DE3027441A1 - DEVICE AND SYSTEM FOR CONTROLLING THE FUEL-AIR RATIO FROM A MIXTURE FEEDED BY AN INTERNAL COMBUSTION ENGINE - Google Patents

Description

Device and system for regulating the fuel-air ratio mixture supplied by an internal combustion engine

Although the automotive industry has made every effort over many years to improve fuel economy of automobile engines, so were that as a result The various authorities considered the progress made to be insufficient. Furthermore, there were official regulations issue which refer to the maximum permitted amounts of carbon monoxide, hydrocarbons and nitrogen oxides, which are allowed to enter the atmosphere with the engine exhaust gases.

Unfortunately, the technology is focused on increasing fuel economy relates, generally opposed to those who are concerned with achieving the official regulations the aim of exhaust emissions.

In order to meet the requirements regarding nitrogen oxide emissions, a system of exhaust gas recirculation has already been used, with at least some of the exhaust gases entering the cylinder of the internal combustion engine is fed back in order to thereby lower the combustion temperature therein and accordingly to the formation of nitrogen oxide to decrease.

030067/0818

It has also already been proposed to provide a crankshaft circulation, with the exhaust gases that would otherwise be released into the atmosphere would be introduced into the engine combustion chambers for combustion.

A fuel metering device has also been proposed provide, which supplies a relatively excessively rich fuel-air mixture of the engine combustion chamber, thereby the formation of nitrogen oxide within the combustion chamber. The use of such an excessively rich fuel-air mixture leads to a considerable increase in carbon monoxide and hydrocarbons in the exhaust gases; this in turn becomes additional Oxygen is required, which is to be supplied to the engine exhaust gases, for example by means of a suitable air gel blower, to complete the oxidation of carbon monoxide and hydrocarbons before they are released into the atmosphere.

It has also already been proposed, as a further measure to reduce the formation of nitrogen oxide, the ignition of the engine to delay. Lower compression ratios have also been used to reduce the resulting combustion temperature lower inside the engine combustion chamber and thereby reduce the formation of nitrogen oxide.

Provision has also been made to inject the fuel in a metered manner, instead of sending it through carburetor. Injecting was done either by injection into the inlet pipe system or directly into the cylinder of an internal combustion engine. However, such injection systems are not only carriers of manufacture, but also have the disadvantage that they do not meter fuel evenly over a sufficiently wide range. Is one of those Injection system at one end of the desired range of fuel flow exactly, so it is at the opposite end this area is relatively imprecise. If, on the other hand, such an injection system is in the middle part of the desired area relatively accurate, so it is again at both ends of the range

030067/0810

less accurate. The problem could also not be solved by introducing feedback means for changing the dosing characteristics a special fuel injection system. In general, several factors play a role, such as the following: effective opening area of the injector nozzle; required Movement of the valve body; Inertia of the nozzle body and nozzle burst pressure (this is the pressure at which the nozzle opens). The lower the desired throughput is, the greater the influence of such factors thereon.

It can be assumed that government regulations will become even stricter, for example 1.0 g / mile of nitrogen oxide allow.

With regard to such expected maximum limits with regard to nitrogen oxide, the use of a three-way catalytic converter in proposed a single bed, which should be arranged in the exhaust gas flow in order to achieve the desired emission values. Such a three-way catalyst (in contrast to a two-way catalyst generally known per se) is a single catalyst or a mixture of catalysts that can oxidize hydrocarbons and carbon monoxides catalyzes and reduces the proportion of nitrogen oxides. Such a three-way catalyst has the following problem emphasized: If the fuel-air mixture to be dosed is too rich, then nitrogen oxide is effectively reduced, the oxidation of carbon monoxide, however, remains incomplete. On the other hand, if the fuel-air mixture to be metered is too lean, then although the proportion of carbon monoxide is reduced, the reduction of nitrogen oxide is incomplete. Such a three-way catalytic converter system To make it work effectively, must for a very precise control of the fuel metering function of the associated Dosing device to the motor are provided. As will be described below, the application has already been implemented proposed by injection means with associated feedback means (on selected indices of engine codes and Parameters responding) in order to continuously change the metering characteristics of the fuel injection. Have such systems

030037/031 θ ₄

BATH ORIGINAL

however, also proved to be not entirely satisfactory.

Furthermore, it has already been proposed to use a fuel metering system of the carburetor type with return means, which on address the presence of selected constituents within the exhaust gases. Such feedback means were used to influence How a main metering rod works in a main fuel metering system a carburetor applied. Tests and experience have shown, however, that previously known carburetors with such associated return means do not ensure the necessary degree of accuracy in metering fuel to an engine, in order to achieve the desired emission values.

The invention is therefore based on the object to take measures or to create a device with which one from The fuel metering device working on the carburetor principle is able to meter the fuel with an accuracy that is sufficient in order to meet the target emission values.

COMPATIBILITY OF THE INVENTION

The invention provides a device which has the combination of the following features: A carburetor has an induction channel passed through it, in which a venturi nozzle is provided, with a main discharge nozzle inside the venturi nozzle and a main fuel metering system, which is in conductive connection with a fuel tank and the main fuel dispensing nozzle, furthermore with an idle fuel metering system between fuel storage tanks and main induction channel switched on at one point which is in close proximity to an edge of a variable open throttle valve; the throttle valve is in turn located within the induction channel, downstream of the main fuel delivery nozzle; he feels also assigned a solenoid valve that controls the throughput of the

030017/0810

to regulate metered fuel by the main fuel metering system and / or the idle fuel metering system able, so that the total throughput of the fuel to be supplied to the engine by the metering system is also accurate is adjustable.

The invention is explained in more detail with reference to the drawing. The following is shown in detail:

Fig. 1 illustrates in side view an internal combustion engine for a vehicle, with one designed according to the invention and other devices according to the invention.

FIG. 2 is an enlarged cross-sectional view of a carburetor usable in the overall system of FIG.

Fig. 3 is an enlarged axial section showing an important one of the elements illustrated in FIG. 2 as well as other elements which are adjacent to it.

Fig. 4 is a sectional view taken along section line 4-4 of Fig. 3 looking in the direction of the arrows.

Fig. 5 shows in the diagram curves of the fuel-air ratio, which can be achieved using the invention.

6 is another diagram from which values of the air-fuel ratio are obtained reveal which can be achieved by applying the invention.

Figure 7 is a circuit diagram relating to the invention applicable electrical circuits (wiring diagram).

030067/0818

3027A41

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The internal combustion engine (motor) IO illustrated in FIG. 1 serves, for example, to drive a motor vehicle via a power transmission device 12. Motor 10 can, for example work with pistons and cylinders. It generally comprises an engine block 14 which in turn includes a number of Contains cylinders with pistons going up and down. A spark plug is assigned to each cylinder, which is also included in the Engine block is carried and electrically connected to an ignition distributor 18, which operates in accordance with the engine operation.

