WO1984002556A1

WO1984002556A1 - Fuel-air control device

Info

Publication number: WO1984002556A1
Application number: PCT/US1982/001832
Authority: WO
Inventors: Juanita Norman; Dan M Norman
Original assignee: Ecotroleum Inc
Priority date: 1982-12-29
Filing date: 1982-12-29
Publication date: 1984-07-05
Also published as: AU1153883A; EP0130181A1

Abstract

A device for aiding in the control of the fuel-air mixture in an internal combustion engine having an accelerator linked mechanically (42) to a carburetor (41) and a ventilation passage (48) from the crankcase of said engine to the intake manifold (46), said device comprising a valve housing (30) having a seat (15) coupled to an air passage (18) adapted to communicate between outside ambient air and the ventilation passage; a valve means (16) for seating in the seat in the valve housing to prevent ambient air from flowing into the air passage, and a valve control cam means (21) coupled to the accelerator to gradually open and close the valve as the accelerator is depressed. This device is used to increase the air in the fuel mixture so as to provide a more complete combustion.

Description

FUEL-AIR CONTROL DEVICE BACKGROUND OF THE INVENTION

This invention relates to devices used in vehicular internal combustion engines to provide efficient control and use of the crankcase fumes.

It has been known that automobiles engines contribute to atmospheric pollution by spewing forth unburned and partially burned gaseous hydrocarbons and even droplets of unburned oil. A principal offender in this respect are the fumes which originate in the crankcase and which in the past were allowed to escape to the atmosphere. In recent times laws have been passed which require the fumes to be channeled back to the air intake manifold of the engine, there to be mixed to the incoming fuel-air mixture so that the unburned hydrocarbons in the fumes will be burned in the engine cylinders.

In existing automobile engines, a crankcase ventilation conduit has its intake end usually located upstream of the carburetor in such manner as to pass fresh air into the crankcase. Ventilation of the crankcase is achieved by drawing off this air and entrained fumes, gases, etc., through a conduit connected to the downstream side of the carburetor or to the air intake manifold. The crankcase fumes and ventilating air pass into the induction system downstream of the carburetor. Because of this, the flow from the crankcase to the intake manifold must be controlled. To provide such control, a pollution control valve or positive crankcase ventilation valve (PCV valve) is located in theconduit connecting the crankcase to the engine air intake manifold. The PCV valve closes during engine idling when the vacuum in the intake manifold is high. When the PCV valve is closed, the ventilated air and fumes either are blocked off entirely or only small amounts are allowed to pass through an orifice in the PCV valve.

As the engine speeds up, the PCV valve opens to permit larger quantities of air and crankcase fumes to be drawn into the intake manifold, thus increasing the ■ventilation effect in the crankcase. The PCV valve operates in a puttering manner, rather than smoothly fully opening and closing. While the PCV valve is quite effective in obtaining less ventilation when the engine is idling and more ventilation when the engine is speeded up, the minimal flow through the PCV valve during idling adversely affects engine idling and increases gasoline consumption. The design of the PCV valve is a compromise between good idling and effective burning of the crankcase fumes.

In engines which are not provided with a PCV valve it is still desirable to increase the air flow into the intake manifold downstream of the carburetor, except when the vehicle is idling and the intake manifold vacuum is high. An additional supply of air reduces the amount of vaporized fuel which is drawn through the carburetor and that would be wasted in the vehicle exhaust and would pollute the environment. The richness of the fuel air mixture is preferably reduced. A more correct air-to-fuel ratio is assured.

In a vehicle having a PCV valve, the device of the present invention is designed for being positioned in the conduit leading from the PCV valve to downstream side or base of the carburetor. The device acts to permit improved idling characteristics and reduced fuel consumption. In a vehicle engine that pipes crankcase fumes through a PCV valve back to the intake manifold, often there is insufficient oxygen for complete combustion of the gasoline plus the unburned combustible hydrocarbons in the crankcase fumes. The device of the invention helps supply that needed oxygen and also breaks up the unburned hydrocarbons to facilitate their combustion. There are many devices which attempt to solve this problem. Such devices of this general type are disclosed in U.S. Patent. No. 3,809,035; U.S. Patent No. 3,923,024; and in my previous patents, U.S. Patent No. 4,183,336 and 4,305,369.

