JP5732232B2 - Internal combustion engine - Google Patents

Description

  The present invention relates to an internal combustion engine provided with an in-cylinder injector and an intake pipe injector for one cylinder.

  In an internal combustion engine including an in-cylinder injector that directly injects fuel into the combustion chamber and an intake pipe injector that injects fuel into the intake pipe, an injection amount by the in-cylinder injector and an injection amount by the intake pipe injector are: Air-fuel ratio feedback control is performed so that the air-fuel mixture of fuel and intake air becomes the stoichiometric air-fuel ratio by sharing at a predetermined sharing rate according to the engine speed and load (for example, Patent Document 1).

JP 2005-307756 A

  There is a feedback correction coefficient as an element of air-fuel ratio feedback control. If the feedback correction coefficient remains fixed, optimal air-fuel ratio feedback control becomes difficult due to changes in the vehicle state and environment. As a result, the fuel consumption is deteriorated, the HC (hydrocarbon) emission amount is increased, and the running performance and controllability of the vehicle are deteriorated. Therefore, in order to learn the feedback correction coefficient for each injector, it is necessary to set a learning opportunity by injecting the injector independently.

  However, the operating state in which the feedback correction coefficient is learned is not always appropriate for the single injection of the injector. (For example, in the case of in-cylinder injection and partial injection, the injector fuel injection amount is the same, but the in-cylinder pressure to be injected is different).

Therefore, this learning causes a temporary deterioration in fuel consumption and an increase in HC (hydrocarbon) emissions.

An object of the present invention is to provide an internal combustion engine capable of reducing fuel consumption, reducing CO ₂ emissions, reducing HC emissions, improving vehicle running performance and maneuverability.

An internal combustion engine according to an embodiment of the present invention includes an in-cylinder injector that directly injects fuel into a combustion chamber, an in-pipe injector that injects fuel into an intake pipe that communicates with the combustion chamber, an in-cylinder injector, and an intake pipe And a control unit for controlling the injector.
The control unit is in an operating state in which the internal combustion engine is operated only by the intake pipe injection injector, and further, the operating state is within a learning range of a fuel injection amount correction coefficient for correcting the fuel injection amount of the intake pipe injection injector. And learning an integral correction coefficient, which is a fuel injection amount correction coefficient, of the fuel injection amount from the intake pipe injector, and calculating the learned integral correction coefficient from the fuel injection amount of the intake pipe injector and the rotational speed of the internal combustion engine. This area is stored for each divided area obtained by dividing the area.
When the internal combustion engine is in an operating state where the in-cylinder injector and the intake pipe injector operate, the control unit determines whether the in-cylinder injector and the intake pipe injector are based on the rotational speed of the internal combustion engine and the load value. The fuel injection ratio is determined, and based on the determined fuel injection ratio, the fuel target injection amount to be injected from the intake pipe injector is calculated and stored in the divided region corresponding to the fuel target injection amount from the intake pipe injector. The amount of fuel injected by the intake pipe injection injector is controlled using the integral correction coefficient of the intake pipe injection injector.
Further, the internal combustion engine is in an operating state in which the in-cylinder injector and the intake pipe injector are operated, and the operating state further learns a fuel injection amount correction coefficient for correcting the fuel injection amount of the in-cylinder injector. When entering the region, the control unit only learns the fuel injection amount of the in-cylinder injector among the learning of the fuel injection amount of the in-cylinder injector and the learning of the fuel injection amount of the in-pipe injection injector, and corrects the fuel injection amount. An integral correction coefficient of the fuel injection amount injected by the in-cylinder injector, which is a coefficient, is learned and stored.

According to a third aspect of the present invention, in the internal combustion engine according to the first or second aspect, the control unit corrects the intake pipe injection amount learning value based on the pressure in the intake pipe .

According to the present invention, when learning a fuel injection quantity correction coefficient of the in-cylinder injection injector, there is no to the operating state of operating alone only in-cylinder injector, deterioration of fuel efficiency, CO 2 _(carbon dioxide ) Increase in emissions and increase in HC (hydrocarbon) emissions can be suppressed.

  In addition, the fuel injection amount of the intake pipe injector can be corrected more accurately in the in-cylinder injector load-rotation speed learning range.

1 is a schematic diagram showing an internal combustion engine according to an embodiment of the present invention. FIG. 2 shown in FIG. 1 is a map defined by volumetric efficiency and rotational speed, showing the operating state of the internal combustion engine body of the internal combustion engine. The map which shows the state which divided | segmented the load-rotation speed learning area for in-pipe injection injectors shown in FIG. 2 into plurality. The map which shows the fuel quantity for an in-pipe injection injector-rotation speed learning area. The map which shows the state which divided | segmented the load-rotation speed learning area | region for in-pipe injection injectors into plurality for the proportional correction coefficient. The map which shows the state which divided | segmented the fuel quantity for the in-pipe injection injector-rotation speed learning area | region for the proportional correction coefficient. The map which shows the state which divided | segmented the load-rotation speed learning area for in-cylinder injectors into the plurality for the integral correction coefficient. The map which shows the state which divided | segmented the load-rotation speed learning area for cylinder injection injectors for the proportional correction coefficient. The map which shows the state in which the pressure value is memorize | stored in each division area of the fuel quantity for intake pipe injection injectors-rotation speed learning area. The flowchart which shows operation | movement of ECU of the internal combustion engine shown by FIG. The flowchart which shows operation | movement of ECU of the internal combustion engine shown by FIG.

  An internal combustion engine according to an embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a schematic view showing an internal combustion engine 10 of the present embodiment. The internal combustion engine 10 includes an internal combustion engine main body 20, an intake pipe 31, an exhaust pipe 32, and an ECU (Electric Control Unit) 50 which is an example of a control unit referred to in the present invention. FIG. 1 is a schematic view showing an internal combustion engine 10.

