KR20050051374A - Hydraulic control system of automatic transmission - Google Patents

Abstract

After the three-speed synchronization is completed by separating before and after the three-speed sync point, the fluid supplied to the release side of the front clutch and the kick-down servo is supplied quickly through the flow path without orifice without being supplied through the orifice. Reduced hold time improves the shifting feeling when shifting 2 → 3 → 4 lift foot-up, and during 3 → 4, 3 → 2 shifting, the fluid supplied to the release side of the front clutch and kick-down servo is discharged through the orifice. To provide a hydraulic control system such that back pressure control can be made;

A switch valve for switching the flow path is arranged at the downstream side of the 2-3 / 4-3 shift valve for switching the supply and release fluid of the release chamber of the front clutch and the kick-down servo by the flow rate. It provides a hydraulic control system of an automatic transmission for a vehicle made.

Description

HYDRAULIC CONTROL SYSTEM OF AUTOMATIC TRANSMISSION}

The present invention relates to a hydraulic control system of an automatic transmission.

In general, an automatic transmission has a torque converter and a multistage shift 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 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.

Referring to the conventional configuration of the hydraulic control system, as shown in Figure 6, the oil pressure generated from the oil pump 200 is a pressure control valve 202, a torque converter control valve 204, a damper clutch control valve ( 206).

In addition, a part of the hydraulic pressure generated from the oil pump 200 is supplied to the reducing valve 208 and the manual valve 210, the constant pressure reduced in the reducing valve 208 is the first pressure control valve ( 212 and the second pressure control valve 214 is controlled to the control pressure of the gear stage.

A part of the hydraulic pressure supplied to the first and second pressure control valves 212 and 214 is supplied to the NR control valve 216, and the hydraulic pressure flows when the manual valve 210 is in the travel (D) range. The pipeline 218 is connected to a shift control valve 220 for switching the flow path under the control of the first solenoid valve S1 and the second solenoid valve S2, and is configured to be manually and automatically shifted together with the manual valve 210 described above. Control is made.

The first speed pipe 222 is branched on the pipe 218 and connected to the first and second pressure control valves 212 and 214 controlled by the third and fourth solenoid valves S3 and S4. Supply pressure.

The shift control valve 220 is connected to the second speed pipeline 224, the third speed pipeline 226, the fourth speed pipeline 228, the second speed pipeline 224 is a 1-2 shift valve 230 and the control It is connected to the switch valve 232 and the fail-safe valve 234, the three-speed pipeline 226 is branched into two pipelines 236, 238 so that the first branch pipeline 236 is a pipeline 2-3 The fourth branch line 238 supplies hydraulic pressure to the control switch valve 232 and the end clutch valve 242.

In addition, the four-speed pipeline 228 is connected to the rear clutch release valve 244 and the 2-3 / 4-3 shift valve 240, and part of the pressure control valve 202 through the high-low pressure valve 246 ) To adjust the line pressure.

The timing control channel 248 of the manual valve 210 is connected to the control switch valve 232 and the high-low pressure valve 246 and controlled by the fifth solenoid valve S5.

In addition, when the manual valve 210 is in the reverse (R) range, the hydraulic pressure supplied to the reverse first control conduit 250 is transferred through the rear clutch release valve 244 and the 2-3 / 4-3 shift valve 240. The hydraulic pressure can be supplied to the release side chamber of the front clutch C4 and the kick-down servo C2, and a control pressure of the fail-safe valve 234 is supplied.

The hydraulic pressure supplied to the reverse second control pipe 252 supplies the hydraulic pressure to the low-reverse brake C5 through the NR control valve 216 and the 1-2 shift valve 230, and the second pressure control. An accumulator AC is disposed on a flow path connecting the valve 214 and the rear clutch release valve 244 to perform a buffering role when hydraulic pressure is supplied to the rear clutch C1.

In the hydraulic control system as described above, the control pressure of the first solenoid valve S3 is supplied to the release pressure of the front clutch C4 and the kick-down servo C2 through the 2-3 / 4-3 shift valve 240. The front clutch is fastened by the action of the front clutch pressure supplied through the upstream orifice OR of the 2-3 / 4-3 shift valve 240 during the shift from the second to the third speed. Simultaneously fill with release pressure to move the piston of the kicktown servo.

However, the piston of the kick-down servo has a problem that the application time pressure is applied, the longer the piston travel time, the longer the shift time.

If 3 → 4 shift or 3 → 2 shift occurs with only 3 speed synchronization, the flow rate is not supplied sufficiently to the release side of the kick-down servo, so back pressure control is not performed until the front clutch pressure is sufficiently formed. The problem involves maintaining the three-speed hold time.

