KR100309008B1 - Hydraulic control system of automatic transmission for vehicle - Google Patents

Abstract

PURPOSE: A hydraulic control system for an automatic transmission of a vehicle is provided to improve shift quality and responsiveness by controlling hydraulic pressure for release in fixing hydraulic pressure of operation during kickdown servo-controlling and controlling frictional factors individually. CONSTITUTION: A hydraulic control system of an automatic transmission for a vehicle is composed of a pressure regulating valve(8) regulating hydraulic pressure from an oil pump(4); a damper clutch control valve(12) operating a damper clutch of a torque converter(2); a shift control unit forming shift mode; a hydraulic control unit regulating shift quality and responsiveness for the shift mode in shifting; and a hydraulic distributing unit supplying hydraulic pressure to frictional factors used as input and reaction factors. Shift quality and responsiveness are improved by controlling frictional factors individually.

Description

Hydraulic Control System of Automotive Transmission

The present invention relates to a hydraulic control system applied to an automatic transmission for a vehicle.

For example, an automatic transmission for a vehicle has a torque converter and a multi-speed gear mechanism connected to the torque converter, and hydraulically operated friction for selecting one of the gear stages of the transmission gear mechanism according to the driving condition of the vehicle. Contains an element.

The hydraulic control system of the automatic transmission for a vehicle operates the hydraulic pressure generated from the oil pump by selecting a friction element through a control valve, so that an appropriate shift can be automatically performed according to the driving state of the vehicle.

And this hydraulic control system is a pressure control means for adjusting the hydraulic pressure generated from the oil pump, manual and automatic shift control means that can form a shift mode, and shifting feeling and responsiveness to form a smooth shift mode when shifting Hydraulic control means, a damper clutch control means for operating the damper clutch of the torque converter, and a hydraulic distribution means for distributing a proper hydraulic supply to each friction element.

Accordingly, the hydraulic distribution of the hydraulic distribution means is made different by the solenoid valves turned on / off by the transmission control unit and the solenoid valves controlled by the duty, and the operation of the friction element is selected to realize the shift stage control.

In such a hydraulic control system, the flow path for operating the kick-down servo operating in the "D" ranges 2 and 4 is usually controlled by the pressure control valve and the orifice, and the operating pressure of the release side chamber. Is controlled to be controlled by the shift valve and orifice together with the working pressure of the front clutch.

Accordingly, when controlling the kick-down servo according to the shift of 2 → 3, 3 → 4, 4 → 3, 3 → 2, the pressure of the release side chamber and the front clutch operated when reversing is Controlled by the pressure difference caused by the orifice, there is a problem in that the shifting response and the shifting feeling are deteriorated.

Therefore, the present invention has been invented to solve the above problems, an object of the present invention is to control the hydraulic pressure on the release side while the operating side hydraulic pressure in the control of the kick-down servo, the other friction elements are each independent The hydraulic control system of the automatic transmission for a vehicle that can improve shift response and shifting feeling by providing the in control is made.

1 is a view showing a hydraulic flow state of the neutral (N) range in the hydraulic control system according to the present invention.

2 is a block diagram of a hydraulic control means applied to the present invention.

Figure 3 is a block diagram of a hydraulic distribution means applied to the present invention.

4 is a view showing a hydraulic flow state in the running (D) range 1 speed in the hydraulic control system according to the present invention.

5 is a view showing a hydraulic flow state at the driving (D) range 2 speed in the hydraulic control system according to the present invention.

6 is a view showing a hydraulic flow state in the traveling (D) range 2 → 3 shifting process in the hydraulic control system according to the present invention.

7 is a view showing a hydraulic flow state at the driving (D) range 3 speed in the hydraulic control system according to the present invention.

Figure 8 is a graph showing the hydraulic supply and disengagement state in the traveling (D) range 2 → 3 shifting process in the hydraulic control system according to the present invention.

9 is a view showing a hydraulic flow state in the traveling (D) range 3 → 4 shifting process in the hydraulic control system according to the present invention.

10 is a view showing a hydraulic flow state at the driving (D) range 4 speed in the hydraulic control system according to the present invention.

Figure 11 is a graph showing the hydraulic supply and disengagement state in the traveling (D) range 3 → 4 shifting process in the hydraulic control system according to the present invention.

12 is a view showing a hydraulic flow state in the traveling (D) range 4 → 3 shifting process in the hydraulic control system according to the present invention.

Figure 13 is a graph showing the hydraulic supply and release state in the traveling (D) range 4 → 3 shifting process in the hydraulic control system according to the present invention.

14 is a view showing a hydraulic flow state in the traveling (D) range 3 → 2 shifting process in the hydraulic control system according to the present invention.

Figure 15 is a graph showing the hydraulic supply and release state in the driving range (D) range 3 → 2 in the hydraulic control system according to the present invention.

16 is a view showing a hydraulic flow state in the three-speed hold state according to the failure in the hydraulic control system according to the present invention.

17 is a view showing a hydraulic flow state in the "L" range in the hydraulic control system according to the present invention.

18 is a view showing a hydraulic flow state of the reverse (R) range in the hydraulic control system according to the present invention.

In order to realize this, the present invention provides a pressure regulating means for regulating hydraulic pressure generated from an oil pump, a damper clutch control means for damper clutch operation of a torque converter, a shift control means for forming a shift mode, and a smooth shift during shifting. Hydraulic control means for adjusting shifting feel and responsiveness for mode formation, and hydraulic distribution means for supplying and distributing proper hydraulic pressure to a plurality of friction elements acting as input and reaction force elements at each speed change stage;

The hydraulic control means may include a first pressure control valve and a first solenoid valve for controlling the hydraulic pressure supplied to the rear clutch operating in the "D" ranges 1,2 and 3 speeds, and the "D" ranges 2 and 4 speeds. A second pressure control valve and a second solenoid valve for controlling the hydraulic pressure supplied to the actuating side chamber of the kick-down servo, an end clutch operating in the "D" ranges 3 and 4, and a low reverse operating in the "L" range. The third pressure control valve and the third solenoid valve for controlling the hydraulic pressure supplied to the brake, and the second to control the hydraulic pressure of the release side of the kick-down servo when shifting 2 → 3, 3 → 4, 4 → 3, 3 → 2 A fourth pressure control valve and a fourth solenoid valve, and an NR control valve which is controlled by the control pressure of the second solenoid valve and controls the reverse pressure supplied to the low reverse brake when shifting “R”;

The hydraulic pressure distribution means is controlled by receiving hydraulic pressure supplied to the manual valve and the end clutch and selectively supplying the pressure of the second pressure control valve to the operating side chamber and the pressure regulating means of the kick-down servo or the hydraulic pressure supplied from the manual valve. The control switch valve for supplying to the actuating side chamber of the kick-down servo, the hydraulic pressure supplied from the third pressure control valve in the "D" range to the end clutch, and the low reverse brake in the "L" range, The hydraulic pressure supplied from the manual valve at the same time as the mediation of the low control valve for distributing and supplying the reverse pressure to the low reverse brake in the "R" range, and the hydraulic pressure supplied from the second pressure control valve to the operating side chamber of the kick-down servo. And a part of the hydraulic pressure supplied to each friction element as the control pressure, respectively, to enable three-speed hold in case of failure Sun-safe valves; It provides a hydraulic control system of an automatic transmission for a vehicle consisting of.

