JP4098188B2 - Control device for internal combustion engine - Google Patents

Description

  The present invention relates to an internal combustion engine control apparatus, and more particularly to an internal combustion engine control apparatus provided with a cylinder deactivation mechanism that deactivates some cylinders of an internal combustion engine having a plurality of cylinders.

  Patent Document 1 discloses an adhesion correction that corrects the amount of fuel supplied to an engine based on a fuel transportation delay caused by a part of the fuel injected into the intake pipe of the internal combustion engine adhering to the inner wall of the intake pipe. It is shown. More specifically, of the fuel injected into the intake pipe in a certain cycle, the direct ratio A, which is the ratio of the fuel that is sucked into the combustion chamber by evaporation or the like during that cycle, and attached to the inner wall of the intake pipe by the previous time The take-off rate B, which is the proportion of the fuel that is drawn into the combustion chamber by evaporation during the cycle, is read from the map set in accordance with the engine coolant temperature and the absolute pressure in the intake pipe. The fuel injection amount is determined using the direct rate A and the take-off rate B that have been issued.

Further, Patent Document 2 shows an internal combustion engine having a cylinder deactivation mechanism, and engine operation includes partial cylinder operation for deactivating some cylinders and all cylinder operation for deactivating all cylinders. It is switched according to the state.
JP-A-5-187293 JP 2001-227369 A

  If the adhesion correction method disclosed in Patent Document 1 is directly applied to control of the amount of fuel supplied to an internal combustion engine having a cylinder deactivation mechanism disclosed in Patent Document 2, the following problems have occurred.

  That is, in an engine equipped with a cylinder deactivation mechanism, even when the engine output is the same, the intake pipe internal pressure tends to be higher during partial cylinder operation than during full cylinder operation, and during partial cylinder operation. Since the air flow in the intake pipe is different from that during all cylinder operation, if the common direct rate A and carry-off rate B are used, appropriate adhesion correction cannot be performed during operation of some cylinders, and exhaust characteristics deteriorate. There was something to do.

  The present invention has been made paying attention to this point, and appropriately corrects the amount of fuel to be supplied to the internal combustion engine equipped with the cylinder deactivation mechanism, so that it can be used in both partial cylinder operation and all cylinder operation. It is an object of the present invention to provide a control device for an internal combustion engine that can maintain good exhaust characteristics.

In order to achieve the above object, the invention according to claim 1 has a plurality of cylinders, all-cylinder operation for operating all of the plurality of cylinders, and partial cylinder for stopping operation of some of the plurality of cylinders. In a control device for an internal combustion engine comprising switching means (30) for switching between operation, operation parameters (TW, TH, TA, NE, VP, GP) of a vehicle driven by the engine, including the operation parameters of the engine Operating parameter detecting means for detecting the engine, command means for instructing the switching means (30) to perform all-cylinder operation or partial cylinder operation according to the operating parameter, and supply to the engine according to the operating parameter a fuel amount calculating means for calculating the amount of fuel (TCYL), part of the fuel injected into the intake pipe of the engine to correct the transport delay of the fuel due to adhering to the intake pipe wall Because of deposition parameters comprising (AFW0AC, BFW0AC, KACS × AFW0AC , KBCS × BFW0AC) and attachment parameter calculating means for calculating, and adhesion correction means for correcting the fuel amount (TCYL) using the deposition parameters, the attachment parameter calculating means, Rukoto to calculate the deposition parameters for the all-cylinder operation (AFW0AC, BFW0AC) or deposition parameters for the partial-cylinder operation (KACS × AFW0AC, KBCS × BFW0AC ) according to a command of said command means It is characterized by.
According to a second aspect of the present invention, in the control device for an internal combustion engine according to the first aspect, the adhesion parameter is a ratio of the fuel directly sucked into the combustion chamber out of the fuel injected into the intake pipe. Rate (AFW0AC, KACS × AFW0AC), and a take-off rate (BFW0AC, KBCS × BFW0AC) which is a ratio of fuel sucked into the combustion chamber out of the fuel adhering to the intake pipe, The adhesion parameter is calculated in accordance with the engine speed (NE) and the intake pipe internal pressure (PBA). At the same engine speed and intake pipe internal pressure, the adhesion parameter (KACS × AFW0AC, (KBCS × BFW0AC) is calculated to be larger than the adhesion parameters (AFW0AC, BFW0AC) for the operation of all cylinders. And wherein the door.

According to the first aspect of the present invention, the attachment parameter for correcting the transportation delay of the fuel caused by a part of the fuel injected into the intake pipe of the engine adhering to the inner wall of the intake pipe is used for all cylinder operation. deposition parameters or deposition parameters for partial-cylinder operation is calculated in response to a command instruction means, since the amount of fuel using the deposition parameters calculated is corrected appropriately performed adhesion correction of the fuel amount, a part Good exhaust characteristics can be maintained during both cylinder operation and all cylinder operation.
According to the second aspect of the present invention, the direct rate and the take-off rate are calculated as the adhesion parameters in accordance with the engine speed and the intake pipe internal pressure, and the same engine speed and intake pipe internal pressure are used for some cylinders. The adhesion parameter is calculated to be larger than the adhesion parameter for all cylinder operation. When comparing at the same engine speed and intake pipe internal pressure, it is considered that the direct rate and the take-off rate both increase because the flow velocity of intake air increases when operating some cylinders compared to when operating all cylinders. Thus, by setting such adhesion parameters (direct ratio and take-away ratio), appropriate adhesion correction can be performed even in partial cylinder operation.

Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 is a diagram showing a configuration of an internal combustion engine and a control device thereof according to an embodiment of the present invention. A V-type 6-cylinder internal combustion engine (hereinafter simply referred to as “engine”) 1 includes a right bank provided with # 1, # 2 and # 3 cylinders, and a left bank provided with # 4, # 5 and # 6 cylinders. And a cylinder deactivation mechanism 30 for temporarily deactivating the # 1 to # 3 cylinders is provided in the right bank. FIG. 2 is a diagram showing a hydraulic circuit for hydraulically driving the cylinder deactivation mechanism 30 and its control system. This diagram is also referred to in conjunction with FIG.

  A throttle valve 3 is arranged in the middle of the intake pipe 2 of the engine 1. The throttle valve 3 is provided with a throttle valve opening sensor 4 for detecting the opening TH of the throttle valve 3, and a detection signal thereof is supplied to an electronic control unit (hereinafter referred to as “ECU”) 5.

  A fuel injection valve 6 is provided for each cylinder slightly upstream of an intake valve (not shown). Each injection valve is connected to a fuel pump (not shown) and electrically connected to the ECU 5 to receive a signal from the ECU 5. Thus, the valve opening time of the fuel injection valve 6 is controlled.

  An intake pipe absolute pressure (PBA) sensor 7 is provided immediately downstream of the throttle valve 3, and an absolute pressure signal converted into an electric signal by the absolute pressure sensor 7 is supplied to the ECU 5. An intake air temperature (TA) sensor 8 is attached downstream of the intake pipe absolute pressure sensor 7 to detect the intake air temperature TA and supply a corresponding electrical signal to the ECU 5.

An engine water temperature (TW) sensor 9 mounted on the main body of the engine 1 is composed of a thermistor or the like, detects the engine water temperature (cooling water temperature) TW, outputs a corresponding temperature signal, and supplies it to the ECU 5.
A crank angle position sensor 10 that detects a rotation angle of a crankshaft (not shown) of the engine 1 is connected to the ECU 5, and a signal corresponding to the rotation angle of the crankshaft is supplied to the ECU 5. The crank angle position sensor 10 is a cylinder discrimination sensor that outputs a pulse (hereinafter referred to as “CYL pulse”) at a predetermined crank angle position of a specific cylinder of the engine 1, and relates to a top dead center (TDC) at the start of the intake stroke of each cylinder. A TDC sensor that outputs a TDC pulse at a crank angle position before a predetermined crank angle (every 120 degrees of crank angle in a 6-cylinder engine) and a CRK that generates a CRK pulse at a constant crank angle period shorter than the TDC pulse (for example, a period of 30 degrees). It consists of sensors, and a CYL pulse, a TDC pulse and a CRK pulse are supplied to the ECU 5. These signal pulses are used for various timing controls such as fuel injection timing and ignition timing, and detection of engine speed (engine speed) NE.

  The cylinder deactivation mechanism 30 is hydraulically driven using the lubricating oil of the engine 1 as hydraulic oil. The hydraulic oil pressurized by the oil pump 31 is supplied to the cylinder deactivation mechanism 30 via the oil passage 32, the intake side oil passage 33i, and the exhaust side oil passage 33e. An intake-side solenoid valve 35i and an exhaust-side solenoid valve 35e are provided between the oil passage 32 and the oil passages 33i and 33e. These solenoid valves 35i and 35e are connected to the ECU 5, and the operation thereof is performed by the ECU 5. Be controlled.

  The oil passages 33i and 33e are provided with hydraulic switches 34i and 34e that are turned on when the operating oil pressure drops below a predetermined threshold, and the detection signals are supplied to the ECU 5. Further, a hydraulic oil temperature sensor 33 for detecting the hydraulic oil temperature TOIL is provided in the middle of the oil passage 32, and a detection signal thereof is supplied to the ECU 5.

  A specific configuration example of the cylinder deactivation mechanism 30 is disclosed in, for example, Japanese Patent Laid-Open No. 10-103097, and the same mechanism is used in this embodiment. According to this mechanism, when the solenoid valves 35i and 35e are closed and the hydraulic pressure in the oil passages 33i and 33e is low, the intake valves and exhaust valves of the cylinders (# 1 to # 3) are normally opened and closed. On the other hand, when the solenoid valves 35i, 35e are opened and the hydraulic pressure in the oil passages 33i, 33e increases, the intake valves and exhaust valves of the cylinders (# 1 to # 3) maintain the closed state. That is, while the solenoid valves 35i and 35e are closed, all cylinders are operated to operate all cylinders. When the solenoid valves 35i and 35e are opened, the cylinders # 1 to # 3 are deactivated, and # 4 to Partial cylinder operation in which only # 6 cylinder is operated is performed.

  Three-way catalysts 23R and 23L for purifying exhaust gas are provided in the exhaust pipe 13R connected to the # 1 to # 3 cylinders in the right bank and the exhaust pipe 13L connected to the # 4 to # 6 cylinders in the left bank. ing. On the upstream side of the three-way catalysts 23R and 23L, proportional air-fuel ratio sensors (hereinafter referred to as “LAF sensors”) 21R and 21L are mounted, and these LAF sensors 21R and 21L are oxygen concentrations (air-fuel ratio) in the exhaust gas. A detection signal that is substantially proportional to is output and supplied to the ECU 5. On the downstream side of the three-way catalysts 23R and 23L, oxygen concentration sensors (hereinafter referred to as “O2 sensors”) 22R and 22L for detecting the oxygen concentration in the exhaust gas are provided. The O2 sensors 22R and 22L have a characteristic that their outputs change abruptly before and after the stoichiometric air-fuel ratio, and their outputs are high on the rich side and low on the lean side. The O2 sensors 22R and 22L are connected to the ECU 5, and the detection signal is supplied to the ECU 5.

