JP2023131374A - Control device for internal combustion engine - Google Patents

Abstract

To suppress an increase in a difference between intake air amounts to be introduced to two cylinder groups.SOLUTION: A control device for an internal combustion engine executes: processing for calculating a first provisional value XR1 as a provisional value of a first upper limit value X1 on the basis of a temperature detected by a first temperature sensor (Step S110); processing for calculating a second provisional value XR2 as a provisional value of a second upper limit value X2 on the basis of a temperature detected by a second temperature sensor (Step S210); and processing for calculating the first provisional value XR1 as the first upper limit value X1 when the first provisional value XR1 is equal to or smaller than a second correction value XH2 obtained by multiplying the second provisional value XR2 by a correction coefficient VU, and calculating a value that is the second provisional value XR2 or larger and is smaller than the first provisional value XR1 as the first upper limit value X1 when the first provisional value XR1 is larger than the second correction value XH2 (Step S130).SELECTED DRAWING: Figure 2

Description

The present invention relates to a control device for an internal combustion engine.

The internal combustion engine disclosed in Patent Document 1 includes a first cylinder group, a first intake passage connected to the first cylinder group, and a first valve located in the middle of the first intake passage. The first valve is a so-called ISC valve (idle rotation speed control valve). Intake air introduced into the first cylinder group flows through the first intake passage. The first valve adjusts the amount of intake air introduced into the first cylinder group during idling operation of the internal combustion engine. Further, the internal combustion engine includes a second cylinder group, a second intake passage connected to the second cylinder group, and a second valve located in the middle of the second intake passage. The second valve is a so-called ISC valve. Intake air introduced into the second cylinder group flows through the second intake passage. The second valve adjusts the amount of intake air introduced into the second cylinder group during idling operation of the internal combustion engine. A control device for an internal combustion engine separately controls the first valve and the second valve.

Japanese Unexamined Patent Publication No. 10-196431

In a technology that separately controls the amount of intake air introduced into the first cylinder group and the amount of intake air introduced into the second cylinder group, as in Patent Document 1, the target value of the amount of intake air introduced into the first cylinder group is may be determined as a value within a certain allowable range. Similarly, the target value for the amount of intake air introduced into the second cylinder group may be determined as a value within a certain allowable range. When adopting such an aspect, if the upper limits of the above ranges are significantly different between the two cylinder groups, the amount of intake air introduced into the first cylinder group and the amount of intake air introduced into the second cylinder group will be different. can make a big difference. The same applies to cases where the lower limit values are different. In these cases, a difference may occur between the first cylinder group and the second cylinder group in the combustion pressure and the corresponding amount of piston movement. As a result, the rotation of the crankshaft may become unstable.

A control device for an internal combustion engine to solve the above problem includes a first cylinder group, a first intake passage that introduces intake air into the first cylinder group, and adjusts the amount of intake air introduced into the first cylinder group. a first throttle valve; a first temperature sensor that detects the temperature of intake air flowing through the first intake passage; a second cylinder group including cylinders different from the first cylinder group; and a second cylinder group that supplies intake air to the second cylinder group. An internal combustion engine comprising: a second intake passage for introducing air; a second throttle valve for adjusting the amount of intake air introduced into the second cylinder group; and a second temperature sensor for detecting the temperature of intake air flowing through the second intake passage. a first control process that is applied to the engine and calculates a first target value that is a target value for the amount of intake air introduced into the first cylinder group, and controls the first throttle valve based on the first target value; , a second control process of calculating a second target value that is a target value of the amount of intake air introduced into the second cylinder group, and controlling the second throttle valve based on the second target value; a first preliminary process of calculating a first provisional value as a provisional value of a first upper limit value which is an upper limit value of the first target value based on the temperature detected by the temperature sensor; a second preliminary process of calculating a second provisional value as a provisional value of a second upper limit value that is an upper limit value of the second target value based on the second provisional value; If the first provisional value is less than or equal to a second correction value multiplied by a predetermined correction coefficient, the first provisional value is calculated as the first upper limit value, and if the first provisional value is greater than the second correction value, a first calculation process of calculating a value greater than or equal to the second provisional value and less than the first provisional value as the first upper limit; and a first calculation process in which the second provisional value is the first provisional value multiplied by the correction coefficient. If the second provisional value is less than or equal to the correction value, the second provisional value is calculated as the second upper limit, and if the second provisional value is greater than the first correction value, the second provisional value is greater than or equal to the first provisional value. It is possible to perform a second calculation process of calculating a value less than the second upper limit value as the second upper limit value.

In the above configuration, due to the difference between the temperature of the intake air in the first intake passage and the temperature of the intake air in the second intake passage, individual differences between the first temperature sensor and the second temperature sensor, etc. A large deviation may occur between the value and the second provisional value. In this case, if these first provisional values and second provisional values are adopted as the first upper limit value and the second upper limit value, the deviation between the respective upper limit values also increases.

According to the above configuration, when the first provisional value is larger than the second provisional value by a certain percentage or more, a value whose difference from the second provisional value is smaller than the first provisional value is calculated as the first upper limit value. Ru. In other words, if the upper limit value is calculated based on each temperature sensor, in a situation where the difference between the first upper limit value and the second upper limit value becomes large, each upper limit value is calculated so that the difference between the two becomes small. Ru. Therefore, it is possible to suppress an increase in the deviation between the first upper limit value and the second upper limit value, and furthermore, the difference between the amount of intake air introduced into the first cylinder group and the amount of intake air introduced into the second cylinder group.

In the first calculation process, the control device for an internal combustion engine calculates the smaller of the first provisional value and the second correction value as the first upper limit value, and in the second calculation process, The smaller of the second provisional value and the first correction value may be calculated as the second upper limit value.

According to the above configuration, the value obtained by dividing the larger one of the first upper limit value and the second upper limit value by the smaller one becomes equal to or less than the correction coefficient. That is, the ratio of the first upper limit value and the second upper limit value can be made closer to 1 than the ratio represented by the correction coefficient.

A control device for an internal combustion engine to solve the above problem includes a first cylinder group, a first intake passage that introduces intake air into the first cylinder group, and adjusts the amount of intake air introduced into the first cylinder group. a first throttle valve, a second cylinder group consisting of cylinders different from the first cylinder group, a second intake passage that introduces intake air into the second cylinder group, and an amount of intake air introduced into the second cylinder group. A first target value is applied to an internal combustion engine having a second throttle valve that adjusts the rotational position of the crankshaft, and a crank position sensor that detects the rotational position of the crankshaft, and is a target value of the amount of intake air introduced into the first cylinder group. and calculating a second target value that is a target value for the amount of intake air introduced into the second cylinder group. a second control process for controlling the second throttle valve based on the second target value; and a second control process for controlling the second throttle valve based on the rotational speed of the crankshaft as a provisional value of the first lower limit value which is the lower limit value of the first target value. a first preliminary process for calculating a first provisional value; and a second preliminary process for calculating a second provisional value as a provisional value of a second lower limit value that is a lower limit value of the second target value based on the rotational speed of the crankshaft. and when the first provisional value is greater than or equal to a second correction value obtained by multiplying the second provisional value by a predetermined correction coefficient smaller than 1, the first provisional value is set as the first lower limit value. and, if the first provisional value is smaller than the second correction value, a first calculation process of calculating a value that is less than or equal to the second provisional value and larger than the first provisional value as the first lower limit value; If the second provisional value is greater than or equal to the first correction value obtained by multiplying the first provisional value by the correction coefficient, the second provisional value is calculated as the second lower limit value, and the second provisional value is equal to or greater than the second provisional value. If it is smaller than the first correction value, it is possible to perform a second calculation process of calculating a value that is less than or equal to the first provisional value and larger than the second provisional value as the second lower limit value.

