JP2000170586A - Control device for engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress the blow-up of an engine speed due to the closing action delay of an ISC valve at the time of shift operation in operation. SOLUTION: Whether shift operation is made or not is judged at the time of lean burn operation (S5-S7), and when the existing of the operation is judged, a timer processing value is calculated (8), to spark-delayably correct ignition timing by the time of a calculated timer processing value (S9 and S10). The blow-up of an engine speed due to the closing action delay of an ISC valve can be the suppressed by spark-delayably correcting the ignition timing at the time of shift operation.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an engine control apparatus for preventing a blow-up due to a delay in closing operation of an idle speed control valve by delaying the ignition timing when performing a shift operation of a manual transmission. About.

[0002]

2. Description of the Related Art Generally, idle speed control (ISC)
The valve adjusts the amount of air supplied to the engine independently of the throttle valve by electronically controlling the valve opening, and performs idle-up control during warm-up operation, rotation speed control during idle operation, etc. Do.

In recent lean burn engines, ISC is used to prevent torque fluctuation due to a drop in air-fuel ratio when switching from operation based on the stoichiometric air-fuel ratio (stoichiometric operation) to operation based on the lean air-fuel ratio (lean burn operation).
A technique has been used in which the valve opening is greatly increased in accordance with the throttle opening to increase the torque.

For example, Japanese Patent Application Laid-Open No. 7-189771 discloses that when the operating state is switched from stoichiometric operation to lean burn operation, a target intake air amount for lean burn operation is set based on the throttle opening and the engine speed. ,
Depending on the deviation between the target intake air amount and the actual intake air amount,
There is disclosed a technique in which an opening degree of an ISC valve is adjusted so that an actual intake air amount converges to a target intake air amount.

[0005]

The actuator of the ISC valve is disclosed in, for example, Japanese Patent Application Laid-Open No. 10-10310.
In the case where a command that causes an operation delay in response to a command from the electronic control device such as a step motor disclosed in Japanese Patent Publication No. 9 is adopted, the electronic control device closes the ISC valve when the driver shifts. Even if the operation command is output, it cannot respond immediately, and the amount of air supplied to the engine does not decrease. Therefore, there is a disadvantage that the engine speed is increased.

In particular, in the lean burn engine, the ISC valve at the time of the lean burn operation is provided with a torque increasing function,
Since the opening of the ISC valve is controlled in accordance with the throttle operation, the engine speed is significantly increased due to the delay of the closing operation of the ISC valve.

The present invention has been made in consideration of the above circumstances, and has as its object to provide an engine control device capable of suppressing an increase in engine speed due to a delay in closing an ISC valve when a driver performs a shift operation. And

[0008]

In order to achieve the above object, a first engine control device according to the present invention is to control an opening degree of an idle speed control valve interposed in an air bypass passage bypassing a throttle valve in an operating state. And a shift operation determining means for determining the presence or absence of a shift operation of the manual transmission, and an ignition timing correcting means for correcting the ignition timing when the shift operation is determined to be performed.

A second engine control device according to the present invention is the first engine control device, wherein the engine control device includes a stoichiometric operation using a stoichiometric air-fuel ratio and a lean air-fuel ratio leaner than the stoichiometric air-fuel ratio. A lean burn operation based on an air-fuel ratio is performed, and during the lean burn operation, the opening of the idle speed control valve is controlled in accordance with the operating state, and the ignition timing is corrected by the ignition timing correction means. .

In a third engine control device according to the present invention, in the first or second engine control device, the ignition timing correction means ends the ignition timing correction when a set time or a set number of ignitions has elapsed. It is characterized by.

A fourth engine control device according to the present invention is characterized in that, in the third engine control device, the set time or the set number of ignitions is set for each operation region.

That is, in the first engine control device, when it is determined that the shift operation of the manual transmission is performed, the ignition timing is corrected so that the engine speed increases due to a delay in the closing operation of the idle speed control valve. To prevent.

In the second engine control device, the first engine control device corrects the ignition timing at the time of the shift operation during the lean burn operation to thereby reduce the engine speed due to the delay in the closing operation of the idle speed control valve. Prevent the number from rising.

