JPS62225730A - A/n abnormal reduction preventing device for engine in tap - Google Patents

Abstract

PURPOSE:To prevent the engine stall beforehand by increase-correcting the supply of mixed gas when the intake air quantity in the intake stroke of an engine is below a prescribed value and an accelerating pedal is in tap (momentary increase). CONSTITUTION:A computer 76 for controlling the operation of an engine is equipped with a mixed gas feed controlling means for controlling an injector 6 and an intake air quantity increase controlling means for controlling a stepping motor 18a as intake air quantity increasing means. Further, a throttle valve opening degree detecting means which receives the output of a throttle position sensor 36 and a throttle valve deceleration speed detecting means are provided. When each detection signal supplied from the both detecting means is received at a same time, a tap detection signal is outputted, and when the output of an A/N sensor is below a prescribed value and an idle switch 38 is ON for idle operation, the stepping motor 18a is operated through an air quantity increase starting means in case of tap.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a device for preventing an abnormal drop in engine A/N when an accelerator pedal is tapped. Regarding engine stop prevention device r!1).

[Conventional technology]

Conventionally, when idling, etc., the tap of the accelerator pedal (
instantaneous increase) based on engine speed,
A method of stopping the engine (hereinafter referred to as "EnsN") has been proposed.

Here, tap refers to a state in which the idle switch 38 [see plS1 figures (a) to (d)] changes from on to off and then on again in a short time at idle, and when the throttle output is low and the engine output is low. This refers to a state in which the opening degree rapidly increases and then decreases, and refers to a state in which the engine speed temporarily increases or decreases.

[Problem that the invention seeks to solve]

However, in such a conventional means for preventing the engine from stalling when tapping, the tap is detected based on the engine speed, and due to the rotational system inertia Y1ffL, the timing of detection is late as information for preventing the tap engine stall, and the tap is detected at a later time. There is a problem in that measures to prevent engine stalling are insufficient.

That is, as shown in FIG. 16(a), when the idle switch 38 changes rapidly from on to off and then back on in a short time (tap time), the throttle valve 14 turns on the engine 2. Opening capacity to the combustion chamber 8!2 Due to the inertial mass of the rotation system, a delay in control occurs, and the ratio of the intake air amount to the throttle opening and the engine speed per intake stroke (A/N) [16th Since a phase shift occurs between the reference 1 and Fig. (c), a state occurs where the engine speed is high and the throttle opening is small, resulting in [Pt
At time t0 reference 1 in Si2 diagram (a), (+)), a shortage of intake air amount occurs and the A/N becomes abnormally low, region Z+S.
is formed, and in this state, if the ISO valve 18 maintains a certain opening degree [$1 (see Figure 3 (d) 1, the necessary amount of air is not supplied to the engine 2, so as shown in Figure 16 (
b) As shown by the symbol Nll01+IN, there is a problem that the engine speed undershoots.
．． The engine may stall.

The present invention aims to solve these problems by detecting tap time at an early stage and temporarily increasing the amount of intake air when the tap is detected. Another object of the present invention is to provide an abnormal A/N drop prevention device for Ennon when tapping, which can reliably prevent tap engine stall.

[Means for solving problems]

For this reason, the A/N of the engine at the time of tap of the present invention is
The abnormal drop prevention device includes a mixture supply means that supplies a mixture to the combustion chamber of the engine, a mixture supply control means that sends a mixture supply control signal to the mixture supply means, and a mixture supply control means that sends a mixture supply control signal to the mixture supply control means. The air-fuel mixture command means for outputting a command signal for the air supply amount, and an A/N sensor for detecting the amount of intake air in one intake stroke of the engine are provided, and the command signal from the mixture command means is instantaneously increased. A tap sensor is provided for detecting the A/N and a momentary increase in the command signal occurs in response to each detection signal from the A/N sensor and the tap sensor, and the sensor detects that the A/N is below a predetermined value. The U feature is that a mixture increasing control means is provided for increasing the amount of mixture supplied by the mixture supplying means when detected.

[For production]

In the engine A/N abnormal drop prevention device at the time of tap of the present invention described above, the air-fuel mixture increase control means causes a tap to occur in the air-fuel mixture command signal (accelerator pedal depression amount), and
When it is detected that the A/N is less than or equal to a predetermined value, the amount of air-fuel mixture supplied to the combustion chamber of the engine can be increased by controlling the amount of air-fuel mixture supplied by the air-fuel mixture supply means.

〔Example〕

Hereinafter, embodiments of the present invention will be explained with reference to the drawings.
tiSi~55 shows an ennon control system for self-gIJIL equipped with the A/N% constant drop prevention during tapping as an embodiment of the present invention.
Figure 1 (a) is its block diagram, Figure 1 (b) is its overall configuration diagram, Figure 1 (c) is a wedge diagram showing a part of the ignition system, and Figure 11 (d) is its essentials. FIG. 2 is a 70-chart showing the first initialization routine, FIG. tItJ3 is a graph for explaining the action during idle speed control, and FIG. 4 is a 70-chart showing the second initialization routine. -Chart, Figure 5(a)
, (b) are schematic cross-sectional views showing the vicinity of the idle speed control valve installation part, and FIG. 6(a)-
(c) is a 70-chart showing the fourth initialization routine, ff17 (a) to (e) are 70-charts showing the third initialization routine, and FIG. 8 is a 70-chart showing the initialization prohibition. 70- showing the routine
Chart, tjS9 figure and figure 10 (a), (1))
are flowcharts and graphs showing the learning control routine, FIGS. 11 and 12 (a) to (d), respectively.
13 and 14 (,) to (d) are flowcharts and graphs showing the lift-up control routine when the cooler relay is turned on, respectively, and 7e+- charts and graphs showing the abnormal rotation speed reduction routine, respectively. Figures 15 and 16 (a) to (h) are flowcharts and graphs showing the abnormal A/N reduction routine and the tap engine stall prevention routine, respectively, and Figures 17 to 19 each explain the method for determining runaway of the combiator. FIGS. 20 and 21 are 70-charts and graphs showing the idle gas mode, respectively. FIG. 22 is a graph for explaining the operation mode for fuel supply control, and FIG. The figure is an electrical circuit diagram showing the connection between the 02 sensor and the computer.
4.25 is the 70-chart, No. 2, for explaining the control mode when the heater current leaks from the 02 sensor.
Figure 6 and Figure 27 respectively show the seven steps of the water temperature sensor.
A main part configuration diagram showing the Rousse 7 function (770-chart, Fig. 28 is a 70-chart for explaining the processing in the overrun cant mode, and Fig. 29 is a 70-chart for setting the air-fuel ratio). ), #S30 diagram (,) is its air-fuel ratio-engine speed characteristic diagram, and Figure 30 (b) is its,
Illustration timing retard amount vs. engine speed characteristic diagram, FIG. 30(e) is the air-fuel ratio vs. engine speed characteristic diagram, FIG. 31 is a 70-chart for explaining processing in other overrun cut modes, Figure 32 is a 70-chart for explaining the processing in the highest speed cutting mode, and Figure 33.
The figure is a 70-chart for explaining control associated with fuel cut during deceleration, Figures 34-36 are graphs for explaining the misfire detection method, and Figures 37-54 are for various types of misfire detection. FIG. 55 is a schematic hII chart showing the arrangement state of the thermo valve provided in the fuel supply path.

The most characteristic feature of this embodiment in relation to the present invention is as shown in FIG. A mixture supply control means that sends a mixture supply control signal to the injector 6, which is a mixture supply means, and an air amount that sends a control signal to the stepping motor 18a, which is an intake air amount increasing means, to increase the amount of air in the mixture. The throttle valve opening is greater than or equal to a predetermined value in response to a throttle valve opening signal from the throttle position sensor 36 that receives a command signal from the accelerator pedal as an air-fuel mixture command means. a throttle valve opening detection means for detecting this, and a throttle valve deceleration detection means for receiving a throttle valve opening signal from the throttle position sensor 36 and detecting that the speed of the throttle valve opening is less than or equal to a predetermined negative value. and a tap detection unit (AND circuit) that detects a tap of the accelerator pedal and outputs an output as a tap sensor when simultaneously receiving detection signals from the throttle valve opening detection means and the throttle valve deceleration detection means; Idle switch 38. In response to detection signals from the A/N sensor and the tap sensor, which are comprised of the air 70 sensor 32, engine speed sensor (top dead center sensor) 44, etc., a tap is generated at idle, and the A/N is The present invention is further provided with tap air amount increase start means (air mixture increase control means) which temporarily operates the intake air amount increase means when it is detected that the intake air amount is below a predetermined value.

Here, since the intake air amount increasing means employs the L-noetro system as described later, it functions as an air-fuel mixture supply means.

The most characteristic effect of the present invention is described below (
1) As described in 1-vii) Abnormal A/N reduction mode of idle speed control (ISC).

Now, in this embodiment, as shown in FIG. 1(b), this V-type 6-cylinder engine 2 is applied. In this system, a so-called multi-point injection system (MPI system) is adopted in which each intake manifold 4 connected to each cylinder has an electromagnetic fuel injection valve (7 fuel injectors) 6.

One end of an intake passage 10 is connected to the intake manifold 4 via a Sarno tank 8, and an air cleaner 12 is attached to the other end of the intake passage 10.

Further, a throttle valve 14 is interposed in the intake passage 10, and a bypass passage 16 is provided in parallel with a portion where the throttle valve 14 is disposed to bypass the throttle valve 14.

The bypass passage 16 has an idle speed control pulp (ISC valve) 18,! A near seven stroke idle valve and a seven valve (FIA valve) 20 are arranged in parallel with each other.

As shown in FIG. 1(b) and FIGS. 5(a) and (b), the idle speed control pulse 7'18 includes a stepping motor (also referred to as a stepper motor) 18a,
It includes a valve body 18b that is driven to open and close by a stepping motor 18a, and a return spring 18c that biases the valve body 18[) in the closing direction. The step 7 pin motor 18a has four fill parts arranged in a ring shape, and these coil parts rotate the rotor (rotating body part) in a space B*.
It is a rotary type (four-phase unipolar, two-phase excitation type) in which the rotor rotates, and when the coil part receives pulse signals in a predetermined order, it rotates left and right by a predetermined angle. The stepper 7 pin motor 18g extender is disposed coaxially with the opening 7 door L8d provided with the valve body 18b, and is screwed into this from the outside. However, the rod 18d is prevented from rotating. As a result, when the stepping motor 18a rotates, the rod 1 with the valve body 18b
8d moves along the axial direction 1 to change the valve opening degree.

7. The asto idle air pulp 20 is of wax type, and when the engine temperature is low, it contracts and opens the bypass passage 16, and as the engine temperature rises, it expands and closes the bypass passage 16. There is.

Note that each electromagnetic fuel injection valve 6 is supplied with fuel from a fuel pump 22, and the fuel pressure from this fuel pump 22 is regulated by a fuel pressure regulator 24. Here, the fuel pressure regulator 24
A control passage 26 is connected to one of two chambers partitioned by a diaphragm, and fuel pressure is adjusted by applying control pressure to the one chamber through the control passage 26. In addition, the fuel pressure regulator 24
A return spring is provided within the notch chamber to determine the reference fuel pressure.

Further, a thermovalve 28 is interposed in the control passage 26 . As shown in Fig. fjtJ55, this thermovalve 28 is equipped with a wax type temperature sensing part 28a in the fuel supply path 30, and a valve element z8I) is attached to this wax type temperature sensing part 28a1. , control passage 2
6 to introduce the intake passage pressure (this pressure is the pressure on the downstream side of the throttle valve 14) into the chamber of the fuel pressure regulator 24 (on the other hand, as the fuel temperature becomes high, the valve body The port 28b is extended to forcibly communicate the atmospheric side opening 28c in the thermovalve 28 with the control passage 26, so that atmospheric pressure can be guided into the chamber of the fuel pressure regulator 24. .

In addition, instead of the wax type thermopulp 28, an electromagnetic thermopulp having the same function may be used.

By the way, regarding this engine 2, the fuel supply control 4
Various controls are performed, such as ignition timing control, idle speed control, overheating control, fuel pump control, cooler relay on/off control, and self-diagnosis (DIAG/SYS) display control. Various sensors are provided. That is, as shown in FIGS. 1(a) to (c), the air 70-sensor 32. Intake temperature sensor 34.
Throttle motion sensor 36. Idle switch 3
8. Water temperature 40. Crank angle sensor 42. Top dead center sensor (TDC sensor?) 44+Ch+f46. (Nihibi'1 switch 48. Cooler switch 50. Cranking switch 52. Ignition switch 54. Ignition key attachment/detachment sensor 55. High temperature switch 56° Power steering switch (power steering switch) 58° Vehicle speed reed switch 609 Diagnosis switch 62. Atmospheric pressure sensor 6
4. Door sensor 92. A lock state sensor 94 and a seat switch 96 are provided.

The air 70-sensor 32 is provided in the air cleaner 12 and is of an oven flutter output type that outputs a frequency pulse proportional to the amount of intake air by detecting the Karman vortex, and is used to detect the amount of intake air. .

The intake air temperature sensor 34 is also provided within the air cleaner 12 and detects the temperature of the intake air (intake air temperature), so a thermistor or the like is used.

The throttle position sensor 36 is connected to the throttle valve 1
A potentiometer (variable pull resistor) type is used to detect the opening of idle switch 3.
Reference numeral 8 detects that the throttle valve 14 is at the idle opening, but also functions as a speed adjusting screw.

The water temperature sensor 40 detects the engine cooling water temperature.
A thermistor or the like is used.

The crank angle sensor 42 and the top dead center sensor 44 are connected to the distributor 68, respectively, as shown in FIG. 1(c).
The crank angle sensor 42 detects the crank angle from the distributor angle (1 degree resolution), and the top dead center sensor 44 detects the timing at or slightly before top dead center for each cylinder (64 tilts). ), and in addition to outputting a cylinder discrimination signal, a pulse signal (reference signal) is detected from the top dead center sensor 44 every 120 degrees of crank angle, so by measuring the interval between these pulse signals, Engine speed can be detected.

The Q2 sensor 46 is provided in the exhaust passage 70 on the downstream side of the collecting part of the exhaust manifold to detect the amount of oxygen in the exhaust gas. As shown in FIG. 23, the 02 sensor 46 can be used as an 02 sensor equipped with a heater 46a.
! has been completed.

The inhibitor switch 48 is a switch that is turned on and off in response to the shift button 5 of the automatic transmission connected to the engine 2, and is turned on when in the P and N ranges and turned off in other ranges.

The cooler switch 50 is a switch that is turned on when the cooler is in operation and outputs a power supply voltage or an H signal, and is turned off at other times and outputs an L signal, and the cranking switch 52 is turned on while the engine is cranking.

The ignition switch 54 is a switch that is turned off at other times, and is turned on when the engine key is placed in the IG or ST positions. Make the spark fly.

