JP2687768B2 - Engine control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel injection pump for an electronically controlled diesel engine applied to an automobile, for example.
And a control device for the engine .

[0002]

2. Description of the Related Art Conventionally, in a fuel injection pump of an electronically controlled diesel engine, a spill port is controlled by, for example, an electromagnetic spill valve or the like so that a fuel injection amount obtained according to a lift of a plunger thereof becomes a target value. I am trying to open it. As a result, the fuel from the high pressure chamber of the plunger overflows (spills) to the fuel chamber, and the pumping of fuel is completed.
That is, the end of fuel injection is controlled to obtain the required fuel injection amount.

In such an electromagnetic spill valve, a target spill angle is usually converted into time by a signal which is synchronized with the lift of the plunger and is input at every constant pump rotation angle, for example, an engine rotation pulse and an average engine rotation speed. Then, the target spill timing is determined, and the electromagnetic spill valve is controlled to be turned on / off based on the target spill timing.

For example, in the technique disclosed in Japanese Unexamined Patent Publication No. 62-267547, an electromagnetic spill is performed at a target spill timing corresponding to the injection end timing in order to obtain a fuel injection amount determined according to the operating state at that time. The valve opens the spill port. Here, in order to determine the target spill timing, based on the engine rotation pulse obtained for each constant crank angle, the pulse count number from one reference position of the engine rotation pulse to the target spill angle and one pulse are less than Find the remainder angle. The remaining angle is converted into time based on the required time for one pulse including the previous spill time (pulse time during spill). Further, for example, Japanese Examined Patent Publication No. 2-43024
The technology disclosed in
Two engines excluding engine rotation pulse of rank angle
Each time the rotation pulse is detected, the instantaneous rotation speed (pulse
The elapsed time is detected, and both instantaneous rotational speeds (when a pulse elapses)
The pulse time at the time of spill based only on the difference between
Then, using this estimated spill pulse time,
The angle was converted to time.

[0005]

However, in the former prior art, the difference in the spill pulse time becomes large when the engine rotation fluctuation is large. For example, when the instantaneous rotation speed around the current target spill time is lower than that around the previous spill time, the current spill time pulse time is longer than the previous spill time pulse time. Therefore, when converted much angle time based on the such rotation greater preceding spill Pulse time obtained in a state of change, the time conversion error becomes very large, the fuel injection amount control The accuracy may have deteriorated. In addition, there is a possibility that the deterioration of the accuracy of the fuel injection amount control may further induce the rotation fluctuation of the engine and cause the output reduction. On the other hand, in the latter conventional technology
Is always near the piston compression top dead center during the spill period.
For this reason, the two instantaneous rotational speeds (when the pulse elapses as described above)
The method of estimating the pulse time during spill from the difference between
Is when the engine speed tends to decrease during the spill period.
And you can't handle both cases
There was a problem.

The present invention has been made in view of the above-mentioned circumstances, and an object thereof is to obtain an engine at a target control signal generation timing without being influenced by an engine rotation fluctuation.
If the engine speed is either increasing or decreasing,
Is to make the engine control accurate .

[0007]

[Means for Solving the Problems]
For this reason, as shown in FIG., DEngine
According to the operating status ofControl signalGetforTargetControl signal
OutbreakCalculate the timeControl signal generationTiming calculation meansM1When,
BeforeNoteEngine rotation pulse at a fixed crank angle
Of each engine rotation pulse
Engine rotation detection means for detecting rotation speedM2When,Said
Engine sequentially detected by the engine rotation detecting means
Based on the rotation pulse, the engine rotation pulse
From the semi-positionGeneration of the control signalPerformed by the timing calculation means M1
Target to be calculatedControl signal generationEngine rotation pulse until the time
The number of scans and the remaining angle less than one pulse
Surplus angle calculation meansM3And the surplus angle calculator
The remainder angle calculated by the step M3Includes extra angle
Angle time converted to time based on the time required for one pulse
Conversion meansM4When,SaidCalculation by surplus angle calculation means M3
Be doneSaidTargetControl signal generationEngine rotation power until the time
Russ counts andSaidSurplus by angle time conversion means M4
The time timing determined from the time conversion value of the angle
ThanGenerate control signal Generate control signalExecution meansM5
When,Generation of the target control signal within the current count cycle
The engine rotation pulse count just before the time is
Ent detected the lowest instantaneous rotational speed within the
Determine whether it is greater than the number of gin rotation pulses
Rotation variation determining means M6 and the rotation variation determining means M
If the determination result of 6 is negative,Angle time conversion hand
Should be used for time conversion in tier M4Said1 pal
Time requiredInstantaneous rotation within the count cycle this time
From the downward trend of speedPredictOn the other hand, the rotation fluctuation determination hand
If the determination result of the stage M6 is affirmative, the one pulse
The time required for the previous control signal within the previous count cycle
Instantaneous rotation speed before the generation time and after the previous control signal generation time
Predict based on the instantaneous rotation speed ofPulse duration predictor
StepM7It has and.