  As shown in FIG. 1, the internal combustion engine body 20 is a reciprocating internal combustion engine having a plurality of cylinders, for example, a four-cylinder gasoline engine, for example. FIG. 1 representatively shows the vicinity of one of a plurality of combustion chambers provided in the internal combustion engine body 20. The internal combustion engine body 20 will be described as a representative structure in the vicinity of one combustion chamber shown in FIG.

  The internal combustion engine body 20 includes a cylinder block 21 and a cylinder head 22 that is assembled to the cylinder block 21. A cylinder 23 is formed in the cylinder block 21. A piston 24 connected to the crankshaft 200 via a connecting rod 201 is accommodated in the cylinder 23. A combustion chamber 25 is formed by the cylinder 23, the piston 24, and the cylinder head 22. In the figure, a part of the connecting rod 201 is omitted.

  The cylinder head 22 is provided with an ignition plug 26, an intake valve 27, and an exhaust valve 28. The intake valve 27 opens and closes an intake port 29 that is formed in the cylinder head 22 and opens to the combustion chamber 25. The exhaust valve 28 opens and closes an exhaust port 30 formed in the cylinder head 22 and opened to the combustion chamber 25. The intake port 29 communicates with the intake pipe 31. The exhaust port 30 communicates with the exhaust pipe 32.

  As the piston 24 descends, air or an air / fuel mixture is supplied into the combustion chamber 25 through the intake port 29. The intake pipe 31 is provided with an air flow meter 33 for detecting the intake air amount and a throttle valve 34 for determining the intake air amount (air amount).

  The cylinder head 22 includes an in-cylinder injector 35. The in-cylinder injector 35 is provided at a position facing the combustion chamber 25. An injection port for injecting fuel from the in-cylinder injector 35 is located in the combustion chamber 25. The in-cylinder injector 35 directly injects fuel into the combustion chamber 25. In the present embodiment, one in-cylinder injector 35 is provided for each cylinder. However, the number of in-cylinder injectors 35 is not limited to one, and a plurality of in-cylinder injectors 35 may be provided.

  The intake pipe 31 is provided with an intake pipe injection injector 36. The intake pipe injection injector 36 injects fuel toward the intake port 29. In the present embodiment, one intake pipe injection injector 36 is provided for one cylinder as an example, but the present invention is not limited to this. For example, a plurality of intake pipe injection injectors 36 may be formed.

  The fuel directly injected into the combustion chamber 25 by the in-cylinder injector 35 is the intake air or air-fuel mixture that flows into the combustion chamber 25 through the intake port 29 in the combustion chamber 25 (air-fuel mixture). Mixed with. The fuel injected by the intake pipe injector is mixed with intake air in the intake pipe 31, and the mixture flows into the combustion chamber 25 through the intake port 29.

  These air-fuel mixtures are compressed by the rise of the piston 24 (compression stroke), and are ignited by the spark generated by the spark plug 26 to burn and explode (combustion stroke). The piston 24 descends again by this combustion / explosion, and the above operation is repeated. Gas generated by combustion / explosion is discharged through the exhaust port 30 when the exhaust valve 28 is opened (exhaust stroke).

  The exhaust pipe 32 is provided with an air-fuel ratio sensor 37 that detects the air-fuel ratio of the exhaust gas, and a catalyst 38 that purifies the exhaust gas. A pressure sensor 39 is provided in the intake pipe 31. The pressure sensor 39 is disposed in the vicinity of the intake pipe injection injector 36 in the intake pipe 31 and detects the pressure in the vicinity of the intake pipe injection injector 36.

  Reference numeral 40 denotes a fuel tank. The fuel tank 40 includes a feed pump 41 for sending out fuel. Fuel is fed from the feed pump 41 to the fuel pipe 42, and the fuel is supplied to the in-cylinder injector 35 by the fuel pipe 42, the branch pipe 43a, and the high-pressure pump 44 on the branch pipe 43a. The fuel in the fuel pipe 42 is supplied to the intake pipe injector 36 by the branch pipe 43b.

  The ECU 50 includes an in-cylinder injector 35, an intake pipe injector 36, an air flow meter 33, a throttle valve 34, an air-fuel ratio sensor 37, a pressure sensor 39, a feed pump 41, a high-pressure pump 44, ignition. A coil 45, a crank angle sensor 46, a coolant temperature sensor 47, an accelerator opening sensor 48, and the like are connected.

  The ignition coil 45 operates under the control of the ECU 50 and supplies a driving voltage for ignition to the ignition plug 26. The crank angle sensor 46 detects the rotation angle of the crankshaft 200 interlocked with the vertical movement of the piston 24 and transmits the detection result to the ECU 50. The coolant temperature sensor 47 detects the coolant temperature of the internal combustion engine body 20 and transmits the detection result to the ECU 50. The accelerator opening sensor 48 detects the accelerator opening (the amount by which the accelerator pedal is depressed) and transmits the detection result to the ECU 50.

  The ECU 50 has the following functions (1) to (8) as main functions related to the control of the internal combustion engine body 20.

  (1) A function of detecting (calculating) the rotational speed Ne of the internal combustion engine body 20 from the detection angle of the crank angle sensor 46. The rotational speed Ne is the rotational speed of the crankshaft 200. The crankshaft 200 is an example of the output shaft referred to in the present invention, and the rotational speed of the crankshaft 200 is an example of the output shaft rotational speed referred to in the present invention.

  (2) A function of detecting the volumetric efficiency Ev of the combustion chamber 25 from the detected opening of the accelerator opening sensor 48 and the detected amount of the air flow meter 33. The volumetric efficiency Ev is an example showing the load referred to in the present invention.

  (3) A fuel injection amount in which the operating state of the internal combustion engine body 20 corrects the fuel injection amount of the in-pipe injection injector 36 or the fuel injection amount of the in-cylinder injector 35 to an optimal amount from the rotational speed Ne and the volumetric efficiency Ev. A function that determines whether or not the learning coefficient learning range is entered.

  This function will be specifically described. FIG. 2 shows a map 60 defined by the volumetric efficiency Ev and the rotational speed Ne, showing the operating state of the internal combustion engine body 20. The map 60 is held by the ECU 50.

