US2649084A - Fuel supply system - Google Patents

Description

Aug. 18, 1953 J. c. BAISCH FUEL SUPPLY SYSTEM Filed Aug. 11, 1948 3nventor I'll, IIIIIIIIIII IllIIIIIIIIIIIIIIIIIIIII I I f Mu? w= Q w. s Q EH 3 m m mm mm 5 8 N om 1 mm U l cccctsccccc a a Q a 2. v a 5 m .5 v a 3 8 Q Q. t 2 Ne mv 9 3 .1. on mm mm N a Q Patented Aug. 18, 1 9 3 UNITED STATES FPATENT OFFICE FUEL-SUPPLY SYSTEM John Carroll Baisch, Whittier, Calif., assignor to Carter Carburetor Corporation, St. Louis, Mo., a corporation of Delaware Application August 11, 1948, Serial No. 43,732

3 Claims. 1 This invention relates generally-tofuel supply systems, and relates more particularly to-such systems wherein the fuel is suppliedunderposn tive pressure.

- engine speed and one or more other operating variables.

Still another object of the invention is toprovide an arrangement of ;this character ,wherein the valve which controls themetering of .the

1 fuel is controlled by a speed responsive centrifugal device, which may be engine driven,. and

means responsive to one or more otherv operating variables.

A further object of the invention is to provide a fuel control systemwherein the fuel control valve may be variously positioned relative to the position effected in accordance with enginespeed.

Other objects and advantages of the invention will be apparent from the followingpart of, the specification.

In the drawings, which are vfor illustrative purposes only,

Fig. 1 is a diagrammatic view, partially in section, of a fuel supply system embodying the present invention;

Fig. 2 is a view taken on line 2--2 of Fig. 1;

Fig. 3 is a sectional view taken on .line 3 3, of Fig. 2;

Fig. 4 is a sectional view taken on line-4,4 of Fig. 3; and

Fig. 5 is a side View of the suction responsive device of Fig. 3 with a modifying control. device operably associated therewith.

Referring to Fig. 1, the fuel supply-system, as shown, includes a fuel supply pump,v indicated generally at Hi, which receivesliquid fuel from an inlet conduit I I, connected to a suitable source of fuel, not shown, and delivers said fuel through an outlet conduit l2. The pump may be operated by any suitable means, such as the engine, for example, and is of the type which suppliesfuel under positive pressure. The pump may be of any well known type and is shown as capable of delivering fuel at a substantially constant pressure (although it may have other deliveryv characteristics), there being a bypass l3 controlled by a pressure responsive valve M. The conduit I 2 is connected with a conduit l5 which leads a. fuel nozzle in the induction passage of the engine pos- -terior to the throttle valve.

Should a supercharger be used, the conduit !5 may be connected to the engine manifold posterior to said supercharger. If desired, a pressure operable nozzle, not shown, of any well known type may be provided, adjacent the discharge end of the conduit l5, which functions in a well known manner.

Variable metering means for controlling the how of fuel to the engine is provided, said metering of fuel being variable in accordance with engine speed. As shown, said variable metering meansincludes a calibrated, restricted metering I Jet. 16 in the fuel line posterior to the pump .19, the effective area of said jet beingcontrolled by a valve ll.

Itis well known that the rate of fuel through a fuel metering orifice is proportional to the square root of the pressure difference across the orifice.

. With an orifice of a given size, supplied by fuel at a substantially constant pressure, as by the pump ID, the supply of fuel to the engine, for various operating conditions, may be varied by variously positioning the valve H in accordance with certain engine or operating variables, as will be hereinafter described.

. The valve l1 has a stem l8 slidable in a guide i9, and connected, by means hereinafter described, to centrifugal means responsive to engine speed. .The centrifugal means is shown as comprising a centrifugal governor, indicated generally at2fi, which positions the valve I] in accordance with engine speed.

Means-for varying the fuel supplied to the engine in accordance with induction passage or 'itsengine speed controlled position, for a purpose to-be hereinafter described. To effect this independent positioning of said valve, the outer end 7 portion, as shown, of the valve stem is slidably received in abore 2i of a member 22 controlled .by the speed responsive device.

