JP2000227034A - Output variable mechanism control device for internal conmbustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform optimum fail safe-control in the case of the occurrence of abnormality in any output variable mechanism, in the output variable mechanism control device for an internal combustion engine. SOLUTION: In a V-type engine equipped with respective output variable mechanisms 5a and 5b independently driven to right and left banks 3a and 3b respectively, the repective mechanisms 5a and 5b are drive-controlled so that the solid drive conditions of the mechanisms 5a and 5b provided on the respective banks 3a and 3b can be made target drive conditions set in accordance with an operating condition, and the target drive condition in all output variable mechanisms can be changed into the lowest speed drive condition when judged that abnormality occurs in at least any of the mechanisms 5a and 5b.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for an internal combustion engine having a plurality of cylinder groups, which is provided with independently driven variable output mechanisms for each cylinder group, and controls the driving of these variable output mechanisms. .

[0002]

2. Description of the Related Art Conventionally, an internal combustion engine (hereinafter, referred to as an internal combustion engine) is provided with a variable output mechanism such as a variable valve timing mechanism and a variable intake mechanism.
Engine) or vehicle driving conditions,
An internal combustion engine (hereinafter referred to as an engine) in which these output variable mechanisms are appropriately driven and controlled is well known.

[0003] For example, Japanese Patent Application Laid-Open No. 6-229212 and Japanese Patent Application Laid-Open No. 10-141097 disclose a V-type engine having a pair of left and right banks (cylinder rows) provided with a variable valve timing mechanism for each of the left and right banks.
As disclosed in an engine valve timing control device that independently drives each variable valve timing mechanism according to the operation state and varies each valve timing in each bank, a plurality of cylinder groups such as a cylinder row are disclosed. An engine having a variable output mechanism for each cylinder group,
There is known a variable output mechanism control device for an engine that independently drives each variable output mechanism.

For example, Japanese Patent Laid-Open Publication No. 2-42107 discloses that when an actual valve timing does not coincide with a target valve timing according to an operating state for a predetermined time, it is determined that an abnormality has occurred, and a fail-safe operation corresponding to the abnormality is determined. As disclosed in a valve timing control device that performs control, when the actual drive state of the variable output mechanism does not match the target drive state, it is determined that there is an abnormality, and the variable output mechanism control device that performs fail-safe control is provided. It is known.

[0005]

In an engine having a plurality of cylinder groups, such as a series of cylinders, like the above-described V-type engine, a variable output mechanism is provided for each cylinder group, and these variable output mechanisms are independent of each other. In the variable output mechanism control device that is driven in the event that all the variable output mechanisms have an abnormality, the abnormality of the variable output mechanism can be determined by the above-described abnormality determination method. When only the mechanism has an abnormality, it is determined that only the variable output mechanism is abnormal, and the fail-safe control is performed only on the variable output mechanism. As described above, if the fail-safe control is performed only on the output variable mechanism in which the abnormality has occurred, a difference occurs in the output characteristics between the cylinder groups, and a problem such as vibration occurs.

In order to eliminate the difference in output characteristics between the cylinder groups, when an abnormality occurs in an output variable mechanism in a certain cylinder group as in the prior art described in Japanese Patent Application Laid-Open No. 1-110817, It is also conceivable to perform fail-safe control for making the output characteristics of the cylinder groups identical to each other by aligning the drive state of the normal output variable mechanism in the other cylinder groups with the drive state of the abnormal output variable mechanism. .

However, when the normal driving state of the variable output mechanism is matched with the driving state of the variable output mechanism having the abnormality, if the driving state of the variable output mechanism having the abnormality is fixed in a high-speed driving state, The variable output mechanisms in all cylinder groups enter the high-speed driving state. As described above, when all of the output variable mechanisms are in the high-speed driving state, when the engine is in the low rotation state, the air-fuel mixture passes to the exhaust side or the actual compression ratio decreases, so that the combustion stability deteriorates. Not only does idling become unstable, but also the problem of increased engine vibration occurs.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and has a variable output mechanism for an internal combustion engine that controls a variable output mechanism provided for each cylinder group of the internal combustion engine having a plurality of cylinder groups in accordance with an operating state. It is an object of the present invention to provide a mechanism control device capable of performing an optimum fail-safe control for an abnormality of a variable output mechanism when the abnormality is determined.

[0009]

In order to solve the above-mentioned problems, the present invention according to a first aspect of the present invention is directed to an output variable, which is provided in each of the cylinder groups of an internal combustion engine having a plurality of cylinder groups and independently driven. Mechanism, actual driving state detecting means for detecting the actual driving state of each of the variable output mechanisms, and target driving state setting means for setting the target driving state of each of the variable output mechanisms in accordance with the operating state of the internal combustion engine Driving means for controlling each of the variable output mechanisms so that the actual driving state of each of the variable output mechanisms becomes the target driving state; abnormality determining means for determining abnormality of each of the variable output mechanisms; Abnormal state changing means for changing each target drive state of all of the output variable mechanisms to the lowest speed drive state when the judgment means judges that an abnormality has occurred in at least one of the output variable mechanisms. It is characterized in.

According to a second aspect of the present invention, in the first aspect, the target drive state setting means sets the target drive states of the respective output variable mechanisms to be the same (that is, the same or substantially the same). The abnormality determining means calculates a deviation between the target drive state and the actual drive state in each of the output variable mechanisms, and when the deviation in any of the output variable mechanisms is larger than a predetermined value, the output variable mechanism Is determined to be abnormal.

According to a third aspect of the present invention, in the first aspect, the target drive state setting means sets the target drive states of the respective output variable mechanisms to be the same (that is, the same or substantially the same). The abnormality determining means calculates a deviation between the target drive state and the actual drive state in each of the output variable mechanisms, calculates a maximum variation value of the deviation between the output variable mechanisms, and calculates the maximum variation value. Is larger than a predetermined value, it is determined that the variable output mechanism is abnormal.

