KR100461753B1 - Hydraulic control system of automatic transmission for vehicle - Google Patents

Abstract

By adding a variable solenoid valve that can control the torque converter operating oil pressure and the oil pressure for lubrication, it is possible to control the use of unnecessary oil pressure and flow rate so as to maintain the optimum state to reduce the load of the oil pump and increase the efficiency of the transmission to improve fuel economy. To provide a hydraulic control system of an automatic transmission;

The hydraulic pressure generated from the oil pump is controlled to a constant pressure in the regulator valve so that a pressure control unit consisting of a manual valve, a plurality of solenoid valves and a pressure control valve, and a hydraulic pressure supplied from the pressure control unit are selectively connected to the flow path. In the hydraulic control system of the automatic transmission for a vehicle comprising a flow path switching unit for supplying hydraulic pressure to the friction element, and a damper clutch control unit for controlling the operating oil pressure and lubrication oil pressure of the torque converter, applied to the damper clutch control unit to operate the torque converter Provided is a hydraulic control system of an automatic transmission for a vehicle configured to be controlled by a variable solenoid valve of a torque converter control valve that constantly controls hydraulic pressure and lubrication oil pressure.

Description

HYDRAULIC CONTROL SYSTEM OF AUTOMATIC TRANSMISSION FOR VEHICLE}

The present invention relates to a hydraulic control system of an automatic transmission for a vehicle, and more particularly, in a hydraulic control system that performs variable variable full-line pressure, a variable solenoid valve capable of controlling torque converter operating hydraulic pressure and lubricating hydraulic pressure is added. The present invention relates to a hydraulic control system of an automatic transmission that can control the use of unnecessary hydraulic pressure and flow rate to maintain an optimum state, thereby reducing the load of the oil pump and increasing the transmission efficiency to improve fuel efficiency.

For example, an automatic transmission applied to a vehicle is controlled by a shift control device controlling a plurality of solenoid valves to control hydraulic pressure according to a traveling speed of a vehicle, an opening ratio of a throttle valve, and various detection conditions, thereby operating a gear shift of a target shift stage. To make the shift.

In other words, when the driver converts the select lever to the desired shift stage, the manual control port is changed in the hydraulic control system, and the hydraulic pressure supplied from the oil pump is selectively selected according to the duty control of the solenoid valve. To make the shifting work.

Among these automatic transmissions, an automatic transmission having shift speeds of five forward and one reverse speeds has been recently installed. The automatic five-speed automatic transmission has a reverse clutch (R / C) that operates only in reverse, as shown in FIG. Low-reverse brake (LR / B) operating in reverse and forward 1 speed, second brake (2ND / B) operating in forward 2, 4 and 5, and underdrive clutch operating in forward 1,2,3 UD / C), overdrive clutch (OD / C) operating at forward 3, 4, 5 speed, reduction brake (RD / B) operating at forward 1, 2, 3, 4 and reverse, 5 forward It has seven friction elements, such as a working direct clutch (D / C).

In addition, the friction elements are shifted by basically operating and controlling two at each shift stage. It is very difficult to control two friction elements at the same time, and in the past, the one-way clutch has not been developed. Asynchronous shift was performed.

That is, instead of controlling two friction elements at once, one element is controlled by a one-way clutch and only one element is controlled by electronic control. In order to alleviate the risk due to non-operation of the engine brake due to the tip off-sixi wheeling of the accelerator pedal, there is a problem that requires the additional installation of friction elements for the engine brake operation.

Recently, however, advances in electronic control technology have enabled precise control of two friction elements, and thus a clutch-to-clutch control method for simultaneously controlling two friction elements independently has been applied.

In view of the above, a configuration of a conventional hydraulic control system for operating the friction element is described. As shown in FIG. 2, the hydraulic pressure generated in the oil pump 202 is controlled at a constant pressure in the regulator valve 204, and thus, manual. Sent to valve 206.