In the above configuration, if the rotational speed of the crankshaft fluctuates, the rotational speed referred to when calculating the first provisional value and the rotational speed referred to when calculating the second provisional value may differ. be. Due to such factors, a large discrepancy may occur between the first provisional value and the second provisional value. In this case, if these first provisional values and second provisional values are adopted as the first lower limit value and the second lower limit value, the deviation between the respective lower limit values also increases.

According to the above configuration, when the first provisional value is smaller than the second provisional value by a certain percentage or more, a value whose difference from the second provisional value is smaller than the first provisional value is calculated as the first lower limit value. Ru. In other words, if the lower limit value is calculated based on the rotational speed of the crankshaft, in a situation where the difference between the first lower limit value and the second lower limit value becomes large, each lower limit value is calculated so that the difference between the two becomes small. Calculated. Therefore, it is possible to suppress an increase in the deviation between the first lower limit value and the second lower limit value, and furthermore, the difference between the amount of intake air introduced into the first cylinder group and the amount of intake air introduced into the second cylinder group.

In the first calculation process, the internal combustion engine control device calculates the larger value of the first provisional value and the second correction value as the first lower limit value, and in the second calculation process, The larger value of the second provisional value and the first correction value may be calculated as the second lower limit value.

According to the above configuration, the value obtained by dividing the smaller one of the first lower limit value and the second lower limit value by the larger one is equal to or greater than the correction coefficient. That is, the ratio between the first lower limit value and the second lower limit value can be made closer to 1 than the ratio represented by the correction coefficient.

FIG. 1 is a schematic configuration diagram of an internal combustion engine. FIG. 2 is a flowchart showing the processing procedure of the first upper limit process and the second upper limit process. FIG. 3 is a flowchart showing the processing procedure of the first lower limit process and the second lower limit process.

Hereinafter, one embodiment of a control device for an internal combustion engine will be described with reference to the drawings.
<Schematic configuration of internal combustion engine>
As shown in FIG. 1, vehicle 300 includes an internal combustion engine 100. Internal combustion engine 100 is located in the engine room of vehicle 300. Internal combustion engine 100 is a driving source for vehicle 300. Internal combustion engine 100 has a first bank portion 110, a second bank portion 120, and a crankshaft 130. In addition, in the following, when the first bank section 110 and the second bank section 120 are to be described without distinction with respect to each part of the internal combustion engine 100 and the control configuration described below, the prefixes of "first" and "second" will be used collectively. It will be abbreviated and the symbol will be omitted.

The first bank portion 110 includes a first cylinder group 10 , a first intake passage 11 , a first exhaust passage 12 , a first supercharger 13 , a first intercooler 14 , and a first throttle valve 15 . The first bank portion 110 also includes a first EGR passage 16 , a first EGR valve 17 , three first spark plugs 18 , and three first injectors 19 .

The first cylinder group 10 is a group of cylinders consisting of three cylinders 10A. The cylinder 10A is a space for combusting a mixture of fuel and intake air. Although not shown, the cylinder 10A accommodates a piston. The piston reciprocates within the cylinder 10A. The piston is connected to the crankshaft 130 via a connecting rod. The crankshaft 130 rotates in response to the movement of the piston. Although not shown, the crankshaft 130 is located within the crankcase. Lubricating oil is collected at the bottom of the crankcase.

The first spark plug 18 is provided for each cylinder 10A of the first cylinder group 10. The first spark plug 18 ignites the air-fuel mixture in the cylinder 10A. The first injector 19 is provided for each cylinder 10A of the first cylinder group 10. The first injector 19 supplies fuel into the cylinder 10A.

The first intake passage 11 is connected to each cylinder 10A of the first cylinder group 10. The first intake passage 11 is a passage for introducing intake air into the first cylinder group 10. The first intercooler 14 is located in the middle of the first intake passage 11. The first intercooler 14 cools intake air. The first throttle valve 15 is located downstream of the first intercooler 14 in the first intake passage 11 . The opening degree of the first throttle valve 15 can be adjusted. The amount of intake air introduced into the first cylinder group 10 changes depending on the opening degree of the first throttle valve 15. That is, the first throttle valve 15 adjusts the amount of intake air introduced into the first cylinder group 10.

The first exhaust passage 12 is connected to each cylinder 10A of the first cylinder group 10. The first exhaust passage 12 is a passage for discharging exhaust gas from the first cylinder group 10. The first supercharger 13 is provided across the first intake passage 11 and the first exhaust passage 12. Specifically, the first supercharger 13 has a first compressor wheel 13A and a first turbine wheel 13B. The first compressor wheel 13A is located on the upstream side of the first intake passage 11 when viewed from the first intercooler 14. The first turbine wheel 13B is located in the middle of the first exhaust passage 12. The first turbine wheel 13B rotates according to the flow of exhaust gas. The first compressor wheel 13A rotates integrally with the first turbine wheel 13B. The intake air is supercharged by rotating the first compressor wheel 13A. Although not shown, the first exhaust passage 12 includes a bypass passage that bypasses the first turbine wheel 13B. This bypass passage has a waste gate valve that opens and closes the bypass passage.

The first EGR passage 16 connects a portion of the first exhaust passage 12 on the upstream side when viewed from the first turbine wheel 13B and a portion of the first intake passage 11 on the downstream side when viewed from the first throttle valve 15. ing. The first EGR passage 16 is a passage for circulating exhaust gas flowing through the first exhaust passage 12 to the first intake passage 11. In the following, the exhaust gas that recirculates from the exhaust passage to the intake passage will be referred to as EGR gas. The first EGR valve 17 is located in the middle of the first EGR passage 16. The opening degree of the first EGR valve 17 can be adjusted. The amount of EGR gas that flows back into the first intake passage 11 changes depending on the opening degree of the first EGR valve 17. That is, the first EGR valve 17 adjusts the amount of EGR gas that flows back into the first intake passage 11.

The second bank section 120 has a symmetrical configuration with the first bank section 110. Therefore, only the outline of the configuration of the second bank section 120 will be explained, and the detailed explanation will be simplified or omitted. The second bank portion 120 includes a second cylinder group 20, a second intake passage 21, a second exhaust passage 22, a second supercharger 23, a second intercooler 24, and a second throttle valve 25. The second bank portion 120 also includes a second EGR passage 26 , a second EGR valve 27 , three second spark plugs 28 , and three second injectors 29 .

The second cylinder group 20 is a cylinder group consisting of three cylinders 20A different from the first cylinder group 10. A piston within the cylinder 20A is connected to a crankshaft 130. The second spark plug 28 is provided for each cylinder 20A of the second cylinder group 20. The second injector 29 is provided for each cylinder 20A of the second cylinder group 20. The second intake passage 21 is a passage for introducing intake air into the second cylinder group 20, and is connected to each cylinder 20A of the second cylinder group 20. The second intake passage 21 is completely independent from the first intake passage 11. The second intercooler 24 is located in the middle of the second intake passage 21. The second throttle valve 25 is located downstream of the second intercooler 24 in the second intake passage 21 . The second throttle valve 25 adjusts the amount of intake air introduced into the second cylinder group 20.

