JP2910411B2 - Control device for internal combustion engine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an internal combustion engine mounted on an automobile, for example, and more particularly to a control device for executing various control contents such as a fuel injection amount and a fuel injection timing related to the operation of the internal combustion engine. is there.

[0002]

2. Description of the Related Art Hitherto, various techniques have been proposed for executing the control contents such as the fuel injection amount and the fuel injection timing of an internal combustion engine such as a gasoline engine or a diesel engine. For example, in a diesel engine,
A so-called electronically controlled diesel engine for electronically controlling a fuel injection pump has already been put into practical use, and various control techniques related thereto have been proposed.

[0003] For example, Japanese Patent Application No. 4-283 filed by the present applicant.
No. 56 proposes a technique aimed at improving controllability of a fuel injection amount in an electronically controlled diesel engine.

According to this technique, a crank for accurately controlling a target spill timing which is determined for each cycle in accordance with an operation state at a time, that is, a timing at which fuel injection from a fuel injection pump to a diesel engine is to be terminated. An angle detection method is disclosed. Here, a disk-shaped pulsar, which is rotated in conjunction with a crankshaft of a diesel engine and has a plurality of protrusions on the outer periphery, is attached to the fuel injection pump. In addition, the fuel injection pump is provided with a rotation speed sensor including an electromagnetic pickup coil so as to face the outer surface of the pulsar. When the pulsar is rotated, the rotation speed sensor detects the passage of each projection on the outer peripheral surface of the pulsar, and outputs an engine rotation pulse signal for each constant crank angle. Then, based on the input of the pulse signal, the electronic control unit (ECU) calculates the number of pulse signals required from a reference position of a series of pulse signals to a target crank angle corresponding to a target spill timing to be detected and one pulse. An angle less than the required angle is required. In the ECU, the surplus angle is converted into time, and the target spill timing is determined based on the converted time and the number of obtained pulse signals. In addition, in the ECU, the current cycle (“18
0 ° CA ”cycle), the previous cycle (the previous“ 1 ”) having the same crank angle phase as the target spill timing
The required time for one pulse in the cycle of “80 ° CA”) is obtained. In addition, the ECU calculates the required time (pulse time) of the two arbitrarily selected pulse signals between the target spill time in the previous cycle and the current cycle, and calculates the difference (instantaneous time) between the two pulse times. (Time difference) is obtained as a value for predicting a change in the engine rotation speed in the current cycle. Furthermore, in the ECU,
The instantaneous time difference is corrected according to a change in the fuel injection timing at that time with respect to a certain reference fuel injection timing, and the remainder angle is converted into a time based on the corrected instantaneous time difference and the required time for one pulse already obtained. Is done. Then, based on the number of pulse signals required until the target spill timing and the time conversion value of the surplus angle, the target spill timing at which the fuel injection from the fuel injection pump should be terminated is controlled.

[0005]

However, in the prior art, when the pulsar and the rotational speed sensor are mounted on the fuel injection pump, they may be fixed in a state where they are slightly shifted from their proper mounting positions. Therefore, in that case, the crank angle corresponding to the output position of each pulse signal matched with the regular mounting position and the crank angle corresponding to the output position of each pulse signal actually output from the rotation speed sensor are determined. There was a gap between them.
Therefore, as shown in FIG. 17, the positions of the arbitrary pulse signals for which the two pulse times are to be obtained are set to “8” and “2” by the number of the pulse counter CNIRQ, respectively.
In this case, as shown in FIG. 17 (A), the angle is shifted to the retard side by an angle difference Δθ from the normal target position shown in FIG. 17 (A), or the angle is advanced as shown in FIG. 17 (C). Angle difference to side Δ
It was shifted by θ. Therefore, when an attempt is made to predict the change in the engine rotation speed in the current cycle from the instantaneous time difference TN between the two pulse times, an error occurs in the prediction due to the difference between the position of each pulse signal and the crank angle. became. As a result, the time conversion accuracy of the surplus angle may be impaired, and the controllability of the fuel injection amount may be deteriorated. In addition, since the prediction error differs for each fuel injection pump due to the difference in the displacement of the pulsar and the rotation speed sensor, the controllability of the fuel injection amount differs for each diesel engine.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described circumstances, and has as its object to convert a required angle up to a target crank angle corresponding to an execution timing of required control contents of an internal combustion engine into a constant crank angle. Regardless of the mounting position deviation from the beginning according to the rotation detecting means that detects the rotation for each angle and outputs it as a pulse signal, it is possible to accurately convert the time taking into account the change in the rotation speed of the internal combustion engine, Accordingly, it is an object of the present invention to provide a control device for an internal combustion engine that can accurately control the execution timing of required control contents.

[0007]

According to the present invention, there is provided a control device for an internal combustion engine which executes various control contents relating to the operation of an internal combustion engine M1, as shown in FIG. Rotation detecting means M3 for detecting rotation at a constant crank angle based on rotation of the crankshaft M2 in the internal combustion engine M1 and outputting it as a pulse signal.
And calculating a required angle from a reference position of the series of pulse signals to a target crank angle corresponding to an execution time of required control contents, based on the pulse signals output from the rotation detecting means M3 in the current cycle of the internal combustion engine M1. And a constant corresponding to an arbitrary plurality of pulse signals of a series of pulse signals output from the rotation detecting means M3 between the target crank angle in the previous cycle and the target crank angle in the current cycle. A predictive correction value calculating means M5 for calculating an angular time required to rotate by the crank angle, and calculating a predictive correction value for predicting a change in the rotational speed of the internal combustion engine M1 based on the plurality of angular times; In the calculation by the value calculating means M5, the phase of the actual pulse signal output from the rotation detecting means M3 is A calculation correction means M6 for correcting the calculation of the predicted correction value in accordance with a phase difference previously confirmed between the phase of a regular pulse signal to be output in accordance with the rotation of the rank shaft M2, and an angle calculation means M4 Is converted into a time based on the angle time calculated corresponding to the predetermined crank angle and the predicted correction value corrected and calculated by the calculation correction means M6 in the prediction correction value calculation means M5. Based on the time conversion value by the time conversion means M7 and the angle time conversion means M7, the internal combustion engine M1
And execution control means M8 for controlling the execution timing of the required control contents related to the operation of the vehicle.

