Vehicle control device

Abstract

To suppress discomfort which a driver feels resulting from an engine rotation number becoming higher than a rotation number adapted to a vehicle speed during the execution of manual gear change processing.SOLUTION: A control device 70 comprises a CPU 71 for controlling an operation of an internal combustion engine 20, and controlling a gear change ratio of a continuously variable transmission 47. The CPU 71 performs specific cylinder stop processing for operating the internal combustion engine 20 in a form of stopping the supply of fuel to some cylinders of a plurality of cylinder 21, and manual gear change processing for changing a gear change ratio of the continuously variable transmission 47 stepwise and setting a target value of an engine rotation number to a rotation number corresponding to a vehicle speed. When performing the specific cylinder stop processing at the non-execution of the manual gear change processing, the CPU 71 raises the target value of the engine rotation number higher than that in the case that of not performing the specific cylinder stop processing, and when performing the specific cylinder stop processing at the execution of the manual gear change processing, the CPU limits an increase in target value of the engine rotation number accompanying the execution of the specific cylinder stop processing.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a vehicle control device that is applied to a vehicle equipped with an internal combustion engine and a continuously variable transmission. [Background technology]

[0002] Patent Document 1 discloses a control device applied to an internal combustion engine having multiple cylinders. This control device executes a specific cylinder deactivation process that stops fuel supply to some of the multiple cylinders while operating the internal combustion engine in a manner that fuel is supplied to the remaining cylinders. During this specific cylinder deactivation process, the control device controls the operation of the internal combustion engine so that the engine speed is higher than when this process is not executed. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-127709 Summary of the Invention [Problem to be solved by the invention]

[0004] When a continuously variable transmission is used as a transmission for a vehicle, a manual transmission mode may be provided as a mode for controlling the gear ratio of the transmission. The manual transmission mode is a mode in which the gear ratio is changed in stages by the driver's gear shift operation. When the gear ratio of the transmission is controlled in the manual transmission mode, the control device controls the operation of the internal combustion engine so that the engine speed corresponds to the vehicle speed.

[0005] Consider a case where the specific cylinder deactivation process is executed when the manual shift mode is selected. For example, when the specific cylinder deactivation process is started when the manual shift mode is selected, the engine speed may become higher than the speed corresponding to the vehicle speed due to the start of the specific cylinder deactivation process. In this case, the driver may feel uncomfortable with the engine speed becoming higher than the speed corresponding to the vehicle speed. [Means for solving the problem]

[0006] A vehicle control device for solving the above problem is applied to a vehicle equipped with an internal combustion engine having multiple cylinders and a continuously variable transmission. This vehicle control device includes an execution device that controls operation of the internal combustion engine based on a target value of engine speed and controls the gear ratio of the continuously variable transmission. The execution device is configured to execute a specific cylinder stop process that operates the internal combustion engine in a manner that stops fuel supply to some of the multiple cylinders while supplying fuel to the remaining cylinders, and a manual shift process that gradually changes the gear ratio of the continuously variable transmission and sets the target value of the engine speed to a speed corresponding to vehicle speed. When the specific cylinder stop process is executed while the manual shift process is not being executed, the execution device sets the target value of the engine speed higher than when the specific cylinder stop process is not executed, and when the specific cylinder stop process is executed while the manual shift process is being executed, the execution device controls the increase in the target value of the engine speed that accompanies the execution of the specific cylinder stop process. , so that the engine rotation speed is lower than the target value when the specific cylinder stop processing is executed when the manual shift processing is not executed. Restrict.

[0007] When a specific cylinder stop process is executed during a manual shift process, the vehicle control device limits an increase in the target value of the engine speed that accompanies the execution of the specific cylinder stop process. Therefore, during the execution of the manual shift process, the engine speed can be prevented from becoming higher than the speed corresponding to the vehicle speed. Therefore, during the execution of the manual shift process, the vehicle control device can prevent the driver from feeling uncomfortable about the engine speed becoming higher than the speed corresponding to the vehicle speed. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a schematic diagram showing the configuration of a vehicle equipped with a control device that is one embodiment of a vehicle control device. [Figure 2] FIG. 2 is a flowchart showing a processing routine executed by the CPU of the control device. [Figure 3] FIG. 3 is a flowchart showing the processing routine executed by the CPU. DETAILED DESCRIPTION OF THE INVENTION

[0009] An embodiment of a vehicle control device will be described below with reference to FIGS. 1 illustrates a vehicle 10 equipped with a control device 70 that functions as a vehicle control device. The vehicle 10 is a hybrid vehicle. The vehicle 10 further includes an internal combustion engine 20, a power transmission device 40, and a plurality of drive wheels 11.

