Internal combustion engine control device

Abstract

Provided is an internal combustion engine control device. The control device is applied to an internal combustion engine that is capable of using fuel containing ethanol. The internal combustion engine is provided with a plurality of cylinders, a plurality of fuel injection valves, an intake passage, and a purge port. The purge port discharges purge gas, which contains fuel vapor generated in a fuel tank, to the intake passage. A processing circuit of the control device individually corrects fuel injection amounts of the plurality of fuel injection valves so that the fuel injection amount of a fuel injection valve corresponding to a cylinder into which a large amount of the purge gas is introduced is smaller than the fuel injection amount of a fuel injection valve corresponding to a cylinder into which a small amount of the purge gas is introduced.

Description

Technical Field

[0001] This disclosure relates to an internal combustion engine control device applied to an internal combustion engine capable of using fuels containing ethanol. Background Technology

[0002] Japanese Patent Application Publication No. 2021-76059 discloses an internal combustion engine capable of using fuel containing alcohol and a control device applied to the internal combustion engine. The internal combustion engine includes multiple cylinders, multiple fuel injection valves, and a purging treatment device. The multiple fuel injection valves are respectively provided corresponding to the multiple cylinders. The purging treatment device releases purge gases containing fuel vapor generated in the fuel tank into the intake passage.

[0003] The aforementioned control device calculates a learning value to compensate for the deviation between the detected air-fuel ratio and the target value caused by the release of purge gas into the intake passage through the purge treatment device. Furthermore, the control device uses the learning value to correct the fuel injection quantity of multiple fuel injection valves. Summary of the Invention

[0004] The problem that the invention aims to solve

[0005] The aforementioned purging device releases purging gas into the intake passage via a purging port connected to the intake passage. The purging gas released into the intake passage is then introduced into multiple cylinders. The amount of purging gas introduced into each cylinder can vary. Therefore, when purging gas is released into the intake passage, the air-fuel ratio of the mixture burned in each cylinder may vary depending on the amount of purging gas introduced into each cylinder.

[0006] Solution for solving the problem

[0007] In one aspect of this disclosure, an internal combustion engine control device is provided. The internal combustion engine is capable of using fuel containing ethanol. The internal combustion engine includes: a plurality of cylinders; a plurality of fuel injection valves corresponding to each of the plurality of cylinders; an intake passage through which air introduced into the plurality of cylinders flows; and a purge port for releasing purge gas into the intake passage, the purge gas containing fuel vapor generated in a fuel canister. The internal combustion engine control device includes a processing circuit for controlling the fuel injection quantity of the plurality of fuel injection valves. The processing circuit is configured to perform cylinder-by-cylinder calibration processing, which individually calibrates the fuel injection quantity of the plurality of fuel injection valves such that the fuel injection quantity of the fuel injection valve corresponding to the cylinder with a large amount of purge gas introduced is less than the fuel injection quantity of the fuel injection valve corresponding to the cylinder with a small amount of purge gas introduced. Attached Figure Description

[0008] Figure 1This is a diagram showing the schematic structure of a control device as one embodiment of an internal combustion engine control device, and the schematic structure of an internal combustion engine controlled by the control device.

[0009] Figure 2 This is a schematic diagram showing the purge gas released from the purge port into the intake passage and its destination in the cylinder.

[0010] Figure 3 It means by Figure 1 A block diagram of the processing circuitry that performs multiple processes in the control device.

[0011] Figure 4 It means Figure 3 A flowchart of an example of concentration estimation processing. Detailed Implementation

[0012] according to Figures 1-4 An embodiment of the internal combustion engine control device will be described.

[0013] Figure 1 An internal combustion engine 10 and a control device 60 applied to the internal combustion engine 10 are shown. The control device 60 corresponds to "internal combustion engine control device".

[0014] <Structure of Internal Combustion Engine 10>

[0015] The internal combustion engine 10 is capable of using fuels containing ethanol. The fuel, for example, contains at least ethanol and ethanol from gasoline. The internal combustion engine 10 is also capable of using fuels containing only gasoline.

[0016] The internal combustion engine 10 includes: multiple cylinders 11, a crankshaft 12, an intake passage 13, multiple fuel injection valves 15, multiple spark plugs 16, and an exhaust passage 17. The multiple cylinders 11 include a first cylinder #1, a second cylinder #2, a third cylinder #3, and a fourth cylinder #4 arranged sequentially in the direction extending from the crankshaft 12.

