JPH0751915B2 - Internal combustion engine controller - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an internal combustion engine control device capable of continuously controlling an internal combustion engine even if an abnormality occurs in a signal indicating the speed of the internal combustion engine. Regarding

(Prior Art) Conventionally, an electronic control device has been used that electronically controls the fuel injection amount, fuel injection timing, exhaust gas recirculation rate (EGR rate), etc. of an internal combustion engine for vehicles. ing. In this type of electronic control device, it has a sensor that electrically detects the value of each parameter indicating the operating state of the internal combustion engine, and the target control amount according to the output result of each sensor is a required value. Controlled to be. In such a control system, the engine speed becomes an important factor that indicates the operating condition of the engine at that time, and therefore, the internal combustion engine rotation sensor that outputs a signal for indicating the engine rotation state fails in particular. Then, control falls into a completely impossible state. In particular, if a mechanical governor mechanism is used to control the fuel injection amount and the fuel injection timing control, EGR rate control, etc. are electronically controlled, if this rotation sensor fails However, the control of the fuel injection amount is normally performed, but the electronically controlled portion such as the fuel injection timing is controlled for the state where the engine speed is zero, and the control state of the engine is extremely low. It becomes a balance, a large amount of harmful components are discharged into the exhaust gas, and in some cases, problems such as damage to the engine occur.

In order to solve this problem, in an apparatus including a sensor that outputs a signal related to the rotational speed of the engine, such as a needle valve lift sensor that detects the lift state of the needle valve of the fuel injection valve, the engine speed sensor has failed. In this case, a configuration in which a signal from a sensor such as a needle valve lift sensor is used for backup has been disclosed (Japanese Utility Model Laid-Open No. 57-49531).

(Problems to be Solved by the Invention) However, the proposed configuration is applied only to a device including a sensor having a function equivalent to that of a rotation speed sensor, such as a needle valve lift sensor. However, it has a problem that its application range is narrow.

The object of the present invention is therefore to provide a malfunction of the rotation sensor if it does not have a sensor, such as a needle valve lift sensor, but is equipped with means for detecting the intake air quantity and means for detecting the magnitude of the load. Another object of the present invention is to provide an internal combustion engine control device capable of backing up the internal combustion engine.

(Means for Solving Problems) A feature of the present invention for solving the above problems is that a first signal related to a rotation speed of an internal combustion engine and a second signal related to an intake air amount of the internal combustion engine. And means for calculating and outputting required control data in response to at least a third signal related to the load of the internal combustion engine, and control for performing required control of the internal combustion engine in response to the control data. An internal combustion engine controller comprising: means for detecting an abnormality of the first signal; and outputting a preliminary rotational speed signal related to the rotational speed of the internal combustion engine based on the second and third signals. Means for calculating and outputting backup data for backup of the required control based on the preliminary rotation speed signal, and the first means in response to the detecting means.
And a means for supplying the backup data to the control means instead of the control data when a signal abnormality is detected.

(Operation) It is known that the amount of intake air to the internal combustion engine changes according to the rotational speed of the engine, and the relationship between the two changes according to the load state of the internal combustion engine at that time. That is, the relationship ES = (Ai, L) is established between the engine speed ES, the intake air amount Ai, and the load L. The output means outputs a preliminary speed signal indicating the engine speed at each time based on the above relational expression.

When the first signal becomes abnormal, the above-described preliminary rotation speed signal is used instead of the first signal for controlling the internal combustion engine, so that the control of the internal combustion engine is backed up even if the first signal falls into an abnormal state. Can be performed by a preliminary rotation speed signal based on signals related to the intake air amount and the engine load, respectively.

(Embodiment) FIG. 1 shows an embodiment of an internal combustion engine controller according to the present invention. In the illustrated embodiment, the internal combustion engine controller 1 includes a diesel engine 2 and a fuel injection pump 3 connected to the diesel engine 2 for injecting fuel to the diesel engine 2 for injecting fuel. It is a device for electronically controlling the advance angle and the exhaust gas recirculation rate (EGR rate), and includes a controller 4 configured by using a microcomputer. Controller 4
Receives a signal indicating the operating state of the internal combustion engine device from each sensor described later, and based on these signals, each of the injection advance and the EGR rate becomes an optimum value corresponding to the operating state of the internal combustion engine device at that time. To control electronically.

