US2924208A - Apparatus for controlling a fuel injection pump, particularly for motor vehicles - Google Patents

Description

Feb. 9, 1960 H. R. GROZINGER ETAL 2,924,208 APPARATUS FOR CONTROLLING A FUEL INJECTION PUMP, PARTICULARLY FOR MOTOR VEHICLES Filed Oct. 1. 1958 F 7 run INJECTION PUMP /2 FUEL CONTROL R00 64% HTTORNE 5 United States Patent APPARATUS FOR CONTROLLING A FUEL IN- JECTION PUMP, PARTICULARLY FOR MOTOR VEHICLES Hans R. Griizinger and Herbert Gauss, Stuttgart-Unterturkheim, Germany, assignors to Daimler-Benz Alttiengesellschaft, Stuttgart-Unterturkheim, Germany Application October 1, 1958, Serial No. 764,661

' Claims priority, application Germany October 4, 1957 11 Claims. (Cl. 123-140) Our invention relates to an apparatus for controlling a fuel injection. pump of an internal combustion engine, particularly for motor vehicles. More especially my 'invention is applicable to pumps for injecting gasoline in motor vehicle engines in which the air-fuel mixture is compressed prior to ignition thereof.

It is the object of our invention to so control the pump that the quantity of fuel injected will be more increased upon a quick depression of the accelerator pedal than upon a slow depression thereof, as is desirable for a powerful acceleration of the motor vehicle.

It is a more specific object of our invention to provide improved means for an accurate control of the boosting of the injected quantity of fuel effected in response to a quick depression of the accelerator pedal and, more specifically, for a very exact control of the duration of such boosting effect.

Further objects of our invention will appear from a detailed description of various preferred embodiments thereof described hereinafter with reference to the accompanying drawings. We wish it to be clearly understood, however, that the terms and phrases used in such detailed description have been chosen for the purpose of illustration rather than that of limitation or restriction of the invention and that the invention is in no way limited to the details of such embodiments but is capable of numerous modifications within the scope of the ap pended claims.

In the drawings: 7

Fig. 1 is a more or less diagrammatic perspective view of the fuel injection pump equipped with our novel controlling apparatus, part of the intake manifold and of a vacuum-responsive device communicating therewith being shown in section,'and

Fig. 2 is a sectional view of a modified means responsive to the speed of the depression of the accelerator pedal shown in Fig. 1.

The fuel injection pump 10 diagrammatically illustrated in Fig. 1 has a driving shaft (not shown) geared to the crank shaft of an internal combustion engine of a motor vehicle and injects intermittently accurately metered quantities of gasoline into the intake manifold or into the cylinders of the engine for subsequent compression of the air-fuel mixture so formed prior to igni-' tion. In order to maintain a ratio of admixture of the fuel to the air favorable to ignition and combustion the quantity of fuel injected is controlled in dependence on the quantity of air sucked into the cylinders of the engine. For that purpose the pump is provided with an adjustable pump control member 12 connected with a vacuum-responsive device 16 which through a suitable duct 18 permanently communicates with a port 20 of the intake manifold 22, such port being located downstream of a butterfly valve 24 which by its position determines the quantity of air sucked into the cylinders and, consequently, the power output of the engine and, for this reason, is mounted in a position upstream of the port 20 enabling it to selectively more or less close or open the pump housing, schematically illustrated in Figure 1,

and extending outwardly therefrom. A spring 26 which is mounted over the outwardly extending end of the slidable rod 12 and which is inserted between the housing and a spring supporting disk 29 fixed to the rod 12 tends to hold the latter in the position in which the quantity of the fuel injected is reduced to zero. The rod 12 which is the fuel adjusting rod of the fuel pump of any conventional construction, for example, including a racktype adjusting rod is operatively connected with the vacuum-responsive device 16 and, more particularly, with a diaphragm 14 thereof by a suitable chain of motion-transmitting means to be described later. The fuel control or adjusting rod 12 is operative in any conventional known manner to adjust the amount of the injected fuel quantity by displacement of the rod 12 in the axial direction thereof, as is conventional and well known with fuel injection pumps.

