JP2010180830A - Control device for internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a control device for an internal combustion engine capable of effectively restricting outbreaks of torque fluctuation, output, fuel economy and deterioration of emission over the whole of the internal combustion engine by restricting combustion failures in groups of cylinders due to control abnormality in a variable valve timing mechanism of any group of cylinders. <P>SOLUTION: In the case wherein any one of variable mechanisms 52 of both of a right and a left banks 12 and 14 is failed to an advance angle side or a retard angle side, control of ignition timing and fuel injection quantity to the group of cylinders on a failed side is switched to the control using an emergency map corresponding to a real angle of displacement of intake cam shafts 40 and 42 to be changed by the failed variable mechanism 52. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a control device for an internal combustion engine that includes a plurality of cylinder groups such as a V-type engine and a horizontally opposed engine and includes a variable valve timing mechanism that changes valve timing for each cylinder group.

  Conventionally, as this type of technology, for example, there are those disclosed in Patent Documents 1 and 2. In the configuration of Patent Document 1, when one of the variable valve timing mechanisms that change the displacement angle of the intake camshaft fails in the advance side in each cylinder group of the V-type engine (failure), this cylinder group on the fail side The fuel supply to is stopped. For this reason, misfire due to the fact that the displacement angle of the intake camshaft is fixed while the valve overlap is large is prevented.

  Further, in the configuration of Patent Document 2, when one of the variable valve timing mechanisms provided in both cylinder groups of the V-type engine fails, the entire engine is operated based on the operating angle of the intake camshaft on the fail side. The target operating angle of the normal variable valve timing mechanism is corrected so that the amount of intake air is the same as when normal. Further, the air-fuel ratio of both cylinder groups is adjusted appropriately by correcting the fuel injection amount for each cylinder group in accordance with the intake air quantity of the cylinder group on the side where the variable valve timing mechanism has failed and the normal side. . As a result, the operating state of the engine is controlled so that the intake air amount of the entire engine is the same as that in the normal state, and the output and emission are well maintained.

  Patent Document 3 discloses a configuration for controlling a variable valve timing mechanism in an in-line engine. In the configuration of Patent Document 3, when a failure is detected in the variable valve timing mechanism, the ignition timing is adjusted based on the engine speed and the load, thereby suppressing the deterioration of combustion.

Japanese Patent Laid-Open No. 11-36907 Japanese Patent Laid-Open No. 2003-41994 Japanese Patent Laid-Open No. 11-37027

  However, in the configuration described in Patent Document 1, since the fuel supply to the cylinder group on which the variable valve timing mechanism fails is stopped, a large difference occurs in the generated torque between the left and right cylinder groups, resulting in engine torque fluctuations. Becomes large and drivability deteriorates.

  Further, the configuration described in Patent Document 2 is intended to control the intake air amount of the entire engine independently of the control of the throttle valve, and controls the fuel injection amount for the fail-side cylinder group. The ignition timing is not controlled according to the actual displacement angle of the intake camshaft on the fail side. For this reason, good combustion is not performed in the cylinder group on the fail side, and it is considered that the output, fuel consumption, and emission of the engine as a whole are reduced.

  Further, in the configuration described in Patent Document 3, when the variable valve timing mechanism fails to the retard side, the ignition timing is merely delayed by a predetermined timing regardless of the magnitude of the failure. Therefore, the combustion control for the fail-side cylinder group cannot be performed with high accuracy, and the output, fuel consumption, and emission of the entire engine cannot be controlled well.

  An object of the present invention is to suppress a combustion failure of a cylinder group caused by a control abnormality of a variable valve timing mechanism of any cylinder group in an internal combustion engine provided with a variable valve timing mechanism in each of a plurality of cylinder groups. It is an object of the present invention to provide a control device for an internal combustion engine that can effectively suppress the occurrence of torque fluctuation, output, fuel consumption, and emission reduction in the entire engine.

