and quickly responsive control.

Intake valves 90 and exhaust valves 92 (FIG. 2) are operated by an overhead cam and follower assembly 94 mounted in a camshaft housing 96 closed by a cover 98. A camshaft 100 (FIG. 3) mounted in bearings in the housing 96 is provided with a sprocket 102, which is driven by a sprocket 104 on the crankshaft 58 through a timing chain 106. The chain and sprockets are encased by a cover 108. At the opposite end of the camshaft 100, and operated thereby, is mounted the ignition breaker point assembly 110. A fan 112 has a hub 114 rotatably mounted on a stub shaft 116 secured to the upper half of the crankcase 34. A V-belt 118 drives the fan 112 from a pulley hub 120 on the crankshaft 58. A fan housing 122 encloses the front end of the engine with an air passage 124 provided in the face of the cover. A starter 126 is mounted by a bracket 128 on the side of the engine 10. The starter 126 cranks the engine 10 by way of a chain 130 and a sprocket 132. A clutching mechanism 134 connects the sprocket 132 to the crankshaft 58. The engine exhausts through ports 136 to exhaust lines 138.

For lubrication, a supply of oil positioned in a sump portion 149 in the lower ends of the passages 76 (FIG. 2) is forced through line 150 to an overhead line 152 having small, downwardly directed nozzle holes in its bottom which mist the oil onto the camshaft 100, rocker arms and valves. The oil goes through the valves to the cylinders and pistons and also lubricates the connecting rods and crankshaft. The nozzle holes in the line 152 are sufficiently small that the escape of oil therefrom has a negligible effect on the pressure in the supercharging chamber.

A cap covered, pressure tight inlet 151 is provided for supplying oil to the sump portion 149.

There is, of course, only a slight leakage from the reservoir past the valves 90 and pistons 12, but this is sufficient to permit easy starting after the engine has been stopped a few minutes. That is, the high supercharged pressure in the reservoir is reduced by the leakage when the engine is stopped for a few minutes to reduce the compression for starting. However, once the engine has been started, the pressure in the reservoir is built up to the normal supercharged pressure very rapidly, for the most part a small fraction of a minute. If desired, the reservoir may be provided with a pressure relief outlet having a normally closed, manually operable valve to relieve the reservoir pressure momentarily for easy starting of the engine.

OPERATION

On the downstroke of the pistons 12 and 14 the fuel-air mixture in the crankcase 34, which is well stuffed, is highly compressed and is forced through the reed check valves 66 into the passages 76, through the passages 76, and directly to the outlets 82 by flowing tangentially around the inner periphery of the pressure tank 78 to the outlets. During this stroke, one of the intake valves 90 is open to one of the cylinders, and the fuel-air mixture flows past the associated throttle 88 and into that cylinder, the piston in the other cylinder making its power stroke. This charges the cylinder being supplied with the supercharged mixture and the valve 90 is closed near the end of the downward stroke. Then, during the upward stroke, the most recently fired cylinder 16 or 18 is exhausted and the supercharged mixture in the other cylinder is compressed, the upwardly moving pistons also drawing fuel-air mixture from the carburetors 24 through the inlet check valves 40 into the crankcase 34. Then, on the next downstroke, the most recently charged cylinder is fired and the most recently exhausted cylinder is charged. The direct flow of the supercharged mixture from the passages 76 to the outlets 82 and the position of the throttles 88 substantially immediately adjacent the intake valves 90 make the engine quickly responsive to adjustments of the throttles which, of course, are keyed to each other so as to always be in positions identical to each other. The carburetor jets are automatically controlled by the pressure changes in the carburetor throats so as to supply fuel in proportion to the air being drawn into the crankcase. The oil is fed through the lines 150 and 152 by the supercharging pressure so that no oil pump is required, a pressure sealed cap (not shown) being provided for introducing the oil into the sump portion of the reservoir.

EMBODIMENTS OF FIGS. 7 AND 8

In FIGS. 7 and 8 an engine 210 forming an alternate embodiment of the invention has a radically cammed valve assembly 212. The engine 210 is provided with supercharging passages 76' directing the fuel-air mixture to a reservoir 78' as in the first embodiment. For low speeds, those up to about 4,500 r.p.m., the fuel-air mixture is fed to the cylinders 214 by way of ports 216 and normally cammed intake valves 218 and is exhausted through valves 220 and ports 222. Low speed throttle valves 224 and high speed throttle valves 225 in ports 216 and 226 are operated simultaneously by a common shaft 228 which is manually controlled. Pistons 230, connecting rods 232 and piston rings 234 are of standard design and operation. As can be seen from the drawings, low speed outlet passages 236 from the reservoir 78' are open whereas high speed passages 238 are closed by cylindrical valve sleeves 240, thus preventing any flow of fuel-air mixture from entering the cylinder 214. When the engine's speed starts to exceed 4,500 r.p.m., a wire 242 responsive to crankshaft speed automatically and gradually withdraws each valve sleeve 240 along its guide 244 against the force of a spring 246 to open the high speed passages 238 to the throttle 225 and the high speed intake valve 248. This arrangement permits rapid speed change at the high level without starving the engine. The timings of the radically cammed, high speed intake valves 248 are advanced substantially over the timings of the low speed valves 218 as is well known in the art.

