US2958318A

US2958318A - Fuel injection system

Info

Publication number: US2958318A
Application number: US837901A
Authority: US
Inventors: Thomas M Ball
Original assignee: Chrysler Corp
Current assignee: Old Carco LLC
Priority date: 1959-09-03
Filing date: 1959-09-03
Publication date: 1960-11-01
Anticipated expiration: 1977-11-01

Description

Nov. 1, 1960 T. M. BALL FUEL INJECTION SYSTEM 2 Sheets-Sheet 1 Filed Sept. 3, 1959 INVENTOR. 772477745 /Y/34//. BY 51W PM Nov. 1, 1960 T. M. BALL FUEL INJECTION SYSTEM 2 Sheets-Sheet 2 Filed Sept. 3, 1959 United tates FUEL 1N JECTION SYSTEM Filed Sept. 3, 1959, Ser. No. 837,901

17 "Claims. (Cl. 123-119) This invention relates to a fuel injection system particularly. suited for use in an automotive internal combustion engine.

An object of the present invention is to provide an improved fuel injection system of the above type wherein pressurized fuel from a fuel pump is supplied by a fuel feed conduit to the engine through fuel metering means operable in response to variations in engine speed and load. A pressure regulating valve in the fuel conduit and responsive to the pressure therein at opposite sides of the fuel metering means maintains a comparatively high predetermined minimum pressure differential across the metering means to minimize vapor formation therein and to assure its reliable operation regardless of variations in fuel pressure resulting from changes in speed, load, inertial effects, vehicle inclination, and the like. In consequence, the tolerances for the fuel pump as well as for the dimensions of the conduit system can be relaxed materially with resulting cost savings and without affecting critical pressure relation across the metering means.

Other objects are to provide an improved fuel injec tion system of the above character including mechanism for actuating the fuel metering means during certain conditions of operation, as for example during starting or acceleration to cause a desired enrichment of the fuel supply to the engine; to provide such a system which is readily susceptible to enrichment as an inverse function of temperature during cold starting or cranking of the engine; and to provide such a system wherein the fuel enrichment is effective only when the engine fuel consumption is comparatively low, as for example during cranking or during engine acceleration at comparatively low speeds.

Another object is to provide a fuel injection system having pressure exerting means operable during engine acceleration, as for example, an accelerator pump which can be linked with the customary accelerator pedal and personally actuated to inject a burst of pressurized fuel into the feed conduit at a location downstream of the metering means for accelerating the engine, and to provide an operable connection between the accelerator pump and the fuel metering means to augment operation of the latter to increase the fuel flow to the engine.

In a type of fuel injection system with which the present invention is particularly adapted, the fuel metering means includes a housing partitioned by a movable wall into a first fuel pressure chamber and a second or fuel pressure balancing chamber. The first chamber comprises part of the feed conduit and has an orifice therein associated with valve means adjustable to vary the orifice and thereby to control the fuel flow to the engine. The movable wall is operably connected with the valve means and with a sensor device responsive to an engine operating condition and is shiftable to adjust the valve means in accordance with the balance of forces effected by the sensor device and the pressure differential between the two chambers.

A atent- O ice A pressure equalizing duct in communication with the pressure balancing chamber and the feed conduit at a location downstream of the metering means maintains thesame pressure differential between the first chamber and said downstream location that exists across the movable wall. In the event of sudden opening of the engine throttle for the purpose of increasing the fuel supply to the engine with such a system, a sudden outflow of fuel from the first chamber results in a momentary change n the forces on the movable wall causing the latter to move in a direction to decrease the volume of the first chamber and to increase the volume of the second chamber. In consequence, without provision to the contrary, fuel is robbed from the feed conduit via the equalizing duct in order to fill the increased volume of the second chamber. This causes momentary leanness of the fuel-air mixture during acceleration.

Another object of the invention is accordingly to provide simple improved means for preventing such an occurrence as for example, an operable mechanical or pressure actuated connection between the engine accelerator mechanism and a portion of said valve means to vary said orifice and augment said movable wall in increasing fuel flow to the engine without necessitating movement of the wall.

Another and more particular object is to provide a shiftable pressure actuated valve seat for said orifice cooperable with a valve element on said movable wall to vary said orifice and to provide a fluid connection between the pressurized fuel of the accelerator pump and said valve seat to adjust the position of the latter with respect to said movable wall to prevent robbing of fuel from the feed conduit during sudden acceleration of the engine; to provide a one-way check valve in said fluid connection to prevent a reverse fluid flow toward the accelerator pump when the latter is not supplying pressurized fuel to said movable portion; and to provide resilient means normally holding the check valve closed and being yieldable to open the check valve for passage of fluid in said fluid connection when the accelerator pump pressure exceeds a predetermined minimum.

Another object is to provide such a structure wherein said pressure regulating valve is applied to vary the restriction in said feed conduit at a point downstream of the aforesaid location associated with said pressure equalizing duct.

Other objects are to provide a branch of said fluid connection opening into said feed conduit at a location downstream of said pressure regulating valve means to supply acceleration fuel to said engine and to provide a one-way check valve in said branch to prevent a reverse fuel flow from said feed conduit to said accelerator pump, the check valve means being yieldably urged to a closed position and being responsive to the accelerator pump output pressure to open when the latter pressure exceeds a predetermined minimum value.

