JP7497166B2 - Determination device, kickdown control device and vehicle - Google Patents

Description

The present disclosure relates to a determination device, a kickdown control device, and a vehicle.

Conventionally, in vehicles that are capable of changing the gears of a transmission, kick-down control is known that shifts the gears of the transmission down to a gear with higher torque in order to obtain the desired acceleration force when the driver fully depresses the accelerator pedal.

In kick-down control, if the vehicle's driving speed increases due to kick-down control and the rotation speed of the drive source after downshifting exceeds a predetermined upper limit, protective control is performed to cancel the kick-down control to protect the drive source.

However, when protective control is performed, the kickdown control is released even if the driver is fully depressing the accelerator pedal, causing the vehicle to gradually stall.

For example, Patent Document 1 discloses a configuration that prevents kickdown control from being executed if the vehicle speed is equal to or greater than a predetermined speed setting before a predetermined reset signal is output, even if the conditions for executing kickdown control are met.

Japanese Patent Application Laid-Open No. 61-17751

However, in the configuration described in Patent Document 1, if the conditions for executing kickdown control continue to be satisfied even after the execution of kickdown control is prevented, the execution of kickdown control remains prevented because the vehicle speed is equal to or greater than the predetermined speed setting before the predetermined reset signal is output.

Therefore, even if the vehicle speed falls below a predetermined speed setting, kick-down control is prevented from being executed. In other words, the configuration described in Patent Document 1 has certain limitations as a configuration for solving the problem of vehicle stall due to kick-down control.

The objective of the present disclosure is to provide a determination device, a kickdown control device, and a vehicle that are capable of suppressing vehicle stall due to kickdown control.

The determination device according to the present disclosure comprises:
an acquisition unit that acquires a parameter related to a speed of the vehicle after downshifting when an execution condition of kick-down control for downshifting a gear of a transmission of a vehicle is satisfied, the execution condition being determined based on an accelerator opening degree of the vehicle ; and
a determination unit that determines whether or not the kick down control is to be executed based on the parameter;
a reservation unit that turns on a reservation signal for the kick down control when an execution condition for the kick down control is satisfied;
Equipped with
the reservation unit switches the reservation signal from ON to OFF when the determination unit determines that the kick down control is to be executed after the reservation signal is turned ON, when a condition for executing the kick down control is not satisfied, or when the gear stage of the transmission of the vehicle is shifted up,
After determining that the kick-down control is not to be executed, the determination unit repeats the determination as to whether or not the kick-down control is to be executed during the period from when the reservation signal is turned ON until when it is turned OFF.

The kickdown control device according to the present disclosure includes:
The above determination device,
an execution unit that executes the kick down control based on a determination result of the determination device;
Equipped with
When a rotation speed of a drive source mounted in the vehicle exceeds an upper limit value after executing the kickdown control, the execution unit cancels the kickdown control.

The vehicle according to the present disclosure includes:
A transmission having a plurality of gear stages;
The kickdown control device described above;
Equipped with.

According to the present disclosure, it is possible to suppress vehicle stall due to kickdown control.

1 is a diagram showing a configuration of a vehicle equipped with a kickdown control device according to an embodiment of the present disclosure. FIG. 4 is a diagram showing an example of a time chart of a gear stage, a kickdown switch, and a reservation signal. FIG. 4 is a diagram showing an example of a time chart of a gear position, a kickdown switch, and a reservation signal. FIG. 4 is a diagram showing an example of a time chart of a gear stage, a kickdown switch, and a reservation signal. FIG. 4 is a diagram showing an example of a time chart of a gear position, a kickdown switch, and a reservation signal. 5 is a flowchart showing an example of a determination control operation in a determination unit.

The present embodiment will be described in detail below with reference to the drawings. Figure 1 is a diagram showing the configuration of a vehicle 1 equipped with a kickdown control device 100 according to an embodiment of the present disclosure.