The second exhaust passage 22 is connected to each cylinder 20A of the second cylinder group 20. The second supercharger 23 has a second compressor wheel 23A and a second turbine wheel 23B. The second compressor wheel 23A is located upstream of the second intercooler 24 in the second intake passage 21. The second turbine wheel 23B is located in the middle of the second exhaust passage 22.

The second EGR passage 26 connects a portion of the second exhaust passage 22 on the upstream side when viewed from the second turbine wheel 23B and a portion of the second intake passage 21 on the downstream side when viewed from the second throttle valve 25. ing. The second EGR valve 27 is located in the middle of the second EGR passage 26. The second EGR valve 27 adjusts the amount of EGR gas that flows back into the second intake passage 21.

Internal combustion engine 100 includes a crank position sensor 93, a first temperature sensor 62, a first air flow meter 63, a second temperature sensor 72, and a second air flow meter 73. Crank position sensor 93 is located near crankshaft 130. Crank position sensor 93 detects rotational position CR of crankshaft 130. The first temperature sensor 62 is located on the upstream side of the first intake passage 11 when viewed from the first compressor wheel 13A. The first temperature sensor 62 detects the temperature (hereinafter referred to as the first temperature) T1 of the intake air flowing through the installation location of the first temperature sensor 62 in the first intake passage 11 . The first air flow meter 63 is located upstream of the first temperature sensor 62 in the first intake passage 11 . The first air flow meter 63 detects the amount of intake air flowing into the first intake passage 11 (hereinafter referred to as the first intake amount) G1. The second temperature sensor 72 is located in the second intake passage 21 on the upstream side when viewed from the second compressor wheel 23A. The second temperature sensor 72 detects the temperature (hereinafter referred to as second temperature) T2 of the intake air flowing through the installation location of the second temperature sensor 72 in the second intake passage 21 . The second air flow meter 73 is located upstream of the second temperature sensor 72 in the second intake passage 21 . The second air flow meter 73 detects the amount of intake air flowing into the second intake passage 21 (hereinafter referred to as the second intake amount) G2.

Vehicle 300 includes a vehicle speed sensor 94, an accelerator sensor 95, and an atmospheric pressure sensor 96. Vehicle speed sensor 94 detects the traveling speed of vehicle 300 as vehicle speed SP. Accelerator sensor 95 detects the amount of depression of the accelerator pedal in vehicle 300 as accelerator operation amount ACC. Atmospheric pressure sensor 96 detects the atmospheric pressure P at the location where vehicle 300 is traveling.

<Schematic configuration of control device>
As shown in FIG. 1, vehicle 300 includes a control device 200. Control device 200 may be configured as one or more processors that execute various processes according to computer programs (software). Note that the control device 200 includes one or more dedicated hardware circuits such as an application specific integrated circuit (ASIC), or a circuit including a combination thereof, which executes at least some of the various processes. It may also be configured as The processor includes a CPU 201 and memories such as RAM and ROM 202. The memory stores program codes or instructions configured to cause the CPU 201 to perform processes. Memory or computer-readable media includes any available media that can be accessed by a general purpose or special purpose computer. The control device 200 has a storage device that is an electrically rewritable nonvolatile memory.

Control device 200 repeatedly receives detection signals from various sensors in vehicle 300. Specifically, the control device 200 receives detection signals for the following parameters.
・Vehicle speed SP detected by vehicle speed sensor 94
・Accelerator operation amount ACC detected by accelerator sensor 95
・Atmospheric pressure P detected by atmospheric pressure sensor 96
- Rotational position CR of the crankshaft 130 detected by the crank position sensor 93
- First temperature T1 detected by the first temperature sensor 62
・First intake air amount G1 detected by the first air flow meter 63
- Second temperature T2 detected by the second temperature sensor 72
- Second intake air amount G2 detected by the second air flow meter 73
The control device 200 calculates the following parameters at any time based on detection signals received from various sensors. Control device 200 calculates engine rotational speed NE, which is the rotational speed of crankshaft 130, based on rotational position CR of crankshaft 130. Further, the control device 200 calculates the engine load factor (hereinafter referred to as the first engine load factor) KL1 of the first bank portion 110 based on the engine rotational speed NE and the first intake air amount G1. Further, the control device 200 calculates an engine load factor (hereinafter referred to as a second engine load factor) KL2 of the second bank portion 120 based on the engine rotational speed NE and the second intake air amount G2. Note that the engine load factor is a parameter that determines the amount of intake air filled into a cylinder, and is a value obtained by dividing the amount of intake air that flows into one cylinder per one combustion cycle by the reference intake air amount. The reference intake air amount changes depending on the engine rotation speed NE.

<General control of the first bank section>
The control device 200 controls various parts of the first bank section 110. For example, the control device 200 controls the first spark plug 18 and the first injector 19. As a result, the control device 200 performs a combustion operation in which the first cylinder group 10 repeatedly burns the air-fuel mixture. Control device 200 may perform a fuel cut to stop fuel injection depending on the driving situation, such as when vehicle 300 is decelerating, for example. Further, the control device 200 controls the first EGR valve 17. In controlling the first EGR valve 17, the control device 200 sets a first target EGR rate W1, which is a target value of the EGR rate in the first bank section 110, based on the engine rotational speed NE, the first engine load factor KL1, etc. Calculate. Then, the control device 200 adjusts the opening degree of the first EGR valve 17 based on the first intake air amount G1 and the like so that the actual EGR rate becomes the first target EGR rate W1. The EGR rate is a value obtained by dividing the amount of EGR gas flowing back into the intake passage by the total amount of gas flowing into the cylinder group. The total amount of gas flowing into the cylinder group is the total amount of EGR gas that flows back into the intake passage and the amount of intake air with which this EGR gas is combined.

Further, the control device 200 performs a first control process for controlling the first throttle valve 15. The control device 200 repeats the following two things in the first control process. First, the control device 200 calculates a first target value A1 that is a target value for the amount of intake air introduced into the first cylinder group 10. The control device 200 then controls the first throttle valve 15 based on the first target value A1. That is, the control device 200 adjusts the opening degree of the first throttle valve 15 so that the amount of intake air introduced into the first cylinder group 10 becomes the first target value A1. Note that in this embodiment, the amount of intake air introduced into the cylinder group refers to the amount of intake air that passes through the throttle valve. In calculating the first target value A1, the control device 200 first calculates a basic value of the first target value A1 based on the accelerator operation amount ACC, the engine rotational speed NE, the first intake air amount G1, and the like. Then, the control device 200 calculates the first target value A1 based on this basic value and the latest information about the allowable calculation range of the first target value A1. That is, when the basic value is between the upper limit and the lower limit of the calculation range, the control device 200 directly sets the basic value as the first target value A1. When the basic value is larger than the upper limit value, the control device 200 sets the upper limit value to the first target value A1. Further, when the basic value is smaller than the lower limit value, the control device 200 sets the lower limit value to the first target value A1.