In the third engine control device, in the first or second engine control device, the correction of the ignition timing is terminated when the set time or the set number of ignitions has elapsed, so that the correction is prolonged more than necessary. Avoid being done.

[0015] In the third engine control device, in the second engine control device, the set time or the set number of ignitions is set for each operation region, so that the correction period is optimized and the engine speed is reduced. Prevent instability.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. First, the overall configuration of the engine will be described with reference to FIG.

In FIG. 1, reference numeral 1 denotes an engine, and a manual transmission (not shown) is connected to the crankshaft 34. The engine 1 is a lean-burn engine. When the operating state is in a low-load / medium-load region, the engine 1 operates with a lean air-fuel ratio (lean-burn operation).
When the engine is in the idling and high load range, an operation based on the stoichiometric air-fuel ratio (stoichiometric operation) is performed. During high-load operation, a rich air-fuel ratio may be obtained due to an increase in fuel due to an increase in acceleration during acceleration or the like, and operation is not necessarily performed at a stoichiometric air-fuel ratio. The operation (rich operation) will be described as being included in the stoichiometric operation.

Cylinder heads 2 are provided in both left and right banks of a cylinder block 1a of the engine 1, respectively.
Each cylinder head 2 has an intake port 2a and an exhaust port 2b.
Are formed.

The intake system of the engine 1 includes an intake port 2a
An intake manifold 3 is communicated with the intake manifold 3, and a throttle chamber 5 is communicated with the intake manifold 3 via an air chamber 4 in which intake passages of the respective cylinders are gathered. Further, an air cleaner 7 is provided upstream of the throttle chamber 5 via an intake pipe 6. Is attached, and the air cleaner 7 is attached to the air intake chamber 8.
Is communicated to.

The throttle chamber 5 is provided with a throttle valve 5a linked to an accelerator pedal.
The intake pipe 6 and the throttle chamber 5 are
The idle rotation speed is controlled by adjusting the amount of bypass air flowing through the air bypass passage 9 according to the valve opening during idle operation. An idle speed control (ISC) valve 10 is interposed.

The ISC valve 10 opens and closes when the throttle valve 5a is closed, and controls the idle speed by adjusting the intake air amount. In addition to the normal idle speed control function, the ISC valve 10 operates during lean burn operation. By performing opening and closing operations according to the engine load and the like, there is no sense of stall due to insufficient torque, and a so-called torque-up function is provided, and the opening thereof is controlled by the step motor 10a.

An injector 12 is provided immediately upstream of the intake port 2a of each cylinder of the intake manifold 3.

On the other hand, an ignition plug 21 whose tip is exposed to the combustion chamber 20 is attached to each cylinder of the cylinder head 2, and an igniter 23 is connected to the ignition plug 21 via an ignition coil 22 provided for each cylinder. Is connected.

The exhaust system of the engine 1 has an exhaust manifold 24 communicating with each exhaust port 2b of the cylinder head 2.
The exhaust pipe 25 is communicated with the collecting portion of the
6 is interposed and communicates with the muffler 27.

Next, sensors for detecting the operating state of the engine will be described. Air cleaner 7 for intake pipe 6
An intake air amount sensor 28 for detecting an amount of intake air passing through the intake pipe 6 is interposed immediately downstream of the throttle valve 5. Further, a throttle valve 5a provided in the throttle chamber 5 is provided with a throttle opening sensor 29a and a throttle valve 5a. O when fully closed
A throttle sensor 29 having a built-in idle switch 29b for N is continuously provided.

A knock sensor 30 is attached to the cylinder block 1a of the engine 1, and a cooling water passage 31 communicating the left and right banks of the cylinder block 1a.
A cooling water temperature sensor 32 is provided. Further, an O2 sensor 33 is disposed upstream of the catalyst 26 of the exhaust manifold 24.

A crank angle sensor 36 is mounted on the outer periphery of a crank rotor 35 which is mounted on a crank shaft 34 of the engine 1.
Further, a cam angle sensor 39 for cylinder discrimination is provided opposite to a cam rotor 38 connected to a camshaft 37 that makes a half rotation with respect to the crankshaft 34.

