KR19980017012A - Hydraulic control system of automatic transmission for vehicles - Google Patents

Abstract

In order to reduce vibration and noise in the parking range and the neutral range to reduce vibration and noise, and to reduce the driving loss of the oil pump by varying the line pressure according to the driving conditions of the driving range, the oil pressure generating means and the A line pressure control means for regulating the oil pressure generated from one means to a constant line pressure and maintaining a minimum pressure line pressure at the parking range and the neutral range, and varying the line pressure according to the driving conditions of the vehicle at the driving range; The line pressure is supplied to the line pressure variable means, and a manual valve for supplying or cutting off the line pressure to the speed change portion by changing the port according to the movement of the selector lever, and a hydraulic pressure lower than the line pressure supplied from the line pressure control means. A shift control means for shift control by receiving a control signal and controlled by the shift control means. Provided is a hydraulic control system for an automatic transmission for a vehicle including a manual and an automatic transmission stage for performing port switching of the respective shift valves for each transmission stage in order to supply the hydraulic pressure to each friction element.

Description

Hydraulic control system of automatic transmission for vehicles

1 is a hydraulic control system according to the present invention.

2 is an enlarged view of a line pressure varying means according to the present invention.

3 is a graph showing a state in which the line pressure is changed by the line pressure variable control means according to the present invention.

The present invention relates to a hydraulic control system of a child transmission, and more particularly, the hydraulic control of an automatic transmission for a vehicle to improve fuel economy and power transmission efficiency by allowing line-a-line control to be performed over the entire range. It's about the system.

It has a torque converter of an automatic transmission for a vehicle and a multistage transmission gear mechanism connected to the torque converter, and a hydraulically operated friction element for selecting one of the gear stages of the transmission gear mechanism according to the driving condition of the vehicle. It is included.

The hydraulic control system of the automatic transmission for a vehicle has a function of operating the hydraulic pressure generated from the oil pump by selecting a friction element through a control valve.

The hydraulic control system is a pressure control means for regulating the hydraulic pressure generated by the oil pump, manual and automatic shift control means that can form a shift mode, and shifting and responsiveness to form a smooth shift mode during shifting Hydraulic control means, damper clutch control means for actuating the damper clutch of the torque converter, and hydraulic distribution means for distributing a proper hydraulic supply to each friction element.

The pressure regulating means includes a line pressure varying means as a method for reducing the driving loss of the oil pump by reducing the line pressure at a relatively high speed.

The line pressure varying means has a configuration capable of returning a part of the hydraulic pressure generated by the oil pump to the oil pan while controlling a regulator valve for adjusting the hydraulic pressure from the oil pump to a constant pressure.

The so-called high-low pressure valve that controls this regulator valve is to make the three-speed or four-speed pressure act on the largest land of the regulator valve by the reducing pressure and the damper clutch control pressure of the torque converter. It has a function to prevent it from working

However, since the line pressure variable means can adjust the line pressure by the on / off control of the damper clutch control solenoid valve, there is a disadvantage in that the line pressure can be changed only at relatively high speed stages 3 and 4 speeds.

The present invention has been invented to solve the problems of the prior art as described above, the object of the present invention is to reduce the noise and fuel economy by varying the line pressure over the entire speed range in the parking range and the neutral range, and driving range The present invention provides a hydraulic control system of an automatic transmission for a vehicle that can improve power transmission efficiency.

In order to realize the object of the present invention as described above, while maintaining the minimum pressure line pressure in the parking range and the neutral range, while adjusting the oil pressure generating means and the oil pressure generated from the above means to a constant line pressure, In the driving range, the line pressure control means for varying the line pressure according to the driving conditions of the vehicle, and the line pressure is supplied to the line pressure variable means, and the port is switched according to the movement of the selector lever to supply the line pressure to the transmission. In order to supply to each friction element the manual valve to cut off, the shift control means which receives a hydraulic pressure lower than the line pressure supplied from said line pressure control means, and performs the shift control, and the hydraulic pressure controlled by the time shift control means. Vehicle including a manual and automatic shift stage for port switching of each shift valve for each shift stage It provides a hydraulic control system of the transmission.

