KR100931054B1 - Engine Torque Control Device and Method of Automatic Transmission - Google Patents

Abstract

In the automatic transmission, the engine torque reduction amount is corrected according to the turbine speed change rate during the kick down shift to secure a stable and consistent shifting feeling.

The present invention detects the turbine speed when the kickdown shift is started, calculates the engine torque reduction control time point and the basic control value, determines the oil pressure of the release element from the turbine rotation rate change rate, and adjusts the correction amount of the engine torque reduction control. And determining the engine torque reduction control by applying the correction amount determined by the turbine speed change rate to the default value of the engine torque reduction control.

Description

Engine torque control device and method of automatic transmission {APPARATUS FOR ENGINE TORQUE CONTROL OF AUTOMATIC TRANSMISSION ON VEHICLE AND METHOD THEREOF}

The present invention relates to an automatic transmission, and more particularly, an engine torque control apparatus for an automatic transmission that corrects engine torque reduction according to a turbine speed change rate during a kick down shift to secure a stable and consistent shifting feeling. It is about a method.

The automatic transmission is controlled by the transmission control unit (TCU) according to the traveling speed of the vehicle and the opening amount [TPS (%)] of the throttle valve to control the hydraulic pressure by operating a plurality of actuators, thereby automatically shifting to the target shift stage. To make it happen.

The automatic transmission has a release side element that is deactivated in the operating state and a coupling element that is converted from the deactivated state when the shift is performed to the target shift stage, and these operating elements are operated by hydraulic pressure.

The automatic transmission generally uses a method of reducing engine torque in the process of supplying hydraulic pressure to the coupling element as a method for smoothing the shifting feeling during a kickdown (power on down shift) shift. .

However, in the clutch-to-clutch shift control that simultaneously controls the release element and the engaging element at the same time as the kick-down shift, the engine torque reduction amount is output at a fixed value already set in the shift control means, thus acting on the release element during shift. There is a problem that a control deviation such as shifting sagging and shifting shock occurs because the pressure does not correspond to a phenomenon in which the actual output torque is fluctuated.

5 is a diagram illustrating an engine torque control structure for each state in a conventional automatic transmission.

As shown in (a), if the hydraulic pressure acting on the release element is appropriate when the gear is shifted from the N stage to the N-1 stage, the engine torque reduction control is executed (RB point). It can be seen that the synchronization is stable and the turbine speed is increased to a stable slope dNT.

However, as shown in (b), if the engine torque reduction control is carried out at a fixed value while the hydraulic pressure acting on the release element is excessive when the kick-down shift is performed from the N stage to the N-1 stage (RB point), the excessive The engine torque reduction control is added to the hydraulic pressure of the release element, and the shift synchronization to the N-1 stage is delayed, resulting in shift sagging.

Therefore, there is a problem that the increase in the turbine speed is greatly delayed, such as the point "A", and the shift response is deteriorated.

Also, as shown in (c), if the engine torque reduction control is performed at a fixed value while the hydraulic pressure acting on the release element is insufficient when the K-down gear is advanced from the N stage to the N-1 stage (RB point), the release is insufficient. The engine torque reduction control is added to the hydraulic pressure, and the shift synchronization to the N-1 stage occurs quickly.

Therefore, there is a problem that an overrun of the turbine rotational speed occurs, such as the point "B", to generate a shift shock.

The present invention has been made to solve the above problems, the object of which is to detect the turbine speed change rate during the kick-down shift, and to determine the excess or lack of hydraulic pressure acting on the release element from the turbine speed change rate engine By correcting the torque reduction amount, it is possible to ensure a stable and consistent shift feeling regardless of the hydraulic variation of the releasing element.

An engine torque control apparatus for an automatic transmission according to a feature of the present invention for realizing the above object,

A kickdown switch for detecting a kickdown shift request;

A turbine rotation speed detection unit detecting a turbine rotation speed;

And a controller for correcting the engine torque reduction amount according to the turbine speed change rate during the kickdown shift.

