JPH0694861B2 - Engine ignition timing control device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an ignition timing control device in a sparring engine (internal combustion engine) such as a gasoline engine.

[Prior Art] Conventionally, ignition timing control of a gasoline engine is performed as follows, for example. That is, the operating state of the engine is detected from the flow rate sensor that detects the intake air amount of the engine and the engine speed sensor that detects the engine speed, and based on the detection results from these sensors,
Basic ignition timing information is obtained from a two-dimensional map having an advance value (ignition timing information) determined by the volumetric efficiency Ev (A / Ne) obtained by dividing the intake air amount A by the engine rotational speed Ne and the engine rotational speed Ne. The ignition timing of the engine is controlled by obtaining and correcting the basic ignition timing information appropriately and activating the ignition means (ignition plug, ignition coil, etc.) based on the ignition timing information obtained in this way. There is.

[Problems to be Solved by the Invention] By the way, appropriate corrections to be made to the above basic ignition timing information include corrections based on the engine cooling water temperature and corrections based on the intake air temperature. When accelerating,
Since knocking occurs due to the following reasons, it is necessary to make some correction to the ignition timing information even during engine acceleration.

First, when the engine is attempted to be accelerated from the partial operation state, the exhaust gas remaining amount in the combustion chamber is small, so that the combustion speed is increased and the actual filling rate is also increased, which easily causes knocking. After the engine acceleration is started, this nossing phenomenon continues for the number of piston steps corresponding to the number of combustion chambers (cylinders) of the engine. For example, in the case of a four-cylinder engine, this knocking phenomenon continues from the start of acceleration up to four steps.

The second reason is that there is usually a process delay in detecting the engine load for determining the ignition timing, and since the ignition process is one process later, this is not a problem alone, but this ignition process also causes a process delay. Occurs, the ignition timing control is delayed, and during acceleration, the ignition timing is advanced beyond a predetermined ignition timing and exceeds the knock critical line, resulting in knocking.

In order to avoid such knocking, the basic ignition timing information may be appropriately corrected (retarded) to the retard side when the engine is accelerated.

Therefore, as indicated by the broken line in the graph of FIG. 8 (the vertical axis of this graph shows the retard angle, that is, the retard amount), the time required for the initial stage of acceleration (for example, the time for four steps in the case of a four-cylinder engine) ), Take a certain amount of retard amount enough to avoid both knocking due to the above-mentioned first and second reasons, and set to gradually decrease the retard amount after the required time has elapsed from the start of acceleration. Then, a means for correcting the ignition timing at the time of acceleration can be considered.

However, the knocking due to the first reason described above continues up to four steps at maximum from the start of acceleration in the case of a 4-cylinder engine, but the knocking due to the second reason described above lasts only up to two steps of the engine. Absent. Therefore, knocking due to the second reason is eliminated first, and then knocking due to the first reason is eliminated after a further predetermined time has elapsed.

For this reason, in the above-mentioned means of taking the retard amount by a fixed amount only after the start of acceleration and gradually reducing the retard amount after the required time has elapsed, the reason for the second knocking is eliminated and the first knocking is performed. Within the period in which the reason (1) remains (for example, the third and fourth steps), the retard amount originally required is reduced, but the correction amount is still corrected with a large retard amount.

Therefore, there is a problem in that the output increase of the engine is suppressed by the amount of the excessive retard amount, and the target acceleration of the engine is delayed accordingly.

The present invention is intended to solve such a problem, and provides an engine ignition timing control device capable of reliably preventing knocking during acceleration while preventing prompt acceleration of the engine as much as possible. The purpose is to do.

[Means for Solving the Problems] Therefore, the engine ignition timing control device of the present invention includes a basic ignition timing setting means for setting a basic ignition timing according to an operating state of an engine having an ignition means, and the engine described above. In addition to the acceleration ignition timing correction amount setting means for setting an acceleration ignition timing correction amount having a functional relationship with the elapsed period after the start of acceleration for correcting the basic ignition timing at the time of acceleration, The ignition timing correction amount for acceleration includes a control means for operating the ignition means based on the basic ignition timing and the ignition timing correction amount for acceleration determined according to the operating state, and The retard amount of 1 is taken, and when the required period has elapsed from the start of acceleration, the second retard amount which is smaller than the first retard amount is taken, and when the required period has passed, the The retard amount of 2 is set to be gradually reduced, and at least one of the first retard amount and the second retard amount is set to a large retard amount when the degree of acceleration is large. It is characterized in that it is configured to be adjusted according to the degree of acceleration.