  The invention according to claim 1 is provided for each of a plurality of cylinder groups each having an intake valve and an exhaust valve, and a variable valve timing mechanism for changing a displacement angle of the intake camshaft with respect to the crankshaft, and an operation for detecting an operation state of the internal combustion engine. A control device for an internal combustion engine comprising state detection means and valve timing control means for controlling each of the variable valve timing mechanisms based on the detected internal combustion engine operating state, wherein an actual displacement angle of the intake camshaft is determined. A displacement angle detecting means for detecting, an abnormality determining means for determining a control abnormality of each variable valve timing mechanism based on the actual displacement angle, and a control abnormality is detected in any of the variable valve timing mechanisms by the abnormality detecting means. Sometimes, the ignition timing and fuel injection amount for the cylinder group provided with this variable valve timing mechanism are Characterized by comprising a driving control means for controlling in response to the actual displacement angle of the intake camshaft groups.

(Function)
In the present invention, when a control abnormality is detected in any of the variable valve timing mechanisms provided for each of the plurality of cylinder groups, the ignition timing and fuel for the cylinder group provided with the variable valve timing mechanisms are detected. The injection amount is controlled according to the actual displacement angle of the intake camshaft of this cylinder group. Therefore, for the cylinder group in which the displacement angle of the intake camshaft deviates from the appropriate target displacement angle based on the operating state due to the control abnormality of the variable valve timing mechanism, the appropriate ignition according to the actual displacement angle of the intake camshaft Combustion control can be performed by setting the timing and the fuel injection amount. As a result, the combustion in the cylinder group on the side where the variable valve timing mechanism has caused the control abnormality is controlled well, the difference in generated torque between the cylinder groups is suppressed, the torque fluctuation of the entire engine is suppressed, and the entire engine Reduction of output, fuel consumption and emission is suppressed.

  According to the present invention, in an internal combustion engine in which a variable valve timing mechanism is provided in each of a plurality of cylinder groups, combustion failure in that cylinder group due to control abnormality of the variable valve timing mechanism of any cylinder group is suppressed, and the internal combustion engine This produces the effect of effectively suppressing the occurrence of torque fluctuations, output, fuel consumption, and emissions in the entire engine.

The schematic block diagram which shows the internal combustion engine apparatus provided with the control apparatus of 1st Embodiment. The side view which shows a variable valve timing mechanism. The flowchart which shows a variable valve failure process. The flowchart which shows a variable valve failure process. The flowchart which shows the variable valve fail process of 2nd Embodiment. The flowchart which shows the variable valve fail process of 3rd Embodiment.

Hereinafter, an embodiment in which the present invention is embodied in a V-type engine will be described with reference to FIGS.
As shown in FIG. 1, an engine 10 as an internal combustion engine is a V-type engine in which a left bank 12 having a left cylinder group and a right bank 14 having a right cylinder group are arranged in a V shape. A piston 17 is disposed in the cylinder bore 16 of the cylinder block 15 in the left bank 12 and a combustion chamber 19 is defined. A piston 17 is disposed in the cylinder bore 16 of the cylinder block 15 in the right bank 14 and a combustion chamber 19 is defined. Each piston 17 in the left bank 12 and each piston 17 in the right bank 14 are connected to one crankshaft 21.

  The left cylinder head 18 is formed with an intake port 22 and an exhaust port 23 facing each combustion chamber 19 of the left cylinder group. Each intake port 22 is provided with an intake valve 24 and an injector 25, and each exhaust port 23 is provided with an exhaust valve 26. The right cylinder head 20 is configured in the same manner as the left cylinder head 18. An air cleaner 28, a throttle valve 29, and a surge tank 30 are sequentially arranged on the intake passage 27 connected to the intake ports 22 of both cylinder heads 18 and 20. This throttle valve 29 is operated by a motor 31. A catalytic converter 33 is disposed on the exhaust passage 32 connected to the exhaust ports 23 of the cylinder heads 18 and 20. An ignition coil 35 with a built-in igniter is mounted on each spark plug 34 disposed in each combustion chamber 19 of both the left and right cylinder groups.

  The left bank 12 is provided with a left intake camshaft 40 that operates each intake valve 24 of the left cylinder group, and a left exhaust camshaft 41 that also operates each exhaust valve 26. The right bank 14 is provided with a right intake camshaft 42 that operates each intake valve 24 of the right cylinder group and a right exhaust camshaft 43 that also operates each exhaust valve 26.