[0017] Air introduced into the multiple cylinders 11 flows in the intake passage 13. A throttle valve 14, which operates to adjust the amount of intake air, is provided in the intake passage 13. A fuel injection valve 15 injects fuel into the corresponding cylinder 11. In the multiple cylinders 11, the air-fuel mixture is combusted by the spark discharge of the corresponding spark plug 16. As a result, the crankshaft 12 rotates. In addition, exhaust gas is generated in the multiple cylinders 11 through the combustion of the air-fuel mixture. The exhaust gas discharged from the multiple cylinders 11 flows in the exhaust passage 17.

[0018] The internal combustion engine 10 includes a fuel supply device 20. The fuel supply device 20 supplies fuel stored in the fuel tank 21 to a plurality of fuel injection valves 15. The fuel supply device 20 includes a delivery pipe 23 and a fuel supply flow path 22. The delivery pipe 23 temporarily stores the fuel supplied to the plurality of fuel injection valves 15. The fuel supply flow path 22 allows fuel supplied from the fuel tank 21 to flow into the delivery pipe 23.

[0019] The internal combustion engine 10 includes a purge treatment device 30. The purge treatment device 30 releases purge gas containing fuel vapor generated in the fuel tank 21 into the intake passage 13. The purge treatment device 30 includes: an adsorption tank 31, a purge passage 32, a purge port 33, and a purge valve 34. The adsorption tank 31 adsorbs the fuel vapor generated in the fuel tank 21. In the purge passage 32, purge gas containing the fuel vapor adsorbed by the adsorption tank 31 flows into the intake passage 13. The purge port 33 is connected to the front end of the purge passage 32. The purge port 33 releases the purge gas flowing in the purge passage 32 into a portion of the intake passage 13 downstream of the throttle valve 14. The purge valve 34 is an electronically actuated valve located midway through the purge passage 32. By controlling the opening degree of the purge valve 34, the flow rate of the purge gas flowing in the purge passage 32 can be adjusted.

[0020] <Sensors for Internal Combustion Engines 10>

[0021] The internal combustion engine 10 is equipped with multiple sensors that output signals corresponding to the detection results to the control device 60. These sensors include: an air flow meter 41, a coolant temperature sensor 42, an air-fuel ratio sensor 43, and a fuel concentration sensor 44. The air flow meter 41 detects the flow rate of air flowing in the intake passage 13. The coolant temperature sensor 42 detects the temperature of the coolant circulating within the internal combustion engine 10. The air-fuel ratio sensor 43 detects the air-fuel ratio of the mixture after combustion in the multiple cylinders 11. The fuel concentration sensor 44 detects the ethanol concentration of the fuel stored in the fuel tank 21.

[0022] Hereinafter, the air flow rate based on the detection signal from the air flow meter 41 will be recorded as "Intake Air Quantity GA". The cooling water temperature based on the detection signal from the water temperature sensor 42 will be recorded as "Cooling Water Temperature TPw". The air-fuel ratio based on the detection signal from the air-fuel ratio sensor 43 will be recorded as "Air-fuel Ratio Detection Value AF". The ethanol concentration based on the detection signal from the concentration sensor 44 will be recorded as "Ethanol Concentration Detection Value CEt".

[0023] <Control device 60>

[0024] The control device 60 includes a processing circuit 61 for controlling the operation of the internal combustion engine 10. One example of the processing circuit 61 is an electronic control device. In this case, the processing circuit 61 includes a CPU 62, a first memory 63, and a second memory 64. The first memory 63 stores various control programs executed by the CPU 62. The second memory 64 stores the calculation results of the CPU 62. By executing the control programs in the first memory 63 through the CPU 62, the processing circuit 61 can control the fuel injection quantity of multiple fuel injection valves 15, the opening degree of the throttle valve 14, and the opening degree of the purge valve 34.

[0025] <Regarding the deviation in the amount of purge gas introduced into cylinder 11>

[0026] Reference Figure 2 The deviation in the amount of purge gas introduced into cylinder 11 is explained. Figure 2 In the diagram, the solid arrow Y1 represents the flow of ethanol in the purge gas, while the dashed arrow Y2 represents the flow of gasoline in the purge gas.