The manual valve of the shift control means includes the first, second, third and fourth pressure control valves of the hydraulic control means in the "D", "2" and "L" ranges, the control switch valve, the low control valve and the safety function. A flow path for supplying hydraulic pressure to the fail-safe valve to be performed, a flow path for supplying control pressure to the low control valve in the "L" range, and a flow path for supplying reverse pressure in the "R" range are selected to select a plurality of friction elements. Provided is a hydraulic control system for an automatic transmission for a vehicle in which a flow path is formed so that hydraulic pressure can be supplied to any friction element.

In the above, the first pressure control valve of the hydraulic control means is supplied to the rear clutch operating in the "D" range 1,2,3 speed through the second conduit, and at the same time, a flow path for supplying the control pressure of the fail-safe valve is formed. It provides a hydraulic control system of an automatic transmission for a vehicle made.

In the above, the second pressure control valve of the hydraulic control means is operated at the control pressure of the low control valve through the third conduit, and at the same time, the kick operated in the "D" range 2, 4 via the control switch valve and the fail-safe valve. Provided is a hydraulic control system for an automatic transmission for a vehicle in which a flow path supplied to an operating side chamber of a down servo is formed.

In the above, the third pressure control valve of the hydraulic control means is supplied to the low control valve through the fourth conduit and is supplied to the end clutch, the control switch valve and the fail safe valve in the "D" ranges 3 and 4, and in the "L" range, Provided is a hydraulic control system for an automatic transmission for a vehicle in which a flow path supplied to a low reverse brake and a fail safe valve is formed.

In the above, the fourth pressure control valve of the hydraulic control means is supplied to the fail-safe valve through the fifth pipe at the "D" range 1 and 3 speeds, and at the same time a flow path is formed to be provided to the release side chamber of the kick-down servo. Provides a hydraulic control system of the transmission.

In the above, the NR control valve is controlled by the hydraulic pressure supplied from the second pressure control valve in the "R" range, and receives a part of the hydraulic pressure supplied from the manual valve to the front clutch through the reverse pressure first pipe, and receives the reverse pressure second pipe. And a hydraulic control system for an automatic transmission for a vehicle in which a flow path for supplying a low reverse brake and a fail safe valve is formed via a low control valve.

The control switch valve of the hydraulic distribution means is controlled by receiving the hydraulic pressure supplied to the manual valve and the end clutch while the pressure of the second pressure control valve is supplied to the operating side chamber of the kick-down servo in the "D" range 2 speed. , In the "D" ranges 3 and 4, the hydraulic pressure supplied from the manual valve is supplied to the actuating side chamber of the kick-down servo and the flow path of the pressure of the second pressure control valve is supplied to the pressure regulating means. Provide hydraulic control system of automatic transmission.

In the "D" range, the low control valve controlled by receiving control pressure from the second pressure control valve supplies hydraulic pressure supplied from the third pressure control valve at the 3rd and 4th speeds to the end clutch and the fail safe valve. In the "L" range, the hydraulic pressure is supplied from the manual valve to be controlled and supplied to the low reverse brake, and in the "R" range, a vehicle is formed in which a flow path for supplying the hydraulic pressure supplied from the second reverse pressure pipeline to the low reverse brake is formed. Provides a hydraulic control system of the transmission.

The fail-safe valve is a part of the hydraulic pressure supplied from the rear clutch, the actuating side chamber of the kick-down servo, the end clutch, the Rio reverse brake, and the hydraulic pressure supplied from the manual valve in the "D" range at the control pressure. While providing a hydraulic pressure control system for a vehicle automatic transmission, in which a flow path is formed to discharge the hydraulic pressure supplied to the release side chamber of the kick-down servo when the transmission control unit is broken and to be held at three speeds.

Hereinafter, with reference to the accompanying drawings, preferred embodiments of the present invention will be described in detail.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows the hydraulic control system by this invention, and shows the state when a select lever is in the neutral (N) range.

A torque converter (2) for receiving torque from the engine and converting the torque to the transmission side, and an oil pump (4) for generating oil required for lubrication and control for the torque converter and the shift stage, and the oil pump (4). The hydraulic pressure generated from the pump 4 is branched and supplied to the pressure regulating and damper clutch control means, the decompression means and the shift control means.

The pressure regulating and damper clutch control means includes a pressure regulating valve 8 for regulating the hydraulic pressure fed from the oil pump 4 to a constant pressure, and the hydraulic pressure supplied from the pressure regulating valve 8 for torque converter and lubrication. Torque converter control valve 10 is constantly adjusted, and the damper clutch control valve 12 for controlling the damper clutch to increase the power transmission efficiency of the torque converter.

The decompression means is composed of a reducing valve 14 to maintain a pressure lower than the line pressure at all times, a portion of the hydraulic pressure reduced through the reducing valve 14 of the control of the damper clutch control valve 12 It is supplied with pressure.

The first and second pressure reducing valves 16, 18, 20 and 22 which form a hydraulic pressure which can be used as a shift stage control pressure, and a part for controlling them independently, respectively Hydraulics consisting of 1, 2, 3, and 4 solenoid valves (S1), S2, S3, and S4, and NR control valves 24 that reduce shift shock when switching modes from the "N" range to the "R" range. Supplied to the control means.

The shift control means is composed of a manual valve 26 for switching the flow path while operating in conjunction with the position of the selector lever in the driver's seat, the manual valve 26 of the "D", "2", "L" range The first, second, third and fourth pressure control valves 16, 18, 20 and 22 of the hydraulic pressure control means, the control switch valve 28, the low control valve 30, and fail to perform safety functions. A flow path for supplying hydraulic pressure to the safety valve 32, a flow path for supplying control pressure to the low control valve 30 in the "L" range, and a flow path for supplying reverse pressure in the "R" range are formed to provide a plurality of frictions. The flow path is converted so that the hydraulic pressure can be supplied to any of the friction elements selected from the elements C1, C2, C3, C4 and C5.