The usual exhaust line is connected to each cylinder, which in turn opens into an overall exhaust line 20. At the outlet end 24 of this line 20, the line 22 connects, which conveys the exhaust gases in the direction of the atmosphere.

An intake line which is connected to an overall intake system 26 is also assigned to the individual cylinder.

A carburetor 28 is on an associated intake manifold 26 arranged. Furthermore, the carburetor 28 may include an air filter 30 wear to purify the air supplied to the carburetor 28 beforehand.

In Fig. 2 you can see more in detail and in an enlarged view the carburetor 28 designed in accordance with the invention. It includes a main carburetor body 32 through which a main induction duct 34 is passed through. Channel 34 has an upper one Inlet end 36, in the area of which there is a throttle valve valve 38 (Choke) is located. This flap is carried by a shaft 40. That The outlet end 44 of the channel 34 communicates with the inlet piping system 26 in connection. One can also see a Venturi section 46 with a Venturi constriction 48 in the channel 34. Essentially in the area the constriction 48 of the Venturi section 46 is a main fuel delivery nozzle 50. This is used to fuel the has already been dosed by the main dosing system, the main induction channel 34 feed.

030067/0819

A further throttle valve flap 52, which is carried by a shaft 54, can also be seen within the channel 34. This serves to regulate the delivery and the throughput of the combustible fuel-air mixture which is fed to the inlet 44 of the inlet distributor line 26. A power transmission mechanism 56 connects to shaft 54, which is operated indirectly by the driver of the vehicle. This throttle valve also about how the individual will be shown below is used, ^p to the dose of one belonging idle fuel metering Kra tstoff set.

The carburetor body 32 can also be designed such that at the same time it receives the reservoir 58 which contains fuel 60. The level of this fuel 60 can be, for example set by a float operated inlet valve.

The main fuel metering system has a channel 62 (see FIG. 2) which creates a conductive connection between the fuel storage container 58 and a standpipe 64 which extends essentially upwards. This standpipe 64 contains a main swelling pipe 66 which has a plurality of bores 68. This creates a conductive connection between the interior of the source pipe 66 and the space surrounding it. Its line 70 serves to connect the upper area of the standpipe 64 with the interior of the dispensing nozzle 50. An air outlet channel 72 with a line 74 and a calibrated measuring point 76 can also be seen. Channel 72 is connected to a supply source of filtered air and to the upper area of the Interior of the source pipe 66. Upstream of the standpipe 64 there is a calibrated throttle point 78 within a line 62, which is used to measure the throughput of the fuel flow from chamber 58 to the standpipe. As is known per se, the interior of the fuel storage container 58 is preferably pressurized, for example by means of a channel 80 which leads from the chamber 58 to the inlet end of the induction channel 34.

030067/0910

BATH ORIGINAL

When the engine is running, air is drawn in through duct 54 and venturi throttle 48 on the intake stroke of each piston. the air flowing through venturi throttle 48 in this way creates one Negative pressure, the so-called Venturi vacuum. The size of this vacuum depends primarily on the speed of the air flowing through the venturi. The speed is of course dependent on the speed and on the output of the engine. The difference between the pressure in the venturi nozzle and the air pressure in Chamber 58 results in a flow of fuel from chamber 58 through the main dosing system. Fuel thus flows through the metering throttle 58, through the line 62, and the standpipe up. After mixing with the inlet channel 72 flowing in Air passes the mixture through the line to the nozzle 50, from where it reaches the induction channel 34. The calibration of the various control elements is generally chosen so that the main flow of the metered fuel at a predetermined The differential between the fuel reservoir and the venturi pressure begins to flow. Such a differential can, for example, at a vehicle speed of around 45 km / h. present with normal road traffic.

Operating conditions of the engine and vehicle that are below the values required to operate the main metering system, are achieved by working the idle dosing system; this is not only necessary during the actual idle operation to work, but also outside of these idle conditions.

When the engine is idling and at other, relatively low engine speeds, the engine does not get enough air through the venturi nozzle 48 passed through to generate a venturi vacuum that is strong enough to operate the main metering system. Because of the almost closed Throttle valve flap 52, which in idle mode and in general at low speeds, the air flow through the If the intake line system 26 is largely throttling, the engine or intake vacuum is relatively high. This high inlet vacuum is used to

030017/0019

BATH ORIGINAL

Generating a pressure differential, which is the idle positioning syst operates.

The idle metering system according to the illustration includes, inter alia, a throttle metering device 8? and a channel 83 which communicates with a fuel source, for example the fuel source 64, and a channel 86 extending substantially upward. The upper end of this channel 86 is in conductive connection with a line 88 extending to the side. It can be seen furthermore a downwardly extending line 0, the upper electrode of which merges into line 83 and the lower end of which is connected to the induction channel 34 via bore Q2 . The effective opening size of the bore can be adjusted by means of an adjusting screw 94 which is screwed into the housing 52. As is known, channel 88 ends in an outlet opening elongated in the vertical direction.This is located in the area of an edge of the throttle valve flap 52 when this flap is in the quasi-idling position or in the closed position, opening 96 is generally referred to as a dispensing slot or transfer slot with which the effective opening area for the fuel to be supplied to the underside of the throttle valve 52 is increased as the valve 52 approaches a more open position.

A channel 98 is equipped with a metering throttle 100 and provides a conductive connection between the top of duct 86 and a source of atmospheric air such as the inlet end 36 of the induction channel 34.

In idle mode, the greatly reduced pressure area underneath ensures the throttle valve for a fuel flow from the chamber and standpipe 64 through line 83 and throttle 82; the fuel mixes with the air flowing in via line 98 and air throttle 100. The fuel-air mixture is made by conduction 86 down and through the lines 88 and 90 finally discharged downstream of throttle valve 52 through bore 92.

10

03D0S7 / 081Ö

BATH

Outside of idle mode, the throttle valve is pivoted in the opening direction. The said edge of the butterfly valve is thus opened further and releases a larger area of the transfer slot 96 to the vacuum, the downstream of the throttle valve prevails. As a result, more idle fuel is of course fed through the transfer slot 96 submitted. When the throttle valve is opened further by pivoting its flap 52 and even higher engine speeds the speed of the air in channel ^ 4 also increases, until finally a point is reached at which the resulting venturi vacuum generated is sufficiently large to to put the main dosing system described above into operation.

The invention specifies measures and means, in addition to those previously described, with which the metering character is ika can be regulated and / or changed by the constants of the flowing circle. With the chosen one Embodiment, in addition to other associated elements, a solenoid valve 102 is provided for such control functions is useful.

Solenoid valve 102 can best be seen in FIG. J5. the the following description refers to this figure. At this point and again with reference to FIG it should be noted that solenoid valve 102 includes an effective upper and an effective lower region, and that this Solenoid valve is carried by the carburetor housing, for example by the fuel reservoir 58, which is in the present case Trap is part of the carburetor housing. As broadly illustrated in Figure 2, the lower, working end is of the solenoid valve 102 let into an opening 104 which is molded onto the fuel reservoir 58. opening or E'ohrung 104 is in turn in a conductive connection with channel 106, which leads to standpipe 64. Fuel idle duct 8 ^ communicates via main standpipe 64, namely by means of of a channel I06, which preferably has a throttle point I08 having.

