JPS5834655B2 - Ninen Kikanno High School Gas Dokuseiji Yokiyosouchi - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a method for adjusting the mass ratio of the fuel-air-mixture supplied to the internal combustion engine, controlled by an exhaust gas measuring probe placed in the exhaust gas stream of the internal combustion engine. The present invention relates to a device for reducing the harmful components of exhaust gases emitted by internal combustion engines using a regulating device with a controllable integrator.

If, in an internal combustion engine, it is desired to influence the mass ratio of the fuel/air/mixture supplied to the internal combustion engine as a function of the composition of the exhaust gas, it is possible to This is carried out using the exhaust gas measuring probe and also by means of a regulating device which, depending on the output signal of the exhaust gas measuring probe, appropriately increases or decreases the instantaneously added fuel quantity relative to the supplied air quantity.

It is known that this change in the mass ratio of fuel/air/mixture takes place both in internal combustion engines equipped with a carburetor and also in internal combustion engines equipped with an injection device.

The regulating devices used to influence the mass ratio of the fuel/air mixture supplied to the internal heat engine exhibit, for example, an integral characteristic.

Therefore, if the setpoint value of the exhaust gas composition changes over a relatively long period of time, an increasingly stronger correction of the fuel-air-mixture mass ratio is carried out.

However, known regulators exhibiting an integral characteristic have the disadvantage that the same time constant of the integral regulator acts independently of the engine speed.

The main delay in the regulating circuit consisting of the exhaust gas measuring probe, the regulating device and the regulating elements that influence the mass ratio of the fuel/air/mixture is caused by the dead time of the mixture passing through the internal combustion engine, so that the composition can already be changed. fuel, air,
The mixture has to pass through four working strokes of the internal combustion engine before the exhaust gas measuring probe in the exhaust system of the internal combustion engine detects a change in the composition of the exhaust gas.

If, for example, the integral time constant of the regulating device is optimally selected at the average speed of the internal combustion engine, then at low engine speeds the traveling time of the fuel, air and mixture in the internal combustion engine is relatively long, so the regulating device is performed too quickly.

Therefore, the mass ratio of fuel, air, and mixture is overcorrected,
This results in undesirably large deviations from the target value in the opposite direction.

On the contrary, at relatively high rotational speeds, the regulating device reacts too slowly and the desired setpoint value is reached only slowly.

In other words, the fundamental problem of the present invention is to develop a device for reducing the harmful components of exhaust gas emitted by an internal combustion engine, and to quickly and accurately readjust the mass ratio of fuel, air, and mixture supplied to the internal combustion engine. It is to do so.

In this case, the readjustment must be carried out very accurately at all engine speeds.

Furthermore, it should be noted that the exhaust gas toxicity removal device should be able to use as much as possible the transmitter for electrical signals installed in the vehicle, so that the device can be configured cost-savingly and effectively. That's true.

To solve this problem, according to the invention, an exhaust gas is arranged in the exhaust gas stream of an internal combustion engine.

Harmful emissions of internal combustion engine emissions are controlled using a regulating device with a time-controllable integrator, which is controlled by a measuring probe and which regulates the mass ratio of the fuel-air-mixture supplied to the internal combustion engine (λ regulation). In the device for reducing the component, the integrator is configured to carry out the integration in stages as a function of a timing pulse derived from the rotational speed pulse of the internal combustion engine, and the regulating device is configured to integrate the exhaust gas probe in a step-by-step manner as a function of a timing pulse derived from a rotational speed pulse of the internal combustion engine. The adjustment device is configured such that when the output voltage exceeds a predetermined limit value, the integration is performed in a direction opposite to the previous integration direction; However, when the timing pulse does not appear, it is configured to integrate with a time constant (including infinity) that is larger than the integration time constant at the time of output.

Advantageous embodiments of the pond according to the invention will be explained in detail with reference to the following examples and figures.

A fuel regulating device 11 is assigned to the internal combustion engine 10 shown in FIG.

The fuel conditioning device 11 is used to distribute a certain amount of fuel/air/mixture to the internal combustion engine 10 .

An exhaust gas measurement sensor 12, which is arranged in the exhaust gas stream leaving the internal combustion engine 10, is used to provide an output signal that is dependent on the composition of the exhaust gas.

This output signal of the exhaust gas measuring probe is fed to a regulating device 13, which output signal is connected to the internal combustion engine 10.
The effect is such that the mass ratio of fuel/air/mixture supplied to the exhaust gas is influenced depending on the composition of the exhaust gas, ie in such a way that a minimum amount of the harmful constituents of the exhaust gas are emitted.

The regulating device 13, which exhibits an integral characteristic, influences the fuel regulating device in stages.

However, in this case, the timing of this stage is determined by a signal that depends on the rotational speed of the internal combustion engine 10.

This rotational speed-dependent signal is obtained, for example, by the ignition system of the internal combustion engine.

However, signals are also used, for example in internal combustion engines equipped with an injection device, to trigger the injection.