EMBODIMENT OF FIG. 9

A supercharged engine 300 forming an alternate embodiment of the invention includes a pair of pistons 302 in phase with one another and is like the engine of FIGS. 1-6 except as brought out hereinbelow. In the engine 300, fuel-air mixture is drawn from a carburetor 304, through intake check valves 306 and into a stuffed crankcase 308 on each upward stroke of the pistons, and is compressed and forced out of outlet check valves 310 as the pistons are moved downwardly. The supercharged mixture is moved upwardly through large volume reservoir passages 312 to a rotary, vane type pump 314 driven by and at the same speed as crankshaft 316. The pump 314 has vanes 318 urged against cylindrical periphery 320 of chamber 322 by springs 323, and further compresses the mixture and feeds it through passages 324 and past manually controlled butterfly valve-type throttles 326 to intake valves 328, the two valves 328 being opened alternately, each on every other downstroke of the pistons. Camshaft assembly 348 has a camshaft driven in timed relationship by the crankshaft, and a distributor of an ignition system (not shown) is driven in synchronism with the crankshaft.

A groove 340 in the bottom of reservoir section 342 forms a sump for oil which is forced through line 344 to an overhead misting line 346 to lubricate camshaft assembly 348 and to be forced under pressure from a sump 350 through nozzles 352 into the cylinders and the crankcase.

Diaphragms 360, which are mounted by a bracket 361 on an intake manifold 362 on which the carburetors 304 are mounted, are actuated by pressure from lines 364 opening into throats 366 of the carburetors to automatically maintain the proper fuel-air mixture through linkage 368 which adjusts shaft 370 on which butterfly valves 372 are keyed. The fuel is sucked up from jets 374. The inlets of the lines 374 are just downstream from the movable upper edges of the butterfly valves so as to be most responsive to changes in pressure from the venturi effect.

EMBODIMENT OF FIG. 10

A supercharged engine 400 forming an alternate embodiment of the invention is similar to the engine 300 but has throttles 402 in throats 404 of carburetors 406, which are manually operated in synchronism with operation of intake throttles 408 positioned very close to intake valves 410. The throttle 402 keeps the mixture substantially uniform at all speeds. Linkage 412 interlocks the throttles 402 and 408. Also, a rotary, vane-type pump 414 is positioned adjacent outlet check valve 416 and feeds into a large volume pressure tank or reservoir 418, which supplies the highly supercharged mixture to manifold passages 520 in which the valves 408 are mounted. The throttles 408 control the speed and the valves 402 are moved in accordance with the throttles 408 to keep the fuel-air mixture desired.

Claims

What is claimed is:

1. In a supercharged engine,

a block having a plurality of cylinders,

a plurality of pistons movable in the cylinders,

crankshaft means driven by the pistons,

the pistons having a predetermined displacement volume when reciprocated,

a reservoir having a volume at least several times as great as said displacement volume of the pistons,

supply means including supercharging means for supplying a fuel-air mixture under pressure to the reservoir,

a plurality of short intake passages connecting the reservoir to the cylinders,

a plurality of intake valve means for connecting the passages to the cylinders,

a plurality of manually controlled throttle means in the passages positioned close to the intake valves for controlling the flow from the reservoir to the cylinders,

the supply means including carburetor means supplying the fuel-air mixture and control means for keeping the proportions of fuel and air supplied by the carburetor means substantially constant.

2. The supercharged engine of claim 1 including a crankcase and wherein the supply means includes first valving connecting the carburetor means to the crankcase and second valving connecting the crankcase to the reservoir.

3. The supercharged engine of claim 2 wherein the first and second valvings comprise check valves.

4. The supercharged engine of claim 2 including pump means for pumping supercharged fuel-air mixture from the crankcase into the reservoir.

5. The supercharged engine of claim 1 including an inlet to the reservoir directed toward the throttle means.

6. The supercharged engine of claim 5 wherein the reservoir has a curved surface tangential with the inlet and the throttle means.

7. The supercharged engine of claim 1 wherein the carburetor means includes an adjustable venturi, and means responsive to pressure in the venturi for adjusting the venturi.

8. The supercharged engine of claim 1 wherein the carburetor means includes adjustable needle valve means for controlling fuel flow, and means responsive to pressure in the throat of the carburetor means for adjusting the needle valve means.

9. The supercharged engine of claim 1 including a crankcase having an inlet opening and an outlet opening to the reservoir, and a valve insert including a valve body having ports and mounted in one of the openings and a plurality of reed valve members mounted on the valve body in normal positions closing the ports and movable by pressure to positions opening the ports.

10. The supercharged engine of claim 9 wherein the body is flanged and tapered with the flange fitting into a counterbored portion of said one of the openings.

