JPH05332172A - Engine split operation control device - Google Patents

Abstract

(57) [Summary] [Purpose] To prevent a reduction in engine torque that occurs when performing a reduced cylinder operation from an all cylinder operation. [Structure] When the operating region of the engine is shifted from the all-cylinder operating region to the reduced-cylinder operating region during all-cylinder operation, the throttle valve opening is set to be larger than the current throttle valve opening in the all-cylinder operating state. It is controlled to open. At this time, the reduced-cylinder operation is not executed, so the increase in engine torque due to the throttle valve opening control is suppressed by the ignition timing retard control. After that, when the throttle valve opening control reaches the target throttle opening during reduced cylinder operation, and the intake air amount obtained at that throttle valve opening is actually secured, the reduced cylinder operation is performed and the ignition timing retard By releasing the control, it is possible to prevent the engine torque from decreasing when starting the reduced cylinder operation.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a divided operation control device for an engine in which cylinders are divided into a plurality of groups and a predetermined specific group of cylinders can be deactivated, and more particularly, when the operation of a specific cylinder is deactivated. The present invention relates to a device that sufficiently suppresses the torque fluctuation.

[0002]

2. Description of the Related Art Generally, an engine has higher thermal efficiency when it is operated at a high load than when it is operated at no load. Therefore, when the engine load is low, stop the operation of the specific cylinder,
Drive with the remaining cylinders to increase the load per cylinder,
A split operation control type engine with improved thermal efficiency as a whole has been developed. For example, in the conventional device disclosed in Japanese Patent Laid-Open No. 62-103430, the torque generated by the engine varies when starting and stopping the operation of a specific cylinder. ,
For the same accelerator opening, during specific cylinder operation, the opening of the throttle valve is controlled to be smaller than the opening of the throttle valve during specific cylinder operation suspension, and conversely, during specific cylinder operation suspension, By controlling the opening of the throttle valve so that it is larger than the opening of the throttle valve during operation of the specific cylinder, the throttle is opened so that the torque generated by the engine is equal when the specific cylinder is operating and when the operation is stopped. Control the degree.

[0003]

However, as in the above-described technique, when the throttle valve is controlled to be larger than the opening degree of the throttle valve during the operation of the specific cylinder when the operation of the specific cylinder is stopped, the operation of the specific cylinder is performed. Immediately after the start of suspension, the intake air amount corresponding to the throttle opening is not obtained, the engine torque is temporarily reduced, and the resulting torque fluctuation cannot be suppressed. This phenomenon will be described with reference to FIG. In FIG. 3A, when the all-cylinder operating range is changed to the reduced-cylinder operating range at time t1 during all-cylinder operation, the throttle valve opening is controlled to be larger than the current throttle valve opening (see FIG. 3).
(Refer to the solid line in (B)), the reduced cylinder operation is started at the same time. (See FIG. 3D) However, the engine torque is as shown in FIG.
As shown in (E), it temporarily decreases after time t1 and converges to the engine torque during all cylinder operation at time t2. This phenomenon is
Even if the opening control of the throttle valve is performed to reach the target throttle valve opening and the target throttle valve opening is reached, at this point (time t1 + α in FIG. 3B), the intake air amount corresponding to the opening is reached. Is not immediately obtained, but occurs because the required intake air amount is obtained at time t2 as shown by the broken line in FIG. 3B, that is, due to the delay in the change of the intake air amount.

The present invention has been made in view of such a problem. The engine torque does not temporarily decrease at the start of the operation stop of the specific cylinder, and the torque fluctuation occurs immediately after the start of the operation of the specific cylinder. The purpose is to suppress.

[0005]

In order to solve the above problems, the engine split operation control device of the present invention divides the cylinders into a plurality of groups and suspends the operation of a predetermined set of cylinders. In the split operation control device for the engine, the first actuator that opens and closes the throttle valve, the optimum ignition timing calculation means that calculates the optimum ignition timing corresponding to the operating state of the engine, and the operating state of the engine are in the all cylinder operating region. Or a reduced-cylinder operating region, and an operating region determination means for determining whether or not it is in the reduced-cylinder operating region, and a throttle valve open instruction signal is output to the first actuator when the operating region determination means determines that the operating state is in the reduced-cylinder operating region. The throttle valve control means for increasing the throttle opening and the increase in engine torque due to the increase in the throttle valve opening by the throttle valve control means are suppressed. And an ignition timing retarding means for delaying the ignition timing from the optimum ignition timing, and an ignition timing retarding release for canceling the ignition timing retarding control when a predetermined time elapses after the throttle opening reaches a predetermined opening. Means and a specific cylinder deactivating means for deactivating the operation of a predetermined specific group of cylinders at the same time as releasing the retard control.