11

030067/0810

EAD ORIGINAL

Carburetor 28 has a housing 110 which is equipped with a cover-like element 112 (cover). This cover sits on container 58. As can also be seen from FIG. 2, the upper region of solenoid valve 102 is inserted into cover 112; this upper part of solenoid valve 102 is let into a recess 114, which in turn is molded onto a cap-like housing part Ho. A relatively wide channel IIS is provided there, which communicates with the laterally extending channels 120 and 122. The two last-mentioned channels are each in conductive connection with downwardly leading channels 124 and 126. A channel 128 molded into housing part 110 serves to connect the lower end of line 124 and the upper end of line 86. A second channel 130, which is also in the housing part 110, serves to connect the lower end of conduit 126 to a source of ambient air, preferably at a location at the air inlet end of induction channel 34 sits.

How to get out of the Pig. 2 and 3 recognizes, in particular from Fig. 3, chamber II8 of the housing part Ho has a cylindrical Channel 133 · This has an axially extending section with an internal thread 135 · This is a sleeve-shaped valve seat 137 screwed in, its innermost end with an O-ring 139 is equipped and thus this inner end of part 137 seals against the outer surface of the cylindrical channel 133. As can also be seen, valve seat member 137 is in its middle Retracted area to form an annular chamber l4l. The chamber l4l is still through a corresponding part of the channel 118 formed with. A large number of radial bores l4j5 are used the completion of the conductive connection between the annular chamber l4l and an axially extending channel l45j in the Housing of the valve seat member 137 is formed. Channel 145 in turn communicates with throttle point 147. After screwing in from valve seat member 137 until the axially correct position is reached, an end cap 149 is inserted into the otherwise screwed open end of chamber II8.

12th

Q388S7 / ÖS1Q

-Al

te

As can be seen, solenoid valve 102 has an outer, im essentially sleeve-shaped housing 151. A slot 153 is provided at its upper end. In the top of Housing 151, a socket 155 is inserted and, for example, secured by pressing into housing 151, possibly also by flanging the edge of the housing 151. The lateral surface 157 of the upper end of the socket 155 is narrow from the bore 114 enclosed.

Further down, an end bushing 159 is arranged, which is inserted in a similar manner into the lower, open end of the housing 151 and is fastened to it, for example by means of crimping. End bushing 159 has a flat 16 against which the front end of housing 151 strikes axially. The lower end of the bush 159 is tightly enclosed by the bore 104. It is equipped with an annular groove that also accepts an O-ring I63. This O-ring serves to seal the lower part of the bushing 159 against the bore 104. The end of the bushing 159 carries a preferably centrally arranged chamber 165. This is provided with an internal thread 167 into which the valve seat member 169 is screwed axially adjustable. Organ I69 forms a calibrated throttle opening for producing a conductive connection between chamber 165 and channel 106. To complete the conductive connection between chamber 165 and the interior of the fuel tank 58, a series of radial bores is provided.

From Fig. 3 you can also see a coil 175 with an axially extending, cylindrical, sleeve-shaped part 177 (sleeve). That The upper end 179 of this sleeve 177 is closely enclosed by a bore 181 which is made in the upper bush 155. Coil 175 is designed like a cup in its upper part. This Cup 183 forms the upper stop 185 against which a flat insulation 187 rests. This insulation 1S7 is in turn applied the lower end face I89 of the upper socket 155 on and around the upper portion 179 of the sleeve 177 around. Sleeve 177 carries a

13th

030067/0910

Winding 191 between the axial end walls 193 and 195 of coil 175 has electrical lines 197 and I99, which in turn passed through V / andteil 193 and connected to an electrical circuit. In the lower area of the FIG. 3 also shows a plate spring 203. This is between the end wall 195 of the coil 175 and the upper end face 205 of the lower bush 159 and serves to To maintain coil 175 and winding 191 in the assembled, illustrated position within housing 151.

A cylindrical armature 207 can slide axially in socket 177. It is guided in a channel 209 which is let into a sleeve 201 is. The sleeve 201 in turn sits in the socket 155. The armature 207 carries an upper projection 211 with an adjoining one Splash 217. These two parts carry an at least somewhat elastic, cup-like valve body 213 · The lower end of the armature 207 is in a similar manner by abutment in operative connection with an element, namely a rod 221 which is passed through a bore 223 in the lower sleeve 159 (including its sleeve-shaped Port set 215, which is in sleeve 177 of coil 175). Rod 221 rests on a valve body 225 arranged below. This also has an axial extension in its lower area 219 and an adjoining flange 251. Here, too, there is at least a somewhat elastic, cup-like one Valve element 227 held. Furthermore, one recognizes a compression spring 229, one end of which against valve seat element I69, and the other end of which rests against a flange 231 of the valve body 225. Usually valve element 227 and fitting 207 pressed axially in the direction away from valve seat element 169, i.e. in the opening direction of valve passage 171

As can be seen, armature 207 performs a reciprocating movement when the winding 191 is switched on and off, so that Valve body 213 opens and closes the calibrated channel 247, while valve body 227 opens the calibrated channel 171

and closes.

030067/0810

-Jit-

First of all, the entire operation should be disregarded. Armature 207 is in its uppermost position and valve body 227 has completely closed off the opening 147, so there is no conductive connection between channels 120 and 122. The only source of any outlet air, which is to be mixed with fuel comes from channel 83 (to form the aforementioned fuel-air mixture), namely through air duct 98 and throttle 100 (see Fig. 2). The mixing ratio of the fuel-air mixture is attached such a requirement depends solely on the throttle characteristics of the air throttle 100.

In the following it is assumed that the valve 207 has reached the lowest position, as shown, and that the valve body 230 hereby completely releases the calibrated channel 147. It can then be seen that such a line is completed via channel 147 by channels 120 and 122. As a result the upper area of line 86 (see FIG. 2) is in a regulated line connection by means of the throttle properties of channel 147 brought to a source of ambient air via lines 128, 124, 120, 143, 145, 147, 122, 126 and 130 and through opening 132 (see FIG. 2). Accordingly, understand it that the discharged air, which is to be mixed with the fuel drawn off from line 83, to the fuel-air mixture to create, through channel 98 and through the throttle 100 as well as through channel 130 flows. Furthermore, one recognizes that among such Prerequisites decidedly more supply air is available and that the resulting fuel-air mixture is accordingly substantial is leaner than in the case when line 98 and throttle are considered as the only sources for supply air.