[0010] <Internal combustion engine> The internal combustion engine 20 includes a plurality of cylinders 21, a plurality of fuel injection valves 22, a plurality of spark plugs 23, and a crankshaft 24. The fuel injection valves 22 inject fuel to be supplied into the cylinders 21. The spark plugs 23 ignite an air-fuel mixture containing fuel and air in the cylinders 21 by spark discharge. In the example shown in FIG. 1 , one fuel injection valve 22 and one spark plug 23 are provided for each cylinder 21. The crankshaft 24 rotates by power generated by combustion of the air-fuel mixture in the plurality of cylinders 21.

[0011] The internal combustion engine 20 includes an intake passage 25 and an exhaust passage 30. The intake passage 25 is a passage through which intake air flows to be introduced into the multiple cylinders 21. A throttle valve 26 is installed in the intake passage 25. The flow rate of intake air in the intake passage 25 is adjusted by adjusting the throttle opening, which is the opening degree of the throttle valve 26. When the air-fuel mixture is combusted in the multiple cylinders 21, exhaust gas is generated. The exhaust gas is discharged from the multiple cylinders 21 to the exhaust passage 30.

[0012] The exhaust passage 30 is provided with an upstream exhaust purification device 31 and a downstream exhaust purification device 32 as devices for purifying exhaust gas. The downstream exhaust purification device 32 is arranged in a portion of the exhaust passage 30 downstream of the upstream exhaust purification device 31. The upstream exhaust purification device 31 is a NOx storage-type three-way catalyst. The downstream exhaust purification device 32 is a particulate filter that captures particulate matter in the exhaust gas and supports the three-way catalyst.

[0013] <Power transmission device> The power transmission device 40 includes a power split mechanism 41, a first motor generator 42, a second motor generator 43, and a reduction gear mechanism 44. The power split mechanism 41 is, for example, a planetary gear mechanism. The crankshaft 24 of the internal combustion engine 20 and the output shaft of the first motor generator 42 are connected to the power split mechanism 41. Therefore, the output from the power split mechanism 41 can be controlled by adjusting the output of the internal combustion engine 20 and the output of the first motor generator 42. The output of the power split mechanism 41 is transmitted to the multiple drive wheels 11 via the reduction gear mechanism 44. The output shaft of the second motor generator 43 is connected to the reduction gear mechanism 44. Therefore, the output of the second motor generator 43 is also transmitted to the multiple drive wheels 11 via the reduction gear mechanism 44.

[0014] The first motor generator 42 and the second motor generator 43 are each connected to a battery 52 via a power control unit 51. When the motor generators are made to function as electric motors, the DC voltage of the battery 52 is converted to AC voltage by the power control unit 51 and supplied to the motor generators. On the other hand, when the motor generators are made to function as generators, the AC voltage generated by the motor generators is converted to DC voltage by the power control unit 51 and supplied to the battery 52.

[0015] In this embodiment, the power split mechanism 41 and the first motor generator 42 constitute an example of a continuously variable transmission 47. The first motor generator 42 corresponds to the "electric motor," and the power split mechanism 41 corresponds to the "transmission mechanism" to which torque is input from both the internal combustion engine 20 and the first motor generator 42. The power split mechanism 41 changes the rotational speed input via the crankshaft 24 and outputs the rotational speed to the reduction mechanism 44. The gear ratio GR of the continuously variable transmission 47 at this time can be varied by driving the first motor generator 42. In other words, the continuously variable transmission 47 is an electric continuously variable transmission. The "gear ratio GR of the continuously variable transmission 47" here refers to the ratio of the rotational speed input from the internal combustion engine 20 to the rotational speed output from the power split mechanism 41 to the reduction mechanism 44.

[0016] The vehicle 10 is provided with an automatic transmission mode and a manual transmission mode as modes for adjusting the gear ratio GR of the continuously variable transmission 47. The automatic transmission mode is a mode in which the gear ratio GR is controlled on the vehicle 10 side. When the gear ratio GR is controlled in the automatic transmission mode, the continuously variable transmission 47 operates so that the gear ratio GR is changed continuously. On the other hand, the manual transmission mode is a mode in which the continuously variable transmission 47 is operated so that the gear ratio GR is changed stepwise by the driver's operation of the operation unit 15. Note that the operation of the operation unit 15 by the driver to change the gear ratio GR is also referred to as a "speed change operation."

