JP7848745B2 - car - Google Patents

Description

This disclosure relates to automobiles, and more specifically, to automobiles equipped with an engine having a supercharger.

Conventionally, in this type of vehicle, a system has been proposed that significantly retards the opening timing of the exhaust valve during deceleration from a turbocharged state, while controlling the opening and closing timing of the intake valve to achieve maximum intake air volume (see, for example, Patent Document 1). In this vehicle, during re-acceleration after such deceleration control, the opening and closing timing of the intake valve and the fuel injection amount are set to predetermined target values, while the opening timing of the exhaust valve is set to the advanced side. These controls suppress turbo lag during re-acceleration from a deceleration state, thereby improving drivability.

Japanese Patent Publication No. 2007-255318

In automobiles equipped with turbocharged engines, one possible method to suppress turbocharger response delay is to increase the intake air volume when certain conditions are met, including accelerator operation below a predetermined opening. In this case, how to achieve the torque required by the driver's accelerator operation becomes a crucial issue.

The present disclosure relates to an automobile equipped with a supercharged engine, primarily aimed at suppressing supercharging response delay while outputting torque from the engine in response to the driver's accelerator input.

The automobile described herein employs the following means to achieve the primary objectives described above.

The automobiles disclosed herein are
An engine having a supercharger that includes a compressor installed in the intake manifold and a turbine installed in the exhaust manifold,
A control device for controlling the engine,
A car equipped with,
The control device performs anti-lag control, which includes prohibiting fuel cut-off, increasing the intake air volume, and retarding the ignition angle according to the accelerator opening, when predetermined conditions are met, including accelerator operation below a predetermined opening.
It is characterized by the following:

In the automobile of this disclosure, as a method for suppressing turbocharging response delay, when predetermined conditions are met, including accelerator operation below a predetermined opening, anti-lag control is performed by prohibiting fuel cut, increasing the intake air volume, and retarding the ignition angle according to the accelerator opening. By prohibiting fuel cut and increasing the intake air volume, the turbocharger's operating state (supercharging state) is maintained, suppressing turbocharging response delay during re-acceleration in response to the driver's accelerator operation. On the other hand, while anti-lag control is being performed, torque corresponding to the driver's accelerator operation is output by retarding the ignition angle according to the accelerator opening. As a result, turbocharging response delay can be suppressed while outputting torque from the engine in response to the driver's accelerator operation.

In the automobile according to this disclosure, if the predetermined condition is not met during the execution of the anti-lag control, the control device may continue ignition retardation to maintain the immediate torque for a predetermined time or until it is determined that the target torque can be achieved without ignition retardation. This prevents a sudden increase in engine output torque that may occur if ignition retardation is terminated immediately. Here, the immediate torque is the control torque that is to be achieved immediately by ignition retardation.

In the automobile of this disclosure, an automatic transmission is provided that changes the speed of the power from the engine and outputs it to a drive shaft connected to the drive wheels, the predetermined condition includes the condition of being idle-on, and the control device may continue the anti-lag control even if the idle turns off during the execution of the anti-lag control. In an automobile equipped with an automatic transmission, it is necessary to suppress the turbocharger response delay and to coordinate with the transmission control. Therefore, even if the condition of being idle-on is included as the start condition for the anti-lag control, by continuing the anti-lag control even if the idle turns off during the execution of the anti-lag control, it becomes possible to output torque in response to accelerator operation below a predetermined opening, and to suppress the turbocharger response delay when re-accelerating due to accelerator operation above a predetermined opening. In this case, the control device may set the degree of gradual change at the end of the intake air volume increase upon termination of the anti-lag control due to the automatic transmission receiving a request to prohibit the anti-lag control during gear shifting and/or lock-up while the anti-lag control is being executed to differ from the degree of gradual change at the end of normal control termination due to the predetermined condition not being met during the execution of the anti-lag control. This allows the degree of gradual change at the end of the intake air volume increase upon termination of the anti-lag control due to the automatic transmission receiving a request to prohibit the anti-lag control during gear shifting or lock-up while the anti-lag control is being executed to correspond to gear shifting or lock-up.

This is a schematic diagram showing the configuration of an automobile 20 as an embodiment of the present disclosure. This flowchart shows an example of anti-lag control performed by the electronic control unit 50.

Next, embodiments for implementing this disclosure will be described. Figure 1 is a schematic diagram showing the configuration of an automobile 20 as an embodiment of this disclosure. As shown in the figure, the automobile 20 of the embodiment includes an engine 22, an automatic transmission 30, an electronic control unit 50, an air conditioning system 72, and a navigation system 74.