Another object is to provide an improved fuel injection system having the shiftable pressure actuated valve seat for said orifice cooperable with the valve element on the movable wall to control the fuel flow to the engine as aforesaid, the shiftable valve seat being quickly responsive to a comparatively small displacement of low pressure fluid and being thereby effectively operative with minimum interruption to the desired pressure balance in the fuel metering system. Thus a fluid pressure pump of nominal size and output only is required for actuation of the shiftable valve seat, so that a portion of the output of a conventional fuel acceleration pump can be feasibly diverted to the shiftable valve seat to actuate the latter.

Other objects of this invention will appear in the following description and appended claims, reference being had to the accompanying drawings forming a part of this 3 specification wherein like reference characters designate corresponding parts in the several views.

Figure 1 is a fragmentary schematic sectional view of a fuel injection system embodying the present invention.

Figure 2 is an enlarged fragmentary view of the valve and shiftable valve seat of Figure 1.

Figure 3 is a view similar to Figure 1, showing a modified form of the invention.

Figure 4 is a view similar to Figure 1, showing still another modification of the invention.

It is to be understood that the invention is not limited in its application to the details of construction and arrangement of parts illustrated in the accompanying drawings, since the invention is capable of other embodiments and of being practiced or carried out in various ways. Also it is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation.

Referring to Figure l, a fuel injection system is shown comprising separate cylinder banks 10, air intake manifold conduits 11, exhaust conduits 12, and exhaust manifolds 13. The system comprises a fuel supply tank 14, an engine operated speed sensor 15, an engine load sensor 16, an accelerator pump 17, and fuel injection nozzles 18. The speed sensor is provided with four housing portions separated from each other by

diaphragms

23, 24, and 25 to provide four chambers 26, 27, 28, and 29. Chamber 26 communicates with fuel tank 14 through conduit 30' and by means of fuel pump 31 submerged in tank 14 is supplied with fuel in adequate volume and pressure to exceed the maximum requirements of the engine regardless of the engine load or speed. A tubular return flow metering orifice member 32 as described below connects chamber 26 with a return flow conduit 33 which extends to fuel tank 14 to return excess fuel thereto. A shiftable rod 19 having at one end a flattened return valve element 35 registering with the upstream side of orifice member 32 is secured to each of the

diaphragms

23, 24, and 25 by suitable grcrrnnets 34.

A flyweight support 36 pivotally supports flyweights 37 at 38 and is secured to a flexible shaft 39 operatively connected to the engine to rotate at a speed directly proportional to engine speed. The flyweights 37 have projections 28 which abut an end portion of rod 19 when the flyweights pivot outwardly in response to rotation of shaft 39, thereby to urge valve element 35 toward orifice member 32 against the opposite force of the fuel pressure in chamber 26 applied to diaphragm 23. As engine speed increases or decreases respectively, valve element 35 is moved toward or away from metering orifice member 32 to restrict or increase the la-tters effective opening.

Although the present invention is illustrated herein by way of example with a return flow type fuel injection system, it will be apparent from the following that the invention has application with other than return flow systems, as for example wherein orifice member 32 is closed and valve 35 is applied to conduit 39 to restrict the fuel flow therethrough with increasing pressure in chamber 26; or wherein conduit 30 is closed and the fuel is pumped in a reverse direction through conduit 33 into chamber 26, and valve 35 is applied to restrict orifice member 32 with increasing pressure in chamber 26.

Chamber 26 is connected with a downstream chamber 40 via load metering orifice 41 and thence with a downstream fuel distribution chamber or rosette 42 via fuel supply conduits 43 and 44 in series. A load metering needle 45 extends through orifice 41 and terminates in a reversely tapered end portion 46 registering with the upstream side of orifice 41. Needle 45 is operatively connected to a piston 47 reciprocable in cylinder 48, which in turn is connected with a low pressure portion of each intake manifold 11 of said engine by conduit 49. Low pressure transmitted through conduit 49 causes piston 47 to move upwardly against the force of spring 50 and to urge the tapered valve 46 into closer proximity with the sides of orifice 41 to progressively restrict the latter. Conversely, with increasing pressure in the intake manifolds, as for example with increasing load, spring 50 urges piston 46 downwardly to increase the opening of orifice 41. Vent duct 49a in the lower portion of cylinder 48 maintains the space below piston 47 at atmospheric pressure.

A separate nozzle feed conduit 51 extends from chamber 42 to each of the fuel injection nozzles 13 located downstream of the throttle valve 52 in the air intake manifold 53. Chamber 40 is also connected to chamber 27 of the speed sensor unit by a pressure equalizing conduit 54 to provide an adjustment of the fuel pressure differential across the metering orifice '41, as explained below.

An idle boost conduit 55 communicates with manifold 53' at a point adjacent the edge of throttle valve 52 and with the chamber 28 of the speed sensor unit in order to augment operation of the flyweights 37 urging rightward movement of valve element 35 when the engine is operated at low speed and light load. By virtue of duct 55, the pressure in chamber 28 during such conditions is lower than in chamber 29- which is vented to the atmosphere by vent 56. The pressure in chamber 23 thus urges valve element 35 toward orifice member 32 to retard the flow of fuel therethrough and provide an enrichment of the engine fuel supply. During high speed or high load operation, the pressure differential across diaphragm 25 has no appreciable eifect.

