JPS59145330A - Over-supply pressure controller of internal combustion engine equipped with turbo over-feeder - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION A) Technical Field The present invention relates to a boost pressure control device for an internal combustion engine equipped with a turbocharger. The present invention relates to a boost pressure control device for an internal combustion engine equipped with a turbocharger that is capable of reducing the boost pressure of an internal combustion engine.

Prior art This type of device is disclosed in German Patent No. 3028944, for example.
Known from the number. Such devices are similarly configured to reduce boost pressure in accordance with the knocking signal, but in this case, the boost pressure is not electronically controlled in advance, so it is difficult to adjust the boost pressure to the optimum level. In addition, it is not possible to control the supercharging pressure according to the knock limit in the preliminary control. For this reason, conventional devices often exceed the knock limit.
Complex knocking control was required depending on the strength of knocking, and it was impossible to optimize boost pressure.

c) Objective - The present invention therefore overcomes these conventional drawbacks and provides an internal combustion engine equipped with a turbocharger that allows optimization of the boost pressure according to the respective driving conditions, i.e. the driving parameters. The purpose of the present invention is to provide a supercharging pressure control device.

2) Examples The present invention will be described in detail below according to embodiments shown in the drawings.

FIG. 1 (This figure shows a schematic configuration of a control device according to the present invention. In the figure, the reference numeral 10 indicates an internal combustion engine. In this internal combustion engine, air necessary for combustion is supplied through an air filter 11 and an air filter 11. Flow rate sensor 12, exhaust gas turbocharger 1
The air is supplied through a compressor 13 of No. 4, a supercharging cooler 15, and an air distributor 16. On the other hand, the exhaust gas is discharged from the exhaust gas port 17 and the exhaust gas turbine 18 of the turbocharger 14 (through the exhaust pipe 19). A supercharging pressure control valve 21 is disposed in the bypass passage.This supercharging pressure control valve 21 can be opened against the urging force of the spring 2 by the supercharging pressure supplied from the compressor 13 via the vibrator 22. Also, the vibrator 22 is provided with a solenoid valve 23, which allows the vibrator 22 to
The supercharging pressure control valve 21 is regulated by controlling the supercharging pressure supplied through the boost pressure control valve 21. Of course, it is possible in principle to provide only one solenoid valve in the bypass path 20.

An electronic control unit 24, preferably constructed as a microprocessor, is provided, by which the solenoid valve 23 and also the ignition control unit 25 are controlled via a signal train with a predetermined duty ratio ST. This ignition control device 25 is supplied with a signal Δα2 from the electronic control device 24, which makes it possible, for example, to retard the ignition timing in the event of a knocking phenomenon occurring in the internal combustion engine. The ignition point can be adjusted by the ignition control device 25, as is well known, according to other parameters P1 or, if necessary, signals stored in a memory. Such parameters may be signals from air flow sensor 12 or temperature signals.

In FIG. 1, the wiring leading to the ignition plug of the internal combustion engine is shown by arrows to simplify the drawing.

A reference mark signal BM ignition signal n obtained from a crankshaft 26 of the internal combustion engine via a sensor 27 is input to the electronic control device 24 . In principle, it is also possible to use other crankshaft-synchronous signals, such as those obtained from an ignition distributor or the like. Furthermore, the electronic control unit 24 includes two knocking sensors 28. ．． The knocking signal gK obtained from 29 is input. Also, instead of using two knock sensors 28, 29, it is possible to use one knock sensor or several knock sensors. In that case, if a plurality of knocking sensors are used, each cylinder is provided with a knocking sensor. When a plurality of knocking sensors are used, a signal Z is required to identify whether the knocking signal is syringe or goo.

This signal can be obtained from a reference mark sensor, which makes it possible to know from which cylinder the knocking signal comes.

Furthermore, the electronic control device 24 includes an air distributor.
The signal GP from the throttle valve position sensor 31 is inputted to the signal line from the boost pressure sensor 30 disposed at 16. This sensor 31 detects the position of a throttle valve 32 arranged in the air supply pipe of the internal combustion engine and generates a load-related signal. Of course, in principle, it is also possible to detect the entire position of the accelerator pedal or to use other load signals.

In a device having such a structure, when a knocking phenomenon occurs, a knocking signal K is generated, and the ignition is adjusted to delay the ignition to return to a state in which there is no knocking phenomenon. This can be done, for example, by adjusting the ignition point in a step-by-step manner to continuously retard it when a knocking phenomenon occurs, and by gradually returning it to its original value once the knocking phenomenon has ended. Such an adjustment of the ignition point is described, for example, in German Patent No. 3009046.
listed in the number. Furthermore, at the same time or after a predetermined period of time has elapsed after the ignition point has been delayed, the turbine 1
By opening the supercharging pressure control valve 21 disposed in the bypass passage 20 of No. 8, the supercharging pressure of the supercharger is reduced.

