KR19980027188A - Automotive Transmission Hydraulic Control System - Google Patents

Abstract

In the hydraulic control system applied to the automatic transmission for a vehicle, the shift is made by electronic control during 2 → 3, 4 → 3 shifting to prevent the occurrence of a temporary neutral state in the shifting process, in particular, 3, 4 speed To provide a hydraulic control system capable of simultaneously controlling friction elements and line pressures operating in the system; Pressure regulating means for regulating the hydraulic pressure generated from the oil pump; Manual and automatic control means for forming a shift mode; Hydraulic control means for adjusting the shifting feeling and responsiveness to form a smooth shifting mode during shifting; Damper clutch control means for operating a damper clutch of the torque converter; Hydraulic distribution means for supplying and distributing the appropriate hydraulic pressure to each friction element acting as an input and reaction force element at each shift stage; The above-mentioned hydraulic pressure distribution means is controlled by the second speed pressure of the shift control valve of the automatic shift control means so that the control pressure controlled by the first pressure control valve is supplied to the friction element acting at the second speed, and the friction operated during the reverse operation. A 1-2 shift valve constituting a flow path so as to be supplied to the urea; The hydraulic pressure supplied from the 1-2 shift valve and the hydraulic pressure supplied from the 3-4 shift valve in the reverse shift stage are selectively controlled by the 3 and 4 speed pressures supplied to the left and right sides at the 3rd and 4th speed shift stages. A 2-3 / 4-3 shift valve for supplying to the friction element acting on the reverse shift stage; It is controlled by a solenoid valve that controls the hydraulic pressure supplied from the 1st speed line, and has a function to supply or release the operating pressure of the friction element acting as an input element of the 3rd and 4th speed stages, and to supply the friction element thereof. A control switch valve having a function of controlling a line pressure by supplying a part of the hydraulic pressure to a pressure control valve of the pressure adjusting means; The hydraulic pressure supplied from the second pressure control valve while being controlled by the four-speed line pressure is supplied to the friction elements operating in 1,2,3, and of course, the hydraulic pressure supplied to the friction elements is directly discharged in the 3 → 4 shift. In the 3 → 4, 3 → 2 shift, the hydraulic pressure supplied to the friction element acting at the 3rd speed and the reverse shift stage is supplied through the manual valve via the 2-3 / 4-3 shift valve and the 1st reverse control line. A 3-4 shift valve which performs a function of causing a discharge; It provides a hydraulic control system of a vehicle automatic transmission comprising a.

Description

Automotive Transmission Hydraulic Control System

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 multistage 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 the hydraulic control system is a hydraulic pressure generated from the oil pump, the hydraulic control system is a pressure control means for regulating the hydraulic pressure generated from the oil pump, manual and automatic shift control means to form a shift mode, and smooth during shifting Hydraulic control means for adjusting the shifting feeling and responsiveness to form the shift mode, damper clutch control means for the damper clutch operation of the torque converter, and hydraulic distribution means for distributing the appropriate hydraulic supply to each friction element.

Accordingly, such a hydraulic control system is operated by the solenoid valves turned on and off by the transmission control unit and the solenoid valves controlled by the duty so that the hydraulic distribution of the hydraulic distribution means is different and the operation of the friction element is selected so that the gear shift control is performed. Is realized.

However, in the hydraulic control system as described above, when the control is made, the shift is made by the hydraulic control at the time of 2 → 3, 4 → 3 shifting, thereby implying that a temporary neutral state may occur during the shifting process.

In addition, there is no structure that can control the line pressure at high speed gear stages such as 3 and 4 speeds, which implies that the line pressure is unnecessarily formed at high speed stages, resulting in driving loss of the engine. have.

Therefore, the present invention has been invented to solve the above problems, the object of the present invention is to make the shift is made by the electronic control during the shift 2 → 3, 4 → 3 is to create a temporary neutral state in the shifting process In particular, the present invention provides a hydraulic control system for an automatic transmission for a vehicle that can increase power transmission efficiency by controlling friction elements and line pressures operating at three and four speeds at the same time.