The accelerator pump 17 has an inlet duct 57 in communication with return flow conduit 33 via ball check valve 58 and receives fuel into the lower portion of cylinder 59 upon upward movement of the accelerator piston 60. In the present instance, piston 60 is connected in accordance with customary practice with the personally operated accelerator linkage 60a. The latter is suitably connected with throttle valve 52 and normally maintains piston 60 in an elevated position against the tension of spring 66b when throttle valve 52 is closed. Upon opening of valve 52 by operation of the throttle linkage, as for example during acceleration or increasing engine load, linkage 60a releases piston 60 for downward movement. The compressed spring 6011 then moves piston 66 downwardly in a pumping stroke to discharge pressurized fuel from cylinder 59. Upon actuation of throttle linkage 6th: to close valve 52, piston 6%) is raised in an intake stroke against the force of spring 69b. Fuel is then drawn into the lower part of chamber 59 below piston 60' via duct 57. Bleed duct 61 connects cylinder 59' above piston 60 with return conduit 33 to facilitate operation of piston 60 and to prevent entrapment of fuel in the upper portion of cylinder 59. Restricted bleed duct 61a interconnects duct 61 and the interior of cylinder 59 as described below.

The pressurized fuel discharged from cylinder 59 upon the spring urged downward movement of piston 60 is directed through conduit 62 to conduit 63 which extends through an enlarged portion 64 of the housing for the speed sensor 15 at the left end of conduit 33. Conduit 33 opens to the left into a chamber or cavity 65 formed in housing portion 64. The cavity 65 in turn enlarges leftward at 66. A tubular adaptor 67 having a threaded right end portion screws snugly into cavity 65 and enlarges radially at 68 within the cavity 66. An O-ring type seal 69 provides a peripheral fluid seal between the juxtaposed enlarged portions 64 and 68 adjacent the outer periphery of the latter. Similarly a sealing gasket 70 provides a fluid seal between the juxtaposed enlargements 64 and 68 around the outer periphery of the threaded portion of the adaptor 67.

As illustrated in Figure 2, the orifice member 32 comprises a short tubular element freely slidable axially in the bore of tubular adaptor 67 and opening into the cavity 65 which in turn opens into conduit 33. A flexible annular diaphragm 71 extends coaxially around the member 32 and is retained in fluid sealing engagement against an annular movement limiting shoulder 72 thereof by an annular retainer 73 which is either snugly pressed or screwed into position around member 32. The outer periphery of diaphragm 71 similarly seats in fluid sealing engagement against an annular shoulder of enlargement 68 and is secured in position by a second annular retainer 74 snugly pressed or screwed into the opening of enlargement 68 to comprise a unitary structure therewith. Thus the tubular orifice member 32 is free for limited leftward movement from the position shown in Figures 1 and 2.

One or more conduits 75 extending axially through enlargement 68 at the right side of diaphragm 72 provides communication between the latter and conduit 63 which extends through housing portion 64. In consequence of the structure disclosed the left side of diaphragm 71 is exposed to the pressure of chamber 26 so that diaphragm '71 will not move leftward until the pressure at its right side exceeds a predetermined force which is a function of engine speed. In this regard it is to be noted that the pressure force of chamber 26 during normal driving bal- .ances the-force exerted by the speed responsive flyweights plus the pressure force of chamber 27, as described below.

It is apparent that when accelerator piston 60 is depressed to discharge fuel from cylinder 59 during an accelerating operation, the fuel pressure discharged from cylinder 59 is directed through conduits 62, 63, and 75 to the right side of diaphragm 71, thereby to move the latter and the freely shiftable orifice member 32 leftward toward valve element 35, provided that the pressure of pump 17 exceeds the speed responsive pressure of chamber 27. In consequence, orifice member 32 is restricted during the initial period of acceleration. The return fuel flow in conduit 33 is reduced with a consequent pressure rise in chamber 26 tending to increase the pressure differential across orifice 41 as desired during acceleration. At high engine speeds the normal operation of the metering system effectively supplies all the fuel required during acceleration, so that the additional fuel supplied by operation of pump 17 is not required. Accordingly, at sufficiently high engine speeds, the speed induced pressure in chamber 26 prevents movement of diaphragm 72 and orifice member 32, which in turn prevents augmentation of the normal fuel delivery for which the metering means 32, 35, 41, 46 is designed.

It is noted that upon opening of throttle 52 during acceleration of the engine, the manifold pressure in conduit 49 increases, enabling spring 50 to move valve 46 downward and decrease the restriction at orifice 41. Without provision to the contrary, the pressure in chamber 26 would drop momentarily and cause rightward movement of diaphragm 23 with a resulting drop in pressure in chambers 27 and 40 which are in communication via conduit 54. The momentary low pressure in chamber 27 would rob fuel from chamber 40 via conduit 54 and reduce the fuel pressure in chamber 40. The fuel supply to the engine would thus be reduced at the very time that acceleration was desired. Coughing or momentary stalling of the engine would result.

By virtue of the conduit 62 connecting pump 17 and the right side of diaphragm 72 and in consequence of the leftward movement of orifice member 32 toward valve element 35, the momentary effect of reducing the restriction at orifice 41 during acceleration is minimized. Orifice member 32 is restricted and the return fuel flow therethrough is reduced to cause a momentary pressure rise in chambers 26 and '27 to give the engine a burst of accelerating fuel as desired. After depression of piston 60 and the momentary burst of accelerating fuel is supplied, the fuel pressure in chamber 59 and at the right side of diaphragm 75 will leak through restricted bleed orifice 61a to the return fuel line.

