US2392060A - Internal-combustion engine - Google Patents

Description

Filed May 23, 1940 2 Sheets-Sheet l I INVEN TOR.

n- 19 6' A. E. OSBORN 2,392,060

INTERNAL-COMBUSTION ENGINE Filed May 23, 1940 2 Sheets-Sheet 2 I NV EN TOR.

Patented Jan. 1, 1946 UNITED STATES PATENT OFFICE,

INTERNAL-COMBUSTION ENGINE Alden E. Osborn, Mount Vernon, N. Y.

Application May 23, 1940, Serial No. 336,685

6 Claims.

The object of my invention is to provide. in four-cycle engines of either spark ignition, surface ignition or compression ignition types, improvements that reduce the number of parts, the weight and the cost, and increase the reliability and efiiciency. My invention is particularly con cemed with the valve mechanism and the means for supplying air and fuel to the cylinder and for scavenging the exhaust gases therefrom. While all of the drawings show my invention applied to engines of the air-cooled type, it is not limited to use in that kind of engine, but is shown in engines without a water or other cooling fluid jacket, because it is particularly suitable for air cooling. It will also be noticed that my drawings illustrate engines of the usual forms with crankshafts and connecting rods for causing the reciprocation of the pistons in the cylinders, altho obviousl it can be used with any other type of engine which has pistons reciprocating in the cylinders. It should also be understood that various parts and details that would be required in the actual working engine have been eliminated from the drawings in order to more clearly illustrate the essential features of my invention.

In the accompanying drawings:

Figure 1 represents a longitudinal sectional elevation showing one form of my invention,

Figure 2 represents a longitudinal sectional elevation of a modification of my invention as shown in Figure 1,

Figure 3 represents an end elevation showing the cam mechanism of Figure 2, and

Figure 4 represents a sectional elevation of a still further modification to be applied to the engine shown in Figure 2.

In the form of my invention shown in Fig. 1, l represents the cylinder, which cylinder is provided with only one valve l5, that is shown as in the cylinder head II and is closed by the spring l6 and operated by the usual rocker lever I'l, push rod 18, cam follower l9 and cam 20, on the usual cam shaft 6 that turns at one half the speed of the crankshaft 5. The crankshaft carries the flywheel 1 that is provided with vanes 8 so that it acts as a blower that forces air thru the channel or casing 9 which connects with the passage [2 leading across the outer surface of the valve I 6 and is provided with a shoulder or bafiie i3 that deflects the air against the outer surface of the valve. There is also a fuel injection nozzle 30, a fuel pump 32, and a variable cam 35 on the shaft 6, for altering the stroke of the fuel pump. In this particular form of my invention an ignition system comprising the spark plug 40, timer I5, and the usual associated parts is provided. A throttle valve 29 is shown in the air passage 9 and is connected by the rod 28 to the lever 3! con-- trolling the stroke of the fuel pump or amount of fuel to be injected into the cylinder. The operation of this form of my invention, which is illustrated as embodied in an engine of the relatively low-compression type, is as follows:

Starting with the piston H at the top of the combustion stroke as shown, the valve l5 remains closed until about before bottom center when the cam 20 would have turned and started opening the valve allowing the exhaust gases to'escape into the passage l2 over the cylinder head H. The valve is continues to remain open during the upward stroke of the piston l4 while the rotation of the crankshaft 5 and flywheel fans would create an air pressure in the passage 02, with the result that the exhaust gases would pass out of the head passage in the opposite direction from the air inlet 9. When the piston M starts to descend, there would be little or none of the exhaust gas in the head passage l2 so that, as the piston l4 descends, air would be'drawn into the cylinder l0 assisted by the considerablepres sure developed in the passage l2 by the fan 8. During this suction stroke fuel would be injected into the air passage l2 thru the nozzle 30 by the fuel pump 32 so that, by the time the valve l5 closes (which is preferably after the piston ll has started upward on the compression stroke) the cylinder would contain a combustible mixture and, upon the piston reaching the proximity of top center, this combustible mixture would be compressed and can then be fired by the spark plug 40 in order to commence a new operating cycle of the engine. In order to control the speed of the engine having this form of my invention, I have arranged a throttle valve 29 in the casing 9 that co-operates with the fuel pump controlling means so that, as the amount of fuel injected and/or the time of injection is-varied, this throttle valve 29. would be opened or closed.

While the closing of this valve 29 would not greatly affect the compression it would regulate the amount of exhaust gas retained in the cylinder l0 because of its control of the amount of scavenging air admitted from the fan 8, and would, therefore, in conJunction with the control of the amount of fuel, have considerable effect on the engine power. and speed. It will be noticed that the outlet side of the passage I2 is much larger than the inlet side where the air enters,

so that, when the valve,v l5 opens, the exhaust gas would escape freely without entering thefalr inlet side of the passage. It is obvious that, if an exhaust pipe or muiller is used, it should have very large passages so as to develop as little back pressure as possible. It must permit the free outlet of the exhaust from the engine and the'air from the fan 8 or other air pressure source. If the air pressure in the valve passage I2 is high, more back pressure might be developed on the exhaust stroke, but a super-compression action would be obtained. The scavenging of the air can be regulated to a considerable extent by the height and position of the baille i3. If this baffle is close to the valve l5 practically all the airwould be turned down thru the valve and into the cylinder l and thereafter out of the exhaust.

