JPS61207853A - Idle operation control device for internal-combustion engine - Google Patents

Abstract

PURPOSE:To perform idling operation with low fuel consumption further with a stable manner, by providing a means, which calculates a control data relating to supply fuel to be output, and a means which supplies this control data to a closed loop control system by cooling water temperature. CONSTITUTION:A control device, adding in an adder part 13 an average speed data N output from a mean value arithmetic part 11 to a target speed data Nt, inputs the addition result to the first PID arithmetic part 14 as an error data De. When cooling water temperature of an engine increases, the control device, closing a switch 31, adds in an adder part 15 a control output data Do to an idle control quantity data Qide being an output of the first PID arithmetic part 14. In this way, idling operation is performed with low fuel consumption further with a stable manner.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an idle operation control device for an internal combustion engine, and more specifically, the present invention relates to an idle operation control device for an internal combustion engine. The present invention relates to an idle operation control device for an internal combustion engine that adjusts the amount of fuel supplied to ensure stable idle operation.

2. Description of the Related Art Conventional fuel injection amount control for multi-cylinder internal combustion engines uniformly controls the fuel injection amount for all cylinders.
The output of each cylinder is not uniform, which significantly impairs the stability of the internal combustion engine, especially at idle speed, increases the amount of harmful components contained in exhaust gas, causes vibration in the engine, and causes noise due to engine vibration. It was easy for problems such as the occurrence of this problem to occur.

In order to solve the above-mentioned problems, various devices have been proposed that control the fuel injected into each cylinder of an internal combustion engine. In this type of device, for example, the average rotational speed of the internal combustion engine is obtained by sampling an integral multiple of the number of cylinders and set as a target value. A device for controlling the fuel injection amount for
(See Publication No. 1).

Problems to be Solved by the Invention However, all of the above-mentioned conventional devices use a so-called learning control method that predicts the next injection amount from the difference between the average engine speed and the speed of each node at that time. It takes time to evaluate learning results in a computer, control responsiveness is poor, and complex algorithms are required to evaluate learning results, which requires a large amount of man-hours to develop. There is a problem with this.

An object of the present invention is to use closed-loop control according to the output difference between each cylinder of a multi-cylinder internal combustion engine without requiring a complicated algorithm to evaluate control results, so that idling is always possible under the current operating conditions. An object of the present invention is to provide an idle operation control device for an internal combustion engine that is stably controlled and can suppress engine vibration to a small level.

Means for Solving the Problems The present invention has a first calculation means for calculating an average speed of a multi-cylinder internal combustion engine, a means for outputting target speed data indicating a desired target idle rotation speed, and a first calculation means for calculating an average speed of a multi-cylinder internal combustion engine. means for outputting first control data related to the amount of fuel to be supplied to the internal combustion engine in order to obtain the target idle rotation speed in response to the calculation result of the calculation means and the target speed data; and the first data. An idle operation control device for an internal combustion engine having a closed loop control system comprising a control means for controlling a necessary speed regulating means so that closed loop control of the idle rotation speed is performed in response to the A detection means for sequentially detecting the instantaneous speed at a predetermined timing, and an instantaneous speed for each cylinder and an instantaneous speed for each cylinder based on a predetermined reference cylinder in response to the detection results sequentially output from the detection means. means for sequentially and repeatedly calculating and outputting difference data corresponding to the difference between the two cylinders; a timing detecting means for detecting the operation timing of each cylinder of the internal combustion engine; means for calculating and outputting second control data related to supplied fuel necessary to make the difference indicated by the data zero;
means for outputting a water temperature signal related to the cooling water temperature of the internal combustion engine; and output control for outputting the second data at a required timing before the next fuel adjustment stroke for each cylinder based on the detection result by the timing detection means. and means for responding to the water temperature signal and supplying the second data from the output control means to the closed loop control system only when the cooling water temperature exceeds a predetermined value. .

According to the above-described configuration, during the feedback control loop in which the average speed of the internal combustion engine is controlled to a desired target idle speed, metering control is performed for each cylinder so that the instantaneous speed of each cylinder of the internal combustion engine becomes equal. Since a feedback control loop is provided to perform this, the angular velocity of the internal combustion engine can be kept constant during fluctuations, and vibrations of the internal combustion engine can be reduced, as well as the noise level and idling speed can be lowered. Therefore, idling operation can be performed stably and with low fuel consumption.

