JPH05240097A - Fuel injection controller of diesel engine - Google Patents

Abstract

PURPOSE:To calculate a variation in momentary engine speed so accurately and predict a desired overflow time of fuel punctually even at a time when the engine speed fluctuates so severely because of being hiccuped. CONSTITUTION:This injection controller is provided with a fuel injection pump 1, a solenoid spill valve 23, a timer unit 26, an engine speed sensor 35, an accelerator opening sensor 73, an engine control unit 71 or the like. A central processing unit of this engine control unit 71 calculates a desired overflow time on the basis of the required time for a portion of one pulse at the desired overflow time in a combustion cycle of the last time and another time conformed to a variation in momentary engine speed at just before the desired overflow time in the combustion cycle at this time. The central processing unit regulates the opening of a timer count valve 33 in the timer unit 26 so as to get a fuel injection performed at the injection phase conformed to a driving state in a diesel engine 2. In addition, this central processing unit regulates the opening of the timer count valve 33 in order to hold the injection phase of fuel forcibly in the specified phase at an area where the throttle opening is fully closed and the engine speed is lower than the specified low one.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel injection control device for a diesel engine mounted on an automobile, for example.

[0002]

2. Description of the Related Art In recent years, with the development of electronic control technology, especially digital control technology, a so-called electronically controlled diesel engine has been put into practical use in which a fuel injection pump of a diesel engine is electronically controlled. There are various methods for electronically controlling the fuel injection pump in this diesel engine, and one of them is to control the injection end timing in the fuel injection pump with an overflow adjustment valve (electromagnetic spill valve). In this method, the spill passage is opened by the electromagnetic spill valve at the target overflow time when the fuel injection amount reaches the target value, and the pressure feeding of fuel is terminated to adjust the fuel injection amount.

For controlling the opening / closing of the electromagnetic spill valve,
A rotation angle signal (engine rotation pulse) detected by the rotation speed sensor at every constant crank angle of the diesel engine is used.

As a method of calculating the time at which the fuel overflows by using the engine rotation pulse, for example, automobile technology casebook No. 7 issue number 92140 (issue date 199)
2.1.20 There is a technology disclosed in Japan Automobile Manufacturers Association Patent Subcommittee). In this technique, the target overflow timing is calculated according to the operating state of the diesel engine, and the number of engine rotation pulses from the predetermined reference position of the engine rotation pulse to the target overflow timing and the surplus angle less than one pulse are calculated. Ask for. Then, from the time required for one pulse at the target overflow timing in the previous combustion cycle and the time corresponding to the change amount of the instantaneous rotation speed immediately before the target overflow timing in the current combustion cycle, the target overflow in the current combustion cycle is calculated. Predict the time required for one pulse in the flow period. Further, time conversion of the surplus angle is performed based on the predicted value, and the electromagnetic spill valve is operated at the overflow time corresponding to the time conversion value and the engine rotation pulse number to end the fuel injection. There is.

According to this technique, even when the engine speed is changing, the surplus angle can be accurately converted into time and the fuel injection can be ended at an appropriate time to obtain the required target injection amount. It is possible.

[0006]

The rotation speed sensor for detecting the engine rotation pulse is generally mounted on a roller ring, and the rotation position of this roller ring is adjusted by a timer device. The timer device includes a timer piston that is displaced by hydraulic pressure, and the hydraulic pressure changes according to the opening of a fluid pressure adjusting valve (timing control valve). Then, the opening of the timing control valve is adjusted so that the actual position of the timer piston becomes the target timer position determined by the engine rotation speed and the injection amount command value.

Therefore, when the target timer position of the timer piston fluctuates, the phase of the engine rotation pulse with respect to the reference crank angle changes with the fluctuation.
Therefore, when calculating the change amount of the instantaneous rotation speed immediately before the target overflow timing as described above, it is necessary to consider the fluctuation of the target timer position.

However, for example, in the case of an automobile diesel engine, a transmission for converting its rotation speed and output torque is selected to a high speed stage (high gear having a small reduction ratio), and the braking device (brake) is operated from this state. When the rotation speed is reduced, a so-called "hiccup" occurs in which the vehicle repeatedly vibrates back and forth. At this time, as shown in FIG. 15, the engine speed fluctuates greatly. Then, the target timer position determined by the engine speed and the injection amount command value also fluctuates drastically as shown in the figure. Along with this, the phase of the engine rotation pulse with respect to the reference crank angle also changes drastically, so that an error occurs in the amount of change in the instantaneous rotation speed. As a result, the fuel overflow time cannot be calculated accurately.

The present invention has been made in view of the above-mentioned circumstances, and an object thereof is to accurately calculate the amount of change in the instantaneous rotational speed even when the engine speed significantly fluctuates due to hiccups or the like. It is possible to provide a fuel injection control device for a diesel engine that can accurately predict a target fuel overflow time.

