US2384282A

US2384282A - Fuel injector control mechanism

Info

Publication number: US2384282A
Application number: US451873A
Authority: US
Inventors: Milton E Chandler
Original assignee: Chandler Evans Inc
Current assignee: Chandler Evans Inc
Priority date: 1942-07-22
Filing date: 1942-07-22
Publication date: 1945-09-04
Anticipated expiration: 1962-09-04

Description

P 1945- M. E. CHANDLER 2,384,282

FUEL INJECTOR CONTROL MECHANISM Filed July 22, 1942 l4 8 /3 I 24 v y as 6 9 26 Q 88 u I 2 7 V /8 J 98 V I I so I f 2 so v I 27 i -86 v Q f 8; Fuel 1 z gp %1\ 11 1/ 19 I as 35 's 44 1 3 4 5 J /2 3, 3 5/ 40 57 6 5a 1 3g mvtrwon Ml H011 Efihan dler BY A WATTORY av.

- ll, suitably connected Patented Sept. 4, 1945 2,384,282 FUEL msscroa comer. MECHANISM Milton E. Chandler, New Britain, Conn., assignor to Chandler-Evans Corporation, a corporation I i ofDelaware Application July 22, 1942, Serial No. 451,873 I 8 Claims. (01. 123-140) My invention relates mechanism.

It has among its objects to provide an improved control mechanism adapted to use in internal combustion engines equipped with fuel injectors, and, more particularly, to control such engines used on airplanes or the like. A further object of my invention is to provide such an improved controlling mechanism wherein the quantity of fuel delivered through the injectors to the engine is so controlled as to vary as a function of air flow. A further object of my invention is to provide improved injector controlling servomechanism controlled as aforesaid and controlling the by-passing of fuel around the fuel injector pump to vary the quantity Of fuel delivered to the injectors. Other objects of my invention are to provide such an improved system especially adapted to use in connection with supercharged engines and wherein the operation of a servomechanism is automatically controlled in an improved manner in accordance with variations in the operation of the engine. These and other objects and advantages of my improvements will, however, hereinafter more fully appear.

In the accompanying drawing, I have shown for purposes of illustration two embodiments which my invention may assume in practice.

In this drawing,

Figure 1 is a diagrammatic view of a supercharged airplane engine equipped with my improvements, the same being shown, for simplicity of illustration. applied to a single cylinder of the engine, and .i

Fig. 2 is a similar diagrammatic view of a modified form of the servo-mechanism.

In the illustrative embodiment in Figure 1, I have shown an airplane engine, generally indicated at I. including a plurality of cylinders, one of which is shown for illustrative purposes at 2 having a piston 3 movable therein, with fuel being supplied to the cylinder through an injector nozzle 4 and air through a connection 5 from a manifold 6 connected to a supercharger l which, in turn, receives its air supply from a scoop 8 through an air venturi 9, while my improved controlling mechanism controls the fuel supply to the injector nozzle 4 in accordance with variations in air flow as hereinafter described. v

The fuel is supplied to the injector 4 from a tanl: III by a constant pressure fuel transfer pump to said tank through an inlet pipe [2, While the pump II delivers through a discharge pipe l3 and a check valve l4 into a to fuel injector control a diaphragm" in a closed casing 3 l venturi 35 and leads chamber I 5 which communicates through a check valve IS with a pipe l'l delivering to the injector As shown, an injector pump l8 acts upon the fuel in the chamber ii to deliver the same to the indector at the desired pressure through the check valve I6, this pump i8 being operated by a suitable eccentric It on theengine I. Further, a by-pass 20 isprovided between the chamber l5 and the inlet of the pump H, and the flow throughthis by-pass 20 is'automatically varied as hereinafter described by an injector controlling valve 2l, herein a needle valve longitudinally adjustable relative to a tapered seat 22 in the wall of casing 23 enclosing the chamber l5 and opposite check valve ll.