According to a fourth aspect of the present invention, in any one of the first to third aspects, the abnormal-time changing means includes:
When the target drive state is changed to the lowest speed drive state, at least one of the ignition timing and fuel injection of the internal combustion engine is controlled according to the lowest speed drive state of the variable output mechanism. .

[0013]

Preferred embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 shows a schematic configuration diagram of an engine having an output variable mechanism control device of the present invention. As shown in FIG. 1, the engine 1 in this embodiment includes:
The engine is constituted by a multi-cylinder V-type engine, and each cylinder is divided into two right and left positions around the crankshaft 2 by the same number of cylinders to constitute left and right banks 3a and 3b.

The right bank 3a has camshafts 4a, 4
A variable valve mechanism (variable valve timing mechanism) 5a for varying the opening / closing timing (valve timing) of the intake valve and the exhaust valve driven to open / close by a 'is provided on the left bank 3b by the camshafts 4b and 4b'. A variable valve mechanism (variable valve timing mechanism) 5b that varies the opening / closing timing (valve timing) of the driven intake valve and exhaust valve is provided as an example of an output variable mechanism. The valve timing of each valve is determined by the variable valve timing mechanism 5a,
5b is continuously controlled.

FIG. 2 shows a main part of the variable valve timing mechanism 5a, which controls opening of an intake valve of one cylinder in a multi-cylinder engine having two intake valves and two exhaust valves per cylinder. FIG. 2 shows a perspective view of a valve operating mechanism.
A camshaft 4a coupled to a cam pulley 6 that is rotationally driven by engine power has two cam portions 7a,
An annular eccentric spacer 8 having a hollow shaft-shaped cam lobe 7 integrally formed with the cam shaft 4a and having a rotation center eccentric from the rotation center of the cam shaft 4a by a predetermined amount is provided at one end. Are externally fitted so as to be relatively rotatable. A control gear 9 is provided integrally with the eccentric spacer 8, and a harmonic ring 10 rotatable about the rotation center of the eccentric spacer 8 is fitted around the eccentric spacer 8 so as to be relatively rotatable.

The harmonic ring 10 is provided with a large hole 10a and a small hole 10b on both sides of one diameter, and the large hole 10a has a camshaft slider 11 having one end fitted and fixed to the camshaft 4a. Are fitted so that they can rotate relative to each other.
A cam lobe-side slider 12 which is slidably fitted in a guide groove 7c provided in the cam portion 7a in the radial direction is fitted to 0b.

A control shaft 13 is disposed in parallel with the camshaft 4a. The control shaft 13 is provided with a small gear 14 meshing with the control gear 9, and has an actuator at one end as a driving means having a built-in angle sensor. The drive shaft 15a is connected. The actuator 15 a uses an electric motor and is fixed to a cylinder head of the engine 1.

An electronic control unit (hereinafter referred to as an ECU) 16 controls an engine speed N detected by a crank angle sensor 17.
e, throttle position sensor (hereinafter, TPS) 18
Operating information, such as the throttle opening θth detected from the engine 1, is input to the actuator 1 according to the operating information of the engine 1.
5a is driven. When the actuator 15a is driven, the rotation center of the eccentric spacer 10 is eccentric with respect to the rotation center of the camshaft 4a. And EC
U16 drives the actuator 15a so that the valve opening period becomes short when the engine 1 is in the low rotation state, and so that the valve opening period becomes long when the engine 1 is in the high rotation state, As shown in FIG. 3, the valve opening period is continuously variably controlled according to the operation state. The actuator 15a according to the present embodiment
Is not limited to an electric motor, and may be, for example, a hydraulic motor. For the detailed structure, refer to
It is the same as that described in Japanese Patent No. 37689,
Detailed description here is omitted.

The exhaust-side camshaft 4a 'in the right bank 3a of the engine 1 is also connected to the intake-side camshaft 4a.
a of the same actuator 15
The valve opening period of the exhaust valve is variably controlled by a. Further, the camshafts 4b, 4b 'on the intake side and the exhaust side in the left bank 3b are similarly constructed, and the valve timing variable mechanism 5b variably controls the valve timing of the intake valve and the exhaust valve by the actuator 15b similarly to the right bank 3a. Is provided.

As described above, the engine 1 according to the present embodiment
Are provided with variable valve timing mechanisms 5a and 5b respectively in the right bank 3a and the left bank 3b, and these variable valve timing mechanisms 5a and 5b are independently controlled by respective actuators 15a and 15b. It has a configuration. In the above-described embodiment, an example in which the actuators 15a and 15b simultaneously and variably control the opening periods of the intake valve and the exhaust valve has been described. However, the present invention is not limited to this. Actuators are set for the intake valve and the exhaust valve so that only the opening period of one of the exhaust valves (for example, the intake valve) is variably controlled, or the opening periods of the intake valve and the exhaust valve are independently controlled. Each of them may be provided separately.

As shown in FIG. 1, the ECU 16 stores an intake air temperature Ti and an intake air pressure Pi detected by an intake air temperature sensor 20 and an intake air pressure sensor 21 provided in an intake pipe 19.
And the camshaft rotation speed Nc and cam position Pc detected by the cam position sensor 22 provided on the camshaft 4a 'side of the right bank 3a, and the position sensors 23a and 23b provided on the valve timing variable mechanisms 5a and 5b. (Actual position) Pr of each actuator 15a, 15b detected from
a and Prb are input. Although not shown, a water temperature sensor, a knock sensor, a vehicle speed sensor, and the like may be provided to input the engine coolant temperature, the knock state, the vehicle speed, and the like.

The ECU 16 sets the valve opening characteristics (valve opening / closing timing and valve opening period) of the intake valve and the exhaust valve based on the input information from various sensors so as to make the valve opening characteristics optimal for the operating state of the engine 1. Then, a drive signal is output to the actuators 15a, 15b of the variable valve timing mechanisms 5a, 5b so as to change continuously or stepwise from the minimum valve opening period to the maximum valve opening period.

