US1082004A

US1082004A - Governing internal-combustion engines.

Info

Publication number: US1082004A
Application number: US?9999607A
Authority: US
Inventors: James S Anthony
Original assignee: General Electric Co
Current assignee: General Electric Co
Publication date: 1913-12-23
Anticipated expiration: 1930-12-23

Description

J. S. ANTHONY. GOVERNING INTERNAL COMBUSTION ENGINES. APPLICATION FILED OCT. 31, 1907.

1,082,004. Patented Dec. 23, 1913.

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WITNESSEEII tinirnn srar p neginnr OFFICE.

JAMES S. ANTHONY, 01! NEW YORK, N. Y., ASSIGNOR T0 GENERAL ELECTRIG COMPANY, A CORPORATION OF NEW YORK.

GOVERNING INTERNAL-GOMBUSTION ENGINES.

Specification of Letters Patent.

Patented Dec. 23, 1913.

Application filed October 31, 1907. Serial No. 899,996.

To all whom it may concern Be itknown that I, JAMES S. ANTHONY, a citizen of the United States, residing at New York, county of New York, State of New York, have invented certain new and useful Improvements in Governing Internal-Combustion Engines, of which the following is a specification.

This invention relates to means for improving the operation of internal combustion engines.

The charge of carbureted air which is drawn into the cylinder by the suction of the piston, is produced by the action of the carburetor. wherein the column of air drawn through the inlet pipe passes a jet connected with a supply of gasolene or other liquid hydrocarbon. A successful carburetor should add a definite predetermined percentage of hydrocarbon vapor to every pound of air passing through it. With a plain jet of the atomizer type the flow of gasolene increases with the suction, and the amount of air per unit of time also depends on the suction, so that the amount of air and the amount of gasolene passing through the carbureter both vary in the same sense at the same time. But unfortunately the incre ments are not in the same proportions. The ,uoportion of gasolene added by the ordinary jet carbureter at high speeds is too great, and the greater the speed the greater the proportionate excess. This may be due to the fact that the higher the speed of the air the less its density, and consequently the actual rate of flow of air varies less rapidly than the actual rate of suction.

The force whit. causes the flow of air and gasolene is the same for both, viz., the suction in the inlet pipe. The rate of discharge from an orifice is always proportional to the square root of the pressure producing it, and the velocity of the air at any point in a pipe, one end of which is in communication with the atmosphere is also proportional to the square root of the suction. But although the speed of the air past the spray nozzle and the speed of the gasolene flow from the nozzle are always proportional to the suction, the density of the air decreases as the velocity increases, and hence the quantity of air by weight varies less mp idly than the quantity of gasolene. A further reason for variation in the proportions of air and gasolene is found in the inertia and elasticity of the air, which cause a reduction of from 25 to 40 per cent. in the quantity of air per stroke taken in at high speeds as compared with that drawn in at low speeds. Moreover, there is a diflerenoc in inertia between the fluid air and the liquid gasolcne which causes the latter to flow longer than the former after being once set in motion. The flow of gasolene is also influenced by the fact that an initial suction is required to lift the gasolene to the mouth of the nozzle before spraying can begin at all. Only the slightest suction is required to draw air through the inlet pipe, but there is a certain minimum suction below which no gasolcne will be fed. As this initial suction required to raise the gasolene to the mouth of the nozzle is a constant, it follows that, as the suction increases, the ratio of this constant to the total suction becomes less, and therefore the mixture becomes richer the greater the suction.

The object of my invention is to counteract this tendency of the mixture to vary with the speed of the engine. Heretofore 8. eat many cxpedients have been suggeste for this purpose, some of which are in use. But so far as I am aware, no one has pro osed to take advantage of the varying spee s of the piston at different portions of its stroke, whereby the column of air drawn through the inlet pipe is caused to move at different speeds during the suction stroke of the iston. The curve of the velocities of a pis n connected to a crank rotating at uniform speed is a double reversed curve starting at zero and rising to a maximum at a oint somewhat in advance of the middle 0 the stroke, depending upon the relative lengths of the connecting rod and crank. Consequently the air in the inlet pipe will theoretically start from a quiescent condition at the beginning of the stroke and acquire its greatest velocity at about the middle thereof. Now if the movement of the air is restrained by closing the inlet until the piston has made part of its stroke, the resulting vacuum in the cylinder will be so great that when the inlet is opened the air will start instantly at a hi h velocity, and the gasolen e spray will also e instant y started, the imtial suction being suflicient to overcome its inertia and weight. The entire volume of air will thus be carbureted.

The closing and opening of the inlet pipe ild may be eflected in any suitable manner and at any suitable point in said pipe. I prefer, however, to control it by means of the ordinary inlet valve, located in proximity to the head of the cylinder. By retarding the opening of this valve at high speeds or with light loads, and gradually shortening the time of retardation as the engine slows down or the load increases, I obtain a much more uniform carburation at all speeds and loads; the richness of the mixture being more nearly equalv at all speeds and loads than where the inlet valve is allowed to open at the beginning of the stroke at all speeds and loads. As a further development of this idea, I propose with high speeds or light loads to open the inlet valve only during the middle portion of the suction stroke when the piston is moving most rapidly, and to increase the length of time the valve remains open by equal increments toward both ends of the stroke until at low speed or full load the valve will remain open during the entire stroke.

In the accompanying drawing, Figure 1 is a vertical section of a portion of an internal combustion engine; Fig. 2 shows an ad- I justable cam for varying the time the inlet valve remains open; Fig. 3 is a diagram showing the positions of the piston, connect ing rod and crank atdifierent points of the stroke; and Fig. 4: is a diagram of piston speed and the region of valve opening.