<General control of the second bank section>
The control device 200 controls various parts of the second bank section 120. The control device 200 controls various parts of the second bank section 120 independently of the first bank section 110. That is, in addition to controlling various parts of the first bank part 110, the control device 200 calculates target values for controlling various parts of the second bank part 120, and controls the second bank part based on the target values. Controls various parts of the bank section 120. Like the first bank section 110, the control device 200 controls the second spark plug 28 and the second injector 29, and controls the second EGR valve 27. In addition, in controlling the second EGR valve 27, the control device 200 sets a second target EGR, which is a target value of the EGR rate in the second bank section 120, based on the engine rotational speed NE, the second engine load factor KL2, etc. Calculate the rate W2.

Further, the control device 200 performs a second control process for controlling the second throttle valve 25. In the second control process, each variable used or calculated in the first control process is replaced with one for controlling the second throttle valve 25. That is, in the second control process, the control device 200 calculates a second target value A2 that is a target value for the amount of intake air introduced into the second cylinder group 20. Then, the control device 200 adjusts the opening degree of the second throttle valve 25 so that the amount of intake air introduced into the second cylinder group 20 becomes the second target value A2. When calculating the second target value A2, the control device 200 calculates a basic value of the second target value A2 based on the accelerator operation amount ACC, the engine rotation speed NE, the second intake air amount G2, and the like. Then, the control device 200 calculates the second target value A2 based on this basic value and the latest information about the allowable calculation range of the second target value A2.

<Summary of upper limit calculation method>
Hereinafter, a method of calculating the calculation range of the first target value A1 and the calculation range of the second target value A2 will be explained. Note that the process of calculating the upper limit value of the calculation range of the first target value A1 (hereinafter referred to as the first upper limit value) X1 and the upper limit value of the calculation range of the second target value A2 (hereinafter referred to as the second upper limit value) ) There is a relationship with the process of calculating X2. In addition, the process of calculating the lower limit value Y1 of the calculation range of the first target value A1 (hereinafter referred to as the first lower limit value) and the lower limit value of the calculation range of the second target value A2 (hereinafter referred to as the second lower limit value) are performed. ) There is a relationship with the process of calculating Y2. Based on this point, below, first, the processes related to the upper limit value will be explained together, and then the processes related to the lower limit value will be explained together.

The control device 200 can execute a first upper limit process for calculating the first upper limit value X1. The first upper limit process includes a first upper limit preliminary process and a first calculation process. In the first preprocessing for the upper limit, the control device 200 calculates a first provisional value XR1 as a provisional value of the first upper limit value X1 based on the first temperature T1 detected by the first temperature sensor 62. Furthermore, in the first calculation process for the upper limit, the control device 200 calculates the first upper limit value X1. At this time, the control device 200 considers the value of the second provisional value XR2, which is a provisional value of the second upper limit value X2 calculated in the second upper limit processing described later. That is, when the first provisional value XR1 is less than or equal to the second correction value XH2 obtained by correcting the second provisional value XR2, the control device 200 directly calculates the first provisional value XR1 as the first upper limit value X1. On the other hand, if the first provisional value XR1 is larger than the second correction value XH2, the control device 200 calculates a value that is greater than or equal to the second provisional value XR2 and less than the first provisional value XR1 as the first upper limit value X1. .

The control device 200 can execute second upper limit processing for calculating the second upper limit value X2. The second upper limit process replaces each variable used or calculated in the first upper limit process with one for calculating the second upper limit value X2. That is, the second upper limit process includes a second pre-process for the upper limit and a second calculation process. In the second pre-processing for the upper limit, the control device 200 calculates the second provisional value XR2 based on the second temperature T2 detected by the second temperature sensor 72. Furthermore, in the second calculation process for the upper limit, if the second provisional value XR2 is equal to or less than the first correction value XH1 obtained by correcting the first provisional value is directly calculated as the second upper limit value X2. On the other hand, if the second provisional value XR2 is larger than the first correction value XH1, the control device 200 calculates a value that is greater than or equal to the first provisional value XR1 and less than the second provisional value XR2 as the second upper limit value X2. .

The control device 200 stores a setting map in advance as information required in the first upper limit process and the second upper limit process (hereinafter referred to as upper limit necessary information). Here, the amount of intake air that can be filled into a cylinder has a limit determined from the specifications of the internal combustion engine 100, such as the volume of the cylinder and the supercharging capacity depending on the shape and body size of each wheel in the supercharger. Regarding the amount of intake air introduced into the cylinder group, a value that can be considered as the optimum maximum value for the amount of intake air determined from the above-mentioned restrictions is referred to as the maximum introduction value. The maximum intake value is basically determined from the specifications of various parts of the internal combustion engine 100 as described above, but in detail, it changes depending on the state of the intake air depending on the environmental field such as temperature and pressure. The setting map represents the relationship between intake air temperature, atmospheric pressure, and maximum intake value. In the setting map, basically, if the atmospheric pressure is the same, the higher the intake air temperature, the smaller the maximum intake value. Furthermore, in the setting map, basically, if the intake air temperature is the same, the lower the atmospheric pressure, the smaller the maximum intake value. Note that the temperature of the intake air specified in the setting map is for a location on the upstream side as seen from the compressor wheel in the intake passage. Further, the setting map is created based on, for example, experiments or simulations.

The control device 200 stores in advance a protection limit value and a circuit limit value for the upper limit as necessary information for the upper limit. The protection limit value is the maximum value that is allowed in terms of the amount of intake air introduced into the cylinder group from the viewpoint of protecting various parts by avoiding the circulation of an excessive amount of gas throughout the intake system and exhaust system of the internal combustion engine 100. . The circuit limit value for the upper limit is a limit value that can be considered not to be an excessive value due to an abnormality in the circuit of the control device 200. The protection limit value and the circuit limit value for the upper limit are calculated based on experiments or simulations, for example.

The control device 200 stores in advance a correction coefficient for the upper limit (hereinafter referred to as an upper limit coefficient) VU as necessary information for the upper limit. The upper limit coefficient VU is predetermined as a value larger than 1. In this embodiment, the upper limit coefficient VU is 1.2. The upper limit coefficient VU is determined as the following value based on, for example, experiments or simulations. Now, assume that there is a difference between the amount of intake air introduced into the first cylinder group 10 and the amount of intake air introduced into the second cylinder group 20. In this case, a difference may occur between the first cylinder group 10 and the second cylinder group 20 in the combustion pressure and the corresponding amount of piston movement. As a result, when the internal combustion engine 100 is in a steady state, the engine rotational speed NE may vary greatly over time. When internal combustion engine 100 is in a steady state, it is not during a transition period in which engine rotational speed NE is changing in accordance with acceleration or deceleration of vehicle 300, but when engine rotational speed NE is approximately constant. The value obtained by dividing the larger amount of intake air introduced into the first cylinder group 10 and the amount of intake air introduced into the second cylinder group 20 by the smaller amount is called an upper limit specific value. The upper limit coefficient VU is the maximum value of the upper limit specific value that can suppress the temporal fluctuation of the engine rotational speed NE within an allowable range when the internal combustion engine 100 is in a steady state.