Then, the manual valve 206 converts the flow path according to the range selection of the select lever, not shown, to the first, second, third, fourth, and fifth solenoid valves S1, S2, S3, S4, and S5 that control hydraulic pressure. Supplied via switch valves 218 or first and second fail-safe valves through first, second, third, fourth and fifth pressure control valves 208, 210, 212, 214 and 216 according to their control. The connection is configured to be supplied via the 220 or 222 directly to the friction element so that the shift is made while operating each friction element as described above at each shift stage.

That is, the first solenoid valve S1 and the first pressure control valve 208 are connected to the low-reverse brake LR / B via the switch valve 218 and the first fail safe valve 220. The two solenoid valve S2 and the second pressure control valve 210 are connected to the second brake 2ND / B via the second fail safe valve 222.

The third solenoid valve S3 and the third pressure control valve 212 are directly connected to the underdrive clutch UD / C, and the fourth solenoid valve S4 and the fourth pressure control valve 214 are overdriven. Directly connected to the clutch (OD / C), the fifth solenoid valve (S5) and the fifth pressure control valve 216 is directly connected to the reduction brake (RD / B) and at the same time through the third fail-safe valve (224). It has a configuration connected to the direct clutch (D / C).

In addition, a part of the hydraulic pressure controlled from the regulator valve 204 is a torque converter control valve 226 which is constantly adjusted for the torque converter TC and lubrication, and a damper clutch to increase the power transmission efficiency of the torque converter TC. Is supplied to the damper clutch control valve 228 to control, the damper clutch control valve 228 is configured to control the on / off operation of the damper clutch while being controlled by the sixth solenoid valve (S6).

Then, the seventh solenoid valve S7 is disposed between the upstream line pressure line 230 of the manual valve 206 and the regulator valve 204, and the line pressure is 10.5 bar, 3, and 4 at 1,2 speeds as before. In 5, 8,5 bar is fixed regardless of vehicle condition, and line pressure can be controlled linearly from minimum value to maximum value.

With this configuration, the first, second, third, fourth, fifth, and sixth solenoid valves are driven under the control of the transmission control unit (TCU), and the hydraulic pressure is supplied / released to the friction element at each shift stage, thereby shifting the speed. Will be done.

However, in the hydraulic control system, there is no problem in the shift control under the control of the transmission control unit (TCU). However, the control of the operating oil pressure and the lubricating oil pressure of the torque converter is not performed. have.

That is, in the downhill or high-speed operating region, although the converter operating hydraulic pressure and the lubricating hydraulic pressure are required to be relatively small, since they cannot be controlled, they are supplied at a high pressure, thereby unnecessarily increasing the load of the oil pump, thereby driving the oil pump. This implies the problem of lowering power loss and fuel economy.

Therefore, the present invention has been invented to solve the above problems, an object of the present invention is to add a variable solenoid valve that can control the torque converter operating hydraulic pressure and lubrication hydraulic pressure to control the use of unnecessary oil pressure and flow rate to optimize It is to provide a hydraulic control system of an automatic transmission that can maintain the state to reduce the load on the oil pump, improve the transmission efficiency to improve fuel economy.

1 is a hydraulic flow chart in the N, P range of the hydraulic control system according to the present invention.

Figure 2 is an enlarged view of the main portion of the present invention.

3 is a hydraulic flow chart in the N, P range of the conventional hydraulic control system.

In order to realize this, the present invention, the hydraulic pressure generated in the oil pump is controlled to a constant pressure in the regulator valve to select a pressure control consisting of a manual valve, a plurality of solenoid valves and a pressure control valve, and the hydraulic pressure supplied from the pressure control unit In the hydraulic control system of the automatic transmission for a vehicle comprising a flow path switching unit for switching the flow path to supply the hydraulic pressure to the friction element connected thereto, and a damper clutch control unit for controlling the operating oil pressure and lubrication oil pressure of the torque converter,

Provided is a hydraulic control system of an automatic transmission for a vehicle, which is applied to the damper clutch control unit and configured to control a torque converter control valve to control torque converter operating oil pressure and lubrication oil pressure by a variable solenoid valve.