That is, the rotation phase of the control disk 9 of the variable valve timing mechanism 5a is controlled to an optimum state by the control means 16 based on the engine speed Ne detected by the crank angle sensor 17. Also, EC
U <b> 16 outputs a drive signal to the control element 101 so as to optimally control the control element 101 relating to combustion control of the engine 1 such as ignition timing and fuel injection according to the operating state of the engine 1. The drive signal to the control element 101 is E
The data is output to the control element 101 using a plurality of maps stored in the map storage means 102 in the CU 16.

That is, the control elements 101 of the engine 1 such as the ignition timing and the fuel injection are controlled by the engine speed Ne and the intake pressure (intake pipe internal pressure) Pi detected by the crank angle sensor 17 and the intake pressure sensor 21. Drive control is performed according to the operation state. Further, when the valve opening characteristics of valves such as an intake valve and an exhaust valve can be controlled, the ignition timing and the fuel can be controlled according to not only the operating state of the engine (engine speed Ne and intake pressure Pi, etc.) but also the valve opening characteristics. The drive of a control element such as injection is controlled.

Control elements 101 such as ignition timing and fuel injection
Is controlled according to the operating state of the engine 1 (engine speed Ne, intake pressure Pi, etc.) and valve opening characteristics,
If the valve opening characteristics are optimal for the engine speed Ne, the valve opening characteristics will be uniquely determined for the engine speed Ne, and the engine speed Ne, the intake pressure Pi, etc. If this is known, the valve opening characteristics are determined in accordance with this operating state, and further, control elements such as ignition timing and fuel injection which are optimal for this operating state and valve opening characteristics are also determined.

Therefore, the variable valve timing mechanism 5a,
5b actual driving state (for example, the control disk 9
Position sensors 23a and 23b are provided as actual drive state detecting means for detecting the rotational phase angle of the motor.
U16 is a state where the actual driving state of the variable valve timing mechanisms 5a and 5b detected by the position sensors 23a and 23b is optimal, that is, the valve opening characteristics are optimal according to the operating state of the engine (engine speed Ne). In the state, the ignition timing and the fuel injection are determined by using the map for the optimal valve opening period (optimal valve opening angle map, abbreviated optimal map) in the optimal valve opening characteristic in the map storage means 102 shown in FIG. Control elements such as (volume efficiency) are set.

The map storage means 102 stores optimum values (control element data) of control elements such as ignition timing and fuel injection with respect to the operating state of the engine 1 (ie, engine speed Ne, intake pressure Pi and valve opening characteristics). The corresponding map at the time of the optimal valve opening, the map at the time of the minimum valve opening, and the map at the time of the maximum valve opening are stored. This optimal valve opening angle map shows the ignition timing, fuel injection, etc. for the engine speed Ne and the intake pressure Pi when the valve opening characteristics are in an optimum state according to the operating state of the engine (engine speed Ne). The control elements such as the ignition timing and the fuel injection (volume efficiency) include the engine speed Ne and the intake pressure P.
The optimal value is set for not only i but also the valve opening characteristics.

The minimum valve opening angle map (hereinafter referred to as the lowest speed map) is obtained by adjusting the control disk 9.
When the valve has the minimum valve opening angle (first valve opening characteristic or minimum valve opening period), optimal ignition for this valve opening characteristic and the detected engine speed Ne and intake pressure Pi. Control elements such as timing and fuel injection correspond to each other. In addition, the maximum valve opening angle map (hereinafter, the highest speed map)
This means that if the valve is at the maximum valve opening angle (second valve opening characteristic or maximum valve opening period) by adjusting the control disk 9, this valve opening characteristic and the detected engine speed Ne In addition, control elements such as optimum ignition timing and fuel injection correspond to the intake pressure Pi.

The ECU 16 calculates the engine speed N
When e is smaller than a predetermined value Ne1 (for example, 4000 rpm), the valve opening characteristic is the minimum valve opening angle (minimum valve opening period).
The drive of the actuators 15a and 15b is controlled so that the rotation phase angle of the control disk 9 at this time becomes 0 °. Further, the engine speed Ne becomes the predetermined value Ne2.
(E.g., 6000 rpm) or more, the actuators 15a and 15b are driven and controlled such that the valve opening characteristic becomes the maximum valve opening angle (maximum valve opening period). At this time, the rotation phase angle of the control disk 9 is 180 °. Become. Also,
The engine speed Ne is equal to or more than a predetermined value Ne1 and the predetermined value N
When the value is smaller than e2, the actuators 15a and 15b are set so that the valve opening characteristic is continuously variably set between the minimum valve opening angle and the maximum valve opening angle in accordance with the operating state of the engine 1.
And the rotation phase angle of the control disk 9 at this time continuously moves between 0 and 180 °.

Control elements 10 such as ignition timing and fuel injection
The setting of 1 is performed by appropriately using the above-described three maps of the optimum map, the lowest speed map, and the highest speed map.
That is, the control element 101 is controlled using the lowest speed map when the engine speed Ne is smaller than the predetermined value Ne1, and using the highest speed map when the engine speed Ne is equal to or more than the predetermined value Ne2. When the engine speed Ne is equal to or more than the predetermined value Ne1 and smaller than the predetermined value Ne2, if the actual valve opening characteristic is the optimum valve opening characteristic corresponding to the engine operating state (engine speed Ne), the optimum map is obtained. It is configured to control the control element 101 based on the interpolation method using the optimum map and the lowest speed map or the highest speed map if the actual valve opening characteristic is not the optimum valve opening characteristic. ing.

As described above, the control device of the variable valve timing mechanism in the present embodiment is
The valve opening characteristics (valve opening / closing timing and valve opening period) of the intake valve and the exhaust valve are continuously or stepwise from the minimum valve opening characteristic (see line I in FIG. 3) to the maximum valve opening characteristic (see line II in FIG. 3). The variable valve timing mechanisms 5a, 5a,
5b is drive-controlled.