[0010]

In order to achieve the above object, the present invention provides a diesel engine M as shown in FIG.
A fuel injection pump M2 that pressurizes the fuel by reciprocating motion of the plunger M2a based on the rotation of 1 and injects the pressurized fuel from the fuel injection valve M3 to the diesel engine M1 and the pressurized fuel of the fuel injection pump M2 overflows. By doing so, the overflow adjustment valve M4 that terminates the fuel injection and adjusts the fuel injection amount, and the engine rotation pulse is detected at every constant crank angle of the diesel engine M1, and the diesel engine M1 is based on the engine rotation pulse. Rotation detection means M5 for detecting the rotation speed of the diesel engine, operation state detection means M6 for detecting the operation state of the diesel engine M1, and fuel in the overflow control valve M4 according to the operation state by the operation state detection means M6. Target overflow timing calculation means M7 for calculating the target overflow timing of the engine and the engine rotation detection means M5. The number of engine rotation pulses required from the predetermined reference position of the engine rotation pulse to the target overflow timing by the target overflow timing calculation means M7 and the surplus angle less than one pulse are calculated, and the target overflow in the previous combustion cycle is further calculated. From the time required for one pulse in the current flow cycle and the time corresponding to the amount of change in the instantaneous rotation speed immediately before the target overflow time in the current combustion cycle, the time required for one pulse in the target overflow time in the current combustion cycle Overflow time calculating means M8 for predicting time, performing time conversion of the surplus angle based on the predicted value, and calculating overflow time from the time conversion value and the engine rotation pulse number, and the overflow time calculation An overflow control means M9 for activating the overflow adjustment valve M4 at the overflow time of the means M8 to end the fuel injection, and a timer piston M10a operated by fluid pressure. By changing the reciprocating timing of the plunger 2a of the fuel injection pump M2 with the timer piston M10a, the phase of the engine rotation pulse with respect to the reference crank angle is adjusted, and the fuel with respect to the reference crank angle is adjusted. A timer device M10 for adjusting the injection phase of the injection pump M2 and a timer piston M of the timer device M10.
Fluid pressure adjusting valve M11 for adjusting the fluid pressure acting on 10a
And an injection phase control means M12 for adjusting the opening degree of the fluid pressure adjustment valve M11 so that fuel injection is performed at an injection phase according to the operation state by the operation state detection means M6. In the fuel injection control device, a throttle opening degree detecting means M for detecting the opening degree of the throttle valve M13 which is interlocked with the depression of the accelerator pedal.
14 and the throttle opening degree by the throttle opening degree detection means M14 is fully closed, and the rotation speed by the engine rotation detection means M5 is lower than a predetermined low rotation speed, the injection phase control means M12 performs the injection. An injection phase holding means M15 for adjusting the opening degree of the fluid pressure adjusting valve M11 is provided to forcibly hold the phase at a predetermined phase.

[0011]

In operation of the diesel engine M1, the fuel pressurized by the reciprocating movement of the plunger M2a of the fuel injection pump M2 is injected from the fuel injection valve M3 to the diesel engine M1. The adjustment of the fuel injection amount by the fuel injection pump M2 is performed by ending the fuel injection as follows. First, the target overflow timing calculation means M7
The target overflow timing of the fuel in the overflow regulating valve M4 is calculated according to the operating state of the diesel engine M1 by the operating state detecting means M6. The overflow time calculation means M8 is less than the number of engine rotation pulses and one pulse required from the predetermined reference position of the engine rotation pulse by the engine rotation detection means M5 to the target overflow timing by the target overflow timing calculation means M7. Find the remainder angle. The overflow time calculation means M8 respectively sets a time required for one pulse at the target overflow timing in the previous combustion cycle and a time corresponding to the amount of change in the instantaneous rotation speed immediately before the target overflow timing in the current combustion cycle. The required time for one pulse at the target overflow timing in the present combustion cycle is predicted from these values, and the remaining angle is converted to time based on the predicted value. Further, the overflow time calculating means M8 calculates the overflow time from the time conversion value and the engine rotation pulse number. Overflow control means M
9 operates the overflow adjusting valve M4 at the overflow time by the overflow time calculating means M8 to end the fuel injection. In this way, the fuel injection amount is adjusted.

The phase of fuel injection by the fuel injection pump M2 with respect to the reference crank angle is determined by the timer device M1.
It is adjusted according to the position of the timer piston M10a at zero. That is, the injection phase control means M12 adjusts the opening degree of the fluid pressure adjusting valve M11 so that the fuel injection is performed in the injection phase according to the operating state by the operating state detecting means M6. Then, the fluid pressure acting on the timer piston M10a is adjusted, and the timer piston M10a moves. As a result, the reciprocating timing of the plunger M2a is changed, and the fuel injection phase in the fuel injection valve M3 is adjusted.

When the position of the timer piston M10a changes as described above, the phase of the engine rotation pulse with respect to the reference crank angle changes with the change.
Particularly, in the case of a diesel engine for automobiles, in a transient operation state in which hiccup occurs, the rotation speed greatly changes and the timer position greatly changes, and the phase of the engine rotation pulse changes drastically.

On the other hand, in the present invention, when the throttle opening is fully closed and the rotation speed of the engine is lower than a predetermined low rotation speed, the rotation speed changes drastically and so-called hiccup occurs. Paying attention to, the following control is performed. That is, in a region where the throttle opening degree detected by the throttle opening degree detection means M14 is fully closed and the rotation speed by the engine rotation detection means M5 is lower than a predetermined low rotation speed, the injection phase holding means M15 causes the injection phase control. The opening of the fluid pressure adjusting valve M11 is adjusted so as to maintain the injection phase of the means M12 at a predetermined phase.

Therefore, when the change amount of the instantaneous rotational speed immediately before the target overflow timing in the present combustion cycle is calculated, the change amount of the timer position is not affected, and the calculation accuracy of the change amount is improved. Along with this, the accuracy of calculating the overflow time by the overflow time calculating means M8 is also improved.

[0016]

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

FIG. 2 is a schematic configuration diagram showing a fuel injection 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 via a belt or the like. And that drive pulley 3
The fuel injection pump 1 is driven by the rotation of, and the fuel is pressure-fed to the fuel injection nozzle 4 as a fuel injection valve provided for each cylinder (four cylinders in this case) of the diesel engine 2 to perform fuel injection.

