KR100220073B1 - Hydraulic control system for automatic transmission - Google Patents

Abstract

The object of the present invention is to enable the forward 4 speed and reverse 1 speed control as well as smooth hydraulic pressure even when a specific valve in the hydraulic circuit is fixed to one side or the transmission control unit (TCU) is in a bad state during 4-2 skip control. The present invention provides a hydraulic control system for an automatic transmission having a safety device to enable control.

The hydraulic control system for an automatic transmission according to the present invention includes: a line pressure control means connected to a line pressure pipeline to control and supply the oil pressure supplied from the oil pressure generating means to a line pressure having a constant pressure amplitude;

A damper clutch control means connected to the torque converter to control a flow path of some of the hydraulic pressures supplied from the line pressure control means to control the damper clutch embedded in the torque converter;

Range control means connected to each range conduit to supply the line pressure supplied from the line pressure control means to a range conduit corresponding to each range according to a range selection operation of the shift lever;

Since each solenoid valve controls the reducing pressure supplied from the reducing pressure control means, it is connected to the friction element so that the line pressure supplied from the range control means may be deutered to be supplied and discharged by the operation and release hydraulic pressure of each friction element. Pressure control means;

The pressure control means is controlled by the range control means pressure and the hydraulic pressure supplied from the control means to change the flow path connecting the pressure control means and the friction element to discharge the hydraulic pressure supplied to the friction element or the hydraulic pressure supplied to the friction element. Flow passage control means provided between the friction elements;

Controlled by the interaction of the hydraulic pressure supplied from the range control means and the pressure control means and the flow path control means so that the transmission control unit (TCU) cannot be controlled during control to a specific shift stage and a part of the flow path control means is inoperable. In any one or more of the cases, it is composed of a fail-safe means for interrupting the hydraulic pressure supplied from the means and discharging the hydraulic pressure acting on a specific friction element to prevent the interlock of the power train.

Description

Hydraulic Control System for Automatic Transmission

The present invention relates to a hydraulic control system for an automatic transmission, and more particularly, to realize a four-speed forward and one reverse speed, while fixing a specific valve of a hydraulic circuit or a malfunction of a transmission control unit (TCU) in a specific shifting process. The present invention relates to a hydraulic control system for an automatic transmission that prevents interlock of a power train.

In general, the hydraulic control system for an automatic transmission turns on a solenoid valve provided in a valve body in which a transmission control unit (TCU) forms a hydraulic circuit according to range selection by a shift lever and driving conditions of a vehicle such as vehicle speed and throttle opening. It is configured to actuate and release the friction elements provided in the power train according to the on / off and duty control.

The hydraulic control system may be configured in various forms according to the type of power train, and may be configured in various forms for the same type of power train.

In particular, there is a power train that employs a combination type planetary gear of the lavender type controlled by three clutches and two brakes. The hydraulic control system for controlling this power train typically employs a shift control valve controlled by two shift control solenoid valves, which are configured to supply and discharge each speed in the D range.

In addition, the hydraulic control system is provided with a hydraulic circuit configured to control the power train in a three-speed hold state when the transmission control unit (TCU) is in an inoperable state during driving.

As a result, the hydraulic control system for an automatic transmission as described above has a safety device that controls the three-speed hold state when the transmission control unit (TCU) is inoperable, but certain valves in the hydraulic circuit are stuck or 4-2 skips. When the transmission control unit TCU is in a bad state during control, the rear clutch 75, the end clutch 99, and the secondary brake 89 tend to be operated simultaneously.

Therefore, the present invention has been invented to overcome the above-mentioned tendency, and an object of the present invention is that even when a specific valve in a hydraulic circuit is fixed to one side or a transmission control unit (TCU) is in a bad state during 4-2 skip control. The present invention provides a hydraulic control system for an automatic transmission equipped with a safety device to enable smooth hydraulic control.