  As shown in FIG. 2, in the map 60, the horizontal axis indicates the rotational speed Ne, and the rotational speed Ne increases as it proceeds to the right side (the direction in which the arrow on the horizontal axis advances). The vertical axis indicates the volumetric efficiency Ev, and the volumetric efficiency Ev increases as it proceeds upward in the figure (the direction in which the vertical axis arrow advances). In the map 60, the boundary between the intake pipe injection area 61 in which the intake pipe injection is performed only by the intake pipe injection injector 36 and the both injector injection areas 62 in which both the intake pipe injection injector 36 and the in-cylinder injector 35 are injected is a boundary line. It is partitioned by 63.

  In the intake pipe injection region 61, the internal combustion engine body 20 is in a low / medium load state. Both injector injection regions 62 are in a high load state.

  Further, in the map 60, a learning area 64 for learning a fuel injection amount correction coefficient for correcting the fuel injection amount of the intake pipe injector 36 or the fuel injection amount of the in-cylinder injector 35 to an optimal amount is surrounded by a one-dot chain line. It is shown.

  The learning area 64 includes a load-rotation speed learning area 65 for the in-pipe injection injector that learns a fuel injection amount correction coefficient that corrects the fuel injection quantity of the in-pipe injection injector 36 to an optimum amount, and the fuel injection of the in-cylinder injector 35. An in-cylinder injector load-rotation speed learning area 66 for learning a fuel injection amount correction coefficient for correcting the amount to an optimum amount is provided.

  The intake pipe injection load-rotation speed learning area 65 is formed in the intake pipe injection area 61. The in-cylinder injector load-rotation speed learning area 66 is formed in both injector injection areas 62. The intake pipe injector load-revolution speed learning area 65 and the in-cylinder injector load-revolution speed learning area 66 are separated by a boundary line 63.

  The optimum fuel injection amount is a value at which the air-fuel ratio in the combustion chamber 25 becomes the stoichiometric air-fuel ratio. In this embodiment, in order to correct the fuel injection amount of the in-pipe injection injector 36 to an optimal amount, and to correct the fuel injection amount of the in-cylinder injector 35 to an optimal amount, a proportional correction coefficient and The fuel injection amount is corrected using the integral correction coefficient. Learning in this embodiment is an integral correction coefficient. The proportional correction coefficient is set in advance and is not learned.

  The ECU 50 determines from the map 60 whether the operating state of the internal combustion engine body 20 is in the learning area 64 from the volume efficiency Ev of the internal combustion engine body 20 and the rotational speed Ne.

  (4) When it is determined that the operating state (rotational speed Ne, volumetric efficiency Ev) of the internal combustion engine main body 20 is in the intake pipe injection injector load-rotation speed learning area 65, the intake pipe injection injector load-rotation speed A function of learning and storing an integral correction coefficient of integral correction control for correcting the fuel injection amount of the intake pipe injector 36 to an optimum amount in each divided region obtained by dividing the learning region 65 into a plurality of regions.

  This function will be specifically described. FIG. 3 is a map 70 showing a state in which the load / rotational speed learning area 65 for the intake pipe injector is divided into a plurality of parts. The ECU 50 has a map 70. As shown in the map 70, in the present embodiment, the load-rotation speed learning area 65 for the in-pipe injector is divided into four in the horizontal axis direction and four in the vertical axis direction. There are divided areas MIZe11 to MIZe44.

  The divided regions MIZe11 to MIZe14 have the same rotation speed region. The divided regions MIZe21 to MIZe24 have the same rotation speed region. The divided regions MIZe31 to MIZe34 have the same rotation speed region. The divided regions MIZe41 to MIZe44 have the same rotation speed region.

  As shown in the map 70, the ECU 50 learns and stores the integral correction coefficient of the intake pipe injection injector 36 in a region corresponding to the operating state of the internal combustion engine body 20 in the divided regions MIZe11 to MIZe44.

  (5) When it is determined that the operating state (rotational speed Ne, volumetric efficiency Ev) of the internal combustion engine main body 20 is in the intake pipe injection injector load-rotational speed learning area 65, the fuel injection amount of the intake pipe injection injector 36 Integral correction that corrects the fuel injection amount of the intake pipe injection injector 36 to an optimum amount in each divided region obtained by dividing the intake pipe injector fuel amount-rotation number learning region 80 defined by Pw and the rotation speed Ne into a plurality of regions. A function that learns and stores the control integral correction coefficient.

  This function will be specifically described. FIG. 4 is a map 81 showing a fuel amount / rotational speed learning area 80 for the intake pipe injector. In the map 81, the horizontal axis indicates the number of rotations. The horizontal axis increases as it proceeds to the right (in the direction of the arrow) in the figure. The vertical axis indicates the fuel injection amount, and increases as it proceeds upward (in the direction of the arrow) in the figure. The intake pipe injector fuel amount-rotational speed learning area 80 is divided into four along the horizontal axis and into four along the vertical axis, and has 16 divided areas MIZp11 to MIZp44. doing.

  The divided regions MIZp11 to MIZp14 have the same rotation speed region. The divided regions MIZp21 to MIZp24 have the same rotation speed region. The divided regions MIZp31 to MIZp34 have the same rotation speed region. The divided regions MIZp41 to MIZp44 have the same rotation speed region.

  In the present embodiment, the intake pipe injector fuel amount-rotation speed learning area 80 is divided in accordance with the division along the horizontal axis of the intake pipe injection load-rotation speed learning area 65. More specifically, the rotation speed range of the divided region MIZe11 of the intake pipe injector load-rotation speed learning area 65 is the rotation speed area of the divided area MIZp11 of the intake pipe injection fuel amount-rotation speed learning area 80. Is the same. The rotational speed region of the divided region MIZe21 in the intake pipe injector load-rotational speed learning region 65 is the same as the rotational speed region of the divided region MIZp21 in the intake pipe fuel amount-rotational speed learning region 80. The rotation speed region of the divided region MIZe31 in the intake pipe injection load-rotation speed learning area 65 is the same as the rotation speed area of the divided area MIZp31 in the intake air injector fuel amount-rotation speed learning area 80. The rotation speed range of the divided region MIZe41 in the intake pipe injection load-rotation speed learning area 65 is the same as the rotation speed area of the divided area MIZp41 in the intake pipe injection fuel amount-rotation speed learning area 80.

