KR100308948B1 - Method for controlling kick-down 4-2-4 return shifting of automatic transmission - Google Patents

Abstract

PURPOSE: A method for controlling kick-down 4-2-4 return shifting of an automatic transmission is provided to reduce the time for shifting by selectively outputting an open duty depending on the condition of power during kick-down 4-2 skip shifting, to reduce a shifting shock, and to freely combine a speed range depending on a travel state. CONSTITUTION: If a kick-down 4-2 skip shift control signal is outputted, a shift control is opened with the output of a kick-down 4-2 skip shift control signal from a memory(S110,S120). If a 2-4 return condition during kick-down 4-2 skip shifting is satisfied, a 2-4 return control opening duty is outputted from the memory in the power-off range(S130-S150).

Description

Kickdown of automatic transmission 4-> 2-> 4 return shift control method

The present invention relates to a kick-down 4-> 2-> 4 return shift control method of an automatic transmission. In detail, an acceleration during a kick-down 4 → 2 skip shift is performed according to a driver's accelerator pedal operation in a four-speed vehicle. The present invention relates to a kick-down control method of the automatic transmission for performing 2 → 4 return control of the shift stage according to the pedal re-operation 4-> 2-> 4 return shift control method.

In general, when the driver starts driving to reach the destination by using the vehicle and is driving at four speeds, and the driver presses the accelerator pedal with the willingness, the vehicle is stored in the memory according to the driver's accelerator pedal operation. Outputs the kick-down 4 → 2 skip shift control signal.

As the kick-down 4 → 2 skip shift control signal is output, the vehicle driving at the fourth speed skips the shift stage to the second speed instead of the third speed, and receives the power output from the engine to increase the output torque. After that, the gear shift stages are sequentially increased, and the gear shift stage is shifted again by four speeds, thereby driving at a faster speed than the current driving speed.

However, as described above, when the driver operates the accelerator pedal with the will to accelerate, the operator moves the accelerator pedal and kicks down the shift stage. In the related art, as shown in FIG. 5, the start duty for stopping the shift of the kick-down 4 → 2 shifting and returning the shift stage from the second to the fourth speed according to the 2 → 4 return control signal stored in the memory is Δd. After the output, the feed back control was performed, and the shift stage was completed at 4 speed.

However, in the above-described conventional technique, in performing the kick-down shift release according to the driver's accelerator pedal re-operation during the kick-down 4 → 2 shift and the 2 → 4 return control of the shift stage, the state of the power according to the driver's accelerator pedal operation is performed. Irrespective of this, by outputting a fixed starting duty Δd during the 2 → 4 return control of the shift stage, the shift time becomes longer during the 2 → 4 return shift of the shift stage, resulting in a shift shock.

In addition, by outputting a fixed starting duty Δd during 2 → 4 return control of the shift stage regardless of the power state according to the driver's accelerator pedal operation state, the shift stage according to the driver's accelerator pedal operation change is targeted. There is a problem that can not be combined freely.

Accordingly, an object of the present invention is to solve the above problems, and if the 2 → 4 return control condition is satisfied during the kick-down 4 → 2 shift, the power state is determined according to the driver's accelerator pedal operation state. Kick-down of automatic transmission for reducing shift time by reducing the shift time by outputting predetermined shift stage 2 → 4 return control start duty selected for each area 4-> 2-> 4 return shift control It is to provide a method.

1 is a block diagram illustrating a shift control apparatus of a general automatic transmission;

2 is a flowchart of a kick-down 4 → 2 → 4 return shift control method of an automatic transmission according to an embodiment of the present invention;

3 is a power state area graph of an automatic transmission according to an embodiment of the present invention,

4 is a duty pattern diagram when controlling the kick-down 4 → 2 → 4 return shift of the automatic transmission according to the embodiment of the present invention;

5 is a kick-down 4 → 2 → 4 return shift control duty pattern diagram of a conventional automatic transmission.

