KR20000067514A - Methode for controlling shift automatic transmission of vehicle - Google Patents

Abstract

PURPOSE: A method for controlling 4 to 2 down skip speed changing in an automatic transmission is provided to increase drive experience with excellent speed changing performance by minimizing the occurrence of an interlock at the finial speed changing. CONSTITUTION: With a 4 to 2 down speed changing signal, a first and a second pressure control solenoid valve are controled by duty. The first pressure control solenoid valve conducts an initial open loop duty control and a feedback duty control, keeping a duty control signal in a certain time which is Ta,Tb,Tc,Td and Te. After the feedback duty control, a feedback final duty value(Di) increases up to 100% and the duty control of the second pressure control solenoid is finished. The 100% of the duty value is kept in a regular time(Ts) and the duty control of the first pressure control solenoid valve is finished.

Description

4 → 2 skip shift control method of automatic transmission for vehicles {METHODE FOR CONTROLLING SHIFT AUTOMATIC TRANSMISSION OF VEHICLE}

The present invention relates to a 4 → 2 skip shift control method of an automatic transmission for a vehicle, and more particularly, to prevent an interlock phenomenon occurring at the end of the shift when the “D” range 4 → 2 is skipped. It relates to a shift control method.

For example, the automatic transmission applied to a vehicle is controlled by the shift control device controlling a plurality of solenoid valves to control hydraulic pressure according to the driving speed of the vehicle, the opening ratio of the throttle valve, and various detection conditions. To make the shift.

In other words, when the driver changes the select lever to the desired gear range, the manual valve port is changed and the hydraulic pressure supplied from the oil pump is selectively operated according to the duty control of the solenoid valve. Let this be done.

The automatic transmission operated according to this operating principle has a friction element that is deactivated in the operating state when the shift to the target shift stage is performed, and a friction element that is converted from the deactivation state to the operating state. Since the shift performance of the automatic transmission is determined according to the timing of deactivation and start of operation of these friction elements, recent studies on shift control methods for better shift performance have been actively conducted.

In view of the technical background of the present invention, the shift control of the automatic transmission according to the driving state of the vehicle upshift shift control in which the shift is sequentially made from the 1st speed, which is the full speed, to 4th speed, and 1 from the 4th forward speed. There are downshift shifting control in which shifting is sequentially performed up to a second speed, and downskip shifting control in which downshifting is performed from 4th speed to 2nd speed, 3rd speed to 1st speed, and the like. Related to.

In other words, if you want to skip the vehicle driving at the fourth speed down to the second speed, the end clutch of the kick-down servo and the end clutch operating at the fourth speed can be released and the rear clutch can be operated. It is to be controlled so as to maintain the end clutch pressure up to the second speed synchronizing point by the feedback control.

However, when the end clutch pressure by the feed back control is maintained to the second speed synchronizing point in the 4 → 2 skip shifting process as described above, the operation of the end clutch is not released while the operating pressure is supplied to the rear clutch. As a result, an interlock is generated to impair the speed change performance and to reduce the riding comfort.

Therefore, the present invention has been invented to solve the above problems, and an object of the present invention is to minimize the interlock occurring at the end of the shift time when the "D" range 4 to 2 skipping, thereby improving shifting performance, thereby improving ride comfort. The purpose of the present invention is to provide a shift control method for skipping 4 → 2 of an automatic transmission.

1 is a block diagram of a transmission of an automatic transmission to which the present invention is applied.

2 is a configuration diagram of a hydraulic system of an automatic transmission to which the present invention is applied.

3A and 3B are flowcharts illustrating a 4 → 2 skip shift control operation according to the present invention.

4 is a flow chart of a 4 → 2 skip shift control subroutine operation according to the present invention;

Fig. 5 is a duty pattern diagram and a hydraulic pattern diagram at 4 → 2 skip shifting according to the present invention.

6A and 6B are graphs for determining synchronization point at 4 → 2 skip shifting according to the present invention.

In order to realize this, in the present invention, when the shift signal from the fourth speed to the second speed is input, the first and second pressure control solenoid valves PCSV-A and B are 4 to 2 down skipped while the duty is controlled.