The ignition key attachment/detachment sensor 55 is a sensor that turns on when the ignition key (enron key) is inserted into the vehicle body side, and turns off otherwise.

The high temperature switch 56 is provided downstream of the catalytic converter 74 disposed in the exhaust passage 70 to detect the exhaust temperature (exhaust temperature).

The buff steering switch 58 is turned on by detecting the oil pressure during power steering operation.

The vehicle speed reed switch 60 detects the vehicle speed by outputting a pulse with a frequency proportional to the vehicle speed, and the diagnostic switch 62
is a switch for diagnosis/sys.

The atmospheric pressure sensor 64 detects atmospheric pressure by outputting a voltage proportional to absolute pressure, and uses, for example, a semiconductor pressure sensor. Note that the atmospheric pressure sensor 64 is built into a fun computer (hereinafter also referred to as FEcUJ) 76.

Further, a door sensor (door state sensor) 92 is attached to the driver's side door to detect the open/closed state of the door, and a lock state sensor (door state sensor) 9
4 is for detecting the locked/unlocked state of the door lock RIR, and the seat switch 96 is for detecting the seated state in the driver's seat.

These sensors 32-64, 92-96 are input to the ECU 76 as shown in FIG. 1(a).

EC1J 76 is a fuel supply control 9 that performs centralized control such as ignition timing control, idle speed control, overheating control, fuel pump control, cooler relay on/off control, and self-diagnosis display control. 721s, processor (CPU), RAM and R
It is configured with memory such as OM.

Further, regarding the software (including those made into 7 armware), detailed programs are set for each of the above-mentioned controls, and such programs are stored in a program memory. The data for control is converted into a 2D or 3D map and stored in RAM or ROM.
Note 1! i! - or temporarily stored in a required latch.

Then, the ECU 76 outputs control signals to each part. That is, six electromagnetic fuel injection valves 61 are sent from the ECU 7G.
Idle speed control valve 18 stepping motor 18a9 ignition timing control section (ignition device) 78. Fuel pump control section 80. Cooler relay 82. Self-diagnosis display section 84. Control signals suitable for each of the eight starters serving as cranking means are output.

The electromagnetic fuel injection valve 6 and the stepping motor 18a of the idle bead control valve 18 are as described above. The stepping motor 18a is a valve that can inject fuel while controlling the valve opening time by driving the stepping motor 18a, and when the required pulse control signal is supplied to the four fill parts, the stepping motor 18a controls the order of energization to each coil part. By turning clockwise or counterclockwise, the valve opening degree of the valve body 18b is adjusted.

The main part of the ignition timing control section 78 is an igniter made of an electronic circuit including a switching transistor, etc., and controls the coil current to the ignition coil 72 at a required timing (ignition timing) by receiving a control signal from the computer 76. This is to block the

The fuel pump control unit 80 is configured as a fuel relay having a plurality of relay switches, and controls the operating state of the fuel pump 22.

When the cooler relay 82 receives an H signal from the ECU 76, it closes and operates the compressor, and when it hears that the signal from the ECU 76 becomes an L signal, it disables the compressor, and functions as a cooler on/off relay.

The self-diagnosis display section 84 is configured as a checker circuit that is separately connected from the outside, and displays a failure code using a blinking pattern of LEDs.

The main r control performed on this engine 2 will be explained below.

(1) Idle speed control (ISO) As the idle speed control method in this embodiment, the stepping motor 18a is made into a 7-cut unit, and the ms of the idler beadcon Y roll pulp 18 provided in the bypass passage 16 is shouldered to idle. A bypass air control system is used to control the rotation speed.

This idle speed control is realized by determining whether each sensor is in one of the following control modes and controlling the drive of the steering motor 18a according to the control zero of each control mode. do.

Each control mode is as follows - 1-1) Initialization mode 1-ii) Starting mode 1-iii) Immediately after starting mode 1-iv) Off-idle mode 1-v) Gu Nxiebont mode 1 yi) Idle mode (I) 1-vii)
Idle mode (I[)1-i) Abnormal A/N reduction mode 1-ix) Abnormal rotation speed reduction mode 1-x) 7-top control mode when cooler relay is on 1-xi) Overheat control mode 1-d)
Others 1-1) Initialization mode Initialization mode is used to calibrate the motor position of the stepping motor 18a (the actual position determined by the number of steps) and the target position in the memory. Preset processing for accurate idle speed control and various subsequent controls in the initialization control mode by moving the motor position to the initial position and resetting the target position M in the memory. means.

The following initialization process not only initializes the stepping motor 18a for idle speed control as in this embodiment, but also initializes the EG.
Even when a stepping motor is used for bypassing the supply pressure (or exhaust pressure) for driving the R valve, initialization can be performed using a similar method.

The following various aspects are possible for the initialization process.

1-i-■) Initialization mode 1 The judgment conditions and initialization method in this initialization mode 1 are as follows. explain.

First, in step 2-1, it is determined whether or not the ENON rotation speed is being fed back. If YES, in step 2-2, it is determined whether the ENON rotation speed is stagnant within the dead zone. If so, step 2-3
Then, it is determined whether the tide retention time has passed a predetermined time or not. If YES, in step 2-4, the cooling water temperature is set to 8.
It is determined whether the temperature is above 0°C, and if it is above 80°C, in step 2-5, it is determined whether the air foundation (sometimes abbreviated as air conditioner, but this air conditioner has a cooling function) is on. is determined to be OFF, the engine is in a specific operating state and satisfies the conditions for initialization, and in step 2-6 it is determined whether the shift engine is in the D range or the N range. If the current stepper motor position is N, the current stepper motor position is defined as the reference position A in step 2-7. That is, initialization is performed, while in the case of D Lenz, the current stepper motor position is defined as the reference point A0a in step 2-8, that is, initialization (
initialization) is performed.

By performing the processing in initialization mode 1, the following effects and advantages can be obtained. In other words, since initialization is not performed when fully closed or fully open, there is no wear or jamming of the valve seat of the ISC valve 18, improving durability, and since there are many opportunities for initialization, step-out phenomena ( A phenomenon in which a discrepancy occurs between the number of stepper motor steps recognized by the computer 76 and the actual number of steps 7 is less likely to occur.

1i-■) Initialization mode 2 The judgment conditions and initialization method in this initialization mode 2 are as follows, and these judgment conditions and initialization method will be explained using the 70-chart of the $4 diagram. . In this initialization mode 2, as shown in FIG. is the predetermined value (basic value) A
o, that is, initialization is performed (step 4-2).

By the way, an optical sensor is used as means for determining whether the stroke of the idle speed control valve 18 is at a predetermined intermediate position. That is, P.J.
As shown in Fig. 5(b), the opening 7 and 18d have a valve body 18b.
An LED (light emitting diode) 86 and a 7-inch transistor 88 are placed between the two, and the LED 86 always emits light, and the light is strained so that it hits the 7-inch transistor 88. At this time, the LED 86 and the 7-year-old totrannosta 88 are the idle speed and troll valve 18.
The loaf is disposed at a position corresponding to a predetermined intermediate position. Therefore, when the stepping motor 18a operates, the idle speed control valve 18's rod 18d strokes up and down, and when the valve body 18b blocks the optical path from the LED 86 to the 7-channel transistor 88, the 7-channel transistor 88 is turned off. do. In other words, 7 oto F runno star 88 is on to o 7:
2 switched or 7 oto) Rannosta 88
If it is detected that the idle speed control valve 18 has been switched from off to on, it can be detected that the stroke of the idle speed control valve 18 has reached a predetermined intermediate position.

Even if this initialization mode 2 is performed, the same effects or advantages as those obtained by the above-mentioned initialization mode 1 can be obtained.In other words, in addition to improving durability, there is also an opportunity for initialization. As there are many cases, tax adjustment phenomena are less likely to occur.

1-1-■) Initialization mode 3 The judgment conditions and initialization means in this initialization mode 3 are as follows. I will explain using

First, when the ignition key attachment/detachment sensor 55 detects that the ignition key is inserted into the key cylinder on the vehicle body side (step 6a-1), it is determined that the driver is starting the vehicle (getting into the vehicle), and the stepping motor 18a is fully activated. Initialize to the closed position (step 6a-
2>.

In addition, instead of FIG. 6(,), 70- as shown in FIG. 6(b) and (e) may be used, and as shown in FIG. 6(b), the detection signal from the door sensor 92 Based on this, when it is detected that the door has shifted from the open state to the open state (step 6b-1), and when it is detected that the seat switch 96 is in the seated state (step 6b-2), initialization is performed. (Step 6b-3), and as shown in FIG. 6(c), 'In the modified example shown in FIG. 6(b), the ignition switch 54 is in the OFF position instead of the seat switch 96. It is also possible to use +11 to detect (steps 6C-1 to 6C-3).

Furthermore, instead of the door sensor 92, a lock state sensor 9
4 may be used, or one may be used that detects that the door lock mechanism has transitioned from the locked state to the unlocked state, based on the detection signal from the lock state sensor 94, before opening the door from the outside. Instead of using a key for unlocking and locking the vehicle, the present invention can be similarly applied to a non-responsive type vehicle that uses a pair of transducers to open and lock the door.

If such processing is performed in initialization mode 3, the following effects or advantages can be obtained. Initialization can be performed even while the ignition key is being turned from OFF to ON, so initialization can be performed before the vehicle starts, and initialization of the stepping motor 18a can be completed before cranking. As a result, the durability of the steering motor 18a can be improved by improving startability and reducing the number of unnecessary initializations.

Furthermore, since initialization can be completed immediately before initialization is required, engine startability can be ensured even if the battery is removed for maintenance or the like.

1-i-■) Initialization mode 4 The judgment conditions and initialization means in this initialization mode 4 are as follows, and these judgment conditions and initialization means are shown in chart 70 of FIG. Explain using.

First, when the ignition switch 54 is in the off state (
Step 7a-1), and when it is detected that the door has shifted from the closed state to the open state based on the detection signal from the door sensor 92 (step 7a-2), the driver stops the vehicle (gets off) L # Determined to be made by J, stepping motor 1
8a is initialized to the fully open position (step 7a-3).

In addition, the flow shown in FIG. 7(b) and (c) may be used instead of FIG. 7(a), and ffi 7121(b)
), when the ignition key attachment/detachment sensor 55 changes from the on state to the off state, that is, it detects that the ignition key has been pulled out from the key cylinder on the vehicle body! (Step 7b-1), the stepping motor 18a may be initialized (Step 7b-2), and as shown in FIG. When the movement to the closed state is detected (step 7c)
1), and when the seat switch 96 detects that the seat is not seated (vacant seat fi) (step 7 cm2)
, you may initialize (step 7cm3
).

Furthermore, instead of the door sensor 92, a lock state sensor 9
4 may also be used, and based on the detection signal from the lock state sensor 94, the door lock (1!) may be used to detect that the mechanism has shifted from the locked state to the unlocked state before opening the door from the inside. It's okay.

If such processing is performed in initialization mode 4, the following effects or advantages can be obtained. Since the initialization is performed in conjunction with the stopping operation of the vehicle, there is an advantage that the initialization can be performed reliably with sufficient time until the vehicle is restarted. Furthermore, by reducing the number of unnecessary initializations, the durability of the stepping motor 18a can be improved, and by completing the initialization X before starting, the startability can be improved.

1i-■) Initialization prohibition mode The judgment conditions and initialization prohibition means for this initialization prohibition mode are as follows.These judgment conditions and initialization prohibition means will be explained using chart 70 in FIG. do.

In response to a control signal from the initialization start means of the ECU 76,
The initialization means starts operating, and the stepping motor 18a
When initializing the and memory, first,
A prohibition signal is sent from the initialization means to the date circuit as a cranking prohibition means, that is, the cranking prohibition mode is set (step 8-1), and a control signal is supplied from the control means to the starter 89 as a cranking means. and upon completion of initialization (step 8-
2) Stop the supply of the prohibition signal from the cranking prohibition means to the date circuit, that is, reset the cranking prohibition mode (Step 8-3), and allow the supply of the control signal from the control means to the starter 89.

Processing in such an initialization prohibition mode cannot be performed, and the following effects or advantages can be obtained. Since initialization is not performed when the vehicle is cranked, there is an advantage in that reliable initialization can be performed.In other words, it is possible to prevent the stepping motor 18a from stopping due to a voltage drop, and the engine is activated before reaching the 7 ast idle opening. It is possible to prevent the engine from starting, and to prevent deterioration of startability.

Incidentally, when the stepping motor 18a is initialized, the operation of a load winter port with a large electrical load may be prohibited (in this case, logic substantially similar to the above-mentioned logic is incorporated).

1ii) Starting mode The conditions for determining this starting mode are as follows.

■ When the cranking switch 52 is on, the engine speed must be less than several hundred rpm.

- When the cranking switch 52 is off, the engine speed is smaller than the number + rp-.

When this condition is met, the following control is executed.

■ When intake temperature < TAo, select and control the starting opening depending on the water temperature.

■ When intake temperature ≧TA, overheat correction is applied to the above starting @ opening degree. In other words, the correction coefficient (
Multiply by ≧1).

1-iii) Immediately after start mode The conditions for determining the immediately after start mode are as follows. In other words, after turning off the 2 ranking switch 520,
If the top-up value is equal to or greater than the basic target opening degree, it is determined that the mode is immediately after startup.

When this condition is met, the intake temperature becomes TA.

When the opening is lower than , a tailing process of 1 step/T 3Lmsec is performed until the basic target opening is reached.

Note that when the intake air temperature is equal to or higher than TA0, overheat correction similar to the above is performed.

1-iv) Off-idle mode The conditions for determining this off-idle mode are as follows. That is, if the idle switch 38 is off and the mode is other than the starting mode, it is determined that the mode is the off-idle mode.

When this condition is satisfied, the dashbot opening is controlled to be the smaller of the engine rotational speed dependent opening or the throttle dependent opening, which is a value obtained by adding the learned value to the basic target opening.

1-v) Dashbot mode The conditions for determining the Gutshubot mode are as follows. That is, as long as the idle switch 38 is on and the dashbot opening degree reaches O, it is determined that the dashbot mode is in effect.

Then, while this condition is satisfied, the following control is executed. First, add the learned value and Butshubot opening to the basic target opening, then set the son step/T DHms
Perform ec tailing.

Then, when the Gutshubot opening degree reaches O, the process automatically ends.

1 vi) Idle mode (I) This idle mode (I) includes a rotation speed feedback control mode and a learning control mode, each of which is activated at predetermined time intervals.

