JPH09203367A - Ignition timing control device for internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To restrain the rotation increase of an engine rotation frequency, remove the unease sense and incompatibility feeling of a driver, and also to suppress a fine acceleration sense, at the time of returning to fuel cut, in an automatic transmission loaded vehicle. SOLUTION: In an engine 1, torque is transmitted to a driving wheel via a torque converter in an automatic transmission 15. An electronic control unit (ECU) 41 controls an injector 4 for supplying fuel to the engine 1, to stop fuel supply to cutoff fuel in accordance with an operating condition needing no fuel supply to the engine 1. Also, the ECU 41 controls the injector 4 to supply fuel in accordance with an operating condition needing fuel supply cutting off the fuel. The ECU 41 varies the spark-retard damping amount at ignition timing based on the ratio between engine and torque convertor rotation frequencies (speed ratio) in spark-retarding ignition timing at the time of fuel supply after cutting off the fuel.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ignition timing control system for an internal combustion engine, and more particularly, to an automatic transmission which is interposed between an internal combustion engine and driving wheels and which is hydraulically controlled to perform a shifting operation. The present invention relates to an ignition timing control device for an internal combustion engine that eliminates a sense of discomfort given to a driver when a fuel cut retard control is performed after a fuel cut is performed during deceleration or the like in a vehicle.

[0002]

2. Description of the Related Art Conventionally, when an internal combustion engine (engine) mounted on a vehicle is in operation, when the throttle valve is decelerated with the throttle valve fully closed, to prevent heating of a catalyst provided in an exhaust system and to save fuel. The so-called fuel cut, which cuts the fuel supply, is generally performed. When the accelerator is operated again, the throttle valve is opened at an opening corresponding to the accelerator operation, so that the electronic control unit (E
CU) returns the fuel cut.

In a vehicle equipped with a manual transmission, a retard angle (AFC) at the time of ignition timing restoration is performed to prevent drivability when the fuel cut is restored. The amount of increase is increased, and on the advance side, the amount of increase in engine output is decreased and the damping is set gently to smooth the torque connection. This is to prevent a torque shock because the torque sharply rises when the fuel is normally returned when the fuel cut is restored.

On the other hand, in a vehicle equipped with an automatic transmission, unlike a vehicle equipped with a manual transmission at the time of fuel cut recovery, a rapid change in torque is absorbed by the torque converter, and there is no drive shock problem of return shock. It is common not to set the retard angle (AFC) at the time of return.

[0005]

However, in a vehicle equipped with an automatic transmission, there is a case in which a large amount of air is introduced at the time of deceleration to restore the fuel cut and immediately increase the rotation as a measure against engine stalling. At this time, particularly when the vehicle speed is high or during deceleration, when the engine is rotated from the drive wheel side via the torque converter, a significant increase in engine rotation may occur when the fuel cut is restored. .
If this is seen from the driver's side with a tachometer, there is anxiety and discomfort that the torque increases, or a slight acceleration feeling of the vehicle is accompanied.

In order to solve the above-mentioned problems, the ignition timing recovery retardation (AF
C) It is possible to perform control. However, in the above-mentioned ignition timing retardation (AFC) in a vehicle equipped with a manual transmission, the amount of damping is determined by the ignition timing, that is, the damping is almost independent of the increase in engine speed due to the influence of the torque converter. Is set to. Therefore, even if such a control method is adopted in a vehicle equipped with an automatic transmission, it is not possible to effectively suppress an increase in engine rotation.

The present invention has been made in view of the above-mentioned circumstances, and an object thereof is to suppress an increase in engine speed when the fuel cut is restored in an ignition timing control device for an internal combustion engine in a vehicle equipped with an automatic transmission. (EN) It is possible to provide an ignition timing control device for an internal combustion engine that can eliminate the driver's anxiety and discomfort, and can suppress the slight acceleration feeling.