The target positions Ppa and Ppb of the variable valve mechanisms 5a and 5b in the right bank 3a and the left bank 3b are set to the same (ie, the same or substantially the same), and the valve opening in each cylinder group is performed. The drive of each of the variable valve mechanisms 5a and 5b is controlled so that the characteristics are the same. Next, the fail-safe control in the control device for the variable valve timing mechanism according to the present embodiment will be described with reference to FIG.
This will be described with reference to FIG.

The flowcharts shown in FIGS.
16 is a routine executed by a periodic interruption for a predetermined time. When the process proceeds to this routine, in step A1, cylinder group A (right bank)
The actual position (actual driving state) Pra of the variable valve timing mechanism (hereinafter, variable valve mechanism) 5a is extracted. Next, in step A2, a target position (target drive state) Ppa set in the variable valve mechanism 5a is extracted. Then, in step A3, the target position P
pa and the actual position Pra, the deviation ΔPa (= | Ppa−
Pra |) is calculated.

Next, in step A4, it is determined whether the deviation ΔPa calculated in step A3 is larger than a predetermined value α. If this determination result is affirmative, that is, if the deviation ΔPa between the target position Ppa and the actual position Pra in the cylinder A is larger than the predetermined value α, the process proceeds to step A5,
This actual position Pra is the previous actual position Pra
It is determined whether it is the same as 0. The determination in step A5 is positive,
That is, if the current actual position Pra is the same as the previous actual position Pra0, the process proceeds to step A6,
The timer A counts up.

The determination in step A4 or step A5 is negative, that is, the deviation ΔPa between the target position Ppa and the actual position Pra in the cylinder group A is equal to or smaller than a predetermined value α, or the present actual position Pra is different from the previous actual position Pra0. If not identical, proceed to step A7,
Reset timer A. Step A6 and Step A
After step 7, the process proceeds to step A8, in which position focusing control is performed. This position convergence control is based on the actual position Pr.
When a is different from the target position Ppa, the actual position Pra quickly becomes the target position Ppa.
The drive correction amount of the actuator 15a is set, and the actuator 15a is driven based on the drive control amount set according to the operation state of the engine 1 and the drive correction amount. In this case, when the deviation ΔPa between the target position Ppa and the actual position Pra is smaller than a predetermined value α ′ (<α), the drive correction amount is set to zero to provide a dead zone. Good.

After the position focusing control in the cylinder group A in step A8 is performed, the routine from step B1 to step B8 is executed. The routine from step B1 to step B8 is the same as that for the cylinder group B (left bank) in the cylinder group A between step A1 and step A8.

That is, in steps B1 to B3,
Deviation ΔPb between actual position Prb and target position Ppb of variable valve mechanism 5b in cylinder group B (left bank)
(= | Ppb-Prb |) is calculated. Then, in steps B4 to B7, the deviation ΔPb in the cylinder group B
Is greater than the predetermined value α, and if the current actual position Prb is the same as the previous actual position Prb0, the timer B is counted up and the deviation ΔPb is set to the predetermined value α.
If not, or if the current actual position Prb is not the same as the previous actual position Prb0, the timer B is reset.

Next, in step B8, when the actual position Prb is different from the target position Ppb, the drive correction amount of the actuator 15b is set so that the actual position Prb quickly becomes the target position Ppb.
Position focusing control for driving the actuator 15b based on a drive control amount set in accordance with the operation state of the engine 1 and the drive correction amount is performed.

After performing the position focusing control in the cylinder group B in step B8, the process proceeds to step C1 in the flowchart shown in FIG. 6, in which the count-up value Ta of the timer A in the cylinder group A and the timer B in the cylinder group B are counted up. T
Extract b. Next, in step C2, it is determined whether one of the count-up values Ta and Tb of the timer A and the timer B is larger than a predetermined value β.

In step C2, one of the count-up values Ta and Tb of the timer A and the timer B is larger than a predetermined value β, that is, the deviation ΔPa between the target position Ppa and the actual position Pra in the cylinder group A is determined. A state where the actual position Pra is larger than the predetermined value α and the actual position Pra is not changed, or a state where the deviation ΔPb between the target position Ppb and the actual position Prb in the cylinder group B is larger than the predetermined value α and the actual position Prb is not changed continues for a predetermined time. In this case, the determining function (abnormality determining means) provided in the ECU 16 determines that an abnormality such as solidification of at least one of the variable valve mechanisms 5a and 5b has occurred, and proceeds to step C3. The fail flag F is set to 1.

Next, the routine proceeds to step C4, in which the changing function (any variable valve mechanism 5a,
When the abnormality is determined for 5b, both variable valve mechanisms 5
a, 5b, the target position Pp in each of the variable valve mechanisms 5a, 5b set based on the operating state of the engine 1.
a, Ppb is the lowest speed position (lowest speed drive state) Pl
a, Plb, and the variable valve mechanism 5a, 5b.
b is driven and controlled by the actuators 15a and 15b to be at the lowest speed positions Pla and Plb.

Here, the lowest speed positions Pla, Plb
Means a position at which the rotational phase angle of each control disk 9 in the actuators 15a and 15b becomes 0 °, and the valve opening characteristic at this time is the minimum valve opening angle (minimum valve opening angle) as shown by a solid line I in FIG. Opening period).
Next, the process proceeds to step C5, where control maps relating to control elements of the engine 1 such as ignition timing and fuel injection are respectively changed to the lowest speed map, and the control element 101 is controlled based on this lowest speed map. Further, the upper limit value (maximum engine speed) Nemax of the engine speed is set to a predetermined value Ne.
max '. Then it returns.

