US3311099A

US3311099A - Fuel injection systems

Info

Publication number: US3311099A
Application number: US502667A
Authority: US
Inventors: Wallace E Beaber
Original assignee: Individual
Current assignee: Individual
Priority date: 1965-10-22
Filing date: 1965-10-22
Publication date: 1967-03-28
Anticipated expiration: 1984-03-28

Description

March 28, 1967 w. E. BEABER 3,311,099

FUEL INJECTION SYSTEMS Original Filed July 22, 1963 4 Sheets-Sheet 2 INVENTOR. 6411,46 2 @IABFI? TZKMQQM March 28, 1967 w E BEABER FUEL INJECTION SYSTEMS 4 Sheets-Sheet 3 Original Filed July 22, 1963 INVENTOR h Anna 4-. 85454-1 az if A TTOk/VAY March 28, 1967 w E. BE B FUEL INJECTION SYSTEMS 4 Sheets-Sheet 4.

Original Filed July 22, 1963 EEAE Emil.

INVENTOR.

WAZAAGE' 361455? United States Patent 3,311,099 FUEL INJECTION SYSTEMS Wallace E. Beaber, 30527 Jeanine Ave., Livonia, Mich. 48152 Continuation of application Ser. No. 296,596, July 22, 1963. This application Oct. 22, 1965, Ser. No. 502,667 9 Claims. (Cl. 123139) This application is a continuation of my application Ser. No. 296,596, filed on July 22, 1963.

The present invention relates to a fuel supply system for an internal combustion engine, and more particularly to a novel continuous-flow fuel injection system using a speed-density fuel control.

Fuel injection systems differ from the more conventional carburation systems in that the fuel is pumped by a constant displacement fuel pump, the fuel so pumped being proportioned between an amount which is injected into the engine cylinders and an amount which is returned to the fuel tank. The constant displacement fuel pump is driven by the engine. The pump will thus deliver a fixed quantity of fuel at any given engine speed regardless of the amount desired for injection into the engine cylinders at that particular time. As a consequence, means must be provided to divert a portion of the fuel back to the fuel tank in order to have only the desired amount injected into the cylinders. The speed-density system acts to proportion the fuel flow into two streams by taking into account the amount of fuel which is being pumped at any instant and the amount desired at that instant. The amount desired at any particular instant is measured in terms of the density of the air in the intake manifold. The amount of fuel being pumped at any instant is measured in terms of the engine speed.

Various speed-density injection systems have been proposed in the past. The previous injection systems, while operable, have generally been commercially adaptable only to mass production techniques and for installation on a specific type of engine. The conventional injection systems have generally required close tolerances in the manufacture of the various parts. Close tolerances can be obtained economically if the unit is manufactured by mass production techniques whicch will lower the per unit cost as is well known. Mass production can only be obtained when there is a market demand for the particular unit. Thus, fuel injection systems in the past have been designed as original equipment for installation on a specific model of a new vehicle. An inexpensive system for installation on many different models of vehicles has not heretofore been available.

The system of the present invention is of the type in which the fuel metering is performed by a variable restriction with a substantially constant pressure drop across that restriction and in which means is provided for delivering fuel at a rate proportional to engine speed. The improvement provided by the invention lies in the positioning of the variable metering restriction by a force proportional to throttle opening biased against a force proportional to manifold pressure, the fuel delivering means providing a datum pressure proportional to engine speed, and the variable restriction holding the charging pressure downstream therefrom proportional to the datum pressure. In a specific embodiment, the forces ar balanced in a two chamber diaphragm which is connected to the variable restriction and which has one chamber communicating with manifold pressure and the other chamber communicating with a reference pressure. The charging pressure downstream from the variable orifice is supplied to one side of another two-chamber diaphragm, the other side of which communicates with a fixed restriction in the return line and a pressure regulator connected to the latter diaphragm. The two sides of the second diaphragm become balanced to maintain the pressure drop across the fixed restriction equal to the pressure drop across the variable restriction. Several further improvements will be brought out in the description which follows.

It is therefore an object of the invention to provide a fuel injection system which is easily adapted to different vehicle makes and models.

Another object of the invention is to provide a fuel injection system which, relative to prior art systems, is simple in design and construction and relatively inexpensive to manufacture in low volumes.

A further object of the invention is to provide such a fuel injection system in which the parts tolerances are not highly critical.

Another object of the invention is to provide a fuel injection system which may be mounted as a replacement for conventional calibration systems or other injection systems without extensive calibration.

A still further object of the invention is to provide a fuel injection system having a constant displacement pump in which the fuel flow from the pump is proportioned between that which is delivered to the engine cylinders and that which is returned to the fuel tank by means of a proportioning device which permits direct proportioning of the fuel.

Other objects of this invention will appear in the following description and appended claims, reference being had to the accompanying drawings forming a part of this specification wherein like reference characters designate corresponding parts in the several views.