[0027] Ethanol has a lower specific gravity than gasoline. Therefore, as... Figure 2 As indicated by arrow Y1, the ethanol component contained in the fuel discharged from the purge port 33 into the intake passage 13 is easily introduced into the cylinders #1, #2, #3, and #4 located furthest from the purge port 33. That is, the amount of ethanol introduced into the fourth cylinder #4, which is furthest from the purge port 33, is the largest. On the other hand, the amount of ethanol introduced into the first cylinder #1, which is closest to the purge port 33, is the smallest.

[0028] like Figure 2 As indicated by arrow Y2, the gasoline components contained in the fuel discharged from the purge port 33 into the intake passage 13 are easily introduced into the cylinders #1 to #4 located near the purge port 33. That is, the amount of gasoline components introduced into the first cylinder #1, which is closest to the purge port 33, is the largest. On the other hand, the amount of gasoline components introduced into the fourth cylinder #4, which is furthest from the purge port 33, is the smallest.

[0029] Therefore, the amount of purge gas introduced into the cylinders varies depending on each cylinder #1 to #4. Furthermore, when the ethanol concentration of the purge gas released from the purge port 33 into the intake passage 13 changes, the amount of purge gas introduced into the cylinders #1 to #4 also changes. The ethanol concentration of the purge gas released from the purge port 33 into the intake passage 13 is recorded as "ethanol concentration CEtR". For example, when the ethanol concentration CEtR is high, the amount of purge gas introduced into the cylinders #1 to #4 furthest from the purge port 33 tends to increase, while the amount introduced into the cylinders near the purge port 33 tends to decrease. Conversely, when the ethanol concentration CEtR is low, the amount of purge gas introduced into the cylinders #1 to #4 near the purge port 33 tends to increase, while the amount introduced into the cylinders far from the purge port 33 tends to decrease.

[0030] When the amount of purge gas introduced into multiple cylinders #1 to #4 deviates, the air-fuel ratio of the mixture burned in multiple cylinders #1 to #4 deviates.

[0031] <Various processes performed by processing circuit 61>

[0032] Reference Figure 3 Various processes performed by the processing circuit 61 in order to adjust the fuel injection quantity of multiple fuel injection valves 15 in a manner that can suppress deviations in the air-fuel ratio of the mixture burned in multiple cylinders #1 to #4 will be described.

[0033] The processing circuit 61 performs the following processes: reference injection quantity calculation processing M11, air-fuel ratio feedback processing M12, common correction processing M13, concentration estimation processing M14, injection quantity estimation processing M15, cylinder-by-cylinder correction processing M16, and injection processing M17. Hereinafter, the air-fuel ratio feedback processing M12 will be referred to as "air-fuel ratio F / B processing M12".

[0034] The reference injection quantity calculation process M11 is the process for calculating the base value of the fuel injection quantity of the fuel injection valve 15, namely the base injection quantity QfB. In the reference injection quantity calculation process M11, the processing circuit 61 calculates the base injection quantity QfB based on the requested torque TqR, which is the requested value of the output torque of the internal combustion engine 10. For example, the processing circuit 61 calculates the base injection quantity QfB in a manner that the larger the requested torque TqR is, the larger the value of the base injection quantity QfB is.

[0035] The air-fuel ratio F / B processing M12 is a process for calculating the corrective injection amount ΔQf. This corrective injection amount ΔQf is a correction amount of fuel injection used to correct the deviation between the target air-fuel ratio AFTr and the detected air-fuel ratio AF. In the air-fuel ratio F / B processing M12, the processing circuit 61 calculates the corrective injection amount ΔQf using feedback control with the deviation between the target air-fuel ratio AFTr and the detected air-fuel ratio AF as input.

[0036] The common correction process M13 calculates the target value of the fuel injection quantity, i.e., the target injection quantity QfTr, by correcting the base injection quantity QfB with the corrected injection quantity ΔQf. In the common correction process M13, the processing circuit 61 calculates the target injection quantity QfTr as the sum of the base injection quantity QfB and the corrected injection quantity ΔQf.

[0037] Concentration estimation process M14 is used to estimate the ethanol concentration CEtR of the purge gas released from purge port 33 into inlet passage 13. The ethanol concentration estimated in concentration estimation process M14 will be recorded as "Estimated Concentration Value CEtRe". The details of concentration estimation process M14 will be described later.