Though not essential, the valve stem may be urged outwardly of said bore by a light spring 23 reacting between the bottom of said bore and the adjacent end of .s'aidstem [8, there being pressure reliefmeans for saidbore shownas a vent 2Q behind the stem end. Thus, as far as relative movement of the stem I8 andmember 23, per se, are concerned,

there is little or no resistance thereto, and movement of. the valve can be effected without working against the forces of the speed responsive mechanism,hereinafterdescribed. That is, thevalve I 7 ,is controlled independently of said speed responsive, device as. Well as being controlled thereby.

'Theend of the member 22 having the bore 2|,

. is provided with a slot 25 for sliding reception of a pin 26 suitablysecured to the portion ,of the stem within saidbore 2 I, as by screw threads or 3 other suitable means. The slot is, of course, of suitable length to permit necessary axial or longitudinal movements of the valve stem, as will be hereinafter described, the side walls of said slot preventing rotation of said pin and stem relative to the member 22.

About the bored end of the member.22 are a pair of annular flanges 21 spaced apart longitudinally of the member 22 with the slot 25 disposed between them. Between the flanges 21 is a sleeve 28 which is rotatable on the member 22 but which is held against longitudinal movement on said member by said flanges. The sleeve may be formed of a plurality of parts so that it may be readily attached to the member between the flanges 21, but as the present drawings are diagrammatic, such construction is not shown.

The sleeve 28 is provided with a helical slot 29 in which the outer end of pin 26 is slidably received, the side walls of said slot 29 serving as cam surfaces for moving the pin longitudinally in the slot 25 upon rotation of said sleeve 28 thereby causing the valve stem to move longitudinally relative to the member 22.

The member 22 is connected to a longitudinally movable end member 30 of the centrifugal device or governor, there being a head or flange 3| on the end of said member 22 adjacent the governor. Then opposite faces of the flange have annular grooves or races for reception of respective ball bearings 32 and 33, the balls 33 being also received .in annular grooves or races in the adjacent face of the member 30. The balls 32 are received in annular grooves 0r races in the inner face of an inturned flange 34 of a retaining cup-like member 35 which is threadably received on a reduced diameter portion of the member 30, or otherwise secured thereto, the flange 34 having a central opening 36 through which the member 22 extends. Thus the member 30 of the governor may rotate relative to the member 22 which is held against rotation by any suitable means which will permit longitudinal movement thereof. As shown, the member 22 has a portion 37 of square cross-sectional shape, although it may be otherwise configured, which is slidably received in a guide or sleeve 38, the bore of which has a cross-sectional shape which corresponds to that of the portion 31, it being understood that the guide 38 is fixed or attached to some convenient fixed part.

The speed responsive means, which may be of any suitable type, is shown as being a centrifugal governor of the fly ball type and includes a stem comprising a pair of telescoping members 40 and 41, the former being secured to the member 30, and to the latter is secured a member 42 by means of a pin 43. The telescoping member 40 has longitudinally extending radial fins 44 which are slidably received in longitudinally extending slots 45 in the member 4! so that the member 40 may move longitudinally relative to the member 4!, but may not rotate relative thereto.

The governor also includes a pair of weights 46 disposed on opposite sides of the telescoping stem, and to each weight is pivotally secured, at 41, the adjacent ends of oppositely disposed links 48. The opposite ends of said links are pivotally secured to ears 49, attached to the respective members 30 and 42. The member 30 is urged to its outer limit of movement by yielding means, shown as comprising a spring 50, disposed about the telescoping stem, which reacts between said members 30 and 42. The member 42 is held against longitudinal movement relative to the axis of the governor by any suitable means which permits rotation of said member, and said means is shown as comprising a part 5! having an annular groove 52 therein, for reception of a peripheral'portion of the member 42. Ball bearings 53 may be used to provide a substantially frictionless connection between the part 5| and member 42. The part 5| may be split if desired, to facilitate assembly, although structural details of said part are not shown as the drawings are diagrammatic and for illustrative purposes only. It is to be understood, of course, that the -part 51 is suitably secured to some convenient fixed part so that it will hold the member 42 against longitudinal movement relative to the axis of the governor.

