JP3506517B2 - Engine and power distribution unit control - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an engine capable of selectively stopping combustion in a predetermined cylinder such as a variable cylinder engine or a bank switchable engine and changing the idle cylinder, a front wheel output shaft and a rear wheel. The present invention relates to a device for controlling a driving force distribution device capable of changing a distribution ratio of a driving force to two output shafts such as an output shaft.

[0002]

2. Description of the Related Art It is well known that various attempts have been made to improve fuel efficiency of vehicles, and a bank switching engine and a variable cylinder engine are known as examples thereof. The former bank switching engine is a bank type engine, and is an engine configured to selectively stop the combustion of cylinders of each bank as a group, and is described in, for example, Japanese Patent Application Laid-Open No. 56-115830. Has been done.

In this type of engine, since the intake system and the exhaust system are provided corresponding to each bank, each bank can be controlled independently. Therefore, by performing one-bank operation, friction etc. It is possible to reduce the mechanical loss of and improve fuel efficiency. Also, in single bank operation, the number of combustions per revolution of the output shaft is half that in both bank operations. Therefore, in order to prevent deterioration of riding comfort due to vibration, single bank operation is performed at a predetermined accelerator opening or more. Also, when a large torque is required, that is, when the accelerator opening is large, both bank operations are performed. Further, since the exhaust purification catalyst is provided corresponding to each bank, in order to maintain each exhaust purification catalyst at the activation temperature, the banks in which combustion is suspended are alternately switched during the single bank operation.

On the other hand, in a variable cylinder engine, it is noted that the efficiency of the engine is better when the relative load is higher to some extent. The load is increased, which improves fuel efficiency. Even in this type of variable cylinder engine, partial cylinder operation is performed at an accelerator opening above a predetermined level in order to maintain a smooth engine drive state and prevent deterioration of riding comfort.In that case, the output torque is naturally small. Become.

[0005]

In the above-described bank-switchable engine, basically, the output characteristic is constant when switching between both-bank operation and one-bank operation, and when switching banks during one-bank operation. The throttle opening in each bank is controlled so that However, during the transition period, the throttle opening for each bank is changing, so the output torque of the engine must be unstable. Further, in the above-mentioned partial cylinder engine, since the engine output changes by changing the number of combustion cylinders, the output torque naturally changes and becomes unstable during the transition period in which the number of combustion cylinders changes. I don't get it.

Therefore, in a part-time four-wheel drive vehicle equipped with the above-described bank switchable engine or variable cylinder engine, a full-time four-wheel drive vehicle capable of differential limiting, or a vehicle having a differential limiting differential, etc. , Changing the distribution ratio of torque to the front and rear wheels or the left and right wheels by switching between the four-wheel drive state and the two-wheel drive state, changing the differential limiting state, etc., and changing the output torque due to the change of the combustion cylinder in the engine. May occur at the same time. In such a case, the torque applied to the wheels will change due to two factors, the change in the engine output and the change in the torque distribution ratio, and the transient state of each change factor cannot be completely controlled. Eventually, the driving force for traveling may become transiently unstable and the drivability may be impaired.

The present invention has been made in view of the above circumstances, and control capable of preventing deterioration of drivability in a vehicle in which the combustion cylinder and the distribution ratio of the driving force can be changed. The purpose is to provide a device.

[0008]

In order to achieve the above object, the invention of claim 1 is an engine capable of selectively suspending combustion in a predetermined cylinder among a plurality of cylinders, and at least an engine. the control device for a power distribution device capable of changing the driving force distribution ratio two drive shafts, determining that the driving force distribution rate for changing the gas cylinder causing combustion
If the judgment to change
The execution of the distribution rate change control is suspended and the engine
Change cylinder switching control by switching
Then, release the hold and change the driving force distribution ratio.
It is characterized by comprising means for executing further control . According to a second aspect of the present invention, an engine capable of selectively stopping combustion in a predetermined cylinder among a plurality of cylinders, and a power distribution capable of changing a driving force distribution ratio for at least two drive shafts. the control device for the device, determining that the driving force distribution rate for changing the gas cylinder causing combustion
If the decision to change
Control of combustion cylinder by switching bank
Execution is suspended and the drive power distribution ratio change control is executed.
Then, after releasing the hold, the bank of the engine
Execute the change control of the combustion cylinder by switching
It is characterized by having means . According to a third aspect of the invention, an engine capable of selectively stopping combustion in a predetermined cylinder among a plurality of cylinders, and a power distribution capable of changing a driving force distribution ratio for at least two drive shafts. In the control device and the device,
Judgment to change the number of cylinders and judgment to change the driving force distribution ratio
If both and are established at the same time, the driving force distribution ratio change
Control and execute the control of changing the number of cylinders,
After that, the hold is released to change the driving force distribution ratio.
It is characterized in that it is provided with means for carrying out control . According to a fourth aspect of the present invention, an engine capable of selectively suspending combustion in a predetermined cylinder among a plurality of cylinders, and a power distribution capable of changing a driving force distribution ratio for at least two drive shafts. the control device for the apparatus, the driving force distribution and determines to change the air cylinder number causing combustion
If the judgment to change the rate is satisfied at the same time, the cylinder
The change control of the driving force distribution ratio.
To execute the control, then release the hold and
It is characterized in that it is provided with means for executing the number change control . The invention of claim 5 is the invention of claim 1 or 2.
In addition to the configuration, bank switching to perform the combustion of said engine, characterized in that the carried out by controlling the opening degree of the throttle valve provided in an intake conduit connected to each bank It is what Claim
The invention of claim 6 is the invention of claims 1 to 5 above.
The power distribution device described above gradually changes the engaging force
Change the drive force distribution ratio for at least the two drive shafts
It is characterized by having a clutch.

