KR0131304B1 - Hydraulic pressure control valve - Google Patents

Abstract

To ensure the stability and the response characteristic of the oil pressure, this unit comprises the first port which is connected with the line pressure line, the valve body containing the second port and the drainage port, the valve spool including three lands, which is installed to possibly move toward the inner side of the valve body, the detection chamber combined with the depressing line through the third port, and the elastic member for facing the oil pressure applied onto the valve spool.

Description

Pressure Reducing Valve for Hydraulic Control Unit of Automatic Transmission for Automobile

1 is a hydraulic circuit diagram of a pressure reducing valve of the hydraulic control device according to the present invention is applied.

2 is a side cross-sectional view of a pressure reducing valve of the hydraulic control apparatus according to the present invention.

3 is a circuit diagram showing a hydraulic control device of a conventional electronically controlled four-speed transmission.

4 is a view for explaining the operation of the pressure reducing valve to provide a pressure lower than the line pressure in the conventional automatic transmission hydraulic control apparatus for automobiles.

* Explanation of symbols for main parts of the drawings

4 oil pump 6 pressure reducing valve

30: line pressure line 32: first port

34: decompression line 36: second port

38: third port 40: detection chamber

42 discharge port 44 elastic member

46: adjustment screw L4, L5, L6: land

S: valve spool,

The present invention relates to a pressure reducing valve for a hydraulic control unit of an automatic transmission for a vehicle, and more particularly, to a pressure reducing valve capable of improving hydraulic stability and responsiveness.

In general, an automatic transmission for a vehicle has a torque converter and a multi-speed gear mechanism connected to the torque converter, and hydraulic automatic friction for selecting one of gear stages of the transmission gear mechanism according to the operating state of the vehicle. It includes a member.

The hydraulic control system pressurized by the oil pump supplies the hydraulic pressure required to operate the friction member and the control valve.

Commonly used automatic transmission for a vehicle includes a pump impeller connected to the output shaft of the engine and driven together, a turbine runner connected to the input shaft of the transmission and operating together, and a stator disposed between the pump impeller and the turbine runner. It has a fluid torque converter.

This configuration causes the fluid to be circulated by the pump impeller driven by the engine with the aid of the stator, which causes the fluid to flow in a direction that does not interfere with the rotation of the pump impeller when the fluid enters the chump impeller from the turbine runner.

Automatic shifting is achieved by changing the speed ratio in the planetary gear system by the operation of a friction member such as a clutch or a kick-down brake at each shift stage. In addition, the friction member is selectively operated by changing the flow direction of the hydraulic pressure by a plurality of valves of the hydraulic control device, the manual valve is a port conversion to the selected position of the driver's shift lever to supply fluid pressure from the oil pump It is connected to the pipeline to supply the fluid pressure to the shift control valve.

In the case of an electronically controlled four-speed automatic transmission, the shift control valve has a port that is selectively opened by the transmission control unit. An example of a hydraulic control device for an automobile is shown in FIG. 3, which includes a torque converter 1 rotating at the same speed as the engine speed in order to transmit the power of the engine to the input shaft of the multistage gear mechanism of the transmission, and A damper clutch control valve (2) for selectively controlling the damper clutch to actuated / inactive to improve power transmission efficiency inside the torque converter, and a torque converter control valve for regulating the oil pressure for the torque converter and lubrication constantly ( 3), the regulator valve 5 for adjusting the output oil pressure of the oil pump 4 according to the request of the automatic transmission, and the oil pressure stably supplied to the damper clutch solenoid valve and the damper clutch control valve 2 It includes a decompression valve (6) for.

The manual valve 7 connected to the outlet side of the oil pump 4 and supplied with hydraulic pressure forms a connection capable of supplying line pressure to the regulator valve 5 and the shift control valve 8.

The valve spool of the manual valve 7 is moved in accordance with the position change of the shift lever so that each land position is changed.

The above-described shift control valve 8 supplies oil pressure to the 1-2 speed shift valve 9, the end clutch valve 10, the 2-3 speed and 4-3 speed shift valves 11, and the rear clutch. Through the release valve 12, the front clutch 13, the rear clutch 14, the low reverse brake 15, the kick-down servo brake 16, the end clutch 17, etc. can be supplied.

