JPS5934448A - Safety maintenance-emergency operating device - Google Patents

Abstract

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

Description

TECHNICAL FIELD The present invention relates to a safety maintenance/emergency actuation device that acts during idling of an internal combustion engine, for example on an idling air-fuel mixture filling adjustment device. In that case, the idle mixture charge regulating device has a two-winding rotary regulator configured as an air bypass in parallel with the throttle valve, which regulator is controlled by a power stage circuit.

It is known to use microprocessors or microcomputers for controlling electrical or electromechanical devices or for controlling the functions of device systems. This microprocessor or microcomputer generates control signals for operating the regulating elements from one or more operating parameters of the device system. If a device of this kind is installed in a motor vehicle, for example, the fuel injection system, ignition system, transmission control system or idle mixture filling system can be connected separately or via a central logic circuit. , used to operate. Furthermore, devices for monitoring the relationships between the above-mentioned devices are also known. This monitoring device is
The functionality of the device is monitored for failures, and in the event of a failure, an alarm signal is generated and/or an emergency control mechanism is activated.

5AE-Technical Paper Nr, 8
No. 10157 describes an internal combustion engine regulating device controlled by a microcomputer. It was used there (
3) The microcomputer or microprocessor in the system generates predetermined control pulses according to its control program. Since this pulse is processed by the microprocessor, it occurs regularly when there is no malfunction in the functioning of the device. If a program or device malfunctions, it is detected by a storage circuit or other device. This is because in such a case, for example when the computer shuts down, no control pulses are generated. In the monitoring circuit according to SA, E-Paper, a monostable multivibrator is provided, the output signal of which is supplied to the fuel injection device and the ignition device. but,
When the rotational speed of the internal combustion engine is below a certain level, especially when starting it, no regular control pulses occur.

A reset circuit for a microcomputer is known from DE 50 35 896 A1. In this circuit, the control pulse indirectly charges and discharges the capacitor. Therefore, by monitoring the capacitor voltage (4), it is possible to detect the presence or absence of a control pulse. If a change in the control pulse train greater than a predetermined value occurs, the monitoring circuit generates a reset pulse, which resets the microcomputer.

The reset period is followed by an enable period during which the system can begin operation again.

However, even with such known monitoring devices, serious problems arise when monitoring functional operations that may pose a danger when an unspecified failure occurs. For example, when adjusting the mixture filling amount during idling, the
A problem arises in that the two-winding rotary regulator assumes a position that results in an unfavorable supply of air-fuel mixture.

Therefore, it is necessary to provide a monitoring circuit and connect it to the regulating device to prevent it from reaching a dangerous condition even if a fault occurs in the mixture filling regulating device during idling.

Structure and Effects of the Invention In contrast, the device of the present invention having the features set forth in claim 1 detects any disturbance in the area of the air-fuel mixture filling adjustment device during idling, and accordingly: A regulating element, for example a two-winding rotary regulator, can be switched off.

In an advantageous embodiment of the invention, one device is provided, the L of which acts on the two-winding rotary regulator in the current-free state and determines its position. This device is constructed as a spring and guides the adjusting element into an advantageous position in the absence of current. In this advantageous position, no undesirable mixture supply takes place and therefore no dangerous disturbances occur. In other words, when the regulating element is in this position, the internal combustion engine runs at a significantly higher idling speed.

According to the present invention, almost all serious electrical faults occurring in the area of the output stage side splitter and the two-winding rotary regulator of the mixture filling regulator at 742,977 can be detected and detected through the cut-off switch. Then, cut off the current supply to the faulty regulating element. This cut-off switch is preferably an output transistor connected in series with the supply line.

According to the present invention, failures caused by the following causes can be detected. That is, interruption of one or more lines connected to the two-winding regulator, short-circuiting of one or two output stages, and short-circuiting of two control windings connected to the regulator winding. Likewise, the two-winding rotary regulator is shut off when the control logic (usually a microprocessor or the like) controlling the output stage goes into an inconvenient state. When the circuit is in such a state,
If the control pulse to the output stage is no longer generated or a mistake occurs in the control of the pulse train, and when controlling the two-winding rotation regulator, the impulse coefficient of this pulse train is This is because the value will be inappropriate.

In the embodiment section, modified embodiments of the invention described in claim 1 are described.

According to the invention, it is advantageous if the phase (7) of the clock control of the second output stage part controlled by the first output stage part is evaluated. Because 2
This is because the two output stage sections perform push-pull operation, so monitoring one means monitoring the whole.

