US3608532A

US3608532A - Wetting of intake manifold

Info

Publication number: US3608532A
Application number: US820134A
Authority: US
Inventors: Robert N Balluff
Original assignee: Tenneco Inc
Current assignee: Tenneco Inc
Priority date: 1969-04-29
Filing date: 1969-04-29
Publication date: 1971-09-28
Anticipated expiration: 1988-09-28
Also published as: FR2040403A1; DE2016804B2; GB1282340A; DE2016804A1; DE2016804C3; DE7012836U

Abstract

A wetting system for the intake manifold of an automotive internal combustion engine. The system includes an intake manifold and carburetor for delivering a charge to the intake manifold. A device is incorporated for shutting off the flow of fuel during extreme decelerations to reduce the emission of smog producing constituents from the exhaust and nozzles deliver fuel from the accelerating pump to the intake manifold for rewetting the manifold upon reacceleration for promoting smoother operation.

Description

United States Patent m1 3,608;532

[72] Inventor Robert N. Ballutf 3,254,638 6/1966 Walker et al. 123/97 B Rives Junction, Mich. 3,437,081 4/1969 Mennesson 261/341 [21] Appl. No. 820,134 3,447,516 6/1969 Bartholomew. 123/97 B [22] Filed Apr. 29,1969 2,291,431 7/1942 Hartz 123/1 19 [45] i Sept 1971 Primary ExaminerLaurence M. Goodridge [73] Ass'gnee Tenneco Attorney-Harness, Dickey & Pierce Houston, Tex.

[S4] WETTING 0F INTAKE MANIFOLD 1 Claim, 2 Drawing Figs.

[52] U.S.C1. 123/139 AU, ABSTRACT: A wetting System for the intake manifold of an 123/119 y 123/139 Aw automotive internal combustion engine. The system includes [51] Int. Cl F02m 19/00 an intake if id and carburetor for delivering a charge m 0 Search B, the intake manifold A device is incorporated for hutting off 261/341 the flow of fuel during extreme decelerations to reduce the emission of smog producing constituents from the exhaust and References Cited nozzles deliver fuel from the accelerating pump to the intake UNITED STAT PATENTS manifold for rewetting the manifold upon reacceleration for 3,198,187 8/1965 Bartholomew 261/34.1 promoting smoother operation.

s {X}; j l J? 0/]? 4" f E, 2. 1/ *7 l I I L ,7 ,7! i '/4 W WETTING OF INTAKE MANIFOLD BACKGROUND OF THE INVENTION This invention relates to an internal combustion engine and more particularly to an improved fuel distribution system for such an engine and especially one which incorporates a structure for rewetting the manifold after extreme decelerations.

In the past few years, considerable work has been done toward reducing the emission of smog producing constituents from the exhaust gases of internal combustion engines. One avenue toward this result has concentrated on the improvement of the operating efficiency of the engine. Various arrangements have been proposed for use in connection with this approach. One engine-operating condition during which emission is high is under extreme decelerations. Under such an operating condition, the engine acts as a pump and draws raw fuel from the idle circuits of the carburetor which fuel is not burned and thus is directly discharged to the atmosphere. It has been proposed, therefore, to provide some system for shutting off the flow of fuel from the carburetor to the intake manifold during extreme decelerations. Such devices obviously will reduce the emission of unburned hydrocarbons under this operating condition. As with many of the smog reducing devices, such fuel shut off devices adversely affect the engine performance. Since the fuel discharge circuits of the carburetor are spaced at some distance from the induction ports of the engine, there is a considerable lag in the delivery of fuel to the cylinders upon reacceleration This lag results in hesitation or stumbling in the engine operation during reacceleration.

In order to cure the aforenoted defect, various devices have been proposed for admitting additional fuel to the intake manifold during reacceleration. Such devices are, however, not completely satisfactory since the additional fuel must still travel the length from the carburetor to the cylinders. In addition, the devices previously proposed for this purpose have been generally complicated and, therefore, costly.

It is, therefore, a principal object of this invention to provide an improved device for rewetting the intake manifold of an internal combustion engine after deceleration.

It is another object of the invention to provide a simplified manifold rewetting device.

It is a further object of this invention to provide a manifold rewetting device that delivers fuel directly from the carburetor accelerating pump to the manifold contiguous to the cylinders.

SUMMARY OF THE INVENTION This invention is particularly adapted to be embodied in an automotive internal combustion engine having an induction manifold for delivering a charge to a cylinder, a charge forming device for delivering a combustible charge to the induction BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a cross-sectional, partially schematic view of an internal combustion engine embodying this invention.

FIG. 2 is an enlarged cross-sectional view taken along the line 2-2 of FIG. 1.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An internal combustion engine embodying this-invention is illustrated schematically and is identified generally by the.

reference numeral 11. The engine'll includes one or more cylinders 12, an induction manifold 13 having indiyidualintakepassages or runners 14 for each of the cylinders 12 and a carburetor or other charge forming device 15 for delivering a combustible charge to the manifold 13. In addition, a device of any known type (not shown) is provided for shutting off the flow of fuel from the carburetor 15 to the induction manifold 13 upon extreme decelerations. Any of the known fuel shut off device normally provided for this purpose may be employed in connection with this invention and for this reason such a device has not been shown. Generally, such devices are responsive to induction system vacuum and operated to stop the flow of fuel to the manifold 13 when manifold vacuum exceeds a predetermined value. The fuel shutoff may be accomplished by valves in the idle discharge circuit of the carburetor 15, by means of air bleeds or in accordance with any other method generally used for this purpose.