[0017] <Control device> The detection system of the control device 70 has multiple sensors that output signals corresponding to the detection results to the control device 70. The detection system includes a crank angle sensor 61, a catalyst temperature sensor 62, a vehicle speed sensor 63, and an accelerator position sensor 64. The crank angle sensor 61 detects the rotation angle of the crankshaft 24 of the internal combustion engine 20 and outputs a signal corresponding to the rotation speed of the crankshaft 24. The catalyst temperature sensor 62 detects the temperature of the three-way catalyst of the upstream exhaust purification device 31. The vehicle speed sensor 63 detects the traveling speed of the vehicle 10. The accelerator position sensor 64 detects the amount of accelerator pedal operation by the driver of the vehicle 10. The rotation speed of the crankshaft 24 based on the detection signal of the crank angle sensor 61 is referred to as the "engine speed NE." The catalyst temperature based on the detection signal of the catalyst temperature sensor 62 is referred to as the "catalyst temperature TMP." The traveling speed based on the detection signal of the vehicle speed sensor 63 is referred to as the "vehicle speed SPD." The amount of accelerator pedal operation based on the detection signal of the accelerator position sensor 64 is referred to as the "accelerator opening AC."

[0018] An operation signal is input to the control device 70 from the operation unit 15. That is, when the manual transmission mode is selected, the control device 70 controls the continuously variable transmission 47 based on a required transmission ratio, which is the transmission ratio selected by operating the operation unit 15.

[0019] The control device 70 includes a CPU 71 and a memory 72. The memory 72 stores a control program executed by the CPU 71. The CPU 71 executes the control program to control the operation of the internal combustion engine 20, the drive of the first motor generator 42, and the drive of the second motor generator 43. In other words, the CPU 71 corresponds to an "execution device" that controls the operation of the internal combustion engine 20 and the gear ratio GR of the continuously variable transmission 47.

[0020] <Manual shifting process> 2, a processing routine showing the manual shifting process executed by the CPU 71 will be described. The manual shifting process is a process for gradually changing the gear ratio GR of the continuously variable transmission 47 and setting the target value of the engine speed to a speed corresponding to the vehicle speed SPD. The CPU 71 repeatedly executes this processing routine at each predetermined control cycle.

[0021] In step S11, the CPU 71 determines whether or not the manual shifting mode has been selected. If the manual shifting mode has been selected (S11: YES), the CPU 71 proceeds to step S13. On the other hand, if the manual shifting mode has not been selected (S11: NO), the CPU 71 temporarily ends this processing routine because the automatic shifting mode has been selected. In other words, the CPU 71 does not execute the manual shifting process.

[0022] In step S13, the CPU 71 acquires the current vehicle speed SPD. Subsequently, in step S15, the CPU 71 determines whether or not a gearshift operation has been performed. For example, if a signal requesting a change in the gear ratio GR is received from the operation unit 15, it is assumed that a gearshift operation has been performed. On the other hand, if the signal is not received from the operation unit 15, it is assumed that no gearshift operation has been performed. If the CPU 71 determines that a gearshift operation has been performed (S15: YES), it proceeds to step S17. On the other hand, if the CPU 71 determines that no gearshift operation has been performed (S15: NO), it proceeds to step S19.

[0023] In step S17, the CPU 71 operates the continuously variable transmission 47 so that the gear ratio GR of the continuously variable transmission 47 becomes the required gear ratio. At this time, the CPU 71 controls the driving of the first motor generator 42 to make the gear ratio GR of the continuously variable transmission 47 equal to the required gear ratio. When the change of the gear ratio GR is completed, the CPU 71 proceeds to step S19.

[0024] In step S19, the CPU 71 derives a temporary target engine speed NETr1, which is a temporary value for the target value of the engine speed, in accordance with the current vehicle speed SPD. For example, the CPU 71 derives a larger value as the vehicle speed SPD increases. Thereafter, the CPU temporarily ends this processing routine.

[0025] Note that even when the automatic shift mode is selected, the CPU 71 derives the tentative target rotation speed NETr1. In this case, the CPU 71 may derive a rotation speed corresponding to the vehicle speed SPD as the tentative target rotation speed NETr1, for example.

[0026] <Specific cylinder stop processing> 3, a processing routine showing the specific cylinder stop processing executed by the CPU 71 will be described. The specific cylinder stop processing is processing for operating the internal combustion engine 20 in a manner that stops the supply of fuel to some of the multiple cylinders 21 while supplying fuel to the remaining cylinders. The CPU 71 repeatedly executes this processing routine for each predetermined control cycle.