First, the structure of the fuel injection pump 3 will be described. The fuel injection pump 3 is a mechanical governor device (not shown).
And a hydraulic timer 32, which is a distributed fuel injection pump, and has a rotation sensor 33 that outputs a pulse train signal S ₁ having a cycle corresponding to the rotation speed of the fuel injection pump 3 at each time. The fuel injection pump 3 is driven by the diesel engine 2. Therefore, the pulse train signal S _{1 also} serves as a signal indicating the rotational speed of the diesel engine 2 at each time.
The hydraulic timer 32 includes a timing valve 34 that operates in response to a timer control signal C ₁ output from the controller 4, and the opening degree of the timing valve 34 is adjusted by the timer control signal C ₁ so that Fuel injection pump 3
The fuel injection advance angle of is adjusted. Reference numeral 35 indicates that
It is an actual advance sensor for detecting the actual advance value from the position of a timer piston (not shown) provided in the timer 32 at any given time. Actual advance signal S ₂ indicating the actual advance value at each moment
Is output. The fuel injection pump 3 further includes a lever position sensor 37 for detecting the position of the control lever 36.
The lever position sensor 37 outputs a position signal S ₃ indicating the position of the control lever 36 at each moment. The actual advance signal S ₂ and the position signal S ₃ are input to the control unit 4, respectively.

Next, the fuel metered by the mechanical governor device supplies fuel to the fuel injection pump 3 at a timing determined by the timer 32.
The configuration of the diesel engine 2 supplied to each cylinder will be described below. The diesel engine 2 has an intake passage 21
Intake manifold 22 to connect the intake port of each cylinder
And an exhaust manifold 23 connected to the exhaust port of each cylinder. In order to perform so-called EGR control for returning a part of the exhaust gas to the intake side, a passage 24 for returning a part of the exhaust gas discharged from the exhaust manifold 23 to the intake side of the engine is provided with the exhaust manifold 23 and the intake manifold 22. The EGR valve 25, which is provided between the passage 24 and the intake manifold 22, adjusts the opening of the EGR valve 25.
The GR rate can be adjusted. An intake throttle valve 26 is arranged in the middle of the intake passage 21,
The EGR valve 25 and the intake throttle valve 26 are connected to electromagnetic valves 27 and 28, respectively. The solenoid valves 27 and 28 are connected to an accumulator 6 in which a negative pressure generated by a vacuum pump 5 driven by the diesel engine 2 is stored, and control signals C ₂ and C ₃ output from the controller 4 are supplied to the solenoid valves 27 and 28, respectively. In response, the opening of each of the solenoid valves 27, 28 is adjusted, whereby the operation amounts of the EGR valve 25 and the intake throttle valve 26 are adjusted.

To detect the desired operating conditions of the diesel engine 2 required for performing EGR control and or fuel injection advance angle control, a water temperature sensor 7 that outputs a detects the temperature of cooling water temperature signal S _w, the pressure of the atmosphere an atmospheric pressure sensor 8 for outputting atmospheric pressure signal S _a indicating the detected atmospheric pressure, an intake quantity sensor 9 that outputs an intake air amount signal S _i indicating the detected intake air amount of intake air amount of the diesel engine 2 Is equipped with a water temperature signal
The S _w , the atmospheric pressure signal S _a and the intake air amount signal S _i are input to the controller 4, respectively.

The controller 4 is further provided with a hydraulic signal S ₀ from the hydraulic switch 11 which is closed in response to the rotation of the diesel engine 2 to give the control unit 4 information as to whether or not the diesel engine 2 is rotating. Entered in
Further, a start signal S _s indicating whether or not the key switch 12 is at the start position is input from the key switch 12.

As will be described later, the controller 4 is configured to include a microcomputer, performs the necessary calculation based on the above-mentioned input signal, and controls the timing valve 34 of the timer 32 by controlling the control signals C ₁ and EGR rate. Control signal for
Outputs C ₂ and C ₃ . The controller 4 further determines whether or not any failure has occurred in the rotation sensor 33,
If a failure occurs in the rotation sensor 33, the display signal C _d is output to notify the occurrence of the failure and the failure display lamp 12 is turned on, and the control is continued even for the failure of the rotation sensor 33. The backup process can be carried out as if it were done later.