<Specific processing procedures for the first upper limit process and the second upper limit process>
When the engine rotational speed NE is greater than zero, the control device 200 repeatedly executes the first upper limit process. As shown in FIG. 2A, when the control device 200 starts the first upper limit process, it first performs the process of step S110. Control device 200 calculates first provisional value XR1 in step S110. Specifically, the control device 200 refers to the setting map, the latest first temperature T1, and the latest atmospheric pressure P. Then, the control device 200 calculates the maximum introduction value corresponding to the latest first temperature T1 and the latest atmospheric pressure P in the setting map. After this, the control device 200 compares the introduction maximum value, the protection limit value, and the circuit limit value for the upper limit. Then, the control device 200 calculates the smallest value among these values as the first provisional value XR1. After calculating the first provisional value XR1, the control device 200 advances the process to step S120. Note that the process in step S110 is the first preliminary process for the upper limit.

In step S120, control device 200 calculates second correction value XH2. Specifically, the control device 200 refers to the latest second provisional value XR2 calculated in the second upper limit process. Then, the control device 200 multiplies this second provisional value XR2 by the upper limit coefficient VU. Then, the control device 200 sets the obtained value as the second correction value XH2. After calculating the second correction value XH2, the control device 200 advances the process to step S130.

In step S130, the control device 200 calculates the first upper limit value X1. Specifically, the control device 200 sets the smaller value of the first provisional value XR1 calculated in step S110 and the second correction value XH2 calculated in step S120 as the first upper limit value X1. After calculating the first upper limit value X1, the control device 200 temporarily ends the series of processes for the first upper limit value. After this, the control device 200 performs the process of step S110 again. Note that the processing in step S120 and step S130 is a first calculation process for the upper limit.

When the engine rotational speed NE is greater than zero, the control device 200 repeatedly executes the second upper limit process in parallel with the first upper limit process. That is, as shown in FIG. 2(b), the control device 200 first calculates the second provisional value XR2 in step S210. The method for calculating the second provisional value XR2 is the same as the method for calculating the first provisional value XR1 above, except that the second temperature T2 is used instead of the first temperature T1 used in the first upper limit process. It is. In subsequent step S220, the control device 200 refers to the latest first provisional value XR1 calculated in the first upper limit processing, and sets the value obtained by multiplying the first provisional value XR1 by the upper limit coefficient VU as the first correction value XH1. do. In the following step S230, the control device 200 sets the smaller value of the second provisional value XR2 calculated in step S210 and the first correction value XH1 calculated in step S220 as the second upper limit value X2. Then, the control device 200 temporarily ends the series of processes for the second upper limit. Note that the process in step S210 is second pre-processing for the upper limit. The processes in step S220 and step S230 are second calculation processes for the upper limit.

<Summary of how to calculate the lower limit value>
The control device 200 can execute the first lower limit process. The first lower limit process is a process for calculating the first lower limit value Y1, which is the lower limit value of the calculation range of the first target value A1. In the first upper limit processing described above, the first upper limit value X1 was calculated so as to reduce the deviation between the first upper limit value X1 and the second upper limit value X2. Similarly, the first lower limit process calculates the first lower limit value Y1 so as to reduce the deviation between the first lower limit value Y1 and the second lower limit value Y2, which is the lower limit value of the second target value A2. It is the content. The first lower limit process includes a first preliminary process and a first calculation process for the lower limit. In the first pre-processing for the lower limit, the control device 200 calculates a first provisional value YR1 as a provisional value of the first lower limit value Y1 based on the engine rotational speed NE. Furthermore, in the first calculation process for the lower limit, the control device 200 calculates the first lower limit value Y1. At this time, the control device 200 considers the value of the second provisional value YR2, which is a provisional value of the second lower limit value Y2 calculated in the second lower limit process described later. That is, when the first provisional value YR1 is equal to or greater than the second correction value YH2 obtained by correcting the second provisional value YR2, the control device 200 directly calculates the first provisional value YR1 as the first lower limit value Y1. On the other hand, if the first provisional value YR1 is smaller than the second correction value YH2, the control device 200 calculates a value that is less than or equal to the second provisional value YR2 and larger than the first provisional value YR1 as the first lower limit value Y1. .

The control device 200 is capable of executing second lower limit processing for calculating the second lower limit value Y2. The second lower limit process replaces each variable used or calculated in the first lower limit process for calculating the second lower limit value Y2. That is, the second lower limit process includes a second preprocess for the lower limit and a second calculation process. In the second pre-processing for the lower limit, the control device 200 calculates the second provisional value YR2 based on the engine rotational speed NE. In addition, in the second lower limit calculation process, if the second provisional value YR2 is equal to or greater than the first correction value YH1 obtained by correcting the first provisional value YR1, the control device 200 calculates the second provisional value YR2. is directly calculated as the second lower limit value Y2. On the other hand, if the second provisional value YR2 is smaller than the first correction value YH1, the control device 200 calculates a value that is less than or equal to the first provisional value YR1 and larger than the second provisional value YR2 as the second lower limit value Y2. .

The control device 200 stores a misfire map in advance as information required in the first lower limit process and the second lower limit process (hereinafter referred to as lower limit necessary information). Here, the minimum value of the amount of intake air that needs to be introduced into the cylinder group to avoid misfire during execution of the above-mentioned combustion operation in which the air-fuel mixture is combusted is referred to as a first minimum value. The misfire map represents the relationship between the engine rotational speed NE, the EGR rate, and the first minimum value. Note that the misfire map also includes the relationship between the engine rotational speed NE and the first minimum value when the EGR rate is zero. In the misfire map, for example, when the EGR rate is zero, basically, the higher the engine rotational speed NE, the larger the first minimum value becomes. Note that the misfire map is created based on, for example, experiments or simulations.

The control device 200 stores a negative pressure map in advance as necessary information for the lower limit. Here, while the fuel cut is being executed, the opening degree of the throttle valve is reduced. At this time, the so-called engine brake is applied, which may increase the negative pressure in the intake passage on the downstream side when viewed from the throttle valve. When this negative pressure becomes excessively large, the lubricating oil in the crankcase is sucked upward from the piston in the cylinder through the gap between the cylinder and the piston. Since the sucked up lubricating oil is later burned together with the air-fuel mixture, the amount of lubricating oil that can be used to lubricate the internal combustion engine 100 is reduced. Regarding the amount of intake air introduced into the cylinder group, the minimum value of the amount of intake air that can prevent the negative pressure in the intake passage from becoming excessively large during execution of the fuel cut is referred to as a second minimum value. The negative pressure map represents the relationship between the engine rotational speed NE and the second minimum value. In the negative pressure map, basically, the higher the engine rotational speed NE, the larger the second minimum value. The negative pressure map is created based on, for example, experiments or simulations.

The control device 200 stores in advance a circuit limit value for the lower limit as necessary information for the lower limit. The lower limit circuit limit value is a limit value that can be considered not to be too small due to an abnormality in the circuit of the control device 200. The circuit limit value for the lower limit is calculated based on experiments or simulations, for example.

The control device 200 stores in advance a lower limit correction coefficient (hereinafter referred to as a lower limit coefficient) VD as necessary information for the lower limit. The lower limit coefficient VD is predetermined as a value smaller than 1. In this embodiment, the lower limit coefficient VD is 0.8. Like the upper limit coefficient VU, the lower limit coefficient VD is predetermined, for example, by experiment or simulation, taking into consideration the degree of variation in the engine rotational speed NE. That is, the value obtained by dividing the smaller amount of intake air introduced into the first cylinder group 10 and the amount of intake air introduced into the second cylinder group 20 by the larger amount is called the lower limit specific value. The lower limit coefficient VD is the minimum value of the lower limit specific value that can suppress the temporal fluctuation of the engine rotational speed NE within an allowable range when the internal combustion engine 100 is in a steady state.

