JP2007046573A - Controller for internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To diagnose control for improving performance of exhaust gas purification with high precision irrespective of fluctuation of rotation of an engine accompanying with driving of auxiliary machinery to prevent a controller for an internal combustion engine from performing erroneous fail-safe operation. <P>SOLUTION: This controller for the internal combustion engine is provided with a compensation setting processing part 202 for determining diagnosis for compensating the contents of determination of a diagnosis processing part 204 based on the control amount of the auxiliary machinery set by an auxiliary machinery driving control means and/or an auxiliary machinery driving condition detected by an auxiliary machinery driving condition detection means and a diagnosis mask setting processing part 203 for masking diagnosis of the diagnosis processing part during a period of time when auxiliary machinery load affects the diagnosis processing part 204. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a control device for an internal combustion engine used in a vehicle or the like, and more particularly to a control device for an internal combustion engine having an exhaust purification performance improvement control means.

  In order to purify the exhaust gas exhausted from the internal combustion engine, the catalyst provided in the exhaust passage is in an inactive state at low temperatures and cannot exhibit the purification performance. It is desirable to make it. Therefore, a technique is known in which immediately after startup, the intake air amount of the internal combustion engine is increased from that during normal idling, and the ignition timing is controlled in the retarded direction to improve the temperature rise characteristics of the catalyst.

  However, if the intake air volume increase or ignition timing retardation control (hereinafter referred to as exhaust purification performance improvement control) cannot be performed correctly, this will affect the exhaust purification performance, so the failure is diagnosed. There is a need to.

  In view of this, as a conventional technique, the engine speed and the ignition timing are monitored from the time when a predetermined delay time has elapsed after the start of the exhaust gas purification performance improvement control. There is known a diagnostic device that determines that a failure occurs when a state equal to or greater than the determination threshold continues for a determination time or longer (for example, Patent Document 1).

  As another conventional technique, exhaust sensors are installed upstream and downstream of the catalyst while taking into account the activation state of the catalyst, and the number of inversions of the upstream and downstream exhaust sensor outputs is compared with a criterion value to reduce the deterioration of the catalyst. In addition, a different determination reference value is set according to the exhaust temperature. When the exhaust temperature is lower than the predetermined value, the determination of catalyst deterioration is stopped, and when the predetermined temperature exceeds the predetermined value, the determination reference is determined according to the exhaust temperature. Diagnosis of performing catalyst deterioration diagnosis by comparison with a value is known (for example, Patent Document 2).

JP 2001-132526 A JP-A-8-177468

  However, in the above-described prior art, when a load is caused by an auxiliary machine, the influence on the engine speed due to the auxiliary machine load is not considered. Therefore, when such an auxiliary machine load occurs, engine rotation fluctuations occur, and even if the exhaust purification performance improvement control is abnormal, the diagnosis is normal, or conversely, the exhaust purification performance improvement control is normal However, there is a possibility that the diagnosis becomes an abnormality determination and an erroneous fail-safe operation is entered.

  The present invention has been made in view of the above-described points, and an object of the present invention is to perform exhaust purification regardless of engine rotation fluctuation accompanying the driving of auxiliary equipment when performing exhaust purification performance improvement control of a catalyst. It is an object of the present invention to provide a control device for an internal combustion engine capable of accurately diagnosing performance improvement control and preventing erroneous fail-safe operation.

  In order to achieve the above object, an internal combustion engine control apparatus according to the present invention comprises an exhaust purification performance improvement control means for performing control for improving the exhaust purification performance of an internal combustion engine, and sets the auxiliary machine control amount to drive the auxiliary machine. In an internal combustion engine control device having auxiliary drive control means for controlling and / or auxiliary drive state detecting means for detecting the drive state of the auxiliary equipment, the control device has diagnostic means for diagnosing the exhaust purification performance improvement control means The diagnosis means comprises: a diagnosis processing section for determining whether or not the exhaust purification performance improvement control means is functioning normally; an accessory control amount set by the accessory drive control means; and / or the accessory drive state A diagnostic determination correction setting processing unit that corrects the determination content of the diagnostic processing unit based on the accessory driving state detected by the detection means.

  The control device for an internal combustion engine according to the present invention includes an exhaust purification performance improvement control means for performing control for improving the exhaust purification performance of the internal combustion engine, and an auxiliary drive for controlling the drive of the auxiliary equipment by setting an auxiliary equipment control amount. A control device for an internal combustion engine having a control means and / or an accessory drive state detection means for detecting a drive state of the accessory, comprising: a diagnosis means for diagnosing the exhaust purification performance improvement control means; Means for determining whether or not the exhaust gas purification performance improvement control means is functioning normally; an auxiliary machine control amount set by the auxiliary machine drive control means and / or the auxiliary machine drive state detection means A diagnosis mask setting processing unit that determines a period during which the auxiliary load affects the diagnosis processing unit based on the detected accessory driving state and masks the diagnosis of the diagnosis processing unit over the period.