In order to realize this, the present invention includes a pressure regulating means for regulating the hydraulic pressure generated from the oil pump; Manual and automatic control means for forming a shift mode; Hydraulic control means for adjusting the shifting feeling and responsiveness to form a smooth shifting mode during shifting; Damper clutch control means for operating a damper clutch of the torque converter; Hydraulic distribution means for supplying and distributing the appropriate hydraulic pressure to each friction element acting as an input and reaction force element at each shift stage; The above-mentioned hydraulic pressure distribution means is controlled by the second speed pressure of the shift control valve of the automatic shift control means so that the control pressure controlled by the first pressure control valve is supplied to the friction element acting at the second speed, and the friction operated during the reverse operation. A 1-2 shift valve constituting a flow path so as to be supplied to the urea; The hydraulic pressure supplied from the 1-2 shift valve and the hydraulic pressure supplied from the 3-4 shift valve in the reverse shift stage are selectively controlled by the 3 and 4 speed pressures supplied to the left and right sides at the 3rd and 4th speed shift stages. A 2-3 / 4-3 shift valve for supplying to the friction element acting on the reverse shift stage; It is controlled by a solenoid valve that controls the hydraulic pressure supplied from the 1st speed line, and has a function to supply or release the operating pressure of the friction element acting as an input element of the 3rd and 4th speed stages, and to supply the friction element thereof. A control switch valve having a function of controlling a line pressure by supplying a part of the hydraulic pressure to a pressure control valve of the pressure adjusting means; The hydraulic pressure supplied from the second pressure control valve while being controlled by the four-speed line pressure is supplied to the friction elements operating in 1,2,3, and of course, the hydraulic pressure supplied to the friction elements is directly discharged in the 3 → 4 shift. In the 3 → 4, 3 → 2 shift, the hydraulic pressure supplied to the friction element acting at the 3rd speed and the reverse shift stage is supplied through the manual valve via the 2-3 / 4-3 shift valve and the 1st reverse control line. A 3-4 shift valve which performs a function of causing a discharge; It provides a hydraulic control system of a vehicle automatic transmission comprising a.

The 1-2 shift valve is a port for receiving a control pressure from the shift control valve in the forward 2, 3, 4 speed shift stage; A port for receiving controlled hydraulic pressure from the first pressure control valve of the hydraulic control means; A port receiving reverse pressure from a manual valve at a reverse shift stage; A port for supplying a control pressure supplied from said first pressure control valve to a friction element acting at second and fourth speeds; A port for supplying the reverse pressure to the fifth friction element acting only on the reverse shift stage; It provides a hydraulic control system of an automatic transmission for a vehicle, characterized in that comprises a.

The control switch valve is a port for receiving the control pressure to the right end from the branch line branched from the first speed line of the manual valve; A port for receiving hydraulic pressure from the third speed pipeline of the shift control valve and supplying the friction element and the pressure control valve operating at the third and fourth speeds; And a port for discharging the release hydraulic pressure through the third speed pipe again when the operating pressure of the third friction element is released; The port receiving the hydraulic pressure from the first speed pipeline provides a hydraulic control system of an automatic transmission for a vehicle that can be controlled by a solenoid valve.

In the above, when the hydraulic pressure of the friction element acting in the third and fourth is released, a check valve is disposed on the pipeline connected to the port for discharging the release hydraulic pressure through the three-speed pipeline. A hydraulic control system for an automatic transmission for a vehicle is provided.

The 3-4 shift valve is a port for receiving hydraulic pressure from the fourth speed line; A port in communication with the second pressure control valve; Two ports in communication with the reverse first control conduit; It provides a hydraulic control system of an automatic transmission for a vehicle, characterized in that it comprises a port for supplying the hydraulic pressure supplied from the second pressure control valve to the first friction element.