[0038] The introduction volume estimation process M15 is a process for estimating the amount of purge gas introduced into multiple cylinders #1 to #4. Hereinafter, the estimated amount of purge gas introduced into cylinder #n is recorded as "Introduction Volume Estimation Value Qpge(n)". The cylinder number is substituted into "n". Therefore, the introduction volume estimation value Qpge in the first cylinder #1 is recorded as "Introduction Volume Estimation Value Qpge(1)".

[0039] In the import volume estimation process M15, the processing circuit 61 calculates the import volume estimation values ​​Qpge(1), Qpge(2), Qpge(3), and Qpge(4) of multiple cylinders #1 to #4 based on the concentration estimation value CEtRe calculated in the concentration estimation process M14 and the opening of the purge valve 34.

[0040] The following describes an example of the injection volume estimation processing M15. The processing circuit 61 calculates an estimated value, RLpg, of the amount of purge gas released from the purge port 33 into the intake passage 13 based on the opening degree Vpg of the purge valve 34. For example, the processing circuit 61 calculates the injection volume estimation value RLpg in such a way that the larger the opening degree Vpg, the larger the injection volume estimation value RLpg.

[0041] Furthermore, the processing circuit 61 calculates multiple injection quantity estimates Qpge(1) to Qpge(4) by allocating the emission quantity estimate RLpg to multiple cylinders #1 to #4 based on the concentration estimate CEtRe. For example, when the concentration estimate CEtRe is relatively high, the processing circuit 61 calculates the multiple injection quantity estimates Qpge(1) to Qpge(4) in a manner that increases the allocation of the emission quantity estimate RLpg for cylinders far from the purge port 33 and decreases the allocation of the emission quantity estimate RLpg for cylinders near the purge port 33. On the other hand, when the concentration estimate CEtRe is relatively low, the processing circuit 61 calculates the multiple injection quantity estimates Qpge(1) to Qpge(4) in a manner that decreases the allocation of the emission quantity estimate RLpg for cylinders far from the purge port 33 and increases the allocation of the emission quantity estimate RLpg for cylinders near the purge port 33.

[0042] Therefore, when the concentration prediction value CEtRe is high, the processing circuit 61 can increase the predicted amount of injection Qpge (4) of the fourth cylinder #4, which is located furthest from the purge port 33, compared to when the concentration prediction value CEtRe is low. In addition, the processing circuit 61 can decrease the predicted amount of injection Qpge (1) of the first cylinder #1, which is located closest to the purge port 33.

[0043] The target injection quantity of multiple fuel injection valves 15 is individually corrected by the cylinder calibration process M16 in such a way that the fuel injection quantity of the fuel injection valve 15 corresponding to the cylinder with a large input quantity prediction value Qpge among multiple cylinders #1~#4 is less than the fuel injection quantity of the fuel injection valve 15 corresponding to the cylinder with a small input quantity prediction value Qpge.

[0044] In the cylinder calibration process M16, the processing circuit 61 calculates the reduction calibration amount dQf(n) of the fuel injection quantity for each cylinder #1 to #4. The cylinder number is substituted into "n". Therefore, the reduction calibration amount dQf of the fuel injection quantity of the fuel injection valve 15 corresponding to the first cylinder #1 is recorded as "reduction calibration amount dQf(1)". In addition, hereafter, the reduction calibration amount dQf(n) of the fuel injection quantity of the fuel injection valve 15 corresponding to cylinder #n is recorded as "reduction calibration amount dQf(n) of cylinder #n".

[0045] An example of the calculation method for the reduction correction amount dQf(1) of the first cylinder #1 will be explained. The processing circuit 61 calculates the reduction correction amount dQf(1) based on the estimated input amount Qpge(1) of the cylinder #1. For example, the processing circuit 61 calculates the reduction correction amount dQf(1) in a manner that the larger the estimated input amount Qpge(1) is, the larger the value of the reduction correction amount dQf(1) is.

[0046] The calculation methods for the reduction correction amounts dQf(2), dQf(3), and dQf(4) of cylinders #2, #3, and #4 (other than cylinder #1) are the same as those for the reduction correction amount dQf(1). Therefore, the explanation of the calculation methods for the reduction correction amounts dQf(2) to dQf(4) is omitted.

