US3494337A - Intake manifold pressure responsive fuel injection system - Google Patents

Description

Feb. 10, 1970 R. ALDERSON 3,

INTAKE MANIFOLD PRESSURE RESPONSIVE FUEL INJECTION SYSTEM 2 Sheets-Sheet 1 m mh INVENTOE EDW/A/RAZDEQSO/V 5 QRNEV Q w m E e m J Q. m ow O F Feb. 10, 1970 R; ALDERSON v 3,494,337

INTAKE MANIFOLD PRESSURE RESPONSIVE FUEL INJECTION SYSTEM Filed June 24, 1968 8 I INVENTOIE 1 [aw/m2 Amz-Psav I'M- H I BY XM A ORNEY United States Patent INTAKE MANIFOLD PRESSURE RESPONSIVE FUEL INJECTION SYSTEM Edwin R. Alderson, Decatur, Ill., assignor to Borg- Warner Corporation, Chicago, lll., a corporation of Delaware Filed June 24, 1968, Ser. No. 739,349 Int. Cl. F02d 11/08, 1/04, 1/06 US. Cl. 123103 8 Claims ABSTRACT OF THE DISCLOSURE A fuel injection system including a fuel metering arrangement responsive to engine intake manifold pressure. A fuel delivery control mechanism including a throttle controlled modulation valve is responsive to throttle position and provides a modifying signal which alters the normal metering signal. By this action, the fuel rate at a given intake manifold pressure is increased providing additional fuel for that position of the engine throttle.

Background of the invention This invention relates to a control mechanism for an internal combustion engine fuel delivery system. More particularly, it relates to a throttle actuated modulator valve for varying fuel delivery rate of a fuel injection system.

In certain types of fuel injection systems such as those shown in United States Patents 2,984,232, 3,100,449 and 3,149,619, intake manifold pressure is used as a signal to control the fuel delivery rate. As the manifold pressure varies, the fuel delivery rate is proportionately altered.

For certain operating conditions, control of fuel delivery rate solely in proportion to intake manifold pressure provides satisfactory engine performance. However, in general, engine fuel demand is affected by other operating parameters such as engine speed, and engine load. Additionally, operational characteristics of the fuel injectors, fuel delivery and metering apparatus, and the control servo-mechanism all contribute to the establishment of a non-linear relationship :between intake manifold pressure signal and actual fuel demand at a particular speed and load. For these reasons, the fuel rate needed for proper engine operation at a given load point may not be reflected by the intake manifold signal received. That is to say, the same intake manifold signal, and consequently, the same fuel rate, may be obtained at various combinations of speed, load and throttle position. This fuel rate, however, may be the most desirable for only one of these various operation positions. It is desirable therefore, to provide an arrangement for modulating the manifold pressure signal in order to compensate for the effects of the other engine parameters mentioned.

As is well known, the principal control mechanism for an internal combustion engine is the throttle. It has been found that modulation of the intake manifold signal in relation to throttle fly position provides an effective solution to the problem of proper fuel delivery under all operating conditions.

Accordingly, it is the principal object of the present invention to provide an improved fuel delivery system which effectively modulates the fuel metering signal in response to throttle fly position.

Summary of the invention A modulator valve is provided which is responsive to engine throttle fly position to vary the signal received by the fuel metering arrangement. This valve introduces a signal which modulates the sensed manifold pressure 3,494,337 Patented Feb. 10, 1970 signal to produce a combined signal providing increased fuel rate at a given intake manifold pressure.

Particular objects and advantages of the present invention will become more readily apparent with reference to the following description and accompanying drawings.

Description of the drawings FIGURE 1 is an elevational view, partly in section, and partially schematic, of an apparatus illustrating various features of the present invention;

FIGURE 2 is a plan view of a portion of the apparatus of FIGURE 1;

FIGURE 3 is a fragmentary view, partly in section, illustrating an alternate position of a portion of the apparatus of FIGURE 1; and

FIGURE 4 is an elevational view of a part of the apparatus of FIGURE 1 illustrating particular details of the apparatus.

