DE2215325A1 - Control device for an electronically controlled fuel injection system - Google Patents

Description

K a r I A. ^ - r o s e

-lnu.

Dip

D -8023 Munich - Pullach
Wler.erslr.2.1. Mchn.7930570.7931782

v.l / sta - 4721-A Munich-Pullach, March 27, 72

THE BENDIX CORPORATION, Executive Offices, Bendix Center, Southfield, Michigan 48 075, Michigan, USA

Control device for an electronically controlled fuel injection system

The invention relates to the field of power control circuits used to control the supply of power to electromagnetic Control windings. In particular, the invention relates to that portion of the aforementioned field at to which the energy is supplied in discrete, time-controlled pulses in order to deliver fuel to an internal combustion engine to control. In particular, the invention relates to the control device for controlling the energy supplied by the electromagnetic Windings of various electromagnetic injection valves is used and dispensed.

According to the prior art, it is proposed that the electromagnetic Injectors of electronic fuel injection systems to be connected directly to the output of a main computer circuit via suitable power amplifier stages, see above that these are energized intermittently in accordance with the occurrence of pulses which the current fuel requirement the assigned machine. In view of the fact that the output of the voltage regulator, which is part of the charging circuit for the vehicle battery, the output voltage fluctuates within wide ranges. ken, attempts have been made in various ways according to the prior art to detect the instantaneously available voltage value in order to excite the injectors and

"209 848/0616

the duration of the injection control pulses generated by the main computer circuit was calculated to adjust so as to ensure that the entire during the injection opening cycle injected fuel quantity for constant operating conditions of the machine and changing voltage on the injectors is essentially uniform.

Such developed compensation arrangements, however, are significant add to the cost and complexity of the main computer circuitry, and they also introduce additional potential Errors or sources of error to the detriment of the accuracy, partly in view of the fact that the additional Circuit for controlling the pulse length introduces inhgrent factors, which can change during the life of the system and can also change from system to system. It It is therefore an object of the invention to provide a system for controlling fuel injector excitation to create which does not affect or interfere with the main computer circuit. It is also the goal of Invention to provide a device for controlling the energization of the injectors which does not require a Feed compensation signal of the main computer circuit. It is also an object of the invention to provide a device for controlling to create the excitation of the injection valves, which the influence of fluctuations in the output signal of the voltage regulator eliminates the fluctuations common in current electronic fuel injection systems were observed.

It is well known in the art that one of the difficulties with fuel injection systems arises from the fact arises that, although the excitation pulses can be made substantially rectangular in shape, the response an injection valve is relatively sluggish, so that the The opening characteristic of the valve no longer has anything to do with rectangular. Hence the calculation of the through a valve injected fuel, which has a non-rectangular opening response has, very complex, and above

209848/0616

in addition, the total amount of fuel is reduced below what would ordinarily be injected if that Valve would have a rectangular response characteristic. It is also an object of the invention to provide a device for controlling the energization of fuel injectors which comprises a allows faster opening characteristic curve or characteristic of the valve, thereby a valve opening behavior "or response behavior to achieve, which comes closer to the rectangular shape than is currently achieved with the known systems can be. It is also an object of the invention to provide a device to control the excitation of injectors so designed that the closing of the valve by reducing the total Energy stored in the electromagnetic field is largely simplified.

In the known systems According to energize the .Einspritzventi was! Device or the electromagnetic coils _(the maximum standing for grouting voltage or voltages used to achieve so that the injection valves open as soon as possible. The prior art has, for example, proposed to overexcite such valves with voltages above the maximum available voltage In all of these known systems there is a strong current flow through the electromagnetic windings in steady-state operation To reduce the destruction of the large amounts of energy, resistors with high resistance values have been connected in series with the electromagnetic coils or windings to destroy the energy. These resistors are expensive in that they must be designed for high energy dissipation. In addition, mac If they destroy original lenses, the execution of which leads to their use. It is therefore a particular object of the invention to provide a device for improving the opening times of the injection valves, but no series connections of resistors with high Y / resistance values are required. It is also an object of the invention to provide a system for excitation

209848/0616

of injection valves "or their electromagnetic windings to create which has a lower voltage value the electromagnetic Feeds windings, but at the same time improving the opening times of the valves.

The invention solves the problem with the help of an injection control system, and according to the invention, the maximum voltage supplied to the injection valves is regulated to a value that is slightly below the minimum voltage output value of the voltage regulating device, which is commonly used in the charging system for the vehicle battery which, however, can be made uniformly constant. Furthermore, according to the invention, a flow control device is used in order to keep the current supplied to the injection valves at a value which is not particularly above that fourth which is required to keep the valves open. These punctures are achieved by continuously probing the voltage applied to the injection valves and the current supplied to them, and these continuously recorded samples or sample-taken values are compared with reference values. Each of the comparison stages is then used to control a valve-type variable switch so that the maximum voltage supplied to the injectors and the maximum current flowing to them do not exceed the values predetermined by the reference quantities. These valve type switches are arranged in series so that the effects of control are cumulative. The invention is also characterized by simultaneous control of the maximum voltage applied to the injection valve device and the maximum current flowing to it, including with the aid of voltage sampling or probing techniques and with the aid of comparisons between the voltage samples and the reference values and a resultant therefrom Control of the standard coupled energy flow which controls valve-type variable switches to maintain the desired values. According to the invention, a first maximum current flow is established, the maximum urnrit.telbar to a lower second value reduc- ■) '' - X, the bit is located above that current value

20 98 A 87 06 16

to keep the injection valve device open, taking into account the bias of the valve closing device is sufficient. By limiting that of the injector device supplied energy or the electromagnetic windings supplied energy, the devices currently required to destroy the high energy become superfluous, and that The response of the valve device is improved at the same time. .