[0009]

In the engine targeted by the control device of the present invention, combustion is stopped or released from a predetermined cylinder in accordance with the traveling state such as throttle opening and vehicle speed. Further, the driving force distribution device changes the distribution ratio of torque to at least two driving shafts such as the front wheel driving shaft, the rear wheel driving shaft, or the driving shafts of the left and right wheels according to the traveling state. And determination of the change of the cylinders performing combustion in accordance with the running state, if the determination of the change in the distribution ratio of the driving force are established at the same time, the simultaneous execution of the change and changes the driving force distribution ratio of the cylinders performing combustion Is prohibited
To be done . As a result, for example, the distribution ratio of the driving force is changed after changing the combustion cylinder, or conversely, the combustion cylinder is changed after changing the distribution ratio of the driving force. Therefore, the torque fluctuations due to these change controls do not overlap,
It is possible to stabilize the torque, reduce shock, and improve drivability.

[0010]

EXAMPLES The present invention will now be described in detail based on examples. FIG. 1 is a block diagram showing the basic construction of an embodiment of the present invention, in which an engine Eg capable of changing the combustion state in each cylinder for each bank is used as a power transmission switching device in a running state. The automatic transmission At and the four-wheel drive transfer Tf, which change gears based on the engagement / disengagement state of the friction engagement device, are connected to each other.

The automatic transmission At is, for example, a torque converter having a lock-up clutch built-in, and a gear transmission capable of setting five forward gears and one reverse gear including overdrive gears. Controller 17
The lock-up clutch is ON / OFF-controlled and the shift is controlled by supplying / discharging the hydraulic pressure. The hydraulic control device 17 includes first to third solenoid valves S1, S2, S3 for mainly setting the first to fifth speeds and reverse gear, and a linear solenoid valve for controlling the lockup clutch. SLU
And a linear solenoid valve SLT for controlling the line oil pressure PL according to the throttle opening and a linear solenoid valve SLN for controlling the accumulator back pressure.

An electronic control unit (T-ECU) 18 for controlling these solenoid valves is provided,
This is a central processing unit (CPU) and a storage element (R
OM, RAM) and input / output interface, which are the signals from the input speed sensor to the automatic transmission At, the vehicle speed signal, the signal from the neutral start switch, the signal from the oil temperature sensor, and the pattern select. The signal from the switch, the signal from the overdrive switch, the signal from the stop lamp switch, the signal from the transfer switch, and other signals are input. An electronic control unit (E-ECU) 19 for an engine is connected to the electronic control unit 18 so that data can be communicated with each other. A signal from the throttle position sensor, a signal from the water temperature sensor, a signal indicating the temperature of the exhaust purification catalyst, and other signals are input to the electronic control unit 19 for the engine.

Electronic control unit 18 for the automatic transmission described above
Controls the gear position to be set and the engagement / release of the lock-up clutch based on each input signal and a map stored in advance, and the engine electronic control unit 19 controls the torque during gear shifting. A signal is output to execute the down control.

The engine Eg to which the above-mentioned automatic transmission At is connected is an engine configured so as to perform combustion pause control or control of the combustion state by the ignition timing and the fuel injection amount, with a predetermined number of cylinders as a group. An example thereof is a V-type engine that performs the above control for each cylinder of the left and right banks. FIG. 2 is a diagram schematically showing this engine Eg. Intake pipe lines 22 and 23 are provided for each cylinder (not shown) of the left bank 20 and the right bank 21 as a group. Electronic throttle valves 24 and 25 whose openings are electrically controlled are provided on the paths 22 and 23. The exhaust ports (not shown) of the cylinders of the left and right banks 20 and 21 are connected to the exhaust manifold 2
Exhaust pipes 28, 29 are connected via 6, 27. And each of those exhaust pipes 2
Exhaust gas purification catalysts 30 and 31 are provided at 8 and 29.

Further, portions of the exhaust pipes 28 and 29 slightly upstream of the exhaust purification catalysts 30 and 31 and the electronic throttle valves 24 and 24 of the intake pipe passages 22 and 23, respectively.
25, a circulation pipe line 32 that connects a part on the slightly downstream side of 25,
33 is provided, and exhaust gas recirculation (EG) for opening and closing the pipelines 32, 33 is provided in the middle of the circulation pipelines 32, 33.
R) Valves 34 and 35 are provided respectively.