As shown in FIG. 1, the vehicle 1 has a propeller shaft 2, a differential gear 3, drive wheels 4, an engine 5, a transmission 6, a rotation sensor 7, a kickdown signal output unit 8, and a kickdown control device 100.

The engine 5 is an internal combustion engine (drive source) such as a diesel engine. The power of the engine 5 is transmitted to the transmission 6 via a clutch (not shown), and the power transmitted to the transmission 6 is transmitted to the drive wheels 4 via the propeller shaft 2 and the differential gear 3.

The transmission 6 is a gearbox such as an automatic transmission (AMT (Automated Manual Transmission)) and is configured with multiple gear stages. In other words, the transmission 6 has a gear change mechanism that connects or disconnects the output shaft of the engine 5 and the propeller shaft 2 and changes the gear ratio.

The rotation sensor 7 is, for example, a known sensor that detects the rotation speed of the output shaft of the transmission 6. The rotation sensor 7 detects the rotation speed of the output shaft and outputs the detected rotation speed to the kickdown control device 100 (calculation unit 120).

The kickdown signal output unit 8 outputs a kickdown signal when the kickdown switch 8A is activated. The kickdown switch 8A is a switch that is activated, for example, when the driver fully depresses the accelerator pedal 8B to rapidly accelerate the vehicle 1. Activation of this kickdown switch 8A establishes the conditions for executing kickdown control, which will be described later.

In addition, the kickdown signal output unit 8 continues to output the kickdown signal when the kickdown switch 8A continues to operate (when the execution condition of the kickdown control continues to be satisfied). When the kickdown switch 8A is not operated (when the execution condition of the kickdown control is not satisfied), the kickdown signal output unit 8 does not output the kickdown signal. Note that the position of the kickdown signal output unit 8 is on the left side of the axle in FIG. 1, but it may be in any position as long as the signal of the kickdown switch 8A can be acquired. In addition, the kickdown switch 8A and the accelerator pedal 8B are arranged on the right side of the axle in FIG. 1 for convenience, but they can be appropriately changed according to the configuration of the vehicle 1. In addition, in this embodiment, the kickdown signal output unit 8 outputs the kickdown signal by acquiring the signal of the kickdown switch 8A, but the present disclosure is not limited to this. For example, the position of the accelerator pedal 8B (accelerator opening degree, etc.) may be detected to determine whether or not to execute the kickdown control, and then the kickdown signal output unit 8 may output the kickdown signal.

The kickdown control device 100 includes a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), and an input/output circuit (not shown). The kickdown control device 100 controls the execution of kickdown control, which shifts down the gears of the transmission 6 of the vehicle 1 based on a preset program to rapidly accelerate the vehicle 1.

The kickdown control device 100 has an execution unit 110, a calculation unit 120, a reservation unit 130, and a determination unit 140. The calculation unit 120, the reservation unit 130, and the determination unit 140 correspond to the "determination device" of this disclosure.

The execution unit 110 executes kick-down control based on the determination result of the determination unit 140. Furthermore, after executing the kick-down control, if the rotation speed of the engine 5 exceeds the upper limit value, the execution unit 110 executes kick-down release control to release the kick-down control. The upper limit value is appropriately set to the maximum value of the rotation speed of the engine 5, a value close to the maximum value, a value with some margin from the maximum value, etc.

When the driver attempts to perform kickdown while the vehicle 1 is traveling, if the vehicle 1 is moving at a relatively high speed, the engine 5 speed after downshifting may exceed the upper limit. In this case, the load on the engine 5 becomes excessive, so kickdown release control is performed to protect the engine 5.

When the execution condition for kick-down control is satisfied, the calculation unit 120 calculates the rotation speed of the engine 5 after a downshift in the kick-down control. Specifically, when the calculation unit 120 acquires a kick-down signal, it acquires the rotation speed detected by the rotation sensor 7 and calculates the rotation speed of the engine 5 after a downshift based on the acquired rotation speed.

