US3103211A

US3103211A - Manifold sensing device

Info

Publication number: US3103211A
Application number: US143879A
Authority: US
Inventors: Donald J Cameron
Original assignee: Holley Carburetor Co
Current assignee: Holley Performance Products Inc
Priority date: 1961-10-09
Filing date: 1961-10-09
Publication date: 1963-09-10
Anticipated expiration: 1980-09-10

Description

Sept. 10, 1963 D. J. CAMERON 3,

MANIFOLD SENSING DEVICE Filed Oct. 9. 1961 u u z 56 I 55 INVENTOR. flan/1940 d (PINE/Po BY 60 W9 M United States Patent 3,103,211 MANIFOLD SENSING DEVMIE Donald .1. Cameron, Roseville, Mich assignor to Holley Carburetor Company, Warren, Mich, a corporation of Michigan Filed Oct. 9, 1961, Ser. No. 143,879 12 Claims. (Cl. 123-440) The present invention relates to fuel metering and pumping systems in conjunction with internal combustion engines and the like and refers more specifically to an improved manifold sensing device for use with such systems including means for compensating for erroneous engine manifold vacuum indications at idle speeds.

The recent trend in engine design has been toward engines of greater size requiring greater air flows and having increased compression ratios. With such engines it has been found that in order to maintain the higher compression ratios at higher speeds an increased valve overlap, which may be defined as that number of engine degrees by which the opening and closing of the intake or exhaust valves of an internal combustion engine overlap each other, is required.

However, it has been discovered that due to the increased valve overlap the manifold vacuum existing at idle speeds is actually less than the theoretical manifold vacuum because of exhaust gases escaping into the intake manifold. This phenomenon diminishes as the speed of the engine increases. Accordingly if manifold vacuum is used as a parameter to the metering of fuel to the engine in accordance with the speed of the engine it will be apparent that if the fuel flow is adjusted so as to be proper for idle conditions that the fuel flow becomes excessively rich for subsequent speeds.

It is therefore an object of the present invention to provide improved means for metering fuel to an internal combustion engine or similar device in accordance with engine manifold vacuum.

Another object is to provide a manifold sensing device for use with internal combustion engines or the like including means for compensating for the effect of valve overlap on manifold vacuum at idle speeds.

Another object is to provide pump means for pumping fuel to an internal combustion engine or similar device, means for metering the amount of fuel pumped in accordance with manifold vacuum and means to compensate the manifold vacuum for the effect of valve overlap thereon at idle speeds.

Another object is to provide means for pumping fuel to an internal combustion engine, means for metering the fuel pumped to the engine including an adjustable abutment positionable to determine the quantity of fuel metered, a vacuum cylinder having a piston therein which piston is actuated by manifold vacuum to adjust the abutment, and means for compensating for the effect of valve overlap at engine idle speed on the position of the piston comprising a cylinder within the first mentioned piston, a piston within the last mentioned cylinder and means for connecting the last mentioned cylinder to manifold vacuum at idle speeds.

Another object is to provide a fuel pumping and metering system as set forth above wherein the vacuum applied to the last mentioned cylinder is varied in accordance with the position of the speed control member of the engine.

Another object is to provide a fuel pumping and metering system as set forth above including means for adjusting the manifold vacuum applied to the last mentioned cylinder at idle engine speed.

Another object is to provide a manifold sensing device which is simple in construction, economical to manufacture and efficient in use.

ice

Other objects and features of the invention will become apparent as the description proceeds, especially when talcen in conjunction with the accompanying drawing, illustrating a preferred embodiment of the invention, wherein:

The FIGURE is a diagrammatic representation of a fuel metering and pumping system for fuel injection apparatus including a manifold sensing device in accordance with the invention.

With particular reference to the figure of the drawing one embodiment of the present invention will now be disclosed.

