KR20010001273A - Hydraulic control system of automatic transmission - Google Patents

Abstract

PURPOSE: A hydraulic control system of an automatic transmission is provided to minimize a shift quality due to speed change in manual speed changing. CONSTITUTION: In speed change from a range D to a range N, a second port(112) communicates with a first exhaust port(EX1) and the hydraulic pressure supplied to forward movement and to a back up friction element(108) is exhausted via the first exhaust port. By a second orifice(ORI2), the hydraulic pressure is released slowly even at normal or high temperatures. Herein, the discharge of hydraulic pressure becomes smooth by an accumulator(128). With the completion of speed changing, a solenoid valve(SOL1) controls a pressure control valve to promptly discharge residual pressure. At a low temperature, interlock performance is degraded and the discharge of hydraulic pressure is delayed. Herein, the hydraulic pressure of the friction element is discharged via a manual valve(104) by controlling the pressure control valve. Thereby, a shock due to speed change doesn't occur.

Description

HYDRAULIC CONTROL SYSTEM OF AUTOMATIC TRANSMISSION}

The present invention relates to a hydraulic control system applied to an automatic transmission for a vehicle.

For example, an automatic transmission for a vehicle has a torque converter and a multi-speed gear mechanism connected to the torque converter, and hydraulically operated friction for selecting one of the gear stages of the transmission gear mechanism according to the driving condition of the vehicle. Contains an element.

In such an automatic transmission for a vehicle, an example of a hydraulic control system will be described. As shown in FIG. 1, an oil pump 2 for generating an improved hydraulic pressure during engine operation and a torque converter 4 for transmitting engine power to an input shaft of a transmission are shown in FIG. 1. ), A regulator valve 6 for regulating the oil pressure generated by the oil pump to a constant oil pressure, that is, a line pressure, a torque converter control valve 8 for constantly adjusting the torque converter and lubrication oil pressure, and a damper installed in the torque converter. It comprises a damper clutch control valve 10 for controlling the hydraulic pressure acting on the clutch.

And a reducing valve 12 for producing a constant hydraulic pressure lower than the line pressure, a manual valve 14 for switching the flow path in conjunction with the shift lever position and sending or discharging the line pressure to each valve, and two shift controls. The shift control valve 16 which switches a flow path by the ON / OFF action of the solenoid valves A and B is included.

In addition, it has a pressure control valve (18) 29, which is controlled by the pressure control solenoid valves (C, D) to prevent a shock during shifting, and a shock to prevent a shock when shifting from the neutral range to the reverse range. It has a prevention valve 22.

And a 1-2 shift valve 24 for controlling the flow of line pressure when shifting from 1 speed to 2 speeds, and for controlling a hydraulic passage connected to a friction element acting when reversing, and operating by line pressure. It has a 2-3 / 4-3 shift valve 26 which supplies a working pressure to the first friction element C1 and a second friction element C2 and a release pressure to the third friction element C3.

It also has an end clutch valve 28 which supplies a working pressure to the fourth friction element C4 and a fifth friction element C5 which acts in the "L" and "R" ranges, respectively.

And discharges the hydraulic pressure of the second friction element (C2) when shifting from three speeds to four speeds, and controls the time of hydraulic pressure supplied to the second friction element (C2) when shifting from four speeds to three speeds. It has a rear clutch release valve 30 which prevents.

The friction element C1 communicates with the 2-3 / 4-3 shift valve 26 and the end clutch valve 28 through the conduit D1, and is a release side chamber of the third friction element C3. Communicating.

In addition, the second friction element C2 communicates with the rear clutch release valve 30 through the conduit D2, and the third friction element C3 has the 1-2 shift valve 24 through the conduit D3. Communicating with

The fourth friction element C4 is connected to the end clutch valve 28 through the conduit D4, and the fifth friction element C5 is connected to the 1-2 shift valve 24 through the conduit D5. It is connected.

In the hydraulic control system configured as described above, the second friction element C2 operates at the first forward speed, the second friction element C2 and the third friction element C3 operate at the second speed, and the second friction element C2 at the third speed. ), The first friction element (C1) and the fourth friction element (C4) is operated, the third and fourth friction elements (C3) and (C4) are operated in the fourth speed, and the reverse, the first and fifth friction Elements C1 and C5 are activated.

In the hydraulic control system configured and operated as described above, the second friction element C2 is commonly operated in the "D" range 1 speed and the "R" range, and according to the hydraulic supply and release to the friction element C2, This has a significant effect on shift shock generation during manual shifting.

That is, manual shifting by the shift lever (P ↔ R ↔ N ↔ D) must be carried out at the start and stop while driving a car. At this time, the second friction element (C2) is always supplied with hydraulic pressure. Shifting shocks from supply and release have a profound effect on shifting feeling.