Furthermore, it is clear that the two assumed conditions are extreme values from a whole range of conditions. There Furthermore, the armature 207 and valve member 213 intermittently open and close channel 147 during operation percentage of the period of time within a predetermined reference period during which channel 147 is open, the The extent to which such additional supply air is available for the purpose of mixing with fuel.

15th

8300S7 / 0818

■ u

In summary, the following can be said: With proportional the throughput decreases with increasing passage of idle supply air of the metered idling fuel proportionally. This leads to a depletion of the fuel-air mixture of fuel on the way of this mixture through induction duct 34 and to the intake system 26. The reverse also applies: The greater the extent to which channel 147 - expressed as a period of time, almost is completely closed, the more the total throughput of idle supply air depends on the comparatively reduced, effective flow area of the throttle 100, wherein the throughput of the idle supply air decreases proportionally and the throughput of the metered idling fuel increases proportionally. This in turn leads to a fatter one Fuel-air mixture, which via the induction channel 34 the Inlet system 26 is fed.

By further disregarding the overall function of the invention, it is understood that the degree of fatness of the mixture supplied by the main fuel metering system for any metering pressure differential between Venturi vacuum P _v

and pressure P_ in container 58 by simply moving a

Valve body 227 in the direction of the associated opening 17I or can be modulated away from this. For every given pressure differential, the throughput of metered fuel is also included increasing effective opening area of opening I71 larger, since one of the factors determining this throughput is the effective opening size of the dosing surface. Of course with the chosen one Embodiment the effective size of the opening area 171 a fixed value. The throughput that passes through here depends, however, on the percentage time span within a selected one Period of time as the reference period during which opening 171 is open (valve body 225 and valve body 227 are moved away from channel 171), with an increase in the flow of fuel through channels 173 * 165, 171 and 106 to the main standpipe 64 takes place (see FIG. 2). With such a When the passage 171 opens, it can be seen that the metering surface of the opening 171 becomes the effective metering surface of the opening 78

16

'λ I' ** ■

is to be added. Accordingly, a comparatively increased throughput of metered fuel is supplied to the induction channel J) K through nozzle 50. The reverse is also true. The smaller the size of the opening 171, the more the metering area decreases and approaches the area defined by the throttle 78 (see FIG. 2). Accordingly, the total throughput of metered main fuel flow decreases and fuel with a relatively low throughput passes through nozzle 50 into induction channel J> K.

In Fig. 1 is also a logic control device schematically 160 indicated. This comprises conductors 1β2, 164, 166 and 168 for the supply of electrical signals to conduct the signals Input signals to the controller. These signals give certain Operating parameters again. It is of course clear that such input signals provide the desired information in the form of the Can transmit the size of the signal, but also simply by the fact whether such a signal is even there or not. Output electrical conductors 170 provide the output electrical control signal from logic controller 160 to an electrically operated one Control valve 172 continues. At the logic controller 160 is an electrical potential 17 ^ connected to the control valve a ground 176.

In the illustrated embodiment, the various electrical conductors 162, 164, 166 and 168 are each on devices 178, 180 and 182 connected, which are used to record parameters and generate corresponding signals. In which illustrated embodiment includes means 178 an oxygen sensor, which in exhaust line 22 at a point upstream of a catalytic converter 184 is switched on. Transducer 180 may include an electrical switch arranged to be actuated by a corresponding lever is operated. This lever I86 is of a throttle rod 54 can be actuated and pivoted with this for the purpose of switching switch 180 on and off in order to obtain a signal which indicates that the throttle valve 52 has reached a predetermined position.

17th

0300β7 / 0δ10

Transducer 182 can include a thermometer in the broadest sense, for example a thermocouple that detects the engine temperature and generates an electrical signal accordingly.

The topic illustrated in Fig. 7 shows how such a topic logic circuit 160 of FIG. 1 could be constructed. In such a scheme one recognizes a first operational amplifier 301 with input terminals 303 and 305 and an output terminal 306. Singangesterminal 303 is electrical via conductors 308 as well as a connection terminal 310 to the electrical Output conductor 162 connected, which leads from oxygen sensor 178 ago. Excellent results have been obtained by using a Bosch oxygen sensor achieved - see the book "Automotive Electronics II", February 1975 edition, published by Society of Automotive Engineers, there pages 137 144. Other solutions are of course also conceivable. Such an oxygen sensor comprises a ceramic tube or a cone made of zirconium dioxide alloyed with certain metal oxides, the inner and outer surfaces of which are coated with platinum are. The ceramic tube or cone carries electrodes that deliver a voltage that represents the proportion of the Reproduce the internal exhaust gases of the oxygen present in the ceramic tube. With decreasing oxygen content in the exhaust gases the voltage developed by the oxygen sensor also decreases.

A second operational amplifier 312 has input terminals 314 and 136 and an output terminal 318. An inverting one Input terminal 314 is connected to output 306 of amplifier 301 via a conductor 320 and a resistor 322. Amplifier 301 has an inverting input 305 which is electrically connected to output via a feedback circuit with resistor 324 306 is connected via conductor 320. Input terminal of amplifier 312 is via conductor 326 to a potentiometer 328 connected.

A third operational amplifier 330 can also be seen. This has input terminals 332 and 334 and an output terminal 336. Its inverting input terminal 332 is

18 ORIGINAL BATHROOM

electrically connected to output 318 of amplifier 312 via conductor 338, wherein a diode 340 and a resistor are connected in series.

First and second transistors 344 and 346 have emitter terminals 348 and 350, respectively. These are at points 354 and 354 356 is connected to a conductor 352, which instead of 447 is connected to Head 455 is brought up. Resistor 358 is with a End connected to conductor 455 with the other end connected to conductor 359, that from input terminal 334 to ground 361 via resistor 363 leads. The opposite ends of a further resistor 360 are at positions 3 ^ 5 and 367 Conductors 359 and 416 connected. A feedback loop with resistor 362 is electrical to the output and input terminals 336 and 332 connected.

A voltage divider circuit having resistors 364 and 366 is one end connected to conductor 352, between junction 354 and resistor 358. The other electrical The end of this voltage divider circuit is connected to a switch 368 connected. When this switch is closed, the circuit at 370 is grounded. Base terminal 372 of transistor 344 is on the voltage divider is connected at a point between resistors 364 and 366.

A second voltage divider circuit including resistors 374 and 376 has one electrical end connected to conductor 352 at a point between 354 and 356. The other electrical end this voltage divider is connected to a second switch 378. This connects the circuit to earth 380 when closed. Base terminal 390 from transistor is connected to the voltage divider at a point between resistors 374 and 376. Collector electrode 382 of FIG Transistor 346 is electrically connected to conductor 384 and in series to resistor 386 (which can be a slide resistor), on conductor 338, namely at point 388 between diode 3 ^ 0 and

19th

Q300S7 / QS1G

BATH ORIGINAL

3Q27441

Resistor 342. Similarly, collector electrode 392 of transistor 344 is electrically connected by conductor 394 and connected in series Resistor 396 (which can be a slide resistor) connected to conductor 384 at location 398 between Collector 382 and Resistor 386.