In the above, the reverse first control conduit forms a circulation conduit at an end portion thereof, and the conduit conduit forms a conduit therethrough so that one end of the conduit communicates with the 3-4 shift valve, and the other end thereof has 2-3 / 4. It is in communication with a -3 shift valve, and provides a hydraulic control system of an automatic transmission for a vehicle, characterized in that the valve to close the return flow path is arranged in a predetermined position of the circulation pipe to control the release pressure. .

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

Figure 2 is a view showing the hydraulic flow state of the reverse (R) range in the hydraulic control system according to the present invention.

3 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.

4 is a view showing a hydraulic flow state at the time of driving (D) range 1 → 2 upshift in the hydraulic control system according to the present invention.

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

Fig. 6 is a diagram showing a hydraulic flow state at the time of driving (D) range 2 → 3 upshift in the hydraulic control system according to the present invention.

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

8 is a view showing a hydraulic flow state at the time of driving (D) range 3 → 4 upshift in the hydraulic control system according to the present invention.

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

10 is a view showing a hydraulic flow state at the time of driving (D) range 4 → 3 downshift in the hydraulic control system according to the present invention.

11 is a view showing a hydraulic flow state at the time of driving (D) range 3 → 2 downshift in the hydraulic control system according to the present invention.

12 is a view showing a hydraulic flow state at the time of driving (D) range 2 → 1 downshift in the hydraulic control system according to the present invention.

1 is a view showing the hydraulic flow in the neutral range in the hydraulic control system according to the present invention, a torque converter (2) for receiving torque from the engine to convert the torque to the transmission side, and the torque converter and the shift stage control It includes an oil pump (4) for generating and dispensing the oil required for lubrication.

In the pipeline 6 through which the hydraulic pressure generated from the oil pump 4 flows, a pressure regulating valve 8 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 10 and the damper clutch control valve 12 for increasing the power transmission efficiency of the torque converter are connected to constitute a pressure regulating means and a damper clutch control means.

Some of the oil generated from the oil pump 4 switches the flow path while interlocking with the reducing valve 14 for maintaining a pressure lower than the line pressure at all times and depending on the position of the selector lever in the driver's seat. The flow path that can be supplied to the manual valve 16 is configured.

The constant pressure reduced in the reducing valve 14 is supplied to the first pressure control valve 18 and the second pressure control valve 20 to constitute a hydraulic control means that can be used as the shift stage control pressure.

Part of the hydraulic pressure supplied to the first and second pressure control valves 18 and 20 is a flow path that can use the control pressure of the NR control valve 22 to reduce the shift shock when the mode is changed from the neutral range to the reverse range. Making.

The first solenoid valve S1 and the second solenoid valve S2 controlled on / off by the transmission control unit to the pipeline 24 through which hydraulic pressure flows when the manual valve 16 is in the travel D range. The shift control valve 26 which switches a flow path by the function of the communication is connected, and comprises the manual and automatic shift control means with the manual valve 16 mentioned above.

The shift control valve 26 is connected to the second speed pipeline 28, the third speed pipeline 30, and the fourth speed pipeline 32 to control the hydraulic pressure by the shift valves of the hydraulic distribution means for controlling the respective shift stages. It is configured to supply.

In addition, a first speed pipe 34 is branched on the pipe 24 to supply line pressure to the first and second pressure control valves 18 and 20, and the first and second pressure control valves 18 are provided. 20 is configured to switch the flow path by the third and fourth solenoid valves S3 and S4 so that the first pressure control valve 18 can supply control pressure to the friction element during shift control. The second pressure control valve 20 is formed with a flow path to supply the drive pressure to the first friction element (C1) acting as the input element of the first speed.

The second speed pipeline 28 of the shift control valve 26 is supplied to the left end port of the 1-2 shift valve 34 to control the valve.

In addition, the three-speed pipeline 30 is configured to be supplied to the left end port of the 2-3 / 4-3 shift valve 38 to control the valve, and at the same time, the third friction element ( C3) is configured to supply hydraulic pressure.

And the four-speed pipeline 32 is configured to communicate with the left end port of the 3-4 shift valve 44 and the right end of the 2-3 / 4-3 shift valve 38 to control its valve.

