US3820332A

US3820332A - Fuel metering control for fuel injection systems

Info

Publication number: US3820332A
Application number: US00362573A
Authority: US
Inventors: E Crowe
Original assignee: Individual
Current assignee: Individual
Priority date: 1971-06-07
Filing date: 1973-05-21
Publication date: 1974-06-28
Anticipated expiration: 1991-06-28

Abstract

A fuel metering control device for use in controlling the position of an adjustable shuttle stop in a fuel distributing unit employed in a fuel injection system for internal combustion engines automatically controls the fuel-air mixture in response to throttle position as well as air pressure in the intake manifold.

Description

United States Patent 1191 1111 3,820,332 Crowe 1 1 June 28, 1974 1 FUEL METERING CONTROL FORFUEL 2,827,852 3/1958 Links 123/139 AM INJECTION SYSTEMS 3,650,257 3/1972 Soltay et a1 123/140 CC [75] Inventor: Eugene Melroy Crowe, Corte M d ,C l'f. I a era a] 1 Primary Examiner-Carlton R. Croyle 1 Asslgneer ph y Hammond. a Assistant Examiner-Warren Olsen par Interest Attorney, Agent, or Firm-Merriam, Marshall, Shapiro 22 Filed: May 21, 1973 211 Appl. No.: 362,573

Related US. Application Data [63] Continuation of Ser. No. 150,688, June 7, 1971, [57] ABSTRACT abandoned.

[52] us. CLW 60/13 R, 123/139 AM 123/140 CC A fuel metering control device for use in controlling 51 1m. 01. .f. F02b 37/04 an adjustable Shuttle in a fuel of Search" AM 140 tributing unit employed in a fuel lfljCCtlOl'l system for 60/13 internal combustion engines automatically controls the fuel-air mixture in response to throttle position as [56] References Cited well as air pressure in the intake manifold.

UNITED STATES PATENTS 2,670,724 3/1904 Reggio 123/140 cc 4 Claims, 4 Drawing Figures PATENTEI] Jul 28 H74 FIG. 4

INVENTOR EUGENE CROWE BYM,MJA Mf/%J ATTORNEYS FUEL METERING CONTROL FOR FUEL INJECTION SYSTEMS This is a continuation of application Ser. No. 150,688, filed June 7, 1971, now abandoned.

SUMMARY OF THE INVENTION The present invention relates to a fuel metering control device. In general, it concerns a control device for use in automatically controlling the air-fuel mixture in a fuel injection system. More particularly, it pertains to a fuel metering control device for use in controlling the position of an adjustable shuttle stop in a fuel distributing unit employed in a fuel injection system for internal combustion engines.

BACKGROUND OF THE INVENTION Fuel injection systems are employed'with internal combustion engines used in passenger cars as well as racing cars. As compared to carbureted engines, engines employing fuel injection systems generally offer the potential advantages of improved fuel economy at equivalent performance or, conversely, increased performance for equivalent consumption. In addition, fuel injection systems when properly operated afford a practical means for decreasing exhaust emissions. In racing cars, fuel injection systems are, of course, generally used in attempts to improve performance. In such instances, turbochargers or superchargers are also commonly employed in order to obtain greater horsepower output from the engine by pressurizing the air supplied to the intake manifold of the engine. One commonly employed fuel injection system, sometimes referred to as the Lucas fuel injection system, employs a fuel metering or distributing unit which receives fuel at a constant pressure (for example, 100 lbs. per sq. inch) and the metering unit distributes the fuel to the fuel injectors. The metering and distributing unit employs a reciprocating shuttle which, in association with a rotor and suitable inlet and outlet ports, provides each cylinder of the engine with an injection of fuel, the amount of which is determined by the axial movement of the shuttle. The axial movement of such a shuttle is determined by an adjustable shuttle stop. The position of the adjustable shuttle stop is generally controlled by a device which changes the position of the shuttle stop in response tochanges in throttle position. US. Pat Nos. 2,807,252, 3,452,729, 3,487,821 and 3,491,738 for example, disclose such fuel injection systems employing fuel distributing units which employ a reciprocating shuttle, an adjustable shuttle stop, and means for controlling the adjustable shuttle stop.

