JP2000073841A - Warning lamp trouble diagnosis device and method for internal combustion engine and control method at trouble time - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a warning lamp trouble diagnosis device and method for an internal combustion engine which can report the abnormality of a control system to a driver and the control method at a trouble time, even in the case of the trouble diagnosis of a warning lamp and a warning lamp control line and also the generation of the trouble in the warning lamp and warning lamp control line itself. SOLUTION: The warning lamp trouble detection necessary judging means 3041 of a warning lamp trouble diagnosis means 304 judges a warning lamp trouble diagnosis condition based on an inputted detection signal and outputted lighting signal. A warning lamp trouble detection means 3042 detects the trouble of the warning lamp and warning lamp control line based on the judged warning lamp trouble diagnosis condition. A warning lamp trouble judging means 3043 is decides and judges by comparing the detected trouble with a preset decided condition. A fail-safe control means 3044 carries out the fail-safe control of a fuel cut based on the decided and judged trouble result and the outputted trouble signal.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus and method for diagnosing a warning light failure of an internal combustion engine and a control method at the time of failure. The present invention relates to an apparatus and method for diagnosing a warning light failure of an internal combustion engine, which secures an alternative warning means for a warning light to a driver when a failure occurs, and a control method at the time of failure.

[0002]

2. Description of the Related Art In a conventional engine control device, if any one of the control devices fails, a failure determination is made, and a warning lamp is turned on at the time of failure to warn the driver of an abnormality.

[0003] As an engine control device provided with such a warning light, for example, in Japanese Patent Application Laid-Open No. 9-125938,
Deterioration of the catalyst that purifies the exhaust gas of the engine is determined,
A technique for turning on a warning light when the deterioration is determined is proposed.

[0004]

The above-mentioned conventional system realizes that an abnormality is transmitted to a driver by turning on a warning light when an engine device is determined to be out of order.

[0005] However, if the warning light and the warning light control line that should report an abnormality break down, the method of transmitting the abnormality to the driver is impaired, and the driver cannot recognize the abnormality of the engine. There is a problem.

SUMMARY OF THE INVENTION The present invention has been made in view of the foregoing problems, and it is an object of the present invention to surely diagnose a failure of a warning light and a warning light control line, and to provide a warning light and a warning light control line itself. An object of the present invention is to provide an internal combustion engine warning light failure diagnosis device, method, and failure control method that can notify a driver of a control system abnormality even when a failure occurs.

[0007]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention is characterized in that a detection signal taken from various sensors of an internal combustion engine control system and a failure signal outputted from failure determination means. The warning light failure diagnosis condition is determined based on the above, the failure of the warning light and the warning light control line is detected based on the determined warning light failure diagnosis condition, and the detected failure is compared with a predetermined fixed condition. Or to control the internal combustion engine based on the determination.

Specifically, the present invention provides the following apparatus and method.

According to the present invention, there is provided input processing means for receiving detection signals from various sensors of an internal combustion engine control system, failure determination means for determining the presence or absence of a failure based on the captured detection signals, and outputting a failure signal. Warning light lighting means for outputting a lighting signal based on the output failure signal to light a warning light, and warning light failure diagnosis means for diagnosing a failure of the warning light and the warning light control line. The present invention provides a warning light failure diagnosis device for an internal combustion engine.

Preferably, the warning light failure diagnosis means determines the warning light failure diagnosis condition based on a detection signal input from the input processing means and a lighting signal output from the warning light lighting means. Warning light failure detection necessity determining means, warning light failure detecting means for detecting a failure of the warning light and the warning light control line based on the determined warning light failure diagnosis condition, and detecting the detected failure in advance. Warning light failure determination means for determining the determination by comparing with the set determination condition.