[0047] Furthermore, the processing circuit 61 sets the value obtained by subtracting the reduction correction amount dQf(1) from the target injection amount QfTr to the target injection amount QfTr(1) of the fuel injection valve 15 corresponding to the first cylinder #1. The processing circuit 61 sets the value obtained by subtracting the reduction correction amount dQf(2) from the target injection amount QfTr to the target injection amount QfTr(2) of the fuel injection valve 15 corresponding to the second cylinder #2. The processing circuit 61 sets the value obtained by subtracting the reduction correction amount dQf(3) from the target injection amount QfTr to the target injection amount QfTr(3) of the fuel injection valve 15 corresponding to the third cylinder #3. The processing circuit 61 sets the value obtained by subtracting the reduction correction amount dQf(4) from the target injection amount QfTr to the target injection amount QfTr(4) of the fuel injection valve 15 corresponding to the fourth cylinder #4.

[0048] The injection process M17 controls the fuel injection of multiple fuel injection valves 15 by adjusting the energization of these valves. In the injection process M17, the processing circuit 61 operates the fuel injection valve 15 corresponding to cylinder #1 based on a target injection quantity QfTr (1). The processing circuit 61 operates the fuel injection valve 15 corresponding to cylinder #2 based on a target injection quantity QfTr (2). The processing circuit 61 operates the fuel injection valve 15 corresponding to cylinder #3 based on a target injection quantity QfTr (3). The processing circuit 61 operates the fuel injection valve 15 corresponding to cylinder #4 based on a target injection quantity QfTr (4).

[0049] <Concentration estimation treatment M14>

[0050] Reference Figure 4 An example of a series of processes representing concentration estimation process M14 will be described. Processing circuit 61 repeatedly executes concentration estimation process M14 at predetermined control cycles.

[0051] In step S11, the processing circuit 61 obtains the detected value of the ethanol concentration of the fuel stored in the fuel tank 21, namely the ethanol concentration detection value CEt. In the next step S13, the processing circuit 61 calculates the estimated value of the ethanol concentration CEtR of the purge gas released from the purge port 33 into the air intake passage 13, namely the concentration estimation value CEtRe. For example, the processing circuit 61 calculates the concentration estimation value CEt obtained in step S11 as the concentration detection value CEtRe. Then, the processing circuit 61 moves the processing to step S15.

[0052] Here, the volatility of gasoline is almost independent of temperature. On the other hand, the volatility of ethanol varies with temperature. When the temperature of ethanol exceeds a specified temperature, the amount of ethanol volatilized increases sharply compared to when the temperature of ethanol is below the specified temperature. That is, even if the ethanol concentration of the fuel stored in fuel tank 21 is the same, the ethanol concentration CEtR of the purge gas released from purge port 33 into intake passage 13 may change depending on whether the temperature of the fuel is higher than the aforementioned specified temperature.

[0053] Therefore, in step S15, the processing circuit 61 obtains the temperature of the fuel stored in the fuel tank 21, i.e., the fuel temperature TPf. For example, the processing circuit 61 obtains an estimated value of the fuel temperature based on the water temperature TPw as the fuel temperature TPf. At this time, the processing circuit 61 can calculate the estimated value of the fuel temperature in a way that the higher the water temperature TPw, the larger the estimated value of the fuel temperature. Alternatively, the processing circuit 61 can also obtain an estimated value of the fuel temperature based on the temperature of the engine oil circulating in the internal combustion engine 10 as the fuel temperature TPf. In addition, if a sensor for detecting the temperature inside the fuel tank 21 is provided, the processing circuit 61 can also obtain the detection value of the sensor as the fuel temperature TPf.

[0054] In the next step S17, the processing circuit 61 determines whether the fuel temperature TPf obtained in step S15 is above a predetermined temperature TPfth. The predetermined temperature TPfth is a criterion for determining whether ethanol is readily volatile. For example, the predetermined temperature TPfth is set to the aforementioned specified temperature or a temperature corresponding to that specified temperature. If the fuel temperature TPf is above the predetermined temperature TPfth (S17: Yes), the processing circuit 61 moves the processing to step S19. If the fuel temperature TPf is below the predetermined temperature TPfth (S17: No), the processing circuit 61 does not perform the processing in step S19 and temporarily terminates the concentration estimation processing M14.