Turbocharged or supercharged engines are of course, operated over a range of conditions including low air pressure (i.e., no boost or low boost) and high air pressure (i.e., high boost) conditions. As a result, unless the air-fuel mixture is changed to compensate for such changes in condition, at certain times the engine receives an over-rich fuel mixture while at other times it may receive an over lean fuel mixture. In attempts to overcome this problem, and to obtain the correct mixture for all RPM and power ranges some. turbocharged fuel injected engines have employed two separate fuel control systems or circuits, one of which is a manually operated circuit for controlling the air-fuel mixture when the engine is operating at low speed, low boost conditions. The other or second circuit which operates in response to throttle changes is for high speed, high boost conditions. However, these later systems do not permit a smooth transition when going from low speed, low boost to high speed, high boost conditions, and as a result, an engine so equipped often manifests an RPM range where the engine does not receive the correct air-fuel mixture. Accordingly, there is a need for a fuel metering control device which will provide automatic control of the air-fuel mixture at all conditions of engine operation.

DESCRIPTION OF THE INVENTION According to the present invention, there is provided an improved fuel metering control device particularly useful, for example, with turbocharged engines. The device provides a means for automatically controlling the fuel-air mixture by adjusting the volume of fuel in the mixture in response to both changes in throttle position and changes in air pressure in the intake manifold. The present invention will be better understood by reference to the accompanying illustrative drawings in which:

FIG. 1 is a fragmentary perspective view of a turbocharged fuel injected internal combustion engine equipped with a fuel metering control device of the present invention.

FIGS. 2, 3 and 4 are all fragmentary elevational view showing the relative positions of certain parts of the control device.

Referring to the drawings, there is shown an internal combustion engine 10 provided with twin turbochargers 11 and 12. Turbochargers 11 and 12 supply pressurized air to air box or plenum chamber 13 via conduits l6 and 17 respectively. Engine 10 is further equipped with a fuel injection system generally comprising fuel injector stacks l4 and fuel distributor 20. Pressurized air from plenum chamber 13 is supplied to injector stacks 14 and from the stacks 14 to engine 10 via intake manifold 15. Fuel distributor 20 is pulley mounted to engine 10 by a half speed jack shaft (not shown). The other end of fuel distributor 20 is provided with a control device housing 21. Housing 21 supports spindle or shaft 23. Engine 10 is further equipped with an air motor 30 affixed to engine 10 by a mounting bracket 31. Air motor connecting rod 32 connects or fastens to lever or arm 26 by connecting or fastening means 33. Air motor 30 includes a pressure sensing conduit (not shown) which provides means for communicating intake manifold air pressure to air motor 30. Throttle linkage means 36 connects arm or lever 35 which is fixadly attached to shaft 23 in such a manner that when lever 35 is moved by throttle linkage means 36, shaft 23 rotates.

As can be best seen in FIGS. 2, 3 and 4, an intermediate portion of shaft 23 is provided with an eccentric cam 24. Arm 26 is preferably provided with a bushing 25 to provide a bearing surface between arm 26 and cam 24.

Stops

28 and 29 which are shown as integral to housing 21 limit the travel of arm 26. Arm 26 is provided with a profiled surface 27 which abutts adjustable shuttle stop 22. The size and shape of eccentric cam 24 as well as the size and shape of profiled surface 27 of arm 26 will, of course, depend in part upon the particular fuel distributor 20 with which these elements are used. Those skilled in the art will be able to develop the desired sizes and shapes of both cam 24 and profiled surface 27 for any particular application by routine experimentation using, for example, dynamometer readmgs.

Air motor 30 is a device which is capable of sensing pressure and providing a mechanical displacement proportioned thereto. Such devices are known in the art and generally comprise, for example, a bellows-type diaphram with an attached piston which may be spring resisted and which when air pressure is applied'results in the piston moving or displacing a distance proportional to the applied air pressure.