Looking at the configuration of the flow path from the manual valve 26 to each valve in order to supply the hydraulic pressure as described above, the first, second on the first pipe (D1) to which the forward pressure of the manual valve 26 is supplied in the "D" range , 3, 4 pressure control valves 16, 18, 20, 22, control switch valves 28, and fail-safe valves 32 are disposed.

The hydraulic pressure controlled by the first pressure control valve 16 is supplied to the rear clutch C1 operating in the "D" range 1,2,3 speed through the second pipeline D2, and at the same time, the fail-safe valve 32 Has a flow path supplied at a control pressure.

The hydraulic pressure controlled by the second pressure control valve 18 operates at the control pressure of the low control valve 30 through the third conduit D3 and simultaneously controls the control switch valve 28 and the fail safe valve 32. It has a flow path supplied to the operating side chamber h1 of the kick-down servo C2 operating in the "D" ranges 2 and 4 via.

The hydraulic pressure controlled by the third pressure control valve 20 is supplied to the low control valve 30 through the fourth conduit D4 and the end clutch C3 and the control switch valve 28 in the “D” ranges 3 and 4. ) And the fail-safe valve 32, and to the low reverse brake C3 and the fail-safe valve 32 in the "L" range.

The hydraulic pressure controlled by the fourth pressure control valve 22 is supplied to the fail-safe valve 32 through the fifth conduit D5 at the “D” range 1 and 3 speed and at the same time, the release side of the kick-down servo S2. It is supplied to the chamber h2.

And the NR control valve 24 is controlled by the hydraulic pressure supplied from the second pressure control valve 18 in the "R" range while the front clutch C5 from the manual valve 26 through the reverse pressure first conduit R1. Receives a portion of the hydraulic pressure supplied to the supply via the reverse pressure second pipeline (R2) and the low control valve 30 has a flow path for supplying to the low reverse brake (C4) and the fail-safe valve (32).

The control switch valve 28 controlled by the hydraulic pressure supplied from the manual valve 26 is controlled by receiving a part of the hydraulic pressure supplied to the end clutch C3 operating in the "D" range 3, 4 speed. The hydraulic pressure supplied from the pressure control valve 18 is supplied to the pressure regulating valve 8 for line pressure control, and the hydraulic pressure supplied from the manual valve 26 is actuated on the operating side chamber h1 of the kick-down servo C2. It has a flow path to supply.

The low control valve 30 which is controlled by receiving the control pressure from the second pressure control valve 18 in the "D" range controls the hydraulic pressure supplied from the third pressure control valve 20 at the 3rd and 4th speeds. C3) and the fail-safe valve 32 and supplied to the low reverse brake C4 while being controlled by receiving hydraulic pressure from the manual valve 26 in the "L" range, and the reverse pressure second in the "R" range. It has a flow path which supplies the hydraulic pressure supplied from the conduit R2 to the low reverse brake C4.

The fail safe valve 32 includes a part of the hydraulic pressure supplied from the rear clutch C1, the actuating side chamber h1 of the kick-down servo C2, the end clutch C3, the Rio reverse brake C4, The hydraulic pressure supplied from the manual valve 26 in the "D" range is supplied as the control pressure, and when the transmission control unit fails, the hydraulic pressure supplied to the release chamber h2 of the kick-down servo C2 is discharged. It has a flow path that can be held at three speeds.

And a first conduit D1 for supplying hydraulic pressure to the first, second, and third pressure control valves 16, 18, and 20, and second, third, for supplying the pressure controlled from these valves to another place. Between the four pipes (D2), (D3), and (D4) are connected to each other via a check valve (CB1), (CB2) (CB3), respectively, the reverse pressure first pipe (1) for supplying hydraulic pressure to the ND control valve (24) A check valve CB4 is disposed between R1) and the reverse pressure second conduit R2 for supplying the pressure controlled from the valve to another place, so that a quick discharge is performed when the operating pressure is discharged.

Looking at the configuration of the valve in detail in order to form such a flow path as shown in Figure 2, first, the valve body of the first pressure regulating valve 16 forming the hydraulic control means is decompressed from the reducing valve (14) A first port 40 which receives hydraulic pressure; A second port 42 which receives hydraulic pressure from the manual valve 26; A third port 44 for supplying the hydraulic pressure supplied to the second port 42 to the rear clutch C1; And a fourth port 46 which receives the control pressure from the first solenoid valve S1.

The valve spool embedded in the valve body may include a first land 48 having a small diameter so as to selectively discharge the hydraulic pressure supplied to the first port 40 to the discharge port; A second land (50) for actuating hydraulic pressure supplied to the first port (40) and selectively opening and closing the second port (42); And a third land 52 which selectively connects the second port 42 and the third port 44 together with the second land 50, and the third land 52 and the valve body. An elastic member 54 is disposed therebetween so that the valve spool is always moved to the right in the drawing.

The first solenoid valve for controlling the first pressure control valve 16 as described above is a well-known three-way valve, and when it is controlled on, the first pressure control valve 16 controls the supply of the reduced pressure hydraulic pressure. When the hydraulic pressure supplied by the pressure is discharged and vice versa, the discharge port is a valve having a flow path capable of supplying the closed and reduced pressure hydraulic pressure to the fourth port 46 of the first pressure control valve 16. Detailed description of the configuration will be omitted.

When the first solenoid valve S1 is turned on by the above configuration, the valve spool of the first pressure regulating valve 16 is moved to the left side in the drawing to close the second port 42, and conversely, the off control is performed. As the ground control pressure is supplied, the valve spool is moved to the right in the drawing to connect the second port 42 and the third port 44 to supply the working pressure to the rear clutch C1.

The second pressure control valve 18 and the second solenoid valve S2 have the same configuration as the first pressure control valve 16 and the first solenoid valve S1, except that the first pressure control valve 16 is used. ), The flow path configuration is different.

That is, the valve body of the second pressure control valve 18 includes a first port 56 which receives the reduced pressure from the reducing valve 14; A second port 58 supplied with hydraulic pressure from the manual valve 26; The kick-down servo C2 is operated through the control switch valve 28 and the fail-safe valve 32 while supplying the hydraulic pressure supplied to the second port 58 to the control pressure of the low control valve 28. A third port 60 for supplying to the side chamber h1; And a fourth port 62 that receives the control pressure from the second solenoid valve S2.

The valve spool embedded in the valve body may include a first land 64 having a small diameter so as to selectively discharge the hydraulic pressure supplied to the first port 56 to the discharge port; A second land 66 which selectively opens and closes the second port 58 while the hydraulic pressure supplied to the first port 56 acts; And a third land 68 that selectively connects the second port 58 and the third port 60 together with the second land 66, and the third land 68 and the valve body. An elastic member 70 is disposed therebetween so that the valve spool is always moved to the right in the drawing.

