US2991055A

US2991055A - Fuel injection system

Info

Publication number: US2991055A
Application number: US649716A
Authority: US
Inventors: Robert J Powell; James E Champion
Original assignee: Continental Motors Corp
Current assignee: Continental Motors Corp
Priority date: 1957-04-01
Filing date: 1957-04-01
Publication date: 1961-07-04
Anticipated expiration: 1978-07-04

Description

July 4, 1961 R. J. POWELL ET AL 2,991,055

FUEL INJECTION SYSTEM Filed April 1, 1957 2 Sheets-Sheet 1 INVENTORS ROBERT J. POWELL BY JAMES E. CHAMPION ATTOR July 4, 1961 R. J. POWELL ET AL 2,991,055

FUEL. INJECTION SYSTEM Filed April 1, 1957 2 Sheets-Sheet 2 I FIG-.3.

52 gg 4s K W 390 4 39b l5 VJ 5| 59 580 set) INVENTORS ROBERT J. POWELL Y JAMES E.CHAMP|ON ATTO S FUEL INJECTION SYSTEM Robert J. Powell and James E. Champion, Muskegon, Mich, assignors to Continental Motors Corporation, Detroit and Muskegon, Mich., a corporation of Vir- Filed Apr. 1. 1957, Ser. No. 649,716

This invention relates to fuel injection systems for internal combustion enginesfand more particularly to a continuous flow fuel injection system preferably adapted foruse' in mutli-cylinder type engines and having a simplified fuel pressure delivery system.

Continuous flow fuel injection systems are desirable for multi-cylinder engines,particularly for aircraft, because of the relative simplicity of construction and operation and the fact that such systems reduce icing. However, these systems heretofore failed to meet efiicient and reliable performance standards without being made correspondingly complex. The fuel metering .valve and associated components are particularly susceptible to failure and variations in operation the more complex they become, as well as being highly expensive and. dilficult to adjust and repair.

Another complication that arises in continuous flow fuel injecion systems is the fact that variations in fuel pump inlet pressure makes the maintenance of a uniform maximum fuel pump delivery pressure very difiicult.

An object of the present invention is to provide effective fuel injection for internal combustion engines by constructing a continuous flow fuel pressure delivery and metering system.

Another object of the invention is to improve fuel injection by providing a rugged and simplified fuel injection system operable to deliver and meter fuel efficiently under all engine operating conditions.

A further object of the invention is to provide an inexpensive and dependable fuel injection system for internal combustion engines by constructing a simplified continuous flow metering valve operable to meter fuel effectively in response to engine throttle operation and provided with means fonmaintaining a substantially uniform maximum fuel pump delivery pressure to the metering valve irrespective of fuel pump inlet pressure variations.

'A still further object of the invention is to improve fuel injection by providing a relief valve associated with the fuel pump delivery outlet and operable to maintain a substantially uniform maximum delivery pressure irlivery pressure caused by variation in pump inletpressure.

For a more complete understanding of the invention, reference may be had to the accompanying drawings illustrating" a preferred embodiment of the invention in which like characters refer to like parts throughout the several views and in which i r FIG. 1 is a diagrammatic view of a preferred fuel in- 2,991,055 Patented July 4, 1961 valve structure 15, a fuel distributing manifold 16, and a plurality of fuel injectors 17 adapted to inject fuel into an air intake manifold 18, an injector being installed for each engine cylinder air intake. An air throttle valve 19 is adjustably disposed in an air intake section 18a of the manifold 18 .and is preferably connected by suitable linkage 20 to the fuel metering valve 15.

Fuel is pumped from the tank 10 through pipes or

conduits

25 and 26 into the intake side of the pump assembly 14. Fuel under pressure is then pumped through a conduit 28 to the fuel meteringvalve 15, where a metered amount of fuel is delivered to the fuel manifold 16 through a conduit 24 for distribution to the injectors 17 in accordance with engine fuel requirements as determined by. the operation of the throttle 19.

For proper mixture control, a'portion of the fuel may be spilled from the metering valve 15 to return through a conduit 29 for recirculation to the pump assembly 14.