Therefore, the present invention has been invented to solve the above-mentioned conventional problems, and an object of the present invention is to distinguish between the front clutch and the kick-down servo after the three-speed synchronization is completed by dividing before and after the three-speed sync point in the 2 → 3 shift. Reduces the 3-speed shifting time by allowing fluid to be supplied to the release side through the orifice without flow through the orifice, thereby reducing the shifting time when shifting 2 → 3 → 4 lift foot-ups. To provide a hydraulic control system.

In the case of shifts of 3 → 4 and 3 → 2, the fluid supplied to the release side of the front clutch and the kick-down servo is discharged through the orifice to control the back pressure, thereby improving the feeling of shifting and improving the overall shifting performance. Provide hydraulic control system.

In order to realize this, the present invention converts a flow path by a shift control valve controlled by two solenoid valves, a manual valve linked to a select lever operated by a driver, and hydraulic pressure supplied from first and second pressure control valves. At the same time, this hydraulic pressure is applied to the rear clutches operating in forward 1,2,3 speeds, kick-down brakes operating in 2nd and 4th forwards, front clutches operating in 3rd forward and reverse, and 3rd and 4th forwards. And a plurality of spool valves to selectively supply hydraulic pressure to the low-reverse brakes operating in reverse,

A switch valve for switching the flow path is arranged on the downstream side of the 2-3 / 4-3 shift valve for switching the supply and release fluid of the release chamber of the front clutch and the kick-down servo to the flow path. It provides a hydraulic control system of an automatic transmission for a vehicle made.

Hereinafter, with reference to the accompanying drawings, preferred embodiments of the present invention that can specifically realize the above object will be described in detail.

1 is a hydraulic circuit diagram of a hydraulic control system according to the present invention. The torque converter 2 receives power from an engine and converts torque to a transmission side, and an oil pump 4 is required for the torque converter and the shift stage control. It generates and discharges oil and oil necessary for lubrication.

The oil pressure generated from the oil pump 4 includes a pressure regulating valve 6 which makes the oil pressure constant, a torque converter control valve 8 which constantly adjusts the torque converter and lubrication oil pressure, and a power of the torque converter. It is supplied to a damper clutch control valve 10 to increase the transmission efficiency.

In addition, a part of the oil generated from the oil pump 4 is a manual valve for switching the flow path while interlocking with the reducing valve 12 and the selector lever in the driver's seat to keep the pressure always lower than the line pressure. The constant hydraulic pressure supplied to the valve 14 and reduced in the reducing valve 12 is supplied to the control pressure of the first pressure control valve 16 and the second pressure control valve 18.

A part of the hydraulic pressure supplied to the first and second pressure control valves 16 and 18 is supplied to the NR control valve 20 which reduces shift shock when the mode is changed from the neutral range to the reverse range. When 14 is in the travel (D) range, the hydraulic passage flows through the channel 22 under the action of the first solenoid valve S1 and the second solenoid valve S2 controlled on / off by the transmission control unit. The switching shift control valve 24 communicates with each other to achieve manual and automatic shift control together with the manual valve 14 described above.

In addition, a first-speed pipe line 26 is branched on the pipe line 22 to supply line pressure to the first and second pressure control valves 16 and 18, and the first and second pressure control valves 16 are provided. 18, the flow path is switched by the control pressure of the third and fourth solenoid valves S3 and S4.

As described above, the control pressure of the first pressure control valve 16 among the pressure control valves controlled by the third and fourth solenoid valves S3 and S4 branches through the 1-2 shift valve 28 so that a part of the pressure is low. -To the reverse brake (C5), some branched again from the control switch valve (30) to the application chamber (S / A) of the kick-down brake (C2) via the end clutch (C3) or fail-safe valve (32); ) Or to the 2-3 / 4-3 shift valve 34.

The control pressure of the second pressure control valve 18 is supplied to the rear clutch C1 via the rear clutch release valve 36, and the second pressure control valve 18 and the rear clutch release valve 36 are provided. Accumulator (AC) is disposed on the pipe connecting the to perform a buffer against the hydraulic pressure flowing through the flow path.

The shift control valve 24 is connected to the second speed pipe 38, the third speed pipe 40, and the fourth speed pipe 42, and the second speed pipe 38 controls the 1-2 shift valve 28. Simultaneously with the supply of pressure, the operating pressure of the kick-down brake C2 is supplied through the control switch valve 30 and the fail-safe valve 32.

The third speed line 40 supplies the control pressure of the 2-3 / 4-3 shift valve 34 to the end clutch C3 via the end clutch valve 44 and the control switch valve 30. Supply hydraulic pressure.

In addition, the four-speed pipeline 42 supplies the control pressure of the rear clutch release valve 36 and is supplied to the pressure regulating valve 6 at the fourth forward speed through the high-low pressure valve 46 to supply the line pressure. Will be adjusted.