If the count-up values Ta and Tb of the timer A and the timer B are both equal to or smaller than the predetermined value β in step C2, the routine returns. As described above, the variable valve mechanisms 5a, 5b in the present embodiment
In this control device, independently controlled variable valve mechanisms are provided in each of the cylinder group A (right bank) and the cylinder group B (left bank), and any one of the cylinders in the cylinder group A or the cylinder group B is provided. In the variable valve mechanism in the group, the actual positions Pra,
Deviation ΔP between Prb and target positions Ppa, Ppb
If a and ΔPb are larger than the predetermined value α and the actual positions Pra and Prb are not changed, it is determined that an abnormality has occurred in the variable valve mechanism.

For example, the target positions Ppa, Ppb
Is set to change from the low-speed side to the high-speed side as shown by the solid line in FIG. 9, and when the variable valve mechanisms 5a and 5b are variably controlled from the low-speed side to the high-speed side, one of the cylinder groups If a problem occurs in the driving means of the variable valve mechanism and the actual position in the variable valve mechanism becomes invariable as shown by the dashed line I in FIG. 9, the target in the variable valve mechanism in which the actual position becomes invariable The deviation between the position and the actual position increases, and when the deviation becomes larger than a predetermined value α, it is determined that the position is abnormal.

If the deviation between the target position and the actual position of the variable valve mechanism in any one of the cylinder groups becomes larger than a predetermined value α due to the solidification of the variable valve mechanism, an abnormality is determined. Thus, the abnormality of the variable valve mechanism can be accurately and promptly detected. In FIG. 9, solid lines indicate target positions Ppa, Pp of the variable valve mechanisms 5a, 5b that are set according to the operating state of the engine 1.
b, and the broken line indicates that the variable valve mechanism
This is the actual position when the drive is normally controlled along a, Ppb. As described above, the reason why the actual position in the normal variable valve mechanism is delayed from the target position is that the drive means (actuators) 15a and 15b of the variable valve mechanisms 5a and 5b transmit a signal from the control means (ECU) 16. This is because some response delay occurs due to a time lag from reception to actual driving, and a dead zone is set in order to prevent control hunting. Therefore, when the variable valve mechanism is variably controlled, it is driven with a slight delay as shown by the broken line from the target position shown by the solid line in FIG.

In a V-type engine having a plurality of cylinder groups, such as a right bank and a left bank, a variable valve mechanism which is independently driven and controlled is provided for each cylinder group. When an abnormality occurs in the variable valve mechanisms in the cylinder groups, the variable valve mechanisms 5a and 5b in the cylinder groups A and B, that is, the target positions Ppa and Ppb of all the variable valve mechanisms are changed to the lowest speed positions Pla and Pl.
Then, the variable valve mechanisms 5a and 5b are driven and controlled to be at the lowest speed positions Pla and Plb.

If the variable valve mechanism in which the abnormality has occurred cannot be driven and controlled due to solidification or the like, only the variable valve mechanism in which no abnormality has occurred is switched to the lowest speed position. If the variable valve mechanism that caused the failure cannot control the drive to the highest speed position, the variable valve mechanism that caused the abnormality can also control the drive to the lowest speed position. And the variable valve mechanism in which an abnormality has occurred, that is, all the variable valve mechanisms are driven and controlled to the lowest speed position. As described above, when an abnormality occurs in the variable valve mechanism in any of the cylinder groups, at least the cylinder group A or the cylinder group B
The variable valve mechanism on the side where no abnormality has occurred is driven and controlled at the lowest speed position.

Therefore, if an abnormality occurs in any of the variable valve mechanisms provided for each cylinder group, all the variable valve mechanisms provided for each cylinder group are controlled to switch to the lowest speed position, and at least the abnormality is established. Is switched to the lowest speed position, so that combustion stability during idling can be ensured, and operation in the low to middle speed range can be performed. Then, since the variable valve mechanism having no abnormality is driven by the lowest speed position, even if an abnormality occurs in the variable valve mechanism having no abnormality thereafter, the drive at the lowest speed position is continued and idling is performed. The combustion stability at the time and the operation in the low to medium speed region can be ensured.

Further, in this embodiment, when an abnormality occurs in any of the variable valve mechanisms provided in the cylinder group, the control map relating to the control elements of the engine 1 such as ignition timing and fuel injection is changed to the lowest speed map. Then, this control element is controlled according to the lowest speed map. That is, the control element is controlled to be suitable for the driving state of the variable valve mechanism. Therefore, control elements such as ignition timing and fuel injection (volume efficiency) are optimally controlled according to the valve opening characteristics of intake and exhaust valves by a variable valve mechanism that is switched to the lowest speed position due to occurrence of abnormality. As a result, the combustion stability is further improved, the generation of vibration and abnormal noise is suppressed, and the reduction in durability due to the occurrence of an abnormality can be avoided, thereby ensuring the durability.

In this embodiment, if an abnormality occurs in any of the variable valve mechanisms provided for each cylinder group, the target position of the variable valve mechanism is changed to the lowest speed position, and the control map of the control element is changed. Is changed to the lowest speed map, the upper limit value (maximum engine speed) Nemax of the engine speed Ne is reduced. As described above, by lowering the maximum engine speed Nemax in accordance with the drive control by the lowest speed position of the variable valve mechanism, the bounce of the intake / exhaust valve due to the high-speed movement at the lowest speed position of the variable valve mechanism can be reduced. As a result, the durability of the engine can be ensured.

Next, a control device for a variable valve timing mechanism as a control device for a variable output valve mechanism according to a second embodiment of the present invention will be described. The second embodiment differs from the first embodiment only in the method of determining an abnormality of the variable valve timing mechanism (also referred to as a variable valve mechanism) 5a, 5b, and the configuration of the variable valve mechanism 5a, 5b is different. This is similar to the first embodiment described above.