[0008]

In order to achieve the above object, in the invention described in claim 1, an automatic transmission for transmitting torque on the internal combustion engine side to a drive wheel via a torque converter, and to the internal combustion engine Fuel supply means for supplying fuel,
In accordance with an operating state in which the fuel supply to the internal combustion engine is stopped by stopping the fuel supply to the internal combustion engine to control the fuel in accordance with an operating state in which the fuel supply to the internal combustion engine is not necessary, And a fuel supply control means for controlling the fuel supply means to supply the fuel, the fuel supply control means delays the ignition timing when the fuel is supplied after the fuel is cut off. The gist is an ignition timing control device for an internal combustion engine having an automatic transmission, which is equipped with an ignition timing varying means for varying the amount of attenuation based on the ratio of the engine rotational speed and the torque converter rotational speed.

According to a second aspect of the present invention, the ignition timing varying means reduces the retardation attenuation amount when the ratio between the engine speed and the torque converter speed is large, and the ratio between the engine speed and the torque converter speed is reduced. When is small, the ignition timing control device for an internal combustion engine having an automatic transmission according to claim 1 is characterized in that the retarding amount is large.

(Operation) According to the configuration of the invention described in claim 1, the fuel supply control means controls the fuel supply means in accordance with an operating state of the internal combustion engine in which fuel supply is not required, and the internal combustion engine is operated. The fuel supply is stopped to perform fuel cut, and the fuel is supplied by controlling the fuel supply means according to the operating state in which the fuel supply after the fuel cut is required.

When the fuel supply control means supplies the fuel after the fuel cut, the ignition timing varying means delays the ignition timing, and the ignition timing retarding amount is used to determine the retardation attenuation amount of the ignition timing. Variable based on number ratio.

According to the second aspect, the ignition timing varying means is
When the ratio of the engine speed to the torque converter speed is large, the retardation damping amount is made small, so that the increase in the engine speed is suppressed and the torque connection becomes smooth. Further, the ignition timing varying means increases the retardation attenuation amount when the ratio of the engine speed and the torque converter speed is small, that is, when the engine speed increase from the vehicle side is small. As a result,
The engine speed rises quickly without overshooting.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which an ignition timing control device for an internal combustion engine according to the present invention is embodied in a gasoline engine will be described in detail below with reference to FIGS.

FIG. 1 is a schematic configuration diagram showing an ignition timing control device for an engine mounted on a vehicle in this embodiment. As shown in the figure, an engine 1 as an internal combustion engine takes in outside air from an air cleaner 3 through an intake passage 2. At the same time as the intake of the outside air of the engine 1, the engine 1 takes in the fuel injected from the injector 4 as the fuel supply means provided for each cylinder near the intake port 2a. Then, a mixture of the taken-in fuel and the outside air is introduced into the combustion chamber 1a through the intake valve 5 provided for each cylinder, and exploded and burned in the combustion chamber 1a to obtain a driving force. Further, the exhaust gas after the explosion and combustion is led out of the combustion chamber 1a via the exhaust valve 6 to the exhaust passage 7 where the exhaust manifold for each cylinder is gathered, and is discharged to the outside.

A throttle valve 8 which is opened / closed in conjunction with the operation of an accelerator pedal (not shown) is provided in the middle of the intake passage 2. And this throttle valve 8
Is opened and closed, the amount of air taken into the intake passage 2 is adjusted. On the downstream side of the throttle valve 8,
A surge tank 9 for smoothing the pulsation of the intake air is provided.

In the middle of the intake passage 2, the bypass intake passage 1 bypassing the throttle valve 8, that is, connecting the upstream side and the downstream side of the throttle valve 8 with each other.
0 is provided. And this bypass intake passage 1
In the middle of 0, a linear solenoid type idle speed control valve (ISCV) 11 for adjusting the flow rate of air flowing through the passage 10 is provided. This I
In the SCV 11, the solenoid 11a is basically duty-controlled when the throttle valve 8 is closed and the engine 1 is in the idle state. The duty ratio is controlled to open and close (drive) the ISCV 11 as appropriate. By this opening and closing, the air flow rate (intake air amount) of the bypass intake passage 10 is adjusted. Then, the engine speed NE as the engine speed during idling is controlled by adjusting the intake air amount.