  The ECU 50 learns and stores the integral correction coefficient of the intake pipe injector 36 in the divided areas MIZp11 to MIZp44 of the intake pipe injector fuel quantity-rotation speed learning area 80.

  Next, a proportional correction coefficient for correcting the fuel injection amount of the intake pipe injector 36 will be described. In the present embodiment, as described above, the proportional correction coefficient uses a preset value and is not learned. The intake pipe injector load-rotation speed learning area 65 is divided into a plurality of proportional correction coefficients, and a proportional correction coefficient is set in each divided area.

  FIG. 5 shows a map 90 obtained by dividing the intake pipe injector load-rotation speed learning area 65 into a plurality of proportional correction coefficients. The ECU 50 has a map 90. As an example, the map 90 is divided into two along the horizontal axis, and is divided into two along the vertical axis, and has four areas MPZe11 to MPIZe22. A proportional correction coefficient is set in advance for each region.

  FIG. 6 shows a map 100 obtained by dividing the fuel amount for the in-pipe injection injector-rotational speed learning area 80 for the proportional correction coefficient. The ECU 50 has a map 100. As shown in FIG. 6, the fuel amount for the in-pipe injection injector-rotational speed learning region 80 is divided into two along the horizontal axis and into two along the vertical axis, and is divided into four regions MPZp11. ~ MPZp22.

  (6) When it is determined that the operating state (rotational speed Ne and volumetric efficiency Ev) of the internal combustion engine body 20 is in the in-cylinder injector load-rotational speed learning area 66, the fuel injection ratio of the intake pipe internal injector 36 And a function for obtaining the fuel injection ratio of the in-cylinder injector 35.

  This function will be specifically described. The injection ratio of the intake pipe injector 36 and the fuel injection ratio of the in-cylinder injector 35 are determined in advance according to the operating state of the internal combustion engine body 20, and are stored in a map, for example. The ECU 50 has this map. The ECU 50 determines the injection ratios of the injectors 35 and 36 from this map based on the operating state of the internal combustion engine body 20.

  (7) When it is determined that the operating state (rotation speed Ne, volumetric efficiency Ev) of the internal combustion engine body 20 is in the in-cylinder injection injector load-rotation speed learning area 66, the in-cylinder injection injector load-rotation A function of learning and storing an integral correction coefficient of integral correction control for correcting the fuel injection amount of the in-cylinder injector 35 to an optimum amount in each divided region obtained by dividing the number learning region 66 into a plurality of regions.

  This function will be specifically described. FIG. 7 is a map 110 showing a state where the in-cylinder injector load-rotation speed learning area 66 is divided into a plurality of integral correction coefficients. The ECU 50 has a map 110. As shown in the map 110, in this embodiment, the in-cylinder injector load-rotation speed learning area 66 is divided into four in the horizontal axis direction for learning the integral correction coefficient, and four divided areas DIZe11. ~ DIZe14.

  The ECU 50 learns and stores the integral correction coefficient in a region corresponding to the operating state of the internal combustion engine body 20 among the divided regions DIZe11 to DIZe14.

  Here, the proportional correction coefficient for correcting the fuel injection amount of the in-cylinder injector will be described. As described above, the proportional correction coefficient is preset in the in-cylinder injector load-rotation speed learning area 66 and is not learned.

  FIG. 8 is a map 120 showing a state where the in-cylinder injector load-rotation speed learning area 66 is divided for the proportional correction coefficient. The ECU 50 has a map 120. As shown in FIG. 8, the in-cylinder injector load-rotation speed learning area 66 is divided into two divided areas along the horizontal axis as an example in the present embodiment, and has DPZe11 and DPZe12. Yes. Different proportional correction coefficients are preset and stored in the respective regions DPZe11 and DPZe12.

  (8) A function of correcting the fuel injection amount of the intake pipe injector 36 based on the pressure in the intake pipe 31 in the in-cylinder injector load-rotation speed learning area 66.

  This function will be specifically described. FIG. 9 shows a map 81 of the intake pipe injector fuel amount-rotational speed learning area 80. The map 81 shown in FIG. 9 indicates that pressure values Pb11 to Pb44 corresponding to the operation state of each region are set in advance in each divided region MIZe11 to MIZe44. This pressure value is a value obtained by, for example, experiments. More specifically, the pressure value is detected a plurality of times in each operation state, and the average value is stored as the pressure value in each region.

When the ECU 50 determines the fuel injection amount of the intake pipe injector 36 in the in-cylinder injector load-rotation speed learning region 66, the ECU 50 determines the pressure value RPb in the intake pipe 31 (intake pipe injection injector 36 in the intake pipe 31). Of the fuel amount for the intake pipe injector-rotation speed learning area 80 that is searched based on the target fuel injection amount and the rotation speed Ne of the intake pipe injection injector 36, of the divided regions MIZp11 to MIZp44 The pressure correction value is calculated based on the pressure value (any one of Pb11 to Pb14) stored in the corresponding divided area. If the pressure correction value is X,

  It becomes. Here, Pb is any one of Pb11 to Pb44, and is a pressure value stored in the corresponding divided region.

  The ECU 50 applies the pressure correction value X obtained by the above formula to the fuel injection amount of the in-pipe injection injector 36 in the in-cylinder injector load-rotation speed learning region 66, so that the fuel of the in-pipe injection injector 36 Correct the injection amount.

