US2596461A

US2596461A - Speed presponsive valve for fuelfeeding systems

Info

Publication number: US2596461A
Application number: US43731A
Authority: US
Inventors: Baisch John Carroll
Original assignee: Carter Carburetor Corp
Current assignee: Carter Carburetor Corp
Priority date: 1948-08-11
Filing date: 1948-08-11
Publication date: 1952-05-13
Anticipated expiration: 1969-05-13

Description

y 13, 1952 J. c. BAISCH 2,596,461

SPEED RESPONSIVE VALVE FOR FUEL-FEEDING SYSTEMS Filed Aug. 11, 1948 Summer Patented May 13, 1952 SPEED RESPON SIV E VALVE FOR- FUEL- FEEDING SYSTEMS John Carroll Baisch, Whittier, Calif., assignor to Carter Carburetor Corporation, St. Louis, Mo., a corporation of Delaware Application August 11, 1948, Serial No. 43,731

8 Claims.

This invention relates generally to fuel supply systems, and relates more particularly to such systems wherein the fuel is supplied under positive pressure.

While the invention has utility as a fuel supply system for various devices, it is particularly useful for supplying fuel to internal combustion engines, and is shown and described in such connection.

It is an object of the invention to provide a fuel supply system which will provide the proper quantity of fuel for the engine fuel mixture under various operating conditions.

It is another object of the invention to provide a device of this character wherein the metering of the fuel is controlled in accordance with engine speed and one or more other operating variables.

Still another object of the invention is to provide an arrangement of this character wherein the valve which controls the metering of the fuel is controlled by a speed responsive centrifugal device, which may be engine driven, and means responsive to one or more other operating variables.

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

Another object of the invention is to provide a device of this character wherein the means for varying the position of the fuel control valve relative to the position effected by engine speed may be one or more means responsive respectively to engine charging pressure, engine tem perature and/or barometric pressure.

Still another object of the invention is to provide a device of this character that is simple in construction and operation.

Other objects and advantages of the invention will appear from the following part of the specification.

Referring to the drawings, which are for 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 of the outside of the piston housing as seen from the right hand side in Fig. 1;

Fig. 3 is a sectional view of an induction passage showing alternative connections for the pressure responsive device; and

Fig. 4 is a fragmentary view of means for varying the position of the metering valve in accordance with temperature and/or barometric pressure. 7

Referring to Fig. 1, there is shown a fuel supply to the throttle valve.

system wherein the fuel is supplied by a pump, indicated generally at It. The pump may be of any well known type capable of deliveringfuel at a substantially constant pressure (although it may have other delivery characteristics). Liquid fuel is supplied to the pump ill by means of a conduit II connected to a suitable source of fuel, not shown, and the pump delivers the fuel through a conduit 12 which leads to a fuel nozzle in the induction passage of the engine posterior Should a supercharger be used, the conduit l2 may be connected to the intake manifold posterior to said supercharger. If desired, a pressure operable nozzle, not shown, of any well known type, may be used, adjacent the discharge end of the conduit l2, said pressure operable nozzle functioning in the well known manner. Within the conduit 121 there is disposed a calibrated restricted metering jet or orifice [3 controlled by a tapered movable valve [4 which is provided with a stem l5 slidable in a guide [6.

Means for controlling the position of the valve [4 in accordance with engine speed comprises a speed responsive centrifugal device, indicated generally at 23, and shown as comprising a fly ball governor of well known type having a 1'0- tatable shaft 21 connected to a rotating part of the engine, not shown, by any suitable well known means such as gearing or the like, also not shown. The speed responsive device 20 may rotate at engine speed or at some other speed proportional to or representative of engine speed. To the shaft 2| is fixed amember 22 which has no longitudinal movement, but which rotates the said shaft 2|, said member 22 having a depending, diametrically extending part 23. As shown in the drawings, the upper ends of a pair of arms 24 are pivoted, as at 25, to the opposite sides of the part 23, said arms 24 having weights 26 adjacent their lower ends. A pair of links 21 are provided, each of which is pivoted, at 28, adjacent one end to an intermediate part of the arms 24, the opposite ends of said links being pivoted at 29 to oppositely disposed ears 30 of a member 31 having an axial bore 32 for slidable reception of a guide rod 33.