1-vi-■) Rotation speed feedback control mode The conditions for determining the rotation speed feedback control mode are as follows. That is, this control mode is determined when the idle switch 38 is on and all of the following conditions are met.

n) T +c8+ has elapsed after starting mode b) T1^ seconds A after turning on/off the cooler switch 5o
C) TND seconds have elapsed since the dashbot was controlled cl) TND seconds or TDN seconds have elapsed since switching from N range to D range or from D range to N range e) Idle TID seconds have elapsed since switch 38 was turned on f) T17 seconds had elapsed after the vehicle speed reached almost O g) % Tps#+ had elapsed after power steering was turned off, or the following conditions When this is satisfied, this control mode is determined.

h) When in the N range i) When the cooler switch 50 is off j) When the actual rotation speed ≦ the target rotation speed And if these conditions are satisfied, the following control is executed. That is, feedback control is performed so that the target rotational speed is achieved. The specific control at this time is such that the target opening degree of the idle speed hunt roll pulp 18 is (
The basic opening degree is controlled to be 10 learning values 10 ΣaS).

1 v Knee ■) Learning control mode The determination conditions for performing learning control are as follows. First, as a prerequisite, as shown in Fig. 9, the actual rotation speed is subtracted from the target rotation speed to find the rotation speed difference (rotation speed error) ΔN (step 9-1), and then the rotation speed difference (rotation speed error) ΔN is calculated based on the following formula. Positive din (step number/rotation speed) Go or negative gain Go (here, Go”Gu) to the rotational speed difference aN
The opening correction amount aS is determined by multiplying by (step 9-2).

iS=ΔNxfG:1 An example of the relationship between ΔN and ΔN is shown in FIG. 3.

Then, the integrated value ΣΔS of the opening correction amount ΔS is determined (step 9-3). That is, the idle switch 38 is on, the water temperature ≧TL, and LNI≦Nb (corresponding to the dead band width) is maintained for TLRm, provided that the power steering switch 5
8 is off (step 9-4).

Then, when the rotation speed error ΔN becomes less than the set value,
It is determined that the rotation speed has stabilized and reached the target rotation speed,
When these conditions are satisfied, if the learned value + integrated value ΣΔS is between the upper limit value SUL and lower limit value SLL, the learned value integrated value ΣΔS is set as a new learned value and the integrated value is reset (ΣΔ5= O) [.

and update the learning value. Further, if the rotation speed error is larger than the set value, learning is not completed.

That is, the sum of the integrated value Σ118 and the previous learning value S'L is taken as the new learning value SL (step 9-5), and if the learning value SL is between the upper limit value SOL and the lower limit value SLL. (Step 9-6.7), and reset the integrated value ΣΔS to zero (Step 9-8).

Furthermore, if the learned value SL is equal to or greater than the upper limit value 5LIL, the learned value SL minus the upper limit value SUt is set as a new integrated value (step 9-9), and the upper limit value 5LIL is set as the new learned value SL. (Step 9-10).

Furthermore, if the learned value SL becomes less than or equal to the lower limit value SLL, the value obtained by subtracting the lower limit value SLL from the learned value SL is set as a new integrated value (step 9-11), and the lower limit value SLL is set as the new learned value SL. (Step 9-12).

That is, if the learned value SL is greater than or equal to the upper limit value SuL or less than or equal to the lower limit value SLL, the following equations are satisfied.

SA=sB+s'L×ΣΔ5=S8+5L=SB+(SuL)+(SL 5UL)=SB+(SL
L) 10 (SL-8LL) Here, ST is the number of steps corresponding to the target opening, and SB is the number of steps corresponding to the basic opening, which is determined depending on the water temperature, cooler on/off, N, and D ranges. It is something that

Such integrated values ΣiS have one thing in common, and the learned value SL is determined by the inhibitor switch 48.
, N, and D ranges, and the cooler switch 50 has 6 types of items multiplied by OFF, Lo, and Hi.
Only two types, N and D Lenz, are battery backup states.

Then, each of these learned values SL is repeatedly called and stored without being reset in response to changes in the six types of states. It is designed to respond to changes over time, and is reset when there is a RAM memory error or when the battery is removed.

Furthermore, when the six types of states change, the integrated value ΣΔS is used for each state by being reset, and is used for feedback.

If processing in such a learning control mode is carried out, effects or advantages similar to those of dogs can be obtained. Learning can be performed in a stable state of Ennon rotation speed,
The above equation and FIG. 10(a).

As shown in (I)), the learned value SL is the limit S IJ
Even if L+S L, L is exceeded, the amount exceeding the above limit (SL-3IJL) or (SL-3LL) is reflected as an integrated value and returned to the feedback control amount to determine the target opening degree. Therefore, there is no rotational fluctuation before and after learning, and continuous feedback control is possible, which has the advantage of reducing the shock that occurs in a single unit.

1-vii) Idle mode (II) The principle for determining the idle mode (n) is that the idle switch 38 is on and the rotation speed feed/<tsuku is prohibited. It is.

The control details at this time are as follows. That is, the opening degree of the idle speed control valve 18 is controlled so as to be a value obtained by adding the learned value and the required value to the basic target opening degree.

1-F) Abnormal A/N Decrease Mode In order to be in the abnormal A/N decrease mode, the idle switch 38 must be on and the following conditions must be satisfied at the same time.
This is the time from when the engine enters the or-idle main shaft rotation speed feedback control.

a) When rotation speed feedback is prohibited; b) When the power steering switch 58 is on; C) When the density correction value is less than a predetermined value. The control details at this time are as follows. In other words, the target opening degree is set to ff! in FitoFre mode (II)!
The opening degree is controlled by adding a predetermined amount 7) upflsewIg to the opening degree.

Further, when the idle switch 38 transitions from the on state to the off state, an abnormal A/H decrease occurs, and this state occurs, for example, when the accelerator pedal is suddenly depressed for a short period of time. This mode prevents the engine from stalling even if there is a momentary increase in the amount of air-fuel mixture during tap.

In this engine stall prevention mode when tapping the accelerator pedal, as shown in FIG. 1),
In addition, when the differential value dsR/dt of the step number S is negative and smaller than the predetermined value e (>O) (step 1
5-2), it is determined that the accelerator pedal is being tapped, and the tapping flag ITAP is turned on (step 15).
-3) If the tapping flag ITAP is on (step 15-4), the engine load condition is under the required condition, that is, if the A/N is smaller than the set value d (step 15-5) , listen to the ISC valve IB for a given time (
Step 15-6), by supplying the intake air that has bypassed the throttle valve 14 to the combustion chamber of the engine 2, the amount of intake air is increased, and the 7-lag ITAP on tap is reset (Step 15-7).

Furthermore, if the A/N is greater than or equal to the set value d, the 7 lag τ^P is turned on at the time of tap, and if a predetermined time related to dsR/dt has elapsed (step 15-8), then at the time of tap If the flag ITAP is not reset (step 15-9), the current state of the tap time 7 lag I-P is maintained.

If such processing is performed in engine stall prevention mode 1 when the accelerator pedal is tapped, the following effects or advantages can be obtained.

Conventionally, as shown in FIG. 16(, ), when the throttle changes rapidly (Tara-y'lI) when the idle switch 38 changes from on to off and then on again in a short time, the engine Inertia of a one-volume rotation system up to the combustion chamber of 2! The amount of Ii causes a delay in control, and the ratio of intake air amount to throttle opening and engine speed per intake stroke (A/N) [Figure 16 (c)
Since there is a phase shift between reference 1 and reference 1, a state occurs where the engine speed is high and the throttle opening is small [@
Figure 16(a).

(see time L0 in (b))], a shortage of intake air amount occurs,
There is a region Z14 where the A/N is abnormally low, and in this state, if the ISO valve 18 maintains a constant opening [see Fig. 16(d)], the necessary amount of air will be supplied to the engine 2. Therefore, the symbol N DO in FIG. 16(b)
As indicated by IJN, the engine speed may undershoot and stall.

In contrast, in this embodiment, as shown in FIG. 16(e), even when the engine speed is high and the throttle opening is small during rapid throttle changes (tap) 16 (e) and (f). Reference], I
The SO valve 18 temporarily increases its opening degree [see Fig. 16 (h)], thereby bypassing the intake air amount and temporarily increasing the intake air amount to compensate for the deficiency in the intake air amount. As shown by the solid line and two-dot chain line in Fig. 16(g), the drop in A/N is prevented and the necessary amount of air is always supplied to the engine 2, so that the engine speed is not too low. Shooting is prevented, thereby preventing tap engine stalling (engine stalling that occurs when the accelerator pedal is tapped).

Note that a sensor may be attached to the accelerator pedal to detect the accelerator depression degree, and in the tap sensor described above, change information from off to on (or from on to off) from the idle switch 38 is used. For example, the output from the above-mentioned tap sensor may be allowed for a predetermined period of time from when the idle switch 38 is detected to be turned from on to off, and the tap output is not allowed at other times. If the idle switch 38 is configured so that it does not occur, or if the idle switch 38 changes from on to off, then to on,
A tamp may be detected when a short time is detected.

1ix) Abnormal rotation speed reduction mode In order to be in the abnormal rotation speed reduction mode, the period from when the idle switch 38 is on and the following two conditions are met at the same time until the power steering switch 58, which is a load component, is turned off. The mode is between.

a) The power steering switch 58 is on. Here, NN is the set rotation speed of the N range, and No (
< N N) is the set rotation speed of D Lenz.

That is, as shown in FIG. 13, the power steering switch (P/5) 58 is on (step 13-1).
), when the engine rotational speed N becomes smaller than the set rotational speed NN or ND [Fig. 14(a), step 13-2], the operation 7 lag I of this abnormal rotational speed reduction mode is zero. (inactive) (step 13
-3), as shown in FIG. 14(b), the idle is increased by a predetermined amount (step 13-4), and first, the motor opening is rapidly stepped up until it reaches the set value S1,
When the motor opening reaches the set value S, it is gradually decreased (tailing) to the set value 82, which corresponds to the target opening when the power steering is turned on, and the power steering switch 5 is turned on.
8 is turned on, the idle up state is maintained [FIGS. 14(c) and (d)].

Next, wJ7 Lague with abnormal rotation speed reduction mode.

(step 13-5), and this operation 7
The reset condition for lag Iυ is power steering switch 5.
8 is in the off state (step 13-6)
.

By performing processing in such an abnormal rotational speed reduction mode, the following effects or advantages can be obtained. At idle, after the load components start operating,
Instead of immediately increasing the idle, after detecting a drop in the rotational speed as part of the operating state, the idle increases, and once the idle increases when the load component is turned on, it gradually decreases (overshoots).
It not only prevents the engine speed from increasing, but also reduces the drop in the engine speed, which has the advantage of allowing the engine to idle up in a short period of time, causing load components to repeatedly operate and deactivate. Even in such a case, hunting during idle up operation can be prevented.

1-x) 7-top control mode when the cooler relay is on In order to be in the 7-top control mode when the cooler relay is on, the following conditions must be satisfied at the same time.

a) The cooler switch 50 is on b) The mode is other than the engine stall/start mode C) Immediately after starting and after the fuel increase d) Immediately after starting and after the 7-top up e) Engine speed is greater than the rotation speed when the air conditioner is turned on f) A predetermined period of time has elapsed after the above e) was established. [) A predetermined period of time has elapsed after the cooler switch was turned on. h) The target rotation speed is lower than the engine rotation speed. is also small and
If the rotation speed is within a predetermined number of rotations, that is, as shown in FIG. 11.12, if the cooler switch 50 is turned on (step 1l-1), the number of steps is increased to the number of steps SAC corresponding to the target opening degree when the cooler is turned on. It was detected that the engine speed increased by SL from the normal idle (step 1l-2), and then the engine speed N became a speed (NAc-N1) smaller by a predetermined speed IN than the target speed NAC when the cooler was on. or after a predetermined period of time has passed since the cooler switch 50 was turned on (
Step 1l-3), assuming that the cooler relay ON condition is satisfied, the number of steps is further increased by 82 to SU (step 1l-4), and when this step-up opening degree SU is reached (step 1l-5), the cooler relay 82 is turned on (step 1l-6), and the number of steps is gradually decreased to the number of steps SAc corresponding to the target opening degree when the cooler is turned on again (step 1l-7).

The following effects or advantages can be obtained by carrying out the process in the second way - lift-up control mode at the time of release. At idle, in addition to the idle up amount for the load components, the idle up amount is provided to prevent shock when the cooler is turned on, which has the advantage of preventing shock when the cooler compressor operates with a relatively large engine load. This has the effect of preventing overshoot during upward movement and allowing smooth transition to feedback control.

1-xi) Overheating control mode The overheating here means, for example, a 3% uphill slope of 1201 on.
If you stop the engine immediately after driving under high load, such as driving at 40km/h on a 10% uphill slope, the cooling fan and cooling water circulation will stop, causing the engine room to heat up. This refers to a case where the temperature reaches around 100° C. after 30 to 40 minutes, and this may cause bubbles to form in the fuel, causing problems in subsequent fuel supply control, etc.

For this purpose, this overheating control is performed, the details of which will be described later.

1-xi) Others 1-xi-■) How to reset when the ECU 76 goes out of control If the ECU 76 goes out of control for some reason, it will interfere with the idle speed control by the stepping motor 18a. Therefore, E
It is determined and detected that the CU 76 has gone out of control, and a reset is performed.

a) First method (see FIG. 17) The flow of processing according to this first method will be explained using FIG. 17. First, in step 17-1, stepper motor motors are stored in different memory areas MA and MB, respectively. In this case, for example, a stack area is selected as one memory area MA, and a memory area distant from the stack area is selected as the other memory area MB. Note that the stack area is a portion used when an interrupt execution instruction is entered, and is normally considered a memory area that is easily destroyed when the ECU 76 goes out of control.

Next, in step 17-2, the target opening (target opening) is set, but after that, at 7°17-3,
The contents of memory areas MA and MB are loaded, and in step 17-4, the contents of memory areas MA and MB are loaded.

Check whether the contents of MB match. If the contents of memory areas MA and MB match ν, the ECU 7
6 is operating normally, and the process proceeds to step 17-5.
Then, the stepper motor 188 is driven by the required amount. However, if the contents of memory areas MA and MB do not match, E
CU76 is out of control and it's 4! I+ is determined, and the ECU 76 is reset in step 17-6.

As a result, it is possible to sufficiently prevent the ECtJ 76 from running out of control and causing the idle speed control to become abnormal, thereby increasing the reliability of the idle speed control.

b) Second method (see FIG. 18) The flow of processing according to this second method will be explained using FIG. 18. First, in step 118-1, the input stepper motor function 5 is stored as it is in one memory area MA, and the other memory area MB is subjected to the calculations in step 7 and step 9. Store. In this case, the following calculations are performed, for example.

That is, if the stepper motor position data has 8-bit information, only the upper or lower 4 bits of this 8-bit information are taken and the rest are not stored. Therefore, memory area MB
In this case, 4 bits of step 7 motor control input data are stored.

As for the memory areas MA and MB in this case, one memory area MA is for the throttle position sensor 3, as in the case of the first method (see FIG. 17).
A portion (for example, a stack area) that is likely to be destroyed in the event of runaway of 6 is selected, and a memory area away from the stack area is selected as the other memory area MB.