  The control device for an internal combustion engine according to the present invention includes an exhaust purification performance improvement control means for performing control for improving the exhaust purification performance of the internal combustion engine, and an auxiliary drive for controlling the drive of the auxiliary equipment by setting an auxiliary equipment control amount. A control device for an internal combustion engine having a control means and / or an accessory drive state detection means for detecting a drive state of the accessory, comprising: a diagnosis means for diagnosing the exhaust purification performance improvement control means; Means for determining whether or not the exhaust gas purification performance improvement control means is functioning normally; an auxiliary machine control amount set by the auxiliary machine drive control means and / or the auxiliary machine drive state detection means Determining a period during which an accessory load affects the diagnosis processing unit based on the detected accessory driving state, and masking the diagnosis of the diagnosis processing unit over the period; Machine load status Preliminary / or based on the operating state of the internal combustion engine and a diagnostic method selection unit for selecting a diagnostic mask by the diagnostic content correction and the diagnosis mask setting processing unit according to the determination correction setting processing unit.

  The control device for an internal combustion engine according to the present invention includes an exhaust purification performance improvement control means for performing control for improving the exhaust purification performance of the internal combustion engine, and an auxiliary drive for controlling the drive of the auxiliary equipment by setting an auxiliary equipment control amount. A control device for an internal combustion engine having a control means and / or an accessory drive state detection means for detecting a drive state of the accessory, and determines whether or not the exhaust purification performance improvement control means is functioning normally And an auxiliary machine drive control amount restriction means for restricting the drive of the auxiliary machine during a period when the load of the auxiliary machine affects the diagnostic means.

  The control device for an internal combustion engine according to the present invention includes an exhaust purification performance improvement control means for performing control for improving the exhaust purification performance of the internal combustion engine, and an auxiliary drive for controlling the drive of the auxiliary equipment by setting an auxiliary equipment control amount. A control device for an internal combustion engine having a control means and / or an accessory drive state detection means for detecting a drive state of the accessory, and determines whether or not the exhaust purification performance improvement control means is functioning normally The auxiliary load affects the diagnosis processing unit based on the diagnosis processing unit and the auxiliary control amount set by the auxiliary drive control unit and / or the auxiliary drive state detected by the auxiliary drive state detection unit. A diagnosis unit including a diagnosis mask setting processing unit for determining a period to affect and masking the diagnosis of the diagnosis processing unit over the period, and a period during which the load of the auxiliary device affects the diagnosis unit The drive of And a diagnostic mask correction by the diagnostic mask setting processing unit and a diagnostic content correction by the determination correction setting processing unit based on a load state of the auxiliary machine and / or an operating state of the internal combustion engine. And the auxiliary machine drive restriction by the auxiliary machine drive control amount restriction means is selected.

  In the control apparatus for an internal combustion engine according to the present invention, preferably, the determination correction setting processing unit is (i) a threshold value related to diagnosis normality / abnormality determination, and (ii) detection detected by the diagnosis processing unit related to diagnosis normality / abnormality determination. Correct at least one of the values.

  In the control apparatus for an internal combustion engine according to the present invention, preferably, the diagnostic mask setting processing unit includes at least (i) a predetermined period from the start of driving of the auxiliary machine, and (ii) a predetermined period from the stop of driving of the auxiliary machine. Period (iii) The diagnosis of the diagnosis processing unit is masked over at least one of the periods during which the accessory is being driven.

  In the control apparatus for an internal combustion engine according to the present invention, preferably, the auxiliary machine drive control amount limiting means includes (i) a predetermined period from the start of driving of the auxiliary machine, and (ii) a predetermined time from when the auxiliary machine is stopped. Period (iii) Limiting the driving of the auxiliary machine over at least one of the auxiliary machine driving periods.

  In the control apparatus for an internal combustion engine according to the present invention, preferably, the drive restriction of the auxiliary machine by the auxiliary machine drive control amount limiting means is (i) not to drive the auxiliary machine, and (ii) gradually driving the drive of the auxiliary machine. (Iii) limiting the control amount of the auxiliary machine, or a combination of (i) to (iii).

  According to the present invention, the exhaust purification performance improvement control diagnosis can be performed in a state where the determination value related to the diagnosis of the exhaust purification performance improvement control is in the normal range and / or in the state where the determination value is in the normal range. Even when engine speed fluctuations due to auxiliary load occur, it is possible to prevent erroneous diagnosis and avoid the possibility of exhaust deterioration.

  An embodiment of an automobile engine (internal combustion engine) to which a control device according to the present invention is applied will be described with reference to the drawings.

  FIG. 1 shows the overall configuration of the internal combustion engine of the above embodiment. The engine 507 of FIG. 1 includes a piston 507a, a cylinder block 507b, a spark plug 508, and an injector 509. The spark plug 508 and the injector 509 are controlled by a control unit 515 that is an engine control device.

  An intake pipe 501 and an exhaust pipe 519 are connected to the combustion chamber 507c. A catalyst 520 is provided in the exhaust pipe 519.

  The intake pipe 501 and the exhaust pipe 519 are connected by a side pipe 525 that is a bypass pipe. The side pipe 525 is provided with an EGR valve 524 for adjusting the exhaust gas recirculation flow rate.