Furthermore, under operating conditions where the engine cooling water temperature is below a predetermined value and fuel combustion at each node is likely to be unstable, output of the second control data is stopped, and each simple control at low temperatures is canceled. Therefore, stable idle operation control at low temperatures can be achieved. That is, when the cooling water temperature is low, fuel combustion is unstable, which is a prerequisite for controlling each cylinder.

This is because the condition that periodic fluctuations with the same tendency appear in each cylinder is no longer satisfied, so in such a case, it is better to stop the injection amount control for each cylinder.

Example Hereinafter, the present invention will be explained in detail with reference to an embodiment shown in the drawings.

FIG. 1 shows a block diagram of an embodiment in which the idle operation control device for an internal combustion engine according to the present invention is applied to idle operation control of a diesel engine. The idle operation control device 1 is a device for controlling the idle rotation speed of the diesel engine 3, which can control the injection and supply of fuel from the fuel injection cylinder 2.

The crankshaft 4 of the diesel engine 3 is equipped with:
A known rotation sensor 7 comprising a rotor 5 and an electromagnetic pickup coil 6 is provided. In the illustrated embodiment, the diesel engine 3 is a 4-cycle, 4-cylinder engine, and the cogs 5a and 5c of the cogs 5a to 5d formed at 90° intervals on the periphery of the diesel engine 30 are connected to the four cylinders of the diesel engine 30. When each piston of the two cylinders reaches the top dead center, ・9 is placed so that it faces the electromagnetic pickup coil 6.
The relative positional relationship between the Lusa 5 and the crankshaft 4 is determined.

Figure 2 (&) shows the instantaneous rotational speed N of the diesel engine 3.
is shown, and FIG. 2(b) shows the waveform of the alternating current signal AC obtained from the rotation sensor 7 at this time.

The alternating current signal AC has a waveform whose level fluctuates between positive and negative every time each cog faces the electromagnetic pickup coil 6, producing a pair of positive and negative peaks, and the zero crossing point between each positive and negative peak is time t1. *tS, ts e..., tl
te corresponds to the top dead center timing of one of the cylinder pistons of the diesel engine 3, respectively. Time tl'
e t4... indicates the timing when the crankshaft has passed 90° from the top dead center. On the other hand, the instantaneous rotation speed N is 6
The time when the valley is tt # ts, 't, e”・
- tt'r is the explosion timing in each cylinder, and this explosion causes the engine speed N to increase until time t! , t4.
... At tts, the engine speed N begins to decrease, and the engine speed N reaches a minimum value just before the explosion stroke of the cylinder that will explode next. The instantaneous speed of the diesel engine 3 fluctuates periodically for the above-mentioned reason, and the fluctuation period corresponds to seven rotations of the crankshaft 4.

Strictly speaking, the six valleys of the instantaneous rotational speed N may not coincide with the times when the piston of each cylinder is at the compression top dead center, but in this specification, for the sake of convenience, they will be explained as being coincident.・Here, the four cylinders of diesel engine 3 are each cylinder Ct.
8cm * (named l Ca, these cylinders C
! C4 to C4 are respectively at times jl ejl eL5, t,
The following explanation will be given assuming that the cylinder enters the explosion stroke in this order, and then each cylinder enters the explosion stroke in this order.

In order to detect which cylinder the timing indicated by each zero cross point of the alternating current signal AC indicates, the alternating current signal AC The needle valve lift signal NLPI is input to the timing detection section 10 to which it is applied as a reference timing signal.The needle valve lift signal NLP1 is shown in FIG. tle, which is the explosion timing of cylinder C1, as shown in
It is output immediately before F, t17, . The timing detection section 10 counts the number of input pulses in response to positive direction pulses of the alternating current signal AC, and also outputs a needle valve lift signal NLP.

The binary counter is configured as a binary counter that is reset by
is output as Therefore, with this identification data D1, it is possible to easily identify which cylinder and which operating timing a given zero cross point in the alternating current signal AC corresponds to. The identification data D1 is taken out via a switch SW which is controlled as described later, and is input to the speed detection section 8.

