US3577966A

US3577966A - Engine antidieseling device

Info

Publication number: US3577966A
Application number: US884444A
Authority: US
Inventors: Wilford R Collingwood; William M Hutchison; Frank E Mangas
Original assignee: Ford Motor Co
Current assignee: Ford Motor Co
Priority date: 1969-12-12
Filing date: 1969-12-12
Publication date: 1971-05-11
Anticipated expiration: 1988-05-11
Also published as: DE2058153A1; DE2058153B2; GB1293835A; CA920898A

Abstract

A container stores a small quantity of air and pumps the air into the idling system of a carburetor when the engine ignition system is turned off. The air reduces the supply of idling fuel to the engine for a time period sufficient to stop engine dieseling. An electrical solenoid valve connected to the engine ignition system controls the injection of the air into the idling passage.

Description

United States Patent Inventors Wilford R. Collingwood Dearborn;

William M. l-lutchison, Allen Park; Frank E. Mangas, Southfield, Mich.

Dec. 12, 1969 May 11, 1971 Ford Motor Company Dearborn, Mich.

Appl. No. Filed Patented Assignee ENGINE ANTIDIESELING DEVICE 7 Claims, 2 Drawing Figs.

US. Cl 123/12411, 123/97B, 123/1 19D, 123/198DC Int. Cl F02m 7/06,

F02d 31/00, F02d 13/08 Field of Search 123/198,

198 (DA), 198 (DB), 198 (DC), 97 (B), 119, 124

[56] References Cited UNITED STATES PATENTS 2,817,325 12/1957 Meissner 123/198DC 2,943,615 7/1960 Kainz 123/198DC 3,158,144 ll/l964 Walker l23/198DC 3,354,877 ll/1967 Zub et a]... l23/198DA 3,374,777 3/1968 Walker l23/97B 3,398,731 8/1968 Johansson 123/198DC 3,482,557 12/1968 De Larue et al.. 123/97B 3,482,502 12/1969 Ranft l23/198DC 3,491,737 1/ 1970 Bumia 123/97B Primary Examiner-Wendell E. Burns Attorneys-John R. Faulkner and Glenn S. Arendsen ABSTRACT: A container stores a small quantity of air and pumps the air. into the idling system of a carburetor when the engine ignition system is turned off. The air reduces the supply of idling fuel to the engine for a time period sufficient to stop engine dieseling. An electrical solenoid valve connected to the engine ignition system controls the injection of the air into the idling passage.

ENGINE ANTIDIESELING DEVICE SUMMARY OF THE INVENTION The large amount of emission control equipment required on modern day internal combustion engines has resulted in a condition known commonly as dieseling in which the engine continues to run after the ignition switch has been turned off.

Dieseling typically results from the ignition of the f uel-air mixing dieseling under most engine operating conditions, it is ineffective when the fast idle cam of the engine is being used to position the throttle blade during engine warmup. Dieseling in fact is probably most acute when the fast idle cam is in effect since just a few cycles of engine operation can heat small deposits in the engine combustion chamber to incandescence and the rich mixture supplied to the combustion chamber by the partially closed choke and the open throttle blade can be ignited readily by the deposits.

This invention provides a system for preventing positively engine dieseling under all conditions of engine operation. In an internal combustion engine having a source of electrical energy, an induction passage for supplying fuel and air to a combustion chamber, a movable throttle blade in the induction passage and an idling passage for supplying idling fuel to the induction passage downstream of the throttle blade, the system of this invention comprises a mechanism that includes a small container for storing a relatively small quantity of air. A conduit connects the container with the idling passage and a valve located in the conduit permits communication between the container and the idling passage when the ignition system is turned off. Air from the container then flows into the idling passage to reduce the supply of idling fuel and stop engine operation.

In an advanced embodiment of this invention, the container includes a diaphragm that has one side exposed to the intake manifold vacuum of the engine and the other side communicating with the valve and via the valve with the conduit. The valve is made up of a valve rod movable onto a lower seat formed at the entrance to the conduit and an upper seat that communicates with the atmosphere. A spring normally urges the valve rod onto its upper seat but an electrical solenoid actuated with the engine ignition system overcomes the force of the spring to move the valve rod onto the lower seat.