It is to be noted further that the structure shown provides for leftward movement of orifice member 32 dur- .6 ing acceleration with a pump 17 of minimum fluid displacement. Accordingly the structure illustrated is not only immediately responsive to operation of the accelerator mechanism 60a, but a conventional fuel accelerating pump can be employed for the pump 17. If desired, a major portion of the output from pump 17 can be supplied directly to the engine in accordance with customary practice and a small portion of the output of pump 17 can be applied to shift orifice member .32 leftward as de scribed below as in regard to Figure 3.

The structure shown is also readily adaptable to supply enrichment fuel to the engine during starting or cranking, particularly during cold weather. in this regard, a thermostatically controlled device indicated schematically at 76 is provided for supplying pressure to the right side of diaphragm 72 via conduits 77 and 73 in enlargements 64 and 63 respectively. The device 76 may be any well known pressure exerting means operable during engine cranking to discharging fluid pressure via conduits 77 and 78 and is accordingly not illustrated in further detail. It is sufficient to note that the pressure exerted by 76 during engine cranking is applied to the right side of diaphragm 71 to move orifice member 32 leftward toward valve element 35, thereby to decrease the fuel flow through line 33 and to increase the fuel pressure in chamber 26 and the fuel flow through orifice 41 and thence to the engine as desired. The pressure discharged by device 76 may be modulated inversely with the inlet air temperature by any suitable thermostatic control device known to the art, so as to decrease the starting fuel enrichment with increasing inlet air temperature.

Also as illustrated in Figure 1, the lower chamber 79 of a fluid containing pressure regulator or pressure increasing valve housing Stl is connected by duct 81 with the return flow conduit 33, the housing being partitioned by a flexible diaphragm 82 to provide the aforesaid lower chamber 79 and an upper chamber 83. A needle valve element 84 secured to diaphragm 82 to move therewith extends upwardly to register with a metering orifice 85 which communicates with conduit 44 adjacent its juncture with conduit 43. A biasing spring 86 under compression between the underside of diaphragm 82 and a lower portion of housing 80 urges needle valve element 84 upwardly to maintain a predetermined minimum differential between the fuel pressure in conduit 43 and the fuel pressure in the return flow conduit 33, as described below.

As is apparent from Figure 1, the pressure in conduit 33 augments the force of spring 86 urging diaphragm 82 and needle valve 84 upwardly in opposition to the pres sure in feed conduit 43 urging diaphragm 82 downwardly. Upward or downward movement respectively of valve element 84 progressively restricts or opens orifice 85. In the event of a pressure increase in conduit 33 for any cause, as for example on inclination of the vehicle to raise fuel tank 14 with respect to metering orifice member 32, the pressure increase is transmitted to the under side of diaphragm 82 to increase the restriction of orifice 85 when the pressure in feed conduit 44 drops below a predetermined minimum value, as for example when the engine is operating at low load. The pressure in feed duct 43 is thereby increased to increase the pressure in chamber 27 via conduit 54 and also to increase the pressure in chamber 83 via duct 87 connected with feed conduit 43.

The increased pressure in chamber 27 urges diaphragm 23 to the right because of its larger area with respect to the area of diaphragm 24, causing valve element 35 to increase the restriction of metering orifice 32. The latter action reduces the pressure in return conduit 33 and also in chamber 79. The resulting reduced upward force on diaphragm 82, augmented by the increased pressure in chamber 83, tends to restore the opening of orifice 85 to the extent predetermined by biasing spring 86. Accordingly, any tendencyto increase the pressure in return conduit 33 results in a corresponding tendency to increase the pressure in chambers 26 and 40, so that the pressure differential between conduits 33 and 43 will not drop below a predetermined minimum value determined by the force of spring 86. This structure is particularly important during light engine loads when the pressure downstream of port 85 is a minimum. Valve 84 assures a comparatively high minimum pressure upstream of port 85 and minimizes the tendency of fuel vapor formation during such conditions in the metering system.

The operation of the speed sensor 15 and load sensor 16 will be described in relation to a static engine operating condition, that is constant engine speed and load. Under static conditions, the force exerted on valve element 35 by fiyweights 37 equals the force exerted on valve 35 by the fuel pressure differential across diaphragm 23, whereby valve 35 is positioned with respect to orifice member 32 so as to maintain a pressure differential across orifice 41 determined by engine speed. In this static condition, the amount of fuel delivered to the rosette 42 is constant and is equal to the amount of fuel delivered to the system by the pump 31 less the amount of fuel being returned to the fuel tank 14 through the return flow conduit 33.