  Next, the operation of the ECU 50 will be described. 10 and 11 are flowcharts showing the operation of the ECU 50. This flowchart is periodically executed after the operation of the internal combustion engine 10 (internal combustion engine body 20) is started. In the flowcharts shown in FIGS. 10 and 11, the in-pipe injection injector 36 is described as MPI, and the in-cylinder injection injector 35 is described as DI. The load-rotation speed learning area for the intake pipe injector is referred to as an MPIEv-Ne learning area. The fuel amount for the in-pipe injection injector-rotational speed learning area is described as an MPIPw-Ne learning area. The in-cylinder injector load-rotation speed learning area is referred to as a DIEv-Ne learning area. The operation pattern of the ECU 50 has the following three.

  (1) Operation in a state where the operating state of the internal combustion engine body 20 is not in the learning area 64.

  (2) Operation in a state where the operating state of the internal combustion engine body 20 is in the intake pipe injector load-rotation speed learning region 65.

(3) internal combustion engine body 20 load operating conditions cylinder injection injector - operation in the presence of the rotation speed learning region 6 6.

  First, the operation (1) in a state where the internal combustion engine body 20 is not in the learning area 64 will be described.

  As shown in FIG. 10, in step ST <b> 1, the ECU 50 detects the rotational speed Ne from the detection angle of the crank angle sensor 46. When the rotational speed Ne is detected, the process proceeds to step ST2.

  In step ST <b> 2, the ECU 50 detects the volume efficiency Ev from the detected opening of the accelerator opening sensor 48 and the detected amount of the air flow meter 33. When the volumetric efficiency Ev is detected, the process proceeds to step ST3.

  In step ST3, the ECU 50 determines whether or not the operating state of the internal combustion engine body 20 is in the learning area 64 shown in the map 60 of FIG. 2 from the rotational speed Ne and the volumetric efficiency Ev. Since the operating state of (1) is not in the learning area 64, the ECU 50 determines that the operating state of the internal combustion engine body 20 is not in the learning area 64. When the operating state of the internal combustion engine body 20 is not in the learning range 64, open loop control is performed, and learning of the correction coefficient for the fuel injection amount is not performed.

  Next, the operation of the ECU 50 in the state (2), in which the operating state of the internal combustion engine body 20 is in the intake pipe injector load-rotation speed learning region 65, will be described. In addition, until step ST3, it is the same as the driving | running state of (1). In step ST4, since the operating state of (2) is in the intake pipe injector load-rotation speed learning region 65, the process then proceeds to step ST5. In step ST5, the ECU 50 determines whether or not the operating state of the internal combustion engine body 20 is in the intake pipe injector load-rotational speed learning region 65. As described above, since the internal combustion engine main body 20 is in the intake pipe injector-load-rotation speed learning area 65, the process proceeds to step ST6.

  In step ST6, the ECU 50 calculates the fuel injection amount Pw of the intake pipe injector 36. Pw = {(volume efficiency Ev) ÷ 100 × (stroke volume) × (air specific gravity) ÷ (14.7) × (A / F−F / B coefficient) × MPI learning value}.

  The (A / F−F / B) coefficient is (proportional correction coefficient + integral correction coefficient). The ECU 50 uses the map 90 in which the load-rotation speed learning area 65 for the intake pipe injection injector is divided into a plurality of proportional correction coefficients, to the area corresponding to the operating state of the internal combustion engine body 20 among the divided areas MPZp11 to MPZp22. Search the stored proportional correction coefficient.

  Further, the ECU 50 corresponds to the operating state of the internal combustion engine main body 20 in the divided areas MIZe11 to MIZe44 using the map 70 in which the load-rotation speed learning area 65 for the in-pipe injection injector is divided into a plurality for integral correction. The integral correction coefficient stored in the area is searched. When the integral correction coefficient has never been learned, the integral correction coefficient stored in each of the divided regions MIZe11 to MIZe44 is, for example, 1 as an initial value.

  The MPI learning value is a coefficient for correcting the amount of fuel injected from the intake pipe injection injector 36 so that the air-fuel ratio in the combustion chamber 25 becomes the stoichiometric air-fuel ratio. Based on the detection value of the air-fuel ratio sensor 37, the MPI learning value changes so that the mixture of fuel and air supplied to the combustion chamber 25 becomes the stoichiometric air-fuel ratio. The MPI learning value is a value that varies between 0 and 2, for example. More specifically, when it is determined that the air-fuel ratio is richer than the stoichiometric air-fuel ratio, the MPI learning value is set to 1 or less in order to reduce the amount of fuel injected from the intake pipe injection injector 36. When it is determined that the air-fuel ratio is leaner than the stoichiometric air-fuel ratio, the MPI learning value is set to 1 or more so as to increase the amount of fuel injected from the intake pipe injector 36.

  The MPI learning value is determined in a later step by performing feedback control on the fuel amount set in step ST6 based on the detection value of the air-fuel ratio sensor 37. In a state where the MPI learning value has never been learned, the MPI learning value is set to 1 as an initial value, for example. When the fuel injection amount of the intake pipe internal injector 36 is calculated, the process proceeds to step ST7.

  In step ST7, the ECU 50 operates the intake pipe injection injector 36 to inject fuel in order to inject the fuel amount calculated in step ST6. When the fuel is injected, the process proceeds to step ST8.

In step ST8, the ECU 50 corrects the MPI learning value based on the detection result of the air-fuel ratio sensor 37 so that the fuel injection amount approaches the theoretical air-fuel ratio. Then, the process proceeds to step ST9.

  In step ST9, the ECU 50 collects information on the volume efficiency Ev, the rotational speed Ne, the fuel injection amount Pw, and the integral correction coefficient × MPI learning value obtained in steps ST1, ST2, and ST6. Then, the process proceeds to step ST10.

  In step ST10, the ECU 50 determines whether it is a learning timing. The learning timing is a timing determined in advance and deviates at predetermined time intervals. In this embodiment, as an example, the learning timing is set at intervals of 0.5 seconds.

If it is not the learning timing, the process proceeds to step ST11. In step ST11, the divided area MIZe11 of the intake pipe injector load-rotation speed learning area 65 is obtained from the information of the volume efficiency Ev, the rotation speed Ne, the fuel injection amount Pw, and the integral correction coefficient × MPI learning value summarized in step ST9. The average value of the integral correction coefficient × MPI learning value is calculated in the corresponding region of ˜MIZ e 44. Then, the process proceeds to step ST12.