In the fuel injection pump 1, the drive pulley 3 is attached to the tip of the drive shaft 5.
Further, a fuel feed pump (developed by 90 degrees in this figure) 6 which is a vane type pump is provided in the middle of the drive shaft 5. Further, a disc-shaped pulsar 7 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 are mounted along the circumference of the roller ring 9 so as to face the cam face 8a of the cam plate 8. .. Cam face 8a
Are 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 via 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 horizontal direction in the figure. Is driven back and forth. Further, the plunger 12 is reciprocatingly driven in the same direction while being rotated in accordance with the reciprocating driving. 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 conversely, the plunger 12 is moved back when the cam face 8a rides on the cam roller 10. It

The plunger 12 is fitted in a cylinder 14 formed in the pump housing 13, and a high pressure chamber 15 is provided between the tip end surface of the plunger 12 and the bottom surface of the cylinder 14.
Has become. Further, 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, whereby fuel is supplied from a fuel tank (not shown) into the fuel chamber 21 through the fuel supply port 20. Further, during the intake stroke in which the plunger 12 is moved back and the high pressure chamber 15 is decompressed, one of the intake grooves 16 communicates with the intake port 19 so that fuel is introduced from the fuel chamber 21 to the high pressure chamber 15. 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 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 overflow adjusting valve 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 when the coil 24 is de-energized (off), the valve body 25 is opened and the high pressure chamber 1
The fuel in 5 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 spill of fuel from the high pressure chamber 15 to the fuel chamber 21 is adjusted. Then, by opening the electromagnetic spill valve 23 during the compression stroke of the plunger 12, the fuel 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, a timer device (developed by 90 degrees in this figure) 26 for adjusting the phase of fuel injection (injection phase) with respect to a reference crank angle is provided. .. This timer device 26
Is for changing 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. is there.

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.

Fuel pressurized by the fuel feed pump 6 is introduced into the pressurizing chamber 30. The position of the timer piston 28 (hereinafter referred to as "piston position") 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 piston position, and the reciprocating timing of the plunger 12 is determined via the cam plate 8.

In order to adjust the fuel pressure acting as the control oil pressure of the timer device 26, the timer device 26 is provided with a timer control valve (TCV) 33 as a fluid pressure adjusting valve 33. Specifically, the pressurizing chamber 30 and the low pressure chamber 29 of the timer housing 27 are communicated with each other by a communication passage 34, and a TCV 33 is interposed in the communication passage 34. The TCV 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 adjusting the opening of the TCV 33. Then, by adjusting the fuel pressure, the reciprocating timing of the plunger 12 is changed, and the injection phase by each fuel injection nozzle 4 is controlled.

A rotation speed sensor 35 as an engine rotation detecting means is attached to the upper portion of the roller ring 9 so as to face the outer peripheral surface of the pulsar 7. This rotation speed sensor 3
An electromagnetic pickup coil 5 outputs a detection signal each time a protrusion formed on the outer peripheral surface of the pulsar 7 crosses.
Then, the rotation speed of the fuel injection pump 1, that is, the rotation speed of the diesel engine 2 is detected from this detection signal.

In this embodiment, as shown in FIG.
The 64 projections are arranged such that two toothless portions 7a are formed at every 90 ° (180 ° CA in crank angle) from the state where 64 protrusions are arranged at equal intervals. Therefore, when the crankshaft 40 of the diesel engine 2 rotates, as shown by the detection output after waveform shaping in FIG.
Every 720 ° CA / 64 = 11.25 ° CA, the engine rotation pulse is output by each tooth, and the 14th engine rotation pulse is 11.2 by the toothless portion 7a.
One engine rotation pulse (reference position signal) of 5 ° CA × 3 = 33.75 ° CA is output.

That is, on the outer peripheral surface of the pulsar 7, the same number as the number of cylinders of the diesel engine 2, that is, in this case, four toothless portions 7a are formed at equal angular intervals, and further toothless portions 7a adjacent to each other. 14 pieces in total (56 pieces in total)
Individual projections are formed at equal angular intervals. for that reason,
By waveform-shaping the detection signal from the rotation speed sensor 35, a reference position signal synchronized with the fuel injection cycle and a rotation signal representing the rotation speed are obtained.

CNIRQ in FIG. 6 is a pulse counter (initial value 0) indicating the number of engine rotation pulses after the reference position signal is output. Next, the diesel engine 2 will be described. As shown in FIG. 2, in the diesel engine 2, the cylinder 41 and the piston 4 are
The main combustion chamber 44 corresponding to each cylinder is formed by 2 and the cylinder head 43. A sub combustion chamber 45 communicating with each main combustion chamber 44 is provided for each cylinder. And, in each sub combustion chamber 45,
Fuel is injected from each fuel injection nozzle 4. 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. Further, the intake pipe 47 is provided with a compressor 49 of a turbocharger 48 constituting a supercharger, and the exhaust pipe 50 is provided with a turbine 51 of the turbocharger 48. Also,
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 rotates the compressor 49 coaxially with the turbine 51 to pressurize the intake air. Due to this action, a high-density air-fuel mixture 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 a recirculation pipe 54 for recirculating a part of the exhaust gas in the exhaust pipe 50 to the intake port 53 of the intake pipe 47. In the middle of the recirculation pipe 54, an exhaust gas recirculation valve (EGR valve) 5 for adjusting the recirculation amount of exhaust gas is provided.
5 are provided. The EGR valve 55 is opened and closed by a vacuum switching valve (VSV) 56.