In the form of my invention shown in Figure 2 the following modifications are illustrated. In this figure the cylinder [0 is shown as provided with a separate combustion chamber 25 into which fuel is injected thru the nozzle 30, which combustion chamber is also provided with a spark plug 40. The cylinder head II in this case is shown as a separate casting screwed On to the cylinder Hi. The cylinder I0 is provided with ports 26 that are uncovered and open into the cylinder at the outer end of the piston stroke. These ports communicate with the passage 2'! into which air is forced by the centrifugal blower 22 that is geared to the engine crankshaft 5. The fuel pump 32 is arranged to have its time of injection and length thereof controlled by an adjustable cam 35 or other means. In order to control the speed a modified mechanism is used in which the timing of the valve I5 is regulated. This method of controlling the timing of the valve I5 consists of using a slidable lever or cam follower 2| between th valve lifter i9 and cam 20, which lever 2| can be moved parallel to the cam shaft 8 to assume different positions along the cam 20. The cam has slanting cam surfaces on its trailing edge and th intermediate follower lever 2| that rests on the cam is moved sideways by the lever 23, shaft ll, lever 24, and rod 42 connected to the lever 24 controlling the fuel pump cam 35. This form of my invention operates on the same principle as that shown in Figure 1, excepting that each time the'plston reaches the end of the explosion or power stroke and after the valve I! has been opened to allow the escape of the exhaust gases, the air inlet ports 26 open and air is let in to assist in scavenging the cylinder. These ports 26 also open at the end of the inlet or suction stroke to admit additional air to the cylinder, and therefore, to give a super-compression effect and greater power. The modified means for regulating the speed and power shown in this figure operates to regulate the compression and the amount of air in the cylinder, as well as the amount of fuel injected. The movement of the intermediate cam follower lever 2 I, to that part of the cam 20 which holds the valve l5 open for a longer time results in letting the air Pass out of the valve on the compression stroke so that not only is the compression lowered, but the amount of air compressed is reduced and at the same time the fuel injected into the cylinder is reduced by the shifting of the cam 35 or by other means. This method .of regulating the engine speed is not suitable for compression ignition engines as, when operating at low power output, the compression would be so reduced that ignition by spark or other means is essential.

The modification shown in Figure 4 illustrates practically the same super-compression device as is illustrated in Figure 2 except that the blower inlet is provided with a passage 33 that can be connected with a carburetor or combustible-mixture producing device 34 or an air inlet 38 by operating a valve which has its vane 31 arranged so that when the passage 33 to the carburetor I4 is opened the air admission 38 is closed. While this carburetor 34 can be the sole means for supplying fuel to the engine, it is especially suited for starting and, in some cases, for the operation of the engine at low speeds or powers. When the parts are arranged for operating on fuel from the carburetor or mixing device for starting only, the cam 20 would have that part which comes into action when starting so cut that the valve l5 would remain closed longer than under normal running conditions. The valve closing, when starting, would occur at the beginning of the inlet stroke instead of after the piston has passed lower center and has started upward at the compression stroke, as is the case when the engine is operated as heretofore described.

With this arrangement of carburetor and valve timing in use for starting the engine the action is as follows:

Upon the piston ll descending on the suction stroke a vacuum is produced in the cylinder by reason of the early closing of the valve l5 so that, when the piston has passed the ports 26, a 'combustible charge i drawn into the cylinder from the carburetor. The upward travel of the piston compresses the charge after which it is ignited by the spark and the piston descends on the explosion or power stroke, but before Opening the ports 28, the valve l5 opens, letting out a large part of the exhaust so that there would not be any blow -back into the carburetor 34. The valve i5 would remain open during the exhaust stroke and would close at about top center when the parts have returned to the first-mentioned position and the suction stroke is again about to take place. As the valve 15 would open considerably before the ports 26, the gases left in the cylinder would be greatly cooled and there would not be an greater tendency to backfire than there is in the usual two cycle engine. In this :Figure 4, and in Figure 2 the supercharger and scavenging pressure is provided by a high speed centrifugal blower altho other kinds of blowers can be used. such as the sliding vane or Roots type.

It is obvious that various modifications will I occur to those skilled in the art and that my invention may be employed in structures of various kinds and that no limitation is intended by the phraseology of the description or by the method of illustrating my invention in the accompanying drawings, except as indicated in the appended claims.