[Operation] In the engine ignition timing control device of the present invention described above, the ignition timing correction amount for acceleration takes the first retard amount at the initial stage of acceleration start, and the first retard amount after the required period has elapsed from the start of acceleration. Is set to gradually decrease the second retard amount after a required period has elapsed, and the first retard amount and the second retard amount are set to be gradually reduced. At least one of the amount and the amount is configured to be adjusted according to the degree of acceleration so as to take a large retard amount when the degree of acceleration is large, and therefore, depending on the reason for knocking that occurs during acceleration, The ignition timing for acceleration is finely corrected to prevent knocking while promptly completing the retard correction of the advance amount during acceleration.

[Embodiment] An engine ignition timing control device as an embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a control block diagram thereof, and FIG. 2 is an overall configuration diagram showing an engine system having the device. FIG. 3 is a control block diagram of the engine system, FIG. 4 is a fuel control block diagram of the engine system, FIG. 5 (a) is an electric circuit diagram of the ignition driver, and FIG. 5 (b) is the ignition. Schematic control block diagram for timing, FIG. 6 is a flow chart for explaining how to determine the volumetric efficiency, and FIG. 7 is a knock critical line and MB
A graph showing the relationship with the T line by plotting the volume efficiency on the vertical axis and the ignition timing on the horizontal axis, FIG. 8 is an enlarged view of the correction map at the time of acceleration, and FIGS. 9 (a) and 9 (b) are the same. It is a flowchart which shows the correction procedure in the correction means at the time of acceleration.

Now, the in-vehicle gasoline engine system controlled by this device is as shown in FIG. 2, and in FIG. 2, a gasoline engine E (hereinafter, simply referred to as engine E) has an intake passage communicating with its combustion chamber 1. 2 and the exhaust passage 3, the intake passage 2 and the combustion chamber 1 are controlled to communicate with each other by the intake valve 4, and the exhaust passage 3 and the combustion chamber 1 are also provided.
The exhaust valve 5 controls the communication with.

Further, in the intake passage 2, the air cleaner 6,
A throttle valve 7 and an electromagnetic fuel injection valve (injector) 8 that constitutes a first engine adjusting element that influences the operation of the engine are provided. A catalytic converter (three-way catalyst) 9 and a muffler (silencer) not shown are provided.

The injectors 8 are provided in the intake manifold portion by the number of cylinders. The engine E of this embodiment is now in series 4
If it is a cylinder engine, four injectors 8 will be provided. That is, it can be said that the engine is a so-called multipoint fuel injection (MPI) type engine.

Further, the throttle valve 7 is connected to the accelerator pedal via a wire cable, so that the opening degree is changed according to the depression amount of the accelerator pedal.
Further, the idle speed control motor (ISC motor) 10 is also driven to open and close, so that the opening of the throttle valve 7 can be changed without pressing the accelerator pedal when idling. There is.

Further, each cylinder has a spark plug toward its combustion chamber 1.
18 (Originally, in the vicinity of the combustion chamber 1 in FIG.
18 should be drawn, but due to space limitations, spark plugs 18 are provided in different positions) and each spark plug 18 is connected to a distributor 50, which in turn It is connected to the coil 51. And the power transistor 52 with the ignition coil 51
A high voltage is generated in the ignition coil 51 by the off operation of the above, and any one of the four spark plugs 18 connected to the distributor 50 is sparked. The ignition coil 51 starts charging when the power transistor 52 is turned on. The ignition plug 18, the distributor 50, the ignition coil 51, and the power transistor 52 constitute an ignition means.

With such a configuration, the air sucked through the air cleaner 6 according to the opening degree of the throttle valve 7 is mixed with the fuel from the injector 8 in the intake manifold portion so as to have an appropriate air-fuel ratio, and the spark plug is set in the combustion chamber 1. By igniting 18 at an appropriate timing, it is made to burn,
After the engine torque is generated, the air-fuel mixture is discharged as exhaust gas to the exhaust passage 3, and the catalytic converter 9 purifies the three harmful components of CO, HC, and NOx in the exhaust gas, and is then silenced by a muffler to be discharged into the atmosphere. It is designed to be released to the side.

Further, various sensors are provided to control the engine E. First, on the intake passage 2 side, an air flow sensor 11 as a volume flow meter for detecting the intake air amount from the Karman vortex information, an intake air temperature sensor 12 for detecting the intake air temperature, and an atmospheric pressure are detected in the air cleaner installation portion. An atmospheric pressure sensor 13 is provided, and a position of the throttle valve 7 is a potentiometer-type throttle sensor 14 that detects the opening of the throttle valve 7, an idle switch 15 that detects an idling state, and an ISC motor 10 position. A motor position sensor 16 is provided.

On the exhaust passage 3 side, on the upstream side of the catalytic converter 9, near the combustion chamber 1, the oxygen concentration in the exhaust gas (O ₂ concentration)
An oxygen concentration sensor (O ₂ sensor) 17 for detecting the is provided. Here, the O ₂ sensor 17 is an application of the principle of a solid electrolyte oxygen concentration battery, and its output voltage has a characteristic that it changes rapidly near the logical air-fuel ratio, and the voltage on the lean side is lower than the theoretical air-fuel ratio. , The voltage on the rich side is higher than the stoichiometric air-fuel ratio.