The device 16 comprises a cup-shaped sheet metal member mounted in stationary position on the housing of pump 10 and closed by the flexible diaphragm 14. A spring 27 inserted between the diaphragm 14 and the bottom of the cup-shaped sheet metal member tends to urge the diaphragm to the left with reference to Fig. 1. The atmospheric pressure acting on the outer face of the diaphragm 14, however, will compress the spring 27 when a vacuum prevails in the intake manifold 22 downstream of the throttle valve 24 and is communicated through the duct 18 to the interior of the cup-shaped member. Hence, the diaphragm 14 represents an element which is responsive to the position of the throttle valve 24 and of a suitable adjustable member mounted for actuation by the operator, such as an accelerator reduce the vacuum prevailing in the device 16, thereby.

permitting spring 27 to move diaphragm 14 outwardly. The chain of motion-transmitting means now to be described transfer this motion to rod 12, whereby this rod will be depressed contrary to the tendencyof spring 1 26, thereby increasing the quantity of fuel injected.

The chain ofmotion-transmitting means comprises lever arms 42 and 44 and an interconnecting pin 46. The lever arm 42 has its lower end fulcrumed on a horizontal pivot 45 and its other end pivotally connected to a rod 48 connected to the center of the diaphragm 14 and extending substantially parallel to the rod 12. The horizontal pivot extends at right angles to the rods 12 and 48 spaced therefrom. In order to insure a rigid guidance of lever arm 42, the lower end 50 there of maybe U-shaped and provided with two coaxially disposed spaced bearing portions journaled' on the pivot 45. The lever arm 44 extends substantially parallel to lever arm '42 and has its upper end pivotally connected to the end of'rod 12, whereas its lower end is bifurcated straddling a horizontal rod'52 which extends substantialindicated at 54. A' spring 56 extended between a clip 58 fixed to rod 52 and an anchoring member 60 fixed to the housing 10 tends to hold the end of rod 52 in em gagement with an abutment 62 fixed to housing 10. The

- Patented Feb. 9,1960

horizontal pin 46 which extends parallel to pin 45 and at right angles to the rods 12, 48 and 52 is rigidly secured to the link 42 between the ends thereof and extends through a vertical slot 64 formed by a loop-shaped portion 66 of link 44. 2 r

A solenoid 68 mounted on the pump housing in co-axial relationship withtherod '52 has a movable armature 70 rigidly connected to rod 52' and normally held by. the spring 56in the position shown. When the coil 72 of solenoid 68 is energized, the armature 70-and therod 52 connectedth'erewith are pulled to the right with reference to Fig. l into contact with an abutment formed-by the end of an adjustable screw 74 engaging a threaded'bore of a bracket 76 fixed to the pump hous ing 10-and arrested in adjustable position by a nut 78. Thebifurcated lower end of link 44 carries a pivot pin (not shown) which extends through a transverse bore of rod 52, thereby'pivotally connecting same with the lower end of link 44. p

'The solenoid 68 and rod 52 constitute an electrc magnetic actuator connected with electrical impulse-producing means which are responsive-to the speed of actuation of the adjustable member 28 in the directionof the arrow 80. This is the direction of actuation which increases the quantity of the fuel injected; When the speed of actuation of the adjustable member 28 in the direction of arrow=80 exceeds a certain limit, the impulseproducing means now to be described produce an electrical impulse of a predetermined duration for ener-' gization of the electrical actuator 68. For this purpose the impulseproducing means comprises-a pair of relays 82 and 83, a switch 84 for-controlling the relays 82 and 83 and themeans 34 which are responsive to the speed of actuation of the adjustable member 28 in the direction of the arrow 80. The relay 82 is a slow-acting relay, whereas'relay 83 is of'a fast-acting type.

