JPH0745863B2 - Failure transmission device for internal combustion engine controller - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a failure transmission device for an internal combustion engine controller, and more specifically, it is separate from a basic control unit that arithmetically controls basic ignition timing and fuel injection. In a control device for an internal combustion engine provided with a knocking control unit, the present invention relates to a fault transmitting device for transmitting a fault occurring in the knocking control unit or the like to a basic control unit.

(Prior Art) It is well known to perform knocking control in a control device for an internal combustion engine, and one example thereof is Japanese Patent Publication No. 56-1270.
The technique described in Japanese Patent No. 6 can be mentioned. In this conventional example, the ignition timing is determined in the delay control circuit 6 according to the knocking occurrence frequency.

(Problems to be Solved by the Invention) Although it is not always clear from this conventional example, when the knocking control unit is constructed, the knocking control unit is also constructed separately from the basic control unit. In that case, if a failure occurs in the signal transmission means such as a cable connecting the knocking control unit or the ignition control device at the latter stage, it may be necessary to stop the fuel injection to protect the exhaust system. In such a case, if the knocking control unit is constructed separately from the basic control unit, it is usually necessary to provide a dedicated failure signal transmitting means from the knocking control unit to the basic control unit. Further, in order to ensure the transmission function, an abnormality monitoring circuit of the transmission means must be further provided, and in any case, the device configuration becomes complicated, which contributes to high cost and its reliability. There was an inconvenience that reduced the property.

Further, when the knocking control unit has a failure, for example, a failure such as disconnection of the output signal transmission line of the knock sensor,
Normally, a backup system is used as an alternative, but if such a failure is left unattended for a long time, inconveniences such as performance deterioration or fuel consumption increase are likely to occur, so the failure status is memorized immediately or during a regular maintenance inspection at a later date. It is desirable to have a fault diagnosis memory circuit that can issue a warning. However,
In the case of a separate structure, it is also inconvenient in terms of cost and reliability to equip the knocking control unit with such a memory circuit.

Therefore, an object of the present invention is to eliminate the above-mentioned drawbacks of the prior art, and in an internal combustion engine control device in which a basic control unit and a knocking control unit are separately configured, they are connected to each other to transmit an ignition timing signal. The transmission means is used to transmit a failure signal from the knocking control unit when a failure occurs, thereby eliminating the need to provide a dedicated failure signal transmission means for the knocking control unit, and further, the knocking control unit and the ignition device described above. An internal combustion engine capable of detecting whether an abnormality has occurred in the signal transmission means for connecting the control signal, the knock sensor output signal transmission line, or the transmission means for connecting the basic control unit and the knocking control unit. It is to provide a failure transmission device for a control device.

Furthermore, the failure signal is sent to the basic control unit via the transmission means for the ignition timing signal and stored in the failure diagnosis memory circuit, so that it is unnecessary to provide the knocking control unit with the failure diagnosis memory circuit. An object is to provide a failure transmission device for an engine control device.

(Means and Actions for Solving Problems) In order to achieve the above object, the present invention, as shown in FIG. 1, is a basic control means 10 for calculating and controlling the ignition timing and the fuel injection amount of an internal combustion engine, A knock sensor 66 for detecting knocking generated in the internal combustion engine, which is configured separately from the basic control means, is connected via a first signal transmission means and receives an ignition timing signal output from the basic control means. At the same time, the output of the knock sensor is input through the second signal transmission means, and the knocking control means 12 delays the ignition timing by a predetermined amount when knocking occurs, and the third signal transmission to the knocking control means. An internal combustion engine control device comprising an ignition means 14 connected via means for inputting an output of the knocking control means to ignite an air-fuel mixture in an internal combustion engine cylinder, and at least the first When the first signal transmission means is judged to be abnormal, the first failure transmission means 16 for sending out a first failure signal indicating the abnormality to the basic control means, and the knocking. When it is included in the control means and monitors at least the second and third signal transmission means and determines that the second signal transmission means is abnormal,
When the second failure signal indicating that is judged to be abnormal by the third signal transmission means, a third failure signal indicating it is sent to the basic control means via the first signal transmission means. And a second failure transmitting means 18, which is provided, and the basic control means detects at least an abnormality of the first, second and third signal transmitting means through the first, second and third abnormality signals. Configured as

Embodiment An embodiment of the present invention will be described below with reference to the accompanying drawings.

