KR100427375B1 - Hydraulic control system of automatic transmission for vehicle - Google Patents

Abstract

By the solenoid valve control pressure is supplied to the hydraulic pressure supplied to the reverse clutch during N → R manual shifting, to minimize the shift shock during N ↔ R manual shifting;

The flow path is changed from the manual valve to the first, second, third, fourth, and fifth solenoid valves that control the hydraulic pressure by changing the range of the select lever, and the first, second, third, fourth, and fifth pressure control according to their control. The valve is configured to be fed via the first switch valve or the first, second and third fail-safe valves or directly to the friction element so that the shift is performed by selectively operating seven friction elements operating at each shift stage. And downstream of the fifth pressure control valve, the control pressure of the fifth solenoid valve and the line pressure supplied from the regulator valve are selectively supplied to the reduction brake operated and controlled in the forward 1,2,3 and R, N, P ranges. And arranging a second switch valve for supplying the control pressure of the fifth pressure control valve to the reverse clutch selectively operating in the R range. Provides a hydraulic control system of an automatic transmission for a vehicle.

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, by allowing clutch-to-clutch control to simultaneously control two friction elements during an N → R manual shift, The present invention relates to a hydraulic control system of an automatic transmission that can mitigate the occurrence of shift shock and improve shift response.

In general, the automatic transmission is configured in various ways depending on the connection relationship between the multi-speed transmission device consisting of a planetary gear and the friction element consisting of a clutch and a brake for controlling the transmission.

Among these automatic transmissions, an automatic transmission having a five-speed forward and one-speed reverse speed 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 and 5 speeds, and underdrive clutch operating in forward 1,2,3,4 ( UD / C), overdrive clutch (OD / C) operating at forward 3, 4, 5 speed, reduction brake (RD / B) operating at forward 1, 2, 3 and reverse, 4, 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 the tip off of the accelerator pedal, there is a problem that requires the additional installation of the friction element for the engine brake operation as a means for mitigating the risk due to the non-operation of the engine brake due to free wheeling.

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, the configuration of the conventional hydraulic control system for operating the friction element is described. As shown in FIG. 6, the hydraulic pressure generated in the oil pump 202 is controlled at a constant pressure in the regulator valve 204, and thus the manual. Sent to valve 206.

The manual valve 206 then 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, S5 for controlling the hydraulic pressure. Supplied via the first, second, third, fourth, fifth pressure control valves 210, 212, 214, 216, 218 according to their control to switch valve 220 or first and second fail safe valves. 222, 224 is configured to be connected to or directly supplied 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 210 are connected to the low-reverse brake LR / B via the switch valve 220 and the first fail safe valve 222. The two solenoid valve S2 and the second pressure control valve 212 are connected to the second brake 2ND / B via the second fail safe valve 224.

The third solenoid valve S3 and the third pressure control valve 214 are directly connected to the underdrive clutch UD / C, and the fourth solenoid valve S4 and the fourth pressure control valve 216 are overdriven. Directly connected to the clutch (OD / C), the fifth solenoid valve (S5) and the fifth pressure control valve 218 is directly connected to the reduction brake (RD / B) and at the same time through the third fail-safe valve (226). It has a configuration connected to the direct clutch (D / C).

In addition, part of the hydraulic pressure controlled from the regulator valve 204 is the torque converter 228 and the torque converter control valve 230 that is constantly adjusted for lubrication, and the damper clutch to increase the power transmission efficiency of the torque converter 228. The damper clutch control valve 232 is supplied to control the damper clutch control valve 232 is configured to control the on / off operation of the damper clutch while being controlled by the sixth solenoid valve (S6).

However, in the hydraulic control system as described above, as shown in FIG. 6, two friction elements, namely, a reverse clutch and a low-reverse brake, are controlled at a reverse shift, in which the line pressure supplied from the manual valve is directly supplied without control. The solenoid control of the low-reverse brake causes a double shift shock.

In addition, even when manual shifting from the reverse shift state to the neutral position prevents hydraulic control, there is a problem that a shift shock occurs.