[0008]

[0009]

[Action] According to the above arrangement, during the operation of the engine, control
The control signal generation timing calculation means M1 depends on the engine operating state.
The target control signal generation time is calculated in order to obtain the control signal . The engine rotation detecting means M2 is configured to detect an engine rotation pulse every predetermined crank angle of the d Nji down, it detects the instantaneous rotational speed of the engine per revolution pulses. Further, the surplus angle calculating means M3 is based on the engine rotation pulse sequentially detected by the engine rotation detecting means M2 , and moves from the reference position where the engine rotation pulse is present to the front position.
Target calculated by the control signal generation timing calculation means M1
The number of engine rotation pulses counted up to the control signal generation time and the surplus angle less than one pulse are calculated.
Further, the angle-time conversion means M4 time-converts the surplus angle calculated by the surplus angle calculation means M3 based on the required time for one pulse including the surplus angle . And the control signal
The signal generation executing means M5 is based on the time timing determined from the count number of the engine rotation pulse until the target control signal generation timing calculated by the surplus angle calculating means M3 and the time conversion value of the surplus angle by the angle time converting means M4. Control
Generate a signal .

Here, the rotation fluctuation determining means M6 is
Immediately before the target control signal generation time in the und cycle
The engine rotation pulse count is within the previous count cycle
Engine rotation speed detected at the lowest instantaneous rotation speed in
It is determined whether or not it is larger than the count number of Ruth. or,
The pulse required time predicting means M7 is the rotation fluctuation determining means.
If the determination result of M6 is negative, the angle time conversion is performed.
The one packet to be used for time conversion in the means M4.
The required time for the lus is instantly counted within the current count cycle.
While predicting from the downward trend of the rolling speed, the rotation fluctuation determination
If the determination result of the means M6 is affirmative, the one pulse
Minute control time within the previous count cycle
Instantaneous rotation speed before signal generation time and last control signal generation time
Predict based on the subsequent instantaneous rotation speed .

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An engine control device according to the present invention will be described below.
It will be described in detail with reference to an embodiment embodying a fuel injection amount control <br/> equipment for diesel engines in motor vehicles in FIGS 12.

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 which is drivingly connected to a crankshaft 40 of the diesel engine 2 via a belt or the like. The fuel injection pump 1 is driven by the rotation of the drive pulley 3, and the fuel is injected 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, a 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 disc-shaped pulsar 7 is attached to the base end side of the drive shaft 5. The diesel engine 2 is attached to the outer peripheral surface of the pulsar 7.
In this case, four cutting teeth are formed at equal angular intervals, that is, four cutting teeth are formed at equal angular intervals, and between each cutting tooth, 14 (total of 56) projections are formed at equal angular intervals. I have. 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 the coupling, so that the cam plate 8 rotates and engages with the cam roller 10 to reciprocate in the left-right direction by the same number as the number of cylinders. Driven. Further, the plunger 12 is driven to reciprocate 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 12 is moved back while the cam face 8a rides down the cam roller 10.

The plunger 12 is fitted into a cylinder 14 formed in the pump housing 13, and a high pressure chamber 15 is formed between the tip of the plunger 12 and the bottom 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.
A distribution passage 18 and a suction port 19 are formed in the .

Then, the drive shaft 5 is rotated to drive the fuel feed pump 6, whereby fuel is supplied from a fuel tank (not shown) into the fuel chamber 21 through 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. In the middle of the spill passage 22, there is provided an electromagnetic spill valve 23 as an overflow regulating valve for adjusting the fuel spill from the high-pressure chamber 15. 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 the high-pressure chamber 1 is opened.
The fuel in 5 is spilled into the fuel chamber 21. Also, coil 2
When 4 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.