The engine 22 is configured as an internal combustion engine driven by hydrocarbon fuels such as gasoline or diesel, and its output shaft 23 is connected to an automatic transmission 30. This engine 22 is equipped with a turbocharger 27 that uses exhaust energy to provide supercharging.

The supercharger 27 includes a compressor 27b located in the intake pipe 24 connected to the air cleaner 25, a turbine 27a located in the exhaust pipe 26, a connecting shaft 27c connecting the compressor 27b and the turbine 27a, and a wastegate valve 27e provided in a bypass pipe 27d connecting the upstream and downstream sides of the turbine 27a in the exhaust pipe 26. In this supercharger 27, by adjusting the opening degree of the wastegate valve 27e, the distribution ratio of the amount of exhaust gas flowing through the bypass pipe 27d and the amount of exhaust gas flowing through the turbine 27a is adjusted (the smaller the opening degree of the wastegate valve 27e, the less exhaust gas flows through the bypass pipe 27d and the more exhaust gas flows through the turbine 27a), the rotational driving force of the turbine 27a is adjusted, the amount of compressed air from the compressor 27b is adjusted, and the boost pressure (intake pressure) of the engine 22 is adjusted. Furthermore, when the wastegate valve 27e is fully open, engine 22 can operate in the same way as a naturally aspirated engine without a supercharger 27.

The automatic transmission 30 comprises a torque converter 32 and an automatic transmission 34. The torque converter 32 is configured, for example, as a well-known torque converter with a fluid-type lock-up clutch. The automatic transmission 34 is configured, for example, as a hydraulically driven transmission with six forward gears and one reverse gear. The output shaft of the automatic transmission 34 is connected to a drive shaft 36, which is connected to the drive wheels 39a and 39b via a differential gear 38.

The electronic control unit 50 is a microcomputer centered around a CPU 51. In addition to the CPU 51, it includes a ROM 52 for storing programs, a RAM 52 for temporarily storing data, a flash memory 54 for storing data, and input/output ports (not shown).

The electronic control unit 50 receives signals from various sensors via input ports. Signals input to the electronic control unit 50 via input ports include the ignition signal from the ignition switch 60, the shift position SP from the shift position sensor 62 (which detects the position of the shift lever 61), the accelerator opening Acc from the accelerator pedal position sensor 64 (which detects the amount of depression of the accelerator pedal 63), and the brake position BP from the brake pedal position sensor 66 (which detects the amount of depression of the brake pedal 65). Other signals include the vehicle speed V from the vehicle speed sensor 68 and the switch signal from the mode selection switch 69 (which selects the driving mode). Driving modes selectable via the mode selection switch 69 include normal mode, eco mode (prioritizing fuel efficiency), and circuit mode (for sporty driving).

Various control signals are output from the electronic control unit 50 via its output ports. Examples of control signals output from the electronic control unit 50 via the output ports include those used for throttle control (control of throttle opening), fuel injection control (control of fuel injection amount and timing), and ignition control (control of ignition timing), all necessary for controlling the operation of the engine 22; drive control signals for the wastegate valve 27e; and drive control signals for the automatic transmission 30. Additionally, display control signals for the display device 70 mounted near the driver's seat and air conditioning control signals for the air conditioning system 72 that harmonizes the air in the passenger compartment are also output.

Next, the operation of the automobile 20 of the embodiment configured in this way, and the operation when suppressing supercharging lag, will be described. Figure 2 is a flowchart showing an example of the control (anti-lag control) that suppresses supercharging response lag, performed by the electronic control unit 50 of the embodiment.

In anti-lag control, the electronic control unit 50 first determines whether predetermined conditions for executing anti-lag control are met (step S100). These predetermined conditions include: a history of the accelerator opening Acc being set to a relatively large first predetermined opening A1 or higher, and the accelerator opening Acc being set to a relatively small second predetermined opening A2 or lower; the engine speed Ne of the 22 being less than or equal to a predetermined rotational speed Nref; being in circuit mode; the vehicle speed V being greater than or equal to a predetermined vehicle speed Vref; and being idle-on. In step S100, if any of the above conditions are not met, it is determined that the predetermined conditions are not met; and if all of the above conditions are met, it is determined that the predetermined conditions are met. Therefore, step S100 is a process of waiting until the predetermined conditions are met.

