KR100290404B1 - 2-3/4-3 shift valve for hydraulic control system - Google Patents

Abstract

PURPOSE: A 2-3/4-3 shift valve for a hydraulic control system is provided to improve the durability of an automatic transmission, and to reduce shift shock by restricting the stick of a valve with preventing leakage of line pressure. CONSTITUTION: Line pressure from a manual valve(1) corresponding to each range is supplied to a shift control unit(3), a pressure control unit(5) and a hydraulic distributing unit(7) to control friction factors including a front clutch, a rear clutch, an end clutch, a low reverse brake and a kickdown band brake. A valve spool(37) is installed in a bore, and hydraulic pressure is discharged corresponding to fluctuation of line pressure. Control pressure from the pressure control unit is prevented from leaking into the control passage with a line pressure discharge unit. Valve stick or leakage of line pressure is prevented by discharging the fluctuation of line pressure.

Description

2-3 / 4-3 Shift Valve for Hydraulic Control System

The present invention relates to a hydraulic control system for an automatic transmission, and more particularly to a 2-3 / 4-3 shift valve for a hydraulic control system to prevent the stick of the valve spool to improve the durability and shifting feeling of the transmission.

In general, the hydraulic control system which realizes 4 forward speed and 1 reverse speed by controlling the front transmission, rear clutch, end clutch, low-reverse brake and kick-down band brake by the friction element is supplied from the oil pump. It is configured to control the hydraulic pressure to the line pressure to supply to the manual valve.

In addition, the hydraulic control system has a friction corresponding to the shift stage through a flow path formed by the shift control unit, the pressure control unit, and the hydraulic distributor in the manual valve according to the range selection operation of the manual valve that operates corresponding to the range selection of the shift lever. It is formed to supply hydraulic pressure to the element.

The hydraulic distributor may be controlled by a control pressure supplied from a manual valve and a shift control unit to supply the hydraulic pressure supplied from the pressure control unit or the shift control unit to a friction element corresponding to the shift stage, or to learn the supplied hydraulic pressure. Angular velocity shift valves (1-2 shift valves, 2-3 / 4-3 shift valves) and clutch valves (rear clutch release valves and end clutch valves) are provided to change the flow paths so as to change the flow paths.

The 2-3 / 4-3 shift valve is configured to be controlled at 2, 3, and 4 speeds, respectively, and is connected to supply a shift control part and a line pressure and to supply a control pressure from the pressure control part.

Therefore, in order to prevent the 2-3 / 4-3 shift valve because the line pressure supplied from the shift control unit leaks to the control flow path and the control pressure deviation may be caused by the difference in the leakage amount due to the line pressure fluctuation, The bore is machined to have tight tolerances to minimize leakage of line pressure.

However, the 2-3 / 4-3 shift valve for the hydraulic control system as described above has a tightly processed tolerance between the valve spool and the bore to which the valve spool is mounted. Therefore, the valve is frequently shifted to 2, 3 and 4 speeds. There is a disadvantage in that the spool is a stick phenomenon that is fixed to the bore, deteriorating the durability and the sense of shift of the automatic transmission due to the malfunction of the friction element.

Therefore, the present invention was created to solve the above disadvantages, an object of the present invention is to prevent the leakage of the line pressure to the control channel while preventing the valve stick to deteriorate the durability and the sense of shift of the automatic transmission due to the valve stick. Provides 2-3 / 4-3 shift valves for hydraulic control systems.

In order to realize this, the 2-3 / 4-3 shift valve for the hydraulic control system according to the present invention;

Forming a flow path for supplying hydraulic pressure to the friction element or discharging the supplied hydraulic pressure by controlling the hydraulic pressure distribution part by the line pressure supplied by the shift control part supplied with the hydraulic pressure from the manual valve and the hydraulic pressure supplied by the manual valve;

In the hydraulic control system for operating the friction element by supplying a pressure controlled control pressure in the pressure control unit to the flow path from the pressure control unit supplied with the hydraulic pressure from the manual valve,

As a component of the hydraulic distribution unit, while mounting the valve spool to the bore at a general tolerance, the hydraulic pressure corresponding to the pressure fluctuations of the line pressure supplied from the shift control unit is discharged, thereby rubbing the control pressure supplied from the pressure control unit. Pressure fluctuation line pressure discharge means for preventing leakage to the control flow passage to the urea is provided.