The speed detection unit 8 calculates the time θ111θ required for the crankshaft 4 to rotate 90' after the explosion timing in each cylinder.
! 1. ..., θ41. θ! Goose, θ2! , . . . based on the AC signal ACK, and a specific circuit thereof is shown in FIG. Referring to FIG. 3, the speed detection unit 8 is in phase synchronization with the alternating current signal AC, and outputs a count 9 pulse CP based on the alternating current signal AC, which has a sufficiently higher frequency than the alternating current signal AC. 81, and a counter 82 for counting the number of /4 pulses of the count trus CP. The counter 82 is
Input terminal 82a to which count/dulse CP is input
In addition to the above, there is also a start/four pulse t-signal for resetting the counting contents of the counter 82 and starting the counting operation.
It is provided with a start terminal 82b for stopping the counting operation of the counter 82 and a stop terminal 82c for giving a stop signal to stop the counting operation of the counter 82 and hold the counting contents. A decoder 83 is provided at each terminal 82b, 82c.
．． 84 output lines 83a*84m are connected, and these decoders 83 and 84 receive identification data D1.
is entered.

As already explained, the identification data Di is the needle valve 7.
This counter indicates the number of positive direction pulses subsequently occurring in the alternating current signal AC by a counter reset by the needle lift signal NLP, which in the illustrated embodiment is reset by the needle lift/start pulse signal NLP. The timing detection unit 10 is configured so that the content of the identification data Di becomes zero at some times. Therefore.

As shown in FIG. 2(d), the contents of the identification data DI are: l at t'=t1, t! 2, tg, 3
In this way, each time the positive direction of the AC signal AC occurs, it increases by 1, and after reaching 8 at ts,
Needle valve lift signal NLP output just before ts
1 becomes 0, and the contents change in the same way thereafter.

The decoder 83 determines that the content of the identification data D1 is 1.3°5.
7, the output line 83
The level of a is set to the rHJ level for a short time, and this causes υ
A start pulse is supplied to the start terminal 82b of the counter 82. On the other hand, in response to the content of the identification data Di becoming one of 2.4.6.8, the decoder 84 sets the level of its output line 84m to "H" level for a short time, thereby causing the counter 82 stop terminal 82c
We supply K-Stop-Gurus.

As a result, the counter 82 determines the explosion timing (
tl * ts e tg e"') If the count/arm pulse CP is counted only until the crankshaft 4 rotates 90', then it becomes K. Therefore, each time θ111θzt
+..., θ41. θl! , . . . is output from the counter 82. The counting data CD is further inputted to a conversion circuit 85 into which data Is relating to the engine speed at the time measured based on the alternating current signal AC' is inputted from the speed detector 86.
The counting data CD is calculated from the data ESK at each time θ11. θ Goose 1. ..., and this data is sequentially output as instantaneous speed data representing the instantaneous engine speed of the engine immediately after the explosion of each cylinder.

As described above, the time 011. θ goose! , . . . are obtained from the speed detection unit 8. Hereinafter, in this specification, the instantaneous speed data indicating the instantaneous rotational speed for the cylinder C1 will be obtained according to the order in which they were detected by the speed detection unit 8. , generally expressed as N1n (n=1 +2, . . . ).

Therefore, the instantaneous speed data N output from the speed detection section 8
The contents of in are shown in FIG. 2 (•).

The instantaneous speed data N1n is input to the average value calculation section 11, where the average speed of the diesel engine 3 is calculated. Reference numeral 12 denotes a target speed calculation unit that calculates a target idle rotation speed that is appropriate to the current operating state of the diesel engine 3 and outputs target speed data N indicating the calculation result.

The target speed calculation unit 12 has a known configuration that outputs target speed data indicating the optimum idle rotation speed according to the current operating state according to the required operating speed meter of the diesel engine 3. The illustration of the configuration will be omitted. The average speed data N and the target speed data Nt, which are also output from the average value calculating section 11, are added in the adding section 13 with the polarity shown, and the addition result is the error data D0.
The data is input to the first PID calculation unit 14 as a signal, and data processing for PID control is performed.

The calculation result in the first PID calculation unit 14 is taken out as data Qi de in the dimension of injection amount, and is inputted via the addition unit 15 to the conversion unit 16 to which the average speed data N is input, and the content of the error data D0 is A target position signal 5 indicating the target position of the injection amount adjusting member 17 necessary to make the injection amount zero.
IIC converted. The position sensor 18 detects the current position of the injection amount adjusting member 17 for adjusting the injection amount of the fuel injection pump 2, and outputs an actual position signal S! indicating the position. Outputs the actual position signal S! is added to the target position signal S1 from the converter 16 in the adder 19 with the polarity shown.