Next (2) In step 18-2, the target position (target opening degree) is calculated, and then in step 18-3, the memory areas MA and MB are loaded. Then, in step 18-
In step 4, a required operation is performed on the contents of memory area MA, which is the same operation as that performed in step 18-1 above. In other words, the contents of memory area MA are 8
Since it is bit information, only the upper or lower 4 bits of this 8-bit information are taken and the rest is not stored. Therefore, by this calculation, the value read from memory area MA becomes 4-bit information.

Thereafter, in step 18-5, it is determined whether the contents of the memory area MB match the contents of the memory area MA subjected to the calculation. If the ECU 76 is not running out of control, the two should match. If they match, it is determined that the ECU 76 is normal and the stepper motor 18a is driven by the required amount in step 18-6. However, if the two do not match, the ECU76
It is determined that the EC is out of control, and in step 1-7, the
U76 is reset.

In this case, not only the same data is stored in two different memory areas MA and MB, but also seven calculation professionals are added, that is, the same calculation is performed twice with a VF interval, so that the ECU 76 The reliability of runaway determination can be increased.

C) Third method (see FIG. 19) This third method uses a watchdog timer (hardware). The flow of processing according to this third method will be explained using FIG. 19.

First, in step 19-1, a watchdog timer is set. This watchdog timer is externally attached to the board of the computer, and after the required time has elapsed after setting, the
It outputs a CU76 heliset signal. Therefore, after setting the watchdog timer, wait until the required time JN has elapsed (step 19-2).
), in step 1-3, a reset is applied to the combiator.

Note that in the first to third methods described above, computer reset means processing such as program initialization, whereby the stepper motor bonition of the idle speed control valve 18 is initialized.

(2) Fuel supply control (2-1) Fuel supply control As the fuel supply control method in this embodiment, an MPI method having electromagnetic fuel injection valves 6 for each of six cylinders is adopted. Immediately after the power is turned on, the microprocessor (combiator 76) is reset, and based on the input from various sensors, it determines which of the following operating modes it is in, and each operating mode (see Figure 22)
The electromagnetic fuel injection valve 6 is driven at the drive timing and drive time TINJ defined by .

Note that Tl)H=TBXK+To+TER. Here, T [I is the basic driving time of the electromagnetic fuel injection valve 6, Kl:
i: correction coefficient, TD is invalid injection correction time, and TE is temporary injection correction time.

The above operation modes are as follows.

2-1-i) Stop mode 2-1-ii) Start mode 2-1-iii) Fuel restriction mode 2-1--
iv) Air-fuel ratio A/F 7 E-back mode 2-1-v) High-speed full-open mode 2-1-vi) Others 2-1-i) Stop mode The judgment conditions for this stop mode are as follows. . That is, if the cranking switch 52 is on and the engine speed is lower than 10 to 20 rpm, or if the cranking switch 52 is off and the engine speed is lower than 30 to 40 rpm.
If it is lower than p+*, it is determined that the mode is in stop mode. In this case, no fuel injection is performed.

2--1 ii) Starting mode The conditions for determining whether or not this starting mode is valid are as follows. That is, when the cranking switch 52 is on and the engine speed is between 10 and 20 rpm and several hundred pm or less, it is determined that the engine is in the starting mode.

If such a determination is made, fuel is injected into all cylinders simultaneously at the required number of times per rotation, but the injector drive time at this time is shortened as the cooling water temperature increases.

2 1-iii) Fuel restriction mode This fuel restriction mode includes an A/N cut mode.

There are an overrun cut mode, a high speed cut mode, and an idle cut mode, and the purpose of cutting fuel in this way is to limit engine power to fflll, prevent misfires, and improve fuel efficiency.

2-1-1ii-■) A/N cut mode this A/
The conditions for determining the N-cut mode are as follows. That is, the engine speed is greater than the predetermined value NANFC, and the engine load state meets the required condition (η, 8NP
C) is below +1 (see Fig. 22), and if these conditions continue for 11 times, it is determined that the A/N cut mode is in effect, and the fuel is cut. Here, A/N is
It means the amount of intake air per engine revolution, and has engine load information.

2-1 1ii-■) Overrun cut mode The conditions for determining whether or not the overrun cut mode is active are as follows. That is, the engine speed is the predetermined value N. RFC(
(for example, 6300 rpm) (see FIG. 22), it is determined that the overrun cut mode is in effect, and the fuel is cut.

By the way, before entering the overrun cut mode, control is performed to bring the air-fuel ratio to the stoichiometric air-fuel ratio and retard the ignition timing. Explain to the dog the above-mentioned overrun cut and control in the overrun cut prestep mode.

a) First method As shown in FIG. 28, in step 28-1r, the engine speed N is compared with N PORFC (for example, 6100 rpm), and if N≧6100, in step 28-2, the engine speed N is set to Nonrc. (For example, 6300rp theory)
If N<6300, the overrun cut prestep mode is selected. That is, step 28-
Step 3: Set the air-fuel ratio A/F to the stoichiometric air-fuel ratio,
In step 28-4 1. The transfer period will be retarded.

When the engine speed N further increases to 6,300 rpm or more in this state, the fuel in all cylinders is cut off in step 28-5.

Note that when the engine speed N is lower than 6100 rpm, normal control is performed (step 28-6).

By doing so, the following effects or advantages can be obtained. In other words, before entering the overrun cut as described above, the air-fuel ratio is often set to be too rich. There is a risk that the exhaust gas temperature will rise and the catalyst 74 will melt, but if you return the air-fuel ratio to the on side, that is, to the stoichiometry, before entering the overrun cut as described above, the exhaust gas temperature will rise and the catalyst 74 may melt. There will be no fear.

The reason for retarding the ignition timing at the same time as adjusting the air-fuel ratio is to avoid the occurrence of overshooting.
・Here, the air-fuel ratio A/F and retard amount are determined by the engine speed N.
The air-fuel ratio A/F is set according to the gear ratio [see Figures 30 (a) and (b) 1] Also, as shown in Figure 30 (c), the air-fuel ratio A/F can actually be changed according to the gear ratio. In addition, it is limited by the limiter λ2.

Next, the air-fuel ratio setting flow will be briefly explained using FIG. 29. First, in step 29-1, A/N and N
The air-fuel ratio information λ1 determined from (engine speed) is read out from the map, and then in step 29-2, the air-fuel ratio information (limiter) λ2 corresponding to the engine speed N is read out and calculated, and in step 29-3, It is determined whether λ2>λ.

If ^2〉enters, then in step ゛29-4, λ1=λ
2, the air-fuel ratio is set based on λ1 in step 29-5. Also, in step 29-3, λ2≦λ,
If so, step 29-5 jumps to set the air-fuel ratio based on λ1.

b) Second method This second method is as shown in FIG.

That is, in step 31-1, the engine rotation speed N is
oupc (e.g. 6300 rpm), N≧6
300, in step 31-2, the engine speed N is compared with N PORFC (e.g. 6100 rpm);
If N≧6100, the engine speed N is compared with 6300 again in step 31-3. At this time, N<63
If the value is 00, the overrun cut prestep mode is selected. That is, in step 31-4, the air-fuel ratio A/F is set to the stoichiometric air-fuel ratio (stoichiometry), and in step 3
In step 1-5, it is decided to retard the ignition timing. Then, the Ennon rotation speed N increased again to 63.
When the engine speed reaches 00 rpm or higher, fuel in all cylinders is cut off in step 31-6.

In addition, if No in step 31-1 and step 3
If No in 1-2, normal control is performed in step 31-7.

In this case, the engine speed increases and the
If the rpm exceeds 100 rpm, do not perform the overrun cut pre-step processing (steps 31-4 and 31-5), and once the rpm exceeds the 6300 rpm mark,
If it exceeds jpl, overrun cut pre-step processing is performed. The reason why the overrun cut pre-step process is not performed when the speed exceeds 6100 rpm for the first time is to prevent the acceleration feeling from being impaired.

Therefore, by applying this second method, it is possible to eliminate problems such as afterburning without impairing the acceleration feeling.

In addition, the above 1. By implementing the second method, the risk of catalyst melting can be avoided, so when implementing the first and second methods above, instead of cutting fuel on all cylinders, it is possible to cut fuel only on some cylinders. A fuel cut may be performed.

Furthermore, even if the number of cylinders to perform fuel cut is determined according to the intake air amount, vehicle speed, and other non-engine load conditions, the conditions for determining the maximum speed cut mode are as follows: It is as follows. That is, when the vehicle speed is greater than a predetermined value (180 m/h), it is determined that the maximum speed cut mode is in effect, and fuel is cut.

By the way, in this maximum speed cut mode, before performing fuel cut, control is performed to bring the air-fuel ratio to the stoichiometric air-fuel ratio and retard the ignition timing. Next, control in the above-mentioned maximum speed cutting mode will be explained.

As shown in FIG. 32, in step 32-1, the vehicle IVC
180km/h or more is judged as 180km/h or more.
If it is a+/h or more, the highest speed cut pre-step mode is selected. That is, in step 32-2, the air-fuel ratio A/
Set F to the stoichiometric air-fuel ratio (stoichiometry), and step 32-3
So 1. The fire timing is set to 1/litre.

After that, in step 32-4, the acceleration: lVC/c
It is determined what state lt is in. If dV
If C/dt>O, in step 32-5, for example, the first .
Fuel cut is performed for the fourth cylinder. In the case of V6 Ennon, one bank is equipped with 1st, 3rd and 5th cylinders in order, the other bank is equipped with 2nd and 4.6th cylinders in order, and 1st (4th, 6th) cylinders and tjS2 ( 3,5) The cylinders are arranged to face each other, and the firing order is girJl,
Since the order is 2, 3, 4, 5.6 cylinders, the first... ! Even if a fuel cut is applied to @4 cylinders, problems such as vibration will not occur. In this case, the number of cylinders to which fuel should be cut may be all cylinders, and the number of cylinders to which fuel should be cut may be all cylinders. Combinations other than PJ 4 cylinders (1
Furthermore, the number of cylinders for which fuel should be cut may be determined according to the engine load state, such as the intake air amount and vehicle speed.

Furthermore, X? In the case of Tsubu 32-4T, dVc/l≦o,
Without fuel cut (step 32-6), it is determined in step 32-7 whether the vehicle speed \/C is equal to or greater than 175+n/h. If VC≧175, step 3
The process jumps to 2-4 and the subsequent processing is performed again.

Also, in step 32-1, the vehicle speed\/C is 180km/
If the vehicle speed is smaller than h, or in step 33-7, the vehicle speed ■C
is smaller than 175kIn/h, normal control (
The air-fuel ratio (1 ignition timing) is adjusted (step 32-8).
.

In this case as well, as in the case of the above-mentioned overrun cut, so-called after-production does not occur, and catalyst melting loss does not occur.

2--1-1ii-■) Idle cut mode The conditions for determining the idle cut mode are as follows. That is, as shown in FIG. 20, the idle switch 38 is on (step 2O-1), and the engine load condition is under the required condition (ηVANFC)B (step 21).
．． 22), that is, the A/N is smaller than the set value (Step 20-2), the engine speed is larger than the predetermined value N+oFc (Step 2O-3), and the cooling water temperature is larger than TIDL. In this case, it is determined that the idle cut mode is in effect, and the fuel is cut (step 2O-4).

Also, the idle switch 38 is on (step 2
O-1), the condition that the ennon load state is required (ηVANF
C) is below B (see Figure 21.22), i.e. A
/N is smaller than the set value (step 2O-2) and furthermore, even if the engine speed is less than the predetermined value NIDFe (step 2O-3), the detection signal from the inhibitor switch 48 causes the D lens (or Which gear (high shift, medium shift).

(low shift) is detected (step 2O-5), and the vehicle speed is set to the set value (Ns: ++Ns4+N5) corresponding to the gear position.
s) (step 2O-6), if the cooling water temperature is greater than TIDL, it is determined that the idle cut mode is in effect, and the fuel is cut (step 2O-6).
-4).

That is, if the shift position is high, the engine is less likely to stall, so the above setting value becomes smaller.

Incidentally, among the above-mentioned conditions, the cooling water temperature condition may be removed, and if each condition is not satisfied, the fuel cut mode is activated (step 2O-7).

If such idle cut mode processing is performed, the following effects or advantages can be obtained. Engine speed, A/
By adding various judgment conditions for N and vehicle speed according to the gear position, if the vehicle speed is above a predetermined value in the area where the possibility of engine stalling is small (such as when the clutch is on and the driving force is transmitted between the engine and the gear position), , Zoo (!ll521
The fuel cut area can be extended to the area shown by the mesh hatching in the figure, and fuel consumption can be reduced.

In other words, the IN area Z+o, where fuel cut was conventionally performed.
' (see the shaded area in Figure 121) can be expanded to a region where the engine speed is low. Note that this eye-torque mode can also be applied to vehicles equipped with a manual transmission.

By the way, after a fuel cut during deceleration (for example, A/N cant mode), if you stop this fuel cut and restore fuel supply control, a shock may occur. To prevent this, the following steps are taken. processing is performed. That is, as shown in FIG. 33, first step 33
-1, it is determined whether the fuel cuff 1F7C) is in use during deceleration, and if No, step 33-2 determines whether the fuel cut is canceled and the fuel supply is resumed (immediately after F/C return). It will be decided whether If YES, the ignition timing is retarded in step 33-3. This reduces the engine generated torque and reduces the return shock after the fuel cut is canceled.

If YES in step 33-1, jump to step 33-3 and perform 1. The fire timing is retarded. In this way, by retarding the ignition timing during the fuel cut, that is, by preparing the ignition timing, it is possible to smoothly perform ignition timing retard control immediately after the F/C is restored.

2-1-iv) Air-fuel ratio feedback mode (
A/F FB mode) The conditions for determining that the mode is A/F FB mode (W/FBV-on) are as follows. That is, the second
As shown in Figure 2, the engine load condition is within a predetermined range ([
(ηvr+u,) greater than (ηVFBII)C
or the throttle opening THFBI+ mapped by the engine speed), the cooling water temperature is greater than TFB (<TID), and the fixed time has elapsed after starting, A. /FFB mode is determined, and the electromagnetic fuel injection valve 6 is driven at the required timing and for the required time. This allows A/F F
Fuel supply control optimal for B mode is performed. In this case, the correction coefficients multiplied by the injector basic drive time T are a feedback correction coefficient, an intake temperature correction coefficient, and an atmospheric pressure correction coefficient.

By the way, control in this A/F FB mode uses the detection signal from the 02 sensor 46, but the 02 sensor 4
6 has a heater 46a as shown in FIG. Since the detection section 46b of the sensor 46 and the heater 46a are housed in the same puffer tube through the same connector 4Gc, there is a risk that the current flowing through the heater 46a may leak to the 02 sensor detection section 46b. If leakage occurs in this way, the 02 sensor 46 outputs a high voltage (for example, about 12V), which may cause damage to the ECU 76. Therefore, in this example,
02 sensor 46 output is at a certain level (for example, 1.SV)
If this occurs, it is assumed that the heater current is leaking, and the relay switch 90 shown in FIG. 23 is opened to cut off the heater current.