The manual valve 14 is connected to the timing control pipe 48 so that the hydraulic pressure flowing along the pipe is controlled by the fifth solenoid valve S5 to control the control valve 30 and the high-low pressure valve 46. Will be controlled.

When the manual valve 6 is in the reverse range, the hydraulic pressure supplied to the reverse first control conduit 50 is supplied to the control pressure of the rear clutch release valve 36 and at the same time a 2-3 / 4-3 shift valve. The supply pressure is controlled by the control pressure of the release chamber S / R of the front clutch C4 and the kick-down servo C2 and the fail-safe valve 32 through the 34.

The hydraulic pressure supplied to the second reverse control conduit 52 is supplied to the low-reverse brake C5 acting as a reaction force element at the reverse shift stage via the 1-2 shift valve 28 through the NR control valve 20. Supplied.

In addition, the 2-3 / 4-3 shift valve 34 is selectively controlled to supply the hydraulic pressure of the third speed pressure or the second pressure control valve 18 to the rear clutch C1 and the front clutch C4 while being controlled by the third speed pressure. Done.

 In such a hydraulic control system of an automatic transmission for a vehicle, the present invention arranges the switch valve 60 on the downstream side of the 2-3 / 4-3 shift valve 34 so that the front clutch C4 and the kick-down servo ( The hydraulic pressure supplied to C2) was controlled.

To this end, the switch valve 60 is configured as shown in Figure 2, the valve body of the switch valve 60 is the first port 62 is supplied with hydraulic pressure from the 2-3 / 4-3 shift valve 34 And a conduit 56 branched upstream of the orifice OR1 of the conduit 54 for supplying hydraulic pressure from the 1-2 shift valve 28 to the 2-3 / 4-3 shift valve 34. The hydraulic pressure supplied to the second port 64 and the first port 62 and the second port 64 is selectively provided to the release chamber S / R and the front clutch C4 of the kick-down servo C2. Including a third port 66 for supplying, a fourth port 68 for receiving a part of the hydraulic pressure supplied to the front clutch C4, and a fifth port 70 for supplying four speed pressures as a control pressure, Is done.

The valve spool embedded in the valve body has a first land 72 that selectively opens and closes the first port 62 while acting on a control pressure supplied to the fourth port 68, and the first land 72. ) And a second land 74 which communicates the third port 66 with the first port 62 and the second port 64, and at one side of the second land 74. It comprises an elastic member (76) having an elastic force for pushing the valve spool to the right in the figure.

In addition, the 2-3 / 4-3 shift valve 34 for supplying the control pressure of the first pressure control valve 16 to the switch valve 60 has the same structure as the prior art, the valve body is the first pressure control The first port 80 to receive the control pressure of the valve 16, the second port 82 to supply the control pressure of the first port 80 to the switch valve 82, and the reverse pressure to be supplied. And a third port 84 serving as a discharge port, a fourth port 86 supplied with three speed pressures, and a fifth port 88 supplied with four speed pressures.

The valve spool embedded in the valve body is supplied to the first land 90 and the fifth port 88 to open and close the third port 84 while acting on the hydraulic pressure supplied to the fourth port 86. It comprises a second land 92 acting on the hydraulic pressure to open and close the first port 80, one side of the second land 92 has a repulsive force to push the valve spool to the left in the drawing It comprises an elastic member 94 to.

As a result of the above configuration, at the initial stage of the shift 2 → 3, the third speed pressure is supplied to the 2-3 / 4-3 shift valve 34 as shown in FIG. Ports 80 and 82 are communicated.

Then, the control pressure waiting at the first port 80 is supplied to the first port 62 of the switch valve 60, and the switch valve 60 is provided with the valve spool by the elastic force of the elastic member 76. Since the first and third ports 62 and 66 communicate with each other and the hydraulic pressure supplied to the first port 62 is released through the third port 66, the release chamber of the kick-down servo C2 ( S / R) and front clutch C4.

When the control pressure is supplied to the front clutch C4 in the above-described process, and the shift to the third speed is started, a certain hydraulic pressure is formed on the conduit, and as shown in FIG. 3, a part of the hydraulic pressure is applied to the switch valve 60. The valve spool supplied to the four ports 68 and moved to the right is forcibly moved to the left in the drawing.

Then, the first land 72 closes the first port 62, opens the third port 64, and releases the three-speed pressure supplied to the port 62 of the release chamber S of the kick-down servo C2. / R) and front clutch (C4).

At this time, the third speed pressure is supplied to a separate conduit 56 without passing through the orifice OR1, so that the supply of the fluid is made quickly.

If the shift to the third speed is made quickly as described above, when the 2 → 3 → 4 speed shift is made by the lift foot up, it is possible to minimize the 3 speed hold time, thereby improving the feeling of shifting. You can do it.