[0008]

According to the above arrangement, as shown in FIG. 1, during operation of the internal combustion engine M1, the rotation detecting means M3 detects rotation at a constant crank angle based on the rotation of the crankshaft M2 and outputs a pulse signal. Is output as

At this time, the angle calculating means M4 calculates a required angle from a certain reference position of the series of pulse signals in the current cycle to a target crank angle corresponding to a timing of executing required control contents. The predictive correction value calculating means M5 needs to rotate by a constant crank angle between the target crank angle in the previous cycle and the target crank angle in the current crank in response to a plurality of arbitrary pulse signals in a series of pulse signals. The angle times are respectively calculated. Further, the prediction correction value calculating means M5
A prediction correction value for predicting a change in the rotation speed of the internal combustion engine M1 is calculated based on the plurality of angle times. Here, when the prediction correction value calculation means M5 performs the calculation, the calculation correction means M
According to 6, the calculation of the predicted correction value is corrected in accordance with the phase difference previously confirmed between the phase of the actual pulse signal and the phase of the normal pulse signal.

Further, in the angle time converting means M7, the required angle calculated by the angle calculating means M4 is obtained by calculating the angle time obtained corresponding to the predetermined crank angle and the predicted correction value calculating means M5 by the calculating and correcting means M6. The time is converted based on the corrected and calculated predicted correction value. Then, the execution control unit M8 controls the execution timing of the required control content related to the operation of the internal combustion engine M1 based on the time conversion value by the angle time conversion unit M7.

Accordingly, when the predicted correction value calculating means M5 calculates the predicted correction value of the change in the rotational speed of the internal combustion engine M1, the calculation is based on the phase difference between the actual pulse signal phase and the normal pulse signal phase. , The error of the predicted correction value due to the displacement of the rotation detecting means M3 is eliminated. Therefore, the angle time conversion means M7
Then, the required angle is converted into time after the prediction of the rotation speed change is optimized based on the predicted correction value. Further, the execution control means M8 optimizes the execution timing based on the time conversion value.

[0012]

【Example】

(First Embodiment) A first embodiment in which the control device for an internal combustion engine according to the present invention is embodied in an electronically controlled diesel engine of an automobile will be described in detail with reference to FIGS.

FIG. 2 is a schematic structural view of a diesel engine system with a supercharger according to this embodiment, and FIG. 3 is a sectional view showing the distribution type fuel injection pump 1. The fuel injection pump 1 includes a drive pulley 3 which is drivingly connected to a crankshaft 40 of a diesel engine 2 as an internal combustion engine via a belt or the like. The fuel injection pump 1 is driven by the rotation of the drive pulley 3,
Fuel is fed under pressure to each fuel injection nozzle 4 provided for each cylinder (four cylinders in this case) of the diesel engine 2 to perform fuel injection.

In the fuel injection pump 1, the drive pulley 3 is attached to a tip of a drive shaft 5.
In the middle of the drive shaft 5, there is provided a fuel feed pump (developed at 90 degrees in this figure) 6 composed of a vane type pump. Further, a disk-shaped pulser 7 is attached to the base end side of the drive shaft 5. As shown in FIG. 5, on the outer peripheral surface of the pulsar 7, the same number of cylinders of the diesel engine 2, that is, four missing teeth 7a (eight in total) in this embodiment are formed at equal angular intervals. Further, 14 projections 7b (56 in total) are formed at equal angular intervals between each missing tooth 7a. The base end of the drive shaft 5 is connected to the cam plate 8 via a coupling (not shown).

A roller ring 9 is provided between the pulsar 7 and the cam plate 8, and a plurality of cam rollers 10 facing the cam face 8a of the cam plate 8 are mounted along the circumference of the roller ring 9. I have. Cam face 8
a is provided as many as the number of cylinders of the diesel engine 2. The cam plate 8 is always urged and engaged with the cam roller 10 by the spring 11.

A base end of a fuel pressurizing plunger 12 is attached to the cam plate 8 so as to be integrally rotatable. The cam plate 8 and the plunger 12 are rotated in conjunction with the rotation of the drive shaft 5. That is, the rotational force of the drive shaft 5 is transmitted to the cam plate 8 via a coupling (not shown), so that the cam plate 8 rotates and engages with the cam roller 10 to rotate in the left-right direction by the same number as the number of cylinders. Is reciprocated. Further, the plunger 12 is reciprocally driven in the same direction while rotating with the reciprocation. That is, the plunger 12 is moved forward (lift) while the cam face 8a of the cam plate 8 rides on the cam roller 10 of the roller ring 9, and conversely, the plunger 1 is moved while the cam face 8a rides down the cam roller 10.
2 is reactivated.

The plunger 12 is fitted into a cylinder 14 formed in a pump housing 13, and a high pressure chamber 15 is formed between a tip surface of the plunger 12 and a bottom surface of the cylinder 14.
It has become. Also, on the outer periphery of the tip side of the plunger 12,
The same number of intake grooves 16 and distribution ports 17 as the number of cylinders of the diesel engine 2 are formed. In addition, these suction grooves 16
And the pump housing 13 corresponding to the distribution port 17.
Is formed with a distribution passage 18 and a suction port 19.

When the drive shaft 5 is rotated and the fuel feed pump 6 is driven, fuel is supplied from a fuel tank (not shown) into the fuel chamber 21 via the fuel supply port 20. Also, during the suction stroke in which the plunger 12 is moved back and the high-pressure chamber 15 is depressurized, the suction groove 1
The fuel is introduced from the fuel chamber 21 to the high-pressure chamber 15 when one of the ports 6 communicates with the suction port 19. On the other hand, during the compression stroke in which the plunger 12 is moved forward and the high-pressure chamber 15 is pressurized, fuel is pressure-fed from the distribution passage 18 to the fuel injection nozzle 4 of each cylinder and injected.

The pump housing 13 is provided with a spill passage 22 for fuel spill that connects the high-pressure chamber 15 and the fuel chamber 21. An electromagnetic spill valve 23 for adjusting fuel spill from the high-pressure chamber 15 is provided in the middle of the spill passage 22. The electromagnetic spill valve 23 is a normally open type valve. When the coil 24 is not energized (off), the valve body 25 is opened and fuel in the high-pressure chamber 15 is spilled to the fuel chamber 21. When the coil 24 is energized (turned on), the valve body 25 is closed, and the spill of fuel from the high-pressure chamber 15 to the fuel chamber 21 is stopped.

Therefore, by controlling the energization time of the electromagnetic spill valve 23, the valve 23 is controlled to close and open, and the spill of fuel from the high-pressure chamber 15 to the fuel chamber 21 is adjusted. Then, by opening the electromagnetic spill valve 23 during the compression stroke of the plunger 12, the fuel in the high-pressure chamber 15 is reduced in pressure, and the fuel injection from the fuel injection nozzle 4 is stopped. That is, even when the plunger 12 moves forward, the fuel pressure in the high-pressure chamber 15 does not increase while the electromagnetic spill valve 23 is open, and the fuel injection from the fuel injection nozzle 4 is not performed. Further, during the forward movement of the plunger 12, by controlling the timing of closing and opening the electromagnetic spill valve 23, the end timing of the fuel injection from the fuel injection nozzle 4 is adjusted, and the fuel injection amount is controlled. .

Below the pump housing 13, there is provided a timer device (developed at 90 degrees in this figure) 26 for controlling the fuel injection timing to the advance side or the retard side. The timer device 26 changes the position of the roller ring 9 with respect to the rotation direction of the drive shaft 5, thereby changing the timing at which the cam face 8a engages with the cam roller 10, that is, the reciprocating drive timing of the cam plate 8 and the plunger 12. It is for.

The timer device 26 is driven by control hydraulic pressure. A timer housing 27, a timer piston 28 fitted in the housing 27, and a low pressure chamber 29 on one side of the timer housing 27 also serve as a timer. A timer spring 31 for urging the piston 28 toward the other pressurizing chamber 30 is provided. The timer piston 28 is connected to the roller ring 9 via a slide pin 32.

In the pressurizing chamber 30 of the timer housing 27,
The fuel pressurized by the fuel feed pump 6 is introduced. The position of the timer piston 28 (hereinafter, referred to as “timer piston position”) is determined based on the balance between the fuel pressure and the urging force of the timer spring 31. Further, by determining the timer piston position, the position of the roller ring 9 is determined, and the reciprocating timing of the plunger 12 via the cam plate 8 is determined.

The timer device 26 is provided with a timer control valve (TCV) 33 for adjusting the fuel pressure acting as the control oil pressure of the timer device 26. That is, the pressurizing chamber 30 and the low-pressure chamber 29 of the timer housing 27
4 and the TC in the middle of the communication passage 34.
V33 is provided. The TCV 33 is an electromagnetic valve whose opening and closing are controlled by a duty-controlled energization signal, and the fuel pressure in the pressurizing chamber 30 is adjusted by controlling the opening and closing of the TCV 33. By adjusting the fuel pressure, the lift timing of the plunger 12 is controlled, and the fuel injection timing from each fuel injection nozzle 4 is controlled to be advanced or retarded.

As shown in FIGS. 2, 3, and 5, a rotational speed sensor 35 composed of an electromagnetic pickup coil is mounted on the upper part of the roller ring 9 so as to face the outer peripheral surface of the pulser 7. The pulsar 7 and the rotation speed sensor 35 constitute a rotation detecting means. When the projection 7b of the pulsar 7 crosses the rotation detection unit, the rotation speed sensor 35 detects the passage of the protrusion and outputs a series of timing signals. That is, as shown in FIG. 7, the rotation speed sensor 35 outputs an engine rotation pulse signal for each constant crank angle (11.25 ° CA). At the same time, as shown in FIG. 7, the rotation speed sensor 35 detects a constant crank angle (33.75 ° C.) due to the missing tooth 7a.
An engine rotation pulse signal corresponding to A) is output as a reference position signal. The rotation speed sensor 35 outputs a series of engine rotation pulse signals as signals for obtaining the engine rotation speed NE. Here, the rotation speed sensor 3
5 is integrated with the roller ring 9 and outputs a reference engine rotation pulse signal to the plunger lift at a constant timing regardless of the control operation of the timer device 26.

In FIG. 7, a pulse counter CNI is used.
The number of RQs is the number of engine rotation pulse signals counted out from when a certain reference position signal is output until the next reference position signal is output with an initial value of “0”.
In addition, a period between a certain reference position signal and the next reference position signal corresponds to “180” corresponding to each cylinder of the diesel engine 2.
° CA ”.

Next, the diesel engine 2 will be described. In FIG. 2, in this diesel engine 2,
Cylinder bore 41, piston 42 and cylinder head 4
3, the main combustion chamber 44 corresponding to each cylinder is formed. A sub-combustion chamber 45 communicating with each of the main combustion chambers 44 is provided for each cylinder. Each sub-combustion chamber 45 is supplied with fuel injected from each fuel injection nozzle 4. Further, a well-known glow plug 46 as a start-up assist device is attached to each sub-combustion chamber 45.

The diesel engine 2 has an intake passage 47
And an exhaust passage 48 are provided. The intake passage 47 has a turbocharger 4 that constitutes a supercharger.
Nine compressors 50 are provided, and a turbine 51 of a turbocharger 49 is provided in the exhaust passage 48.
The exhaust passage 48 is provided with a waste gate valve 52 for adjusting the supercharging pressure PiM. As is well known, the turbocharger 49 uses the energy of the exhaust gas to rotate the turbine 51, and rotates the compressor 50 on the same axis as the turbine 51 to increase the pressure of the intake air.
By this action, a high-density air-fuel mixture is sent into the main combustion chamber 44 to burn a large amount of fuel, and the diesel engine 2
Output is increased.

In the diesel engine 2, an exhaust gas recirculation valve passage (E) for recirculating a part of the exhaust gas in the exhaust passage 48 to the intake passage 47 is provided.
(GR passage) 54 is provided. And the EGR
An EGR valve 55 for adjusting the exhaust gas recirculation amount (EGR amount) is provided in the middle of the passage 54. Also, the EG
In order to open and close the R valve 55, an electric vacuum regulating valve (EVRV) 56 whose opening is adjusted is provided. And EVRV
When the EGR valve 55 is opened and closed by the 56, the amount of EGR guided from the exhaust passage 48 to the intake passage 47 through the EGR passage 55 is adjusted.

Further, in the middle of the intake passage 47, a throttle valve 58 which is opened and closed in conjunction with the depression amount of an accelerator pedal 57 is provided. A bypass passage 59 is provided in parallel with the throttle valve 58, and a bypass throttle valve 60 is provided in the bypass passage 59.
The bypass throttle valve 60 is controlled to open and close by an actuator 63 having a two-stage diaphragm chamber driven by ON / OFF control of two vacuum switching valves (VSV) 61 and 62. The opening and closing of the bypass throttle valve 60 is controlled in accordance with various operation states. For example, it is controlled to a half-open state during idle operation to reduce noise and vibration, to a fully opened state during normal operation, and to a fully closed state during smooth operation to stop smoothly.

The electromagnetic spill valve 2 provided on the fuel injection pump 1 and the diesel engine 2 as described above
3, the TCV 33, the glow plug 46, the EVRV 56, and the VSVs 61, 62 are electronic control units (hereinafter simply referred to as “EC
U ") 71, and their drive timings are controlled by the ECU 71.

As sensors for detecting the operating state of the diesel engine 2, the following various sensors are provided in addition to the rotation speed sensor 35 described above. That is, near the air cleaner 64 provided at the entrance of the intake passage 47, an intake air temperature sensor 72 for detecting the intake air temperature THA is provided. Further, an accelerator sensor 73 for detecting an accelerator opening ACCP corresponding to the load of the diesel engine 2 from the open / close position of the throttle valve 58 is provided. In the vicinity of the intake port 53, the turbocharger 4
9, the intake air pressure after supercharging, ie, the supercharging pressure P
An intake pressure sensor 74 for detecting iM is provided. Further, a water temperature sensor 75 for detecting the cooling water temperature THW of the diesel engine 2 is provided. Further, a crank angle sensor 76 for detecting a rotation reference position of the crankshaft 40, for example, a rotation position of the crankshaft 40 with respect to a top dead center of a specific cylinder is provided. Further, the transmission (not shown) is provided with a vehicle speed sensor 77 for detecting a vehicle speed (vehicle speed) SPD by turning on / off a reed switch 77b by a magnet 77a rotated by rotation of the gear. Further, a transmission (not shown) is provided with a vehicle speed sensor 77 for detecting a vehicle speed (vehicle speed) SPD. This vehicle speed sensor 77
Is provided with a magnet 77a rotated by rotation of a gear in a transmission, and the magnet 77a
The reed switch 77b is turned on / off by the
PD is detected.

The fuel injection pump 1 of this embodiment has
A correction resistor 78 for correcting a machine difference that differs for each fuel injection pump 1 is externally provided. This correction resistor 78 is a normal resistor to be output in accordance with the phase of the actual engine rotation pulse signal output from the rotation speed sensor 35 and the rotation of the crankshaft 40, that is, the rotation of the drive shaft 5. Has a resistance value corresponding to the timing correction voltage VRT determined according to a phase difference previously confirmed between the phase of the engine rotation pulse signal and the phase of the engine rotation pulse signal.
The correction resistor 78 is mounted before shipment of the fuel injection pump 1, and its timing correction voltage VR
The resistance value according to T is determined in an adjustment stage before shipment.

In this embodiment, the ECU 71 controls the angle calculation means, the predicted correction value calculation means, the calculation correction means,
Angle time conversion means and execution control means are configured,
The above-described sensors 72 to 77 and the correction resistor 78 are connected to the ECU 71, respectively.
Is connected. In addition, the ECU 71 controls the sensors 35, 7
The electromagnetic spill valve 23, the TCV 33, the glow plug 46, the EVRV 56, and the respective VSVs 61, 62 are suitably controlled based on the detection signals output from 2 to 77 and the resistance value of the correction resistor 78.

Next, the configuration of the ECU 71 will be described with reference to the block diagram of FIG. The ECU 71 has a central processing unit (CPU) 81, a read-only memory (RO) storing a predetermined control program, a map, and the like in advance.
M) 82, a random access memory (RAM) 83 for temporarily storing the operation results and the like of the CPU 81, a backup RAM 84 for storing previously stored data, and the like, and a bus 87 for connecting these components to the input port 85 and the output port 86.
As a logical operation circuit.

The input port 85 is provided with the aforementioned intake air temperature sensor 72, accelerator sensor 73, intake air pressure sensor 74, and water temperature sensor 75 in buffers 88, 89, 90, 91, respectively.
They are connected via a multiplexer 93 and an A / D converter 94. The input port 85 has a correction resistor 78.
Are connected via a multiplexer 93 and an A / D converter 94. Similarly, the input port 85 is connected to the rotation speed sensor 35, the crank angle sensor 76, and the vehicle speed sensor 77 via a waveform shaping circuit 95.
Then, the CPU 81 reads, as input values, the detection signals of the sensors 35, 72 to 77, etc., which are input via the input port 85, and the timing correction voltage VRT of the correction resistor 78. The output port 86 is connected to each drive circuit 96,
97, 98, 99, 100, 101, the electromagnetic spill valve 23, the TCV 33, the glow plug 46, the EVRV 56
And the VSVs 61 and 62 are connected.

Then, the CPU 81 controls each of the sensors 35 and 72.
, The electromagnetic spill valve 23, T
CV33, glow plug 46, EVRV56 and each VS
V61, 62, etc. are suitably controlled. The CPU 81 in this embodiment has a function of a free running counter.

Next, the operation of the crank angle detection for controlling the fuel injection amount executed by the ECU 71 will be described with reference to FIGS. First, the flowchart of FIG. 8 shows an “NE interrupt routine” that is interrupted by a rising edge of an engine rotation pulse signal for the engine rotation speed NE input from the rotation speed sensor 35, among the processes executed by the ECU 71. .

When the process proceeds to this routine, first, in step 101, the number of the pulse counter CNIRQ is added by "1", and the addition result is set as a new number of the pulse counter CNIRQ.

Subsequently, at step 102, the previous interruption time ZNEIN is subtracted from the current interruption time (current time) NEIN, and the result of the subtraction is set as the current pulse time TNINT (i). The current time NEIN and the previous interrupt time ZNEIN refer to the time measured by the above-described free running counter.

In step 103, the engine rotation speed NE is read based on the detection signal of the rotation speed sensor 35, and the timing correction voltage VRT obtained from the resistance value of the correction resistor 78 is read.

Next, at step 104, it is determined whether or not the engine rotation pulse signal due to the current interruption is a reference position signal. Specifically, the current pulse time TNINT (i) obtained in step 102 is the same as the previously obtained pulse time TNINT (i-1).
It is determined whether it is 5 times or more. Here, if the current pulse time TNINT (i) is not equal to or more than "1.5" times that of the previous time, it is determined that the current time is not the reference position signal, and the process directly proceeds to step 106. On the other hand, when the current pulse time TNINT (i) is equal to or more than “1.5” times the previous pulse time, in step 105, the number of the pulse counter CNIRQ is reset to “0”, and the process proceeds to step 106. I do.

Then, step 104 or step 10
5 and in step 106, the current time N
EIN is set as the previous interrupt time ZNEIN. Next, in step 107, it is determined whether or not the number of the pulse counter CNIRQ determined this time is “2”. If the number of pulse counters CNIRQ is not “2”, it is determined in step 108 whether or not the number of pulse counters CNIRQ is “8”. Here, if the number of the pulse counter CNIRQ is not “8” in step 108, the subsequent processing is temporarily terminated. If the number of the pulse counter CNIRQ is “8” in step 108, the current pulse time TNINT (i) obtained in step 102 corresponds to “8” of the pulse counter CNIRQ in step 109. It is set as the instantaneous time TN8 as an angle time to perform, and the subsequent processing is temporarily ended.

On the other hand, if the number of pulse counters CNIRQ determined this time is “2” in step 107, the current pulse time TNINT (i) determined in step 102 is replaced by a pulse counter in step 110. It is set as an instantaneous time TN2 as an angle time corresponding to “2” of CNIRQ.

Here, "2", "8" of the pulse counter CNIRQ determined in steps 107 and 108.
Is located between the end time of the fuel injection in the previous cycle, that is, the target spill time of the current cycle and the target spill time of the current cycle. The positions "2" and "8" of the pulse counter CNIRQ correspond to positions where the same instantaneous rotation speed is obtained when the change in the engine rotation speed NE is substantially the same between the previous cycle and the current cycle. doing.

Next, in step 111, the instantaneous time TN8 obtained in step 108 is subtracted from step 110
Is subtracted, and the result of the subtraction is set as the instantaneous time difference TN. That is, as shown in FIG. 6, the instantaneous time difference TN before being corrected by the later-described timing correction time ΔTNVRT is obtained.
The instantaneous time TN is a value representing a change in the engine rotation speed NE, that is, a rotation fluctuation of the diesel engine 2.

Subsequently, in step 112, a missing tooth position correction value tAVRT for timing correction is calculated based on the timing correction voltage VRT read in step 103. As shown in FIG. 9, the missing tooth position correction value tAVRT is obtained by referring to a map in which the relationship between the missing tooth position correction value tAVRT and the timing correction voltage VRT is predetermined. In this map, the missing tooth position correction value tAVRT is set to increase substantially in proportion to the timing correction voltage VRT.

In step 113, a timing correction time ΔTNVRT is calculated based on the missing tooth position correction value tAVRT obtained in step 112 and the engine rotational speed NE read in step 103. As shown in FIG. 10, the timing correction time ΔTNVRT is obtained by referring to a map in which the relationship between the missing tooth position correction value tAVRT and the timing correction time ΔTNVRT with respect to the engine speed NE is determined in advance. here,
The missing tooth position correction value tAVRT is obtained from the timing correction voltage VRT correlated with the phase difference of the engine rotation pulse signal actually output from the rotation speed sensor 35 as described above. In this map, since the rotation fluctuation increases as the engine rotation speed NE decreases, "16
When the engine speed NE is kept constant at less than “00 rpm”, the timing correction time ΔTNVRT is set to increase substantially in proportion to the missing tooth position correction value tAVRT. Also, as the rotation speed becomes lower, the timing correction time Δ
TNVRT is set large. Furthermore, "1600
rpm ”or higher, the timing correction time ΔTNV
RT is set to be small (almost “0”). Therefore, the timing correction time ΔTNVRT is obtained as a time reflecting the phase difference between the actually output engine rotation pulse signals and the magnitude of the engine rotation speed NE.

In step 114, the above-mentioned instantaneous time difference TN is corrected. See Step 1
Subtracting the timing correction time ΔTNVRT calculated in step 113 from the instantaneous time difference TN calculated in step 11;
The result of the subtraction is set as a new instantaneous time difference TN. Thus, in step 114, the instantaneous time difference TN
Is corrected, and the subsequent processing is temporarily terminated.

Next, a description will be given of a calculation process of the spill time TSPON and the spill timing pulse number CANGL performed using the instantaneous time difference TN obtained in the "NE interrupt routine" as described above.

The flowchart of FIG. 11 shows a processing routine for calculating the spill time TSPON and the number of spill timing pulses CANGL among the processing executed by the ECU 71, and is executed by interruption every predetermined time interval.

When the process proceeds to this routine, first, in step 201, the engine speed NE is determined based on the detection signals of the rotation speed sensor 35 and the accelerator sensor 73.
And the accelerator opening ACCP.

Subsequently, at step 202, the read engine speed NE and accelerator opening ACCP are read.
, The spill opening angle ANGSPV as the target crank angle corresponding to the timing for ending the current fuel injection, that is, the target spill timing. As shown in FIG. 12, the spill opening angle ANGSPV is a pulse counter CNIRQ.
, And corresponds to the angle from the generation of the engine rotation pulse signal which becomes “0” to the time when the electromagnetic spill valve 23 is opened.

Next, in step 203, the spill timing pulse number CANGL and its surplus angle θ REM are calculated by using the following equation (1). ANGSPV = 11.25 * CANGL + θREM (1) That is, in this calculation formula (1), as shown in FIG.
The spill opening angle ANGSPV is divided by the angle of “11.25 ° CA” corresponding to the angle of one pulse, the quotient is set as the spill timing pulse number CANGL, and the remainder is the remaining angle θ.
It is determined as REM. Here, the spill timing pulse number CANGL corresponds to the total number of engine rotation pulse signals from the time when the reference position signal is generated to immediately before the spill opening angle ANGSPV ("3" in FIG. 12).
The surplus angle θ REM is obtained from the engine rotation pulse signal immediately before the spill opening angle ANGSPV.
This corresponds to an angle of less than one pulse up to SPV.

Subsequently, in step 204, it is determined whether or not the engine speed NE read in step 202 is equal to or lower than a predetermined speed NE1. Here, the predetermined rotation speed NE1 is a predetermined rotation speed on the low rotation side. If the engine rotational speed NE is equal to or less than the predetermined rotational speed NE1, in step 205, as a prediction correction value for predicting a change in the engine rotational speed NE based on the instantaneous time difference TN obtained in the "NE interrupt routine". Is calculated. This prediction correction coefficient KDT is a coefficient for correcting the spill time TSPON according to the instantaneous time difference TN, that is, according to the rotation fluctuation of the diesel engine 2. Here, as shown in FIG. 13, the prediction correction coefficient KDT is obtained with reference to a map in which the relationship between the instantaneous time difference TN and the prediction correction coefficient KDT is predetermined. In this map, the prediction correction coefficient KDT is set to decrease as the instantaneous time difference TN increases. Moreover, when the instantaneous time difference TN is "0", the prediction correction coefficient KDT is set to "1.0", that is, the spill time TSPON is not corrected by the prediction correction coefficient KDT.

On the other hand, if the engine rotational speed NE is not equal to or lower than the predetermined rotational speed NE1 in step 204, in step 206, the prediction correction coefficient KDT is uniformly set to "1.0". That is, the prediction correction coefficient KDT
Is set so that the spill time TSPON is not corrected.

As described above, steps 204 to 2
06, the reason why the prediction correction coefficient KDT is set according to the magnitude of the engine rotation speed NE is that the spill time TSPON is set only when the diesel engine 2 is rotating at a low speed with a large fluctuation in rotation.
This is because the prediction correction is not required at the time of middle / high rotation where the rotation fluctuation is small.

Next, step 205 or step 206
In step 207, the pulse times TS1, TS2, and TS3 in the previous cycle are read. That is, as shown in FIG. 12, the pulse time TNINT (i) for one pulse including the target spill timing in the previous cycle (the pulse counter CNI in FIG. 12).
RQ value between "3" and "4") and the pulse time TS2
Read as Further, the pulse time TNINT (i-1) immediately before the pulse time T2 is set as the pulse time TS1, and the pulse time TNINT (i +
1) is read as the pulse time TS3.

Subsequently, in step 208, one of the pulse times TS1 to TS3 is changed to the pulse time for calculating the spill time TSPON in the current cycle based on the spill opening angle ANGSPV obtained in step 202. Select as TSi. Here, the processing in steps 207 and 208 is for obtaining the required time for one pulse in the previous cycle at the same crank angle phase corresponding to the target spill timing to be detected this time.

Then, in step 209, the residual angle θREM obtained in step 203 and step 2
08 and the pulse time TSi obtained in step 205
The spill time TSPON is calculated using the following formula (2) based on the prediction correction coefficient KDT obtained in the above.
That is, the remaining angle θREM of the current cycle is converted into time.

TSPON = (θREM / 11.25) * TSi * KDT (2) In the above formula (2), the multiplication result of the pulse time TSi and the prediction correction coefficient KDT is the spill predicted in the current cycle. It corresponds to the hour pulse time TS1125.
The spill-time pulse time TS1125 is a predicted time required for one pulse including the time when the electromagnetic spill valve 23 should be closed in the current cycle. Thus, the surplus angle θ
After the REM is converted into time and obtained as the spill time TSPON, the subsequent processing is temporarily terminated.

When the spill timing pulse number CANGL and the spill time TSPON are obtained in the above processing routine, the ECU 71 determines the values CANGL and TSP.
A signal for closing the electromagnetic spill valve 23 is output at a timing based on ON. As a result, the electromagnetic spill valve 23 is closed and the end timing of the fuel injection from the fuel injection pump 1, that is, the fuel injection amount is adjusted.

As described above, in this embodiment, the time required for one pulse in the previous cycle at the same crank angle phase as the spill opening angle ANGSPV in the current cycle is the pulse time for converting the remainder angle θREM into time. Required as TSi. Also, the spill opening angle ANGSPV in the previous cycle and the spill opening angle A in the current cycle
The two instantaneous times TN8 obtained with the NGSPV,
The instantaneous time difference TN between TN2 is the engine speed NE.
, That is, as a representative value of the rotation fluctuation of the diesel engine 2. And the instantaneous time difference TN
Is corrected by the timing correction time ΔTNVRT reflecting the phase difference of the actually output engine rotation pulse signal and the magnitude of the engine rotation speed NE. Further, a prediction correction coefficient KDT for predicting a change in rotation speed is obtained from the corrected instantaneous time difference TN. Further, based on the prediction correction coefficient KDT and the pulse time TSi, the remaining angle θ
The REM is converted to time to determine the spill time TSPON. Then, the end timing of the fuel injection related to the operation of the diesel engine 2 is controlled based on the determined spill time TSPON.

Therefore, in this embodiment, the prediction correction coefficient K
When calculating the DT, the instantaneous time difference TN is corrected according to the phase difference between the actually output engine rotation pulse signal and the normal pulse signal, so that the instantaneous time difference TN is caused by the displacement of the pulser 7 and the rotation speed sensor 35 Predicted correction coefficient KDT
Is eliminated. That is, even if the fixed position of the pulsar 7 or the rotation speed sensor 35 in each individual fuel injection pump 1 is slightly shifted from the normal position, the phase shift of the engine rotation pulse signal caused by the position shift is compensated. You. Therefore, the calculation error of the prediction correction coefficient KDT is compensated, and the prediction correction coefficient KDT is optimized.

For this reason, the spill time TSPON determined based on the prediction correction coefficient KDT and the pulse time TSi
Is obtained after the prediction of the change in the engine speed NE is optimized by the appropriate prediction correction coefficient KDT, and
M is obtained by time conversion. As a result, the time conversion of the surplus angle θREM can be accurately performed while considering the rotation fluctuation of the diesel engine 2 more accurately, and thus the spill time TSPON can be accurately determined.

Further, since the spill time TSPON can be accurately determined, the determination of the end timing of the fuel injection in each cycle of the diesel engine 2 is optimized. As a result, the end timing of the fuel injection in each cycle, that is, the fuel injection amount can be accurately controlled. Furthermore,
Since the fuel injection amount can be controlled with high accuracy, it is possible to further improve the shear, surge and vibration of the vehicle.

(Second Embodiment) Next, a second embodiment in which the control device for an internal combustion engine according to the present invention is embodied in an electronically controlled diesel engine of an automobile will be described with reference to FIGS. In this embodiment, the structure is the same as that of the first embodiment, and the same members are denoted by the same reference numerals and description thereof will be omitted. In the following, in particular, the ECU 71
Only different points in the processing operation executed by the above will be described.