And control after cutting off the heater current! ! ! The details are as follows.

a) Control mode 1 (FIG. 24) The processing in this mode 1 is as shown in FIG. 24.
First, in step 24-1, A/F FB back mode (
If the mode is FB mode, it is determined in step 24-2 whether the 02 sensor 46 is in the active state.

Here, in order for the 02 sensor 46 to be determined to be inactive, one of the following conditions may be satisfied.

a-1) A predetermined time has elapsed since the key was turned on.

a-2) Crosses the activation determination voltage.

a-3) In the FB mode, the output does not cross a certain value (lower than the activation determination voltage value) for a predetermined period of time.

If it is determined that the O2 sensor 46 is activated, the O2 sensor output is checked at step 24-3. Here, for example, 1. If it is detected that the current is equal to or higher than SV, it is assumed that the heater current is leaking, and feedback control is prohibited in step 24-4. Therefore, after that, control other than feedback (W10FB control) is performed (step 24-5).

Thereafter, it is determined whether a certain period of time has elapsed (step 24-6), and if it has elapsed, the heater 46a is energized again in step 24-6. Thereafter, in step 24-3, the 02 sensor output is detected again. In this way, since the noni heater 46a is reenergized after a predetermined period of time has elapsed after the FB control is prohibited, it is possible to increase the chances of canceling the FB control prohibition.

Note that in step 24-3, the 02 sensor output is 1, and the SV
If it is less than 02, the output of the 02 sensor is detected again in step 24-8. If it is less than 0.SV, feedback correction is applied to make it rich in step 24-9, and if it is 0.5v or more, feedback correction is applied to make it lean in step 24-10.

As a result, it is possible to prevent the air-fuel ratio from becoming leaner due to an abnormal increase in signal voltage due to leakage of heater current, and as a result, it has the advantage of sufficiently preventing the occurrence of engine non-stop (engine stall) and deterioration of drivability. .

If it is determined in step 24-1 that the mode is Wlo FB mode, or if it is determined that the 02 sensor is active in step 24-2, the Wlo FB mode is determined in step 24-11.
FB control is performed.

b) Control mode 2 (@Fig. 25) The processing in this mode 2 is as shown in Fig. 25.
First, in step 25-1, A/F FB back mode (
FB mode, 02FB mode), and if it is FB mode, in step 25-2, 7 lag F
It is determined whether LG1=1. Initially FLG1=O
Therefore, take the No route, and in step 25-3, 0
2 sensor 46 is in an active state.

Here, the conditions for determining that the 02 sensor 46 is inactive are as described above.

If it is determined that the 02 sensor 46 is activated, the 02 sensor output is checked in step 25-4. Here, if it is detected that the voltage is, for example, 1.5V or more, it is assumed that the heater current is leaking in step 25-5, and feedback control is prohibited, and step 25-6
Returns with FLG=1. Therefore, after that, control other than feedback (W/○FB control) is performed (step 25-11).

In addition, in step 25-4, the 02 sensor output is 1.5V.
If it is less than 02, the output of the 02 sensor is detected again in step 25-7. If it is less than 0.5V, feedback correction is applied to make it rich in step 25-8, and if it is 00SV or more, feedback correction is applied to make it lean in step 25-9.

Thereby, it is possible to prevent the air-fuel ratio from becoming lean due to an abnormal increase in the signal voltage due to leakage of heater current, and as a result, there is an advantage that occurrences such as engine stalling and deterioration of drivability can be sufficiently prevented.

In addition, once the 7-lag FLG1 becomes 1, it holds FLG=1 until the ignition switch 54 is turned off, so when it is determined that it is in A/F FB mode,
After that, feed control is always prohibited. but,
When the ignition switch 54 is turned off, FLG1
=O, so the feedbank control can be restored.

Note that if it is determined that Stay7"25-1t' is in Wlo FB mode, or if it is determined that 02 Sensane is active in Step 25-3, Step 25-10C',
Wlo FBY+IImMt%h7r.

2-1-v) High-speed full-open mode The conditions for determining the high-speed full-open mode are as follows. That is, as shown in FIG. 22, when the engine load state is higher than a predetermined value (THALPHN) and this state has been in this state for a predetermined period of time (a short period of time), it is determined that the high speed full throttle mode is in effect, and the A/ Similarly to the FFB mode, the electromagnetic fuel injection valve 6 is driven at the required timing and for the required time. In this case, the correction coefficients multiplied by the injector basic drive time TH are the intake temperature correction coefficient, the atmospheric pressure correction coefficient, the Wifi correction coefficient, the immediately after startup correction coefficient, and the air-fuel ratio correction coefficient.

2 1-vi) Others 2-1-vi-■) Wlo FB control mode This W
The 10FB control mode is determined to be the Wlo FB control mode in cases other than the above-mentioned operation modes [see FIG. 22]. In this control mode, the same correction coefficient as in the high-speed full-open mode is multiplied by the injector basic drive time T11. Innoecta drive timing is A/F FB
Same as mode.

2-1-vi-■) Water temperature sensor 72-7W1
The water temperature sensor 40 is equipped with a simulated water temperature generating device for the vehicle engine as a function of the water temperature sensor 40, and as shown in FIG. The value is sent to the temperature input section 77 via the wire 4Q41, and this temperature input section 7
7 is configured to send the partial pressure value to the I10 boat of the ECU 76 through an A/D converter, etc. When the water temperature TW is low, the resistance value between the sensor terminals is large, so the partial pressure value of the temperature input section 77 is The value is large, and when the water temperature TW is high, the resistance value between the sensor terminals is small, and therefore the partial pressure value of the temperature input section 77 is small.

As shown in Figure 1527, when the resistance value, which is the output of the water temperature sensor, is smaller than the first set value corresponding to the cooling water temperature of 120°C (step 27-1), that is, it is detected that the temperature is 120°C or higher. Occasionally, abnormality (water temperature sensor abnormality)
is detected, the process goes to step 27-3, and the resistance value is lower than the second set value corresponding to the cooling water temperature -40°C (the value corresponding to the cooling water temperature lower than the cooling water temperature corresponding to the first setting value). It's big! (step 27-2), i.e. -40
When it is detected that the temperature is below .degree. C., it is assumed that an abnormality (wire breakage) is detected, and the process proceeds to step 27-3. Note that once it is determined that the wire is broken, the disconnection determination is maintained thereafter.

If the water temperature sensor 40 is determined to be abnormal, in step 27-3, the pseudo water temperature function is activated, and then the above-mentioned starting mode [see 1-ii) Starting mode]
(step 27-4), and if it is the start mode, the initial value of the simulated water temperature is set to 20°C to simulate the actual warm-up state, and the rising simulated water temperature is simulated for a certain period of time. The simulated temperature is outputted sequentially from the memory mapped in advance for each time, and the pseudo temperature is increased and changed as appropriate, for example, raised to 80'C at equal intervals, and the output value that is kept constant thereafter is used as the water temperature in the ECU 76 (step 27-5). , if it is outside the starting mode, it is assumed that it has warmed up, and the pseudo water temperature is set to 80.
℃, a constant value is used as the water temperature in the ECU 76 (step 27-6).

Further, if the resistance value is between the first set value and the second set value, it is determined that the water temperature sensor 40 is normal, and the ECU
In step 76, the output value of the water temperature sensor 40 is used (step 27-7).

Note that an atmospheric temperature sensor, a memory, a seasonal switch, etc. may be provided to change the simulated water temperature when warm in winter and summer.

If the water temperature sensor is processed by the 7-Ruse 7 functions, the following effects and advantages can be obtained.

Even when the water temperature sensor 40 is abnormal, if it is in the start mode, the average warm-up state can be simulated and the FA can be simulated based on the water temperature.For example, by making the A/N rich, this will start! I] or ITJ1 Iso operation can be carried out completely, and if it is outside the starting mode, for example, the A/N can be made lean and the exhaust condition etc. can be improved as a state after warm-up. It is possible to control the engine by making full use of the 7 ability.

Note that in place of the water temperature sensor 40, another sensor that detects the engine temperature may be used.

(2-2) Misfire detection and fuel supply control By the way, if a misfire occurs in a certain cylinder, the unburned gas is directly discharged to the exhaust system, causing an afterburning phenomenon and There is a risk that Humbartough 4 may be damaged by melting. Therefore, in this embodiment, when a misfire occurs in a certain cylinder, the fuel supply to that cylinder can be stopped, thereby solving the problem caused by the misfire.

The following detection methods are available for determining whether a misfire is likely to occur in a certain cylinder.2-2-i) Misfire Detection Technique The internal pressure P, .

Now, if we limit it to idling, the indicated mean effective pressure Pi
can be expressed as a function of the pressure P, which is determined from the change in angular velocity during the expansion stroke.

Here, P,, is ωCJ 2-ωci”)/2
It can be determined based on Vnl:m. In other words, if the moment of inertia H of the engine rotation system, the angular velocity (crankshaft angular velocity) at the top dead center of a certain cylinder (0011), the angular velocity (crankshaft angular velocity) ωcj at the top dead center of the next cylinder, and the stroke volume Vn are known, then the cylinder Internal pressure P. can be calculated.

Next, although it is for a 4-cylinder engine, P is determined from a shiatsu pressure gauge installed in each cylinder and a shiatsu pressure i diagram during continuous idling operation and angular velocity measurements at every 2 degrees of crank angle.

Fig. 34 shows a comparison between the two. From the part marked Q in this diagram, it can be seen that the P of the misfiring cylinder fluctuates significantly to the negative side (in this case, it is possible to collect continuous data because it is a measure against heat damage during idling). )
. That is, if P, , J of a certain cylinder continuously fluctuate to the negative side by a certain value or more, it can be determined that that cylinder is misfiring.

Furthermore, it can be seen from the part marked O in Figures 35 and 36 that the engine displacement and engine speed are also reduced due to the misfire.

The experimental results shown in Figures 34 to 36 were carried out using a 4-cylinder engine, but since this phenomenon is essentially unrelated to the number of cylinders, the results are similar for the 6-ennon engine. That is clear.

In addition, for the crankshaft angular velocity meter αI, it is possible to use the electronic advance angle hardware (known) using the crank angle counting method as is, and even in those with electronic advance angle hardware using the periodic measurement method, it is possible to use the slit. It is possible to deal with this problem by adding .

In this way, according to this misfire detection method I, it is possible to sufficiently identify a cylinder in which a misfire is occurring, so that fuel injection from the electromagnetic fuel injection valve 6 that supplies fuel to this misfire cylinder is stopped. It's fine if you do. This prevents the above-mentioned problems from occurring.

2-2-ii) Misfire detection method ■ The second method ■ uses exhaust information (exhaust temperature and oxygen concentration in exhaust gas)
Detection method (2) mainly involves detecting a misfire in one of the cylinders, and then sequentially stopping fuel injection from the injectors 6 one by one. There are two types of detection methods.

2-2-ii-■) Misfire detection method by detecting exhaust temperature at catalyst outlet In this method, first, the temperature of the exhaust gas at the outlet of the catalyst humidifier 4 is detected by the high temperature switch 56.

If a misfire occurs in any cylinder, the outlet temperature of the catalytic converter 74 should be rising due to an afterburning phenomenon, or if the temperature detected by the high temperature switch 56 is above a certain value. , it is determined that one of the cylinders has misfired. With this alone, it is not possible to determine in which cylinder the misfire occurred, so the next step is to stop the fuel injection from the injector 6 for each cylinder in turn. A time corresponding to the cycle of is set. By sequentially stopping the injectors 6 in this way, the exhaust temperature decreases at the cylinder where the misfire actually occurs. This allows the misfire cylinder to be detected. In this case, Misfire detection and fuel supply control are seamlessly integrated.

2-2 ii-■) Misfire detection method by measuring 02 concentration at the catalyst inlet This method first measures the 02 concentration of the catalytic converter 74 using the 02 sensor 46 (in this case, it is preferable to use a linear 02 sensor as the 02 sensor 46). be done. If a misfire occurs in any cylinder, the air-fuel ratio should become lean while the air usage rate decreases.

Therefore, when a lean state is detected by the 02 sensor 46, it is determined that a misfire has occurred in one of the cylinders.

In this case as well, although this alone does not indicate that a misfire has occurred in the cylinder, fuel injection from the injector 6 for each cylinder is stopped in turn. At this time, the stopping time is set to a time corresponding to a required period during which the influence of misfire will be removed. In this way, injector 6
When the engine is stopped, the 02 concentration changes in the cylinder where one misfire actually occurred. In other words, the lean state is eliminated. This makes it possible to detect a misfiring cylinder. In this case as well, misfire detection and fuel supply control are performed in a harmonious manner.

In addition, in this misfire detection method (2), it takes two steps to detect a misfire in a specific cylinder, so the specific cylinder number in which a misfire was detected is memorized, and when a misfire occurs again, this memorized number can be used. First, the supply of fuel is stopped from the specified cylinder. It learns which cylinders have misfired. In this way, the fuel supply is preferentially stopped for cylinders that have once misfired, which is expected to contribute to shortening the misfire detection time.

2-2-iii) Misfire detection method■This method■
Output every 120° in crank angle TD
A misfire is detected by adding the period of the reference signal from the C sensor 44 to ff1l+2.

In other words, the rate of change in engine speed in a range that includes the explosion stroke is detected, but in this case,
If a misfire occurs in a certain cylinder, the reference signal period becomes non-uniform. For example, if the first cylinder misfires, the interval between the first cylinder reference signal and the second cylinder reference signal becomes longer.

In this way, a misfiring cylinder can be detected and the supply of fuel to that cylinder is stopped.

This eliminates the problem caused by the misfire.

2-2-iv) Other misfire detection methods 2-2-
iv-■) Misfire detection method by measuring the exhaust temperature of each cylinder exhaust port This method requires six sensors in total to detect the exhaust temperature of each cylinder exhaust port;
In b), if a certain cylinder misfires, the exhaust boat exhaust temperature of that cylinder should drop abnormally, so this will be detected and the This stops fuel injection.

This also solves the problem caused by the misfire.

2-2-iv-■) Misfire detection method by measuring 02 concentration at each cylinder exhaust port In this method, 02 sensors (6 in total are required) to detect the 02 concentration at each cylinder exhaust port; (a
), (not shown in (b)) are provided.

If a cylinder misfires, the 4th cylinder of that cylinder
fl: ○ with air port, the sensor is supposed to output a signal, so this is detected and fuel injection to that cylinder is stopped.

This also solves the problem caused by the misfire.

