US2897808A - Fuel injection system - Google Patents

Description

Aug. 4, 1959 w. c. SUTTLE FUEL INJECTION SYSTEM 3 Sheets-Sheet l Filed July .31, 1956 INVENTOR. W/QQD C. SUTTLE.

ATTORNEY.

Aug. 4, 1959 w. c. sUTTLE 2,897,808

'FUEL INJECTION SYSTEM Filed July 3l, 1956 5 Sheets-Sheet 2 IN VEN TOR.

WYRD C. SUTTLE 4 gM/w A TTORNEY.

Aug. 4, 1959 W. C. SUTTLE FUEL INJECTION SYSTEM Filed July 51, 195e 5 Sheets-Sheet 3 RE TURN T0 SUPPLY TANK .E d RL N m-. R mw m W5 ff. A C. MQW Mw A v T l-El FUEL INJECTION SYSTEM 4Ward C. Suttle, South Bend, Ind., assignor to Bendix Aviation Corporation, South Bend, Ind.,'a corporation of Delaware The present invention relates generally to fuel injection systems and more particularly to systems of the type wherein fuel is injected into the induction passage for cylinders of an engine in thev form of individual charges in timed relation to engine operation.

It is an object of the present invention to provide in a fuel injection system a control for accurately modulating in accordance with engine requirements the quantity of fuel injected as a function of manifold pressure.

It is another object of the invention to provide in a wobble plate type injection pump an improved control for varying the angular position of the wobble plate as a function of manifold pressure.

Itis a further object of the invention toprovide in a fuel injection system `for accurately modulating in accordance with engine requirements the quantity of fuel linjected as a function of engine operating conditions such as manifold pressure and engine temperature.

It is still a further object of the invention to provide an improved control for a fuel injection system which is responsive to changes in atmospheric pressure, engine or ambient temperature and induction passage pressure to modulate the quantity of fuel supplied to the engine in accordance with engine requirements.

Other objects and advantages of the present invention will become apparent during the course of the following description, reference being had therein to the accompanying drawings, in which:

Figure 1 is a vertical sectional View of a fuel injection system embodying my invention taken along line 1--1 of `Figure 2; t

`Figure 2 is a view taken along line 2--2 of Figure 1;

Figure 3 is a sectional View taken along line 3-3 of Figure 2; v t.

Figure 4 is a sectional view taken along line 4-4 of Figure l; and e Figure 5 is a partial view of Figure 1 showing the servo valve in open position.

Referring now to the drawings, there is shown a fuel injection system Ihaving a housing containing a plurality of cylinders 12 in each of which is located a plunger 14 urged outwardly by a spring 16 into engagement with a wobble plate or thrust member 18 which is pivoted to a shaft 20 by means o f a pin 22. Shaft 20 is adapted to be driven as a function of engine speed by appropriate means (not shown). Wobble plate 18 is provided with an annular carbon bearing face 24 which is positioned in a backing member 26 formed with two rearwardly projecting bifurcated members 28 and 30. A link 32 is pivotally secured at one end to member 28 and at the other end to a turned out portion 34 formed on a dish-shaped element 36. Diametrically opposed to portion 34 is a turned out portion 38 formed on element 36 for slidable reception within the bifurcated member 30. The dish-shaped element 36 is secured to a sleeve 40 which is reciprocably mounted on shaft 20. A second sleeve 42 reciprocably mounted on sleeve 40 is secured to a cylinder 44 as by a press t. Cylinder 44 'is provided with a pair of diametrically opposed pins 4S and a turned over portion `46 the latter being per-v forated at 48 to reciprocably receive a guide pin 50 `which is secured to the housing 10.

United States Patent O 5 nce Pins 45 are adapted to be received in the bifurcated ends of a U-shaped actuating member 52 which is secured to a rod 54 by appropriate means such as dowel 56. Rod S4 is journalled in housing 10 for rotation by a Icontrol device designated generally at 58 to reciprocably actuate sleeve 44 to engage dished element 36 causing element 36 and sleeve 40 to move axially whereby through link 32 wobble plate 18 is caused to rotate about its pivot 22.