Further, in the middle of the intake pipe 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 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.

As the sensor constituting the operating condition detecting means of the diesel engine 2, the rotation speed sensor 35 described above is used.
In addition, the following various sensors are provided. In the vicinity of the air cleaner 64 provided at the inlet of the intake pipe 47,
An intake air temperature sensor 72 for detecting the intake air temperature THA is provided.

Further, there is provided an accelerator opening sensor 73 for detecting an accelerator opening ACCP corresponding to the load of the diesel engine 2 from the opening / closing position of the throttle valve 58. The accelerator opening sensor 73 constitutes a throttle opening detecting means. A fully closed position switch for detecting the fully closed position of the throttle valve 58 is integrally incorporated in the accelerator opening sensor 73. In such an accelerator opening sensor 73, the throttle valve 58
Is in the fully closed state, the fully closed signal LL from the fully closed position switch is turned on, and when the throttle valve 58 is opened, the fully closed signal LL from the fully closed position switch is turned off and the accelerator opening ACCP is increased. To be detected.

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, the cooling water temperature TH of the diesel engine 2
A water temperature sensor 75 that detects W is provided. Also,
A crank angle sensor 76 is provided for detecting a rotation reference position of the crankshaft 40, for example, a rotation position of the crankshaft 40 with respect to a top dead center (TDC) of a specific cylinder. further,
The transmission (not shown) is provided with a vehicle speed sensor 77 that detects the vehicle speed (vehicle speed) SP by turning on / off the reed switch 77b with a magnet 77a rotated by the rotation of the gear.

Each of the sensors 35, 72 to 77 described above is an EC
Each is connected to U71. Then, the ECU 71
Controls the electromagnetic spill valve 23, the TCV 33, the glow plug 46, and the VSVs 56, 61, 62 based on the detection signals output from the sensors 35, 72 to 77.

Next, the structure of the above-mentioned ECU 71 will be described with reference to the block diagram of FIG. The ECU 71 stores in advance a target overflow timing calculation means, an overflow time calculation means, an overflow control means, an injection phase control means, a central processing unit (CPU) 81 as an injection phase holding means, a predetermined control program, a map and the like. Read-only memory (ROM)
82, a random access memory (RAM) 83 for temporarily storing the calculation result of the CPU 81, etc., and a backup RAM 84 for storing prestored data. These units are connected to an input port 85 and an output port 86 by a bus 87. There is. 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 pressure sensor 74, and the water temperature sensor 75 are connected to the buffers 88, 89, 90, 9 respectively.
1, the multiplexer 92, and the A / D converter 93. 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 input via the input port 85 as input values. Further, 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 and 62 are connected.

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 are preferably controlled.

In the present embodiment constructed as described above, a constant crank angle (target spill timing) is calculated in order to calculate the timing (target spill timing) at which the electromagnetic spill valve 23 in the closed state is opened to cause fuel to overflow. The engine rotation pulse (see FIG. 12) output every 11.25 ° CA) is used. The valve opening timing of the electromagnetic spill valve 23 is given as an angle from a certain reference engine rotation pulse (the rising edge of the engine rotation pulse of the pulse counter CNIRQ = 0 in FIG. 12).

More specifically, from the rise of the engine rotation pulse of which the value of the pulse counter CNIRQ is "0" to the rise of the engine rotation pulse of "8" is a direct angle, and in this case, it is calculated as the spill timing pulse number CANGL.
Further, the surplus angle θREM which is less than one pulse in the engine rotation pulse of “8” cannot be directly calculated in the current combustion cycle. Therefore, the surplus angle θR
The EM is converted to time by prediction as follows. That is, 1 at the target overflow timing in the previous combustion cycle
The required time for the pulse is defined as a reference time TS1125, and from this reference time TS1125 and the time corresponding to the change amount of the instantaneous rotation speed immediately before the target overflow timing in the present combustion cycle, the target overflow timing in the current combustion cycle is determined. The required time for one pulse is predicted, and the surplus angle θR is calculated based on the predicted value (predicted pulse time TS1125A during spill).
Convert EM into time. The time-converted value is represented by the spill time TSPON.

Next, the calculation process of the spill time TSPON is shown in the flowchart of FIG. The calculation process of the reference time TS1125 is shown in the flowchart of FIG. The processing routine of FIG. 11 is started at a predetermined timing, and the processing routine of FIG. 7 is started by being interrupted by the rising of the engine rotation pulse of the rotation speed sensor 35.

First, the reference time calculation routine of FIG. 7 will be described. When the processing shifts to the routine of FIG. 7, CP
In step 101, the U 81 sets, as the pulse time TNINT, the difference between the current time FC at the time of the current NE interrupt obtained by the free running count operation and the interrupt time T0 at the time of the previous NE interrupt. In the time chart of FIG. 8, the pulse counter CNI
One pulse from when the RQ value becomes “10” to when it becomes “11” is taken as an example, and the time required to advance by the crank angle (11.25 ° CA) corresponding to this one pulse. Is calculated, and this is set as the pulse time TNINT.

Next, in step 102, the CPU 81 determines whether or not the value of the pulse counter CNIRQ is "13". Here, the pulse counter CNIRQ
If the value of is not "13", the CPU 81 proceeds directly to step 104. On the other hand, when the value of the pulse counter CNIRQ is “13”, the CPU 81 determines in step 103 that the pulse time TNINT previously obtained in step 101 is set to the rotation increasing time TN13.
Set as. As shown in FIG. 8, the rotation increasing time TN13 is "1" at the crank angle from when the value of the pulse counter CNIRQ becomes "12" to when it becomes "13".
Pulse time TNI required to advance by 1.25 ° CA "
It is equivalent to NT. Further, the position of the rotation increasing time TN13 in FIG. 8 corresponds to the vicinity of the time when the instantaneous rotation speed becomes the average rotation speed during the rotation increasing in the same combustion cycle of the diesel engine 2.