In addition, the first speed pipe 34 is connected to the branch pipe 44 so that the drive pressure flowing along the first speed pipe 28 can be used as the control pressure of the control switch valve 40, which Controlled by the fifth solenoid valve S5 disposed on the branch line 44.

And when the manual valve 16 is in the reverse (R) range, the hydraulic pressure supplied to the reverse first control conduit 46 through the 3-4 shift valve 42 and the 2-3 / 4-3 shift valve 38 The hydraulic pressure is supplied to the fourth friction element C4 and the hydraulic pressure supplied to the reverse second control pipe 48 acts as a reaction force element at the reverse shift stage via the 1-2 shift valve 36. 5 It is configured to supply hydraulic pressure to friction element (C5).

In the above, a part of the hydraulic pressure supplied to the fourth friction element C4 can be simultaneously supplied to the release side chamber h2 of the second friction element C2.

In the valves forming the hydraulic distribution means as described above, the 1-2 shift valve 34 is controlled by the second speed pressure of the shift control valve 26 while the control pressure controlled by the first pressure control valve 18 is controlled. The flow path is supplied to the operating side chamber h1 of the second friction element C2 acting as the reaction force element of the second speed, and to supply the hydraulic pressure on the reverse second control pipe 48 to the fifth friction element C5. Consists of.

Accordingly, the 1-2 shift valve 36 includes a port for receiving control pressure from the shift control valve 26 at the forward 2, 3, and 4 speed shift stages; A port for receiving controlled hydraulic pressure from the first pressure control valve 18 of the hydraulic control means; A port for receiving reverse pressure from the manual valve 16 at the reverse shift stage; A port for supplying the control pressure supplied from the first pressure control valve to the operating side chamber h1 of the second friction element C2; And a port for supplying the reverse pressure to the fifth friction element C5.

The 2-3 / 4-3 shift valve 38 is hydraulically supplied from the 1-2 shift valve 34 while being controlled by the third and fourth speed pressures supplied to the left and right sides at the third and fourth speed shift stages, and the reverse shift. At this stage, the hydraulic pressure supplied from the 3-4 shift valve 42 is selectively supplied to the release side chamber h2 and the fourth friction element C4 of the second friction element C2.

Accordingly, the 2-3 / 4-3 shift valve 38 thereof has a port to which the third speed line 30 and the fourth speed line 32 interlock with each other; A port in communication with the 1-2 shift valve 36; A port in communication with the 3-4 shift valve 42; And a port in communication with the release side chamber h2 of the second friction element C2 and the fourth friction element C4.

Accordingly, the control switch valve 40 supplies the operating pressure of the friction element C3, which is controlled by the fifth solenoid valve S5 for controlling the first speed pressure and serves as an input element of the third speed and the fourth speed. It has a function for releasing the working pressure, it has a function to adjust the line pressure by supplying a portion of the hydraulic pressure supplied to its friction element (C3) to the pressure control valve (8) of the pressure regulating means.

Accordingly, the control switch valve 40 includes a port for receiving the control pressure from the branch line 44 branched from the first speed line 34 of the manual valve 16 to the right end; A port for receiving hydraulic pressure from the third speed line (30) of the shift control valve (26) and supplying it to the third friction element (C3) and the pressure control valve (8); When the operating pressure of the third friction element (C3) is released including a port for discharging the hydraulic pressure back through the third speed pipe (30), the port receiving hydraulic pressure from the first speed pipe (34) 5 has a configuration that can be controlled by the solenoid valve (S5).

And when the hydraulic pressure is supplied to the three-speed pipeline 30 on the pipe connected to the port for discharging the release hydraulic pressure again through the three-speed pipeline 30 when the operating pressure of the third friction element (C3) in the closing The valve 50 is disposed to release the release when the hydraulic pressure of the third friction element C3 is released.