FIG. 2 shows the overall configuration of the device according to the present invention. In the figure, reference numeral 10 indicates a basic control unit which is the basic control means. The unit 10 includes a basic ignition timing calculation device 20, an output circuit 22, a failure signal monitoring circuit 24, and a failure mode determination circuit 2
6, a storage means 28, a display device 30, and a fuel injection control device 32, and most of the configuration is a microcomputer.

A crank angle sensor 36 arranged near the rotating portion of the internal combustion engine 34 and a negative pressure sensor 38 arranged in an air introduction path near the throttle valve are connected to the basic ignition timing calculation device 20 to provide a reference crank angle signal, engine Input the rotation speed signal and negative pressure signal,
A known method is used to make an appropriate correction from the basic point or the timing (in some cases, the engine cooling water temperature detected through a water temperature sensor (not shown), etc., but this specification also includes the case where the correction is made. Ignition timing calculated by the basic ignition timing calculation device 20 is called "basic ignition timing")
It is sent to the output circuit 22 via 40.

The output circuit 22 includes resistors 22a and 22b and a transistor 22c. The collector potential of the transistor 22c is connected to the signal line 44 via the connection point 42. The signal line 44 is connected to the signal transmission means 16 (the first signal transmission means) and also to the failure signal monitoring circuit 24. Signal line
A Zener diode 22d is inserted between 44 and the base terminal of the transistor 22c.

The fault signal monitoring circuit 24 includes a transistor 24c that connects the signal line 44 to its base terminal via a voltage dividing circuit composed of resistors 24a and 24b, and its collector terminal is connected to a voltage source via a resistor 24d. At the same time, it is connected to one input terminal of the exclusive OR gate 24f via the connection point 24e. The other input terminal of the gate 24f is connected to the signal line 40
To the failure mode discriminating circuit 26 at its output terminal.

The failure mode determination circuit 26 includes a counter 26a and a monostable multivibrator 26b. The input terminal of the counter 26a is connected to the output terminal of the gate 24f, and the reset terminal thereof is connected to the output terminal of the multivibrator 26b. The input terminal of the multivibrator 26b is connected to the signal line 40 via a connection point 48. The signal of the counter 26a is stored in the storage means 28 and the fuel injection control device 32.
Entered in. In addition, although it is actually input through the CPU, the input / output interface, etc., it is shown as being input directly for convenience of illustration.

The storage means 28 is composed of a RAM or the like, receives the output of the counter 26a, and functions as the above-mentioned failure diagnosis storage circuit.
The failure mode stored in the storage means is appropriately displayed on the display device 30 as needed.

The fuel injection control device 32 operates in synchronization with the basic ignition timing calculation device, inputs the outputs of the crank angle sensor 36 and the negative pressure sensor 38 to calculate the fuel injection control value, and the fuel including the injection valve and its drive circuit. Output to the injection device 50. Further, the fuel injection control device stops the fuel injection as described later according to the output value of the counter 26a.

In the next stage of the basic control unit 10, the signal transmission means described above is provided.
16 is provided to connect the basic control unit 10 to the knocking control unit 12, which is the knocking control means described above.
In the present specification, "signal transmission means" is used to mean a connection connector made of a conductor, a cable, a conductor of a printed board, and a circuit element.

The knocking control unit 12 includes an input circuit 52, a knocking arithmetic unit 54, an output circuit 56, an abnormality detection circuit 58, a backup circuit 60, and a failure signal output circuit 18 which is the failure signal output means described above.

The input circuit 52 is connected to the signal transmission means 16 via a signal line 62, and has a pull-up resistor 52a and resistors 52b, 52c, 5
The input switch circuit is composed of 2d, 52e, 52f, transistors 52g, 52h and diode 52i, and its output is connected to the knocking arithmetic unit 54 via a signal line 64.