As you can also see, there is an electrical end of each Resistor 400 and capacitor 402 are connected to conductors at points 388 and 4 () 4, while the other, electrical end is grounded at 4θβ and 4θ8. Point 4o4 lies between input terminal 332 and resistor 342.

A Darlington circuit 410 with transistors 412 and 414 is electrical at the output 336 of the operational amplifier 330 via conductor 4lo and series connected resistor 4l8 and connected to base terminal 420 of transistor 4l2. the Emitter electrode 422 of transistor 414 is connected to earth 424, while its collector 425 is electrically connected Conductor 426 at 428 and 430 to the associated solenoid valve is connected and leads to an associated current source 174, is also grounded at 432.

Collector 434 of transistor 412 is electrically connected connected to point 436 but its emitter 438 is electrical connected to base terminal 440 of transistor 414.

A diode 442 is preferably connected in parallel to solenoid valve 102, and a light-emitting diode 444 is also connected to the Provided for the purpose of visually indicating the operating conditions. Diodes 442 and 444 are electrically on conductor 426 connected by conductors 446 and 448.

Conductor 450 connected to power source 174 by conductor 446 is and series connected diode 452 and resistor 454 is connected to conductor 455 at 457, between amplifier 312 and one side of a zener diode 456, the other side of which is connected to earth at 458

20th

O3ÖQß7 / QiS18

• ORIGINAL BATHROOM

is. An additional resistor 46o is connected in series between potentiometer 328 and point 457 of conductor 455. Conductor 455 also serves as a power supply line to the amplifier 312. The conductors 462 and 462 serve in the same way 464, each of which is connected to conductor 455, as a fuel supply conductor for the operational amplifiers 301 and 330 respectively.

OPERATION OF THE EMBODIMENT ACCORDING TO THE INVENTION

Oxygen sensor 178 detects the oxygen content present in the exhaust gas and in dependence thereon emits an output voltage signal which is proportional or otherwise is related to this. This voltage signal is then input to the electronic logic controller 160 via conductor I62, which in turn compares the sensor voltage signal with a reference voltage, which in turn is a measure of the desired oxygen content is. The resulting difference between the sensor voltage signal and the set voltage is an indication for the actual deviation. A corresponding, electrical error or deviation signal is then added is used to generate a related operative voltage which is ultimately supplied to the solenoid valve 102 via conductors 197 and 199 will.

The graph shown in Fig. 5 shows curves of the ratio of the fuel-air mixture, which with the invention is achievable. For purposes of illustration, assume that curve 200 represents a combustible mixture which has a ratio of 0.068 pounds of fuel per pound of air. The carburetor 28 could deliver a combustible mixture in one area, and that mixture could be anywhere between one selected lower air-fuel ratio - see for example Curve 202 - and an uppermost air-fuel ratio see curve 204 - are located. As you can see, the invention can

21st

03006 ^ / 0010

■ If

stone infinite family '' an unlimited host) of such Generate air-fuel ratio curves between curves 202 and 204. This becomes especially clear when one takes into account that the portion of curve 202 between points 206 and 208 is reached when Ventilelerr.ent 213 of FIG. 3 in the sense of a further opening up of opening 147 is shifted towards the maximum intended opening, thereby introducing the greatest amount of supply air is effected. In the same way, the area of curve 202 between points 208 and 210 can be achieved if Valve element 227 of FIG. 3 is moved down to close opening 171 and to the smallest possible opening (i.e. to full closure), which simply stops the flow of fuel.

The comparison results in the following: That area of curve 204, which is located between points 212 and 214, then becomes eMelt when valve element 213 of FIG. 3 in the sense of closing from opening 147 to the intended minimum opening (i.e. fully closed position) is moved and when the throughput of supply air is cut off. In the same way, lets that area of curve 2C4 which is located between points 214 and 216 can be reached by valve element 227 is moved upwards in the sense of opening from opening 171 to for the maximum achievable open position, with which a corresponding maximum throughput of fuel is achieved.

It is also understood that the degree of opening of the openings 147 and 171 during operation by the control signal that is generated by the logic controller 160. It is also clear that the control signal thus generated is essentially depends on the input signal provided by the oxygen sensor, in relation to the aforementioned reference signal. Accordingly, it is with knowledge of the composition of the exhaust gas from the engine possible to control the logic controller ΐβθ in such a way program that it generates signals indicating deviations from the desired composition and, accordingly, the effective one opening of channels 147 and 171 changed. The change leads

0300 & 7 / 0S18

then either a decrease or an increase in the degree of patency of the fuel-air mixture that corresponds to the Motor is metered. Such changes in fuel composition are of course again sensed by oxygen sensor 178 which continues to determine the air-fuel ratio to change such a metered throughput until the desired exhaust gas composition is reached. As can be seen, the disclosed system includes a closed loop feedback loop that operates continuously to the fuel-air ratio of a metered, combustible Alter the mixture and ensure that the mixture is in terms of the desired air-fuel ratio the then existing operating parameters.

Furthermore, it goes without saying that the uppermost curve 204 shown in the illustration according to FIG Curve 218 will be; such a curve 218 is used, to illustrate a hypothetical curve showing the best air-fuel ratio of a combustible mixture, to get the maximum power from engine 10, as with wide open throttle operation (WOD). In such a case insert a Trarslucer I80 (see Fig. 1) with a lever 186 is then in operative connection when the throttle valve flap is brought into the WOD position. Arranged at this point the resulting signal going out from transducer I80, which is input to the controller ΐβθ, this controller ΐβθ to a corresponding one Answer by further changing the effective openings 147 and 171. Assuming that the curves 2l4 to 216 can be obtained when the opening 171 is opened to a position which is less than the maximum effective Is position, a further opening can be brought about by initiating a proportionally longest (expressed as a duration) opening process of the valve element 227. During one such an operating phase, the dosing becomes an open-loop function, and the input signal to the logic controller ΐβθ according to In fact, solid material sensor 178 remains out of consideration for so long than the WOD signal consists of transducer 180.

23

0300 & 7 / 081Q

■ iA

Due to a number of factors, it can happen with some engines It may be desirable to enrich a lean mixture immediately after starting the cold engine. Accordingly, engine temperature transducers 182 can be used to generate 3in signal that is less than a predetermined range Motor temperature is given, and the logic controller 16o is fed in, so that this in turn generates a control signal and sends it to solenoid valve 102 via conductors 197 and 199. This solenoid valve then ensures that the fuel-air mixture is given a ratio that is consistent, for example with curve 202 of FIG. 5, or some similar relatively lean relationship.