In the kick-down 4 → 2 → 4 return shift control method of the automatic transmission of the present invention for achieving the above object, the driver's accelerator pedal in a vehicle running at four speeds by receiving a signal detected by the vehicle driving state sensing means Determining whether a kick-down 4 → 2 skip shift control signal according to the operation is output; In the above step, when the kick-down 4 → 2 skip shift control signal is output according to the driver's accelerator pedal operation, the TCU outputs the kick down 4 → 2 skip shift control signal stored in the memory to initiate the shift control. ; In the above step, during the kick-down 4 → 2 skip shifting, the throttle valve opening amount is changed below the predetermined reference value due to the driver's accelerator pedal re-manipulation to determine whether the kick-down shifting is released. Determining whether the 2 → 4 return condition is satisfied; When the shift stage 2 → 4 return condition is satisfied during the kick-down 4 → 2 skip shifting in the above step, the TCU determines the power state region according to the vehicle speed and the throttle opening degree, and if the power off region corresponds to the predetermined power stored in the memory, Outputting a 2 → 4 return control start duty d1.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention, which can be achieved and realized in detail by the above objects, will be described in detail with reference to the accompanying drawings.

As shown in FIG. 1, a shift control apparatus of an automatic transmission to which the present invention is applied includes a vehicle driving state sensing means 10 that detects a signal that is variable and output according to a driving state of a vehicle and outputs a predetermined electric signal; TCU 20 for performing a kick-down 4 → 2 shift when a kick-down 4 → 2 shift control signal is output from a vehicle that is driving at 4 speeds by receiving a predetermined electric signal output from the driving state detecting means 10; The actuator 30 controls the flow of hydraulic pressure according to the duty control signal output from the TCU 20 and performs kickdown 4 → 2 control.

In the above, the vehicle driving state detection means 10, the throttle valve opening degree detection unit 11 for detecting the opening degree of the throttle valve whose opening and closing state is variable in conjunction with the operation state of the accelerator pedal and outputs a predetermined signal; The vehicle speed sensor 12 detects the output shaft rotational speed of the vehicle and outputs a predetermined signal corresponding to the traveling speed of the vehicle, and when the gear stage is varied according to the throttle valve opening amount and the vehicle speed, A shift stage detection unit 13 for detecting a state and outputting a corresponding signal, and a turbine shaft rotation speed detection unit 14 for detecting a rotation speed of a turbine shaft of a torque converter connected to an input shaft of a transmission and outputting a predetermined signal. ), An engine rotation speed detection unit 15 for detecting a rotational speed of the crankshaft which is variable according to the operating state of the engine and outputting a predetermined signal, and a kick for hydraulic control of the kick-down servo brake. The kick down switch 16 detects an operation time of the down servo brake and outputs a corresponding signal.

A kick-down 4 → 2 → 4 return shift control method applied to the shift control apparatus of the automatic transmission having the above configuration will be described with reference to FIG.

When the driver drives the vehicle and drives at four speeds, the TCU 20 determines whether the kick-down 4 → 2 skip shift control has occurred according to the driver's accelerator pedal operation (S100). S110).

When the kick down 4 → 2 skip shift occurs according to the driver's accelerator pedal operation state, the TCU 20 outputs the kick down 4 → 2 skip shift duty control signal stored in the memory to the actuator 30 (S120). ).

At this time, the actuator 30 is driven in response to the kick-down 4 → 2 skip shift duty control signal output from the TCU 20 to start releasing the four speed pressure acting on the end clutch and gradually applying the two speed pressure to the rear clutch. Start supplying

When the driver's acceleration will be changed while the driver is re-operating the accelerator pedal while performing the kick-down 4 → 2 skip shift according to the driver's accelerator pedal operation, the TCU 20 releases the kick-down shift and shifts. It is determined whether the stage satisfies the shift stage 2 → 4 return condition of returning to the fourth speed (S130).

When the shift stage 2 → 4 return condition according to the driver's operation of the accelerator pedal is satisfied, the TCU 20 shifts the shift stage 2 → 4 according to the power state region according to the variable throttle valve opening value as shown in FIG. The return control start duty value is stored in the memory, and the power state region is determined by the variable throttle valve opening value according to the driver's accelerator pedal re-operation, and the corresponding shift stage 2 → 4 return control start duty value is stored in the actuator. Output

The power state region according to the throttle valve opening value is divided into a power on region, a power off region, and an intermediate region belonging to the middle portion of the power on and off regions, and the shift stage 2 → 4 return control start duty values are d3 and d1. divide it into d2 and store it in memory.

The shift stage 2 → 4 return control start duty value according to the power state region is stored in the memory as d3, d1, d2, and the shift stage 2 → 4 return control start duty value in the power-on area is d3 The throttle valve opening amount can be corrected and calculated by the equation (1) at the shift stage 2-4 return control start duty value d1 in the off region.

In addition, since the turbine change rate is different in the power-on area and the power-off area, the target turbine change rate must also be set separately.