  In step ST12, based on the information of the volume efficiency Ev, the rotational speed Ne, the fuel injection amount Pw, the integral correction coefficient × MPI learning value summarized in step ST9, the divided region of the intake pipe injector fuel amount-rotational speed learning region 80 The average value of the integral correction coefficient × MPI learning value is calculated in the corresponding region of MIZp11 to MIZp44.

  Until the learning timing comes in step ST10, the operations in steps ST1 to ST12 are repeated. When the learning timing comes in step ST10, the process proceeds to step ST13. In step ST13, the integral correction coefficient × MPI learning value calculated in step ST11 is stored as a new integral correction coefficient in the divided areas MIZe11 to MIZe44 of the load-rotation speed learning area 65 for the in-pipe injector. Then, the process proceeds to step ST14.

  In step ST14, the integral correction coefficient × MPI learning value calculated in step ST12 is stored as a new integral correction coefficient in the divided areas MIZp11 to MIZp44 of the intake pipe injector fuel amount-rotational speed learning area 80. Thus, in steps ST13 and ST14, the integral correction coefficient is learned.

  The above-described operations from step ST1 to ST14 are repeated while the operating state of the internal combustion engine body 20 is in the intake pipe injector load-rotation speed learning region 65.

  Next, the operation of the ECU 50 in a state where the operating state of the internal combustion engine main body 20 in the above (3) is in the in-cylinder injector load-rotational speed learning region 66 will be described. Up to step ST4, the operation is the same as (2). Since the internal combustion engine body 20 is in the in-cylinder injector load-rotation speed learning region 66, the process proceeds from step ST5 to step ST15. In the in-cylinder injector load-rotation speed learning region 66, the in-pipe injection injector 36 and the in-cylinder injector 35 perform injection. Step ST15 is shown in FIG.

  As shown in FIG. 11, in step ST15, the ECU 50 determines the fuel injection ratio of the in-pipe injection injector 36, the in-cylinder injector from the volumetric efficiency Ev information obtained in steps ST1 and ST2 and the information on the rotational speed Ne. A fuel injection ratio of 35 is calculated. When the fuel injection ratio of the in-pipe injection injector 36 and the injection ratio of the in-cylinder injector 35 are detected, the process proceeds to step ST16.

  In step ST16, the ECU 50 calculates the fuel injection amount of the in-cylinder injector 35. When the fuel injection amount of the in-cylinder injector 35 is Z, Z = (volume efficiency Ev) / (100) × (stroke volume) × (air specific gravity) ÷ 14.7 × (A / F−B / F coefficient) × DI learning value × in-cylinder injector injection ratio.

  The A / F−B / F coefficient is (proportional correction coefficient + integral correction coefficient) of the in-cylinder injector 35. The ECU 50 searches the maps 110 and 120 for a proportional correction coefficient and an integral correction coefficient stored in a region corresponding to the operating state of the internal combustion engine body 20. In the state where the integral correction coefficient has never been learned, for example, 1 is stored as the initial value of the integral correction coefficient.

The DI learning value is a coefficient for correcting the amount of fuel injected from the in-cylinder injector 35 so that the air-fuel ratio in the combustion chamber 25 becomes the stoichiometric air-fuel ratio. Based on the detection value of the air-fuel ratio sensor 37, the DI learning value changes so that the mixture of fuel and air supplied to the combustion chamber 25 becomes the stoichiometric air-fuel ratio. The DI learning value is a value that changes between 0 and 2, for example. More specifically, if it is determined that the air-fuel ratio is richer than the stoichiometric air-fuel ratio, the DI learning value is set to 1 or less in order to reduce the amount of fuel injected from the in- cylinder injector 35 . When it is determined that the air-fuel ratio is leaner than the stoichiometric air-fuel ratio, the DI learning value is set to 1 or more so as to increase the fuel injected from the in- cylinder injector 35 .

Incidentally, DI learned value, a fuel amount set in the step ST 1 6, by feedback control based on the detected value of the air-fuel ratio sensor 37 is determined in a later step. In a state where the DI learning value has never been learned, the DI learning value is set to, for example, 1 as an initial value. When the fuel injection amount injected from the in-cylinder injector 35 is calculated, the process proceeds to step ST17.

  In step ST17, the ECU 50 calculates the fuel target injection amount of the intake pipe injection injector from the fuel injection ratio of the intake pipe injection injector 36. When the fuel target injection amount is calculated, the process proceeds to step ST18.

  In step ST18, a proportional correction coefficient and an integral correction coefficient for correcting the fuel injection amount of the intake pipe injector 36 are searched. Specifically, the ECU 50 calculates the intake pipe internal injector fuel amount-rotational speed learning area 80 from the rotational speed Ne obtained in step ST1 and the target fuel injection amount of the intake pipe internal injector 36 calculated in step ST17. The proportional correction coefficient and the integral correction coefficient stored in the corresponding area of the divided areas MIZp11 to MIZp44 are searched. When the proportional correction coefficient and the integral correction coefficient are retrieved, the process proceeds to step ST19.

  In step ST19, the ECU 50 acquires the current pressure value RPb information in the intake pipe 31. Then, the process proceeds to step ST20.

  In step T20, the ECU 50 calculates the fuel amount for the in-pipe injection injector-rotation speed learning area 80 from the target fuel injection amount of the in-pipe injection injector 36 calculated in step ST17 and the rotational speed Ne information acquired in step ST1. The pressure value Pb stored in the corresponding divided region among the divided regions MIZp11 to MIZp44 is searched. Then, the process proceeds to step ST21.

In step ST21, a pressure correction value X is calculated from the pressure value RPb in the intake pipe 31 acquired in step ST19 and the pressure value detected in step ST20.

  It becomes. Then, the process proceeds to step ST22.