In addition, the 3-4 shift valve 42 is controlled by the fourth speed pressure of the shift control valve 26, and the hydraulic pressure supplied from the second pressure control valve 20 at the 1,2,3 speed is applied to the first friction element ( C1) is supplied, as well as the hydraulic pressure supplied to the first friction element (C1) at 3 → 4 shifting directly discharged, and the release side chamber of the second friction element (C2) at 3 → 4, 3 → 2 shifting And the hydraulic pressure supplied to the fourth friction element C4 are discharged through the manual valve 16 via the 2-3 / 4-3 shift valve 38 and the reverse first control conduit 46. Done.

Accordingly, the valve thereof has a port for receiving hydraulic pressure from the fourth speed line 32; A port in communication with the second pressure control valve 20; Two ports in communication with the reverse first control conduit 46; And a port for supplying the hydraulic pressure supplied from the second pressure control valve to the first friction element.

In the above, the two ports communicating with the first control conduit 46 are formed to form a circulation conduit 52 at the distal end of the first control conduit 46, whose circulation conduit 52 passes therethrough. This is because one of the flow passages is formed to communicate with the 3-4 shift valve 42, and the other end thereof communicates with the 2-3 / 4-3 shift valve 38.

And the predetermined position of the circulation conduit 52 is arranged so that the check valve 54 for closing the flow path returned to the reverse first control conduit 46 side to control the release pressure.

In the figure, reference numeral S6 denotes a sixth 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. 1, in the neutral (N) range, the hydraulic pressure discharged from the oil pump 4 is regulated to a constant hydraulic pressure by the pressure control valve 8 while reducing the reducing valve. After the pressure is reduced through 14, the damper clutch control valve 12 and the first and second pressure control valves 18 and 20 are respectively supplied.

At this time, the third and fourth solenoid valves S3 and S4, which are duty controlled by the transmission control unit, are controlled to be in an off state to move the spools of these pressure control valves to the right as shown in the drawing.

In this state, when the selector lever is selected as the reverse (R) range, as shown in FIG. 2, the reverse first control conduit 46 and the 2-3 / 4-3 shift valve 38 are released from the manual valve 16. Through this, the hydraulic pressure is directly supplied to the release side chamber h2 and the fourth friction element C4 of the second friction element C2.

A part of the hydraulic pressure supplied to the manual valve 16 is shifted 1-2 through the reverse first control pipe line 48 while passing through the NR control valve 22 controlled by the duty control of the third solenoid valve S3. As it is supplied to the valve 34, the valve spool of the valve is moved to the right, and is supplied to the fifth friction element C5 which acts as a reaction force element in the reverse direction.

When the selector lever is selected as the driving range D in the state of neutral N, a part of the hydraulic pressure supplied to the manual valve 16 is shifted to the shift control valve 26 and the first and second as shown in FIG. It is supplied to the pressure control valves 18 and 20.

At this time, the first and second solenoid valves S1 and S2 of the shift control means are all controlled in the on state, and thus maintain the port of the shift control valve 26 in the initial state.

In this state, the hydraulic pressure supplied to the first and second pressure control valves 18 and 20 of the pressure control means is controlled by the third solenoid valve S3 being turned on, so that the hydraulic pressure supplied from the first speed line 34 is controlled. Since it is cut off, this hydraulic pressure is supplied to the 1st friction element C1 which acts as an input element at the 1st forward speed via the 3-4 shift valve 42 via the 2nd pressure control valve 20, and completes 1st speed control. Done.

Of course, at this time, the reaction force element is determined by the action of the one-way clutch.

If the opening rate of the throttle valve is increased while the vehicle speed is increased in such a first speed control state, as shown in FIG. 4, the transmission control unit controls the second solenoid valve S2 that is controlled in the on state to be in the on state. The hydraulic pressure supplied to the shift control valve 26 is supplied to the second speed pipeline 28.

It is then supplied to the left port of the 1-2 shift valve 36 to move its valve spool to the right in the figure.