The fail-safe control according to the second embodiment will be described with reference to FIGS. The flowcharts in FIGS. 7 and 8 are also routines executed by the ECU 16, and are executed at regular intervals of a predetermined time. When the processing shifts to this routine, step A
At 21, the actual position (actual driving state) Pra of the variable valve mechanism 5a in the cylinder group A (right bank) is extracted. Next, at step A22, a target position (target driving state) P in the variable valve mechanism 5a set to have an optimal valve opening characteristic according to the operating state of the engine 1.
Extract pa. Then, in step A23, cylinder group A
Is calculated, the deviation ΔPa (= | Ppa−Pra |) between the target position Ppa and the actual position Pra is calculated.

Next, in step A24, the position focusing control described in step A8 in the first embodiment is performed. That is, the deviation Δ calculated in step A23
The actual position Pra becomes the target position P according to Pa.
variable valve mechanism 5 in cylinder group A so as to match pa
a is driven and controlled. Then, the process proceeds to step A25, and the maximum value ΔPamax and the minimum value ΔPamin of the deviation ΔPa calculated in step A23 in a predetermined period are extracted.

Next, proceeding to step B21, the same routine as steps A21 to A25 in the cylinder group A is performed for the cylinder group B as described above with respect to steps B21 to B25.
Perform in. That is, the deviation ΔPb between the actual position Prb and the target position Ppb in the variable valve mechanism 5b provided in the cylinder group B is calculated, and the actual position Prb is calculated.
Is adjusted so as to match the target position Ppb, and the maximum value ΔPbm of the deviation ΔPb
ax and the minimum value ΔPbmin are extracted.

Next, the process proceeds to step C21 shown in FIG.
The maximum value ΔPamax and the minimum value ΔPamin of the deviation ΔPa in the variable valve mechanism 5a extracted in step A25.
And the maximum value ΔPbmax and the minimum value ΔPbmi of the deviation ΔPb in the variable valve mechanism 5b extracted in step B25.
n, the maximum value ΔPab between the deviation ΔPa and the deviation ΔPb (where ΔPamax−ΔPbmin> ΔPb)
When bmax−ΔPamin, ΔPab = ΔPa
max−ΔPbmin, ΔPbmax−ΔPamin>
When ΔPamax−ΔPbmin, ΔPab = Δ
Pbmax−ΔPamin) is calculated.

Next, the process proceeds to step C22,
It is determined whether the variation maximum value ΔPab calculated in 21 is larger than a predetermined value γ. If the determination in step C22 is affirmative, that is, if the maximum variation value ΔPab is larger than the predetermined value γ, the process proceeds to step C23, where the timer C
Is operated to count up. Next, the routine proceeds to step C24, where it is determined whether or not the count-up value (operation time) Tc of the timer C is greater than a predetermined value (predetermined time) β '. If the determination in step C24 is affirmative, that is, if the state in which the maximum variation value ΔPab is larger than the predetermined value γ has continued for a longer time than the predetermined time β ′, the determination function (abnormality determination means) provided in the ECU 16 It is determined that an abnormality such as solidification of at least one of the variable valve mechanisms 5a and 5b has occurred, and the process proceeds to step C25 to set the fail flag F to 1.

Next, the routine proceeds to step C26, where the ECU 16
The target position (target drive state) Pp of the variable valve mechanism 5a of the cylinder group A and the variable valve mechanism 5b of the cylinder group B by a change function (abnormality change means) provided therein.
a, Ppb is the lowest speed position (lowest speed drive state) Pl
a, Plb. This lowest speed position Pla,
The setting to Plb is the same as step C4 in the first embodiment described above, and is performed by setting the fail flag F set to 1 in step C25.

Then, the process proceeds to a step C27, wherein the control maps relating to the control elements of the engine 1 such as the ignition timing and the fuel injection are respectively changed to the lowest speed map, and the ECU 16 controls the control elements based on the lowest speed map. I do. Also,
The upper limit value (maximum engine speed) Nemax of the maximum speed of the engine 1 is reduced to a predetermined value Nemax ′. This step C27 is the same as step C5 in the first embodiment described above. Then, the process is returned.

In step C22, the maximum variation Δ
If Pab is equal to or smaller than the predetermined value γ, Step C28
And resets the timer C and returns. If the count-up value Tc of the timer C is equal to or smaller than the predetermined value β 'in step C24, the process returns from step C25 to step C27. As described above, in the second embodiment, in the control device of the variable valve mechanism, which is provided in the cylinder group A (right bank) and the cylinder group B (left bank) and is independently driven and controlled, Variation maximum value ΔPab between deviation ΔPa between actual position Pra and target position Ppa in variable valve mechanism 5a of cylinder group A, and deviation ΔPb between actual position Prb and target position Ppb in variable valve mechanism 5b of cylinder group B. Is larger than the predetermined value γ for a predetermined time, it is determined that an abnormality has occurred in one of the variable valve mechanisms 5a and 5b.

For example, the target positions Ppa, Ppb
Is set to change from the low-speed side to the high-speed side as shown by the solid line in FIG. 9, and when the variable valve mechanisms 5a and 5b are variably controlled from the low-speed side to the high-speed side, one of the cylinder groups A malfunction occurs in the driving means of the variable valve mechanism, and the responsiveness of this variable valve mechanism becomes worse than that of the other variable valve mechanism as shown by the two-dot chain line II in FIG. When the resulting deviation between the target position and the actual position in the variable valve mechanism becomes larger than the deviation in the other variable valve mechanisms, it is determined that an abnormality has occurred in the variable valve mechanism.

As described above, the response of the variable valve mechanism in one of the cylinder groups becomes worse than that of the variable valve mechanism in the other cylinder group. If the deviation from the position is larger than the deviation in the other variable valve mechanisms, it is determined that an abnormality has occurred, so that the abnormality of the variable valve mechanism can be detected accurately and promptly. In the abnormality determination according to the second embodiment, as described in the first embodiment, an abnormality is detected even when the variable valve mechanism becomes invariable due to solidification of the variable valve mechanism. can do.