The 2-3 / 4-3 shift valve for the hydraulic control system configured as described above discharges the pressure fluctuation of the line pressure supplied when the pressure fluctuation line pressure discharge means is shifted, thereby preventing the line pressure from leaking to the control flow path. do.

BEST MODE Hereinafter, preferred configurations and operations of the present invention will be described in detail with reference to the accompanying drawings.

1 is a hydraulic circuit diagram formed at D range 2 speed of a hydraulic control system to which a 2-3 / 4-3 shift valve according to the present invention is applied.

Figure 2 is a hydraulic circuit diagram formed in the D range 2-3 shifting process of the hydraulic control system to which the 2-3 / 4-3 shift valve according to the present invention is applied.

3 is an operational state diagram showing in detail a state in which a 2-3 / 4-3 shift valve according to the present invention is controlled at D-speed 3;

4 is a hydraulic circuit diagram formed in a 3-4 shift process of the hydraulic control system to which the 2-3 / 4-3 shift valve according to the present invention is applied.

Fig. 5 is an operational state diagram showing in detail a state in which a 2-3 / 4-3 shift valve according to the present invention is controlled at D-speed 4;

> Explanation of symbols for main parts of drawing <

25: 2-3 / 4-3 shift valve 37: valve spool 39: bore 41, 43: control passage 45, 49, 51, 53: 1st, 2, 3, 4 land 55: pressure fluctuation line pressure discharge hole 59 61: 1st and 2nd oil leakage land EX: discharge port

1 is a hydraulic circuit diagram formed at the D range 2 speed of a hydraulic control system to which a 2-3 / 4-3 shift valve according to the present invention is applied, and shifts the line pressure corresponding to each range from the manual valve 1. It is supplied to the control unit 3, the pressure control unit 5, and the hydraulic distribution unit 7 to supply the front clutch (F / C), the rear clutch (R / C), the end clutch (E / C), and the low reverse brake. (LR / B) and kickdown band brakes (KD / B) are configured to control the friction elements.

The shift control unit 3 controls the 2, 3 and 4 speeds by the first and second shift control solenoid valves SS1 and SS2 controlled on and off by the transmission control unit TCU. It consists of a shift control valve 15 for discharging 2, 3, 4 speed pressures which were supplied or supplied to the conduits 9, 11 and 13.

In addition, the pressure control unit 5 is the first and second pressure control solenoid valves PS1 and PS2 duty-controlled by the transmission control unit TCU, and thus the line pressure supplied from the manual valve 1. It is composed of NR control valve 17, the first and second pressure control valves (19, 21) for supplying pressure to the hydraulic distribution unit (7) to discharge the control pressure was supplied.

On the other hand, the hydraulic distribution unit 7 is controlled by the hydraulic pressure supplied from the manual valve 1 and the shift control unit 3, so that the hydraulic pressure supplied from the hydraulic control unit 5 and the shift control unit 3 is shifted to each shift stage. It is configured to enable the formation of a flow path for discharging the hydraulic pressure supplied or supplied to the friction element corresponding to the.

That is, the hydraulic distribution unit 7 is a 1-2 shift valve 23, a 2-3 / 4-3 shift valve 5, a rear clutch discharge valve 27, an end clutch valve 29 operated at an angular speed. And a control switch valve 31 operated according to on / off control of the third shift control solenoid valve SS3, a high-low pressure valve 33, and a fail-safe valve 35 to prevent the transmission from failing. do.

The 2-3 / 4-3 shift valve 25 is operated at speeds 2, 3 and 4, respectively, to release the front clutch (F / C) and to release the kickdown band brate (KD / B). The valve spool 37 is provided in the bore 39 with a general tolerance.