In the drawings:

FIGURE 1 is a diagrammaatic illustration of a fuel injection system in accordance with one embodiment of the present invention;

FIGURE 2 is a diagrammatic illustration of a refined version of the FIGURE 1 fuel injection system;

FIGURE 3 is a longitudinal cross-sectional view of of a fuel injection structure embodying the principles of the invention;

FIGURE 4 is a sectional view taken along the line 44 of FIGURE 3 looking in the direction of the arrows;

FIGURE 5 is a sectional view taken along the line 55 of FIGURE 3 looking in the direction of the arrows;

FIGURE 6 is a view similar to FIGURE 5 illustrating a multiple fuel distribution connection;

FIGURE 7 is a sectional view of a vapor separator;

FIGURE 8 is a longitudinal sectional view of the device illustrated in FIGURE 7;

FIGURE 9 is a sectional view taken substantially along the line 99 of FIGURE 1 looking in the direction of the arrows;

FIGURE 10 is a view similar to FIGURE 9 illustrating the valve element in a position of high fuel flow;

FIGURE 11 is a sectional view illustrating a fuel throttle adjustable biasing means;

FIGURE 12 is a sectional view of a barrel type air throttle valve taken substantially along the line 1212 of FIGURE 13 looking in the direction of the arrows;

FIGURE 13 is a sectional view of the valve taken substantially along the line 13-13 of FIGURE 12 look ing in the direction of the arrows;

FIGURE 14 is an enlarged longitudinal sectional view of a fuel injection nozzle;

FIGURE 15 is a top view of the device illustrated in FIGURE 14;

FIGURE 16 is an enlarged longitudinal cross-sectional view of a fuel injection nozzle having a remote source of air supply;

FIGURE 17 is a top view of the device illustrated in FIGURE 16;

FIGURE 18 is a diagrammatic view of a fuel injection system auxiliary control for matching fuel and air supply at high'engine speeds; and

FIGURE 19 is a diagrammatic view of a fuel system auxiliary control for adjusting fuel supply back pressure.

Before explaining the present invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and arrangement of parts illustrated in the accompanying drawings, since the invention is capable of other'embodiments and of being practiced or carried out in various ways Also, it is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. The basic fuel injection system of the present invention is illustrated in FIGURE 1. As shown in FIGURE 1, an internal combustion engine 20 is equipped with and directly drives a fuel pump 21 The pump 21 is a constant displacement pump and delivers a predetermined quantity of fuel upon each revolution of the engine 20. The pump 21 may be, for example, a gear pump, vane pump, piston pump or diaphragm pump. Delivery of fuel from the pump 21 is preferably coordinated with the cycle of the engine 20. As will be appreciated, the engine 20 may be of any type or style.

A fuel tank 22 is provided as a reservoir for fuel. A supply line 23 leads from the tank 22 to the pump 21. A main feed line 24 leads from the pump 21. Fuel passing through the main fuel line 24 is divided to flow through both return line 25 and a throttle feed line 26. The throttle feed line 26 leads to a fuel throttle 27 which regulates the rate of fuel flow through a nozzle feed line 28 which leads to a nozzle 29. One nozzle 29 is illustrated. However, it will be appreciated that a nozzle 29 may be provided for each cylinder in a multicylinder engine.

A restriction 30 is provided in the return line 25. The restriction 30 has a constant cross-sectional flow area. The restriction 30 is utilized in proportioning fuel flow from the pump 21 between that returned to the tank 22 and that which passes through the fuel throttle 27.

The fuel throttle 27 includes a variable orifice with the cross-sectional flow area thereof being controlled by an air density signal in a manner subsequently to be described.

The engine 20 is privoded with an intake manifold 31. An air throttle valve 32 is provided in the manifold 31 to control the admission of ambient air into the manifold. The valve 32 serves to regulate the air density within the manifold 31. Air is drawn into the engine cylinders on the suction stroke of each piston. This creates a negative or below atmospheric pressure within the manifold 31 resulting in the air density therein being lower than the ambient air exterior of the manifold. It is this air density or pressure which is utilized as a control for determining the amount of fuel injected into the cylinders.

The fuel throttle 27 includes a fuel inlet chamber 33 which is connected to the throttle feed line 26. The throttle 27 also has an outlet chamber 34 which is conn'ected to the nozzle feed line 28. The

chambers

33, 34 are divided by a wall 35 in which is provided an orifice 36 for flow of fuel from chamber 33 to chamber 34. A valve stem or metering needle 37 extends into the throttle casing and through the orifice 36. The valve stem 37 has a gradually reduced cross-sectional area at the orifice 36 to vary the flow area at the orifice to permit variation in the proportion of fuel passing through the orifice 36 and restriction 30. An O-ring 38 is fixed on the stem 37. The O-ring 38 is positioned to contact the wall 35 and close the orifice 36 when it is desired to prevent fuel flow through the orifice It should be noted that the reduced section of the valve stem 37 may take any desired form such as, for example, fluting, graduated steps, inclined steps or a frustoconical shape.