-A suitable source of current86 hasone of its terminalsgrounded, whereas the other terminal is connected by leads 88 and 90 to one terminal of the coil of relay 83 and to one terminal of a switch 92 which is normally open and'is closed upon energization of coil 83. The other terminal of coil 83 is connected by lead 94 to one of the contactsof switch 84, whereas the other contact thereof is grounded at 96. v

The relay coil 82 has one of its terminals grounded'at 98, whereas its otherterminal is connected by a lead 100 to the switch 92 and by a lead 102 to one terminal of a relay switch 104which is normally closed and is openedupon energization of coil 82. The other terminal ofswitch 104 is connected by a lead 106 to one terminal of the coil 72 of the electromagnetic actuator, whereas the otherterminal 108 thereof is grounded. A condenser 110 which preferably is of an adjustable type is shunted across the coil 72 being connected between theterminal 108 and the lead 106.

"The contacts of switch84 are mounted on the/opposed ends of a pair of parallel two armed levers "1121 and 114 fulcrumed on a common horizontal axis 116, the other arms of these levers being connected by a tension spring 118 which inrelaxedcondition keeps the leversin the relative position shown in which the switch 84 is open. The operation of our control apparatus is as follows:

In the position shown the accelerator 'pedal 28 is slightly depressed and by means of the linkage '30, 32, 34, 36 and 38 keeps the butterfly throttle valve 24' in slightly opened position. As theengine is running, its

cylinders suck air through the intake manifold 22 past theslightly opened throttle valve 24 maintaining a substantial vacuum downstream thereof. As this vacuum is transferred through the duct 18 to the device 16,-the diaphragm 14 is pulled inwardly compressing the spring 27 r and holding the motion-transmitting linkage 42,' 44 and 46 in the positionshown in which the pump control member 12 adjusts the pump so as to inject comdepresses the accelerator pedal 28 at a slow speed, downward motion of link 32 will be transmitted by spring 118 to the link 36. As the spring 118 is more powerful than the spring 40, levers 112 and 114 will swing through equal angles about their pivot 116, thus keeping contacts of switch 84 in separated relationship. Links32 and 36 moving downward in unison will rock the arm 38 so as to open the throttle valve 24. As a result, the vacuum prevailing in the intake manifold 22 downstream of the throttle valve will be reduced or, in other words, the pressure prevailing at; the port 20 and in the device 16 will rise permitting spring 27 to push rod 48 to the left causing lever arm 42 to swing anti-clockwise and by its pin 46 to impart asimilar anti-clockwise movement to lever arm 44, whereby control member 12 will be pressed inwardly contrary to the tendency of spring 26,

thereby increasing the quantities of fuel injected. The.

velocity than. lever 114, whereby the contacts of switch 84 will engage closing a circuit through the coil of relay 83. This will immediately establish a circuit extending from the ground through battery '86, lead 88, lead 90, relay switch 92which is now closed, lead 100,lead 102,: relay switch 104 which is still closed, lead 106, coil 72,.

terminal 108 and ground. In this circuit the electromagnetic actuator 68 will be energized, whereby armature 70 thereof will be abruptly moved into contact with the abutment formed by screw 74. This will impart an anti-clockwise swinging movement to link 44 which is superimposed on the swinging movement imparted by the diaphragm 14, rod 48, lever arm 42 and pin'46, as above described. As a result, thejquantity of fuel injected will be so increased as to change the ratio of. the fuel-air mixture in a manner increasing the power output of the engine for quick acceleration of the vehicle.