Then, in step 104, the CPU 81 determines whether or not the value of the pulse counter CNIRQ is "6". Here, if the value of the pulse counter CNIRQ is not "6", the CPU 81 directly proceeds to step 109.
Move to.

On the other hand, in step 104, the pulse counter C
If the value of NIRQ is "6", the CPU 81 sets the pulse time TNINT previously obtained in step 101 as the rotational speed decrease time TN6 in step 105. As shown in FIG. 8, the rotation decrease time TN6 is “11.25 ° C.” in crank angle from when the value of the pulse counter CNIRQ becomes “5” to “6”.
This corresponds to the pulse time TNINT required to advance by "A". Further, the position of the time TN6 when the rotation speed is low in FIG. 8 corresponds to the vicinity of the time when the instantaneous rotation speed becomes the average rotation speed when the rotation speed is low in the same combustion cycle.

Subsequently, the CPU 81 determines in step 106 that the rotation increase time TN13 in step 103 described above.
And a deviation from the rotation speed decrease time TN6 in step 105 is calculated, and the calculation result is set as a time deviation ΔTN. The time deviation ΔTN corresponds to the change in the rotation speed at that time.

Further, in step 107, the CPU 81 calculates the time correction coefficient KDT1 according to the time deviation ΔTN. The time correction coefficient KDT1 is a coefficient for correcting the reference time TS1125 for calculating the spill time, and is obtained by referring to the map in FIG. In this map, when the time deviation ΔTN is positive, that is, the engine speed N
When E rises, the time correction coefficient KDT1 is set to a value smaller than "1.0" in order to correct the reference time TS1125 small. Also, the time deviation ΔTN
Is negative, that is, when the engine speed NE is decreasing, the time correction coefficient KDT1 is set to a value larger than "1.0" in order to largely correct the reference time TS1125.

Further, in step 108, the CPU 81 similarly calculates a speed correction coefficient KNE for correcting a later-described reference rotational speed NE1 from the time deviation ΔTN. The speed correction coefficient KNE is calculated with reference to the map of FIG. In this map, when the time deviation ΔTN is positive, that is, when the engine rotation speed NE is increasing, the reference rotation speed NE1 should be largely corrected,
The speed correction coefficient KNE is set to a value larger than "1.0". When the time deviation ΔTN is negative,
That is, when the engine rotation speed NE is decreasing, the speed correction coefficient KNE is set to a value smaller than "1.0" in order to correct the reference rotation speed NE1 to be small.

Then, in step 109, the CPU
Reference numeral 81 determines whether or not the value of the pulse counter CNIRQ is "1". Here, if the value of the pulse counter CNIRQ is not "1", the CPU 81 directly proceeds to step 1
Go to 11. On the other hand, the pulse counter CNIR
If the value of Q is "1", the CPU 81 proceeds to step 110.
Then, the reference rotational speed NE1 for calculating the injection amount command value is calculated. As shown in FIG. 8, the reference rotational speed NE1 corresponds to the instantaneous rotational speed at pulse intervals of "45 ° CA" in the crank angle until the value of the pulse counter CNIRQ changes from "13" to "1". is doing. Further, the position of the reference rotational speed NE1 in FIG. 8 is near the time when the engine rotational speed NE becomes the highest in the same combustion cycle, and also corresponds to the time when the fuel injection is started.

Next, in step 111, the CPU 8
1 determines whether or not the value of the pulse counter CNIRQ is "9". Here, if the value of the pulse counter CNIRQ is not "9", the CPU 81 directly proceeds to step 11
Move to 3. On the other hand, the pulse counter CNIRQ
If the value of is equal to "9", the CPU 81 determines in step 112 that the pulse time TNINT at that time is the reference time T.
It is set as S1125. This reference time TS1125
Corresponds to the pulse time TNINT required to advance the crank angle by "11.25 ° CA" from when the value of the pulse counter CNIRQ becomes "8" to when it becomes "9" as shown in FIG. ing. Further, the position of the reference time TS1125 in FIG. 8 corresponds to the vicinity of the timing when the engine rotation speed NE becomes the minimum, and the injection end timing for obtaining the target injection amount determined according to the operating state of the diesel engine 2. It is equivalent.

Then, in step 113, the CPU
81 sets the current time FC in step 101 as the previous interrupt time T0, and then ends the subsequent processing. In this way, the reference time TS1125, the reference rotation speed NE1 and the like are calculated.

Next, the spill time TSPO in FIG.
The calculation process of N will be described. When the processing shifts to this routine, the CPU 81 first reads the accelerator opening ACCP based on the detection value of the accelerator opening sensor 73 in step 201. Further, the time correction coefficient KDT1, the speed correction coefficient KNE, the reference rotation speed NE1 and the reference time TS1125 in FIG. 7 are read.

Subsequently, the CPU 81 determines in step 202 the speed correction coefficient KNE and the reference rotational speed NE1.
Then, the calculation rotational speed NEQB is calculated. This calculation rotational speed NEQB is for calculating a target injection amount that predicts the rotational speed change, and is calculated according to the following equation (1).