It should also be considered that under certain operating conditions and with certain oxygen sensors, measuring the temperature of the oxygen sensor itself may be of interest. Accordingly, for example, a thermocouple can be used which detects the temperature of the working area of the oxygen sensor 178 and which feeds a corresponding signal via conductor 16k to the electronic controller ΐβΟ. It can be assumed here that the measurement of the temperature of the sensor area of the oxygen sensor 178 is necessary in order to determine that this sensor 178 is sufficiently hot to emit a meaningful signal with regard to the composition of the exhaust gas. For example, engine temperature and engine coolant temperature may be normal (sensed by transducer 182) after restarting a hot engine; however, oxygen sensor I78 may still be too cold and therefore not be able to give a meaningful signal of the exhaust gas composition a few seconds after starting the engine. Since a cold catalyst will not get clean with a rich mixture, it is advantageous to provide a relatively lean mixture during the time during which the sensor 178 is accordingly too cold. The temperature signal supplied in this way by sensor I78, which is passed on via conductor 164, can be used to cause controller ΐβθ to generate and supply a control signal via conductors 197 and 199 to solenoid valve 102. The magnitude of this signal is such that the resulting fuel-air ratio of the combustible mixture metered in, for example curve 202 from Pig. 5 or some other predetermined, relatively lean mixture

is equivalent to. 030ÖS7 / 081Q

24

Pig. 6 illustrates fuel-air mixture curves that can be obtained using the invention, and FIG although under different operating conditions of the engine. Flow rate curve 220 is a typical curve of a fuel throttle, while curve 226 is achieved when the engine is performing at its best and the throttle valve is wide open. the Curves 222 and 224 are examples of a family of curves middle range. In the illustrated embodiment of the invention, the weight of anchor 207 and the associated Components lifted by the force and the bias of the spring 229, and always when the winding IQ1 is applied is, with valve element 213 lying completely against channel 147, while valve element 227 is completely free of channel 171.

As you can see, the assigned vehicle remains functional even if the entire electronic system is completely fails.

7 and the logic circuit illustrated therein will be discussed in greater detail below. Oxygen sensor 178 generates a voltage input signal via Head l62, Terminal 310 and Head ΐβ2, Terminal 310 and Conductor 308 to input terminal 303 of the operational amplifier 301. One such input is a voltage signal which is the level of that present in the exhaust gases and sensed by sensor I78 Reproduces oxygen.

Amplifier 301 is used as a buffer and preferably has a very high input impedance. The output voltage at the output 306 of amplifier 301 is the same magnitude with respect to earth as the output voltage of oxygen sensor 178. Accordingly the output at terminal 306 follows the output of the oxygen sensor 178.

The output from amplifier 301 is via conductor 320 and resistor 322 to the inverting input terminal 3l4 of Ver

25th

Ö300 & 7 / 081Q

stronger 312 fed. Feedback resistor 313 causes amplifier 312 to a predetermined "gain" so that the resulting amplified output at terminal 318 via conductors 338 is fed to the inverting input 332 of amplifier 330. At this point it can be foreseen that The output signal of input signal 314 becomes positive Terminal 318 goes negative, then the exit at 336 is from Amplifier 330 positive.

Input 316 of amplifier 312 is connected to the slide of potentiometer 328 to establish a predetermined ( reference) point for the system which then represents the desired or reference value of the fuel-air mixture so that one is able to detect deviations therefrom by the value of the signal sensed by sensor 178.

Switch 368, which may include a transducer switch l82, causes the transistor in the closed state when the temperature of the motor is below a predetermined value 344 to go into conductive connection; this causes a current through emitter 348 and its collector 392 as well as through resistor 396, point 388 and resistance 400 to earth 4θ6. This occurs when, for example, switch 378, which may be a throttle operated switch 181 while WOD operation is closed. During such WOD conditions (or Areas of throttle opening movement) it is transistor 346, who becomes leading. In either case, both transistors 344 and 346 result in a flow of current into the resistor when they become conductive 400

An oscillator circuit includes resistor 342, amplifier 330 and Capacitor 402. Connects to the left end of resistor 342 When voltage is applied, a current flows through resistor 342, the charges capacitor 402. For the purpose of closer examination, it is assumed that the potential of the inverting input 332 is lower than that of the non-inverting input 334 for some reason, the output of the operational

26th

030067/0810

■ si-

stronger at 336 is relatively high and close to or equal to the supply voltage all operational amplifiers derived from zener diode 456.

Accordingly, current flows from point 367 through resistor 360 Item 365 and ladder 359> which leads to the non-inverting input 334 of amplifier 330, as well as through resistor 363 to Earth 361. For this reason it can be seen that if amplifier 330 is conductive, a current component through resistance 360 passes, which leads to an increase in the voltage drop across resistor 363.

If a current flows through resistor 342, capacitor 402 is charged. Such charging will continue as long as until the potential is the same as that of the non-inverting input 33 ^ - of amplifier 330. Is that potential is reached, the size of the output at 336 of the operational amplifier is essentially at ground potential spent and resistor 360 practically grounded. Accordingly, the value of the voltage of the non-inverting input terminal falls 334 suddenly decreases and the inverting input 332 is obtained suddenly a higher potential than the non-inverting input 334. At the same time, resistor 362 is effectively grounded, resulting in capacitor 402 being discharged.

Capacitor 402 then releases its charge and accomplishes that now reduced potential of the non-inverting input 334. As soon as the potential of the capacitor 402 equals the potential of the non-inverting input 334, the output 336 of amplifier 330 suddenly reaches its relatively high level Value and potential of the non-inverting input 33 ^ suddenly becomes much higher than that of the discharged capacitor 402.

The previous oscillating process is then repeated. The ratio of the "on" time to the "off" time of the amplifier 330 depends on the voltage 388. Is the tension high, capacitor 402 charges and discharges very quickly

27 030067/08 1 0

BATH ORIGINAL

■ J3-

slow, and amplifier 330 will remain on a low output for a long period of time. The opposite is the outcome of amplifier 330 will be high for an extended period of time when the voltage at 388 is low.

The resulting signal, which is generated by switching amplifier 330 on and off, becomes the basic circuit of the Darlington Circle 410. If the output of amplifier 330 is on or, as previously noted, relatively high, the Darlington circuit 410 is made conductive and thus acts on the winding 191 of the solenoid valve 102. The diode 442 ensures to suppress high voltage transients that can be generated by winding 191 while LED is in use if so desired, to provide a visual indication of the operation of winding I9I.

As can be seen, the ratio of the "on" period or the high output period of amplifier 330 to the "off" determines Duration or duration of the low output of amplifier 330 indicates the relative percentage or fraction of the cycle time duration or operating cycle, during which winding 19I is applied and thus directly the effective opening size of the opening 147 certainly.

For purposes of description, assume that the output of oxygen sensor 178 has become positive or has increased, meaning that the fuel-air mixture has become richer. A voltage signal that has risen in this way is fed to input 314 of amplifier 312; Output 318 of amplifier 312 drops in voltage due to the inverting of input J> \ K. Thus, a lower voltage is applied to resistor 342, so that it takes longer time to charge capacitor 402. Accordingly, the ratio of the "on" period or high output period to the "off" period or low output period of amplifier 330 increases. This ultimately results in more average current being supplied to winding 191, which in turn means that Valve opening l47 longer in terms of percentage of time

030067/0810 ²⁸

is opened while valve port 171 is closed longer remains blocked and thus the throughput of the measured fuel through the main and idle fuel system longer remain.