The ND control valve 18, which is installed to reduce the shift shock when the shift lever is changed from the N range to the D range, is connected to the manual valve 7 so that the valve spool is moved by hydraulic pressure to change the land position. It's supposed to be. The N-D control valve 18 is connected to the rear clutch release valve 12 to supply the hydraulic pressure to the rear clutch 14.

In addition, the NR control valve 19, which is installed to reduce shift shock when the shift mode is changed from the N range to the R range, can supply hydraulic pressure to the low reverse brake 15 via the 1-2 speed shift valve (). The NR control valve 19 is opened by the transmission control unit.

The pressure control solenoid valve 20, which is duty controlled by the transmission control unit, controls the pressure control valve 21 installed to prevent the occurrence of shock during shifting in addition to the N-R control valve 19 described above.

The pressure control valve 21 is connected to the N-D control valve 18 to supply hydraulic pressure.

In the conventional automatic transmission hydraulic control device for a vehicle made in this way, the pressure control solenoid valve 20 which is off when the driver changes the manual valve 7 from the N range to the D range via the shift lever. The hydraulic control solenoid valve 21 is in a state of blocking the flow path because it is turned on by the control unit to discharge the hydraulic pressure generated by the oil pump 4 and supplied via the pressure reducing valve 6.

A part of the hydraulic pressure passing through the manual valve 7 acts on the regulator valve 5 to push the valve spool to open the discharge port so that a constant pressure can be maintained at all times, and another part of the hydraulic pressure is a rear clutch release valve ( The rear clutch 14 is operated via 12).

At this time, the speed of the vehicle is increased and the shift is made according to the stepping amount of the accelerator pedal. At this time, the pressure control solenoid valve 20 is duty controlled by the transmission control unit to be turned off and connects the port of the pressure control valve 21. Will let you.

Accordingly, the hydraulic pressure supplied from the manual valve 7 is turned on the valve 21 and passes through the port of the 1-2 speed shift valve 9 via the ND control valve 18 to apply the kick-down servo brake 16. It works.

When the valve 7 is changed to the R range, a part of the hydraulic pressure supplied from the oil pump 4 is supplied to the regulator valve 5 to regulate the line pressure constantly, and a part of the hydraulic pressure is the NR control valve. It is supplied to the low reverse brake 15 while passing through the port of the 1-2 speed shift valve 9 through 19 to activate the brake.

When such a shifting operation is performed, the pressure reducing valve 6 generates a constant pressure lower than the line pressure, and forms a control pressure from the pressure control solenoid valve 20 and the damper clutch control solenoid valve by this hydraulic pressure, thereby forming the pressure control valve 21 and the damper. The clutch control valve 2 is activated.

That is, as shown in FIG. 4, when the oil pressure generated from the oil pump enters between the first land L1 and the second land L2, the hydraulic pressure is adjusted to the reducing pressure and then supplied to the pressure control valve along the return line.

At this time, due to the area difference between the first land L1 and the second land L2, the valve spool is always pushed to the right and the hydraulic pressure is supplied to the return line as shown in a). If it moves further to the right as shown in b), the discharge port is opened to reduce the hydraulic pressure.

Then, as shown in FIG. 4 c), the discharge port is blocked while returning to the original state again, so that the hydraulic pressure is increased again.

Since this action is made by the spring force and the inlet pressure of the spring holding the valve spool, there is a problem that the reliability of the hydraulic pressure is lowered and the response characteristics are not good, so that accurate control is not achieved.

The present invention has been invented to solve the problems of the prior art as described above, the object of the present invention is to improve the stability of the hydraulic pressure and to improve the response characteristics to ensure the control of the damper clutch control valve and the pressure control valve To provide a pressure reducing valve for the hydraulic control unit of an automatic transmission for a vehicle.