NEQB = NE1 · 4 · KNE (1) Next, in step 203, the CPU 81 calculates the injection amount command value QFIN as the target injection amount from the accelerator opening ACCP and the calculation rotational speed NEQB. To do. The injection amount command value QFIN is calculated according to a predetermined calculation formula and is represented by a crank angle (° CA).

Then, in step 204, the CPU 81 calculates the spill timing pulse number CANGL and the remainder angle θREM from the injection amount command value QFIN. These respective values CANGL and θREM are obtained by referring to the following equation (2).

QFIN = 11.25 · CANGL + θREM (2) That is, as shown in FIG. 12, the injection amount command value QFIN corresponds to an angle for one engine rotation pulse, “11.2.
5 ”and divide the quotient by the spill time pulse count CANG
L is calculated, and the remainder is calculated as a remainder angle θREM.

Next, in step 205, the CPU 81 calculates the reference time TS1125 according to the following equation (3).
Is corrected by the time correction coefficient KDT1. The corrected value is the pulse time for one pulse in the vicinity of the target spill time in the current combustion cycle, and is represented by the spill time predicted pulse time TS1125A.

TS1125A = TS1125 · KDT1 (3) Then, in step 206, the CPU 81 determines the surplus angle θREM and the spill time predicted pulse time T that have been previously obtained.
The spill time TSPON is calculated by S1125A. That is, the surplus angle θREM is converted into time based on the spill time predicted pulse time TS1125A. The spill time TSPON is calculated according to the following equation (4).

TSPON = (θREM / 11.25) · TS1125A (4) By the processing in step 206, the remainder angle θREM
Is converted into time, the CPU 81 ends this routine.

When the spill timing pulse number CANGL is obtained in step 204 and the spill time TSPON is obtained in step 206, the CPU 81 sends a signal for turning off the electromagnetic spill valve 23 based on both values CANGL and TSPON. Output. Then, the closing timing of the electromagnetic spill valve 23 adjusts the end timing of the fuel injection from the fuel injection pump 1, that is, the fuel injection amount. In FIGS. 7 and 11, the predicted pulse time TS during spill
The reason why the reference time TS1125 is corrected based on the time deviation ΔTN when calculating 1125A is as follows. For example, when the diesel engine 2 is decelerating or accelerating, even when the engine rotation speed NE greatly decreases or rises, the spill time predicted pulse time TS1125A is properly predicted according to the rotation speed change, and the surplus angle θ
This is because the REM time conversion is performed accurately.

Further, when the injection amount command value QFIN is calculated, the value (calculation rotational speed NEQB) that predicts the change in the engine rotational speed NE in the present combustion cycle is used because the engine rotational speed NE decreases. This is to obtain an appropriate injection amount command value QFIN suitable for the engine rotation speed NE when the fuel injection is actually performed even when is large.

When the fuel injection amount control is performed, the fuel injection phase with respect to the reference crank angle is adjusted as follows. The flowchart of FIG. 13 shows a routine for calculating the target crank angle timing TRGCA which is the target timer position of the timer device 26. In addition, in the flowchart of FIG.
6 shows a routine for duty-controlling the TCV 33 using the target crank angle timing TRGCA in order to adjust the control hydraulic pressure in 6. The routine of FIG. 13 is started every predetermined time (39 milliseconds in this embodiment), and the routine of FIG. 14 is started at a predetermined timing.

First, the target crank angle timing calculation routine of FIG. 13 will be described. When the processing shifts to this processing routine, in step 301, the CPU 81 reads the fully closed signal LL from the fully closed position switch incorporated in the accelerator opening sensor 73, and whether or not the fully closed signal LL is turned on, That is, it is determined whether the accelerator is fully closed. Further, in step 302, the CPU 81 determines whether or not the engine rotation speed NE by the rotation speed sensor 35 is lower than a predetermined low rotation speed. In this embodiment, the target idle rotation speed NF is used as the predetermined low rotation speed. The target idle speed NF is a value calculated in another processing routine according to the operating state of the diesel engine 2, for example, the cooling water temperature THW, the shift position of the transmission, the operating state of the air conditioner, and the like.

When the full-close signal LL is off in step 301, the accelerator is not fully closed, and the engine speed NE is equal to or higher than the target idle speed NF, the CPU
81 calculates the target crank angle timing TRGCA in the normal operation state in steps 303 to 305. First, CPU8
In step 303, in step 303, the injection amount command value QFIN obtained by the spill time calculation routine is read, the injection amount command value QFIN is corrected according to the following equation (5), and the correction value is corrected injection amount command value QFINS. And

QFINS = QFIN− (ab−NE) (5) In the above formula (5), a and b are constants. Then C
In step 304, the PU 81 calculates the basic target crank angle timing CABASE according to the corrected injection amount command value QFINS and the engine speed NE. For this calculation, a two-dimensional map in which a relationship between the corrected target injection amount command value QFINS and the basic target crank angle timing CABASE with respect to the engine rotation speed NE is predetermined is used.

Next, in step 305, the CPU 81 sets the basic target crank angle timing CABASE to
The target crank angle timing TRGCA is calculated by performing cold advance correction, highland advance correction, and the like as necessary.

On the other hand, when the full-close signal LL is off (the accelerator is fully closed) in step 301 and the engine speed NE is lower than the target idle speed NF in step 302, the CPU 81 shifts the transmission shift position. Is selected for the high speed stage (high gear with a small reduction ratio), the rotation speed is reduced by the operation of the brake, and as a result, the car repeatedly vibrates back and forth,
It is determined that so-called "hiccuping" has occurred. At this time, the engine rotation speed NE is largely changed, so when the target crank angle timing TRGCA is calculated in the processing of steps 303 to 305, the value is drastically changed along with the change of the engine rotation speed NE.