A spark plug 12 provided for each cylinder of the engine 1 is connected to the ECU 5, and a drive signal of the spark plug 12, that is, an ignition signal is supplied from the ECU 5.
The ECU 5 includes an atmospheric pressure sensor 14 that detects the atmospheric pressure PA, a vehicle speed sensor 15 that detects the traveling speed (vehicle speed) VP of the vehicle driven by the engine 1, and a gear position that detects the gear position GP of the transmission of the vehicle. Sensors 16 are connected, and detection signals from these sensors are supplied to the ECU 5.

  The ECU 5 shapes input signal waveforms from various sensors, corrects the voltage level to a predetermined level, converts an analog signal value into a digital signal value, etc., and a central processing circuit (hereinafter referred to as “CPU”). A storage circuit for storing various calculation programs executed by the CPU and calculation results, and an output circuit for supplying a drive signal to the fuel injection valve 6. The ECU 5 controls the valve opening time and ignition timing of the fuel injection valve 6 on the basis of detection signals from various sensors, and opens and closes the electromagnetic valves 35i and 35e, and performs all-cylinder operation of the engine 1 and a part thereof. Switching control with cylinder operation is performed.

FIG. 3 is a flowchart of processing for determining execution conditions of cylinder deactivation (partial cylinder operation) for deactivating some cylinders. This process is executed by the CPU of the ECU 5 every predetermined time (for example, 10 milliseconds).
In step S111, it is determined whether or not the start mode flag FSTMOD is “1”. If FSTMOD = 1 and the engine 1 is being started (cranking), the detected engine water temperature TW is used as the start mode water temperature. Stored as TWSTMOD (step S113). Next, the TMTWCSDLY table shown in FIG. 4 is searched according to the start mode water temperature TWSTMOD, and the delay time TMTWCSDLY is calculated. In the TMTWCSDLY table, in the range where the start mode water temperature TWSTMOD is equal to or lower than the first predetermined water temperature TW1 (for example, 40 ° C.), the delay time TMTWCSDLY is set to the predetermined delay time TDLY1 (for example, 250 seconds), and the start mode water temperature TWSTMOD is the first predetermined water temperature. In the range higher than TW1 (for example, 40 ° C.) and lower than the second predetermined water temperature TW2 (for example, 60 ° C.), the delay time TMTWCSDLY is set to decrease as the start mode water temperature TWSTMOD increases, and the start mode water temperature TWSTMOD becomes the second predetermined water temperature. In a range higher than TW2, the delay time TMTWCSDLY is set to “0”.

  In the subsequent step S115, the downcount timer TCSWAIT is set to the delay time TMTWCSDLY and started, and the cylinder deactivation flag FCYLSTP is set to “0” (step S125). This indicates that the execution condition for cylinder deactivation is not satisfied.

  If FSTMOD = 0 in step S111 and the normal operation mode is set, it is determined whether or not the engine water temperature TW is higher than the cylinder deactivation determination temperature TWCSTP (for example, 75 ° C.) (step S112). When TW ≦ TWCSTP, it is determined that the execution condition is not satisfied, and the process proceeds to step S114. When the engine water temperature TW is higher than the cylinder deactivation determination temperature TWCSTP, the process proceeds from step S112 to step S116, and it is determined whether or not the value of the timer TCSWAIT started in step S115 is “0”. While TCSWAIT> 0, the process proceeds to step S125, and when TCSWAIT = 0, the process proceeds to step S117.

  In step S117, the THCS table shown in FIG. 5 is searched according to the vehicle speed VP and the gear position GP, and the upper threshold THCSH and the lower threshold THCSL used for determination in step S118 are calculated. In FIG. 5, the solid line corresponds to the upper threshold value THCSH, and the broken line corresponds to the lower threshold value THCSL. The THCS table is set for each gear position GP, and is set such that the upper threshold THCSH and the lower threshold THCSL increase as the vehicle speed VP increases roughly at each gear position (second to fifth gears). Has been. However, when the gear position GP is the second speed, an area is provided in which the upper threshold value THCSH and the lower threshold value THCSL are kept constant even if the vehicle speed VP changes. When the gear position GP is 1st gear, all cylinder operation is always performed, so the upper threshold value THCSH and the lower threshold value THCSL are set to “0”, for example. If the vehicle speed VP is the same, the threshold values (THCSH, THCSL) corresponding to the low-speed side gear position GP are set to be larger than the threshold values (THCSH, THCSL) corresponding to the high-speed side gear position GP.

  In step S118, it is determined whether or not the throttle valve opening TH is smaller than the threshold value THCS with hysteresis. Specifically, when the cylinder deactivation flag FCYLSTP is “1”, when the throttle valve opening TH increases and reaches the upper threshold value THCSH, the answer to step S118 becomes negative (NO), and the cylinder deactivation flag FCYLSTP is set. When it is “0”, when the throttle valve opening TH decreases and falls below the lower threshold value THCSL, the answer to step S118 becomes affirmative (YES).

  If the answer to step S118 is affirmative (YES), it is determined whether or not the atmospheric pressure PA is equal to or higher than a predetermined pressure PACS (for example, 86.6 kPa (650 mmHg)) (step S119), and the answer is affirmative (YES) ), It is determined whether the intake air temperature TA is equal to or higher than a predetermined lower limit temperature TACSL (eg, −10 ° C.) (step S120). If the answer is affirmative (YES), the intake air temperature TA is predetermined. It is determined whether the temperature is lower than an upper limit temperature TACSH (for example, 45 ° C.) (step S121). If the answer is affirmative (YES), the engine water temperature TW is lower than a predetermined upper limit water temperature TWCSH (for example, 120 ° C.). (Step S122), and if the answer is affirmative (YES), it is determined whether or not the engine speed NE is lower than a predetermined engine speed NECS (step S122). -Up S123).