When it is determined in step S100 that a predetermined condition has been met, fuel cut is prohibited (step S110), and the wastegate valve 27e is closed (step S120). Then, the intake air volume is increased (step S130), and ignition timing retardation is started in accordance with the accelerator operation (step S140). By prohibiting fuel cut with the wastegate valve 27e closed and increasing the intake air volume, the supercharging state by the supercharger 27 (the state in which the turbine 27a and compressor 27b are rotating) can be maintained. As a result, it is possible to suppress supercharging delay when the driver presses the accelerator pedal 63 to re-accelerate. The amount by which the intake air volume is increased can be the amount of air necessary to maintain the supercharging state by the supercharger 27, and can be determined by experimentation or machine learning according to the rotational speed Ne of the engine 22, etc. The ignition timing retardation in response to accelerator operation involves adjusting the ignition timing so that torque corresponding to the accelerator opening (Acc) is output from the engine 22. Because the intake air volume is increased, the ignition timing is adjusted to be more retarded than under normal conditions. This allows the engine 22 to output torque corresponding to the driver's accelerator operation.

Next, the idle-on condition included in the execution conditions (predetermined conditions) for anti-lag control is masked (excluded) from the execution conditions (step S150). Then, the system waits for a positive determination to be made in one of the following processes: determining whether there is a request to prohibit anti-lag control output when the automatic transmission 30 is shifting or locked up (step S160); determining whether a predetermined time has elapsed since the start of anti-lag control (step S170); or determining whether any of the execution conditions (predetermined conditions) for anti-lag control, excluding the idle-on condition, are not met (step S180). The predetermined time in step S170 is the time for continuing anti-lag control, and can be 2 seconds, 3 seconds, 4 seconds, etc.

When it is determined in step S170 that a predetermined time has elapsed since the start of anti-lag control, or when it is determined in step S180 that any of the execution conditions (predetermined conditions) for anti-lag control, excluding the idle-on condition, are not met, the normal termination process for terminating anti-lag control is performed by releasing the intake air volume increase through rate processing using the first rate value Qrt1 (step S190), waiting for a predetermined extension time to elapse or until it is determined that the target torque can be achieved without ignition retardation (step S210), then terminating the ignition retardation corresponding to the accelerator operation (step S220), and terminating this control. The reason for continuing the ignition retardation corresponding to the accelerator operation until the extension time has elapsed or until it is determined that the target torque can be achieved without ignition retardation is to prevent excessive torque from being output from the engine 22 by returning the ignition timing to the normal timing before the intake air volume increase is complete. Furthermore, the reason for masking (excluding) the idle-on condition from the anti-lag control execution conditions is to ensure that torque can be output from the engine 22 when the accelerator opening Acc is below the second predetermined opening A2 while the anti-lag control is running and the accelerator is off.

In step S160, if it is determined that the automatic transmission 30 has a request to disable anti-lag control during gear shifting or lock-up, the system terminates the anti-lag control as a termination process for such a request. This involves releasing the intake air volume increase using a second rate value Qrt2 (step S200), waiting for a predetermined extension time to elapse or for the target torque to be achieved without ignition retardation (step S210), then terminating the ignition retardation corresponding to the accelerator operation (step S220), and ending this control. The second rate value Qrt2 is determined based on experimental and machine learning results to prevent torque shocks from occurring due to the termination of anti-lag control during gear shifting or lock-up. Note that the second rate value Qrt2 may be the same value as the first rate value Qrt1 used in the normal termination process.

In the automobile 20 of the embodiment described above, when predetermined conditions for executing anti-lag control are met, including a history of the accelerator opening Acc being set to a relatively large first predetermined opening A1 or higher, and a condition in which the accelerator opening Acc is set to a relatively small second predetermined opening A2 or lower, the wastegate valve 27e is closed, preventing fuel cut-off, increasing the intake air volume, and retarding the ignition angle in accordance with the accelerator operation. This allows the supercharging state by the supercharger 27 (the state in which the turbine 27a and compressor 27b are rotating) to be maintained, and torque corresponding to the driver's accelerator operation can be output from the engine 22. Therefore, when the driver subsequently depresses the accelerator pedal 63 to re-accelerate, supercharging lag can be suppressed. As a result, supercharging response lag can be suppressed while torque corresponding to the driver's accelerator operation is output from the engine 22.

In the automobile 20 of this embodiment, when a predetermined time has elapsed since the start of anti-lag control, or when any of the execution conditions (predetermined conditions) for anti-lag control (excluding the idle-on condition) are not met, the intake air volume increase is released by rate processing using the first rate value Qrt1. At the same time, the ignition timing is continued in accordance with the accelerator operation until a predetermined extension time has elapsed or it is determined that the target torque can be achieved without ignition timing retardation. This prevents excessive torque output from the engine 22 by returning the ignition timing to the normal timing before the intake air volume increase is complete.

In the automobile 20 of this embodiment, when the anti-lag control is terminated by a request to prohibit anti-lag control output during gear shifting or lock-up in the automatic transmission 30, the intake air volume increase is released by rate processing using a second rate value Qrt2, which is different from the normal first rate value Qrt1. This allows the degree of gradual change when the intake air volume increase ends to be adjusted according to gear shifting or lock-up.