The ignition timing, the fuel injection amount, the throttle opening, and the EGR valves 34 and 35 in the cylinders of the left and right banks 20 and 21 described above are constructed so that they can be controlled independently of each other. The engine electronic control unit 19 includes a left bank control engine computer 36 and a right bank control engine computer 37. Each of these engine computers 36, 37 is connected to the automatic transmission electronic control unit 18 in a data communicable manner, and the temperatures of the corresponding left and right exhaust purification catalysts 30, 31 are input as data. The engine computers 36, 37 control the ignition timing or the fuel injection amount in the corresponding left and right electronic throttle valves 24, 25 and the corresponding cylinders in the left and right banks 20, 21.

The above engine Eg and automatic transmission At
In addition, in the vehicle equipped with the four-wheel drive transfer Tf, the operating state of the engine Eg is switched between the two-bank operation in which combustion is performed in all cylinders and the one-bank operation in which combustion is performed in the cylinders in one bank according to the traveling state. However, during the bank switching, bank switching control is executed so that the engine torque continues smoothly, that is, the output characteristic of the engine Eg is maintained constant. In other words, even if the operation is switched from one-bank operation to both-bank operation, the engine torque is not doubled but maintained constant at the time of switching. That is, each bank 20,
By providing the intake and exhaust system individually in 21,
One-bank operation is performed in order to reduce mechanical loss such as friction and improve fuel efficiency. Therefore, as shown in FIG. 3, the accelerator opening TA is in a relatively small range TA1 to T1.
In A2, one bank operation in which one of the banks 20 and 21 burns is executed, and in that case, the bank 2 that is operated
The throttle opening θ for 0 (or 21) is expanded to about twice as large as that for both banks. Therefore, the output torque of the engine Eg basically changes smoothly.

Further, when the one-bank operation is performed in this way, the temperature of the exhaust purification catalyst 30 (or 31) on the bank side which is stopped gradually decreases. Therefore, when the one-bank operation is continued, the exhaust gas is exhausted. In order to maintain the activity of the purification catalyst, the banks to be operated are switched. Further, the EGR valve on the bank side in which combustion is stopped is fully opened, and the opening degree of the EGR valve on the bank side in which combustion is being performed is controlled according to the operating state. Then, when switching between banks during one-bank operation or between one-bank operation and both-bank operation, the throttle opening degree for each bank 20, 21 corresponds to one opening degree and the other opening degree. It is controlled by an adjusting coordinated control, so that the engine output characteristic is kept constant. It should be noted that the two-bank operating region and the one-bank operating region are shown in FIG. 4 when the vehicle speed and the throttle opening are shown as parameters.

The four-wheel drive transfer Tf is connected to the output shaft 15 of the above-mentioned automatic transmission At, and is provided with a set of planetary gear mechanisms 38 for performing front and rear wheel differentials, and a difference consisting of a multi-disc clutch. And a motion limiting clutch 39. The output shaft 15 of the automatic transmission At is connected to the carrier 40 of the planetary gear mechanism 38, and the sun gear 41
Is connected to the drive sprocket 42, and the ring gear 43 is further connected to the rear propeller shaft 44. The driven sprocket 4 connecting the drive sprocket 42 and the front propeller shaft 45.
A chain 47 is wound around 6 and. A differential limiting clutch 39 is provided between the carrier 40 and the sun gear 41.

Therefore, when the differential limiting clutch 39 is completely released, the torque input from the carrier 40 is transmitted to the ring gear 43 and the sun gear 4 in the planetary gear mechanism 38.
1, that is, distributed to the rear wheel side and the front wheel side. On the other hand, if the engagement force of the differential limiting clutch 39 is gradually increased, a part of the torque input from the carrier 40 is directly transmitted to the front wheels, so that the torque distribution ratio to the front and rear wheels changes. A four-wheel drive hydraulic control device (4WD-hydraulic control device) 48 is provided to control the differential limiting clutch 39 in this manner. This hydraulic control device 48 is
The hydraulic pressure corresponding to the input electric signal is supplied to the differential limiting clutch 39 to adjust the differential limiting force, that is, the distribution ratio of the torque to the front and rear wheels.

Furthermore, an electronic control unit (4WD-ECU) 49 for controlling the hydraulic control unit 48 is provided. The electronic control unit 49 is mainly composed of a central processing unit (CPU), storage elements (ROM, RAM) and an input / output interface, like the electronic control units 18 and 19 described above. It is connected to the control devices 18 and 19 so as to be capable of data communication. Further, the electronic control unit 49 includes steering angle sensor 50, wheel speed sensor 51 provided for each wheel, yaw rate sensor 52, throttle opening sensor 53 and other sensors, neutral start switch 54 and idle switch 55 and the like. The signal from the switch is input, and the electronic control unit 49 controls the differential limiting force by performing calculation based on the data input from these sensors and switches.