  In step ST22, the ECU 50 calculates the fuel injection amount Pw of the intake pipe injector 36. The fuel injection amount of the intake pipe injector 36 obtained here is obtained by multiplying the fuel target injection amount calculated in step ST17 by the pressure correction value calculated in step ST21.

  Specifically, the fuel injection amount Pw of the intake pipe injector 36 = (volume efficiency Ev) / 100 × (stroke volume) × (air specific gravity) ÷ 14.7 × (A / F−F / B coefficient) × pressure Correction value × MPI injection ratio. The A / F-F / B coefficient is stored in the divided areas MIZp11 to MIZp44 of the intake pipe injector fuel amount-rotation speed learning area 80 (proportional correction coefficient + integral correction coefficient). When the fuel injection amount of the intake pipe injector 36 is calculated, the process proceeds to step ST23.

  In step ST23, the fuel injection amount calculated in step ST16 is injected from the in-cylinder injector 35, and the fuel injection amount calculated in step ST22 is injected from the intake pipe injector 36. Then, the process proceeds to step ST24.

  In step ST24, the ECU 50 corrects the DI learning value based on the detection result of the air-fuel ratio sensor 37 so that the stoichiometric air-fuel ratio is obtained. Then, the process proceeds to step ST25.

In step ST25, summarized the volumetric efficiency Ev information acquired in step ST1, the rotation speed Ne information acquired in step ST2, the the calculated information of the integral correction factor × DI learned value in step ST 16 to one. Then, the process proceeds to step ST26.

In step ST26, it is determined whether it is a learning timing. The learning timing is a timing determined in advance and deviates at a predetermined time interval. In this embodiment, as an example, the learning timing is set at intervals of 0.5 seconds . If it is determined in step ST26 that it is not the learning timing, then the process proceeds to step ST27.

In step ST27, the load cylinder injector - in the dividing regions DIZe11~DIZe14 speed learning region 6 6, the volumetric efficiency Ev information gathered in step ST25, the rotation speed Ne information, information of the integral correction factor × DI learned value Then, the average value of the integral correction coefficient × DI learning value is calculated in the corresponding divided area. Until the learning timing is determined in step ST26, the operations in steps ST1 to ST26 are repeated.

  If it is determined in step ST26 that the learning timing is reached, the process proceeds to step ST28. In step ST28, the average value of the integral correction coefficient × DI learning value calculated in the divided areas DIZe11 to DIZe14 in step ST27 is stored as a new integral correction coefficient.

  The above-described operations from step ST1 to ST28 are repeated while the operating state of the internal combustion engine body 20 is in the in-cylinder injector load-rotation speed learning region 66.

In the internal combustion engine 10 configured as described above, when only the intake pipe injection injector 36 performs injection, the optimum value of the integral correction coefficient of the intake pipe injection injector 36 is learned, and the intake pipe injection injector 36, the in-cylinder injection injector 35, By learning the optimum value of the integral correction coefficient of the in-cylinder injector 35 when performing fuel injection, the fuel consumption can be reduced, the CO ₂ emissions can be reduced, and the HC emissions can be reduced.

Further, in order to correct the fuel injection amount of the intake pipe injector 36 in the in-cylinder injector load-rotation speed learning area 66, each divided region MIZe1 1 of the intake pipe injector fuel quantity-rotation speed learning area 80 is corrected. The proportional correction coefficient and the integral correction coefficient stored in the corresponding divided region among -MIZe44 and MIZp11-MIZp44 were used. Thus, the fuel injection amount of the intake pipe injector 36 in the in-cylinder injector load-rotation speed learning region 66 can be calculated more accurately.

  This point will be specifically described. As an example, a case will be described in which the fuel injection amount of the intake pipe injection injector 36 is corrected in the operating state of the internal combustion engine body 20 at the position indicated by reference numeral P1 in FIG. In order to correct the fuel injection amount of the intake pipe injector 36, the proportional correction coefficient and integral correction stored in the intake pipe injector load-rotation speed learning area 65, defined by the volumetric efficiency Ev and the rotational speed Ne. When the coefficient is used, the integral correction coefficient and the proportional correction coefficient stored in the divided areas MIZe14 and MPZe12 shown in the maps 70 and 90 are used.

  However, the divided areas MIZe14 and MPZe12 deviate from the position P1, and therefore are not proportional correction coefficients and integral correction coefficients appropriate for the position P1.

  On the other hand, by using the intake pipe injector fuel amount-rotational speed learning area 80 defined by the fuel injection amount Pw and the rotational speed Ne, the fuel injection amount Pw and the rotational speed Ne at the position P1 are in the same state. A proportional correction coefficient and an integral correction coefficient can be obtained. Thus, the fuel injection amount of the intake pipe injector 36 in the in-cylinder injector load-rotation speed learning region 66 can be calculated more accurately.

  Further, when the integral correction coefficient is learned in the in-cylinder injector load-rotation speed learning area 66, it is stored in the divided areas MIZe11 to MIZe44, MIZp11 to MIZp22 of the in-pipe injection fuel quantity-rotation speed learning area 80. Although an integral correction coefficient and a proportional correction coefficient are used, the pressure values in the intake pipe 31 in the divided regions MIZe11 to MIZe44 and MIZp11 to MIZp22 are different from the pressure values in the intake pipe 31 at the time of learning. However, by correcting the fuel injection amount of the in-cylinder injector 36 in the in-cylinder injector load-rotation speed learning area 66 based on the pressure value in the intake pipe 31, the in-cylinder injector load-rotation is corrected. The fuel injection amount of the intake pipe injector 36 in the number learning area 66 can be calculated more accurately.