In the above state, while the third solenoid valve S3 is duty controlled, the hydraulic pressure supplied from the first speed pipeline 34 is controlled by the first pressure control valve 18 so that the control pressure is controlled by the 1-2 shift valve 36. ) Is supplied to the operating side chamber h1 of the second friction element C2.

At this time, some of the hydraulic pressure passing through the 1-2 shift valve 34 is supplied to the 2-3 / 4-3 shift valve 38 and waits there.

In this state, as in FIG. 5, when the third solenoid valve S3 is controlled to be off, the pressure supplied to the operating side chamber h1 of the second friction element C2 is the second speed line 28 pressure at the control pressure. 2 speed control is completed.

When the vehicle speed increases in the two-speed control state as described above, and the opening degree of the throttle valve increases, as shown in FIG. 6, the first and second solenoid valves S1 and S2 of the shift control means are turned off. do.

Under such control, hydraulic pressure flows into the second-speed pipeline 28 and the third-speed pipeline 30. At this time, the hydraulic pressure of the third-speed pipeline 30 is the left port of the 2-3 / 4-3 shift valve 38. As it flows into the valve spool is moved to the right side as seen in the drawing.

Due to this action, the hydraulic pressure, which has been waited at the 2-3 / 4-3 shift valve 38 during the second speed control, is supplied to the release side chamber h2 of the second friction element C2, and this second friction element C2 is applied. At the same time to stop the operation of the supply of the control pressure to the fourth friction element (C4).

In this state, as shown in FIG. 7, when the fifth solenoid valve S5 that is being controlled to be off is controlled to be off, the operating side chamber of the second friction element C2 moves to the left while the valve spool of the control switch valve 40 is moved to the left. At the same time as the pressure supplied to (h1) is converted from the control pressure to the second speed line 28 pressure, the third speed line 30 is supplied to the third friction element C3, and the third speed control is completed.

A part of the hydraulic pressure supplied to the third friction element C3 in the third speed control is supplied from the control switch valve 40 to the pressure control valve 8 to adjust the line pressure.

That is, when the line pressure variable at the third speed is not changed during the 2 → 3 shift, the shift is completed and the valve spool of the control switch valve 40 moves to the right in the drawing by the off control of the fifth solenoid valve S5. Since the variable is to be made, at this time the third friction element (C3) is also made to operate at the same time.

And the line pressure control as described above is to substantially lower the line pressure, which is to reduce the driving loss of the oil pump to achieve the effect of improving fuel economy at high speed.

In addition, since the operation of the third friction element (C3) is controlled by the fifth solenoid valve (S5) at the time of completion of the shift when shifting from the second to the third speed as described above, it is temporarily neutral in the process of shifting while driving. This can be prevented.

When the vehicle speed further increases and the opening ratio of the throttle valve increases in the three-speed control state as described above, the transmission control unit simultaneously controls the first solenoid valve S1 as shown in FIG. The fifth solenoid valve S5 is controlled in an on state so that hydraulic pressure flows through all of the second, third, and fourth speed pipelines 28, 30, and 32, and the third solenoid valve S3 is duty controlled. .

Then, the hydraulic pressure supplied to the operating side chamber h1 of the second friction element C2 is changed to the control pressure, and the valve spool of the 3-4 shift valve portion 42 is supplied from the supply of the fourth speed line 32 pressure in the drawing. At the same time as moving to the right, the valve spool of the 2-3 / 4-3 shift valve 38 is moved to the left in the drawing.

In the above, the valve spool of the 2-3 / 4-3 shift valve 38 may move to the left side even though the three-speed line pressure 30 acts on the left side, even if the same pressure is supported on the right side of the valve spool. It is made possible by the elastic force of the elastic member.

As described above, the hydraulic pressure supplied to the first friction element C1 at the third speed according to the operation of the 2-3 / 4-3 shift valve 38 and the 3-4 shift valve 42 is a 3-4 shift valve 42. Discharged quickly through the discharge port (Ex).