Control device 58 includes means responsive to changes in induction passage pressure 60, a temperature responsive element 62 and means responsive to changes in atmospheric pressure 64. Means 60 includes a piston or movable wall 66 which is mounted in a cylinder 68 formed in housing 10. Piston 66 is subjected to induc tion passage or manifold pressure through a conduit 70 which opens into cylinder 68. A spring 72 is located in cylinder 68 and exerts a force on piston 66 in opposition to the force of manifold pressure. One end of spring 72 engages a spring retainer 74 which in turn is engaged by an abutment member 76 the latter being centrally secured to a diaphragm 78. Diaphragm 78 is marginally clamped to housing 10 by a cover member 80 and is subjected on one side to atmospheric pressure in chamber 82 and on the other side to fuel pressure in chamber 84. Fuel is supplied under pressure to chamber 84 from a source (not shown) via conduit 86 and restriction 87. Fuel is conducted from chamber 84 to a place of lower pressure such as the supply tank via drilled rod 88 and conduit 92. Drilled rod 88 is rotatably mounted in cover member for actuation by atmospheric pressure responsive member 64 so as to coact with a half-ball valve 94 secured to diaphragm 78. Atmospheric pressure responsive means 64 includes a bellows 96 mounted in a housing 98 for exposure to the atmosphere through a port or vent 100. The free end of bellows 96 is connected to rod 88 by a lever 102 whereby movement of the bellows causes rotation of rod 88. The servo pressure in chamber 84 is thus regulated as a function ofambient air pressure.

Piston 66 is formed at one end with a bifurcated lug 104 which is bored at 106 to receive a dat sided pin 108. Pin 108 is provided with a transverse bore 110 to receive a rod 112 which is secured to the bifurcated ends of a cam 114. The mounting of cam A114 on piston 66 is such as to permit co-planar rotation and translation vof. the cam with respect to pin 108.

A cam follower 116 pivotally mounted in housing 10 is urged into engagement with cam 114 by a spring 118. Spring 118 is opposed by temperature responsive element 62 including probe 120, bellows 122 and tube 124 which are filled with a thermoresponsiveuid. Probe 120 is adapted to be subjected to a temperature which varies as a function of engine temperature. When heated to a predetermined temperature, bellows 122 acting through a spring 125 urges cam follower 116 into engagement with an adjustable abutment 126. Although a specific temperature responsive element has been described it is to .be understood that other means for indicating engine temperature such as a bimetallic element may be used.

A cam follower 128 is secured to rod 54 for engagement with cam 114 on the side opposite to cam follower 116. An adjusting screw 130 is provided to Ivary'the angular relationship of cam follower 4128 with rod 54.

Housing 10 is provided with a'fuel inlet 132 which is connected to cylinders 12 by a passage 134 and appropriate branch passages 135. The inlet to each cylinder is controlled by a check valve 136 which isurged toward closed position by a conical shaped spring 138. The discharge from cylinders 12 is conducted through passages 140, check valves 142, to outlets 144 which-are adapted for connection with appropriate fuel 'nozzles Vupon starting of the engine and to present solid, vapor free fuel to passages 135, shaft 20is provided with passage 146. Fuel passes from inlet 132 through passages 134 and 146 and into the wobble plate cavity of body 10. This fuel is released through a conduit 148 which Yconducts it to an appropriate back pressure regulator 150 ,in the supply pump (not shown) and thence to the tank.

In operation, the effective stroke or discharge of the pump is controlled by varying the angular position of wobble plate 18 about its pivot 22. Plate 18 is rotated by control `device 58 through cam follower 128, rod 54, actuating member 52, pins 45, sleeve 42, element 36 and link 32. Cam follower 128 is rotated in response to movement of cam 114 which is moved axially as a function of changes in induction passage pressure and ambient pressure by elements 60 and 64.

It has been found that in many engines the required percentage increase of fuel Varies non-linearly with engine speed and manifold pressure. Cam 114 is contoured to .provide for non-linear relation between fuel requirements and manifold pressure and is formed with three distinct portions 114a, b and c providing respectively for overrunning idle or fuel cut-off, road load operation and full throttle operation.