The rotation speed of the engine 5 after the downshift is calculated, for example, from the gear ratio between the gear before the downshift (the gear set when the kickdown signal is acquired) and the gear after the downshift, and the rotation speed of the output shaft detected by the rotation sensor 7.

In this embodiment, the rotation speed of the output shaft detected by the rotation sensor 7 is used to calculate the rotation speed of the engine 5, but other parameters, such as the rotation speed of the input shaft, may also be used to calculate the rotation speed of the engine 5.

When the conditions for executing kickdown control are met, that is, when the kickdown switch 8A is activated, the reservation unit 130 turns the reservation signal for kickdown control ON. In addition, after turning the reservation signal ON, the reservation unit 130 switches the reservation signal OFF if the determination unit 140 determines that kickdown control is to be executed, if the conditions for executing kickdown control are not met, or if the gear of the transmission 6 is shifted up.

When the conditions for executing kick-down control are met, the determination unit 140 obtains the rotation speed of the engine 5 after the downshift from the calculation unit 120, and determines whether or not to execute kick-down control based on the rotation speed of the engine 5 after the downshift. The determination unit 140 corresponds to the "acquisition unit" of this disclosure.

Specifically, if the rotation speed of the engine 5 after the downshift is greater than a predetermined value, the determination unit 140 determines not to execute kick-down control, and if the rotation speed of the engine 5 after the downshift is less than the predetermined value, the determination unit 140 determines to execute kick-down control. The predetermined value is, for example, a rotation speed at which the kick-down release control is performed, such as a value at which the rotation speed of the engine 5 is as close as possible to an upper limit value.

Then, if the predetermined condition is satisfied after the determination unit 140 has determined that kick-down control should not be executed, the determination unit 140 repeats the determination of whether or not kick-down control should be executed. Specifically, if the above-mentioned reservation signal is ON after the determination unit 140 has determined that kick-down control should not be executed, the determination unit 140 again acquires the rotation speed of the engine 5 after the downshift from the calculation unit 120, and determines whether or not kick-down control should be executed based on the reacquired rotation speed of the engine 5 after the downshift.

The engine 5 RPM after downshifting that is acquired again by the determination unit 140 is calculated by the calculation unit 120 based on the latest detection result of the rotation sensor 7.

In this way, the determination unit 140 determines whether or not kick-down control is to be performed. In this embodiment, therefore, if the rotation speed of the engine 5 after downshifting is greater than a predetermined value, kick-down control is not performed.

For example, if the driver attempts to perform a kickdown when the speed of the vehicle 1 is relatively high before kickdown control is executed, the kickdown release control described above is executed immediately after kickdown control is executed.

In this case, kick-down control, i.e., downshifting of the transmission 6, is not performed even though the driver is trying to kick down, and the vehicle 1 may gradually stall.

In contrast, in this embodiment, in such a case, that is, when the rotation speed of the engine 5 after downshifting is greater than a predetermined value, kick-down control is not executed. This makes it possible to suppress stalling of the vehicle 1 caused by kick-down release control. Then, after it is determined that kick-down control will not be executed, if the reservation signal is ON, the determination of whether or not to execute kick-down control is repeated.

If the determination as to whether or not to perform kickdown control is not repeated after it has been determined that kickdown control will not be performed, it is possible that kickdown control will not be performed indefinitely even though the kickdown switch 8A is activated. As a result, there is a risk that the vehicle 1 will gradually stall because no downshifts are performed in the transmission.

In contrast, in this embodiment, if it is determined that kickdown control is not to be performed and the reservation signal is ON, the determination of whether or not to perform kickdown control is repeated. For example, as shown in FIG. 2, if the kickdown switch 8A is activated while the vehicle 1 is traveling, the reservation signal is turned ON, but if the rotation speed after downshifting is greater than a predetermined value, kickdown control is not performed, and the gear of the transmission 6 is not shifted down.