Further, as other sensors, a water temperature sensor 19 for detecting the engine cooling water temperature is provided, and a crank angle sensor 21 for detecting the crank angle (this crank angle sensor
Since 21 also serves as an engine speed sensor for detecting the engine speed N, hereinafter, the crank angle sensor 21 may be referred to as an engine speed sensor, if necessary.)
A TDC sensor 22 for detecting the top dead center of the first cylinder (reference cylinder) is provided in the distributor 50.

By the way, the detection signals from the sensors 11 to 17, 19, 21, and 22 are input to the electronic control unit (ECU) 23.

A voltage signal from a battery sensor 25 that detects the voltage of the battery 24 (see FIG. 3) and a signal from an ignition switch (key switch) 26 are also input to the ECU 23.

Further, the hardware configuration of the ECU 23 is as shown in FIG. 3, and this ECU 23 has a CPU 27 as its main part, and the CPU 27 has an intake air temperature sensor 12, an atmospheric pressure sensor 13,
The detection signals from the throttle sensor 14, O ₂ sensor 17, water temperature sensor 19 and battery sensor 25 are input interfaces 28
And the detection signals from the idle sensor 16 and the ignition switch 26 via the input interface 29, and the detection signals from the air flow sensor 11, the crank angle sensor 21 and the TDC sensor 22. Is directly input to the input port.

Further, the CPU 27 uses a bus 24 to store a program data and fixed value data in a ROM 31, a RAM 32 that is updated and sequentially rewritten, and a battery 24 that causes a battery 24.
Battery backup RAM (B
It is designed to exchange data with URAM) 33.

The data in the RAM 32 is erased and reset when the ignition switch 26 is turned off.

In addition, the ignition timing control signal is sent from the CPU 27 to the ignition driver 53.
Is output to the power transistor 52 via the ignition coil 51, and further, for example, four spark plugs 18 are sequentially sparked from the ignition coil 51 via the distributor 50.

The ignition driver 53, as shown in FIG.
Flip-flops 531 and 532 and flip-flop 5 that receive the signals due to the pulses from the crank every 180 °
AND gate 534 receiving the output of 31 and the clock from the clock generator 538, AND receiving the output of the flip-flop 532 and the clock from the clock generator 538
The second preset counter 536, the second preset counter 537, which starts the countdown by being triggered by the signals from the gate 535 and the AND gates 534, 535, respectively, are set by the signal output when the first preset counter 536 becomes zero. Flip-flop that is reset by the signal output when the preset counter 537 reaches zero
533, and the power transistor 52 is turned on / off by the output of the flip-flop 533.

The first preset counter 536 and the second preset counter 537 are respectively input with preset values M1 and M2 from the CPU 27 and are counted down to values corresponding to the preset values M1 and M2, and when they reach zero, a pulse signal to that effect is output. It is designed to output.

When the flip-flop 533 is reset, the power transistor 52 is turned off and the flip-flop 533 is turned off.
Is set, the power transistor 52 is turned on, so the first preset counter 536 determines the ignition timing timing and the second preset counter 537 determines the ignition coil charging timing. In general, since charging is performed after ignition, first the first preset counter 53
The preset value M1, so that the output pulse is output from 6 and then the output pulse is output from the second preset counter 537.
M2 (M1 <M2) is set.

Furthermore, in order to determine the preset values M1 and M2, ECU23
Has the following means. That is, schematically, as shown in FIG. 5 (b), E _VP and engine speed N, which will be described later, are set.
Two-dimensional ignition timing data (advance data) θ determined by e
An ignition timing data storage means 54 for storing ₀ in the ignition timing map MP3 and a closing angle data storage means 55 for storing closing angle data θ'determined by the engine speed Ne in the closing angle map MP4 are further provided. 11, Ignition timing map MP3 in response to signal from engine speed sensor 21
The ignition timing data determined by E _VP and the engine speed Ne is read from the ignition timing determining means 56 for setting the time data corresponding to the read ignition timing data as the preset value M1 at the address ST1, and the engine speed. Sensor
In response to the signal from 21, the closing angle map MP4 reads the closing angle data determined by the engine speed Ne, and the time data corresponding to the read closing angle data is read out at the address ST.
2 has a closing angle determining means 57 for setting the preset value M2.

Therefore, from the ignition timing determination means 56, the preset value M1
Preset signal with information is the first preset counter
In addition to being output to 536, a preset signal having preset value M2 information is output from the closing angle determining means 57 to the second preset counter 537.

