US2872912A

US2872912A - Fuel injection system

Info

Publication number: US2872912A
Application number: US567830A
Authority: US
Inventors: Paul E Braun
Original assignee: Ford Motor Co
Current assignee: Ford Motor Co
Priority date: 1956-02-27
Filing date: 1956-02-27
Publication date: 1959-02-10
Anticipated expiration: 1976-02-10

Description

Feb. 10, 1959 P. E. BRAUN 2,872,912

FUEL INJECTION SYSTEM Filed Feb. 27, 1956 2 Sheets-Sheet l III/III "Illllllrlll/ llllli REBRAUN INVENTOR. .5. 971051; BY v 5454/1641 ATTORNEYS Feb. 10, 1959 P. E. BRAUN FUEL INJECTION SYSTEM 2 Sheets-Sheet 2 Filed Feb. 27, 1956 P. E. BRAUN INVENTOR.

ATTORNEYS 2,372,912 7 I FUEL INJECTION SYSTEM Paul E. Brauu, Birmingham, Mich., assignor to Ford Motor Company, Dearborn, Mich, corporation of Delaware 1 Application February 27, 1956, Serial No. 567,830

6 Claims. or. 125-439 This invention relates to internal combustion engines andrnore particularly to an apparatus for metering and distributing liquid fuels into the intake system of" such engines. The apparatus of this invention is conspicuous because of ease and economy with which it can be manufactured and maintained, chiefly due to the absence of close tolerances and critical fits.

This invention may best be understoodfrom a study of the figures of drawing in which.

Figure 1 is an elevation partially in section of one embodiment'of the invention; and

Figure 2 is a sectional drawing taken alongthe line 2-2 of Figure l; and

Figure 3 is a section drawing taken along the line 3-3 of Figure 2; and

Figure 4 is a partial cross section taken along the line 4-4 of Figure 3; and

Figure 5 is a plan view of a cam employable in this invention.

This invention is directed primarily to a metering and distributing device in contradistinction to the means employed for generating the pressure necessary to inject the fuel. The device of this invention'is designed to receive the fuel from any suitable pressure source under a moderate pressure and to distribute this pressurized fuel to the proper combustion area at the desired time and in the proper amount. The pressure difference between the inlet and outlet of the metering and distributing device is desirably very small.

The heart of this apparatus is piston which oscillates axially within the limits imposed by

stops

12 and 19. This structure is shown in Figures 2 and 4. Each complete oscillation of piston 10 fuels two cylinders, one being fueled as the piston 10 moves to the right and the second as piston 119 moves to the left. Piston 10 is propelled exclusively by the pressure of the fuel. Figures 2 and 4 show that the movement of piston 10 to the left is limited by a fixed stop 19, the position of which remains fixed once established. The movement of piston 11) to the right is controlled by movable stop 12. It is the position of movable stop 12 which controls the quantity of fuel metered by each stroke of piston 10. The farther piston 11) is permitted to move to the right by movable stop 12, the greater is the quantity of fuel handled for each stroke in each direction.

Since the quantity of fuel to be metered for each stroke is a readily ascertainable function of the absolute pressure in the intake manifold, this parameter is employed to fix the position of movable stop 12. Figure 1 illustrates one apparatus employed for this purpose. Intake manifold pressure, or a pressure which is a function of intake manifold pressure is introduced into dome 11 through opening 24. Diaphragm 25 is spring biased downwardly and assumes an equilibrium position in which the spring bias is balanced by atmospheric pressure. Control rod 22 is secured to diaphragm 25 and moves axially in response to movements of diaphragm 25. Control rod 22. is provided intermediate its ends with a ramp 23 which is aligned with movable stop 12 (Figure 2). Movable stop 12 is spring biased to the left to "ice partially relieve the thrust to the right generated by the fuel pressure upon movable stop 12.

The flow of fuel through the apparatus is controlled by an arrangement of poppet valves which are controlled by cam 13 (Figures 2 and 5) which is rotated at camshaft speed. lt can be seen from Figure 5 that cam 13 is divided into an inner section 16 and an outer section 14, inner section 5 having four equally spaced lobes and outer section 14 having only one lobe, said lobe being spaced intermediate an adjacent pair of the lobes on inner section 16. The flow of fuel through outlets 18 (Figures 2 and 3) is controlled by means of the lobes on outer section 1 1 and the flow of fuel through the inlets 211 (Figure '4) is subject to the control of the sole lobe on inner section 16.