By the above configuration, when the second solenoid valve S2 is turned on, the valve spool of the second pressure control valve 18 is moved to the left in the drawing to close the second port 58, and conversely, the off control is performed. As the ground control pressure is supplied, the valve spool is moved to the right in the drawing to connect the second port 58 and the third port 60 to supply the control pressure of the low control valve 28 and at the same time the control switch valve 30 The hydraulic pressure is supplied to the operating side chamber h1 of the kick-down servo C2 via the fail-safe valve 32.

The third pressure control valve 20 and the third solenoid valve S3 have the same configuration as the first pressure control valve 16 and the first solenoid valve S1, except that the third pressure control valve 20 is used. ), The flow path configuration is different.

That is, the valve body of the third pressure control valve 20 includes a first port 72 which receives the reduced pressure from the reducing valve 14; A second port 74 supplied with hydraulic pressure from the manual valve 26; A third port (76) for supplying hydraulic pressure supplied to the second port (74) to the end clutch (C3) or the low reverse brake via the low control valve (30); And a fourth port 78 that receives the control pressure from the third solenoid valve S3.

The valve spool embedded in the valve body may include a first land 80 having a small diameter so as to selectively discharge the hydraulic pressure supplied to the first port 72 to the discharge port; A second land 82 which selectively opens and closes the second port 74 while the hydraulic pressure supplied to the first port 72 acts; And a third land 84 that selectively connects the second port 74 and the third port 76 together with the second land 82, wherein the third land 84 and the valve body are formed. An elastic member 86 is disposed therebetween so that the valve spool is always moved to the right in the drawing.

When the third solenoid valve S3 is turned on by the above configuration, the valve spool of the third pressure regulating valve 20 is moved to the left side in the drawing to close the second port 74, and conversely, the off control is performed. As the ground control pressure is supplied, the valve spool is moved to the right in the drawing to connect the second port 74 and the third port 74 to supply the hydraulic pressure supplied from the manual valve 26 to the low control valve 30. do.

The fourth pressure control valve 22 and the fourth solenoid valve S4 have the same configuration as the first pressure control valve 16 and the first solenoid valve S1, except that the fourth pressure control valve 22 is used. ), The flow path configuration is different.

That is, the valve body of the fourth pressure regulating valve 22 includes a first port 88 which receives the reduced pressure from the reducing valve 14; A second port 90 which receives hydraulic pressure from the manual valve 26; A third port 92 for supplying the hydraulic pressure supplied to the second port 90 to the release side chamber h2 of the kick-down servo C3; And a fourth port 94 that receives the control pressure from the fourth solenoid valve S4.

The valve spool embedded in the valve body may include a first land 96 having a small diameter so as to selectively discharge the hydraulic pressure supplied to the first port 88 to the discharge port; A second land (98) for selectively opening and closing the second port (90) while the hydraulic pressure supplied to the first port (88) acts; And a third land 100 for selectively connecting the second port 90 and the third port 92 together with the second land 98, and the third land 100 and the valve body. An elastic member 102 is disposed therebetween so that the valve spool is always moved to the right in the drawing.

When the fourth solenoid valve S4 is turned on by the above configuration, the valve spool of the fourth pressure regulating valve 22 is moved to the left side in the drawing to close the second port 90, and conversely, the off control is performed. As the ground control pressure is supplied, the valve spool is moved to the right in the drawing to connect the second port 90 and the third port 92 to release the kick-down servo C2 from the hydraulic pressure supplied from the manual valve 26. Supply to the side chamber (h2).

The N-R control valve 24 controlled by the control pressure of the second solenoid valve S2 includes: a first port 104 supplied with a control pressure of the second solenoid valve S2 to a valve body; A second port 106 supplied with hydraulic pressure from the manual valve 26; A third port 108 is formed to supply the hydraulic pressure supplied to the second port 106 to the low reverse brake C4 through the low control valve 30.

The valve spool embedded in the valve body may include a first land 110 through which hydraulic pressure supplied to the first port 104 acts; Optionally comprising a second land 112 connecting the second port 106 and the third port 108, an elastic member 114 is installed between the second land 112 and the valve body thereof. If the control pressure is not supplied, the valve spool is always moved to the right side of the drawing.

3 is a view for explaining the configuration of the distribution means applied to the present invention, the valve body of the control switch valve 28, the first and second ports 116, 118 receiving hydraulic pressure from the manual valve 26 And a third port 120 receiving hydraulic pressure from the second pressure control valve 18, and a hydraulic pressure supplied from the second and third ports 118 and 120 selectively via the fail safe valve 122. Fourth port 122 for supplying to the actuation side chamber h1 of the kick-down servo C2 and a fifth port for supplying hydraulic pressure supplied to the third port 120 to the pressure regulating valve 8. 124 and a sixth port 126 that receives a part of the hydraulic pressure supplied to the end clutch C3 at a control pressure.

In addition, a valve spool embedded in the valve body may include a first diameter 128 having a smaller diameter, and a larger diameter than the first land 128, in which the hydraulic pressure supplied to the first port 116 acts. The second land 130 which selectively connects the hydraulic pressure supplied to the 118 with the fourth port 122 and the hydraulic pressure supplied to the third port 120 may be selectively connected to the fourth port 122 or the fourth port 122. And a third land 132 connecting to the fifth port 124 and a fourth land 134 to which the hydraulic pressure supplied to the sixth port 126 is applied.

Accordingly, while the hydraulic pressure is supplied from the manual valve 26 in the "D" and "2" ranges, a part of the hydraulic pressure supplied to the end clutch C3 at the third and fourth speeds is supplied to the pressure regulating valve 8 to supply the line pressure. Allow adjustments.

In addition, the row control valve 30 may include a first port 136 that receives hydraulic pressure from the third pressure regulating valve 20, and a second port 138 that receives hydraulic pressure from the manual valve 26 in the “L” range. ), A third port 140 receiving hydraulic pressure from the second pressure control valve 18, a fourth port 142 receiving hydraulic pressure from the NR control valve, and the first port 136. ), The hydraulic pressure supplied to the end clutch C3, the control switch valve 28 and the fail-safe valve 32, the fifth port 144, and the fourth port 142 are supplied. And a sixth port 146 for supplying the reverse brake C4 and the fail safe valve 32.

The valve spool embedded in the valve body acts on the control pressure supplied to the second port 138 and selectively blocks the fourth port 142 and the first port 136. The second land 150 to selectively connect the fifth and sixth ports 144 and 146, and the third land 152 to selectively connect the fifth port 144 to the discharge port EX. The elastic member 154 is installed between the third land 150 and the valve body.