  Two left intake side timing pulleys 44 a and 44 b (shown in FIG. 2) are attached to one end of the left intake camshaft 40, and a left exhaust side timing pulley 45 is attached to one end of the left exhaust camshaft 41. Yes. The left intake side timing pulley 44 b and the left exhaust side timing pulley 45 are connected by a left secondary timing chain 46. Further, two right intake side timing pulleys (only one is shown in FIG. 1) 47 are attached to one end of the right intake camshaft 42, and a right exhaust side timing pulley 48 is attached to one end of the right exhaust camshaft 43. It is installed. One of the right intake side timing pulley 47 and the right exhaust side timing pulley 48 are connected by a right secondary timing chain 49. Further, the left intake side timing pulley 44 a and the other of the right intake side timing pulley 47 are connected to a crank sprocket 50 fixed to one end of the crankshaft 21 via a primary timing chain 51. The left intake camshaft 40 and the left exhaust camshaft 41, and the right intake camshaft 42 and the right exhaust camshaft 43 rotate once for every two rotations of the crankshaft 21.

  The left and right banks 12 and 14 have variable valve timing mechanisms (hereinafter referred to as variable mechanisms) for continuously changing the displacement angles (rotational phases) of the left and right intake camshafts 40 and 42 with respect to the rotation of the crankshaft 21. ) 52 are provided. The displacement angle of the intake camshafts 40 and 42 is changed to change the valve overlap amount of the intake valve 24 and the exhaust valve 26 and the closing timing of the intake valve 24 in the left and right cylinder groups.

  As shown in FIG. 2, the variable mechanism 52 is configured between the left intake side timing pulleys 44 a and 44 b and the left intake camshaft 40, and rotates from the left intake side timing pulleys 44 a and 44 b to the left intake camshaft 40. The displacement angle of the left intake camshaft 40 with respect to the left intake side timing pulleys 44a and 44b can be changed. The variable mechanism 52 includes a motor 53 as a power source.

Next, the electrical configuration of this embodiment will be described.
As shown in FIG. 1, an accelerator opening sensor 61 is provided in the vicinity of the accelerator pedal 60, and a throttle opening sensor 62 is provided in the vicinity of the throttle valve 29. An intake air temperature sensor 63 and an air flow meter 64 are provided on the intake passage 27. A crank angle sensor 65 for detecting the crank angle and the engine speed is disposed in the vicinity of the crankshaft 21. The cylinder block 15 is provided with a water temperature sensor 66. Cam angle sensors 67 are disposed in the vicinity of the left and right intake camshafts 40 and 42, respectively.

  In addition, for example, in the engine compartment (not shown) of the vehicle, signals are input from the above-described sensors, and based on the input signals, the injector 25, the ignition plug 34, the ignition coil 35 with a built-in igniter, and the motor 53 of both the left and right variable mechanism 52 An electronic control device (hereinafter referred to as an ECU (Electric Control Unit)) 68 to be controlled is provided. In this embodiment, an accelerator opening sensor 61, a throttle opening sensor 62, an intake air temperature sensor 63, an air flow meter 64, a crank angle sensor 65, a water temperature sensor 66, a cam angle sensor 67, and an ECU 68 constitute an operating state detection means. ing. Further, the crank angle sensor 65, the cam angle sensor 67, and the ECU 68 constitute a displacement angle detection means. Further, the ECU 68 is a valve timing control unit, an abnormality determination unit, and an operation control unit.

  The ECU 68 includes a ROM 68a in which control programs for fuel injection control and ignition control control of the engine 10 and a map for obtaining target values of fuel injection amount and ignition timing in each control are stored. The ROM 68a also stores a variable valve timing control program for controlling the left and right variable mechanisms 52, and a map for determining the target displacement angles of the left and right intake camshafts 40 and 42 in this control. Yes. Further, the ROM 68a stores a control program for executing valve timing fail control for suppressing deterioration of the operating state of the engine 10 due to the failure when any of the left and right variable mechanisms 52 fails. Has been. The failure of the variable mechanism 52 means that the deviation between the target displacement angle and the actual displacement angle exceeds a predetermined value due to, for example, a foreign object biting in the variable mechanism 52 or a decrease in response due to damage to the motor 53. In this state, the excessive state continues for a predetermined time.

  The ECU 68 includes a CPU 68b that executes arithmetic processing based on each control program stored in the ROM 68a. Further, the ECU 68 includes a RAM 68c that temporarily stores calculation results in the CPU 68b, data input from each sensor, and the like, and a backup RAM 68d that holds various data stored in the RAM 68c when power supply is stopped. Yes.