In order to realize this, the hydraulic control system for an automatic transmission according to the present invention includes: a line pressure control means connected to a line pressure line to control and supply the oil pressure supplied from the oil pressure generating means to a line pressure having a constant pressure amplitude;

A damper clutch control means connected to the torque converter to control a flow path of some of the hydraulic pressures supplied from the line pressure control means to control a damper clutch embedded in the torque converter;

A reducing pressure control means connected to a reducing pressure pipe to control the line pressure supplied from the line pressure control means to a reducing pressure which is a control pressure of each solenoid valve and to supply each solenoid valve;

Range control means connected to each range conduit to supply the line pressure supplied from the line pressure control means to a range conduit corresponding to each range according to a range selection operation of the shift lever;

Each solenoid valve controls the reducing pressure supplied from the reducing pressure control means, so that the pressure is connected to the friction element so that the line pressure supplied from the range control means can be duty controlled to supply and discharge the respective friction elements by operating and releasing hydraulic pressure. Control means;

The pressure control means is controlled by the hydraulic pressure supplied from the range control means and the pressure control means to change the flow path connecting the pressure control means and the friction element so as to discharge the hydraulic pressure supplied to the friction element or the hydraulic pressure supplied to the friction element. Flow passage control means provided between the friction elements;

Controlled by the interaction of the hydraulic pressure supplied from the range control means and the pressure control means and the flow path control means so that the transmission control unit (TCU) cannot be controlled during control to a specific shift stage and a part of the flow path control means is inoperable. In any one or more of the cases, fail-safe means for interrupting the hydraulic pressure supplied from said means and for discharging the hydraulic pressure acting on a particular friction element to prevent interlocking of the power train.

Hereinafter, the preferred configuration and operation of the present invention will be described in more detail with reference to the accompanying drawings.

1 is a hydraulic circuit diagram formed in the N range of the hydraulic control system for an automatic transmission according to the present invention.

2 is a hydraulic circuit diagram formed in a first speed state of a hydraulic control system for an automatic transmission according to the present invention.

Figure 3 is a hydraulic circuit diagram formed in the 1-2 shifting process of the hydraulic control system for automatic transmission according to the present invention.

Figure 4 is a hydraulic circuit diagram formed in the 2-3 shift process of the hydraulic control system for automatic transmission according to the present invention.

Figure 5 is a hydraulic circuit diagram formed in the 3-4 shift process of the hydraulic control system for automatic transmission according to the present invention.

Figure 6 is a hydraulic circuit diagram formed in the N-R shift process of the hydraulic control system for automatic transmission according to the present invention.

Figure 7 is a hydraulic circuit diagram formed in the N-L speed change process of the hydraulic control system for automatic transmission according to the present invention.

8 is a hydraulic circuit diagram formed at three speeds in a state in which a specific valve is fixed to one side of the valves of the hydraulic control system for an automatic transmission according to the present invention.

9 is a hydraulic circuit diagram formed at three speeds in a TCU operation failure state during a 4-2 skip shifting process of the hydraulic control system for an automatic transmission according to the present invention.

1 is a hydraulic circuit diagram formed in the N range of the hydraulic control system for an automatic transmission according to the present invention, which realizes four forward speeds and one reverse speed, and is controlled by a transmission control unit (TCU) during control at a specific shift stage. It is configured to prevent interlocking of the power train when it is disabled and when a particular valve is inoperative.

That is, the oil pump 3 mounted on the oil pump drive hub (not shown) of the torque converter 1 generates a hydraulic pressure at the same time as driving the engine (not shown) and supplies it to the regulator valve 5 so as to supply it to the regulator valve 5. ) Is connected.

The regulator valve (5) is supplied with hydraulic pressure to the pipe (7) and discharged to the return pipe (9) while adjusting to a line pressure having a range of pressure deviation of the line to the line pressure pipe (11) connected to the pipe (7) It is formed and connected to supply pressure.

The line pressure line 11 is connected to one side of the reducing valve 13 for reducing the line pressure to the reducing pressure, and the reducing valve 13 controls the reducing pressure with the damper clutch control solenoid valve 15. It is connected to each reducing pressure line (23, 25) so that it can be supplied to the 1,2,3 pressure control solenoid valves (17, 19, 21). That is, the reducing valve 13 is provided between the line pressure line 11 and the reducing pressure lines 23 and 25.

On the other hand, the regulator valve 5 is connected to supply the hydraulic pressure to the torque converter control valve 29 through the conduit 27, the torque converter control valve 29 is connected to the hydraulic power supply to the pipeline 27 power train The lubrication part and the damper clutch 31 embedded in the torque converter 1 are connected to the damper clutch control valve 33 for supplying to the conduit 35.