The control means for positioning the valve stem 37 relative to the orifice 36 include a diaphragm 40 which is mounted between housing member 41, 44a. The housing member 41 forms, with the diaphragm, a reference pressure chamber 42. The chamber 42 communicates to the ambient atmosphere by means of a duct 43. The reference pressure in chamber 42 is thus atmospheric pressure. However, it will be appreciated that other reference pressures may be supplied to chamber 42 if desired.

The housing 44a forms with the diaphragm 40 a signal pressure chamber 44. The diaphragm 40 is thus subjected to the opposing pressures in

chambers

42, 44. An air duct 45 leads from the intake manifold 31 at a point downstream from the air throttle valve 32 to the chamber 44. The valve stem 37 projects through the housing member 44a into contact with the diaphragm 40.

As previously mentioned, the pressure within the manifold 31 is a negative or below atmospheric pressure. Any change in this pressure is communicated via duct 45 to the chamber 44. A rise in pressure in manifold 31 results in the diaphragm 40 moving to the right while a drop in pressure in manifold 31 results in the diaphragm moving to the left as viewed in FIGURE 1. It will be appreciated that a rise in pressure in intake manifold 31 may be caused by either of two conditions. One condition would be opening of the air throttle valve 32 to create a larger intake orifice into manifold 31. The other condition causing a rise in this pressure would be a decrease in engine speed whereby the suction caused by the intake of air into the cylinders is decreased. As will be understood, the converse is true, that is, that pressure in manifold 31 will drop upon an increase in engine speed or a decrease in the orifice of air throttle valve 32.

Spring biasing means 36 are provided to engage the end of the valve stem 37 to bias the stem 37 to the right as viewed in FIGURE 1 against the diaphragm 40 to thus oppose the reference pressure in chamber 32. This bias tends to move the stem 37 to increase the flow are-a through orifice 36. A lever 47 is provided to adjust the bias provided by the spring 46. The lever 47 may either be preadjusted to various positions or may be selectively manually operated while the engine is in operation.

In operation of the device as thus far described, it will be appreciated that engine power output may be increased by opening air throttle valve 32 and decreased by closing air throttle valve 32. Upon opening of air throttle valve 32, an increased amount of air enters intake manifold 31 resulting in an increase in air density. As previously discussed, this is reflected in signal pressure chamber 44 causing the diaphragm 40 to move to the right as viewed in FIGURE 1 and permitting the spring 46 to move the valve stem 37 to the right thus increasing the size of orifice 36. This results in an increased amount of fuel flowing through this orifice, the increased amount of fuel being commensurate with the increased air delivery introduced into the intake manifold 31 by opening of the air throttle valve 32. The converse is true upon closing of the air throttle valve 32.

It will be appreciated that the proportioning system thus far described would result in substantially proportioning the fuel between the

lines

25 and 26 on a basis which does not take into account the amount of fuel being pumped at any given time by the pump 21. The amount of fuel being delivered by pump 21 is, of course, directly related to engine speed and must be taken into account when proportioning fuel between return to the tank 22 and injection into the cylinders of engine 20.

This factor is taken into account by means of a back pressure booster 50. Back pressure booster 50 is disposed in a return line 25a which is downstream from the restriction 30. The booster 59 includes a housing having an interior separated by a diaphragm 51 which divides the housing into a regulated back pressure chamber 52 and a regulating fuel nozzle pressure chamber 53. A variable restriction back pressure valve is disposed in the regulated pressure chamber 52 and is adapted to variably restrict the outlet therefrom. The reference orifice 30 passes fuel into the regulated pressure chamber 52 and fuel exits from this chamber by the valve 54 into the return line 25a. The valve 54 is directly connected to the diaphragm 51 so as to be responsive to nozzle created back pressure in the nozzle feed line 28. Increased restriction of the valve 54 augments the back pressure upstream in the return line 25.

A regulating pressure chamber 53 of booster 50 is connected to the fuel nozzle line 28 by a fuel line 55. As previously mentioned, this communicates the feed line pressure at the nozzle point and directly to the regulating pressure chamber 53 in opposition to the return line pressure in the regulated chamber 52 to control the posi tion of the variably restrictive valve 54.

In operation of the fuel pressure booster 50, when the fuel throttle 27 is displaced to increase the flow area at orifice 36, the pressure in the nozzle line 28 is increased. This increase in pressure is communicated to the line 55 to the regulating pressure chamber 53 causing the valve 54 to increase the degree of restriction of the downstream portion of the return line 25a. This immediately causes a back pressure increase in chamber 52 and return 25 furnishing an immediate boost in the main line 24 fuel pressure which is exerted upon the fuel throttle 27. This pressure in line 24 in turn is applied to the fuel nozzle line 28 through the throttle 27 to further elevate pressure in line 28 and to increase the flow through the throttle 27. Upon the nozzle fuel line 28 rising in pressure, the increase in pressure is again set back to the booster 50 in the manner described. As a consequence, increase fuel demand results in increasing the feeding pressure, and decreased fuel demand results in decreasing feeding pressure. Thus, pressure is responsive to demand.