In addition, the engine torque control method of the automatic transmission according to a feature of the present invention,

Detecting a turbine speed when the kickdown shift is started, and calculating an engine torque reduction control time point and a basic control value;

Determining a correction amount of the engine torque reduction control by determining the oil pressure of the release element from the turbine rotation rate change rate;

And applying the correction amount determined by the turbine rotation rate change rate to the default value of the engine torque reduction control.

According to the above-described configuration, in the present invention, when the turbine rotation rate change rate is less than the reference value, the hydraulic pressure of the release element is excessive. Therefore, the engine torque reduction amount is reduced more than usual, and when the turbine rotation rate change rate is larger than the reference value, Since the case where the oil pressure is insufficient, the engine torque reduction amount is increased to reduce the input torque, and thus an effect of ensuring a stable and consistent shift feeling at all times can be expected regardless of the oil pressure variation of the releasing element.

DETAILED DESCRIPTION Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention.

Since the present invention can be implemented in various different forms, the present invention is not limited to the exemplary embodiments described herein, and parts not related to the description are omitted in the drawings in order to clearly describe the present invention.

1 is a view schematically showing an engine torque control apparatus for an automatic transmission vehicle according to an embodiment of the present invention.

The present invention includes a kick-down switch 10, the turbine speed detection unit 20, the control unit 30 and the fuel injection device (40).

The kickdown switch 10 is operated by an accelerator pedal operated by the driver, detects the driver's kickdown shift request, and applies information about the kickdown shift request to the controller 30.

The turbine rotational speed detection unit 20 detects the turbine rotational speed in the state where the kickdown shift is in progress according to the driver's request, and applies information about the turbine rotational speed to the control unit 30.

The controller 30 detects the driver's kickdown shift request, controls the shift from the N stage to the N-1 stage when the kickdown shift is required, and the turbine rotation speed change rate in the state where the shift is performed in the N-1 stage. dNT) is detected to determine whether the hydraulic pressure acting on the release side element is excessive or insufficient, and the engine torque reduction control is executed by applying a correction amount calculated by the turbine speed change rate at the engine torque reduction start point (RB point).

The fuel injection device 40 injects the fuel amount determined in each combustion chamber according to the control signal applied from the control unit 30 to execute the engine torque reduction amount.

The control of the engine torque reduction amount can be executed by advancing or perceiving the ignition timing in addition to adjusting the fuel injection amount.

Referring to the operation of performing the engine torque reduction control during the kickdown in the present invention including the above-described function as follows.

When the kick-down shift is started to the N-1 stage according to the driver's request detected through the kickdown switch 10 in the state in which the N stage, which is an arbitrary shift stage, is driven (S101), the controller 30 rotates the turbine. The turbine rotational speed during the kickdown shift is detected from the water detection unit 20 (S102).

Then, the control unit 30 calculates an engine torque reduction control start point (RB point) for executing engine torque reduction control from the turbine rotational speed (S103).

The engine torque reduction control start point (RB point) is typically a point slightly ahead of the shift synchronizing point, and is a rotational speed set at a point slightly slower than the target turbine rotational speed of the N-1 stage.

Thereafter, it is determined whether the engine torque reduction control start point (RB point) is reached (S104), and when the engine torque reduction control start point (RB point) is reached, a default value for the engine torque reduction control (ETR) is calculated (S105). ).

Thereafter, the change rate dNT of the turbine rotation speed is calculated to determine whether the hydraulic pressure acting on the release side element is excessive or insufficient (S106), and the correction amount of the engine torque reduction control ETR is calculated according to the determined result (S106). S107).

As shown in the accompanying FIG. 3, the correction amount of the engine torque reduction control is determined by the fact that the hydraulic pressure acting on the release element is excessive when the turbine speed change rate dNT is smaller than the reference value (target dNT). When the turbine speed change rate dNT is larger than the reference value (target dNT), it is determined that the oil pressure acting on the release side element is insufficient, and the increase correction amount is determined.

When the correction amount according to the turbine speed change rate dNT is determined as described above, the engine torque reduction control is executed by applying the correction amount determined by the turbine speed change rate dNT to the basic value of the engine torque reduction control determined in S105 ( S108) (S109).

