DE2928075C2 - Device for controlling the power output of a spark-ignition internal combustion engine - Google Patents

Description

The invention relates to an apparatus for controlling so the power output of a spark-ignited, multi-cylinder internal combustion engine according to the preamble of claim 1.

Externally ignited internal combustion engines operating with a throttle valve have in the partial load range as a result the poorer cylinder filling and the resulting reduced mean pressure as well as due to the Throttle valve caused flow losses a relatively poor efficiency, which to leads to increased specific fuel consumption.

From DE-ÖS 26 12 172 a control is the Known power output, the number for briefly in partial cylinder operation with the throttle valve open the work cycles of the cylinders according to specified patterns compared to the number of work cycles in the Full cylinder operation - with the same number of crankshaft rotations - is reduced. Of the Transition of power control through cylinder deactivation in the area of full cylinder operation in which is controlled by the throttle valve, is done by jumping the throttle valve, such that the power output of the internal combustion engine runs essentially without a jump

Furthermore, from DE-OS 27 39 223 a device is known that allows the operation of a fremdgezün- - Deten internal combustion engine without throttle valve should enable this known internal combustion engine, which with electronically controlled fuel injection works is controlled in their power output by that fuel is not supplied to all piston-cylinder units, so that less on average over time Work cycles take place. However, each individual work cycle delivers the maximum possible performance, the one Can deliver piston-cylinder unit in one work cycle, d. H. takes place with good efficiency.

A problem that arises in such "intermittently" working, spark-ignited internal combustion engines is due to the fact that at low speeds a for the practical operation of unacceptable out-of-round running is obtained, which noticeably affects the comfort and can lead to great stresses on the bearings of the internal combustion engine. The reason for this out-of-round Run lies in the fact that when the required performance is low, the time interval between the work cycles gets too big.

The invention is based on the object of creating an internal combustion engine of the generic type the unacceptable runout at low speeds and high loads for practical operation is avoided.

The object is achieved with the features of claim 1

According to the invention, a spark-ignited internal combustion engine works in operating ranges in which over the intermittent operation no satisfactory concentricity is achieved, with filling control by means of a Throttle. If the speed increases above a predetermined value, the throttle is not more engaged, but fully open, and in this disengaged state the throttle valve takes place Output control now via the number of work cycles taking place per unit of time or the ratio of the work cycles to the suppressed work cycles by means of the control unit, which the sequence of Work cycles and suppressed work cycles according to the position of the accelerator pedal controls instead

Claim 2 characterizes a particularly simple and functionally reliable embodiment of the Device according to the invention, in which the control device from which the individual work cycles accordingly the position of the accelerator pedal, only activated when the throttle valve is disconnected from the accelerator pedal is.

Claim 3 characterizes a particularly functionally reliable embodiment of the invention Device that allows the control unit to be bypassed completely.

The invention can be used advantageously in all types of spark-ignition internal combustion engines. Internal combustion engines with piston-cylinder units that use the fuel are particularly advantageous is metered individually, since it is possible to intervene directly in the metering and on this Way a work cycle can be suppressed. An interference in the activity of the respective not working piston-cylinder units assigned

Valves is not absolutely necessary in the device according to the invention.

The invention is illustrated in the following with the aid of a schematic Drawings, for example, explained with advantageous details.

It represent

Fig. 1 is a block diagram of a device for Controlling the power output of an internal combustion engine, and

Fig.2 a device for coupling the in the Internal combustion engine according to FIG. 1 provided throttle valve with a connected to the accelerator pedal Actuator.

■ According to FIG. 1, an internal combustion engine 5 has four piston-cylinder units 7, each of which has a Suction line 9 are connected to a suction pipe 11, at the inlet of which an air filter 13 is arranged

For fuel supply for the individual piston-cylinder units is a known electronic injection system with each piston-cylinder unit 7 associated, electrically controlled injection valves are provided, which are not shown here and with below constant pressure are applied to fuel.

The amount and time of the fuel supplied to the individual piston-cylinder units is determined by the point in time and duration of the injection pulses supplied by the individual injection valves.

A known injection pulse generator 15 is provided for generating these injection pulses. with each injection valve via its own line 17 with output stage 19 arranged therein connected is. The injection pulse generator 15 is supplied via a line 20 from a clock pulse generator 21 supplied with clock pulses attached to the crankshaft or camshaft of the internal combustion engine Marks. Each clock pulse corresponds to the duty cycle of a piston-cylinder unit, with the Clock pulse can be specially marked for a particular cylinder. The generator 15 via the Line 20 supplied clock pulses serve the various piston-cylinder units. assigned To control outputs of the generator 15 sequentially. In addition, the generator receives the clock pulses supplied via line 22.

The injection pulse generator 15 generates the injection pulses from these clock pulses, taking into account the measured by an air flow meter 23 air throughput through the intake manifold 11, which is of a Tachometer 25 measured speed and other operating parameters, such as air temperature, engine temperature etc., which are communicated to the Einspntzimpulsgenerator 15 from sensors 27 and 29.