In FIG. 1, reference numeral 56 indicates a front differential, and reference numeral 57 indicates a front drive shaft.

In the engine Eg, bank switching control for performing combustion is executed based on a running state such as throttle opening and vehicle speed, and differential limitation in the four-wheel drive transfer Tf, that is, a torque distribution ratio between the front and rear wheels is performed. Is controlled based on the traveling state such as the vehicle speed, the steering angle, or the yaw rate. Since the bank switching control and the torque distribution ratio control are basically determined independently of each other, these two determinations may be made in duplicate. If these two controls are executed at the same time, the fluctuation factors of the torque may overlap and the output torque may change intricately, which may deteriorate the drivability. Therefore, the present invention controls as follows.

FIG. 5 is a flowchart showing an example of the control routine. After the input signal is processed (step 1), the throttle valves 24 and 25 for the left and right banks 20 and 21 are cooperatively controlled. It is determined whether or not there is (step 2). This coordinated control is provided for the left and right throttle valves 24 and 25 when switching between both banks operation and one bank operation or when switching banks during one bank operation.
Is controlled so that the output characteristic of the engine becomes constant by controlling the opening degrees of the two.

When it is determined in step 2 that the cooperative control is being executed, the differential limiting clutch (C / D)
It is determined whether or not it is determined to execute control of changing the differential limiting force by 39, that is, changing the torque distribution ratio to the front and rear wheels (step 3). Differential limiting clutch 39
If there is no factor for changing the differential limiting force due to, the determination result in step 3 is "NO", and in this case, the routine is exited without performing any particular control. On the other hand, if there is a factor that should change the torque distribution ratio to the front and rear wheels, the determination result of step 3 becomes "yes",
In this case, the bank switching in the engine and the torque distribution ratio changing control in the four-wheel drive transfer Tf are judged simultaneously.

Therefore, in the present invention, the differential limiting force changing control (C / C) by the differential limiting clutch 39 is performed in order to avoid simultaneous execution of the bank switching control and the driving force distribution ratio changing control.
D switch control) is suspended (step 4). In the hold control of step 4, only the change control based on a specific factor may be held instead of the change control based on all factors. For example, the changing control of the differential limiting force at the time of cornering is control that requires immediacy (timeliness), and thus such control may be executed without being held. Then, the flag F1 indicating that the suspension control is being executed is set to "1" (step 5).

The control routine shown in FIG. 5 is executed at predetermined time intervals, and the throttles for the left and right banks 20 and 21 are held while the switching control of the differential limiting force by the differential limiting clutch 39 is suspended as described above. Coordinated control of the valves 24 and 25 is executed, and when the coordinated control is completed, the determination result of the step 2 becomes "no". It should be noted that the result of this determination in step 2 is "No" if the bank switching has not been determined because the running state has not changed.
If the determination result of step 2 is "no", step 6
Then, it is judged whether the flag F1 is set to "1". If the flag F1 is not set to "1", it means that the change of the differential limiting force by the differential limiting clutch 39 has not been judged. In this case, therefore, the routine proceeds to step 7 and the differential limiting clutch 39 is used. It is determined whether it is determined that the differential limiting force switching control should be performed. If the determination result is "no", the control routine is exited without performing any control, and if it is determined that the differential limiting force is switched, the differential limiting force changing control by the differential limiting clutch 39 is executed. (Step 8). Then, the flag F1 is set to "0" (step 9).

If the flag F1 is set to "1" in step 6 and the result of the judgment is "yes",
Since it has already been determined that the differential limiting force is changed by the differential limiting clutch 39, in this case, the process immediately proceeds to step 8 and the differential limiting force changing control by the differential limiting clutch 39 is executed. To do.

In the determination of the differential limiting force change control by the differential limiting clutch 39 in step 3 or step 7 described above, for example, the ΔNFR control, which is the control based on the difference in the rotational speeds of the front and rear wheels, or the start control or the difference. Motion restriction OFF
Whether the hydraulic pressure of the differential limiting clutch 39 is switched by the control or not is determined.

The above-described suspension of the differential limiting force switching control is performed when switching control from both bank operation to one bank operation or when switching from one bank operation to both bank operation.
Alternatively, it is executed when the bank is switched in the single bank operation state. Each of these cases will be specifically described with a time chart.

FIG. 6 shows an example in which the switching control of the differential limiting force is suspended when switching from both bank operation to one bank operation, and is used to change the running state such as throttle opening and vehicle speed. When it is determined that the bank is to be switched at time T1, the throttle valve cooperative control is performed after a predetermined delay time has elapsed. That is, both banks are operating at the time of T1, and the left and right throttle valves 2
The openings of 4 and 25 are set to be substantially equal. In addition, the EGR valves 34 and 35 are also in the respective banks 2
The openings of 0 and 21 are set according to the openings of the throttle valves 24 and 25.