The addition output signal from the adder 19 is sent to the second PID calculation unit 2.
0, and after being subjected to signal processing for PID control, it is input to the pulse width modulator 21, and the signal is input to the second PID
An error signal PS having a duty ratio corresponding to the output from the calculation section 20 is output. - The master pulse signal ps is applied to the actuator 23 for controlling the position of the injection amount adjustment member 17 via the drive circuit 22, so that the injection amount adjustment member 17 adjusts the position of the diesel engine 3 at the target idle speed. The position is controlled so that it is idling.

The closed-loop control system described above, which is responsive to the average engine speed and the actual position of the injection quantity control member, provides control to match the average idle rotational speed of the diesel engine 3 to the desired target idle rotational speed.

The device 1 further controls the output of each cylinder of the diesel engine 3 to be the same. A separate closed-loop control system is provided for controlling each part. Next, this closed-loop control system will be explained.

The closed-loop control system for controlling each cylinder is for adjusting the fuel supplied to each cylinder so that the difference in instantaneous speed of each cylinder becomes zero, and in response to instantaneous speed data Nln,
A speed difference calculating section 24 is provided that calculates the difference between the instantaneous speeds for each of the cylinders C1 to C4 and a reference instantaneous speed for a reference cylinder predetermined for each cylinder. In this example, the instantaneous speed obtained immediately before the instantaneous speed for the cylinder of interest is considered as the reference instantaneous speed.
Therefore・Ni1−N鵞1 eNl1−Nss *Nst
−N, . The output timing of these difference data is shown in FIG. 2<f). It is desirable that the instantaneous speeds of each cylinder be the same value, and the difference data D
It is desired that - of d be zero. Therefore, the difference data D
d is added to the reference data Dr whose content is zero in the adder 25 with the polarity shown, and the addition result is the third
After the necessary processing for PID control is performed in the PID calculation unit 26, the control data D0 having the dimension of injection amount is
is output as

Note that the average speed data N of the diesel engine 3 is updated every time new instantaneous speed data N1n is output from the speed detection section 8, and therefore its contents are Nl eNl as shown in FIG. 2(g). It is changing like e...

The output control unit 27 is for controlling the output timing of the control output data D0 based on the difference data Dd,
According to the identification data Di, the output timing is controlled as follows.

In other words, the control output data D0 obtained at the timing when the control data D0 is outputted for the next fuel adjustment operation control for the cylinder C1+1 among the cylinders C1 and C1+1 related to the difference data on which the control data is based. The first
Idle control amount data Q that is the output of the PID calculation unit 14
It is added to tde in the adding section 15. Therefore, for example, the difference data Nd (= Nll
-N2t) indicates the instantaneous speed difference between cylinders C1 and 021, therefore, at least before the time 111 when cylinder C2 next enters the Maroma explosion stroke, cylinder C1 It is output at a timing υ after the explosion time t9. Therefore, in this case, the control data D0 based on the sN11-2'JztO difference data is added to the idle control amount data Qide corresponding to the average speed data N3. As a result, the position control of the injection amount adjusting member is performed so that the previous speed difference Nil -N2t becomes zero, and the positions of the cylinders C1 and C! Adjustment control is performed to equalize the instantaneous speeds of the two.

The above-mentioned output control section controls the output difference between cylinders C and C3,
Output difference between cylinders C3 and C4, and cylinders C4 and Ci
cylinder C! so that the output difference between them becomes zero, respectively. and C!
The same control as in the case where the output difference between the two cylinders is made zero is performed, whereby the fuel injection amount to be supplied to each cylinder is controlled for each cylinder, and the output of each cylinder is made equal.

On the output side of the output control section 27, the loop control section 28
A switch 29 for on/off control is provided.
Only when the loop control unit 28 detects that the predetermined conditions that allow each pre-control to be performed stably are satisfied, the switch 29 is closed and each pre-control is performed. The configuration is such that the switch 29 is opened to cancel each pre-control, thereby preventing the idling operation from becoming unstable due to each pre-control.

That is, the angular velocity control by each of the pre-controls described above is desirably performed in a stable state in which the idle rotational speed is within a predetermined range with respect to a desired target value. This occurs when variations in the injection system and internal combustion engine appear periodically and regularly.

This is because each of the above-mentioned pre-controls works well. Therefore,
When acceleration/deceleration operations are being performed, or when an abnormality has occurred in the control system, performing each pre-control will actually make the idling operation unstable.