The computation of control amounts for actuators such as the injector 12, the spark plug 21, and the ISC valve 10, and the output of control signals, ie, engine control such as fuel injection control, ignition timing control, and idle speed control, are shown in FIG. Is performed by an electronic control unit (ECU) 40 shown in FIG.

The ECU 40 includes a CPU 41, a ROM 42,
A RAM 43, a backup RAM 44, a counter / timer group 45, and an I / O interface 46 are mainly configured by a microcomputer connected to each other via a bus line, and a constant voltage circuit 47 for supplying a stabilized power to each unit. A peripheral circuit such as a drive circuit 48 and an A / D converter 49 connected to the O interface 46 is built in.

The counter / timer group 45 includes various counters such as a free-run counter, a counter for counting the input of a cam angle sensor signal (cam pulse), a fuel injection timer, an ignition timer, and a periodic timer for generating a periodic interrupt. Various timers such as an interrupt timer, a timer for measuring an input interval of a crank angle sensor signal (crank pulse), and a watchdog timer for monitoring a system abnormality are collectively referred to for convenience.
A timer may be used.

The constant voltage circuit 47 is connected to the battery 51 via a first relay contact of a power relay 50 having two relay contacts.
Are connected via an ignition switch 52. Further, the constant voltage circuit 47 is directly connected to the battery 51, and the ignition switch 52
Is turned on and the contacts of the power supply relay 50 are closed, the ECU
While power is supplied to each section in the power supply 40, a backup power supply is always supplied to the backup RAM 44 regardless of whether the ignition switch 52 is ON or OFF.

The input ports of the I / O interface 46 include a vehicle speed sensor 56, an idle switch 29b, a knock sensor 30, a crank angle sensor 36, and a cam angle sensor 3.
9. A neutral switch 57 which is turned on when the clutch is depressed or when the shift lever is moved to the neutral position is connected, and further, via the A / D converter 49, the intake air amount sensor 28, the throttle opening sensor 29
a, the cooling water temperature sensor 32 and the O2 sensor 33 are connected, and the battery voltage VB is inputted and monitored.

On the other hand, to the output port of the I / O interface 46, a step motor 10a for operating the ISC valve 10 and the injector 12 are connected via a drive circuit 48, and the igniter 23 is connected.

The CPU 41 processes the detection signals from the sensors and switches, which are input via the I / O interface 46, the battery voltage, and the like, according to the control program stored in the ROM 42. Based on the data, various learning value data stored in the backup RAM 44, fixed data stored in the ROM 42, and the like, the fuel injection amount, ignition timing, I
Step motor 10 for controlling the opening of SC valve 10
The number of steps a and the like are calculated, and engine control such as suitable fuel injection control, ignition timing control, and idle speed control is performed for each operation region.

In such an engine control system, EC
In U40, based on the engine operating state detected by each sensor or the like, it is determined whether the engine operating state is a lean region such as a low or medium load operation or a stoichiometric region such as an idle or a high load operation. In order to improve the fuel consumption and the exhaust emission, the fuel injection amount is reduced and corrected to perform the lean burn operation with the lean air-fuel ratio.
When the engine operating state is in the stoichiometric range, the stoichiometric operation based on the stoichiometric air-fuel ratio is performed in order to secure the engine output.

Here, during the combustion in the stoichiometric region, the ignition is performed when the air-fuel mixture flowing into the combustion chamber 20 is diffused into a homogeneously mixed state. On the other hand, during the combustion in the lean region, it is necessary to ignite the air-fuel mixture that has flowed into the combustion chamber 20 at an early stage before the mixture is diffused. Whether the operating state is in the lean burn operation area or the stoichiometric operation area is determined by a map search or the like based on, for example, the engine load and the engine speed. In general,
The lean burn operation is set when the operation state is in the low and medium load operation range, and the stoichiometric operation is set when the operation state is in the idle and high load operation range.

When the operating state is the lean burn operation, the opening degree of the ISC valve 10 is controlled in accordance with the engine load and the engine speed to avoid a sense of stall due to insufficient torque and to close during a shift operation. An ISC valve opening degree control is performed to prevent the engine speed from rising when operated.