Preferably, the warning light failure diagnosis means determines the warning light failure diagnosis condition based on a detection signal input from the input processing means and a lighting signal output from the warning light lighting means. Warning light failure detection necessity determining means, warning light failure detecting means for detecting a failure of the warning light and the warning light control line based on the determined warning light failure diagnosis condition, and detecting the detected failure in advance. Fail-safe control that includes a warning lamp failure determination unit that performs determination by comparing with a set determination condition, and that performs fail-safe control of fuel cut based on the determined failure result and the output failure signal. Means.

[0012] Preferably, the warning light failure determining means determines that the failure of the detected warning light and the warning light control line has continued for a predetermined time or a predetermined number of times.

[0013] Preferably, the fail-safe control means, when it is determined that the internal combustion engine control system has failed based on the determined failure result and the output failure signal, rotates the internal combustion engine. A fuel cut to the fuel injection valve is performed so that the number does not exceed a predetermined value.

Further, the present invention determines whether or not a failure has occurred based on detection signals taken from various sensors of the internal combustion engine control system, and outputs a lighting signal based on the failure signal output based on the determination result. The warning light failure diagnosis condition is determined based on the captured detection signal and the output lighting signal, and based on the determined warning light failure diagnosis condition, the failure of the warning light and the warning light control line is determined. A method for diagnosing a warning lamp failure of an internal combustion engine, comprising detecting the detected failure and comparing the detected failure with a preset determination condition.

Further, according to the present invention, the presence or absence of a failure is determined based on detection signals taken from various sensors of the internal combustion engine control system, and a lighting signal is output based on the failure signal output based on the determination result. The warning light failure diagnosis condition is determined based on the captured detection signal and the output lighting signal, and based on the determined warning light failure diagnosis condition, the failure of the warning light and the warning light control line is determined. Detecting and comparing the detected failure with a preset determination condition, and performing fail-safe control of fuel cut based on the determined failure result and the output failure signal. A method for controlling a failure of a warning light of an internal combustion engine is provided.

[0016]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing an apparatus and a method for diagnosing a warning light failure of an internal combustion engine according to an embodiment of the present invention;

FIG. 1 shows the overall configuration of an engine system provided with a failure control device according to an embodiment of the present invention. As shown in FIG. 1, air to be taken in by the engine 8 is taken in from the inlet 2 of the air cleaner 1 and enters the collector 7 through a throttle valve device 6 provided with a throttle valve 5 for controlling the amount of intake air.

The throttle valve 5 is connected to a motor 10, and the throttle valve 5 is operated by driving the motor 10. The throttle valve 5 is operated to control the amount of intake air. The intake air reaching the collector 7 is distributed to each intake air pipe 9 connected to each cylinder 23 of the engine 8 and is guided into the cylinder 23.

On the other hand, fuel such as gasoline is sucked and pressurized from a fuel tank 11 by a fuel pump 12, and then supplied to a fuel system 24 in which a fuel injection valve (injector) 13 and a variable fuel pressure regulator 14 are piped. Is done.

The fuel system is adjusted to a predetermined pressure by the above-mentioned variable fuel pressure regulator 14, and is injected into the cylinders 23 from the injectors 13 having the fuel injection ports opened in the respective cylinders 23. Further, a signal representing the intake flow rate is output from the air flow meter 3 and input to the control unit 15.

Further, a throttle sensor 18 for detecting the opening of the throttle valve 5 is attached to the throttle valve device 6, and the output thereof is also input to the control unit 15.

Reference numeral 16 denotes a crank angle sensor, which is driven to rotate by a cam shaft 25, and outputs a signal indicating the rotational position of the crank shaft. This signal is also input to the control unit 15.

Further, reference numeral 20 denotes an A /
An F (air-fuel ratio) sensor detects and outputs the actual operating air-fuel ratio from the exhaust gas component, and outputs the signal to the control unit 15.