As throttle valve 52 is moved to a more open position by operation of the engine accelerator including linkage 60a, an increase in manifold pressure is transmitted to the load sensor piston 47 through conduit 49, enabling spring 59 to move piston 47 downwardly and thereby to move the load metering valve 46 to a more open position with respect to the metering orifiice 41. The pressure differential existing across orifice 41 and therefore across diaphragm 23 consequently tends to decrease as more fuel is allowed to flow into chamber 40. To prevent such a condition and to maintain the pressure differential across orifice 41 at a value Where the flow of fuel therethrough will satisfy the increased engine load requirement, the fuel pressure in chamber 26 is increased by movement of the return flow metering valve 35 closer to orifice member 32 in consequence of the increased pressure in chamber 27 which communicates via duct 54 with chamber 49. Thus the return fuel flow in conduit 33 is decreased and the fuel flow to the engine via conduits 43 and 44 is increased, Simularly when the engine sped is increased, the flyweights 37 exert increased force on valve 35 urging the latter rightward to restrict orifice member 32. The result is to decrease the return fuel flow in conduit 33 and increase the flow to the engine via conduits 43 and 44. The converse operation will of course occur in the event of a reduction in engine load or speed.

Figure 3 shows a modified form of the present invention wherein the pressurized fuel discharged from cylinder 59 upon downward movement of piston 60 during acceleration is directed through conduit 62a to the upper chamber 99 of a fluid containing pressure operated check valve housing 91 which is partitioned by a flexible diaphragm 92 into the aforesaid upper chamber 90 and a lower chamber 93. A shiftable needle valve element 94 secured to diaphragm 92 to move therewith has a tapered upper end registering with an acceleration orifice 95 to close the latter. Upon downward movement of valve element 94, chamber 99 communicates with chamber 42 via port 95 and duct 44. Needle valve 94 is normally maintained in the closed position shown by a biasing coil spring 96 under compression between the underside of diaphragm 92 and a lower portion of the housing 91. Chamber 93 is in communication with return flow conduit 33 via duct 97, whereby excess pressure buildup in chamber 93 is avoided and the return flow in conduit 33 is employed to augment spring 96 in maintaining valve element 94 in the closed position. In Figure 3, conduit 62 connects duct 63 with chamber 90 instead of directly with cylinder 59 as in Figure 1.

In accordance with the foregoing, when accelerator 8 piston 60 is depressed to discharge fuel from cylinder 59 during an accelerating operation, the first fuel output of pump 17 is directed into chamber and thence by conduits 62, 63, and 75 to the right side of diaphragm 72 to cause leftward shifting of orifice member 32 as described above. Thereafter upon continued downward movement of piston 60, the fuel discharged from cylinder 59 into cylinder 90 forces diaphragm 92 downwardly against the tension of spring 96, thereby causing valve element 94 to open orifice 95. Opening of the latter orifice admits the accelerating fuel into conduit 44 and thence into chamber 42 and to the engine via the various fuel supply conduits 51. Accordingly, a small portion of the fuel pump discharge is applied to shift orifice member 32 and to prevent a momentary pressure drop in chambers 26 and 27, whereas the primary output of pump 17 discharges directly to the engine as required during rapid acceleration. Inasmuch as the fuel discharged from pump 17 is consumed by the engine, the bleed duct 61a of Figure l is not essential in Figure 3 because leakage around piston 60 for example will dissipate residual pressure in chamber 90 when port 96 is closed. However, such a duct may be employed if desired. In all other respects, the structure and operation of the mechanism illustrated in Figure 3 is the same as in Figure 1, so that corresponding parts are numbered the same in both drawings.

The structure of Figure 3 is advantageous because it is undesirable to move orifice member 32 too far to the left during acceleration. Too great a restriction of orifice member 32 would result in an unbalancing of the fuel metering system and flooding of the engine and fuel waste during acceleration. In Figure 1, this problem is made by suitably determining the size of the accelerator pump 17 and the resistance to fuel flow in lines 62, 63, and 75. In Figure 3, on the other hand, greater versatility and control is enabled with relaxed production tolerances. The accelerating fuel pressure in excess of a desired value determined by spring 96 is supplied directly to the engine, so that the tendency to unbalance the metering system, including the relationship between valve 35 and orifice member 32 and the pressure drop across orifice 41, is avoided.

It is also to be noted in regard to Figures 1 and 3 that during deceleration of the engine and movement of throttle valve 52 toward its closed position shown, the accelerator pump piston 60 is raised for the fuel inlet stroke. Fuel then enters cylinder 59 both through duct 57 and through conduit 62 from chamber 90. This latter effect reduces the pressure at the right side of diaphragm 72 and enables orifice member 32 to move rightward to the limit of its movement illustrated. The fuel pressure in both chambers 26 and 40, as well as the fuel flow to the engine, is thereby reduced to minimize unburned fuel in the engine exhaust system during rapid deceleration.

Figure 4 illustrates a structure similar to Figure 3 wherein a plug 100 is interposed in conduit 44 between chamber 42 and orifice 95. Also distinguishing from Figure 3, conduit 62 connects conduit 63 with conduit 44 at a location between the plug 100 and port 95. Accordingly upon operation of the accelerating pump 17, no fuel pressure is supplied to conduit 62 until the fuel pump discharge pressure in chamber 94 exceeds the predetermined pressure of spring 96. At such a pressure, diaphragm 92 and valve 94 are forced downwardly to open port and connect the discharge from pump 17 to conduit 62, thereby to shift orifice member 32 leftward in the manner and for the purpose as explained above in connection with Figure 1. In this structure, the discharge from pump 17 is not fed directly to the engine, so that bleed duct 61a is employed to bleed the pressure from chamber 59 after the momentary need for accelerating fuel passes.