It is also clear that a control device for controlling the injection of the internal combustion engine must be provided in addition to the above-mentioned control device. To simplify the drawing, these control devices are not shown here. Furthermore, the electronic control device 24, the ignition control device 25, and the injection control device can each be configured by individual microprocessors;
It goes without saying that this control can be implemented using a single computer.In principle, such control can also be performed for a device that has one or more carburetors and does not perform fuel injection.

FIG. 2 shows a schematic configuration of the electronic control unit 24 as a block diagram, in which the rotational speed signal n is generated by a characteristic signal generator TVT consisting of a memory device 40, 41;
It is also input to PLsoll, and the value stored there is read out. These storage devices or characteristic signal generators are ROMs.

It can be constructed from FROM or EPROM. Furthermore, the load signal GPI obtained from the throttle valve position signal GP is manually input to these storage devices 40, 411]. Furthermore, the comparison stage 42 receives the signal GPI. these(
This will be explained in more detail later. A signal GPI is taken out from this comparison stage 42 as an output signal. Communication fG
P is guided to a processing path 43 having a D component (differential component) and a digital filter 44 connected to the subsequent stage, and this filter suppresses values whose fluctuations are less than ΔGPmin, thereby forming a signal gGP. be done.

The value stored in the storage device 40 is inputted to the signal generation circuit 46 via the comparison stage 45, where a Varnu voltage with a predetermined duty ratio ST is obtained according to the value number obtained from the storage device 40, and then The position of the solenoid valve 23 is controlled by the solenoid valve 23. This duty ratio is preferably limited between 15 and 80%.

The output of the storage device 41 is also connected to a comparison stage 48 via a low-pass filter 47. This comparison stage 48 further includes a signal PList from the sensor 3o that measures the actual value of the boost pressure.
is input. The output of comparison stage 48 is connected to switching element 4
9 and a regulator 50 and a Q-limiting circuit 51, preferably with PI characteristics, to a comparison stage 45.

A reference mark signal BM and a knocking signal K from a knocking sensor are input to the knocking control unit 52. The knocking control unit 52 outputs a signal Δ
αzk is created so that the ignition timing is retarded in the event of knocking. This output signal is selectively switched to αZma via the changeover switch 53.
A limiting circuit 54 for limiting xl or αZmaX2.
Either one of the 55 will be manually operated. In that case, the limiting circuit 5
The limit value α 1 of 4 is determined according to the rotation speed n. Further, the outputs of both limiting circuits 54 and 55 are input to a comparison stage 56,
The output becomes a signal ΔαZ and is input to the ignition control device 25G.

The output signal of the knocking control unit 52 is further input to a comparison stage 59 via a switching element 57 and a low-pass filter 58. This comparison stage 59 is further inputted with a value α leakage which varies as a function of the rotational speed. This value corresponds to a predetermined maximum permissible regulation signal. It is input to the comparison stage 42.

An identification circuit 61 is provided to identify the driving state of the internal combustion engine, such as whether the exhaust gas turbocharger 14 is operating or not.
Thereby, the changeover switch 53 and the switching elements 4'9 and 57 are controlled.

This identification is made on the basis that the turbocharger is not operating when the load GP and the rotational speed n are in a predetermined state. When the turbocharger is not operating, both switching elements 49 and 57 are opened and the output of the knocking control unit 52 is connected to the control circuit 55.
It will be done. Furthermore, the above-mentioned switching elements and changeover switches can also be controlled directly via the storage devices 40, 41. This is because each value stored in the storage device is associated with a predetermined boost pressure. Therefore, if the supercharging pressure falls below a predetermined limit value, it can be considered that the turbocharger is not operating.

The basic feature of the embodiment shown in FIG. 2 is that the boost pressure is stored in the storage device 4 (H) as a characteristic signal TVI according to the rotational speed n (load GM (throttle valve position)).

is controlled to a predetermined value. n row 9koG
A predetermined duty ratio is associated with each of the first shifts of the storage device 40 that are accessed by P or GP, and the opening of the bypass passage 20 is controlled via the signal generation circuit 46 from that number, and the boost pressure is increased. A predetermined value number is adjusted. If the load fluctuation is constant or slow, the Q signal is G.
P corresponds to the signal GP1 (knocking is not considered). On the other hand, when the driver rapidly changes the load, the processing circuit 43 causes the boost pressure to become twice as large as the new steady value or to decrease below the new steady value for a short period of time (D component). This improves the response characteristics of the turbocharger.