Accordingly, in the "D" ranges 3 and 4, the hydraulic pressure of the third pressure control valve 20 is supplied to the end clutch C3, while the "L" range is supplied to the low reverse brake C4, and the "R" range. In the above, the hydraulic pressure supplied from the NR control valve 24 is supplied to the low reverse brake C4.

The fail-safe valve 32 as a safety means includes a first port 156 supplied with hydraulic pressure from the manual valve 26 and a second port 158 supplied with hydraulic pressure from the low control switch valve 28. And a third port 160 to receive a part of the hydraulic pressure supplied to the end clutch C3, a fourth port 162 to receive a part of the hydraulic pressure supplied to the low reverse brake C4, and a rear clutch ( A fifth port 164 to receive a part of the hydraulic pressure supplied to C1), a sixth port 166 to receive a part of the hydraulic pressure supplied to the release chamber h2 of the kick-down servo C2, And a seventh port 168 for supplying hydraulic pressure supplied to the second port 158 to the operating side chamber h1 of the kick-down servo C2.

The valve spool embedded in the valve body includes a first land 170 acting on the hydraulic pressure supplied to the fourth port 162 and a second land 172 acting on the hydraulic pressure supplied to the fifth port 164. And a third land 174 acting on the hydraulic pressure supplied to the third port 160, and selectively connecting the second port 158 and the seventh port 168 to the seventh port 168. A fourth land 176 selectively connected to the discharge port EX, a fifth land 178 connecting the second port 158 and the seventh port 168 together with the fourth land 176; And a sixth land 180 acting on the hydraulic pressure supplied to the first port 156, and a seventh land 182 acting on the hydraulic pressure supplied to the sixth port 166.

Due to this configuration, the fail-safe valve 32 maintains a state in which the valve spool is automatically moved to the right side when a failure occurs during the 1,2-speed and 4-speed running, while the hydraulic pressure of the operating side chamber h1 of the kick-down servo C2 is maintained. By discharging it to be fixed at three speeds, it is possible to ensure stability while driving.

In the figure, reference numeral S5 denotes a fifth solenoid valve for controlling the damper clutch control valve 12 to activate or deactivate the damper clutch.

In the hydraulic control system of the present invention as described above, as shown in FIG. After the pressure is reduced through 14, the damper clutch control valve 12 and the first, second, third and fourth pressure control valves 16, 18, 20 and 22 are respectively supplied.

At this time, the first, second, third, and fourth solenoid valves S1, S2, S3, and S4 controlled by the transmission control unit are maintained in the off state.

And in the forward 1 speed of the running (D) range, as shown in FIG. 4, the hydraulic pressure supplied to the manual valve 26 is first, second, third, and fourth pressure control valves 16 ( 18, 20 and 22, wherein the first solenoid valve S1 of the hydraulic control means is controlled to be in an off state, and the second, third and fourth solenoid valves S2, S3 and S4 are on. Controlled by state.

Then, the valve spool of the second, third and fourth pressure control valves 18, 20 and 22 is turned to the left in the drawing by the on control of the second, third and fourth solenoid valves S2, S3 and S4. As the bar is moved, the hydraulic pressure supplied thereto becomes a standby state by blocking the flow path, and the hydraulic pressure supplied to the first pressure control valve 16 is supplied to the rear clutch C1 by forming a flow path due to the right movement of the valve spool. The first speed shift is made.

In this first speed control state, when the vehicle speed is increased and the opening ratio of the throttle valve is increased, the speed is changed to second speed. In this case, as shown in FIG. 5, the transmission control unit turns off the first solenoid valve S1. Duty control of the second solenoid valve S2, which was controlled in the ON state in the state of fixed control, by means of the control switch valve 28 and the fail-safe valve 32. It is supplied to the actuating side chamber h1 of the kick-down servo C2 and shifts at 2 speeds.

If the opening speed of the throttle valve is increased while the vehicle speed is further increased in the two-speed control state as described above, the first and second solenoid valves S1 of the hydraulic control means are fixedly controlled to the off state in the second speed state. In the third, fourth solenoid valve (S3) (S4) is a duty control for the operating pressure supply is made.

Then, as shown in FIG. 6, the control pressure is supplied to the release side chamber h2 and the end clutch C3 of the kick-down servo C2 by the duty control of the third and fourth solenoid valves S3 and S4. As you start, the gear shifts slowly.

In this shifting process, as shown in FIG. 7, the duty-controlled third and fourth solenoid valves S3 and S4 are controlled off so that the release side chamber h2 and the end clutch of the kick-down servo C2 are controlled. The control pressure supplied to C3) is converted to the line pressure to complete the shift to the third speed.

Looking at the state of the hydraulic pressure supplied to the friction element during 2 → 3 shift as described above, as shown in Figure 8, the operating pressure of the operating side chamber (h1) of the rear clutch (C1) and the kick-down servo (C2) is fixed In the state, the control pressure of the release side chamber h2 of the kick-down servo C2 is first increased by the duty control of the fourth solenoid valve S4 to release and control the kick-down servo C2. The control pressure of the end clutch C3 gradually rises by the duty control of the solenoid valve S3.

And at the third speed thereof, a part of the line pressure supplied to the end clutch C3 is operated at the control pressure of the control switch valve 28, so that the valve spool thereof is moved to the left in the drawing so that a part of the hydraulic pressure thereof is the pressure regulating valve 8 ) To adjust the line pressure.

The line pressure adjustment as described above substantially lowers the line pressure, which is to reduce the driving loss of the oil pump so as to obtain an effect of improving fuel efficiency at high speed.

When the opening degree of the throttle valve is increased while the vehicle speed is further increased in the third speed control state as described above, in the third speed state, in the state in which the third solenoid valve S3 of the shift control means is fixedly controlled in the off state, The second solenoid valve S2 is controlled to be in an on state to cut off the hydraulic pressure supplied to the pressure regulating valve 8, and the first and fourth solenoid valves S1 and S4 are subjected to duty control for release.

Then, as shown in FIG. 9, the hydraulic pressure supplied to the rear clutch C1 by the release duty control of the first solenoid valve S1 is gradually released through the first pressure control valve 16, and the fourth solenoid valve S4. The hydraulic pressure supplied to the release side chamber h2 of the kick-down servo C2 is gradually discharged through the fourth pressure control valve 22 by the release duty control.