In each of these prior art devices there is a means for opening a passageway to permit ambient air to enter the fuel-air mixture leaving the carburetor under selected low speed conditions and also to suddenly admit large amounts of such air. There has been no attempt in the past to provide a device which will gradually admit more and more ambient air as the speed of the engine is increased, and to reduce that ambient air at still higher speeds. It has been found that the optimum operation of this device is to provide no ambient air at idling conditions and to increase the amount of ambient air as the vehicle speed is increased to about 88 km./hr. and there¬ after to decrease the amount of ambient air as the speed is increased to about 113 km./hr until the ambient air is shut off completely and remains in that condition at still higher speeds. Accordingly it is an object of this in¬ vention to provide an improved fuel-air control device. It is still another object of this invention to provide an improved fuel-air control device that provides the optimum amount of ambient air at different speeds of the engine. It is still another object of this invention to provide such a device that is mechanically operated and does not rely upon electronic sensing. Yet another object is to obtain lower exhaust emissions of pollutants from the engine. Still other objects will be apparent from the more detailed description of this invention which follows.

BRIEF SUMMARY OF THE INVENTION This invention provides a device for aiding in the control of the fuel-air mixture in an internal com¬ bustion engine having an accelerator linked mechanically to a carburetor and having a ventilation passage from the crankcase of said engine to the intake manifold, said device comprising:

(a) a valve housing having a seat coupled to an air passage, said air passage adapted for communication between the ambient air and said ventilation passage;

(b) a valve means for seating in said seat to prevent ambient air from flowing into said air passage; and

(c) a valve control cam means coupled to the accelerator linkage to gradually open and close said valve means as the accelerator is depressed. In a preferred embodiment of this invention the valve control cam means is a sliding plate having a cam surface and said valve means having a roller cam follower urged against the cam surface. In an especially preferred embodiment of this invention the cam surface is an elongated slot positioned along the length of the plate with the roller means riding in the slot and attached to the valve body by a yoke, and the sliding plate being attached to the accelerator linkage by a flexible cable.

BRIEF DESCRIPTION OF THE DRAWINGS

The novel features believed to be characteristic of this invention are set forth with particularity in the appended claims. The invention itself, however, both as to its organization and method of operation, together with further objects and advantages thereof, may best be under¬ stood by reference to the following description taken in connection with the accompanying drawings in which:

FIG. 1 is a top plan view of the device of this invention.

FIG. 2 is a cross sectional view taken at 2-2 of FIG. 1.

FIG. 3 is an elevational view of the valve body of this device.

FIG. 4 is a front elevational view of the sliding plate cam of this device.

FIG. 5 is an end elevational view of the sliding plate cam of this device.

FIG. 6 is a schematic illustration of the device of this invention operatively connected to an internal combustion engine.

DETAILED DESCRIPTION OF THE INVENTION

The device of this invention can be best under¬ stood as a complete assembly in FIGS 1 and 2 of the drawings. This device is attached to the ventilation passage which joins the crankcase of the engine to the intake manifold. For this purpose an outlet conduit 10 is provided for connection to the ventilation passage by a rubber hose or its equivalent. The outlet conduit is connected at 13 to a rubber hose that is attached to the ventilation passage leading from the PCV valve to the air intake manifold at the outlet of the carburetor. This attachment is accomplished by cutting the ventilation passage, which normally is a flexible rubber hose, inserting a tee connector and attaching all three hose ends to it as shown in FIG.6, which will be described more fully below.

The device of this invention comprises a valve housing 30 into which is formed a valve seat 15, which in this instance is a 45° countersunk recess. Connected to valve seat 15 is a vertical bore 31 which is designed to contain a cylindrical valve body 16 having a 45° conical head 17 adapted to mate with seat 15. Inlet passages 14 provide conduits for ambient air outside of the device to enter into bore 31 and to pass through the opening between valve head 17 and valve seat 15 (when the valve is opened) and to conduct that ambient air into air passage 18 and thence through outlet conduit 10 into the ventilation passage to be conducted on to the intake manifold. When the valve is closed between head 17 and seat 15 ambient air is not admitted into air passage 18. A suitable sponge like air filter 40 is placed around valve body 30 to prevent dirt from entering passages 14, and may be attached to base plate 35 by a suitable adhesive. A preferred material for filter 40 is polyurethane foam having pores of about .0025mm. in size.

The components of the device which control the functioning of the valve body 16 are enclosed in a U-shaped channel housing 24 with a removal cover 25 to permit access to the moving parts inside. Cover 25 is preferably fitted onto housing 24 without using any separate fastening means, although self-threading drive screws or machine screw connections may be employed, if desired. The moving parts of the device comprise a sliding cam plate 21 which is followed by a roller means 19 on the bottom of valve body 16. Plate 21 is contained in two longitudinal grooves 26 extending throughout the length of housing 24. The preferred embodiment of the cam surface 20 is a slot passing through plate 21 and having the necessary configuration to permit a roller to be positioned through the slot and attached valve body 16 by a yoke containing means for attaching roller 19 firmly to valve body 16.