Accordingly, by controlling the energization time of the electromagnetic spill valve 23, the valve 23 is controlled to close and open, and the spill amount 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 amount of fuel injected from the fuel injection nozzle 4 is controlled.

Below the pump housing 13, there is provided a timer device (expanded 90 degrees in this figure) 26 for adjusting the fuel injection timing. 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 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. 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 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 plunger 1 is moved through the cam plate 8.
2 is determined.

The timer device 26 is provided with a timing control valve 33 for adjusting the fuel pressure of the timer device 26, that is, the control oil pressure. That is, the pressurizing chamber 30 and the low-pressure chamber 29 of the timer housing 27
The timing control valve 33 is provided in the middle of the communication passage 34. The timing control valve 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 timing control valve 33. Then, the lift timing of the plunger 12 is controlled by the fuel pressure adjustment, and 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 an engine rotation detecting 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 detects passage of the protrusions of the pulsar 7 and the like when the protrusions and the like of the pulsar 7 cross each other to detect engine speed NE
The engine rotation pulse is output as a timing signal corresponding to, that is, a rotation angle signal for each predetermined crank angle (11.25 ° CA). Also, this rotation speed sensor 35
Detects the instantaneous rotation speed for each engine rotation pulse. Further, since the rotation speed sensor 35 is integrated with the roller ring 9, the rotation speed sensor 35 outputs a reference timing signal to the plunger lift at a constant timing regardless of the control operation of the timer device 26.

Next, the diesel engine 2 will be described. In the diesel engine 2, a main combustion chamber 44 corresponding to each cylinder is formed by the cylinder 41, the piston 42, and the cylinder head 43. or,
Each of the main combustion chambers 44 is connected to a sub-combustion chamber 45 provided correspondingly for each cylinder. Then, the fuel injected from each fuel injection nozzle 4 is supplied to each sub combustion chamber 45. 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 is provided with an intake pipe 47 and an exhaust pipe 50, respectively. The intake pipe 47 is provided with a compressor 48 of a turbocharger 48 constituting a supercharger, and the exhaust pipe 50 is provided with a turbocharger. 48
Turbine 51 is provided. The exhaust pipe 50 is provided with a waste gate valve 52 for adjusting the supercharging pressure PiM. As is well known, the turbocharger 48 uses the energy of the exhaust gas to rotate the turbine 51, and a compressor 49 on the same axis as the turbine 51.
To increase the pressure of the intake air. Thus, a high-density air-fuel mixture is sent into the main combustion chamber 44 to burn a large amount of fuel, thereby increasing the output of the diesel engine 2.

The diesel engine 2 has an exhaust pipe 5
A recirculation pipe 54 is provided for recirculating a part of the exhaust gas in the cylinder 0 to the suction port 53 of the intake pipe 47. An exhaust gas recirculation valve (EGR valve) 55 for adjusting the amount of exhaust gas recirculation is provided in the middle of the recirculation pipe 54. The opening and closing of the EGR valve 55 is controlled by the control of a vacuum switching valve (VSV) 56.

Further, a throttle valve 58 is provided in the middle of the intake pipe 47 so as to open and close in accordance with the amount of depression of an accelerator pedal 57. Also, its throttle valve 5
A bypass passage 59 is provided in parallel with 8, and a bypass throttle valve 60 is provided in the bypass passage 59. The opening and closing of the bypass throttle valve 60 is controlled by an actuator 63 having a two-stage diaphragm chamber driven by control of two VSVs 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 in the fuel injection pump 1 and the diesel engine 2 as described above
3, the timing control valve 33, the glow plug 46, and the VSVs 56, 61, 62 include control signal generation timing calculation means, surplus angle calculation means, angle time conversion means, and control.
Signal generation execution means, an electronic control unit that constitutes the rotational fluctuation determination means and pulse duration predicting means (hereinafter simply "EC
U ”) and each of the EC
U71 controls the drive timing of them.