According to a further feature of the invention, a control device for the flow of energy is provided to virtually the need for series connected resistors to eliminate what achieved by using the electromagnetic windings of the injection valve device as an energy-destroying device will.

In the following, the invention is explained in more detail using an exemplary embodiment with reference to the drawing. It shows:

Fig. 1 is a schematic circuit diagram of an electronic Fuel control system used in piston internal combustion engines can be applied;

Pig. 2 schematically shows a circuit diagram of an embodiment a main computer circuit of an electronic fuel control system in which the present invention can be practiced;

3 shows a block diagram of an injection control device according to the present invention;

Figure 4 schematically shows a circuit diagram of the signal amplifier stages of the electromagnetic injection device and an injection control device according to an embodiment of the invention; -. _R,

209848 / Q6A6

Mg. 5 a series of graphs, the selected Reproduce signal values which, in the case of the injection control device, during an operating cycle occur, and a curve which represents the opening time of the injection valve; and

Mg. 6 is a sectional view of an injection valve of the same Type to which the present invention can be applied.

Fig. 1 shows in schematic form an electronic fuel control system. The system consists of a computer circuit 10, a pressure manifold scanner 12, a temperature scanner 14, an input timer 16 and off various further samplers 18. The sampler 12 for sampling the intake manifold pressure and the associated further samplers 18 are arranged on the throttle body 20. The output of the computer circuit 1C is to an injector electromagnetic part 22 coupled, which is located in the Ausaugrohr 24 and is arranged so that fuel from the tank 26 via a Pump 28 and through suitable fuel lines 30 into a combustion cylinder 32 of an internal combustion engine (not shown) can be dispensed, although the injection valve part 22 is shown as such is that a fuel spray into an open inlet valve 34 is delivered, it should be emphasized that this representation is only intended to apply as an example, and that other delivery devices which are well known can be used. It is still well known in the art that the computer circuit 10 is an injector device can control that from one or from several injection valve parts 22, which are operated either individually or in groups with changing numbers in a sequence, but are also operated simultaneously. The computer circuit is energized by battery 36, which may be a vehicle battery or a separate self-contained battery.

Fig. 2 now shows the main computer circuit 110 of an electrical

209848/0616

- T -

niche fuel control system. The circuit is excited by a • power supply, which is designated ¹ B + "in various places. In the application of this system in a fuel control system of an engine, the power supply from the battery 36 and / or the battery charging system can be represented, which is usually the The person skilled in the art recognizes that the electrical polarity of the supply voltage can also be reversed.

The circuit 110, which includes a portion of the electronic control unit 10, 'receives together with the supply * supply voltage various scanner input variables, in the form of voltage signals, which in this exemplary embodiment characteristic of various operating parameters of the assigned Machine are. The manifold pressure sensor 12 sees one Before voltage, which is characteristic of the pressure in the intake pipe, the temperature sensor 14 changes the voltage across this associated resistor connected in parallel to provide a voltage signal which shows the machine temperature reproduces, voltage signals are also input which are indicative of the number of machine revolutions and from the Singangs-time control device 16 at the circuit input terminal 116 appear. This signal can be derived from any source representative of the engine's crank angle, but is preferably from the engine's ignition distributor derived.

The circuit 110 sees two successive pulses more variable Duration before and between successive networks at node 118 in order to thereby control the "ON" time of transistor 120. The first impulse will be from that section the circuit 110 provided via the resistor 122, the input variables of which are indicative of the crank angle of the Machine and the pressure in the suction pipe are. The end of this pulse initiates a second pulse produced by the circuit section the circuit 110 via the resistor 124

20 9 8487 0616

will see which section an input variable from the temperature

f .. scanner 14 receives. These impulses appear consecutively; at node 118, and they turn on transistor 120; "ON", i.e. H. the transistor 120 is in the conductive state. ; triggered, and it appears at the output terminal 126 of the switching | - a relatively low voltage signal. This connection can; via the circuit according to the present invention (Fig. 5) and suitable inverter stages and / or amplifier stages with the injection valve device (shown in Fig. 6) so connected, ι

that the selected injector device is energized, always, when transistor 120 is turned "ON". It is usual to use a switch device for controlling, among other things which of the injection valve devices to the circuit ί point 126 if the system is used to actuate fewer than all fuel injectors at any one time. Because the injection valve device is relatively slow operates compared to the speed of electronic devices, those at node 118 perform sequentially appearing impulses to the fact that the injection valve device remains open until the end of the second pulse.