The 2-3 / 4-3 shift valve 25 is configured to supply the line pressure supplied from the third speed pressure line 11 of the shift control unit 3, the four speed pressure line 13, and the rear clutch discharge valve 27. The hydraulic pressure corresponding to the pressure variation of the line pressure supplied via the gas is discharged, and the front clutch F / is connected via the first pressure control valve 19 and the 1-2 shift valve 23 of the pressure control part 5. And a pressure fluctuation line pressure discharge means for preventing the control pressure supplied to C) and the kick-down band brake KD / B from leaking to the control flow passages 41 and 43.

The pressure fluctuation line pressure discharging means discharges the pressure fluctuation of the line pressure supplied from the third speed pipeline 11 of the shift control section 5 at the time of 2-3 and 4-3 shifts, and at the time of 3-4 shifts. In order to simultaneously discharge the pressure fluctuations of the line pressure supplied through the third pressure pipeline 11 of the shift control unit 3 and the four-pressure pipeline 13 and the rear clutch discharge valve 27. Preferably formed.

The 2-3 / 4-3 shift valve 25 having such a pressure fluctuation line pressure discharging means is formed by the valve spool 37 and the bore 39 forming the ports.

That is, the valve spool 37, as shown in Fig. 3 and 5, the first land 45 and the four-speed pressure pipe to which the line pressure supplied from the three-speed pressure pipe 11 of the shift control unit 3 acts. (13) and a sleeve 47 to which the line pressure supplied via the rear clutch discharge valve 27 acts.

And the valve spool 37 and the front clutch (F / C) as a friction element to control the pressure supplied via the first pressure control valve 19, 1-2 shift valve 23 of the pressure control unit (5) Second and third lands 49 and 51 are formed between the first land 45 and the sleeve 47 so as to discharge the control pressure supplied or supplied to the kick-down band brake KD / B.

Furthermore, the valve spool 37 has a line pressure which acts on the first land 45 and leaks to the second land 49 and a fourth land formed on the side of the third land 51 by acting on the sleeve 47. A pressure fluctuation line pressure discharge hole 55 is formed inside thereof so as to discharge the line pressure leaked to the 53 side.

The valve spool 37 is supported by the elastic member 57 interposed between the fourth land 53 and the sleeve 47 provided on the opposite side thereof.

In addition, between the first and second lands 45 and 49 of the valve spool 37, the first leakage prevention for preventing the leakage of the line pressure acting on the first land 45 to the control lines 41 and 43, which leaks. The land 59 is formed, and the second leakage preventing land (L) is formed between the third and fourth lands 51 and 53 to prevent the line pressure acting on the sleeve 47 from leaking to the control lines 41 and 43. 61) is formed.

On the other hand, the bore 39 is provided with a discharge port (EX) for discharging when the line pressure acting on any one or more sides of the valve spool 37 is leaked.

It is preferable that the discharge port EX and the pressure fluctuation line pressure discharge hole 55 are always communicated.

As described above, the first and second leakage preventing lands 59 and 61 formed in the valve spool 37 and the bore 39 and the discharge port EX are illustrated as one of the pressure fluctuation line pressure discharge means. Even if the configuration is not the same, all of the above functions are included in the pressure fluctuation line pressure discharge means.

When the vehicle having the hydraulic control system to which the 2-3 / 4-3 shift valve 25 is configured as described above is started, the D lever is selected as the shift lever, and the throttle opening degree is increased. The TCU controls the first, second, and third shift control solenoid valves SS1, SS2, and SS3 on / off and the duty control of the first and second pressure control solenoid valves PS1 and PS2.

(2 speed)

First, as shown in FIG. 1, the transmission control unit TCU turns off the first, second and third shift control solenoid valves SS1, SS2, and SS3, respectively, in order to realize the second speed. And the first and second pressure control solenoid valves PS1 and PS2 are duty controlled.