When the first pressure control solenoid valve (PCSV-A) enters a shift stage of 4 → 2, the initial open loop maintains the duty control signal at predetermined time Ta, Tb, Tc, Td and Te, respectively, and increases or decreases it. Performing control;

Performing 4 → 2 down skip shift feed back control when the initial open loop duty control ends in the step;

When the feed back control is finished, increasing the feed back final duty value Di to a duty ratio DELTA d by 100%;

When the duty value Di reaches 100%, determining whether the duty control of the second pressure control solenoid valve PCSV-B which performs the coupling side duty control is terminated;

When the duty control of the second pressure control solenoid valve (PCSV-B) is finished in this step, the duty value of the first pressure control solenoid valve (PCSV-A) is terminated while maintaining the duty value of 100% for a predetermined time (Ts). It is characterized in that it provides a shift control method at the time of skipping 4 → 2 of an automatic transmission for a vehicle.

Hereinafter, with reference to the accompanying drawings, preferred embodiments of the present invention that can realize the above object will be described in detail.

1 is a configuration diagram of a shift control apparatus to which the control method of the present invention is applied, wherein the shift control apparatus is a rotational speed of a turbine on an output side when a rotational power is output by torque conversion from the engine 10 through the torque converter 20. Is detected and input to the shift control unit 30, and the overall state such as the vehicle speed, the throttle opening rate, and the temperature of the transmission is detected from the driving state detection unit 40, and an electrical signal corresponding thereto is input to the shift control unit 30. do.

Then, the shift control unit 30 determines the overall driving state of the vehicle based on the signal applied from the driving state detecting unit 40, and outputs a duty pattern signal for hydraulic control based on the data of the set map table. Will drive (50).

The hydraulic system 50 controls each friction element by driving each solenoid valve for shift stage synchronization according to a control signal applied from the shift control unit 30, thereby controlling the opening rate and vehicle speed and torque converter of the throttle valve. According to the turbine rotational speed in the target shift stage is to perform the up shift or down shift.

Figure 2 shows an example of the hydraulic control system to which the present invention is applied, looking at its hydraulic system configuration, the torque converter 102 to convert the torque received from the engine to the torque transmission to the transmission side, and the torque converter and the gear stage It includes an oil pump 104 for generating and discharging the oil required for control and the oil required for lubrication.

In the pipeline 106 through which the hydraulic pressure generated from the oil pump 104 flows, a pressure regulating valve 108 for making the oil flowing along the pipeline to a constant pressure, and a torque for constantly adjusting the pressure of the torque converter and the lubricating oil. The converter control valve 110 and the damper clutch control valve 112 for increasing the power transmission efficiency of the torque converter are connected.

And some of the oil produced from the oil pump 104, the reducing valve 114 to maintain the pressure at all times lower than the line pressure, and a manual valve for switching the flow path while interlocking depending on the position of the selector lever in the driver's seat The constant hydraulic pressure supplied to 116 and depressurized by the reducing valve 114 is supplied to the first pressure control valve 118 and the second pressure control valve 120 to be used as the shift stage control pressure.

A part of the hydraulic pressure supplied to the first and second pressure control valves 118 and 120 is supplied to the NR control valve 122 which reduces shift shock when the mode is changed from the neutral range to the reverse range, and the manual valve ( The first shift control solenoid valve (SCSV-A) and the second shift control solenoid valve, which are controlled on / off by the transmission control unit, to the pipeline 124 through which hydraulic pressure flows when the 116 is in the travel (D) range. The shift control valve 126 which switches the flow path by the action of SCSV-B is connected, and manual and automatic shift control is performed with the manual valve 116 mentioned above.

In addition, the shift control valve 126 is connected to the 2nd speed line 128, the 3rd speed line 130, and the 4th speed line 132, and the 1st speed line 134 is branched on the said line 124, Line pressure is supplied to the first and second pressure control valves 118 and 120, and the first and second pressure control valves 118 and 120 are first and second pressure control solenoid valves (PCSV-A) (PCSV-). The flow path is switched by B) so that the first pressure control valve 118 supplies the control pressure to the friction element during the shift control, and the second pressure control valve 120 acts as an input element of the first speed stage. ) To drive pressure.