By the way, a more detailed block diagram for controlling the ignition timing is shown in FIG. That is, as shown in FIG. 1, this ignition timing control device includes a basic ignition timing setting means (ignition timing calculation means) having an ignition timing map MP3 for storing two-dimensional basic ignition timing data (advance angle data) θ _0. ) 58, a water temperature correction means 59 having a water temperature correction map MP5, an acceleration correction means 60 as an acceleration ignition timing correction amount setting means having an acceleration correction map MP6, and an intake air temperature correction map MP7. In addition, the intake air temperature correction means 61 and the idle stabilization correction means 62 having the idle stabilization correction map MP8 are provided.

Here, in the ignition timing map MP3, if the intake air amount / engine speed, that is, the volume efficiency and the engine speed Ne are known, the basic ignition timing θ ₀ is determined from the map value. The value of is different from the conventional one,
Atmospheric pressure is corrected in advance.

In order to perform the atmospheric pressure correction on the volumetric efficiency in advance in this way (the volumetric efficiency obtained by performing the atmospheric pressure correction in this way is referred to as _EVP ), first, step a in FIG.
At 1, the intake air amount A, the engine speed Ne, and the atmospheric pressure P are input, and at step a2, A × (P / 760) is set to A ′, so that the intake air amount A is normalized to 1 atm, Step a3
Then, A '/ Ne and _EVP are set. In this way, the volumetric efficiency of the ignition timing map MP3 could be corrected in advance by the atmospheric pressure. After that, step a4 in FIG.
Then, the basic ignition timing data (advance angle data) θ ₀ is set based on this E _VP and Ne, and these relations are set to the ignition timing map.
It is stored in MP3.

The water temperature correction map MP5 stores the relationship between the cooling water temperature WT and the advance amount θ _WT, and the relationship is such that the higher the water temperature, the smaller the advance value θ _WT .

As shown in FIG. 8, the acceleration correction map MP6 stores the relationship between the time t after the start of acceleration and the retardation amount θ _AC . As shown in FIG. Regarding the relationship with the angular amount (retard amount) θ _AC , the first retard amount (level 8 in this embodiment) is taken at the initial stage of acceleration start, and when the required time elapses from the acceleration start time, the first retard amount is more than the first retard amount. Taking a small second retard amount (level 4 in this embodiment),
When the required time further elapses, the second retard amount is set to be gradually reduced.

Then, in the acceleration correction means 60 as the acceleration ignition timing correction amount setting means having the acceleration correction map MP6, the throttle opening change is used as information for determining the acceleration.

That is, the throttle opening change value .THETA. Detected by the throttle sensor 14 is time differentiated by the throttle opening change calculation means 71 to calculate the throttle opening change value (d.THETA./dt=.DELTA..THETA.). Then, the acceleration determination means 72 compares the value ΔΘ of the throttle opening change with a reference value α ₁ (α ₁ > 0),
When Θ is larger than the reference value α ₁ (ΔΘ> α ₁ ), it is determined that the engine is in the acceleration state.

The main acceleration determination means 72 is also configured to determine that the engine is in a decelerating state. That is, the value ΔΘ of the change in throttle opening is set to the reference value −α ₂ (α ₂
> 0), Δθ is smaller than the reference value −α ₂ (ΔΔ
Θ <-α ₂₎ sometimes it is determined that the engine is in a deceleration state.

Also, this acceleration determination means 72 is, for example, 5 msec (0.005 seconds)
The throttle opening change value ΔΘ is fetched for each time to make acceleration determination and deceleration determination [see steps b1 and b2 in FIG. 9 (a)].

On the other hand, in the acceleration correction means 60 as the acceleration ignition timing correction amount setting means, based on the acceleration determination information from the acceleration determination means 72, when ΔΘ is larger than the reference value α ₁ , the process counter count C Is reset to 0 [step b3 in FIG. 9 (a)], and when ΔΘ is smaller than the reference value −α ₂ , the count number C is set to a predetermined value (here, 10).
[Step b4 in FIG. 9 (a)].

In the acceleration correction means 60, as shown in the flow chart of FIG. 9 (b), each process of each cylinder (every 180 ° of crank angle) is performed as shown in the flow chart of FIG. 9 (b). Then, the retard amount can be set.

That is, it is determined whether the count number C determined as described above is 10 (step c1), and when the count number C is not 10, [in this case, as can be seen from FIG. 9 (a), C becomes 0. ], The retard amount R is set by the function f (C) based on the count number C (step c2),
The advance amount is retarded based on the retard amount R.

The function R = f (C) is an ignition timing correction amount setting means for acceleration.
It is conceivable that it is set at 72, for example, the retard sequence shown in Table 1 below is set.

The value of each count number C corresponds to the number of processes in each cylinder after acceleration stabilization. In other words, C = 0,1,2, ...
・, 7,8,9 are the first, second, third, and third of each cylinder after acceleration judgment.
..., corresponding to the 8th, 9th, and 10th steps.