  In addition to factors such as intake air temperature THA, intake air amount GA, engine speed NE, accelerator opening degree ACC, throttle opening degree TA, and cooling water temperature THW, the ECU 68 performs actual control of the left and right intake camshafts 40 and 42 as fuel injection control. A fuel injection amount QF is determined using a map from a factor formed by the displacement angle. This actual displacement angle is an actual displacement angle of the intake camshafts 40 and 42 with respect to the crankshaft 21. Then, the ECU 68 controls the injector 25 so as to inject fuel of this fuel injection amount QF.

  In addition to the factors such as the intake air temperature THA, the intake air amount GA, the engine speed NE, the accelerator opening degree ACC, the throttle opening degree TA, and the cooling water temperature THW, the ECU 68 performs both left and right intake camshafts 40, 42 as ignition timing control. The ignition timing is determined using a map from a factor consisting of the actual displacement angle. The ECU 68 controls the ignition coil 35 with a built-in igniter so that the ignition plug 34 is operated at this ignition timing.

  In addition to the factors such as the intake air temperature THA, the intake air amount GA, the engine speed NE, and the accelerator opening degree ACC, the ECU 68 controls the cam angle CA of the left and right intake camshafts 40 and 42 and the crankshaft as variable valve timing control. The target displacement angles of the left and right intake camshafts 40 and 42 are determined using a map from a factor consisting of 21 crank angles. This target displacement angle corresponds to the opening / closing timing of the intake valve 24 with respect to the operating state of the engine 10 at that time. In the variable valve timing control, the ECU 68 obtains the actual displacement angle of the intake camshafts 40 and 42 from the cam angle CA and crank angle of the left and right intake camshafts 40 and 42, and the actual displacement angle and the target displacement. The left and right variable mechanisms 52 are controlled so that the deviation from the corner becomes small.

  Next, the valve timing fail control executed by the ECU 68 will be described with reference to the flowcharts shown in FIGS. This control process is executed by interruption every predetermined crank angle.

  As shown in FIG. 3, in the valve timing fail control, first, in step (hereinafter abbreviated as “S”) 101, the cam angle CA is based on the cam angle signals input from the cam angle sensors 67 of the left and right banks 12 and 14. Is acquired, and the crank angle is acquired based on the crank angle signal input from the crank angle sensor 65. Then, based on the cam angle CA and the crank angle, the left actual displacement angle VTBL and the right actual displacement angle VTBR, which are actual displacement angles from the most retarded angle positions of the intake camshafts 40 and 42, are obtained.

  Next, in S102, the engine speed NE is acquired based on the crank angle signal input from the crank angle sensor 65, and the cooling water temperature THW is acquired based on the signal input from the water temperature sensor 66.

  In the subsequent S103, it is determined whether or not a failure detection condition capable of determining a failure of the variable mechanism 52 is satisfied based on the acquired engine speed NE or the coolant temperature THW. The fail detection condition is that the engine speed NE is equal to or higher than a predetermined value, or the coolant temperature THW is equal to or higher than a predetermined value. If it is determined in S103 that the failure detection condition is not satisfied, this process is terminated.

  On the other hand, if it is determined in S103 that the fail detection condition is satisfied, then in S104, a map is used from the intake air amount GA, the engine speed NE, the cam angle CA of the left intake camshaft 40, the crank angle, and the like. Thus, the left target displacement angle VTTL of the left intake camshaft 40 is obtained. Further, the right target displacement angle VTTR of the right intake camshaft 42 is obtained using a map from the intake air amount GA, the engine speed NE, the cam angle CA of the right intake camshaft 42, the crank angle, and the like.

  Next, in S105, either the deviation of the left actual displacement angle VTBL with respect to the left target displacement angle VTTL or the deviation of the right actual displacement angle VTBR with respect to the right target displacement angle VTTR is larger than a predetermined value on the advance side. It is determined whether or not a certain state has continued for a predetermined time or more.

  If an affirmative determination is made in S105, then in S106, it is determined that the variable mechanism 52 whose actual displacement angles VTBL and VTBR are shifted toward the advance side with respect to the target displacement angles VTTL and VTTR is an advance side failure. Next, S201 described later is executed.

  On the other hand, if a negative determination is made in S105, then in S107, either the deviation of the left actual displacement angle VTBL with respect to the left target displacement angle VTTL or the deviation of the right actual displacement angle VTBR with respect to the right target displacement angle VTTR is delayed. It is determined whether or not the state that is larger than a predetermined value on the corner side continues for a predetermined time or more.