The lower end 35 of the member 3| is of larger diameter than the upper end and is externally threaded for reception of an internally threaded cap 36, there being a shoulder 31 on said enlarged part 35, against which the upper or inner end of the cap 86 abuts. The cap has an inwardly extending annular flanged!) with an axial opening 4| therein forreception of a stem 42 0f a cylin said head being of smaller diameter than the 7 internal diameter of the chamber 44 and being located adjacent the upper end of said stem 42.

Ball bearings 46 ar disposed between the head 45 and the adjacent part 35 and also between said head and the flange 40, suitable raceways being provided in the respective parts to retain; Thus, the member 3| may rotate substantially without friction and without the balls 46 in place.

the member 3| may freely move. Also, there is a spring 54a which reacts between the bottom wall 53 of the cylinder 52 and the piston 54.

It is also desirable to limit the inward movement of the piston 54 and means for thus limiting said movement is provided and comprise a part 53d which extends inwardly of the cylinder 52 from the wall 53 and has an internally threaded bore for reception of a screw 53b. The free end of said screw 53 is disposed in spaced relation to th piston 54 so that it will limit inward movementof said piston.

imparting rotation to the cylindermember 43,

which is axially or longitudinally slidablewithin the bore 41 of a guide 48 and is held against rotation by a laterally extending tubular portion 49 slidable longitudinally in the slot 55. The guide 48 is;provided with a laterally extending bracket 5 I which is adapted to besecured to any convenient fixed support (not 'shownlywhfereby the guide 48 will be held in a fixed'position.

The cylinder member 43 has a cylindrical bore 52 extending from the end thereof 'opposite'the stem 42, said bore being closed at the inner end by a wall 53 from which-saidst'em 42 projects.

The valve stem I5 is provided with a piston 54 which is slidable in the cylindrical bore 52, the latter being connected to a source of engine charging; pressure by means of a pas'sag'e'55 in the portion 49 and conduit '56) The conduit -55, or at least a portion thereof, is flexibleto permit free sliding movement of the cylinder'member 43 in the bore 41 of the uide 48. The opposite end of the conduit 55 is shown as being connected to the engine intake passage or manifold 51 posterior tothe throttle valve 58 and'if desired a re stricted calibrated orifice 5515 provided in the connection between the intake manifold or passage-and thecylinder 52. The end portion of the cylinder 52 opposite the wall 53'has an external thread for reception of an internally threaded cap 50 whichdoes not extend beyond the plane of the internal bore 52, so as to prevent any binding between the parts, said cap fiIl'having an inwardly extending flange 6| which limits outward movementpf the piston 54. The cap 60 also has an'axial opening-62 for the free reception of the valvestemIB. l i

The adjacent end of the guide alsohas an externally threaded portion forreception 'of an internally threaded cap 63 which has an end wall I 64 limiting downward movement of the cylinder member 43, as shown inthe drawings, said wall 34 having an axial opening 65 through which the valve stem I5 freely extends. threadedly adjustable on the guide 43 so as to adjust the position'o f the valve I4 relative to the orifice 13. This is so that, if desired, the valve I4--;may-be positioned in a slightly open position for supplying idling fuel and the cap is provided with aset screw 67 for securing same in adjusted positions.

In order tomaintain the valve I4 in the closed ersubstantially closed position when the mechanism is at rest, a spring 43a is provided in the guide 48 which reacts betweenan'inturned abutment or flange 43w andthe 'i'nnn'end of' the cylinder member 43. It is to beunderstoo'd that the flange 48a is of jsufilcient si'ie to permit adequate engagementwith the spring, but-provides an opening in which the enlarged portion 35 of The cap 63 is In Fig. 3 there is shown an arrangement whereby the cylinder 52 may be connected to part of the intake passage or manifold other than as shown in Fig. 1. In Fig. 3 there is shown a large venturi' I0 and a small venturi II. The cylinder 52 may be connected with either of these venturis, as indicated at I2 and I3 respectively, and there is metering means or orifices I4 and I5 respectively in'these connections.