Plate 21 is moved from left to right by means of flexible cable 23 attached to the accelerator linkage such that when the accelerator is depressed plate 21 is moved from left to right. Plate 21 is returned to its original position as shown in FIG 2 by means of spring 27 which is attached at one end to plate 21 by hole 28 and at the other end to housing 24 by an attachment means 29. It will be seen that as plate 21 moves from the position shown in FIG.2 to the right roller 19 will pass through a curved portion of cam slot 20 causing valve body 16 gradually to move downwardly and thereby to open the valve to permit ambient air to pass into air passage 18 and to ventilation passage 10 until at the bottom of curved portion slot 20 that valve is at its widest open position. As plate^* 21 is moved still further to the right valve body 16 will be urged upwardly until at the end of the curved portion the valve will be closed and no further ambient air will be admitted into air passage 18. As plate 21 moves still further to the right slot 20 remains in a position to maintain the valve closed, admitting no ambient air. Flexible cable 23 preferably is a stainless steel cable covered with nylon.

Valve body 16 is mounted in bearing 34 which may be Teflon or other nonlubricated or lubricated bearing material. Bearing ^*34 is retained in base plate 35 which is attached to housing 24 by suitable bolts 36 or other known fastening means. Encircling valve body 16 is spring 32 which is biased in the direction of maintaining valve head 17 against seat 15 such that the valve is closed when no other forces are operating against vavle body 16.

In FIG. 3 the structure of valve body 16 is seen in more detail as having a conical head 17, a groove 33, and a yoke structure 38. Groove 33 provides a means for securing spring 32 at the end of valve body 16 adjacent head 17. Yoke structure 38 provides a means for attaching valve body 16 to sliding cam plate 21 and having roller 19 pass completely through slot 20 in plate 21. Roller 19 is

OMPI preferably made of nylon or other suitable resilent material and is attached to valve body 16 by a suitable central pin shaft 39.

The structure of cam plate 21 is shown in FIGS. 4 and 5 as a thin rectangular plate having a suitable cam surface 20 in the form of a slot passing completely through the plate and extending longitudinally from one end of plate 21 to the other. Hole 22 is provided for attachment of a flexible cable 23 that connects plate 21 to the accelerator linkage. Hole 28 is provided for attachment of one end of spring 27 that returns plate 21 to its position when the engine is idling or not operating. In place of hole 28 there may be used a projecting pin for attachment of spring 27. Cam slot 20 may be conveniently divided into three portions. Portion 40 is designed to maintain the valve in a closed position whereby no ambient air is admitted to the ventilation passage between the PCV valve and the intake manifold. Portion 42 is designed to maintain the valve in the same closed position, and these two portions are essentially straight linear sections of the cam surface. In between these portions 40 and 42 is curved portion 41 which smoothly connects the two linear portions with a downwardly directed curved section that is essentially symmetrical about an axis passing through the lowest point of the curved portion 41. It will be appreciated that as roller 19 moves downwardly in a smooth gradual manner to open the valve and permit ambient air to pass into the air passage 18 in an increasing amount until roller 19 reaches the lowermost extent of the curve in portion 41. Beyond this point the roller will move upwardly and gradually close the valve until it reaches the beginning of portion 42 when the valve will be completely closed and will permit no ambient air to pass into the ventilation passage at any higher speeds.

In FIG. 6 there is shown how the device of this invention is attached to a typical automotive internal combustion engine. Carburetor 41 sits on top of engine block 45 and is attached to the accelerator through linkage 42 to cam 43. As the accelerator is depreseed to increase

OMPI ° the engine speed, cam 43 is caused to rotate clockwise increasing the volume of fuel-air mixture from carburetor to intake manifold 46 leading to the cylinders of the engine. Spring 44 is attached to cam 43 to provide a force in the counter-clockwise direction so as to return cam 43 to the idling position when the pressure on the accelerator is released. PCV valve 47 is located on the transmission housing and fumes therefrom are conducted through tubing 48 to an inlet fitting 55 on intake manifold 46.

The control device of this invention 49 is mounted on block 45 through an appropriate bracket support 56. Flexible cable 51 is connected to cam 43, the other end being connected internally of device 49 to cam plate 21 (see FIG.2) . Flexible cable 51 is attached to cam 43 such that as the accelerator is depressed and cam 43 rotates clockwise, cable 51 will be pulled outwardly from control device 49. The additional ambient air admitted through device 49 as described above is conducted through tubing 52 to a tee fitting 53 and thence into conduit 48 leading to inlet 55 of manifold 46. Since tubing 48 normally is rubber tubing it can be cut at a convenient location, tee 53 inserted therein, and tubing 52 (also normally rubber tubing) attached easily. An added feature of this invention which is preferably, but not necessary in all instances, is the inclusion of valve 50 in tubing 52. Valve 50 performs an added safety function of keeping tubing 52 closed until the engine reaches an acceptable operating temperature. A preferred device for valve 50 is a thermowax switch which is attached to the outside surface of intake manifold 46 and opens tubing 52 when the switch senses a temperature of about 38°C. Another type of device for this purpose is a helical coil switch which performs the same function. Valve 50 is inserted in tubing 52 by cutting the tubing attaching both ends to opposite ports of valve 50 and thereby permitting the flow from tubing 52 to tubing 54 to be unobstructed when the engine is above a minimum operating temperature and to be stopped when the engine temperature is too low. It has been determined that for optimun operation of the internal combustion engine there should be no ambient air admitted to the ventilation passage when the engine is at low speeds such that the vehicle is moving up to about 56 km. /hr. which is represented by point 43 on slot 20. As the vehicle speed is increased ambient air is admitted to the ventilation passage in increasing amounts until the speed reaches about 88 km./hr. which represents point 44 on slot 20. As the speed is increased beyond this point less and less ambient air is needed until the speed reaches about 113 km./hr. represented at point 45, and thereafter at higher speeds no ambient air is admitted to the ventilation passage.