I claim:

1. In a fuel system for an internal combustion engine, fuel conduit means for supplying said engine with fuel, fuel metering means for regulating the fuel flow in said conduit means to said engine, said fuel metering means including a port in said conduit means, an adjustable valve seat at said port, a shiftable valve element cooperable with said seat to regulate the fuel flow through said port, valve actuating means responsive to an operating condition of said engine for shifting said valve element, a pressure actuated member operably connected with said valve seat for adjusting the latter, fluid pressure exerting means responsive to an operating condition of said engine during acceleration for applying fluid pressure to said member to actuate the latter, and means for applying the fuel pressure in said conduit means at the high pressure side of said port to said member in opposition to actuation thereof by the fluid pressure of said pressure exerting means.

2. In a fuel system for an internal combustion engine, fuel conduit means for supplying said engine with fuel, fuel metering means for regulating the fuel flow in said conduit means to said engine, said fuel metering means including a port in said conduit means, an adjustable valve seat at said port, a shiftable valve element cooperable with said seat to regulate the fuel flow through said port, valve actuating means responsive to an operating condition of said engine for shifting said valve element, a pressure actuated member operably connected with said valve seat for adjusting the latter, fluid pressure exerting means responsive to an operating condition of said engine during acceleration for applying fluid pressure to one side of said member to actuate the latter to adjust said valve seat to augment operation of said metering means tending to increase the fuel flow to said engine, and means applying the fuel pressure in said conduit means at the high pressure side of said port to said member in opposition to said one side.

3. In a fuel system for an internal combustion engine, fuel conduit means for supplying said engine with fuel, fuel metering means for regulating the fuel flow in said conduit means to said engine, said fuel metering means including a port in said conduit means comprising an annular valve seat member slidable axially in a relatively fixed portion of said conduit means, a. flexible annular diaphragm around said seat member, the inner and outer peripheries of said annular diaphragm being secured to said member and fixed portion respectively in fluid sealing engagement therewith, a shiftable valve element cooperable with said seat member to regulate the fuel flow through said port, valve actuating means responsive to an operating condition of said engine for shifting said valve element, fluid pressure exerting means responsive to an operating condition of said engine during acceleration for applying fluid pressure to one side of said diaphragm to actuate the latter and adjust said seat member to augment operation of said metering means tending to increase the fuel flow to said engine, and means connecting the side of said diaphragm opposite said one side to the fuel pressure of said conduit means at the high pressure side of said port.

4. In a fuel system for an internal combustion engine, fuel conduit means for supplying said engine with fuel, fuel metering means for regulating the fuel flow in said conduit means to said engine, said fuel metering means including a port in said conduit means comprising an annular valve seat member slidable axially in a relatively fixed portion of said conduit means, a flexible annular diaphragm around said seat member, the inner and outer peripheries of said annular diaphragm being secured to said member and fixed portion respectively in fluid sealing engagement therewith, a shiftable valve element cooperable with said seat member to regulate the fuel flow through said port, valve actuatingmeans responsive to an operating condition of said engine for shifting said valve element, acceleration fuel pumping means selectively operable to supply pressurized fuel to said engine, means for applying the pressure of said pressurized fuel to one side of said diaphragm to actuate the latter and adjust said seat member to augment operation of said metering means tending to increase the fuel flow to said engine, and means connecting the side of said diaphragm opposite said one side to the fuel pressure of said conduit means at the high pressure side of said port.

5. In a fuel system for an internal combustion engine, fuel conduit means for supplying said engine with fuel, fuel metering means for regulating the fuel flow in said conduit means to said engine, said fuel metering means including a port in said conduit means, an adjustable valve seat at said port, a shiftable valve element cooperable with said seat to regulate the fuel flow through said port, valve actuating means responsive to an operating condition of said engine for shifting said valve element, a pressure actuated member operably connected with said valve seat for adjusting the latter, fluid pressure exerting means responsive to an operating condition of said engine during acceleration for exerting fluid pressure, a duct connecting said pressure exerting means and said member to actuate the latter, pressure actuated valve means normally closing said duct at a location between said pressure exerting means and member and being responsive to a predetermined pressure exerted by said pressure exerting means to open said duct at said location, and means for applying the fuel pressure in said conduit means at the high pressure side of said port to said member in opposition to actuation thereof by the fluid pressure of said pressure exerting means.

6. In a fuel system for an internal combustion engine, fuel conduit means for supplying said engine with fuel, fuel metering means for regulating the fuel flow in said conduit means to said engine, said fuel metering means including a port in said conduit means, an adjustable valve seat, at said port, a shiftable valve element cooperable with said seat to regulate the fuel flow through said port, valve actuating means responsive to an operating condition of said engine for shifting said valve element, a pressure actuated member operably connected with said valve seat for adjusting the latter, fluid pressure exerting means responsive to an operating condition of said engine during acceleration for exerting fluid pressure, a duct connecting said pressure exerting means and one side of said member to actuate the latter during acceleration to adjust said valve seat to augment operation of said metering means tending to increase the fuel flow to said engine, pressure actuated valve means normally closing said duct at a location between said pressure exerting means and member and being responsive to a predetermined pressure exerted by said pressure exerting means to open said duct at said location, and means applying the fuel pressure in said conduit means at the high pressure side of said port to said member in opposition to said one side.