Cooperating with this injector control valve 2| is improved controlling mechanism therefor controlled by the air flow through the air scoop l and air venturi I to the supercharger I. Herein, this mechanism includes a pipe 24 connected to the scoop I and a pipe 25 connected to the throat of the air venturi 9. As shown, a valve 26 controlled by an aneroid 21 is also connected in a by-pass 2! connecting the pipes 24 and 25 in such manner as to compensate for variations in altitude. The pipe 24 connected to the scoop is also connected by a pipe 29 leading to one side of while a pipe 32 leads from the pipe 25 and the venturi throat, to the opposite side of the diaphragm 30 in the casing 3|. As shown, a valve stem 33. is connected to the diaphragm 30 and a coil sprin 33 normally biases this diaphragm and valve stem to the right. Thus, it will be apparent that as the airflow to the supercharger 1 and engine manifold 6 varies, the pressures in the throat of the venturi 9 and scoop 8 will be transmitted to opposite sides of the spring loaded diaphragm 30 in such manner as to adjust the valve stem 33 in accordance with variations in the differential of throat and scoop pressures.

Operatively associated with the mechanism including the air controlled diaphragm 30 is also fuel pressure controlled diaphragm mechanism. As shown, a venturi 35 is provided in the fuel inlet pipe l2 .--leading to the fuel pump H, and a pip 36 leads from the one side of a fuel pressure controlled diaphragm 31 in a closed casing 38, corresponding to the casing 3!, while a pipe 39 is also connected to the fuel inlet pipe l2 on the inlet side of the to the opposite side of the diaphragm 31.

Operatively connected to the valve stem 33 is an improved cooperating servo-mechanism, generthroat of this venturi to bers 43 and 48, respectively, to a common return side of the pump 48.

passage 88 to the intake having pipes 8|a, 82a

Outlet ports 8| and 82 leading therefrom are also controlled by the spools 4| and 42, and one of these pipes lilo communicates with a cylinder 88 on one side of a piston 84 carrying the injector controlling valve 2|, while the other pipe 82a delivers to said cylinder on the opposite side of the piston 84.

Thus, as the valve stem 88 is adjusted to the left upon an increase in air flow through the air venturi 8, the spools 4|, 42 will be moved to the left relative to the ports 8|, 82 in the servomechanism 48, and oil will be supplied from the pump 48 through the inlet 41 and the port 8| to the pipe 5|a to move the piston 84 to the left and thereby tend to close the injector control valve 2|, while the oil on the opposite side of the piston 84 will be free to return through the pipe 82a to port 82 and chamber 48, and, through the causes a reduction in the pressure differential on the opposite sides of diaphragm 88, and a consequent movement of the spools 4| and 42 to the right, thereby connecting the outlet of oil pump 48 thru inlet 41, chamber 44, port 82 and pipe 82a to cylinder 83 at the left of piston 84. At the same time, the cylinder at the right of piston 84 is vented thru pipe ila, port 8|, chamber 43, and passages 48 and 88 to the inlet side of pump 48. The piston 54 therefore moves to the right, opening the by-pass valve 2|, and decreasing the quantity of fuel flowing to the engine.

It will, accordingly, be evident that the injector control valve 2| will be moved to the-left, i. e., to reduce the amount of fuel discharged from the chamber l8 through the by-pass 28, and returned to the inlet side of the fuel pump II and thereby increase the flow to the injector 4, whenpassages 48 and 58, to the inlet side of the pump On the other hand, a decrease in theair ever the air flow to the engine increases in such manner as to cause the air diaphragm 88 to be moved to the left. Similarly, when the air flow decreases, the valve 2| will be opened to increase,

the fuel flow through the by-pass 28 and accordingly increase the amount of by-passed fuel and reduce the fuel supply to the injector 4.