The booster device is calibrated to automatically supplement the reference orifice 30 in the return line 25 and to maintain return line pressure downstream of orifice 30 in balance against one another and by use of valve 54 to maintain an equal pressure drop across each

orifice

30, 36 for each engine operating condition.

As stated earlier, the relative flow quantities distributed to each of the two orifices is fed by the pressure in the main line 24 and will be equal to the relative area of each orifice with respect to the total area of all orifices, in this case two, i.e. 30 and 36, if the downstream pressure of all orifices are equal. The two

chambers

52 and 53 of booster 50 are separtaed by pressure-type diaphragm wall 51 which is free to move in either direction. Therefore, any pressure unbalance will tend to move the wall 51 toward the pressure chamber having the lower pressure. The valve 54 is connected to the chamber dividing wall 51 in the chamber 52 and is displaceable with the wall to provide a pressure balance between the two chambers under all normal operating conditions. The pressure in the nozzle supply line 28 downstream of the metering orifice 30 (the nozzle fuel pressure) is communicated to the chamber 53 (the control chamber) and the downstream pressure of the reference orifice 30 is communicated to the other chamber 52 (the regulated pressure chamber). This arrangement effects an equal pressure drop across both orifices. :If more than one reference or metering orifice are used the above-described relationship holds true such that the quantity of flow through each orifice is equal to the relative area of that orifice with respect to the total area of all orifices, so long as the pressures downstream of all orifices are equal.

FIGURE 2 discloses a refined version of the FIGURE 1 system. Where appropriate, the same reference numerals have been employed.

In FIGURE 2 a shut-off valve 60 is located in the nozzle fuel line 28 to completely cut off flow of fuel to the engine when the engine is not operating or to conserve fuel when the engine is in an overrun coasting condition with the air throttle 32 closed or under conditions of load overrun such as occur in downhill braking.

The shutoff valve 60 is controlled by a diaphragm 62 provided in a housing 61. The diaphragm 62 defines a reference pressure chamber 63 and a fuel pressure chamber 64. The diaphragm 62 may have a natural bias or this bias may be augmented by a spring 66. Thus, the delivery of fuel to the nozzle is subject to the action of the valve 68 to a selected fuel pressure level. A distributing head 69 may also be included in the feed line 28 to feed several nozzles 29. Obviously, the feed distribution head 69 may be used with or without the valve 60 and the valve 60 used without the distributiong head '69.

A choke valve 68 is disposed in the system to facilitate engine starting. The valve 68 is located on the back pressure side of the system at any convenient point. The choke valve 68 may be automated if desired or may be manually controlled to facilitate gradual engine warm up. A relief valve 67 is also provided. The valve 67 is a spring biased pressure relief device and is utilized to avoid dangerous pressure conditions in this system.

The system of FIGURE 2 is also modified from that of FIGURE 1 by the provision of a barrel-type air throttle valve 76 in place of the simple valve 32 provided in FIGURE 1. The valve 70 is more specifically illustrated in FIGURES 12 and 13. The valve 70 is positoned in the intake manifold 31a as shown in FIGURE 2. The valve 70 includes an enlarged cylinder which lies transversed to the axis of the intake manifold 31a. The cylinder 75 is formed by a pair of arcuate side walls 71, 72 and end

walls

73, 74. The cylinder 75 encloses a barrel 76 which is transversed thereto. The barrel 76 has an internal diameter which is preferably substantially equal to the internal diameter of the intake manifold 31a so as to permit full communication to atmospheric pressure and density. The barrel is pivoted on

pinions

78, 79. A sealing-wiper plate 77 is disposed on the barrel 76 at an angle thereto. The plate is also offset relative to the axis of the pivotal motion of the barrel and is located downstream of the

pinions

78, 79 with respect to the barrel 76.

The barrel 76 may be turned from the full axially aligned position with the intake manifold 31a to the complete angular shut-01f position without the wiper sealing plate 77 moving out of sealing relationship with the arcuate walls 71, 72 and end

walls

73, 74 of the cylinder 75. In other words, the barrel 76 shuts off communication to the barrel when its ends are within the cylinder arcuate side walls 71, '72 and permits full communication through the barrel to the intake manifold when the ends thereof are in axial alignment with the intake manifold. The wiper plate 77 maintains sealing relationship with the wall 71-74 at all times behind the trunnions. This places the trunnions and bearings outside of any downstream pressure drop.

The barrel 76 is pivotally supported on

trunnions

78, 79. A barrel operating arm 80, shown in FIGURE 2, is connected to the extending trunnion 79 for turning the barrel relative to the intake manifold 31a. The trunnions and bearings need not be sealed because they lie I upstream of any manifold vacuum. The barrel air throttle 70 may be manually operated in a manner similar to that of air throttle valve 32 of FIGURE 1. However, automatic control of these elements may be provided as desired.