I claim:

1. In a four cycle internal combustion engine a cylinder, a piston in said cylinder, a valve in said cylinder, a passage across the outer surface of said valve and having an opening at,each side 01' said valve, means for causing a current of air to pass thru one said opening and over said valve and out thru said 'other opening, a port insaid cylinder and adapted to be opened into said cylinder by said piston when said piston is in its outward position, a blower for forcing air thru said port, controllable means for opening said valve during the combustion stroke of said piston before said piston opens said port and for holding said valve open or closing said valve during the suction stroke of said piston, and for, if said valve is not closed during said suction stroke, controllably closing said valve during the compression stroke of said piston, controllable means for injecting fuel into said cylinder at properly timed intervals, and means whereby said means for controlling the fuel injection is regulated simultaneously with the operation of said valve controlling means.

2. In a four cycle internal combustion engine a cylinder, a piston in said cylinder, a valve in said cylinder, a passage across the outer surface of said valve and having an opening at each side of said valve, means for causing a current of air to pass thru one said opening and over said valve and out thru said other opening, a port in said cylinder and adapted to be opened into said cylinder by said piston when said piston is in its outward osition, a blower connected to said port, an air inlet passage to said blower, a controllable valve in said passage, a combustible-mixture-producing device communicating with said passage when said controllable valve is in one position and an air inlet communicating with said passage when said controllable valve is in another position, controllable means for opening said cylinder valve during the combustion stroke of said piston before the piston reaches said port in said, cylinder, for holding said cylinder valve open during the following exhaust stroke, and for either holding saidcylinder valve open or for closing said valve during the suction stroke of said piston and for, if said valve is opened during said suction stroke, closing said valve during the compression stroke of said piston, controllable means for injecting fuel into said cylinder at properly timed intervals, means whereby said means for controlling the fuel injection is simultaneously regulated with the operation of said cylinder valve controlling means, and means whereby the movement of the controllable valve of said blower inlet to close said air inlet to said passage and to open said combustible-mixture-producing device to said passage, operates said controlling means for said cylinder valve to close said valve during the suction stroke of said piston to cause a vacuum in said cylinder and to draw a combustible charge from said device into said cylinder when said cylinder port is opened by said piston.

3. In a four cycle internal combustion engine, a cylinder, a, cylinder head, a piston in the cylinder, a passage within the cylinder head across the cylinder, a valve opening formed in the wall of said passage intermediate the ends thereof and common to the cylinder and formed with a valve seat, a valve to close the opening, means for causing a current of air to pass through said passage over said valve and a baflle in said passage adjacent to said valve to deflect air passing through said passage against the outer surface of said valve and through the valve opening into the cylinder when the valve is open.

4. In a four cycle internal combustion engine, a cylinder, a cylinder head, a piston in the cylinder, a passage within the cylinder head across the cylinder, a valve opening formed in the wall of said passage intermediate the ends thereof and common to the cylinder and formed with a valve seat, a valve to close the opening, means for causing a current of air to pass through said passage over said valve and a generally transverse baflle in said passage adjacent to said valve to deflect air passing through said passage against the outer surface of said valve and through the valve opening into the cylinder when the valve is open, said baille being so proportioned that the cross-sectional area of the passage between the bafile and the outer surface of the valve when in closed position is less than the cross-sectional area of the said passage when the valve is in open position.

5. In a four cycle internal combustion engine, a cylinder," a cylinder head, a piston in the cylinder, a passage within the cylinder head across the cylinder, a valve opening formed in the wall of said passage intermediate the ends thereof and common to the cylinder and formed with a valve seat, a valve to close the opening and having a valve stem, means for causing a current of air to pass through said passage over said valve and a generally transverse baflle in said passage adjacent to said valve to deflect air passing through said passage against the outer surface of said valve and through the valve opening into the cylinder when the valve is open, said baffle being so proportioned that the cross-sectional area .of the passage between the baflleand the outer surface of the valve when in closed position is less than the cross-sectional area of the said passage being offset with reopen position, said bafile being offset with respect to the valve stem in the direction-irom which the current of air flows whereby the crosssectional area of the passage between the baflle and the valve on the side from which the current of air flows is less than the cross-sectional area of the passage between the baille' and the valve on the outlet side of the valve whereby exit of the exhaust gases is facilitated while the inlet of fresh air is retarded to permit such exit of the exhaust gases.

6. In a four cycle internal combustion engine, a cylinder, a cylinder head, a piston in the cylinder, a passage within the cylinder head across the cylinder, a valve opening formed in the wall of said passage intermediate the ends thereof and common to the cylinder andformed with a valve seat, a valve to close the opening, means for causing a current of air to pass through said passage over said valve and a generally transverse batlle in said passage adjacent to said valve to deflect air passing through said passage against the outer surface of said valve and through the valve opening into the cylinder when the valve is open, said baflle being offset with respect to the valve stem in the direction from which the current of air flows whereby the area of the valve opening uncovered by the valve on the inlet side of the baffle is less than the area of the valve opening through which exhaust gases escape on the outlet side of the baflle.

ALDEN E. OSBORN.

v Certificate of Correction Patent No. 2,392,060.

[sun] LESLIE FRAZER,

First Assistant Commissioner of Patents.

January 1, 1946. ALDEN E. OSBORN

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