As has been noted, the manifold 13 has separate runners or passages 14 that supply a combustible charge to the respective cylinders 12. The flow of such gases to the cylinders 12 is controlled by means of one or more poppet valves 16 that are positioned at the mouth of a port 17 in the cylinder head 18 of the engine.

The carburetor 15 includes a throttle valve 19 that controls the flow of air and fuel mixture through the carburetor induction passage 21. Fuel is delivered to this induction passage 21 from a fuel bowl 22 via one or more fuel delivery circuits which may include an idle and a main fuel circuit (not shown). In addition, the carburetor 15 includes an accelerating pump, indicated generally by the reference numeral 23. The accelerating pump is comprised of a bore 24 in which a piston 25 is supported. The piston is connected to a piston rod 26 that is, in turn, connected in any suitable manner to the throttle linkage (not shown) that serves to actuate the throttle valve 19. When the throttle valve 19 closes, the piston 25 is drawn upwardly in the bore 24 to the position shown in FIG. 1 and fuel is drawn into the bore 24 by means of a passage 27 in which a spring-biased ball check valve 28 is interposed. When the throttle valve 19 is opened rapidly, the piston 25 is driven downwardly and fuel is driven from the cylinder bore 24 into the carburetor induction passage 21 through a passage 29, past a check valve 31 and out of a discharge port 32. The construction thus far described is conventional.

As has been noted, the engine 11 includes some form of device for shutting off the flow of fuel from the carburetor 15 to the intake manifold 13 upon extreme decelerations. As a result, substantially no combustible mixture will be drawn into the cylinders 12 when the engine is otherwise operating as a pump and the emission of unburned hydrocarbons from the exhaust gases will be substantially if not completely reduced. During this condition, however, any liquid fuel droplets which may have accumulated in the runners 14 will be passed through the cylinders 12 leaving the manifold runners 14 completely dry of fuel. When the throttle valve 19 is reopened, there will be a small but nevertheless significant time lag before fuel is again transmitted from the fuel is again transmitted from the carburetor 15 through the runners 14 to the cylinders 12. Although the accelerating pump 23 will drive additional fuel into the carburetor induction passage 21 during this condition, there will nevertheless be such a time or power lag and performance of the associated vehicle will be adversely affected.

In order to preclude this unsatisfactory performance characteristic, injection nozzles 33 are provided in each of the manifold runners 14 adjacent the valve 16. A conduit 34 extends from each of the injection nozzles back into a common supply pipe 35 (FIG. 2) that intersects the discharge nozzle 33 of the accelerating pump 23. Thus, when the accelerating pump 23 is operated, in addition to delivering supplemental fuel to the carburetor induction passage 21, it will deliver fuel almost directly to each of the cylinders 12 through the opened intake valves 16. The fuel thus delivered will insure adequate power until the main fuel supply has had time to pass from the carburetor-15 into therunners 14 It should be readily apparent that this arrangement is extremely simple in construction and requires no complicated modifications to the engine carburetor or induction manifold. In addition, the supplemental fuel required upon reacceleration is admitted almost directly to the cylinders and need not travel the length of the runners 14.

What is claimed is:

1. In an automotive internal combustion engine having an intake manifold for delivering a fuel charge to an intake valve, said manifold having walls subject to becoming fuel dry upon reacceleration of the automobile and thereby causing lag in engine operation, a charge-forming device for delivering a combustible charge of fuel and air to the intake manifold. said device including an accelerating pump unit having an outlet passage for pumped liquid fuel and a charge forming chamber for mixing liquid fuel with air, said outlet passage leading to said'chamber, said pump including a bore and a piston in the bore, said piston having means for connection to throttle linkage of the engine so the liquid fuel is forced into said outletpassage upon accelerating movement of the throttle, means forming a second passage intersecting said outlet passage and receiving liquid fuel'thereform, an open conduit connected at one end to said second passage to receive liquid fuel upon operation of the pump, a nozzle in said intake manifold positioned to spray liquid fuel in said manifold toward said intake valve, the other end of the conduit being connected to and delivering fuel to the nozzle whereby operation of the accelerating pump delivers liquid fuel directly to the intake manifold to counteract dry wall and overcome lag in operation of the engine.

Claims

1. In an automotive internal combustion engine having an intake manifold for delivering a fuel charge to an intake valve, said manifold having walls subject to becoming fuel dry upon reacceleration of the automobile and thereby causing lag in engine operation, a charge-forming device for delivering a combustible charge of fuel and air to the intake manifold, said device including an accelerating pump unit having an outlet passage for pumped liquid fuel and a charge forming chamber for mixing liquid fuel with air, said outlet passage leading to said chamber, said pump including a bore and a piston in the bore, said piston having means for connection to throttle linkage of the engine so the liquid fuel is forced into said outlet passage upon accelerating movement of the throttle, means forming a second passage intersecting said outlet passage and receiving liquid fuel therefrom, an open conduit connected at one end to said second passage to receive liquid fuel upon operation of the pump, a nozzle in said intake manifold positioned to spray liquid fuel in said manifold toward said intake valve, the other end of the conduit being connected to and delivering fuel to the nozzle whereby operation of the accelerating pump delivers liquid fuel directly to the intake manifold to counteract dry wall and overcome lag in operation of the engine.