An intake air temperature sensor 21 for detecting the intake air temperature THA is provided near the air cleaner 3 in the intake passage 2. In the vicinity of the throttle valve 8,
A throttle sensor 22 for detecting the opening degree (throttle opening degree) θ is provided, and an idle switch 23 for turning on when the throttle valve 8 is fully closed to detect an idle state is provided. Further, the surge tank 9 is provided with an intake pressure sensor 24 that communicates with the tank 9 and detects an intake air pressure (intake pressure) PiM.

On the other hand, the engine 1 is provided with a water temperature sensor 26 for detecting the temperature of the cooling water (cooling water temperature) THW. An ignition signal distributed by a distributor 13 is applied to an ignition plug 12 provided for each cylinder of the engine 1. The distributor 13 is for distributing the high voltage output from the igniter 14 to each spark plug 12 in synchronization with the crank angle of the engine 1.

The distributor 13 is provided with a rotation speed sensor 27 for detecting the rotation speed (engine speed) NE of the engine 1 from the rotation of a rotor (not shown) built in the distributor 13. The distributor 13 is also provided with a cylinder discrimination sensor 28 that detects the first cylinder of the engine 1 according to the rotation of the rotor.

At the same time, the automatic transmission 15 drivingly connected to the engine 1 has a torque converter and a forward low 2
and a speed change gear mechanism having a first reverse speed, and the rotational torque of the engine 1 is transmitted to a drive wheel (not shown) through the torque converter and the speed change gear mechanism. To do. The automatic transmission 15 has
A vehicle speed sensor 29 is provided. This vehicle speed sensor 29
Can detect the speed (vehicle speed) SPD of the vehicle at that time and output a signal indicating the value.

In addition, a shift position sensor 30 is provided inside the shift gear mechanism of the automatic transmission 15. The shift position sensor 30 detects whether the current shift position is the 4th speed of Low, 2nd, 3rd, 4th, or the 1st reverse speed. Further, the automatic transmission 15 is provided with an output shaft rotation speed sensor 31 for detecting the output shaft rotation speed of the automatic transmission 15.

The sensors 21, 22, 24,
The operating states of the engine 1 are properly detected by the 26 to 31 and the idle switch 23, and these constitute an operating state detecting means.

Further, each injector 4, the solenoid 11a for the ISCV 11, the igniter 14 and the intake control valve 1
The actuator 17 of No. 6 is electrically connected to an electronic control unit (hereinafter, simply referred to as “ECU”) 41,
The drive timing of them is controlled by the operation of U41. The ECU 41 constitutes fuel supply control means and ignition timing varying means. Next, the ECU 41
The configuration will be described with reference to the block diagram of FIG. E
The CU 41 includes a central processing unit (CPU) 42, a read-only memory (R
OM) 43, a random access memory (RAM) 44 for temporarily storing calculation results of the CPU 42, a backup RAM 45 for storing prestored data, and the like. In addition, the ECU 41 includes the external input circuit 4 and these units.
6, the external output circuit 47 and the like are connected by a bus 48 as a logical operation circuit.

The external input circuit 46 includes the intake air temperature sensor 21, the throttle sensor 22, and the idle switch 2 described above.
3, an intake pressure sensor 24, a water temperature sensor 26, a rotation speed sensor 27, a cylinder discrimination sensor 28, a vehicle speed sensor 29, a shift position sensor 30, an output shaft rotation speed sensor 31, and the like are connected to each other. Then, the CPU 42 causes each sensor 21, 22, 24, 26 to 3 through the external input circuit 46.
1 and the output signal from the idle switch 23 is read as an input value. Then, the CPU 42, based on these input values, the injector 4 connected to the external output circuit 47,
The solenoid 11a, the igniter 14, etc. are suitably controlled. The learning values and flags in this embodiment are stored in the backup RAM 45 described above.

Next, of the various processes executed by the ECU 41, the main routine of the retard control at return will be described. FIG. 3 shows that after the engine 1 is started, E
It is a flow chart which shows only the processing performed about the retard angle at the time of fuel cut return in the "main routine" performed by CU41. The main routine is
It is executed by a regular interruption every predetermined time.