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 flow chart in the N, P range of the hydraulic control system according to the present invention, the hydraulic pressure generated in the oil pump (2) is controlled to a constant pressure in the regulator valve (4) the manual valve (6) and the hydraulic control unit (A) and the like.

In the manual valve (6), the flow path is converted and supplied to the hydraulic control unit (A) according to the range selection of the select lever (not shown), and the hydraulic pressure controlled by the hydraulic control unit (A) is the flow path switching unit (B) or direct friction. Supplied with urea.

The hydraulic control unit A is the first, second, third, fourth, fifth solenoid valves S1, S2, S3, S4, S5 and the first, second, respectively controlled by these solenoid valves. 3, 4, 5 pressure control valves 10, 12, 14, 16 and 18.

The flow path switching unit B includes a switch valve 20 and first, second and third fail safe valves 22, 24 and 26, and the manual valve 6 and the hydraulic control unit A. Looking in detail with respect to the connection relationship between the flow path switching unit (B) as follows.

In the manual valve 6, the D range pressure line 28, the N range pressure line 30, and the R range pressure line 32 communicate with each other to supply the hydraulic pressure of the line pressure line 34 in accordance with the range change. do.

The D range pressure line 28 is in communication with the second, third and fourth pressure control valves 14, 16 and 18 and the second, third and fourth solenoid valves S2, S3 and S4. The range pressure line 30 is in communication with the regulator valve 6 and the first fail-safe valve 22 so that the hydraulic pressure can be supplied, the R range pressure line 32 is operated in the reverse (R) range Communication with the operating pressure of the reverse clutch R / C and the control pressure of the 2nd fail-safe valve 24 is communicated.

The line pressure is directly supplied to the first and fifth solenoid valves S1 and S5 as a control pressure, and the line pressure is also supplied to the first and fifth pressure control valves 10 and 18 so that the first and fifth solenoid valves are supplied. Controlled by (S1) (S5) is supplied to the switch valve 20 at the second control pressure or directly to the reduction brake (R / B).

The first solenoid valve S1 and the first pressure control valve 10 of the hydraulic control unit A are provided with a low-reverse brake (LR / B) via a switch valve 20 and a first fail-safe valve 22. Is connected to the direct clutch D / C via the third fail-safe valve 26, and the second solenoid valve S2 and the second pressure control valve 12 are connected to the second fail-safe valve 24. ) Is connected to the second brake (2ND / B).

The third solenoid valve S3 and the third pressure control valve 14 are directly connected to the underdrive clutch UD / C, and the fourth solenoid valve S4 and the fourth pressure control valve 16 are overdriven. The clutch OD / C is directly connected, and the fifth solenoid valve S5 and the fifth pressure control valve 18 are directly connected to the reduction brake RD / B.

By the above configuration, the reverse clutch (R / C) operates in reverse, the low-reverse brake (LR / B) operates in reverse and forward 1 speed, and the second brake (2ND / B) moves forward 2, 4, 5 Inside, underdrive clutch (UD / C) operates forward 1, 2, 3, overdrive clutch (OD / C) operates forward 3, 4, 5, reduction brake (R / B) operates at forward 1, 2, 3, 4 and reverse, and the direct clutch (D / C) is shifted while operating pressure is supplied at 5 forward.

In addition, part of the hydraulic pressure controlled from the regulator valve 6 includes the torque converter TC which is the damper clutch control unit C, the torque converter control valve 36 which is constantly controlled for lubrication, and the power of the torque converter TC. The damper clutch control valve 38 is supplied to a damper clutch control valve 38 for controlling the damper clutch in order to increase the transmission efficiency, and the damper clutch control valve 38 is controlled by the sixth solenoid valve S6 to perform the on / off operation of the damper clutch. It is configured to be controlled.