C = 0,1, that is, the first and second cylinders of each cylinder after acceleration stabilization
In the second engine step, a large retard amount R (first retard amount R ₁ = 8) is provided so that both the first reason and the second reason among the knocking reasons that occur during engine acceleration can be dealt with. C = 2,3, that is, in the 3rd and 4th engine processes of each cylinder after acceleration determination, the first reason out of the knocking reasons that occur during acceleration of the engine can be dealt with. , Set to a medium retard amount R (second retard amount R ₂ = 4) smaller than the first retard amount, and after C = 4, that is, the fifth retard of each cylinder after acceleration determination. After the engine process, the retard amount is gradually reduced to avoid a rapid advance amount correction, and C = 7.
Therefore, the retard amount R is set to 0.

The solid line L _{1 in} FIG. 8 corresponds to the retard sequence in Table 1. The sequence in Table 1 is
The present invention relates to a four-cylinder engine, and this sequence is appropriately changed according to the number of engine cylinders. In FIG. 8, the horizontal axis represents time, but this time scale corresponds to the engine process, and the time scale interval may be linear to the actual time depending on the operating speed of the engine. Does not mean

The intake air temperature correction map MP7 shows the intake air temperature AT, the retard angle, and the advance angle θ _AT
The relationship between the intake air temperature AT is low and the intake air temperature AT is high, and the relationship is 0 when the intake air temperature AT is medium.

The idle stabilization correction map MP8 includes, for example, proportional control (P control) and differential control (D control).
For control, the relationship between the engine speed Ne and the ignition timing information θ _IDP is stored, and the relationship is that the engine speed Ne is
ISC (idle speed control) target engine speed setting means 73 sets the ISC target engine speed Ne ₀
When the engine speed Ne is lower than the ISC target engine speed Ne ₀ , the engine is retarded when the engine speed Ne is higher than the above. Also, for D control, engine speed change ΔNe
And the ignition timing information θ _IDD are stored, and the relationship is retarded while the engine speed is increasing,
It is designed to be advanced when the engine speed is reduced. A dead zone is provided to prevent hunting.

Further, the basic ignition timing data θ ₀ from the basic ignition timing setting means 58 and the water temperature correction data θ _WT from the water temperature correction means 59 are added by the addition means 63, and the acceleration correction data θ _AC from the acceleration correction means 60 is added. Intake temperature data θ from the intake temperature correction means 61
_AT is added by the adding means 64, and the data (θ _AC + θ _AT ) from the adding means 64 is appropriately corrected by the operating state correcting means 69 according to the engine operating state.

Furthermore, the data from the driving state correction means 69 is added to the addition means.
By 65, the data (θ ₀ + θ _WT ) from the adding means 63 is added.

The data from the addition means 65 is further added by the addition means 66 to the idle stabilization data θ _IDP and θ _IDD from the idle stabilization correction means 62, and the timing control unit 68
It will be sent to.

A switch 67 is provided between the idle stabilization compensating means 62 and the adding means 66.
When the idle switch 15 is turned on when the engine is idle, it is closed, and open otherwise.

Further, the timing control unit 68 uses various correction data (θ _WT , θ _AC , θ _AT , θ _IDP , θ) as the basic ignition timing data θ _0.
The ignition timing is determined from the data including _IDD ) and constitutes a part of the ignition timing determining means 56 of FIG. 5 (b).

By the way, as shown in FIG. 3, a fuel injection control signal is output from the CPU 27 via the injector driver 34, and four injectors 8 are sequentially driven, for example.

A functional block diagram for such fuel injection control (injector drive time control) is shown in FIG. In other words, if you look at this ECU23 in terms of software, this ECU23
, First have a basic driving time determining means 35 for determining a basic drive time T _B for the injector 8, the basic drive time determining means 35, the intake air amount / the engine rotational speed (A /
Ne) 1-dimensional basic drive time data (T _B ) i [=
F (A / Ne)] (where i is a positive integer) is stored in the basic drive time map MP1, and the basic drive time determination means 35 further includes a basic drive time determination means 35. Receiving signals from sensor 11, crank angle sensor (engine speed sensor) 21, etc., basic drive time map MP1 to A
/ Ne at determined reading the basic drive time data includes means for determining the read data as the basic drive time T _B which was in the current engine operating condition. As the basic drive time determining means 35, the basic drive time map MP1
Alternatively, the basic driving time T _B [= a (A / Ne)] may be obtained by multiplying A / Ne by a required coefficient a without having.

Further, the air-fuel ratio correction means 36 and O ₂ for performing the air-fuel ratio correction by setting the correction coefficient K _AF1 according to the engine speed and the engine load (the A / Ne information has the engine load information).
An O ₂ sensor feedback correction means 37 is provided for performing correction by setting a correction coefficient K _AF2 at the time of sensor feedback, and the air-fuel ratio correction means 36 and the O ₂ sensor feedback correction means 37 are switched in conjunction with each other. It is designed to be selectively selected by 38,39.

