KR20160064359A

KR20160064359A - Shift control method for vehicle with dct

Info

Publication number: KR20160064359A
Application number: KR1020140167713A
Authority: KR
Inventors: 조성현; 하상모
Original assignee: 현대자동차주식회사; 기아자동차주식회사
Priority date: 2014-11-27
Filing date: 2014-11-27
Publication date: 2016-06-08

Abstract

The present invention can more appropriately control the transmission torque of the releasing-side clutch and the engaging-side clutch in consideration of the physical characteristics of the actuator in performing the torque handover at the time of shifting in the DCT vehicle equipped with the dry clutch, Thereby improving the quality of shifting and ultimately improving the merchantability of the vehicle.

Description

TECHNICAL FIELD [0001] The present invention relates to a shift control method for a DCT vehicle,

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a shift control method for a DCT vehicle, and more particularly, to a technique for improving shift quality at the time of shifting of a DCT-equipped vehicle.

DCT {DUAL CLUTCH TRANSMISSION} is a so-called torque handover method in which the clutch (engagement side clutch) of the input shaft connected to the target speed change stage is engaged while releasing the clutch (release side clutch) HAND OVER) is generated.

On the other hand, in the vehicle equipped with the DCT using the release side clutch and the engagement side clutch as the dry clutch among the DCTs, on the basis of the TS curve indicating the characteristic of the transmission torque transmitted by the clutch to the linear stroke of the actuator during shifting And controls the release side clutch and engagement side clutch.

Figs. 1 and 2 are diagrams for explaining the stroke of an actuator necessary for reducing or increasing the transmission torque of the same magnitude in the release side clutch and the engagement side clutch, respectively. In order to reduce the transmission torque of 50 Nm in the release side clutch of Fig. The stroke of the actuator needs to be moved by about 1.5 mm. However, in the case of the engagement side clutch of FIG. 2, in order to increase the transmission torque of 50 Nm, the stroke of about 6 mm must be moved. Lt; / RTI >

The above-described phenomenon is an inevitable problem at present due to the physical characteristics of the clutch transmission torque with respect to the linear stroke of the actuator. This phenomenon makes it difficult to control the transmission torque appropriately at the beginning of the torque phase at the time of shifting.

That is, in performing the torque handover in the torque phase, the basic control direction is to increase the transmission torque at the engagement side clutch by the transmission torque reduced by the release side clutch so that the sum of the overall transmission torques of the two clutches is kept constant When the actuator of the releasing clutch and the actuator of the engaging clutch are started in the same manner at the start of the torque phase, when the transmitting torque is reduced by, for example, 50 Nm in the releasing clutch, The control intention and the control result are different from each other, and this causes not only the durability of the clutch, such as inducing excessive slip of the clutch but also the shifting process is not smoothly proceeded, And the like.

It is to be understood that the foregoing description of the inventive concept is merely for the purpose of promoting an understanding of the background of the present invention and should not be construed as an admission that it is a prior art already known to those skilled in the art. Will be.

KR 1020140034548 A

SUMMARY OF THE INVENTION The present invention has been conceived to solve the above-mentioned problems, and it is an object of the present invention to provide a DCT-equipped vehicle equipped with a dry clutch, in consideration of the physical characteristics of the actuator, And more particularly, to provide a shift control method for a DCT vehicle in which the durability of the clutch can be prevented from being lowered, the shift quality can be improved, and ultimately the commerciality of the vehicle can be improved.

In order to accomplish the above object, the present invention provides a shift control method for a DCT vehicle,

A handover judgment step of judging whether or not a torque handover period is entered during a shift;

A release side delaying step of, when the torque handover is started as a result of the handover determination step, delaying the torque handover control of the release side clutch for a predetermined reference time;

And an actual handover step of performing torque handover control even in the release side clutch when the release side delaying step is completed.

Further, the shift control method of the DCT vehicle according to the present invention

Determining whether a torque handover is initiated in shifting;

When the torque handover is started, the torque handover control of the engagement side clutch is started first, and then the torque handover control of the release side clutch is started;

And a waiting time of 20 msec to 100 msec between the start of the torque handover control of the engagement side clutch and the start of the torque handover control of the release side clutch.

1 is a graph for explaining the relationship between the transmission torque of the release side clutch and the actuator stroke,
2 is a graph for explaining the relationship between the transmission torque of the engagement side clutch and the actuator stroke,
3 is a flowchart showing an embodiment of a shift control method of a DCT vehicle according to the present invention,
4 is a graph illustrating a shift control method of a DCT vehicle according to the present invention.