  If a negative determination is made in S107, the deviation between the actual displacement angle of the left and right intake camshafts 40, 42 and the target displacement angle is within an allowable range, and this process is terminated, assuming that both the left and right variable mechanisms 52 are not failed. The

  On the other hand, if an affirmative determination is made in S107, then in S108, it is determined that the variable mechanism 52 whose actual displacement angle is shifted to the retard side with respect to the target displacement angle is a retard side failure, and then S201 described later is executed.

  If it is determined in S106 that one of the left and right variable mechanisms 52 is an advance side failure, as shown in FIG. 4, next, in S201, the left side actual variable mechanism 52 of the left bank 12 is changed. Whether or not the displacement angle VTBL is normal is determined based on the left target displacement angle VTTL.

  If an affirmative determination is made in S201, then in S202, the map used for controlling the ignition timing and fuel injection amount for the right cylinder group is the right intake camshaft in which the variable valve timing mechanism 52 is in the advanced side failure. The emergency map corresponding to the right actual displacement angle VTBR of 42 is switched. This emergency map is different from the map used when the variable valve timing mechanism 52 is normal, and the actual displacement angles VTBL and VTBR of either one of the intake camshafts 40 and 42 are abnormal with respect to the operating state of the engine 10. The ignition timing and the fuel injection amount are set in order to satisfactorily control the combustion in the cylinder group on the abnormal side.

  Next, in S203, the left target displacement angle VTTL of the variable mechanism 52 of the left bank 12 where the left actual displacement angle VTBL is normal is set to the same value as the right actual displacement angle VTBR of the right intake camshaft 42.

  Next, in S204, the map used for the ignition timing control and fuel injection control for the left cylinder group is switched to the emergency map map corresponding to the newly set left target displacement angle VTTL.

  On the other hand, when a negative determination is made in S201, next, in S205, whether or not the right actual displacement angle VTBR of the variable mechanism 52 of the right bank 14 is normal is determined based on the right target displacement angle VTTR.

  If an affirmative determination is made in S205, then the map used for controlling the ignition timing and the fuel injection amount for the left cylinder group in S206 is the left intake cam in which the variable valve timing mechanism 52 is in the advance side failure. The emergency map corresponding to the left actual displacement angle VTBL of the shaft 40 is switched.

  Next, in S207, the right target displacement angle VTTR of the variable mechanism 52 of the right bank 14 in which the right actual displacement angle VTBR is normal is set to the same value as the left actual displacement angle VTBL of the left intake camshaft 40.

  Next, in S208, the map used for the ignition timing control and fuel injection control for the right cylinder group is switched to the emergency map corresponding to the newly set right target displacement angle VTTR.

  Further, when it is determined in S108 that either of the left and right variable mechanisms 52 is the retard side fail, the processing of S201 to S208 is executed in the same manner as when it is determined in S106 that the advance side is failed. The

The embodiment described above in detail has the following effects.
(1) When one of the left and right variable mechanisms 52 fails to advance or retard, the ignition timing and fuel injection amount control for the failed cylinder group is changed by the failed variable mechanism 52. The control is switched to the control using the emergency map corresponding to the actual displacement angle VTBL (or VTBR) of the intake camshaft 40 (or 42). This emergency map favorably controls the combustion in the cylinder group on the abnormal side when the actual displacement angle VTBL, VTBR of either one of the intake camshafts 40, 42 is abnormal with respect to the operating state of the engine 10. Therefore, the ignition timing and the fuel injection amount are set. For this reason, the ignition timing and the fuel injection amount for the cylinder group in which the variable mechanism 52 has failed to advance or retard are appropriately controlled according to the actual displacement angle VTBL (or VTBR) on the fail side. The occurrence of poor combustion in the cylinder group can be prevented. Accordingly, it is possible to suppress a difference in torque generated between the left and right cylinder groups to suppress the torque fluctuation of the entire engine 10 and to effectively prevent a decrease in output, fuel consumption and emission of the entire engine 10. Further, afterburning due to incomplete combustion in the combustion chamber 19 can be prevented, and an increase in catalyst temperature due to this afterburning can be prevented, and damage to the catalytic converter 33 can be prevented.