The fuel metering and pumping system 10 illustrated in the figure comprises the pumping apparatus .12 for pumping fuel to the fuel injection nozzle 14 for injection into the internal combustion engine 16. The fuel pumped to the nozzle '14 is metered by means of the adjustable abutment 18 in accordance with engine parameters, such as manifold vacuum by the metering means 20. Metering means 20 includes the manifold vacuum sensing device 22 which in accordance with the invention is provided with means 24 for compensating for the effect of valve overlap on manifold vacuum at idle engine speeds.

More specifically the pumping means 12 comprises a housing 26 including an inlet conduit 28 from a source of fuel under pressure (not shown) and outlet conduits 30 and 32. for alternately feeding fuel to fuel injection nozzles associated with the engine 16. Pumping means 12 further includes the bearing sleeve 34 secured within housing 26, the rotatable metering sleeve 36 and the metering shuttle 38 movable between the adjustable abutment 18 and a fixed abutment 40' in reciprocal pumping strokes.

The bearing sleeve 34 is provided with the openings 42 and 44 extending transversely therethrough. Openings 42 and '44 connect'at one end with the passages 46 and 48 respectively. Passages 46 and 4 -8 lead respectively to the outlet conduits 30 and 62 of the pumping means 12. Openings 42 and 44 connect at the other end with a longitudinally extending recess 50. Recess 50 is in communication with inlet conduit 28.

Metering sleeve 36 is provided with restricted openings 5-2 and 54 therein which on rotation of sleeve 36 alternatively connect the inlet conduit 28 to the interior of conduit 36 at opposite ends of shuttle 3'8 through recess 50 and passages 42 or 44.

Thus in operation of the pumping means 12 as the sleeve 36' is rotated the fuel under pressure in conduit 28 will cause reciprocal movement of the shuttle valve 38 between the abutments 18 and 40 to alternately pump a metered amount of fuel through conduits 30' and 32. The pumping stroke of shuttle valve 38 and thus the amount of fuel pumped per stroke is determined by the initial positioning of the fixed abutment 40' and the position of the movable abutment 18 which is adjusted in accordance with engine parameters by fuel metering means Zll.

For a more complete explanation of the functioning of the pumping means .12 reference is made to U.S.

Patents Nos. 2,965,090 and 2,965,092.

The fuel metering means 26 includes the carriage 56 having the inclined surface 58 thereon engageable with the end 60 of the movable abutment 1 8. The inclination of the surface 58 of the carriage 56 is determined by the position of the lever 62 which is rotatable about a pivot mounting 63 in accordance with particular engine parameters, such as the condition of operation of the engine 16 and the temperature thereof as is also more fully set forth in the United States patents referred to previously.

The transverse position of the carriage 56 is determined by movement of carriage 56 in accordance with the manifold vacuum of the engine 16 by the manifold vacuum sensing device 22 to which the carriage 56 is connected by link 64 through pivot connection 66. It will be understood that both the transverse position of the carriage 56 and the inclination of the surface 58 of carriage 56 will cooperate to determine the axial position of the adjustable abutment l8 and therefore the fuel metered to the combustion engine 16 on each stroke of shuttle 38.

The manifold sensing device 22 comprises the cylinder as having an end cover 68 Which end cover is secured to the body member 26 by convenient means, such as screws 70. A piston 72 is mounted for reciprocation within the cylinder 66 and is urged to the [right by means of the spring 74 as shown in the figure. The cylinder 66 is connected to the intake manifold '76 of the engine d6 by means of conduit 78 as illustrated. Thus the piston 72 is positioned axially of the cylinder 66 in accordance with engine manifold vacuum to transversely position the carriage 56 in a manner previously known during operation of the engine 16.

Such operation has however been found to improperly meter fuel to the engine 16 when, the engine 16 has an increased valve overlap provided as required due to greater air flows and higher compression ratios in modern engines. That is to say, with large high compression modern engines, for proper engine operation both the inlet and exhaust valves of the engine are opened for a sufiicient length of time so that exhaust pressures are felt in the engine manifold at idle speeds. Thus if the fuel metered to such engines is adjusted for manifold vacuum atidle speeds the fuel will be excessively rich for speeds above idle speeds.