And the hydraulic pressure supplied to the release side chamber h2 of the fourth friction element C4 and the second friction element C2 is a 2-3 / 4-3 shift valve 38, a 3-4 shift valve 42, It is discharged through the manual valve 16 via the reverse first control conduit 46, at which time the release pressure is transmitted to the check valve 54 disposed on the circulation conduit 52 of the reverse second control conduit 46. The delay is released while being controlled.

After the control is performed as described above, as shown in FIG. 9, while the fifth solenoid valve S5 is controlled to be in an off state, the valve spool of the control switch valve 40 is moved to the left in the drawing to form the second friction element C2. The normal drive pressure is supplied to the actuating side chamber h1 and the third friction element C3, thereby completing the four speed control.

When the downshift is performed according to the driving conditions of the vehicle while driving, the first solenoid valve S1 controlled on the fourth speed as shown in FIG. 10 when the downshift is performed from the fourth speed to the third speed is first performed. The hydraulic pressure, which was supplied to the fourth speed line 32 while the control valve is off, is discharged through the shift control valve 26, and the valve spool of the 3-4 shift valve 44 is moved to the left.

In addition, a part of the hydraulic pressure controlled by the first pressure control valve 18 by the duty control of the third and fourth solenoid valves S3 and S4 and passing through the 1-2 shift valve 36 is reduced to the second friction element ( Supplied to the actuating side chamber h1 of C2), the remaining part of which is to be released to the fourth friction element C4 and the second friction element C2 via the 2-3 / 4-3 shift valve 38. h2).

At the same time, the hydraulic pressure controlled by the second pressure control valve 20 is supplied to the first friction element C1 via the 3-4 shift valve 42.

That is, in the 4 → 3 shift as described above, since the first friction element C1 is supplied under the duty control of the third solenoid valve S3, the shift shock does not significantly occur, and in the shift process, It will be able to prevent the neutral state.

FIG. 11 is a view for explaining a 3 → 2 downshift process. In this case, the first solenoid valve S1 that is controlled off at the third speed is turned on to control the hydraulic pressure supplied to the third friction element C3. It is quickly discharged through the speed line 30 and the shift control valve 26.

Accordingly, the hydraulic pressure supplied to the release side chamber h2 and the fourth friction element C4 of the second friction element C2 is controlled by the 2-3 / 4-3 shift valve 38 and the 3-4 shift valve 42. The exhaust pressure for the line pressure control, which is supplied to the pressure control valve 8, is discharged through the manual valve 16 through the reverse first control pipe 46, and is discharged through the control switch valve 40.

In addition, the hydraulic pressure supplied to the operating side chamber h1 of the second friction element C2 by the duty control of the third solenoid valve S3 is changed to the control pressure by the operation of the control switch valve 36 and shifting is completed. It is then converted into the visible drive pressure and supplied to the off control of the third solenoid valve S3.

FIG. 12 shows the hydraulic flow state during 2 → 1 downshift, in which the second solenoid valve S2 is controlled in the off state while the first solenoid valve S1 is kept in the on state. The fifth solenoid valve S5 is maintained in the off state during the shift.

Accordingly, the hydraulic pressure supplied to the second speed pipeline 28 is rapidly discharged through the discharge port Ex of the shift control valve 26, and the hydraulic pressure supplied to the operating side chamber h1 of the second friction element C2 is supplied. Is discharged through the first pressure control valve 18 in accordance with the valve spool movement of the 1-2 shift valve 36 to achieve a 2 → 1 shift.

As described above, in the hydraulic control system according to the present invention, the shift is performed by the electronic control during the shift of 2 → 3, 4 → 3, thereby preventing the occurrence of a temporary neutral state in the shifting process. .

In particular, it is possible to simultaneously control the friction element and the line pressure operating in the third, fourth speed to increase the power transmission efficiency.