  (2) The intake camshaft 40 (or the target displacement angle VTTR (or VTTL) of the intake camshaft 42 (or 40) changed by the variable mechanism 52 on the normal side is changed by the variable mechanism 52 on the failed side. 42) is set to the same value as the actual displacement angle VTBL (or VTBR). Then, the control of the ignition timing and the fuel injection amount for the cylinder group on which the variable mechanism 52 is normal is switched to the control using the emergency map corresponding to the target displacement angle VTTR (or VTTL). Therefore, the intake air amount supplied to both the left and right cylinder groups can be made equal, thereby eliminating the difference in torque generated between the banks 12 and 14 and suppressing the torque fluctuation of the engine 10.

(Second Embodiment)
Next, a second embodiment embodying the present invention will be described with reference to FIG. In the following embodiments, differences from the first embodiment will be mainly described.

  In the valve timing fail process of this embodiment, as shown in FIG. 5, the processes of S203, S204, S207, and S208 in the first embodiment are not executed, and instead, the variable mechanism 52 of the right bank 14 advances. When a corner-side failure occurs, normal variable valve timing control is continued for the variable mechanism 52 of the normal left bank 12. Further, when the variable mechanism 52 of the left bank 12 becomes an advance side failure, the normal variable valve timing control is continued for the variable mechanism 52 of the normal right bank 14. For the cylinder group on which the variable mechanism 52 is normal, a normal map corresponding to the actual displacement angles VTBL and VTBR of the intake camshafts 40 and 42 changed by the variable mechanism 52 of the cylinder group is used. Thus, the ignition timing and the fuel injection amount are controlled.

  As in the case where either of the left and right variable mechanisms 52 is advanced, the normal variable mechanism 52 is detected when either of the left and right variable mechanisms 52 is delayed. The normal variable valve timing control is continued. For the cylinder group on which the variable mechanism 52 is normal, a normal map corresponding to the actual displacement angles VTBL and VTBR of the intake camshafts 40 and 42 changed by the variable mechanism 52 of the cylinder group is used. Thus, the ignition timing and the fuel injection amount are controlled.

This embodiment described in detail above has the following effects in addition to the effects described in (1) of the first embodiment.
(3) When one of the left and right variable mechanisms 52 fails, the normal variable valve timing control based on the operating state of the engine 10 is continued for the normal variable mechanism 52. For the cylinder group on which the variable mechanism 52 is normal, a normal map corresponding to the actual displacement angles VTBL and VTBR of the intake camshafts 40 and 42 changed by the variable mechanism 52 of the cylinder group is used. Thus, the ignition timing and the fuel injection amount are controlled. For this reason, when one of the left and right variable mechanisms 52 fails, the normal operation focusing on fuel consumption and exhaust gas can be continued for the cylinder group on which the variable mechanism 52 is normal.

(Third embodiment)
Next, a third embodiment of the present invention will be described with reference to FIG.
In the variable mechanism 52 fail processing of this embodiment, as shown in FIG. 6, the following processing is executed instead of the processing of S203, S204, S207, and S208 in the first embodiment.

In S301 executed after S202, the left target displacement angle VTTL of the variable mechanism 52 of the left bank 12 where the left actual displacement angle VTBL is normal is set to the most retarded angle.
Next, in S302, the map used for the ignition timing / fuel injection amount control for the left cylinder group is switched to the emergency map corresponding to the newly set most retarded angle.

In S303 executed after S206, the right target displacement angle VTTR of the variable mechanism 52 of the right bank 14 in which the right actual displacement angle VTBR is normal is set to the most retarded angle.
Next, in S304, the map used for the ignition timing control and the fuel injection control for the right cylinder group is switched to the emergency map corresponding to the newly set most retarded angle.

  As in the case where either of the left and right variable mechanisms 52 is advanced, the normal variable mechanism 52 is not affected when either of the left and right variable mechanisms 52 is delayed. Changed to the most retarded angle. Then, for the cylinder group on the side where the variable mechanism 52 is changed to the most retarded angle, the control of the ignition timing and the fuel injection amount using the emergency map corresponding to the most retarded angle is executed.