Considering this point, the hydraulic supply path to the friction element (the second friction element in FIG. 1) operating in the conventional "D" range 1 speed and the reverse range is generated from the oil pump 200 as shown in FIG. The hydraulic pressure is regulated to a constant pressure by the pressure regulating valve 202 and supplied to the manual valve 204, and the manual valve 204 is moved forward and backward through the pressure control valve 206 controlled by the solenoid valve SOL. The hydraulic element is configured to be supplied to the friction element 208.

By controlling the pressure control valve 206 by the solenoid valve (SOL) in the N-D manual shift by the above configuration, it is possible to achieve a desired shift feeling by gradually increasing the hydraulic pressure supplied to the forward and backward friction elements 208. On the contrary, by directly releasing the hydraulic pressure to the manual valve 204 in the state as shown in FIG. 5 without the electronic control by the solenoid valve SOL during the D-N manual shift, the hydraulic release characteristic is fast, and excessive shift shock is performed at room temperature and high temperature. There is a problem that occurs.

Accordingly, in recent years, the accumulator 210 is disposed on the flow path between the pressure control valve 206 and the forward and backward friction elements 208, or the orifice ORI is disposed on the flow path thereof.

However, in the case of applying the accumulator as described above, it is intended to soften the hydraulic release, but there is a problem that the effect is very weak at high temperature because the resistance on the flow path connected to the manual valve is not large.

In the latter case, in the case of arranging the orifice, if the size is reduced considering only D → N, the hydraulic pressure is released too slowly during low temperature operation, so that P → R, N → R, P → D, When shifting from N to D, the automatic transmission becomes locked and causes a large impact, and also has a problem of being burned in the case of a friction element having a small capacity.

In addition, if the brake pedal is released after P → N, the vehicle may be in a driving state for a predetermined time, thereby causing a safety accident.

Therefore, the present invention has been invented to solve the above problems, an object of the present invention is to provide a hydraulic control system that can minimize the shift shock during manual shift.

1 is a view schematically showing an embodiment of a hydraulic control system for explaining the scope of the present invention.

Fig. 2 is a hydraulic circuit diagram showing the main part of the present invention in the "D" range.

Figure 3 is a hydraulic circuit diagram showing the main part of the present invention in the "N" range state.

4 is a partial excerpt hydraulic circuit diagram in the "D" range state for explaining the prior art.

5 is an excerpted hydraulic circuit diagram in the "N" range state for explaining the prior art.

In order to realize this, the present invention can minimize the shift shock by allowing the hydraulic pressure to be discharged using the discharge port of the pressure control valve without releasing the pressure of the forward and backward friction elements to the manual valve during the manual shift. It would be.

More specifically, the hydraulic pressure generated from the oil pump is regulated to a constant pressure in the pressure regulating valve and supplied to the manual valve, and at least one friction element is passed through the pressure control valve during manual shifting from the manual valve to the D and R ranges. In the hydraulic control system of an automatic transmission for a vehicle in which a "D" range and a reverse range are shifted while hydraulic pressure is supplied,

During manual shifts such as D → N, R → N, D → P, R → P, the hydraulic pressure supplied to the friction element can be released to the first discharge port of the pressure control valve without releasing it to the flow path to the manual valve. To provide a hydraulic control system of an automatic transmission for a vehicle.

And an orifice is disposed on a flow path connecting the manual valve and the pressure control valve and a flow path connecting the pressure control valve and the friction element, and an accumulator is disposed on the flow path connecting the pressure control valve and the friction element. Provide hydraulic control system of automatic transmission.

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

Figure 2 is an excerpt of the present invention, the hydraulic pressure generated in the oil pump 100 is adjusted to a constant pressure in the pressure control valve 102 is supplied to the manual valve 104.

Of course, some of the hydraulic pressure in the pressure regulating valve 102 is supplied to the operating and non-operating pressure of the torque converter not shown in FIG.

In addition, the hydraulic pressure supplied to the manual valve 104 is supplied to the pressure control valve 106 and the shift control solenoid valve (not shown) as the port is changed according to the range change of the shift lever, and a part of the pressure control valve ( 102 is supplied with the forward and reverse control pressure.

The hydraulic pressure supplied to the pressure control valve 106 is supplied to the forward and backward friction elements 108 while the port conversion is made under the control of the solenoid valve SOL1.

To this end, the valve body of the pressure control valve 106 is in communication with the first port 110, which receives the hydraulic pressure from the manual valve 104, and the first port 110 to the forward and backward friction elements 108 A second port 112 for supplying hydraulic pressure, a third port 114 for receiving a control pressure of the solenoid valve SOL1, a fourth port 116 for receiving a line pressure or a reducing pressure, and A first discharge port EX1 formed adjacent to the second port 112 and selectively communicating with the second port 112, and a second discharge port disposed at an opposite side end of the first discharge port EX1 ( EX2).