The line pressure control means includes a regulator valve for making the hydraulic pressure supplied from the work pump to a constant line pressure, two ports for receiving a pressure lower than the line pressure from a reducing valve for varying the in-pressure, and a line pressure from the manual valve. Pressure control valve having a port supplied with and a second port for multiplying the line pressure flowing through the port to the land having the largest hydraulic action surface of the line pressure variable land of the regulator valve; Provided is a hydraulic control system for an automatic transmission for a vehicle including a line pressure control solenoid valve installed at one port to which hydraulic pressure is supplied to vary the hydraulic pressure of the port by a transmission control unit to a minimum or maximum.

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

1 is a view showing a hydraulic control system to which the line pressure variable means according to the present invention is applied, which is provided between a torque converter 2 installed between an engine pipe transmission of a vehicle and transmitting power to an input shaft of a transmission, respectively, A plurality of friction elements C1, C2, C3, C4 and C5 are shown to connect the input side member to the output side member or to fix the rotational shaft member by the hydraulic pressure provided for the shift stage selection.

The transmission unit for supplying hydraulic pressure to the torque converter or the friction elements or discharging the hydraulic pressure supplied thereto to perform the shift stage control, includes an oil pump 4 for pumping oil by the power of the engine, and an oil pump 4. The regulator valve 6 which produces | generates the produced | generated hydraulic pressure to a constant line pressure, and the line pressure control which returns a part of the hydraulic pressure discharged from an oil pump to the oil pan 8 by varying the valve spool position of this regulator valve 6 The valve 10 constitutes a line pressure varying means.

The line pressure control valve 10 has a first port 14 and a second port 16 which receive a reduced pressure from a reducing valve 12 which makes the line pressure lower and use it as a control pressure. And a third port 20 which receives the line pressure from the manual valve 18 and a fourth port which flows out the line pressure introduced into the third port 20 to use the control pressure of the regulator valve 6. It has 22.

Hydraulic pressure is formed by the second line 16 line pressure control solenoid valve LS, or the hydraulic pressure formed can be released.

The torque converter control valve 26 which receives the adjusted line pressure from the regulator valve 6 and supplies oil for lubrication to the operating pressure of the torque converter 2 and the friction part of the transmission is a damper clutch control valve ( It is connected to 28) and constitutes a flow path that can supply hydraulic pressure so that it can be used for damper clutch control that increases power efficiency.

The damper clutch control valve 28 is a two-channel (D1) which is converted into a port by the damper clutch control solenoid valve (DS), which is usually on and off controlled by the transmission control unit and supplied to the torque converter (2) The control for supplying the hydraulic pressure to any one of the pipelines of D2) is performed.

On the other hand, the hydraulic pressure reduced from the reducing valve 12 is a pressure control solenoid valve for controlling the first and second pressure control valves 30 and 32 to control the line pressure while being duty controlled when a shift command is issued. It constitutes a flow path that can be used as a control pressure of PA) (PB).

The first and second pressure control valves 30 and 32 are moved from the manual valve 18 for changing the supply direction of the line pressure while moving to the corresponding position according to the range selection of the selector lever. The flow path can be supplied to the 1-2 shift valve 36 and the 2-4 / 3-4 shift valve 38, respectively, by supplying the line pressure to the control pressure.

Said 1-2 shift valve 36 is a friction element C2 by the 2nd speed | path 42 which runs from the shift control valve 40 which performs a port conversion by two shift control solenoid valves SA and SB. Another friction element C5 constitutes a flow path through which hydraulic pressure can be selected and supplied.

The three-speed pipe passage 44 leading from the shift control valve 40 receives hydraulic pressure from the 1-2 shift valve 36, and part of the hydraulic pressure is supplied by the release pressure of the friction element C2, The hydraulic pressure is connected with a 2-4 / 3-4 shift valve 46 which supplies at the working pressure of another friction element C3.