Therefore, the CPU 81 steps 303 to 3
In step 306, the target crank angle timing TRGCA is set to a predetermined value α without executing the processing of 05, and this routine is ended. As the predetermined value α, for example, the target crank angle timing TRGCA when the diesel engine 2 is in the idle operation state is used.

In this way, the target crank angle timing TRGCA is calculated in the processing of step 305 or step 306. Next, the TCV control routine of FIG. 14 will be described. When the processing shifts to this routine, the CPU
81 is the crank angle sensor 76 in step 401.
The actual crank angle timing ACTCA is calculated from the reference crank angle signal (TDC signal) by the engine rotation pulse by the engine speed sensor 35. Then, the CPU 81 reads in step 402 the target crank angle timing TRGCA obtained in the processing routine of FIG. 13, and in step 4
At 03, the deviation ΔT between the target crank angle timing TRGCA and the actual crank angle timing ACTCA is calculated.

Then, the CPU 81 sets the deviation ΔT to "0", that is, the actual crank angle timing ACT.
The duty ratio of the TCV 33 is feedback-controlled so that CA becomes the same as the target crank angle timing TRGCA. That is, in step 404, the deviation ΔT
A target on-duty ratio FTDUTY, which is a duty ratio command value, is calculated based on the above, and in step 405, the TCV 33 is duty-controlled with the target on-duty ratio FTDUTY.

As described above, in this embodiment, the target overflow timing (injection amount command value QFIN) corresponding to the operating state of the diesel engine 2 is calculated (step 203). In addition, the injection amount command value Q from the predetermined reference position of the engine rotation pulse
Number of pulses required until FIN (spill time pulse number CA
NGL) and a surplus angle θREM that is less than one pulse (step 204), and further, the time required for one pulse at the target overflow timing in the previous combustion cycle (reference time TS1125) and the target overflow in the current combustion cycle. The time required for one pulse at the target overflow timing in the current combustion cycle is predicted from the time (time deviation ΔTN) corresponding to the amount of change in the instantaneous rotation speed immediately before the flow timing, and the predicted value (prediction during spill) Based on the pulse time TS1125A), the surplus angle θREM is time-converted, and the overflow time is calculated from the time-converted value (spill time TSPON) and the engine rotation pulse number (step 20).
5,206).

In this embodiment, the diesel engine 2
The opening degree of the TCV 33 is adjusted in order to perform the fuel injection at the injection phase according to the operating state of (steps 303 to 3).
05), in a region where the accelerator opening ACCP is fully closed and the engine rotational speed NE is lower than the target idle rotational speed NF, the target crank angle timing TRGCA is set to a predetermined value in order to forcibly maintain the injection phase at the predetermined phase. The value α is set (steps 301, 302, 306).

Therefore, in a transient operation state in which the hiccup occurs, the engine speed NE greatly fluctuates and the timer position largely fluctuates.
Although the phase of the engine rotation pulse with respect to the reference crank angle signal of 6 drastically changes, such a state is determined by the accelerator opening ACCP and the engine rotation speed NE, and the timer piston 28 is held at a predetermined position. The injection phase can be kept constant. Therefore, when the amount of change in the instantaneous rotational speed immediately before the target overflow timing in the current combustion cycle is calculated, it is possible to improve the calculation accuracy of the amount of change without being affected by the change in the timer position. Along with this, the accuracy of calculating the overflow time can be improved.

The present invention is not limited to the above-described embodiments, but can be implemented as follows with a part of the configuration appropriately modified without departing from the spirit of the invention. (1) In the above embodiment, the target idle rotation speed NF was used as the predetermined low rotation speed in step 302 of FIG. 13, but it is changed to a value other than this, for example, a value slightly lower than the target idle rotation speed NF. May be.

(2) Normally, the engine rotational speed NE becomes lower than the predetermined low rotational speed (target idle rotational speed NF) when the brake is actuated. Therefore, steps 301 and 302 in FIG. In addition to the judgment process of
It may be possible to determine whether or not the brake is operating. In this way, the occurrence of hiccups can be grasped more reliably.

(3) In the above-described embodiment, when the change amount of the instantaneous rotation speed immediately before the target overflow timing is calculated, the rotation from the time when the value of the pulse counter CNIRQ changes from "12" to "13". Rise time TN13 and pulse counter CN
The rotation lowering time TN6 during which the value of IRQ changes from "5" to "6" is used, but it is not limited to this. For example, the value of the pulse counter CNIRQ is changed from "11" to " The rotation increasing time TN12 until it reaches 12 "and the rotation decreasing time TN7 until the value of the pulse counter CNIRQ changes from" 6 "to" 7 "may be used.

(4) In the above embodiment, as the rotation speed used for calculating the command value QFIN of the target injection amount, the following "1" is set after the value of the pulse counter CNIRQ becomes "13" in the same combustion cycle. The reference rotation speed NE1 up to "4" is used, but the reference rotation speed NE1 is not limited to this. For example, the instantaneous value between the value "13" and "4" of the pulse counter CNIRQ in the same combustion cycle. The rotation speed can be appropriately selected and used.

(5) In the above embodiment, the present invention is embodied in the diesel engine 2 having the turbocharger 48 as the supercharger. However, the diesel engine having the supercharger as the supercharger and the supercharger It can also be embodied in a diesel engine without a machine.