"'It-is'to be understood that the connection be tween the cylinder 52 and the induction passagemay be by any one of the conduits or -con'nections disclosed herein or by means of all of them, or various combinations thereof; in' accordance with requirements of various installations. I J 7 Inasmuch as it is also desirable n many-types of installations topro'vide a temperature control of the fuel supply, such control may be effected by 'a temperature responsive device IIy-Fig. 4; which has one end attached'to the stem I5of the valve I4 andthe opposite end-connected with the piston'54' bymeans of a'st'em 18'; T 5

The jet or-orifice' I3 and the valve I I comprise variable metering means for controlling the flow of fuel to the engine. As is' well-known, the' rate of liquid fuel ilow through afuel'metering' orifice is proportional to the square rootof the pressure diiference across said orifice. With an orifice'o'f a given size, supplied with fuel at-a -substantially constant pressure, as by the pump II]; the supply of fuel to the engine may be varied by variously positioning the valve I4 in accordance withcertain engine oroperatingvariables In the'present arrangement, one of these engine operating variables," provided for varying the position of the valve I4, and hency varying the 'efiective size of the orifice, comprises the centrifual'device20. 7 v I I 'When the engine is inoperative, the valve 14 is in the closed position: (althoughit may beotherwise positioned for some installations) 'Upon rotation of the speed responsive device 25",'centrifu gal forcewill cause the weights 26 to move outwardly and move upwardly (as shown in "the drawings) the member 3 I, stem 42, cylinder'member 43, valveste'm I5, and valve I4.- This movement will be e fiected against the force of/the spring 43a, it being understood 'that'the valve stem I5 and valve I4 will move in accordancewith the movements of the member'43 due to 'the action of thesp'ring 54a. 'Further;jthis movement of the valve in the opening direction-will be substantially proportional to the square of engine speed because of the inherent operating characteristics of the centrifugal device which'characteristics are well known. 3.

Ihus with this arrangement, the effective area of the orifice I3 is controlled substantially in'proportion to the squareof engine-speed by means of theoentri'fugalg'overhorF As the quantity =of fuel-which --wi-llflow through a metering orificei'of a given. size will vary in proportion to the square root of differential pressure across said orificeor on opposite sides thereof, and as the size of the orifice is varied in accordance with 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 jets or orifices l3 will vary directly as the engine speed. However, the valve l4 may be contoured differently from the contouring shown, to provide other metering characteristics. The means for controlling the valve l 4 in accordance with engine intake passage or engine charging pressure includes the cylinder member 43 and the piston 54. The piston 54 is subjected to the engine charging pressure by reason of the conduit connection 56 with the cylinder 52. As shown in the drawings, air passes through the passage 5'! from top to bottom, the air entering at the top. The induction passage 5! has its outlet connected to the engine cylinders, or to a supercharger inlet, should a supercharger be used. A supercharger might alternatively be connected to the inlet of the induction passage or there might be a supercharger connected to both the inlet and outlet. Should a supercharger be used, the conduit 56 would be connected to the engine intake manifold posterior to said supercharger.

Therefore, in view of the fact that the Weight of airflow to an internal combustion engine at a given manifold pressure varies substantially in direct proportion to the speed of the engine, the device herein described will supply fuel to the engine in accordance with airflow therethrough.

Thus, when engine charging pressure is low (or the manifold vacuum high), the pressure in the cylinder 52 will be low and the differential of pressure across the piston 54 will cause said piston to move inwardly in said cylinder and increase the eifective size of the metering orifice 13. Thus, it will be apparent that the valve 14 is controlled in accordance with engine charging pressure which reflects throttle pressure and engine speed and load.

Assuming that the engine is operating within its normal range, say, at a speed between idling and the power range, the piston 54 will be maintained at its outmost position by the spring 54a, it being understood that under these conditions, said spring is so calibrated that the difierential of pressure across the piston 54 will be insufficient to overcome the force thereof. At this time the quantity of fluid supplied to the engine will therefore be controlled in accordance with engine speed. However, the force of the spring 54a is overcome by the differential of pressure across the piston 54 when the throttle valve is in a substantially closed or idling position, and the engine pressure is consequently relatively low. Thus, the piston 54 will be actuated to eifect suitable opening of the valve I l to enrich the mixture. The engine charging pressure is also relatively low when the engine is operating at high speed. At this time the force of resistance of the spring 54a is also overcome by the differential of pressure across the piston 54 so that the valve I4 is moved to an open position, greater than that effected by the speed responsive device, and the fuel mixture enriched as is required under such conditions.