When the fluctuation speed is less than a predetermined value (ΔGPmin), the output signal of the filter 44 and the processing circuit 43 is suppressed. With respect to such a (open loop) control circuit for controlling boost pressure, another closed loop control circuit for controlling boost pressure is connected redundantly, that is, in parallel. This closed-loop control circuit corrects the boost pressure that has already been adjusted to a predetermined value, resulting in a more precise adjustment. This closed-loop control circuit has a characteristic signal generator PLsoll which is stored in a storage device 41 and generates a setpoint value for the boost pressure according to the rotational speed n and the load Gp1+. This [[ value is passed through a low-pass filter 47 to the comparison stage 4
The work will be carried out manually after 8pm. This delay time is then adapted to the dynamic characteristics of the charge pressure build-up. Subsequently, the control deviation is manually applied to the adjustment i1'50, which preferably has a PI characteristic, the correction value of which is, for example, ±20% after passing through the limiting circuit 51.
Limited to values between . The correction values obtained for this control are subsequently added in a comparator stage 45 and input to a signal generator 46 . Here, the signal is limited to a duty ratio of, for example, 15 to 85%. The influence of component tolerances of the exhaust gas turbocharger and of the bypass valve on the charging pressure and on the dynamic characteristics can be compensated for by this closed-loop control circuit. This control circuit is activated via switching element 49 only when there is a valid boost pressure.

When the knocking signal K appears, the ignition timing is adjusted in a step-by-step manner by the knocking control unit 52, as is well known, until the knocking phenomenon ceases. A control signal ΔαZ is then generated.

When the turbocharger is operating effectively, the adjustment of the ignition point based on knocking is limited to α. This limit is implemented in order to prevent the exhaust gas temperature from becoming too high, and the limit value is controlled according to the rotational speed n in order to achieve a precise adjustment. When the turbo supercharger does not operate, the changeover switch 53 operates to set the limit value αZ.
maX2 is enabled, thereby allowing greater ignition point adjustment.

If knocking is slight or rare, adjusting the ignition point is sufficient to escape the typical knocking range. However, if the knocking continues and it causes further (larger ignition point adjustments),
If the value αzm is reached (this value is preferably varied as a function of the rotational speed), a further reduction in the boost pressure takes place. That gap will only decrease if you repeat it. A closed-loop or open-loop control of the charging pressure is effected by varying the load value GPI from the comparator stage 42 via the regulator 60. When boost pressure is controlled based on such a knocking phenomenon, it is performed when the amount of knock-resistant fuel becomes low or when the exhaust gas temperature becomes too high. In this way, the internal combustion engine is protected from the dangers arising from engine firing. It will be switched again.

In addition, in the case of the embodiment of the front vehicle, the switching element 49°57
The arrangement number switching device 53 can also be omitted. In this case, one limiting circuit 54 will be provided.

Furthermore, it is also possible to use other conventional means to move the operation of the internal combustion engine out of the knocking range in the event of a knocking phenomenon. Such measures include, for example, injecting water, introducing substances that reduce knocking, or changing the fuel/air mixture.

(e) Effects As explained in (ii), according to the present invention, the boost pressure is adjusted according to each driving state (load,
The output is maximized according to the number of revolutions).

In addition, fuel consumption is reduced and exhaust gas values can be optimally adjusted.

As a result, the knocking phenomenon either does not appear at all or only occurs very rarely, and even if it does occur, it can be overcome very quickly by reducing the boost pressure or adjusting the ignition point.

Furthermore, according to the present invention, in addition to the advantage that the boost pressure can be precisely adjusted by electronic means, when knocking occurs, the ignition timing is adjusted to be delayed and the boost pressure is adjusted via a single knock control unit. This has the effect of reducing the This allows for relatively simple control over the control of boost pressure and ignition point, and by being able to adjust the ignition point very quickly, knocking can normally be overcome. The advantage is that the reduction in boost pressure can be reserved only in extreme cases, such as when adjusting the ignition point alone is not sufficient. In this way, it is possible to reduce the influence on the rotational torque in the normal case.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the basic structure of an apparatus according to the present invention, and FIG. 2 is a block diagram showing a more detailed structure of the electronic control device. 10... Internal combustion engine 1]... Air filter 12... Air flow rate sensor 13... Compressor 14... Exhaust gas turbo supercharger 15... Supercharging cooler 18... Turbine 1
9...Exhaust pipe 20...Bypass path 2]
...Supercharging pressure control valve 23...Solenoid valve 24...
Electronic control device 25...Ignition control device 26-y rank axis 28.29...Knocking sensor 30...Supercharging pressure sensor 31...Throttle valve position sensor 32
. . . Throttle valve 40. 41 . . Storage device 46 . Limiting circuit 60...Adjuster 61
...Identification Circuit Agent Patent Attorney Takashi Kato 17 FIG, 1 Continued from page 1 0 Inventor Bernhard Miller Federal Republic of Germany 7000 Stuttgart-Henstrasse 31 0 Inventor Siegfried 7141 Schwiberdingen-Memelv, Federal Republic of Rhode Island 1 @ Inventor Herbert Schramm, Federal Republic of Germany 7000 Stuttgart 1 im Gerazen 5 0 Inventor Walter Huis, Federal Republic of Germany 7132 Illingen Stinger strasse 54