In addition, the regulator valve 6 is controlled by the seventh solenoid valve S7 which controls the line pressure and supplies the control pressure so as to control the line pressure in accordance with the vehicle driving conditions.

In addition, the torque converter control valve 36 is controlled by the eighth solenoid valve (S8) for supplying the line pressure to the control pressure to independently control the operating pressure and lubrication oil pressure of the torque converter (TC). The eight solenoid valve S8 is controlled in cooperation with the seventh solenoid valve S7.

Accordingly, when the line pressure is controlled low, the operating pressure and the lubrication hydraulic pressure of the torque converter are also controlled low, but not the same as the line pressure.

Looking at the configuration for controlling the torque converter control valve 36 with the eighth solenoid valve (S8), as shown in Figure 2, the valve body of the torque converter control valve 36 is the first port (line pressure) is supplied ( 50, a second port 52 for returning a part of the hydraulic pressure supplied to the first port 50, and a hydraulic pressure supplied to the first port 50 to the damper clutch control valve 38. And a fourth port 56 connected to the third port 54 and the eighth solenoid valve S8.

The valve spool embedded in the valve body has a communication area between the first land 58 acting on the hydraulic pressure supplied to the fourth port 56 and the first port 50 and the second port 52. It comprises a second land 60 for controlling, the elastic member 62 is supported between the second land 60 and the valve body to always push the valve spool to the right in the drawing.

When the control pressure controlled by the eighth solenoid valve S8 by the above configuration is supplied to the fourth port 56, the hydraulic pressure thereof pushes the valve spool to the left in the drawing while overcoming the elastic force of the elastic member 62. By returning the hydraulic pressure supplied to the first port 50 to the second port 52, the hydraulic pressure supplied to the damper clutch control valve 38 and lubrication is controlled.

Of course, by applying the eighth solenoid valve S8 for variable control, the hydraulic pressure may be linearly controlled to control the operating oil pressure and the lubrication oil pressure of the torque converter in an optimal state.

As described above, according to the present invention, by adding a variable solenoid valve that can control the torque converter operating oil pressure and lubrication oil pressure to control the use of unnecessary oil pressure and flow rate to maintain the optimum state to reduce the load of the oil pump and the transmission It is an invention which can improve fuel efficiency by increasing efficiency.

Claims (3)

The hydraulic pressure generated from the oil pump is controlled to a constant pressure in the regulator valve so that a pressure control unit consisting of a manual valve, a plurality of solenoid valves and a pressure control valve, and a hydraulic pressure supplied from the pressure control unit are selectively connected to the flow path. In the hydraulic control system of an automatic transmission for a vehicle comprising a flow path switching unit for supplying hydraulic pressure to the friction element, and a damper clutch control unit for controlling the operating oil pressure and lubrication oil pressure of the torque converter, The hydraulic control system of the automatic transmission for a vehicle, characterized in that configured to be controlled by a variable solenoid valve torque converter control valve applied to the damper clutch control unit to control the torque converter operating oil pressure and lubrication oil pressure. The hydraulic control system of an automatic transmission for a vehicle according to claim 1, wherein the variable solenoid valve for controlling the torque converter control valve is configured to supply and control line pressure. The damper clutch of claim 1, wherein the torque converter control valve includes a first port to which line pressure is supplied, a second port to return a part of the oil pressure supplied to the first port, and a hydraulic pressure supplied to the first port. A valve body having a third port for supplying a control valve and a fourth port connected to the variable solenoid valve; And a first land acting on the hydraulic pressure supplied to the fourth port, and a second land for controlling an area of communication between the first port and the second port, wherein the second land and the valve body are elastic. A hydraulic control system for an automatic transmission for a vehicle, characterized in that the member is carried out and comprises a valve spool.