When the rotation speed after the downshift falls below a predetermined value, kick-down control is executed, the gear is shifted down, and the reservation signal is turned OFF. In other words, because the kick-down control is finally executed, it is possible to suppress stalling of the vehicle 1 caused by not performing the kick-down control.

In addition, when the above reservation signal is turned OFF, the determination unit 140 does not determine whether or not kick-down control is to be performed. For example, as shown in FIG. 3, when kick-down control is performed, that is, when the gear of the transmission 6 is shifted down, the reservation signal is immediately turned OFF.

Also, as shown in FIG. 4, after the kickdown execution conditions are met, there are cases where the kickdown execution conditions are not met before kickdown control is executed. For example, this is the case when the kickdown switch 8A is activated and then released. In this case, the reservation signal is ON while the kickdown switch 8A is activated, but is turned OFF when the kickdown switch 8A is released.

Also, as shown in FIG. 5, if the gear shifts up after the kickdown execution conditions are met, the reservation signal is ON if the gear does not change because kickdown control is not executed, but is OFF if the gear shifts up.

In this way, when the reservation signal is switched to OFF, there is no need to execute kickdown control, so there is no need to determine whether or not kickdown control should be executed. Therefore, unnecessary determinations as to whether or not kickdown control should be executed can be suppressed.

Next, an example of the operation of the determination control in the determination unit 140 will be described. FIG. 6 is a flowchart showing an example of the operation of the determination control in the determination unit 140. The process in FIG. 6 is executed as appropriate, for example, when kick down is activated.

As shown in FIG. 6, the determination unit 140 obtains the rotation speed after the downshift and determines whether or not the rotation speed after the downshift is greater than a predetermined value (step S101). If the result of the determination is that the rotation speed after the downshift is equal to or less than the predetermined value (step S101, NO), the determination unit 140 determines to execute kick down control (step S102). After step S102, this control ends.

On the other hand, if it is determined that the rotation speed after the downshift is greater than the predetermined value (step S101, YES), the determination unit 140 determines that kick-down control is not to be executed (step S103). Next, the determination unit 140 determines whether the reservation signal is OFF or not (step S104).

If the result of the determination is that the reservation signal is ON (step S104, NO), the process returns to step S101. On the other hand, if the reservation signal is OFF (step S104, YES), this control ends.

According to the present embodiment configured as described above, if a predetermined condition is satisfied after it is determined that kickdown control should not be performed, the determination as to whether or not to perform kickdown control is repeated, so that kickdown control is ultimately performed as long as it is necessary to perform kickdown control. As a result, stalling of the vehicle 1 due to kickdown control can be suppressed.

In addition, the reservation signal is used to identify whether or not kickdown control needs to be performed, so this control can be performed with simple control.

In addition, the system determines whether or not to execute kick-down control based on the engine 5 RPM after downshifting, so kick-down control can be reliably executed when necessary.

According to the above embodiment, the case where the predetermined condition is satisfied is defined as the case where the reservation signal is ON, but the present disclosure is not limited to this. For example, the predetermined condition may be a condition indicating the possibility of executing kickdown control, such as kickdown control not being executed after the execution condition for kickdown control is satisfied, the execution condition for kickdown control not being unsatisfied after the execution condition for kickdown control is satisfied, or the gear stage of the transmission 6 not being shifted up. In this case, for example, the determination unit 140 may obtain a signal or the like that identifies a condition indicating the execution of kickdown control, and thereby determine whether the predetermined condition is satisfied.

In addition, in the above embodiment, the parameter related to the speed of the vehicle 1 after a downshift is the RPM of the engine 5 after a downshift, but the present disclosure is not limited to this. For example, the parameter may be something other than the RPM of the engine 5 after a downshift, as long as it is related to the speed of the vehicle 1 after a downshift, such as the speed of the vehicle 1 after a downshift.