When a predetermined low absolute manifold pressure 4spring 118 urges cam follower 116 into engagement with cam 114 to move cam follower 128 in a direction to increase the pump stroke 4and thus the fuel ow to the engine. When a predetermined temperature has been reached cam follower 116 is moved into engagement with `abutment 126 wherein it is ineffective to enrichen the fuel mixture ratio.

Ambient pressure responsive device 64 compensates for changes in atmospheric pressure by regulating the servo pressure on diaphragm 78 which `acts through abutment 76 to influence the position of piston 66 and cam 114.

Although a particular embodiment of my invention has been described, it will be understood by those skilled in the art that the objects of the invention may be attained by the use of consructions different in certain respects from that disclosed without departing from the underlying principles of the invention.

I claim:

1. In a fuel injection system for an internal combustion engine having an induction passage, a housing, a shaft in said housing, a thrust member pivotally mounted on said shaft, a cylinder in said housing, a pump plunger in said cylinder, a spring adapted to urge said plunger into engagement with said member, a rst sleeve reciprocably mounted on said shaft, means connecting said first sleeve to said member, a second sleeve reciprocably mounted on said first sleeve and adapted for engagement Awith said means, a wall in said housing movable in revsaid iirst sleeve guides said means to move said thrust 4 member about its pivot to plunger.

2. In a fuel injection pump for an internal `combustion engine having an induction passage, a housing, a cylinder in said housing, a pump plunger in said cylinder, a wobble plate'in said housing pivotally mounted to engage change the stroke of said ,said plunger to impart a pumping stroke thereto, a

chamber, a cam longitudinally and transversely movable in said chamber, means responsive to induction passage pressure for moving said cam in one direction, means responsive to engine temperature for moving said cam in another direction transverse said one direction, means responsive to movement of said cam in both directions operatively connected to said wobble plate whereby said plate is moved about its pivot to change the stroke of said plungers. v

3. In a fuel injection pump for an internal combustion engine having an induction passage, a housing, a cylinder in said housing, a pump plunger in said cylinder, a thrust member in said housing pivotally mounted to engage said plunger to impart a pumping stroke thereto, a movable wall in said housing, a pivot formed on said wall, a cam slidably and rotatably mounted on said pivot, means responsive to induction passage pressure operatively connected to said cam to move said cam in one direction, engine `temperature responsive means operatively connectedto said cam to move said cam in a direction transverse to said one direction, a cam follower adapted to engage said cam, and means connecting said follower to said thrust member whereby said member is positioned by movement of said cam in both directions.

4. In a fuel injection pump for an internal combustion engine having an induction passage, a housing, a cylinder Vin said housing, a pump plunger in said cylinder, a thrust member in said housing pivotally mounted -to engage said plunger for imparting a pumping stroke thereto, a cam in said housing, means responsive to induction passage pressure for moving said cam in one direction, means responsive to engine temperature for moving said cam in another direction y transverse to said one direction, and means for transmitting motion of vsaid cam to said member.

5. In a fuel injection pump for an internal combustion engine having an induction passage and a source of fuel,

van inlet and an outlet for` said pump, means adapted to connect said inlet with said source, means for varying the effective discharge from said pump, a housing, a piston in said housing movable in response to changes in induction passage pressure, a chamber, a diaphragm in said chamber operatively connected to said piston, a conduit connecting said chamber with said outlet, a valve in said conduit, a bellows responsive to change in atmospheric pressure operatively connected to said valve, a

cam operatively connected to said piston, and means operatively connecting said cam to said control means.

6. In a fuel injection pump for an internal combustion engine having an induction passage, a housing, la cylinder in said housing, a plunger in said cylinder, a wobble plate in said housing pivotally mounted to engage said plunger and impact a pumping stroke thereto, a movable wall responsive to changes in induction passage pressure, a cam mounted on said wall for transverse movement with respect to said wall, means responsive to an engine operatingcondition such as engine temperature for imparting transverse motion to said cam, and means connecting said cam to said wobble plate whereby the position of said wobble plate is determined by both longitudinal and transverse movement of said cam.

References Cited in the tile of this patent UNITED STATES PATENTS 2,052,737 Zubaty Sept. 1, 1936 2,213,683 Banning Sept. 3, 1940 2,245,562 Becker June 17, 1941 2,778,350 Reggio Ian. 22, 1957

Images