The knocking arithmetic unit 54 is composed of a microcomputer separate from the microcomputer mainly constituting the basic control unit 10, and the basic ignition transmitted by the basic control unit 10 via the input circuit 52 and the signal transmission means 16. When the timing signal is input, the output of the knock sensor 66 arranged in the vicinity of the cylinder of the internal combustion engine 34 is input through the knock signal transmission means 660 (the second signal transmission means) composed of a cable, a wire, etc. Detects knocking. When knocking is detected, the basic ignition timing signal is appropriately retarded, and when knocking is not detected, the basic ignition timing signal is sent as it is to the next stage via the output circuit 56. Further, the knocking calculation device 54 includes an abnormality determination circuit and a storage unit (both not shown) for monitoring the device failure therein.

The output circuit 56 is composed of resistors 56a and 56b, a transistor 56c and a zener diode 56d. The base terminal of the transistor 56c is connected to the output terminal of the knocking operation device via the resistor 56a and the changeover switch 68, and
The collector terminal is output to the outside of the unit via the signal line 70.

The abnormality detection circuit 58 includes resistors 58a, 58b, 58c and a transistor 5
Composed of 8d. The base terminal of the transistor 58d is
It is connected to the signal line 70 via the resistor 58a and the connection point 72, and its collector terminal is connected to the knocking arithmetic unit 54 via the signal line 74.

The backup circuit 60 is an alternative means at the time of abnormality of the knocking operation device 54 and the like, and is connected to the output end of the input circuit 52 via the connection point 76 and to the output circuit 56 via the changeover switch 68.

The failure signal output circuit 18 includes resistors 18a and 18b and a transistor 1
Composed of 8c. The base terminal of the transistor 18c is connected to the knocking arithmetic unit 54 through the signal line 78 via the resistor 18a.
, And its collector terminal is connected to the signal line 62 of the input circuit 52 via the connection point 80.

The signal transmission means 82 of the same kind as the signal transmission means 16 (the third
Signal transmission means) is connected to the output end of the knocking control unit 12 through a signal line 70, and is connected to the ignition device 14 which is the ignition means on the other side.

The ignition device 14 is composed of an igniter circuit or the like, and ignites a cylinder mixture through an ignition plug (not shown).

Next, the operation of the apparatus will be described with reference to FIGS. 2 and 3 to 4.

The basic ignition timing calculation device 20 calculates the basic ignition timing and sends a pulse signal (Fig. 3a) to the output circuit 22. The level of the signal is inverted by the output circuit (b in the figure), sent to the knocking control unit 12 through the signal transmission means 16 and input to the knocking operation unit 54 through the input circuit 52 thereof. The knocking calculation device 54 corrects or does not correct the basic ignition timing signal according to the presence or absence of knocking, and outputs it as an energization signal, and the output signal is output via the output circuit 56 and the signal transmission means 82 to the ignition device 14 To ignite the air-fuel mixture (FIG. 7 (c)). If the device is normal, this operation is repeated.

On the other hand, in the basic control unit 10, the output terminal of the output circuit 22 and the potential of the signal transmission means 16 outside the unit connected thereto are also input to the failure signal monitoring circuit 24 via the signal line 44, and the input pulse Is inverted by the transistor 24c again (d in the figure) and then input to one input terminal of the exclusive OR gate 24f. The gate 2
The basic ignition timing signal (a in the figure) is input to the other input terminal of 4f via a connection point 46. When the device is operating normally, both input pulses coincide with each other, so that the output of the gate 24f is at "L" level (e in the figure), but the signal transmission means 16
If a failure such as open, short circuit to ground or instability occurs,
As a result of the input pulse being fixed to the "L" level, the gate output outputs one pulse per change of one cycle of the basic ignition timing signal. The gate output is input to the counter 26a of the failure mode determination circuit 26. Since the counter 26a receives the basic ignition timing signal at its reset terminal via the multivibrator 26b and is reset every cycle at an appropriate time (f in the same figure), the output pulse number of the gate 24f is cycled. And sends it to the storage means 28 and the fuel injection control device 32. When the counter value is "1", the storage means 28 promises a failure of the signal transmission means 16, turns on the flag as the first failure mode, stores the data as failure diagnosis information, and appropriately displays it on the display device 30. Display and warn.
Further, the fuel injection control device 32 stops the fuel injection to protect the exhaust system. In this way, the failure of the signal transmission means 16 is detected and dealt with by the basic control unit 10 on the upstream side.