The damper clutch control valve 33 is configured to operate as the damper clutch control solenoid valve 15 controls the oil pressure supplied to the reducing pressure line 23, and the oil pressure and line pressure line supplied to the line 35 ( 11) one of the hydraulic pressures supplied to the branched pipe line 37 in the branch line is selectively supplied to the torque converter 1 to release and operate the damper clutch 31, and the hydraulic pressure discharged from the torque converter 1 is transferred to the power train. The pipes 39, 41 and 43 are connected to each other so as to be supplied to the lubrication portion of the pipes.

In addition, the line pressure line 11 is connected to supply the line pressure to the manual valve 45 that is linked to the operation of the shift lever (not shown), the manual valve 45 is a regulator valve (5) for forward and reverse It is connected to the front and back pressure pipelines (47, 49) to supply the control pressure to the furnace, and consists of a structure that can supply the line pressure to each flow path corresponding to the P, R, N, D, 2, L range. .

The hydraulic pressure is supplied from the line pressure line 11 to control the regulator valve 5 together with the hydraulic pressure supplied to the front and rear pressure line lines 47 and 49 to control the pressure on one side of the regulator valve 5. The fourth pressure control solenoid valve 51 is connected to one side of the regulator valve 5 by a conduit 53 so as to act.

In this way, the manual valve 45 for supplying the forward and backward pressure so that the regulator valve 5 can control the line pressure is the first, second, and third pressure control valves 55, 57, 59 when the D, 2, L range is selected. It is connected to the pipeline 61 so that the line pressure can be supplied to), and is connected to the pipeline 65 so that the line pressure can be supplied to the NR control valve 63 when the R range is selected.

The first and second pressure control valves 55 and 57 control the line pressure supplied to the conduit 61 of the first and second pressure control solenoid valves 17 and 19 controlled by the transmission control unit (TCU). In operation it is constructed and connected to supply duty controlled hydraulic pressure to the conduits 67 and 69 connected to each of these valves 55 and 57.

And the third pressure control valve 59 and the NR control valve 63 is the third pressure control solenoid valve 21 is controlled by the transmission control unit (TCU) the line pressure supplied to each of the pipelines (61, 65) ) Is configured and connected to supply duty controlled hydraulic pressure to conduits 71 and 73 connected to each of these valves 59 and 63.

The pipeline 67 for supplying the hydraulic pressure controlled by the first pressure control valve 55 is connected to the rear clutch 75 so as to release the hydraulic pressure that has been operated and supplied, thereby releasing it. At the same time, the conduit 67 supplies hydraulic pressure to the control switch valve 75 to control the hydraulic pressure, the hydraulic pressure is supplied to the servo release control valve 77, and the hydraulic pressure is supplied to the fail-safe valve 79 to control this. Are connected to each. The pipeline 67 is connected to the pipeline 61 via the check ball 81.

The pipeline 69 for supplying the hydraulic pressure controlled by the second pressure control valve 57 is connected to supply the hydraulic pressure to the low control valve 83 or to discharge the supplied hydraulic pressure. And the pipeline 69 is connected to the pipeline 61 via the check ball 85.

The conduit 71 supplying the hydraulic pressure controlled by the third pressure control valve 59 is connected to the servo application 91 of the kickdown brake 89 connected to the conduit 87 through the fail-safe valve 79. The hydraulic pressure is supplied to discharge and release the hydraulic pressure that has been operated and supplied, and at the same time, the hydraulic pressure is supplied to one side of the row control valve 83 or connected to discharge the hydraulic pressure.

The pipeline 73 for supplying the hydraulic pressure controlled by the NR control valve 63 supplies the hydraulic pressure to the low-reverse brake 93 or discharges the hydraulic pressure that has been supplied, and at the same time, the hydraulic pressure is supplied to one side of the fail-safe valve 79. It is connected to supply or discharge.

Meanwhile, the low control valve 83 receiving the hydraulic pressure supplied to the pipeline 69 connected to the second pressure control valve 57 is the hydraulic pressure supplied to the pipeline 71 and the pipeline 95 connected to the manual valve 45. Controlled by the interaction of the supplied hydraulic pressure, the hydraulic pressure supplied to the conduit 69 is supplied to the end clutch 99 through the conduit 97 to discharge and release the hydraulic pressure that has been operated and supplied, or the conduit 101 And a valve spool 103 connected to the low-reverse brake 93 through the conduit 73 connected thereto so as to discharge and release the hydraulic pressure that has been operated and supplied thereto, and to enable such control. have.

In addition, the pipeline 97 supplies a part of the hydraulic pressure supplied to the end clutch 99 to the servo release control valve 95, the control switch valve 77, and the fail safe valve 79 so that they can be simultaneously controlled. It is connected.