As a sensor for detecting the operating state, the following various sensors are provided in addition to the rotation speed sensor 35. That is, the intake pipe 47 is provided with an intake air temperature sensor 72 for detecting the intake air temperature THA near the air cleaner 64. Further, an accelerator opening sensor 73 for detecting the accelerator opening ACCP corresponding to the load of the diesel engine 2 from the open / close position of the throttle valve 58 is provided. An intake pressure sensor 74 for detecting the intake air pressure after supercharging by the turbocharger 48, that is, the supercharging pressure PiM is provided near the intake port 53. 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 of the diesel engine 2, 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) SP by turning on / off the reed switch 77b by a magnet 77a rotated by the rotation of the gear.

The above-mentioned sensors 72 to 77 are respectively connected to the ECU 71, and the rotation speed sensor 3 is connected.
5 is connected. In addition, the ECU 71 controls each sensor 35,
Based on the signals output from 72 to 77, the electromagnetic spill valve 23, the timing control valve 33, the glow plug 46, the VSVs 56, 61, 62, etc. are suitably controlled.

Next, the structure of the above-mentioned 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.
Are configured as logical operation circuits connected with each other.

The input port 85 is provided with the above-described intake air temperature sensor 72, accelerator opening sensor 73, intake pressure sensor 74, and water temperature sensor 75 in buffers 88, 89, 90, and 9, respectively.
1, 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, detection signals of the sensors 35, 72 to 77, etc., which are input through the input port 85. Each drive circuit 9 is connected to the output port 86.
The electromagnetic spill valve 23, the timing control valve 33, the glow plug 46, the VSVs 56, 61, 62 and the like are connected via 6, 97, 98, 99, 100, 101.

Then, the CPU 81 controls the sensors 35 and 72
Based on the input value read from ~ 77, the electromagnetic spill valve 2
3. The timing control valve 33, the glow plug 46, and the VSVs 56, 61, 62 are suitably 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. The flowchart of FIGS.
Among the respective processes executed by No. 1, the NE interrupt routine interrupted at the rising edge of the engine speed pulse of the engine speed NE input from the speed sensor 35 is shown.

When the processing shifts to this routine, first, at step 101, it is judged if the number of pulse counters CNIRQ for counting engine rotation pulses is "0". In this embodiment, the pulse counter CNI
The number of "0-12" is periodically counted by RQ,
The fuel injection amount control process is executed each time the counting cycle is performed. Then, in step 101, when the number of pulse counters CNIRQ is not "0", the process directly proceeds to step 103.

If the number of pulse counters CNIRQ is "0" in step 101, the maximum pulse time TM as the maximum value of the pulse time TNINT obtained in the previous count cycle is determined in step 102.
AX is reset to "0", and then the process proceeds to step 103. Here, the pulse time TNINT means a crank angle (1
This is the time required to advance only 1.25 ° CA).

In step 103, which is a transition from step 101 or step 102, the pulse time TNINT corresponding to the number of pulse counters CNIRQ in the present control cycle is obtained, and the time is calculated as the pulse time array TNI.
Sequentially store with NT (i). That is, as shown in FIG.
The required pulse times TNINT are sequentially stored in RAM in the order in which the number of pulse counters CNIRQ changes from “0 to 12”.
It is stored in 83. Here, each pulse time TN
The reciprocal of the magnitude of INT corresponds to the magnitude of the instantaneous rotation speed.

Then, in step 104, the spill opening angle ANGSPV is calculated by adding the phase correction voltage VRP to the final spill angle (final injection amount) QFIN. Here, the final injection amount QFIN is a value calculated based on the engine speed NE, the accelerator opening ACCP, the cooling water temperature THW and the like by a separate main routine.

Then, in step 105, from the obtained spill opening angle ANGSPV, according to the following calculation formula (1), as shown in FIG.
ANGLa and the remainder angle θREM are calculated.

ANGSPV = 11.25 × CANGLa + θREM (1) After that, in step 106, the spill timing pulse number CANGLa obtained this time and the pulse number that becomes the minimum instantaneous rotation speed obtained in the previous counting cycle (minimum speed The number of pulses) CBOTM is compared to determine whether the spill timing pulse number CANGLa is less than or equal to the lowest speed pulse number CBOTM.