The engine torque reduction control is executed by adjusting the fuel injection amount or advancing or perceiving the ignition timing.

In the state of executing the engine torque reduction control as described above, it is determined whether the shift synchronization is completed to the N-1 stage, which is the target shift stage (S110).

If the shift synchronization is not completed in step S110, the process returns to step S109. If the shift synchronization is completed, the engine torque reduction control is terminated and normal control is executed (S111).

4 is a diagram illustrating an engine torque control structure for each state in an automatic transmission according to an exemplary embodiment of the present invention.

As shown in (a), if the hydraulic pressure acting on the release element is appropriate when the kick-down shift is performed from the N stage to the N-1 stage, the engine is reduced to the N-1 stage by executing the engine torque reduction control using the default value. It can be seen that the turbine speed is made stable and made stable.

Further, as shown in (b), when the kick-down shift is performed from the N stage to the N-1 stage, a correction value ΔE determined by the turbine rotation rate change rate dNT in the state where the hydraulic pressure acting on the release element is excessive. It can be seen that the turbine rotation speed is increased stably with the engine torque reduction control applied to

Further, as shown in (c), when the kick-down transmission progresses from the N stage to the N-1 stage, a correction value ΔE1 determined by the turbine rotation rate change rate dNT in a state in which the hydraulic pressure acting on the release element is insufficient. It can be seen that the turbine rotation speed is stably increased due to the stable engine speed reduction control with the N-1 stage.

Although the embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements of those skilled in the art using the basic concepts of the present invention defined in the following claims are also provided. It is included in the scope of rights.

1 is a view schematically showing an engine torque control apparatus of an automatic transmission according to an embodiment of the present invention.

2 is a flowchart for executing engine torque control in an automatic transmission according to an embodiment of the present invention.

3 is a diagram illustrating the concept of engine torque control in an automatic transmission according to an embodiment of the present invention.

4 is a diagram illustrating an engine torque control structure for each state in an automatic transmission according to an exemplary embodiment of the present invention.

5 is a diagram illustrating an engine torque control structure for each state in a conventional automatic transmission.

<Explanation of symbols for the main parts of the drawings>

10: kick down switch 20: turbine speed detection unit

30: control unit 40: fuel injection device

Claims (7)

A kickdown switch for detecting a kickdown shift request; A turbine rotation speed detection unit detecting a turbine rotation speed; An engine torque control apparatus for an automatic transmission comprising a control unit for correcting an engine torque reduction amount according to a turbine speed change rate during a kickdown shift. And the controller is configured to reduce and correct the engine torque reduction control when the hydraulic pressure is excessive according to the turbine rotation rate change rate, and to increase and correct the engine torque reduction control when the hydraulic pressure on the release side is insufficient. delete delete Detecting a turbine speed when the kickdown shift is started, and calculating an engine torque reduction control time point and a basic control value; Determining a correction amount of the engine torque reduction control by determining the oil pressure of the release element from the turbine rotation rate change rate; Executing engine torque reduction control by applying a correction amount determined by a turbine rotation rate change rate to a default value of engine torque reduction control; Engine torque control method of an automatic transmission comprising a. The method of claim 4, wherein And if the inclination of the turbine rotation rate change rate is greater than or equal to the reference value, increases the engine torque reduction control, and if the inclination is less than or equal to the reference value, reduces and corrects the engine torque reduction control. The method of claim 4, wherein The engine torque control method of the automatic transmission which corrects by reducing the engine torque reduction control when the hydraulic pressure acting on the release element is excessive, and increases the engine torque reduction control when the hydraulic pressure is insufficient. A function of detecting a turbine speed change rate in a state where a kickdown shift is in progress; Determining a correction amount by determining whether the hydraulic pressure acting on the release element is excessive or insufficient from the turbine rotation rate change rate; A function of executing engine torque reduction control by applying a correction amount determined by a turbine speed change rate at an engine torque reduction start point; Engine torque control device for an automatic transmission in which a program including a recorded in the control unit.

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