[0006]

This operation will be described with reference to FIG. First, FIG.
In (A), when it is determined at time t1 during the operation of all the cylinders that the operating range determination means has changed from the all-cylinder operating range to the reduced-cylinder operating range, the first based on the output signal output from the throttle valve control means. The opening control of the throttle valve is performed by the actuator, and the throttle valve opening becomes larger than the current throttle valve opening (see FIG. 4 (B)).
At this point, the cut-out cylinder operation is not yet started (Fig. 4).
(D)). However, if the throttle opening is increased with all cylinders operating, the engine torque will increase. Therefore, in order to suppress the increase in the engine torque, the ignition timing is set to be higher than the optimum ignition timing obtained by the optimum ignition timing calculation means. Ignition is performed on the retard side by shifting the ignition timing retard means. (See FIGS. 4C and 4E). After that, as shown by the broken line in FIG. 4B, at a time t2 after a certain time has elapsed after the predetermined opening at time t1 '+ α (in other words, the required intake air amount is obtained and the engine torque difference is (It becomes zero during all cylinder operation and reduced cylinder operation)
Then, the reduced cylinder operation is executed by the specific cylinder deactivating means, and the ignition timing retard control is released by the ignition timing retard releasing means (see FIGS. 4C and 4D). That is, time t1 '
From this, the ignition timing is retarded for a predetermined time corresponding to time t2 '.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS This embodiment will be described below with reference to the drawings. FIG. 2 shows the overall arrangement of the split operation control device for the engine of the first embodiment. Reference numeral 1 denotes an engine, and the engine 1 has four cylinders 1 to 4 from the left side to the right side in FIG. 2, and intake manifolds 2a to 2d and exhaust manifolds 3a to 3d are connected to the respective cylinders. The upper ends of the intake manifolds 2a to 2d are provided with the intake passage 2
In addition, the lower ends of the exhaust manifolds 3a to 3d have the exhaust passage 3
Respectively connected to. Each intake manifold 2a-
2d is provided with first to fourth fuel injection valves 4a to 4d. An air cleaner 5 for taking in the atmosphere, an air flow meter 6 for detecting the flow rate of the intake air taken into the intake passage 2 by the air cleaner 5, and a throttle actuator 7 are provided upstream of the intake passage 2. A throttle valve 8 for controlling the flow rate of intake air that is opened and closed in conjunction with each other, and a throttle sensor 9 for detecting the opening of the throttle valve 8 are provided. In the case of this embodiment, the load state of the engine is detected by the throttle sensor 9. An accelerator pedal 13 is connected to the throttle valve 8 by a known link mechanism. Further, the accelerator pedal 13 is provided with an accelerator pedal opening sensor 14 for detecting the accelerator pedal opening. The ignition device 10 includes an igniter and an ignition coil (both not shown). Crank angle sensor 1
The 1a and the reference position sensor 11b are provided in the distributor 11 and detect the rotation of a distributor shaft (not shown), so that the crank angle sensor 11a detects the rotation of the crankshaft 3 (not shown).
The signal for every 0 degree rotation is detected, and the reference position sensor 11b detects the top dead center of the first cylinder. The crank angle sensor 11a serves as an engine speed sensor. The control device 12 includes an input circuit 12a as an internal circuit for converting an input signal into a digital signal and the like, and a CPU (central processing unit) 12b as a central processing unit.
An output circuit 12c, a ROM (read-on memory) 12d in which a control program and initial data are stored,
A RAM (random access memory) 12e is provided for temporarily reading and writing data input to the electronic control circuit and data necessary for arithmetic control. In the input circuit 12a, the rotation speed detection value from the crank angle sensor 11a, the top dead center signal of the predetermined cylinder from the reference position sensor 11b, the throttle valve opening signal from the throttle sensor 9, and the air flow meter 6 are input. The intake air amount detection value and the accelerator opening signal from the accelerator opening sensor 14 are input.
Opening / closing control of the throttle valve 8, fuel injection control, and ignition timing control are performed by the output signals from the output circuit 12c calculated based on the data input to the input circuit 12a. Ignition timing control is based on an optimal ignition timing value corresponding to the engine speed and the intake air amount (a reference position including an advance value and a retard value at the ignition timing for generating maximum torque, for example, from top dead center). Is stored in advance in the ROM 12d in the control device 12, and every time a reference position signal from the reference position sensor 11a is given, the engine speed (calculated from the angle signal) and the intake air amount at that time are corresponded to. ROM 12 in the control device 12 for the optimum ignition timing
It is read from d and the ignition timing is sent when the cylinder is at or immediately before the intake stroke. A high voltage is generated in the ignition coil 10 by this ignition signal and ignition is performed. In addition, in accordance with the engine operating state by an arbitrary combination of the accelerator opening degree and the engine speed, it is divided into a reduced-cylinder operation (low load) region and an all-cylinder operation (high load) region that are obtained in advance by experiments. The area data is stored in the ROM 12d.