The duration of the first pulse is determined by the monostable multivibrator network controlled to which the transistors 128 and 130 are assigned. By the appearance of a pulse on the input terminal 116 the multivibrator is triggered in its unstable state, the transit gate 128 being in the conductive state State and the transistor 130 are in the non-conductive state. The period of time during which transistor 128 is conductive is determined by that provided by suction pressure sensor 12 Voltage signal controlled. The conduction of the transistor 128 has the consequence that the collector 128 c of the same has a relatively low! total voltage potential, which is close to earth or ground or the common voltage potential. These low voltage causes the base 134b of the transistor 134 drops to a low voltage, below that Value that is necessary to ensure the transit

209848/0816

to trigger disturb 134 into a conductive state, so that the Transistor 134 is closed. The voltage at the collector I34 ο therefore rises to the B + value and is transferred via resistor 122 to node 118, where the transistor 120 is triggered into its conductive state and consequently a relatively low voltage at the circuit connection appears. As mentioned earlier, the presence of one causes low voltage signal at circuit terminal 126 that the selected injection valve or injection valve device opens. When the voltage signal from the manifold pressure sensor 12 has dropped to a value that is required in order for the multivibrator to return to its stable state, the transistor 130 becomes the conductive state and the transistor 123 triggered into the non-conductive state. This will transistor 134 is again conductive, transistor 120 is not conductive, and the injection control signal is from the circuit connection 126 removed.

During the period of time during which transistor 134 is in was kept in a non-conductive state, the relatively high voltage at the collector 134 c could reach the base of the transistor 136, whereby transistor 136 was triggered to conduct. The Y / resistor network I38, which is connected to the power supply, acts in conjunction with the transistor 136 as Current source, so that current through the conducting transistor 136 flows and the capacitance I40 is charged. At the same time, de the transistor 142 in the conductive. Condition pre-stressed, whereby the resistor network 144 together with this a second Represents power source. The currents from "both sources flow to the base of transistor 146, which keeps this transistor conductive and a low voltage appears at collector 146c. This low voltage is applied across the Resistor 124 is transferred to the base of transistor 120.

When transistor 128 closes, indicating the end of the first pulse, transistor 134 is switched "EIH", and the potential at collector 134 c drops to a low value. Of the

209 848/0616

^: - 10 -

Current from the current source, consisting of transistor 136 and d the resistor network I38, now flows through the base of the transistor 136, and the capacity 140 will no longer charge. The capacitance is then charged with the polarity shown in FIG Impulses. However, at the end of the first pulse, when transistor 134 is turned "ON", the collector-base junction becomes des .Transistor 134 forward biased so that the positive side of the capacitance 140 is only slightly positive with respect to ground or earth, i.e. as a result of their separation from ground or earth by some PN junctions. Through this a negative voltage is impressed on node 143, which reverse biases diode 150 and transistor 146 closes. This creates a high voltage signal at the collector of the transistor 146 and passes through the resistor 124 to the node 118, which signal the transistor 120 in the conductive state triggers, so that a second Iinjection control pulse appears at circuit terminal 125. The time between the first and the second pulse is sufficiently short so that the injection valve ileinri cht not in the short term Signal failure can respond.

While the diode 150 is reverse biased, the current flows au3 from the current source consisting of the transistor 142 and the resistor network 144, via the node 143 into the Capacitance 140, so that the capacitance is charged to a point corresponding to which the node 143 is again positive is. This then - the diode 150 is forward biased, and transistor 146 is turned "ON" again. This ends the second pulse and the injection valve device (not shown) then closes.

The duration of the second impulse is a puncture of the time for node 143 is required to be in sufficient Measures for forward biasing diode 150 to become positive. Again, this is a function of the charge on the capacitance HO and the size of the charging current that is supplied by the power source,

209848/0616

consisting of the transistor 142 and the resistor network 144, is supplied. The charge on the capacity is 140 • of course, a puncture for the duration of the first impulse. The size of the charging current is, however, a puncture of the base voltage at Transistor 142. This value is determined by the voltage divider networks 152 and 154 controlled, with the effect that the network 154 by the mass temperature sensor 14 is variable is controlled.

It should be noted here that the present invention does not apply to applications is limited, in which a circuit arrangement similar to that described (Pig. 2) is used, but that the embodiment according to Pig. 2 just for example represents an embodiment of a main computer circuit and other designs are well known.

Pig. 3 now shows the subject matter of the invention in a block diagram, wherein the main components used in the present invention and other functional relationships and effects are illustrated. The block diagram contains a power amplifier stage 302, which receives a signal from the circuit connection. conclusion 126 the pig. 2 receives which signal a voltage pulse represents the duration of which is indicative of the fuel requirement of the assigned machine. The performance level 302 also receives the B + voltage and is valve-type via the first and second variable switches labeled 304 and 3 ^ 6 are connected to ground or earth. the Switches 304 and 306 are connected in series so that their effect on the circuit according to the invention is cumulative. the Power stage 302 sees an excitation current via resistor 3u8 for the various injection valves 22 or in particular for the electromagnetic windings 606 of the same. The logic diagram of the invention also includes a first comparison stage 310 and a second comparison stage 312. The first comparison stage 310 checks the voltage on the power stage is on the side of the resistor 30S at the circuit point 314, while the second comparison stage ■ 312 - .. the; : - ■

209848/0616

Voltage checked that the various electromagnetic 7 / winding 606 at node 316 is supplied.