Therefore, the manual valve 1 supplies the line pressure to the 2nd pressure pipeline 9 and the 1st, 2nd pressure control valves 19 and 21 via the shift control valve 15. FIG. The line pressure supplied to the second speed pipeline 9 controls the hydraulic distribution unit 7 so that the 1-2 shift valve 23 is fitted at the second speed.

Therefore, the control pressure controlled by the second pressure control valve 21 is supplied to the rear clutch R / C through the rear clutch valve 27 to operate it, and the control pressure controlled by the first pressure control valve 19. Is supplied to the servo application (S / A) of the kick-down band brake (KD / B) via the 1-2 shift valve (23), the control switch valve (31), and the fail-safe valve (35). 2 speeds are achieved.

At this time, the control pressure via the 1-2 shift valve 23 is supplied to the 2-3 / 4-3 shift valve 25 through the control pressure line 43, and the third and fourth lands 51, 53 thereof. Is stopped by).

(2-3 shift)

When the throttle opening degree is increased in the second speed state as described above, the transmission control unit (TCU) turns off the first, second and third shift control solenoid valves SS1, SS2, and SS3 as shown in FIG. And ON, respectively, and duty-control the first and second pressure control solenoid valves PS1 and PS2.

Therefore, the line pressure supplied to the three-speed pressure pipe 11 connected to the shift control valve 15 is supplied to the 2-3 / 4-3 shift valve 25 to move the valve spool 37 to the right as shown in the drawing. The control passages 41 and 43 are interlocked to supply the control pressure, which has been waiting, to the front clutch F / C to operate it.

And the control pressure for operating the front clutch (F / C) is supplied to the servo release (S / R) to release the kick-down band brake (KD / B) even when the servo application (S / A) is operated. At this time, the hydraulic pressure supplied to the servo application S / A is controlled by the second speed pipeline 9, the control switch valve 31 controlled by the third shift control solenoid valve SS3, and the fail safe valve 35. It is line pressure passing through.

And the pressure-controlled hydraulic pressure in the first pressure control valve 19 is supplied to the end clutch (E / C) via the 1-2 shift valve 23, the control switch valve 31 to operate it 2-3 shifts To realize.

When realizing the 2-3 shift as described above, the line pressure supplied to the 3-speed pressure pipe 11 is the first land 47 of the 2-3 / 4-3 shift valve 25, as shown in FIG. This valve spool 37 is moved to the right as seen in the drawing.

At this time, if the line pressure acting on the first land 45 has a large pressure fluctuation, the pressure fluctuation line pressure discharge hole 55 as shown by the arrows by the first land 45 and the first leakage preventing land 59. Guided to the discharge port (EX) is discharged.

Accordingly, while the valve stick is prevented during the 2-3 shift, the line pressure is prevented from leaking to the control passages 41 and 43 even though the line pressure has a large pressure fluctuation.

(3-4 shift)

Increasing the throttle opening degree in the three-speed state as described above causes the transmission control unit (TCU) to turn on and off the first, second and third shift control solenoid valves SS1, SS2 and SS3 as shown in FIG. And off, respectively, and duty-control the first and second pressure control solenoid valves PS1 and PS2.

Therefore, the line pressure supplied to the four-speed pressure line 13 connected to the shift control valve 15 is supplied to the rear clutch discharge valve 27 to control the discharge, thereby discharging the control pressure for operating the rear clutch R / C. Free this.

At the same time, the line pressure supplied to the four-speed pressure line 13 is supplied to the 2-3 / 4-3 shift valve 25 via the rear clutch discharge valve 27, and the valve spool 37 thereof is shown on the left side in the drawing. To control the flow paths 41 and 43, and discharge the control pressure acting on the front clutch F / C and the servo release S / R to the manual valve 1 so that the front clutch F / C Free)

Since the control pressure of the servo release S / R is released and the servo application S / A continues to operate, the kickdown band brake KD / B is activated and the end clutch E / C continues. Operate to achieve 3-4 shifts.