  The intake air taken from the inlet portion 502 a of the air cleaner 502 is guided to the collector 506 through the air flow meter (air flow sensor) 503 and the throttle body 505. The air sucked into the collector 506 is distributed to each intake pipe 501 connected to each cylinder 507b of the engine 507, and then merged with recirculated air from the side pipe 525, that is, EGR air, to each combustion chamber. Guided to 507c. Accordingly, the air flow rate Qc introduced into the combustion chamber 507c is the sum of the intake air flow rate Qa and the EGR air flow rate Qe.

The fuel in the fuel tank 514 is primarily pressurized by the fuel pump 510, regulated to a constant pressure (eg, 3 kg / cm ² ) by the fuel regulator 512, and secondarily pressurized to a higher pressure by the fuel pump 511, The fuel regulator 513 adjusts the pressure to a constant pressure (for example, 30 kg / cm ² ) and supplies the pressure to the injector 509. This fuel is injected from the injector 509 into the combustion chamber 507c.

  The spark plug 508 inputs an ignition signal that has been high voltage by the ignition coil 522, and generates a spark. The fuel thus injected into the combustion chamber 507c is ignited by the spark plug 508.

  A part of the exhaust gas from the combustion chamber 507c is led to the side pipe 525 as recirculated air, and the rest is discharged to the atmosphere through the catalyst 520 of the exhaust pipe 519.

  A signal representing the intake flow rate detected by the air flow sensor 503 is input to the control unit 515.

  The throttle body 505 is provided with an electric throttle valve 505a for controlling the intake flow rate and a throttle sensor 504 for detecting the opening degree of the electric throttle valve 505a. The electric throttle valve 505a is driven by an electric throttle actuator 526. The opening degree of the electric throttle valve 505 a detected by the throttle sensor 504 is input to the control unit 515.

  A fuel pressure sensor 523 is provided at the outlet of the fuel pump 511. The fuel pressure detected by the fuel pressure sensor 523 is input to the control unit 515.

  A crank angle sensor 516 is provided on the crankshaft 507d. An angle signal POS representing the rotational position of the crankshaft 507d detected by the crank angle sensor 516 is input to the control unit 515.

  The exhaust pipe 519 is provided with an air-fuel ratio (A / F) sensor 518 at a position upstream of the catalyst 520. The exhaust gas detection signal detected by the air-fuel ratio (A / F) sensor 518 is input to the control unit 515.

  The control unit 515 inputs sensor signals from the above-described sensors, and also inputs an activation signal from the ignition switch 101 and an accelerator opening signal from the accelerator opening sensor (APS) 521, and an EGR valve 524, electric throttle Control signals are output to each of the actuator 526, the fuel pump 510, the fuel pressure regulator 513, the injector 509, and the ignition coil 522.

  The control unit 515 inputs an accelerator opening signal from the accelerator sensor (APS) 521, an activation signal from the ignition switch 101, and a cam angle signal from the cam shaft sensor 517.

  The control unit 515 receives an on / off signal Sa from the external auxiliary machine switch 107 of the auxiliary machine 531 and also receives a driving state signal (feedback signal) Sb indicating the driving state of the auxiliary machine 531 from the auxiliary machine 531. The auxiliary machine control amount signal Sc is output to the auxiliary machine 531.

  The auxiliary machine 531 is directly or indirectly driven by the engine 507, and is not specifically limited.

  The configuration of the main part of the control unit 515 will be described with reference to FIG. The control unit 515 is of a microcomputer type and includes an I / O circuit board 601, an EP-ROM 602, an MPU 603, and a RAM 604.

  The I / O circuit board 601 includes an interface circuit and an A / D converter, and further includes an injector driving circuit 118, an electric throttle driving circuit 119, and a spark plug driving circuit 120.

  The interface circuit of the I / O circuit board 601 includes an air flow sensor 503, a throttle sensor 504, a crank angle sensor 516, a cam shaft sensor 517, an air-fuel ratio (A / F) sensor 518, an accelerator opening sensor (APS) 521, and a fuel pressure sensor. Signals from 523, the ignition switch 101, the external auxiliary machine switch 107, and the like are input, and the A / D converter performs AD conversion of these signals.

  The MPU 603 performs various calculations based on the input signals of the various sensors and switches described above, generates a control signal, and outputs the control signal to each of the injector drive circuit 118, the electric throttle drive circuit 119, and the spark plug drive circuit 120. To do.

  These drive circuits 118, 119, and 120 perform predetermined calculation processing and generate various drive signals as the calculation results. This drive signal is output to each injector 509, electric throttle actuator 526, and ignition coil 522. The I / O circuit board 601 also supplies drive signals to the fuel pump 510, the EGR valve 524, the auxiliary machine 531 and the like.

  The control unit 515 calculates an ignition timing, that is, an ignition timing ADVS, which is indicated by an estimated amount from top dead center according to the following formula (1), and supplies a signal for driving the spark plug 508 to the ignition coil 522.