The cylinder 1, piston 2, connecting rod 3, crank 4, inlet pipe 5 and inlet valve 6 are all of the usual construction. The valve is closed by a spring 7 and opened by a rotating cam 8, as usual. In ordinary engines this cam opens the valve at the beginning of the suction stroke. By my invention, I so design the cam that it will not open the valve until the piston has traveled a certain portion of the stroke; a possiblesituation being the one shown in the drawing, where the valve is just beginning to open, although the piston has made about a third of a stroke from the upper end of the cylinder.

In case it is desired to vary the time during which the valve will remain open, an adjustable cam may be used, as shown in Fig. 2, Where the cam 9 is made tapering and is splined on the cam shaft 10 so that it can beslid lengthwise thereon by a shifting lever- 11; actuated either manually or by a speed governor as desired. It will be seen that owing to the shape of the cam 9 the valve 6 will always be quickly opened to its normal full open position and quickly closed, whether its period of opening be long or short as compared with the whole suction stroke.

In Fig. 4 the curve 12 shows the variation in piston speed during the stroke, the curve being plotted for a connecting-rod whose length is about four and a half times that ipsaooe of the crank, as shown in Fig. 3. The point a of maximum speed is slightly in advance of the middle of the stroke. The

lines

13, 14, 15, 16 indicate difi'erent portions of the stroke during which the inlet valve may be opened dependin upon the speed and load of the engine. T iese lines also indicate that at high speed or under light loads the valve may be open only during the fastest travel of the piston, and that as the speed decreases the open periods may be successively len thened by equal increments in both directions until at low speed or full load the valve will remain open for practically the entire stroke.

In accordance with the provisions of the patent statutes-I have described the principle of operation of my invention, together with the apparatus which I now consider to represent the best embodiment thereof; but I desire to have it understood that the apparatus shown is only illustrative, and that the invention can be carried out by other means. 1

What I claim as new and desire to secure by Letters Patent of the United States, is,-

1. In an internal combustion engine, the combination of a cylinder, a piston therein, a shaft that is driven by the piston, a carbureter through which air is drawn by the suction action of the piston and into which the fuel is drawn by the action of the flowing stream of air, a valve for controlling communication between the carbureter and the cylinder, a'device for opening and closing the valve that is actuated by the shaft and keeps the valve fully open during a period corresponding with a region including to the middle portion of the suction stroke of the piston under the light load conditions, and means for varying the action of the device on the valve so that it is kept fully open for successively longer periods as the speed decreases or the load increases.

2. In an internal combustion engine, the combination of a cylinder, a iston therein, a shaft that is driven by the piston, a carbureter through which air is drawn by the suction action of the piston and into which fuel is drawn by the action of the flowing stream of air, an inlet valve for controlling the flow of the charge from the carbureter to the cylinder, a device for opening and closing the valve that is actuated by the shaft and keeps the valve fully open during a period corresponding to a region at the middle portion of thesuction stroke of the piston under light load conditions, and means for varying the action of the device on the valve so that it is kept fully open for successively longer periods as the speed decreases or the load increases, the variation being by equal increments on each side of said region.

3. In an internal combustion engine, the combination of a cylinder a piston therein, a carbureter through which air is drawn by the suction action of the piston and into which fuel is drawn by the action of the flowing stream of air, an inlet valve for controlling the admission of the charge to the cylinder, a cam which under light load and high speed fully opens the valve so that it admits a charge and subsequently closes it while the piston is assing through a region including the mid le portion of its suction stroke, and means for varying the action of the cam on the valve to cause [said valve to remain fully open for successively longer periods as the speed decreases and the load increases, the variation being by equal increments on each side of said reglon.

4. In an internal combustion engine, the combination of a cylinder, a iston therein, a main shaft driven by the plston which is arranged transversely to the axis of the cylinder, a carbureter through which air is drawn by the suction action of the piston and into which fuel is drawn by the action of the flowing stream of air, a valve for regulatin the admission of the charge to the cylin er, a stem for the valve which is parallel to the axis of the cylinder, a cam shaft parallel to the main shaft and driven therefrom, a variable throw cam on the shaft which cooperates with the stem to fully open and close the valve during the middle portion of the suction stroke of the piston, and means for moving the cam axially to vary its action on the valve.

5. In an internal combustion engine, the combination of a cylinder, a piston therein, a carbureter through which air isidrawn by the suction action of the piston and into which fuel is drawn by the action of the flowing stream of air, a valve for controlling the flow through the carbureter into the cylinder, and a cam for actuating the valve which always opens it full open after the beginning of the suction stroke of the iston and closes it before the end of said stro re.,

6. In an internal combustion engine, the combination of a cylinder, a piston, a carbureter through which air is drawn by the suction action of the piston and into which fuel is drawn by the action of the flowing stream of air, a valve for controlling the flow through the carbureter into the cylinder, a cam for actuating the valve which always opens it full open after the beginning of t e suction stroke of the piston and closes it before the end of said stroke, and means for varyin the action of the cam on the valve to there y vary the length of time that the valve remains fully open.

7. In an internal combustion engine, the combination of a cylinder, a piston, a carbureter through which air is drawn by the suction, action of the piston and into which fuel is drawn by the action of the flowing stream of air, a valve controlling the flow through the carbureter into the cylinder, a variable throw cam which operates the valve to admit a charge during the middle portion of the suction stroke of the piston under light load conditions, and means for shifting the cam to cause the valve to admit the charge during longer portions of said stroke as the load increases, said portions increasing by equal increments on both sides of said middle portion, and said valve always opening full open for admission of the charge.

n witness whereof, I have hereunto set my hand this 25th day of October, 1907.

JAMES S. ANTHONY Witnesses:

I. BONEPARTH, Lao C. Foss.