  The determination in step S123 is performed with hysteresis as in step S118. That is, when the cylinder deactivation flag FCYLSTP is “1”, when the engine speed NE increases and reaches the upper speed NECSH (for example, 3500 rpm), the answer to step S123 becomes negative (NO), and the cylinder deactivation flag FCYLSTP When the engine speed NE decreases and falls below the lower speed NECSL (for example, 3300 rpm), the answer to step S123 becomes affirmative (YES).

  When the answer to any of steps S118 to S123 is negative (NO), it is determined that the cylinder deactivation execution condition is not satisfied, and the process proceeds to step S125. On the other hand, when all the answers in steps S118 to S123 are affirmative (YES), it is determined that the cylinder deactivation execution condition is satisfied, and the cylinder deactivation flag FCYLSTP is set to “1” (step S124).

  When the cylinder deactivation flag FCYLSTP is set to “1”, a partial cylinder operation is performed in which the # 1 to # 3 cylinders are deactivated and the # 4 to # 6 cylinders are operated, and the cylinder deactivation flag FCYLSTP is set to “0”. ”Is set, the all-cylinder operation for operating all the cylinders # 1 to # 6 is executed.

  FIG. 6 is a flowchart of processing for calculating the valve opening time of the fuel injection valve 6, that is, the fuel injection amount TOUT. This processing is executed by the CPU of the ECU 5 in synchronism with the generation of the TDC signal pulse. . The fuel amount (fuel injection amount) in the present embodiment is actually calculated as the valve opening time of the fuel injection valve 6. However, since the fuel injection amount is proportional to the fuel injection time, the fuel amount or It is described as the fuel injection amount.

  In step S11, engine operating parameters detected by the various sensors are read, and then the TiMF calculation process shown in FIG. 7 is executed (step S12). In this process, the basic fuel amount for starting TiMST and the basic fuel amount for starting TiM are calculated, and these are corrected according to the intake air temperature TA, the atmospheric pressure PA, and the engine water temperature TW. The total basic fuel amount TiMF is calculated using a transition coefficient KMTIM for smoothing the transition of the supply amount.

  In step S13, the adhesion parameter calculation process shown in FIGS. 10 and 11 is executed. In this process, the attachment parameters used for correcting the fuel transportation delay due to the part of the fuel injected from the fuel injection valve 6 adhering to the inner wall of the intake pipe 2, that is, the direct rate AFWF and the carry-off rate BFWF are obtained. calculate. The direct rate AFWF is the ratio of the fuel injected into the intake pipe in a certain cycle, and the fuel taken into the combustion chamber during that cycle. The carry-off ratio B is the ratio of the fuel that has adhered to the intake pipe wall up to the previous time. The ratio of fuel sucked into the combustion chamber by evaporation or the like during the cycle.

In step S14, the required fuel amount TCYL (N) is calculated from the following equation (1).
TCYL (N) = TiMF × KCMD × KLAF × KTOTAL (N)
(1)
Here, (N) is given to indicate that it is a parameter calculated for each cylinder, TiMF is the total basic fuel amount calculated in step S12, KCMD is the engine speed NE, The target air-fuel ratio coefficient, KLAF, which is set according to the engine operating parameters such as the throttle valve opening TH, the engine water temperature TW, and the outputs of the O2 sensors 22R, 22L, is set according to the outputs of the LAF sensors 21R, 21L. The fuel ratio correction coefficient, KTOTAL (N), is another correction coefficient calculated based on engine operating parameters from various sensors (however, intake air temperature correction coefficients KTA, KTAST, atmospheric pressure correction coefficients KPA, KPAST described later, and engine) Excluding water temperature correction coefficients KTW, KTWST, target air-fuel ratio coefficient KCMD, and air-fuel ratio correction coefficient KLAF Which is the product. At the time of start-up, the product KTOTAL (N) of the air-fuel ratio correction coefficient KLAF and other correction coefficients is set to a predetermined value (for example, 1.0).

In step S15, the required fuel amount TCYL (N) calculated in step S14 is applied to the following equation (2) to directly supply fuel amount TNET (N) as the amount of fuel to be directly supplied to the combustion chamber in the current cycle. Is calculated.
TNET (N) = TCYL (N) + TTOTAL (N)
-BFWF x TWP (N) (2)
Here, TTOTAL (N) is the sum of all addition correction terms (for example, acceleration increase correction term TACC, etc.) calculated based on engine operating parameters from various sensors. However, the invalid time TV set according to the voltage of the battery that drives the fuel injection valve 6 is not included. TWP (N) is the amount of fuel adhering to the intake pipe (predicted value) calculated in the process of FIG. 15, and BFWF × TWP (N) is equivalent to the amount of fuel taken away from the fuel adhering to the intake pipe to the combustion chamber. To do. Since the amount of fuel taken away does not need to be newly injected, this amount is subtracted from the required fuel amount TCYL (N) in equation (2).

In the subsequent step S16, it is determined whether or not the directly supplied fuel amount TNET (N) is a positive value. When TNET (N) ≦ 0, the fuel injection amount (opening time of the fuel injection valve 6) TOUT is set. On the other hand, when “0” is set (step S18), and TNET (N)> 0, the fuel injection amount TOUT is calculated by dividing the direct supply fuel amount TNET (N) by the direct rate AFWF by the following equation (3). Calculate (step S19). This is because TOUT × AFWF (= TNET (N)) is supplied directly to the combustion chamber among the injected fuel.
TOUT = TNET (N) / AFWF (3)

By instructing the fuel injection valve 6 to be opened for a time obtained by adding the invalid time TV set in accordance with the battery voltage to the TOUT value calculated by the equation (3), the combustion chamber (TNET (N ) + BFWF × TWP (N) = TCYL (N) + TTOTAL (N)).
In the subsequent step S19, the TWP calculation process shown in FIG. 15 is executed to calculate the intake pipe adhering fuel amount TWP (N), and this process ends.