Claims (6)

Pressure regulating means for regulating the hydraulic pressure generated from the oil pump; Manual and automatic control means for forming a shift mode; Hydraulic control means for adjusting the shifting feeling and responsiveness to form a smooth shifting mode during shifting; Damper clutch control means for operating a damper clutch of the torque converter; Hydraulic distribution means for supplying and distributing the appropriate hydraulic pressure to each friction element acting as an input and reaction force element at each shift stage; The above-mentioned hydraulic pressure distribution means is controlled by the second speed pressure of the shift control valve of the automatic shift control means so that the control pressure controlled by the first pressure control valve is supplied to the friction element acting at the second speed, and the friction operated during the reverse operation. A 1-2 shift valve constituting a flow path so as to be supplied to the urea; The hydraulic pressure supplied from the 1-2 shift valve and the hydraulic pressure supplied from the 3-4 shift valve in the reverse shift stage are selectively controlled by the 3 and 4 speed pressures supplied to the left and right sides at the 3rd and 4th speed shift stages. A 2-3 / 4-3 shift valve for supplying to the friction element acting on the reverse shift stage; It is controlled by a solenoid valve that controls the hydraulic pressure supplied from the 1st speed line, and has a function to supply or release the operating pressure of the friction element acting as an input element of the 3rd and 4th speed stages, and to supply the friction element thereof. A control switch valve having a function of controlling a line pressure by supplying a part of the hydraulic pressure to a pressure control valve of the pressure adjusting means; The hydraulic pressure supplied from the second pressure control valve while being controlled by the four-speed line pressure is supplied to the friction elements operating in 1,2,3, and of course, the hydraulic pressure supplied to the friction elements is directly discharged in the 3 → 4 shift. In the 3 → 4, 3 → 2 shift, the hydraulic pressure supplied to the friction element acting at the 3rd speed and the reverse shift stage is supplied through the manual valve via the 2-3 / 4-3 shift valve and the 1st reverse control line. A 3-4 shift valve which performs a function of causing a discharge; Hydraulic control system of a vehicle automatic transmission comprising a. The method of claim 1, wherein the 1-2 shift valve comprises: a port for receiving control pressure from the shift control valve in the forward 2, 3, 4 speed shift stage; A port for receiving controlled hydraulic pressure from the first pressure control valve of the hydraulic control means; A port receiving reverse pressure from a manual valve at a reverse shift stage; A port for supplying a control pressure supplied from said first pressure control valve to a friction element acting at second and fourth speeds; A port for supplying the reverse pressure to the fifth friction element acting only on the reverse shift stage; Hydraulic control system of a vehicle automatic transmission, characterized in that comprises a. The control switch valve of claim 1, further comprising: a port for receiving a control pressure at a right end from a branch line branched from the first speed line of the manual valve; A port for receiving hydraulic pressure from the third speed pipeline of the shift control valve and supplying the friction element and the pressure control valve operating at the third and fourth speeds; And a port for discharging the release hydraulic pressure through the third speed pipe again when the operating pressure of the third friction element is released; The hydraulic pressure control system of the automatic transmission for a vehicle is configured such that a port receiving hydraulic pressure from the first speed pipeline is controlled by a solenoid valve. The method according to claim 1 or 3, wherein when the hydraulic pressure of the friction element acting in the third and fourth, the hydraulic pressure is supplied to the three-speed pipeline on the pipe connected to the port for discharging the hydraulic pressure back through the three-speed pipeline, Hydraulic control system for an automatic transmission for a vehicle, characterized in that the valve is arranged. The system of claim 1, wherein the 3-4 shift valve comprises: a port receiving hydraulic pressure from the fourth speed line; A port in communication with the second pressure control valve; Two ports in communication with the reverse first control conduit; And a port for supplying the hydraulic pressure supplied from the second pressure control valve to the first friction element. The method of claim 5, wherein the reverse first control pipe is formed in the end of the circulation pipe, the circulation pipe is formed through the flow path passing through the one end of the flow path of the 3-4 shift valve, the other end thereof 2- A hydraulic control system for an automatic transmission for a vehicle, characterized in that the valve is in communication with the 3 / 4-3 shift valve, and the release valve is disposed at a predetermined position of the circulation pipe so as to control the release pressure. .