A preferred construction for the fuel injection metering valve structure 15 is illustrated in FIG. 3 as comprising a valve housing 35 having a fuel inlet port 36 adapted for connection with the outlet side of the pump assembly 14 through the conduit 28, a fuel delivery outlet port 37 adapted for connection with the fuel distributing manifold 16 through the conduit 24, and a fuel spill outlet port 38 adapted for connection with the intake side of the pump assembly 14 through the conduit 29 and the vapor separator 55.

A longitudinal bore 39 extends through the housing 35, and is separated by a fixed or stationary divider element 40 into two bore sections 39a and 3%. A fuel metering passage 41in the divider element 40 is open on opposite faces thereof respectively to the bore sections 39a and 39b.

A fuel mixture control valve member 42 is rotatably supported in the bore section 39a and abuts the face of the fixed divider element 40. An adjustable fuel metering control valve member 43 is rotatably supported in the bore section 3912 and abuts the opposite face of the divider element 40. The metering control valve member 43 is provided with a lever 44 which is adapted to be operatively connected to the linkage 20 shown in FIG. 1 for operation relative to operation of the throttle valve 19. The

control valve members

42 and 43 are preferably axially aligned in the bore 39.

An annular groove 45 is provided in the valve member 42 and is continuously openly connected with a fuel inlet passage 46 indicated by dotted lines in FIG. 3, provided in the housing 35 and connected with the inlet port 36. The passage 46 extends from the inlet port 46 up ward behind the member 42 shown in FIG. 3 and interice sects the side of the bore 39 hidden from view by the member 46. A groove 47 is provided on the end of the valve member 42 which abuts the divider element 40 and a fuel passage 48 in the valve member 42 connects the groove 47 with the annular groove 45. Fuel is thereby continuously conducted from the port 36 through the passage 46 to the groove 45 and thence through the passage 48 to the arcuate groove 47.

A fuel 'spill passage50 provided in the housing 35 connects the bore section 39a with the fuel spill outlet port 38. The groove 47 of the valve member 42 is arranged so that angular adjustment thereof will open and close the spill passage 50 simultaneously as the metering passage 41 is respeotively closed and opened.

In the rich mixture position of the valve member 42, the metering passage 41 is fully open and the spill passage 50 is fully closed. A full flow of fuel under pressure is provided through the metering passage 41. In the lean mixture position of the valve member 42, the metering passage 41 is partially closed and the spill passage is partially open. In the fuel cutoff position of the valve member 42, the metering passage 41 is fully closed and the spill passage 50 is fully open, providing for a full return of all the fuel to the intake side of the pump 14. A lever 51 is preferably provided on the outer end of the valve member 42 for manual operation thereof or for connection to any desired type of suitable actuating means.

The end of the metering control valve 43 which abuts the divider element 40 is provided with a groove 52 which upon operation of the valve 43 in response to throttle operation, selectively opens and closes the fuel metering passage 41 to provide effective metering of fuel. A fuel passage 53 connecting the bore section 39b with the fuel delivery outlet port 37 is arranged to be open to the groove 52.

The fuel pump assembly 14 as illustrated diagrammatically in FIG. 1 preferably includes a vapor separator 55 connected with the conduit 26, a fuel pump 56 having an inlet 56a connected with the vapor separator 55 and an outlet 56b connected with the conduit 28 and through a restricted orifice 57 with an inlet 58a of a relief valve 58. A relief valve outlet 58b is connected through a suitable passage 59 with the vapor separator 55 and thence with the inlet 56a of the pump 56. The vapor separator 55 in essence is a chamber in which the fuel from

conduits

26 and 59 is angular-1y whirled before discharging into the passage leading to the intake 56a of the pump '56. Vapor thus collects in the center of the chamber and is withdrawn by means of a venturi 55a through which fuel under pressure passes from a passage 55b to a conduit 55c leading to the fuel tank 10. A bypass passage 55d is also provided. The vapor separator itself is the subject matter of our copending application Serial No. 640,044 and is not illustrated here in detail.

As may be seen from FIG. 2, the relief valve 58 comprises a two-part housing 59 preferably having a valve member 60. A fuel pressure inlet chamber 61 connected with the inlet 58a is opened and closed on axial movement of the valve member 60 shown in open position to relieve excess fuel pressure into an outlet fuel chamber 62, connected with the outlet 58b.