When it is determined at T2 after T1 that the differential limiting clutch 39 should switch the differential limiting force, the switching control is suspended and is not immediately executed. That is, prohibition control is performed. On the other hand, the left and right throttle valves 2
The openings of Nos. 4 and 25 are changed so as to shift from the both bank operation to the one bank operation. For example, the opening of the throttle valve 24 of the left bank 20 is gradually increased, and the opening of the throttle valve 25 of the right bank 21 is decreased according to the opening of the left throttle valve 24. When the left throttle valve 24 is fully opened, the right throttle valve 5 is fully closed almost at the same time. After that, the left throttle valve 24 is slightly throttled so that the engine output corresponds to the accelerator opening degree, and the right throttle valve 24 is opened. The throttle valve 25 is slightly opened. In this way, when the left and right throttle valves 24, 25 are cooperatively controlled, the engine torque slightly fluctuates due to the change in the opening degree of each throttle valve 24, 25, resulting in an unstable state. The engine torque becomes constant as the cooperative control ends. The engine torques during both bank operation and one bank operation are maintained at substantially the same value. On the other hand, the EGR valves 34 and 35 are controlled in accordance with the throttle openings 24 and 25 in the banks 20 and 21, respectively. Specifically, the opening degree of the EGR valve 34 on the left side is switched according to the opening degree of the corresponding throttle valve 24. Further, since the throttle valve 25 corresponding to the EGR valve 35 on the right side is finally fully closed, the EGR valve 35 on the right side is controlled to be fully open at the end of the cooperative control. In this way, the differential limiting force switching control by the differential limiting clutch 39 is executed at time T3 when the switching from the both bank operation to the single bank operation by the coordinated control of the left and right throttle valves 24 and 25 is completed.

FIG. 7 shows an example in which one-bank operation is switched to both-bank operation in response to a request to increase the output torque. That is, when the bank switching is determined at time T1, if the left bank 20 is operating at that time, the throttle valve 24 for the left bank 20 is gradually increased after a predetermined delay time. Further, the throttle valve 25 for the right bank 21 is once fully closed immediately after the left-side throttle valve 24 is almost fully opened, and thereafter, the opening degree of the left-side throttle valve 24 decreases as the opening degree of the left-side throttle valve 24 decreases. The throttle valves 24 and 25 are enlarged, and finally both throttle valves 24 and 25 are set to substantially the same opening degree.

On the other hand, the EG for each bank 20, 21
The R valves 34 and 35 are controlled according to the throttle opening corresponding to each, and especially the EGR for the right bank 21 is performed.
The valve 35 is once fully closed when the throttle valve 25 is fully closed, and then set to an opening degree according to the opening degree of the throttle valve 25. Therefore, the engine torque is increased with respect to the one-bank operation state.

Such left and right throttle valves 24,
If it is determined that the limiting control of the differential limiting clutch 39 by the differential limiting clutch 39 is performed at the time T21 during execution of the coordinated control of 25, this switching control is performed by the throttle valves 24, 25.
It is suspended until the cooperative control of is completed. That is, the inhibition control is performed, and the differential limiting force switching control by the differential limiting clutch 39 is executed at time T31 after the termination of the cooperative control.

FIG. 8 shows an example of a case in which the differential limiting force switching control of the differential limiting clutch 39 is determined when switching banks during single-bank operation. That is, when the bank switching is judged due to a decrease in the temperature of the catalyst while the left bank is operating (at time T1),
After a predetermined delay time, the throttle valve 24 for the left bank 20 is gradually opened. At the same time, the throttle valve 25 for the right bank 21 is gradually closed until fully closed. After that, the left throttle valve 24
The opening of the right throttle valve 25 is gradually increased while gradually closing the opening of the left throttle valve 25, and when the left throttle valve 24 is almost fully closed, the right throttle valve 25 is almost equal to the maximum opening of the left throttle valve 24. Increase to equal opening. Thereafter, the throttle valve 25 on the right side is throttled to an opening degree corresponding to the accelerator opening degree, and together with this, the throttle valve 24 on the left side is maintained in a slightly opened state.

On the other hand, the EGR valves 34 and 35 are once closed until they are completely closed, and the left throttle valve 24 is closed.
In addition, during the transition period in which the right throttle valve 25 is opened, both EGR valves 34 and 35 are maintained in the fully closed state, and the left side of the throttle valve 24 and 25 is closed together with the completion of cooperative control of these throttle valves 24 and 25. The EGR valve 34 is fully opened, and the EGR valve 35 on the right side is the throttle valve 2
The opening is set according to the opening of 5.

The left and right throttle valves 24, 2 described above
At the time of T22 during the cooperative control of 5, the differential limiting clutch 39
If it is determined that the differential limiting force switching control is performed, the switching control is not immediately executed but is suspended. That is, prohibition control is performed. Then, at time T32 after the cooperative control of the throttle valves 24 and 25 is completed, the differential limiting force switching control by the differential limiting clutch 39 is executed.