ADVS = STDMAP + ADVHOS-FIRTD (1)
Here, STDMAP is a basic value of ignition timing calculated by searching a map set according to the engine load calculated based on the engine speed NDATA and the cylinder intake air amount, and ADVHOS is a control unit according to the operating state. 515 is an ignition timing correction amount calculated. FIRTD is a first idle retard control ignition in which the engine speed NDATA is set to be lower than the speed NFIRTD as the exhaust gas purification performance improvement control (hereinafter referred to as the first idle retard control) of the catalyst 520 during the cold state immediately after the engine 507 is started. Delay angle correction.

  When the exhaust gas temperature rises, the exhaust gas purification performance of the catalyst 520 can be improved, so that the HC amount HCEX in the exhaust gas decreases. In this way, in order to improve the exhaust purification performance of the catalyst 520, ignition timing retard control is performed to adjust the ignition timing to the retard side (retard), and the exhaust temperature is raised early.

  As shown in FIG. 3, the control unit 515 includes a control for improving the exhaust gas purification performance of the catalyst 520 and means for diagnosing it by execution of a computer program, as well as related means, and a rotation speed detection processing unit 111. And a load detection processing unit 102, a first idle retard control (exhaust purification performance improvement control) means 103, a first idle retard control diagnostic means 105, and an auxiliary equipment control means 106.

  A rotation speed detection processing unit (rotation speed calculation means) 111 calculates an engine rotation speed NDATA based on a signal from the crank angle sensor 516.

  The load detection processing unit (load calculation means) 102 calculates the engine load from the signal from the crank angle sensor 516 and the signal from the airflow sensor 503.

  The engine speed NDATA calculated by the speed detection processing unit 111 is input to the first idle retard control means 103 that is an exhaust purification performance improvement control means of the catalyst 520. The first idle retard control means 103 performs ignition timing retard control that adjusts the ignition timing to the retard side (retard) in order to improve the exhaust gas purification performance of the catalyst 520, and sends a retard command signal to the ignition timing calculation unit. To 104.

  The first idle retard control diagnosing means 105 includes an engine load signal from the load detection processing section 102, an engine speed (NDATA) signal from the rotation speed detection processing section 111, and an auxiliary machine drive from the auxiliary machine drive control means 106. Diagnosis processing is performed based on the state signal Sd and the auxiliary machine control amount signal (control amount signal) Sc.

  The auxiliary machine control means 106 receives an auxiliary machine drive state signal Sd and an auxiliary machine control amount signal using the on / off signal Sa of the external auxiliary machine switch 107 and the feedback signal Sb from the auxiliary machine 531 indicating the state of the auxiliary machine 531 as input information. Sc is generated, the accessory drive state signal Sd is input to the diagnosis unit 105, and the accessory control amount signal Sc is output to the control target accessory 531 and the diagnosis unit 105.

  Details of the auxiliary machine control means 106 will be described with reference to FIG. The auxiliary machine control unit 106 includes an auxiliary machine drive state detection unit 301, an auxiliary machine drive control amount limiting unit 302, and an auxiliary machine drive control unit 303.

  The accessory drive state detection means 301 calculates the accessory drive state based on the on / off signal Sa of the external accessory switch 107, the feedback signal Sb from the accessory 531 and the information signal Se from the first idle retard control means 103. Then, the accessory driving state signal Sd is generated.

  The auxiliary machine drive control amount restriction unit 302 restricts the drive of the auxiliary machine 531 during a period when the load of the auxiliary machine 531 affects the diagnosis unit 105.

  The auxiliary machine drive control amount limiting means 302 includes (i) a predetermined period from the start of driving of the auxiliary machine 531, (ii) a predetermined period from when the driving of the auxiliary machine 531 is stopped, and (iii) a period during which the auxiliary machine is being driven. The driving of the auxiliary machine 302 is limited for at least one of the periods.

  The drive restriction of the accessory 531 by the accessory drive control amount limiting means 302 is (i) not to drive the accessory, (ii) gradually driving the accessory 531, (iii) the control amount of the accessory 531. Or a combination of (i) to (iii).

  The accessory drive control means 303 outputs a control amount signal Sc for the accessory 531 based on the accessory drive state signal Sd and the signal from the accessory drive control amount limiting means 302.

  Next, details of the diagnostic means 105 for the first idle retard control will be described with reference to FIG.

  The diagnostic unit 105 includes a diagnostic processing unit 204, a diagnostic determination correction setting processing unit 202, a diagnostic mask setting processing unit 203, and a diagnostic method selection unit 201.

  The diagnosis processing unit 204 determines whether or not the first idle retard control unit 103 is functioning normally.

  The diagnosis determination correction setting processing unit 202 determines the determination contents of the diagnosis processing unit 204 based on the auxiliary machine control amount set by the auxiliary machine drive control unit 303 and the auxiliary machine drive state detected by the auxiliary machine drive state detection unit 301. to correct.

  The determination correction setting processing unit 202 corrects at least one of (i) a threshold related to diagnosis normality / abnormality determination and (ii) a detection value detected by the disconnection processing unit 204 related to diagnosis normality / abnormality determination.