When this main routine process is performed, the ECU 41 first causes the sensors 21 to 24, 26 to operate.
31 to 31 (for example, intake air temperature THA, throttle opening θ, intake air pressure PiM, cooling water temperature THW, engine speed NE, vehicle speed SPD, shift position, output shaft speed, etc.) are read.

In this main routine, steps (hereinafter,
Steps are called S) 100, S110, S120
This is a process for determining whether or not the retard control prohibition condition is satisfied. In S100, the engine speed NE
(NE may be represented by NEn for convenience of description) is 75
It is determined whether it is less than 0 rpm. If the engine speed NE is less than 750 rpm, the process proceeds to S200. S2
00 is the upper limit value, which is the fuel cut delay angle control amount AF
Clear C to 0. In this embodiment, the fuel cut control amount AFC is represented by hexadecimal "FEFF".
The upper two digits of the fuel cut control amount AFC are the upper byte (the digit represented by the upper "FE" in the above example) and the lower two digits are the lower byte (the upper digit represented by the "FF" in the above example). ) Sometimes expressed. When the process of S200 ends, the process proceeds to S190 described below.

Further, in S100, if the engine speed NE is 750 rpm or more. The determination in S100 is "NO", and the process proceeds to S110. In S110, the difference ΔNE (= NEn-1) between the engine speed NEn-1 during the previous control and the engine speed NEn during the current control.
It is determined whether or not NEn) exceeds the rotational speed drop determination value (50 rpm in this embodiment). If ΔNE is larger than the rotation speed drop determination value, it is determined that the "rotation drop" of the engine rotation speed is large, the determination in S110 is "YES", and the process proceeds to S200.

If ΔNE is equal to or less than the rotation drop determination value, it is determined that the "rotation drop" of the engine speed NE is small, and the determination at this step is "NO", and the process proceeds to S120.
In S120, XIDL (idle flag) is 1
It is determined whether or not (ON). If the signal from the idle switch 23 is turned off, the XIDL outputs the ECU 41
As a result, it is reset to "0" during the main routine processing, and is set to "1" if it is ON. S120
In, if XIDL is reset to "0",
If it is not in the idle state, that is, it is in the acceleration state, it is determined to be "YES", and the process proceeds to S200. Also, XID
If L is 1, it is determined to be in the idle state and "NO" is determined, and the process proceeds to S130.

As described above, if the engine speed NE exceeds a predetermined low engine speed in S100, or if the "revolution of rotation" is larger than the determination value in S110, or in S120. If it is determined that the non-idle state is set instead of the idle state, the retard control is prohibited.

Therefore, if it is determined "NO" in all of S100 to S120, it is determined that the retard control prohibition condition is not satisfied, and the process proceeds to S130. The steps of S100 to S120 constitute a retard angle control prohibition condition determination means. Further, S100 constitutes an engine speed condition determining means, S110 constitutes a rotation drop condition determining means, and S120 constitutes an idle state condition determining means.

In S130, it is determined whether or not the signal from the shift position sensor 30 detects the 3rd position. In S130, the automatic transmission 15 is 3r
If it is not the shift position of d, it is determined to be "NO" and S19.
Move to 0. In S130, the automatic transmission 15 is set to 3
If it is the shift position of rd, it is determined to be "YES" and S1
In S140 of shifting to 40, it is determined based on the history flag XFCIDO stored in the history flag register whether or not the fuel cut was performed in the previous control. The method of setting the history flag XFCIDO will be described later. Note that, when the fuel cut is decelerating with the throttle valve fully closed when the engine 1 mounted on the vehicle is operating, it is determined that the fuel cut operating condition is satisfied, and the ECU 41 supplies the fuel to each cylinder. Is to cut.