The servo release control valve 95 controlled by the interaction between the hydraulic pressure supplied to the conduit 97 and the hydraulic pressure supplied to the forward pressure conduit 47 is a conduit 67 connected to the first pressure control valve 55. The hydraulic pressure supplied to the control switch valve 77 connected to the conduit 105 and the servo release 109 connected to the conduit 107 may be released to release the kickdown brake 89 or to discharge the supplied hydraulic pressure. The valve spool 111 is connected so as to enable the control.

And the control switch valve 77 configured to supply the hydraulic pressure supplied to the pipeline 105 to the servo release 109 is controlled by the interaction of the hydraulic pressure supplied to the pipelines 67 and 97 as described above, One side of the hydraulic pressure supplied to the conduit 105 and the hydraulic pressure supplied to the conduit 97 is selectively connected to the servo release 109 connected to the conduit 107 or discharged the supplied hydraulic pressure, and The valve spool 113 which enables the same control is provided.

On the other hand, the fail-safe valve 79 is a hydraulic pressure supplied to the conduit 71 by the interaction of the hydraulic pressure supplied to the conduit (67, 73, 97) and the hydraulic pressure supplied to the conduit (47, 107) to act in a direction that resists it. The valve spool 115 is connected to the servo application 91 connected to the conduit 87 so as to discharge the hydraulic pressure which has been supplied, and enables the control.

When the valve spool 115 of the fail-safe valve 79 is unable to control the transmission control unit (TCU) during the 4-2 skip control by the hydraulic pressure acting on both sides as described above, the row control valve 83 is shown in the drawing. When it is moved to the right side and fixed in view, the hydraulic pressure supplied to the conduit 71 is shut off, and the hydraulic pressure acting on the servo application 91 of the kick-down brake 89 is discharged to release it. It is configured to prevent interlock.

In addition, the reverse pressure pipe 49 connecting the manual valve 45 and the regulator valve 5 is connected to supply hydraulic pressure directly to the front clutch 117 when the R range is selected.

In the hydraulic control system for an automatic transmission configured as described above, the transmission control unit (TCU) has a solenoid valve (15, 17, 19, 21) according to the range selection operation of the shift lever and the driving situation of the vehicle such as the vehicle speed and the throttle opening. 51 is controlled on / off and duty to the shift stage appropriate to the driving situation.

(N range)

First, when the N range is selected by the shift lever, and the engine is driven, the torque converter 1 and the oil pump 3 are driven to generate hydraulic pressure, as shown in FIG. Supplied to the regulator valve 5 and controlled to a line pressure having a constant pressure amplitude, so that the reducing valve 13, the manual valve 45, the damper clutch through the line pressure line 11, a branched line 37 therefrom. It is supplied to the control valve 23, respectively.

In this state, the transmission control unit TCU controls all of the damper clutch control valve 15 and the first, second, third and fourth pressure control valves 17, 19, 21 and 55 to be off.

Therefore, the hydraulic pressure supplied to the regulator valve 5 through the conduits 47 and 53 acts so that the regulator valve 5 can control the line pressure corresponding to the N range. The regulator valve 5 supplies hydraulic pressure to the torque converter 1 through the pipe line 27, the torque control valve 29, and the pipe lines 35 and 39 connected thereto to release the damper clutch 31 and control the damper clutch. It continues to supply to the lubrication part of the power train through the pipe lines 41 and 43 communicated by the valve 33.

The line pressure supplied to the reducing valve 13 is controlled to the reducing pressure by the reducing valve 13, and the controlled reducing pressure is the damper clutch control solenoid valve 15 connected to the reducing pressure lines 23 and 25. And first, second, and third pressure control solenoid valves (17, 19, 21).

In addition, the line pressure supplied to the manual valve 45 is supplied to the servo release control valve 95 through the conduit 47 connected thereto to move the valve spool 111 to the right as seen in the drawing, and at the same time fail. It is supplied to the safe valve 79 to move its valve spool 115 to the left in the figure.

(1-2 shift)

As shown in FIG. 3, when the throttle opening degree is increased in the D range 1 speed state as described above, the transmission control unit TCU controls the damper clutch control solenoid valve 15 and the first, 2, 3, 4 pressure control solenoid valves 17, 19, 21, 51 are controlled on, off, off, on and off, respectively.