The second comparison stage 312 is connected to the second switch 306. The second comparator 312 receives a reference voltage labeled Vp and compares the voltage at node 316 with the reference voltage Vp to control the valve-type variable switch 3 ^ 6 to maintain the voltage at node 316 at the reference value Vp. For example, in practice, that is, in an embodiment of the system according to the invention, it was determined to set the reference voltage V ₂ at 9.5 volts, which ensures that the voltage obtained at node 316 is not lower than Ixe reference voltage, with the exception of cases in which outer switch 304 dominates. The second comparison stage 312 controls the start or opening phase of the operation of the injection valve device 22.

The first comparison stage 310 is with the first switch 304 coupled and receives a reference voltage labeled V, 2i with which the voltage present at node 314 is compared. The first comparison stage 310 controls the switch 3 ^ 4 in such a way that the Voltage is almost equal to the instantaneous value of V. However, in those cases where switch 306 dominates, that is Voltage at node 314 slightly lower than the reference voltage magnitude.

Switches 3C4 and 306 were dated as variable switches Valve type, whereby this designation expresses brin-. to ensure that the amount of electrical energy that flows through it, can be controlled so that a larger or a smaller amount of energy from the power supply or B + through the power stage 3C2, via the switches 3u4 and 3 ^ 6 to ground or earth can be directed. The first comparison stage 310 and the second comparison stage 312 can therefore use the switches and 3υ6 so that a larger or a smaller energy

209848/0616

amount through the power level 3u2 to the electromagnetic Windings 606 can flow. In this regulation, the task of the first and second comparison stage, the Schalster 304 and 3O6 open or close to varying degrees. ''

It should be noted that a switch in the closed position allows energy to pass and a switch in the open position Position does not let energy through. For certain operating phases, one or the other of the comparison stages controls theirs associated switch in order to close it more completely, since the one received from the comparison stage from node 314 or 316 Significant voltage, below the applied reference voltage can lie. In such cases, the comparison level has an influence and its associated switch do not, in fact, disable the operation of the injector assembly 22, due to the fact that a switch can only be closed to the maximum extent below which a further effort is made to close the switch to close, will have no effect.

The reference voltage applied to the first comparison stage 31C is generated by voltage generator 318. Voltage generator 318 receives and receives the B + input voltage as well that prevailing at voltage point 316 as a feedback signal Tension. The voltage generator 318 is made with the aid of Means which are well known and an embodiment will be described below, i.e. an output voltage V build up a first value during the initial operation of the circuit according to the invention and has a second lower value during the subsequent operation. Very little flows during the initial period Current through the electromagnetic coils 606 and the voltage at node 316 is regulated to the Vg reference value. However, if more and more electricity begins to flow, then so the voltage at node 314 reaches the first reference value V i. The sbroma flow is then adjusted to the value then present limited. Since the current value then remains constant or the

209 848/0616

Current does not change any further, the voltage at node 316 drops, and this drop is detected by the voltage generator using feedback path 320 which ends at node 316. After the voltage drop occurs at node 316, the output voltage V of voltage generator 318 drops to the second value, and first comparison stage 310 determines that the voltage then appearing at node 314 is above the reference voltage V then established. The first comparison stage 310 then regulates the first switch 304 in a suitable manner in order to reduce the energy flowing from the power stage 302 to the electromagnetic windings 606 so that the voltage at the node 314 drops to the reference value Y again. Its decrease in the voltage at node 314 causes a further decrease in the voltage at node 316, and the second comparison stage 312 tries to close switch 306 further, but since switch 304 dominates, this attempt to close switch 306 further remains , with no effect on the voltages at nodes 314 and 316.

The reference voltage Vp is established by the voltage regulator 322. The voltage regulator 322 appropriately sees a reference voltage with a fixed value for the second comparison stage 312 before.

In an operating cycle of the block diagram according to FIG the initial supply of power across the nodes 314 and 316, by receiving an injection control pulse from main computer circuit 110 via terminal 126 of the circuit, takes place under the inductance transition conditions in which the electromagnetic windings 606 the energy flow to oppose a high resistance. The second comparison stage closes when an attempt is made to determine the voltage at node 316 To regulate the switch 306 essentially up to a point so that it is at that point of the leiafcungsstufe The voltage supplied to the electromagnetic windings 606 is close to the maximum regulation value. Additionally