If the current spill timing pulse number CANGLa is equal to or less than the previous lowest speed pulse number CBOTM in step 106, the current spill timing pulse number CANGLa is an inflection point of the previous instantaneous rotational speed change. Assuming that the value has not exceeded, the process proceeds to step 107. Then, in the same step 107, from the pulse counter CNIRQ "0" in the current count cycle, the spill timing pulse number C in the current count cycle
Each pulse time TNIN up to the number one before ANGLa
Based on the value of T, the change in the instantaneous rotational speed at this time is approximated by the least squares curve as shown by the broken line in FIG. And
Based on the approximation result of the instantaneous rotation speed change, the pulse time TNINT in a number one after the spill timing pulse number CANGLa in the present count cycle is calculated, and the calculation result is set as the spill time pulse time TS1125a. That is, the spill pulse time TS1125a at the predicted inflection point of the instantaneous rotation speed change is set. After that processing, the process proceeds to step 111.

On the other hand, in step 106, if the current spill timing pulse number CANGLa is not less than or equal to the previous minimum speed pulse number CBOTM, the current spill timing pulse number CANGLa exceeds the inflection point of the previous instantaneous rotational speed change. If so, the process proceeds to step 108. Then, in step 108, the value of the pulse time TNINT at a number two before the current spill timing pulse number CANGLa is set to the pulse time before the inflection point TNIN.
Set as TK. That is, the time immediately before the predicted inflection point of the instantaneous rotation speed change is set as the pulse time TNINT.

Next, at step 109, a rotation increase correction coefficient KFIRE of the explosive force in the explosion stroke of the diesel engine 2 is calculated. That is, the spill opening angle ANGSPV obtained this time and the spill opening angle ANG obtained last time
From the difference with the previous spill opening angle ANGB as SPV,
First, referring to the map of FIG. 10, the temporary rotation increase correction coefficient KF
Ask for IREA. Next, the temporary rotation increase correction coefficient KF
IREA, actual injection timing ACTCA, previous actual injection timing A
Using CTB and engine speed NEFIR at the time of explosion,
The rotation increase correction coefficient KFIRE is calculated according to the following calculation formula (2).
Is calculated.

KFIRE = 1- {KFIREA + 0.1 × (ACTCA-ACTB)} × (2400-NEFIR) / 2000 (2) Here, the actual injection timing ACTCA is a value indicating the actual injection timing, and is separately provided. In the main routine, it is obtained based on the phase difference between the detection timing of the engine rotation speed pulse by the rotation speed sensor 35 and the detection timing of the reference position signal indicating the predetermined rotation position of the crankshaft 40 by the crank angle sensor 76. Further, the engine speed NEFIR at the time of explosion is a value uniquely determined according to the engine speed NE at that time, and the engine speed NE is "24".
"2400 rpm" when larger than "00 rpm"
Further, when the engine speed NE is smaller than "400 rpm", it is set to "400 rpm".

Then, in step 110, the pulse time after the previous inflection point TNINTA, the pulse time before the previous inflection point TNINTB, the pulse time before the inflection point TNI
Based on NTK and the rotation increase correction coefficient KFIRE, the spill pulse time TS1 at this time is calculated according to the following calculation formula (3).
Calculate 125a. Then, the process proceeds to step 111.

TS1125a = TNINTK × (TNINTA / TNINTB) × KFIRE (3) In step 111 after moving from step 107 or step 110, the current spill timing pulse number CAN
The value of the pulse time TNINT in the number one before GLa is set as the pulse time before spill timing TS1125b.

Then, at step 112, the spill time TSPONa is calculated from the spill time TS1125a and the remainder angle θREM according to the following calculation formula (4).

TSPONa = (θREM / 11.25) × TS1125a (4) Subsequently, in step 113, the spill time TSPONa is set to a predetermined value in order to prevent the delay due to the multiple interruption in consideration of the processing speed of the ECU 71. "88μs"
Is less than or equal to. Where spill time T
When SPONa is smaller than the predetermined “88 μs”, in step 114, as shown in FIG. 11, the spill time before pulse time TS1 is added to the spill time TSPONa.
The result of adding 125b is set as the final spill time TSPON. In step 115, the result obtained by subtracting “1” from the spill timing pulse number CANGLa is set as the final spill timing pulse number CANGL, and the process proceeds to step 118.