7. In a fuel system for an internal combustion engine, fuel conduit means for supplying said engine with fuel, fuel metering means for regulating the fuel flow in said conduit means to said engine, said fuel metering means including a port in said conduit means comprising an annular valve seat member slidable axially in a relatively fixed portion of said conduit means, a flexible annular diaphragm around said seat member, the inner and outer peripheries of said annular diaphragm being secured to said member and fixed portion respectively in fluid sealing engagement therewith, a shiftable valve element cooperable with said seat member to regulate the fuel flow through said port, valve actuating means responsive to an operating condition of said engine for shifting said valve element, fluid pressure exerting means responsive to an operating condition of said engine during acceleration for exerting fluid pressure, a duct connecting said pressure exerting means and one side of said diaphragm to actuate the latter during acceleration and adjust said seat member to augment operation of said metering means tending to increase the fuel flow to said engine, pressure actuated valve means normally closing said duct at a location between said pressure exerting means and diaphragm and being responsive to a predetermined pressure exerted by said pressure exerting means to open said duct at said location, and means connecting the side of said diaphragm opposite said one side to the fuel pressure of said conduit means at the high pressure side of said port.

8. In a fuel system for an internal combustion engine, fuel conduit means for supplying said engine with fuel, fuel metering means for regulating the fuel flow in said conduit means to said engine, said fuel metering means including a port in said conduit means comprising an annular valve seat member slidable axially in a relatively fixed portion of said conduit means, a flexible annular diaphragm around said seat member, the inner and outer peripheries of said annular diaphragm being secured to said member and fixed portion respectively in fluid sealing engagement therewith, a shiftable valve element cooperable with said seat member to regulate the fuel flow through said port, valve actuating means responsive to an operating condition of said engine for shifting said valve element, acceleration fuel pumping means selectively operable to supply pressurized fuel to said engine, duct means for applying the pressure of said pressurized fuel to one side of said diaphragm to actuate the latter and adjust said seat member to augment operation of said metering means tending to increase the fuel flow to said engine, said duct means connecting said pumping means and said one side of said diaphragm, pressure actuated valve means normally closing the fuel connection between said pumping means and engine at a location with respect to said pumping means downstream of the connection be tween the latter and said duct means, said pressure actuated valve means being responsive to a predetermined pressure exerted by said fuel pumping means to open said connection, and means connecting the side of said diaphragm opposite said one side to the fuel pressure of said conduit means at the high pressure side of said port.

9. In a fuel system for an internal combustion engine, fuel conduit means for supplying said engine with fuel, fuel metering means for regulating the fuel flow in said conduit means to said engine, said fuel metering means including a port in said conduit means, an adjustable valve seat at said port, a shiftable valve element cooperable with said seat to regulate the fuel flow through said port, valve actuating means responsive to an operating condition of said engine for shifting said b1e element, a pressure actuated member operably connected with said valve seat for adjusting the latter, acceleration fuel pumping means selectively operable to supply pressurized fuel to said engine, means for applying the pressure of said pressurized fuel to said member to actuate the latter, and means for applying the fuel pressure in said conduit means at the high pressure side of said port to said member in opposition to actuation thereof by the fluid pressure of said pressurized fuel.

10. In a fuel system for an internal combustion engine, fuel conduit means for supplying said engine with fuel, fuel metering means for regulating the fuel flow in said conduit means to said engine, said fuel metering means including a port in said conduit means, an adjustable valve seat at said port, a shiftable valve element cooperable with said seat to regulate the fuel flow through said port, valve actuating means responsive to an operating condition of said engine for shifting said valve element, a pressure actuated member operably connected with said valve seat for adjusting the latter, acceleration fuel pumping means selectively operable to supply pressurized fuel to said engine, means for applying the pressure of said pressurized fuel to said member to actuate the latter, the last named means comprising a duct connecting said pumping means and member, pressure actuated valve means normally closing the fuel connection between said pumping means and engine at a location with respect to said pumping means downstream of the connection between the latter and said duct, said pressure actuated valve means being responsive to a predetermined pressure exerted by said fuel pumping means to open said connection, and means for applying the fuel pressure in said conduit means at the high pressure side of said port to said member in opposition to actuation thereof by the fluid pressure of said pressurized fuel.

11. In a fuel system for an internal combustion engine, fuel conduit means for supplying said engine with fuel, fuel metering means for regulating the fuel flow in said conduit means to said engine, said fuel metering means including a port in said conduit means, an adjustable valve seat at said port, a shiftable valve element cooperable with said seat to regulate the fuel flow through said port, valve actuating means responsive to an operating condition of said engine for shifting said valve element, a pressure actuated member operably connected with said valve seat for adjusting the latter, acceleration fuel pumping means selectively operable to supply pressurized fuel to said engine, means for applying the pressure of said pressurized fuel to one side of said member to actuate the latter to adjust said valve seat to augment operation of said metering means tending to increase the fuel flow to said engine, and means applying the fuel pressure in said conduit means at the high pressure side of said port to said member in opposition to said one side.