The second speed conduit 128 of the shift control valve 126 is supplied to the left end port of the 1-2 shift valve 136 to control the valve, and the third speed conduit 130 includes two conduits 138 ( Branched to 140, the first branch pipe 138 is supplied to the left end port of the 2-3 / 4-3 shift valve 142 to control the valve, the second branch pipe 140 is The distal end is branched to supply hydraulic pressure to the end clutch valve 145 and the high low pressure valve 146.

In addition, the four-speed pipeline 132 is in communication with the left end port of the rear clutch release valve 148 and the right end of the 2-3 / 4-3 shift valve 142 to control these valves, a part of the hydraulic distribution means The fail-safe function is the most ideal gearshift stage when a stick phenomenon occurs between the valve and at least two friction elements, the inability of the transmission control unit (hereinafter referred to as TCU) or the respective valves forming the hydraulic distribution means. The fail-safe valve 150 is disposed as a safety means to perform the operation.

A timing control conduit 152 is connected to the manual valve 116 and uses hydraulic pressure flowing along the conduit as a control pressure of the control switch valve 144, and is disposed on the timing control conduit 152. Controlled by a shift control solenoid valve (SCSV-C).

And when the manual valve 116 is in the reverse (R) range, the hydraulic pressure supplied to the reverse first control conduit 154 is front via the rear clutch release valve 148 and the 2-3 / 4-3 shift valve 142. A low-reverse brake that enables hydraulic pressure to be supplied to the clutch C4 and at the same time the hydraulic pressure supplied to the reverse second control conduit 156 acts as a reaction element in the reverse shift stage via the 1-2 shift valve 136. Hydraulic pressure is supplied to C5, and a part of the hydraulic pressure supplied to the front clutch C4 can be simultaneously supplied to the release side chamber h2 of the kick-down servo C2.

In addition, the end clutch valve 160 which can be controlled by the end clutch C3 operating pressure on the second branch conduit 140 of the three-speed conduit 130 supplying the three-speed pressure to the control switch valve 144. Was placed.

The control switch valve 144 is controlled by the third shift control solenoid valve (SCSV-C) while kicking down the second speed line 128 of the shift control valve 126 at 2, 3, and 4 speeds. The actuating side chamber of the kick-down servo C2 is supplied to the actuating side chamber h1 of (C2) and supplied with the control pressure of the first pressure control valve 118 via the 1-2 shift valve 136. (h1) or the end clutch C3.

With this configuration, the rear clutch C1 operates at the first forward speed, the rear clutch C1 and the kick-down servo C2 operate at the second speed, and the rear clutch C1, the end clutch C3, And the front clutch (C4) is operated, the shift is made while the kick-down servo (C2) and the end clutch (C3) in the fourth speed.

In such a hydraulic control system, when downshifting from the 4th speed to the 2nd speed, it is controlled by the duty pattern as shown in FIG. 5B. When a shift signal from the 4th speed to the 2nd speed is input, the TCU is shown according to the driving conditions. It is determined whether it is located in the second speed region on the shift pattern not shown in (S100, S105).

In the above, the running condition is a change amount of the throttle valve opening amount Th and the output shaft rotational speed No.

That is, when the throttle valve opening amount Th and the output shaft rotation speed No are skipped down from the fourth speed region on the shift pattern to the second speed region and positioned in the second speed region, the TCU outputs a 4 → 2 down skip shift start signal. Output

The first shift control solenoid valve (SCSV-A) turns off immediately after the shift start detection, and the second shift control solenoid valve (SCSV-B) remains on for a predetermined time (t1, 20,) after the shift start. Is controlled to be in an on state, and the third shift control solenoid valve (SCSV-C) is continuously on.

And the first and second pressure control solenoid valves (PCSV-A, B) is a duty control is made, the second pressure control solenoid valve (PCSV-B) for engaging the rear clutch (C1) on the coupling side is the TCU As shown in FIG. 5B, the first pressure control solenoid valve PCSV-A for duty control by releasing the duty control signal and releasing the line pressure acting on the end clutch C3 on the release side is shown in FIG. The same duty control is achieved.