And, the four-speed pipe passage 48 from the shift control valve 40 can use the control pressure of the above-described 2-4 / 3-4 shift valve 38 and 2-3 / 4-3 shift valve 46. And a flow passage capable of supplying hydraulic pressure to the extension pipe passage 52 to be used as a control pressure of the end clutch valve 50 which releases the pressure of the friction element C3 or forms the pressure. do.

The accumulator 54 is installed between the end clutch valve 50 and the friction element C3 to prevent the engine from running up caused by the rapid release of the hydraulic pressure supplied to the friction element C3. It is possible to delay the working pressure discharge timing.

FIG. 2 is an enlarged view of the line pressure variable control means related to the present aspect, wherein the line pressure control valve 10 includes a first land 56 on which the pressure pressure flowing into the first port 64 acts; Has a valve spool having a second land 58 having a larger hydraulic action surface than the first land, and a third land 62 on which the spring 60 is supported while the hydraulic pressure flowing into the second port 16 acts. have.

The regulator valve 6 includes a first port 64 supplied with the line pressure from the manual valve 18 in the forward range, a second port 66 supplied with the line pressure in the reverse range, and the line pressure described above. The third port 68 is provided with a line pressure supplied from the fourth port 24 of the control valve 10.

Then, the fourth port 70 to which the hydraulic pressure is supplied from the oil pump 4 and the fifth and sixth ports 72 and 74 to supply the line pressure introduced to the fourth port to the torque converter control valve 36. It further includes, and has a discharge port 75 for returning the line pressure to the oil pan (8).

The valve spool of the regulator valve 6 has a first land 76 to which the line pressure supplied to the first port 64 acts, and a line pressure supplied to the second port 66 to the second land 78. ), The third land 80 to which the line pressure supplied to the third port 68 acts, and the fourth land to determine the opening amount of these ports between the fourth port 70 and the discharge port 75. And a fifth land 84 on which the spring is supported.

In the figure, reference numeral 90 denotes an N-R control valve that reduces shift shock during manual shifting into the reverse range.

In the hydraulic control system of the present invention, the shift command is output by the transmission control unit for controlling the respective solenoid valves, and thus the operation of shifting is the same as before.

That is, in the forward range 1 speed, the shift control solenoid valves SA and SB are all controlled to the ON state, so that no hydraulic pressure is formed in the 2, 3, and 4 speed pipes 42, 44, and 48. By supplying the hydraulic pressure to the 34, the hydraulic pressure is supplied to the friction element C1, which is the rear clutch, via the second pressure control valve 32 controlled by the pressure control solenoid valve PB to realize the first speed control. .

Then, when the vehicle speed increases and the opening ratio of the throttle valve increases in such a single speed control state, the transmission control unit controls the shift control solenoid valve SA to be turned off to supply hydraulic pressure to the second speed pipe 42. As a result, the valve spool of the 1-2 shift valve 36 is moved to the right. The first pressure control valve in which the hydraulic pressure of the first speed pipe 34 is duty controlled by the pressure control solenoid valve PA is controlled by this control. The hydraulic pressure of the first speed pipeline 34 via 30 is supplied to the friction element C2, which is the kick-down servo, via the 1-2 shift valve 36 to perform the two-speed shift control.

If the opening speed of the throttle valve starts to increase as the vehicle speed increases in the second speed state, the transmission control unit also controls the shift control solenoid valve SB to be in the off state so that hydraulic pressure also flows in the third speed line 4. .

By this control, the valve spool of the 2-3 / 4-3 shift valve 46 is moved to the right side, where a part of the hydraulic pressure supplied to the friction element C2 is supplied to the release chamber of the key down servo while While the operation of the element C2 is stopped, the third speed control is realized while being supplied to the friction element C3 via the end clutch valve 50.

In addition, when the opening ratio of the throttle valve increases and the vehicle speed increases further in the third speed state, the shift control solenoid valve SA is controlled to the on state so that hydraulic pressure is also formed in the four-speed pipe line 48 so as to provide 2-4 / 3. The valve spool of the -4 shift valve 38 and the 2-3 / 4-3 shift valve 46 is moved to the right, and the valve spool of the end clutch valve 50 is also moved to the right.

