JP2002147274A - Control device for internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress the slipping condition of a vehicle by properly reducing the output torque of an internal combustion engine by combining an ignition system, a fuel system and a throttle control. SOLUTION: When the output torque of the internal combustion engine 10 is reduced by a combination of a lag control at the time of ignition, the cylinder cut off control of a fuel supply cylinder, and the closed valve control of the throttle valve, a limit value is provided for a torque down ratio by the lag control at the time of ignition. Therefore, torque down requirements are clearly distributed to the lag control at the time of ignition and the cylinder cut off control of the fuel supply cylinder. Thereby, the torque down by the lag control at the time of ignition is most effectively carried out, and the slipping condition of the vehicle can be most properly suppressed while preventing the excessive temperature rise of the exhaust of the internal combustion engine.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control apparatus for an internal combustion engine that suppresses a slip state by reducing an output torque of the internal combustion engine in accordance with a slip state of a vehicle.

[0002]

2. Description of the Related Art Heretofore, there has been known an apparatus in which when a vehicle slips, a torque down control is performed so as to reduce the output torque of an internal combustion engine so as to suppress the slip state. As the torque down control, at least one or any of a combination of retard control of ignition timing, reduction of fuel supply, reduction of cylinders of a fuel supply cylinder, and throttle control of closing a throttle valve is used. Has been achieved.

[0003] As a prior art document related to this, one disclosed in Japanese Patent No. 2600756 is known. In this system, when the torque is most needed during a transition such as immediately after the occurrence of a vehicle slip, the ignition timing is retarded and the fuel supply cylinder is reduced. In order to prevent the rise, a technique is disclosed in which the rotation of the drive wheel is controlled only for a predetermined period until it temporarily decreases.

[0004]

As described above, when the torque needs to be reduced during a transition such as immediately after the occurrence of a slip in the vehicle, that is, the ignition timing is retarded and the fuel supply cylinder is reduced. Even if it is desired to achieve a rapid torque reduction by combining the controls, it is necessary to control the ignition system and the fuel system by time management. Therefore, the control by the ignition system and the fuel system is suddenly terminated at the elapse of a predetermined time, and thereafter, only the throttle control is used. Was impossible.

In view of the above, the present invention has been made to solve such a problem, and a clear torque down request distribution to the ignition system and the fuel system is performed, and the output torque of the internal combustion engine is obtained by combining the throttle control. It is an object of the present invention to provide a control device for an internal combustion engine that can appropriately reduce the vehicle speed and suppress the slip state of the vehicle.

[0006]

According to the control apparatus for an internal combustion engine of the present invention, the ignition timing is controlled by the ignition timing control means, the fuel supply cylinder is reduced by the fuel supply control means, and the throttle control means is controlled. When the output torque of the internal combustion engine is reduced by combining at least one or any one of the throttle valve closing controls by the torque-down means, the limit value is set to the torque-down rate by the ignition-timing retard control by the limit value setting means. With this arrangement, an excessive increase in the exhaust gas temperature of the internal combustion engine is prevented, and the slip state of the vehicle is optimally suppressed.

In the torque-down means in the control apparatus for an internal combustion engine according to the second aspect, the remaining output torque to be reduced after setting a limit value for the torque-down rate by the ignition timing retard control is reduced by the number of fuel supply cylinders. By achieving the control with the reduced cylinders, the torque reduction request distribution for the ignition timing retard control and the reduced cylinder control of the fuel supply cylinder is appropriately performed.

According to a third aspect of the present invention, when the number of reduced cylinders of the fuel supply cylinder calculated from the torque reduction rate obtained by the ignition timing retard control is not an integer value, the fuel supply control means in the internal combustion engine control device may delay the ignition timing. Due to the limit value of the maximum achievable torque down rate by the angle control, it is not possible to further increase the distribution of the ignition timing to the torque down rate by the retard control, so the number of cylinders of the fuel supply cylinder is increased. As a result, the torque reduction request is clearly distributed to the ignition timing retard control and the fuel supply cylinder decrease cylinder control, and the torque reduction by the ignition timing retard control is performed as effectively as possible.