  FIG. 7 is a flowchart of the TiMF calculation process executed in step S12 of FIG. In step S21, the starting basic fuel amount TiMST, the starting intake air temperature correction coefficient KTAST, the starting atmospheric pressure correction coefficient KPAST, and the starting engine water temperature correction coefficient used to calculate the fuel supply amount suitable for starting the engine. KTWST is calculated.

  Specifically, the starting basic fuel amount TiMST is calculated by searching a starting basic fuel amount map (not shown) according to the engine speed NE and the intake pipe absolute pressure PBA. The starting basic fuel amount map is set so that the air-fuel ratio is optimum for starting the engine in the operating state corresponding to the set values of the engine speed NE and the intake pipe absolute pressure PBA.

  The starting intake air temperature correction coefficient KTAST is calculated by searching a KTAST table indicated by a broken line in FIG. 8A according to the intake air temperature TA. The KTAST table is set so that the correction coefficient KTAST decreases as the intake air temperature TA increases. The starting atmospheric pressure correction coefficient KPAST is calculated by searching a KPAST table indicated by a broken line in FIG. 8B according to the atmospheric pressure PA. The KPAST table is set so that the correction coefficient KPAST decreases as the atmospheric pressure PA decreases. The starting engine water temperature correction coefficient KTWST is calculated by searching a KTWST table indicated by a broken line in FIG. 8C according to the engine water temperature TW. The KTWST table is set so that the correction coefficient KTWST decreases as the engine coolant temperature TW increases.

In the subsequent step S22, each parameter calculated in step S21 is applied to the following equation (4) to calculate a modified starting basic fuel amount TiMSTM suitable for starting the engine.
TiMSTM = TiMST × KTAST × KPAST × KTWST (4)

  In step S23, after starting the engine, that is, after starting basic fuel amount TiM used for calculating a fuel supply amount suitable for normal operation, after starting intake air temperature correction coefficient KTA, after starting atmospheric pressure correction. A coefficient KPA and a post-startup engine water temperature correction coefficient KTW are calculated.

  Specifically, the post-startup basic fuel amount TiM is calculated by searching a post-startup basic fuel amount map (not shown) according to the engine speed NE and the intake pipe absolute pressure PBA. The post-startup basic fuel amount map is set so that the air-fuel ratio matches the stoichiometric air-fuel ratio in the operating state corresponding to the set values of the engine speed NE and the intake pipe absolute pressure PBA. This after-starting basic fuel amount (TiM) map is different from the set value of the starting basic fuel amount (TiMST) map even in the same operating state (the same engine speed NE and the same intake pipe absolute pressure PBA). After starting, that is, a value suitable for normal operation is set.

  The post-startup intake air temperature correction coefficient KTA is calculated by searching a KTA table indicated by a solid line in FIG. 8A according to the intake air temperature TA. The KTA table is set so that the correction coefficient KTA decreases as the intake air temperature TA rises. Also, the KTA table is set to a value smaller than the start correction coefficient KTAST in the low temperature range, and conversely the start correction coefficient in the high temperature range. A value larger than KTAST is set. The post-startup atmospheric pressure correction coefficient KPA is calculated by searching a KPA table indicated by a solid line in FIG. 8B according to the atmospheric pressure PA. The KPA table is set so that the correction coefficient KPA decreases as the atmospheric pressure PA decreases, and is set to a value larger than the starting correction coefficient KPAST. The post-startup engine water temperature correction coefficient KTW is calculated by searching a KTW table indicated by a solid line in FIG. 8C according to the engine water temperature TW. The KTW table is set so that the correction coefficient KTW decreases as the engine water temperature TW increases, and is set to a value smaller than the start correction coefficient KTWST in the low temperature range, and conversely the start correction coefficient in the high temperature range. It is set to a value larger than KTWST (= 1.0).

In the subsequent step S24, each parameter calculated in step S23 is applied to the following equation (5) to calculate a corrected post-start basic fuel amount TiMM suitable for normal operation after the engine is started.
TiMM = TiM × KTA × KPA × KTW (5)
In step S25, the KMTIM calculation process shown in FIG. 9 is executed, and a transition coefficient KMTIM that gradually decreases with the lapse of time from the completion of the start is calculated according to the engine water temperature TW being started.

In step S26, the total basic fuel amount TiMF is calculated by applying the corrected starting basic fuel amount TiMSTM and the corrected starting basic fuel amount TiMM calculated in steps S22 and S24 to the following equation (6).
TiMF = TiMM × (1-KMTIM) + TiMSTM × KMTIM
(6)

  At the time of starting, by setting the transition coefficient KMTIM of the equation (6) to “1.0”, the total basic fuel amount is set to the modified starting basic fuel amount TiMSTM suitable for starting, and the transient control immediately after the start is completed. , The transition coefficient KMTIM is gradually decreased to smoothly shift the value of the total basic fuel amount TiMF from the corrected starting basic fuel amount TiMSTM to the corrected post-starting basic fuel amount TiMM. After the time point when KMTIM = 0, the total basic fuel amount TiMF becomes equal to the corrected post-start basic fuel amount TiMM suitable after the start, and the fuel amount suitable after the start is calculated. As a result, the fuel amount suitable for each operation state is calculated both at the start and after the start, and the fuel amount does not change suddenly at the completion of the start, so in the period from the initial start to the warm-up operation. The control accuracy of the fuel supply amount can be improved, and the exhaust characteristics can be adapted to the extremely low level exhaust gas regulations.