Next, the configuration of the controller 4 will be described. FIG. 2 is a block diagram showing the configuration of the controller 4. The controller 4 includes a central processing unit (CPU) 41 and a ROM
The pulse train signal S ₁ from the rotation sensor 33 is input to the first interface circuit 43, where the waveform is shaped and the pulse P is input to the CPU 41 as the pulse P. Start signal S _s and hydraulic signal S ₀
Is input to the second interface circuit 44, where it is level-matched and then input to the CPU 41. Actual advance signal S ₂ , position signal S ₃ , atmospheric pressure signal S _a , water temperature signal S _w , intake air amount signal
S _i is input to a multiplexer (MPX) 45, and these signals are selectively input to an analog-digital (A / D) converter 46 by a control signal MC output from the CPU 41, where each input signal is Converted to digital format signal, CPU4
1 is sent to the bus line 47 connecting the ROM 42 with 1.

A predetermined control program is stored in the ROM 42, and the CPU 41 performs control calculation based on each input information according to this control program, outputs control signals C _{1 to} C ₃ , and causes an obstacle to the rotation sensor 33. Output the detection signal C _d indicating whether or not the control signal C _{1 to} C ₃ and the detection signal C _d
Are taken out via amplifiers A _{1 to} A ₄ .

FIG. 3 shows a block diagram showing the control function of the control program executed by the CPU 41, and this block diagram comprises an EGR control unit 50 and an injection advance control unit 80.

The EGR control unit 50 further includes an EGR valve control unit A and an intake throttle valve control unit B. The EGR valve control unit A responds to the engine speed data N indicating the engine speed and the position signal S _3, and calculates and outputs the target intake air amount data D ₁ indicating the optimum EGR rate at that time. , Engine speed data N and water temperature signal _Sw
A water temperature correction calculation unit 52 for calculating and outputting water temperature correction data D _1w indicating a correction amount of the target intake air amount data D ₁ according to the cooling water temperature at each time, an engine speed data N and an atmospheric pressure signal S _a.
Further, it has an atmospheric pressure correction calculation unit 53 for calculating and outputting the atmospheric pressure correction data D _1A indicating the correction amount of the target intake air amount data D ₁ according to the value of the atmospheric pressure at each moment. The target intake air amount data D ₁ is added to the water temperature correction data D _1w and the atmospheric pressure correction data D _1A in the adding unit 54, whereby the water temperature and atmospheric pressure of the target intake air amount data D ₁ are corrected, and the adding unit The corrected first control target data DT ₁ is output from 54 and input to another adder 55. The adding section 55, the intake air amount signal S _i is input, the error data ED ₁ according to the difference between the target intake air amount indicated by the intake air amount and the first control target data DT ₁ represented by the intake air amount signal S _i Is output.
Data processing necessary for PID control is performed on the error data ED _{1 in the} PID calculation unit 56, and the first control data CD ₁ indicating the processing result is transmitted via the switch 57 to the pulse width modulation unit (PWM) 58. Entered in. The drive pulse signal having the duty ratio according to the first control data CD ₁ is the pulse width modulation section (PW
M) 58 outputs the control signal C ₂ to the solenoid valve 27 via the amplifier A ₂ shown in FIG. The solenoid valve 27 is ON / OFF controlled in response to the control signal C ₂ which is a pulse signal, and the average opening degree thereof is adjusted thereby, so that the target intake air amount according to the first control target data DT ₁ is obtained. EGR valve
Twenty-five adjustment operations are performed by closed loop control.

The switch 57 also includes a first backup data calculation unit 60.
Backup data BD _{1 from} is applied. When the failure detection unit 90, which will be described later, detects that a failure has occurred in the rotation sensor 33, the switch 57 is switched by the switching signal SS output from the failure detection unit 90 as shown by the dotted line, and the first control data CD instead of _1, the backup data BD ₁ is input to the pulse width modulation unit 58 from the first backup data calculating unit 60. First backup data calculation unit 60
The, the preliminary speed data N _a from the preliminary speed calculator 59 which operates in response to the switching signal SS and the position signal S ₃ is inputted.