On the other hand, if the spill time TSPONa is equal to or greater than the predetermined "88 μs" in step 113, then in step 116, the spill time TSPONa is directly changed to the final spill time TSP as shown in FIG.
Set as ON. Further, in step 117, the spill timing pulse number CANGLa is set as it is as the final spill timing pulse number CANGL, and the routine proceeds to step 118.

Then, step 115 or step 11
In step 118 after shifting from 7, the electromagnetic spill valve 23 is turned off based on the set final spill timing pulse number CANGL and final spill time TSPON.
The end timing of the fuel injection from the fuel injection pump 1, that is, the fuel injection amount is controlled. Then, the process proceeds to step 119.

In step 119, it is determined whether or not the current pulse time TNINT is equal to or longer than the maximum pulse time TMAX in the previous count cycle. here,
When the pulse time TNINT is not longer than the maximum pulse time TMAX, the process directly proceeds to step 122. Also, the pulse time TNINT is the maximum pulse time TMA
If X or more, in step 120, the current pulse time TNINT is set as the maximum pulse time TMAX for use in the calculation of the next count cycle.

Then, in step 121, the number of the pulse counter CNIRQ of this time is set as the provisional minimum speed pulse number CBOTMa in the current count cycle, and then the process proceeds to step 122.

Then, step 119 or step 12
In step 122 after shifting from 1, it is determined whether or not the number of pulse counters CNIRQ this time is "12". Here, the number of pulse counters CNIRQ is "1.
If it is not “2”, the process directly proceeds to step 126. If the pulse counter CNIRQ is "12", the provisional lowest speed pulse number CBOT is used in step 123 for use in the calculation of the next count cycle.
Pulse time TNINT at a number one after the number of Ma
(CBOTMa + 1) after inflection point pulse time TNINT
Set as A.

Further, in step 124, the pulse time TNINT (CBOTMa-1) at a number one before the number of provisional lowest speed pulse number CBOTMa is also used for the pulse before the inflection point in order to use it in the calculation of the next count period. Set as time TNINTB.

Further, in step 125, the provisional lowest speed pulse number CBOTMa is set as the lowest speed pulse number CBOTM to be used in the next count cycle calculation in order to be used in the next count cycle calculation. Move to.

At step 126 after shifting from step 122 or step 125, the current number of pulse counters CNIRQ is the final spill timing pulse number CANGL.
Then, it is determined whether or not the electromagnetic spill valve 23 is turned off. Here, when the above determination is negative, the subsequent processing is temporarily terminated. If the above determination is affirmative, in step 127, the spill opening angle ANGSPV obtained in the current counting cycle is set as the previous spill opening angle ANGB in order to use the calculation in the next counting cycle.

Then, in step 128, the current actual injection timing ACTCA is set as the previous actual injection timing ACTB, and the subsequent processing is temporarily terminated. The fuel injection amount control of the diesel engine 2 is executed as described above. In this embodiment, the surplus angle θREM
The time required for one pulse used for time conversion is more accurately predicted and set. That is, the current spill timing pulse number CANGLa is the previous lowest speed pulse number C.
When it is equal to or smaller than BOTM, as indicated by a broken line in FIG. 8, the pulse counter CNIRQ “0” in the current count cycle is immediately before the spill timing pulse number CANGLa in the current count cycle. Based on the value of each pulse time TNINT up to a number, the present change in the instantaneous rotation speed is approximated by a least squares curve. or,
Based on the approximation result of the instantaneous rotation speed change, the pulse time TNINT in a number one after the spill timing pulse number CANGLa in the present count cycle is calculated, and the calculation result is set as the spill time pulse time TS1125a. That is, the change in the instantaneous rotation speed in the current count cycle is approximated by a curve, and the current spill pulse time TS1125a is predicted from the curve approximation.