Detailed description Referring now to the drawings there is shown a fuel delivery control arrangement for an engine having a fuel injection system which is illustrative of the principles of the present invention.

As best seen in FIGURE 1 the fuel delivery system generally designated 10 is associated with an engine including an intake manifold 12 and a throttle or air valve 14. The system includes a fuel tank 16, a fuel injection metering and delivery pump 18, a metering servo 20 and a modulator valve 24.

The throttle valve 14 includes a generally vertical throat 26 extending between an inlet air filter assembly 28 and the intake manifold. An aperture 30 is provided in the manifold to allow passage of air from the throat 26 to the manifold for distribution to the engine combustion chambers.

A throttle fly 32 is pivotally supported within the throat 26 upon an actuator shaft 34 which extends outwardly of the throat. The fly 32 is operatively connected to a linkage 36 (see FIGURES 2 and 3) including a lever arm 38, to which is pivotally connected a motion transfer lever 40 associated with the accelerator (not shown) of a vehicle. Movement of the accelerator by the operator of the vehicle will therefore be effective to position the throttle fly for proper air flow through the throttle valve throat 26.

The linkage 36 also includes a curved following lever 42 secured to the shaft 34 for rotation therewith. An adjustable turn-buckle type link 44 (see FIGURE 4) is pivotally secured to the lever 42 and is operatively connected to the modulator valve 24 for purposes as will become apparent shortly.

The throttle valve 14 additionally includes a retention flange 46 defining a transverse passage 48 communicating with the throat 26 downstream of the throttle fly.

Turning again to the fuel delivery control system 10, the fuel metering and delivery pump 18 is adapted to receive fuel from the tank 16 and accomplish controlled distribution of metered quantities of fuel to a series of injectors (not shown) through delivery lines 50 (only one of which is shown). The fuel is metered by the servo 20 which moves in response to a manifold pressure signal to position a cam (not shown) connected to an operator shaft 52. This movement in turn controls the pump delivery volume to provide a metered fuel charge. These system elements are well known in the art and representative arrangements are shown in United States Patents 2,984,232; 3,100,449, and 3,149,619. The important factor to be noted is that the fuel is metered in response to a sensed manifold pressure signal.

The metering serve 20 is in communication with a manifold pressure signal through a conduit 54 connected between the servo and the modulator valve 24.

The modulator valve, best seen in FIGURES. 1 and 2, includes a housing 56, conduit couplings 58 (see FIG- URE 2) and 60 and spool 62.

The housing includes a mounted flange 63 secured to the retention flange of the throttle fly in overlying relation to the transverse passage 48. This flange 63 includes aperture 64 open to the interior of the housing. An orifice plate 65 is secured to the flange 63 and includes a restricting orifice 66 communicating between the passage 48 and the interior of the housing 56 through the aperture 64.

The housing 56 is divided into a manifold signal receiving chamber 67 adjacent the aperture 64 and a modulating signal receiving chamber 68 by a pair of spaced apart inwardly directed sealing lands 70. A pair of spaced apart support hubs 72, best seen in FIGURE 2 are provided in general alignment with the lands. These hubs rotatably support the valve spool 62.

The conduit coupling 58 is connected to one of the hubs as shown in FIGURE 2. This hub includes an appropriately formed receptacle. This coupling is also connected to the conduit 54 extending between the servo 20 and the modulator valve 24. The other conduit coupling 60 is connected to the portion of the housing forming the modulation signal receiving chamber 68.

Each coupling includes a central passageway in communication with the interior of the housing 56. Thus the servo 20 is in communication with the interior of the modulator valve housing at the hub 72 and the chamber 68 is in communication with the atmosphere through the coupling 60. The coupling 60 may, if desired, be connected to a conduit (not shown) which extends into the intake air filter 28 to prevent introduction of contaminated air into the system.

The valve spool 62 is generally cylindrical in shape and is rotatably supported within the hubs 72. A shaft portion 76 extends from an appropriate opening in the hub 72 and is provided with a lever 77 connected to the turnbuckle link 44. Movement of the throttle fly 32 therefore causes corresponding movement of the spool 62.