Therefore, the present invention has been invented to solve the above problems, the object of the present invention is to supply the hydraulic pressure supplied to the reverse clutch when the N → R manual shifting solenoid valve control pressure, the shift during N ↔ R manual shifting It is to provide a hydraulic control system to minimize the impact.

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

2 is a block diagram of a switching valve applied to the present invention.

Figure 3 is an operation of the switching valve in the N, P range.

4 is an operation of the switching valve in the reverse range.

5 is a hydraulic flow chart in the reverse range of the hydraulic control system according to the present invention.

6 is a hydraulic flow chart in the reverse 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 is sent to the manual valve, in which the flow path is converted according to the range selection of the select lever in the first valve to control the hydraulic pressure Via a first switch valve or a first, second or third fail-safe valve through a first, second, third, fourth or fifth solenoid valve In a hydraulic control system in which a shift is made while selectively operating seven friction elements operating at each shift stage and configured to be directly supplied to the friction element,

Downstream of the fifth pressure control valve, the control pressure of the fifth solenoid valve and the line pressure supplied from the regulator valve are selectively supplied to the reduction brake operated and controlled in the forward 1,2,3 and R, N, P ranges. And a second switch valve arranged so as to supply the control pressure of the fifth pressure control valve selectively to the reverse clutch operating in the R range.

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 flow chart of the hydraulic pressure in the N, P range of the hydraulic control system according to the present invention. Looking at the configuration, the hydraulic pressure generated in the oil pump 2 is controlled to a constant pressure in the regulator valve 4, the manual valve ( 6) are sent to.

Then, this manual valve (6) is converted to the first, second, third, fourth, fifth solenoid valves (S1, S2, S3, S4, S5) for controlling the oil pressure by changing the flow path according to the range selection of the select lever (not shown). Supplied via the first, second, third, fourth, fifth pressure control valves 8, 10, 12, 14, 16 according to their control; The three fail-safe valves 20, 22 and 24 are connected to each other so as to be directly supplied 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 8 are connected to the low-reverse brake LR / B via the switch valve 18 and the first fail safe valve 20. The two solenoid valve S2 and the second pressure control valve 10 are connected to the second brake 2ND / B via the second fail-safe valve 22.

The third solenoid valve S3 and the third pressure control valve 12 are directly connected to the underdrive clutch UD / C, and the fourth solenoid valve S4 and the fourth pressure control valve 14 are overdriven. Directly connected to the clutch (OD / C), the fifth solenoid valve (S5) and the fifth pressure control valve 16 is directly connected to the reduction brake (RD / B) and at the same time through the third fail-safe valve (24). It has a configuration connected to the direct clutch (D / C).

Accordingly, 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) operates in forward 2 and 5 speed. The underdrive clutch (UD / C) operates at forward 1,2,3,4 and the overdrive clutch (OD / C) operates at forward 3,4,5.

And the reduction brake (R / B) is to operate in the forward 1, 2, 3 speed and the reverse, the direct clutch (D / C) is to operate in the forward 4, 5 speed.

In addition, a part of the hydraulic pressure controlled from the regulator valve 4 is the torque converter 26 and the torque converter control valve 28 which is constantly adjusted for lubrication, and the damper to increase the power transmission efficiency of the torque converter 26. Supplied to the damper clutch control valve 30 for controlling the clutch, the damper clutch control valve 30 is configured to control the on / off operation of the damper clutch while being controlled by the sixth solenoid valve (S6).

In such a hydraulic control system, the present invention arranges the second switch valve 40 on the downstream side of the fifth pressure control valve 16 so that the control pressure of the fifth solenoid valve S5 and the regulator valve 4 are provided. The line pressure supplied from is selectively supplied to the reduction brake R / B, and the control pressure of the fifth pressure control valve 16 can be selectively supplied to the reverse clutch R / C.