It has been found that in the normal operation of an internal combustion engine which has no fuel-air control device such as that of this invention there will be an air-to- fuel ratio of about 13.2 to 13.5. When the engine of this invention is involved the air-to-fuel ratio is increased through the same range of engine speeds to about 14.2 to about 14.4, thus providing an increased amount of air for total combustion of the fuel and hydrocarbons in the intake manifold.

While the invention has been described with respect to certain specific embodiments, it will be appreciated that many modifications and changes may be made by those skilled in the art without departing from the spirit of the invention. It is intended, therefore, by the appended claims to cover all such modifications and changes as fall within the true spirit and scope of the invention.

Claims

1. A device for aiding in the control of the fuel-air mixture in an internal combustion engine having an accelerator linked mechanically to a carburetor and a venti¬ lation passage from the crankcase of said engine to the intake manifold, a valve housing having a seat coupled to an air passage said air passage adapted for communication between the amibient air and said ventilation passage; and a valve means for seating in said seat to prevent ambient air from flowing into said air passage; wherein the improvement comprises a valve control cam means mechanically coupled to the accelerator linkage to gradually open and close said valve means as the accelerator is depressed.

2. The device of Claim 1 wherein said valve control ^" cam means is a sliding plate having a cam surface and said valve means has a roller cam follower urged against said cam surface.

3. The device of Claim 2 wherein said sliding plate is attached to said accelerator linkage by a flexible cable.

4. The device of Claim 3 wherein said -sliding plate is attached to a spring urging said plate in the opposite direction to that produced by said cable.

5. The device of Claim 1 wherein said valve means includes an elongated valve body slidable axially toward and away from said seat.

6. The device of Claim 5 wherein said seat is a conical and said valve body includes a conical head adapted to mate with said seat.

7. The device of Claim 6 wherein said valve body is attached to a spring urging said head into said seat.

8. The device of Claim 1 wherein said valve control cam means is a sliding plate having an elongated slot positioned along the length of the plate and said valve means having a yoke attached to the ends of a roller passing through said slot and bearing against the edges of said slot.

9. The device of Claim 5 wherein said valve body is a cylindrical member slidably mounted in a bearing.

10. The device of Claim 1 in an automotive vehicle wherein said cam means is adjusted to begin admitting ambient air when said engine is to drive the vehicle at about 56 km./hr. and to gradually increase the amount of said ambient air as the vehicle speed increases to about 88 km./hr. and thereafter to gradually decrease the amount of said ambient air to zero when said vehicle speed increases to about 113 km./hr.

11. A device for aiding in the control of the fuel-air mixture in an automotive internal combustion engine having a foot operated accelerator connected to a carburetor by mechanical linkage, and having a ventilation passage from the crankcase to the air intake manifold, said device including a valve housing having a σoniσally recessed seat connected to an air passage adapted to be a conduit for ambient air to flow there through into said ventilation passage; and a valve means for operatively mating with said seat to prevent said ambient air from flowing into said air passage; wherein the improvement comprises a valve control cam means slidably connected to said accelerator linkage to cause said valve means to gradually move from being closed against said seat to be fully open and thereafter to be again closed against said seat as said accelerator is operated to increase the speed of said engine.

12. The device of Claim 11 wherein said valve means comprises a cylindrical valve body having a conical head to fit said seat and having roller adapted to bear against and follow said cam means.

O PI

13. The device of Claim 12 wherein said cam is an elongated surface on a slidable plate that is movable at right angles to the axis of said roller.

14. The device of Claim 13 wherein said surface is an edge of a slot passing through said plate, and said roller is mounted on a yoke at the lower end of said valve body.

15. The device of Claim 13 wherein said plate is attached to said accelerator linkage by a flexible cable.

16. The device of Claim 15 wherein said plate is attached to a spring biased against movement of said cable.

17. The device of Claim 12 wherein said valve body is attached to a spring biased to cause seating of said valve means.