The control unit 15 has a processing means (CPU) 27 which receives various signals for detecting the operating state of the engine, such as the above-described crank angle signal and throttle opening signal, as input signals, and performs predetermined arithmetic operations. And outputs various control signals calculated as a result of the calculation, and outputs predetermined signals to the injector 13, the ignition coil 17, and the motor 10 for operating the throttle valve to control fuel supply and ignition timing. Then, the intake air amount control is executed.

Reference numeral 28 denotes a warning light which is turned on when any one of these various control systems fails to notify the driver of an abnormality.

FIG. 2 shows the control unit 15 of FIG.
3 shows the control system. Note that, in the drawings described below, parts common to FIG. 1 are denoted by the same reference numerals.

The control unit 15 includes a CPU 15a serving as a control center, an input processing circuit 15b for performing predetermined processing (for example, A / D conversion, etc.) on detection signals from various sensors described below, and data transfer. Bus 15 to do
c, and an output processing circuit 15d that outputs data that has been subjected to predetermined arithmetic processing by the CPU 15a.

The input processing circuit 15b includes a crank angle sensor 17, a throttle sensor 18, an accelerator sensor 10
7, detection signals from the water temperature sensor 108, the air flow meter 3, the ignition switch 109, the starter switch 110, and the battery voltage 111 are taken in. These signals are subjected to predetermined processing by the input processing circuit 15b and converted into data. After that, the CPU
15a.

Further, an interrupt signal is given to the interrupt controller 104 from the input processing circuit 15b.

When various detection data is given via the bus 15c, the CPU 15a responds to the various detection data by R
After performing arithmetic processing based on a predetermined program or the like stored in the OM 101, the arithmetically processed data is stored in RA
M102, backup RAM 106, warning light 28, injectors 13a to 13d, throttle motor 10, fuel pump 12, igniter 17
, And outputs a control signal via the output processing means 15d.

FIG. 3 shows a functional configuration of a fault control device according to an embodiment of the present invention. As shown in FIG. 3, the failure control device includes an input processing unit 301 and a failure determination unit 30.
2, warning light lighting means 303, warning light failure diagnosis means 3
04.

When a failure occurs in the control system of the internal combustion engine, the input processing means 301 outputs the battery voltage 111, the crank angle sensor 17, the air flow meter 3, and the accelerator sensor 10.
A detection signal such as 7 is captured.

The failure determining means 302 determines whether or not a failure has occurred based on the output signals of the various sensors.
Outputs a failure signal.

The warning light lighting means 303 outputs a lighting signal based on the output failure signal, and lights the warning light 28.

The warning light failure diagnosis means 304 is used to
Diagnose the failure of the warning light control line.

The warning light failure diagnosis means 304 includes a warning light failure detection necessity determining means 3041 and a warning light failure detection means 30.
42, a warning light failure determination means 3043, and a fail-safe control means 3044.

The warning light failure detection necessity determining means 3041
On the basis of the detection signal input by the input processing means 301 and the lighting signal output from the warning light lighting means 303, the conditions under which the warning light failure diagnosis can be reliably performed, for example, the voltage of the battery voltage 111 for operating the control system is sufficient. Is determined.

The warning light failure detecting means 3042 detects whether the warning light 28 and the warning light control line have failed when the warning light failure diagnosis condition is satisfied (permitted).

The warning light failure determination means 3043 determines whether the result detected by the warning light failure detection means 3042 is an erroneous detection, and determines the failure. That is, when the detected failure state of the warning light and the warning light control line continues for a predetermined time or a predetermined number of times, it is determined to be a failure.

The fail-safe control means 3044 performs fail-safe control for the injectors 13a to 13d based on the determination result from the warning light failure determination means 3043 and the failure signal output from the failure determination means 302.

Only when the warning light fails, the engine control system parts,
For example, as long as the sensors, actuators, and the like do not fail, there is no problem in running even if fail-safe is not executed.