This step-wise integration ensures that the regulating device adjusts the fuel-air-mixture mass ratio constant for each operating stroke, regardless of the rotational speed of the internal combustion engine.

As a result of this, the integral time constant of the regulating device changes automatically and is matched to the instantaneous rotational speed of the internal combustion engine.

This occurs almost without delay.

Therefore, the amplitude of the adjustment vibration is approximately equal for each rotational speed of the internal combustion engine.

The regulating circuit can therefore be optimally adjusted without great difficulty.

The embodiment of the regulating device shown in Figure 2 is used to change the composition of the fuel/air/mixture in stages.
In this case, the timing of the step change is formed by a rotational speed-dependent signal.

The regulating device has a limit value switch 14, a switching device 15 and a regulating amplifier 16.

A limit value voltage formed by a voltage divider is applied to a first input of an operational amplifier 17 provided in the limit value switch 14 .

In this case, the voltage divider is a resistor 20 connected between the + side line 18 and the one side line 19 and whose tap is connected to the input side of the operational amplifier 17.

The exhaust gas measuring sonde 12 is connected to the second input terminal of the operational amplifier 17.
is connected.

FIG. 3a shows the course of the output voltage of the exhaust gas measuring sensor 12 over time t.

The dashed line shows the limit voltage regulated by resistor 20.

When the output voltage of the exhaust gas measuring sonde 12 exceeds the limit value voltage, the output voltage of the operational amplifier takes the value shown at 21 in FIG. The output voltage takes the value shown at 22 in Figure 3.0 The output side of the operational amplifier 17 of the limit value switch 14 is connected to the resistor 2.
3 to the bases of transistors 24 and 25.

Transistors 24 and 25 are elements of switching device 15 which also has switching transistor 26 .

The reference electrode of switching transistor 26 is connected to resistors 27 and 28.
connected to the tap of a voltage divider consisting of

In this case, one side of the resistor 21 is connected to the + side line 18, and the resistor 28 is connected to the one side line 19.

The output electrode of switching transistor 26 is connected to the bases of transistors 24 and 25.

The emitters of transistors 24 and 25 are connected to resistors 29.
30 and 31 are each connected to one tap of the voltage divider.

In this case, the resistor 29 is connected to the + side line 18 and the resistor 31 is connected to the one side line 19.

The emitter of transistor 24 is connected to the junction of resistors 29 and 30, and the emitter of transistor 25 is connected to the junction of resistors 30 and 31.

The collectors of the two transistors 24 and 25 are interconnected and connected via a resistor 32 to a first input of an operational amplifier 33 belonging to the regulating amplifier 16 .

The operational amplifier 33 has an integrating capacitor between its output and its first input, which causes the regulating amplifier 16 to form an integral characteristic.

A voltage divider tap consisting of resistors 27 and 2B is connected to the second input of the operational amplifier.

At the output of the operational amplifier 33, a correction voltage is taken off which is used to influence the fuel regulator.

For example, this voltage can affect the carburetor and fuel
An adjustment member is changed that changes the air/mixture mass ratio.

This regulating element can also be a simple resistor arranged in the electronic control unit of an electronically controlled gasoline injection device.

By varying the output voltage of the operational amplifier 33, it is therefore possible to vary, for example, the opening duration of the injection valve and thus the quantity of fuel/air/mixture to the internal combustion engine 10.

The switching transistor 26 of the switching device 15 is controlled via a resistor 35 by a monostable multivibrator 36 .

This monostable multi-bicycle break 36 is triggered, for example, by an ignition signal of an ignition device of internal combustion engine 10 or a timing pulse signal resulting from an injection pulse of internal combustion engine 10 .

The timing pulses provided to monostable multivibrator 36 are shown in FIG. 3C.

The output pulses belonging to this pulse of the monostable multi-bibrake are shown in FIG. The corresponding output signal is shown in FIG. 3e.

The operation of the circuit device described above will now be described.

Since the output voltage at the output of the monostable multivibrator 36 is less than the voltage applied to the resistor 28 and thus to the emitter of the switching transistor 26, it is assumed that the transistor 26 is initially switched off.

When the output signal of the operational amplifier 17 takes the value shown in 21 of FIG. 3, that is, it is positive, the transistor 24
becomes conductive through the collector-base diode, and current flows through the resistor 32 to the first input terminal of the operational amplifier 33.

Since the output signal of the operational amplifier 33 is fed back to the first input of the operational amplifier 33 via the integrating capacitor 34, a change in the linearity of the output voltage of the operational amplifier 33 takes place.

By the way, the monostable multivibrator 36 is configured to generate a negative pulse when a trigger pulse is applied, as shown in FIG.

When the negative pulse so generated is applied from the monostable multi-bibreak 36 to the transistor 26, the negative pulse edge turns off the transistor 26, integrating with a relatively small time constant as described above. is performed, but on the other hand, when it is no longer added, it is turned on.