In operation, air motor 30 is used as part of the fuel metering control device of the present invention to sense the pressure intake manifold 15 and to provide a displacement of connecting rod 32 an amount proportional to the pressure sensed. Rod 32 in turn mechanically actuates arm 26 and rotates arm 26 about shaft 23 as illustrated by the change in position of arm 26 in FIGS. 3 and 4. As is apparent from the drawings, such change in position of arm 26 causes its profiled surface 27 which abutts shuttle stop 22, to move stop 22, and thus change the distance which a reciprocating shuttle (not shown) can travel. ln changing from the position shown in FIG. 3 to that shown in FIG. 4, the profiled surface 27 of arm 26 has moved stop 22 downward and thus reduced the distance that the shuttle can travel and therefore also reduced the quantity of each fuel increment leaving distributor 20. Such a change would be initiated by air motor 30 sensing a decrease in intake manifold pressure.

The change in positions of lever 35, shaft 23, cam 24 and stop 22 from the positions illustrated in FIG. 2 to the positions shown in FIG. 3 depict the control action which occurs when a decrease in throttle actuates a reduction in fuel. As is apparent from the above description the control device of the present invention provides means for automatically adjusting the fuelair mixture in response to both changes in throttle position and intake manifold pressure.

While the present invention has been described and with reference to certain preferred illustrated embodiments obvious modifications with the spirit and scope of the invention will be apparent to those skilled in the art.

What is claimed is:

1. A fuel metering control device for usein regulating the position of an adjustable shuttle stop in a fuel .distributing unit employed in a fuel injection system for an internal combustion engine and said engine having an intake manifold for feeding fuel to the engine and also having an exhaust manifold for removing exhaust gases, and said fuel metering control device being responsive to both intake manifold pressure and the position of a throttle linkage mechanism, said control device comprising:

an air motor adapted to continuously sense the pressure in the intake manifold and having a connecting rod extending therefrom to provide a mechanical displacement proportional to pressure changes within said intake manifold;

a profiled cam member abutting the shuttle stop and being rotatable to reciprocate the shuttle stop;

a rotatable cam shaft having a cam portion located eccentrically with respect to the cam shaft, and further said cam portion providing a bearing for rota-- tional movement of the profiled cam member whereby rotation of. said cam shaft provides vertical displacement of the profiled cam member; lever means connecting the profiled cam member and the rotatable cam shaft with the connecting rod of the air motor and the throttle linkage v whereby movement of either or both the throttle linkage and the connecting rod will produce responsive reciprocal movement of the shuttle stop.

tion engine having a fuel injection system.

Claims

1. A fuel metering control device for use in regulating the position of an adjustable shuttle stop in a fuel distributing unit employed in a fuel injection system for an internal combustion engine and said engine having an intake manifold for feeding fuel to the engine and also having an exhaust manifold for removing exhaust gases, and said fuel metering control device being responsive to both intake manifold pressure and the position of a throttle linkage mechanism, said control device comprising: an air motor adapted to continuously sense the pressure in the intake manifold and having a connecting rod extending therefrom to provide a mechanical displacement proportional to pressure changes within said intake manifold; a profiled cam member abutting the shuttle stop and being rotatable to reciprocate the shuttle stop; a rotatable cam shaft having a cam portion located eccentrically with respect to the cam shaft, and further said cam portion providing a bearing for rotational movement of the profiled cam member whereby rotation of said cam shaft provides vertical displacement of the profiled cam member; lever means connecting the profiled cam member and the rotatable cam shaft with the connecting rod of the air motor and the throttle linkage whereby movement of either or both the throttle linkage and the connecting rod will produce responsive reciprocal movement of the shuttle stop.

2. The control device of claim 1 in which said lever means includes a first lever member connecting the profile cam member with the rod extending from the air motor; and; a second lever member connecting the throttle linkage with the rotatable cam shaft.

3. The control device of claim 1 in which said cam portion of the rotatable cam shaft is integrally formed with the cam shaft.

4. The control device of claim 1 in which the internal combustion engine is a turbo charged internal combustion engine having a fuel injection system.