Therefore, in this case, even if the instantaneous rotation speed around the current target spill time is greatly reduced due to the rotation fluctuation of the diesel engine 2 as compared with that around the previous spill time, The spill pulse time TS1125a around the target spill timing can be predicted and obtained with higher accuracy by curve approximation of the instantaneous rotation speed change. Since the surplus angle is converted into time based on the highly accurate predicted spill time pulse TS1125a, a more accurate spill time TS is obtained.
PONa can be determined. Since the fuel injection amount control is executed by using the highly accurate spill time TSPONa, the fuel injection amount control can be performed accurately without being affected by the rotation fluctuation even if the rotation fluctuation occurs in the diesel engine 2. It can be performed well and the accuracy of fuel injection amount control can be improved. Further, since the accuracy of the fuel injection amount control can be improved, it is possible to prevent the engine rotation fluctuation from being induced and suppress the output reduction of the diesel engine 2.

On the other hand, the current spill timing pulse number CANG
When La becomes larger than the previous lowest speed pulse number CBOTM, the value of the pulse time TNINT at a number two before the current spill timing pulse number CANGLa is set as the current inflection point pulse time TNINTK. .
Also, the rotation increase correction coefficient KFI due to the explosive force in the explosion stroke
Calculate RE. And the pulse time T before the inflection point this time
The NINTK, the rotation increase correction coefficient KFIRE, sets the result of multiplying the ratio of pulse time TNINTA after the inflection point of the last relative to the previous inflection temae pulse time TNINTB as the current spill during the pulse time TS1125a <br /> In other words, the engine rotation just before this target spill time
Pulse count number CANGLa and previous lowest speed pulse
As a result of comparison with several CBOTM, at the time of this target spill
It was determined that the engine speed in the
In this case, the spill pulse time TS1125a is corrected based on the difference between the previous and present explosive forces.

Therefore, in this case, the influence of the rotational fluctuation of the diesel engine 2 is compensated, and therefore the spill pulse time TS1125a can be predicted and obtained with higher accuracy. Further, since the surplus angle is time-converted based on the highly accurate predicted spill time pulse time TS1125a, a more accurate spill time TSPONa can be obtained. Since the fuel injection amount control is executed by using the highly accurate spill time TSPONa, the fuel injection amount control can be performed accurately without being affected by the rotation fluctuation even if the rotation fluctuation occurs in the diesel engine 2. It can be performed well and the accuracy of fuel injection amount control can be improved. Further, it is possible to prevent the engine rotation fluctuation from being induced and suppress the output reduction of the diesel engine 2.

Further, in this embodiment, the fuel injection amount control is executed without being affected by the engine rotation fluctuation as described above. Therefore, there is no difference in the fuel injection amount controlled between different diesel engines that employ a mechanism such as a normal flywheel or a flywheel damper that has different rotation fluctuations, and the same fuel injection amount control is used. There is no problem even if the injection amount command value of is used.

Furthermore, when the flywheel damper is used in a diesel engine, engine rotation fluctuations that are not proportional to an integral multiple of the engine speed occur. However, even in this case, according to the present embodiment, since the fuel injection amount control can be performed with high accuracy without being affected by the engine rotation fluctuation, it is possible to suppress an increase in the engine rotation fluctuation. As a result, it is possible to improve drivability in an extremely low speed region.

It should be noted that the present invention is not limited to the above-described embodiment, and may be carried out as follows by appropriately changing a part of the configuration without departing from the spirit of the invention. (1) In the above embodiment, in order to approximate the change in the instantaneous rotational speed at this time by the least squares curve, the spill timing pulse number CANGL in the current count cycle is changed from “0” of the pulse counter CNIRQ in the current count cycle.
Although the values of each pulse time TNINT up to the number one before a are used, a plurality of values appropriately selected from them are used without using the values of all the pulse times TNINT. Good.

(2) In the above embodiment, the diesel engine 2 with a supercharger was described as an example, but it may be embodied as a diesel engine without a supercharger.

[0066]

As described above in detail, according to the present invention, it is determined from the count number of the engine rotation pulse until the target control signal generation timing and the time conversion value of the surplus angle which is less than one pulse. Control signal according to time timing
In the engine control device that is designed to generate
The time required for one pulse used for time conversion of the surplus angle this time is the engine rotation at the target control signal generation timing.
If it is determined that the number is declining, count this time
Prediction from the downward trend of the instantaneous rotation speed within a cycle
On the other hand, the engine speed tends to increase when the target control signal is generated.
If it is determined that the
Instantaneous rotation speed before previous generation of control signal and previous control
Since the prediction based on the instantaneous engine speed after the signal generation timing, without being influenced by the engine rotation fluctuation, also eyes
The engine speed tends to increase at the time when the target control signal is generated.
Or also can be performed much angle time conversion to be able to determine the time required for one pulse of the target with high accuracy with high precision when in any downward trend, with the engine
It has an excellent effect of improving control accuracy.