When the ignition system is turned on and the engine has been started, manifold vacuum applied to the bottom of the diaphragm in the container urges the diaphragm to a lowered position. Actuation of the ignition system moves the valve rod to its lower position so the downward movement of the diaphragm draws air past the upper valve seat and into the chamber. The components stay in this position throughout normal engine operation; since the valve rod is closing the conduit, the system does not interfere with engine operation. When the ignition switch is turned off to shut down the engine, deactivation of the solenoid permits movement of the valve rod to its upper seat, thereby connecting the container with the engine idling passage. At the same time the rising manifold pressure permits a spring to move the diaphragm of the container to an upward position, thereby forcing air through the conduit and into the carburetor idling passage where the air cuts off fuel flow to stop any engine dieseling.

BRIEF DESCRIPTION OF THE DRAWING FIG. I is a schematic view of an installation of the system of this invention showing the relationship of the container to the engine ignition system and the carburetor during normal engine operation.

FIG. 2 is a sectional view of the container and the valve assembly showing the relationship of the components when the engine is shutoff.

DETAILED DESCRIPTION Referring to the drawing, a carburetor for an internal combustion engine has an induction passage 12 for supplying fuel and air to a combustion chamber of the engine. A throttle blade I4 is mounted pivotally in induction passage 12 tocontrol the flow of fuel and air through the induction passage. Upstream of throttle blade 14 is a venturi section I6 that produces an appropriate main fuel metering signal. Downstream of throttle blade 14, induction passage I2 communicates with the engine intake manifold passage I8 that communicates with the engine combustion chamber.

A fuel reservoir is located in carburetor I0 alongside induction passage I2. Reservoir 20 communicates with a fuel well 22 that supplies fuel to an idling passage 24 through a metering jet 26. Idling passage 24 communicates through a port 28 with induction passage I2 downstream of throttle blade 14.

Mounted near carburetor '10 is a small air container 30 that has a movable diaphragm 32 mounted therein to divide the container into an upper chamber 34 and a lower chamber 36. A compression spring 37 is located in lower chamber 36 where it urges diaphragm 32 toward an upper position shown in FIG. 2. The bottom of the container includes a ferrule 38 and a hose 39 mounted on the ferrule connects lower chamber 36 with induction passage 12 at all times at a point downstream of throttle blade 14. A guide rod 40 attached to the diaphragm slides in ferrule 38 to maintain proper alignment of the diaphragm.

A cap 41 mounted on top of container 30 has a small space 42 defined partially by a lower plate 43 that fits on top of chamber 34. Space 42 communicates with chamber 34 through a short passage 44 in plate 43. Plate 43 also contains a valve seat 46 at the opening into space 42 of a passage 48. Another valve seat 50 is located in the upper part of cap 41 in alignment with valve seat 46. Valve seat 50 is the opening into space 42 of a passage 52 that communicates with a port 58 at the upper part of induction passage 12. A movable valve rod 54 is positioned to seat on either of the upper and lower valve seats. Rod 54 is urged onto seat 50 by a spring 56. The valve rod is made of a material that is movable by a magnetic'field. Passage 48 communicates with a passage 60 formed in the carburetor that in turn communicates with idling passage 24.

Positioned around the outside of the upper part of cap 41 is a solenoid coil 62. Coil 62 is connected electrically to the vehicle ignition system indicated by numeral 64 which is connected to an ignition switch 66 and the vehicle battery 68. Switch 66 is actuated manually by the vehicle driver and is closed when the engine is operating. Solenoid coil 62 thus is energized when the engine is operating; when energized the coil applies a magnetic field to valve rod 54 that moves the valve rod onto lower seat 46. When the valve rod is in this lowered position, upper chamber 34 communicates with the atmosphere via passage 44, space 42, valve seat 50, passage 52 and port 58.

The system of this invention .operates in the following manner. When the vehicle operator starts the engine, the solenoid moves valve rod 54 as described above to connect upper chamber 34 with the atmosphere. The reduced intake manifold pressure in the intake manifold passage I8 draws diaphragm 32 into a lowered position as shown in FIG. 1, thereby filling the upper chamber 34 with a small quantity of air. During continued engine operation, variations in manifold pressure can move diaphragm 32 slightly, but this movement has no effect on engine operation since the air simply moves back and forth through port 58.