"A branch of the circuit just described extends from lead through the coil of relay 82 to the terminal 98, whereby the slow-acting relay 82 will be energized simultaneously with the solenoid68. After a predeterw mined period ,of time the slow-acting relay 82 will open its normally closed contact 104, whereby the electrO:

magnetic actuator" will be de-energized permitting spring H 56 to return the rod 52 tothe position shown, thereby restoring the quantity of fuel injected to the normal rate. From the above it will appear that the quantity of fuel injected will be more increased upon a quick depression of the accelerator pedal 28 than upon a slow depression thereof. r

The device 34 which is responsive to the speed of actuation of the adjustable member 28 in a direction increasing the quantity of fuel injected is capable of nu.- merous modifications. In Fig.2 .we have shown such a modification. In thisv embodiment the links 32 and 36 r are pivoted by a pivot pin 120 to each other and to an arm 122 of a cylindrical housing 124 mountedfor rotation about its axis 126 which extends at right angles to the links 32, .36 at a suitable distance therefrom. Within the housing 124 a member 128is mounted on the pivot 126 for rotation. A tension spring 130 having one of its ends anchored to the housing 124 and the other end attached to the member 128 tends'to turn the same into anti-clockwise direction with reference to the housw ing'124, thereby keeping a radial face 132. of the member-128 'incontactwith'a stop pin 134 which is fixed r to the housing 124pand extends into the latter in radial direction. The radial face 132 of themember 128 is:

formed by a recess into which a contact arm 136 extends through an aperture 138 of the housing from a bracket 140 of insulating material fixed to the outside of the housing 124. The lead 94 is connected to the contact arm 136, whereas the housing 124 is grounded. A radial face 142 of the member 128 is slightly spaced from the contact arm 136 when the parts assume the position shown in Fig. 2. They will remain in this relative position upon a slow depression of the accelerator pedal 28, Fig. 1, causing rotation of the housing 30 and the elements mounted thereon at a low angular speed. When the driver desirous of accelerating the vehicle depresses the pedal 28 abruptly, however, the heavy mass constituted by the member 128 will not be able to follow the rotation of the housing 124 but will lag behind, thereby stretching spring 130 and-causing contact between contact arm 136 and the face 142, whereby relay 83 will be energized.

If desired, the restoration of the rotary member 128 to its normal position relative to the housing 124 may be retarded by suitable means, such as hydraulic dampening means.

In the embodiment shown, the rotary member 128 is provided with a second recess for this purpose and a radial partition 142 suitably fixed to the housing 124 extends into this recess dividing same into a pair of chambers 144 and 146 which are filled with a suitable liquid. The clearance between the rotary member 128 and the inner surface of the housing 124 is preferably so small that the liquid in the chambers 144 and 146 cannot escape therethrough. The partition 142 has an aperture which is normally closed by a spherical valve member 148 resiliently held in closed position by a leaf spring 1500. The spherical valve member 148 constitutes a check valve opening into chamber 146. Rotation of member 128 in clockwise direction relative to housing 124 in response to an abrupt depression of the accelerator pedal 28 causes liquid to be displaced from chamber 144 into chamber 146 past the check valve 148 which will not substantially obstruct such flow. The relative restoring rotation of member 128 in anticlockwise direction, however, is slowed down by the liquid entrapped in chamber 146 which must seep past the partition 142 into chamber 144. This will insure maintenance of the energization of relay 83 for a period of time suflicient to insure a reliable response of such relay.

The responsiveness of the device illustrated in Fig. 2 to abrupt depression of the accelerator pedal may be increased by insuring that the rotary velocity of the housing 124 will be high relative to the speed of displacement of the links 32, 36. This may be insured by reducing the length of arm 122 to a minimum or by other suitable means.

The duration of energization of the electromagnetic actuator may be increased, if desired, by increasing the capacity of the condenser 110.

While the invention has been described in connection with a number of preferred embodiments thereof, it will be understood that it is capable of further modification, and this application is intended to cover any variations, uses, or adaptations of the invention following, in gen eral, the principles of the invention and including such departures from the present disclosure as come within known or customary practice in the art to which the invention pertains, and as fall within the scope of the invention or the limits of the appended claims.