[Brief description of the drawings]

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

FIG. 2 is a schematic configuration diagram illustrating a fuel injection amount control device for an over-payment diesel engine in one embodiment embodying the present invention.

FIG. 3 is a sectional view showing a fuel injection pump according to one embodiment.

FIG. 4 is a block diagram illustrating a configuration of an ECU according to one embodiment.

FIG. 5 is a flowchart illustrating an NE interrupt routine executed by the ECU and interrupted at the rising edge of an engine rotation pulse in one embodiment.

FIG. 6 is an NE performed by the ECU in one embodiment.
It is a flowchart explaining the continuation of an interruption routine.

FIG. 7 is an NE performed by the ECU in one embodiment.
It is a flowchart explaining the continuation of an interruption routine.

FIG. 8 is an explanatory diagram illustrating a method of obtaining a spilling pulse time with respect to a change in instantaneous rotation speed in one embodiment.

FIG. 9 is a time chart for explaining how to obtain the number of spill timing pulses, a surplus angle, and the like in one embodiment.

FIG. 10 is a diagram showing a map in which a relationship between a rotation increase correction coefficient and a difference between a spill opening angle and a previous spill opening angle in one embodiment is predetermined.

FIG. 11 is a time chart illustrating a correspondence relationship between an engine rotation pulse and an electromagnetic spill valve operation, a final spill timing pulse number, a final spill time, and the like when the spill time is shorter than 88 μs in one embodiment.

FIG. 12 is a time chart for explaining the correspondence between the engine rotation pulse and the operation of the electromagnetic spill valve, the final spill timing pulse number, the final spill time, and the like when the spill time is 88 μs or more in one embodiment.

[Explanation of symbols]

1. Fuel injection pump 2. Diesel engine 12.
Plunger, 15 ... high-pressure chamber, 23 ... conductive magnetic spill valve 35
... Revolution speed sensor as engine rotation detection means, 71 ...
Target control signal generation timing calculation means, surplus angle calculation means, angle time conversion means, control signal generation execution means, rotation fluctuation determination
And T constituting the means and the pulse duration prediction means
S1125a ... Pulse time at the time of spill when the control signal is generated , θREM ... Surplus angle.

Claims (1)

(57) [Claims] 1. A computes a target control signal generation timing for obtaining a control signal in accordance with the operating state of the engine control signal onset
Raw timing calculating means, prior detects the engine rotation pulse every predetermined crank angle of the disappeared engine, an engine rotation detecting means for detecting the instantaneous rotation speed of the engine per revolution pulse, sequentially by said engine rotation detection means Based on the detected engine rotation pulse, the count number of the engine rotation pulse from a certain reference position of the engine rotation pulse to the target control signal generation timing calculated by the control signal generation timing calculation means and one pulse thereof are not reached. and remainder angle calculating means for calculating a remainder angle, less the remainder angle that is calculated by the remainder angle calculating means
And angle time conversion means for converting time based on the time required for one pulse that includes angle, the target control signal, which is calculated by the previous SL-odd angle calculating means
Generating a control signal by a time timing determined from the time conversion value of the remainder angle by counting the number of said angle time conversion unit of the engine rotation pulses to No. occurrence time
Control signal generation execution means and the target control signal generation timing within the current count cycle
The previous engine rotation pulse count is the previous count
Engine whose minimum instantaneous rotation speed is detected within the cycle
Determine whether it is greater than the count number of rotation pulses
If the determination result of the rotation variation determination means and the rotation variation determination means is negative,
The angle the duration of one pulse to be used in time conversion means for time conversion to the current count period
While predicting from the downward trend of the instantaneous rotation speed in
If the determination result of the rotation fluctuation determining means is affirmative,
Set the required time for one pulse to the previous value within the previous count cycle.
Instantaneous rotation speed before the generation time of the rotation control signal and the previous control signal
Control <br/> control device features and to Rue engine further comprising a pulse duration predicting means for predicting, based on the instantaneous engine speed after occurrence time.