Next, description will be made on the detection of a failure such as a ground short circuit of the same type of signal transmission means 82. As shown in FIG. 2, the potential of the signal transmission means 82 is the transistor 58d of the abnormality detection circuit via the signal line 70 and the connection point 72. Is driven on and off, and its collector potential is input into the knocking arithmetic unit 54 via the signal line 74. Therefore, the abnormality determination circuit (not shown) in the internal circuit determines that potential by the transistor 56c of the output circuit 56.
In comparison with the collector potential of the above, if it is determined that the signal transmission means 82 is out of order when the predetermined dead zone abnormality is not synchronized, the second failure mode is set, and the number of pulses to be generated is promised to be two, and the storage means (in the arithmetic unit 54 ( (Not shown).

In addition, when the output level of the knock sensor 66 drops below a predetermined value and the state continues for a predetermined number of ignitions,
The abnormality judging circuit judges that an abnormality has occurred in the knock sensor 66, or an abnormality such as a disconnection of the knock signal transmission means 660, a ground short circuit, etc., and a third failure mode (the number of pulses to be generated) "3") promises to remember. Furthermore,
The abnormality determination circuit monitors whether or not the retard amount is within a predetermined allowable range even when the backup circuit 60 is not operating, and if it is outside the allowable range, a fourth failure mode (pulse to be generated) Promise that the number is "4") and remember. Other,
The output circuit 56 is also monitored for abnormalities in the signal system, etc., and the failure mode and the number of pulses to be generated are negotiated accordingly. This can be summarized as follows.

Next, except for the case of the failure mode 1, the case of transmitting the failure mode stored in the knocking operation device 54 to the basic control unit 10 as described above will be described. As shown in FIG. , When the basic ignition timing pulse (FIG. 3 and FIG. 4b) input to the input circuit 52 is at “H” level, the number of pulses corresponding to the failure mode is supplied to the failure signal output circuit 18 via the signal line 78. It sends out and drives the transistor 18c on / off. This transistor 1
Since the collector potential of 8c is input to the failure signal monitoring circuit 24 via the connection point 80, the signal line 62, the signal transmission means 16 and the signal line 44, the gate 24f outputs the pulse of the number (see FIG. 4). e), the number of output pulses is counted by the counter 26a. The output section of the failure mode pulse is divided into the "H" level section of the ignition signal determined by the detected values of the crank angle sensor 36 and the negative pressure sensor 38 so that even the maximum number of pulse trains can be transmitted. , And set a transmission prohibition section for a predetermined time before and after that to avoid erroneous transmission. Further, the knocking calculation device 54 does not accept the energization start signal input as the basic ignition timing pulse when the failure mode pulse is output, and prevents the ignition device 14 from malfunctioning.

FIG. 5 is a flow chart showing the failure signal receiving procedure on the basic control unit side. After the counter 26a is reset and the number of pulses is counted, it is judged whether or not the number of pulses is larger than "0" (step 84, 86,88). If there is no pulse, it means no failure, but if the number of pulses is "1", signal transmission means
When it is judged that there are 16 failures, the failure mode flag is turned on and stored, and fuel injection is stopped and a display warning is given (steps 90, 92, 94, 96). If the number of pulses is "2" or more, the flag of the failure mode is turned on and stored, and if the signal transmission means 82 fails, fuel injection is similarly stopped (steps 98, 100, 94), In either case, it is displayed and warned (steps 96 and 102). Storage means of basic control unit 28
However, as described above, the failure diagnosis storage circuit of the knocking control unit is also used as described above.

FIG. 6 shows a second embodiment of the present invention and shows another configuration example 52 ', 18' of the input circuit and the failure signal output circuit of the knocking control unit. Since the operation is the same as that of the first embodiment, the description is omitted.

FIG. 7 shows a third embodiment of the present invention, showing still another input circuit example 52 ″. The fault signal output circuit is composed of an electronic switch 104.

FIG. 8 shows a fourth embodiment of the present invention, in which the basic control unit 10 transmits a reception confirmation pulse within a data reception confirmation section after a lapse of a predetermined time from the energization start time of the basic ignition timing signal. The knocking arithmetic unit 54 can be configured to receive the pulse, confirm the transmission of the failure mode, and send the data again when the pulse is not returned. It should be noted that the knocking arithmetic unit 54 is configured not to accept the energization start signal even in this section.

Although the data communication has been described only by the failure information through the above embodiments, the data communication is not limited thereto and may be used for transmitting and receiving the control data, the operation state data, and the like.