This monitoring is performed by a simple out-of-threshold 1 circuit. The threshold circuit generates a cutoff pulse that cuts off the current supply to the two-winding rotary regulator when the signal applied to its input falls below a predetermined level.

DESCRIPTION OF EMBODIMENTS Next, the present invention will be described in detail with reference to embodiments with reference to the drawings.

The figure is a block diagram of an embodiment of the safety-emergency actuation device according to the invention. This figure shows an output stage 10, a regulating element 11 controlled by the output stage, and an additional circuit 12. The regulating element is realized in the form of a two-winding rotary regulator. The additional circuit 12 is also essentially a safety-emergency activation device according to the invention. Also shown in the figure is a safety threshold circuit 13 (8) which evaluates the operating signal of the output stage and generates a blocking or blocking signal. The circuit '13 is part of the overall motor vehicle control system, for example a computer or a microprocessor, and is connected to the additional circuit 12. An alarm circuit 14 is further connected to the safety threshold circuit 13. This warning circuit generates an acoustic and/or optical warning, for example by means of a flashing light on the dash board of a motor vehicle.

The two-winding rotational regulator 11 is used as a regulating element to control the air-fuel mixture filling at idle and normally acts as an air bypass in parallel to the throttle valve. The two-winding rotation regulator 11 has a first winding 11a and a second winding 11b. One of the terminals of both windings is brought together at the connection point M+ and is connected in this embodiment to the positive voltage source +UB via an additional circuit 120 circuit element. Terminal IV of both windings
N, M2 are controlled separately by output stage 10. The windings determine the relative position of the slider within the air bypass depending on this degree of control.

In this embodiment, the control of the two individual windings 11a, 11b is effected by timed signals from the output stage 10. Specifically, the winding 11a is controlled by a switching transistor 10a, and the winding 11b is controlled by a switching transistor 10b by a semiconductor switch assigned to each winding. The control 1 of the windings 11a and 11b by the semiconductor switch is as follows: Ic
It is done in L. In short, the two semiconductor switches have a push-pull operation, so that when one switching transistor 10b is conducting, the other switching transistor 10a is always blocked.

With this configuration, the slider of the two-winding rotation regulator assumes an average position depending on the impulse coefficient of the control pulse train 15.

The circuit configuration of the output stage 10 is as follows. first,
Switching transistor 10a.

The emitter of 10b is directly connected to a conductor 16 extending from ground to negative potential. On the other hand, the collectors of both transistors are connected to the positive voltage -4-uB via diodes 17 and 18 which are connected in the blocking direction to this voltage.

'-J:, Zener diode 19 is connected in parallel with the emitter-collector path of transistor 10a, same < +-
A parallel V Zener diode 20 is connected to the emitter-collector path of the lanso star 10b. A second downstream transistor 10 is controlled via a diode 21, a resistor 22 in series with it, and a further resistor 23 connected to ground. In this case, diode 2
1 is connected in the forward direction to the positive voltage −+−UB K,
Therefore, a base current can be supplied to the switching transistor 10b. The collector of the transistor 10a is connected to the terminal M1 of the two-winding rotation regulator and the transistor 10b.
The collectors of are connected to the terminal 142, respectively.

Therefore, the following operation is performed.

If the control pulse train, which is a rectangular pulse train with a preadjustable impulse coefficient, conducts, for example, the first output stage transistor 10a with the corresponding polarity, the positive voltage source - U
The entire current of B flows to ground through the individual windings, wire 11a and the emitter-collector path of the conducting transistor 10a. In this case, it is assumed that the cutoff switch of the additional circuit 12 is closed. This switch conducts when implemented as a switch transistor. At the same time as the first output stage transistor 10a becomes conductive, the second output stage transistor 10a connected downstream
prevent b. This is because the anode of control diode 21 drops substantially to ground potential.

The first output stage transistor 10a has a control pulse train 1
The force blocked by the negative half-wave of 5, ru. At this time, a weak base current flows through the first individual winding 1 as the current of the positive voltage source.
1a and the now conducting diode 21 to the base of transistor 10b. The transistor 10b is therefore conductive and the full voltage of the voltage source is applied to the second individual frame line 11b. Therefore, unless a failure occurs, a timing-controlled output signal always appears at the collector of the second output stage transistor 101.

The additional circuit 12 includes a second transistor 10b of the output stage 10.
The collector is inspected for defects in the timing-controlled output signal. In this example, rectification -
The test is performed by the charging circuit 24. On the output side 25 of the circuit 24, 'fx' (Logi
A compatible) output signal is generated. This signal reaches a predetermined threshold when the timed output signal is normal, and goes to approximately zero potential when there is a fault. The output signal of the additional circuit 12 appearing at the circuit point 25 is supplied to the safety threshold circuit 13.