[0084]

As described above in detail, according to the present invention, the injection phase is maintained at the predetermined phase in the region where the throttle opening is fully closed and the engine rotation speed is lower than the predetermined low rotation speed. Since the opening of the fluid pressure control valve is adjusted accordingly, even if the engine speed changes drastically due to hiccups or the like, the amount of change in the instantaneous speed can be accurately calculated, and the target fuel It has the excellent effect of being able to predict the overflow time.

[Brief description of drawings]

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

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

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

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

FIG. 5 is a diagram for explaining a rotation speed sensor in one embodiment.

FIG. 6 is a diagram showing a detection output waveform of a rotation speed sensor in one embodiment.

FIG. 7 is a reference time T executed by the CPU and interrupted by the rising edge of the engine rotation pulse in one embodiment.
It is a flowchart explaining the calculation routine of S1125.

FIG. 8 is a time chart illustrating a correspondence relationship between a change in engine rotation speed and an engine rotation pulse in the embodiment.

FIG. 9 is a map defining a relationship between a time deviation and a time correction coefficient in one embodiment.

FIG. 10 is a map defining a relationship between a speed correction coefficient and a time deviation in one embodiment.

FIG. 11 is a flowchart illustrating a spill time TSPON calculation routine executed by the CPU in the embodiment.

FIG. 12 is a time chart illustrating a correspondence relationship between an engine rotation pulse and electromagnetic spill valve operation in one embodiment.

FIG. 13 is a flowchart illustrating a target crank angle timing calculation routine executed by a CPU in the embodiment.

FIG. 14 is a flowchart illustrating a TCV control routine executed by a CPU in an embodiment.

FIG. 15 is a diagram showing a correspondence relationship between a vehicle speed, an engine speed, and a target timer position in the prior art.

[Explanation of symbols]

1 ... Fuel injection pump, 2 ... Diesel engine, 4 ... Fuel injection nozzle (fuel injection valve), 12 ... Plunger, 23
... electromagnetic spill valve (overflow adjustment valve), 26 ... timer device, 2
8 ... Timer piston, 33 ... TCV (fluid pressure adjusting valve),
35 ... Revolution speed sensor (engine rotation detecting means), 57 ...
Accelerator pedal, 58 ... Throttle valve, 73 ... Accelerator opening sensor (throttle opening detecting means), 81 ... C
PU (target overflow timing calculation means, overflow time calculation means, overflow control means, injection phase control means and injection phase holding means),
QFIN ... Injection amount command value (target overflow timing), CANGL
... number of spill timing pulses (number of engine rotation pulses required from a predetermined reference position of engine rotation pulse to target overflow timing), θREM ... surplus angle, TS1125 ... reference time (1 at target overflow timing in previous combustion cycle) Pulse required time), ΔTN ... Time deviation (time corresponding to the amount of change in the instantaneous rotation speed), TS1125A ... Spill time predicted pulse time (time required for one pulse at the target overflow timing in the present combustion cycle), TSPON ... spill time (time conversion value of surplus angle), ACCP ... accelerator opening (throttle opening), TRGCA ... target crank angle timing, NE
… Engine speed, NF… Target idle speed (predetermined low speed)

Claims (1)

[Claims] 1. A fuel injection pump that pressurizes fuel by reciprocating motion of a plunger based on rotation of a diesel engine and injects the pressurized fuel from a fuel injection valve to a diesel engine; and a pressurized fuel of the fuel injection pump overflows. Flow control, which terminates the fuel injection and adjusts the fuel injection amount, and detects an engine rotation pulse at each constant crank angle of the diesel engine, and rotates the diesel engine based on the engine rotation pulse. An engine rotation detecting means for detecting a speed, an operating state detecting means for detecting an operating state of the diesel engine, and a target overflow timing of fuel in an overflow adjusting valve according to an operating state by the operating state detecting means. Target overflow timing calculation means, and a predetermined reference of the engine rotation pulse by the engine rotation detection means Position and the target overflow timing calculated by the target overflow timing calculation means, the number of engine rotation pulses required and the surplus angle that is less than one pulse are obtained, and one pulse at the target overflow timing in the previous combustion cycle is calculated. The required time for one pulse at the target overflow timing in the current combustion cycle is predicted from the required time of the current combustion cycle and the time corresponding to the amount of change in the instantaneous rotation speed immediately before the target overflow timing in the current combustion cycle, and the prediction is performed. Overflow time calculation means for calculating the overflow time from the time conversion value and the engine rotation pulse number by performing time conversion of the surplus angle based on the value, and overflow time at the overflow time by the overflow time calculation means. An overflow control means for activating the flow regulating valve to terminate the fuel injection, and a timer piston operated by the fluid pressure are provided, and the timer piston is used to control the fuel injection pump. A timer device that adjusts the phase of the engine rotation pulse with respect to a reference crank angle by changing the reciprocating motion of the injector and the injection phase of the fuel injection pump with respect to the reference crank angle; A fluid pressure adjusting valve that adjusts the fluid pressure acting on the timer piston of the device, and an opening degree of the fluid pressure adjusting valve so that fuel injection is performed at an injection phase according to the operating state by the operating state detecting means. A fuel injection control device for a diesel engine, comprising: an injection phase control means for adjusting; a throttle opening detection means for detecting an opening of a throttle valve interlocked with depression of an accelerator pedal; Is fully closed, and the rotation speed of the engine rotation detecting means is lower than a predetermined low rotation speed. In a region even lower than that of the diesel engine, an injection phase holding means for adjusting the opening degree of the fluid pressure adjusting valve to forcibly hold the injection phase by the injection phase control means at a predetermined phase is provided. Fuel injection control device.