<Specific processing procedures for the first lower limit process and the second lower limit process>
When the engine rotational speed NE is greater than zero, the control device 200 repeatedly executes the first lower limit process. As shown in FIG. 3A, when the control device 200 starts the first lower limit process, it first performs the process of step S310. Control device 200 calculates first provisional value YR1 in step S310. Specifically, control device 200 refers to either a misfire map or a negative pressure map depending on the operating state of internal combustion engine 100. Control device 200 refers to the misfire map during execution of combustion operation. At the same time, the control device 200 refers to the latest engine rotational speed NE and the latest first target EGR rate W1. Then, the control device 200 calculates a first minimum value corresponding to the latest engine rotational speed NE and the latest first target EGR rate W1 in the misfire map. Then, the control device 200 calculates the larger value of the first minimum value and the lower limit circuit limit value as the first provisional value YR1. On the other hand, the control device 200 refers to the negative pressure map during execution of the fuel cut. At the same time, the control device 200 refers to the latest engine rotation speed NE. Then, the control device 200 calculates a second minimum value corresponding to the latest engine rotational speed NE in the negative pressure map. Then, the control device 200 calculates the larger value of the second minimum value and the lower limit circuit limit value as the first provisional value YR1. After calculating the first provisional value YR1, the control device 200 advances the process to step S320. Note that the process in step S310 is a first preliminary process for the lower limit.

In step S320, control device 200 calculates second correction value YH2. Specifically, the control device 200 refers to the latest second provisional value YR2 calculated in the second lower limit process. Then, the control device 200 multiplies this second provisional value YR2 by the lower limit coefficient VD. Then, the control device 200 sets the obtained value as the second correction value YH2. After calculating the second correction value YH2, the control device 200 advances the process to step S330.

In step S330, the control device 200 calculates the first lower limit value Y1. Specifically, the control device 200 sets the larger value of the first provisional value YR1 calculated in step S310 and the second correction value YH2 calculated in step S320 as the first lower limit value Y1. After calculating the first lower limit value Y1, the control device 200 temporarily ends the series of processes for the first lower limit. After this, the control device 200 performs the process of step S310 again. Note that the processing in step S320 and step S330 is a first calculation process for the lower limit.

When the engine rotational speed NE is greater than zero, the control device 200 repeatedly executes the second lower limit process in parallel with the first lower limit process. That is, as shown in FIG. 3(b), the control device 200 first calculates the second provisional value YR2 in step S410. The method for calculating the second provisional value YR2 is the same as that of the first provisional value YR1, except that the second target EGR rate W2 is used instead of the first target EGR rate W1 used in the first lower limit process. The calculation method is the same. In subsequent step S420, the control device 200 refers to the latest first provisional value YR1 calculated in the first lower limit process, and sets the value obtained by multiplying the first provisional value YR1 by the lower limit coefficient VD as the first correction value YH1. do. In subsequent step S430, the control device 200 sets the larger value of the second provisional value YR2 calculated in step S410 and the first correction value YH1 calculated in step S420 as the second lower limit value Y2. Then, the control device 200 temporarily ends the series of processes for the second lower limit process. Note that the process in step S410 is second pre-processing for the lower limit. The processing in step S420 and step S430 is a second calculation process for the lower limit.

<Effect 1 of the embodiment: Regarding the first upper limit process and the second upper limit process>
There may be a difference between the first temperature T1 and the second temperature T2. This is due to, for example, differences in the arrangement of the intake passages in the engine compartment of the vehicle 300 and individual differences between the first temperature sensor 62 and the second temperature sensor 72. As described above, the control device 200 uses a setting map that includes the intake air temperature as a parameter in calculating the first provisional value XR1. Therefore, the first provisional value XR1 may increase or decrease depending on the first temperature T1. Similarly, the second provisional value XR2 may increase or decrease depending on the second temperature T2. Therefore, under a situation where there is a difference between the first temperature T1 and the second temperature T2 due to the above-mentioned matters, a deviation may occur between the first provisional value XR1 and the second provisional value XR2.

Now, assume that the latest first provisional value XR1 is larger than the latest second provisional value XR2 by a certain percentage or more due to the difference between the first temperature T1 and the second temperature T2. Specifically, it is assumed that the first provisional value XR1 is larger than the second correction value XH2 obtained by correcting the second provisional value XR2. In this case, the control device 200 calculates the second correction value XH2 as the first upper limit value X1 in the first upper limit process (step S130). On the other hand, in the second upper limit process, since the second provisional value XR2 is smaller than the first provisional value XR1, the control device 200 calculates the second provisional value XR2 as the second upper limit value X2 (step S230). Here, the second correction value XH2, which is set as the first upper limit value X1 in the first upper limit process, has a smaller difference from the second provisional value XR2 than the first provisional value XR1. Therefore, compared to the case where the first provisional value XR1 is the first upper limit value X1, the first upper limit value X1 of this embodiment is the difference with the second provisional value XR2, that is, the difference with the second upper limit value X2. becomes smaller.

In the above, the case where the first provisional value XR1 is larger than the second provisional value becomes smaller.

<Action 2 of the embodiment: Regarding the first lower limit process and the second lower limit process>
As described above, in calculating the first provisional value YR1, the control device 200 uses a misfire map that includes the engine rotation speed NE and the EGR rate as parameters, or uses a negative pressure map that includes the engine rotation speed NE as a parameter. or use it. Therefore, the first provisional value YR1 changes depending on the engine rotational speed NE and the first target EGR rate W1. Similarly, the second provisional value YR2 changes depending on the engine rotation speed NE and the second target EGR rate W2. Therefore, for example, if the engine rotational speed NE suddenly changes due to sudden acceleration or deceleration of the vehicle 300, a discrepancy may occur between the first provisional value YR1 and the second provisional value YR2 for the following reasons. That is, if the timing at which the control device 200 refers to the engine rotation speed NE when calculating each provisional value is slightly different, the engine rotation speed NE used to calculate the first provisional value YR1 and the second provisional value YR2 may be The engine rotational speed NE to be used deviates. Accordingly, a deviation may occur between the first provisional value YR1 and the second provisional value YR2, for example, before and after a sudden change in the engine rotational speed NE. Furthermore, as mentioned above, each provisional value changes depending on the target EGR rate, so even in a situation where there is a difference between the first target EGR rate W1 and the second target EGR rate W2, the first provisional value YR1 and A deviation may occur between the second provisional value YR2 and the second provisional value YR2.

Now, assume that the latest first provisional value YR1 is smaller than the latest second provisional value YR2 by a certain percentage or more due to the reasons described above. Specifically, it is assumed that the first provisional value YR1 is smaller than the second correction value YH2 obtained by correcting the second provisional value YR2. In this case, the control device 200 calculates the second correction value YH2 as the first lower limit value Y1 in the first lower limit process (step S330). On the other hand, in the second lower limit process, since the second provisional value YR2 is larger than the first provisional value YR1, the control device 200 calculates the second provisional value YR2 as the second lower limit value Y2 (step S430). Here, the second correction value YH2, which is set as the first lower limit value Y1 in the first lower limit process, has a smaller difference from the second provisional value YR2 than the first provisional value YR1. Therefore, compared to the case where the first provisional value YR1 is set as the first lower limit value Y1, the first lower limit value Y1 of this embodiment is the difference with the second provisional value YR2, that is, the difference with the second lower limit value Y2. becomes smaller.