An atmospheric pressure chamber 63 is separated from the outlet fuel chamber 62 by a diaphragm member 64 connected between the valve member 60 and the housing 59. The diaphragm member 64 has an effective area equal to the effective area of the valve member 60. A spring element 65 tends to urge the valve member 60 into the closed position. The atmospheric pressure chamber 63 is connected with atmosphere preferably through a port 66, so that fuel pump inlet pressure in the chamber 62 is effectively balanced against atmospheric pressure. Thus fuel pump inlet pressure variations are effectively nullified and will not affect fuel pump delivery pressure, which remains at a substantially uniform maximum value during normal system operation, this maximum value being determined as in the usual relief valve by the pressure exerted by the spring 65. Since the fuel pump delivery is generally always greater than engine requirements, the relief valve member 61 will be normally continuously open, permitting excess fuel to pass back to the inlet side of the pressure pump 56. The restricted orifice 57 is provided to set up resistance to undesirable increased fuel flow through the relief valve 58 in response to any increased engine speed which increases fuel pump delivery pressure when there is no change in the regulated outlet area of the fuel metering passage 41 of the fuel metering valve 15.

We claim:

1. 'A fuel injection system for direct continuous injection of fuel into the air induction system of an internal combustion engine, said air induction system having an air induction manifold and an adjustable air throttle valve associated therewith for varying engine speed, said fuel injection system comprising a fuel supply source, a fuel pressure pump adapted to'be driven by said engine, said pump assembly having an intake connected with said fuel supply source a delivery outlet and, a fuel metering valve structure having an inlet connected with said pump delivery outlet and a regulatablefuel discharge outlet connected with said air induction system downstream of said throttle valve, a metering valve means operatively .connected with said throttle valve to vary the opening of said discharge outlet in response to throttle valve operation, a fuel pressure relief valve associated with said fuel pump delivery outlet, said relief valve constructed and arranged to normally maintain a substantially uniform maximum fuel pump delivery pressure irrespective of variations in fuel pump intake pressure, and a restrictedorifice of fixed predetermined size disposed ahead of said relief valve to restrict increased fuel flow to said relief valve on an increase of fuel pump delivery while said [fuel metering discharge outlet opening remains substantially constant, said relief valve comprising valve actuating means connected with atmosphere and with said pump intake and operable to balance pump intake pressure against atmospheric pressure to nullify the effect of pump intake pressure on pump delivery pressure.

i 2. A fuel injection system for direct continuous injection of fuel into the air induction system of an internal combustion engine, said air induction system having an air induction manifold and an adjustable air throttle valve associated therewith for varying engine speed, said fuel injection system comprising a fuel supply source, a fuel pressure pump adapted to be driven by said engine; said pump assembly having a delivery outlet and an intake connected with said fuel supply source, a fuel metering valve structure having an inlet conected with said pump delivery outlet and a regulatable fuel discharge outlet connected with said air induction system downstream of said throttle valve, a metering valve means operatively connected with said throttle valve to vary the opening of said discharge outlet in response to throttle valve operation, a fuel pressure relief valve associated with said fuel pump delivery outlet, said relief valve constructed and arranged to normally maintain a substantially uniform maximum fuel pump delivery pressure irrespective of variations in fuel pump intake pressure, and a restricted orifice of fixed predetermined size disposed ahead of said relief valve to restrict increased fuel flow to said relief valve on an increase of fuel pump delivery while said fuel metering discharge outlet opening remains substantially constant, said relief valve comprising a valve housing structure having an inlet openingly connected with said orifice and an outlet openly connected with said fuel pump intake, valve means in said housing and normally operable to maintain the aforesaid maximum pump delivery pressure, said valve means having a pressure responsive element connected between said valve outlet and atmosphere and operable to nullify the effect of pump intake pressure on pump delivery pressure.

References Cited in the file of this patent UNITED STATES PATENTS 1,376,201 Harris Apr. 26, 1921 2,136,959 Winfield Nov. 15, 1938 2,759,468 Powell Aug. 21, 1956 2,785,669 Armstrong Mar. 19, 1957 2,791,205 Platner et a1. May 7, 1957 2,813,522 White et al Nov. 19, 1957 2,816,745 McCain Dec. 17, 1957 2,849,999 Morris Sept. 2, 1958 2,851,026 Dah-l et 'al Sept. 9, 1958