An intake air amount signal S _i indicating the intake air amount of the diesel engine 2 is input to the preliminary speed calculation unit 59, and a position signal S ₃ is output as a signal indicating the load value of the diesel engine 2 at each time.
Has been entered. It is generally known that there is a predetermined functional relationship between the engine speed ES and its intake air amount A _i, and this relationship is affected by the magnitude of the load L of the engine, and therefore the engine speed is Generally, ES = (Ai, L) ... (1) can be expressed by the following formula.

FIG. 6 shows the relationship between the intake air amount A _i and the engine speed ES with the load L as a parameter, where L ₁
<L ₂ , ... <L _n .

Preliminary speed calculation unit 59 stores in advance map data determined by experiments based on the relational expression shown in equation (1), and the intake signal S _i and the position signal that are input signals are stored.
In response to S ₃ , a required map calculation is performed, and preliminary speed data N _a indicating the speed of the diesel engine 2 at each time is output.

The intake throttle valve control unit B controls the engine speed data N and the position signal S ₃
In response to preparative, a second calculation unit 61 for calculating output target intake air amount data D ₂ indicating the occasional optimum EGR rate, according to prevailing cooling water from the engine speed data N and the water temperature signal S _w From the water temperature correction calculation unit 62 that calculates and outputs the water temperature correction data D _2w indicating the correction amount of the target data D ₂ , the target data D according to the value of the atmospheric pressure at that time from the engine speed data N and the atmospheric pressure signal S _{a. An} atmospheric pressure correction calculation unit 63 that calculates and outputs the atmospheric pressure correction data D _2A indicating the correction amount of ₂ is included. The target intake air amount data D ₂ is added to the water temperature correction data D _2w and the atmospheric pressure correction data D _2A in the adding unit 64, whereby the water temperature and atmospheric pressure of the target intake air amount data D ₂ is corrected, and the adding unit The corrected second control target data DT ₂ is output from 64 and input to another adder 65. The addition section 65 is inputted intake air amount signal S _i, the error data ED ₂ according to the difference between the intake air amount indicated by the intake air amount and the second control target data DT ₂ indicated by the intake air amount signal S _i Is output. Data processing necessary for PID control is performed on the error data ED _2.
The second performed by the PID calculator 66 and showing the processing result.
The control data CD ₂ is transmitted via the switch 67 to the pulse width modulation section (P
WM) 68, a drive pulse signal having a duty ratio according to the second control data CD ₂ is output as a control signal C ₃ ,
It is applied to the solenoid valve 28 via the amplifier A ₃ shown in FIG.
The solenoid valve 28 is ON / OFF controlled in response to a control signal C ₃ which is a pulse signal, and the average opening degree is adjusted by this, so that the intake air amount according to the second control target data DT ₂ is obtained. The adjusting operation of the throttle valve 26 is performed by closed loop control.

The switch 67 also includes a second backup data calculation unit.
The backup data BD ₂ from 70 is applied, the switch 67 is switched by the switching signal SS from the failure detection unit 90 as shown by the dotted line, and the backup data BD ₂ is replaced by the pulse width of the second control data CD _2. It is input to the modulator 68. The second backup data calculation unit 70 is configured to output the backup data BD ₂ based on the preliminary speed data N _b from the preliminary speed calculation unit 69 that operates in response to the switch switching signal SS and the position signal S _3. ing.

This preliminary speed calculation unit 69 is also the above-mentioned preliminary speed calculation unit 59.
The configuration is similar to that of the intake air amount signal S _i and position signal.
Preliminary speed data N _b is output in response to S ₃ .

As can be seen from the above description, the intake air amount is adjusted by operating the EGR valve 25 with the control signal C ₂ and operating the intake throttle valve 26 with the control signal C _3. The intake throttle valve 26 is adjusted only when the intake air amount cannot be throttled by adjusting the EGR valve 25 to obtain a required intake air amount.