In the above, the case where the first provisional value YR1 is smaller than the second provisional value YR2 is taken as an example, but the difference between each lower limit value can be similarly applied when the second provisional value YR2 is smaller than the first provisional value YR1. becomes smaller.

<Effects of embodiment>
(1) As mentioned above, if there is a difference between the amount of intake air introduced into the first cylinder group 10 and the amount of intake air introduced into the second cylinder group 20, the first cylinder group 10 and the second cylinder group 20 There may be a difference in the amount of piston movement. If the difference in the amount of operation is large, the following concerns arise. That is, the internal combustion engine 100 may vibrate, and the riding comfort for the occupants of the vehicle 300 may deteriorate. Furthermore, when the internal combustion engine 100 is in a steady state, the engine rotational speed NE increases over time, and there is a possibility that it will be erroneously determined that a misfire has occurred.

In this regard, by performing the first upper limit processing and the second upper limit processing described above, the following is possible. That is, the difference between the first upper limit value X1, which is the upper limit of the amount of intake air introduced into the first cylinder group 10, and the second upper limit value X2, which is the upper limit of the amount of intake air introduced into the second cylinder group 20, becomes larger. In such a situation, each upper limit value can be calculated so that the difference between the two becomes small. Moreover, when calculating each upper limit value, the smaller value of the provisional value and the corrected value is selected. In this case, the value obtained by dividing the larger one of the first upper limit value X1 and the second upper limit value X2 by the smaller one is equal to or less than the upper limit coefficient VU used to calculate each correction value. That is, the ratio between the first upper limit value X1 and the second upper limit value X2 can be made closer to 1 than the ratio represented by the upper limit coefficient VU. Therefore, the deviation between the first upper limit value X1 and the second upper limit value X2, and furthermore, the difference between the amount of intake air introduced into the first cylinder group 10 and the amount of intake air introduced into the second cylinder group 20 becomes larger. can be suppressed.

(2) As described in the above operation, the following is possible in the first lower limit process and the second lower limit process. That is, the difference between the first lower limit value Y1, which is the lower limit of the amount of intake air introduced into the first cylinder group 10, and the second lower limit value Y2, which is the lower limit of the amount of intake air introduced into the second cylinder group 20, becomes larger. In such a situation, each lower limit value can be calculated so that the difference between the two becomes small. Moreover, in calculating each lower limit value, the larger value of the provisional value and the corrected value is selected. In this case, the value obtained by dividing the smaller one of the first lower limit value Y1 and the second lower limit value Y2 by the larger one is equal to or greater than the lower limit coefficient VU used to calculate each correction value. That is, the ratio between the first lower limit value Y1 and the second lower limit value Y2 can be made closer to 1 than the ratio represented by the lower limit coefficient VD. Therefore, the deviation between the first lower limit value Y1 and the second lower limit value Y2, and furthermore, the difference between the amount of intake air introduced into the first cylinder group 10 and the amount of intake air introduced into the second cylinder group 20 becomes larger. can be suppressed.

<Example of change>
Note that the above embodiment can be modified and implemented as follows. The above embodiment and the following modification examples can be implemented in combination with each other within a technically consistent range.

- The upper limit coefficient VU is not limited to the example of the above embodiment. The upper limit coefficient VU may be set so that the difference between the amount of intake air introduced into the first cylinder group 10 and the amount of intake air introduced into the second cylinder group 20 can be kept within an appropriate range. . The upper limit coefficient VU may be a value larger than 1. The upper limit coefficient VU may be changed depending on the operating state of the internal combustion engine 100. For example, the upper limit coefficient VU may be changed during so-called idling operation, in which the internal combustion engine 100 is operating at the minimum engine speed NE that allows it to continue operating independently, and during normal operation. Further, the upper limit coefficient VU used when calculating the first correction value XH1 and the upper limit coefficient VU used when calculating the second correction value XH2 may be different values. Due to the difference in the arrangement of the first intake passage 11 and the second intake passage 21, etc., there is a difference in the amount of intake air introduced into the first cylinder group 10 and the amount of intake air introduced into the second cylinder group 20. Such an embodiment is also effective if it is known that it exists.

- Similar to the above modification example, the lower limit coefficient VD is not limited to the example of the above embodiment. The lower limit coefficient VD may be a value smaller than 1. Similar to the upper limit coefficient VU, the lower limit coefficient VD may be changed depending on the operating state of the internal combustion engine 100, or a different lower limit coefficient VD may be set when calculating the first correction value YH1 and the second correction value YH2. Good too.

- The method of calculating the first provisional value XR1 in the first pre-processing for the upper limit is not limited to the example of the above embodiment. The first provisional value XR1 may be calculated based on the first temperature T1 detected by the first temperature sensor 62. For example, the maximum value introduced at the standard atmospheric pressure and reference intake air temperature is stored in advance as the basic maximum value, and the basic maximum value is corrected according to the magnitude of the first temperature T1 and the atmospheric pressure P. A final value of the maximum value may be calculated. Then, the first provisional value XR1 may be calculated by comparing the final value with a protection limit value or the like.

- Similar to the above modification example, the method of calculating the second provisional value XR2 in the second pre-processing for the upper limit is not limited to the example of the above embodiment. The second provisional value XR2 may be calculated based on the second temperature T2 detected by the second temperature sensor 72.

- The method of calculating the first upper limit value X1 in the first calculation process for the upper limit is not limited to the example of the above embodiment. That is, when calculating the first upper limit value X1, it is not essential to use a method of selecting the smaller value between the first provisional value XR1 and the second correction value XH2. The method for calculating the first upper limit value X1 may be any method as long as it satisfies the following. If the first provisional value XR1 is less than or equal to the second correction value XH2, the first provisional value XR1 is directly calculated as the first upper limit value X1. If the first provisional value XR1 is larger than the second correction value XH2, a value that is greater than or equal to the second provisional value XR2 and less than the first provisional value XR1 is calculated as the first upper limit value X1. For example, when the first provisional value XR1 is larger than the second correction value XH2, the second provisional value XR2 may be calculated as the first upper limit value X1. Furthermore, in the above case, the middle value between the first provisional value XR1 and the second provisional value XR2 may be calculated as the first upper limit value X1.

- Similar to the above modification example, the method of calculating the second upper limit value X2 in the second upper limit calculation process is not limited to the example of the above embodiment. The method for calculating the second upper limit value X2 may be any method as long as it satisfies the following. If the second provisional value XR2 is less than or equal to the first correction value XH1, the second provisional value XR2 is directly calculated as the second upper limit value X2. If the second provisional value XR2 is larger than the first correction value XH1, a value that is greater than or equal to the first provisional value XR1 and less than the second provisional value XR2 is calculated as the second upper limit value X2.

- The method of calculating the first provisional value YR1 in the first pre-processing for the lower limit is not limited to the example of the above embodiment. The first provisional value YR1 may be calculated based on the engine rotational speed NE. For example, when the first EGR passage 16 is abolished as in a modification example described later, the first provisional value YR1 may be calculated without considering the first target EGR rate W1.

- Similar to the above modification example, the method of calculating the second provisional value YR2 in the second pre-processing for the lower limit is not limited to the example of the above embodiment. The second provisional value YR2 may be calculated based on the engine rotational speed NE.