  As will be described later, when the engine water temperature TW at the time of starting is high, such as at the time of hot restart of the engine, the initial value of the transition coefficient KMTIM is set to a value smaller than 1, and normal control (control that becomes TiMF = TiMM) ) To complete the transition to).

FIG. 9 is a flowchart of the KMTIM calculation process executed in step S25 of FIG. 7. In this process, the transition coefficient KMTIM is set according to the engine water temperature TW being started.
In step S31, it is determined whether or not the engine 1 is starting. If the engine 1 is starting, a TDC counter TDCAST that counts the number of TDC signal pulses generated after the start is set to “0” (step S32). It is determined whether or not the engine water temperature TW is equal to or higher than a first predetermined water temperature TWKML (for example, 15 ° C.) (step S33). When TW ≧ TWKML, it is further determined whether or not the temperature is equal to or higher than a second predetermined water temperature TWKMH (for example, 50 ° C.) higher than the first predetermined water temperature TWKML (step S35). As a result, when TW <TWKML, the warm-up state variable MTWKM indicating the warm-up state of the engine is set to “0” (step S34), and when TWKML ≦ TW <TWKMH, the warm-up state variable MTWKM Is set to “1” (step S36), and when TW ≧ TWKMH, the warm-up state variable MTWKM is set to “2” (step S37), and the process proceeds to step S39.

When the engine is not being started in step S31, that is, after the start is completed, the TDC counter TDCAST is incremented by “1” (step S38), and the process proceeds to step S39.
In step S39, it is determined whether or not the value of the warm-up state variable MTWKM is “0”. If MTWKM> 0, it is further determined whether or not the value is “1” (step S42). ). When MTWKM = 0, the KMTIM0N table shown in FIG. 14A is searched according to the value of the TDC counter TDCAST, and the transition coefficient value KMTIM0N for low temperature is calculated (step S40). KMTIM is set to the low-temperature transition coefficient value KMTIM0N (step S41). The KMTIM0N table has KMTIM0N = 1.0 when TDCAST = 0, and the transition coefficient value KTIM0N decreases to “0” as the value of the TDC counter TDCAST increases, that is, with the lapse of time after the start is completed. Is set to

  If MTWKM = 1, the KMTIM1N table shown in FIG. 14A is searched according to the value of the TDC counter TDCAST, the transition coefficient value KMTIM1N for the intermediate temperature is calculated (step S43), and the transition coefficient KMTIM is calculated. Is set to the intermediate temperature transition coefficient value KMTIM1N (step S44). The KMTIM1N table has KMTIM1N = 1.0 when TDCAST = 0, and the transition coefficient value KMTIM1N decreases to “0” as the value of the TDC counter TDCAST increases, that is, with the lapse of time after the start is completed. Is set to The KMTIM1N table is set so as to increase the speed at which the set value decreases, that is, the speed at which the transition coefficient decreases, compared to the KMTIM0N table.

  When MTWKM = 2, the KMTIM2N table shown in FIG. 14A is searched according to the value of the TDC counter TDCAST, the transition coefficient value KMTIM2N for high temperature is calculated (step S45), and the transition coefficient KMTIM is calculated. Is set to the high-temperature transition coefficient value KMTIM2N (step S46). In the KMTIM2N table, when TDCAST = 0, the coefficient value KMTIM2N is set to a predetermined value smaller than 1.0, and the transition coefficient value KTIM2N decreases as the value of the TDC counter TDCAST increases, that is, as time elapses after the start is completed. Is set to “0”. The KMTIM2N table is set so that the transition coefficient value becomes “0” earlier than the KMTIM1N table.

  As described above, the transition coefficient KMTIM is set by the process of FIG. 9 so that the transition speed becomes faster or the transition completion point is earlier as the engine water temperature TW at the start is higher. Therefore, by applying this transition coefficient KMTIM to the equation (6), it is possible to perform appropriate transient control according to the engine temperature at the time of starting, and to further improve the control accuracy of the fuel supply amount.

10 and 11 are flowcharts of the adhesion parameter calculation process in step S13 of FIG.
In step S51, it is determined whether or not the engine 1 is being started. When the engine 1 is being started, the AFWCR table shown in FIG. 12A and the BFWCR table shown in FIG. To calculate the starting direct rate AFWCR and the starting take-off rate BFWCR (step S52), and the process proceeds to step S55. The AFWCR table and the BFWCR table are set such that the direct rate AFWCR and the carry-off rate BFWCR increase as the engine coolant temperature TW increases.

  When the engine is not being started, that is, after the start is completed, the AFW0AC map shown in FIG. 13 (a) and the BFW0AC map shown in FIG. 13 (b) are retrieved according to the engine speed NE and the intake pipe absolute pressure PBA, and all cylinder operation is performed. A map value AFW0AC for the direct ratio for use and a map value BFW0AC for the take-out ratio for all cylinder operation are calculated (step S53). The AFW0AC map is set so that the map value AFW0AC increases as the intake pipe absolute pressure PBA increases and as the engine speed NE increases. The BFW0AC map is set such that the map value BFW0AC decreases as the intake pipe absolute pressure PBA increases and the engine speed NE increases.

  In step S54, it is determined whether or not a cylinder deactivation flag FCYLSTP is “1”. When FCYLSTP = 0 and all cylinders are operating, the direct rate map value AFW0 and the carry-off rate map value BFW0 are set to the all-cylinder operation map values AFW0AC and BFW0AC calculated in step S53, respectively ( Step S55). Thereafter, the process proceeds to step S58.