Claims (1)

[Claims] 1) A boost pressure control device for an internal combustion engine equipped with a turbocharger capable of reducing boost pressure in response to a signal from at least one knocking sensor, comprising: a storage device ( 40
), the characteristic signal of the boost pressure is stored in the load (GP
) and rotational speed (n) according to the parameters of boost pressure (PL)
A supercharging pressure control device for an internal combustion engine equipped with a turbocharger, characterized in that the supercharging pressure is adjusted via a regulating device (23, 21). 2) Providing a sensor (30) for measuring the actual value of boost pressure,
A closed-loop control circuit (41, 47, 51) is provided to overlap the control circuit that adjusts the boost pressure, so that the adjusted boost pressure can be corrected within a predetermined range according to the control deviation. A boost pressure control device for an internal combustion engine equipped with a turbocharger according to claim 1. 3) A target value for the closed loop control circuit is stored in a boost pressure characteristic signal generator (41). 5) The target value is guided to a low-pass filter (47) to obtain dynamic characteristics with respect to boost pressure. A boost pressure control device for an internal combustion engine equipped with a turbocharger according to 2. 5) A processing circuit (43
) A supercharging pressure control device for an internal combustion engine comprising a turbocharger according to any one of claims 1 to 4. 6) A digital filter (44) is provided to suppress the D component below a predetermined value (ΔGPmin). Boost pressure control device. 7) A signal from at least one knocking sensor (in a boost pressure control system for an internal combustion engine equipped with a turbocharger capable of reducing boost pressure in response to the load (GP) and rotation speed ( n) for adjusting the boost pressure according to the parameters of
a knocking control unit (52) for controlling the ignition of the internal combustion engine;
A boost pressure control device for an internal combustion engine equipped with a turbocharger characterized by multiplying the output signal by the load or rotational speed by g (double effect). 8) Low-pass output signal from the knocking control unit. Claim 7 in which the filter (58) is guided to the filter (58).
A boost pressure control device for an internal combustion engine equipped with a turbocharger according to 2. 9) The output signal from the knock control unit is compared with a predetermined value (α2m) in the comparison stage, and if the output signal exceeds the value, the supercharging pressure is reduced. Or a boost pressure control device for an internal combustion engine equipped with a turbocharger according to item 8. 10) Claim 9, wherein the predetermined value is changed according to the rotational speed (a supercharging pressure control device for an internal combustion engine equipped with a turbocharger according to this aspect). 11) The knocking control unit (52) ) is input to at least one limiting circuit (54, 55) for limiting the adjustment of the ignition point in the event of knocking. A supercharging pressure control device for an internal combustion engine, comprising the turbocharger according to item 1. 12) The boost pressure control device for an internal combustion engine equipped with a turbocharger according to claim 11, wherein the limit value can be adjusted according to the rotational speed (n). 13) Two limiting circuits with different limiting values (54°55
), and an identification circuit (61) for identifying whether or not the turbocharger is operating effectively. Claim 11 provides for a greater restriction of the adjustment of the ignition point when in effective operation.
12. A boost pressure control device for an internal combustion engine comprising a turbocharger according to item 1 or 12. 14) An identification circuit (61) is provided to identify the state in which the turbocharger is operating effectively, and when the turbocharger is not operating, the knocking sensor controls the circuit for controlling the supercharging pressure. A supercharging pressure control device for an internal combustion engine, comprising a turbo supercharger according to claim 7 or 13, wherein the turbo supercharger is configured to be shut off in accordance with a signal. 15) The adjusting device is a control valve (23) to which a signal of a predetermined duty ratio is applied, whereby the cross section of the bypass path leading to the turbocharger (14) is controlled. 15. A boost pressure control device for an internal combustion engine, comprising the turbocharger according to any one of items 1 to 14.