In the process of shifting from the third speed to the fourth speed, the fourth speed pressure is supplied to the fifth port 88 of the 2-3 / 4-3 shift valve 34 as shown in FIG. 4 in the third speed state as shown in FIG. And, the bar is supplied to the fifth port 70 of the switch valve 60, the valve spool of the 2-3 / 4-3 shift valve 34 is moved to the left in the drawing to the second, third port 82 ( 84) and the switch valve 60, the valve spool is moved to the right in the drawing to communicate the first and third ports 62 and 66, the discharge is made.

When the hydraulic pressure supplied to the release chamber S / R of the kick-down servo C2 and the front clutch C4 is discharged as described above, the third port of the 2-3 / 4-3 shift valve 34 84) Back pressure control of the release chamber S / R and the front clutch C4 of the kick-down servo C2 is performed while being controlled by an orifice (OR2 (shown in FIG. 1)) arranged in the side conduit. .

In the case where the shift is performed at the second speed in the third speed state, no control pressure is supplied to the 2-3 / 4-3 shift valve 34 and the switch valve 60 as shown in FIG. The valve spool of the 3 / 4-3 shift valve 34 is moved to the right in the drawing by the elastic member 76, and the valve spool of the switch valve 60 is moved to the left in the drawing by the elastic member 94. The hydraulic pressure supplied to the release chamber S / R and the front clutch C4 of the kick-down servo C2 is discharged.

When the hydraulic pressure is discharged in this way, the release chamber of the kick-down servo C2 is controlled by the orifice OR2 disposed in the pipeline of the side of the third port 84 of the 2-3 / 4-3 shift valve 34. Back pressure control of the S / R and the front clutch C4 is made.

As described above, according to the present invention, the fluid supplied to the release side of the front clutch and the kick-down servo is not supplied through the orifice after the three-speed synchronization is completed by dividing before and after the three-speed sync point at the time of 2 → 3 shift. It can be supplied quickly through the flow path without orifices, thereby reducing the three-speed shift time.

Accordingly, when 2 → 3 → 4 shift is performed by the lift put up, the 3 speed hold time is shortened, thereby improving the shifting feeling.

In the case of shifts of 3 → 4 and 3 → 2, the fluid supplied to the release side of the front clutch and the kick-down servo is discharged through the orifice to control the back pressure, thereby improving the shifting feeling. Will be able to improve.

1 is an N-range hydraulic circuit diagram of a hydraulic control system according to the present invention.

Fig. 2 is an operation diagram when shifting 2 → 3 in a 2-3 / 4-3 shift valve and a switch valve applied to the present invention.

Figure 3 is an operation of 3 → 4 shift in the 2-3 / 4-3 shift valve and switch valve applied to the present invention.

Figure 4 is an operation of the three-speed shift complete state in the 2-3 / 4-3 shift valve and switch valve applied to the present invention.

Fig. 5 is an operation diagram at the time of 3 → 2 shift in a 2-3 / 4-3 shift valve and a switch valve applied to the present invention.

6 is a hydraulic circuit diagram of a conventional hydraulic control system.

Claims (2)

The hydraulic pressure supplied from the first and second pressure control valves and the manual valve linked to the selector lever operated by the driver, the shift control valve controlled by the two solenoid valves, and the pressure control valves are moved forward. Rear clutches operating in 2 and 3 speeds, kick-down brakes operating in 2nd and 4th forwards, front clutches operating in 3rd and 4th forwards, end clutches operating in 3rd and 4th forwards, and reverse Including a plurality of spool valve to selectively supply hydraulic pressure to the low-reverse brake operating in A switch valve for switching the flow path is arranged on the downstream side of the 2-3 / 4-3 shift valve for switching the supply and release fluid of the release chamber of the front clutch and the kick-down servo to the flow path. Hydraulic control system of an automatic transmission for a vehicle, characterized in that made by. The switch valve of claim 1, wherein the switch valve comprises: a first port for receiving hydraulic pressure from the 2-3 / 4-3 shift valve; and a pipeline for supplying hydraulic pressure from the 1-2 shift valve to the 2-3 / 4-3 shift valve. A second port connected to a conduit branch upstream of the orifice, a third port for selectively supplying hydraulic pressure supplied to the first port and the second port to a release chamber and a front clutch of a kick-down servo, and the front A valve body having a fourth port for receiving a part of the hydraulic pressure supplied to the clutch and a fifth port for receiving the fourth speed pressure as a control pressure; A first land for selectively opening and closing the first port while acting on the control pressure supplied to the fourth port, and a second land for communicating the third port to the first port and the second port together with the first land; It is made, including, the one side of the second land hydraulic control system of the automatic transmission for a vehicle, characterized in that comprises a valve spool is disposed.