11. The supercharged engine of claim 1 wherein the reservoir is mounted on the block and has fins for cooling the supercharged fuel-air mixture.

12. The supercharged engine of claim 1 including linkage means interlocking the manually controlled throttle means and the control means.

13. In a supercharged engine,

a block having cylinders,

pistons movable in the cylinders,

crankshaft means driven by the pistons,

the pistons having a predetermined displacement volume when a reservoir having a volume at least several times as great as said displacement volume of the pistons,

supply means including carburetor means and supercharging means for supplying a fuel-air mixture under pressure to the reservoir,

and intake valve means for connecting the reservoir to the cylinders,

the intake valve means including normally timed intake valves and radically timed intake valves.

14. The supercharged engine of claim 13 including valve means for permitting flow to the radically timed valves only at speeds greater than a predetermined speed.

15. The supercharged engine of claim 13 wherein the radically cammed valves comprises valve ports and valve members adapted to open and close the ports, the valve means including manifold passages leading to the valve ports and gate valves adapted to close the passages at a speed up to said predetermined speed.

16. In a supercharged engine, a block having cylinder means,

piston means movable in the cylinder means,

crankshaft means driven by the pistons means,

the piston means having a predetermined displacement volume when reciprocated,

a reservoir having a volume at least several times as great as said displacement volume of the piston means,

supply means including crankcase supercharging means for supplying a fuel-air mixture under pressure to the reservoir,

intake valve means for connecting the reservoir to the cylinder means,

an oil sump portion having oil therein exposed to the pressure of the fuel-air mixture in the reservoir,

and oil passage means leading from the oil sump portion to moving parts of the engine.

17. The supercharged engine of claim 16 including a camshaft housing, the oil passage means including a line from the sump portion to the camshaft housing and nozzle means connected to the line.

18. The supercharged engine of claim 17 including a second sump portion in the camshaft housing, a crankcase, and a second line leading from the second sump portion to the crankcase.

19. The supercharged engine of claim 18 including second nozzles connected to the second line and directed upwardly into the cylinder means.

20. In a supercharged engine,

a block having cylinders,

piston means movable in the cylinders,

crankshaft means driven by the piston means,

the piston means having a predetermined displacement volume when reciprocated,

a reservoir having a volume at least several times as great as said displacement volume of the piston means,

supply means including carburetor means and supercharging means for supplying a fuel-air mixture under pressure to the reservoir,

intake valve means for connecting the reservoir to the cylinder means,

a crankcase,

unidirectional valve means connecting the carburetor means to the crankcase,

and second stage supercharging means in series with the crankcase, to reservoir and the intake valve means.

21. The supercharged engine of claim 20 wherein the second stage supercharging means comprises a vane pump driven by the engine at a speed proportional to the speed of the crankshaft.

22. In a supercharged engine,

a block having a plurality of cylinders,

a plurality of pistons movable in the cylinders,

crankshaft means driven by the pistons,

a reservoir having a volume at least several times as great as said displacement volume of the pistons,

supply means including supercharging means for supplying a fuel-air mixture under pressure to the reservoir,

a plurality of short intake passages connecting the cylinders individually to the reservoir,

a plurality of intake valves for connecting the intake passages to the cylinders,

and a plurality of manually controlled interlocked throttles in the intake passages close to the valves for controlling flows of the fuel-air mixture individually in the passages.

23. The supercharged engine of claim 22 including a crankcase, a carburetor, first check valve means permitting flow from the carburetor to the crankcase, second check valve means permitting flow from the crankcase to the reservoir, and control means for adjusting the carburetor to keep the fuel-air mixture substantially constant over a wide range of air flow through the carburetor.

24. The supercharged engine of claim 23 wherein the control means comprises throttle means in the carburetor and mechanical linkage means interconnecting the throttles and the throttle means.

25. The supercharged engine of claim 23 wherein the control means comprises means responsive to rate of flow of air through the carburetor for adjusting the fuel flow.

26. In a four-stroke cycle supercharged engine,

a block having cylinder means,

piston means movable in the cylinder means,

crankshaft means driven by the piston means,

the piston means having a predetermined displacement volume when reciprocated,

a reservoir having a volume at least several times as great as said displacement volume of the piston means,

a crankcase,

supply means including crankcase supercharging means for supplying a fuel-air mixture under pressure to the reservoir,

short intake passage means connecting the reservoir to the cylinder means,

intake valve means for connecting the passage means to the cylinder means,

manually controlled throttle means in the passage means positioned close to the intake valve means for controlling the flow from the reservoir to the cylinder means,

the supply means including carburetor means supplying the fuel-air mixture to the crankcase and keeping the proportions of fuel and air supplied substantially constant,

first check valve means permitting flow from the carburetor means to the crankcase,

and second check valve means permitting flow from the crankcase to the reservoir.

27. The supercharged engine of claim 26 including a throttle in the carburetor means and mechanical linkage means interconnecting the throttle and the throttle means.

28. The supercharged engine of claim 26 wherein the carburetor means includes means responsive to rate of flow of air through the carburetor means for adjusting the fuel flow.