The control of the ISC valve opening during the lean burn operation by the ECU 40 is specifically performed by the routine for controlling the ISC valve opening during the lean burn operation shown in FIG.
In this routine, first, in step S1, each sensor,
The output value of the switch is read, and in step S2, it is determined based on the output values of the sensor and the switch whether or not the lean burn operation is being performed based on the lean burn execution condition. The lean burn conditions are, for example, as follows. (1) The elapsed time after starting the engine is the set time (for example,
20 to 40 seconds), (2) the operating state is in the lean burn operation range of low load to medium load operation, (3) warm-up is completed, or (4) vehicle speed is high (for example, 120 km / h). Below)

When all of the conditions (1) to (4) are satisfied, it is determined that the lean burn condition is satisfied, and it is determined that the lean burn condition is not satisfied if any one of the conditions is not satisfied.

If it is determined in step S2 that the condition for performing the lean burn is not satisfied, the routine exits from the routine. If it is determined that the condition for performing the lean burn is satisfied, the process proceeds to step S3.

In step S3, in order to increase the amount of intake air during lean burn operation to increase torque,
The drive amount of the C valve 10 (step motor 10a) is calculated. The drive amount of the ISC valve 10 (step motor 10a) is set to be smaller as the rotation speed and the load become lower, and to gradually increase as the rotation speed and the load become higher. Therefore, when the driver releases the accelerator pedal to perform a shift operation and depresses the clutch pedal, the amount of intake air decreases and the engine speed decreases.
The ISC valve 10 is driven in the closing direction.

In step S4, the drive control of the ISC valve 10 is performed based on the ISC valve drive amount. This IS
In the C valve drive control, for example, the current ISC valve drive amount is compared with the ISC valve drive amount, and the number of steps of the step motor 10a is set according to the difference.

Thereafter, in steps S5 to S7, it is determined whether or not a shift operation has been performed. The determination of the shift operation presence / absence is determined by the output value of the idle switch 29b (S5), the vehicle speed S (S6),
This is performed based on the output signal (S7) of the neutral switch 57. When the idle switch 29b is ON, the slot is fully closed, the vehicle speed S is less than the set value, and the neutral switch 57 is ON, it is determined that the shift operation condition is satisfied (the shift operation is performed), and the process proceeds to step S8. or,
If even one of the shift operation determination conditions is not satisfied,
It is determined that the shift operation condition is not satisfied (the shift operation is not performed or the shift operation is completed), and the process branches to step S11. The determination of the presence or absence of the shift operation is not limited to the determination by the idle switch 29b, the vehicle speed S, and the neutral switch 57.

In step S8, a timer processing value for determining a time for retarding the ignition timing is calculated. In the present embodiment, the timer processing value is a fixed value, but may be a variable value set for each operation region, or the timer processing value may be a count value for setting the number of ignitions. .

In this case, the timer processing value or the count value is shorter (smaller) as the engine speed is lower and the load is lower, and is higher as the engine speed and the engine load are higher.
Longer value (larger value) as it shifts to high load operation
Is set to By making the timer processing value or the number of times of ignition a variable value, it becomes possible to return the ignition timing in accordance with the closing timing of the ISC valve 10, and the ignition timing is not unnecessarily retarded. Good driving feeling can be obtained.

Then, the process proceeds to a step S9, wherein an ignition timing retard correction amount is calculated. The ignition timing retard correction amount is set by referring to a map with interpolation calculation based on the engine speed and the engine load. The ignition timing retard correction amount is smaller as the engine speed is lower and the load is lower, and is set to a larger value as the operation shifts to the higher speed and the higher load operation.

Thereafter, the routine proceeds to step S10, in which the ignition timing retard correction flag is set, and the routine exits.

The ignition timing retard correction amount is read in an ignition timing setting routine (not shown), and is added as a correction term when calculating the ignition timing during lean burn operation, thereby retarding the ignition timing during lean burn operation.

On the other hand, when it is determined that the shift operation condition is not satisfied and the process proceeds to step S11, the value of the ignition timing retard correction flag is referred to, and when it is set, the process proceeds to step S12. If the ignition timing retard correction flag is cleared, the routine exits from the routine.