Therefore, the damper clutch control valve 33 is controlled to communicate the conduit 37 with the conduit 41, thereby supplying hydraulic pressure supplied to the conduit 37 to the damper clutch 31 operating side of the torque converter 1 to operate it. .

And the hydraulic pressure supplied to the pipeline 61 communicated with the manual valve 45 is supplied to the 3rd pressure control valve 59, if only the part different from 1st speed is demonstrated.

At this time, the third pressure control valve 59 is operated by the off control of the third pressure control solenoid valve 21 so that the hydraulic pressure supplied to the pipeline 61 is supplied through the pipeline 71. The hydraulic pressure supplied to the conduit 71 is supplied to the servo application 91 through the fail safe valve 79 and the conduit 87 connected thereto to operate the kick down brake 89. Therefore, the D range second speed is realized together with the actuating rear clutch 75.

At the same time, the hydraulic pressure supplied to the conduit 71 is supplied to the row control valve 83 to move the valve spool 103 to the left in the drawing.

(2-3 shift)

As shown in FIG. 4, when the throttle opening degree is increased in the D range 2 speed state as described above, the transmission control unit (TCU) has a damper clutch control solenoid valve 15 and the first, The 2, 3 and 4 pressure control solenoid valves 17, 19, 21 and 51 are controlled on, off, off, off and on respectively.

Therefore, the regulator valve 5 controls the line pressure only by the hydraulic pressure supplied to the forward pressure pipeline 47 as the control pressure of the fifth pressure control solenoid valve 51 is released.

And the hydraulic pressure supplied to the pipeline 61 communicated with the manual valve 45 is supplied to the 2nd pressure control valve 57, if it demonstrates only a part different from 2nd speed.

At this time, the second pressure control valve 57 is operated by the off control of the second pressure control solenoid valve 19 so that the hydraulic pressure supplied to the pipeline 61 is supplied through the pipeline 69. The hydraulic pressure supplied to the conduit 69 is supplied to and operated by the end clutch 99 through the row control valve 83 and the conduit 97 connected thereto.

In addition, some of the hydraulic pressure supplied to the pipeline 97 is supplied to the control switch valve 77 and supplied to the servo release 109 through the pipeline 107, and at the same time, the valve spool 113 is moved to the left in the drawing. In addition, it is supplied to the servo release control valve 95 to move its valve spool 111 to the left in the drawing.

Therefore, some of the hydraulic pressure supplied to the rear clutch 75 through the conduit 67 is a servo release control valve 95, a control switch 77 connected to the conduit 105, and a servo connected to the conduit 107. Supplied to release 109 to release kick-down brake 89.

As a result, the end clutch 99 is operated together with the actuating rear clutch 75 to realize the D range third speed.

At this time, the hydraulic pressure acting on the servo release 109 acts on one side of the fail-safe valve 79.

(3-4 shift)

As shown in FIG. 5, when the throttle opening degree is increased in the D range 3 speed state as described above, the transmission control unit TCU controls the damper clutch control solenoid valve 15 and the first, 2, 3, 4 pressure control solenoid valves 17, 19, 21, 51 are controlled on, on, off, off and on, respectively.

Therefore, when only the third speed and the other parts are described, the first pressure control valve 55 operates in reverse to discharge the hydraulic pressure supplied to the conduit 67 to release the rear clutch 75, and to release the servo release 109. Release the kickdown brake to actuate 89.

As a result, the kick-down brake 89 in accordance with the operation of the pre-operating end clutch 99 and the servo application 91 is operated to realize the D range 4 speed.

At this time, the hydraulic pressure acting on one side of the fail-safe valve 79 and one side of the control switch valve 77 is discharged from the first pressure control valve 55, and the hydraulic pressure acting on the other side of the fail-safe valve 79 is It is discharged through the control switch valve 77 and the servo release control valve 95.

(N-R shift)

If the shift lever is moved to the R range and the throttle opening degree is increased in the N range as described above, as shown in Fig. 6, the transmission control unit (TCU) has a damper clutch control solenoid valve to realize the R range 1 speed. Each of the 15 and the first, second, third and fourth pressure control solenoid valves 17, 19, 21 and 51 is turned off, on, off, off and off.

Therefore, when only the N range and other parts are described, the line pressure supplied to the manual valve 45 is supplied to the front clutch 75 through the conduit 49 to operate the reverse pressure, and simultaneously the pipe 65 is operated. It is supplied to the NR control valve 63 through.