In its simplest form, this circuit 13 is a comparator consisting of an ordinary operational amplifier, and sends a blocking signal to the input side 26 of the additional circuit 12 when the output signal that can be processed by the logic circuit falls below a predetermined threshold. supply This blocking signal causes
At least indirectly, the current supply to the common terminal 11+ of the two individual windings 11a, 11b of the two-winding rotation regulator 11 is interrupted.

In the illustrated embodiment, the isolation switch has a series output transistor 27. A power supply +UB and a common terminal M+ are connected in series with the collector-emitter path of this transistor 27. Transistor 27 is controlled by driver transistor 28. Series output! - A resistance circuit consisting of a resistor 29 is connected to the run source 27, and a resistor 30 is connected to the driver transistor 28.

The rectifier-charging circuit 24 includes a parallel diode 31 that leaks negative pulses to ground, a rectifier diode 32 connected in the forward direction for positive voltages, a charging capacitor 33 connected downstream thereof, and a resistive voltage divider circuit. 34, and a Zener diode 35 in parallel thereto. The potential built up in the charging capacitor 33 exceeds a predetermined voltage threshold when normal timing control is performed with a predetermined duty factor. Conversely, when a failure occurs, the safety threshold circuit 13 detects it. At this time, the following operation is performed. If the rectified safety signal appearing on the output side 25 falls completely below a predetermined threshold, for example, if the voltage value is 5■ in an actual usage example, the safety threshold circuit 13 detects the occurrence of a fault. and driver transistor 28
be controlled accordingly. Accordingly, series transistor 2
7 cuts off the current supply from the power supply →-UB to the 2nd winding and wire rotation regulator. This operation also takes place in the event of a short circuit to ground due to the current limitation of the switching transistor.

In this no-current condition, a spring 36 in the two-winding rotation regulator moves the slider to an advantageous position corresponding to a high idle speed. In the above example, the safety threshold circuit 13 (may be a microprocessor. This microprocessor has a
A control signal having a predetermined duty factor for the output stage 10 is generated.

The device according to the invention detects almost all serious electrical faults occurring in the area of the output stage and the two-winding rotary regulator and then interrupts the current supply via an additional series output transistor.

The spring then determines the position of the slider.

This device detects, for example, the following faults.

a) Interruption analysis in one or more lines connected to the two-winding rotary regulator, b) Short circuit of one or two output stages, C) Terminals +, +1. of the two-winding rotary regulator. Short circuit in the control line connected to M2.

The device of the present invention can also be used to detect a failure in the microprocessor itself that generates the control pulse train. This is because, if these pulse trains are not generated, the clock control of the second output stage transistor 10 is not performed and the circuit will malfunction. In this case, the safety threshold circuit also provides an operational connection to the microprocessor, if it is not a microprocessor, or if it is configured as a kind of watchdog circuit.
A reset signal can also be generated.

[Brief explanation of the drawing]

The figure is a block diagram of an embodiment of a safety maintenance-emergency activation circuit according to the present invention. 10... Output stage, 10a, iob... Output stage transistor, 11... 2-winding rotation regulator, 11a. 111]...Individual winding, 12...Additional circuit, 13...
・Threshold value circuit for safety maintenance, 14...Alarm circuit, 15...
・Control pulse, 24... Rectifier-charging circuit, 27...
Series output transistor, 28...driver transistor, 36...spring.

Claims (1)

[Claims] 1. For an idling air-fuel mixture charge regulating device having a two-winding rotation regulator (11) configured as an air bypass in parallel with a throttle valve and controlled by a power stage circuit (10). , a two-winding rotation regulator (11
) output stage semiconductor switches (transistors 10a, 10b) assigned to each winding (lla, 1lb) of
a timed control pulse train is detected by one of the following, wherein said semiconductor switch is pulled by a pulse having a shock coefficient presetting the desired intake air cross-section; and said control in the event of a fault. connected to the current supply path to the common terminal (M+) of the two-winding rotation regulator (11) so that the two-winding rotation regulator (11) is placed in a no-current state by the output stage according to the evaluation value of the pulse train; Safety maintenance-emergency activation device, characterized in that a read cut-off switch (27°28) is controlled. 2. The second output stage transistor (10b) whose timing at the time of failure occurrence is evaluated is controlled by the first output stage transistor (10a, 2. Safety and emergency actuation device according to claim 1, wherein a control pulse train with a presettable coefficient of impact on the regulator is provided.