KR20010059437A - Shift controlling methode for automatic transmission of vehicle - Google Patents

Abstract

PURPOSE: A gearshift control method controls a first frictional element transmitting the power of an engine to the input side so as to control the gearshift range to neutral when a car stops and control the first frictional element to be engaged on a slope during creep driving. CONSTITUTION: A control method comprises three steps. The first step(S110, S120) is to compare and determines whether the slope of a road is over a standard value if the creep driving condition is determined. The second step(S130, S140) is to compare and determine whether the car stops for more than a certain time if the slope of the road is under the standard value. The third step(S150) is to output a certain duty control signal and an engine torque reducing demanding signal controlling gearshift range to neutral condition if the car is determined to stop for more than a certain time.

Description

SHIFT CONTROLLING METHODE FOR AUTOMATIC TRANSMISSION OF VEHICLE}

The present invention relates to an automatic transmission for a vehicle, and more particularly, to a shift control method of an automatic transmission for a vehicle for neutrally controlling a shift stage when a vehicle is stopped during creep driving.

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, thereby operating the gear shift of the target shift stage. 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 such an operation source has a friction element that is deactivated in the operating state and a friction element that is converted from the deactivation state to the operating state when the shift to each target shift stage is performed. Among the friction elements, the first friction element C1 operates at speeds 1, 2 and 3, the second friction element C2 operates at speeds 2 and 4, and the third friction element C3 is The third friction element C4 operates at the third and fourth speeds, and the fourth friction element C4 operates at the third forward and backward movements, and the fifth friction element C5 operates at the reverse.

In a vehicle with an automatic transmission having the friction elements described above, when the vehicle stops the vehicle by operating a brake pedal while driving the creep, the hydraulic control solenoid valve is conventionally provided with a first friction element and a second friction as shown in FIG. 4. Only elements could be controlled.

However, the above-described method requires the reaction force or the input side to be no-loaded in order to make the fuel economy neutral and creep, but to release the second friction element on the reaction side, the one-way clutch (OWC), which is a mechanical reaction force (1) is in the D1 speed state, so the first friction element must be controlled, but the hydraulic logic implies that neutral control is impossible due to the operation of the ND valve.

Accordingly, the present invention for solving the above problems, in the improved automatic transmission improved the existing hydraulic system by controlling the first friction element that transmits the engine power to the input side to shift the shift stage to a neutral state when the vehicle is stopped during creep driving In the control, the rolling is to provide a shift control method of an automatic transmission for a vehicle that can be coupled to control the first friction element.

1 is a block diagram of a shift control apparatus of an automatic transmission for a vehicle applied to the present invention.

2 is a hydraulic circuit diagram applied to the present invention.

3 is a flowchart illustrating a shift control method of an automatic transmission for a vehicle according to the present invention;

4 is a conventional hydraulic circuit diagram.

According to an aspect of the present invention, if it is determined that the vehicle is a creep driving condition while driving, comparing and determining whether the slope of the driving road is greater than or equal to a set reference value; Comparing and determining whether the predetermined time has elapsed while the vehicle is stopped if the slope of the driving road is less than or equal to a predetermined reference value in the step; When it is determined that the predetermined time has elapsed while the vehicle is stopped, the predetermined duty control signal and the engine torque reduction request signal for controlling the shift stage to a neutral state may be output.

Hereinafter, a total control method of an automatic transmission for a vehicle will be described in detail with reference to the accompanying drawings, which is a preferred embodiment of the present invention which can realize the above object.

1 is a block diagram of a shift control apparatus of an automatic transmission for a vehicle according to the present invention. The throttle valve opening amount 11, the output rotational speed 12, the brake pedal switch 13, Vehicle running state detection means (10) for detecting a change in oil temperature (14), shift lever position (15), turbine speed (16), engine speed (17), and gradient path (18); When it is determined that the vehicle is in a creep driving condition by receiving the vehicle driving state signal detected by the detecting means 10, it is determined whether the slope of the driving road is less than or equal to the set reference value by comparing whether the slope of the driving road is greater than or equal to the setting reference value. When the vehicle is stopped and the predetermined time has elapsed and it is determined that the predetermined time has elapsed while the vehicle is stopped, the shift speed outputting a predetermined duty control signal for controlling the shift stage to a neutral state My Means (20) and; It consists of a drive means 30 for engaging or releasing the friction element by a predetermined control signal output from the shift control means 20.

2 shows an example of a hydraulic control system to which the present invention is applied. Looking at the hydraulic system configuration thereof, a torque converter 102 receives torque from an engine and converts torque to a 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 controlled on / off by the transmission control unit in 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 the valve SCSV-B communicates with each other to achieve manual and automatic shift control together with the manual valve 116 described above.

In addition, the shift control valve 126 is connected to the second speed pipe 128, the third speed pipe 130, and the fourth speed pipe 132, and the first speed pipe 134 is branched on the pipe 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.