This embodiment has the following effects in addition to the effects described in (1) of the first embodiment.
(4) When one of the left and right variable mechanisms 52 fails, the normal variable mechanism 52 is changed to the most retarded angle. Then, the control of the ignition timing and the fuel injection amount for the cylinder group on the side where the variable mechanism 52 is changed to the most retarded angle is switched to the control using the emergency map corresponding to the most retarded angle. For this reason, when the actual displacement angles VTBL and VTBR of the failed variable mechanism 52 are not the most retarded angle, the normal variable mechanism 52 is changed to the most retarded angle, thereby ensuring the brake negative pressure and enabling the retreat travel. be able to. Further, when the actual displacement angles VTBL and VTBR of the failing variable mechanism 52 are the most retarded angles, the intake air amount supplied to both the left and right cylinder groups can be made uniform, so that the generated torque in the left and right cylinder groups can The difference in torque can be suppressed by eliminating the difference.

(Other embodiments)
Note that this embodiment can also be embodied in a horizontally opposed engine in which two cylinder groups are opposed in the horizontal direction and a W engine having three cylinder groups.

Hereinafter, technical ideas that are grasped from the respective embodiments and are not listed as claims will be described.
(1) In the control apparatus for an internal combustion engine according to claim 1, the operation control means is configured such that when the abnormality determination means determines that one of the variable valve timing mechanisms is in a control abnormality, a normal variable valve The displacement angle of the intake camshaft changed by the timing mechanism is controlled to the same value as the actual displacement angle of the intake camshaft changed by the variable valve timing mechanism in which the control abnormality is detected, and the variable valve timing mechanism is normal. A control apparatus for an internal combustion engine, wherein an ignition timing and a fuel injection amount for a group are controlled according to an actual displacement angle.

  (2) In the control apparatus for an internal combustion engine according to claim 1, when the operation control means determines that one of the variable valve timing mechanisms is abnormal in control by the abnormality determination means, a normal variable valve The intake camshaft displacement angle changed by the timing mechanism is controlled to the most retarded angle position, and the variable valve timing mechanism controls the ignition timing and fuel injection amount for the normal cylinder group according to the most retarded angle position. A control device for an internal combustion engine characterized by the above.

  (3) In the control apparatus for an internal combustion engine according to claim 1, the operation control means is configured such that when the abnormality determination means determines that one of the variable valve timing mechanisms is in a control abnormality, a normal variable valve While controlling the displacement angle of the intake camshaft changed by the timing mechanism based on the operating state of the internal combustion engine, the variable valve timing mechanism determines the ignition timing and the fuel injection amount for the normal cylinder group, and the intake cam of this cylinder group A control device for an internal combustion engine, wherein control is performed according to an actual displacement angle of a shaft.

  DESCRIPTION OF SYMBOLS 10 ... Engine as an internal combustion engine, 21 ... Crankshaft, 24 ... Intake valve, 26 ... Exhaust valve, 40 ... Left intake camshaft, 42 ... Right intake camshaft, 52 ... Variable valve timing mechanism, 61 ... Operating state detection means , The throttle opening sensor, 63 ... the same intake air temperature sensor, 64 ... the same air flow meter, 65 ... the crank angle sensor constituting the operating state detecting means and the displacement angle detecting means, 66 ... the driving Water temperature sensor constituting state detection means and abnormality detection means, 67... Cam angle sensor constituting operation state detection means and displacement angle detection means, 68... Valve timing constituting operation state detection means and displacement angle detection means, abnormality determination Electronic control device as means and operation control means, VTBL, VTBR ... actual displacement angle, QF ... Fuel injection amount.

Claims (1)

A variable valve timing mechanism that is provided for each of a plurality of cylinder groups including an intake valve and an exhaust valve and changes a displacement angle of the intake camshaft with respect to the crankshaft;
An operating state detecting means for detecting an operating state of the internal combustion engine;
A control device for an internal combustion engine, comprising: valve timing control means for controlling each of the variable valve timing mechanisms based on the detected internal combustion engine operating state;
A displacement angle detecting means for detecting an actual displacement angle of the intake camshaft;
An abnormality determining means for determining a control abnormality of each variable valve timing mechanism based on an actual displacement angle;
When a control abnormality is detected in any of the variable valve timing mechanisms by this abnormality detection means, the ignition timing and the fuel injection amount for the cylinder group provided with this variable valve timing mechanism are set to the intake camshaft of this cylinder group. A control device for an internal combustion engine, comprising: an operation control means for controlling according to an actual displacement angle.

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