The member 4| is connected to any suitable rotating part of the engine and may rotate at engine speed or at some other speed proportional to or representative of engine speed.

When the engine is inoperative the valve [1 is in the closed position (although it may be otherwise positioned for some installations). Upon rotation of the governor, centrifugal force will cause the weights 46 to move outwardly relative to the axis of the telescoping stem of the governor, thereby causing member 30, member 22, stem 18 and valve H to move toward the right, as shown in the drawing. This movement is in the valve openingdirection and because of the characteristics of the centrifugal device, which characteristics are well known, the opening of the valve is substantially proportional to the square of engine speed.

Thus with this arrangement the eifective area of the orifice 16, which may be termed a variable metering orifice or jet, is controlled substantially in proportion to the square of engine speed by means of the centrifugal governor. As the quantity of fuel which will flow through a metering orifice of a given size will vary in proportion to the square root of the differential of pressures across said orifice or on opposite sides thereof, and as the size of the orifice is varied in accordance with the square of engine speed, it will be apparent that the above described arrangement provides a fuel control wherein the quantity of fuel supplied to the engine through the metering jet or orifice 16 will vary directly as the engine speed. However, the valve I! may be contoured differently from the contouring shown, to provide other metering characteristics.

Means for rotating the sleeve 28 on the mem ber 22 is provided so as to vary the position of the valve l1 relative to the positioning thereof eifected by the centrifugal device. This means is shown as comprising a lever 55 integral with or attached to said sleeve and extending laterally or radially thereof, the outer or free end portion of said lever being received in a slot 55 of a guide 5'! extending substantially parallel at all times with the axis of member 22 so that as the stem is and member 22 assembly is moved axially or longitudinally by the centrifugal device, the lever 55 will slide longitudinally in said slot. Thus, with the guide 57 in a given position, the lever 55 will slide in a plane substantially parallel with the axis of the stem [8 and member 22, and no rotation of the sleeve 28 will be efiected.

The guide is mounted, adjacent its ends, on pins 58 secured in a fixed base 59, said guide being slidable vertically on said pins, as shown in the drawings, and is urged toward said base 59 by springs 60' disposed on said pins, and which react between heads 6| adjacent the-free ends of said pins and the adjacent side of the guide. With this arrangement said vertical movement of the guide will cause rotation of the sleeve 28 and a corresponding longitudinal or axial fold pressure, and comprises a flexible diaphragm 63 which is connected to the guide 51 by a rod '64. The diaphragm 63 is marginally secured between a flange 555 of a housing 65, and an annular member 6? by screws or the like, not shown. The housing 66 and diaphragm 63 define a chamber 68, and the member 61 has a central opening 69 therein through which the rod 64 extends. The housing 66 is, of course, secured by any suitable means to a fixed support, not shown.

Washers ll] are provided on opposite sides of the diaphragm for reinforcing the central portion thereof, and said washers have marginal portions ll turned awayfrom the respective adjacent sides of the diaphragm to prevent cutting thereof. Means for limiting the movements of the guide 51 may be provided and, if desired, the

annular member Bl may be so arranged that the rim portion of the outer washer 10 will engage same and be limited in its outward movement, which in turn limits-the downward movement, as shown, of said guide 51. Such outward move-- ment of the washer and diaphragm is effected by a spring '12 disposed within chamber 68 which reacts between the interior washer 10 and a spring retainer 13 secured to the inner end of a screw 14 which threadably extends through the rear Wall 15 of the housing for adjusting the ef- .fective force of said spring 13. Upward movement of the guide 5! may be limited by stops 1%. If desired, other means may be used to limit movement of the guide.

The chamber 68 is subjected to engine charging pressure, and is shown as connected, by a conduit 8!], with the induction passage 8! of the engine, posterior to the throttle valve 82 which controls said induction passage. The induct1on passage has an air inlet and a mixture outlet connected with the intake manifold of an internal combustion engine, or to a supercharger inlet should a supercharger be used, A supercharger might alternately be connected to the inlet of the induction passage or there may be a supercharger connected to both said inlet and outlet, and should a supercharger be used, the conduit 80 would be connected to the engine intake manifold posterior to said supercharger.