The diameter of the spool 62 is approximately equal to the distance between the sealing lands 70 so that the spool effectively seals the chamber 67 from the chamber 68.

The valve exterior diameter is provided with a flat 78 which, when aligned with one of the sealing lands 70, defines a port 80 communicating between the chambers 67 and 68, as best seen in FIGURE 3.

As can be appreciated, rotation of the valve spool 62 between the closed position shown in FIGURE 1 and the open position shown in FIGURE 3 varies the effective orifice size of the port 80 to produce variable flow between the chamber dependent upon the particular position of the spool 62.

The spool 62 additionally includes a longitudinal passage 82 open at the hub 72 which includes the coupling 58. A transverse passage 84 is provided which is in communication with the passage 82 and open at the flat 78. Appropriate seals are provided between the housing hubs 72 and the spool 62 to prevent leakage between the chambers 67 and 68 when the valve is in the closed position or leakage between the hub 72 containing the coupling 58 and the chamber 68.

When the spool 62 is in the closed position, a manifold pressure signal is communicated to the servo 20 through the restricting orifice 66, the aperture 67, the passages 82 and 84 of the spool 62, the coupling 58 and the conduit 54. So long as the spool remains in the closed position engine fuel rate will be determined by intake manifold pressure. Variations in the manifold pressure 'will therefore produce corresponding variations in fuel delivery rate.

When the spool 62 is positioned such that the fiat 78 is aligned with the opposing sealing land 70 to define the port 80 communicating between the chambers 68 and 67 a modified signal is produced. Atmospheric pressure .is communicated to the transverse passage 84 through the port to modify the sensed manifold pressure signal. Since the manifold pressure is below atmospheric pressure the combined signal will be increased, resulting in an increased fuel delivery rate.

It is of the utmost importance that the modulation of the manifold pressure signal takes place at the appropriate condition of engine operation. For that reason, the spool 62 of the modulator valve 24 is connected through the turn-buckle link 44 to the throttle fly linkage. Thus movement of the throttle fly 32 produces corresponding movement of the modulator valve spool between its closed and open positions.

The link 44 is adjusted to establish the proper relationship between throttle fly position and spool position to produce initiation of the modulation signal at the proper time.

Experience with the injection systems described in the previously mentioned patents has shown that at a given load there is a tendency for the system to go lean as engine speed is increased. That is to say, the fuel output per stroke of the injection pump at a given intake manifold pressure will decrease as engine speed is increased. By modulating the fuel control signal in response to throttle fly opening, the output of the pump can be increased to produce the desired fuel delivery rate.

The relationship between size of the restricting orifice 66, diameter of the passage in the conduit coupling 60 and the set length of the turn-buckle type link 44 determine the modulation characteristics of the valve. The link 44 is adjusted to establish the point of opening of the valve with respect to throttle fly position. The size of the restricting orifice 66 controls the vacuum rate and thereby determines the amount of modulating signal admitted into the system. This is true because of the pressure difference across the orifice 66 provides for flow of the modulating signal air into the throttle valve throat 26 and the orifice size determines the maximum flow rate. The size of the passage in the conduit coupling 60 in turn determines the maximum modulating air flow rate by limiting the air source. By adjusting these elements, a system of modulation can be established which provides a fuel delivery signal precisely matched to the engine fuel requirements throughout the entire range of speed and load.

Various features of the invention have been particularly shown and described in connection with the illustrated embodiment of the invention. However, it must be understood that these particular arrangements merely illustrate and that the invention is to be given its fullest interpretation within the terms of the appended claims.