The injection advance angle control unit 80 responds to the engine speed data N and the position signal S ₃ and outputs a target injection advance angle data D ₃ indicating the optimum injection advance angle value at that time by a third operation unit 81. water temperature correction data D indicating the correction amount of the target injection advance angle data D ₃ in accordance with the times of cooling water from the engine speed data N and the water temperature signal S _w
Atmospheric pressure correction data indicating the correction amount of the target injection advance data D ₃ according to the value of atmospheric pressure at that time from the water temperature correction calculation unit 82 that calculates and outputs _3w and the engine speed data N and the atmospheric pressure signal S _a.
It has an atmospheric pressure correction calculation unit 83 for calculating and outputting D _3A . The target injection advance data D ₃ is added to the water temperature correction data D _3w and the atmospheric pressure correction data D _3A in the adding section 84, whereby the water temperature and atmospheric pressure of the target injection advance data D ₃ are corrected, and the adding section is added. Third control target data DT corrected from 84
₃ is output and input to another adder 85. The actual injection advance signal S ₂ is input to the adder 85, and the actual injection advance signal S ₂ is input.
The actual injection advance indicated by S _2, error data ED ₃ according to the difference between the target injection advance represented by the third control target data DT ₃ is output. Data processing necessary for PID control is applied to the error data ED ₃ by the PID calculation unit 86, and the second control data CD ₃ indicating the processing result is transmitted via the switch 87 to the pulse width modulation unit (PWM) 88. Drive pulse signal having a duty ratio according to the third control data CD ₃ is output as the control signal C ₁ and the amplifier A ₁ shown in FIG.
Is given to the timing valve 34 via. The timing valve 34 is turned on and off in response to the control signal C ₁ , whereby closed loop control is performed so that the actual injection advance angle matches the target injection advance angle.

The switch 87 also includes a third backup data calculation unit.
The backup data BD ₃ from 91 is applied, and it is detected that the rotation sensor 33 has failed in the failure detection unit 90 that operates as described later in response to the pulse train signal S ₁ and the hydraulic signal S ₀ . In this case, the switch 87 is switched by the switching signal SS as shown by the dotted line, and the third control data CD
Instead of ₃ , the backup data BD ₃ is input from the third backup data calculation unit 91 to the pulse width modulation unit 88. The third backup data calculation unit 91 uses the switch switching signal SS
Backup data BD on the basis of the preliminary speed data N _c from the preliminary speed calculator 89 which operates in response to the position signal S ₃ to the
It is configured to output ₃ .

This preliminary speed calculation unit 89 also receives the intake air amount signal S _i and the position signal.
The preliminary speed data N _c is output in response to S ₃ .

When the failure detection unit 90 detects a failure of the rotation sensor 33, a display signal C _d for failure display is output, and the display signal C _d is output.
C _d is configured to be applied to the failure indicator lamp 12 via the amplifier A ₄ shown in FIG. As a result, when the rotation sensor 33 fails, the failure indicator lamp 12 lights up.

The failure detection unit 90 will be described with reference to FIG. The failure detection unit 90 configures a rotation detection unit 92 that responds to the hydraulic signal S ₀ from the hydraulic switch 11 to detect whether the hydraulic switch 11 has been activated, and a pulse train signal S ₁ that responds to the pulse train signal S ₁ . And an output detection unit 93 that monitors the output state of the rotation sensor 33 based on the generation interval of each pulse to detect the presence or absence of an output from the rotation sensor 33. The detection results of the rotation detection unit 92 and the output detection unit 93 are input to the determination unit 94, and based on the detection results of both detection units 92 and 93, it is determined whether or not the rotation sensor 33 has a failure. Is performed. When the rotation detector 33 cannot detect that the rotation sensor 33 regularly outputs the pulses even though the rotation detector 92 confirms that the diesel engine 2 is rotating, the determination unit 94 determines whether the rotation sensor 33 is rotating. It is determined that a failure has occurred in the sensor 33, the switching signal SS is output and the switches 57, 67 and 87 are output.
While switching as shown by the dotted line in FIG. 3,
The display signal C _d is output and the failure display lamp 12 is turned on.
The failure indicator lamp 12 may be turned on by the switching signal SS.

In the circuit shown in FIG. 3, a preliminary speed calculation unit is separately provided for each control system, and preliminary speed data output from each preliminary speed calculation unit 59, 69, 89 is suitable for each control system. However, it is also possible to provide only one preliminary speed calculation unit and to provide the preliminary speed data obtained thereby in common to each control system.