Therefore, in this embodiment, (1) the difference between the target idle rotation speed and the actual idle rotation speed continues to exceed the predetermined value a for a predetermined period of time; Only when the following conditions are satisfied: (1) The amount of accelerator pedal depression is not greater than a predetermined value of 12.

Switch 29 is closed, configuring the control loop for each precontrol.

On the other hand, ■ the difference between the target idle rotation speed and the actual idle rotation speed is greater than or equal to the predetermined value ms (≧al), and ■ the amount of depression of the accelerator pedal is the predetermined value &4 (≧al).
) If at least one of the following conditions occurs: (1) some abnormality has occurred in the control system, the switch 29 is opened to cancel each pre-control, and the idle speed is adjusted according to the average speed data. Only a closed loop control system is configured to control the injection amount adjusting member 17 so that the speed reaches a desired target value.

Further, in the above embodiment, at the same time as the switch 29 is closed by the loop control unit 28.

The frequency of the delta pulse compensation code PS from the delta pulse width modulator 21 is
The frequency is changed to a predetermined frequency that does not interfere with the rotational speed of the diesel engine, thereby improving the responsiveness of the actuator 23 when controlling each cylinder.

The present device 1 further stabilizes engine idle speed control immediately after starting the engine in a cold region, for example, and when the engine cooling water temperature is about the same as the ambient temperature. In order to make this possible, each pre-control canceling section 30 is provided for temporarily stopping each pre-control based on the output data D0 until the engine cooling water temperature reaches a predetermined value.

Each pre-control release unit 30 includes a switch 31 arranged in series with the switch 29, a water temperature sensor 32 that outputs a water temperature signal SW indicating the cooling water temperature of the diesel engine 3, and a water temperature signal S.
In response to W, it is determined whether the cooling water temperature T is equal to or higher than a predetermined value Tr, and if TV≧Tr, the switch 31 is closed, and “w<
switch 31 to open switch 31 in case of “r”.
The switch control circuit 33 outputs a switch control signal S3 for controlling the opening and closing of the switch. With this configuration, when the cooling water temperature TV is smaller than the predetermined value T, the switch 31 is opened and the output data D0 is supplied to the adding section 15 regardless of the operating state of the switch 29. is stopped, and each pre-control is released.

Therefore, the temperature of the engine is low and the combustion state of fuel in each cylinder is unstable. Therefore, the output of each cylinder fluctuates irregularly, and the changes and fluctuations in the output difference between each cylinder are constant. If the preconditions for successfully performing each pre-control are not met, each pre-control will be canceled.

In this case, the idle rotation speed is only controlled so that it reaches the required target value according to the average speed data of the engine, but in the above state, each pre-control does not operate well, and each pre-control is not performed. Without it, the idle rotation speed can be controlled more stably.

When the engine cooling water temperature rises to a value TrK that ensures stable fuel combustion in each cylinder,
The switch 31 is closed, and as a result, the above-mentioned pre-controls are also executed, and the idle speed control is performed extremely stably, allowing the diesel engine 3 to idle with low fuel consumption and low noise.

In the above embodiment, a case has been described in which the switch 31, which opens and closes depending on the temperature of the cooling water, is provided separately from the switch 29. However, as can be understood from the above description, for example, the switch control signal S3 from the switch control circuit 33 is The loop control unit 28 may be inputted to include a condition as to whether the cooling water temperature T is equal to or higher than a predetermined value Tr in the opening/closing conditions for the switch 29 described above.

According to the above-mentioned configuration, the closed loop control based on the average speed of the diesel engine and the position of the injection amount adjusting member is used to control transient changes such as engine speed undershoot and bring the idle rotation speed approximately to the target value. As a result, in a state where the idle rotational speed is substantially stable, each pre-control is performed so that the angular velocity fluctuations of each cylinder are the same. Average speed control is not performed even when each pre-control is being performed.
It is responsible for most of the output amount, and each precontrol has the function of correcting it. In addition, when the cooling water temperature is below a predetermined value, each pre-control is canceled and each pre-control is performed when the temperature is low to prevent idle rotation speed control from becoming unstable. , it is possible to stably control the idle operation of the internal combustion engine under all conditions.

As mentioned above, each pre-control is configured to be executed only when the idle rotation speed is near the target value.
In such a region, the gain of the average idle rotational speed control is set small so as not to have a large effect on the operation of each pre-control.