Whenever the piston 84 starts to move the valve 2| in either direction, the motion continues until the valve stem 88 is restored toits normal position wherein does not occur until the fuel flow is changed by an amount such that the new fuel differential pressure acting on diaphragm 81 balances the new air differential pressure acting on diaphragm 38.

Cooperating with the above described servomeehanism further to control the position of the spools 4| and 42 is mechanism controlled by the pressure in the manifold 6. As shown, an extension is provided on the right hand end of the valve stem 38 and extends into an end aneroid chamber 55a, while a coiled spring 58 acts beports 8| and 82 are closed. This lever 58 and has its opposite end fixed to the casing 82, while a coiled spring 88 inside the aneroid normally expands the latter. As shown, a pipe 84 connects the chamber a with the manifold. Thus, as the air flow to the engine increases and the pressure increases in the manifold 8, whenever the bellows 8| collapses sumciently to overcome the spring 88, the upper end of lever 58 will be swung to the left to impart a further movement of the stem 88 to the left and thereby enrich the mixture; while upon a decrease in pressure in the manifold, the aneroid expands, thereby causing a'movement of stem 88 to the right, in a fuel flow decreasing direction. When the bellows 8| expands far enough so that the upper end of lever 88 is stopped by the casing 82, the valve stem 88 is then placed wholly under the control of diaphragms 28 and 81.

In the operation of the complete device, the variations in air flow to the supercharger 'I will cause adjustment of the air diaphragm 88 as a function of the differential of throat and scoop pressures in the air venturi 8, while the fuel diaphragm 81 will act to balance the air diaphragm 88 due to its connection to the throat and scoop of the fuel venturi 88. With the spools 4| and 42 movable with the valve stem 88, oil flow from the inlet 41 will be controlled by the diaphragms 88 and 81 and spools 4|, 42, in such manner as to adjust the injector control valve 2| to open or close the by-pass 28, and, as a result, decrease or increase the quantity of fuel delivered by the injector pump i8 through the pipe l1 to the injector nozzle 4. Thus, the fuel supplied by the injector nozzle 4 to the cylinder 2 will be varied as a function of the quantity of air being delivered to the cylinder throughout the normal operation of the engine. When, however, the pressure in the manifold 8 increases, as, for example, during overload, the pressure therein will be transmitted through pipe 84 to aneroid 8|, and a further movement of the spools 4|, 42 in the same direction will be effected as a result of the increase in air flow, in such manner as thereby further to enrich the mixture automatically as a function of the in, crease in pressure in the manifold.

A throttle 88 is located in the air induction system downstream from the venturi 8. The throttle 88 rotates on a shaft which also carries an arm 82, manually operable by means of a suitable handle 88. Arm 82 is pivotally attached to a link 84 whose opposite end is pivoted on an arm 88. The arm 88 is pivotally mounted on a fixed support 88. The arm 88 carries near its upper end a pin 88.

A rod 82 is attached to the piston 84 and extends to the outside of cylinder 88. The outer end of rod 82 is pivotally connected to a link 84, which is pivoted at an intermediate point on an arm 88 whose opposite end is attached to the fixed support 88. The lower-end of link 84 carries a cam 88 which cooperates with the pin 88.

When the parts are in the positions shown in the drawing, the throttle is somewhat more than half open, and the pin 88 has been moved to a position where it is not in the path of motion of cam 88. As the throttle is moved toward closed position, the arms82 and 88 are moved counterclockwise, carrying the pin 88 to the right. As

the motion of'pin 88 to the right continues, a

position is reached where it engages cam and forces the link 64 to rotate in a counterclockwise direction, thereby moving the piston 54 and valve 2| to the left, or in a valve closing direction. This closing movement of valve 2| causes an increased discharge of fuel to the engine by the pump I6 and hence results in an enrichment of the mixture of fuel and air supplied to the engine.