Therefore, the target turbine change rate in the power off region can be calculated by Equation 2.

Therefore, in the above, when the driver kicks down the accelerator pedal and the kick-down shift is released and the shift stage returns to the fourth speed, the TCU 20 may not operate the accelerator pedal again. The power state region is detected by the throttle valve opening amount, and it is determined whether the detected power state region is the power-off region (S140).

When the power state region detected according to the throttle valve opening amount according to the driver's accelerator pedal re-operation is the power off region, the TCU 20 returns to the shift stage 2 → 4 corresponding to the power off region stored in the memory. The control duty d1 is outputted to the actuator 30 (S150).

However, when the power state region detected according to the throttle valve opening amount according to the driver's accelerator pedal re-operation is not the power-off region, the TCU 20 detects according to the throttle valve opening amount according to the driver's accelerator pedal re-operation. It is determined whether the power state region is a power-on region (S160).

When the power state region detected according to the throttle valve opening amount by the driver's accelerator pedal re-operation is not the power on region or the power off region, the TCU 20 detects the driver's accelerator pedal re-operation according to the throttle valve opening amount. It is determined that the power state region to be the middle region between the power on and the power off regions, and the shift stage 2 → 4 return control duty d2 corresponding to the intermediate region stored in the memory is output to the actuator 30 (S170).

However, when the power state region detected according to the throttle valve opening amount according to the driver's accelerator pedal re-operation is the power on region, the TCU 20 shifts the gear stage 2 → 4 corresponding to the power on region stored in the memory. The return control duty d3 is output to the actuator 30 (S180).

Therefore, as described above, when the power state region detected according to the throttle valve opening amount is detected by the driver's accelerator pedal re-operation, the corresponding gear shift stage 2 → 4 return control duty d stored in the memory is output to the actuator 30. The actuator 30 is driven according to the duty control signal output from the TCU 20 to release the second speed pressure acting on the rear clutch to return the shift stage to the fourth speed, and applies the fourth speed pressure to the end clutch. By supplying line pressure without shock and engaging the end clutch, the gear shifting speed is restored by 4 speeds (S190).

The above embodiments are described as the most preferred embodiments, and the present invention is not limited thereto, and the embodiments can be easily described from the above embodiments.

As described above, when the power state region is detected according to the throttle valve opening amount by the driver's accelerator pedal re-operation as described above, the shift stage 2 → 4 return control duty corresponding to the detected power region is found in the memory. By outputting, it is possible to shorten the shift time during shifting, thereby reducing the shift shock, and kick-down of an automatic transmission having the effect of improving the freedom of shift stage coupling. 4-> 2-> 4 A return shift control method can be provided.

Claims (3)

Determining, by the TCU, whether a kick-down 4 → 2 skip shift control signal is output according to an accelerator pedal operation of a driver in a vehicle driving at four speeds by receiving a signal detected by the vehicle driving state detecting means; In the above step, when the kick-down 4 → 2 skip shift control signal is output according to the driver's accelerator pedal operation, the TCU outputs the kick down 4 → 2 skip shift control signal stored in the memory to initiate the shift control. ; In the above step, during the kick-down 4 → 2 skip shifting, the throttle valve opening amount is changed below the predetermined reference value due to the driver's accelerator pedal re-manipulation to determine whether the kick-down shifting is released. Determining whether a 2 → 4 return condition is satisfied; When the shift stage 2 → 4 return condition is satisfied during the kick-down 4 → 2 skip shifting in the above step, the TCU determines the power state region according to the vehicle speed and the throttle opening degree, and if the power off region corresponds to the predetermined power stored in the memory, And a step of outputting a 2 → 4 return control start duty (d1). The method of claim 1, further comprising: determining whether the power state region is the power on region when the 2 → 4 return condition is satisfied during the kick-down 4 → 2 skip shifting; Outputting the shift stage 2 → 4 return control duty d3 stored in the memory when the power state region is the power-on region when the 2 → 4 return condition is satisfied during the kickdown 4 → 2 skip shift in the above step; Kickdown 4 → 2 → 4 return shift control method of automatic transmission. The memory according to claim 1 or 2, wherein when the power state region is not the power-off region or the power-on region when the 2 → 4 return condition is satisfied during the kick-down 4 → 2 skip shift, the power state region is determined to be an intermediate state region. And outputting the shift stage 2 → 4 return control duty d2 stored in the automatic downshift control system.