Therefore the means 24 for compensating for valve overlap at idle speeds in these engines is provided. Compensating means 24 comprises the cylinder 34?: within piston 72 and the piston 82 [reciprocally mounted in cylinder 86. The bias spring 84 biasing the piston 82 to the right in cylinder 80 as illustrated is also part of compensating means 24.

The piston $2 is pivotally connected by pivot means 86 directly to link 64. The transverse position of the carriage 56 is therefore determined by the position of the piston 82 Within the cylinder 80 as well as by the position of the piston '72 in the cylinder 66.

Cylinder Si is connected to the manifold side of the carburetor induction passage 90 at a point 92 just below the throttle valve ge through the conduit 96, the radially extending passage 98 and the axial recess M in the piston '72.

It will therefore be apparent that manifold vacuum will be felt in cylinder 8d only when throttle valve 9% is positioned to place orifice 92 on the manifold side thereof.

' Thus in operation at idle speeds before the throttle valve 94 is rotated counterclockwise toward an open position the adjustment of the transverse position of carriage 56 is accomplished both by the compensating means 24 and the usual manifold vacuum responsive piston 72. At this time full manifold vacuum is present in cylinders 66 and 8t acting against

springs

74 and 84 to move pistons 72 and 52 into a leftward limiting position as shown in the figure to move carriage 56 so that it positions abutment 18 for proper metering of fuel at idle engine speeds.

As the throttle valve 94 is rotated in a counterclockwise direction to increase the speed of the engine the vacuum present in cylinder Sil will gradually be reduced to the vacuum on the venturi side of the throttle valve 94 due to gradual movement of the adjacent edge of throttle valve 94 past orifice 92 on the initial counterclockwise rotation of throttle valve 94 from the closed position thereof. During this reduction in vacuum in cylinder 80 the spring 84 gradually moves piston 82 to its rightward limiting position in cylinder 80". Thus after the initial counterclockwise movement of the throttle j valve 94 the compensating means 24 is ineffective to position carriage 56 and control of the transverse position of carriage 56 is accomplished in the usual manner by means of piston '72, which is still under the influence of manifold vacuum as felt in cylinder 66.

The effect of the compensating means 24 on the position of the carriage S6 at idle speeds may be adjusted by means of the adjusting screw 102i and spring 184 threaded in the passage 1% in carburetor housing 108. The screw M2 includes a valve end 11% for regulating the opening of the orifice 112 on the venturi side of the closed throttle valve 94 which is connected by passage 114 to the conduit 96. Thus the vacuum in cylinder 66 and the position of piston 82 and carriage 56 at idle engine speed may be controlled by screw 102 to provide desired compensation for different engines or engine operating conditions to insure optimum fuel metering at both idle engine speeds and above even with the increased valve overlap required in large high compression modern engines.

The drawings and the foregoing specification constitute a description of the improved manifold sensing device in such full, clear, concise and exact terms as to enable any person skilled in the art to practice the invention, the scope of which is indicated by the appended claims.

What I claim as my invention is:

l. A fuel pumping and metering system for an internal combustion engine having an intake manifold comprising pumping means for delivering fuel to the engine, metering means operably associated with the pumping means for metering the fuel pumped by the pumping means in accordance with the position of the metering means, positioning means comprising a cylinder in communication with the engine manifold and a piston mounted in said cylinder for movement therein in accordance with manifold vacuum, and compensating means connecting the metering means to the piston for movement therewith comprising a second cylinder formed in said piston, a second piston mounted in the second cylinder and connected to the metering means, and means connecting the second cylinder to the engine manifold at engine idle speed.

2. Structure as claimed in claim 1 wherein the engine includes a throttle valve and the means connecting the second cylinder to the engine manifold comprises a conduit extending between the second cylinder and engine manifold connected to the engine manifold at a point adjacent the throttle valve which point is on the engine manifold side of the throttle valve only when the throttle valve is in substantially engine idle position.