In addition, in the above embodiment, in order to detect the angular velocity of each cylinder, it is based on the time from when the focused cylinder reaches compression top dead center until the crankshaft rotates 90 degrees, so the explosion torque It is able to detect fluctuations in the air most effectively, and is useful for improving control performance.

FIG. 4 shows another embodiment of the present invention in which the idle operation control device is implemented using a microcomputer. Among the various parts of the idle operation control device 40 shown in FIG. 4, the same parts as those shown in FIG. 1 are given the same reference numerals, and the explanation thereof will be omitted. Reference numeral 41 indicates a waveform shaping circuit, in which the alternating current signal A
The arm lux corresponding to the 9 lus in the positive direction of C is output, and is output as the top dead center I4 lus TDC. This top dead center I#
The needle valve lift/arm pulse signal NLP 1 from the needle valve lift sensor 9 and the actual position signal Shirayuki from the position sensor 18 are input to a microcomputer 43 equipped with a read-only memory (ROM) 42. There is. R.O.
A control program is stored in the M42 to perform the same function as the idle rotation speed control executed by the device shown in FIG. By executing this, the required idle rotation speed control is performed.

A 70-chart of the control program stored in ROM 42 is shown in FIG. The main control program 2 consists of a step 120 for initialization after the start of the program, and a step 121 for calculating the target injection amount according to the operation amount of the accelerator (darle) and controlling the position of the injection amount adjustment member 17. In addition to the control program 122, there is an interrupt program INT1 that is executed in response to the output of the needle valve lift cell signal NLP1, and another program that is executed in response to the output of the top dead center/gurus TDC. The interrupt program INT2 is also provided.

In step 123, the interrupt program INT1 first sets the contents of the soft counter TDCTR to 8.
Next, the flag TF is set to rOJ and the execution ends. This flag TF is a flag for determining whether to calculate the injection amount data Q1 or output the calculated injection amount data Qi in the interrupt program 2, which will be described later. The interrupt program INT2 is executed in response to the occurrence of the top dead center/main pulse TDC, and decreases the contents of the soft counter TDCTR by 147 points (step 12).
5), determination of whether TDCTR=O or not is executed in step 126.

If TDC'TR=Of), proceed to step 127.

After setting the contents of the soft counter TDCTR to 8,
Proceeding to step 128, the flag TF is inverted. If the determination result in step 126 is No.

Proceeding to step 128, the flag TF is inverted. Thereafter, based on the interval between occurrences of the top dead center t4 pulse TDC, data Ml + indicating the time interval between adjacent pulses is generated.
M+... is calculated, and the rotational speed is calculated based on it (step 129). Next, Stella f130
Then, it is determined whether or not the needle valve sensor 9 is out of order. In this determination, if the content of the counter TDCTR is greater than 8 and a fuel injection is detected, it is determined that there is a failure (NG). If the needle valve sensor 9 is not malfunctioning, it is checked in steps 131 to 133 whether the engine cooling water temperature Tw is above a predetermined value Tr and whether the accelerator pedal depression amount θ is below a predetermined value 12. It is determined whether or not the difference N-Ni between the target idle rotation speed Nj and the average idle rotation speed N is not equal to or greater than al for a predetermined period of time or more, and all determination results from steps 131 to 133 are determined. Only in the case of YES, each pre-control calculation based on the instantaneous engine speed for idle operation is performed (step 134), and in step 135 the idle rotational speed based on the average engine speed takes into account the calculation result of each pre-control calculation. It is done as follows. On the other hand, step 1
If the determination result in at least one of 31 to 133 is N
In the case of O, each pre-control calculation in step 132 is not executed, and only idle rotation control based on the average engine speed is executed.

In addition, when the cooling water temperature is low, combustion is unstable, so the explosion does not show the same tendency, and the output torque is unstable, which is the premise of each pre-control. Periodic fluctuations of the same tendency in combustion cannot be guaranteed. In this way, the state of the cooling water temperature can be considered as one of the seven actors for determining the preconditions when performing each precontrol, and therefore, when TV≧T, each precontrol is It is configured to allow this.

If the needle valve lift sensor 9 is out of order, a flag F is set in step 136 to indicate whether or not each pre-control is performed.
A determination is made as to whether ATC is “1” or not, and FATC=r
If it is lJ, proceed to step 131 and FATC=rO
If it is J, the process proceeds to step 137. Step 137
Then, it is determined whether the idling state has been continued for a predetermined time period of 10 or more. If the determination result is NO, the process proceeds to step 135; if the determination result is YES, the process proceeds to step 138. .