The power control of the internal combustion engine takes place at least in partial areas by means of an im Intake pipe 11 arranged throttle valve 30, which is connected to an accelerator pedal 31 via a connecting mechanism 32 is coupled.

The arrangement described so far is known per se and therefore does not need to be explained in detail to become.

To increase the efficiency of the internal combustion engine, especially in the partial load range, the The throttle valve 30 can be uncoupled from the accelerator pedal 31 and moved into its fully open position.

When the throttle valve is decoupled, the power of the internal combustion engine is controlled in that sequential

not all piston-cylinder units work (intermittent operation).

First, the device for controlling intermittent operation will be explained:

A control unit 35 is connected via a line 37 to a position sensor 39, which determines the position «des Gas pedal and thus the required power. Another input of the control unit 35 is via a Line 41 to the output of the clock pulse generator

21 connected. The output of the control unit is over a line 43 with an input of one in the line

22 arranged AND gate 44 connected, so that a blocking of the clock pulse in the control unit for The result is that this clock pulse does not reach the injection pulse generator and the corresponding piston-cylinder unit is not charged with fuel.

The function of the control device 35, which is known per se and is therefore not described in detail here, is The following:

When the throttle valve is uncoupled from the accelerator pedal 31 and fully open, the control unit 35 allows the clock pulses generated by the control unit to pass through according to programs stored in the control unit, which depend on the position cc of the accelerator pedal. With increasing actuation of the accelerator pedal (increasing load requirement), the number of pulses allowed through increases in relation to the number of blocked pulses, so that more piston-cylinder units work in the unit of time. Each program corresponds to a specific steering of the accelerator pedal 31. If "= 0 idling and a = a _m " means full throttle, the following assignment between the individual programs is possible, for example:

Accelerator-
position Number of each
η clock pulses
let through blocked
Impulse Impulse 0
/ 7-1
fl-2
/ 7-3 0
O-max 0
1
2
3 η
I * max η
3 a mn

Is the accelerator pedal 31 z. B. half stepped through, so the internal combustion engine is half of the maximum

f> o performance required, '.o are the same on average over time many piston-cylinder units out of service as in service. It will be understood that the sequential sequence of Allowed and blocked impulses are chosen in this way is that the internal combustion engine runs as smoothly as possible, that in particular harmonics of the resonance frequencies the engine suspension and the drive train can be avoided and that the operation of individual Piston-cylinder units no more often than two to

three times so that these piston-cylinder units do not cool down too much.

The described, known intermittent operation is in the lower * part load range z. B. not possible because here the number of suppressed work cycles is too large and the work cycles that only take place infrequently lead to impermissible shaking of the internal combustion engine. The intermittent operation can therefore can be suppressed and the usual throttle valve control can be used. in

For this purpose, a logic circuit is provided, which the control device except in certain operating states Function sets and in these operating states the throttle valve 30 couples with the accelerator pedal:

A first comparator 49 and a second comparator 51 are connected to the tachometer 25, the first comparator 49 generating a signal when the rotational speed n> /? I, and the second comparator generating a signal when the rotational speed n> lh . Where / 72> / Ji.

Two comparators 53 and 55 are also connected to the position sensor 39, the comparator 53 generating an output signal when the deflection <x <oc \ , the comparator 55 generating a signal when the deflection <x <λ ₂ and oc ₂ ><xi.

The outputs of the comparators 49 and 53 are connected to an AND gate 57. The outputs of the Comparators 51 and 55 are connected to an AND gate 59. The outputs of the AND gates 57 and 59 are fed to an OR gate 61, the output of which is in turn connected to an input of the via a line 62 Control device 35 is connected. The control unit 35 is activated by a positive signal on the line 62. If there is no signal, the control unit is deactivated.

F i g. 2 shows the coupling device between the throttle valve 30 and the accelerator pedal 31:

The throttle valve 30 is mounted in the intake manifold on a shaft 63, the outer end of which is chamfered 65 is provided. A further shaft 69 is located in a sleeve 67 connected to the suction pipe 11 stored, which is provided with a bevel 71 corresponding to the bevel 65. In addition, the Shaft 69 has a flat 73 on which an actuating member 75 engages in a form-fitting manner, which in turn is connected to the accelerator pedal 31 and belongs to the link mechanism 32. At the end of the The sleeve 67, which is provided with a recess 77 for the actuating member 75 to pass through, is a bush 79 screwed, which contains an electromagnet 81 and a spring 83, which the shaft 69 in the direction so presses on the shaft 65, whereby the two shafts are rotatably coupled to one another.

When the electromagnet 81 is activated, the shaft 69 is drawn into it, i. H. from the shaft 65 removed, so that the non-rotatable connection between the two shafts and the throttle valve 29 is canceled is moved by a spring 85 to its fully open position. If the electromagnet 81 is switched off, so the shaft 69 returns to its original position, i.e. H. the non-rotatable connection between the two t> o Shafts 65 and 69 and thus the clutch between the accelerator pedal 31 and the throttle valve 29 is again manufactured

The electromagnet 81 is activated when a line 87 branching off from the line 62 (FIG. 1) a b5 Signal leads.