The second switch valve 40 is a spool valve, consisting of a valve body and a valve spool. Looking at the configuration, as shown in Figure 2, the valve body is a first port in communication with the fifth pressure control valve 16 (42), the second port (44) in communication with the line pressure, the third port (46) connected to the reverse pressure pipeline (32) of the manual valve (6), and the first port (42) The fourth port 48 for supplying the hydraulic pressure to the reverse clutch R / C, and the hydraulic pressure supplied to the first and second ports 42 and 44, selectively the reduction brake R / B and the third And a fifth port 50 for supplying the control pressure of the fail safe valve 24.

The valve spool embedded in the valve body selectively connects the first land 52 to which the hydraulic pressure supplied to the third port 46 acts, and the second port 44 and the fifth port 50. A second land 54, a third land 56 selectively connecting the first port 42 to the fourth port 48, and between the third land 56 and the valve body. It comprises an elastic member 58 for exerting a resilient force for pushing the valve spool to the right in the figure.

Accordingly, since the reverse pressure is not supplied from the manual valve 6 in the N, P, and D ranges, as shown in FIG. The hydraulic pressure supplied to 42 forms a flow path supplied to the reduction brake R / B through the fifth port 50.

In the R range, the control pressure is supplied to the third port 46 through the reverse pressure pipe 32 of the manual valve 6, and the control pressure thereof overcomes the elasticity of the elastic member 58. As in, the valve spool is pushed to the left in the drawing.

Then, the first port 42 is in communication with the fourth port 48, the second port 44 is in communication with the fifth port 50, the reverse clutch (R / C) that is a newly operated friction element is The operation brake is controlled by the control pressure of the fifth solenoid valve S5, and the reduction brake R / B, which has been supplied with the solenoid valve pressure, is operated and controlled while being replaced with the reverse pressure.

Looking at the hydraulic system according to this operation, as shown in Figure 1, in the N, P range, the low-reverse brake (LR / B) and reduction brake (R / B), respectively, the first solenoid valve (S1) and fifth It is controlled by the control pressure of the solenoid valve S5.

In this state, when the manual shift to the R range is made, as shown in FIG. 5, the control pressure is supplied through the reverse pressure pipeline 32, and the second switch valve 40 performs the port change while reducing the reduction brake R The hydraulic pressure supplied to / B) is converted from the control pressure to the reverse pressure, and the newly operated reverse clutch R / C is controlled by the fifth solenoid valve S5.

As such, the newly operated hydraulic pressure is controlled by the control pressure of the solenoid valve, thereby minimizing the shift shock.

As described above, according to the present invention, by adding a single switch valve so that the solenoid control pressure instead of the line pressure can be supplied to the newly operated friction element during N → R shift, the shift shock during the N ↔ R manual shift It is an invention that can be minimized.

Claims (2)

The hydraulic pressure generated from the oil pump is controlled at a constant pressure from the regulator valve and is sent to the manual valve, in which the flow path is converted according to the range selection of the select lever to control the hydraulic pressure. Connection to be supplied to the solenoid valve and supplied directly to the friction element or via the first switch valve or the first, second and third fail-safe valves through the first, second, third, fourth and fifth pressure control valves according to their control. In a hydraulic control system in which shifting is performed by selectively operating seven friction elements operating at each shift stage, Downstream of the fifth pressure control valve, the control pressure of the fifth solenoid valve and the line pressure supplied from the regulator valve are selectively supplied to the reduction brake operated and controlled in the forward 1,2,3 and R, N, P ranges. And arranging a second switch valve to selectively supply the control pressure of the fifth pressure control valve to the reverse clutch operating in the R range. 2. The second switch valve of claim 1, wherein the second switch valve comprises: a first port communicating with a fifth pressure control valve; a second port communicating with a line pressure; a third port connected with a reverse pressure pipeline of a manual valve; And a fourth port for supplying the hydraulic pressure supplied to the port to the reverse clutch, and a fifth port for selectively supplying the hydraulic pressure supplied to the first and second ports to the control pressure of the reduction brake and the third fail-safe valve. A body; A first land embedded in the valve body and having a hydraulic pressure supplied to the third port, a second land selectively connecting the second port and the fifth port, and selectively connecting the first port to the fourth port And a valve spool including a third land connected to the second land and an elastic member disposed between the third land and the valve body to exert a resilient force.