  The diagnosis mask setting processing unit 203 determines whether the load on the auxiliary machine 531 is based on the auxiliary machine control amount set by the auxiliary machine drive control unit 303 and / or the auxiliary machine drive state detected by the auxiliary machine drive state detection unit 301. A period affecting 204 is determined, and diagnosis of the diagnosis processing unit 204 is masked over the period.

  The diagnostic mask setting processing unit 203 includes at least (i) a predetermined period from the start of driving of the auxiliary machine 531, (ii) a predetermined period from when the driving of the auxiliary machine 531 is stopped, and (iii) a period during which the auxiliary machine is being driven. The diagnosis of the diagnosis processing unit is masked over at least one of the periods.

  The diagnostic method selection processing unit 201 selects the diagnostic content correction by the determination correction setting processing unit 202 and the diagnostic mask by the diagnostic mask setting processing unit 203 based on the load state of the auxiliary machine 531 and / or the operating state of the engine 507. To do.

  As a result, the diagnostic unit 105 performs diagnostic processing with diagnostic content correction or a diagnostic mask based on the setting selected by the diagnostic method selection processing unit 201.

  Next, internal processing until the diagnostic processing is executed while the diagnostic means 105 is in fast idle retard control will be described with reference to the flowchart shown in FIG. In FIG. 6, the physical quantity of the auxiliary machine drive control amount signal Sc is indicated by ACTL, and the physical quantity of the auxiliary machine drive state signal Sd is indicated by ACCST. The engine speed is indicated by NDATA, and the engine load state is indicated by LDATA.

  A series of processing is executed at a constant cycle (for example, 10 ms), and the processing is terminated at any of the processing blocks of Steps 404, 405, 406, and 408.

  First, it is determined whether or not the auxiliary machine 531 is being driven (step 400). If the auxiliary machine 531 is not being driven, a transition is made to normal diagnosis processing (step 404), and this processing ends.

  On the other hand, when the accessory 531 is being driven, whether the accessory drive control amount ACTRL is higher than the accessory drive amount first threshold ACC40, and / or the accessory drive state ACCST is the accessory drive state. It is determined whether it is higher than the first threshold ACC41 (step 401).

  If CTRL ≦ ACC40 and / or ACCST ≦ ACC41, the first correction setting of the diagnostic judgment value for diagnostic processing is performed (step 405), and this processing is terminated.

  In contrast, when CTRL> ACC40 or / and ACCST> ACC41, it is determined whether or not the accessory drive control amount ACTRL is higher than the accessory drive amount second threshold ACC42, and / or the accessory drive state ACCST is It is determined whether or not the auxiliary machine driving state is higher than the second threshold ACC43.

  When CTRL> ACC42 or / and ACCST> ACC43, the process proceeds to the determination block of Step 403, and when CTRL ≦ ACC42 and / or ACCST ≦ ACC43, the process proceeds to the determination block of Step 407.

  When the process proceeds to the determination block of step 403, it is determined whether or not the engine speed NDATA is higher than the predetermined speed N43 and / or whether or not the engine load LDATA is higher than the predetermined load L44.

  When NDATA> N43 or / and LDATA> L44, a diagnostic mask is set (step 406), and this process is terminated.

  On the other hand, when NDATA ≦ N43 and / or LDATA ≦ L44, the process proceeds to the determination block of step 407.

  In the determination block of step 407, it is determined whether or not the engine speed NDATA is lower than a predetermined speed N45. If NDATA <N45, a diagnostic mask is set (step 406), and this process is terminated. On the other hand, if NDATA ≧ N45, the second correction setting of the diagnostic judgment value for diagnostic processing is performed (step 408), and this processing is terminated.

  Next, the first idle retard control process executed in the control unit 515 will be described with reference to the time chart of FIG.

  FIG. 7A is a time chart of the ignition timing ADVS, and FIG. 7B is a time chart of the engine speed NDATA.

  Cranking is started at time T70, engine start is started at time T71, fast idle retard control is started at time T72, and diagnosis of fast idle retard control is started at time T73. As shown in FIG. 7B, the engine speed NDATA initially increases, and then is narrowed down to the target speed for normal control.

  In FIG. 7A, the first idle retard control ignition delay angle correction FIRTD is indicated by reference numeral 702, and the operation of the ignition timing ADVS is indicated by reference numeral 701.

  During the first idle retard control, the ignition timing ADVS is controlled to be retarded from the normal control value (STDMAP + ADVSHOS). After the time point T74, the first idle retard control is gradually ended, and the control shifts to the normal control. CA00 is the ignition timing at the top dead center position, 710 is a cranking period, 711 is a fast idle control period, and 712 is a normal ignition control period.

  FIG. 8 is a time chart when a failure occurs. This time chart shows an example in which the failure cannot be correctly performed by the conventional failure detection method when the failure state and the auxiliary load are generated at the same time.

  FIG. 8A shows the ignition timing ADVS, FIG. 8B shows the engine speed NDATA, FIG. 8C shows the diagnosis timer operation for failure determination, and FIG. 8D shows the on / off signal Sa for the external auxiliary machine switch. The actual operation of each of ADVS and FIRTD is indicated by a solid line, and the desired operation is indicated by an intermittent line.