Since the fuel cut was not performed last time, if the history flag XFCIDO is set to 0, it is determined to be "NO", and the process proceeds to S190. or,
If the fuel cut control was previously performed and the history flag XFCIDO is set to 1, the ECU
41 determines “YES” and moves to S150. S1
At 50, it is determined whether or not the fuel cut control is being performed in this control, based on the fuel cut execution flag XFCIDL stored in the execution flag register.

The fuel cut execution flag XFC
In other steps of this main routine, the IDL is "1" when the idle switch 23 is on, that is, the throttle valve 8 is fully closed and the engine speed NE is equal to or higher than a predetermined high speed speed. Is set to 0, otherwise it is set to "0". Therefore, when the execution flag XFCIDL is set to "1", although not described in detail here, when the interrupt processing of the fuel cut control routine is performed based on the fuel cut execution flag, the deceleration fuel is The cut is done.

Returning to the main routine, when the fuel cut execution flag XFCID is "0", it is determined that the fuel cut control is not performed this time, and "YES" is determined, and the process proceeds to S160. When the fuel cut execution flag XFCIDL is "1", it is determined that the fuel cut control is being performed this time, and "NO" is determined, and S190
Move to Next, in S160, it is determined whether or not the natural return flag XFCR is set to "1".

The natural return flag XFCR will be described. In the main routine, the case where the fuel cut control is turned off is monitored. That is, whether the idle switch 23 is turned off (the throttle valve 8 is opened) and the fuel cut control is turned off, that is, whether the fuel cut control is forcibly restored, or the XFCIDL is "1" while the engine speed NE is kept. When the fuel cut control is turned off, that is, whether the fuel cut control is turned off, that is, whether the fuel cut control is performed naturally, is monitored in the process of the main routine to determine whether the fuel cut control is performed naturally or forcibly. If it is a natural return, the natural return flag XFCR is set to "1" in the process of the main routine. Further, in the case of forced recovery, the natural recovery flag XFCR is set to "0".

At S160, the natural return flag XFC
When R is "1", it is determined to be "YES" and the process proceeds to S170, and when the natural return flag XFCR is "0", "N" is set.
It is determined to be "O", and the process proceeds to S190.

The steps S140 to S160 constitute a natural return judging means. In S170, the vehicle speed SPD
Is a predetermined low speed (several km / h in this embodiment) or more, or the water temperature THW is a predetermined temperature (in this embodiment, 50
℃) or more other conditions are both satisfied, it is judged whether or not. That is, the conditions of S170 and S130 are preconditions for setting an initial value, which will be described later, and when the operating condition satisfies these conditions,
The initial value is set only when the conditions of S140 to S160 that constitute the natural recovery determination means are satisfied.

The above S130 and S170 constitute a precondition satisfaction judging means. In S170, if the vehicle speed SPD and the water temperature THW are equal to or higher than the predetermined low speed and the predetermined temperature, it is determined to be "YES", and the process proceeds to S180.
If the above conditions are not satisfied, the ECU 41 determines "N
It is determined to be "O", and the process proceeds to S190.

At S180, the fuel cut retard control amount AFC is set to "000" as an upper limit initial value.
0 ”(specifically in this embodiment, −5 ° CA)
It is set in a predetermined memory area of the AM 44, and the process proceeds to S190. The above "0000" represents the fuel cut retard control amount AFC in hexadecimal notation. Said S
180, or when S200 shifts to S190, S1
At 90, the execution flag XFCIDL is stored in the history flag register as the history flag XFCIDO.

As described above, the ECU 41 performs other processing after the processing that is performed for the fuel cut return retard angle, and ends the main routine. Next, the attenuation processing routine will be described. FIG. 4 shows a damping processing routine, which is executed every 180 ° CA, that is, every ignition.
This routine is a routine for performing processing for dividing the retardation attenuation amount according to the speed ratio REVR of the automatic transmission 15.

The speed ratio REVR is "the automatic transmission 15
Output shaft speed * gear ratio / NE ”.
In this embodiment, the output shaft rotation speed of the automatic transmission 15 * gear ratio is the torque converter rotation speed.