What is claimed is:

1. In a fuel injection system for an internal combustion engine, a fuel delivery control mechanism including, a servo responsive to a pressure signal to control engine fuel delivery rate, a modulator valve including a housing defining a manifold signal receiving chamber and a modulating signal receiving chamber, said valve including means for connecting said manifold signal receiving chamber with a source of engine intake manifold pressure, and means for connecting said modulating signal receiving chamber with the atmosphere, said valve further including a spool disposed intermediate said chambers movable between a closed position separating said chambers and at least one open position providing communication therebetween, said spool including a passage communicating with said manifold signal receiving chamber when said spool is in said closed position and in communication with both said chambers when in said open position, a conduit connected to said modulator valve and said servo communicating between said passage in said spool and said servo, and a linkage connected to said spool to effect movement between said closed and open positions, said linkage being adapted for connection to a throttle fly of said engine to move said spool in response to movement of said throttle fly.

2. A fuel delivery control mechanism as claimed in claim 1 wherein said spool is movable between said closed position and a plurality of open positions providing varying degrees of communication between said chambers.

3. A fuel delivery control mechanism as claimed in claim 2 wherein said housing includes a pair of spaced apart sealing lands disposed intermediate said chambers and said spool is generally cylindrical and sized to sealingly engage said lands when in said closed position, said spool further including a fiat formed on the exterior thereof positionable with respect to one of said lands upon movement of said spool to define a port between said fiat and said land providing communication between said chambers.

4. A fuel delivery control mechanism as claimed in claim 3 wherein said means connecting said manifold signal receiving chamber with a source of engine intake manifold pressure includes a restricting orifice, said means communicating said modulating signal receiving chamber with the atmosphere including a coupling including a passage therethrough, and wherein said linkage includes an adjustable turn-buckle type link.

5. A fuel injection system for an internal combustion engine having an intake manifold, an air throttle secured to said intake manifold including a movable throttle fly for controlling the passage of intake air through said air throttle, said fuel injection system including a fuel delivery and metering pump, a fuel delivery control mechanism to control the fuel delivery rate comprising; a servo responsive to a pressure signal to control engine fuel delivery rate, a modulator valve including a housing defining a manifold signal receiving chamber and a modulating signal receiving chamber, said valve including means connecting said manifold signal receiving chamber with a source of engine intake manifold pressure, and means connecting said modulating signal receiving chamber with the atmosphere, said valve further including a spool disposed intermediate said chambers movable between a closed position separating said chambers and at least one open position providing communication therebetween, said spool including a passage in communication with said manifold signal receiving chamber when said spool is in said closed position, and in communication with both said chambers when in said open position, a conduit connected to said modulator valve communicating between said passage in said spool and said servo and a linkage connected to said spool to effect movement between said closed and open positions, said linkage being connected to said throttle fiy of said engine to move said spool in response to movement of said throttle fly.

6. A fuel injection system for an internal combustion engine as claimed in claim 5 wherein said spool is mov able between said closed position and a plurality of open positions providing varying degrees of communication between said chambers.

7. A fuel injection system for an internal combustion engine as claimed in claim 6 wherein said housing includes a pair of spaced apart sealing lands disposed intermediate said chambers and said spool is generally cylindrical and sized to sealingly engage said lands when in said closed position, said spool further including a fiat formed on the exterior thereof positionable with respect to one of said lands upon movement of said spool to define a port between said flat and said land providing communication between said chambers.

8. A fuel injection system for an internal combustion engine as claimed in claim 7 wherein said means connecting said manifold signal receiving chamber with a source of engine intake manifold pressure includes a restricting orifice, said means communicating said modulating signal receiving chamber with the atmosphere including a coupling including a passage therethrough, and wherein said linkage includes an adjustable turnbuckle type link.

References Cited UNITED STATES PATENTS 2,132,445 10/ 1938 Schweizer. 2,659,354 11/1953 Nicolls. 2,702,029 2/ 1955 Burton. 2,727,504 12/ 1955 Peras. 2,751,897 6/1956 Schweizer et a1. 2,821,372 1/1958 Nystrom et al. 2,841,131 7/ 1958 Zupancic. 2,849,999 9/ 195 8 Morris. 2,984,232 5/1961 Arndt. 3,100,449 8/ 1963 Dahl.

WENDELL E. BURNS, Primary Examiner US. Cl. X.R.

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