Next, referring to FIG. 5, a routine for performing the reduced cylinder operation from the all cylinder operation will be described. It should be noted that this routine is executed by the CPU 12b as a central processing unit, which is a part of the internal circuit of the control device 12, at predetermined time intervals. First, when entering this routine, step 100
In accordance with the engine operating state according to an arbitrary combination of the accelerator opening degree and the engine rotation speed stored in advance in the ROM 12d in the control device 12, the experiment is performed based on the current accelerator opening degree and the engine rotation speed. Based on the region data divided into the reduced-cylinder operation (low load) region and the all-cylinder operation (high load) region obtained by the above, it is determined whether the all-cylinder operation region or the reduced-cylinder operation region. Step 1
If it is determined that the reduced-cylinder operation region is YES (YES), the routine proceeds to step 101, where it is determined whether the reduced-cylinder operation is being performed. If it is determined in step 101 that all cylinders are in operation (NO), the process proceeds to step 102, where the ROM in the control device 12 is based on the current accelerator opening and engine speed.
The target throttle valve opening for reduced cylinder operation transition, which is experimentally obtained, is calculated by an arbitrary combination of the accelerator opening and the engine speed stored in advance in 12d. In the following step 103, the throttle actuator 7 controls the opening of the throttle valve 8 based on the output signal output from the control device 12 so that the reduced-cylinder operation transition target throttle valve opening calculated in step 102 is achieved.
In the following step 104, the current throttle valve opening is detected by the throttle sensor 9, and it is determined whether the detected throttle valve opening has reached the target throttle valve opening for transition to reduced cylinder operation calculated in step 102. To judge. When it is determined in step 104 that the current throttle valve opening has not reached the target throttle valve opening for transition to reduced cylinder operation (NO), the process proceeds to step 108,
An ignition timing retard amount that suppresses an increase in engine torque corresponding to the current increase in intake air amount is calculated. For example, the intake air amount at the time when it is first determined that the transition to the reduced cylinder operation region is stored, and the difference between the current intake air amount and the intake air amount initially stored at the time of the reduced cylinder operation transition is calculated. The retard amount according to this difference is calculated from the retard amount map stored in the ROM 12d in the control device 12. Continued Step 1
In 09, based on the ignition timing retard amount calculated in step 108, the ignition timing is delayed from the optimum ignition timing value by a fixed angle or a value corresponding to the ignition timing value, and this routine ends. If it is determined in step 104 that the current throttle valve opening has reached the target throttle valve opening for transition to reduced cylinder operation (YES), in the following step 105,
It is determined whether or not a predetermined time has elapsed since the current throttle valve opening reached the target throttle valve opening for transition to reduced cylinder operation. That is, it is judged whether or not the current intake air amount has become the actual intake air amount that is taken in at the target throttle valve opening degree during the reduced cylinder operation transition, depending on whether or not a predetermined time has elapsed. Since the setting of the predetermined time differs depending on the setting and the state of the engine, the data obtained by the experiment in advance may be stored in the ROM 12d in the control device 12. Instead of steps 104 and 105, it may be determined whether or not a predetermined time has elapsed since it was determined to be in the reduced-cylinder operation region during all-cylinder operation. If it is determined in step 105 that the predetermined time has not elapsed, the above-described step 10
8 and step 109 are executed, and this routine is ended. In step 105, a predetermined time has passed (Y
If it is determined to be ES), in step 106, the generation of the injection pulse signal applied to the fuel injection valves 4b and 4c is stopped, and the second cylinder and the third cylinder are put into the inactive state. (This state is referred to as the reduced cylinder operation.) In the following step 107,
Immediately after the reduced-cylinder operation is started, the ignition timing retard control is released, and this routine is ended. Also, step 100
Therefore, it is not in the reduced-cylinder operating region (that is, in all-cylinder operating region) (N
If it is determined to be O), the process proceeds to step 110, where the control device 12 is operated based on the current accelerator opening and engine speed.
The target throttle valve opening for all cylinders, which is experimentally obtained, is calculated by an arbitrary combination of the accelerator opening and the engine speed stored in advance in the ROM 12d therein.
In the following step 111, the control device 1 is operated so that the target throttle valve opening for all cylinders calculated in step 110 is reached.
The throttle actuator 7 controls the opening of the throttle valve 8 based on the output signal output from the control unit 2, and the present routine ends. When it is determined in step 101 that the reduced cylinder operation is being performed (YES), the process proceeds to step 112, in which the accelerator stored in advance in the ROM 12d in the controller 12 is based on the current accelerator opening and the engine speed. The target throttle valve opening degree for cylinder reduction obtained by the experiment is calculated by an arbitrary combination of the opening degree and the engine speed. In the following step 113, the throttle actuator 7 controls the opening of the throttle valve 8 based on the output signal output from the control device 12 so as to reach the target throttle valve opening degree for cylinder reduction calculated in step 112, and this routine is executed. finish.