2 2-iv-■) / Misfire detection method using a /tsuku sensor In this method, the presence or absence of combustion (presence of misfire p! &) is detected using a /tsuku sensor. ) is installed, and if a certain cylinder misfires, the vibration in that cylinder should decrease, so this will be detected and fuel injection to that cylinder will be stopped.

Even in this case, the above misfire (common trouble) can be solved.

2-2-iv-■) Misfire detection method by measuring the voltage waveform on the primary side of the ignition filter 72 This method is based on the fact that an abnormality on the high voltage side of the ignition coil 72 also affects the primary side. A misfire is detected by detecting the presence or absence of the primary voltage and the signal waveform. That is, if there is no spark at the ignition plug in a certain cylinder, a misfire occurs, and in this case, fuel supply to the cylinder in which no spark occurs is stopped.

This eliminates the problem caused by the misfire.

However, with this method, it is impossible to detect a misfire even if the spark plug becomes stale, so it is used in combination with each of the above-mentioned methods.

(3) Ignition timing control In the ignition timing control in this embodiment, it is determined which of the following operation modes is in place based on inputs from various sensors, and the fill current is set at the optimum ignition timing θ according to each operation mode. It is done to cut off the

Note that θ=θ. +θAT+θklT or θ=θID. Here, θ0 is the basic ignition timing, θ^T is the ignition timing intake temperature correction value, 01 is the ignition timing water temperature correction value, and θ10
is the idle ignition timing.

In addition, the above basic ignition timing θ. On the other hand, energization angle control is also performed to start energizing the coil a required energization angle earlier.

By the way, the operation modes include initial set mode, starting mode, idle (1) mode, and idle (I) mode.
I) mode, air 71:1-sensor 7 air mode and normal mode.

In order to be determined to be in initial set mode, the advance angle adjustment switch (not shown) must be on and the engine speed and vehicle speed must be below a predetermined value, and also to be determined to be in starting mode. In order to do so, the advance adjustment switch must be off, the air 70-sensor 32 must be on, and the carrot rotation speed must be below a certain low value, and in either case, the required ignition timing (fixed value) will be achieved. It is controlled as follows.

The idle (I) mode is determined to be this mode at the time of idle other than the next idle (II) mode, and the idle (I)
In principle, the I) mode is determined to be this mode during A/F feedback control, but if it is determined to be the idle (1) mode, the ignition timing is controlled to the required ignition timing (fixed value), and the idle ( II) When it is determined that the mode is
The ignition timing is controlled to be the required ignition timing.

In order to determine that the air 70-sensor 7 fail mode is in effect, it is necessary that the engine rotational speed be greater than or equal to a predetermined value and the output of the air 70-sensor 32 be less than or equal to a predetermined value.

The normal mode is determined to be the mode when the above-mentioned modes are not entered.

When it is determined that the air 70-sensor 7 air mode and normal mode are in effect, the ignition timing is set to θ. Control is performed such that 1θ^d 10-d.

In addition, starting mode, idle (I) mode, idle (
n) mode, air 70-sensor 7 As a premise for determining the air mode and normal mode, the advance angle adjustment switch must be off.

(4) Control during overheating This control during overheating is carried out due to the following necessity. In other words, for example, if you immediately stop the engine after driving under a high load (such as after climbing a 3% uphill slope at a vehicle speed of 120 km/l+, or after climbing a 10% uphill slope at a vehicle speed of 40 ks+/h), Since the cooling fan stops and the cooling water is no longer circulated, the temperature inside the engine compartment increases rapidly, reaching the maximum temperature after 30 to 40 minutes. As a result, the fuel temperature also rises, and there is a risk that bubbles will be generated in the fuel, making it impossible to perform accurate fuel supply control. For ¥ like this! ! ! In order to prevent this, this overheating control is executed.

Various types of overheat control will be explained below.

4-1) Overheat control 1 As already explained using the Pt555 diagram, this is
This method uses a thermovalve 28 to adjust the fuel pressure according to the fuel temperature, and when the fuel fj is high, atmospheric pressure acts on the fuel pressure regulator 24 by the thermovalve 28. Thereby, for example, during idling operation after cranking, the pressure in the control passage 26 suddenly decreases, the fuel pressure suddenly decreases, and it is possible to sufficiently prevent the fuel from boiling.

Of course, a solenoid valve (ECU) can appropriately switch between the throttle downstream pressure side and the atmospheric pressure side of the intake passage 10.
7G) may be provided in the middle of the control passage 1m26, so that the solenoid valve can be switched to the atmospheric pressure side from cranking to idling operation.

4-ii) Overheat control 2 This method is
When a person is expected to get into the car, the fuel pump 22 is activated to remove air bubbles from the fuel. Specifically, the following method is adopted.

4-1;-■) Technique (see Figure 37) As shown in Figure 37, first it is determined whether the door handle (outside) is grabbed (step 37-1). If it is grabbed, the fuel pump 22 is energized in step 37-2, expecting that someone will get on the vehicle afterwards, and when t'17 seconds have elapsed (step 37-3), the fuel pump 22 is turned on. The energization is stopped (step 37-4). As a result, the fuel in the fuel tank 98 and the fuel supply path 30 is circulated through the fuel pressure regulator 24, and bubbles in the fuel are removed during this circulation.

Note that if the door handle is not gripped, the fuel pump 22 remains in the non-driving state (step 37-5).

In this case, the fuel is driven to the ring even if there is no overheating condition.

4- ii- In that case, I expected that people would get on board after that.
Determine whether it is in overheat mode. That is, first, in step 38-2, it is determined whether the cooling water temperature is equal to or higher than T.sub.A. , @ If the temperature is T A 3 s ”C or higher, it is determined that the mode is overheat mode (step 38-4).
), in step 38-5, the fuel pump 22 is energized and t
When ze seconds have passed (step 38-6), the fuel pump 2
2 is turned off (step 38-7). As a result, the fuel in the fuel tank 98 and the fuel supply path 30 is circulated through the fuel pressure regulator 24, and air bubbles in the fuel are removed during this circulation.

Note that if the door handle is not gripped, the fuel pump 22 remains in the non-driven state (step 38-8).

In this case, it is overheating! ! (Step 38-2.
38-3 are both in the YES state), the fuel circulation drive is not performed, thereby eliminating the need to drive the fuel pump 22 unnecessarily.

4-Air) Overheat control 3 This method drives the fuel pump 22 to remove air bubbles in the fuel when the engine key is inserted into the door key ring.Specifically, the following method is used. taken.

4-1ii-■-a) Method [Refer to FIG. 45(a)] As shown in FIG. 45(,), first, it is determined whether or not the engine key is inserted into the door key ring (step 45-1). If it is inserted, in step 45-2, the fuel pump 22 is energized, and when t<5 seconds have elapsed, in step 45-3), assuming that a person will get on the vehicle soon. (Step 45-4). As a result, the fuel in the fuel tank 98 and the fuel supply path 30 is circulated through the fuel pressure regulator 24, and bubbles in the fuel are removed during this circulation.

Note that if the engine key is not inserted into the door key ring, the fuel pump 22 remains in the non-driving state (step 45-5).

In this case, even if the engine is not in an overheating state, when the engine key is inserted into the door keyring, fuel circulation is performed in anticipation that the f/occupant will get in the vehicle.

4-1ii-■-b) Technique [Refer to FIG. 45(b)] As shown in FIG. 45(b), first, it is determined whether or not the engine key is inserted into the door key ring (step 45b-1). If it is plugged in, step 4
In step 5b-2, it is determined whether the door is in an unlocked state (7-in-row state), and if the door is unlocked, it is assumed that a person will get into the vehicle soon thereafter, and in step 45b-
3, the fuel pump 22 is energized, and when L4Sb seconds have elapsed (step 45b-4), the energization to the fuel pump 22 is stopped (step 45b-5). As a result, fuel tank 9
8 and the fuel in the fuel supply path 30 is supplied to the fuel pressure regulator 2
4, air bubbles in the fuel are removed during this circulation.

Note that if the engine key is not inserted into the door keyring or the door is not unlocked, the fuel pump 22 remains in the non-driving state (step 45b-6).

In this case, even if the engine is not in an overheating state, when the engine key is inserted into the door keyring and the door is unlocked, the fuel circulation drive is performed in anticipation that a passenger will enter the vehicle.

4-1ii-■-a) Method ■ [See Figure 46 (a)] As shown in Figure 46 (,), it is first determined whether the engine key is inserted into the door key ring (step 46-1), If it is plugged in, it is determined whether the vehicle is in overheat mode, assuming that a person will get on the vehicle soon afterward.

That is, first in step 46-2, the cooling water temperature is TW,
It is determined whether the intake temperature is 6° C. or higher, and if YES, it is determined in step 46-3 whether the intake air temperature is TA□° C. or higher. Then, if the intake temperature is T A 4 s ”C or higher,
It is determined that the mode is overheat mode (step 46-
4), in step 46-5, energize the fuel pump 22;
When t's seconds have passed (step 46-6), the power supply to the fuel pump 22 is stopped (step 46-7), and from this point on, the fuel in the fuel tank 98 and the fuel supply path 30 is circulated through the fuel pressure regulator 24. During this circulation, air bubbles in the fuel are removed.

Note that if the answer in step 46-1.46-2.46-3 is No, the fuel pump 22 remains in the non-driving state (step 46-8).

In this case, the overheat condition (step 46-2.46
-If both of 3 are not in the YES state g), fuel circulation drive is performed and 1. This eliminates the need to drive the fuel pump 22 unnecessarily.

4-1ii-■-b) Technique ■ [Refer to FIG. 46(b) 1 As shown in FIG. 46(b), first, it is determined whether or not the engine key is inserted into the door key ring (step 46-1). If plugged in, step 46
In b-2, it is determined whether the door is in the unlocked state (unlocked state!r!i), and if the door is unlocked, it is assumed that a person will get into the vehicle immediately after that, and the overheat mode is activated. Determine whether That is, first in step 46b-3, it is determined whether the cooling water temperature is equal to or higher than T W -s b "C, and if YES, step 46b-4
Then, it is determined whether the intake air temperature is equal to or higher than TA+cb"C. If the intake temperature is equal to or higher than TA+6b"C, it is determined that the overheat mode is present (step 46b-5).
At step 46b-6, the fuel pump 22 is energized and t
When 4 sb seconds have passed (step 46b-7), the power supply to the fuel pump 22 is stopped (step 46b-8). Since the fuel in the fuel tank 98 and the fuel supply path 30 is circulated through the fuel pressure regulator 24, air bubbles in the fuel are removed during this circulation.

Note that steps 46b-1, 466-2, 46b-3,
If NO at 46&-4, the fuel pump 22 remains inactive (step 46b-9).

In this case, the overheating state (steps 46b-3, 46b-3)
If both Gb-4 are not in the YES state, fuel circulation drive will not be performed. This eliminates the need to drive the fuel pump 22 unnecessarily.

4-iv) Overheat control 4 This method is
When the door is opened from the outside, the fuel pump 22 is driven to remove air bubbles from the fuel. Specifically, the following method is adopted.

4-:v-■) Method I (see FIG. 39) As shown in FIG. 3 - 2, it is judged whether the door was opened from the inside of the door or not.If NO1, that is, the door was opened from the outside, then the step At step 39-3, the fuel pump 22 is energized, and when hs seconds have elapsed (step 39-4), the energization to the fuel pump 22 is stopped (step 39-5). Since the fuel is circulated through the fuel pressure regulator 24,
During this circulation, air bubbles in the fuel are removed.

In addition, if NO in step 39-1 and step 3
If YES in step 9-2, the fuel pump 22 remains in the non-driving state (step 39-(3)).

In the second case, even if the vehicle is not in an overheating state, if the door is opened from outside the IL and the driver is just about to get into the vehicle, fuel circulation will be performed.

4-iv-■) Technique (see Figure 40) As shown in Figure 40, it is determined by the insect door sensor 92 whether the door has been opened (step 4O-1). If the door is open, it is determined in step 40-2 whether the door has been opened from inside the door. If No, that is, if the door is opened from the outside, it is assumed that the vehicle will get into the vehicle immediately thereafter, and it is determined whether the vehicle is in overheat mode.

That is, first in step 40-3, the cooling water temperature is T W
4. It is determined whether the temperature is equal to or higher than 'C, and if YES, in step 40-4, the intake air temperature is TA. It is determined whether it is ゛C or higher. And the intake temperature is TA. If it is above ℃,
It is determined that the mode is overheating (step 4O-
5), in step 40-6, energizing the fuel pump 22;
T. When seconds have elapsed (step 4O-7), the power supply to the fuel pump 22 is stopped (step 4O-8). As a result, the fuel in the fuel tank 98 and the fuel supply path 30 is circulated through the fuel pressure regulator 24, and air bubbles in the fuel are removed during this circulation.

Note that in the case of No in step 40-1.40-3.40-4 and in the case of YES in step 40-2, the fuel pump 22 remains in the non-driving state (step 4O-9).
).

In this case, the overheat condition (step 40-3.40
-4 are all YES), fuel circulation drive will not be performed. This wastes fuel pump 2.
There is no need to drive 2.

4-iv=■) Method III (see Fig. 41) As shown in Fig. 41, first, in step 41-1, it is determined whether or not the G-to-sinch 96 is off, and if YES, in step 41-2, A door sensor 92 determines whether the door is open.

If YES, it is determined that the door has been opened from the outside, and it is assumed that the passenger will board the vehicle immediately thereafter, and step 41
-3, the fuel pump 22 is energized, and when Lt seconds have elapsed (
Step 41-4), and the power supply to the fuel pump 22 is stopped (Step 4l-5). As a result, the fuel in the fuel tank 98 and the fuel supply path 30 is circulated through the fuel pressure regulator 24, and air bubbles in the fuel are removed during this circulation.

In this case, the fuel pump 22 remains in the non-driving state (step 41-6).

In this case, even if the vehicle is not in an overheating state, the fuel circulation drive is performed just before the door is opened from outside the vehicle and the occupant gets into the vehicle.

4-iv-■) Method ■ (See Figure 42) As shown in Figure 42, first in step 42-1, the seat switch 9
It is determined whether 6 is off, and if YES, step 4
At 2-2, the door sensor 92 determines whether the door is open. If YES, it is determined that the door has been opened from the outside, and it is assumed that the vehicle will enter the vehicle immediately thereafter, and it is determined whether the vehicle is in overheat mode.

That is, first in step 42-3, the cooling water temperature is set to TW4.
If the answer is YES, it is determined in step 42-4 whether the intake air temperature is TA and whether it is 2°C or more. Then, if the intake air temperature is TA, 2°C or higher, it is determined that the overheat mode is present (step 42-5),
At step 42-6, the fuel pump 22 is energized and t42
When seconds have elapsed (step 42-7), the energization to the fuel pump 22 is stopped (step 42-8). As a result, the fuel in the fuel tank 98 and the fuel supply path 30 is circulated through the fuel pressure regulator 24. Air bubbles in the fuel are removed during circulation.