A suitable automatic control for the air throttle 70 is illustrated in FIGURE 2. A link 81 is connected to the air throttle arm at one end and at the other end to a diaphragm 82. The diaphragm 82 is disposed in a housing 83 and divides the housing into a reference air pressure chamber 84 and a signal air pressure chamber 85. The reference air pressure chamber 84 is connected by a duct 84a to the air pressure chamber 44 in the manner as previously described in connection with FIGURE 1.

A restriction 86 is located in the air line 45 supplying signal pressure from the intake manifold 31a to the previously described signal pressure chamber 44. This restriction delays communication and full effect of any changes in the air pressure to the signal pressure chamber 44. It will be understood that the change in reference air pressure in chamber 44 will be delayed due to the restriction86. Air pressure line 87 connects the intake manifold 31a with the signal pressure chamber '85 of the air throttle control deviceand immediately and directly communicates the density and pressure in the intake manifold 31a and any change therein through the signal pressure chamber 85. Since the intake manifold pressure is delayed in communication to the reference chamber 84 and is communicated immediately to the signal chamber 85, it is obvious that before a balance can occur, the signal chamber pressure will effect a movement of the diaphragm 82 to move the link 81 and the arm 80 to adjust the position of the air throttle valve 76.

Referring again to FIGURE 2, it will be appreciated that even though engine speed does not have an effect on the fuel volume delivery per engine revolution, it does have an effect on fuel velocity. Fuel velocity is thus a characteristic of engine speed. Fuel velocity is used for control purposes at the air throttle.

A housing 160' is provided. The housing 160 is divided into chambers 161, 162 by means of a diaphragm 163. The diaphragm 163 is connected by rneans of a link 164 to the air throttle valve arm 80 and is used to effect engine speed responsive adjustments to the air throttle.

A venturi 165 is placed in the supply line 24 downstream of the pump 21. A low pressure line 166- leads from the venturi 165 to the chamber 162 on one side of the diaphragm 163. The chamber 161 on the other side of the diaphragm 163 is connected to the fuel supply line 24 upstream of the venturi 165 by a line 167. At low engine speeds, the velocity of fuel passing by the venturi 165 reduces the relative pressure in the low pressure line 166 and chamber 162 only a slight amount. Cont-rariwise, at high engine speeds this pressure reduction is substantial. The difference in low pressure due to differencein velocity is balanced against fuel pressure upstream of the venturi in the line '167' and chamber 161. The balance of the difference in the pressure at the diaphragm 162 moves the diaphragm 166 which in turn displaces the link 164 and arm 89 to change the setting of air throttle 70 and thereby regulate engine speed.

The engine power may also be measured and utilized to make compensating adjustments to the air throttle. Furthermore, fuel consumption as indicated by fuel pressure at the injection nozzles may be measured as an indication of power. To accomplish this, a housing 170 is provided. A diaphragm 173 within the housing 170 divides the interior thereof into chambers 171, 172. The diaphragm 173 is connected by the line 164 to the air throttle barrel arm 80' and movement thereof is used to make power responsive adjustments to the air throttle. Nozzle fuel pressure is fed to the chamber 171 by means of a line 174. This results in a signal pressure being provided on one side of the diaphragm 173. A reference pressure, such as atmospheric or exhaust manifold pressure, is fed to the chamber 172 on the opposite side of the diaphragm 173 by means of a duct 175. The power developed by the engine 20' is therefore measured by balancing fuel pressure at the nozzles against the reference pressure. This is an indication of fuel delivery which affects the engine power. The balance of the signal and reference pressures at the diaphragm moves the diaphragm 173, link 174 and air throttle barrel arm 80 in a compensating direction responsive to increased and decrease-d fuel pressure at the nozzles.

A vapor separator 120 is illustrated in FIGURES 2, 7 and 8. The separator 120 is disposed in the fuel line 23 as shown in FIGURE 2 ahead of the pump 21 to separate vapor from the fuel prior to delivery to the 8 pump. Fuel is introduced to the vapor separator through a channel 121 (FIGURES 7 and 8) disposed at a tangent to the annular internal chamber 122. The channel 121 is adjacent the top of the chamber 122.

An outlet channel 123 leads from a chamber 122 adjacent its bottom and is adapted to deliver fuel to the pump 21. A vapor escape channel 124 leads axially upwardly from the chamber 122. As the fuel is swirled in the chamber 122 because of the tangential introduction thereof, the denser portion of the fuel containing the least vapor will travel adjacent the side walls of the chamber 122 with the less dense portion of the fuel lying in the axial center of the chamber 122. The less dense portion of the fuel 122 is drawn off through the conduit 124 through the line 125 in which a venturi device 126 is disposed upstream of the tank 22. The most dense portion of the fuel, therefore the portion of the fuel most devoid of vapor, is drawn off by the lower conduit 123 adjacent the peripheral wall of the chamber 122 at the point of highest centrifugally imposed pressure and density. This separates the vapor from the fuel so that only fuel having the least amount of vapor is fed to the pump 21.

It will thus be seen that the system illustrated in FIGURE 2 is refined with respect to the basic system illustrated in FIGURE 1 to result in more efficient and improved operation thereof.