As described above, in this embodiment,
When the all-cylinder operating range is changed to the reduced-cylinder operating range, first, the throttle valve is controlled in the opening direction so as to reach the target throttle valve opening required during the reduced-cylinder operation. As a result, the engine torque inevitably increases. Therefore, the ignition timing is retarded to suppress the increase in the engine torque. After a lapse of a predetermined time after reaching the target throttle valve opening by the throttle valve opening control (in other words, the actually required intake air amount was secured, that is, the engine torque difference during all cylinder operation and reduced cylinder operation And becomes zero), at this point the reduced cylinder operation is executed,
By canceling the ignition retard control at the same time as the execution of the reduced cylinder operation, the engine torque generated during the all cylinder operation can be obtained immediately after the reduced cylinder operation is started.
It is possible to eliminate the torque shortage that occurs when the reduced cylinder operation starts.

Although the embodiment has been described above with reference to the drawings, the specific configuration is not limited to this embodiment, and the present invention can be applied even if there is a design or the like within a range not departing from the gist of the invention. included.

For example, in the embodiment, only the fuel injection is stopped when the reduced cylinder operation is performed, but the ignition may be stopped at the same time.

[0012]

According to the present invention, when the all-cylinder operating region is changed to the reduced-cylinder operating region, first, the throttle valve is controlled in the opening direction so that the target throttle valve opening required for the reduced-cylinder operation is reached. When the throttle valve opening control is performed, an increase in engine torque that is inevitably caused is suppressed by the ignition timing retard control, and after a predetermined time has elapsed since the target throttle valve opening was reached by the throttle valve opening control (in other words, in reality, Required intake air amount was secured, that is, the engine torque difference becomes zero between all cylinder operation and reduced cylinder operation.) At this time, reduced cylinder operation is executed and ignition timing retard control is performed. By releasing the engine torque, the engine torque generated during the all-cylinder operation can be obtained immediately after the start of the reduced-cylinder operation, and the torque shortage that occurs at the start of the reduced-cylinder operation can be eliminated.

[Brief description of drawings]

FIG. 1 is a block diagram of the invention.

FIG. 2 is an overall view of a split operation control device for an engine.

FIG. 3 is a time chart at the time of operation of a split operation (conventional).

FIG. 4 is a time chart at the time of operation of a split operation (this embodiment).

FIG. 5 is a flowchart when a divided operation is executed.

[Explanation of symbols]

 a ... Throttle valve b ... First actuator c ... Optimal ignition timing detection means d ... Operating area determination means e ... Throttle valve control means f ... Ignition timing retardation means g. .. Ignition timing retard release means h ... Specific cylinder deactivating means 1 ... Engine 2 ... Intake passages 2a to d ... Intake manifold 3 ... Exhaust passages 3a to d ... Exhaust manifolds 4a to d ..Fuel injection valve 5 ... Air cleaner 6 ... EF flow meter 7 ... Throttle actuator 8 ... Throttle valve 9 ... Throttle sensor 10 ... Ignition device 11a ... Reference position sensor 11b・ ・ ・ Crank angle sensor 12 ・ ・ ・ Control device 12a ・ ・ ・ Input circuit 12b ・ ・ ・ CPU 12c ・ ・ ・ Output circuit 12d ・ ・ ・ ROM 12e ・ ・ ・ RAM 13 ... Accelerator pedal 14 ... Accelerator pedal opening sensor

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification number Office reference number FI technical display location F02D 43/00 301 B 7536-3G K 7536-3G F02P 5/15 B

Claims (1)

[Claims] 1. A divided operation control device for an engine, wherein a cylinder is divided into a plurality of groups, and the operation of a cylinder of a predetermined specific group can be suspended, and a throttle valve is opened and closed.
Actuator, optimum ignition timing calculation means for calculating the optimum ignition timing corresponding to the operating state of the engine, and operating range determining means for determining whether the operating state of the engine is in the all cylinder operating range or the reduced cylinder operating range. When the operating range determining means determines that the cylinder is in the reduced cylinder operating range during all cylinder operation, a throttle valve opening instruction signal is output to the first actuator to increase the throttle opening, and the throttle valve control means. Ignition timing retarding means for delaying the ignition timing from the optimum ignition timing so as to suppress an increase in engine torque due to an increase in the throttle valve opening by the control means, and a predetermined time after the throttle opening becomes the predetermined opening. Ignition timing retard control for canceling the ignition timing retard control, and a predetermined set of gas at the same time when the retard control is released. Division operation control device for an engine, characterized in that it comprises a specific cylinder deactivation means to pause the operation.