In the embodiment of the automobile 20, an automatic transmission 30 is provided, but a manual transmission may also be provided. In this case, the condition of being idle-on may be excluded from the execution conditions (predetermined conditions) for anti-lag control.

The correspondence between the main elements of the embodiment and the main elements of the invention described in the section on means for solving the problem will be explained. In this embodiment, the supercharger 27 corresponds to "supercharger," the engine 22 corresponds to "engine," and the electronic control unit 50 corresponds to "control device."

Furthermore, the correspondence between the main elements of the embodiment and the main elements of the invention described in the "Means for Solving the Problem" section is merely an example to specifically illustrate a form for carrying out the invention described in the "Means for Solving the Problem" section, and does not limit the elements of the invention described in the "Means for Solving the Problem" section. In other words, the interpretation of the invention described in the "Means for Solving the Problem" section should be based on the description in that section, and the embodiment is merely a specific example of the invention described in the "Means for Solving the Problem" section.

The above describes the forms in which this disclosure can be implemented. However, this disclosure is not limited to these embodiments, and it can, of course, be implemented in various forms without departing from the gist of this disclosure.

This disclosure is applicable to industries such as the automotive manufacturing industry.

20 Automobile, 22 Engine, 23 Output shaft, 24 Intake pipe, 25 Air cleaner, 26 Exhaust pipe, 27 Supercharger, 27a Turbine, 27b Compressor, 27c Connecting shaft, 27d Bypass pipe, 27e Wastegate valve, 30 Automatic transmission, 32 Torque converter, 34 Automatic transmission, 36 Drive shaft, 38 Differential gear, 39a, 39b Drive wheels, 50 Electronic control unit, 51 CPU, 52 ROM, 53 RAM, 54 Flash memory, 60 Ignition switch, 61 Shift lever, 62 Shift position sensor, 63 Accelerator pedal, 64 Accelerator pedal position sensor, 65 Brake pedal, 66 Brake pedal position sensor, 68 Vehicle speed sensor, 69 Mode selection switch, 70 Display device, 72 Air conditioning system, 74 Navigation system.

Claims (4)

An engine having a supercharger that includes a compressor installed in the intake manifold and a turbine installed in the exhaust manifold,
A control device for controlling the engine,
A car equipped with,
The control device performs anti-lag control, which involves prohibiting fuel cut, increasing the intake air volume, and retarding the ignition angle according to the accelerator opening, when all of the following predetermined conditions are met: the accelerator opening has been set to a relatively large first predetermined opening or higher, and the accelerator opening is set to a relatively small second predetermined opening or lower; the engine speed is below a predetermined speed; the vehicle is in circuit mode; the vehicle speed is above a predetermined vehicle speed; and the vehicle is idle .
If the predetermined condition is not met during the execution of the anti-lag control, the control device continues to retard the ignition angle so that the immediate torque is maintained for a predetermined time or until it is determined that the target torque can be achieved without ignition retardation.
An automobile characterized by the following features.
car. The automobile according to claim 1 ,
The system includes an automatic transmission that changes the speed of the power from the engine and outputs it to the drive shaft connected to the drive wheels,
The control device continues the anti-lag control even if it becomes idle-off during the execution of the anti-lag control.
car. An engine having a supercharger that includes a compressor installed in the intake manifold and a turbine installed in the exhaust manifold,
An automatic transmission that changes the speed of the power from the engine and outputs it to the drive shaft connected to the drive wheel,
A control device for controlling the engine,
A car equipped with,
The control device performs anti-lag control, which involves prohibiting fuel cut, increasing the intake air volume, and retarding the ignition angle according to the accelerator opening, when all of the following predetermined conditions are met: the accelerator opening has been set to a relatively large first predetermined opening or higher, and the accelerator opening is set to a relatively small second predetermined opening or lower; the engine speed is below a predetermined speed; the vehicle is in circuit mode; the vehicle speed is above a predetermined vehicle speed; and the vehicle is idle-on. The control device continues the anti-lag control even if the vehicle is idle-off during the execution of the anti-lag control.
An automobile characterized by the following features. The automobile according to claim 2 or 3 ,
The control device shall ensure that the degree of gradual change at the end of the intake air volume increase when the anti-lag control is terminated due to the automatic transmission receiving a request to prohibit the anti-lag control during gear shifting and/or lock-up while the anti-lag control is being performed is different from the degree of gradual change at the end of the intake air volume increase when the control is normally terminated due to the predetermined condition not being met while the anti-lag control is being performed.
car.