Now, when entering this routine, in S300, it is necessary to determine whether or not the fuel cut retard control amount AFC stored in the predetermined memory area of the RAM 42 is "FEFF", that is, the retard control. To determine. If "FEFF" is set, it means that the retard control is prohibited, and the process proceeds to S390. "F
If "EFF" is not set, the process proceeds to S310, and the difference ΔNE (= NEn-1 -NEn) between the engine speed of the previous control cycle and the engine speed of this time is-.
It is determined whether it is less than 15 rpm.

Here, if .DELTA.NE is smaller than -15 rpm (that is, the rotation increase is 15 rpm or more), it is determined to be "YES", and this processing routine is exited. In this case, the fuel cut retard control amount AFC is held as it is, and this processing routine is exited. That is, if the fuel cut retard control amount AFC is attenuated here, the ignition timing is advanced and the engine speed NE is further increased, which is avoided. On the contrary, if ΔNE is −15 rpm or more, the ECU 41 determines whether the engine speed NE has not increased, or even if the engine speed NE has increased, −1
Since it is less than 5 rpm, which is small, it is determined to be "NO" and S320.
Move to The step S310 constitutes engine speed increase determination means for determining whether or not the engine speed is higher than the previous control cycle by a predetermined amount or more.

Next, in S320, the CPU 42 stores 2.00 ° CA in the lower byte accumulator B, and proceeds to S330. In S330, the speed ratio REVR is calculated based on the output shaft speed of the automatic transmission 15, the gear ratio and the engine speed NE during the control, and it is determined whether the speed ratio REVR is less than 1.00.
The gear ratio is a unique value uniquely determined according to the shift position of the automatic transmission 15, and a value corresponding to the shift position determined based on the detection signal from the shift position sensor 30 is called from the ROM 43. And is used to calculate this speed ratio REVR.

If the speed ratio REVR is less than 1.00,
Assuming that the vehicle is in the accelerated state, the process proceeds to S370 described later.
If the speed ratio REVR is 1.00 or more, it is determined that the vehicle is in the deceleration state, and the process proceeds to S340. In S340,
Store 0.35 ° CA in the lower byte accumulator B and move to S350. In S350, it is determined whether the speed ratio REVR is less than 1.15. Speed ratio R
If the EVR is less than 1.15, it is determined that the deceleration is small and "YES" is determined, and the process proceeds to S370. If the speed ratio REVR is 1.15 or more, it is determined that the deceleration is large and the determination is “NO”, and the process proceeds to S360. In S360, the lower byte accumulator B receives 0.12 ° C.
Store A and move to S370.

In S370, the fuel cut retard control amount A stored in the predetermined memory area of the RAM 44.
The value of the lower byte accumulator B is added to the value of FC, and the addition result is the accumulator D of the CPU 42.
Store in Therefore, when it is determined to be “YES” in S330 and the process proceeds to S370, 2.00 ° CA is added as the value of the lower byte accumulator B. or,
When it is determined to be “YES” in S350 and the process proceeds to S370, the value of the lower byte accumulator B is 0.
35 ° CA is added. Further, when the process is shifted from S360, 0.12 ° CA which is the value of the lower byte accumulator B is added. Therefore, when this control routine is executed for each ignition and S370 is processed, the advance value for which the damping process has been gradually performed is obtained.

Next, at S380, the fuel cut retard control amount AFC stored in the accumulator D is stored.
Value of the upper byte accumulator A that stores the upper byte is less than “FE”. When the value of the high-order byte accumulator A is less than "FE", it is determined that the attenuation is not complete and "YES" is determined, and the process proceeds to S400. Further, when the value of the high-order byte accumulator A is equal to or larger than "FE", it is considered that the delay angle at the time of returning to the fuel cut is completely attenuated and "N
It is determined to be “O”, and the process proceeds to S390. That is, the S
At 370, the value of the low-order byte accumulator B is added, and as a result, the low-order byte overflows and the high-order byte is incremented. As a result, the upper limit is exceeded, and the process proceeds to S390.