What we claim is:

1. Apparatus for controlling a fuel injection pump of an internal combustion engine comprising an adjustable pump control member for metering the quantity of fuel injected by the pump, an adjustable member mounted for actuation by the operator, an element responsive to the position of said adjustable member, a chain of motiontransmitting means connecting said element with said '6 control member and enabling said element to determine said quantity of fuel in dependence on said position, an electromagnetic actuator connected with said means for increasing, when energized, said quantity of fuel determined by said element, a switch for energizing said electromagnetic actuator, and means co-ordinated to said switch and responsive to the speed of actuation of said adjustable member in a direction increasing said quantity for actuating said switch to cause energization of said actuator, when said speed exceeds a certain limit, where by said quantity will be more increased upon a quick actuation of said adjustable member by the operator than upon a slow actuation thereof.

2. Apparatus as claimed in claim 1 further comprising means for de-energizing said actuator after it has been energized for a predetermined period of time.

3. Apparatus for controlling a fuel injection pump of an internal combustion engine comprising an adjustable pump control member for metering the quantity of fuel injected by the pump, an adjustable membermounted for actuation by the operator, an element responsive to the position of said adjustable member, a chain of motion-transmitting means connecting said element with said control member and enabling said element to determine said quantity of fuel in dependence on said position, an electromagnetic atcuator connected with said means for increasing, when energized, said quantity of fuel determined by said adjustable member, impulse-producing means responsive to the speed of actuation of said adjustable member in a direction increasing said quantity for producing an electrical impulse when said speed exceeds a certain limit, and means connecting said impulse-producing means with said electromagnetic actuator for energization thereof by said impulse, whereby said quantity will be more increased upon a quick actuation of said adjustable member by the operator than upon a slow actuation thereof.

4. Apparatus as claimed in claim 3 in which said impulse-producing means comprises a pair of relays, a switch for controlling said relays, means responsive to the speed of actuation of said adjustable member in a direction increasing said quantity for actuating said swltch to cause energization of said relays, one of said relays being a fast-acting relay including a switch causing energization of said electromagnetic actuator and the other relay being a relatively slow-acting relay causing de-energization of said electro-magnetic actuator.

5. Apparatus as claimed in claim 4 in which the switch included in said fast-acting relay is mounted to be closed upon energization thereof and the switch included in that relatively slow-acting relay is mounted to be opened by energization thereof, both switches, a source of current and said electromagnetic actuator being included in a common circuit.

6. Apparatus as claimed in claim 3, further comprising an electrical condenser shunted across the winding of said electromagnetic actuator.

7. Apparatus as claimed in claim 1 in which said electro-magnetic actuator includes a movable armature connected with said motion-transmitting means, said apparatus further comprising an adjustable stop so mounted as to limit the motion imparted to said armature by energization of said electro-magnetic actuator.

8. Apparatus as claimed in claim 1 in which said switch comprises a pair of contacts and said means responsive to the speed of actuation of said adjustable member comprises a pair of two-armed levers, each carrying one of said contacts, said levers being fulcrumed about a common axis and a spring connecting said levers so as to urge same into a relative contact-opening position, one of said levers being connected to said adjustable member so that a motion thereof causing said element to increase the quantity of fuel tends to close said contacts contrary to the tendency of said spring, when the mass resistance of the other one of said levers exceeds a certain limit.

9. Apparatus as claimed in claim 1 in which said means ing, said mass being movable contrary to the tendency of said spring when the speed of actuation of said adjustable member in a direction increasing said quantity exceeds a certain limit, said switch being mounted on 1 said: pump;

said housing for actuatioii'by saidmassupon movement thereof wmraryw ag spring,"

10. Apparatus us Tim iagram 9 further comprising' means for retardingthe'restoration of said mass relative to said: housing by said" spring" during movement of said: adjustable member in a direction decreasing said quantity. t t

11. Apparatus as claimed in claim 1 in which said electromagnetic actuator is mounted on the housing of No' references cited.

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