The lines 87 and 62 are via a further line 89 with the inverting input of a NAND gate 91 connected, which is in a line 93 connecting the line to the line 43 is arranged.

A signal on line 62 thus causes:

Activate the control unit 35, the electromagnet 81 and lock the NAND element 91.

No signal in line 62 causes:

Shutdown of the control unit 35, the electromagnet 81 and the passage of clock pulses through the NAND gate and thus via line 22 to injection pulse generator 15.

The described arrangement works as follows:

1. Starting

The engine speed is below / j | during starting and / J ₂ , so that the OR element 61 does not generate a signal and the electromagnet 33 and the control unit 39 are therefore not activated. The throttle valve 29 is coupled to the accelerator pedal. The clock pulses pass through the NAND element 91 and the AND element, bypassing the control unit 35, to the injection pulse generator 15. The internal combustion engine functions like a conventional internal combustion engine with electronically controlled gasoline injection and throttle valve control.

2. Accelerate

After starting, the engine comes up to speed, the accelerator pedal 31 being deflected through a relatively large angle α. When the speed is n> /? 2 and the accelerator pedal is _{rotated by an angle λι <«<λ 2} , the AND element 59 is activated. The control unit 35 and the electromagnet 81 are activated via the OR gate 61, the NAND gate 91 blocks. The electromagnet 33 uncouples the throttle valve 30 from the front of the accelerator pedal 31. The throttle valve 30 moves to its fully open position. The internal combustion engine is switched to intermittent operation. The power control takes place via the accelerator pedal 31 and the control unit 35 with the throttle valve 30 constantly fully open.

3. Constant speed

If the accelerator pedal 37 is deflected by an angle i 2, the control unit 39 remains effective as long as the speed of the internal combustion engine is above / J ₂ . In overrun mode, in which the accelerator pedal can be taken back a long way, that is to say ct <«i, the control device remains effective as long as the speed of the internal combustion engine is greater than n _t . If the accelerator pedal is completely released, there is no longer any work cycle in the internal combustion engine if the control device 35 is programmed accordingly. The fuel supply is practically completely interrupted.

4. Sudden acceleration

Is suddenly accelerated out of the push mode, i. H. Give it a lot of gas, so stay tuned if one of the two conditions controlling the AND gates 57 and 59 is met, the control unit 39 continues in operation or the control unit 39 is switched off, so that immediately at full power can be accelerated.

The coupling and uncoupling of the throttle valve 30 takes place with the described arrangement without

Load jump. This is achieved in that the throttle valve 30 in the coupled state with the accelerator pedal the power output by the internal combustion engine at a certain accelerator pedal position is so great like the one with the same accelerator pedal position and fully open throttle valve with intermittent operation under from Control device 35 forth resulting control output power.

The described arrangement can be in manifold Way to be modified. For example, the logic circuit can be changed so that the Limit speeds at which the control unit is put out of operation, directly from the throttle valve position depend. The control unit 35 can also be constructed in such a way that programs with strongly intermittent Operation only at higher speeds

are controlled, whereby an unacceptably irregular running of the internal combustion engine is avoided.

The internal combustion engine can be injected continuously, with the pulse generator 21 Pulses are generated which interrupt the injection. Even with an internal combustion engine where for Each individual piston-cylinder unit is provided with its own genius preparation, the invention can be used by the fuel supply for genetic preparation when the piston-cylinder units are switched off is interrupted.

The coupling between the accelerator pedal and the throttle valve can also be modified in various ways be done, for example, via a servomotor, etc.

For this purpose 2 sheets of drawings

Claims (3)

Patent claims: 1. Device for controlling the power output of a spark-ignited, multi-cylinder internal combustion engine, with a control unit which, when the throttle valve of the internal combustion engine is in the open position controls the performance by being within a certain number of Revolutions of the internal combustion engine taking place work cycles a more or less large number takes place in accordance with patterns depending on the position of an accelerator pedal without work submission, wherein the throttle valve is by means of a clutch gentle accelerator pedal with a predetermined fixed assignment can be coupled between the position of the accelerator pedal and the throttle valve, the position of the The throttle valve changes by leaps and bounds when uncoupling, and a coupling process when it exceeds K. the accelerator pedal position takes place above a predetermined value, characterized in that that the coupling process only at a speed less than a predetermined value takes place, and in the uncoupled state the throttle valve (30) is always fully open 2. Apparatus according to claim 1, characterized in that the throttle valve (30) is arranged on a shaft (63) and a second, coaxially arranged to this, with the accelerator pedal (31) connected shaft (69) is provided which by means of a *> Electromagnet (81) is axially displaceable relative to the throttle valve shaft and is non-rotatably connected to the shaft (63) of the throttle valve (30) in a fixed angular relationship when the electromagnet is in rest 3. Apparatus according to claim 1 or 2, wherein the fuel supply to the individual piston-cylinder units the internal combustion engine through the clock pulses corresponding to the position of the crankshaft is controlled, soft with activated control unit to are sequentially interrupted, characterized in that a gate circuit (91, 44) is provided is which, when the control device (35) is disabled, a bypassing the control device (35) Signal path (line 93) opens "5