In step 138, the current interrupt program IN is selected from among the data indicating the time interval between adjacent top dead center I4 pulses TDC.
A comparison is made between the data Mn obtained during the execution of T2 and the data Mn-1 obtained during the previous execution of the interrupt program INT2. Figure 2(a),
As can be easily inferred from (b), the interval of 19 russ of top dead center and e russ TDC alternates between long states and short states, so by comparing data Mn and Mn-1, , it is possible to determine which state the operating timing of each cylinder is in.

If Mn<Mn-1, the top dead center/mother pulse TI)C that caused the current interrupt program INT2 to be executed
The timing when the cylinder corresponding to reaches the middle of the explosion stroke (
In Fig. 2, this indicates the timing corresponding to t2 @t4 *t61...). On the other hand, M
If n > Mn-1, find the timing when the cylinder piston reaches the top dead center just before one of the cylinders enters the explosion stroke (timing corresponding to tl, t3.tsl... in Figure 2). I'm reminded of how it turned out to be Luz.

Therefore, if the determination result in step 138 is No,
Each pre-control calculation is not performed, and the process proceeds to step 135, and if the determination result is YES, the process proceeds to step 139,
A determination is made as to whether the flag FN is "1" or not. The flag FN is provided to determine whether the determination result in step 137 is YES even once, and if FN is rOJ, the determination result in step 139 is NO. Then, in step 140, FN=
rlJ and the contents of variable N are stored as counter 'rDC.
The contents of the TR are set, and the process proceeds to step 135. Therefore, from next time onwards, the determination result in step 139 will be YES and the process will proceed to step 141.

In step 141, K=+1 is set, and then, in step 142, it is determined whether K=4. K increases by one each time one of the cylinders undergoes an explosion stroke. If the determination result in step 142 is No, the process advances to step 135. If the determination result in step 142 is YES, the process proceeds to step 144, where it is determined whether the value of the variable N matches the value of the counter TDCTH, and one cycle has elapsed (the crankshaft has rotated 7200 times). If N = TDCTH, proceed to step 145 and calculate rATc = rt J , TDCT
After setting R = 8, T F = rOJ, Stella f
Proceed to 135. If the determination result in step 1440 is No, the process advances to step 143, where K=“0”.

rN=r　OJ, and the process proceeds to step 135.

In this way, if it is determined that the needle valve lift sensor 9 is not malfunctioning, the process immediately proceeds to Stella 7'131, but if the needle valve lift sensor 9 is malfunctioning, the data town and M...
The operating timing of each cylinder of the engine, which is busy at the time, is determined by comparing the magnitude with Each pre-control calculation will be explained with reference to the detailed chart 7a of FIG.

First, the flag TF is determined in step 150, and if the flag TF is rOJ, steps for calculating control data for each dynamic control are executed thereafter, while the flag TF is "rOJ". 1'', steps for outputting control data for each dynamic control are executed thereafter. When the flag TF is "0", an even number of top dead center pulses TDC have been output since the needle valve lift/cruise signal NLPI has been output, and the next top dead center pJ? This is a state in which the pulse TDC has not yet been output.

In other words, this is a period in which each cylinder is not in the explosion stroke, and the second
In the figure, t2 to t1. t4~1s, 1. ~11°・
It corresponds to each period of... On the other hand, the flag TF is “1”
'', as can be seen from the above explanation, is a period in which any cylinder is in the explosion stroke, and in Fig. 2, t1
~F+t3~t4. ts~t6. It corresponds to each period of...

If the flag TF' is "0", it is determined in step 151 whether or not the operating conditions of the engine at that time satisfy the necessary conditions for performing each dynamic control, and the determination result is No. When this happens, the content of the data indicating the fuel injection control amount to each cylinder for each dynamic control is set to zero (step 152).In this specification, the injection amount control data for each dynamic control is generally referred to as QAin. shall be displayed as here.

Let l indicate the cylinder number, and n indicate the timing at which this data was calculated. After that, in step 153, injection amount control data Qi for idle rotation control based on the average speed is calculated, and in step 154
In this case, injection amount control data QA(i+1) for the next cylinder calculated one cycle before is added to this control data Ql.
(n-1) is added to the control data Ql. This control data Q1 is transmitted to the RA in the microcomputer 43.
Stored in M44.