When the vehicle enters the 4 → 2 shifting step S110 according to the driving conditions, the TCU raises the duty value Da of 0% to the duty ratio ΔDa to release the line pressure acting on the end clutch C3. It maintains for 1st time Ta (S110-S120).

Thereafter, when the predetermined first duty holding time has elapsed in the step S120, the TCU raises the duty value Di to the duty ratio ΔDb and maintains it for a predetermined second time Tb (S125−). S135).

Subsequently, when the predetermined second duty holding time Tb elapses in the step S135, the TCU decreases the duty value Di to the duty ratio ΔDc and maintains it for the predetermined third time Tc ( S140-S150).

Subsequently, when the predetermined third duty holding time Tc has elapsed in the step S150, the TCU raises the duty value Di to the duty ratio ΔDe and maintains it for a predetermined fourth time Te. S155-S165).

Subsequently, when the predetermined fourth duty holding time Te has elapsed in the step S165, the TCU generates an initial open loop duty control signal for raising the duty value Di to the duty ratio ΔDf by using the first pressure control solenoid valve ( PCSV-A), and the initial open loop duty control is terminated (S170).

Accordingly, the first pressure control solenoid valve PCSV-A is duty controlled and attached to the end of FIG. 2 with inclination a and inclination b as shown in FIG. 5C with the line pressure acting on the end clutch C3. It is rapidly released by the clutch valve 145.

As the initial open loop duty control ends in step S170, the TCU constantly adjusts the line pressure acting on the end clutch C3 by the slope c as shown in FIG. 5C attached by the feedback duty control. A subroutine that outputs a duty control signal for releasing to the first pressure control solenoid valve PCSV-A is executed (S175).

The TCU performing the feed back duty control subroutine of step S175 first calculates the duty value Du by the following arithmetic expression (S200).

[Equation 1]

En ~ = ~ dNi ~-~ (dNt) n

E_n-1 ~ = ~ dNi ~-~ (dNt) _n-1

{Where Di is the feedback control duty value,

(Di) n is the current duty value,

(Di) n-1 is the previous duty value,

Ki is the integral operator,

En is the turbine change rate difference value,

En-1 is the last turbine change rate,

Kp is proportional gain,

Kd is differential gain,

Ki is the integral operator,

dNi is the target turbine change rate,

dNt is the actual turbine change rate,

(dNt) n-1 is the last real turbine change rate.}

The feed back duty value Di calculated in the step S200 is output to the first pressure control solenoid valve PCSV-A, and the line pressure acting on the end clutch C3 is fixed by the end clutch valve 145. Release it.

In addition, the TCU releases the line pressure acting on the end clutch C3 by the feed back duty value Di calculated in the step S200, which is the engagement side as shown in FIGS. 6A and 6B. It is determined whether or not the rear clutch C1 has reached the second speed coupling primary synchronization point (S210).

In the above, the primary synchronization point is detected when the turbine speed Nt becomes equal to the output shaft speed No.

When the rear clutch C1 on the engagement side reaches the second-speed first synchronization point in step S210, the TCU controls the feedback duty for a predetermined fifth time Te1 at the time when the first synchronization point is detected. In operation S220 and S230, when the fifth time Te1 elapses, the feedback duty control ends and returns to the main routine in operation S240.

That is, while the turbine speed Nt reaches the target turbine speed Ni, {dNt (turbine change rate) <0} & {| Nt-Nt ₂ | &Lt; DELTA N _F } & If the condition that the predetermined time Te1 has passed after the first synchronization determination is satisfied, the TCU determines that the engagement of the rear clutch C1 is completed as shown in FIG. Thereafter, the end clutch pressure is sequentially removed while increasing the duty of the first pressure control solenoid valve (PCSV-A).

However, even if the above conditions are not satisfied, as shown in FIG. 6B, the rear clutch C1 is engaged, and | Nt-Nt ₂ | If the condition of ΔN _F is maintained for a predetermined time or more and a condition occurs in which the rear clutch (C1) stroke calculation total value is larger than the predetermined integrated total amount, the TCU determines that the rear clutch (C1) stroke integration total amount is more than a predetermined reference value. When the larger condition is satisfied, the end clutch C3 is sequentially removed.