By this control, the hydraulic pressure supplied to the friction element C1, which is the rear clutch, is cut off, and the hydraulic pressure is supplied to the end clutch valve 50 via the 2-4 / 3-4 shift valve 38. The end clutch The valve has been supplied with hydraulic pressure from the first pressure control valve 30 so far, but at this time, the hydraulic pressure supplied to the rear clutch is supplied from the second pressure control valve 32.

The friction element C2, which is the kick-down servo that has been released, is discharged with the release side hydraulic pressure passing through the 2-3 / 4-3 shift valve 46, thereby completing the four-speed shift control in which the friction element operates again. do.

In the reverse range, the friction element C4, which is the front clutch, is directly supplied with hydraulic pressure from the manual valve 18, and the hydraulic pressure passing through the NR control valve 90 passes through the 1-2 shift valve 36 to provide low / low pressure. The reverse brake is supplied to the friction element C5 to reverse the vehicle.

While the shift control is conventionally performed, the line pressure control valve 10 is operated by the damper clutch control solenoid valve DS that operates the damper clutch in the torque converter to regulate the line pressure. The solenoid valve LS is controlled at the maximum duty ratio in the parking range P and the neutral range N while the damper clutch control is controlled separately from the solenoid valve DS, and the driving range is adjusted to the driving conditions of the vehicle. Accordingly.

That is, in the parking range and the neutral range, since the line pressure control solenoid valve LS is controlled at the largest duty ratio (100%), the hydraulic pressure of the second port 16 of the line pressure control valve 10 is hardly formed. The hydraulic pressure flowing into the first port 14 causes the valve spool to move completely to the left.

Therefore, the line pressure flowing from the manual valve 18 into the third port 20 is introduced into the third port 68 of the regulator valve 6 through the fourth port 24. Since the hydraulic pressure flowing into the third port acts on the third land 80 having the largest hydraulic pressure acting surface, the valve spool of the regulator valve is left more than when the hydraulic pressure is supplied to the first and second ports 64 and 66. By moving to the discharge port 75 most open to increase the amount of oil returning to the oil pan (8) can maintain the minimum line pressure.

3 is a graph showing the relationship between the regulated line pressure and the duty rate of the line pressure control solenoid valve, and the line pressure is adjusted from the minimum pressure to the maximum pressure while the duty ratio is varied in the driving range.

As described above, the hydraulic control system according to the present invention can reduce the noise and vibration because the line pressure control is controlled to the minimum pressure in the parking range and the neutral range, and the load of the oil pump can be reduced through the variable line pressure in the driving range. Since it can be reduced, there is an effect that can improve the power transmission efficiency and fuel economy.

Claims (2)

Oil pressure generating means, The line pressure control means for adjusting the oil pressure generated from the above means to a constant line pressure and maintaining the minimum pressure line pressure in the parking range and the neutral range, and the line pressure in the driving range according to the driving conditions of the vehicle; , A manual valve for supplying the line pressure to the line pressure variable means and supplying or blocking the line pressure to the speed change portion by port switching according to the movement of the selector lever; Shift control means for shift control by receiving hydraulic pressure lower than the line pressure supplied from the line pressure control means; And a manual and automatic transmission stage for performing port switching of respective shift valves for each shift stage in order to supply the hydraulic pressure controlled by the shift control means to each friction element. The method of claim 1, wherein the line pressure control means, A regulator valve for making a constant line pressure of hydraulic pressure supplied from an oil pump, The two ports that receive pressure lower than the line pressure from the reducing valve that changes the line pressure, the port that receives the line pressure from the manual valve, and the line pressure flowing through the port are the most of the line pressure variable lands of the regulator valve. A line pressure control valve having another port for supplying a land having a large hydraulic action surface, And a line pressure control solenoid valve installed at one port to which hydraulic pressure lower than the above-mentioned line pressure is supplied to change the hydraulic pressure of this port by a transmission control unit to a minimum or maximum.