Although only one cylinder has been described, the present invention can be similarly applied to a case having a plurality of cylinders. In addition, the present invention is not limited to the above-described embodiment as it is, and can be embodied by modifying the constituent elements without departing from the scope of the invention in the implementation stage. Various inventions can be formed by appropriately combining a plurality of constituent elements disclosed in the above-described embodiments.
Hereinafter, the invention described in the scope of claims of the present application will be appended.
[1]
An in-cylinder injector that injects fuel directly into the combustion chamber;
An intake pipe injection injector for injecting fuel into an intake pipe communicating with the combustion chamber;
Comprising
Fuel control learning of the intake pipe injector is performed in an operating state in which only the intake pipe injector operates.
The fuel control learning of the in-cylinder injector is performed in an operating state in which the in-cylinder injector and the intake pipe injector operate.
An internal combustion engine characterized by that.
[2]
An in-cylinder injector that injects fuel directly into the combustion chamber;
An intake pipe injection injector for injecting fuel into the intake pipe communicating with the combustion chamber;
A controller for controlling the in-cylinder injector and the intake pipe injector
Comprising
The controller is
The fuel from the intake pipe injector is divided into a plurality of intake pipe injection load-rotation speed learning areas which are injected only by the intake pipe injection injector and defined by the load and the output shaft speed. The fuel injection amount correction coefficient for correcting the injection amount is learned and stored, and only the intake pipe injection injector injects and the fuel quantity for the intake pipe injection injector defined by the fuel injection amount and the output shaft rotational speed-rotation In each divided region obtained by dividing the number learning region into a plurality of regions, a fuel injection amount correction coefficient for correcting the fuel injection amount from the intake pipe injector is learned and stored,
The in-cylinder injector and the intake pipe injector inject fuel at the respective fuel injection ratios, and in the in-cylinder injector load-rotation speed learning range defined by the load and the output shaft speed, the intake air The fuel injection amount of the in-pipe injection injector is determined as the correspondence among the divided regions of the intake-pipe injection injector fuel amount-rotation number learning region using the fuel target injection amount of the intake pipe injection injector and the output shaft rotational speed. The in-cylinder injector in each divided region that is determined by correcting using the fuel injection amount correction coefficient that is set in the region that is to be divided, and that is divided into a plurality of load-rotation speed learning regions for the in-cylinder injector Learn and store the fuel injection amount correction coefficient for correcting the fuel injection amount from
An internal combustion engine characterized by that.
[3]
The control unit further corrects the fuel injection amount of the intake pipe injector in the learning area for the in-cylinder injector based on the pressure in the intake pipe.
The internal combustion engine according to [2], wherein
[4]
The fuel injection amount correction coefficient that the control unit learns in the intake pipe injector load-rotation speed learning range is an integral correction coefficient, and the control unit is in the intake pipe injection load-rotation speed learning area. Learning and storing the integral correction coefficient while correcting the fuel injection amount of the intake pipe injector using a predetermined proportional correction coefficient;
The fuel injection amount correction coefficient that the control unit learns in the in-cylinder injector load-rotation speed learning area is an integral correction coefficient, and the control section is in the in-cylinder injector load-rotation speed learning area. The integral correction coefficient is learned and stored while correcting the fuel injected from the in-cylinder injector using a predetermined proportional correction coefficient.
The internal combustion engine according to [2] or [3], wherein

  DESCRIPTION OF SYMBOLS 10 ... Internal combustion engine, 25 ... Combustion chamber, 31 ... Intake pipe, 35 ... In-cylinder injection injector, 36 ... Intake pipe injection injector, 50 ... ECU (control part), 65 ... Load-rotation speed learning area for intake pipe injection injectors , 66... In-cylinder injector load-rotation speed learning range, 80. Intake pipe injector fuel amount-rotation speed learning range, 200... Crankshaft (output shaft).

Claims (3)

An in-cylinder injector that injects fuel directly into the combustion chamber;
An intake pipe injection injector for injecting fuel into the intake pipe communicating with the combustion chamber;
In an internal combustion engine comprising a control unit for controlling said intake pipe injector and the in-cylinder injector,
The controller is
When the internal combustion engine is in an operating state in which only the intake pipe injection injector operates , and further, the operating state falls within a fuel injection amount correction coefficient learning range for correcting the fuel injection amount of the intake pipe injection injector. ,
The integral correction coefficient, which is the fuel injection amount correction coefficient, of the fuel injection amount from the intake pipe injector is learned, and the learned integral correction coefficient is used as the fuel injection quantity of the intake pipe injector and the rotation of the internal combustion engine. Memorize each divided area divided into a number of areas ,
In the operating state in which the internal combustion engine operates the in-cylinder injector and the intake pipe injection injector,
Based on the rotational speed and load value of the internal combustion engine, determine the fuel injection ratio of the in-cylinder injector and the intake pipe injector,
Based on the determined fuel injection ratio, a fuel target injection amount to be injected from the intake pipe injector is calculated,
Using the integral correction coefficient of the intake pipe injector stored in the divided region corresponding to the fuel target injection quantity from the intake pipe injector to control the fuel injection amount injected by the intake pipe injector;
Further, the internal combustion engine is in an operating state in which the in-cylinder injector and the intake pipe injector are operated, and the operating state further corrects the fuel injection amount of the in-cylinder injector. Once inside the learning area for the correction factor,
Of the learning of the fuel injection amount of the in-cylinder injector and the learning of the fuel injection amount of the intake pipe injection injector, only the learning of the fuel injection amount of the in- cylinder injector is performed , and the fuel injection amount correction coefficient. An internal combustion engine that learns and stores an integral correction coefficient of a fuel injection amount injected by the in-cylinder injector . The internal combustion engine according to claim 1, wherein the control unit corrects the fuel injection amount correction coefficient of the intake pipe injection injector based on a pressure in the intake pipe . The controller is
When the internal combustion engine is in an operating state in which only the intake pipe injection injector operates, the integral correction coefficient of the fuel injection quantity from the intake pipe injection injector is set to the fuel injection quantity from the intake pipe injection injector and the rotation of the internal combustion engine. And corresponding to the number of revolutions and load value of the internal combustion engine,
2. The fuel injection amount of the intake pipe injection injector is controlled using an integral correction coefficient of the intake pipe injection injector stored in correspondence with the rotational speed of the internal combustion engine and a load value. Or the internal combustion engine of 2.

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