FIG. 4 shows the lighting control of the warning light 28 shown in FIG. 1. The warning light 28 is provided on the driver's seat inter-panel 30, as shown in FIG. The warning light 28 is turned on by electric power from the battery voltage VB. Further, for example, the transistor Tr is driven by the CPU 15a in the control unit 15,
When the Tr is driven, the warning light 28 is turned on.

Further, in order to detect disconnection and short circuit between the warning light 28 and the transistor Tr, the warning light 28
A voltage generating resistor R and a warning lamp voltage detection circuit 15e are provided between the transistor Tr and the transistor Tr.

On the other hand, for example, A of the control line in FIG.
When the disconnection occurs in the portion, as shown in the warning lamp failure diagnosis input / output table of FIG. 5, when the warning lamp lighting output (base output from the CPU 15a to the transistor Tr) is Low, the transistor Tr is in the off state. Also, since no voltage is generated in the voltage generation circuit R, the read value of the warning light lighting input IC (signal from the warning light voltage detection circuit 15e to the CPU 15a) becomes Low.

When a short circuit occurs in the portion A of the control line in FIG. 3, as shown in FIG. 5, a warning lamp lighting output (base output from the CPU 15a to the transistor Tr).
Is High, a voltage is generated in the voltage generation circuit R even when the transistor Tr is on, so that the warning light lighting input IC read value (from the warning light voltage detection circuit 15e to C
The signal to the PU 15a) becomes High. By the above,
It is determined that the warning light 28 is disconnected and a short-circuit failure is present.

FIG. 6 shows a flowchart for diagnosing a disconnection of the warning light 28 and a short-circuit failure. As described with reference to FIG. 4, the disconnection and the short-circuit failure are determined from the relationship between the output of the CPU 15a and the output of the voltage detection circuit 15e.

That is, in step 601, it is determined whether the failure detection of the warning lamp is permitted. The detection permission determination condition here is that, for example, if the battery voltage 111 is too low, the control system malfunctions and accurate failure diagnosis cannot be performed.
The determination is made according to the voltage state of the battery voltage 111 and the like.

Next, at step 602, a warning lamp lighting control state corresponding to the failure determination of various sensors such as the crank angle sensor 17, the air flow meter 3, and the accelerator sensor 107 shown in FIG. 3 is detected.

Next, when the warning light lighting control is performed, the output value of the warning light voltage detection circuit 15e is taken in step 603. As described with reference to FIG. 5, when the warning lamp lighting control is performed, that is, when the CPU 15a outputs a High signal to the transistor Tr, the warning lamp voltage detection circuit 15e outputs a Low output to the CPU 15a. Thus, the CPU 15a determines that there is no short circuit.

On the other hand, for example, when a short circuit occurs at the portion A in FIG. 4, when the CPU 15a outputs a High signal to the transistor Tr as described above,
When the warning lamp voltage detection circuit 15e becomes High to the CPU 15a, the CPU 15a determines that there is a short circuit.

If it is determined that there is a short circuit, in step 604, the count is incremented by the MILSCNT counter, and in step 605, it is determined whether or not the counter value has reached a specified NG (MILSNG) value. Here, the reason why the specified NG value is provided is to prevent the erroneous diagnosis due to the count-up of the MILSCNT counter due to noise or the like by setting the specified NG value to a predetermined value.

On the other hand, when it is determined in step 603 that there is no short circuit, in step 606, the MILSC
The NT counter is cleared.

Next, when the warning light lighting control is not performed in step 602, the output value of the warning light voltage detection circuit 15e is fetched in step 607 as in step 603. As described with reference to FIG. 5, when the warning light lighting control is not performed, that is, when the CPU 15a outputs a Low signal to the transistor Tr, the voltage detection circuit 15e outputs a High output to the CPU 15a. , The CPU 15a determines that there is no disconnection.

On the other hand, for example, when a disconnection occurs at the portion A in FIG. 4 and the low signal is output from the CPU 15a to the transistor Tr as described above, the warning light voltage detection circuit 15e is connected to the CPU 15a. When it becomes Low, the CPU 15a determines that there is a disconnection.