  When FCYLSTP = 1 in step S54 and partial cylinder operation is being performed, the map values AFW0AC and BFW0AC for all cylinder operation are multiplied by the correction coefficients KACS and KBCS, respectively, so that the map value AFW0 and the direct ratio value are obtained. A map value BFW0 of the leaving rate is calculated (step S56). The correction coefficients KACS and KBCS are both set to a value larger than “1.0” (for example, 1.2). When compared with the same engine speed NE and the absolute pressure PBA in the intake pipe, the flow rate of the intake air increases during the operation of some cylinders compared to the operation of all cylinders. It is taken into consideration. By correcting the direct rate and the take-off rate in this way, appropriate adhesion correction can be performed even in partial cylinder operation. After execution of step S56, the process proceeds to step S58.

  In step S58, a direct rate temperature correction coefficient KATW and a take-off rate temperature correction coefficient KBTW are calculated according to the engine coolant temperature TW, and the process proceeds to step S59. These correction coefficients are set such that the values thereof increase as the engine coolant temperature TW increases.

  In step S59, it is determined whether or not the warm-up state variable MTWKM calculated in the process of FIG. 9 is “0”. If MTWKM = 0, FIG. 14B is set according to the value of the TDC counter TDCAST. ) Is searched, and a transition coefficient value KMFW0N for low temperature is calculated (step S60). In the KMFW0N table, KMFW0N = 1.0 when TDCAST = 0, and the transition coefficient value KMFW0N decreases to “0” as the value of the TDC counter TDCAST increases, that is, as time elapses after the start is completed. Is set to In the subsequent step S61, the transfer coefficient KMFW is set to the low-temperature transfer coefficient value KMFW0N, and the process proceeds to step S64 (FIG. 11).

  On the other hand, when MTWKM = 1 or 2 in step S59, the KMFW1N table shown in FIG. 14B is searched according to the value of the TDC counter TDCAST, and the transition coefficient value KMFW1N for high temperature is calculated (step S62). . In the KMFW1N table, KMFW1N = 1.0 when TDCAST = 0, and the transition coefficient value KMFW1N decreases to “0” as the value of the TDC counter TDCAST increases, that is, as time elapses after the start is completed. Is set to The KMFW 1N table is set so as to increase the rate at which the set value decreases, that is, the rate at which the transition coefficient decreases, compared to the KMFW 0N table. In the subsequent step S63, the transition coefficient KMFW is set to the transition coefficient value for high temperature KMFW1N, and the process proceeds to step S64 (FIG. 11).

  In step S64, it is determined whether or not the transition coefficient KMFW is “0”. When KMFW> 0, immediately, and when KMFW = 0, “1” is set from the engine start to the end of the transient control. The set transient control flag FKMSTFW is set to “0” (step S65), and the process proceeds to step S66.

In step S66, it is determined whether or not the transient control flag FKMSTFW is “1”. When FKMSTFW = 1, the starting direct rate AFWCR and the starting take-off rate BFWCR calculated in step S52, and in step S53. The calculated post-start direct rate map value AFW0, post-start take-off ratio map value BFW0, the temperature correction coefficients KATW and KBTW calculated in step S54, and the transition coefficient KMFW set in step S61 or S63 are expressed by the following formula ( 7) Applying to (8), the total direct rate AFWF and the total carry-off rate BFWF are calculated (steps S67 and S68), and this process is terminated.
AFWF = AFW0 × KATW × (1-KMFW)
+ AFWCR × KMFW (7)
BFWF = BFW0 × KBTW × (1-KMFW)
+ BFWCR × KMFW (8)

  On the other hand, when FKMSTFW = 0 in step S66 and the transient control is completed, values obtained by multiplying the total direct rate AFWF and the total take-off rate BFWF by the map values AFW0 and BFW0 and the temperature correction coefficients KATW and KBTW, respectively. (Step S69), and this process is terminated.

  As described above, according to the processing of FIG. 10, the transition coefficient KMFW is set to “1” at the start, and the total direct rate AFWF and the total carry-off rate BFWF are substantially the start adhesion correction parameters. The direct start rate AFWCR and the start take-off rate BFWCR are set, and in the transient control immediately after the start is completed, the transition factor KMFW is gradually decreased to increase the direct rate for the start (AFW0 × KATW) and the take-off rate. It is set so that it smoothly transitions to (BFW0 × KBTW), and after the end of the transient control, it is set to the direct rate for starting (AFW0 × KATW) and the take-off rate (BFW0 × KBTW). Adhesion correction suitable for each operating state is performed both at the start and after the start, and the adhesion correction parameter is suddenly Without, it is possible to perform highly accurate fuel supply amount control than considering fuel adhering to the intake pipe wall.

  Further, the direct rate map value AFW0 and the take-off rate map value BFW0 are calculated according to the engine speed NE and the intake pipe absolute pressure PBA and the number of operating cylinders (all cylinder operation or partial cylinder operation). In both the all-cylinder operation and the partial cylinder operation, appropriate adhesion correction can be performed and good exhaust characteristics can be maintained.

FIG. 15 is a flowchart of the TWP calculation process executed in step S19 of FIG.
In step S71, it is determined whether or not the fuel injection amount TOUT calculated in step S17 or S18 in FIG. 6 is larger than a predetermined minimum value TOUTMIN. If TOUT> TOUTMIN is satisfied, the following equation (9) is attached. A fuel amount TWP (N) is calculated (step S72).
TWP (N) = (1-BFWF) × TWP (N) (n−1)
+ (1-AFWF) × TOUT (9)

  Here, TWP (N) (n−1) is the previous value of the attached fuel amount TWP (N), and the first term on the right side is the fuel that has been left unremoved this time among the fuels previously attached. The second term on the right side corresponds to the amount of fuel newly attached to the intake pipe among the fuel injected this time.