In addition, step 42-1.42-2.42-3゜42-
If the answer is No in step 4, the fuel pump 22 remains in the non-driving state (step 42-9).

In this case, is it overheating? ! ! (YES in both steps 42-3 and 42-4), the fuel circulation drive is not performed, thereby eliminating the need to drive the fuel pump 22 unnecessarily.

4-iv-■) Method ■ (Refer to Figure 43) As shown in Figure 43, first, in step 43-1, it is determined whether t43-1 minutes have elapsed since the ignition switch 54 was turned off, and if YES, In step 43-2, door sensor 92 determines whether the door is open. If YES, it is determined that the door was opened from the outside,
Anticipating that you will be riding soon after that, step 4
At step 3-3, the fuel pump 22 is energized, and when t41 seconds have elapsed (step 43-4), the energization to the fuel pump 22 is stopped (step 43-5).
The fuel in the fuel supply path 30 is transferred to the fuel pressure regulator 24.
During this circulation, air bubbles in the fuel are removed.

Note that if the answer is NO, the fuel pump 22 remains in the non-driving state (step 43-13).

In this case, even if the vehicle is not in an overheating state, if the door is opened from outside the vehicle and the occupant is about to get into the vehicle, the fuel circulation drive will be turned off.

4-iv-■) Method ■ (See Figure 44) As shown in Figure 44, first in step 44-1, it is determined whether t44-1 minutes have elapsed since the ignition switch 54 was turned off, and the answer is YES. In step 44-2, it is determined whether the door is open or not. If YES, it is determined that the door has been opened from the outside, and it is determined whether the vehicle is in the overheat mode, assuming that the vehicle will soon get into the vehicle. That is, first in step 44-3, the cooling water temperature is T.
It is determined whether the temperature is W,.°C or more, and if YES, in step 44-4, the intake air temperature is TA4. It is determined whether the temperature is above °C. Then, if the intake temperature is TA,,'C or higher,
It is determined that the mode is overheating (step 44-
5), in step 44-6, energizing the fuel pump 22;
When t44 seconds have elapsed (step 44-7), the power supply to the fuel pump 22 is stopped (step 44-8), and as a result, the fuel in the fuel tank 98 and the fuel supply path 30 is circulated through the fuel pressure regulator 24. During this circulation, air bubbles in the fuel are removed.

In addition, step 44-1.44-2.44-3゜44-
If the answer is No in step 44, the fuel pump 22 remains in the non-driving state (step 44-9).

In this case, an overheat state occurs (step 44-3).

44-4 are both in the YES state), the fuel circulation drive is not performed. This eliminates the need to drive the fuel pump 22 unnecessarily.

4-iv-■) Additionally, after the door is opened from the outside and the occupant is seated in Sea F, the over-1 o'clock control may be executed. In this case, after the step ``Is the door dark?'' shown in Figures 39 to 44 above, the ``Is the seat switch on?''
All you need to do is to include step 7, which says, ``If the seat switch is on, control is performed to energize the fuel pump.'' If this method is used, the fuel pump 22 will be activated in a state that would be close to just before starting the engine. be done.

4-v) Overheat control 5 This control method 5 is to temporarily perform fuel increase control (enrichment) during overheat mode. In this way, even if there are bubbles in the fuel, more fuel will be injected, resulting in an appropriate amount of fuel being supplied.

This control method includes the following.

4-v-■) Method ■ (see Figure 47) In this method I, as shown in Figure 47, step 47
-1, when starting, that is, when the ignition switch 54 is turned on from off, it is determined whether the overheat mode is present. That is, in step 47-2, it is determined whether the cooling water temperature is equal to or higher than T W = y'C;
If YES, in step 47-3, the intake temperature T A
4 It is determined whether the temperature is above Y ℃, and if YES,
It is determined that it is in overheat mode (step 47-4)
.

Note that if NO in step 47-2 or 47-3, it is determined that the mode is other than the overheat mode, and injection is performed at the base injection amount (step 47-5).

When it is determined that the Stella 7' 47-4 is in overheat mode, in step 47-6, injection 1 is calculated according to the cooling water temperature at the time of starting (when the ignition switch 54 is turned on from OFF), and the start is started. At this time, injection is performed at 0 times the base injection amount (step 47-7).
), where α is a value depending on the cooling water temperature, for example 1
．． It is set as 1,1.2°1.3.

After that, in step 47-8, it is determined whether ttt seconds have elapsed since the start, that is, the complete explosion, and if the elapsed time has elapsed, α-fold injection is continued (step 47-8).
-9). And t4? When seconds have elapsed, it is decided to return to the base injection amount (step 47-10).

In this way, when the overheat mode is started, the mu increase is controlled, so even if there are many bubbles in the fuel due to overheating, more fuel is injected, and as a result, an appropriate amount of fuel is injected. Fuel is supplied and the engine starts smoothly.

4=v-■) Method II (see tIS48 diagram) This method ■
Then, as shown in FIG. 48, in step 48-1, starting, that is, turning the ignition switch 54 from off to on (
If it becomes 2, it is determined whether or not it is in overheat mode. That is, in step 48-2, the cooling water temperature is T.
It is determined whether W is 4*°C or more. If YES, it is determined in step 48-3 whether the intake air temperature T A is 4s°C or more. If YES, it is determined that the overheat mode is present (step 48-3). 4).

Note that if No in step 48-2 or 48-3, it is determined that the mode is other than the overheat mode, and injection is performed at the base injection amount (step 48-5).

When it is determined in step 48-4 that the overheat mode is present, in step 48-6, the injection amount is calculated according to the cooling water temperature of the starting hit (when the ignition switch 54 is turned on from off), and upon starting, Injection is performed at 0 times the base injection amount (step 48-7).
), where α is a value depending on the cooling water temperature, for example 1
, 1, 1.2° 1.3.

Thereafter, in step 48-8, tailing processing is performed to reduce α by a constant amount over time.

Then, in step 48-9, it is determined whether α≧1, and if α≧1, then in step 48-10, it is determined by half a second whether t4a seconds have passed since the start, that is, from the complete explosion.

Thereafter, when α becomes 1 or t4e seconds elapse, the injection amount is returned to the base injection amount (step 48).
-11>.

In this way, when the overheat mode starts, fuel increase control is executed, so even if there are many bubbles in the fuel due to overheating, more fuel will be injected, and as a result, the appropriate amount of fuel will be injected. In addition to being able to achieve a smooth engine start by supplying fuel, the amount of increase is not fixed and is reduced over time (tailing process), so smooth control can be achieved.

4v-■) Method ■ (see Figure 49) In the second method ■, as shown in Figure 49, step 49
-1, when starting, that is, when the ignition switch 54 is turned on from off, it is determined whether the overheat mode is present. That is, in step 49-2, it is determined whether the cooling water temperature is TW4s'C or higher, and if YE
If S, in step 49-3, the intake temperature T A 4s'
It is judged whether it is C or higher, and if it is '1' E S,
It is determined that it is in overheat mode (step 49-4)
.

Note that if NO in step 49-2 or 49-3, it is determined that the mode is other than the overheat mode, and injection is performed at the base injection amount (step 49-5).

If it is determined that the overheat mode is present in Step 4-4, then in Step 4-6, the injection amount is calculated according to the cooling water temperature at the time of starting (when the ignition switch 54 changes from OFF to ON (2)), Upon starting, injection is performed at 0 times the base injection amount (step 49-7).
, where α is a value depending on the cooling water temperature, for example 1.
It is set as 1,1,2°1.3.

Thereafter, in step 49-8, it is determined whether the O2 sensor 46 detects a rich state. If it is rich, in step 49-9, a tailing process is performed to reduce α by a fixed amount over time.

Then, in Step 7 49-10, it is determined whether α≧1, and if α≧1, it is determined in Step 49-11 whether Qj+s seconds have passed since the start, that is, from the complete explosion.

After that, while the 02 sensor signal is rich, α
If t4s4s elapses, the injection amount must be returned to the permanent injection amount (step 49-12).

In addition, ○, when the sensor signal becomes lean (or is lean), tailing processing is not performed and 0x injection is performed.
The process continues (step 49-13).

As a result, tailing processing is performed while the o22 sensor signal is rich, and 0x injection processing is performed while it is lean (if α becomes lean during tailing, the value of α during tailing is selected), In any case, after LJj' has elapsed, the injection amount is returned to the base injection amount. Therefore, even if the above-mentioned processing is mixed and L4141 seconds elapsed α has not become smaller than 1, the injection amount is forcibly returned to the base injection amount after t41 seconds have elapsed.

In this way, when starting the overheat mode, fuel increase control is executed, so even if the fuel contains a large number of bubbles due to overheating, more fuel is injected, and as a result, an appropriate amount of fuel is injected. In addition to supplying fuel and achieving a smooth engine start, if the 02 sensor signal is rich, it is assumed that there are fewer air bubbles, and the degree of increase is not fixed, but the degree of increase is reduced over time (tailing). processing) is performed, so that even smoother control can be realized.

4-vi) Control method 6 for overheating control temporarily increases the amount of intake air during overheating mode (in this case, since the L-JETRO method is adopted, when the amount of intake air is increased, , the amount of fuel is increased accordingly.

That is, the air-fuel mixture is controlled to increase. Hereinafter, the term "intake air amount increase control" means the same thing. If you do this, the result will be the same as racing by pressing the accelerator pedal, so you will be able to quickly use fuel that contains air bubbles, and as a result, you will quickly reach an appropriate fuel supply control state. It will be migrated.

This control method includes the following.

4 vi-■) Method I (see Fig. 50) In this method, as shown in Fig. 50, when starting, that is, the ignition switch 54 is turned on from off in step 50-1, it is determined whether the engine is in overheat mode or not. It will be determined whether That is, in step 50-2, the cooling water temperature is TW,
. It is determined whether the temperature is equal to or higher than °C, and if YES, in step 50-3, the intake air temperature TA. It is determined whether the temperature is higher than or equal to .degree. C., and if YE or S, it is determined that the overheat mode is present (step 50-4).

In addition, X y −/F50-2 + 50-3 TeN
It is determined that the mode is not O, overheat mode, and the base intake air amount is set (Step 5O-5).
.

Here, the intake air amount is controlled by changing the area of the bypass passage using the idle speed control valve 18, but the throttle opening degree may also be changed.

Next, in step 50-4, if it is determined that the overheat mode is present, in step 50-6, the amount of intake air (specifically Specifically, the number of steps of the stepping motor 18a and the throttle opening are calculated, and upon starting, injection is performed at α1 times the base intake air amount (step 5O-7). Here, α1 is a value depending on the cooling water temperature, for example, 1.1, 1.2, 1.
It is set as 3.

Thereafter, in step 50-8, it is determined whether tso seconds have elapsed since the start, that is, from the complete detonation, and if tso seconds have elapsed, α1 time inhalation is continued (step 50-8).
9). Then, after t5 seconds tiX, the intake air amount is returned to the base intake air amount (step 5O-10).

In this way, since the intake air amount is increased when the overheat mode is started, even if the fuel contains many air bubbles due to overheating, it is possible to quickly shift to an appropriate fuel supply control state. This allows for smooth engine starting.

Note that, in reality, this method is used in combination with the method 4-v-(2) described above. That is, the air-fuel mixture increase control and the air-fuel ratio enrichment control are used in combination. In that case, 70- is shown as shown in FIG. 50 with parentheses added.

4-vi-■) Method ■ (See Fig. 51) In this method, as shown in Fig. 51, when the engine starts, that is, the ignition switch 54 is turned on from off in step 51-1, it is in the overheat mode. It is determined whether That is, in step 51-2, the cooling water temperature is TW,
,"C or higher. If YES, it is determined in step 51-3 whether or not the intake air temperature TA6.C or higher is determined. If YES, it is determined that the overheat mode is present (step 5l-4).

Note that if NO in step 51-2 or 51-3, it is determined that the mode is other than the overheat mode, and the intake air amount is set to the base intake air amount (step 5l-5).

Here, the intake air amount is controlled by rSC as in the case described above.
This is done by unifying the valve opening and throttle opening.

Next, in step 51-4, if it is determined that the overheat mode is present, in step 51-6, the amount of intake air (specifically In this step, the number of valves of the stepping motor 18a and the throttle opening are calculated, and upon starting, injection is performed at α1 times the base intake air amount (step 5l-7). Here, α1 is a value corresponding to the cooling water temperature, for example, 1.1, 1.2, 1.
It is set as 3.

Thereafter, in step 51-8, tailing processing is performed to reduce al by a constant amount over time.

Then, in step 51-9, it is determined whether α1≧1, and if α1≧1, it is determined in step 51-10 whether ts+ seconds have passed since the start, that is, from the complete explosion.

Thereafter, when α1 becomes 1 or 1 second elapses, the intake air amount is returned to the base intake air amount (step 5l-11).

In this way, when the overheat mode is started, the intake air amount is increased, so even if the fuel contains many air bubbles due to overheating, it is possible to quickly shift to an appropriate fuel supply control state and smoothly control the intake air. In addition to realizing a smooth engine start, the degree of increase is not fixed and is reduced over time (tailing processing), so it is possible to realize smooth control.

Note that this method is actually used in combination with the above-mentioned method 4-v-■. It is used in combination with air-fuel mixture increase control and air-fuel ratio enrichment control. Showing 70- in that case,
Shown in Figure 51? This is an addition of Book A.

4-vi-■) Method ■ (See Figure 52) In this method, as shown in Figure 52, in step 52-1, when starting, that is, the ignition switch 54 is turned off or turned on, the overheat mode is activated. It is determined whether or not. That is, in step 52-2, the cooling water temperature is T.
W It is determined whether the temperature is 52℃ or higher, and if YES,
In step 52-3, it is determined whether the intake air temperature TA is 2° C. or higher, and if YES, it is determined that the overheat mode is present (step 52-4).

Note that if NO in step 52-2 or 52-3, it is determined that the mode is other than the overheat mode, and the intake air amount is set to the base intake air amount (step 52-5).

Here, the intake air amount is controlled by the IS
This is done by changing the C pulp opening and throttle opening.

Next, in step 52-4, if it is determined that the overheat mode is present, in step 52-6, the intake air fA (J !4: Specifically, the number of steps of the stepping motor 18a and the throttle opening degree) are calculated, and upon starting, injection is performed at α1 times the base intake air amount (step 52-7). here,
α1 is a value depending on the cooling water temperature, for example 1. i, 1.
2.1.3 above (This is set.

Thereafter, in step 52-8, it is determined whether or not the O2 sensor 46 detects a rich state. If it is rich, a tailing process is performed in step 52-9 to reduce α1 by a fixed amount over time.

Then, in step 52-10, it is determined whether α1≧1, and if α1≧1, it is determined in step 52-11 whether ts2 seconds have elapsed since the start, that is, the complete explosion.