- The method of calculating the first lower limit value Y1 in the first calculation process for the lower limit is not limited to the example of the above embodiment. That is, in calculating the first lower limit value Y1, it is not essential to use a method of selecting the larger value of the first provisional value YR1 and the second correction value YH2. The first lower limit value Y1 may be calculated by any method as long as it satisfies the following. If the first provisional value YR1 is greater than or equal to the second correction value YH2, the first provisional value YR1 is directly calculated as the first lower limit value Y1. If the first provisional value YR1 is smaller than the second correction value YH2, a value that is less than or equal to the second provisional value YR2 and larger than the first provisional value YR1 is calculated as the first lower limit value Y1. For example, when the first provisional value YR1 is smaller than the second correction value YH2, the second provisional value YR2 may be calculated as the first lower limit value Y1. Furthermore, in the above case, the middle value between the first provisional value YR1 and the second provisional value YR2 may be calculated as the first lower limit value Y1.

- Similar to the above modification example, the method of calculating the second lower limit value Y2 in the second lower limit calculation process is not limited to the example of the above embodiment. The method for calculating the second lower limit value Y2 may be any method as long as it satisfies the following. When the second provisional value YR2 is greater than or equal to the first correction value YH1, the second provisional value YR2 is directly calculated as the second lower limit value Y2. If the second provisional value YR2 is smaller than the first correction value YH1, a value that is less than or equal to the first provisional value YR1 and larger than the second provisional value YR2 is calculated as the second lower limit value Y2.

- The overall configuration of the internal combustion engine 100 is not limited to the example of the embodiment described above. For example, the number of cylinders in a cylinder group may be changed. The installation position of the temperature sensor may be changed. For example, the temperature sensor may be placed downstream of the intercooler in the intake passage. If the installation position of the temperature sensor is to be changed, a setting map targeting the installation position may be created. Both or one of the first EGR passage 16 and the second EGR passage 26 may be eliminated. That is, the first bank section 110 and the second bank section 120 do not have to have a completely symmetrical configuration. The internal combustion engine 100 includes a first cylinder group 10 , a first intake passage 11 that introduces intake air into the first cylinder group 10 , and a first throttle valve 15 that adjusts the amount of intake air introduced into the first cylinder group 10 . It is enough if you have it. The internal combustion engine 100 also includes a second cylinder group 20 , a second intake passage 21 that introduces intake air into the second cylinder group 20 , and a second throttle valve 25 that adjusts the amount of intake air introduced into the second cylinder group 20 . It is sufficient if it has the following. Only from the viewpoint of calculating the first upper limit value X1 and the second upper limit value X2, the crank position sensor 93 is not essential. Speaking only from the viewpoint of calculating the first lower limit value Y1 and the second lower limit value Y2, the first temperature sensor 62 and the second temperature sensor 72 are not essential.

10... First cylinder group 10A... Cylinder 11... First intake passage 15... First throttle valve 20... Second cylinder group 20A... Cylinder 21... Second intake passage 25... Second throttle valve 62... First temperature sensor 72... Second temperature sensor 93... Crank position sensor 100... Internal combustion engine 130... Crankshaft 200... Control device

Claims (4)

The first cylinder group,
a first intake passage that introduces intake air into the first cylinder group;
a first throttle valve that adjusts the amount of intake air introduced into the first cylinder group;
a first temperature sensor that detects the temperature of intake air flowing through the first intake passage;
a second cylinder group consisting of cylinders different from the first cylinder group;
a second intake passage that introduces intake air into the second cylinder group;
a second throttle valve that adjusts the amount of intake air introduced into the second cylinder group;
a second temperature sensor that detects the temperature of intake air flowing through the second intake passage;
Applicable to internal combustion engines with
a first control process of calculating a first target value that is a target value of the amount of intake air introduced into the first cylinder group and controlling the first throttle valve based on the first target value;
a second control process of calculating a second target value that is a target value of the amount of intake air introduced into the second cylinder group, and controlling the second throttle valve based on the second target value;
a first preliminary process of calculating a first provisional value as a provisional value of a first upper limit value that is an upper limit value of the first target value based on the temperature detected by the first temperature sensor;
a second preliminary process of calculating a second provisional value as a provisional value of a second upper limit value that is an upper limit value of the second target value based on the temperature detected by the second temperature sensor;
When the first provisional value is less than or equal to a second correction value obtained by multiplying the second provisional value by a predetermined correction coefficient larger than 1, the first provisional value is calculated as the first upper limit value. , a first calculation process of calculating a value greater than or equal to the second provisional value and less than the first provisional value as the first upper limit value when the first provisional value is larger than the second correction value;
If the second provisional value is less than or equal to the first correction value obtained by multiplying the first provisional value by the correction coefficient, the second provisional value is calculated as the second upper limit value, and the second provisional value is equal to or less than the first correction value. a second calculation process of calculating a value greater than or equal to the first provisional value and less than the second provisional value as the second upper limit value when the value is larger than the first correction value;
A control device for an internal combustion engine that can perform In the first calculation process, the smaller of the first provisional value and the second correction value is calculated as the first upper limit value,
The control device for an internal combustion engine according to claim 1, wherein in the second calculation process, a smaller value of the second provisional value and the first correction value is calculated as the second upper limit value. The first cylinder group,
a first intake passage that introduces intake air into the first cylinder group;
a first throttle valve that adjusts the amount of intake air introduced into the first cylinder group;
a second cylinder group consisting of cylinders different from the first cylinder group;
a second intake passage that introduces intake air into the second cylinder group;
a second throttle valve that adjusts the amount of intake air introduced into the second cylinder group;
a crank position sensor that detects the rotational position of the crankshaft;
Applicable to internal combustion engines with
a first control process of calculating a first target value that is a target value of the amount of intake air introduced into the first cylinder group and controlling the first throttle valve based on the first target value;
a second control process of calculating a second target value that is a target value of the amount of intake air introduced into the second cylinder group, and controlling the second throttle valve based on the second target value;
a first preliminary process of calculating a first provisional value as a provisional value of a first lower limit value that is a lower limit value of the first target value based on the rotational speed of the crankshaft;
a second preliminary process of calculating a second provisional value as a provisional value of a second lower limit value that is a lower limit value of the second target value based on the rotational speed of the crankshaft;
When the first provisional value is greater than or equal to a second correction value obtained by multiplying the second provisional value by a predetermined correction coefficient smaller than 1, the first provisional value is calculated as the first lower limit value. , a first calculation process of calculating a value that is less than or equal to the second provisional value and larger than the first provisional value as the first lower limit value when the first provisional value is smaller than the second correction value;
If the second provisional value is greater than or equal to the first correction value obtained by multiplying the first provisional value by the correction coefficient, the second provisional value is calculated as the second lower limit value, and the second provisional value is equal to or greater than the second provisional value. a second calculation process of calculating a value that is less than or equal to the first provisional value and greater than the second provisional value as the second lower limit value if it is smaller than the first correction value;
A control device for an internal combustion engine that can perform In the first calculation process, the larger of the first provisional value and the second correction value is calculated as the first lower limit value,
The control device for an internal combustion engine according to claim 3, wherein in the second calculation process, a larger value of the second provisional value and the first correction value is calculated as the second lower limit value.

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