In this shifting process, as shown in FIG. 10, the duty-controlled first and fourth solenoid valves S1 and S1 are turned on, and the second solenoid valve S2 is turned off while being controlled with the rear clutch C1. The hydraulic pressure supplied to the release side chamber h2 of the kick-down servo C2 is completely discharged, and the line pressure via the second pressure control valve 18 is again supplied through the control switch valve 28. 8), the line pressure is adjusted and the shift to the fourth speed is completed.

Looking at the change in the hydraulic pressure during the 3 → 4 shift as described above, as shown in Figure 11, the first solenoid valve in the operating pressure of the operating side chamber (h1) of the end clutch (C3) and the kick-down servo (C2) is fixed (S1) The hydraulic pressure of the rear clutch C1 is abruptly discharged by the release duty control, and the control pressure of the release chamber h2 of the kick-down servo C2 is controlled by the duty control of the fourth solenoid valve S4. It is discharged rapidly at the initial stage, and then it is rapidly discharged while maintaining the current pressure until the middle of the gearbox.

FIG. 12 is a view illustrating a 4 → 3 shifting process. In the fourth speed state, the third solenoid valve S3 of the shift control means is fixed to the off state, and the second solenoid valve S2 is It is controlled to the on state to shut off the hydraulic pressure supplied to the pressure regulating valve (8), the first, fourth solenoid valve (S1) (S4) is a duty control for the supply is made.

Then, the control pressure is supplied to the rear clutch C1 by the duty control of the first solenoid valve S1, and the release side chamber h2 of the kick-down servo C2 by the duty control of the fourth solenoid valve S4. As the control pressure is supplied to), the shift to the third speed is made slowly.

In the shifting process, the first and fourth solenoid valves S1 and S4 which are duty controlled at the end of the shifting are controlled off as shown in FIG. 7 to release the chamber h2 and the end clutch C3 of the kick-down servo C2. The line pressure is supplied, and the line pressure is adjusted while the second solenoid valve S2 is controlled off to complete the shift to the third speed.

Looking at the state of the hydraulic pressure supplied to the friction element during the 4 → 3 shift as described above, as shown in Figure 13, the operating pressure of the operating side chamber (h1) of the end clutch (C3) and the kick-down servo (C2) is fixed In the state, the control pressure of the release side chamber h2 of the kick-down servo C2 is first increased by the duty control of the fourth solenoid valve S4 to release and control the kick-down servo C2 and simultaneously release the first solenoid. Due to the duty control of the valve S1, the control pressure of the end clutch C1 gradually rises, thereby shifting.

FIG. 14 is a view illustrating a 3 → 2 shifting process, wherein the first and second solenoid valves S1 and S2 of the shift control means are fixed to the off state in the third speed state. 4 solenoid valve (S3) (S4) is made to the duty control for the operating pressure release.

Then, when the control pressure is supplied to the release side chamber h2 of the end clutch C3 and the kick-down servo C2 by the duty control of the third and fourth solenoid valves S3 and S4, 4 As the discharge is made through the pressure control valves 20 and 22, the shift to the second speed is made slowly.

In this shifting process, the third and fourth solenoid valves S1 and S4 that are duty controlled at the end of the shifting are turned on as shown in FIG. 5 to release the chamber h2 and the end clutch C3 of the kick-down servo C2. The operating pressure that was supplied to) is completely discharged to complete the shift to 2 speed.

Looking at the change in hydraulic pressure during the 3 → 2 shift as described above, as shown in Figure 16, the third solenoid valve in a state in which the operating pressure of the operating side chamber (h1) of the rear clutch (C1) and the kick-down servo (C2) is fixed (S3) The hydraulic pressure of the end clutch C3 is suddenly discharged by the release duty control, and the control pressure of the release side chamber h2 of the kick-down servo C2 is controlled by the duty control of the fourth solenoid valve S4. It is discharged rapidly at the initial stage, and then it is rapidly discharged while maintaining the current pressure until the middle of the gearbox.

FIG. 16 illustrates a state in which the transmission control unit is held at three speeds while the vehicle is in a broken state. In this case, the first, second, third, and fourth solenoid valves S1 (S2) may be caused by a failure of the transmission control unit. (S3) (S4) is left in the off state.

Then, all of the first, second, third and fourth pressure control valves 16, 18, 20, and 22 form a flow path, and the hydraulic pressure supplied from the manual valve 26 causes three frictions through these valves. It is supplied to the elements C1, C2, and C3, in which the fail-safe valve 32 moves the valve spool to the right in the drawing due to the difference in the area of each land acting on the hydraulic pressure supplied thereto. The hydraulic pressure supplied from the control valve 18 is cut off, the operating pressure of the kick-down servo C2 is released, and it is held in the third speed state in which the rear clutch C1 and the end clutch C3 operate, thereby making it emergency. It will be possible to operate.

FIG. 17 is a hydraulic flow chart in the “L” range, in which the first and third solenoid valves S1 and S3 are controlled off in the transmission control unit, and the second and fourth solenoid valves S2 and S4 are controlled. To control.

Then, the line pressure is directly supplied from the manual valve 26 to the low control valve 30 to move the valve spool to the right in the drawing. The pressure of the third pressure control valve 18 is transferred to the low reverse brake C4. It is supplied, the pressure of the first pressure regulating valve 16 is supplied to the rear clutch (C4) while the shift is made.

18 is a flow chart of the hydraulic pressure in the reverse shift stage, in which reverse pressure is supplied from the manual valve 26 to the front clutch C5 and the NR control valve 24, where the NR control valve 24 is the second solenoid. The valve spool is moved to the left side of the drawing in accordance with the off-control of the valve S2 to form a flow path so that the hydraulic pressure supplied from the manual valve 26 is moved to the left in the drawing by the elastic force of the elastic member 154. The reverse shift is performed by supplying the low reverse brake C4 through the moved low control valve 30.

As described above, the hydraulic control system of the present invention controls the hydraulic pressure of the release side while the operating side hydraulic pressure of the kick-down servo is fixed at the shift of 2 → 3, 3 → 4, 4 → 3, 3 → 2. By shifting, it is very easy to improve the shifting feeling.

In addition, the frictional elements are controlled independently by pressure regulating valves, respectively, thereby improving shift response.