In the ignition timing control means in the control apparatus for an internal combustion engine according to the fourth aspect, since the number of cylinders of the fuel supply cylinder is determined, the optimal ignition timing according to the current output torque of the internal combustion engine is determined. A retard amount is calculated.

The limit value setting means in the control device for an internal combustion engine according to the fifth aspect increases the limit value of the torque down rate by the ignition timing retard control with the lapse of time, so that the limit value of the vehicle immediately after the occurrence of a slip. The slip state of the vehicle is optimally suppressed promptly and accurately in response to a torque down request during a transient.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below based on examples.

FIG. 1 is a schematic diagram showing the overall configuration of a control device for an internal combustion engine according to one embodiment of the present invention.

In FIG. 1, an internal combustion engine 10 is, for example,
The combustion chamber 11 of each cylinder of the internal combustion engine 10 has an intake passage 13 through an intake valve 12.
Are connected to each other, and the exhaust passage 1 is
5 are connected. A throttle valve 21 for adjusting the amount of intake air supplied into the combustion chamber 11 from an air cleaner (not shown) is provided upstream of the intake passage 13. Further, an electric motor 22 such as a step motor or a torque motor for driving the opening and closing of the throttle valve 21 and a throttle opening sensor 23 for detecting the throttle opening of the throttle valve 21 at that time are provided.

An injector (fuel injection valve) 24 for supplying fuel injection is provided before the intake valve 12 on the downstream side of the intake passage 13. The internal combustion engine 10
In each of the combustion chambers 11, an ignition plug 25 is provided. The crankshaft 16 of the internal combustion engine 10 is provided with a rotation speed sensor 17 for detecting the engine rotation speed.

Reference numeral 30 denotes an ECU (Electronic Control Unit).
An electronic control unit), and the ECU 30 includes a CPU 31 as a central processing unit that executes various known arithmetic processing,
ROM 32 storing a control program, RAM 33 storing various data, B / U (backup) RAM 3
4. It is configured as a logical operation circuit including an input circuit 35, an output circuit 36, a bus line 37 connecting them, and the like.

The ECU 30 has a throttle opening sensor 23
The throttle opening signal from the engine, the engine speed signal from the speed sensor 17, and a well-known ABS (Antiloc
A signal or the like relating to a torque reduction request for the internal combustion engine 10 is input from the ABS control circuit 40 for achieving slip control by the k brake system. The ABS control circuit 40 receives wheel speed signals from wheel speed sensors (not shown) disposed on the left, right, front and rear wheels of the vehicle.
Also, a drive signal from the ECU 30 to the electric motor 22,
An ignition signal to an ignition circuit 26 for applying a high voltage to the ignition plug 25, a signal relating to a torque down situation to an ABS control circuit 40, and the like are output.

Next, the CPU 31 in the ECU 30 used in the control apparatus for an internal combustion engine according to one embodiment of the present invention is required to rapidly reduce the torque of the internal combustion engine, such as immediately after the occurrence of a vehicle slip. A description will be given with reference to FIG. 4 based on the flowchart of FIG. 2 showing the processing procedure of the output torque control at the time of the transition. Here, FIG.
3 is a time chart showing transition states of various control signals and the like corresponding to the processing of FIG. Note that this output torque control routine is repeatedly executed by the CPU 31 at predetermined time intervals.

In FIG. 2, at step S101, A
It is determined whether there is a torque down request from the BS control circuit 40. When the determination condition of step S101 is satisfied, that is, when a sudden torque reduction is required as in a transient state immediately after the occurrence of a slip of the vehicle, the process proceeds to step S102,
The torque-down permission flag for executing the torque-down control is set to “1 (permitted)” (see time t01 shown in FIG. 4). Next, the process proceeds to step S103, and a limit value of the maximum achievable torque-down rate without causing catalyst deterioration due to an increase in exhaust gas temperature by ignition timing retard control is calculated in advance.

As shown in FIG. 4, the limit value of the torque down ratio by the ignition timing retard control is increased with time while providing a margin on the safe side. That is,
As the torque down execution time elapses, it is possible to change to the side that increases the torque down ratio by the fuel system,
It is assumed that the value is previously stored as a table value for time.