At this time, the hydraulic pressure supplied to the forward pressure pipeline 47 is discharged through the manual valve 45. Therefore, the hydraulic pressure acting on one side of the fail-safe valve 79 and the servo release control valve 95 is also discharged, and the valve spool 111 of the servo release valve 95 is moved to the left side in the drawing.

The N-R control valve 63 is operated and the line pressure supplied to the conduit 65 is supplied to the low-reverse brake 93 through the conduit 73 communicated thereto to operate the reverse-speed 1 to achieve the reverse speed.

At this time, the hydraulic pressure supplied to the low-reverse brake 93 is supplied to one side of the fail-safe valve 79 to move the valve spool 115 to the right in the drawing.

(N-L manual shifting)

If the shift lever is moved to the L range and the throttle opening degree is increased in the N range as described above, as shown in Fig. 7, the transmission control unit (TCU) is a damper clutch control solenoid valve to realize the L range 1 speed. 15 and the first, second, third and fourth pressure control solenoids 17, 19, 21 and 51 are controlled to be off, off, off, on and off, respectively.

Therefore, only the parts different from the N range, the line pressure supplied to the manual valve 45 is controlled by the first, second and third pressure control valves 55, 57, 59 and the low control through the pipe lines 61 and 95. Each is supplied to the valve 83. And the hydraulic pressure supplied to the row control valve 83 acts on one side thereof to move the valve spool 103 to the right side as seen in the drawing to communicate the pipelines (69, 101).

At this time, the first pressure control valve 55 is operated by the off control of the first pressure control solenoid valve 17 so that the hydraulic pressure supplied to the pipeline 61 is supplied through the pipeline 67. The hydraulic pressure supplied to this conduit 67 is supplied to the rear clutch 75 to operate it.

Then, the second pressure control valve 57 is operated by the off control of the second pressure control solenoid valve 19 so that the hydraulic pressure supplied to the pipeline 61 is supplied through the pipeline 69. The hydraulic pressure supplied to the conduit 69 is supplied to and operated by the low-reverse brake 93 via the conduits 101 and 73 connected thereto via the row control valve 83.

Therefore, the low-reverse brake 93 is operated together with the rear clutch 75 to realize the L range 1 speed.

At the same time, the hydraulic pressure supplied to the conduit 67 is supplied to the control switch valve 77 to move its valve spool 113 to the right side as shown in the drawing, and is supplied to the servo release control valve 111 to stand by and fail. It is supplied to one side of the safe valve 79 and acts. In addition, the hydraulic pressure passing through the pipelines 69, 101, and 67 also acts on one side of the fail-safe valve 79 to overcome the hydraulic pressure supplied to the pipeline 47, and move the valve spool 115 to the right in the drawing.

(3 speed control with low control valve stuck to the right)

On the other hand, when the valve spool 113 of the lower control valve 83 is fixed to the right at the specific speed change stage, and the driving state of the vehicle such as the vehicle speed and the throttle opening degree satisfies the 3-speed condition, the transmission control unit (TCU) 8 controls all of the first, second and third pressure control solenoid valves 17, 19 and 21 in the OFF state as shown in FIG.

Therefore, the hydraulic pressure supplied to the conduit 47 connected to the manual valve 45 is supplied to the servo release valve 95 to move its valve spool 111 to the right side in the drawing.

The hydraulic pressure supplied to the conduit 61 connected to the manual valve 45 is supplied to the first, second and third pressure control valves 55, 57 and 59.

At this time, the first pressure control valve 55 is operated by the off control of the first pressure control solenoid valve 17 so that the hydraulic pressure supplied to the pipeline 61 is supplied through the pipeline 67. The hydraulic pressure supplied to this conduit 67 is supplied to the rear clutch 75 to operate it.

Then, the second pressure control valve 57 is operated by the off control of the second pressure control solenoid valve 19 so that the hydraulic pressure supplied to the pipeline 61 is supplied through the pipeline 69. The hydraulic pressure supplied to the conduit 69 is supplied to the low-reverse brake 93 via the conduits 101 and 73 connected thereto via the row control valve 83 to which the valve spool 103 is fixed to the right. It works.

Therefore, the low-reverse brake 93 is operated together with the rear clutch 75 to realize the same state as the L range 1 speed.