On the other hand, since the third shift control solenoid valve SS3 is controlled to be off, the control switch valve 31 is operated so that the hydraulic pressure for operating the end clutch E / C and the servo application S / A is a three-speed pipeline 11. ) And the control pressure of the first pressure control valve 19 via the 1-2 shift valve 23, respectively.

When realizing the 3-4 shift as described above, the line pressure supplied to the four-speed pressure line 13 is a 2-3 / 4-3 shift valve via the rear clutch discharge valve 27, as shown in FIG. It acts on the sleeve 47 of 25 to move this valve spool 37 to the left as seen in the figure.

At this time, if the line pressure acting on the sleeve 47 has a large pressure fluctuation, the discharge port is guided by the sleeve 47, the fourth land 53, and the second leakage preventing land 61 as an arrow. Discharged to (EX).

Thus, while the valve stick is prevented at the time of 3-4 shift, the line pressure is prevented from leaking to the control passages 41 and 43 even if the line pressure has a large pressure fluctuation.

(4-3 shift)

Since the 4-3 shift process is considered to be the inverse of the 3-4 shift process, a detailed description thereof will be omitted.

At this time, the 2-3 / 4-3 shift valve 25 is controlled and operated in the state of FIG. 3, and thus has the same effect as when shifting 2-3.

As described above, the 2-3 / 4-3 shift valve for the hydraulic control system according to the present invention discharges the pressure fluctuation of the line pressure supplied when the pressure fluctuation line pressure discharging means is shifted while the valve spool is mounted to the bore at a general tolerance. Therefore, it is possible to prevent the valve stick phenomenon and to prevent the line pressure from leaking to the control channel.

As described above, the 2-3 / 4-3 shift valve for the hydraulic control system of the present invention can prevent deterioration of durability and shifting feeling of the automatic transmission due to the valve stick.

Claims (5)

As a manual valve, the hydraulic pressure is controlled by the line pressure supplied from the shift control unit supplied with the hydraulic pressure from the valve and the hydraulic pressure supplied from the manual valve to form a flow path for supplying hydraulic pressure to the friction element or discharging the supplied hydraulic pressure. In the hydraulic control system for operating the wagon element by supplying a pressure controlled control pressure to the flow path from the pressure control unit received the hydraulic pressure from the manual valve, As a component of the hydraulic distribution unit, the valve spool is mounted to the bore with a general tolerance, so that the hydraulic pressure corresponding to the pressure variation of the line pressure supplied from the shift control unit during the 2-3, 3-4, and 4-3 shifts can be applied. A pressure fluctuation line pressure discharge means for discharging to prevent leakage of the control pressure supplied from the pressure control part to the control flow path for supplying the friction element, The pressure fluctuation line pressure discharge means includes a first element and a sleeve in which the line pressure supplied from the shift control unit acts, and a control pressure formed between the first land and the sleeve and supplied from the pressure control unit. Second and third lands formed so as to discharge the control pressure that has been supplied or supplied to the first and second line formed on the side of the third land by acting on the line pressure and the sleeve that acts on the first land and leak to the second land. A valve spool including a pressure fluctuation line pressure discharge hole formed to discharge the line pressure leaked to the four land side; A 2-3 / 4-3 shift valve for a hydraulic control system, comprising a bore having a discharge port for discharging the line pressure acting on at least one side of both sides of the valve spool. The 2-3 / 4-3 shift valve for a hydraulic control system according to claim 1, wherein the valve spool interposes an elastic member between the fourth land and the sleeve interposed therebetween. The hydraulic control method according to claim 1, wherein a first leakage preventing land is formed between the first and second lands of the valve spool to prevent the line pressure acting on the first land from leaking into the control line. 2-3 / 4-3 shift valve for the system. 2. The hydraulic leakage control system of claim 1, wherein a second leakage prevention land is formed between the third and fourth lands of the valve spool to prevent leakage of the line pressure acting on the sleeve to the control line. / 4-3 shift valve. The 2-3 / 4-3 shift valve for a hydraulic control system according to claim 1, wherein the pressure fluctuation line pressure discharge hole and the discharge port are formed to be always in communication.

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