FIG. 5 is a flow chart showing an example of a program that can achieve the same functions as those shown in FIGS. 3 and 4. This program includes a main program 100 that is repeatedly executed and an interrupt program 120 that is started in response to an output pulse from the rotation sensor 33.
And consists of. Interrupt program 120 is rotation sensor 3
The pulse train signal S ₁ obtained from 3 is activated in response to the generation of each pulse, and the generation time interval T of these pulses is calculated (step 121), and then step 1
At 22, the flag F ₂ indicating that this interrupt program is activated is set to "1", and the process returns to the main program 100.

The main program 100 is initialized in step 101, then various data is read in step 102, and thereafter, the rotational speed data ND is calculated based on the time interval T obtained in step 121 (step 103).

Next, the routine proceeds to step 104, where the flag F ₁ is "1".
Whether or not it is determined. The flag F ₁ is a flag that is set when it is determined that the rotation sensor 33 has a failure. In this case, the flag F ₁ is reset to “0” in the initialization step 101. Therefore, the determination result of step 104 is NO, and the process proceeds to step 105.
In step 105, it is determined whether or not there is an interrupt within 0.5 seconds, and if the determination result is NO, the process proceeds to step 106. In step 106, it is determined whether or not the flag F ₂ is “1”. If F ₂ = “1”, the process proceeds to step 107, in which the value of the rotation speed data ND is less than or equal to a predetermined value α. Whether or not it is determined. YES at step 107
In the case of, that is, when there is no interruption within 0.5 seconds, the interrupt program 120 has been operated previously, and the rotation speed is less than or equal to the predetermined value α, there is no abnormality in the rotation sensor 33 and the rotation of the engine Is determined to be stopped, the flag F ₂ is reset to “0” in step 108, and then ND is set in step 109.
= 0. Then, in step 110, the failure indicator lamp is turned off, the EGR rate is normally controlled (step 111), and the process returns to step 102.

If the determination result in step 105 is YES, that is, if there is an interrupt within 0.5 seconds, it is determined that the rotation sensor 33 has no abnormality, and therefore the process proceeds to step 111.

If the determination result in step 106 is NO, the process proceeds to step 112, and it is determined whether or not the hydraulic switch 11 is turned on. If the hydraulic switch 11 is on,
Since the engine is in a stopped state, the flag F ₂ is "0".
However, it is determined that the rotation sensor 33 has not failed, and the process proceeds to step 108.

If the determination result in step 112 is NO, it means that the engine is rotating, so in step 113 it is determined whether or not the hydraulic switch 11 remains off for a predetermined time T ₀ or more. Whether or not the rotation sensor 33 has a failure is determined. That is, when there is no interruption within 0.5 seconds, the flag F ₂ is “0”, and the hydraulic switch 11 is continuously OFF for T ₀ or more, it is determined that the rotation sensor 33 has a failure, and steps 114 to 117 are performed. Backup processing is executed. If the determination result in step 113 is NO, the rotation sensor 33 is determined to be normal, and the process proceeds to step 108.

In step 114, the flag F ₁ is set to "1", and then in step 115, the failure indicator lamp is turned on. Then, the process proceeds to step 116, where the position signal S ₃
The preliminary rotation speed data N _x is calculated from the intake air quantity signal S _i and the backup data using this preliminary rotation speed data N _x , and the EGR valve 25, the intake throttle valve 26 and the timer 3 are operated.
Control 2 is executed (step 117).

Also in this embodiment, the calculation of the preliminary rotation speed data N _x executed in step 116 is performed based on the equation (1). Here, only one kind of the preliminary rotation speed data N _x is calculated. The rotation speed data N _x is commonly used in control calculations that require speed data. Step
After performing the backup control by 117, the program will return to step 102.

When the flag F ₁ is set to "1" in step 114, the determination result in step 104 is YES, and steps 105, 106,
Without executing each determination for determining the failure of the rotation sensor 33 in 112, 113, the process proceeds to step 114,
Perform predetermined backup control. This backup control continues until the operation of the engine is stopped.