Therefore, in view of the fact that the weight of air flow to an internal combustion engine ata given manifold pressure varies substant ally in direct proportion to the speed of the engine, the device herein described will supply fuel to the engine in accordance with the airflow thereto.

Thus, when engine charging pressure is low (or the manifold vacuum high), the pressure in chamber 68 willbe low and the differential of pressure across or on opposite sides of the diaphragm '63 will cause said diaphragm to move inwardly of the chamber 68 so that the guide 51 will be moved-upwardly; asshown in the drawings, rotating the sleeve 28 and causing th valve ii to be moved to a-wider open positionthan that eifected by the governorifl, it being understood speed and the power range, the assembly comprisingthe valve ll, stem l 8 and member 22, will be extended to the maximum, it being understood that under these conditions the spring 12 of the suction responsive device controlling the guide 5'! and the springs '60 are so calibrated that the differential of pressure across the diaphragm- 63 will be insufficient to overcome the force of said springs which therefore maintain the guide at its lower limit of movement whereat the lower washer it engages the member 61. The quantity of fuel supplied to the engine will therefore be controlled in accordance with engine speed through the instrumentality of the speed responsive or centrifugal means. However, the force of the spring 12 and springs 63 is overcome by the diiferential of pressure across the diaphragm 63 when the throttle valve is in a substantially closed or idling position when the engine charging pressure is relatively low, that is, when the manifold vacuum or suction is relatively high. The diaphragm 63 will then raise the guide 51 and cause an additional opening of the fuel valve ll relative to the normal position thereof, effected in accordance with engine speed or a given engine R. P. M., so that the fuel mixture is enriched for idling as is desired. The engine charging pressure is also relatively low (or manifold vacuum is high) when the engine is operating at high speed as when it is in the power range. At this time the force or resistance of the spring 12 and springs 50 is also overcome by the differential of pressure across the diaphragm, the guide 57 raised, and the fuel mixture enriched for speed and power as is desired. Of course, the spring 12 and the springstil may be otherwise calibrated and the device otherwise arranged to provide other fuel metering characteristics.

If desired, the chamber 68 may be connected with a large venturi 83 anterior to the throttle valve 82 by a conduit 8G, or with a small venturi 85, anterior to the throttle valve, by a conduit 86. Or one or more of these connections (88, 84 and 88) may be used and suitable restricted, calibrated orifices, not shown, may be used in these conduits to get various desired control characteristics. For example, should one of the conduits 84 or at be used in connection with conduit til, the former will modify the action of the manifold pressure posterior to the throttle valve by bleeding air to the chamber 68 at low air flows in the venturi, and at higher air flows will cooperate with said manifold pressure in urging the valve in the closing direction. Also, should the chamber 68 be connected only to one of the venturis 83 or 85 anterior to the throttle, the

valve member I! will be controlled solely in ac- 1 cordance with the pressure or air flow within said venturi. With this arrangement there will be the desired fuel mixture enrichment for, power operation of the engine. Other combinations of these connections may also be used, if desired.

If desired, the position of the valve I! may be further controlled by a device responsive to enginetemperature, as by a bellows or Sylphon 90, Fig. 5, interposed between the diaphragm 63 and the guid 51. In this figure there is a rod 9] having one end connected to said diaphragm and the other end connected to one end of the bellows 90. The other end of said bellows is connected to a rod 92 which in turn has its opposite end connected to the guide 51. a

The bellows may be of such character as to be responsive only to temperature and may be located adjacent a suitable part of the engine. When the bellows is at normal engine operating temperature, the guide 57 is positioned for providing the normal fuel to air ratio for the fuel mixture. However, with a cold engine the bellows will be contracted to raise the guide relative to the diaphragm and cause the valve I! to open to a greater degree, relative to the position effected by the centrifugal device, so as to enrich the mixture for a cold start, and for the warm up. Of course, as the engine warms up, the fuel mixture will gradually be leaned to the normal fuel to air ratio as the bellows expands under the influence of higher engine temperature.