(Effects of the Invention) The present invention is an internal combustion engine control device in which knocking control means is provided separately from the basic control means, and at least the first signal transmission means is monitored to determine that the first signal transmission means is abnormal. When making a determination, the first failure transmission means for sending out a first failure signal indicating it to the basic control means and the knocking control means, and at least the second and third signal transmission means, are included. When monitoring and judging that the second signal transmitting means is abnormal, a second failure signal indicating that is detected, and when judging that the third signal transmitting means is abnormal, a third failure signal indicating that is detected. , A second failure transmission means for sending to the basic control means via the first signal transmission means, wherein the basic control means includes at least the first abnormality signal through the first, second and third abnormality signals. Difference between first, second and third signal transmission means Since it is configured to detect the normal state, it is possible to transmit the failure information from the knocking control means to the basic control means without providing a dedicated failure signal transmission means and its abnormality monitoring circuit, and it is possible to simplify the device configuration. The reliability is improved and the cost can be reduced. In addition, the basic control means can detect in which part the abnormality has occurred while detecting the abnormality itself of the transmission means for transmitting the ignition timing signal. Therefore, the fuel injection can be stopped and the exhaust system can be changed accordingly. Measures such as protection can be taken.

Further, since the failure information of the knocking control means is transmitted to the basic control means and stored in the storage means, it is no longer necessary for the knocking control means itself to have a storage circuit for failure diagnosis. It has the advantages of simplicity, increased reliability, and reduced cost.

[Brief description of drawings]

FIG. 1 is a diagram corresponding to the claims of the present invention, FIG. 2 is a block diagram showing a circuit configuration of an apparatus according to the present invention, FIGS. 3 and 4 are output waveform diagrams of the respective circuits, and FIG. 5 is a basic control. FIG. 6 is a flow chart showing a procedure for receiving a failure signal of the unit, FIG. 6 is a circuit diagram showing a second embodiment of the present invention, FIG. 7 is a circuit diagram showing a third embodiment of the present invention, and FIG. It is an output waveform diagram which shows the 4th Example of this invention. 10 ... Basic control means (basic control unit), 12 ... Knocking control means (knocking control unit), 14 ... Ignition means (ignition device), 16 ... Signal transmission means, 18 ... Fault signal output means (fault) Signal output circuit), 20 ... Basic ignition timing calculation device, 28 ... Storage means, 32 ... Fuel injection device, 54
...... Knocking calculator

Claims (3)

[Claims] Claims: 1. a. Basic control means for calculating and controlling ignition timing and fuel injection amount of the internal combustion engine, b. Knock sensor for detecting knocking occurring in the internal combustion engine, c. Separate from the basic control means And inputting the ignition timing signal output from the basic control means connected through the first signal transmitting means, and inputting the output of the knock sensor via the second signal transmitting means. A knocking control means for delaying the ignition timing by a predetermined amount at the time of occurrence, and d. Connected to the knocking control means via a third signal transmission means, and inputting the output of the knocking control means to the internal combustion engine cylinder An internal combustion engine control device comprising: an ignition means for igniting the air-fuel mixture, which e. Monitors at least the first signal transmission means, and when it determines that the first signal transmission means is abnormal, Indication First
A failure signal transmitted to the basic control means, and f. At least the second and third signal transmission means included in the knocking control means and monitoring the second signal transmission. When the means determines that it is abnormal, a second failure signal indicating it is output, and when the third signal transmission means determines that it is abnormal, a third failure signal indicating that is output, the first signal transmission means. Second failure transmitting means for sending to the basic control means via the above-mentioned basic control means, wherein the basic control means transmits at least the first, second and third abnormality signals through the first, second and third abnormality signals. A failure transmission device for an internal combustion engine control device, characterized in that an abnormality of a signal transmission means is detected. 2. The second failure transmission means comprises pulse output means, and outputs the second and third failure signals with different output pulse numbers. A failure transmission device for an internal combustion engine controller according to claim 1. 3. The basic control means comprises storage means for inputting and storing the pulse in the storage means, and at least one of the first, second and third failure signals is sent out. The failure transmission device for an internal combustion engine control device according to claim 2, wherein the fuel injection is stopped in the event of a failure.