Should the cylinder 52 be connected to either the large or small venturi, the piston 54 will be actuated in accordance with the pressure anterior to the throttle. Should both of the

connections

12 and 13 be used, a similar result would be effected as modified by the action of the venturis. Should either or both of the connections I2, 13 be combined with the connection 56, the former would bleed air to the cylinder 52 when the throttle valve is closed and thus modify the action of the pressure posterior to the throttle. However, when the throttle valve is opened, the pressures in either or both of the venturis and pressure posterior to the throttle would. be com bined to move the piston 54 inwardly.

If desired, the position of the valve M may be further modified by the temperature responsive device 11, which may be placed adjacent some portion of the engine so as to be subjected to the temperature thereof. Thus, when the engine is cold, the bellows 71 would be contracted to a degree, depending upon the subnormal operating temperature, and thus effect a further opening of the valve M to enrich the mixture for cold operating conditions. As the engine warms up to normal operating temperature, the bellows I? would expand accordingly to lean the mixture as desired. It is to be understood, of course, that means may be provided for limiting expansion of the bellows should such an arrangement be found necessary.

The bellows may be of such character as to be responsive only to temperature or it may be so constructed and arranged as to be responsive to barometric pressure. Or, the bellows may be so constructed and arranged in the well known manner as to be responsive to both temperature and barometric pressure.

It is to be understood, of course, that the device responsive to engine charging pressure may vary the position of the valve M relative to the position which would otherwise be effected by the speed responsive device 20, and the same is true of the temperature responsive device TI.

While particular types of mechanisms are shown herein, it is to be understood that other types of speed responsive centrifugal devices may be employed and other types of pressure responsive devices may be used. Also, other types of temperature and/or barometric responsive devices may be used instead of the bellows shown in Fig. 4.

I claim:

1. In fuel control means: a fuel conduit; variable metering means for said conduit, said variable metering means including a movable valve part; a casing having a cylindrical chamber; a device slidable in said chamber and having a cylindrical bore therein; a piston in said bore, said piston being connected to said valve part; means for connecting said bore to a source of variable pressure for actuating said piston; and speed responsive means connected to said device and adapted to move same in said chamber.

2. The invention defined by claim 1 wherein there is a temperature responsive device interposed between said piston and said valve part.

3. The invention defined by claim 1 wherein there is adjustable means for limiting movement of the device in one direction in said chamber.

4. The invention defined by claim 1 wherein there is adjustable means for limting movement of the piston in one direction.

5. In a fuel control mechanism: a fuel conduit; a variable metering valve for said conduit, including a movable valve part; a casing having a cylindrical chamber; a device slidable in said chamber, said device having a cylindrical bore; a piston slidable in said bore, said piston being connected to said valve part; means for connecting said bore to a source of varying pressure for actuatin said piston; yielding means urging the piston in a direction to close said valve; means limiting piston movement in said direction; yielding means urging said device in-the valve closing direction; means limiting movement of said device in said direction; and'speed responsive means connected to said device for moving said device in the opposite direction.

6. The invention defined by claim 5 wherein there is adjustable means limiting movement of the piston against the force of the yielding means acting on said piston.

7. The invention defined by claim 5 wherein the means limiting movement of the device in the valve closingdirection comprises'acap threaded to the casing for adjustably limiting the movement of said device in said direction.

8. The invention defined by claim 5 wherein the casing has a longitudinally extending slot and 81' saiddevice has: a laterally extending projection slidable in said'slot. V I

JOHN CARROLL BAISCH.

7 REFERENCES oiTEn The following references are of record in the file of this patent:

UNITED STATES PATENTS v Date Number v Name 1,154,530 Merriam et a1 Sept. 21, 1915 2,245,562 Becker June 1'7, 1941 2,281,411 Campbell Apr. 28, 1942 2,382,707- Gosslau et a1 Aug. 14, 1945 2,426,749 Mock Sept. 2, 1947 2,440,567 Armstrong et a1 Apr. 27, 1948 2,449,468. Greenland Sept. 14, 1948 2,456,604

Barfod et a1 Dec. 14, 1948