If it is determined that there is a disconnection, step 60
At 8, the MILDCNT counter counts up, and at step 609, it is determined whether or not the counter value has reached a specified NG (MILDNG) value. Here, the reason why the specified NG value is provided is to prevent the erroneous diagnosis due to the count-up of the MILDCNT counter due to noise or the like by setting the specified NG value to a predetermined value.

On the other hand, when it is determined in step 607 that there is no disconnection, in step 610, MILDCNT
Performs counter clear processing.

Next, in step 611, when it is determined in step 605 or step 609 that the warning light 28 is disconnected or short-circuited, it is determined that the warning light 28 and the warning light control line are faulty. .

FIG. 7 shows a flowchart after the above-mentioned warning lamp failure is determined. In step 701,
For example, if an NG determination is made in step 605 (warning lamp disconnection failure detection) or step 609 (warning lamp short failure detection) shown in FIG. 6, it is determined in step 702 whether there is a warning lamp lighting request.

At this time, since the warning light 28 and the warning light control line are out of order, lighting cannot be performed according to the warning light lighting control request. So, when there is a warning light lighting request,
That is, when there is a request to turn on the warning lamp when the control system of the internal combustion engine has failed, it is determined in step 703 whether or not the engine speed is equal to or higher than a predetermined value (MILNGFC). At 704, fuel cut is performed. When the fuel is cut, the engine speed decreases, so that the driver can detect the engine abnormality even in a failure state where the warning light cannot be turned on.

Even if it is determined in step 701 that the warning light has failed, if there is no warning light lighting request in step 702, that is, if the warning light 28 and the warning light control line have simply failed, the above-described fuel cut-off is performed. Since there is no need to give an alternative warning to the driver such as the above, nothing is performed.

Next, in step 705, when it is determined that the engine speed has fallen below a predetermined value (MILNGRC) due to the fuel cut in step 704, in step 706, fuel cut recovery (restart of fuel injection) is performed. Is done. As a result, engine stall (stall) due to the fuel cut control in step 704 is prevented.

[0062]

According to the present invention, the failure diagnosis of the warning light and the warning light control line is reliably performed, and even if a failure occurs in the warning light and the warning light control line itself, the driver is notified to the driver. Since it is possible to communicate the abnormality of the control system,
Higher security can be ensured.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram of an engine system provided with a failure control device according to an embodiment of the present invention.

FIG. 2 is a configuration diagram of a control system in the control unit of FIG.

FIG. 3 is a functional configuration block diagram of a failure control device according to an embodiment of the present invention.

FIG. 4 is a diagram showing lighting control of a warning light in FIG. 1;

FIG. 5 is an input / output characteristic diagram of a warning light diagnosis applied to the present invention.

FIG. 6 is a flowchart for diagnosing disconnection and short-circuit failure of a warning light and a warning light control line.

FIG. 7 is a flowchart after it is determined that a warning lamp has failed in FIG. 6;

FIG. 8 is a layout view of a warning light applied to FIG. 1;

[Explanation of symbols]

301: input processing means, 302: failure determination means, 303
… Warning light lighting means, 304… warning light failure diagnosis means, 30
41: warning light failure detection necessity determination means, 3042 ... warning light failure detection means, 3043 ... warning light failure determination means, 304
4 ... Fail safe control means