In the control apparatus for the variable valve mechanism according to the second embodiment, if it is determined that an abnormality has occurred in any of the variable valve mechanisms in any of the cylinder groups, the target of the variable valve mechanism in each of the cylinder groups is determined. Since the position is set to the lowest speed position and each variable valve mechanism is driven by the lowest speed position, the driving state of each variable valve mechanism is not variably controlled from the lowest speed position. A difference in output characteristics between the cylinder groups due to a delay in response of the valve mechanism or the like is prevented, and the generation of vibration and abnormal noise is suppressed. Further, similarly to the first embodiment, by driving the variable valve mechanism at the lowest position, the opening characteristics of the intake valve and the exhaust valve become the lowest speed characteristics, so that the combustion stability during idling is ensured, Operation in the low to medium speed range can be enabled.

Further, in the second embodiment, similarly to the first embodiment, if any of the variable valve mechanisms 5a, 5b in the cylinder group A or the cylinder group B becomes abnormal, the ignition timing, fuel injection, etc. The control map relating to the control element of the engine 1 is changed to the lowest speed map, and this control element is controlled according to the lowest speed map. Therefore, control elements such as ignition timing and fuel injection (volume efficiency) are optimally controlled according to the valve opening characteristics of intake and exhaust valves by a variable valve mechanism that is switched to the lowest speed position due to occurrence of abnormality. As a result, the combustion stability is further improved, the generation of vibration and abnormal noise is further suppressed, and the durability is ensured.

Also, in the second embodiment, as in the first embodiment described above, any one of the variable valve mechanisms provided for each cylinder group has an abnormality, so that When the target position is set to the lowest speed position and the control map of the control element is changed to the lowest speed map, the upper limit value (maximum engine speed) Nemax of the engine speed Ne is reduced to a predetermined value Nemax '. .

As described above, in accordance with the drive control based on the lowest speed position of the variable valve operating mechanism, the maximum engine speed N
By reducing the emax, the durability of the engine is ensured. In the first and second embodiments described above, when it is determined that an abnormality has occurred in any of the variable valve mechanisms, an alarm device that alerts or displays to the driver that an abnormality has occurred in the variable valve mechanism. Alternatively, a display device may be provided.

In the first and second embodiments,
The variable output mechanism control apparatus for an internal combustion engine according to the present invention has been described by taking a variable valve mechanism as an example of an output variable mechanism provided for each cylinder group.
The present invention is not limited to the above-described embodiment, but may be any as long as the valve opening characteristics of the intake valve and the exhaust valve can be variably controlled steplessly or stepwise. Further, regarding the valve opening characteristics, the embodiment is a variable valve mechanism that variably controls a valve opening period, but may be configured to variably control a valve lift amount and a valve opening timing.

In the first and second embodiments, the valve opening characteristics of both the intake valve and the exhaust valve are controlled variably. However, the present invention is not limited to this. A variable valve mechanism configured to variably control one of the valve opening characteristics may be used. In the above-described first and second embodiments, the V-type engine provided with the variable valve mechanism that is independently driven and controlled for each of the right bank and the left bank has been described as an example. The output variable mechanism control device of the present invention is not limited to this. For example, an engine in which a linear multi-cylinder engine is divided into a plurality of cylinder groups and a variable valve mechanism that is independently driven and controlled for each of the cylinder groups may be provided.

In the first and second embodiments described above, the target position in each variable valve mechanism is set to be the same, and each variable valve mechanism is made to have the same valve opening characteristics in each cylinder group. An example of the configuration in which the valve mechanism is drive-controlled has been described, but the present invention is not limited to this. That is,
In a configuration in which the target position in each variable valve mechanism is independently set and drive control of each variable valve mechanism is performed so that the valve opening characteristics in each cylinder group are different, If it is determined that an abnormality has occurred in the variable valve mechanism in the cylinder group of the above, the target positions of all the variable valve mechanisms may be changed to the lowest speed positions.

Furthermore, in the first and second embodiments described above, the control device for the variable valve mechanism has been described. However, the control device for the variable output mechanism of the internal combustion engine according to the present invention is not limited to this. The engine output such as the intake mechanism, the variable compression ratio mechanism, and the variable supercharging mechanism can be variably controlled, and if it is a control device for a variable output mechanism provided in each cylinder group of an internal combustion engine having a plurality of cylinder groups such as a cylinder row. Good. Also in this case, each output variable mechanism is configured to be independently driven and controlled, and when an abnormality occurs in the output variable mechanism in any one of the cylinder groups, the output variable mechanisms in all the cylinder groups are changed. The driving state may be switched to the lowest speed position (lowest speed driving state).

In this case as well, if an abnormality occurs in the variable output mechanism in any one of the cylinder groups and the driving state of the variable output mechanism in all of the cylinder groups is switched to the lowest speed position, the control in the engine control element is performed. The map may be set as the lowest speed map, and control may be performed using the lowest speed map, or the maximum engine speed may be reduced.

In the first and second embodiments described above, the control elements 1 such as ignition timing and fuel injection of the engine 1 are controlled.
Although the example in which the control unit 01 is controlled by the optimum map, the lowest speed map, and the highest speed map has been described, the output variable mechanism control device of the present invention is not limited to this. What is necessary is just to be comprised so that it may be controlled according to the driving | running state and the valve opening characteristic of a valve.

[0072]

As described above in detail, according to the internal combustion engine output variable mechanism control apparatus of the first aspect of the present invention, the control apparatus is provided for each cylinder group of the internal combustion engine having a plurality of cylinder groups and independently provided. Drive controlling each output variable mechanism so that the actual driving state of each driven variable output mechanism becomes a target driving state set according to the operating state of the internal combustion engine,
If it is determined that an abnormality has occurred in at least one of the variable output mechanisms, the target drive states of all the variable output mechanisms are changed to the lowest speed drive state. Even if it occurs, at least the output variable mechanism in which no abnormality has occurred is driven and controlled as the lowest speed drive state, so that combustion stability during idling can be ensured, and the minimum traveling, that is, traveling in the low-medium speed region, is performed. Can be possible.