FIGURE 3 illustrates a specific embodiment of a compact fuel throttle unit which integrates the fuel throttle housings, chambers, diaphragms, lines and ducts previously described.

The fuel throttle unit 150 is designed for easy installation on an engine by merely making a few necessary connections. The unit 150 is made in sections. The sections 151 through 156 are designed for interrelation and assembly and securement by tie rods (not shown). The diaphragm 40 is secured between

sections

153, 154, the diaphragm 51 is secured between sections 154, and the diaphragm 82 is secured between sections 155, 156. The respective sections are hollowed out on either side of the respective diaphragms creating the

chambers

42, 44 on opposite sides of the diaphragm 40,

chambers

52, 53 on opposite sides of diaphragm 51, and the

chambers

84, 85 on opposite sides of diaphragm 82.

The fuel throttle valve stem 37 lies in

sections

151, 152, 153 and is disposed against the diaphragm 40. Section 153 is hollowed out around the valve stem 37 creating the fuel air inlet chamber 33. Section 152 is hollowed out around the valve stem 37 creating a fuel outlet chamber 34. The wall 35 and fuel throttle orifice 36 are formed in section 152 around the stem 37. Section 151 contains the spring 46 which carries adjusting lever 47 for adjusting compression thereon. The spring 46 biases the valve stem 37 against the diaphragms 40 in opposition to the pressure in chamber 42 The variably restrictive fuel back-pressure valve 54 lies in section 154 and is controlled by diaphragm 51. The air throttle link 81a is connected to diaphragm 82 and lies in section 156. Prior to assembly the sections are bored and channeled to form the fuel lines and air ducts, described hereinbefore relative to FIGURES l and 2 and now describe-d specifically with respect to FIGURE 3.

The fuel supply line 24 supplies both the engine feed fuel line 26 which leads to the throttle and return line 25 which contains the fixed area restriction or orifice 30. As previously stated, fuel feed line 26 leads to the fuel throttle chamber 33 which communicates with the throttle chamber 34 through the orifice 36 past the wall 35. Fuel from the chamber 34 is channeled into the nozzle feed line 28.

The fuel throttle valve stem 37 is controlled by the balance between a reference pressure in chamber 42 supplied by duct 43, such as atmospheric pressure, and a signal pressure supplied by duct 45, such as intake manifold pressure. The duct 45 may contain a restriction 86 as described in connection with FIGURE 2.

The pressure balancing features of unit 150 are identical with those of the previously described embodiment of FIGURE 1, identical numerals designating the same parts in FIGURE 3. Accordingly, no further description of the structure or operation to the embodiments of FIG-

URES

1 and 3 need be undertaken at this point.

In the device of FIGURE 3, the air throttle control is balanced at the diaphragm 82 in the same manner as described in conjunction with FIGURE 2. The diaphragm 82 is connected to lever 81a which is connected to the line 81 to the air throttle 70. The structure and operation of the air throttle control of FIGURE 3 is otherwise identical with that of FIGURE 2.

Referring now to FIGURES 2 and 3, a lever 157 is used to accommodate operator control of the position of the air throttle and is connected to the barrel operating arm 80 by link 158 in which a spring 159 is interposed. Thus, the operator may change the position of the air throttle and in doing so move the arm 80, link 81 and diaphragm 82, causing a diaphragm pumping action influencing pressure in chamber 84 at diaphragm 82. This is communicated through duct 84a to chamber 44 which controls the fuel throttle valve stem 37 and moves the valve stem 37 ahead of engine-response to the change in air throttle position thereby avoiding a fuel lag. This makes a compensating change in the fuel throttle relative to the change in the air throttle ahead of engine response providing compensating movement in the fuel throttle.

The remaining figures illustrate additional modifications of the basic system. FIGURE 11 illustrates an atmospheric pressure, or temperature, measuring control which may be integrated with bias means 46 shown in FIGURES l and 2 for automatically modifying the adjusted position of the bias on the valve stem 37. This device includes an enclosed hollow gland 90 between the manual adjusting means 92 and the spring 93. The gland 90 is connected by a tube 95 to a pressure or temperature sensitive device 94 which may be disposed in intake manifold 31a. The device, however, may also be open to atmospheric pressure as well as enclosed within the system.

FIGURE 8 illustrates a volumetric eflicien-cy compensation system. The air breathing efficiency of an internal combustion engine will decrease With each speed increment above the speed where its maximum volumetric efficiency is attained. The unit air change inducted by each cylinder is therefore reduced at higher engine speeds. The fuel system must therefore reduce the fuel flow to match the rate of reduction to the unit air charge, thereby effecting fuel flow rate compensation for the decline in engine volumetric efficiency with speed.