209848/0616

the first comparison stage also closes switch 304 so that switches 304 and 306 form a minimum impedance circuit between power stage 302 and ground. When the current begins to flow between nodes 314 and 316 and the electromagnetic windings 606, the voltage received by the second comparison stage from node 316 is regulated _{to the reference value V 2.} If the impedance of the injection devices or electromagnetic coils 606 decreases, the voltage at circuit point 316 drops and the switch 306 is closed further by the second comparison stage 312. If the current flowing through the electromagnetic windings 606 begins to increase and the switch 306 tries to maintain the reference value V ₂ at the node 316, the value from the first comparison stage. voltage received from node 3.14 also exhibits an increase that is a function of the voltage at node 316 (the established reference value) plus the current or amount of current flowing through resistor 308 and multiplied by its resistance value. The purpose of resistor 308 is merely to provide a source of measurement of the current flowing through the electromagnetic coils, and as a result, the resistance of resistor 308 can be kept very small (i.e., from about 1/10 ohms to about 10 ohms) . 2/10 ohms). According to the state of the art, the resistors of a fuel injection system connected in series with the electromagnetic coils had to have significantly higher resistance values, i.e. several orders of magnitude higher resistance values, in order to destroy the energy generated by the high current flow under steady state conditions, if the drop or decrease in resistance across the electromagnetic coils was very small. For example, the resistance of such a prior art resistor in a similar system was 5 or 6 ohms. When the voltage at node 314 begins to increase, which is indicative of increasing current flow (when the injectors reach their open positions), the voltage at 314 approaches the reference value V _r , at which point the first comparison stage begins, switch 304 to

209 8 48/0616

to open.

At the beginning of the opening of switch 304, the amount of energy increases offered by the power level to the electromagnetic coils 6C6. This decrease has the effect of reducing the tension drops at node 316 but also has a decrease the voltage increase corresponding to the current flow on Circuit point 314 result, and the second comparison stage closes switch 3 ^ 6 again at this point. This Closing has no effect on the total power or energy generated by the power stage, or due to eier arrangement of switches 3C4 and 3ü6. However, if the Voltage on node 316 is starting to drop so represents the voltage generator 318 fixes this and it reduces accordingly the value of the output voltage V by a second predeterminable amount. This reduction in the reference voltage V causes that the first comparison stage, which detects that the voltage at node 314 is now significantly above this value is located, the switch 304 opens, which further reduces the amount of energy that is passed by the power stage to the electromagnetic Coils 606 is offered. By suitable selection of the lower value to which the output voltage signal V is set by the Voltage generator 318 is switched, the by the electromagnetic Windings 606 held the amount of current flowing during steady state operation or condition are or are brought, which is only slightly above the current value that is required to keep the injection valve device open 22 is required according to a fuel delivery.

By limiting the maximum voltage directly applied to the electromagnetic coils 606, the requirement is met according to the invention according to expensive, complicated voltage correction schemes that introduce sources of error, which are required according to the prior art, eliminated. By further limiting the The flow of current through the electromagnetic coils is also the total energy stored in each electromagnetic coil; significantly reduced, so that there is also an improvement in the

209848/0616

Valve clip properties or characteristics results. In addition, by limiting the maximum current flow Due to the electromagnetic windings, the requirement for series-connected resistors with a comparatively high resistance value and performance destruction value as performance or Energy destruction element eliminated, and the "entire valve opening characteristic or opening characteristics are improved .

Pig. 4 now shows a circuit diagram according to the invention, in which the various logic circuit blocks of Pig. 3 are shown with their electrical circuit components and result in a preferred embodiment of the invention.

The power stage 3 ^ 2 consists of a power transistor 401 which is controlled by a control transistor 402. The power transistor 401 is in the conductive state whenever it receives appropriate signals from the control transistor 402 receives, and the amount of conduction of transistor 401 becomes determined by the particular current value flowing to base 401b from transistor 402. This value is in turn determined by the specific current value determined, which flows from the base 402 b of the transistor 402. The power stage 302 also includes input transistors 403 and 404. Whenever an input signal is received on input terminal 126, transistor 403 becomes Is turned "OFF" and a B q signal is applied to the base of the transistor 404 is transmitted, thereby turning transistor 404 "ON". Assume that switches 304 and 306 are full are closed (i.e., conductive), current flows through transistor 404 and resistor 406 and becomes through the base 402 b of the control transistor 402 is built up flowing current. Y / ie will emerge in the course of the following description is, so has a 'change in the state (of the conductivity) of the Switch 304 and 3U6 have the effect that the through this base 402 .b The current flowing to the base 401-b is changed des Leii $ tungotrari3i3tor3 401 current flowing is influenced. " In the j] ndoff-ekt, dien leads to a control of the

2 09848/0616

22 Ί 5325

stood 3 ^ 8 the energy offered to the electromagnetic coils 606.

Switches 306 and 304 consist of transistors 4-07 and 4- ^ 8. Transistors 407 and 408 mate with transistor 404 coupled in an emitter-to-collector relationship such that the transistors 404, 4ü7 and 4 ^ 3 evenly one behind the other are switched and connected to the base connections 4υ7 b and 4u8 b of the transistors 407 and 4ü3 flowing currents are changed, which has the effect that the conductivity or the conduction state of transistors 407 and 4u8 is changed. The transistors 407 and 408 thus operate as variable resistors the current flowing through the base 402 b of the transistor 402 to change.