  In the diagnosis of the first idle retard control, when a state where the engine speed NDATA is higher than the threshold value NFIRTD continues for a predetermined time, it is determined as a failure.

  As shown in FIG. 8, cranking is started at time T70, engine start is started at time T71, fast idle retard control is started at time T72, and diagnosis of fast idle retard control is determined at time T73. Although it starts, as indicated by reference numeral 802 in FIG. 8A, the ignition delay correction FIRTD of the first idle retard control does not perform the expected operation, and the ignition timing ADVS does not perform the first idle retard operation.

  For this reason, in the diagnosis of the first idle retard control, since the operation of the engine speed NDATA should not be lower than the threshold value NFIRTD, a failure should be detected.

  For example, the failure determination diagnostic timer in FIG. 8C starts failure determination from time T73. However, as shown in FIG. 8D during diagnosis, when an external accessory drive request is generated at time T80, the engine speed NDATA fluctuates, and failure determination cannot be performed normally. For example, the failure determination diagnostic timer shown in FIG. 8 (c) returns to the initial state due to the rotational speed fluctuation due to the accessory driving at time T82 before the failure confirmation time FIRCNGTM elapses. Cannot judge.

  FIG. 9 is a time chart when a failure occurs, and this time chart shows an example in which failure detection can be accurately performed when a failure state and an auxiliary machine load occur simultaneously.

  9A shows the ignition timing ADVS, FIG. 9B shows the engine speed NDATA, FIG. 9C shows the diagnosis timer operation for failure determination, and FIG. 9D shows the on / off signal Sa for the external auxiliary machine switch. FIG. 9 (e) is a time chart of the drive state signal Sd of the auxiliary machine, showing the actual operation of each of ADVS and FIRTD with a solid line, and showing the desired operation with an intermittent line.

  Cranking is started at time T70, engine start is started at time T71, fast idle retard control is started at time T72, and diagnosis of fast idle retard control is started at time T73. An external accessory drive request is generated at time T80, and the accessory drive state signal 153 becomes higher than '0' at time T90. Then, at time T81, the external accessory drive request is turned off.

  Until time T90, the determination result of the determination block in step 400 of FIG. 6 is “NO”, and normal diagnosis processing is performed from time T73 to time T90, and the failure determination diagnosis timer of FIG. Works.

  At time T90, the determination result of the determination block in step 400 in FIG. 6 is “YES”, and the accessory drive state signal Sd (ACCST) at time T90 is higher than the first threshold ACC41 and the second threshold ACC43. The determination results of the determination block in step 401 and the determination block in step 402 in FIG. 6 are both “YES”.

  Since the engine speed NDATA at time T90 is lower than the threshold value N43 and higher than the threshold value N45, the determination result of the determination block 403 in step 403 in FIG. 6 is “NO”, and the determination result of the determination block in step 407 is “YES”. .

  Therefore, at time T90, the diagnosis is set to be masked, and the failure determination timer shown in FIG. 8C is returned to the initial state. This state continues until time T91.

  The determination result of the determination block in steps 400, 401, and 403 in FIG. 6 at time T91 does not change with respect to the time T90, and the engine speed NDATA becomes higher than the threshold value 45. Therefore, the determination block result in step 407 in FIG. Becomes 'NO'.

  Therefore, at time T91, diagnosis is performed with the diagnosis determination engine speed threshold being changed from NFIRTD to NFIRTD1 as the diagnosis value correction setting.

  Since the diagnosis using the threshold value NFIRTD1 in consideration of the auxiliary machine load can be performed after the time T91, the failure determination diagnostic timer shown in FIG. 8C can be normally counted down, and after the FIRCNGTM time has elapsed, at the time T92. It is determined that the first idle retard control has failed.

  As described above, the exhaust purification performance improvement control diagnosis is performed in a state where the determination value related to the diagnosis of the first idle retard control that is the exhaust purification performance improvement control is in the normal range and / or in the normal range. Therefore, even if engine speed fluctuations due to auxiliary loads occur, it is possible to prevent erroneous diagnosis and avoid the possibility of exhaust deterioration.

  As another embodiment, an engine control apparatus according to the present invention includes a diagnostic content correction by a determination correction setting processing unit 202 and a diagnostic mask setting processing unit based on the load state of the auxiliary machine 531 and / or the operating state of the engine. The diagnosis mask by 203 and the accessory drive restriction by the accessory drive control amount restriction means 302 may be selected.

  In other words, one of the determination correction setting processing unit 202, the diagnostic mask setting processing unit 230, and the auxiliary device drive control amount limiting unit 302 is given priority according to the load state of the auxiliary machine 531 and / or the operating state of the engine. A selection process for operating and prohibiting others is performed.

A processing flow related to the diagnosis of the first idle retard control of this embodiment will be described with reference to the flowchart shown in FIG.
A selection process in which one of the auxiliary drive control amount limiting means 6 is performed with priority according to the engine operating conditions and the other is prohibited will be described.

  A series of processing is executed at a constant cycle (for example, 10 ms), and the processing is terminated at the processing block of Step 404 or Step 1003.