When switching transistor 26 is thus on,
The base voltages of transistors 24 and 25 are adjusted to a value midway between their respective emitter voltages.

This causes both transistors 24 and 25 to be cut off (off).
be done.

Therefore, no current flows through the resistor 32 to the input of the operational amplifier 33 anymore, and the integrating action is interrupted.

In other words, it is integrated with a time constant (including infinity) that is larger than the integration time constant at the time of output.

Therefore, the output voltage of the operational amplifier 33 is held at the value just reached until the next point in time.

In other words, due to the occurrence of a negative output signal of the monostable multi-bicycle break 36, the switching transistor 26 is switched off and held at the value just reached until one of the two transistors 24 and 25 can again become conductive.

Depending on which of the two transistors 24 to 25 is conducting, an integration effect takes place in one direction or the other, with the result that the correction signal at the output of the operational amplifier 33 is further increased or decreased. .

The switching of the switching transistor 26 into a conducting or non-conducting state is controlled by a monostable multi-bibreak 36.

This monostable multivibrator is controlled, for example, by timing pulses emitted by the ignition system of the internal combustion engine 10.

Controlled by each timing pulse.

When each timing pulse signal, e.g. each ignition signal or each injection pulse, triggers a monostable multi-by-break,
This monostable multi-by-break in each case applies a positive pulse of a predetermined duration to the base of switching transistor 261, making it conductive.

As a result, the aforementioned integration process is allowed to proceed in the desired steps.

In this way, the desired correction of the fuel/air/mixture mass ratio is effected by means of the output voltage of the regulating amplifier 16 or operational amplifier 33.

This takes place, for example, by proportionally lengthening or shortening the injection pulse of an electronically controlled gasoline injector or by proportionally varying the nozzle cross-section of the carburetor of the internal combustion engine.

In an advantageous embodiment of the invention, a resistor 4 is connected on the one hand to the resistor 23 and on the other hand to the input of the operational amplifier 33.
0 can be provided.

An integrating capacitor 34 is also connected to this operational amplifier, which together with a resistor determines the integration time constant.

Although embodiments constructed without the connection of resistor 40 operate completely satisfactorily for many applications, in some applications the integral time of the regulator may be too large to simply compensate for speed or load. It may depend on the desired impact.

This is the case, for example, as follows.

That is, when the rotational speed or the load changes over a very wide range.

What is done by the resistor 40 is that during the pause time between the two pulses the regulating amplifier 16 performs a further integrating action, so that the correction signal at the output of the operational amplifier continues to increase during the pause time between the two pulses. It will be or it will be gone.

However, since the resistance value of the resistor 40 is selected to be larger than the resistance value of the resistor 32, the output signal of the operational amplifier 33 changes slowly.

That is, it is performed with a relatively large time constant.

An additional advantage obtained for this is that the limit value switch 1
4 is switched during the pulse pause time, the regulating amplifier 1
The integration direction of 6 is changed immediately, ie, not only upon the arrival of a new pulse.

Therefore, wasted time in the adjustment circuit can be significantly reduced.

The characteristic curve of the voltage occurring at the output of operational amplifier 33 in the circuit arrangement with resistor 40 is shown in FIG. 3f.

As is clear from this diagram, the operational amplifier 33
The output signal changes more significantly during the pulse time, ie with a relatively small time constant, while during the pulse pause time it changes slowly, ie with a relatively small time constant.

[Brief explanation of drawings]

The figures provide a detailed explanation of the present invention: Figure 1 is a block circuit diagram of an exhaust gas toxicity removal device, and Figure 2 is a diagram of a device that affects the fuel, air, and mixture of an internal combustion engine in stages. , FIG. 3 is a pulse arrangement diagram for explaining the apparatus shown in FIGS. 1 and 2. 10... Internal combustion engine, 11... Fuel adjustment device, 12... Exhaust gas measurement sonde, 13...
...Adjustment device, 16 ...Adjustment amplifier, 17
, 33... operational amplifier, 18......+
Side track, 19... - Side track, 36...
Monostable multibibreak.

Claims (1)

[Claims] 1. A time-controllable integrator which is controlled by an exhaust gas measuring probe placed in the exhaust gas stream of the internal combustion engine and which adjusts (λ adjustment) the mass ratio of the fuel, air and mixture supplied to the internal combustion engine. In the device for reducing the harmful components of the exhaust gas emitted by an internal combustion engine using a regulating device provided with the integrator, the integrator integrates in stages depending on a timing pulse derived from a rotational speed pulse of the internal combustion engine. The adjustment device is configured such that when the output voltage of the exhaust gas sonde 12 exceeds a predetermined limit value, integration is performed in a direction opposite to the previous integration direction; The adjustment device 13 is configured to integrate with a relatively small time constant when the timing pulse appears, while integrating with a time constant (including infinity) larger than the integration time constant at the output when the timing pulse does not appear. An exhaust gas toxicity removal device for an internal combustion engine, characterized in that: