JPH07180592A - Control device for internal combustion engine - Google Patents

Abstract

PURPOSE:To improve time conversion precision of a redundant angle and to provide an accurate target control amount responding to an operation state by a method wherein a pulse time at a target spill period is predicted based on data on pulse times and the coefficients of a rotation fluctuation during a spill two times before a present spill and a preceding spill (an overflow of fuel to a fuel chamber). CONSTITUTION:A ratio between a pulse time approximately simultaneous to a period at which the instantaneous number of revolutions of an engine M1 is maximized after a control period of an actuator M4 two times before a present control period is completed and a pulse time approximately simultaneous to the preceding control period of the actuator M4 is calculated as the coefficient of fluctuation of rotation by a rotation fluctuation calculating means M11. Based on the coefficient of rotation fluctuation and a pulse time approximately simultaneous to a period at which the instantaneous number of revolutions of an engine is maximized after the preceding control period of the actuator M4 is completed, a pulse time in the vicinity of a present target crank angle is predicted by a pulse time predicting means M12. Based on the predicted pulse time, a time of a redundant angle is converted by an angle time conversion means M9. This constitution provides an accurate control amount being a target responding to the running state of an engines.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for an internal combustion engine such as a diesel engine or a gasoline engine. For example, in a diesel engine, the operation of an electromagnetic spill valve in a fuel injection pump is adjusted in order to adjust the fuel injection amount. The present invention relates to a control device of an internal combustion engine for controlling.

[0002]

2. Description of the Related Art Generally, for example, in a fuel injection pump of an electronically controlled diesel engine, a spill valve is controlled by controlling an electromagnetic spill valve so that a fuel injection amount obtained according to a lift of a plunger thereof reaches a required target injection amount. The port is now open. As a result, the fuel pressure-fed from the plunger high-pressure chamber overflows (spills) into the fuel chamber, and the end of the pressure-feeding of the fuel, that is, the end timing of fuel injection is controlled to obtain the required target injection amount.

In such an electromagnetic spill valve, opening / closing control is usually performed by utilizing an engine rotation pulse output every time the crankshaft of the engine rotates by a fixed crank angle.

For example, in the technique disclosed in Japanese Patent Laid-Open No. 62-267547, the target spill timing corresponding to the injection end timing is set in order to obtain the fuel injection amount determined according to the engine operating condition at that time. , The spill port is opened by the electromagnetic spill valve. Here, in order to determine the target spill timing, first, the target spill angle as the target crank angle corresponding to the fuel injection amount determined according to the operating state of the engine is obtained. Next, based on the engine rotation pulse obtained for each constant crank angle, the pulse count number from the predetermined reference position of the engine rotation pulse to the target spill angle position and the surplus angle less than one pulse are obtained. The remaining angle is converted into time based on the required time for one pulse including the previous spill time (pulse time during spill). Then, the target spill timing is determined based on the time-converted value of the surplus angle and the pulse count number.

[0005]

However, in the above-mentioned prior art, the time required for one pulse including the previous spill time, that is, the pulse time during the previous spill is used as it is, and the surplus angle in the target spill angle at this time is used. I try to convert it into time. Therefore, when the engine rotation fluctuation becomes large due to a change in engine load or the like, the error in the spill pulse time becomes large.

That is, for example, when the instantaneous engine speed in the vicinity of the target spill time of this time is lower than the instantaneous engine speed in the vicinity of the previous spill time, the pulse time of the current spill time is It is longer than the pulse time during spill. Therefore, when the remaining angle is converted into time based on the previous spill time pulse time obtained in such a state where the rotation fluctuation is large, the error of the time conversion value becomes very large, and the fuel injection amount control The accuracy may have deteriorated. Further, due to deterioration in accuracy of the fuel injection amount control, there is a possibility that the engine rotation fluctuation is further induced to cause a reduction in output or surging occurs.

The present invention has been made to solve the above problems, and an object of the present invention is to perform time conversion of a surplus angle with high accuracy without being affected by rotational fluctuation and rotational change of an internal combustion engine. An object of the present invention is to provide a control device for an internal combustion engine that can reliably obtain a target control amount.

[0008]

In order to achieve the above object, in the invention described in claim 1, as shown in FIG.
A pulse signal output means M3 that outputs a pulse signal every time the crankshaft M2 of the internal combustion engine M1 is rotated by a fixed crank angle, an actuator M4 for adjusting a control amount such as a fuel injection amount in the internal combustion engine M1, and an internal combustion engine. M
A driving state detecting means M5 for detecting the driving state of No. 1 and a target crank angle corresponding to the time when the operation of the actuator M4 should be controlled in order to obtain a control amount determined according to the detected driving state. Based on the pulse signal from the target crank angle calculating means M6 and the pulse signal output means M3, a pulse signal from a predetermined reference position of the pulse signal to the target crank angle position calculated by the target crank angle calculating means M6. Crank angle M2 is a constant crank angle, and the required time between the pulse signal output from the pulse signal output means M3 and the remainder angle calculation means M7 for calculating the number of counts and the remainder angle less than one pulse signal thereof. A pulse time calculating means M8 for calculating a pulse time corresponding to the time required to rotate the angle, and the remainder Angle time conversion means M9 for converting the remainder angle calculated by the degree calculation means M7 based on the pulse time calculated by the pulse time calculation means M8, and the pulse signal calculated by the remainder angle calculation means M7. Control means M1 for controlling the operation of the actuator M4 at the timing determined by the count number and the time conversion value of the surplus angle by the angle time conversion means M9.
In the control device for an internal combustion engine, the internal combustion engine M1
Pulse time around the time when the instantaneous rotation speed of
A rotation fluctuation calculating unit M11 that calculates the ratio of the pulse time of the actuator M4 in the vicinity of the previous control timing as a rotation fluctuation rate, the calculated rotation fluctuation rate, and the internal combustion engine after the previous control timing of the actuator M4 ends. Pulse time predicting means M12 for predicting the pulse time in the vicinity of the current target crank angle by the target crank angle calculating means M6 based on the pulse time in the vicinity of the time when the instantaneous rotational speed of M1 becomes the highest, Based on the predicted pulse time, the angle time conversion means M9 performs time conversion of the surplus angle.

Further, in the invention described in claim 2, as shown in FIG. 1, the pulse time predicting means M12 rotates the deviation of the pulse time at a predetermined time in the previous control cycle and the current control cycle. The present invention is characterized by including a correcting means M13 which is obtained as a change amount and corrects the predicted pulse time based on the rotation change amount.

Further, in the invention as set forth in claim 3, the correction means M13 causes the pulse time in the vicinity of the time when the instantaneous rotational speed of the internal combustion engine M1 becomes maximum during the last control cycle after the end of the control time two times before. In the present control cycle, the deviation from the pulse time in the vicinity of the time when the instantaneous rotational speed of the internal combustion engine M1 becomes maximum after the end of the previous control time is obtained as the rotational change amount.

[0011]

Therefore, according to the first aspect of the invention, as shown in FIG.
As shown in FIG. 5, when the crankshaft M2 of the internal combustion engine M1 is rotated, the pulse signal output means M3 outputs a pulse signal every time the crankshaft M2 is rotated by a fixed crank angle. At this time, the operating state detecting means M5 detects the operating state of the internal combustion engine M1.
Then, in order to obtain the control amount determined according to the detected operating state, the target crank angle calculating means M6
A target crank angle corresponding to the time when the operation of the actuator M4 should be controlled is calculated.

On the other hand, based on the pulse signal from the pulse signal output means M3, the remainder angle calculation means M7 causes the pulse signal count number from the predetermined reference position of the pulse signal to the target crank angle position and the pulse signal 1 thereof. A surplus angle that is less than one is calculated. The required time between the pulse signals is calculated as the pulse time by the pulse time calculating means M8. That is, this pulse time is
This corresponds to the time required for the crankshaft M2 to rotate by a constant crank angle. Then, the calculated remainder angle is converted into time by the angle time conversion means M9 based on the pulse time.

Then, the control means M10 controls the operation of the actuator M4 at a timing determined from the count number of the calculated pulse signal and the time conversion value of the surplus angle. As a result, the control amount such as the fuel injection amount of the internal combustion engine M1 is adjusted.

Here, by the rotation fluctuation calculating means M11,
The ratio of the pulse time in the vicinity of the time when the instantaneous rotational speed of the internal combustion engine M1 reaches the maximum after the end of the control time of the actuator M4 two times before and the pulse time in the vicinity of the previous control time of the actuator M4 is the rotation fluctuation rate. It is calculated.
Then, based on the calculated rotation fluctuation rate and the pulse time in the vicinity of the time when the instantaneous rotation speed of the internal combustion engine M1 becomes maximum after the previous control time of the actuator M4 ends,
The pulse time predicting means M12 predicts the pulse time near the current target crank angle. Then, based on the predicted pulse time, time conversion of the surplus angle is performed by the angle time conversion means M9.

Therefore, even if the rotational fluctuation of the crankshaft M2 of the internal combustion engine M1 becomes large due to a change in the load of the internal combustion engine M1, the fluctuation time is taken into consideration, and the pulse time near the target crank angle at this time is considered. Is predicted with high accuracy. Therefore, the surplus angle is accurately converted into time based on the pulse time predicted in consideration of the rotation fluctuation, and the error of the time conversion value does not increase. as a result,
A target control amount according to the operating state of the internal combustion engine M1 can be reliably obtained.

Further, the time when the instantaneous rotation speed of the internal combustion engine M1 becomes maximum after the control timing of the actuator M4 ends is the time when the instantaneous rotation speed becomes the most stable. Therefore, when predicting the pulse time near the target crank angle this time, it is possible to more accurately predict the pulse time by using the pulse time near the time when the instantaneous rotation speed is most stable.

According to the second aspect of the invention, as shown in FIG. 1, the correction means 13 of the pulse time predicting means M12 causes the pulse at the predetermined time in the previous control cycle and the current control cycle. The time deviation is obtained as the rotation change amount, and the predicted pulse time is corrected based on the rotation change amount.

Therefore, even when the rotation speed of the crankshaft M2 of the internal combustion engine M1 changes significantly, the predicted pulse time is corrected in consideration of the change. Therefore, the surplus angle is time-converted more accurately based on the pulse time corrected in consideration of the rotation change.

Further, according to the third aspect of the invention, the moment when the instantaneous rotation speed of the internal combustion engine M1 becomes maximum after the control timing of the actuator M4 is completed is the time when the instantaneous rotation speed is most stable in the control cycle. is there. Therefore, the correction means M13 obtains the deviation of the pulse time in the vicinity of the time when the instantaneous rotational speed of the internal combustion engine M1 is most stable in the previous control cycle and the present control cycle, as the rotational change amount, and the rotational change amount. Based on the above, the predicted pulse time is corrected more accurately.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is embodied in a fuel injection amount control device for a diesel engine in an automobile will be described in detail with reference to the drawings.

FIG. 2 is a schematic configuration diagram showing a fuel injection amount control device for a diesel engine with a supercharger in 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 drivingly connected to a crankshaft 40 of a diesel engine 2 as an internal combustion engine via a belt or the like. Then, the fuel injection pump 1 is driven by the rotation of the drive pulley 3, and the fuel is pumped to the fuel injection nozzles 4 provided for each cylinder (four cylinders in this case) of the diesel engine 2 to perform fuel injection. Be seen.

In the fuel injection pump 1, the drive pulley 3 is attached to the tip of the drive shaft 5.
Further, a fuel feed pump (developed by 90 degrees in this figure) 6 formed of a vane type pump is provided in the middle of the drive shaft 5. Further, a disc-shaped pulsar 7 having a plurality of protrusions on the outer peripheral surface is attached to the base end side of the drive shaft 5. 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 attached along the circumference of the roller ring 9. There is. Cam face 8
The number a is provided in the same number as the number of cylinders of the diesel engine 2. The cam plate 8 is constantly urged and engaged with the cam roller 10 by the spring 11.

A base end of a fuel pressurizing plunger 12 is integrally rotatably attached to the cam plate 8, and the cam plate 8 and the plunger 12 are rotated in association with the rotation of the drive shaft 5. That is, when the rotational force of the drive shaft 5 is transmitted to the cam plate 8 through a coupling (not shown), the cam plate 8 rotates and engages with the cam roller 10, and the same number as the number of cylinders in the left-right direction in the figure. Is driven back and forth. Also, the plunger 12 is reciprocally driven in the same direction while rotating with the reciprocating motion. That is, the plunger 12 is moved forward (lifted) while the cam face 8a of the cam plate 8 rides on the cam roller 10 of the roller ring 9, and vice versa.
2 is reactivated.

The plunger 12 is fitted in a cylinder 14 formed in the pump housing 13, and the high pressure chamber 1 is provided between the tip end surface of the plunger 12 and the inner bottom surface of the cylinder 14.
It is 5. In addition, as many suction grooves 16 as the number of cylinders of the diesel engine 2 are provided on the outer periphery of the tip end side of the plunger 12.
And a distribution port 17 are formed. A distribution passage 18 and a suction port 19 are formed in the pump housing 13 so as to correspond to the suction groove 16 and the distribution port 17.

Then, the drive shaft 5 is rotated and the fuel feed pump 6 is driven, so that fuel is supplied from a fuel tank (not shown) into the fuel chamber 21 through the fuel supply port 20. Further, during the suction stroke in which the plunger 12 is returned 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 by communicating one of the six 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, the fuel is pressure-fed and injected from the distribution passage 18 to the fuel injection nozzle 4 of each cylinder.

A spill passage 22 for fuel overflow (spill) is formed in the pump housing 13 to connect the high pressure chamber 15 and the fuel chamber 21. An electromagnetic spill valve 23 as an actuator for adjusting the fuel spill from the high pressure chamber 15 is provided in the middle of the spill passage 22.
This electromagnetic spill valve 23 is a normally open type valve and has a coil 24
Is de-energized (OFF), the valve body 25 is opened and the fuel in the high pressure chamber 15 is spilled into 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 closed / opened and the fuel spill adjustment from the high pressure chamber 15 to the fuel chamber 21 is performed. Then, by opening the electromagnetic spill valve 23 during the compression stroke of the plunger 12, the fuel inside the high pressure chamber 15 is depressurized and the fuel injection from the fuel injection nozzle 4 is stopped. That is, even if the plunger 12 moves forward, the fuel pressure in the high pressure chamber 15 does not rise while the electromagnetic spill valve 23 is open, and fuel injection from the fuel injection nozzle 4 is not performed. In addition, by controlling the closing / opening timing of the electromagnetic spill valve 23 during the forward movement of the plunger 12, the injection end 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 (which is expanded 90 degrees in this figure) 26 for controlling the fuel injection timing. The timer device 26 controls the position of the roller ring 9 with respect to the rotation direction of the drive shaft 5 to change 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, and has a timer housing 27, a timer piston 28 fitted in the housing 27, and a timer in a low pressure chamber 29 on one side of the timer housing 27. It is composed of a timer spring 31 and the like for urging the piston 28 against the pressurizing chamber 30 on the other side. The timer piston 28 is connected to the roller ring 9 via the 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 is determined by the equilibrium relationship between the fuel pressure and the urging force of the timer spring 31. Further, the position of the roller ring 9 is determined by determining the position of the timer piston 28, and the position of the roller 1 is determined via the cam plate 8.
2 reciprocating timing is determined.

The timer device 26 is provided with a timer control valve (TCV) 33 in order to adjust the fuel pressure acting as the control hydraulic pressure of the timer device 26. That is, the pressurizing chamber 30 and the low pressure chamber 29 of the timer housing 27 communicate with each other through the communication passage 3
4 are connected to each other, and a TV is provided on the way of the communication passage 34.
C33 is provided. The TVC 33 is an electromagnetic valve that is opened / closed by a duty-controlled energization signal, and the fuel pressure in the pressurizing chamber 30 is adjusted by the opening / closing control of the TVC 33. The lift timing of the plunger 12 is controlled by adjusting the fuel pressure,
The fuel injection timing from each fuel injection nozzle 4 is adjusted.

On the upper part of the roller ring 9, a rotation speed sensor 35 as a pulse signal output means composed of an electromagnetic pickup coil is attached so as to face the outer peripheral surface of the pulsar 7. The rotation speed sensor 35 outputs a pulse signal each time a protrusion formed on the outer peripheral surface of the pulser 7 crosses.
Then, the rotation speed of the fuel injection pump 1, that is, the rotation speed of the crankshaft 40 in the diesel engine 2 is detected from this pulse signal.

In the present embodiment, as shown in FIG. 4, four sets of protrusions 7a on the outer peripheral surface of the pulsar 7 are formed at a constant angle (crank angle of 11.25 ° CA) with 14 sets as one set. The total number is 56. Between the adjacent sets of protrusions 7a, the same number of cylinders as the diesel engine 2, that is, in this case, four cutting teeth 7 are provided.
b are formed at equal angular intervals of 90 ° (180 ° CA in crank angle). The interval between the protrusions 7a and the protrusions 7a which are adjacent to each other with the incised tooth portion 7b interposed therebetween is 33.75 ° CA in terms of crank angle.

When the pulsar 7 is rotated with the rotation of the crankshaft 40 of the diesel engine 2, the rotation speed sensor 35 causes the rotation speed sensor 35 to generate a timing signal corresponding to the engine rotation speed NE every time the projection 7a of the pulsar 7 crosses. That is, the engine rotation pulse is output. That is, as shown by the output signal after waveform shaping in FIG. 7, this engine rotation pulse is rotated every time the pulsar 7 is rotated by the arrangement interval of the protrusions 7a, that is, by a constant crank angle (11.25 ° CA). Is output. Further, between the projections 7a and the projections 7a which are adjacent to each other with the cutting tooth portion 7b interposed therebetween, the output interval of the engine rotation pulse is an interval corresponding to the rotation angle of 33.75 ° CA of the pulsar 7. Note that, hereinafter, the engine rotation pulse output corresponding to the projection 7a immediately after the cutting tooth portion 7b has passed is referred to as a reference position signal. Also, this rotation speed sensor 3
Since 5 is integrated with the roller ring 9, the timer device 2
Regardless of the control operation of 6, the reference position signal is always output to the plunger lift at a constant timing.

Next, the diesel engine 2 will be described. As shown in FIG. 2, in the diesel engine 2, the cylinder 41, the piston 42, and the cylinder head 43.
A main combustion chamber 44 corresponding to each cylinder is formed. Further, each of the main combustion chambers 44 is connected to an auxiliary combustion chamber 45 which is also provided corresponding to each cylinder. Then, the fuel injected from each fuel injection nozzle 4 is supplied to each auxiliary combustion chamber 45. A well-known glow plug 46 as a start-up assisting 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 respectively. The intake passage 47 is provided with a compressor 50 of a turbocharger 49 that constitutes a supercharger, and the exhaust passage 48 is provided with a turbine 51 of the turbocharger 49. or,
A wastegate valve 52 for adjusting the supercharging pressure PiM is provided in the exhaust passage 48. As is well known, the turbocharger 49 uses the energy of exhaust gas to rotate the turbine 51 and the compressor 50 coaxial with the turbine 51 to increase the intake air pressure. As a result, high-density air is sent to the main combustion chamber 44 to burn a large amount of fuel, and the output of the diesel engine 2 is increased.

Further, the diesel engine 2 is provided with an exhaust gas recirculation passage (EGR passage) 54 for returning a part of the exhaust gas in the exhaust passage 48 to the intake port 53 of the intake passage 47. And that E
An EG for adjusting the exhaust gas recirculation amount is provided in the middle of the GR passage 54.
An R valve 55 is provided. This EGR valve 55
Is controlled to be opened / closed by controlling a vacuum switching valve (VSV) 56.

Further, in the middle of the intake passage 47, a throttle valve 58 which is opened / closed in association with the depression amount of the accelerator pedal 57 is provided. Further, 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 be opened / closed by an actuator 63 having a two-stage diaphragm chamber driven by the control of two VSVs 61 and 62. The bypass throttle valve 60 is controlled to open and close according to various operating states. For example, during idle operation, it is controlled to a half open state to reduce noise and vibrations, during normal operation it is controlled to a fully open state, and when operation is stopped, it is controlled to a fully closed state for a smooth stop.

Then, the electromagnetic spill valve 2 provided in the fuel injection pump 1 and the diesel engine 2 as described above.
3, TCV33, glow plug 46 and each VSV56,
The electronic control units 61 and 62 are electrically connected to an electronic control unit (hereinafter simply referred to as “ECU”) 71, and their drive timing is controlled by the ECU 71. In the present embodiment, the ECU 71 constitutes a target crank angle calculation means, a surplus angle calculation means, a pulse time calculation means, an angle time conversion means, a control means, a rotation fluctuation calculation means, a pulse time prediction means, and a correction means. .

In addition to the rotation speed sensor 35, the following various sensors are provided as sensors constituting the operating state detecting means for detecting the operating state of the diesel engine 2. That is, the intake air temperature sensor 72 for detecting the intake air temperature THA is provided near the air cleaner 64 provided at the inlet of the intake passage 47. Further, an accelerator opening sensor 73 for detecting an accelerator opening ACCP corresponding to the load of the diesel engine 2 is provided from the opening / closing position of the throttle valve 58. In the vicinity of the intake port 53, an intake pressure sensor 7 for detecting the intake air pressure after being supercharged by the turbocharger 49, that is, the supercharging pressure PiM.
4 are provided. Further, a water temperature sensor 75 for detecting the cooling water temperature THW of the diesel engine 2 is provided. Also, the crankshaft 40 of the diesel engine 2
A crank angle sensor 76 for detecting the rotation reference position of the crankshaft 40, for example, the rotation position of the crankshaft 40 with respect to the top dead center of the specific cylinder is provided. Further, in a transmission (not shown), a vehicle speed sensor 7 for detecting a vehicle speed (vehicle speed) SPD by turning on / off a reed switch 77b by a magnet 77a rotated by the rotation of the gear.
7 is provided.

The above-mentioned sensors 35, 72 to 77 are connected to the ECU 71, respectively. Also, EC
The U71 suitably controls the electromagnetic spill valve 23, the TCV 33, the glow plug 46, the VSV 56, 61, 62 and the like based on the detection signals output from the respective sensors 35, 72 to 77.

Next, the configuration of the above-mentioned ECU 71 will be described with reference to the block diagram of FIG. The ECU 71 is a central processing unit (CPU) 81, a read-only memory (RO) in which a predetermined control program, maps and the like are stored in advance.
M) 82, a random access memory (RAM) 83 for temporarily storing calculation results of the CPU 81, a backup RAM 84 for storing prestored data, and the like, and a bus 87 for connecting these units, an input port 85, an output port 86, and the like.
It is configured as a logical operation circuit connected by.
Here, the CPU 81 is adapted to perform a free-running count operation for arithmetic processing.

At the input port 85, the intake air temperature sensor 72, the accelerator opening sensor 73, the intake air pressure sensor 74, and the water temperature sensor 75 are connected to the buffers 88, 89, 90, 9 respectively.
1, the multiplexer 93, and the A / D converter 94. Similarly, the rotation speed sensor 35, the crank angle sensor 76, and the vehicle speed sensor 77 described above are connected to the input port 85 via a waveform shaping circuit 95. Then, the CPU 81 reads the detection signals of the sensors 35, 72 to 77, etc., which are input via the input port 85, as input values. Also, each drive circuit 9 is connected to the output port 86.
6,97,98,99,100,101 via electromagnetic spill valve 23, TCV33, glow plug 46 and VSV
56, 61, 62, etc. are connected.

Then, the CPU 81 controls the sensors 35 and 72.
Electromagnetic spill valve 2 based on input values read from ~ 77
3, TCV33, glow plug 46 and VSV56,6
1, 62 and the like are preferably controlled.

Next, the processing operation of the fuel injection amount control executed by the above-mentioned ECU 71 will be described with reference to FIGS. First, the flowchart shown in FIG.
Among the processes executed by the ECU 71, the “NE interrupt routine” is interrupted at the rising edge of the engine rotation pulse corresponding to the engine rotation speed NE input from the rotation speed sensor 35. The description of this flowchart will be given with reference to the time chart of FIG. 7.

When the processing shifts to this routine, first,
At step 101, the current time (current interrupt time) obtained by the free running count operation
The previous interrupt time ZNEIN is subtracted from NEIN, and the result is set as the pulse time TNINT.
That is, as shown in FIG. 7, the crankshaft 40 of the engine 2 is 11.2 from the rising edge of the previous engine rotation pulse to the rising edge of this engine rotation pulse.
The time (TNINT) required to rotate by 5 ° CA or 33.75 ° CA is calculated.

Next, at step 102, it is judged if the engine rotation pulse interrupted this time is a reference position signal. It should be noted that this determination is made based on, for example, whether the pulse time TNINT calculated in the current control cycle is twice or more the pulse time TNINT calculated in the previous control cycle. Here, if the current pulse time TNINT is not more than twice the previous pulse time TNINT, it is determined that the engine rotation pulse interrupted this time is not the reference position signal, and the process proceeds to step 103. In step 103, a count value CNIR of a pulse counter that counts engine rotation pulses
Increment Q by "1".

Subsequently, in step 104, it is determined whether or not the count value CNIRQ is "13". Here, when the count value CNIRQ is "13", the process proceeds to step 105, and the pulse time TNINT obtained previously is set as the instantaneous time TN13n in the present injection cycle. That is, this instantaneous time T
N13n is the count value CNIRQ as shown in FIG.
Corresponds to the pulse time TNINT required for the crankshaft 40 to rotate by 11.25 ° CA from when the value becomes “12” to when it becomes “13”. In addition, the position of this instantaneous time TN13n is near the time when the pulse time TNINT becomes the minimum after the fuel injection in the previous injection cycle ends in the present count cycle, that is, the engine speed NE after the fuel injection in the previous injection cycle ends. This corresponds to the vicinity of the time when the instantaneous rotation speed of is highest.

Next, at step 106, the current time (current interrupt time) NEIN is set as the previous interrupt time ZNEIN, and the subsequent processing is temporarily terminated. On the other hand, in step 102, when the current pulse time TNINT is twice or more the previous pulse time TNINT, it is determined that the engine rotation pulse interrupted this time is the reference position signal. That is, as shown in FIG. 7, when the “NE interrupt routine” is interrupted from the state where the count value CNIRQ is “13”, the pulse time TNINT calculated in step 101 becomes twice or more the previous pulse time TNINT. Become. Therefore,
In this case, it is determined that the engine rotation pulse is the reference position signal, and the process proceeds to step 107. Then, in step 107, the count value CNIRQ is reset to "0" in order to shift to a new count cycle, assuming that the current count cycle has ended. After that, the routine proceeds to step 106, where the current time (current interrupt time) NEIN is set as the previous interrupt time ZNEIN, and the subsequent processing is once terminated.

When it is determined in step 104 that the count value CNIRQ is not "13",
Go to step 108. Then, in step 108, it is determined whether or not the previously obtained pulse time TNINT is the spill time pulse time TS2 corresponding to the spill time which is the fuel injection end time. Here, when the pulse time TNINT is not the spill pulse time TS2, the routine proceeds to step 106. If the pulse time TNINT is the spill pulse time TS2, the pulse time TNIN is determined in step 109.
T is set as the spill pulse time TS2.

In this embodiment, as shown in FIG. 7, the spill timing is set between the count value CNIRQ becoming "4" and the count value "5". That is, the spill pulse time TS2 corresponds to the pulse time TNINT required for the crankshaft 40 to rotate by 11.25 ° CA from when the count value CNIRQ becomes “4” to “5”. ing. The position of the pulse time TS2 during spill corresponds to the vicinity of the time when the pulse time TNINT becomes the maximum, that is, the time when the instantaneous rotation speed of the engine rotation speed NE becomes the minimum.

Next, at step 110, the instantaneous time TN13n is set to the instantaneous time T in the previous injection cycle.
It is set as N13o, and the process proceeds to step 106. In other words, this instantaneous time TN13o is near the timing when the pulse time TNINT becomes the minimum after the fuel injection in the injection cycle before the last in the previous count cycle, that is, the instantaneous engine speed NE after the fuel injection in the injection cycle before the end. This corresponds to the vicinity of the time when the rotation speed becomes the highest.

As described above, in this "NE interrupt routine", as shown in FIG. 7, every time the engine rotation pulse rises, from the rising of the previous engine rotation pulse to the rising of this engine rotation pulse. The required time is calculated as the pulse time TNINT. Then, of the pulse time TNINT, the pulse time TNINT in the vicinity of the spill timing which is the last fuel injection end timing is set as the spill pulse time TS2 in the previous injection cycle. Also, after the fuel injection in the previous injection cycle is completed, the engine speed N
Pulse time T near the time when the instantaneous rotation speed of E becomes the highest
NINT is the instantaneous time TN in this injection cycle
It is set as 13n. Further, the pulse time TNINT near the time when the instantaneous rotational speed of the engine rotational speed NE becomes the highest after the end of the fuel injection in the injection cycle two times before.
Is set as the instantaneous time TN13o in the previous injection cycle.

The spill pulse time TS2 and the instantaneous times TN13n and TN13o thus set are used for predicting and determining the target spill timing in the current injection cycle.

Next, the spill pulse time TS2 and the instantaneous time TN obtained in the above-mentioned "NE interrupt routine".
The processing operation of the fuel injection amount control performed using 13n and TN13o will be described.

The flowchart shown in FIG. 8 is executed by the ECU 71.
Among the processes executed by the above, it is a "main routine" for controlling the fuel injection amount in the fuel injection pump 1, and is executed by a regular interruption every predetermined time. In this embodiment, the instantaneous time TN1 in this injection cycle is
This "main routine" is interrupted after 3n is set. Further, this flowchart will be described with reference to the time chart of FIG.

When the processing shifts to this routine, first, at step 201, the engine speed NE, the accelerator opening ACCP, etc. are read based on the respective detection signals from the rotation speed sensor 35, the accelerator opening sensor 73, etc. Along with this, the spill pulse time TS2 in the previous injection cycle and the instantaneous time TN1 in the current injection cycle, which are obtained by the “NE interrupt routine”
3n, and the instantaneous time TN1 in the previous injection cycle
Read 3o respectively.

Next, at step 202, the engine speed NE and the accelerator opening ACC that have been read in before are read.
Based on P etc., the spill opening angle ANGSPV as the target crank angle corresponding to the target fuel injection amount is calculated. As shown in FIG. 9, the spill opening angle ANGSPV is a timing at which the electromagnetic spill valve 23 is opened (turned off) to spill fuel in order to end the fuel injection from the time when the reference position signal is generated (target spill timing). ) Is an angle corresponding to.

Then, in step 203, the spill timing pulse number CANGL and the surplus angle θREM are respectively calculated based on the spill opening angle ANGSPV previously obtained. The spill timing pulse number CANGL and the remainder angle θREM are obtained according to the following equation (1).

ANGSPV / 11.25 = CANGL + θREM (1) That is, as shown in FIG. 9, the spill opening angle ANGSPV.
Corresponds to the angle of one engine rotation pulse, “11.
25 ”and divide the quotient by the spill time pulse number CAN
It is set as GL and the surplus is set as the remainder angle θREM. Where spill time pulse number CANG
L is the spill opening angle ANG from the time the reference position signal is generated.
It is the pulse count number up to the engine rotation pulse immediately before SPV, and in FIG. 9, the number is “4”. The surplus angle θREM is a value indicating the surplus from the engine rotation pulse immediately before the spill opening angle ANGSPV to the spill opening angle ANGSPV in terms of an angle.
The angle is less than the angle of 1 piece (11.25 ° CA).

Next, at step 204, the spill time pulse time TS2 and the instantaneous time TN previously read.
Based on 13n and TN13o, the final corrected spill pulse time TS2a in the current injection cycle is calculated. The post-correction spill pulse time TS2a is obtained according to the following equation (2).

TS2a = K1 × TN13n− (TN13n−TN13o) × K2 (2) Here, K1 = TS2 / TN13o. That is, an instantaneous time TN13o corresponding to the vicinity of the time when the instantaneous rotational speed of the engine speed NE becomes the highest after the end of the fuel injection in the injection cycle before the preceding injection cycle, and a spill time pulse time TS2 corresponding to the vicinity of the spill timing in the previous injection cycle. Is set as the rotation fluctuation rate K1. That is, this rotational fluctuation rate K1 is from the time when the instantaneous rotational speed of the engine rotational speed NE becomes maximum after the fuel injection two times before the time until the instantaneous rotational speed of the engine speed NE at the time of the previous fuel injection becomes the minimum. , Shows the degree of rotation fluctuation of the crankshaft 40. Then, the rotational fluctuation rate K1 is multiplied by the instantaneous time TN13n corresponding to the vicinity of the time when the instantaneous rotational speed of the engine rotational speed NE becomes the highest after the end of the fuel injection in the previous injection cycle. Further, K2 is a correction coefficient that changes at the time of acceleration or deceleration, and for example, as shown in the map of FIG.
E and engine speed N read in the previous control cycle
It is determined according to the rotation change ΔNE which is the deviation from E.
Then, the above-mentioned instantaneous time TN13n and instantaneous time TN13
The deviation from o is obtained as an instantaneous time difference corresponding to the amount of change in rotation of the crankshaft 40, and the instantaneous time difference is multiplied by the correction coefficient K2 for correction.

That is, based on the instantaneous time TN13n corresponding to the vicinity of the time when the instantaneous rotational speed of the engine rotational speed NE becomes maximum after the end of fuel injection in the previous injection cycle, the instantaneous time TN13n is multiplied by the rotational fluctuation rate K1. . Then, from the multiplication result, the instantaneous time TN1
The result obtained by multiplying the instantaneous time difference, which is the deviation between 3n and the instantaneous time TN13o, by the correction coefficient K2 is subtracted. As a result, the corrected spill pulse time TS2a is calculated in consideration of the rotation fluctuation and the rotation change of the crankshaft 40.

Then, in step 205, the spill time TSPON is calculated based on the previously calculated surplus angle θREM and the corrected spill time pulse time TS2a. That is, the surplus angle θREM is converted into time based on the corrected spill time pulse time TS2a. The spill time TSPON is calculated according to the following equation (3).

TSPON = (θREM / 11.25) × TS2a (3) After that, in step 206, the electromagnetic spill valve 23 is turned off based on the spill timing pulse number CANGL and the spill time TSPON previously obtained. The end timing of the fuel injection from the fuel injection pump 1, that is, the fuel injection amount is controlled, and the subsequent processing is temporarily ended.

The fuel injection amount control in the diesel engine 2 is executed as described above. And
In this embodiment, in order to convert the surplus angle θRAM into time, the corrected spill time pulse time TS2a is used instead of simply using the spill time pulse time TS2 in the vicinity of the previous spill time. Then, in obtaining the corrected spill-time pulse time TS2a, in addition to the spill-time pulse time TS2 in the vicinity of the previous spill timing, the instantaneous speed of the engine speed NE is the highest after the end of each of the fuel injections of the previous time and the previous time. The pulse time TNINT in the vicinity of the time, that is, the instantaneous times TN13n and TN13o are obtained. Further, the ratio of the instantaneous time TN13o and the spill time pulse time TS2 is set as a rotation variation rate K1 indicating the degree of rotation variation of the crankshaft 40. Then, at the instantaneous time TN13n, this rotation fluctuation rate K
By multiplying by 1, the current spill pulse time in consideration of the rotation fluctuation of the crankshaft 40 is predicted.

Further, the deviation between the instantaneous time TN13n and the instantaneous time TN13o is obtained as an instantaneous time difference corresponding to the amount of change in rotation of the crankshaft 40, and a correction coefficient K2 that changes during acceleration or deceleration is calculated for this instantaneous time difference. It is corrected by multiplying. Then, by subtracting the correction value of this instantaneous time difference from the predicted current spill pulse time, the final corrected spill pulse time of this time in which the rotational fluctuation and rotational change of the crankshaft 40 are taken into consideration. TS2a is calculated.

Therefore, even if the rotation fluctuation or rotation change of the crankshaft 40 becomes large due to a change in engine load or the like, the spill pulse time TS2a near the current target spill time is taken into consideration in consideration of the change and change. Can be predicted with high accuracy. Then, the surplus angle θRAM is time-converted based on the highly accurate predicted spill time pulse TS2a, so that a more accurate spill time TSPON can be obtained. Then, the off timing of the electromagnetic spill valve 23 is determined based on the highly accurate spill time TSPON.
Even if a rotation fluctuation or rotation change occurs in the engine, the engine 2 at that time is hardly affected by the fluctuation or change.
It is possible to reliably obtain the target injection amount according to the operating state of. Therefore, the accuracy of fuel injection amount control can be improved. Further, since the accuracy of the fuel injection amount control is improved, it is possible to prevent the rotation fluctuation of the engine 2 in advance and suppress the output reduction of the engine 2 or suppress the occurrence of surging.

Incidentally, if the previous spill-time pulse time TS2 is simply used to convert the surplus angle θRAM into time as in the prior art, as shown in FIG. Difference from TS2a ΔTS2
Can not be compensated. However, in this embodiment, even if there is a large difference ΔTS2 between the previous spill-time pulse time TS2 and the current spill-time pulse time TS2a, this difference ΔTS2 is hardly affected and the current spill-time pulse The time TS2a can be accurately predicted and obtained.

Further, in the present embodiment, when the corrected spill pulse time TS2a is calculated, the instantaneous time corresponding to the vicinity of the time when the instantaneous rotational speed of the engine rotational speed NE becomes the highest after the end of the fuel injection of the previous time and the fuel injection of the previous two times. TN13n,
TN13o is used. That is, the time when the instantaneous rotational speed of the engine rotational speed NE becomes maximum after the end of fuel injection is the time when the instantaneous rotational speed is most stable during the injection cycle. Therefore, the corrected spill pulse time TS
In calculating 2a, the instantaneous time TN13 corresponding to the vicinity of the time when the instantaneous rotational speed of the engine rotational speed NE is most stable.
By using n and TN13o, the post-correction spill pulse time TS2a can be predicted and obtained with higher accuracy.

The present invention is not limited to the above-described embodiment, and the configurations of the respective parts may be modified and embodied as follows, for example, without departing from the spirit of the present invention.

(1) In the above embodiment, when the corrected spill pulse time TS2a is calculated, the pulse time TNINT in the vicinity of the time when the instantaneous engine speed NE becomes maximum after the fuel injection is completed, that is, the instantaneous time TN13n. , T
Although N13o is used, the pulse time TNINT at any other time during the injection cycle may be used.

(2) In the above-described embodiment, the fuel injection amount control of the diesel engine 2 has been described as a specific example. However, it should be applied to a case where a crank angle near the target ignition timing of a gasoline engine is detected. You can also

[0075]

As described above in detail, according to the invention described in claim 1, the pulse time in the vicinity of the time when the instantaneous rotational speed of the internal combustion engine becomes maximum after the end of the control time of the actuator two times before, and the actuator Is calculated as the rotation fluctuation rate, which is the ratio to the pulse time in the vicinity of the previous control timing of, and the calculated rotation fluctuation rate and the time when the instantaneous rotation speed of the internal combustion engine becomes the highest after the end of the previous control timing of the actuator. The pulse time in the vicinity of the target crank angle this time is predicted based on the pulse time in the vicinity. For this reason, it is possible to perform the time conversion of the surplus angle with high accuracy without being affected by the rotational fluctuation of the internal combustion engine, and thus it is possible to reliably obtain the target control amount. In addition, since the pulse time in the vicinity of the time when the instantaneous rotation speed is most stable is used when predicting the pulse time, the pulse time can be predicted with higher accuracy.

Further, according to the invention described in claim 2, the deviation of the pulse time at the predetermined time in the previous control cycle and the present control cycle is obtained as the rotation change amount, and the prediction is made based on the rotation change amount. The applied pulse time is corrected. Therefore, the excellent effect that the surplus angle can be converted into time with higher accuracy without being affected by the rotation change of the internal combustion engine is exerted.

Further, according to the invention as set forth in claim 3, in the previous control cycle, the pulse time in the vicinity of the time when the instantaneous rotational speed of the internal combustion engine becomes maximum after the end of the control time two times before, and the present control During the cycle, the deviation from the pulse time in the vicinity of the time when the instantaneous rotation speed of the internal combustion engine reaches the maximum after the end of the previous control time is obtained as the rotation change amount. Therefore, when the rotation change amount is obtained, the predicted pulse time can be corrected more accurately by using the pulse time near the time when the instantaneous rotation speed is most stable.

[Brief description of drawings]

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

FIG. 2 is a schematic configuration diagram showing a fuel injection amount control device for a diesel engine with a supercharger in one embodiment embodying the present invention.

3 is an enlarged sectional view showing the fuel injection pump of FIG.

FIG. 4 is a partially enlarged front view showing a pulsar and a rotation speed sensor.

FIG. 5 is a block diagram showing an electrical configuration of an ECU.

FIG. 6 is a flowchart illustrating a “NE interrupt routine” executed by the ECU and interrupted at the rising edge of the engine rotation pulse.

FIG. 7 is a time chart illustrating a correspondence relationship between engine rotation pulses and pulse times.

FIG. 8 is a flowchart illustrating a “main routine” for controlling a fuel injection amount executed by an ECU.

FIG. 9 is a time chart showing the relationship between the engine rotation pulse and the operation of the electromagnetic spill valve.

FIG. 10 is a map in which correction coefficients for rotational changes are predetermined.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Fuel injection pump, 2 ... Diesel engine as an internal combustion engine, 23 ... Electromagnetic spill valve as an actuator, 35 ... Rotation speed sensor as pulse signal output means constituting operating state detection means, 40 ... Crankshaft,
71 ... ECU constituting the target crank angle calculation means, the surplus angle calculation means, the pulse time calculation means, the angle time conversion means, the control means, the rotation fluctuation calculation means, the pulse time prediction means and the correction means, 73 ... Operating state detection means Constituting accelerator opening sensor, TNINT ... pulse time, TN13n,
TN13o ... instantaneous time, TS2 ... pulse time at spill,
ANGSPV ... Spill opening angle as target crank angle, CANGL ... Spill timing pulse number, .THETA.REM ... Surplus angle, TS2a ... Corrected spill pulse time, TSPO
N ... spill time, K1 ... rotation fluctuation rate.

Claims (3)

[Claims] 1. A pulse signal output means for outputting a pulse signal each time a crankshaft of an internal combustion engine is rotated by a constant crank angle, an actuator for adjusting a control amount such as a fuel injection amount in the internal combustion engine, and an internal combustion engine. And a target crank for calculating a target crank angle corresponding to the time at which the operation of the actuator should be controlled in order to obtain a control amount determined according to the detected operating state. Angle calculation means, based on the pulse signal from the pulse signal output means, the pulse signal count number from the predetermined reference position of the pulse signal to the target crank angle position calculated by the target crank angle calculation means and its pulse A surplus angle calculating means for calculating a surplus angle which is less than one signal, and an output from the pulse signal output means. The required time between the pulse signals, the pulse time calculation means for calculating as a pulse time corresponding to the time required for the crankshaft to rotate a constant crank angle, and the surplus angle calculated by the surplus angle calculation means, Angle time conversion means for converting time based on the pulse time calculated by the pulse time calculation means, pulse signal count number calculated by the surplus angle calculation means and time conversion value of the surplus angle by the angle time conversion means In a control device for an internal combustion engine having a control means for controlling the operation of the actuator at a timing determined from, in the vicinity of the time when the instantaneous rotational speed of the internal combustion engine becomes maximum after the control time of the actuator two times before the end The ratio between the pulse time and the pulse time near the previous control time of the actuator Based on the rotation fluctuation calculation means for calculating the dynamic ratio, the calculated rotation fluctuation rate, and the pulse time in the vicinity of the time when the instantaneous rotation speed of the internal combustion engine becomes maximum after the last control time of the actuator, The target crank angle calculating means is provided with pulse time predicting means for predicting the pulse time in the vicinity of the target crank angle this time, and the surplus angle is converted into time by the angle time converting means based on the predicted pulse time. A control device for an internal combustion engine, characterized in that. 2. The pulse time predicting means obtains a deviation of pulse time at a predetermined time in a previous control cycle and a current control cycle as a rotation change amount, and based on the rotation change amount, the predicted pulse time is obtained. The control device for an internal combustion engine according to claim 1, further comprising a correction unit that corrects the correction. 3. The correction means, in the last control cycle, the pulse time in the vicinity of the time when the instantaneous rotational speed of the internal combustion engine becomes highest after the end of the control time of the last two times, and in the current control cycle, The control device for an internal combustion engine according to claim 2, wherein a deviation from a pulse time in the vicinity of a time when the instantaneous rotation speed of the internal combustion engine becomes maximum after the control time is finished is obtained as a rotation change amount.