[0027] In step S31, the CPU 71 determines whether or not the execution conditions for the specific cylinder stop process are met. For example, assuming that the temperature range in which the three-way catalyst of the upstream exhaust purification device 31 is activated is the activation temperature range, if the catalyst temperature TMP is equal to or lower than the lower limit of the activation temperature range, the execution conditions are deemed to be met. On the other hand, if the catalyst temperature TMP is higher than the lower limit of the activation temperature range, the execution conditions are deemed not to be met. If the CPU 71 determines that the execution conditions are met (S31: YES), the CPU 71 proceeds to step S33. On the other hand, if the CPU 71 determines that the execution conditions are not met (S31: NO), the CPU 71 temporarily ends this processing routine. In other words, the CPU 71 does not execute the specific cylinder stop process.

[0028] In step S33, the CPU 71 determines whether or not the manual shifting mode has been selected as the mode for adjusting the gear ratio GR of the continuously variable transmission 47. If the manual shifting mode has been selected (S33: YES), the CPU 71 proceeds to step S35. On the other hand, if the manual shifting mode has not been selected (S33: NO), the CPU 71 proceeds to step S37 because the automatic shifting mode has been selected.

[0029] In step S35, the CPU 71 sets the tentative target rotation speed NETr1 derived in step S19 shown in FIG. 2 as the target value NETr of the engine rotation speed. That is, when the specific cylinder stop process is executed during the execution of the manual shift process, the CPU 71 limits the increase in the target value NETr of the engine rotation speed that accompanies the execution of the specific cylinder stop process. More specifically, the CPU 71 stops the increase in the target value NETr of the engine rotation speed that accompanies the execution of the specific cylinder stop process. Then, the CPU 71 proceeds to step S39.

[0030] In step S37, the CPU 71 derives the sum of the tentative target rotation speed NETr1 and the increased correction rotation amount DNE as the target value NETr of the engine rotation speed. The increased correction rotation amount DNE may be a preset value or may be a value that varies depending on the operating state of the internal combustion engine 20. When the CPU 71 executes the specific cylinder stop processing while the manual shift processing is not being executed, the CPU 71 sets the target value NETr of the engine rotation speed higher than when the specific cylinder stop processing is not being executed. Then, the CPU 71 proceeds to step S39.

[0031] In step S39, the CPU 71 controls the operation of the internal combustion engine 20 based on the target engine speed value NETr and the accelerator pedal position AC. Specifically, the CPU 71 stops fuel injection from the fuel injection valve 22 corresponding to one of the multiple cylinders 21, while causing the fuel injection valves 22 corresponding to the remaining cylinders 21 to inject fuel. For example, when the fuel injection amount when the air-fuel ratio is equal to the stoichiometric injection amount is defined as the stoichiometric injection amount, the CPU 71 may increase the fuel injection amount from the fuel injection valves 22 corresponding to the remaining cylinders 21 beyond the stoichiometric injection amount. Thereafter, the CPU 71 temporarily ends this processing routine.

[0032] If the execution condition for the specific cylinder stop process is not met, the CPU 71 controls the engine operation so that fuel is supplied to all of the plurality of cylinders 21. <Action and effect> The operation of this embodiment will be described.

[0033] Regardless of whether the automatic transmission mode or the manual transmission mode is selected as the mode for adjusting the gear ratio GR of the continuously variable transmission 47, the specific cylinder deactivation process is executed when the execution condition for the specific cylinder deactivation process is met. That is, fuel supply to one of the multiple cylinders 21 is stopped, while fuel supply to the remaining cylinders 21 is continued. This allows unburned fuel and air (i.e., oxygen) to be supplied to the three-way catalyst of the upstream exhaust purification device 31. As a result, the unburned fuel is oxidized (burned) in the three-way catalyst, causing the temperature of the three-way catalyst to rise.

[0034] At this time, if the gear ratio GR is adjusted in the automatic transmission mode, the target value NETr of the engine speed is increased by the specific cylinder stop process, i.e., the engine speed NE is increased in accordance with the execution of the specific cylinder stop process.

[0035] On the other hand, when the gear ratio GR is adjusted in the manual shift mode, the increase in the target value NETr of the engine speed resulting from the execution of the specific cylinder stop process is limited. That is, even if the specific cylinder stop process is executed, the engine speed NE does not increase.