Therefore, as the feedback duty control ends in step S240, the TCU raises the final duty value Di of the feedback duty control to a predetermined first duty ratio Δd (S180), and then for a predetermined time Tp. ) And determine whether the duty value Di has reached 100% (S191).

When the duty value Di reaches 100% in the step S191, the TCU ends the duty control of the second pressure control solenoid valve PCSV-B for the second speed coupling of the rear clutch C1 on the engagement side. It is determined whether or not (S192, S193).

When the duty control of the second pressure control solenoid valve PCSV-B is terminated in the step 193, the TCU may perform a predetermined time Ts from the time when the duty control of the second pressure control solenoid valve PCSV-B is terminated. The duty is maintained at 100% until elapses) (S194, S195).

When a predetermined time Ts for maintaining the duty 100% in the step S195 has elapsed, the TCU controls the duty to 0% to terminate the duty control of the first pressure control solenoid valve PCSV-A ( S196).

Thus, the line pressure acting on the end clutch C3 is released by the end clutch valve 145 at the slope d shown in Fig. 5C.

As described above, the first, second, and third shift control solenoid valves (SCSV-A, B, C) and the first and second pressure control solenoid valves (PCSV-A, B) are duty-controlled to perform 4-2 down skipping. In this case, according to the present invention, after the feedback control of the first pressure control solenoid valve PCSV-A is terminated, the duty control is performed to raise the duty value Di to the duty ratio Δd to 100%. By releasing the operating pressure of the end clutch C3, it is possible to prevent the interlock phenomenon at the end of the 4-2 speed change.

As described above, according to the present invention, after the feed back control is terminated at 4 → 2 skip, the duty value Di is increased to the duty ratio Δd to 100% to control the duty, thereby releasing the operating pressure of the end clutch. By preventing the interlock phenomenon that occurs at the end of the shift can prevent the burnout of the clutch, it is possible to improve the shifting performance and thereby the riding comfort.

Claims (3)

When the shift signal from the fourth speed to the second speed is input, the first and second pressure control solenoid valves (PCSV-A, B) are duty controlled while performing 4 → 2 skips. When the first pressure control solenoid valve (PCSV-A) enters a shift stage of 4 → 2, the initial open loop maintains the duty control signal at predetermined time Ta, Tb, Tc, Td and Te, respectively, and increases or decreases it. Performing duty control; Performing 4 → 2 down skip shift feed back control when the initial open loop duty control ends in the step; When the feed back control is finished, increasing the feed back final duty value Di to a duty ratio DELTA d by 100%; When the duty value Di reaches 100%, determining whether the duty control of the second pressure control solenoid valve PCSV-B which performs the coupling side duty control is terminated; When the duty control of the second pressure control solenoid valve PCSV-B is terminated in this step, the duty value of 100% is maintained for a predetermined time Ts and the duty control of the first pressure control solenoid valve PCSV-A is terminated. Shift control method at 4 → 2 skip of automatic transmission for vehicle The method of claim 1, wherein the feedback duty control is performed from the time when the initial open loop duty control is terminated until the predetermined time Te1 elapses after the second speed coupling primary synchronization point of the rear clutch C1 on the coupling side is detected. A shift control method of 4 → 2 skipping of an automatic transmission for a vehicle, characterized in that the. The method according to claim 1, wherein the feed back final duty value Di is increased to the duty ratio DELTA d by 100% after the end of the feed back control, wherein {dNt (turbine change rate) &lt; 0} & {| Nt-Nt ₂ | &Lt; DELTA N _F } & The rear clutch C1 on the engaging side is engaged in a state where the condition after a predetermined time Te1 has elapsed after the first synchronization determination is engaged, and | Nt-Nt ₂ | If the condition that <ΔN _F is maintained for a predetermined time or more and a phenomenon that the condition where the rear clutch (C1) stroke calculation total value is larger than the constant integration total amount occurs occurs, the rear clutch (C1) stroke integration total amount is larger than the predetermined reference value. 4. A shift control method for 4 → 2 skipping of an automatic transmission for a vehicle, characterized in that it increases constantly at a duty rate (Δd) every cycle in order to sequentially remove the end clutch (C3) on the release side when a large condition is satisfied.