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) F02D 41/22 330 F02D 41/22 330E 41/32 41/32 D G05B 23/02 G05B 23/02 T 301 301X G08B 21/00 G08B 21/00 Z (72) Inventor Toshio Hori 2520 Oji Takaba, Hitachinaka-shi, Ibaraki, Ltd. Automobile Equipment Division, Hitachi, Ltd. (72) Inventor Kenichi Goto 2 Takaracho, Kanagawa-ku, Yokohama-shi, Kanagawa-ku Address F-term in Nissan Motor Co., Ltd. (reference) 3G084 BA13 BA33 DA27 DA30 EA07 EA11 EB22 FA00 FA03 FA07 FA10 FA20 FA29 FA33 FA35 FA36 FA38 3G092 AA01 CB05 DE01Y EA09 EA17 FB02 FB05 FB06 HA01Z HA06Z HC08Z HD03Z01 HC03Z JB01 JB08 JB09 JB10 MA24 NA08 NE19 NE23 PA01Z PA11Z PD13Z PE01Z PE03Z PE08Z PE09Z PF16Z PG00Z PG01Z 5C086 AA34 BA22 CA03 DA08 DA10 DA12 DA25 EA11 EA41 EA45 FA11 5H223 AA10 CC08 DD03 EE08 EE11 FF08 FF09

Claims (7)

[Claims] An input processing means for receiving detection signals from various sensors of an internal combustion engine control system; a failure determination means for determining whether a failure has occurred based on the captured detection signals and outputting a failure signal; An internal combustion engine comprising: a warning light lighting means for outputting a lighting signal based on the output failure signal to light a warning light; and a warning light failure diagnosis means for diagnosing a failure of the warning light and the warning light control line. Engine warning light failure diagnostic device. 2. The warning light failure diagnosing means according to claim 1, wherein the warning light failure diagnosing means determines the warning light failure diagnosing condition based on a detection signal input from the input processing means and a lighting signal output from the warning light lighting means. A warning light failure detection necessity determining means for determining, a warning light failure detecting means for detecting a failure of the warning light and the warning light control line based on the determined warning light failure diagnosis condition, and the detected failure And a warning light failure determination unit for determining the determination by comparing the determination with a predetermined determination condition. 3. The warning light failure diagnosing means according to claim 1, wherein said warning light failure diagnosing condition is based on a detection signal input from said input processing means and a lighting signal output from said warning light lighting means. A warning light failure detection necessity determining means for determining, a warning light failure detecting means for detecting a failure of the warning light and the warning light control line based on the determined warning light failure diagnosis condition, and the detected failure And a warning lamp failure determining means for performing determination by comparing with a predetermined determination condition, and performing fail-safe control of fuel cut based on the determined failure result and the output failure signal. A warning light failure diagnostic device for an internal combustion engine, comprising: safe control means. 4. The warning light failure determination means according to claim 1, wherein the warning light failure determination means detects a failure when the detected failure state of the warning light and the warning light control line continues for a predetermined time or a predetermined number of times. And a warning light failure diagnosis device for an internal combustion engine. 5. The internal combustion engine according to claim 3, wherein the failsafe control means determines that the internal combustion engine control system has failed based on the determined failure result and the output failure signal. A diagnostic device for diagnosing a warning light of an internal combustion engine, wherein a fuel cut to a fuel injection valve is performed so that a rotation speed of the engine does not increase to a predetermined value or more. 6. A method for determining the presence or absence of a failure based on detection signals received from various sensors of an internal combustion engine control system, and outputting a lighting signal based on the failure signal output based on the determination result. The warning light failure diagnostic condition is determined based on the signal and the output lighting signal, and the failure of the warning light and the warning light control line is detected based on the determined warning light failure diagnostic condition. A method for diagnosing a warning light failure of an internal combustion engine, wherein the detected failure is determined by comparing the detected failure with a predetermined determination condition. 7. A method for determining the presence or absence of a failure based on detection signals received from various sensors of an internal combustion engine control system, and outputting a lighting signal based on the failure signal output based on the determination result. The warning light failure diagnostic condition is determined based on the signal and the output lighting signal, and the failure of the warning light and the warning light control line is detected based on the determined warning light failure diagnostic condition. Internal combustion, wherein the detected failure is determined by comparing it with a predetermined determination condition, and fail-safe control of fuel cut is performed based on the determined failure result and the output failure signal. Control method when the engine warning light fails.