The air-fuel ratio correction means 36 uses the two-dimensional correction coefficient data (K _AF1 ) ij (where i and j are positive) determined by the intake air amount / engine speed (A / Ne) and engine speed N. The correction coefficient storage means stores the correction coefficient map MP2 in the correction coefficient map MP2. Further, the air-fuel ratio correction means 36 includes an air flow sensor 11, a crank angle sensor (engine speed sensor) 21 A means for receiving a signal from the correction coefficient map MP2 to read the correction coefficient data determined by the A / Ne and the engine speed Ne from the correction coefficient map MP2, and determining the read data as the correction coefficient K _AF1 in the current engine operation state. have.

Further, a cooling water temperature correction means 40 for setting a correction coefficient K _WT according to the engine cooling water temperature, an intake air temperature correction means 41 for setting a correction coefficient K _AT according to the intake air temperature, and a correction coefficient K _{AP for the} atmospheric pressure.
Atmospheric pressure compensating means 42, correction coefficient K _AC for increasing acceleration
The acceleration increase correction means 43 for setting the dead time, the dead time correction means 44 for setting the dead time (ineffective time) T _D for correcting the drive time according to the battery voltage, and finally drive the injector 8. Time T _INJ to T _B × K _WT × K _AT
× at the _{K AP × K AC × (K} AF1 or K _AF2) + T _D, is driving the injector 8 in the time T _INJ.

It should be noted that the CPU 27 outputs a signal to that effect when the air flow sensor 11 fails, and this signal is output to the alarm lamp 70 as shown in FIG.

Next, the control region for the above ignition and injector drive will be shown. The control timing in this case is determined by the interruption of the crank pulse at every 180 °. First, when controlling the ignition timing, the data at the address S1 of the ignition timing determining means 56 (timing control unit 68) (basic ignition timing data) Is set as the preset value M1 in the first preset counter 536 of the ignition driver 53, and the data at the address ST2 of the closing angle determination means 57 (closing angle data) is set as the preset value M2 in the ignition driver. 53
Of the clock pulse (AND gates 534, 535) is opened to issue a countdown command to each preset counter 536, 537. As a result, when the power transistor 52 is turned off and the required spark plug 18 is sparked after the time corresponding to the preset value M1, and then the second preset counter 537 becomes zero, the power transistor 52 is turned on and the ignition coil 51 is turned on.
To charge.

Then, in the acceleration correction means 60, FIG. 9 (a), (b)
The correction is executed as shown in.

That is, the acceleration determination means 72 compares the throttle opening change value (ΔΘ) calculated by the throttle opening change calculation means 71 with the reference value α ₁ (α ₁ > 0) (step b1). When ΔΘ is larger than the reference value α _1, it is determined that the engine is in an accelerating state, and the count number C of the process counter is reset to 0 (step b3). Further, the acceleration determination means 72 compares the throttle opening change value ΔΘ with the deceleration reference value −α ₂ (α ₂ > 0) (step b2), and Δ
When Θ is smaller than the reference value −α _2, it is determined that the engine is in the decelerating state, and the count number C is set to a predetermined value (here, 10) (step b4). If the value ΔΘ of the throttle opening change is (−α ₂ ≦ ΔΘ ≦ α ₁ ), the count number C does not change.

Further, in the acceleration correction means 60, as shown in the flowchart of FIG. 9 (b), as shown in the flowchart of FIG. 9 (b) for each process (crank angle of 180 °) of each cylinder. To set the retard amount.

That is, first, the count number C determined as described above is 10
Is determined (step c1), and here the count number C is
If it is not 10, [In this case, the count number C becomes 0 as can be seen from FIG. 9 (a). ], And the retard amount R is set by a function f (C) based on the count number C (step c2). Then, the advance amount is retarded based on the retard amount R. Further, when the count number C is 10, no retard is performed.

The function R = f (C) is an ignition timing correction amount setting means for acceleration.
At 72, for example, the retard sequence of Table 1 is set, and the retard correction of the advance amount is based on this sequence.

Then, C = 0,1, that is, the first and second cylinders of each cylinder after acceleration determination.
In the second engine step, a large first retard amount R ₁ =
By coping with the first reason and the second reason among the knocking reasons that occur when the engine is accelerated,
= 2,3, that is, in the 3rd and 4th engine steps of each cylinder after the acceleration determination, the second retard amount R ₂ = 4, which is a medium value smaller than the 1st retard amount, causes Address the first of the resulting knocking reasons. Then, after C = 4, that is, after the fifth engine process of each cylinder after the acceleration determination, the reason for knocking has already been solved, but in order to avoid a rapid advance angle correction, the retard is gradually increased. The amount is decreased so that the retard amount R becomes 0 when C = 7.