If desired, the bellows may be only responsive to barometric pressure so that as altitude is gained the device expands, and as altitude is lost it contracts. Thus the fuel mixture ratio is controlled according to barometric pressure. Or, the bellows or aneroid may be so positioned as to be subjected to the air inlet pressure of the engine and thus be responsive to said pressure. For example, said bellows may be within the air inlet passage or in a housing subjected to air inlet pressure.

Further, if desired, the bellows may be of a character as to be responsive to both temperature and barometric pressure.

Bellows or Sylphons which are responsive only to'temperature, or only to barometric pressure, or to both, are well known, and any suitable type may be used.

In cases where the bellows is partially or completely evacuated it is desirable to provide a light compression spring for extending the bellows to a normal balancing position, such a spring being shown in dotted lines, Fig. 5, within the bellows, as indicated at 93. While the spring is shown as being disposed within the bellows, it may, of course, be otherwise located.

It is to be understood, of course, that other types of temperature responsive devices or aneroid devices, or both, may be used and otherwise arranged to effect temperature and barometric modification or control of the relative position of the valve l1. If desired, air temperature compensation may also be effected by suitable bellows or other means.

It is to be understood, of course, that the features above described, may be variously combined to meet the requirements of various installations.

I claim:

1. In a fuel supply system for an internal combustion engine: a source of fuel at a substantially constant superatmospheric pressure; means connecting said source with the engine; a calibrated metering orifice in said connecting means; a longitudinally movable valve, having a stem, for controlling the effective area of said orifice; a member'extendin longitudinally of said valve stem and aligned therewith and having a longitudinally extending bore in one end in which the adjacent end of the valve stem is slidably received; a guide for said member, said guide and member being so constructed and arranged that the member will slide longitudinally therein but will be held against rotation in said guide; a longitudinally extending slot in the bored portion of said member; a part on said stem extending laterally into said slot, the side walls of said slot holding said part against rotative movement so that said valve stem will not rotate relative to said member; a sleeve rotatable on said member and having a helical slot therein receiving the free end portion of said part; means holding the sleeve against longitudinal movement on said member; and means for rotating said sleeve whereby the valve stem will be moved longitudinally within the bore of said member for varying the portion of said valve relative to said member.

2. The invention defined by claim 1 wherein the last mentioned means comprises an arm on said sleeve extending laterally thereof; a guide element having a longitudinally extending slot in which is slidingly received the free end portion of the arm, said slot being substantially parallel with said member; means for slidably supporting the guide element for movement in a direction laterally of the slot; and means responsive to another operating variable for controlling the movement of said guide.

3. The invention defined by claim 1 wherein th last mentioned means comprises an arm on said sleeve extending laterally thereof; a guide element having a longitudinally extending slot in which is slidingly received the arm, said slot being substantially parallel with said member; means for slidingly supporting the guide element for movement in a direction laterally of the slot for maintaining the parallel relationship of said slot with said member; a suction responsive device, including a moveable wall, responsive to engine charging pressure; means connecting said wall with the guide for actuating same in a direction to rotate the sleeve for causing telescopin of the stem and member; calibrated yielding means for urging the guide in the opposite direction; means for limiting movement of said wall in the direction urged by said yielding means; and a collapsible bellows interposed in said connection between the movable wall and guide.

JOHN CARROLL BAISCH.

References Cited in the file of this patent UNITED STATESvv PATENTS Number Name Date 1,154,530 Merriam et al. Sept. 21, 1915 2,245,562 Becker June 17, 1941 2,281,411 Campbell Apr. 28, 1942 2,378,036v Reggio June 12, 1945 2,378,037 Reggio June 12, 1945 2,382,707 Gosslau et al Aug. 14, 1945 2,404,428 Bradbury July 23, 1946 2,405,888 Holley, Jr. Aug. 13, 1946 2,426,740 Mock Sept. 2, 1947 2,440,567 Armstrong Apr. 27, 1948 2,449,468 Greenland Sept. 14, 1948 2,456,604 Barfod Dec. 14, 1948 FOREIGN PATENTS Number Country Date 578,257 Great Britain June 20, 1948

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