Claims (23)

Pressure control means for regulating hydraulic pressure generated from oil pump, damper clutch control means for damper clutch operation of torque converter, shift control means for forming shift mode, shifting feeling and responsiveness for smooth shift mode formation during shifting And hydraulic distribution means for supplying and distributing a proper hydraulic pressure to a plurality of friction elements acting as input and reaction force elements at each shift stage. The hydraulic control means is a first pressure control means for controlling the hydraulic pressure supplied to the rear clutch while selectively operating in the "D" range, and is supplied to the operating side chamber of the kick-down servo while selectively operating the "D" range. Second pressure control means for controlling the hydraulic pressure, third pressure control means for selectively operating in the "D" range, controlling the end clutch and controlling the hydraulic pressure supplied to the low reverse brake in the "L" range, and a kick The fourth pressure control means for controlling the hydraulic pressure of the release side of the kick-down servo during downshifting, and the reverse pressure supplied to the low reverse brake during the "R" shift while being controlled by the control pressure of the second pressure control means An NR control valve; The hydraulic pressure distribution means is controlled by receiving hydraulic pressure supplied to the manual valve and the end clutch and selectively supplying the pressure of the second pressure control means to the operating side chamber and the pressure regulating means of the kick-down servo or the hydraulic pressure supplied from the manual valve. The control switch valve for supplying to the actuating side chamber of the kick-down servo, the hydraulic pressure supplied from the third pressure control means in the "D" range to the end clutch, and the low reverse brake in the "L" range, A low control valve for distributing and supplying reverse pressure to the low reverse brake in the "R" range; In case of failure while intermediating the hydraulic pressure supplied from the second pressure regulating valve to the actuating side chamber of the kick-down servo and using a part of the hydraulic pressure supplied from the manual valve and the hydraulic pressure supplied to each friction element as control pressure, respectively. A fail-safe valve for enabling three speed hold; Hydraulic control system of an automatic transmission for a vehicle, characterized in that consisting of. The method of claim 1, wherein the manual valve of the shift control means is the first, second, third, fourth pressure control means of the hydraulic control means in the range of "D", "2", "L", control switch valve, low control valve, A flow path for supplying hydraulic pressure to a fail-safe valve that performs a safety function, a flow path for supplying control pressure to the low control valve in the "L" range, and a flow path for supplying reverse pressure in the "R" range is formed. A hydraulic control system for an automatic transmission for a vehicle, characterized in that a flow path is formed so that hydraulic pressure can be supplied to any selected friction element among the elements. The vehicle according to claim 1, wherein the first pressure control means comprises a first pressure control valve and a first solenoid valve for controlling the hydraulic pressure supplied to the rear clutch operating in the "D" range 1,2,3 speed. Hydraulic control system of automatic transmission. The method of claim 3, wherein the first pressure control valve is supplied to the rear clutch operating in the "D" range 1, 2, 3 speed through the second conduit, and at the same time a flow path for supplying the control pressure of the fail-safe valve is formed. Hydraulic control system of a vehicle automatic transmission. The method of claim 1, wherein the second pressure control means comprises a second pressure control valve and a second solenoid valve for controlling the hydraulic pressure supplied to the operating side chamber of the kick-down servo operating in the "D" range 2, 4 speed. A hydraulic control system for an automatic transmission for a vehicle. The kick-down valve of claim 5, wherein the second pressure control valve operates at the control pressure of the low control valve through the third conduit and simultaneously operates in the “D” ranges 2 and 4 via the control switch valve and the fail-safe valve. A hydraulic control system for an automatic transmission for a vehicle, characterized in that a flow path is provided to the operating side chamber of the servo. The third pressure control valve of claim 1, wherein the third pressure control means includes: a third pressure control valve and a third pressure control valve for controlling the hydraulic pressure supplied to the end clutch operating in the “D” ranges 3 and 4 and the low reverse brake operating in the “L” range. Hydraulic control system of an automatic transmission for a vehicle, characterized by a solenoid valve. The method of claim 7, wherein the third pressure control valve is supplied to the low control valve through the fourth conduit to the end clutch and control switch valve and the fail-safe valve in the "D" ranges 3 and 4, and low in the "L" range. A hydraulic control system for an automatic transmission for a vehicle, characterized in that a flow path is provided to the reverse brake and the fail-safe valve. The fourth pressure control valve and the fourth solenoid of claim 1, wherein the fourth pressure control means controls the hydraulic pressure of the release side of the kick-down servo when the shift speed is 2 → 3, 3 → 4, 4 → 3, 3 → 2. Hydraulic control system of an automatic transmission for a vehicle, characterized in that consisting of a valve. The method of claim 9, wherein the fourth pressure control valve is supplied to the fail-safe valve through the fifth conduit at the "D" range 1, 3 speed, and at the same time, the flow path is provided to the release side chamber of the kick-down servo Hydraulic control system of automatic transmission for vehicles. The reverse pressure according to claim 1, wherein the NR control valve receives a part of the hydraulic pressure supplied from the manual valve to the front clutch through the reverse pressure first line while being controlled by the hydraulic pressure supplied from the second pressure control valve in the "R" range. And a flow path for supplying the low reverse brake and the fail safe valve via the second conduit and the low control valve is formed. The control switch valve of the hydraulic distribution means is controlled by receiving hydraulic pressure supplied to the manual valve and the end clutch, while the pressure of the second pressure control valve is moved to the operating side chamber of the kick-down servo in the "D" range 2 speed. In the "D" ranges 3 and 4, the hydraulic pressure supplied from the manual valve is supplied to the operating side chamber of the kick-down servo, and the pressure of the second pressure regulating valve is supplied to the pressure regulating means. Hydraulic control system of an automatic transmission for a vehicle, characterized in that formed. The low control valve of claim 1, wherein the row control valve controlled by receiving a control pressure from the second pressure control means in the “D” range includes an end clutch and a fail-safe valve supplied from the third pressure control valve at speeds 3 and 4. In the "L" range, the hydraulic pressure is supplied from the manual valve to be controlled and supplied to the low reverse brake. In the "R" range, a flow path for supplying the hydraulic pressure supplied from the second reverse pressure pipeline to the low reverse brake is formed. Hydraulic control system of an automatic transmission for a vehicle, characterized in that. 2. The fail-safe valve of claim 1, wherein the fail-safe valve includes a part of the hydraulic pressure supplied from the rear clutch, the actuating side chamber of the kick-down servo, the end clutch, the Rio reverse brake, and the hydraulic pressure supplied from the manual valve in the "D" range. A hydraulic control system for an automatic transmission for a vehicle, characterized in that a flow path is formed to be held in three speeds by discharging the hydraulic pressure supplied to the release side chamber of the kick-down servo when the transmission control unit breaks down. The method according to claim 4 or 6 or 8, respectively, between the first conduit for supplying hydraulic pressure to the first, second, third pressure control valves and the second, third, fourth conduit for supplying the pressure controlled from these valves, respectively. The valves are connected to each other through a check valve, and the check valve is disposed between the reverse pressure first pipe for supplying hydraulic pressure to the ND control valve and the reverse pressure second pipe for supplying the