[0055] In step S19, the processing circuit 61 performs an increase correction on the concentration estimation value CEtRe obtained in step S13. For example, the processing circuit 61 calculates the product of the concentration estimation value CEtRe obtained in step S13 and the correction gain Gn as the corrected concentration estimation value CEtRe. The correction gain Gn is a value greater than 1. That is, when the fuel temperature TPf is above the predetermined temperature TPfth, the processing circuit 61 can increase the concentration estimation value CEtRe compared to when the fuel temperature TPf is below the predetermined temperature TPfth. Furthermore, the processing circuit 61 temporarily terminates the concentration estimation processing M14.

[0056] <Function and Effects of This Implementation Method>

[0057] (1) When purge gas is released from the purge port 33 to the intake passage 13 during the operation of the internal combustion engine 10, the processing circuit 61 individually corrects the fuel injection quantity of the multiple fuel injection valves 15 corresponding to the multiple cylinders #1 to #4 by executing the cylinder correction process M16. Specifically, the processing circuit 61 sets the target injection quantity QfTr(1) to QfTr(4) in such a way that the fuel injection quantity of the fuel injection valve 15 corresponding to the cylinder with a large amount of purge gas introduced is less than the fuel injection quantity of the fuel injection valve 15 corresponding to the cylinder with a small amount of purge gas introduced. Furthermore, the processing circuit 61 operates the multiple fuel injection valves 15 based on the target injection quantity QfTr(1) to QfTr(4).

[0058] Therefore, the control device 60 can suppress deviations in the sum of the fuel injection quantity and the purge gas introduction quantity of the fuel injection valve 15 according to each cylinder #1 to #4. Thus, the control device 60 can suppress deviations in the air-fuel ratio of the mixture burned in the cylinder according to each cylinder #1 to #4.

[0059] (2) The ethanol component of the purge gas released from the purge port 33 into the intake passage 13 is easily guided to cylinders #1 to #4 that are located away from the purge port 33. The gasoline component of the purge gas is easily guided to cylinders #1 to #4 that are located near the purge port 33.

[0060] Therefore, the processing circuit 61 calculates the estimated ethanol concentration, CEtRe, of the purge gas released from the purge port 33 into the intake passage 13 by performing the concentration estimation process M14. Furthermore, in the amount of purge gas introduced, the processing circuit 61 estimates that when the concentration estimation value CEtRe is large, compared to when the concentration estimation value CEtRe is small, the amount of purge gas introduced into the fourth cylinder #4, which is furthest from the purge port 33, is more, and the amount of purge gas introduced into the first cylinder #1, which is closest to the purge port 33, is less.

[0061] Based on this input amount, the processing circuit 61 estimates the result of processing M15 and sets the target injection amounts QfTr(1) to QfTr(4). Furthermore, the processing circuit 61 operates the multiple fuel injection valves 15 based on the target injection amounts QfTr(1) to QfTr(4). Thus, the processing circuit 61 can individually adjust the fuel injection amount of the multiple fuel injection valves 15, taking into account the amount of purge gas introduced into the multiple cylinders #1 to #4.

[0062] (3) The processing circuit 61 calculates the concentration estimate CEtRe based on whether the temperature of the fuel stored in the fuel tank 21, i.e., the fuel temperature TPf, is above the predetermined temperature TPfth. That is, the processing circuit 61 can calculate the concentration estimate CEtRe by taking into account the volatility of ethanol. Therefore, the processing circuit 61 can estimate the ethanol concentration of the purge gas released from the purge port 33 into the intake passage 13 with a high degree of certainty.

[0063] <Example of Change>

[0064] The above-described embodiments can be implemented by modification as follows. The above-described embodiments and the following modifications can be combined with each other within the scope of technical inconsistency.

[0065] Even if the amount of purge gas introduced into all cylinders #1 to #4 is the same, there is still a possibility of deviations in the air-fuel ratio of the mixture burned in each cylinder. Ethanol's combustion characteristics differ from those of gasoline. Therefore, deviations in the ethanol concentration in the purge gas introduced into each cylinder can lead to deviations in the air-fuel ratio of the mixture burned in each cylinder.

[0066] Therefore, the processing circuit 61 estimates the ethanol concentration of the purge gas introduced into the cylinder from the intake passage 13 for each cylinder #1 to #4. Furthermore, the processing circuit 61 can also individually correct the fuel injection quantity of multiple fuel injection valves 15, so that when the ethanol concentration of the purge gas introduced into the cylinder from the intake passage 13 is high, the fuel injection quantity of the fuel injection valve 15 corresponding to that cylinder is higher compared to when the ethanol concentration is low. Thus, the processing circuit 61 can further improve the effect of suppressing deviations in the air-fuel ratio of the mixture burning in the cylinder according to each cylinder #1 to #4.