At the same time, the hydraulic pressure supplied to the conduit 67 is supplied to the control switch valve 77 to move the valve spool 113 to the right side in the drawing, and is supplied to the fail-safe valve 79. The hydraulic pressure supplied to the conduits 69, 101, and 73 is also supplied to the fail safe valve 79.

In addition, the third pressure control valve 59 is operated by the off control of the third pressure control solenoid valve 21 so that the hydraulic pressure supplied to the pipeline 61 is supplied through the pipeline 71. The hydraulic pressure supplied to the conduit 71 is supplied to one side of the row control valve 83, but the valve spool 103 is fixed to prevent any action, and is supplied to the fail-safe valve 79.

Therefore, the fail-safe valve 79 is the hydraulic pressure acting on the left side of the valve spool 115 as seen in the drawing to overcome the hydraulic pressure acting on the right side thereof so that the valve spool 115 is moved to the right side as seen in the figure. Therefore, when the servo application 91 is in operation, the hydraulic pressure acting on the servo application 91 may be discharged to prevent the kickdown brake 89 from being operated, thereby preventing the power train from interlocking.

(4-2 Transmission control unit (TCU) malfunction during skip control)

On the other hand, if the transmission control unit (TCU) is in a malfunction state during the skip control at the second speed in the D range 4 speed state as described above, as shown in Figure 9, the first, second, third pressure control solenoid valve ( 17, 19, and 21 are all turned off.

In particular, the second pressure control solenoid valve 19 is controlled on and then off.

Therefore, the hydraulic pressure which operated the end clutch 99 is discharged via the conduit 97, the row control valve 83, the conduit 69, and the second pressure control valve 57 to release the end clutch 99.

As the hydraulic pressure supplied to the conduit 97 is discharged, the valve spool 111 of the servo release control valve 95 is moved to the right as viewed in the drawing by the hydraulic pressure supplied to the conduit 47, and the control switch valve ( The hydraulic pressure acting on one side of 77 is also discharged at the same time.

In the above state, the first pressure control valve 55 is operated by the off control of the first pressure control solenoid valve 17 to supply hydraulic pressure to the rear clutch 75 through the pipe line 67. It is supplied to operate it, and is supplied to the fail-safe valve 79 to move its valve spool 115 to the right.

In addition, the hydraulic pressure supplied to the pipe line 67 waits for supply to the servo release control valve 95, and is supplied to the control switch valve 77 to act on the valve spool 113 thereof to move the valve spool 113 to the right. It is supplied to the fail-safe valve 79 to move the valve spool 115 to the right. Therefore, the hydraulic pressure acting on the servo application 91 is discharged through the conduit 87 and the fail safe valve 87 to release the kickdown brake 89.

In this state, the second pressure control valve 57 is operated by the off control of the second pressure control solenoid valve 19 to supply hydraulic pressure to the pipeline 61 through the pipeline 69 to the low control valve 83. do.

At this time, the third pressure control valve 59 is operated by the off control of the third pressure control solenoid valve 21 so that the hydraulic pressure supplied to the pipeline 61 is supplied to the low control valve 83 through the pipeline 71. Its valve spool 103 is moved to the left as seen in the figure, and is supplied to the fail-safe valve 79 and to the servo application 91 connected to the conduit 87.

Therefore, the hydraulic pressure supplied to the conduit 69 connected to the second pressure control valve 57 is supplied to the end clutch 99 through the conduit 97 communicated by the low control valve 83 to operate the rear clutch. Together with (75), three speeds are achieved.

At this time, the hydraulic pressure supplied to the conduit 97 is supplied to the servo release control valve 95 to move its valve spool 111 to the left as shown in the drawing, and to the fail-safe valve 79 to supply the valve spool. 115 further exerts an action force moving to the right, and is supplied to the control switch valve 77 to move its valve spool 113 to the left as seen in the figure.

Therefore, the hydraulic pressure that has been waiting for the servo release control valve 95 through the pipeline 67 is supplied to the servo release 109 through the pipeline 105, the control switch valve 77, and the pipeline 107 connected thereto. The kick-down brake 89 is released to control the complete D range 3 speed state.

As a result, the fail-safe valve 79 has a hydraulic pressure acting on the right side of the valve spool 115 to overcome the hydraulic pressure acting on the left side. Therefore, when the servo application 91 is in operation, the servo release 109 may be simultaneously operated to prevent the kickdown brake 89 from being operated, thereby preventing the power train from interlocking.