According to the second aspect of the present invention, the target drive state of each variable output mechanism is set identically, and the target drive state of each variable output mechanism is set to the actual drive state. The deviation from the driving state is calculated, and if the deviation in any of the variable output mechanisms is larger than a predetermined value, it is determined that the variable output mechanism is abnormal. And it can be detected quickly.

According to the third aspect of the present invention, the target drive state of each variable output mechanism is set identically, and the target drive state of each variable output mechanism is determined. Since the deviation from the actual driving state is calculated, the maximum variation value of the deviation between the respective output variable mechanisms is calculated, and when the maximum variation value is larger than a predetermined value, it is determined that the output variable mechanism is abnormal. An abnormality due to a response delay of the variable output mechanism can be detected accurately and quickly.

According to the variable output mechanism control device for an internal combustion engine of the present invention, further, an abnormality occurs in the variable output mechanism in any one of the cylinder groups, and each variable output mechanism is set as the target driving state. When the drive control is performed in the lowest speed drive state, at least one of the ignition timing and the fuel injection of the internal combustion engine is controlled in accordance with the lowest speed drive state of the variable output mechanism, so that the control element of the internal combustion engine has a variable output. It is controlled optimally according to the driving state of the mechanism, so that the combustion stability can be further improved, the generation of vibration and abnormal noise can be suppressed, and the durability can be ensured.

[Brief description of the drawings]

FIG. 1 is a schematic overall configuration diagram of an internal combustion engine output variable mechanism control device according to an embodiment of the present invention.

FIG. 2 is a perspective view of an output variable mechanism according to the embodiment of the present invention.

FIG. 3 is a characteristic diagram illustrating operation characteristics of the variable output mechanism according to the embodiment of the present invention.

FIG. 4 is a block diagram of a control device for a variable output mechanism of an internal combustion engine according to an embodiment of the present invention.

FIG. 5 is a flowchart illustrating control of a variable output mechanism of the internal combustion engine according to the first embodiment of the present invention.

FIG. 6 is a flowchart illustrating control of a variable output mechanism of the internal combustion engine according to the first embodiment of the present invention.

FIG. 7 is a flowchart illustrating control of a variable output mechanism of an internal combustion engine according to a second embodiment of the present invention.

FIG. 8 is a flowchart illustrating control of an output variable mechanism of an internal combustion engine according to a second embodiment of the present invention.

FIG. 9 is a diagram illustrating a driving state of the output variable mechanism according to the embodiment of the present invention.

[Explanation of symbols]

Reference Signs List 1 engine 3a right bank (cylinder group A) 3b left bank (cylinder group B) 5a, 5b variable valve mechanism (variable valve timing mechanism) 15a, 15b actuator as drive means 16 ECU 23a, 23b position Sensor 101 Control element 102 Map storage means

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) F02D 43/00 301 F02D 43/00 301B 301H F02M 35/10 F02M 35/10 301F F02P 5/15 F02P 5 / 15 LF term (reference) 3G022 AA01 BA01 CA06 CA08 EA09 GA00 GA05 GA07 3G084 AA03 BA13 BA17 BA23 DA27 DA31 DA33 EA07 EA11 EB09 EB12 EB22 FA00 FA02 FA05 FA10 FA11 FA20 FA25 FA33 FA38 3G092 AA11 EA09 DA01 DA09 DA01 DA09 EA19 EA21 EA22 EC01 FA05 FA13 FB03 FB05 FB06 GA04 GA05 HA04Z HA05Z HA06Z HA13X HA13Y HA13Z HB01X HC05Z HC09X HE01X HE01Z HE03Z HE08Z HF21Z 3G301 HA06 HA08 HA19 JA14 JA37 JB02 J0307 NA03 NE03 LC07 PE10Z

Claims (4)

[Claims] 1. An output variable mechanism provided in each cylinder group of an internal combustion engine having a plurality of cylinder groups and driven independently, and an actual drive state for detecting an actual drive state of each output variable mechanism Detecting means; target driving state setting means for setting a target driving state of each of the variable output mechanisms in accordance with an operating state of the internal combustion engine; and setting the actual driving state of each of the variable output mechanisms to the target driving state. Drive means for controlling the operation of each output variable mechanism; abnormality determination means for determining an abnormality of each output variable mechanism; and abnormality determination means determining that an abnormality has occurred in at least one of the output variable mechanisms. A variable output mechanism control device for an internal combustion engine, comprising: an abnormal time changing unit configured to change each target drive state of all the variable output mechanisms to a minimum speed drive state. 2. The target drive state setting means sets the same target drive state of each output variable mechanism, and the abnormality determination means sets the target drive state and the actual drive state of each output variable mechanism. The internal combustion engine according to claim 1, wherein a deviation from the output variable mechanism is calculated, and when the deviation in any one of the output variable mechanisms is larger than a predetermined value, it is determined that the variable output mechanism is abnormal. Output variable mechanism control device. 3. The target drive state setting means sets the same target drive state of each output variable mechanism, and the abnormality determination means sets the target drive state and the actual drive state of each output variable mechanism. To calculate the maximum deviation value of the deviation between each output variable mechanism,
The variable output mechanism control apparatus for an internal combustion engine according to claim 1, wherein the variable output mechanism is determined to be abnormal when the maximum variation value is larger than a predetermined value. 4. When at least one of the ignition timing and fuel injection of the internal combustion engine is changed to the lowest speed drive state of the variable output mechanism, the abnormal state change means changes the target drive state to the lowest speed drive state. The variable output mechanism control device for an internal combustion engine according to any one of claims 1 to 3, wherein the control is performed in accordance with the following.