To effect this compensation within a contnuous flow fuel injection systems an orifice or venturi restriction 209 may be placed in the metered fuel nozzle line downstream of the fuel throttle 27. A, signal pressure tab is placed at the restriction 209 and is connected to fuel pressure regulating pressure chamber 53 by duct 210. The effect of the restriction 209, added to the basic system, is to induce the pressure drop which is in turn a function of the square of the flow rate of the metered fuel. The basic fuel meter control orifice ratio balance will not be affected by the volumetric efficiency compensation system. Metered fuel flow will be reduced, however, by means of the reduction in the regulating pressure in that chamber. This in turn will lower the regulated fuel pressure in chamber 52 by returning a greater portion of fuel back to the fuel tank. The pressure drop across metering orifice 209 is then lower than that across orifice 30 causing a lower flow through metering orifice 14 than would normally occur. For greater flow efliciency, a venturi restrictor may be used. However, a simple orifice will suffice.

FIGURE 19 illustrates an alternate system for control of altitude or temperature differences. Compensation 10 for air density variation due to variation in ambient air pressure or temperature can be effected by using a bellows segment 204 which will expand upon being subjected to reduce air pressure or increased air temperature thereby moving valve 205 to add flow area to the return fuel line 250 around the restriction 30. This Will effect the change in the ratio of metering orifice area to return or reference orifice area which will reduce the fuel flow to the nozzles by depleting the back pressure.

FIGURES 14 and 15 illustrate a suitable air vented nozzle for injecting fuel into the intake manifolds 31 or 31a. This nozzle 100 includes a body having a connector portion 101 for connection to the intake manifold and a socket portion 102 for connection to a fuel feed line 28. The socket portion 102 has a large internal chamber 103 and an internal chamber of smaller diameter 104. A tube having a relatively small internal diameter is pressed in the chamber 104 and extend-s into the chamber 103. Air vents 106 are formed in the nozzle 100 and lead into the chamber 103 behind the extending end of the tube 105. The tube portion 107 is press fitted in the chamber 103 in spaced relationship to the end of the tube 105 and has an internal diameter relatively larger than the internal diameter of the tube 105.

The operation of the nozzle is such that fuel sent to the socket 102 by fuel line 28 enters the tube 105 and exits therefrom in a small jet into the large internal diameter of the tube 107 which is spaced from the end of tube 105. Air then enters through the apertures 106 to supply a low presusre area with increased atmospheric pressure. Air is thus forced through the aperture 106 by atmospheric pressure into the chamber 103 between the

tubes

105 and 107. The jetting of the fuel from the tube 105 through the tube 107 in conjunction with the air supply causes an efiicient atomization of the fuel in the nozzle 100 as delivered to the intake manifold. The vents 106 may be supercharged as desired.

FIGURES 16 and 17 illustrate another suitable nozzle for introducing atomized fuel to the intake manifold. The nozzle 110 is a non-axial fuel spray nozzle and includes a connecting socket 111 for connecting to the fuel feed line.- A fuel channel 112 transmit fuel to a press fitted tube 113 of relatively small internal diameter which constitutes a fuel jet. The tube 113 has an end extending into an enlarged chamber 114 in which is pressed a tube 115 of an internal diameter relatively larger than the tube 113. The tube 115 is in spaced relationship to the extending end of the tube 113 so that the jet fuel emitting from the tube 113 into the large orifice of the tube 115 creates a low pressure in the chamber 114. The low pressure chamber 114 is fed by an air conduit 116' in the nozzle 110 communicating with atmospheric pressure or an outside pressure which is normally higher than atmospheric pressure such as through the annular chamber 117 formed by the head 118 and supplied by the pressure tube 119. The nozzle shown in FIGURES 16 and 17 therefore provides for supercharging the atomization of the fuel to the intake manifold or the engine induction tract. The nozzle 110 has an off-set delivery end for delivering fuel mixture in axial alignment with the air stream leading to the engine.

Having thus described my invention, I claim:

1. In an internal combustion fuel-air injection system having a continuous-flow engine-driven fuel pump delivering a constant quantity of fuel flow from a fuel tank per engine revolution, a fuel flow responsive control for advancing and retarding the air throttle setting to govern the engine speed, said control comprising a venturi disposed in the fuel line downstream of the pump, a two chamber diaphragm connected to the air throttle so that displacement of the diaphragm correspondingly changes the air throttle setting, one said chamber being in pressure communication with the interior of the venturi near the low pressure throat and the other said chamber being in pressure communication with the higher pressure interior of .parallel to the longitudinal axis of the cylindrical housing,

said barrel being incrementally pivotable between full throttle and shut-off positions, and a sealing wiper plate fixed at one edge to a side wall of the barrel downstream of the trunnion center-line axes at an angle to the barrel air flow axis and frictionally engaging one side of the cylinder housing in sealing relation regardless of the barrel position.