Then, when the process shifts from S300 or S380 to S390, in S390, R
The upper limit value "FE" stored in the predetermined memory area of AM44
FF ”is stored in the accumulator D of the CPU 42, and S
Move to 400. In S400, the value stored in the accumulator D is stored in the predetermined memory area of the RAM 44 as the fuel cut retard control amount AFC, and this processing routine is once ended.

In the attenuation processing routine, S33
0 and S350 are respectively a first speed ratio determining means and a second speed ratio determining means for separating the ignition timing retarding amount.

Then, the ECU 41 executes the engine speed NE in a routine (not shown) executed every predetermined time.
And the basic ignition advance θB (basic injection timing) based on the intake pressure Pi M, and the fuel cut retard control amount AFC described above is added to this basic ignition advance θB, and the added value (final ignition timing). ), The ECU 41
Outputs an ignition signal to the ignition plug 12 to perform ignition. (A) In the embodiment configured as described above, the fuel cut return control is performed when the shift position is 3rd. Therefore, when the automatic transmission 15 is decelerated in the 3rd speed change state, it is possible to prevent the engine speed from increasing. (B) FIG. 5 is a characteristic diagram showing the engine reverse drive performance when the automatic transmission 15 is in the shift position of the 3rd position when the throttle opening is fully closed, and the horizontal axis represents NO (= automatic shift). The output shaft speed of the machine 15 * gear ratio (torque converter speed), and the vertical axis is the engine speed NE. Further, FIG. 6 shows an example of the conventional fuel cut return control in the traveling state in which the shift position is the 3rd position, and shows the fuel cut execution flag XFCID.
L, ΔNE, speed ratio REVR, vehicle speed, engine speed N
The timing chart of E and the throttle opening is shown. Further, FIG. 7 shows the execution flags XFCIDL, ΔNE, during the fuel cut return control in the present embodiment in the traveling state in which the shift position is the 3rd position.
The timing chart of speed ratio REVR, vehicle speed, engine speed NE, ignition timing, and throttle opening is shown.

In the conventional example of FIG. 6, the throttle opening is fully closed (0 °) and the fuel cut execution flag XFCI is set.
When DL changes from "1" to "0", the vehicle speed is decreasing, but the engine speed NE rapidly rises as indicated by X in FIG. This is because even if the vehicle speed is decelerated when the throttle opening is fully closed as shown in FIG. 5, the reverse driving force acts on the engine 1 from the driving wheel side, so the engine speed NE increases. is there.

On the other hand, in the present embodiment, by executing the damping processing routine, the throttle opening is fully closed (0 °) as shown by Y in FIG. 7, and the fuel cut execution flag is set. XFCIDL is "1" to "0"
When, the vehicle speed decreases. At this time, when ΔNE falls below −15 rpm as shown in FIG. 7, in the damping processing routine, the damping processing routine is exited from S310, so the fuel cut control amount AFC is held. Then, after that, the value of the lower byte of the fuel cut retard control amount according to the speed ratio REVR is selected and added, so that the ignition timing is gradually advanced. As a result,
The increase in engine speed can be suppressed. (C) In the present embodiment, the ECU 41 controls the speed ratio RE.
When VR is 1.15 or higher, lower byte value is 0.1
Since the retardation attenuation amount is small at 2 ° CA, it is possible to suppress an increase in the engine speed NE and smooth the torque connection. Also, the ECU 41
When the speed ratio REVR is less than 1, the value of the lower byte is set to 2.00 ° CA and the retardation attenuation amount is made large. Therefore, the engine speed NE rapidly increases without overshooting.

The present invention is not limited to the above embodiment, but may be configured as follows, for example. (1) In the above-described embodiment, the automatic transmission 15 is embodied in four forward gears. However, it is embodied in three forward gears and S110 of the main routine is used as a criterion for a shift position of 3rd. Alternatively, in S110 of the main routine, 4th may be used as the determination reference instead of the shift position of 3rd.

(2) In the above embodiment, the gasoline DJ engine is used as the engine, but a vehicle equipped with the gasoline LJ engine may be used.