That is, in this embodiment, as shown in FIG. 14, the first operation is performed in terms of the processing operation of the "NE interrupt routine".
It is different from that of the embodiment. In this “NE interrupt routine”, the processing contents of steps 301 to 306 are the same as those of steps 101 to 10 in the “NE interrupt routine” of FIG. 8 described in the first embodiment.
6 is completely the same as the processing content. Therefore, the description of steps 301 to 306 is omitted here, and the description will be focused on the processing contents of steps 307 to 317.

Step 30 shifts from step 306
7, the pulse counter CNIR obtained this time is
It is determined whether the number of Q is “2”. If the number of pulse counters CNIRQ is not “2”, it is determined in step 308 whether or not the number of pulse counters CNIRQ is “8”.

If the number of the pulse counter CNIRQ is not "8" in step 308, the subsequent processing is temporarily terminated. Step 308
In the case where the number of the pulse counter CNIRQ is “8” in step 309,
The current pulse time TNINT (i) obtained in is set as the instantaneous time TN8.

Next, in step 310, a missing tooth position correction value tAVRT for timing correction is calculated based on the timing correction voltage VRT read in step 303. The missing tooth position correction value tAVRT is obtained by referring to a map as shown in FIG. 9 as in the first embodiment.

In step 311, the timing correction time TN for the instantaneous time TN 8 is determined based on the missing tooth position correction value tAVRT obtained in step 310 and the engine speed NE read in step 303.
Calculate VRT8. This timing correction time TNVR
T8 is a missing tooth position correction value tAVR as shown in FIG.
The relationship between T and the engine speed NE and the timing correction time TNVRT8 is obtained with reference to a predetermined map. The characteristics of this map are based on those of FIG.

Then, in step 312, the instantaneous time TN8 obtained in step 309 is corrected. Specifically, the timing correction time TNVRT8 obtained in step 311 is subtracted from the instantaneous time TN8, and the result of the subtraction is set as a new instantaneous time TN8. And
Thereafter, the processing is temporarily terminated.

On the other hand, if the number of the pulse counter CNIRQ obtained this time is “2” in step 307, the current pulse time TNINT (i) obtained in step 302 is replaced with the instantaneous time TN 2 in step 313. Set as

Next, at step 314, a missing tooth position correction value tAVRT for timing correction is calculated based on the timing correction voltage VRT read at step 303, as in step 310.

In step 315, the timing correction time TN for the instantaneous time TN2 is determined based on the missing tooth position correction value tAVRT obtained in step 314 and the engine speed NE read in step 303.
Calculate VRT2. This timing correction time TNVR
T2 is a missing tooth position correction value tAVR as shown in FIG.
The relationship between T and the engine speed NE and the timing correction time TNVRT2 is obtained with reference to a predetermined map. The characteristics of this map are also based on those of FIG.

Thereafter, in step 316, the instantaneous time TN2 obtained in step 313 is corrected. Specifically, the timing correction time TNVRT2 obtained in step 315 is subtracted from the instantaneous time TN2, and the result of the subtraction is set as a new instantaneous time TN2.

Then, in step 317, step 3 is performed based on the instantaneous time TN8 obtained in step 312.
The instantaneous time TN2 obtained in step 16 is subtracted, the result of the subtraction is set as the instantaneous time difference TN, and the subsequent processing is temporarily terminated.

That is, according to the processing of this "NE interrupt routine", each timing correction time TNNRT8, T
The instants TN8 and TN2 are corrected by the NVRT2, and the corrected instantaneous times TN8 and TN2 are
The instantaneous time difference TN representing the rotation fluctuation of the diesel engine 2 is obtained.

The ECU 71 uses the obtained instantaneous time difference TN to calculate the spill timing pulse number CANGL and the spill time TSPON in the execution of the same processing routine as shown in FIG. Then, based on the calculated spill timing pulse number CANGL and spill time TSPON, the ECU 71 outputs a signal for closing the electromagnetic spill valve 23. Thereby, the electromagnetic spill valve 23 is closed, and the fuel injection amount from the fuel injection pump 1 is adjusted.

As described above, in this embodiment, the instantaneous time difference TN between the instantaneous times TN8 and TN2 obtained between the spill opening angle ANGSPV in the previous cycle and the spill opening angle ANGSPV in the current cycle is: It is obtained as a representative value of the rotation fluctuation of the diesel engine 2. Moreover, in obtaining the instantaneous time difference TN, each timing correction time T reflecting the phase difference of the actually output engine rotation pulse signal and the magnitude of the engine rotation speed NE.
By using NVRT8 and TNVRT2, each instantaneous time TN8,
TN2 is corrected in advance. Then, the predicted correction coefficient KDT is obtained from the instantaneous time difference TN between the corrected instantaneous times TN8 and TN2. Also, the prediction correction coefficient KDT
The remaining angle θREM is converted into a time based on the pulse time TSi and the spill time TSPON is determined.
Then, based on the determined spill time TSPON and the like, the end timing of the fuel injection related to the operation of the diesel engine 2 is controlled.

Therefore, also in this embodiment, when determining the prediction correction coefficient KDT for predicting the rotation fluctuation of the diesel engine 2, the pulser 7 and the rotation speed sensor 3 are used.
The calculation error of the prediction correction coefficient KDT caused by the position shift of No. 5 is eliminated, and the prediction correction coefficient KDT is optimized.

Therefore, the spill time TSPON is obtained by time conversion of the residual angle θREM after the prediction of the change in the engine speed NE is optimized by the appropriate prediction correction coefficient KDT. As a result, after considering the rotation fluctuation of the diesel engine 2 more accurately, the remaining angle θ
The time conversion of the REM can be accurately performed, and the spill time TSPON can be accurately determined. Further, as a result, the fuel injection amount in each cycle of the diesel engine 2 can be accurately controlled.

The present invention is not limited to the above-described embodiments, but may be implemented as follows, with a part of the configuration being appropriately changed without departing from the spirit of the invention. (1) In each of the above embodiments, the angle required for one pulse corresponding to "8" and "2" in the number of pulse counters CNIRQ between the target spill timing in the previous cycle and the target spill timing in the current cycle. Time is instantaneous time TN
Although calculated as 8, TN2, an angle time obtained corresponding to the number of pulse counters CNIRQ other than "8" and "2" can also be calculated as the instantaneous time.