  First, it is determined whether or not there is a request to drive the auxiliary machine 531 from the external auxiliary machine switch 107 (step 1000). If there is no request to drive the auxiliary machine 531, the process proceeds to a normal diagnosis process (step 404), and this process ends.

  On the other hand, when there is a request to drive the auxiliary machine 531, it is determined whether or not the engine water temperature TWN is lower than the predetermined temperature threshold TW10 as the cold state determination of the engine 507 (step 1001). When TWN <TW10, the auxiliary unit drive amount limiting control is performed by the auxiliary unit drive control amount limiting unit 302 in order to prioritize the diagnosis unit 105 (step 1004), and the process proceeds to step 1002.

  On the other hand, when TWN ≧ TW10, a transition is made to a normal accessory drive control process (step 1003), and this process ends.

  In step 1002, it is determined whether or not the diagnostic processing of the first idle retard control by the diagnostic processing unit 204 has been started and a predetermined time T100 has elapsed after the start of the diagnostic processing.

  If the diagnosis process is not started or the diagnosis process is started but the predetermined time T100 has not elapsed after the start, the process returns to step 1000. On the other hand, when the diagnosis process is started and a predetermined time T100 has elapsed since the diagnosis process was started, a transition is made to normal accessory drive control (step 1003), and this process ends.

  By the above-described processing, it is possible to select an optimal processing according to the engine operating condition in a period that affects the diagnostic processing of the first idle retard control by the diagnostic processing unit 204.

The figure which shows an example of the whole structure of the engine (internal combustion engine) for motor vehicles to which the control apparatus by this invention is applied. The block diagram which shows the internal structure of the engine control apparatus (control unit) of the engine for motor vehicles to which the control apparatus by this invention is applied. The block diagram which shows one Embodiment of the control which improves the exhaust gas purification performance of the catalyst in the engine control apparatus by this invention, the means to perform the diagnosis, and those related means. The block diagram which shows one Embodiment of the internal structure of the auxiliary machine drive means in the engine control apparatus by this invention. The block diagram which shows one Embodiment of the internal structure of the diagnostic means of the exhaust gas purification performance improvement control in the engine control apparatus by this invention. The flowchart which shows one Embodiment of the diagnostic process of the exhaust gas purification performance improvement control in the engine control apparatus by this invention. The timing chart which shows the operation | movement of the exhaust gas purification performance improvement control in the engine control apparatus by this invention. The timing chart which shows the operation | movement when a failure and auxiliary machinery load generate | occur | produce during the exhaust gas purification performance improvement control operation. The timing chart which shows operation | movement when auxiliary machinery load generate | occur | produces during the exhaust gas purification performance improvement control operation | movement which is an application example of the engine control apparatus by this invention. The flowchart which shows other embodiment of the process relevant to the diagnostic process of the exhaust gas purification performance improvement control of the engine control apparatus by this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 101 Ignition switch 102 Engine load detection process part 103 Fast idle retard control means 104 Ignition timing calculation process part 105 Fast idle retard control diagnostic means 106 Auxiliary equipment control means 107 External auxiliary equipment switch 111 Rotation speed detection processing part 201 Diagnosis method selection means 202 Diagnosis correction setting processing unit 203 Diagnosis mask setting processing unit 204 Diagnosis processing unit for fast idle retard control 301 Auxiliary drive state detection means 302 Auxiliary drive control amount limiting means 303 Auxiliary drive control means 501 Intake pipe 502 Air cleaner 502a Air cleaner inlet 503 Air flow sensor 504 Throttle sensor 505 Throttle body 505a Electric throttle valve 506 Collector 507 Engine 507a Piston 507b Da 508 spark plug 509 injector 510 fuel pump 511 fuel pump 512 pressure regulator 513 pressure regulator 514 fuel tank 515 control unit (engine control unit)
516 Crank angle sensor 517 Cam shaft sensor 518 Air-fuel ratio (A / F) sensor 519 Exhaust pipe 520 Catalyst 521 Accelerator opening sensor (APS)
522 Ignition coil 523 Fuel pressure sensor 524 EGR valve 525 Side pipe 526 Electric throttle actuator 531 Auxiliary equipment

Claims (9)