Next, the flow shifts to step S104, where it is determined whether the time is within a predetermined time. When the determination condition of step S104 is satisfied, that is, when the torque down execution time is shorter than the predetermined time, the process proceeds to step S105, and the time counter for measuring the torque down execution time continues counting up as a time counter integration (FIG. Time t shown in 4
01 to t07). Next, the process proceeds to step S106, where A
The ratio between the target torque-down value corresponding to the torque-down request during the transition from the BS control circuit 40 and the current internal-combustion-engine-generated torque value is calculated as the final target torque-down rate. The current internal combustion engine generated torque value is sequentially calculated by calculation.

Next, the routine proceeds to step S107, in which the ratio between the final target torque reduction rate calculated in step S106 and the maximum achievable torque reduction rate by the ignition timing retard control calculated in step S103 is determined by the fuel. It is calculated as the torque down rate by the system, specifically, the torque down rate by the reduced cylinder control. Next, the process proceeds to step S108, in which the number of cylinders of the firing (ignition combustion) is calculated by multiplying the total number of cylinders of the internal combustion engine by the torque reduction rate by the cylinder reduction control calculated in step S107.

Next, the process proceeds to step S109, in which the calculated value of the number of firing cylinders calculated in step S108 is rounded down to the decimal point. That is, the number of firing cylinders is an integer value, and the distribution of the ignition timing to the torque down rate by the retard control is further increased by the limit value of the maximum achievable torque down rate by the ignition timing retard control. Because you can't. Next, the process proceeds to step S110, in which the number of firing cylinders whose decimals have been rounded down in step S109 is subtracted from the total number of cylinders of the internal combustion engine to calculate the number of reduced cylinders (the number of stopped cylinders by the reduced cylinder control) (FIG. 4). Shown at times t01 to t02 and times t04 to t06),
This routine ends. The increase in the number of reduced cylinders due to the truncation of the calculated number of firing cylinders below the decimal point corresponds to a sudden torque-down request.

On the other hand, if the determination condition of step S101 is not satisfied, that is, if there is no torque down request, or if the determination condition of step S104 is not satisfied, that is, if the torque down execution time exceeds a predetermined time, step S
The routine proceeds to step 111, where the torque-down permission flag for executing the torque-down control is set to "0 (non-permission)", and this routine ends.

Next, a diagram showing a processing procedure of a retard amount calculation by a retard control of the ignition timing in the CPU 31 in the ECU 30 used in the control device for the internal combustion engine according to one embodiment of the present invention. Based on the flowchart of 3,
This will be described with reference to FIG. Note that this routine for calculating the amount of retard is repeatedly executed by the CPU 31 at predetermined time intervals.

In FIG. 3, in step S201, the ratio between the final target torque down rate calculated in step S106 in FIG. 2 and the torque down achievement rate by the cylinder reduction control should be achieved by the ignition timing retard control. It is calculated as a torque down rate. Here, the torque reduction achievement rate by the reduced cylinder control is defined by the ratio of the number of firing cylinders to the number of all cylinders.

Next, the process proceeds to step S202, in which the well-known MBT (Minimum spark advance for Best Toe) in the current operating state of the internal combustion engine is reduced to the torque reduction rate to be achieved by the ignition timing retard control calculated in step S201.
rque) is multiplied by the torque deviation rate with reference to MB.
The torque-down request rate based on T is calculated.

Next, proceeding to step S203, the ignition timing to be retarded from the MBT generation ignition timing with respect to the torque down request rate based on the MBT calculated in step S202 is previously set by adaptation. It is calculated by table conversion using a table (not shown). Next, proceeding to step S204, the ignition timing to be retarded is subtracted from the ignition timing of MBT generation calculated in step S203 from the deviation amount from the ignition timing in the current operating state of the internal combustion engine, and the absolute value to be retarded is calculated. The ignition timing retard amount as a value is calculated (see FIG. 4), and this routine ends.