Bank 2 to be operated as described above
When the switching of 0 and 21 is performed, even if it is determined that the distribution ratio of the driving force to the front and rear wheels is switched, the switching control is not immediately executed and is held until the bank switching is completed. As a result, according to the above-described control, two controls, that is, the bank switching and the driving force distribution ratio switching do not occur at the same time, and therefore the output torque becomes unstable, and the drivability deteriorates accordingly. It is prevented from doing.

Next, another embodiment of the present invention will be described with reference to FIG.
Will be described with reference to. This FIG. 9 shows a differential limiting clutch 39.
2 shows a control routine for executing the differential limiting force switching control by means of priority over the cooperative control of the throttle valves 24, 25 for bank switching. First, the input signal is processed (step 20), and then the differential signal is processed. It is determined whether or not the differential clutch force switching control by the limiting clutch 39 is in progress (step 21). If the determination result is "yes", it is determined whether or not it is determined that the cooperative control of the throttle valves 24 and 25 for bank switching should be performed (step 22). If the result of the determination is "no", the control routine is exited without performing any particular control. If the cooperative control of the throttle valves 24 and 25 is determined, the cooperative control is suspended without being immediately executed (step 23). Then, in this case, if the one-bank operation is being performed, the control of the throttle valves 24 and 25 is continued while the left and right throttle valves 24 and 25 are opened differently (step 24). In both bank operating states, the left and right throttle valves 24 and 25 are controlled to have substantially the same opening. Then, in step 25, the flag F3 is set to "1".

The control routine shown in FIG. 9 is also executed at predetermined time intervals, so that the differential limiting force of the differential limiting clutch 39 is applied while the coordinated control of the throttle valves 24 and 25 is suspended as described above. When the switching control progresses, and as a result, the switching control of the differential limiting force by the differential limiting clutch 39 is completed, the determination result of step 21 becomes "NO". Further, the determination result of this step 21 becomes "No" even when it is not necessary to switch the differential limiting force by the differential limiting clutch 39 because the running state has not changed. Then, in this case, it is judged whether or not the flag F3 is "1" (step 26), and if the judgment result is "no", that is, if the coordinated control of the throttle valves 24, 25 is not suspended, then again. It is determined whether or not it is determined that cooperative control of the throttle valves 24 and 25 should be performed (step 27). If the determination result is "no", the control routine is exited without performing any particular control. If the determination result of step 27 is "yes", it means that the determination that the coordinated control of the throttle valves 24 and 25 should be performed is independently established, so the coordinated control is immediately executed (step 28). . Thereafter, the flag F3 is reset to zero (step 29). On the other hand, if the determination result in step 26 is "yes", it means that the determination for cooperative control of the throttle valves 24, 25 has already been established.
In this case, the process immediately proceeds to step 28 without performing step 27, and the cooperative control of the throttle valves 24 and 25 is executed.

Suspend of the coordinated control of the throttle valves 24 and 25 for bank switching during the switching of the driving force distribution ratio described above is performed when switching from both bank operation to one bank operation and from one bank operation to both bank operation. It is executed both for switching and for bank switching in single bank operation. Switching between double-bank operation and single-bank operation will be described with reference to a time chart. FIG. 10 shows an example of suspending the switching from double-bank operation to single-bank operation. Switching of the differential limiting force by the limiting clutch 39 is T10.
When it is judged at the time point, the differential limiting force switching control is executed at the time point T11 when the predetermined delay time has elapsed. When it is determined at T12 during the differential limiting force switching control that the bank switching operation should be switched to the single bank operation, execution of the bank switching control based on the determination is suspended. That is, the bank switching prohibition control is performed.

When the differential limiting force switching control progresses and the differential limiting force switching control is completed at time T13, the bank switching control is released. That is, the left and right throttle valves 24 and 25 and the EGR valves 34 and 35 are set to substantially equal opening degrees to perform both bank operation, and when the suspension of the switching control to the one bank operation is released, for example, the left side is operated. The opening of the throttle valve 24 is gradually increased, and accordingly, the opening of the right throttle valve 25 is gradually reduced. At the same time that the opening of the left throttle valve 24 is almost doubled, the opening of the right throttle valve 25 is almost fully closed. Then, the opening of the left throttle valve 24 becomes the accelerator opening. The opening of the throttle valve 25 on the right side is slightly opened while the opening is set accordingly.

On the other hand, the opening degree of the EGR valve 34 on the left side is
The opening is temporarily increased in accordance with the change in the opening of the throttle valve 24 corresponding to this, but is finally set to substantially the same opening as before the start of control. Further, the EGR valve 35 on the right side is once fully closed as the corresponding throttle valve 25 is fully closed, and thereafter the opening degree is increased until it is fully opened. Therefore, the engine torque is somewhat unstable and fluctuates during the coordinated control of the throttle valves 24 and 25, but is maintained substantially constant before and after the bank switching.