Exhaust purification performance improvement control means for performing control for improving the exhaust purification performance of the internal combustion engine, auxiliary equipment drive control means for setting the auxiliary machine control amount to control the driving of the auxiliary equipment, and / or the driving state of the auxiliary equipment A control device for an internal combustion engine having auxiliary machine drive state detection means for detecting,
Diagnostic means for diagnosing the exhaust purification performance improvement control means,
The diagnosis means includes a diagnosis processing unit that determines whether or not the exhaust gas purification performance improvement control means is functioning normally, and an accessory control amount and / or accessory drive state detection set by the accessory drive control means A control apparatus for an internal combustion engine, comprising: a diagnostic determination correction setting processing unit that corrects the determination content of the diagnostic processing unit based on the accessory driving state detected by the means. Exhaust purification performance improvement control means for performing control for improving the exhaust purification performance of the internal combustion engine, auxiliary equipment drive control means for setting the auxiliary machine control amount to control the driving of the auxiliary equipment, and / or the driving state of the auxiliary equipment A control device for an internal combustion engine having auxiliary machine drive state detection means for detecting,
Diagnostic means for diagnosing the exhaust purification performance improvement control means,
The diagnosis means includes a diagnosis processing unit that determines whether or not the exhaust purification performance improvement control means is functioning normally, an auxiliary machine control amount set by the auxiliary machine drive control means, and / or the auxiliary machine drive state. A diagnostic mask setting processing unit that determines a period during which an auxiliary load affects the diagnostic processing unit based on the auxiliary driving state detected by the detection unit, and masks the diagnosis of the diagnostic processing unit over the period; A control apparatus for an internal combustion engine, comprising: Exhaust purification performance improvement control means for performing control for improving the exhaust purification performance of the internal combustion engine, auxiliary equipment drive control means for setting the auxiliary machine control amount to control the driving of the auxiliary equipment, and / or the driving state of the auxiliary equipment A control device for an internal combustion engine having auxiliary machine drive state detection means for detecting,
Diagnostic means for diagnosing the exhaust purification performance improvement control means,
The diagnosis means includes a diagnosis processing unit that determines whether or not the exhaust purification performance improvement control means is functioning normally, an auxiliary machine control amount set by the auxiliary machine drive control means, and / or the auxiliary machine drive state. A diagnosis mask setting processing unit that determines a period during which an accessory load affects the diagnosis processing unit based on the accessory driving state detected by the detection unit, and masks the diagnosis of the diagnosis processing unit over the period;
A diagnostic method selection processing unit that selects a diagnostic content correction by the determination correction setting processing unit and a diagnostic mask by the diagnostic mask setting processing unit based on a load state of the auxiliary machine and / or an operating state of the internal combustion engine;
A control apparatus for an internal combustion engine, comprising: Exhaust purification performance improvement control means for performing control for improving the exhaust purification performance of the internal combustion engine, auxiliary equipment drive control means for setting the auxiliary machine control amount to control the driving of the auxiliary equipment, and / or the driving state of the auxiliary equipment A control device for an internal combustion engine having auxiliary machine drive state detection means for detecting,
Diagnostic means for determining whether or not the exhaust purification performance improvement control means is functioning normally;
Auxiliary drive control amount limiting means for limiting the drive of the auxiliary machine during a period when the load of the auxiliary machine affects the diagnostic means;
A control apparatus for an internal combustion engine, comprising: Exhaust purification performance improvement control means for performing control for improving the exhaust purification performance of the internal combustion engine, auxiliary equipment drive control means for setting the auxiliary machine control amount to control the driving of the auxiliary equipment, and / or the driving state of the auxiliary equipment A control device for an internal combustion engine having auxiliary machine drive state detection means for detecting,
A diagnosis processing unit for determining whether or not the exhaust purification performance improvement control means is functioning normally, and an auxiliary machine control amount set by the auxiliary machine drive control means and / or an auxiliary machine drive state detection means A diagnostic means that includes a diagnostic mask setting processing unit that determines a period during which an auxiliary machine load affects the diagnostic processing unit based on an accessory driving state, and masks the diagnosis of the diagnostic processing unit over the period;
A period during which the load of the auxiliary machine affects the diagnostic means, and an auxiliary machine drive control amount limiting means for limiting the driving of the auxiliary machine,
Based on the load state of the auxiliary machine and / or the operating state of the internal combustion engine, the diagnostic content correction by the determination correction setting processing unit, the diagnostic mask by the diagnostic mask setting processing unit, and the auxiliary drive control amount limiting unit A control device for an internal combustion engine, wherein a machine drive restriction is selected.   The determination correction setting processing unit corrects at least one of (i) a threshold related to diagnosis normality / abnormality determination and (ii) a detection value detected by the diagnosis processing unit related to diagnosis normality / abnormality determination. The control device for an internal combustion engine according to any one of claims 1, 3, and 5.   The diagnostic mask setting processing unit includes at least (i) a predetermined period from the start of driving of the auxiliary machine, (ii) a predetermined period from the stop of driving of the auxiliary machine, and (iii) a period during driving of the auxiliary machine. The control device for an internal combustion engine according to any one of claims 2, 3, and 5, wherein the diagnosis of the diagnosis processing unit is masked over at least one of the periods.   The auxiliary machine drive control amount limiting means includes (i) a predetermined period from the start of driving of the auxiliary machine, (ii) a predetermined period from the stop of driving of the auxiliary machine, and (iii) a period during driving of the auxiliary machine. 6. The control apparatus for an internal combustion engine according to claim 4, wherein the driving of the auxiliary machine is limited for at least one of the periods.   The auxiliary drive control limit by the auxiliary drive control amount limiting means includes (i) not driving the auxiliary machine, (ii) gradually driving the auxiliary machine, and (iii) limiting the control amount of the auxiliary machine. 6. The control device for an internal combustion engine according to claim 4 or 5, wherein the control device is a combination of (i) to (iii).

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