(3) In the above embodiment, the speed ratio is 1.
Fuel cut control amount A with two values of 00 and 1.15
Although the attenuation amount to be added to FC is selected and decided, the speed ratio for cutting is further increased, or conversely, only the speed ratio of 1.00 or 1.15 is used to control the fuel cut control amount A.
You may decide the attenuation amount added to FC.

The technical ideas which are not described in the claims and can be grasped from the above embodiment will be described below together with their effects. (A) The ignition timing control device for an internal combustion engine according to claim 2, wherein the ignition timing varying means includes a plurality of speed ratio determining means, and the retarding attenuation amount is selected by each of the determining means. With this configuration, since the retardation attenuation amount can be selected according to the speed ratio, it is possible to further suppress an increase in engine speed or improve acceleration performance.

[0058]

As described above in detail, according to the invention of claim 1, it is possible to suppress an increase in the engine speed when the fuel cut is restored, remove the driver's anxiety and discomfort, and perform a slight acceleration. It has an excellent effect of suppressing the feeling.

According to the second aspect of the present invention, when the ratio between the engine speed and the torque converter speed is large, that is, when the amount by which the engine speed can be increased from the vehicle side is large, the retardation attenuation amount is set to a large value. Since it is small, the increase in engine speed can be suppressed, and the torque connection becomes smooth. Further, when the ratio of the engine speed and the torque converter speed is small, that is, when the increase in the engine speed from the vehicle side is small, the retardation damping amount is set to a large value, so that the engine speed quickly Moreover, the vehicle can be restored without overshooting, and the driving feeling can be improved.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing an ignition timing control device for an engine according to an embodiment of the present invention.

FIG. 2 is a block diagram showing an electrical configuration of the ECU.

FIG. 3 is a flowchart showing a main routine.

FIG. 4 is a flowchart showing a damping processing control routine.

FIG. 5 is a characteristic diagram showing reverse drive performance of the engine.

FIG. 6 shows a conventional fuel cut return control,
Execution flag XFCIDL, ΔNE, speed ratio REVR, vehicle speed, engine speed NE, throttle opening timing chart.

FIG. 7 shows execution flags XFCIDL, ΔNE, and speed ratio RE during fuel cut recovery control according to the present embodiment.
A timing chart of VR, vehicle speed, engine speed NE, ignition timing, and throttle opening.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Engine as an internal combustion engine, 2 ... Intake passage, 4 ... Injector constituting fuel supply means, 8 ... Throttle valve, 15 ... Automatic transmission, 22 ... Throttle sensor constituting operation state detecting means, 23 ... Operating state Idle switch constituting detecting means, 24 ... Intake pressure sensor constituting operating state detecting means, 27 ... Rotation speed sensor constituting operating state detecting means, 28 ... Cylinder discrimination sensor constituting operating state detecting means, 29 ... Driving A vehicle speed sensor that constitutes state detection means, 30 ... a shift position sensor that constitutes operating state detection means, 41 ... a fuel supply control means, and an ECU that constitutes ignition timing varying means.

Claims (2)

[Claims] 1. An automatic transmission for transmitting torque on the internal combustion engine side to a drive wheel via a torque converter, fuel supply means for supplying fuel to the internal combustion engine, and an operating state in which fuel supply to the internal combustion engine is not required. Accordingly, the fuel supply means is controlled to stop the fuel supply to the internal combustion engine to perform the fuel cut, and the fuel supply means is controlled to supply the fuel according to the operating state in which the fuel supply after the fuel cut is required. In a vehicle equipped with a fuel supply control means for performing, when the fuel supply control means delays the ignition timing at the time of fuel supply after fuel cut, the retarded amount of ignition timing is set to the engine speed and the torque converter speed. An ignition timing control device for an internal combustion engine having an automatic transmission, characterized by comprising ignition timing varying means for varying based on a ratio. 2. The ignition timing varying means reduces the retardation attenuation amount when the ratio between the engine speed and the torque converter speed is large, and when the ratio between the engine speed and the torque converter speed is small, The ignition timing control device for an internal combustion engine having an automatic transmission according to claim 1, wherein the retardation attenuation amount is large.