3 and 4, an embodiment of a shift control method for a DCT vehicle according to the present invention includes a handover determination step (S10) for determining whether or not a torque handover period is entered during a shift; A release side delaying step (S20) of delaying the torque handover control of the release side clutch for a predetermined reference time when the torque handover is started as a result of the handover determination step (S10); And a substantial handover step (S30) in which, when the release side delay step (S20) is completed, the release side clutch also performs torque handover control.

That is, according to the present invention, it is determined whether or not the torque handover is started at the time of shifting, and when the torque handover is started, the torque handover control of the engagement side clutch is started first and then the torque handover control of the release side clutch is started , When the actual engagement torque starts to increase such that the engagement side clutch with the relatively slow increase in the transmission torque starts to increase the transmission torque first, then the transmission torque of the release side clutch is started to be reduced only at that time, And the torque handover control for keeping the sum of the transmission torque of the release side clutch at a constant level can be performed more appropriately.

It is preferable to have a waiting time of 20 msec to 100 msec between the start of the torque handover control of the engagement side clutch and the start of the torque handover control of the release side clutch.

That is, the reference time may be set at about 20 msec to 100 msec.

However, according to the dry clutch provided in the DCT, the appropriate waiting time may be somewhat varied. By a large number of experiments and analyzes, it is possible to maintain the total transmission torque of the coupling clutch and the release clutch constant, And it is more preferable to appropriately select a value at which excessive clutch slip can be prevented.

In the release side delay step (S20), the release side clutch performs a slip step (S21) for maintaining a state of slipping to a predetermined slip value, and maintains the state from before the torque handover as it is, So that the difference between the speed of the release side clutch and the speed of the engine maintains the predetermined slip value. For example, the release side clutch maintains a slip state of 50 to 100 RPM.

Referring to FIG. 4, at the time of entry into the torque handover, the engagement side clutch is first started to start the torque handover control to start increasing the transmission torque of the engagement side clutch. At this time, When the waiting time elapses, the torque handover control is started and the substantial handover step (S30) is performed, so that the total sum of the engagement-side clutch transmission torque and the release-side clutch transmission torque becomes constant So that it is possible to prevent the excessive slip of the unnecessary clutch by preventing the decrease in durability and to prevent the generation of the shift shock and to improve the shift quality will be.

Of course, depending on the kind of transmission, there exists an actual transmission section in which the speed of the engine changes from the disengagement side input shaft speed to the engagement side input shaft speed before and after the torque handover interval of the present invention as described above, The shift is completed.

For reference, FIG. 4 shows an example of a power-on shift (POWER ON UP SHIFT) in which a shift is performed from a current shift stage to a higher target shift stage in a state in which the driver depresses the accelerator pedal.

While the present invention has been particularly shown and described with reference to specific embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the following claims It will be apparent to those of ordinary skill in the art.

S10; Handover determination step
S20; Release side delay step
S21; Slip phase
S30; Real handover phase

Claims

A handover judgment step (S10) for judging whether or not a torque handover period is entered during a shift;
A release side delaying step (S20) of delaying the torque handover control of the release side clutch for a predetermined reference time when the torque handover is started as a result of the handover determination step (S10);
An actual handover step (S30) in which, when the release side delay step (S20) ends, the release side clutch also performs torque handover control;
And a control unit for controlling the shift of the DCT vehicle.

The method according to claim 1,
In the release side retarding step (S20), the release side clutch is a combination of a slip step for maintaining a state of slipping to a predetermined slip value
Wherein the DCT vehicle is controlled by the control unit.

The method of claim 2,
Wherein the slip step includes feedback control such that the difference between the speed of the releasing clutch and the speed of the engine maintains the predetermined slip value
Wherein the DCT vehicle is controlled by the control unit.

Determining whether a torque handover is initiated in shifting;
When the torque handover is started, the torque handover control of the engagement side clutch is started first, and then the torque handover control of the release side clutch is started;
A waiting time of 20 msec to 100 msec between the start of the torque handover control of the engagement side clutch and the start of the torque handover control of the release side clutch
Wherein the DCT vehicle is controlled by the control unit.

The method of claim 4,
During the standby time, the release side clutch is maintained in a slip state of 50 to 100 RPM
Wherein the DCT vehicle is controlled by the control unit.