In step S12, the timer processing value is compared with the elapsed time. If the elapsed time is less than the timer processing value, the flow proceeds to step S9, and the ignition timing retard correction amount is calculated. If the elapsed time exceeds the timer processing value, the process proceeds to step S13, where the timer processing value is cleared. In step S14, the ignition timing retard correction flag is cleared, and the routine exits.

As a result, when the driver performs the shift operation during the lean burn operation, the ignition timing is immediately corrected for retarding, so that the engine rotation due to the delay of the closing operation of the step motor 10a for opening and closing the ISC valve 10 is performed. The number rise can be suppressed.

It should be noted that the present invention is not limited to the above-described embodiment, and the engine employed is not limited to a lean burn engine, but can be applied to a normal engine based only on the stoichiometric air-fuel ratio, a direct injection type engine, and the like. Nor.

[0053]

As described above, according to the present invention,
When the shift operation of the manual transmission is performed, the ignition timing is corrected for the retard angle, so that the engine speed is prevented from rising due to the delay of the closing operation of the ISC valve, and a good driving feeling can be obtained.

Further, in this case, by setting the ignition timing correction to the set time or the set number of times of ignition, the ignition timing is not retarded longer than necessary and a good driving feeling can be obtained. Further, in this case, by setting the set time or the set number of ignitions for each operation region, the ignition timing can be appropriately retarded in accordance with the delay of the closing operation of the ISC valve, and the operation feeling is further improved. improves.

[Brief description of the drawings]

FIG. 1 is a flowchart showing an ISC valve opening control routine during lean burn operation.

FIG. 2 is a configuration diagram of an engine control system of the engine.

FIG. 3 is a circuit configuration diagram of an electronic control system.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Lean burn engine 5a ... Throttle valve 9 ... Air bypass passage 10 ... Idle speed control valve

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) F02D 41/08 315 F02D 41/08 315 41/16 41/16 P 45/00 335 45/00 335A F02P 5 / 15 F02P 5/15 FEF term (reference) 3D041 AA64 AC01 AC16 AD02 AD04 AD05 AD14 AD32 AD35 AE05 AE07 AE09 AF07 AF09 3G022 AA06 CA03 CA04 CA09 DA01 DA02 EA00 FA05 FA06 FA09 FB14 GA05 GA06 GA08 GA09 GA13 GA19 GA20 BA11 BA17 CA04 CA08 DA00 EA02 EB17 FA05 FA06 FA07 FA10 FA20 FA25 FA26 FA29 FA33 FA38 3G093 AA04 BA00 CA04 CA06 CA07 CB06 CB08 DA01 DA05 DA06 DA07 DA09 DA11 DB05 DB11 DB12 EA04 EA05 EA07 EA13 EC02 FA09 FB02 KA03 FB02 KA04 LC04 MA01 MA11 NB12 NC02 ND21 NE06 NE11 NE12 PA01Z PA11Z PC08Z PD02Z PE01Z PE03Z PE08Z PF01Z PF07Z PF10Z

Claims (4)

[Claims] An engine control device for controlling an opening of an idle speed control valve interposed in an air bypass passage that bypasses a throttle valve in accordance with an operation state, wherein a shift for determining whether a manual transmission shift operation is performed. An engine control device comprising: an operation determination unit; and an ignition timing correction unit that corrects an ignition timing when it is determined that a shift operation is performed. 2. The engine control device according to claim 1, wherein the stoichiometric operation based on the stoichiometric air-fuel ratio and the lean burn operation based on the lean air-fuel ratio having a leaner air-fuel ratio than the stoichiometric air-fuel ratio are performed. 2. The engine control device according to claim 1, wherein the opening of the number control valve is controlled in accordance with an operation state, and the ignition timing is corrected by the ignition timing correction means. 3. The engine control device according to claim 1, wherein said ignition timing correction means terminates the correction of the ignition timing when a set time or a set number of ignitions has elapsed. 4. The engine control device according to claim 3, wherein the set time or the set number of ignitions is set for each operation region.