The second comparison stage 312 consists of a constant current source with the transistor 410, the diode arrangement 411 and the resistor 412, which leads to ground or earth. The constant current source generates an output current with a constant value, which flows from the collector 4IC c of the transistor 410. The collector 410 c is connected to the emitter connections of an emitter-coupled transistor pair 413 »414. Corresponding to the peculiarity of such a Snvi. U. ^ r- ^ ekoppulton ϊ r an? Ί ί η tor pair that transistor conducts whose base is at the lowest potential with respect to ground or ground. The base of the transistor 414 is connected to the circuit point 316 via the Dioda 415. If no current flows at the circuit point 31 β, the base of the transistor 414 is essentially at!, Lass- or earth potential, so that the transistor 414 is normally conductive. The collector of this transistor is connected to the base 407 b of the transistor 407, which represents the switch 306. If the full current generated by the constant current source in the second comparison would flow 312 through the collector 414c, a maximum current flow is thereby caused through the base 407b, and the transistor 407 is in the fully conductive state. The base of the transistor 413 it via the diode 416 with dom voltage. 3-

209848/0616

controller 322 connected. This voltage regulator consists of one Resistor 420, which is between the power supply B + and a , Zener diode 421 is connected. The Zener diode is arranged so that its cathode is at a fixed positive voltage potential between ground or earth and B + of the supply voltage, and this fixed voltage builds the reference voltage Vp on. -

When the current begins to flow in the electromagnetic coil 6o6, the potential at the circuit point 316 rises. As soon as it has reached the value of the reference voltage Vp, the transistor 414 is closed and the transistor 413 is switched "ON". This effect is transmitted to the base 407b, and the transistor 407 is opened, whereby a further voltage increase at the node 316 is limited. The overall effect of this process is to adjust the voltage at node 316 to be substantially equal to or equivalent to the established reference voltage V ₂ .

Similarly, the first comparison stage 310 consists of a constant current source which supplies current for an emitter-coupled transistor pair. The current source consists in this case of the transistor 430, the diode arrangement 431 and the resistor 432, which leads to ground or earth. The emitter-coupled transistor pair 433 and 434 works in almost the same way as the emitter-coupled transistor pair 413 and the second comparison stage 312. The base of the transistor 434 is connected via the diode 435 to the node 314 and monitors or senses the voltage appearing there . The base of transistor 433 is coupled to the emitter of transistor 436 so that transistor 436 controls the voltage that appears at the base of transistor 433. The base of transistor 436 receives a voltage derived from voltage generator 313. The collector 434 c of the transistor 434 is connected to the base 408 b of the transistor 40S ' , which represents the switch 304, and controls the conductive state of the same. Again, the process of controlling and

209 8 48/061 6

the regulation is similar to the one mentioned earlier with reference to the collector 4Hc of transistor 414 and transistor 407 described-. The first comparison stage 310 controls the transistor 408 such that the voltage appearing at node 314 is substantially equal to or equivalent to that of the base of transistor 436 is impressed voltage.

As previously mentioned, the voltage applied to the base of transistor 436 is derived from voltage generator 318. Of the Voltage generator 318 has a constant current source which transistor 440, diode array 441, and resistor 442.

The current supplied by the constant current source, which contains the transistor 440, flows via the resistor network, including the resistors 443 and 444 and the transistor 453,! by mass or earth. The reference voltage output signal V j is tapped from the collector of transistor 440, which corresponds to the; Voltage drop across resistors 443 and 444 corresponds. A second current source resistors on the transistor 445 and the Wi '· 446, 447 and 448 contains, is also included in the voltage generator 318th The applied to resistors 447 and 448; Voltage is derived from a constant voltage source, wel-; before the resistor 449 and the Zener diode 450 contains. Of the ; Those skilled in the art will recognize that this particular reference voltage can also be directly; can be derived from the reference variable V ₂ , which was explained above.

The voltage generator 3I8 further includes the feedback transistor 451, whose emitter leads to the base of transistor 445, and whose collector leads to the cathode of Zener diode 450 and the base leads back to node 316 via line 32u of the circuit. The one generated by the power source Output current, which includes transistor 445, flows through resistor 452 to ground. This creates a which becomes the base of the control transistor 453. The collector of transistor 453 is connected to the

^ 09840/0616

Collector of transistor 440 connected and is therefore ^Ä

also on the reference voltage value V. Depending on the S

by the variable output current of transistor 445:

generated voltage, this current flowing through resistor 452; flows, the transistor 453 is changed in its conductivity. The amount of current flowing through control transistor 453

is a function of its conductivity state, and it becomes ι

drawn from the constant current source which powers transistor 440 ^:

contains. The amount of current flowing through resistor 443.

therefore represents the current · ■ generated by the constant current source which contains the transistor 440, reduced by the through

current flowing through the control transistor 453. The Schaltuhgs-!

point 455, which is the connection point between the resistors. 443 and 444 is connected through diode 456 to line 320 of the circuit which, as previously mentioned, with ^; connected to node 316. Accordingly, the am. Voltage appearing at node 455 is controlled directly as a puncture of the voltage at node 316. Therefore, the. The voltage signal output value V _{r represents} that value which appears at the node 316, increased by the current flowing through the resistor 443 »multiplied by the resistance value of the same.