As described above, the hydraulic control system for an automatic transmission according to the present invention realizes 4 forward speeds and 1 reverse speed as well as a fail-safe means, so that the transmission control unit (TCU) cannot control during the control to a specific shift stage. The hydraulic pressure supplied from the means, and even when a part of the flow path control means is inoperable, releases a specific friction element that generates the interlock, thereby enabling smooth hydraulic control.

Claims (4)

A line pressure control means connected to the line pressure line to control and supply the oil pressure supplied from the oil pressure generating means to a line pressure having a constant pressure amplitude; A damper clutch control means connected to the torque converter to control a flow path of some of the hydraulic pressures supplied from the line pressure control means to control a damper clutch embedded in the torque converter; A reducing pressure control means connected to a reducing pressure pipe to control the line pressure supplied from the line pressure control means to a reducing pressure which is a control pressure of each solenoid valve and to supply each solenoid valve; Range control means connected to each range conduit to supply the line pressure supplied from the line pressure control means to a range conduit corresponding to each range according to a range selection operation of the shift lever; Since each solenoid valve controls the reducing pressure supplied from the reducing pressure control means, the line pressure supplied from the range control means is duty controlled to provide a servo application of the front clutch, the rear clutch, the end clutch, the low-reverse brake and the kick-down brake. And pressure control means connected to supply and discharge hydraulic and hydraulic pressure of each servo release. The pressure control means is controlled by the hydraulic pressure supplied from the range control means and the pressure control means to change the flow path connecting the pressure control means and the friction element so as to discharge the hydraulic pressure supplied to the friction element or the hydraulic pressure supplied to the friction element. Flow passage control means provided between the friction elements; It is controlled by the interaction of the hydraulic pressure supplied from the range control means and the pressure control means and the flow path control means, when the control of the transmission control unit (TCU) during the control to a specific shift stage and a part of the flow path control means are inoperable. And a fail-safe means for interrupting the hydraulic pressure supplied from said means in any one or more of the cases and for discharging the hydraulic pressure acting on a particular friction element to prevent interlocking of the power train. The pressure control means is connected to the line pressure supplied from the range control means to discharge the hydraulic pressure supplied and supplied to one side of the rear clutch and the flow path control means because the first pressure control solenoid valve duty control the reducing pressure. A first pressure control valve; The second pressure control solenoid valve controls the reducing pressure so that the line pressure supplied from the range control means is connected to discharge the hydraulic pressure supplied and supplied to the end clutch, the low-reverse brake and the fail safe means through the flow path control means. 2 pressure control valve; The third pressure control solenoid valve controls the reducing pressure so that the line pressure supplied from the range control means is discharged to the servo application of the kick-down brake and the hydraulic pressure that has been supplied and supplied directly to the low-reverse brake via the fail-safe means. Hydraulic control system for an automatic transmission comprising a third pressure control valve and the NR control valve connected. 2. The flow path control apparatus according to claim 1, wherein: the flow path control means comprises a row control valve, a servo release control valve, and a control switch valve; The row control valve is controlled by the hydraulic pressure supplied from the range control valve and the hydraulic pressure supplied from the second pressure control valve of the hydraulic control means consisting of the first, second, third, NR control valves Connected to discharge hydraulic pressure selectively supplied and supplied between the end clutch and the fail safe means and the low-reverse brake and the fail safe means; The servo release control valve is controlled by the interaction of the hydraulic pressure supplied from the range control means and the hydraulic pressure supplied to the end clutch so that the hydraulic pressure supplied to the rear clutch can be supplied to the control switch valve or the hydraulic pressure that has been blocked and supplied can be discharged. Connected; The control switch valve is controlled by the interaction of the hydraulic pressure supplied to the rear clutch and the hydraulic pressure supplied to the end clutch to selectively supply and supply the hydraulic pressure supplied to the end clutch and the hydraulic pressure supplied from the servo release control valve to the servo release. Hydraulic control system for an automatic transmission, characterized in that connected to discharge the hydraulic pressure. 2. The fail-safe means according to claim 1, wherein the fail-safe means is supplied to a low-reverse brake, a rear clutch, and an end clutch provided in a direction corresponding to the sum of the hydraulic pressure supplied from the range control means and the hydraulic pressure supplied to the servo release. And a fail-safe valve which is controlled by interaction with the hydraulic force and connected to discharge the hydraulic pressure supplied from the third pressure control valve of the hydraulic control means to the servo application. Hydraulic control system for transmission.

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