Figure 3 depicts an inlet and outlet arrangement suitable for a conventional eight cylinder engine. The eight outlets 18 are evenly spaced about the periphery of the mechanism and the two inlets 20 are spaced asymmetrically with respect to each other and intermediate outlets 123. Each of outlets 18 is controlled by its individual outlet poppet valve 17 and each of the inlets 20 is controlled by individual inlet poppet valve 15, outlet poppet valves responding to outer'section 14 of cam 13,

and inlet poppet valves responding to inner section 16 of cam 13.

With reference to Figure 4, gasoline under pressure.

enters inlets 20 (only two in number) and establishes a fuel pressure in passages 61. At the instant of time depicted in Figure 4, cam 13 has opened upper inlet poppet valve 15 and permitted fuel to flow as shown by the dotted arrowed line from upper passage 61 past inlet poppet valve 15 and on into the space between the left side of piston 11) and fixed stop 19 and will tend to drive piston 10 to the right. At an instant later than that shown in Figure 4, upper inlet poppet valve 15 will close and lower inlet poppet valve 15 will open and permit fuel to W past this valve from lower passage 61 as shown by the dotted arrowed line and into the space between the right side of piston 11) and movable stop 12. This flow of fuel will tend todrive piston 10 to the left. Each of inlet poppet valves 15 will open four times for each revolution of the camshaft and their combined effect will be to cause piston 10 to make four complete oscillations and to admit eight discrete quantities of gasoline into the spaces swept by piston 10.

Figure 2 illustrates the operation of the discharge side of the pump. Here is shown two outlets 18 although it is to be understood that for an eight cylinder engine the number of outlets would be eight. (Figure 3). In Figure 2 a dotted arrowed line has been provided showing the path provided for fuel from the space to the right of piston 10 and between piston 10 and movable stop 12 past upper outlet poppet valve 17 and to upper outlet 18. At the instant of time depicted in Figure 2, upper outlet poppet valve 17 is open to permit the passage of fuel being propelled by the movement of piston 10 to the right. Similarly a dotted arrowed line has been provided showing the passages provided for the fuel to flow from the left side of piston 10 and the space between piston 10 and fixed stop 19 past lower outlet poppet valve 17 and to lower outlet 18. It is to be understood that each outlet 18 is similarly connected to one or the other side of piston 10, although in the interest of clarity only two such connections have been shown.

. These connections are made so that successive outlets 18 are connected to alternate sides of piston 10.

The operation of the above described device is as follows.

instant all'four outlet poppet valves 17 in communication One of the lobes on inner section 16 of cam 13 opens one of inlet poppet valves 15 permitting fuel. to enter the space on one side of piston 10. At thiswith this particular side of the piston it; are closed. On the opposite side of the shuttle are, of course, located four more outlet poppet valves 17 and at this instant one of these four valves has been opened by the lobe on outer section 14 of cam 13. 'The fuel which is dis placed by the movement of piston will ii-av. out only throughthis particular outlet poppet valve 17 and to outlet 18 and hence to the proper combustion area. Furthe rotation of the cam will close the inlet poppet valve 15 first opened as well as the outlet poppet valve 1 7 first opened and open the other inlet poppet valve 15 and another outlet poppet valve 17 located on the opposite side of piston it). By a continuation of this operation, fuel is sequentially injected into each of the eight cylinders under consideration.

While this apparatus has been particularly described with reference to an eight cylinder engine, it is to be understood that the number of outlets can readily be adjusted for any desired number of cylinders as one skilled in the art will readily appreciate.

It will be understood that the invention is not to be limited to the exact construction shown'and described, but that various changes and modifications may be made without departing from the spirit and scope of the invention, as defined in the appended claims.

I claim as my invention? 1. A fuel metering and distributing apparatus for an internal combustion engine having combustion cylinders comprising a cylinder, a piston freely and axially movable in saidcylinder, means limiting the axial motion of the piston in the cylinder, at least one of said motion limiting means being adjustable, a fuel inlet passageway leading from said cylinder on one side of said piston to a source of fuel under pressure, a second fuel inlet passageway leading from the cylinder on the other side i of said piston to a source of fuel under pressure, each of said passageways being controlled by a separate poppet valve, and a plurality of separate fuel outlet passageways one each for each combustion cylinder leading alternately from the cylinder on one side ofthe piston and from the cylinder on the other side of the piston, each of said fuel outlet passageways being separately controlled by a separate poppet valve.