At a voltage value corresponding to the regulated value Vp ^a ni. At node 316, the value of V is set or built up to an initial value. This is determined by the conductivity state of transistor 453, which is indirectly controlled by the: conductivity state of transistor 451 and by the coupling of line 320 of the circuit to the switching; junction point 455 through diode 456. When the voltage at junction point 314 reaches the initial value of the output voltage V ^, the emitter-coupled transistor pair 433 »434 is switched, and the conductivity state of transistor 408 * becomes thereby set by. This initial step of adjustment has the consequence that the increase in tension at the viewing point 3-14 is limited. As a consequence of this, the potential at point 316 drops. This waste is via line 320, the SöhaX-j

. 209848/0616 ^^ '

device and the diode 456 to node 455. Hence, the portion of the output voltage signal V that is controlled by the voltage at breakpoint 455 begins to decrease. In addition, the voltage drop at node 316 is transmitted back to the base of transistor 451, as a result of which the conductivity state of the transistor 451 is changed. This change in conductivity results in a change in the current generated by the variable current source including transistor 445, and this change in output current controls the conductivity of transistor 453 such that the portion of the value of output signal V which is passed through Conductivity of transistor 453 is controlled, is also changed. This builds up the second, lower value of V _r and changes the setting of transistor 408, achieved by emitter-coupled transistor pair 433 and 434, to keep node 314 at a new built V / er of V.

Pig. Figure 5 now shows a graph illustrating the current flowing through one of the electromagnetic coils 606 as a function of time, measured from the initial application of the injection control pulse via circuit terminal 126 (of Figure 2). The kink appearing in the curve at time point T. is characteristic of the opening of the valve. It can be seen that when the current flowing through the electromagnetic coil increases to a value marked I "* , the current stops increasing and then suddenly drops to a value marked ^{I" p ^ e ~.} This occurs as a result of the lowering of the reference voltage V to its second lower value. The _{current value labeled I 02} is only slightly greater than

the current value denoted by I _TT , which is the minimum current η

which must flow through the spool 606 to overcome the resistance of the return spring 632 (see Fig. 6). An analysis of the ^! The equation according to which the waveform is controlled shows that the reduction in the total series resistance of the electromagnetic coil of the injector or valve device greatly affects the extent or ratio with which

209848/0616

brazen all the flowing through the electromagnetic coil Current increases, and also greatly affects the speed, and that the speed at which the valve opens is directly applied to the electromagnetic coil 606 . flowing electricity is related. This influences the pole or Advise with which the current flow increases, directly the valve opening times. ·. .

6 shows a typical injection valve 22 in which the subject matter of the invention can be used, in section. The valve 22 consists of a three-part housing 600, 602, 6u4, a solenoid coil 606 and a back and forth! forward, the flow controlling plunger mechanism 608, 'A nozzle part 610 with a measuring port 612 is in the housing; section 602 held by the threaded engagement with the housing section 604. The measuring port 612 is controlled by the lower end portion of the plunger mechanism 6ü8, and the amount of fuel discharged through the opening 612 is a "puncture" of the opening time and the size of the opening achieved by the reciprocating movement of the plunger mechanism 6O8 . ' will.

A pipe socket 614 provided with a flange is arranged on the valve housing section 600. The pusher mechanism 608 includes a tubular core member 616, with a conically shaped surface portion at the upper end thereof, which is conical ab- ^; cut against an adjusting screw 618, which is in the pipe; clip 614 mounted ist.- The core member 616 is longitudinally mj t help of the conical end portion and the Einstellschrau- ■ 618 be adjustable. The lower end of the tubular core 616 extends into the zone within the solenoid coil 606. Both the housing section 600 and the tubular core part 616 are preferably made of a magnetizable material. The movable armature 620 is coaxial in the housing section 602 and in the core part 616 and also extends into the area of the inner area 4er, _t ptile 606 _- so that your upper brew m €> rüäley © eis @. e ± 'ä-sn

Having a distance from the lower end of the core part 616. The fitting part 620 is axially movable in the housing section 602. As used herein, "upper", "lower" refer to the directions corresponding to the various figures of the drawing and are used here for purposes of illustration only, but are not intended to limit the design to any particular orientation relative to other useful designs. Similarly, the term "axial" refers to an "up-down" movement in connection with Pig. 6 _.; A hollow valve pin part 622 is suspended from the fitting part 620 and has a conical lower end which cooperates with the nozzle part 610. The housing section 604, when it is screwed into the threaded section 624 of the housing section 602 via the thread, presses the flange 626 of the nozzle part 610 against a shoulder 628 which is formed in the housing section 602. An elastic sealing ring 630 is arranged between the housing section 604 and the flange 626.