12. In a fuel system for an internal combustion engine, fuel conduit means for supplying said engine with fuel, fuel metering means for regulating the fuel flow in said conduit means to said engine, said fuel metering means including a port in said conduit means, an adjustable valve seat at said port, a shiftable valve element cooperable with said seat to regulate the fuel flow through said port, valve actuating means responsive to an operating condition of said engine for shifting said valve element, a pressure actuated member operably connected with said valve seat for adjusting the latter, acceleration fuel pumping means, a duct connecting said pumping means and conduit means for supplying pressurized fuel to said engine upon operation of said pumping means, a pressure actuated valve normally closing said duct and being responsive to a predetermined fuel pressure exerted by said pumping means to open said duct, a second duct connecting the firstnamed duct and one side of said member to actuate the latter to adjust said valve seat to augment operation of said metering means tending to increase the fuel flow to said engine, the second duct being connected with said first-named duct at a location with respect to said pumping means upstream of said pressure actuated valve, and means applying the fuel pressure in said conduit means at the high pressure side of said port to said member in opposition to said one side.

13. In a fuel system for an internal combustion engine, fuel conduit means for supplying said engine with fuel, fuel metering means for regulating the fuel flow in said conduit means to said engine, said fuel metering means including a port in said conduit means comprising an annular valve seat member slidable axially in a relatively fixed portion of said conduit means, a flexible annular diaphragm around said seat member, the inner and outer peripheries of said annular diaphragm being secured to said member and fixed portion respectively in fluid sealing engagement therewith, a shiftable, valve element cooperable with said seat member to regulate the fuel flow through said port, valve actuating means responsive to an operating condition of said engine for shifting said valve element, acceleration fuel pumping means, a duct connecting said pumping means and conduit means for supplying pressurized fuel to said engine upon operation of said pumping means, a pressure actuated valve normally closing said duct and being responsive to apredetermined fuel pressure exerted by said pumping means to open said duct, a second duct connecting the first named duct and one side of said diaphragm to actuate the latter and adjust said seat member to augment operation of said metering means tending to increase the fuel flow to said engine, the second duct being connected with said first named duct at a location with respect to said pumping means upstream of said pressure actuated valve, and means connecting the side of said diaphragm opposite said one side to the fuel pressure of said conduit means at the high pressure side of said port.

14. In a fuel system for an internal combustion engine, fuel conduit means for supplying said engine with fuel, fuel metering means for regulating the fuel flow in said conduit means to said engine, said fuel metering means including a port, an adjustable valve seat in said port, a shiftable valve element cooperable with said seat to regulate the fuel flow through said port, valve actuating means responsive to an operating condition of said engine for shifting said valve element, and means responsive to an operating condition of said engine during cranking thereof for adjusting the position of said valve seat to augment operation of said metering means tending to increase the fuel flow to said engine.

15. In a fuel system for an internal combustion engine, fuel conduit means for supplying said engine with fuel, fuel metering means for regulating the fuel flow in said conduit means to said engine, said fuel metering means including a port, an adjustable valve seat at said port, a shiftable valve element cooperable with said seat to regulate the fuel flow through said port, valve actuating means responsive to an operating condition of said engine for shifting said valve element, and thermostatically modulated means responsive to an operating condition of said engine during cranking thereof for adjusting the position of said valve seat to augment operation of said metering means tending to increase the fuel flow to said engine as an inverse function of temperature.

116. In a fuel system for an internal combustion engine, fuel conduit means for supplying said engine with fuel, fuel metering means for regulating the fuel flow in said conduit means to said engine, said fuel metering means including a fuel chamber in said conduit means having a port, an adjustable valve seat at said port, a shiftable valve element cooperable with said seat to regulate the fuel flow through said port, a movable partition separating said chamber into two parts with said port being in one thereof, said partition being shiftable in response to changes in the fuel pressure difierential at its opposite sides and being operatively connected with said valve element to shift the same, valve actuating means responsive to an operating condition of said engine and being cooperable with said valve element for shifting the same, a flexible diaphragm connecting said seat and chamber and defining in part a second chamber separate from the first named chamber, said diaphragm being shiftable in response to fluid pressure in said second chamber to adjust the position of said seat, and fluid and thermostatically modulated means responsive to engine cranking, the latter means being operatively connected with said second chamber to vary the pressure therein during cranking to shift said diaphragm to adjust said valve seat and augment said metering means in supplying fuel to said engine. 17. In a fuel system for an internal combustion engine, fuel conduit means for supplying said engine with fuel, fuel metering means for regulating the fuel flow in said conduit means to said engine, said fuel metering means including a port, an adjustable valve seat at said port, a shiftable valve element cooperable with said seat to regulate the fuel flow through said port, valve actuating means responsive to an operating condition of said engine for shifting said valve element, fuel enrichment means responsive to an operating condition of said engine during cranking thereof for adjusting the position of said valve seat to augment operation of said metering means in supplying fuel to said engine, said fuel enrichment means including a fluid pressure chamber defined in part by a movable partition operably connected with said valve seat to shift the same, and thermostatically modulated means responsive to engine cranking for varying the pressure in said chamber as an inverse function of temperature.

No references cited.

UNITED STATES PATENT OFFICE CERTIFICATION OF CORRECTION Patent No. 2,958,318 November 1, 1960 Thomas M Ball It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column "1', line 31 for "oriffice" read orifice line 44, for "increased, Simularly" read increased. Similarly same line, for 'sgoed" Pea d speed column 12, line 67 after "shiitable" strike out the commao Signed and sealed this 25th day of April 1961,

(SEAL) Attest:

ERNEET WM SWIDER DAVID La LADD Attesting Officer Commissioner of Patents