(2) In each of the above embodiments, the remaining angle θREM at the spill opening angle ANGSPV corresponding to the target crank angle is embodied in terms of time. However, the required angle to be converted in time is limited to the remaining angle θREM. It is not something that can be done. For example, depending on the processing, the spill opening angle A
The present invention can also be embodied in a case where all the NGSPVs are converted into time.

(3) In each of the above embodiments, the required control content is specified as the fuel injection amount control of the diesel engine 2 and the end timing of the fuel injection is controlled, but the fuel injection timing control of the diesel engine 2 is performed. May be embodied when the required control content is used, or when the ignition timing control of the gasoline engine is used as the required control content.

(4) In the above embodiment, the diesel engine 2 having the turbocharger 49 as the supercharger is embodied. However, the diesel engine having the supercharger as the supercharger or the supercharger is provided. Not even diesel engines can be embodied.

[0088]

As described above in detail, according to the present invention, in a control device for an internal combustion engine provided with a rotation detecting means for detecting a rotation at a constant crank angle and outputting it as a pulse signal, the present invention provides Any output from the rotation detection means between the two target crank angles of the cycle
A prediction correction value for predicting a change in rotation speed is calculated based on the angle time required for a plurality of pulse signals, and the calculation of the prediction correction value is corrected according to a phase difference between an actual pulse signal and a regular pulse signal. The required angle up to the target crank angle obtained in the current cycle is time-converted based on a predicted correction value or the like calculated and corrected, and the execution timing of the required control content of the internal combustion engine is controlled based on the time converted value or the like. Therefore, in converting the required angle into time, the time can be accurately converted in consideration of the change in the rotation speed of the internal combustion engine regardless of the mounting position shift of the rotation detection means in each internal combustion engine. An excellent effect that the execution timing of the required control content can be accurately controlled is exhibited.

[Brief description of the drawings]

FIG. 1 is a conceptual configuration diagram illustrating a basic conceptual configuration of the present invention.

FIG. 2 is a schematic configuration diagram showing a supercharged diesel engine system according to a first embodiment of the present invention.

FIG. 3 is a sectional view showing a fuel injection pump in the first embodiment.

FIG. 4 is a block diagram showing an electrical configuration of an ECU in the first embodiment.

FIG. 5 is a diagram showing a positional relationship between a pulsar and a rotation speed sensor in the first embodiment.

FIG. 6 is a diagram for explaining a change in pulse time with respect to a crank angle in the first embodiment.

FIG. 7 is a diagram for explaining a relationship between an engine rotation pulse signal output from a rotation speed sensor and the number of pulse counters in the first embodiment.

FIG. 8 is a flowchart showing a “NE interrupt routine” executed by the ECU in the first embodiment.

FIG. 9 is a map in which a relationship between a timing correction voltage and a missing tooth position correction value in the first embodiment is determined in advance.

FIG. 10 is a map in which the relationship between a missing tooth position correction value and a timing correction time with respect to an engine rotation speed is determined in advance in the first embodiment.

FIG. 11 is a flowchart showing a processing routine for calculating a spill timing pulse number and a spill time in the first embodiment.

FIG. 12 is a diagram for explaining a relationship among an engine speed pulse signal, the number of pulse counters, and the operation of an electromagnetic spill valve in the first embodiment when converting the time to a surplus angle.

FIG. 13 is a map in which a relationship between an instantaneous time difference and a prediction correction coefficient is predetermined in the first embodiment.

FIG. 14 shows a second embodiment of the present invention.
9 is a flowchart illustrating an “NE interruption routine” executed by the ECU.

FIG. 15 is a map in which a relationship between a correction value of a missing tooth position and a timing correction time with respect to an engine rotation speed is determined in advance in the second embodiment.

FIG. 16 is a map in which the relationship between the correction value of the missing tooth position and the timing correction time with respect to the engine rotation speed in the second embodiment is also determined in advance.

17A and 17B are diagrams for explaining a change in pulse time with respect to a crank angle in the related art, in which FIG. 17A shows a state corresponding to a normal target position, and FIG. (C) shows a state shifted by a certain angle difference toward the advance side.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Fuel injection pump, 2 ... Diesel engine, 7 ... Pulser, 35 ... Rotation speed sensor (7, 35 comprises rotation detection means), 40 ... Crankshaft, 71 ... EC
U (71 constitutes angle calculation means, prediction correction value calculation means, calculation correction means, angle time conversion means and execution control means), ANGSPV: spill opening angle as target crank angle, θREM: surplus angle, TN2 , TN8: Instantaneous time as angle time, TN: Instantaneous time difference, CANGL
... Spill time pulse number, TSPON ... Spill time.

Continuation of the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) F02D 41/00-41/40 F02D 45/00 362

Claims (1)

(57) [Claims] 1. A control device for an internal combustion engine that executes various control contents related to the operation of the internal combustion engine, comprising: detecting a rotation at a constant crank angle based on a rotation of a crankshaft in the internal combustion engine; A rotation detecting means for outputting, based on a pulse signal output from the rotation detecting means in a current cycle of the internal combustion engine, from a reference position of the series of pulse signals to a target crank angle corresponding to an execution timing of required control content. required angle and angle calculating means for calculating a, the series of pulse signals output from the rotation detecting means between said target crank angle at the target crank angle and the present cycle in the previous cycle, any multiple of Calculate the angle time required to rotate by a certain crank angle corresponding to the pulse signal. , Those
Prediction correction value calculation means for calculating a prediction correction value for predicting a change in the rotational speed of the internal combustion engine based on a plurality of angle times; and in the calculation by the prediction correction value calculation means, an actual output from the rotation detection means. Calculation correction means for correcting the calculation of the predicted correction value in accordance with a phase difference previously confirmed between a phase of a pulse signal and a phase of a regular pulse signal to be output corresponding to the rotation of the crankshaft; The required angle calculated by the angle calculation means is calculated based on the angle time obtained corresponding to a predetermined crank angle and the predicted correction value corrected and calculated by the calculation correction means by the predicted correction value calculation means. Angle time conversion means for performing time conversion based on the time converted by the angle time conversion means; Control apparatus for an internal combustion engine characterized by comprising an execution control means for.