3. Structure as claimed in claim 2 wherein said compensating means further includes resilient means within the second cylinder and acting between the second cylinder and piston in opposition to manifold vacuum which resilient means is operable to gradually move the second piston to a limiting position with respect to the first piston on movement of the throttle valve away from the engine idle position thereof to position the point at which the conduit between the second'cylinder and engine manifold is connected to the engine manifold on the venturi side of the throttle valve.

4. A fuel pumping and metering system for an internal combustion engine having an intake manifold comprising pumping means for delivering fuel to the engine, metering means operably associated with the pumping means for metering the fuel pumped by the pumping means in accordance with the position of the metering means, positioning means comprising a cylinder in communication with the engine manifold and a piston mounted in said cylinder for movement therein in accordance with manifold vacuum, and compensating means connecting the metering means to the piston for movement therewith comprising a second cylinder formed in said piston, a second piston mounted in the second cylinder and connected to the metering means and means connecting the second cylinder to the engine manifold at engine idle speed, and

means for regulating the effect of the compensating means on said metering means.

5. Structure as claimed in claim 4 wherein the engine includes a throttle valve and the means connecting the second cylinder to the engine manifold comprises a vacuum conduit extending between the second cylinder and engine manifold connected to the engine manifold at a point adjacent the throttle valve which point is on the engine manifold side of the throttle valve only when the throttle valve is in substantially engine idle position.

6. Structure as claimed in claim 5 wherein the means for regulating the compensating means effect on said metering means comprises a passage connecting the conduit between the second cylinder and enm'ne manifold to the venturi side of the throttle valve and valve means for adjusting the eifective size of the passage.

7. A fuel pumping and metering system for an in ternal combustion engine, comprising pumping means for delivering fuel to the engine, metering means opena'bly associated with the pumping means for metering the fuel pumped by the pumping means in accordance with the position of the metering'means, a cylinder, a piston mounted in said cylinder and connected to said metering means for moving said mete-ring means in response to an engine parameter, a second cylinder, a second piston mounted in said second cylinder and connected to the metering means for moving the metering means in response to an engine parameter only at predetermined engine speeds.

7 determined engine speed is idle engine speed.

11. A fuel pumping and metering system for an internal combustion engine having an intake manifold comprising pumping means for delivering fuel to the engine, metering means operably associated with the pumping means for metering the fuel pumped by the pumping means in accordance with the position of the metering means, positioning means mechanically connected itO the metering means and directly responsive to manifold vacuum at all engine speeds for positioning the'metering means, and separate compensating means directly rnechanically connected to the metering means and responsive to manifold vacuum for further positioning the metering means in accordance with manifold vacuum at engine idle speed. i

12. Structure as set "forth in claim 11 wherein the separate compensating means is carried by and movable with respect to the positioning means.

References Cited in the file of this patent UNITED STATES PATENTS 2,943,616 Boyer et al. July 5, 1960 2,954,018

Dermond Sept. 27, 1960-

Claims

1. A FUEL PUMPING AND METERING SYSTEM FOR AN INTERNAL COMBUSTION ENGINE HAVING AN INTAKE MANIFOLD COMPRISING PUMPING MEANS FOR DELIVERING FUEL TO THE ENGINE, METERING MEANS OPERABLY ASSOCIATED WITH THE PUMPING MEANS FOR METERING THE FUEL PUMPED BY THE PUMPING MEANS IN ACCORDANCE WITH THE POSITION OF THE METERING MEANS, POSITIONING MEANS COMPRISING A CYLINDER IN COMMUNICATION WITH THE ENGINE MANIFOLD AND A PISTON MOUNTED IN SAID CYLINDER FOR MOVEMENT THEREIN IN ACCORDANCE WITH MANIFOLD VACUUM, AND COMPENSATING MEANS CONNECTING THE METERING MEANS TO THE PISTON FOR MOVEMENT THEREWITH COMPRISING A SECOND CYLINDER FORMED IN SAID PISTON, A SECOND PISTON MOUNTED IN THE SECOND CYLINDER AND CONNECTED TO THE METERING MEANS, AND MEANS CONNECTING THE SECOND CYLINDER TO THE ENGINE MANIFOLD AT ENGINE IDLE SPEED.