And the 2nd speed line 128 of the shift control valve 126 is supplied to the left end port of the 1-2 shift valve 136, and this valve is controlled, and the 3rd speed line 130 is two line 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 pipe 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 operating, in the fourth speed kick-down servo (C2) and the end clutch (C3) is to operate while the shift is made.

A shift control method of an automatic transmission for a vehicle having the above configuration will be described in detail with reference to the accompanying drawings.

3 is a flowchart illustrating a method of controlling a shift of an automatic transmission for a vehicle according to the present invention, in a vehicle equipped with an automatic transmission in which a shift stage is automatically shifted according to a driver's operation state, the automatic transmission being controlled by a preset program. The shift control means 20 outputs a predetermined control signal to the vehicle driving state detection means 10 (S100).

Accordingly, the vehicle driving state detecting means 10 includes the throttle valve opening amount 11, the output side rotational speed 12, the brake pedal switch 13, the oil temperature 14, the turbine rotational speed 15, and the engine of the creep driving vehicle. The throttle valve opening amount Th from the rotational speed 16 and the gradient path 17 detection unit, the output rotational speed No corresponding to the vehicle speed, the brake pedal operating state, the oil temperature AFT, the turbine rotational speed Nt, The engine rotation speed Ne and the detected value of the gradient path are transmitted to the shift control means 20.

Therefore, the shift control means 20 is the throttle valve opening amount Th input from the vehicle driving state detection means 10, the output side rotation speed No corresponding to the vehicle speed, the brake pedal pedal operating state, and the oil temperature AFT. In response to the detection value of the turbine rotation speed Nt, the engine rotation speed Ne, and the gradient path, it is read and compared to determine whether the vehicle satisfies the creep driving condition (S110).

In the above, the creep driving conditions are brake pedal switch on and vehicle speed 10 Km / h or less.

When the creep driving condition is satisfied in the above, the shift control means 20 compares and determines whether the road inclination is greater than or equal to a predetermined set reference value (about 3%) (S120).

When it is determined that the road inclination is less than or equal to a predetermined reference value (about 3%), the shift control means 20 determines whether the vehicle speed is 0 km / h and a predetermined time (eg: 1 sec) has elapsed. Comparative judgment (S130, S140)

When a predetermined time has elapsed at the vehicle speed of 0 km / h, the shift control means 20 outputs a predetermined duty control signal to the driving means 30 for controlling the shift stage of the vehicle to be neutral. The torque reduction request signal for controlling the idle state is output to the engine control means 25 (S150).

The engine control means 25 outputs a predetermined engine control signal for reducing the output of the engine to the driving means 30 in accordance with the engine torque reduction request signal applied from the shift control means 20.

The driving means 30 may include a second friction element and a fifth friction element, which are creep-driven and coupled in response to a predetermined duty control signal and an engine control signal output from the shift control means 20 and the engine control means 25. 2 Releases friction elements to block the transmission of power from the engine to the transmission and delays the ignition of the engine.

However, when the road inclination of the driving vehicle is greater than or equal to the set value (about: 3%) in S110, the shift control means 20 continues to creep the shift stage to prevent the vehicle from being pushed back. Keep it.

Further, if the accelerator pedal operation is performed when the shift stage is neutral due to the creep driving condition, the shift control means 20 immediately engages the second friction element, and then, after a predetermined time (about 1 or 2 sec) elapses, the engine torque Outputs a signal for normal control to the engine control means 25 to prevent burnout of the second friction element.

As described above, the shift control method of the automatic transmission for a vehicle according to the present invention controls a second friction element that transmits engine power to an input side in an improved automatic transmission in which an existing hydraulic system is improved. By controlling the neutral state, and in the hilly control by combining the second friction element, it is possible to improve the fuel economy when the vehicle is stopped, it is possible to improve the ride comfort by preventing the vehicle vibration.

Claims (4)

If it is determined that the vehicle is in a creep driving condition while driving, comparing and determining whether the slope of the driving road is greater than or equal to a set reference value; Comparing and determining whether the predetermined time has elapsed while the vehicle is stopped if the slope of the driving road is less than or equal to a predetermined reference value in the step; If it is determined that the predetermined time has elapsed in the stop state of the vehicle, the automatic transmission for a vehicle, comprising the step of outputting a predetermined duty control signal and an engine torque reduction request signal for controlling the shift stage to a neutral state. Shift control method. The shift control method for an automatic transmission for a vehicle according to claim 1, wherein if the inclined road of the driving road is equal to or larger than a set reference value, the creep driving state is maintained. 2. The shift control method of claim 1, wherein when the creep stops, the accelerator pedal operation is performed, the friction element is immediately engaged and the engine torque steady request signal is output after a predetermined time has elapsed. 4. The shift control method for an automatic transmission for a vehicle according to any one of claims 1 to 3, wherein the predetermined time is 1 sec.