Here, a time chart of FIG. 5 shown as a comparative example of FIG. 4 will be described. As shown in FIG. 5, for example, in slip control based on the ignition timing retard amount, the number of cylinders reduced, and the throttle opening which are time managed by comparing the torque down execution time counter with the exhaust temperature allowable predetermined time, transient The actual torque does not yet converge to the target torque even when the time changes from the steady state to the target torque, and the throttle opening also fluctuates. Therefore, it can be seen that it is difficult to achieve a rapid torque reduction during the transition. That is, in the slip control as shown in FIG. 5, even if an attempt is made to achieve rapid torque reduction by combining ignition timing retard control and fuel supply reduced cylinder control, a clear torque reduction request to the ignition system and the fuel system is required. Since the distribution is not known, there is no choice but to use a uniform control amount. Then, when a predetermined time has elapsed, the control by the ignition system and the fuel system is suddenly terminated, and after that, only the throttle control is used.
It was impossible to improve the responsiveness and control accuracy to a torque-down request during a transition.

On the other hand, according to the control apparatus for an internal combustion engine of the present embodiment, an appropriate torque reduction distribution is executed to the fuel system and the ignition system, and the internal combustion engine is suddenly supplied to the engine immediately after the occurrence of slip of the vehicle. Optimal torque-down control can be quickly and accurately performed on the internal combustion engine during a transient when a great torque-down is required.

As described above, the control apparatus for an internal combustion engine according to the present embodiment includes the ignition plug 2 for controlling the ignition timing of the internal combustion engine 10.
5. Ignition circuit 26, ignition timing control means achieved by ECU 30, injector 24 controlling the fuel supply cylinder of internal combustion engine 10, fuel supply control means achieved by ECU 30, throttle valve 21 of internal combustion engine 10. Motor 22 for controlling the opening of the throttle, throttle opening sensor 2
3. throttle control means achieved by the ECU 30;
In accordance with the slip state of the vehicle output from the ABS control circuit 40, the ignition timing control means controls the ignition timing to be retarded, the fuel supply control means controls the reduction of the fuel supply cylinder, and the throttle control means controls the throttle valve. ECU 30 that reduces the output torque of internal combustion engine 10 by combining at least one or any one of valve closing controls 21
And a limit value achieved by the ECU 30 that sets a limit value for the torque-down rate by retarding the ignition timing in accordance with the current output torque of the internal combustion engine 10 obtained from various sensor information. Setting means. Accordingly, when the output torque of the internal combustion engine 10 is reduced by a combination of the ignition timing retard control, the fuel supply cylinder reduction cylinder control, and the throttle valve 21 valve closing control, a limit value is set for the torque down rate by the ignition timing retard control. Is provided, it is possible to optimally suppress the slip state of the vehicle while preventing an excessive rise in the exhaust gas temperature of the internal combustion engine.

The control device E for the internal combustion engine of this embodiment
The torque-down means achieved by the CU 30 controls the remaining output torque to be reduced after setting a limit value for the torque-down rate by the ignition timing retard control by the reduced cylinder by the reduced cylinder control of the fuel supply cylinder. To achieve. This allows
Thus, the torque reduction request distribution for the ignition timing retard control and the fuel supply cylinder reduced cylinder control is appropriately performed.

The fuel supply control means achieved by the injector 24 and the ECU 30 of the control apparatus for an internal combustion engine according to the present embodiment is a fuel supply cylinder reduced cylinder calculated from the torque reduction rate by the ignition timing retard control. When the number is not an integer value, the number is set in a direction to increase the number of reduced cylinders. In other words, the limit value of the maximum achievable torque down rate by the ignition timing retard control cannot further increase the distribution of the ignition timing to the torque down rate by the ignition timing retard control. Is increased. As a result, the torque reduction request is clearly distributed to the ignition timing retard control and the fuel supply cylinder reduction cylinder control,
Torque reduction by retard control of the ignition timing is performed as effectively as possible.

Further, the ignition timing control means achieved by the ignition circuit 26 and the ECU 30 of the control device for an internal combustion engine according to the present embodiment provides the ignition timing retard amount after the number of reduced fuel supply cylinders is determined. Is calculated. As described above, since the number of cylinders of the fuel supply cylinder has been determined, the optimal ignition timing retard amount according to the current output torque of the internal combustion engine is calculated.