In addition, in the above embodiment, the calculation unit 120 is incorporated in the determination device (kick down control device 100), but the present disclosure is not limited to this, and the determination unit 140 may acquire parameters calculated by an external device.

In addition, in the above embodiment, an engine 5 is used as an example of a drive source, but the present disclosure is not limited to this, and the drive source may be something other than an engine, such as an electric motor, as long as it is a drive source that is mounted on a vehicle.

In addition, in the above embodiment, an AMT is given as an example of a transmission, but the present disclosure is not limited to this, and an automatic transmission (AT), a dual clutch transmission (DCT), or a continuously variable transmission (CVT) may also be used.

In addition, in the above embodiment, the kickdown control execution condition is met when the kickdown switch 8A is activated, but the present disclosure is not limited to this. For example, the kickdown control execution condition may be determined based on the accelerator opening of the accelerator pedal 8B.

In addition, in the above embodiment, the determination device is incorporated into the kickdown control device 100, but the present disclosure is not limited to this, and the determination device may be configured separately from the kickdown control device 100.

In addition, the above embodiments are merely examples of concrete ways of implementing the present disclosure, and the technical scope of the present disclosure should not be interpreted in a limiting manner based on them. In other words, the present disclosure can be implemented in various forms without departing from its gist or main features.

The kickdown control device disclosed herein is useful as a determination device, kickdown control device, and vehicle capable of suppressing vehicle stall due to kickdown control.

REFERENCE SIGNS LIST 1 vehicle 2 propeller shaft 3 differential gear 4 drive wheels 5 engine 6 transmission 7 rotation sensor 8 kickdown signal output unit 8A kickdown switch 8B accelerator pedal 100 kickdown control device 110 execution unit 120 calculation unit 130 reservation unit 140 determination unit

Claims (8)

an acquisition unit that acquires a parameter related to a speed of the vehicle after downshifting when an execution condition of kick-down control for downshifting a gear of a transmission of a vehicle is satisfied, the execution condition being determined based on an accelerator opening degree of the vehicle ; and
a determination unit that determines whether or not the kick down control is to be executed based on the parameter;
a reservation unit that turns on a reservation signal for the kick down control when an execution condition for the kick down control is satisfied;
Equipped with
the reservation unit switches the reservation signal from ON to OFF when the determination unit determines that the kick down control is to be executed after the reservation signal is turned ON, when a condition for executing the kick down control is not satisfied, or when the gear stage of the transmission of the vehicle is shifted up,
the determination unit, after determining that the kick-down control is not to be executed, repeatedly determines whether or not the kick-down control is to be executed during a period from when the reservation signal is turned ON to when the reservation signal is turned OFF.
Judging device. The acquisition unit acquires the parameters again when the reservation signal is ON after the determination unit has determined that the kick down control is not to be executed,
The determination unit determines whether or not the kick down control is to be executed based on the parameters acquired again.
The determination device according to claim 1 . When the reservation signal is turned OFF, the determination unit does not determine whether or not the kick down control is to be executed.
The determination device according to claim 1 or 2. A calculation unit is provided for calculating a parameter related to a speed of the vehicle after a downshift.
The determination device according to any one of claims 1 to 3. The calculation unit calculates a rotation speed of a drive source mounted in the vehicle after a downshift as the parameter.
The determination device according to claim 4. The determination unit determines not to execute the kick down control when the parameter is greater than a predetermined value, and determines to execute the kick down control when the parameter is equal to or less than the predetermined value.
The determination device according to any one of claims 1 to 5. A determination device according to any one of claims 1 to 6,
an execution unit that executes the kick down control based on a determination result of the determination device;
Equipped with
the execution unit cancels the kick-down control when a rotation speed of a drive source mounted in the vehicle exceeds an upper limit value after executing the kick-down control.
Kickdown control device. A transmission having a plurality of gear stages;
The kickdown control device according to claim 7 ;
A vehicle equipped with.

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