3. In a charge forming system for an internal combustion engine having a throttle controlled air passage leading to said engine and a continuous flow fuel feeding system including a fuel pump of the positive displacement type driven from said engine, a passage supplied with fuel at pump pressure, a charging fuel circuit supplied with fuel at pump pressure and delivering fuel to said air passage, a variable area fuel metering restriction in said fuel passage and a pressure regulating means to maintain across said orifice a pressure drop of a predetermined amount including a bypass fuel circuit supplied from said passage,

means for establishing a fuel flow at the delivery end of said bypass circuit proportional to engine speed, a fuel flow regulating valve controlling the pressure of fuel downstream of said variable area restriction and regulated by oppositely acting fuel pressures through connections with said charging fuel circuit and the delivery end of said bypass circuit, the improvement comprising means for positioning said variable area fuel metering restriction in a flowincreasing direction by a force proportional to 'air pressure downstream of said throttle biased against a yielding force decreasing with throttle opening and directly connected to said throttle.

4. The feeding system of claim 3 in which the force related to throttle opening is applied to said variable metering restriction by mechanical means including resilient means urging said variable restriction in one direction, and in which the force proportional to air pressure is applied to said variable metering restriction in the opposite direction by a diaphragm having one chamber communicating with manifold pressure and another chamber communicating with a reference pressure.

5. The feeding system of claim 4 in which said system includes an air throttle and an air throttle control comprising a flow restriction between said one chamber and the intake manifold for delaying communication of each change in the intake manifold pressure to said one chamber, a second two-chamber diaphragm having one chamber in communication with said one chamber of said first diaphragm and having the other chamber thereof in communication with the intake manifold, the diaphragm of said second two chamber diaphragm being connected to the air throttle for adjusting the same.

6. The feeding system of claim 3 further including an air throttle and means operatively connected to said air throttle to compensate for variation in air density in response to variations in atmospheric pressure and temperature.

7. The feeding system of claim 6 in which said compensating means comprises a pressure/ temperature sensor, and means connected to said sensor for adjusting the force proportional to the throttle opening in response to variations of pressure or temperature.

8. The feeding system of claim 6 in which said compensating means comprises a pressure/temperature sensing means, a fixed restrictor and a pressure regulator in a return line, and means for adding variable flow area bypassing said fixed restrictor, the additional flow area being controlled in response to variations in temperature or pressure.

9. The feeding system of claim 3 in which said system includes an air throttle, and a horsepower control for adjusting the air throttle comprising a two chamber diaphragm connected to the air throttle so that displacement of the diaphragm changes the air throttle setting, one of said chambers being in communication with the charging pressure and the other chamber being in communication with a reference pressure such that positive and negative changes in charging pressure displace the diaphragm and correspondingly change the air throttle setting as balanced against an air throttle biasing force.

References (Iited by the Examiner UNITED STATES PATENTS Re. 25,672 10/1964 Armstrong 123119 2,330,650 9/1943 Weiche 261- 2,456,604 12/1948 Barfod et al 123-l19 2,803,233 8/1957 Demtchenko l23-l39.l7

MARK NEWMAN, Primary Examiner.

CARLTON R. CROYLE, Examiner.

L. M. GOODRIDGE, Assistant Examiner.

Claims

3. IN A CHARGE FORMING SYSTEM FOR AN INTERNAL COMBUSTION ENGINE HAVING A THROTTLE CONTROLLED AIR PASSAGE LEADING TO SAID ENGINE AND A CONTINUOUS FLOW FUEL FEEDING SYSTEM INCLUDING A FUEL PUMP OF THE POSITIVE DISPLACEMENT TYPE DRIVEN FROM SAID ENGINE, A PASSAGE SUPPLIED WITH FUEL AT PUMP PRESSURE, A CHARGING FUEL CIRCUIT SUPPLIED WITH FUEL AT PUMP PRESSURE AND DELIVERING FUEL TO SAID AIR PASSAGE, A VARIABLE AREA FUEL METERING RESTRICTION IN SAID FUEL PASSAGE AND A PRESSURE REGULATING MEANS TO MAINTAIN ACROSS SAID ORIFICE A PRESSURE DROP OF A PREDETERMINED AMOUNT INCLUDING A BYPASS FUEL CIRCUIT SUPPLIED FROM SAID PASSAGE, MEANS FOR ESTABLISHING A FUEL FLOW AT THE DELIVERY END OF SAID BYPASS CIRCUIT PROPORTIONAL TO ENGINE SPEED, A FUEL FLOW REGULATING VALVE CONTROLLING THE PRESSURE OF FUEL DOWNSTREAM OF SAID VARIABLE AREA RESTRICTION AND REGULATED BY OPPOSITELY ACTING FUEL PRESSURES THROUGH CONNECTIONS WITH SAID CHARGING FUEL CIRCUIT AND THE DELIVERY END OF SAID BYPASS CIRCUIT, THE IMPROVEMENT COMPRISING MEANS FOR POSITIONING SAID VARIABLE AREA FUEL METERING RESTRICTION IN A FLOW INCREASING DIRECTION BY A FORCE PROPORTIONAL TO AIR PRESSURE DOWNSTREAM OF SAID THROTTLE BIASED AGAINST A YIELDING FORCE DECREASING WITH THROTTLE OPENING AND DIRECTLY CONNECTED TO SAID THROTTLE.