When the operator opens switch 66 to shut down the engine, solenoid 62 is deactivated and spring 56 pushes valve rod onto upper seat 50 (See FIG. 2). Opening switch I66 also deactivates the engine ignition system 64, which produces an increase in the manifold pressure in intake manifold 18. The increase in pressure permits spring 37 to move diaphragm 32 upward into chamber 34 and the air in chamber 34 is forced through passage 48 into the idling passage 24 of the carburetor where it reduces fuel flow through jet 26 and thereby reduces the composition of the fuel air mixture reaching the engine combustion chambers to the point where the mixture no longer is combustible. The engine thus ceases operation without dieseling,

The amount of air necessary to prevent dieseling varies somewhat with engine size and carburetor characteristics and must be determined empirically. A minimum of about I cubic inch of air is needed to prevent dieseling under most anticipated conditions. If desired, a check valve can be included in passage 52 and valve rod 54 then moves onto only one seat controlling airflow into the idling passage.

Thus this invention provides a positively acting system for preventing engine dieseling regardless of the positions of the carburetor choke plate or throttle blade. The system can be incorporated in vehicle production or added to vehicles out in the field by relatively simple operations.

We claim:

1. In an internal combustion engine having a source ofelcctrical energy, an induction passage for supplying fuel and air to a combustion chamber, an ignition system connected to said source of electrical energy for supplying an ignition spark to said combustion chamber, a movable throttle blade mounted in said induction passage, and an idling passage for supplying idling fuel to said induction passage downstream of said throttle blade, a mechanism for preventing engine dieseling comprising:

container means for storing a quantity of air,

a conduit connecting said container means with said idling passage, and

means for transmitting air from said container means via said conduit to said idling passage when said ignition system is turned off. said air reducing the supply of idling fuel via said idling passage to said combustion chamber to stop engine operation.

2. The engine of claim 1 in which the transmitting means comprises a valve located in said conduit for controlling airflow through said conduit, said valve comprising an electric solenoid connected electrically to said ignition system and a valve rod movable by the magnetic field produced by energization of said solenoid. said solenoid closing said valve to prevent airflow through said conduit when the ignition system in turned on and opening said valve when the ignition system is turned off.

3. The engine of claim 2 in which the container means comprises a movable diaphragm dividing said container into first and second chambers, said first chamber communicating with said conduit through said valve, and a spring urging said diaphragm into said first chamber.

4. The engine of claim 3 in which the second chamber communicates with the intake manifold of the engine so the intake manifold vacuum draws said diaphragm out of said first chamber.

5. The engine of claim 4 comprising a valve seat for each end of said valve rod, the first valve seat connecting said first chamber to said conduit and the second valve seat connecting said first chamber to the atmosphere, and a spring urging the valve rod to said second seat, said solenoid moving the valve rod to the first seat when energized.

6. The engine of claim 1 in which the container means comprises a movable diaphragm dividing said container into first and second chambers, said first chamber communicating with said conduit through said valve, and a spring urging said diaphragm into said first chamber.

7. The engine of claim 2 comprising a valve seat for each end of said valve rod, the first valve seat connecting said first chamber to said conduit and the second valve seat connecting said first chamber to the atmosphere, and a spring urging the valve rod to said second seat, said solenoid moving the valve rod to the first seat when energized. 4

Claims

1. In an internal combustion engine having a source of electrical energy, an induction passage for supplying fuel and air to a combustion chamber, an ignition system connected to said source of electrical energy for supplying an ignition spark to said combustion chamber, a movable throttle blade mounted in said induction passage, and an idling passage for supplying idling fuel to said induction passage downstream of said throttle blade, a mechanism for preventing engine dieseling comprising: container means for storing a quantity of air, a conduit connecting said container means with said idling passage, and means for transmitting air from said container means via said conduit to said idling passage when said ignition system is turned off, said air reducing the supply of idling fuel via said idling passage to said combustion chamber to stop engine operation.

2. The engine of claim 1 in which the transmitting means comprises a valve located in said conduit for controlling airflow through said conduit, said valve comprising an electric solenoid connected electrically to said ignition system and a valve rod movable by the magnetic field produced by energization of said solenoid, said solenoid closing said valve to prevent airflow through said conduit when the ignition system in tuRned on and opening said valve when the ignition system is turned off.

7. The engine of claim 2 comprising a valve seat for each end of said valve rod, the first valve seat connecting said first chamber to said conduit and the second valve seat connecting said first chamber to the atmosphere, and a spring urging the valve rod to said second seat, said solenoid moving the valve rod to the first seat when energized.