If the determination result in step 151 is YES, in step 155, the currently output top dead center/ya Lus TD
The speed Nln based on C and the top dead center outputted one time ago.
Differential translation with speed N(1-1)n based on Gurus TDC
Then, in step 156, the difference ΔNIn obtained in step 155 and the difference ΔN1(n-1
) is calculated. Thereafter, each constant for PID control is set in step 157, and the integral term IATCl is loaded (step 158). As a result, PID control calculation is performed (
Step 159), the resulting control data QAin for each pre-control is stored (Step 16o)
. Therefore, in this case, the value of the data stored in step 160 and the previous value of data Qi are added.

This is the final data Qi.

If the determination result in step 1500 is YES,
Control data QApPO according to the amount of depression of the accelerator pedal
Add the value of the data Ql at that time to the value and get the data QDRV
(Step 161), and outputs this as injection amount control data to the cylinder that is in the compression stroke at that time (Step 162).

As can be seen from the above explanation, when the needle valve lift sensor 9 is normal, the flag TF controls the calculation and output of control data for each node control, and when the needle valve lift sensor 9 is out of order, By comparing data Mn and Mn-1, it is possible to determine the execution timing of calculations for controlling each part of υ, and thereby, each pre-control can be performed regardless of whether or not there is a failure in the needle valve lift sensor 9. .

Effects According to the present invention, each pre-control is performed to keep the angular velocity fluctuation width of each cylinder constant, so engine vibration is reduced, the noise level is reduced, and the idling speed can be lowered, resulting in improved fuel efficiency. In addition to being useful for improving performance, unlike the learning method, calculation processing is easy and the configuration is simple. In addition, each pre-control is canceled according to the cooling water temperature of one engine,
At low temperatures, by performing each pre-control, it is possible to improve the loss of control stability, and it is possible to stably perform idle operation control over a wide range.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing one embodiment of the present invention, and FIG. 2 (
Figures a) to 2(g) are time charts for explaining the operation of the device shown in Figure 1, Figure f43 is a detailed block diagram of the speed detection section in Figure 1, and Figure 4 is a diagram showing the operation of the device shown in Figure 1. FIG. 5 is a flowchart of a control program executed by the microcomputer of the apparatus shown in FIG. 4, and FIG. 6 is a part of the flowchart shown in FIG. 5. is a detailed flowchart. 1.40... Idle operation control device, 2... Fuel injection pump, 3... Diesel engine, 4... Crankshaft, 7... Rotation sensor, 8... Speed detection unit, 1o.
...Timing detection section, 11...Average value calculation section, 12
...Target speed calculation unit, 17...Injection amount adjustment member, 2
3... Actuator, 24 "' Speed difference calculation section, 27
...Output control section, 30-...Each cylinder control release section, 31.
...Switch, 32...Water temperature sensor, AC-...AC signal, Di...Identification data, Nln...Instantaneous speed data, Do...Control output data, Nj...Target speed data, N...Average speed data.

Claims (1)

[Claims] 1. a first calculation means for calculating an average speed of the multi-cylinder internal combustion engine; a means for outputting target speed data indicating a desired target idle rotation speed; and a calculation result of the first calculation means and the target speed data. means for responsively outputting first control data related to an amount of fuel to be supplied to the internal combustion engine to obtain the target idle speed; and responsive to the first control data, closed loop control of the idle speed. In an idle operation control device for an internal combustion engine having a closed loop control system comprising a control means for controlling a required speed regulating means so that the speed regulating means is controlled, the instantaneous speed of each cylinder of the internal combustion engine is sequentially detected at a predetermined timing. and in response to the detection results sequentially output from the detection means, all difference data corresponding to the difference between the instantaneous speed for each cylinder and the instantaneous speed for a reference cylinder predetermined for each cylinder are collected. means for sequentially and repeatedly outputting calculations for the cylinders; timing detecting means for detecting the operating timing of each cylinder of the internal combustion engine; and a means for responding to the difference data to make the difference indicated by the difference data zero. means for calculating and outputting second control data related to the necessary supply fuel; and means for outputting a water temperature signal related to the cooling water temperature of the internal combustion engine;
output control means for outputting the second data at a required timing before the next fuel adjustment stroke for each cylinder based on the detection result by the timing detection means; and output control means for outputting the second data at a required timing before the next fuel adjustment stroke for each cylinder; An idle operation control device for an internal combustion engine, comprising means for supplying the second data from the output control means to the closed loop control system only when the output control means is idle.