As a result, as shown by the solid line L _{1 in} FIG. 8, as compared with the case where the retard amount is taken by a fixed amount for the required time after the start of acceleration and the retard amount is gradually decreased after the required time, as shown by the broken line,
Unnecessary retard correction is eliminated, the retard correction can be completed faster, and knocking at the start of acceleration is prevented without hindering an increase in torque required during acceleration.

The sequence in Table 1 relates to a 4-cylinder engine, and this sequence is appropriately changed according to the number of cylinders in the engine. For example, for a 6-cylinder engine, C
= 2 to 5, correction is performed with the _second retard amount R ₂ = 4.

Further, the initial value of the count value C can be appropriately set to a value other than 10 according to a desired correction condition.

The number indicating the retard amount R indicates the retard level for the sake of convenience, and appropriate retard correction is performed in accordance with the number.

Further, if the retard function is described in detail, ΔΘ is classified into more detail, and the retard function R = f (C) is converted into R = f.
₁ (C), R = f ₂ (C) ...
Depending on the acceleration state, if the acceleration amount is large, a larger retard level may be set (see L _{1 in} FIG. 8), and if the acceleration amount is not so large, a fine adjustment may be made to a medium or small retard level. (See L ₂ and L _{3 in} FIG. 8).

On the other hand, when the injector is driven, intake air amount data per 180 ° of crank angle is obtained based on the cycle data between the Kalman pulses generated between the previous crank pulse and the current crank pulse, and is input to the address QCR.

After that, based on this QCR data, the basic drive time T _B
Is set. After that, set the injector drive time T _{INJ
T B × K WT × K AT} × K AP × K AC × ( data of Adosu KAF) + T _D
After this T _INJ is set in the injection timer, the injection timer is triggered. Then, when triggered in this way, fuel is injected only during the time T _INJ .

In this way, the air-fuel ratio control and the ignition timing control can be executed.

Now, focusing on ignition timing control, ignition timing map MP3
When the intake air amount / engine speed, that is, the volume efficiency and the engine speed Ne are known, the basic ignition timing θ ₀ is determined from the map value, and the value of this volume efficiency is
Unlike the conventional one, the atmospheric pressure is corrected in advance.
That is, it can be said that the volume-based volumetric efficiency Ev _VOLUME is mapped using the E _VP that has only been subjected to atmospheric pressure correction in advance. As a result, the output does not decrease even in a highland where the atmospheric pressure is low. That is, when the atmospheric pressure decreases, the knock critical line K ₁ shown in FIG. 7 shifts in the direction of the arrow β as described in the conventional example, but the E _VP in this case corrects the atmospheric pressure. because they are subjected to, E _VP does not decrease. Therefore, at this time, the output of the engine does not decrease.

In this case, since it is equivalent to performing atmospheric pressure correction on all engine operating zones, only the basic ignition timing map MP3 can cover all engine operating zones. .

Further, since the ignition timing control is performed based on the air flow sensor 11, which is a volumetric flow rate sensor, a small intake air temperature correction (may not need to be corrected) is sufficient to sufficiently knock when the intake air temperature rises. It can be avoided.

It should be noted that instead of using a map in which E _VP and Ne are variables, the relationship between E _VP and basic ignition timing information θ ₀₁ is specified 1
Even if a dimensional map and a one-dimensional map that defines the relationship between Ne and the ignition timing information θ ₀₂ are prepared, the basic ignition timing information θ ₀ is obtained from the basic ignition timing information θ ₀₁ and θ _{02 of} these maps. Good.

Further, it goes without saying that the present invention can be applied to a low-voltage power distribution type ignition device which does not use a distributor but distributes to a spark plug by the switching operation of all semiconductor switching elements.

In addition to the MPI engine system,
Of course, it can be applied to the engine system of the method (single point fuel injection method).

[Advantages of the Invention] As described above in detail, according to the engine ignition timing control device of the present invention, the basic ignition timing setting means for setting the basic ignition timing according to the operating state of the engine having the ignition means, The engine is provided with acceleration ignition timing correction amount setting means for setting an acceleration ignition timing correction amount having a functional relationship with the elapsed period after the start of acceleration for correcting the basic ignition timing at the time of engine acceleration. The ignition timing correction amount for acceleration based on the basic ignition timing and the ignition timing correction amount for acceleration determined according to the operating state of When the first retard amount is taken and the required period has elapsed from the start of acceleration, a second retard amount smaller than the first retard amount is taken, and when the required period has elapsed, the second retard amount is reduced. It is set to gradually decrease the retard amount of 2.
In addition, at least one of the first retard amount and the second retard amount is configured to be adjusted according to the degree of acceleration so as to obtain a large retard amount when the degree of acceleration is large. With such a simple configuration, depending on the degree of acceleration, there is an advantage that quick acceleration of the engine is prevented as much as possible, knocking during acceleration is reliably prevented, and smooth acceleration is realized.