In addition, the valve spool 118 embedded in the valve body includes a first land 120 through which the hydraulic pressure of the third port 114 acts, and the first and second ports 110 together with the first land 120. And a second land 122 communicating with 112 and a third land 124 formed at a predetermined interval on the second land 122 to act on the pressure of the fourth port 116.

Accordingly, when the valve spool 118 is moved to the right side in the drawing, the first and second ports 110 and 112 communicate with each other. When the valve spool 118 is moved to the left side, the second port 112 and the first discharge port are connected. The port EX1 is in communication.

In this hydraulic control system, the present invention arranges an accumulator 128 on a flow path 126 that communicates between the pressure control valve 106 and the forward and backward friction elements 108, and the manual valve 104 and The first orifice ORI1 is disposed on the flow path connecting the pressure control valve 106, and the second orifice ORI2 is disposed at the first discharge port EX1.

In addition, the friction element referred to as the forward, backward friction element 108 is a generic term for friction elements that work in common at forward 1 speed or reverse shift, these configurations are limited to any one hydraulic control system Rather, it includes all that the pressure control valve 106 controlled by the solenoid valve SOL1 is applied between these manual valves 104 and the forward and backward friction elements 108.

In addition, although the pressure control valve 106 has been described that the port conversion is made by the control pressure of the solenoid valve SOL1, the present invention is not limited thereto, and a switching valve capable of simply switching the flow path may be used depending on the need. You may.

According to the above configuration, the hydraulic pressure supplied to the forward and backward friction elements 108 during manual shifting such as D → N, R → N, D → P, R → P is not released to the flow path to the manual valve 104. By releasing to the first discharge port EX1 of the pressure regulating valve 106, the shift shock at the time of shifting can be reduced.

As an example, when the manual shift to the "N" range in the "D" range as shown in Figure 2, the second port 112 and the first discharge port (EX1) is communicated as shown in Figure 3, so that forward and backward Since the hydraulic pressure supplied to the friction element 108 is discharged to the first discharge port EX1, the hydraulic pressure is slowly released even at room temperature and high temperature by the second orifice ORI2.

At this time, the accumulator 128 allows the hydraulic pressure to be discharged smoothly together with the second orifice ORI2.

When it is determined that the shift is completed, the solenoid valve SOL1 controls the pressure control valve 106 to communicate the second port 112 with the first port 110, thereby quickly discharging the residual pressure.

In addition, since the fluidity is lowered at low temperatures, when released through the first discharge passage EX1, the delay is too delayed. At this time, the pressure control valve 106 is controlled so that the hydraulic pressure of the forward and backward friction elements 108 is controlled by the manual valve. Discharge through 104 ensures that no impact occurs.

In the above operation process, after the manual valve 104 is moved during the D → N manual shift, the transmission control unit TCU recognizes and controls the solenoid valve, so that the initial hydraulic pressure of the shift is controlled by the first orifice ORI1. Through the manual valve 104.

Therefore, in order to quickly control the pressure control valve 106 in a short time, the release pressure of the friction element acts on the valve spool 118 so that the hydraulic pressure of the valve spool 118 can be released to the second discharge port EX2. It is preferable to give an area difference to the land or to adjust the size of the first orifice ORI1.

The present invention made as described above, the manual transmission, such as D → N, R → N, D → P, R → P in the automatic transmission, without releasing the hydraulic pressure supplied to the front and reverse friction elements to the flow path to the manual valve By releasing to the first discharge port of the pressure control valve, the shift shock is more stable and the shift speed can be minimized.

Claims (4)

The hydraulic pressure generated from the oil pump is regulated to a constant pressure in the pressure regulating valve and supplied to the manual valve. When manual shifting from the manual valve to the D and R ranges, the hydraulic pressure is supplied to at least one friction element through the pressure control valve. In a hydraulic control system of an automatic transmission for a vehicle in which a "D" range and a reverse range shift are made, During manual shifts such as D → N, R → N, D → P, R → P, the hydraulic pressure supplied to the friction element can be released to the first discharge port of the pressure control valve without releasing it to the flow path to the manual valve. So that And an orifice disposed on a flow path connecting the pressure control valve and the friction element to the hydraulic control system of the automatic transmission for a vehicle. The hydraulic control system of an automatic transmission for a vehicle according to claim 1, wherein an orifice is disposed on a flow path connecting the manual valve and the pressure control valve. The hydraulic control system of an automatic transmission for a vehicle according to claim 1, wherein the accumulator is disposed on a flow path connecting the pressure control valve and the friction element. The hydraulic control system of claim 1, wherein the pressure control valve is formed of a spool valve in which a valve spool is operated by the control of the solenoid valve.