FIG. 11 shows an example in which the switching control from one-bank operation to both-bank operation due to an output increase request is suspended. That is, as described above, when the determination of switching the distribution ratio of the driving force of the differential limiting clutch 39 is established at time T10, the engaging force of the differential limiting clutch 39 is changed at time T11 when a predetermined delay time has elapsed. The switching control of the driving force distribution ratio is started by and continues until time T13. Then, T12 immediately after T10 when the switching of the driving force distribution ratio is determined.
When it is determined that the one-bank operating state is switched to the both-bank operating state at that time, the throttle valve that has been substantially fully closed (for example, the right throttle valve 25) is gradually opened. In that case, the EGR valve 35 on the right side is
After being fully closed, the left side EGR valve 34 is opened to an opening degree substantially equal to that of the left side EGR valve 34. Therefore, the engine torque is
It gradually increases.

After the time point T13 when the switching control of the driving force distribution ratio is completed, the opening degree of the left throttle valve 24 is gradually decreased as the opening degree of the right throttle valve 25 increases. That is, the coordinated control of the left and right throttle valves 24 and 25 is suspended until the switching control of the driving force distribution ratio is completed, and then executed. Finally, the opening degrees of the left and right throttle valves 24, 25 become substantially equal to each other, and the engine torque increases as compared with the one bank operation.

Therefore, in both the case of switching from the both-bank operation to the one-bank operation and the case of switching from the one-bank operation to the both-bank operation shown in FIG. Since the rate switching control is held until the end, the two controls of bank switching and driving force distribution rate switching do not occur at the same time, so the output torque becomes unstable, and the driver Deterioration of the ability is prevented.

In the above-described embodiment, an example in which the present invention is applied to the engine Eg that switches the banks so that the output characteristics are constant has been described. However, the present invention is accompanied by a change in the number of combustion cylinders. It is also possible to implement it for an engine whose output characteristics change. FIG. 12 shows a case where an engine whose output characteristics change is targeted.
Change control of differential limiting force by the differential limiting clutch 39 of
(C / D switch control) hold shows an example of a control routine (step 4). This is to change step 2 in the control routine shown in FIG. 5 to a step (step 2-1) for determining whether or not the control for switching the number of combustion cylinders is being performed.
Further, the flag F1 is changed to the flag F2.

Further, when the judgments of the switching of the driving force distribution ratio and the change of the number of cylinders occur at substantially the same time, the above-mentioned FIG.
Contrary to the example shown in 2, the execution of the switching control of the number of cylinders may be suspended. An example thereof is shown in FIG. 13, which changes step 22 in FIG. 9 described above into a step (step 22-1) for determining whether or not the determination of the number of cylinders has been established, and step 27. , The determination step of whether or not the determination of the number of cylinders has been established is established (step 27-1), and the flag F3 is changed to the flag F.
It was changed to 4.

A time chart when the control shown in FIG. 13 is performed is shown in FIG. 14, and when the judgment of the switching of the distribution ratio of the driving force of the differential limiting clutch 39 is established at time T10, the predetermined delay time is established. At the time point T11 after the passage of time, the switching control of the driving force distribution ratio is started by changing the engaging force of the limited slip differential clutch 39, and continues until the time point T13. Then, immediately after the time T10 when the switching of the driving force distribution ratio is judged,
When it is determined that the number of combustion cylinders is switched (for example, the number of combustion cylinders is increased) at 12th time, the switching control is not immediately executed but is suspended. That is, the switching control of the number of cylinders is prohibited. Then, after the time point T13 when the switching control of the driving force distribution ratio is completed, the switching control of the number of cylinders is executed. In addition, the engine torque increases accordingly.

Therefore, regardless of whether the control shown in FIG. 12 or the control shown in FIG. 13 is performed, a change in the driving force distribution ratio and a change in engine torque due to an increase in the number of cylinders occur simultaneously. Therefore, deterioration of drivability is prevented in advance.

In each of the above-described embodiments, the four-wheel drive transfer Tf including the planetary gear mechanism 38 and the differential limiting clutch 39 serves as means for switching the distribution ratio of the driving force.
Showed, this invention has been not limited to the above embodiment, the hand stage to obtain switching the driving force distribution ratio,
May be a device for selectively switched between two-wheel drive state and a four-wheel drive state and limited regardless the equipment for changing the distribution ratio of the driving force to the front and rear wheels, the distribution ratio of the driving force to the left and right wheels It may be a device for selectively switching.

[0053]

As described above, according to the control device of the present invention, engine switching control involving engine torque fluctuations such as switching of banks for combustion and changing of the number of combustion cylinders, and four-wheel drive state are performed. When it becomes a state where control to change the distribution ratio of driving force such as switching to the two-wheel drive state should be performed, it is prohibited to execute these two switching controls at the same time or in duplicate, and only one of them is switched. Since the other switching control is executed after the control is completed, it is possible to prevent the running torque from becoming unstable and the drivability from being deteriorated accordingly.