This throttle controlidle mechanism is provided to insure that the mixture will be sufficiently rich during idling to enable the engine to run smoothly. I

In Fig. 2, I have shown a modified construction of servo-mechanism. This mechanism generally corresponds to that heretofore described, save that a reversible electric motor 66 is provided connected through any usual telescopic threaded connection 61 with an injector control valve 66 corresponding to the valve 2|, while a reversing switch 69 has}; control lever HI disposed between spaced spools H on a valve stem 12 to the valve stem 33. The remainder of the mechanism being that heretofore described, it will be evident that this mechanism will function essentially similarly, with the reversing switch 69 operated as the valve stem 12 is moved reversely, and this switch 69 acting to reverse the motor 66 in such manner as thereby, through the threaded connection 61, to reversely operate the injector controlling valve 68 in the same sequence as heretofore.

It will be understood that in the use of my improved construction for airplane engines, I contemplate the provision of the usual ignition mechanism (not shown) in the cylinder. It will be evident, however, that if desired, the above described control mechanism may be used without such ignition mechanism in a usual Diesel installation.

While I have in this application described certain fornis which my invention may assume in practice, it will be understood that the same are shown forpurposes of illustration, and that the invention may be modified and embodied in v various other forms without departing from its spirit or the scope of the appended claims.

What I claim as new and desire to secure by Letters Patent is:

1. In a fuel injector control mechanism, an air conduit, controlling means responsive to variations in the quantity of air flowing through said conduit, hydraulic control mechanism controlled by said controlling means, fuel injector mechanism including an injector pump having a valve for varying the delivery of,said pump, means controlled by said hydrauliccontrol mechanism for adjusting said valve to vary the delivery of said pump as a function of air flow, a throttle controlling the air flow through said conduit, and means controlled by said throttle for automatically varying the delivery of said pump during idling.

2. In a fuel injector control mechanism, an air conduit, controlling means responsive to variations in air fiow through said conduit, fuel injector mechanism including an injector pump having a valve for varying the delivery of said pump, a reversible motor for reversely operating said valve, and means including a reversing switch for said motor reversely operated by said controlling means as the air flow through said conduit increases or decreases for operating said motor and actuating said valve to vary the delivery of said pump as a function of air flow.

3. In a fuel supply system for an internal comcorresponding bustion engine, a first conduit for supplying combustion air to said engine, means for creating a first differential pressure indicative of the quantity of air fiowing thru said conduit, a second conduit for supplying fuel to said engine, means ,;said motor means, means for controlling the supply of energy to said motor means including a member having a normaljijposition in which said motor means is stationary and effective upon movement from said normal position in opposite directions to cause operation of said motor means in opposite directions, first flexible diaphragm means responsive to said first pressure differential, second flexible diaphragm means responsive to said second pressure differential, and means connecting both said diaphragm means to said member so as to cause movement of said member when" the forces acting on said diaphragm means are unbalanced, said member being effective whenmoved from said normal position to cause operation of said motor means in the proper direction to vary said one differential pressure until said diaphragms and member are returned to said normal positiomso that said diaphragms remain in said normal position when the differential pressures are balanced, regardless of the position of said control means, and means responsive to the pressure in the intake manifold of said engine and effective when said intake manifold pressure exceeds a predetermined value to apply to said member a force opposed to that applied by said second diaphragm means so as to cause operation of said motor means in a direction to increase the ratio of fuel-to-air supplied to said engine.

4. In a fuel injection system for an internal combustion engine, a first conduit for supplying combustion air to said engine, means associated with said conduit for producing two unequal pressures whose difference is a measure of the rate of flow of air thru said conduit, a throttle for controlling the fiow of air thru said conduit, injector pump means for delivering fuel at high pressure to the combustion chambers of said engine, a second conduit for conveying fuel to said injector pump means, a metering restriction in said second conduit for producing a differential pressure indicative of the quantity of fuel flowing therethru, means responsive to the difference between said air diiferential pressure and said fuel differential pressure for controlling the delivery of said injector pump means, and means controlled by said throttle for varying the delivery of said pump means during idling.