On the other hand, when TOUT ≦ TOUTMIN is established in step S71, the fuel is hardly injected or not injected at all, and the attached fuel amount TWP (N) is calculated by the following equation (10) (step) S73).
TWP (N) = (1-BFWF) × TWP (N) (n−1) (10)
This expression (10) corresponds to the expression (9) in which the second term on the right side is deleted. This is because there is no newly attached fuel when the amount of injected fuel is extremely small.

  After executing Step S72 or S73, the process proceeds to Step S74, and it is determined whether or not the calculated attached fuel amount TWP (N) is equal to or greater than a predetermined guard value TWPLG. This guard value TWPLG is set to a minute value close to zero. If TWP (N) <TWPLG, TWP (N) = 0 is set (step S75). If TWP (N) ≧ TWPLG, the process is immediately terminated.

According to the process of FIG. 15, the attached fuel amount TWP (N) is calculated using the fuel injection amount TOUT and the attachment parameters AFWF and BFWF, and an accurate attached fuel amount TWP (n) (predicted value) can be obtained. The amount of fuel sucked into each cylinder can be accurately controlled.
In this embodiment, the cylinder deactivation mechanism 30 constitutes a switching means, and includes a throttle valve opening sensor 4, an intake pipe absolute pressure sensor 7, an intake air temperature sensor 8, an engine water temperature sensor 9, a crank angle position sensor 10, a vehicle speed sensor 15, The gear position sensor 16 constitutes an operation parameter detection means, and the ECU 5 constitutes a command means, a fuel amount calculation means, and an adhesion correction means. More specifically, the processing in FIG. 3 corresponds to the command means, steps S11, S12, and S14 in FIG. 6 correspond to the fuel amount calculation means, and steps S13, S15 to S19 correspond to the adhesion correction means.

  The present invention is not limited to the embodiment described above, and various modifications can be made. For example, in the above-described embodiment, a 6-cylinder engine is shown, but the present invention can also be applied to a 4-cylinder engine or an 8-cylinder engine. Further, the number of cylinders to be deactivated is not limited to 3 cylinders. For example, in a 4-cylinder engine, 1 cylinder or 2 cylinders may be deactivated, and in an 8-cylinder engine, 4 cylinders may be deactivated.

  The present invention can also be applied to control of a marine vessel propulsion engine such as an outboard motor having a crankshaft as a vertical direction.

It is a figure which shows the structure of the internal combustion engine and its control apparatus concerning one Embodiment of this invention. It is a figure which shows the structure of the hydraulic control system of a cylinder deactivation mechanism. It is a flowchart of the process which determines a cylinder deactivation condition. It is a figure which shows the TMTWCSDLY table used by the process of FIG. It is a figure which shows the THCS table used by the process of FIG. It is a flowchart of the process which calculates fuel injection time (TOUT). It is a flowchart of the process which calculates total basic fuel amount (TiMF). It is a figure which shows the table used by the process of FIG. It is a flowchart of the process which calculates a transfer coefficient (KMTIM). It is a flowchart of the process which calculates an adhesion parameter. It is a flowchart of the process which calculates an adhesion parameter. It is a figure which shows the table used by the process of FIG. It is a figure which shows the map used by the process of FIG. It is a figure which shows the table used by the process of FIG. 9, or the process of FIG. It is a flowchart of the process which calculates the fuel quantity (TWP) adhering to the intake pipe inner wall.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Internal combustion engine 2 Intake pipe 4 Throttle valve opening sensor (operating parameter detection means)
5 Electronic control unit (command means, fuel amount calculation means, adhesion correction means)
6 Fuel injection valve 8 Intake air temperature sensor (operating parameter detection means)
9 Engine water temperature sensor (operating parameter detection means)
10 Crank angle position sensor (operating parameter detection means)
15 Vehicle speed sensor (Driving parameter detection means)
16 Gear position sensor (operating parameter detection means)
30 cylinder deactivation mechanism (switching means)

Claims (2)

In a control device for an internal combustion engine having a plurality of cylinders and comprising switching means for switching between all-cylinder operation for operating all of the plurality of cylinders and partial cylinder operation for stopping operation of some of the plurality of cylinders. ,
An operation parameter detecting means for detecting an operation parameter of a vehicle driven by the engine, including the operation parameter of the engine;
Command means for instructing the switching means to perform the all-cylinder operation or the partial cylinder operation in accordance with the operation parameter;
A fuel amount calculating means for calculating a fuel amount to be supplied to the engine according to the operating parameter;
An adhesion parameter calculating means for calculating an adhesion parameter for correcting a transportation delay of fuel caused by a part of the fuel injected into the intake pipe of the engine adhering to the inner wall of the intake pipe ;
An adhesion correction means for correcting the amount of fuel using the adhesion parameter ,
The attachment parameter calculating means, the control apparatus for an internal combustion engine, characterized that you calculate the deposition parameters or deposition parameters for the partial-cylinder operation for the all-cylinder operation according to a command of the command means.   The adhesion parameter is a direct ratio that is a ratio of fuel directly injected into the combustion chamber among the fuel injected into the intake pipe, and a ratio of fuel that is sucked into the combustion chamber among fuel adhered to the intake pipe. A certain take-away rate,
  The adhesion parameter calculation means calculates the adhesion parameter according to the engine speed and the intake pipe internal pressure, and the adhesion parameter for the partial cylinder operation is the same for all cylinders at the same engine speed and intake pipe internal pressure. 2. The control apparatus for an internal combustion engine according to claim 1, wherein the controller is calculated so as to be larger than an adhesion parameter for operation.

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