2. A fuel metering and distributing apparatus for an internal combustion engine comprising a cylinder, a piston freely and axially movable in said cylinder, a fixed stop limiting movement of the piston in one direction, a movable stop responsive to engine operating conditions limiting the movement of the piston in the other direction, a fuel inlet passageway leading from said cylinder on one side of said piston to a source of fuel under pressure, a second fuel inlet passageway leading from the cylinder to the other side of said piston to a source of fuel under pressure, each of said passageways being controlled by a separate cam actuated poppet valve, and a plurality of fuel outlet passageways leading alternately from the cylinder on one side of the piston and from the cylinder on the other side of the piston, each of said fuel outlet passageways being separately controlled by a separate cam actuated poppet valve, and engine driven means operable to open said valves in timed sequence.

3. The combination of an internal combustion engine having a plurality of combustion cylinders and a fuel metering and distributing apparatus, said fuel metering and distributing apparatus comprising a cylinder, a piston freely and axially movable in said cylinder, a fixed stop limiting movement of the piston in one direction, a movable stop responsive toengine operating conditions limiting the movement of'the piston in. the other direction, a fuel inlet passageway'leading from said cylinder on one side of said piston to a source of fuel under pressure, a. second fuel inlet passageway leading from the cylinder on the other side of said piston to a source of fuel under-pressure, each of said passagewaysbeing' controlled 4 .r by engine driven valve means, and a fuel outlet passage for each combustion cylinder of said internal combustion engine, said fuel outlet passageways leading alternately from the cylinder on one side of the piston and from the cylinder on the other side of the piston, each of said fuel outlet passageways being separately controlled by engine driven valve means, and at least one of said valve means including a poppet valve.

4. The combination of an internal combustion engine having 2 N combustion cylinders and a fuel metering and distributing apparatus, said fuel metering and distributing apparatus comprising a cylinder, 2. piston freely and axially movable in said cylinder, a separate means limiting the movement of saidpiston at each end of said cylinder, said means including at least one means responsive to engine operating conditions, a fuel-inlet passageway leading from saidcylinder on one side of said piston to a source of fuel under pressure, a second fuel inlet passageway leading from the cylinder on the other side of said. piston-to a source of fuel under pressure, each of said passageways being controlled by a separate poppet valve, 9. fuel outlet passage for-each combustion cylinder of said internal combustion engine, said fuel outlet passageways leading alternately from the cylinder on one side of said piston and from the cylinder on the other side of the piston, each of: said fuel outlet passageways being separately controlled by a separate poppet valve, and cam means for operating said poppet valves, said cam means being driven at camshaft speed, having a single lobe for operating the outlet poppet valves and N lobes for operation of the inlet poppet valves.

5. A fuel injection system comprising a fuel chamber, a shuttle in said chamber, a fuel pressure source, fuel inlet valves, fuel discharge valves, valve opening means, at least one of said fuel inlet valves and said discharge valves being in a communicating position with each side of said shuttle in said chamber, said shuttle moveable axially in said chamber under pressure from fuel entering through said fuel inlet valves, said valve opening means providing timing of said inlet valves and said discharge valves so that an inlet valve provides fuel to one side ofsaid shuttle forcing said shuttle axially toward an open discharge valve, said valve opening means providing valve-operating cams, said cams arranged to open and close said'valves in timed relation.

"6. A fuel injection assembly for an engine having a plurality of combustion areas comprising a pressure source, a' metering chamber, a shuttle member, means for directing fluid alternately toward the ends of said shuttle causing said shuttle to reciprocate in said chamher, said means providing a directed fuel discharge to a combustion area on each stroke of said shuttle, pressure source check valves being between said pressure source.

itlld 'said metering chamber, combustion area check valves being between said metering chamber and combustion areas, said valves being reciprocally mounted and urged to a closed position, valve operating means to open said pressure source valves intermittently to provide fluid entry'to said chamber and to open said combustion area valves to provide fluid exit from said chamber, said valve operating means including a drivable face plate having a pair of substantially circular and concentric cams thereon, and'a valve opening push rod for each valve operable by said cams and arranged so that one of said cams controls said pressure source valves and the other of said cams controls said combustion area valves.

References Eited in the file of this patent UNlTED STATES PATENTS Vincent Sept. 8, 1936 2,655,907 Downing Oct. 20, 1953 2,673,662 Bensinger Mar. 30, 1954 FOREIGN PATENTS