[0036] In this embodiment, the following effects can be obtained. When the control device 70 executes the specific cylinder stop process during the execution of the manual shift process, it stops the increase in the target value NETr of the engine speed that accompanies the execution of the specific cylinder stop process. Therefore, during the execution of the manual shift process, it is possible to prevent the engine speed NE from becoming higher than the speed corresponding to the vehicle speed SPD. Therefore, during the execution of the manual shift process, the control device 70 can prevent the driver from feeling uncomfortable about the engine speed NE becoming higher than the speed corresponding to the vehicle speed SPD.

[0037] <Example of change> The above embodiment can be modified as follows: The above embodiment and the following modifications can be combined with each other within the scope of technical compatibility.

[0038] When a specific cylinder stop process is executed during a manual shift process, the increase in the engine speed target value NETr may not be stopped if the increase in the engine speed target value NETr associated with the execution of the specific cylinder stop process can be limited. For example, when a specific cylinder stop process is executed during a manual shift process, the target value NETr may be calculated as the sum of a value lower than the increased correction amount DNE and the temporary target speed NETr1. Even in this case, it is possible to expect some effect in preventing the engine speed NE from becoming higher than the speed corresponding to the vehicle speed SPD during the execution of the manual shift process.

[0039] The number of cylinders to which fuel supply is stopped during execution of the specific cylinder stopping process does not have to be 1. Furthermore, the cylinders to which fuel supply is stopped by the specific cylinder stopping process may be changed as appropriate.

[0040] The continuously variable transmission does not have to be an electric continuously variable transmission that adjusts the gear ratio by driving a motor generator. In this case, the vehicle does not have to be a hybrid vehicle as long as it is equipped with an internal combustion engine 20.

[0041] The control device 70 is not limited to a device that includes a CPU and a ROM and executes software processing. In other words, the control device 70 may have any one of the following configurations (a) to (c). (a) The control device 70 includes one or more processors that execute various processes according to a computer program. The processor includes a CPU and memory such as RAM and ROM. The memory stores program code or instructions that cause the CPU to execute processes. Memory, i.e., computer-readable media, includes any available media that can be accessed by a general-purpose or special-purpose computer.

[0042] (b) The control device 70 includes one or more dedicated hardware circuits that perform various processes. Examples of dedicated hardware circuits include application-specific integrated circuits (ASICs) or FPGAs. ASIC stands for "Application Specific Integrated Circuit," and FPGA stands for "Field Programmable Gate Array."

[0043] (c) The control device 70 includes a processor that executes some of the various processes in accordance with a computer program, and a dedicated hardware circuit that executes the remaining processes of the various processes. [Explanation of symbols]

[0044] 10...vehicle, 20...internal combustion engine, 21...cylinder, 41...power split mechanism, 42...first motor generator, 47...continuously variable transmission, 70...control device, 71...CPU

Claims

1. The present invention is applied to a vehicle equipped with an internal combustion engine having a plurality of cylinders and a continuously variable transmission, an execution device that controls operation of the internal combustion engine based on a target value of engine rotation speed and controls a gear ratio of the continuously variable transmission; The execution device a specific cylinder stop process for stopping fuel supply to some of the plurality of cylinders while operating the internal combustion engine in a manner that fuel is supplied to the remaining cylinders; a manual speed change process for changing the speed ratio of the continuously variable transmission in a stepwise manner and setting the target value of the engine speed to a speed corresponding to the vehicle speed, The execution device When the specific cylinder stop process is executed while the manual shift process is not executed, the target value of the engine rotation speed is set higher than when the specific cylinder stop process is not executed; When the specific cylinder stop process is executed while the manual shift process is being executed, an increase in the target value of the engine speed accompanying the execution of the specific cylinder stop process is limited to be lower than the target value of the engine speed when the specific cylinder stop process is executed while the manual shift process is not being executed. Vehicle control device.

2. When the specific cylinder stop process is executed during the execution of the manual shift process, the execution device stops an increase in the target value of the engine rotation speed that accompanies the execution of the specific cylinder stop process. The vehicle control device according to claim 1 .

3. the continuously variable transmission includes an electric motor and a transmission mechanism to which torque is input from both the internal combustion engine and the electric motor, and is configured to vary the gear ratio by adjusting the torque output from the electric motor; The execution device controls the electric motor based on a required value of the gear ratio when changing the gear ratio of the continuously variable transmission. The vehicle control device according to claim 1 or 2.

Images