controlled pressure from the valve. Hydraulic control system of a vehicle automatic transmission characterized in that. The method of claim 4, wherein the first pressure control valve comprises: a first port for receiving the reduced pressure from the reducing valve; A second port for receiving hydraulic pressure from the manual valve; A third port for supplying hydraulic pressure supplied to the second port to the rear clutch; A valve body having a fourth port for receiving a control pressure from the first solenoid valve; A first land having a small diameter so as to selectively discharge the hydraulic pressure supplied to the first port to a discharge port; A second land to which the hydraulic pressure supplied to the first port operates and selectively opens and closes the second port; A valve spool including a second land selectively communicating with the second port and a third port together with the second land, wherein an elastic member is disposed between the third land and the valve body; Hydraulic control system of a vehicle automatic transmission, characterized in that comprises a. The method of claim 6, wherein the second pressure control valve comprises: a first port for receiving the reduced pressure from the reducing valve; A second port for receiving hydraulic pressure from the manual valve; A third port which supplies the hydraulic pressure supplied to the second port to the control pressure of the low control valve and simultaneously supplies the hydraulic pressure to the operating side chamber of the kick-down servo via the control switch valve and the fail-safe valve; A valve body having a fourth port for receiving a control pressure from the second solenoid valve; A first land having a small diameter so as to selectively discharge the hydraulic pressure supplied to the first port to a discharge port; A second land for selectively opening and closing a second port at the same time the hydraulic pressure supplied to the first port is operated; A valve spool including a third land selectively connecting the second port and a third port together with the second land, wherein an elastic member is disposed between the third land and the valve body; Hydraulic control system of a vehicle automatic transmission, characterized in that comprises a. The method of claim 8, wherein the third pressure control valve comprises: a first port for receiving the reduced pressure from the reducing valve; A second port for receiving hydraulic pressure from the manual valve; A third port for supplying hydraulic pressure supplied to the second port to an end clutch or a low reverse brake via a low control valve; A valve body having a fourth port for receiving a control pressure from the third solenoid valve; A first land having a small diameter so as to selectively discharge the hydraulic pressure supplied to the first port to a discharge port; A second land for selectively opening and closing the second port while acting on the hydraulic pressure supplied to the first port; A valve spool including a third land selectively connecting the second port and a third port together with the second land, wherein an elastic member is disposed between the third land and the valve body; Hydraulic control system of a vehicle automatic transmission, characterized in that comprises a. The method of claim 10, wherein the fourth pressure control valve comprises: a first port for receiving the reduced pressure from the reducing valve; A second port for receiving hydraulic pressure from the manual valve; A third port for supplying hydraulic pressure supplied to the second port to a release side chamber of a kick down servo; A valve body having a fourth port for receiving a control pressure from the fourth solenoid valve; A first land having a small diameter so as to selectively discharge the hydraulic pressure supplied to the first port to a discharge port; A second land for selectively opening and closing the second port while acting on the hydraulic pressure supplied to the first port; A valve spool including a second land selectively communicating with the second port and a third port together with the second land, wherein an elastic member is disposed between the third land and the valve body; Hydraulic control system of a vehicle automatic transmission, characterized in that comprises a. The N-R control valve according to claim 1, further comprising: a first port supplied with control pressure from the second pressure control means; A second port for receiving hydraulic pressure from the manual valve; A valve body having a third port configured to supply hydraulic pressure supplied to the second port to a low reverse brake through a low control valve; A first land on which hydraulic pressure supplied to the first port acts; A valve spool selectively including a second land connecting the second port and the third port, wherein an elastic member is supported between the second land and the valve body; Hydraulic control system of a vehicle automatic transmission, characterized in that comprises a. The control switch valve of claim 1, wherein the control switch valve selects first and second ports supplied with hydraulic pressure from a manual valve, a third port supplied with hydraulic pressure from a second pressure control means, and hydraulic pressure supplied from the second and third ports. The fourth port for supplying to the actuation side chamber of the kick-down servo via the fail-safe valve, the fifth port for supplying the hydraulic pressure supplied to the third port to the pressure regulating valve, and the hydraulic pressure supplied to the end clutch. A valve body having a sixth port supplied with a part of the control pressure; A first land having a small diameter acting on the hydraulic pressure supplied to the first port, a second land having a larger diameter than the first land and selectively connecting the hydraulic pressure supplied to the second port with a fourth port; A valve spool having a third land for selectively connecting the hydraulic pressure supplied to the third port with a fourth or fifth port, and a fourth land for acting on the hydraulic pressure supplied to the sixth port; Hydraulic control system of a vehicle automatic transmission, characterized in that comprises a. The low control valve of claim 1, wherein the row control valve includes a first port supplied with hydraulic pressure from the third pressure regulating means, a second port supplied with hydraulic pressure from a manual valve at an “L” range, and a hydraulic pressure from the second pressure control means. A third port receiving control pressure, a fourth port receiving hydraulic pressure from the NR control valve, and a fifth port supplying hydraulic pressure supplied to the first port to the end clutch, the control switch valve, and the fail safe valve. And a valve body having a sixth port for supplying the hydraulic pressure supplied to the fourth port to the low reverse brake and the fail safe valve. A first land acting on the control pressure supplied to the second port and selectively blocking the fourth port, a second land selectively connecting the first port to the fifth and sixth ports, and optionally a fifth A valve spool including a third land connecting the port to the discharge port, wherein an elastic member is installed between the third land and the valve body; Hydraulic control system of a vehicle automatic transmission, characterized in that comprises a. The failsafe valve of claim 1, wherein the fail-safe valve includes: a first port supplied with hydraulic pressure from a manual valve, a second port supplied with hydraulic pressure from a low control switch valve, and a third port supplied with a part of hydraulic pressure supplied to an end clutch; The fourth port receives a part of the hydraulic pressure supplied to the low reverse brake, the fifth port receives a part of the hydraulic pressure supplied to the rear clutch, and a part of the hydraulic pressure supplied to the release chamber of the kick-down servo. A valve body having a sixth port for receiving and a seventh port for supplying hydraulic pressure supplied to the second port to an operating side chamber of a kick-down servo; A first land acting on the hydraulic pressure supplied to the fourth port, a second land acting on the hydraulic pressure supplied to the fifth port, a third land acting on the hydraulic pressure supplied to the third port, and a second port; A fourth land for selectively connecting a seventh port and a seventh port for selectively connecting a seventh port to an outlet port, a fifth land for connecting a second port and a seventh port together with the fourth land, and a first land; A valve spool having a sixth land acting on the hydraulic pressure supplied to the port, and a seventh land acting on the hydraulic pressure supplied to the sixth port; Hydraulic control system of a vehicle automatic transmission, characterized in that comprises a.

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