In the control device for an internal combustion engine according to the present embodiment,
The limit value setting means achieved by the CU 30 increases the limit value of the torque down rate by the ignition timing retard control with the passage of time. As a result, the ignition timing retard control, the fuel supply cylinder reduction control, and the throttle valve closing control of the throttle valve 21 are quickly and accurately performed in response to a torque reduction request during a transition such as immediately after the occurrence of a vehicle slip. ,
The slip state of the vehicle can be optimally suppressed.

In the above embodiment, a signal or the like relating to a torque reduction request for the internal combustion engine 10 is input from the ABS control circuit 40. However, the present invention is not limited to this. , Each wheel speed signal from a wheel speed sensor disposed on the left, right, front and rear wheels of the vehicle
Even if the request is input directly to the CU 30 and the ECU 30 generates a request for torque reduction for the internal combustion engine 10,
Similar actions and effects can be expected.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing an entire configuration of a control device for an internal combustion engine according to an example of an embodiment of the present invention.

FIG. 2 is a diagram showing a CP in an ECU used in a control device for an internal combustion engine according to an embodiment of the present invention;
6 is a flowchart illustrating a processing procedure of output torque control in U.

FIG. 3 is a diagram showing a CP in an ECU used in a control device for an internal combustion engine according to an embodiment of the present invention;
9 is a flowchart illustrating a processing procedure of a retard amount calculation in U.

FIG. 4 is a time chart showing transition states of various control signals and the like corresponding to the processes of FIGS. 2 and 3;

FIG. 5 is a time chart showing transition states of various control signals and the like as a comparative example of FIG. 4;

[Explanation of symbols]

 Reference Signs List 10 internal combustion engine 21 throttle valve 22 electric motor 23 throttle opening sensor 24 injector 25 spark plug 26 ignition circuit 30 ECU (electronic control unit) 40 ABS control circuit

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI theme coat ゛ (reference) F02D 41/12 330 F02D 41/12 330J 43/00 301 43/00 301B 301K 301H F-term (reference) 3G065 AA04 CA10 DA06 DA15 EA05 GA00 GA10 GA41 HA21 HA22 KA02 3G084 BA05 BA13 BA17 DA10 DA17 DA28 EA11 FA05 FA06 FA10 FA33 3G092 AA01 AA05 BA09 BB01 CA07 CA08 DC01 DE01Y DG07 EA02 EA04 EA09 EC01 FA03 FA05 FA20 HA06Z01 AE07 DA01 DA06 DB15 DB17 EA05 EA08 EA09 EA13 EB04 EC01 FA04 FA08 FB05 3G301 HA01 HA06 JA38 KA16 LA03 LB02 LC04 MA11 NA06 NA08 NB03 NB15 NE07 PA11Z PE01Z PF00

Claims (5)

[Claims] An ignition timing control means for controlling an ignition timing of the internal combustion engine; a fuel supply control means for controlling a fuel supply cylinder of the internal combustion engine; and a throttle control means for controlling an opening of a throttle valve of the internal combustion engine. In response to the slip state of the vehicle, the ignition timing control means for controlling the ignition timing retard, the fuel supply control means for reducing the number of fuel supply cylinders, and the throttle control means for closing the throttle valve. At least one of them
A torque-down means for reducing the output torque of the internal combustion engine, and a limit value for setting a limit value for a torque-down rate by the retard control of the ignition timing according to a current output torque of the internal combustion engine. A control device for an internal combustion engine, comprising: a setting unit. 2. The fuel-down cylinder according to claim 2, wherein said torque-down means reduces the remaining output torque to be reduced after providing a limit value to the torque-down rate by said ignition-timing retard control, by reducing the fuel supply cylinder. The control device for an internal combustion engine according to claim 1, wherein the control is achieved by: 3. The fuel supply control means, if the number of cylinders of the fuel supply cylinder calculated from the torque reduction rate by the ignition timing retard control is not an integer value, increases the number of cylinders to be reduced. 3. The method according to claim 2, wherein the setting is performed.
3. The control device for an internal combustion engine according to claim 1. 4. The internal combustion engine according to claim 3, wherein the ignition timing control means calculates a retard amount of the ignition timing after the number of cylinders of the fuel supply cylinder is determined. Control device. 5. The control device for an internal combustion engine according to claim 1, wherein said limit value setting means increases a limit value of a torque down rate by retard control of said ignition timing as time elapses. .