Reference should also be made to the following: If at least one of the two switches 368 and 378 is closed, then there is a resistance 342 a higher voltage is applied, reducing the charging time of capacitor 402 is decreased. This in turn leads, as mentioned above, to changing the ratio of the "on" time duration to the "off period of amplifier 330.

If current is sent through the winding I9I via Darlington circuit 40 (see FIG. 3), the resulting magnetic field moves the armature 207 with the valve elements 213 and 227 downwards (by a proportionally longer period of time) - see FIG Valve element 227 for sealing against valve seat 169, whereby any flow between channel 106 and chamber 165 ceases. At the same time, the downward movement of valve 213 allows a conductive connection via opening 147 between channels 120 and 122. If no more current flows through Darlington circuit 440, namely when the output of amplifier 330 is low or "off", there is no more current More magnetic field, which had previously been generated by winding 19I. Spring 229 now moves armature 207 and valve element 213 and 227 upwards, so that valve element 213 rests sealingly on valve seat 137 in order to prevent a conductive connection between channels 120 and 122. At the same time, the upward movement of valve element 227 allows a conductive connection via opening 171 between channel I06 and chamber 165. Accordingly, it can be seen that if an excessively rich mixture is detected (amplifier 330 is switched on), a conductive connection between channel 106 and chamber 165 is terminated while the communication between channels 120 and 122 is established. If, on the other hand, the throughput of fuel that is supplied and detected (amplifier is switched off) is insufficient, a conductive connection between channel 106 and chamber 165 is established and a conductive connection between channels 120 and 122 is terminated.

29

030067/0810

-ss-

In the preferred embodiment of the invention, the spring 229 is dimensioned so that the valve elements 213 and 227 with amplifier 330 switched off, a position opposite that in Pig. Take 3 shown. However, this could also be done change, to the effect that in the "off" state of the amplifier 330 armature 207 and valve elements 213 and 225 are in the lowest position. In the illustrated embodiment, in the event of a complete failure of the associated electrical System, the mixture that is metered to the engine, rich. Are anchors 207 and elements 213 and 227 during the "Off" state of the amplifier 330 in a lowermost position, so if the associated electrical system fails, the mixture that is metered into the engine becomes lean.

Threaded elements can be used to selectively adjust and set the exact gap width on the solenoid valve armature and the stroke Use 169 and 137. During the assembly and calibration or adjustment of the solenoid valve 102, these end elements 169 and 137 for forcibly positioning ftter 207 cheaper Position used relative to pole piece 215 to set the maximum stroke of armature 207.

The following also emerges from FIG. 3: It is assumed that the entire solenoid valve system 102 is in a suitable configuration or built into a suitable housing, but part 137 not yet inserted. Furthermore, a suitable display instrument should be installed, namely against the axial end faces or end faces of valve element 213. Now the adjustment element 169 twisted by screwing in such a way that it moves downward as seen in FIG. This downward movement from Element 169 is accompanied by a downward movement of rod 221 and anchor 207. Element 169 is moved sufficiently far below, the essentially conical end of armature 207 finally strikes the opposite, conical, concave end top surface of pole piece 215. At this point element I69 is rotated (screwed) again so that, as seen in FIG. moved up. Such a movement is continued until the indicator indicates that armature 207 is due

030067/0810

the effect of rod 221 has moved up 0.015 inches (The invention is not particularly applicable to this in practice Dimensioning limited). Due to the ability to relate the position of armature 207 to that of pole piece 215 To determine selectively, an accurate gap can be established between the two. This also ensures that that armature 207 can move down a sufficiently large distance during operation to shut off valve element 227 from channel 171. It was also found that the magnitude of the generated magnetic force is approximately in Dependence on the mutual distance between armature 207 and pole piece 215 varies. For example, in a particular embodiment that has been tried and tested, there was a distance of 0.015-0.030 inches axially between armature 207 and Pole piece 215, so that armature 207 was in a position in which the magnetic force could act most effectively.

Once the lower, adjustable element 169 has been adjusted in this way, the display device can be removed. Item 137 is then screwed in and twisted in such a way that it moves downward - as seen in FIG. With increasing downward movement eventually opening l47 through the valve area of Valve element 213 closed, which can be determined, for example, by an associated flow meter. Then element 137 is rotated in the opposite direction so that it moves up to a point at which the lower end is approximately is 0.015 inches from the valve face of valve element 213. The result is the desired armature-pole piece air gap first set, and then the total stroke of armature 207 is determined; the latter can for example 0.030 inches.

Instead of the indicated display device, it is also possible to display the actual axial extension of the threads of the elements 137 and 169 to define and determine the axial movement. It would also be possible to record when the Valve openings 147 and 171 are blocked, namely by assigned Flow meter or the like.

31

030067/0810

BATH

While the solenoid valve device is in such a test or Calibration or calibration device is located, can the actual throughputs through the openings 14? and 171 Easily determined for different operating conditions by means of the assigned test flow meter. Minor deviations the prescribed limits can be compensated for by further settings of element 137 and / or loQ.

A valuable advantage is that the inventive Solenoid valve device can be fully calibrated in a test bench or the like, and that it is not necessary is to have the calibration carried out only after it has been installed in an appropriate carburettor. The solenoid valve device 102 is a fully integrated and self-contained valve device and as such can be easily calibrate or calibrate to produce the desired throughput through openings 147 and 171 for very specific operating conditions, Have without this solenoid valve device only in a carburetor would have to be installed, only in connection with components carried separately from the carburetor a complete flow system that can be calibrated is produced would be. Accordingly, by applying the invention, it is possible, if necessary, to create a fancy one according to the invention To remove the solenoid valve device from a carburetor and against another, already calibrated, solenoid valve device according to the invention to be exchanged, without any further adjustments on the carburetor. This results in the following in detail reached: (a) The dead time of a vehicle, which was caused by the failure of the solenoid valve device, is reduced to a minimum;

(b) labor costs are reduced;

(c) The overall dosing system and the fermenting parts remain untouched, which means, for example, that the engine exhaust emissions have the prescribed limit values.

Of the numerous conceivable deviations from the preferred embodiment comes into consideration, for example, the winding

32

030067 / 081Ö

-YY

Lines 197 and 109 '' see Fig. 3} through suitable spacers 50C and 50? through (see Fig. 4) and continue through elements 504 and 50o hindu ^ ch (an arm part 512 molded), and then through eyes 508, 510 to lead the further enlarged ladder extensions of the ladder 197 and 199 record fine such extension 514 is a section can be seen in Fig. 3). Such extensions can of course also be led out of the carburetor housing to the To include conductors 197 and 199 according to FIGS.