[Brief description of drawings]

1 to 9 show an ignition timing control device for an engine as an embodiment of the present invention, FIG. 1 is a control block diagram thereof, and FIG. 2 is an overall configuration diagram showing an engine system having this device, 3 is a control block diagram of the engine system, FIG. 4 is a fuel control block diagram of the engine system, and FIG. 5 (a) is an electric circuit diagram of an ignition driver thereof.
FIG. 5 (b) is a schematic control block diagram for the ignition timing,
FIG. 6 is a flow chart for explaining how to determine the volumetric efficiency, and FIG. 7 is a graph showing the relationship between the knock critical line and the MBT line with the vertical axis representing the volumetric efficiency and the horizontal axis representing the ignition timing. FIG. 8 is an enlarged view of the acceleration correction map, and FIGS. 9A and 9B are flowcharts showing the correction procedure in the acceleration correction means. 1 ... Combustion chamber, 2 ... Intake passage, 3 ... Exhaust passage, 4 ...
Intake valve, 5 exhaust valve, 6 air cleaner, 7
Throttle valve, 8 ... Solenoid valve (injector), 9 ...
Catalytic converter, 10 …… ISC motor, 11 …… Air flow sensor (volume flow meter), 12 …… Intake air temperature sensor, 13 …… Atmospheric pressure sensor, 14 …… Throttle sensor, 15 …… Idle switch, 16 …… Motor Position sensor, 17 ... O ₂ sensor as oxygen concentration sensor, 18 ... spark plug that constitutes ignition means, 19 ... water temperature sensor, 20 ... starter switch, 21 ... crank angle sensor (engine speed sensor) , 22 …… TDC sensor, 23 …… Electronic control unit (EC
U), 24 …… Battery, 25 …… Battery sensor, 26 ……
Ignition switch (key switch), 27 …… CP
U, 28, 29 ... Input interface, 30 ... A / D converter, 31 ... ROM, 32 ... RAM, 33 ... Battery backup RAM (BURAM), 34 ... Injector driver, 35 ...
Basic drive time determination means, 36 ...... Air-fuel ratio correction means, 37 ......
O ₂ sensor feedback correction means, 38, 39 ...... switching means, 40 ...... cooling water temperature correction means, 41 ...... intake air temperature correction means, 42 ...... atmospheric pressure correction means, 43 ...... acceleration increase correction means, 44 ...... Dead time correction means, 50 ... Distributor, 51 ... Ignition coil, 52 ... Ignition timing control power transistor, 53 ... Ignition driver, 54 ... Ignition timing data storage means, 55 ... Closing angle data storage means, 56 ……
Ignition timing determining means, 57 ... Closing angle determining means, 58 ... Ignition timing setting means (ignition timing calculating means), 59 ... Water temperature correcting means, 60 ... Accelerating as ignition timing correction amount setting means for acceleration Compensation means, 61 ... Intake air temperature compensation means, 62 ... Idle stabilization compensation means, 63-66 ... Addition means, 67 ... Switch, 68 ... Timing control section constituting control means, 69 ...
... Operating state correction means, 70 ... Alarm lamp, 71 ... Throttle opening change calculation means, 72 ... Acceleration determination means, 73 ...
… ISC target engine speed setting means, 531,532,533 …… Flip-flop, 534,535 …… AND gate, 536 …… First
Preset counter, 537 …… Second preset counter, 538 …… Clock generator, E …… Engine, M
P1 …… Basic drive time map, MP2 …… Air-fuel ratio map, MP3
...... Basic ignition timing map, MP4 ...... Closed angle map, MP5 ...
… Water temperature correction map, MP6 …… Acceleration correction map, MP7 ……
Intake temperature correction map, MP8 …… Idle stabilization correction map.

Continuation of the front page (56) References JP-A-62-17368 (JP, A) Actually opened 60-131669 (JP, U) Actually opened 61-33972 (JP, U)

Claims (1)

[Claims] 1. A basic ignition timing setting means for setting a basic ignition timing according to an operating state of an engine having an ignition means, and an elapsed period after the start of acceleration for correcting the basic ignition timing during acceleration of the engine. In addition to the acceleration ignition timing correction amount setting means for setting the acceleration ignition timing correction amount having a functional relationship, the basic ignition timing and the acceleration ignition timing obtained in accordance with the operating state of the engine are provided. The ignition timing correction amount for acceleration has a first retard amount at the initial stage of acceleration start, and the first ignition timing correction period has elapsed after a required period has elapsed since the start of acceleration. It is set to take a second retard amount smaller than the retard amount and to gradually decrease the second retard amount when the required period elapses, and the first retard amount is set to the first retard amount. At least one of the retard amount and the second retard amount is configured to be adjusted according to the degree of acceleration so as to obtain a large retard amount when the degree of acceleration is large. , Engine ignition timing control device.