[0067] When the ethanol concentration of the fuel supplied by the fuel supply device 20 to the multiple fuel injection valves 15 changes, the air-fuel ratio detection value AF changes. Therefore, the processing circuit 61 can also estimate the ethanol concentration stored in the fuel tank 21 based on the air-fuel ratio detection value AF.

[0068] • Processing circuit 61 may also calculate the concentration prediction value CEtRe without considering the temperature of the fuel stored in fuel tank 21, i.e., whether the fuel temperature TPf is above the predetermined temperature TPfth. In this case, the concentration prediction processing can also be omitted. Figure 4 The processing of steps S15, S17, and S19 in the process.

[0069] • An internal combustion engine using the application control device 60 can have a structure with two or more cylinders arranged in the direction of the crankshaft 12 extension, or it can be a combination of... Figure 1The internal combustion engine 10 shown has different structures. For example, the internal combustion engine can also be an internal combustion engine with three cylinders arranged in the direction of the extension of the crankshaft 12.

[0070] • The processing circuit 61 is not limited to a structure that has a CPU and ROM and performs software processing. That is, the control device 60 can be any of the structures in (a), (b) and (c) below.

[0071] (a) The processing circuit 61 includes one or more processors that perform various processes according to a computer program. The processor includes a CPU and memories such as RAM and ROM. The memories store program code or instructions configured to cause the CPU to perform processes. Memory, or computer-readable medium, includes all available media that can be accessed by a general-purpose or special-purpose computer.

[0072] (b) The processing circuit 61 has one or more dedicated hardware circuits for performing various processes. Examples of dedicated hardware circuits include application-specific integrated circuits, i.e., ASICs or FPGAs. ASIC is an abbreviation for "Application Specific Integrated Circuit," and FPGA is an abbreviation for "Field Programmable Gate Array."

[0073] (c) The processing circuit 61 has one or more processors that execute a portion of various processes according to a computer program and one or more dedicated hardware circuits that execute the remaining processes in the various processes.

[0074] Furthermore, the expression "at least one" as used in this specification refers to "more than one" of the desired options. For example, if the number of options is two, the expression "at least one" as used in this specification means "only one option" or "both options". As another example, if the number of options is three or more, the expression "at least one" as used in this specification means "only one option" or "any combination of two or more options".

Claims

1. An internal combustion engine control device for controlling an internal combustion engine, The internal combustion engine is capable of using fuel containing ethanol. The internal combustion engine has the following features: Multiple cylinders; Multiple fuel injection valves, corresponding to each of the multiple cylinders; An intake passage through which air is introduced into the plurality of cylinders flows; and The purge port releases purge gas into the intake passage; the purge gas contains fuel vapor generated inside the fuel tank. The internal combustion engine control device includes a processing circuit configured to control the fuel injection quantity of the plurality of fuel injection valves. The processing circuit is configured to perform cylinder-by-cylinder calibration processing, which individually calibrates the fuel injection amount of the plurality of fuel injection valves so that the fuel injection amount of the fuel injection valve corresponding to the cylinder with a large amount of purge gas introduced is less than the fuel injection amount of the fuel injection valve corresponding to the cylinder with a small amount of purge gas introduced.

2. The internal combustion engine control device according to claim 1, wherein, The processing circuit is configured to perform the following processing: Concentration estimation processing to estimate the ethanol concentration of the purge gas released from the purge port into the inlet passage; and The injection volume estimation process estimates that, when the ethanol concentration of the purge gas is high, compared to when the ethanol concentration is low, the amount of purge gas injected into the cylinder furthest from the purge port is estimated to be greater, and the amount injected into the cylinder closest to the purge port is estimated to be less.

3. The internal combustion engine control device according to claim 2, wherein, The processing circuit is configured such that, in the concentration estimation processing... Determine whether the temperature of the fuel stored in the fuel tank is above a predetermined temperature. If it is determined that the temperature of the fuel stored in the fuel tank is above the predetermined temperature, it is presumed that the ethanol concentration of the purge gas is higher than if the temperature of the fuel is below the predetermined temperature.

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