[Brief description of drawings]

FIG. 1 is a block diagram schematically showing an embodiment of the present invention.

FIG. 2 is a block diagram schematically showing a supply / exhaust system and a control system of a V-type engine capable of bank switching.

FIG. 3 is a diagram schematically showing a change in throttle opening and a change in output torque for one of the banks due to bank switching.

FIG. 4 is a diagram showing a one-bank operating region and both-bank operating regions by a vehicle speed and a throttle opening.

FIG. 5 is a flowchart showing an example of a control routine that suspends execution of power distribution ratio switching control.

FIG. 6 is a time chart when the execution of the differential limiting force switching control is suspended during the coordinated control of the throttle valve for switching from both bank operation to one bank operation.

FIG. 7 is a time chart when the execution of the differential limiting force switching control is suspended during the coordinated control of the throttle valve for switching from one bank operation to both bank operation.

FIG. 8 is a time chart when the execution of the differential limiting force switching control is suspended during the coordinated control of the throttle valve for switching from the left bank operation to the right bank operation.

FIG. 9 is a flowchart showing a control routine for suspending execution of throttle valve emphasizing control during differential limiting force switching control.

FIG. 10 is a time chart when the throttle valve cooperative control for switching from the two-bank operation to the one-bank operation is suspended during the differential limiting force switching control.

FIG. 11 is a time chart when the coordinated control of the throttle valve for switching from one-bank operation to both-bank operation is suspended during the differential limiting force switching control.

FIG. 12 is a flowchart showing a control routine that suspends execution of differential limiting force switching control during cylinder number switching control.

FIG. 13 is a flowchart showing a control routine that suspends execution of the cylinder number switching control during the differential limiting force switching control.

FIG. 14 is a time chart when the execution of the cylinder number switching control is suspended during the differential limiting force switching control.

[Explanation of symbols]

17 Hydraulic control device 18 Electronic control unit 19 Electronic control unit 20,21 banks 24,25 electronic throttle valve 39 Limited differential clutch 44 Rear propeller shaft 45 front propeller shaft 48 four-wheel drive hydraulic control device Eg engine At automatic transmission Tf four-wheel drive transfer

─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-64-36934 (JP, A) JP-A-5-96978 (JP, A) JP-A-2-176264 (JP, A) Actual development Sho-60- 24836 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) F02D 17/02 B60K 17/348 B60K 41/04 F02D 29/00 F02D 41/02

Claims (6)

(57) [Claims] 1. An engine capable of selectively stopping combustion in a predetermined cylinder among a plurality of cylinders, and a power distribution device capable of changing a driving force distribution ratio for at least two drive shafts. in the control device, varying the driving force distribution ratio a determination to change the air cylinder causing combustion
If the judgment to change is established at the same time, the driving force distribution
Hold the execution of the rate change control
The combustion cylinder change control is executed by switching the
After that, the hold is released to control the change of the driving force distribution ratio.
A control device for an engine and a power distribution device, which is provided with a means for executing . 2. An engine capable of selectively suspending combustion in a predetermined cylinder among a plurality of cylinders, and a power distribution device capable of changing a driving force distribution ratio for at least two drive shafts. in the control device, varying the driving force distribution ratio a determination to change the air cylinder causing combustion
If the decision to change is made at the same time, the engine
Implementation of change control of combustion cylinder by switching banks
Hold the line, execute the change control of the driving force distribution ratio,
After that, the hold is released and the engine bank is turned off.
A control device for an engine and a power distribution device, which is provided with a means for executing change control of a combustion cylinder by changing the combustion cylinder . 3. An engine capable of selectively stopping combustion in a predetermined cylinder among a plurality of cylinders, and a power distribution device capable of changing a driving force distribution ratio for at least two drive shafts. in the control device, the determining that the driving force distribution rate for changing the gas cylinder number causing combustion
If the judgment to change is satisfied at the same time, the driving force
Hold the control to change the distribution rate and change the number of cylinders.
Control, then release the hold and release the driving force.
A control device for an engine and a power distribution device, which is provided with a means for executing a change ratio control. 4. An engine capable of selectively stopping combustion in a predetermined cylinder among a plurality of cylinders, and a power distribution device capable of changing a driving force distribution ratio for at least two drive shafts. in the control device, the determining that the driving force distribution rate for changing the gas cylinder number causing combustion
If the decision to change is made at the same time, the number of cylinders
Suspend change control and change control of drive force distribution ratio
Control, then release the hold and reset the number of cylinders.
A control device for an engine and a power distribution device, which is provided with means for executing change control . 5. A bank switching to perform the combustion of said engine, and characterized in that which is performed by controlling the opening degree of the throttle valve provided in an intake conduit connected to each bank The control device for the engine and the power distribution device according to claim 1 or 2. 6. The power distribution device gradually changes the engagement force.
Drive force for at least the two drive shafts
It is characterized by having a clutch that changes the distribution ratio
The engine and operation according to any one of claims 1 to 5.
Control device for force distributor.