06/23/80
DrW / MJ

030067/0810

BATH ORIGINAL

Claims (29)

Lawyer file: P + G 581
Password: "fuel regulation" Colt Industries Operating Corp. Claims Device for regulating the flow rate of the fuel, which is intended for an internal combustion engine, particularly for a carburetor of such a motor, characterized in that the following elements are provided da'd: First and second flow ports are provided with a housing having first and second end members having; there is also a solenoid valve drive is provided with an axially extending coil, which is a substantially having centrally arranged sleeve-shaped part, further a coil winding carried by the coil itself; furthermore there is a reciprocable anchor inside the sleeve-shaped area provided; a first opening is provided in the first end member for free axial movement to allow the anchor; the second end member has a second opening to restrict free axial movement of the armature allow; a first valve element is connected to a first axial end of the armature so that it is the first opening is adjacent; a second valve member is connected to a second axial end of the armature opposite the first axial end, so that it is adjacent to the second flow opening; the first and second valve members move together with the anchor; a spring is provided which transmits only that spring force to the armature that the first valve member against the first throughflow opening and that the second valve member is moved away from the second throughflow opening. 030067/0810 2. Apparatus according to claim 1, characterized in that the first opening in the first end member comprises a flat which cooperates with the anchor. Sifo- J). Apparatus according to claim 1, characterized in that a bushing is provided which is located within the first opening of said first end member and which is capable of slidingly receiving the armature. k. Apparatus according to claim 1, characterized in that the second end member comprises a second region which is located within the sleeve-shaped part and extends axially therein, and in that the second opening in the second end member passes through the second region. 5. Device according to claim J>, characterized in that the second end member comprises a second region which is located within the sleeve-shaped part and extends axially therein, and in that the second opening in the second end member passes through the second region. 6. The device according to claim 1, characterized in that the armature comprises an axially extending port set, the is passed through the second opening in the second end member, and that the second valve member rests against the port set . 7. Apparatus according to claim 6, characterized / that the housing comprises resilient means which the coil against the press first end link. 8. The device according to claim 1, characterized in that the first valve member engages the armature in such a way that it is against the axial Sliding movement is secured relative to the anchor. 930067/0819 30274Α 1 9 · Device according to claim 1, characterized in that the first valve member engages the armature in such a way that any axial and transverse movement relative to the anchor is excluded. 10. The device according to claim 1, characterized in that the resilient means on the armature due to the operative connection transmit spring forces with the second valve member. 11. The device according to claim 1, characterized in that the second flow opening is formed by the second end member or is worn. 12. The device according to claim 1, characterized in that the second flow opening is carried by the second end member, and that the resilient means spring force on the armature by operative connection with the second valve member and the second Transfer flow opening. I ^ · Device according to claim 12, characterized in that the second valve member comprises a valve which rests axially on the armature, and that the resilient means, the resilient application bring about. 14. Device for variably limiting the throughput of flowing Medium through a first and a second opening, with a housing having a substantially sleeve-shaped part comprises a first end closure part and a second end closure part, a solenoid valve drive extending axially in a spool having a substantially centrally located one sleeve-shaped portion comprises, a winding carried by the coil, an axially extending armature, the able to move back and forth within the sleeve-shaped region of the coil, a first opening in the first closure end region, to allow free axial movement of the armature therein, a second opening in the second closure end portion, to allow free axial movement of the armature therein, 630087/0818 a first valve member which is in operative connection with the first axial end of the armature in such a way that it is in the area the first throughflow opening is effective, and a second valve member which is in operative connection with the second axial The end of the armature is opposite the first axial end in order to be effective in the region of the second flow opening, wherein the first and the second valve member move together with the armature, and with elastic means with which on the armature only that spring force is applied that is necessary to move the first valve member in the direction of the first flow opening and to move the second valve member away from the second flow opening. 15. The device according to claim 14, characterized in that the first opening in the first end closure part a seat surface that cooperates with the anchor. 16. The device according to claim 14, characterized in that one Bushing is provided carried by the first end closure member and which is able to take up the anchor in a sliding manner. 17. The device according to claim Ik, characterized in that the second end closure part comprises a further area which is located within the sleeve-shaped coil area and extends axially therein, and that the second opening in the second end closure part is passed through this further area is. 18. The device according to claim 16, characterized in that the end closure part comprises a further area which extends within of the sleeve-shaped part is located and axially extends therein, and that the second opening in the second end closure part is passed through the further area is. 030067/0616 19. Device according to claim 14, characterized in that the armature comprises an axially extending extension which passes through passed through the second opening in the second end closure part is, and that the second valve member rests against the port set. 20. The device according to claim 19, characterized in that elastic Means are provided within the housing for urging the spool against the first end closure region. 21. The device according to claim 14, characterized in that the first valve member is attached to the armature in such a way that it is secured against any axial movement relative to the armature. 22. The apparatus according to claim 14, characterized in that the first valve member is secured to the armature in such a way that any axial and transverse movement relative to the armature is excluded. 23 · Device according to claim 14, characterized in that the elastic means transmit spring force to the armature as a result of the operative connection with the second valve member. 24. The device according to claim 14, characterized in that the second opening is carried by the second end closure part. 25 · Device according to claim 14, characterized in that the second flow opening carried by the second end closure member is and that the elastic means on the armature as a result of the operative connection with the second valve member and the second Transfer through flow opening. 26. The device according to claim 25 *, characterized in that the second valve member comprises a valve piece which rests axially on the armature, and that the elastic means for an elastic engagement care for. 030067/0810 27 · Device according to one of claims 1 to 26, characterized by a carburetor with a carburetor housing, an inlet duct, a variably adjustable throttle valve for regulation of the flow of flowable medium through the inlet duct and into the engine, with a fuel reservoir, the is preferably arranged within the housing, with an idle fuel metering system, which is in conductive connection with the reservoir and the inlet channel stands, with a main fuel metering system that is connected to the fuel tank and in conductive communication with the inlet duct and having modulating valve means extending from the carburetor housing is carried and the flow of metered fuel through the main fuel metering system to the intake port regulates, furthermore with a valve device, which comprises an electrically actuatable solenoid valve, with a valve body and an associated valve opening area, one of these two elements being in operative connection with the solenoid valve, and wherein d's solenoid valve oscillates one of these elements to the other element at least during certain operating periods moved to and from the other element to thereby in a predetermined manner the flow rate of fuel through the Limit valve opening. 28. Device according to one of claims 1 to 27, characterized in that that the main fuel metering system has a second, calibrated flow opening comprises, and that said valve opening and the second flow opening are so parallel-held are that they both communicate with the fuel tank. 29. Device according to one of claims 27 or 28, characterized in that that the modulating valve means comprises a second fuel nozzle opening, and that the first and second Fuel metering orifices are connected in parallel so that they both communicate with the fuel tank. Heidenheim, July 8th, 1980
DrW / Srö 030Ö & 7 / 081Q