According to the above configuration, the execution state of the interrupt program due to the pulses forming the pulse train signal S ₁ output from the rotation sensor 33 is monitored, and an abnormality (including stoppage of pulse generation) occurs in this pulse interval. If the hydraulic switch 11
Whether the engine is rotating is judged from the on / off state of the engine, and the rotation sensor 33 has failed only when the execution of the interrupt program is abnormal despite the rotation of the engine. Judged as something.

Then, when it is detected that the rotation sensor 33 has failed, backup data is supplied instead of the normal control data, and the operation control of the diesel engine 2 can be continued without any trouble. As described above, the failure of the rotation sensor 33 is determined by detecting whether the engine is actually rotating based on the output state of the pulse from the rotation sensor 33 and the operating state of the hydraulic switch 11 and the like. Since the failure determination of the rotation sensor 33 is performed based on the detection result, the failure of the rotation sensor 33 can be detected not only after the complete explosion of the engine but also during the cranking of the engine. Therefore,
When the rotation sensor 33 fails, the backup control can always be performed regardless of the operating state of the engine, which is particularly convenient for the internal combustion engine device in which the control is partially electronic. is there.

In the above embodiment, the on / off state of the hydraulic switch 11 is detected to determine whether the diesel engine 2 is rotating. However, the on / off state of the hydraulic switch 11 is detected. Alternatively, or in addition to this,
Based on the actual injection advance signal S ₂ indicating the movement of the timer piston (not shown) in the timer 32, it is detected whether or not the timer piston has moved from a predetermined position corresponding to the stop of the engine, and based on this detection result Alternatively, it may be determined whether or not the diesel engine 2 is rotating. In addition, the actual injection quantity signal when cranking time and complete combustion using instead of the position signal S ₃ indicating the position of the control lever 36, since the always fuel injection amount is greater than zero, using the actual injection quantity signal Then, the determination as to whether or not the diesel engine 2 is in the rotating state may be performed alone or in combination with the above-described other determination results.

(Effects) According to the present invention, as described above, the preliminary speed signal indicating the speed of the engine at that time is obtained from the signal related to the intake air amount and the signal related to the engine load, and the normal engine speed detector is used. If there is a problem with the output of, the backup speed signal can be used to perform backup control of the engine.
This is especially useful in the case of a device that does not include a substitute sensor similar to a rotation detection sensor such as a needle valve lift sensor, and can significantly improve the control reliability.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of an internal combustion engine control device equipped with a rotation sensor failure detection device according to the present invention, and FIG. 2 is a block diagram showing the hardware configuration of the controller 4 shown in FIG. FIG. 3 is a block diagram showing the control function of the controller shown in FIG. 1, FIG. 4 is a block diagram showing the basic function of the failure detection unit shown in FIG. 3, and FIG. 5 is a failure detection shown in FIG. FIG. 6 is a flowchart showing an example of a program when a function equivalent to that of the unit is realized by a microcomputer, and FIG. 6 is a graph showing an example of the relationship between the engine speed, the intake air amount, and the engine load. 1 ... Internal combustion engine control device, 2 ... Diesel engine, 3 ...
... Fuel injection pump, 4 ... Controller, 11 ... Hydraulic switch, 32 ... Hydraulic timer, 33 ... Rotation sensor, 37 ...
… Lever position sensor, 90 …… Failure detection section, 92 …… Rotation detection section, 93 …… Output detection section, 94 …… Discrimination section, S ₁ …… Pulse train signal, S ₀ …… Hydraulic signal, SS …… Switch Signal, S _i …… Intake amount signal, S ₃ …… Position signal, N _a , N _b , N _c …… Preliminary speed data.

Claims (1)

[Claims] 1. A first signal related to the rotational speed of the internal combustion engine, and a second signal related to the intake air amount of the internal combustion engine,
Means for computing and outputting required control data at least in response to a third signal related to the load of the internal combustion engine; and control means for performing required control of the internal combustion engine in response to the control data. An internal combustion engine control device comprising: a detection unit that detects an abnormality of the first signal; and a unit that outputs a preliminary rotation speed signal related to the rotation speed of the internal combustion engine based on the second and third signals. And means for computing and outputting backup data for backup of the required control based on the preliminary rotation speed signal, and replacing the control data when an abnormality of the first signal is detected in response to the detecting means. And a means for supplying the backup data to the control means.