5. In a fuel supply system for an internal combustion engine, a first conduit for supplying com- 1 bustion air to said engine, means for creating a first differential pressure indicative of the quantity of air flowing thru said conduit, a second conduit for supplying fuel to said engine, means for creating a second differential pressure indicative of the quantity of fuel flowing thru said ,second conduit, means for controlling the flow thru one of said conduits and thereby one of said differential pressures, electrical motor means for operating said flow controlling means, a source of electrical energy for said motor means, means for controlling the supply of electrical energy to said motor means including a switch having a normal position in which said motor means 4 is stationary and eifective upon movement from said normal position in opposite directions to close electrical circuits which cause operation of said motor means in opposite directions, first flexible diaphragm means responsive to said first pressure diiferential. second flexible diaphragm means responsive to said second pressure differential, and means connecting both said diaphragm means to said switch so as to cause'movement of said switch when the forces acting on said diaphragm means are unbalanced, said switch being effective when moved from said normal position to cause operation of said motor means in the proper direction to vary said one differential pressure until said diaphragms and member are returned to said normal position, so that said diaphragms remain in said normal position when the differential pressures are balanced, regardless of the position of said control means, and means responsive to the pressure in the intake manifold of said engine and effective when said intake manifold pressure exceeds a predetermined value to apply to said switch a force opposed to that applied by said second diaphragm means so as to cause operation of said motor means in a direction to increase the ratio of fuelto-air supplied to said engine.

6. In a fuel supply system for an internal combustion engine, a first conduit for supplying combustion air to said engine, means for creating a first differential pressure indicative of the quantity of air flowing thru said conduit, a second conduit for supplying fuel to said engine, means for creating a second diilerentiai pressure indicative of the quantity of fuel flowing thru said second conduit, means for controlling the flow diaphragm means so as to cause operation of said thru one of said conduits and thereby one of said differential pressures, hydraulic motor means for operating said fiow controlling means, a source of fluid under pressure for supplying energy to said motor means, means for controlling the supply of fluid to said motor means including a valve having a normal position in which said motor means is stationary and eifective upon movement from said normal position in opposite directions to cause operation of said motor means in opposite directions, first flexible diaphragm means responsive to said first pressure differential, second flexible diaphragm means responsive to said second pressure differential, and means connecting both said diaphragm means to said valve so as to cause movement of said valve when the forces acting on said diaphragm means are unbalanced, said valve being effective when moved motor means in a direction to increase the ratio of fuel-to-air supplied to said engine.

'7. In a fuel supply system for an internal combustion engine, a first conduit for supplying combustion air to said engine, means for creating a first diiferential pressure indicative of the quantity of air flowing thru said conduit, a second conduit for supplying fuel to said engine, means for creating a second differential pressure indicative of the quantity of fuel flowing thru said second conduit, means for controlling the flow thru one of said conduits and thereby one of said differential pressures. first diaphragm means responsive to said first pressure differential, second diaphragm means responsive to said second pressure differential, means connecting both said diaphragm means to said flow controlling means, said diaphragm means being effective to operate said flow controlling means to maintain a substantially constant fuel-to-air ratio, and means responsive to the pressure in the intake manifold of said engine and effective when said intake manifold pressure exceeds a predetermined value to apply to said valve a force opposed to that applied by said second diaphragm means so as to cause operation of said motor means in a direction to increase the ratio of fuel-to-air supplied to said engine.

8. In a fuel supply system for an internal combustion engine, in combination, means for conveying air to said engine for combustion purposes, an injector pump for delivering fuel to said engine, a fuel pump for supplying the inlet of said injector pump with fuel under superatmospheric pressure, means for controlling the quantity of fuel delivered to said engine by said injector pump, electrical motor means for driving said delivery controlling means, and means responsive to the quantity of air supplied to said engine for controlling said electrical motor means.

MILTON E. CHANDLER.