Subject to receipt of an excitation current signal at the solenoid coil 606, an electromagnetic field is built up, causing the armature or armature 620 together with the one attached to it Valve pin part 622 is pushed up towards the stationary core part 616, against the action of the return spring 632. The lower end of the valve pin 622 is lifted from its seat, whereby the opening 612 in the nozzle portion 610 is opened and fuel, which is supplied under pressure to the upper end of the pipe socket 614, through the cylindrical parts 616, 620 and 622 and from there through a transverse opening 634. into the chamber 636 and through the opening 612. To At the end of the excitation signal, the return spring 632 moves the armature 620 downward so that the valve pin 622 returns to the i Edge of the opening 612 touches down and the injection valve part 22 'is closed.

It should be noted that changes can be made in the electrical polarity and also in the design of _i without a - leave ?, in the scope of the invention.

209 848/0616

All mentioned in the description and in the drawings illustrated technical details are important to the invention.

2098A8 / 0616

Claims (9)

- 26 - Claims Control device for controlling the to an electrically operated injection valve device of an electronic fuel injection system an internal combustion engine output energy, which system with an energy source, operating parameters of the machine detecting scanners, one on the Scanner appealing computer equipment is equipped and energizing the electrically operated injector means by the source via interposed circuit portions can be which circuit sections on the computer device can respond to control the amount of fuel delivered to the engine, characterized in that that the control device has the following features and devices: an injection control device (304, 306, 310, 312), which is assigned to the intermediate circuit sections (302) and on the computer device (110) can respond, as well as the current value flowing to the injection valve device (22) and the value of the excitation voltage, which is supplied to the injection valve device (22) can respond in such a way that it reaches the maximum excitation voltage the injection valve device and the interposed circuit arrangement (302) the possibility is to allow a certain maximum current flow for the injection valve device (22). 2. St transverse device according to claim 1, characterized in that: that the injection control device (304, 3 ^ 6, 31 ^, 312) follows Devices and features have: a first comparison stage (31C) which establishes a specific maximum current flow value in the injection valve device (22); one first control means (304), which is responsive to the first comparison stage (310), to determine the extent of the transmission or Communication of the interposed circuit arrangement (302) to limit 30 that thereby the value of the in the injection valve device (22) current flowing is maintained at or below a built-up value. 209848/0616 3. Control device according to claim 1, characterized in that . that the injector your device (304, 306, .3Iu, 312) the following Features and facilities comprises: a second level of comparison (312), which has a maximum excitation voltage value for the injection valve device (22) that easily "is below the minimum voltage value, which is normally can be obtained from a battery charging system of a vehicle; a second controller (306) which is based on the second comparison stage (312) can respond to the extent to limit the transmission or communication of the intermediate circuit arrangement (302) in such a way that thereby the excitation voltage value is kept at or below the built-up maximum. 4. Control device according to the. Claims 2 and 3 »characterized in that that the first and second control means (304-, 306) are connected in series. 5. Control device according to claim 2, characterized in that that the first comparison stage (31u) receives a first reference voltage (V) and a signal which is indicative of is the current flowing into the injection valve device (22), and that the first comparison device is the first reference voltage (V) compares with said signal and generates a first signal which shows the result of the comparison reproduces. ■. 6. Control device according to claims 3 and 5, characterized in that the second comparison stage (312) _{receives a second reference voltage (V 2} ) and a signal which is indicative of the excitation voltage supplied to the .Einspr it zventileinrichtung (22), and that the second comparison device the second reference voltage (V ₂ ) - .mit. A compares the said signal and generates a second signal which reproduces the result of the comparison. .,. ·! 7. Control device according to claim 5 _9, characterized., that the first controller (304) can be responsive to the first signal and the extent of the connection or communication the interposed circuit arrangement (302) can be changed in such a way that the to the injection valve device (22) flowing current is kept at a value which is equal to or below that value, the corresponds to the first reference voltage (V). 8. Control device according to claim 6, characterized in that the second control device (3 ^ 6) to the second signal can respond and the extent of the transmission or communication of the intermediate circuit arrangement (302) can change in such a way that thereby the excitation voltage supplied to the injection valve device (22) at a value which is equal to or below the second reference voltage (Vp). 9. Control device according to claims 5 and 6, characterized in that the first reference voltage (V) is generated by a voltage signal generator (318) which can change its voltage characteristic as a function of the signal which is characteristic of that supplied to the injection valve device (22) Is excitation voltage, and that the voltage signal generator (318) comprises the following devices and features: a constant current source (440, 441 »442) and a variable current source (445, 446, 447, 448); a resistor network (443, 444) which provides a current flow path between the constant current source (440, 441, 442) and ground or earth and _{supplies the first reference voltage (V 3} J {and a controllable transistor connected in parallel to the resistor network {443 »444) ( 453) »which, depending on a control signal from the variable current source {445 - 448), provides a variable impedance path tiaoli ground or earth, whereby the ¥ ön dtr Eotistantstroa * ial (440, 441, 442) generated current, is in a fcssti & a * 1ar way between the two strobe paths according to Misse or I'ie can divide, and one to the rer & nderliofce stream- 09848/0616 2215323 source (445 - 448) connected device (45I), which can respond to the signal, which characterizes the excitation voltage supplied to the injection valve ^ device (22) to the variable current source (445 - 448) and thereby the first reference voltage (V) . _t that is derived from the resistor network (443 »444) to regulate or set. 209848/0616