Thereafter, while the 02 sensor signal is rich, when α1 becomes 1 or when ts2 seconds elapse, the intake air amount is returned to the base intake air amount (Step 7 52-12).

Note that when the 02 sensor signal reaches lean 1 (or is lean), the tailing process is not performed and the α1 times intake is continued (step 52-13).

As a result, while the 02 sensor signal is rich, tailing processing is performed, and when it is lean, α1 times the intake processing (if α1 becomes lean during tailing, the value of α1 during tailing is selected), In any case, ts
After □ seconds have elapsed, the amount of intake air is returned to the base amount. Therefore, the above processing is mixed, and α becomes 1 when t5□ seconds elapse.
Even if it has not become smaller, it will be forcibly returned to the base intake air amount after 2 seconds.

In this way, when the overheat mode is started, the intake air amount is increased, so even if the fuel contains many air bubbles due to overheating, it is possible to quickly shift to an appropriate fuel supply control state and smoothly control the intake air. In addition to realizing a smooth engine start, when the O2 sensor signal is rich, it is assumed that there are fewer air bubbles, and the amount of increase is not fixed, but the amount of increase is reduced over time (tailing process). Furthermore, smoother control can be realized.

Note that, in reality, this method is used in combination with the method 4-v-■ described above. That is, the air-fuel mixture increase control and the air-fuel ratio control to 7% are used in combination. Showing 70- in that case,
This is Figure 52 with parentheses added.

4-vii) Overheat control 7 This control method 7 is to temporarily advance the ignition timing during overheat mode, that is, perform advance angle control. In this way, even if the fuel contains air bubbles and only a small amount of fuel is supplied as a result, the torque can be increased by advancing the ignition timing.
In addition to realizing a smooth engine start, it also causes a decrease in engine output due to insufficient torque.It is said that if the angle is advanced by 1 degree, it will cause problems with exhaust gas, but this will not be a problem when in overheat mode. .

This control method is similar to that of dogs.

4-vii-■) Methodology (see Figure 53) This method I
Then, as shown in figure f553, in step 53-1,
When the engine starts, that is, when the ignition switch 54 is turned on from off, it is determined whether the engine is in overheat mode. That is, in step 53-2, the cooling water temperature is T.
W S 3 'C or higher is judged, if YE
If S, in step 53-3, the intake temperature T A S 3
It is determined whether it is 'C or higher, and if YES, it is determined that the overheat mode is present (step 53-4).

Note that if No in step 53-2 or 53-3, it is determined that the mode is other than overheat mode, and injection is performed at the base injection amount (step 47-5).

When the overheat mode is determined in step 53-4, in step 53-6, an advance amount is calculated according to the cooling water temperature at the time of starting (when the ignition switch 54 is turned on from off). At the time of starting, it is necessary to advance the angle by α2° from the base advance angle (step 5).
3-7). Here, a2 is a value depending on the cooling water temperature.

Thereafter, in step 53-8, it is determined whether tss seconds have elapsed since the start, that is, from the complete detonation, and until this time has elapsed, the α2° advance angle continues (step 53-8).
9), and when tsi seconds have elapsed, the advance angle value is returned to the base advance value [this value is stored in a map formed by (N, A/N)] (step 53-10).

In this way, when the overheat mode is started, advance angle control of α2° is executed, so even if many air bubbles are created in the fuel due to overheating, and as a result, only a small amount of fuel is supplied. , the generated torque can be increased accordingly, which not only makes it possible to realize a smooth engine start but also to obtain sufficient engine output.

4-vii-■) Method■ (See Figure 54) This method■
Now, as shown in FIG. 54, in step 54-1, when the engine is started, that is, when the ignition switch 54 is turned on from off, it is determined whether or not it is in the overheat mode. That is, in step 54-2, the cooling water temperature is T.
W, it is determined whether or not it is 4°C or more. If YES, it is determined in step 54-3 whether the intake air temperature TA', -4).

NAO, STELLA 7' 54 2954-3 TE NO Nara, it is determined that the mode is not overheat mode, and the base advance angle value is set (step 54-5).

If it is determined in step 54-4 that the engine is in overheat mode, in step 54-6, an advance angle value is calculated according to the cooling water temperature at the time of starting (when the ignition switch 54 is turned on from OFF). , the base lead angle is advanced by α2° (step 5).
4-7). Here, α2 is a value depending on the cooling water temperature.

Thereafter, in step 54-8, tailing processing is performed to reduce α2 by a constant amount over time.

Then, in step 54-9, it is determined whether the angle is more advanced than the base value, and if YES, step 54-1
0, it is determined whether t54 seconds have passed since the start, that is, from the complete explosion.

After that, it becomes the base advance value (N in step 54-9).
o) or L54 seconds have elapsed, then Y at step 54-10.
ES) Then, the return to the base advance angle value is performed (
Step 54-11).

In this way, when starting the overheat mode, advance angle control of α2° is executed, so even if the fuel contains many bubbles due to overheating and as a result, only a small amount of fuel is supplied, The generated torque can be increased by that amount, which makes it possible to start the engine smoothly, obtain sufficient engine output, and reduce the degree of throughput over time (tailing processing), so smooth control can be achieved.

In addition, in this control method 7, α2° is added to the base advance angle value.
I performed a calculation that advances the base lead angle by α
An operation such as advancing by 2° may also be performed.

In this case, step 54- in the flow shown in FIG.
9 becomes "α2'>1?"

Moreover, the cooling water temperature value as one of the overheat mode determination conditions may be set to the same value or different values in each of the above-mentioned overheat controls 1 to 5. If the same value is used here, for example, a value of 90°C is selected.

Furthermore, the intake air temperature, which is another one of the overheat mode determination conditions, may be set to the same value or different values in each of the above-mentioned overheat controls 1 to 5. If the same value is used here, for example, a value of 60° C. is selected.

In addition to cooling water temperature and upper air temperature, fuel temperature and lubricating oil temperature may be used as temperature information for overheat mode determination. Furthermore, as a condition for determining overheat mode, cooling water temperature is above a predetermined value and the intake air temperature is above a predetermined value, and in addition to satisfying the AND condition that the temperature is above a predetermined value, the overheat mode is activated when any of the cooling water temperature, intake air temperature, @fuel temperature, and lubricating oil temperature is above a predetermined value. (Furthermore, the overheat mode may be determined by logical determination of the detection results of these multiple temperatures.

In the above-mentioned overheat control 1 to 3, in the case where the overheat countermeasure is performed without determining whether or not the mode is overheat, "I grabbed the door handle" (step 37-1), r Did you open the door from the inside?'' (Step 39-2), ``Did you open the door from the inside?'' (Step 39-2)
Step 41-2.43-2) Next to whether the key is inserted into the door keyring (step 45-1), check the step "Is the battery voltage above a predetermined value?" If YES, First stage processing (steps 37-2.39-3.41-3.4) to prevent subsequent overheating
3-3°45-2) and the subsequent processing, and if NO, the fuel pump may not be driven. This eliminates the difficulty of starting the engine due to buffing.

Of course, in the above-mentioned overheat control 1 to 3,
Regarding overheating control 4 to 7, which determines whether or not it is in overheating mode, it is also possible to add a step such as ``Is the battery voltage above a predetermined value?'' before and after this overheating mode determination. .

(5) Fuel Pump Control This fuel pump control is a control in which the fuel pump relay is turned on for a predetermined period of time and then turned off every time the reference signal (120° signal) from the top dead center sensor 44 is input.

Furthermore, when the battery power supply 66 to the ECU 7G is turned off,
Also turn off the fuel pump relay.

(6) Cooler relay on/off control This cooler relay on/off control is performed using the cooler switch 50.
Although the cooler relay is turned on when the cooler inch 50 is turned on, the cooler relay is kept off in the stop mode during idle speed control, the start mode, the immediately after start mode, etc. even when the cooler inch 50 is turned on.

(7) Self-diagnosis display control This control outputs a required fault hood when a part of this system is determined to be malfunctioning or abnormal according to required judgment conditions, and is configured in the self-diagnosis display section 84. The fault code is displayed by turning off the LED of the external checker circuit.

Note that the malfunctioning hoods are repeatedly displayed in sequence according to a predetermined priority order.

Furthermore, all details of the failure are stored from the time the failure occurs until the battery power source 66 is turned off, including when the key is turned off, and an indicator inside the vehicle is displayed to indicate the failure when the key is turned on.

In FIG. 1(b), reference numeral 11 indicates a canister, and reference numeral 27 indicates a ventilator valve installed in the passage connecting the cylinder head and the intake passage 10.

〔Effect of the invention〕

As described in detail above, according to the engine A/N abnormal drop prevention device during tap of the present invention, the air-fuel mixture supply means that supplies the air-fuel mixture to the combustion chamber of the ennon, and the air-fuel mixture supply means that supplies the air-fuel mixture to the air-fuel mixture supply means. A mixture supply control means for sending a supply control signal, a mixture command means for outputting a command signal of a mixture supply amount to the mixture supply control means, and A for detecting an intake air amount in one stroke of the engine. A/N sensor is provided, and a tap sensor is provided which detects an instantaneous increase in the command signal from the mixture command means, and receives each detection signal from the A/N sensor and the tap sensor to generate a command signal. A simple method is provided in which a mixture increasing control means is provided to increase the supply of mixture by the mixture supply means when it is detected that an instantaneous increase in A/N occurs and the A/N is below a predetermined value. The advantage of this structure is that it is possible to detect tap time at an early stage, and to temporarily increase the amount of air-fuel mixture when tap is detected, thereby reliably preventing the engine speed from slowing down and stalling. There is.

[Brief Explanation of the Drawings] Figures FA1 to FA55 show an automobile engine control system equipped with a device for preventing abnormal A/N drop during tough conditions as an emergency embodiment of the present invention. (a
) is its block diagram, f51 diagram (b) is its overall configuration diagram, @i diagram (c) is a schematic diagram showing a part of its ignition system,
Figure (d) is the main part block diagram, Pt52 diagram is the first part.
70-chart showing the initialization routine of
The figure is a graph for explaining the action during idle speed control, Figure 4 is a 70-chart showing the second initialization routine, and FA5 figures (a) and (b) are both idle speed control pulp arrangement. 6(a) to 6(c) are schematic cross-sectional views showing the vicinity of the installation part 70-, which show the initialization routine of f:A4.
7(a) to 7(c) are a 70-chart showing the third initialization routine, FIG. 8 is a flowchart showing the initialization prohibition routine, and FIG.
Figures 10(a) and 10(b) respectively show the learning control routine.
Figures 70 and tIS12 (a) to (d) respectively show the 7F up control routine when the cooler relay is turned on.
- Char Y and graphs, Figures 13 and 14 (,
) to (d) are flowcharts showing the abnormal rotation speed reduction routine, respectively.
i2 Figures (a) to (h) are flowcharts and graphs showing the abnormal A/N reduction routine and the tap engine stall prevention routine, respectively, and Figures 17 to 19 are 70-70 diagrams for explaining the runaway tq method of the computer. The charts, FIG. 20 and tjt121 respectively show the 7+17-chart and graph showing the idle cut mode, PJ22 is a graph for explaining the operation mode for fuel supply control, and FIG. 23 shows the 02 sensor and computer. Electrical circuit diagram showing the connection between m2
4 and 25 are both 70-charts and 2nd charts for explaining the control mode when the heater current leaks from the Oz sensor.
Fig. C and Fig. 27 are a main part configuration diagram and a 70-chart showing the 7PIi performance of the water temperature sensor, respectively, Fig. 28 is a 70-chart for explaining the processing in the overrun cut mode, and Fig. 29 30(a) is a 70-chart for setting the air-fuel ratio, FIG. 30(a) is a characteristic diagram of the air-fuel ratio vs. engine speed, and FIG. figure(
c) is the air-fuel ratio vs. engine speed characteristic diagram, FIG. 31 is a 70-chart for explaining the processing in other overrun cut modes, and FIG. 32 is for explaining the processing in the maximum speed cut mode. 70-chart, FIG. 33 is a 70-chart for explaining the control accompanying fuel cut during deceleration, FIGS. 34 to 36 are graphs for explaining the misfire detection method, and FIG. 54 are all 7 for explaining the various types of overheating control.
0-chart, FIG. 55 is a schematic configuration diagram showing the arrangement state of the thermo valve provided in the fuel supply path. 2. V type 6 ki? 3 engine, 4... intake manifold,
6...Electromagnetic fuel injection valve (7 fuel injector), 8
... Surge tank, 10. Intake passage, 11. Cannibalance, 12. E-cleaner, 14. Throttle valve, 16. Bypass passage, 18. Idle speed control valve (ISC pulp), 18a... Stepping motor, 18b...valve body, 18c...return spring, 18cl...rod, 20...77 stroke idle air valve (FIA valve), 22...fuel pump, 24...fuel pressure regulator, 26... Control passage, 27...Positive crankcase ventilation valve, 28...Thermo valve, 28a...Wax type temperature sensing part, 28b...Valve body, 28c...Atmospheric side opening, 3
0... Fuel supply path, 32... F70-sensor, 34...
・Intake temperature sensor, 36... Throttle position sensor, 38... Idle switch, 40... Water temperature sensor, 4
1...Wiring, 42...Crank angle sensor, 44...Top dead center sensor (TDC sensor), 46...02 sensor, 46
a...Heater, 46b...02 sensor detection section, 46c...
・Connector, 48.. Inhibitor switch, 50.. Cooler switch, 52.. Cranking switch, 54.
・Ignition switch, 55...Ignition key removable sensor, 56...High temperature switch, 58...Power steering switch (power steering switch), 60...Vehicle speed reed switch, 62...Diagnostic switch, 64...Atmospheric pressure sensor, 66...Battery power supply, 68...Distributor, 70...Exhaust passage, 72...Ignition coil,
74...Catalytic converter, 76...Computer (EC
U), 77...Temperature input section, 78...Ignition timing control section,
80...Fuel pump control unit, 82...Cooler relay, 8
4. Self-diagnosis display section, 86.. LED, 88.. 7 automatic transistor, 89.. Starter constituting cranking means, 90.. Relay switch, 92.. Door sensor as door condition sensor, 94.. Lock state sensor as door state sensor, 9G... seat switch.

Claims (1)

[Claims] A mixture supply means that supplies a mixture to the combustion chamber of the engine, a mixture supply control means that sends a mixture supply control signal to the mixture supply means, and a command signal for the amount of mixture supplied to the mixture supply control means. and an A/N sensor that detects the amount of intake air in one intake stroke of the engine, and a tap sensor that detects an instantaneous increase in the command signal from the mixture command means. The command signal is instantaneously increased in response to each detection signal from the A/N sensor and the tap sensor, and the A/N
The abnormal A/N reduction of the engine at the time of tap is provided, characterized in that a mixture increasing control means is provided for increasing the supply of the mixture by the mixture supplying means when it is detected that the mixture supplying means is below a predetermined value. Prevention device.