In order to realize this, the present invention includes a plurality of valves for selectively transmitting the rotational force of the torque converter to the respective gear elements by controlling a plurality of clutch and brake means in proportion to the forward and reverse speed by the hydraulic pressure generated in the oil pump. In the hydraulic control system of automatic transmission, the line pressure is always used as a constant pressure lower than the line pressure, and this pressure is used to improve the stability and response characteristics of the hydraulic pressure when operating the pressure control valve and the damper clutch control valve. In order to: A valve body having a first port communicating with a line pressure line, a second port communicating with a decompression line and a discharge port, a valve spool having three lands movably installed inside the valve body, A detection chamber formed at one side of the valve spool and communicating with a decompression line through a third port; An elastic member for responding to the oil pressure acting on the spool bracket to provide a hydraulic control pressure reducing valve of the vehicle automatic transmission is made.

Provided is a pressure reducing valve for the hydraulic control unit of the automatic transmission for a vehicle, characterized in that the orifice is formed on the inlet side of the detection chamber.

The pressure of the decompression line provides a pressure reducing valve for the hydraulic control unit of the automatic transmission for a vehicle, characterized in that the control in proportion to the opening and closing area of the second port.

The elastic member provides a pressure reducing valve of the hydraulic control unit of the automatic transmission for an automobile, characterized in that the elastic force is adjusted by the adjustment screw to enable the operating pressure change.

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

1 is a hydraulic circuit diagram in which a pressure reducing valve according to the present invention is applied, and the same reference numerals refer to the same parts as in FIG. 3.

A torque converter (1) which rotates at the same speed as the engine speed to transmit power to the input shaft of the multistage gear mechanism of the transmission, and the damper clutch is activated / deactivated to improve power transmission efficiency inside the torque converter. The damper clutch control valve (2) for selective control, the torque converter control valve (3) for constantly adjusting the above-mentioned torque converter and lubrication oil pressure, and the output oil pressure of the oil pump (4) in accordance with the request of the automatic transmission And a regulator valve 5 for regulating, and a pressure reducing valve 6 for stably supplying oil pressure to the damper clutch solenoid valve and the damper clutch control valve 2.

The manual valve 7 connected to the outlet side of the oil pump 4 and supplied with hydraulic pressure forms a connection capable of supplying line pressure to the regulator valve 5 and the shift control valve 8.

The valve spool of the manual valve 7 is moved in accordance with the position change of the shift lever so that each land position is changed.

The above-described shift control valve 8 supplies oil pressure to the 1-2 speed shift valve 9, the end clutch valve 10, the 2-3 speed and 4-3 speed shift valves 11, and the rear clutch. Through the release valve 12, the front clutch 13, the rear clutch 14, the low reverse brake 15, the kick-down servo brake 16, the end clutch 17, etc. can be supplied.

Hereinafter, it has the same configuration as in FIG. 3, but the pressure reducing valve 6 provided in the present invention is configured to vary the position of the spool S by the opening area of the outlet port for reducing the line pressure and the opening of the discharge port. .

For this purpose, the first port 32 communicates with the line pressure line 30 for supplying the line pressure supplied from the oil pump to the valve body, and the pressure reduction line 34 communicates with the first port 32. The second port 36 is formed, and the third port 38 communicating with the decompression line 34 is connected to the detection chamber 40.

In addition, a discharge port 42 is formed between the second port 36 and the third port 38 to reduce the line pressure. The valve spool S has lands L4 and L5 having three equal areas. And L6) to open and close the ports as these lands so that the hydraulic pressure can be adjusted.

One side of the valve spool (S) is supported by the elastic member 44 to change the position of the valve spool (S) in response to the adjustment pressure, the elastic member 44 to the adjustment screw 46 By adjusting the elastic force, the working pressure can be changed. An orifice 48 is formed in the line flowing into the detection chamber 40 through the third port 38 to gradually change the detection pressure.

The pressure reducing line 34 is connected to displace the valve spool of the damper clutch control valve 2.

In the hydraulic control unit pressure reducing valve of the present invention as described above, when the oil pump is driven and the line pressure is supplied along the line pressure line 30, the land of the same area as the land L4 introduced through the first port 32 is provided. Actuating between the (L5) and the valve spool (S) is not subjected to the hydraulic control, since one end of the valve spool (S) is supported by the elastic member 40, the valve spool 44 is the right side in the drawing Will be moved to (see Figure 2).

In such a state, the land L5 opens the second port 36 separately, so that the line pressure flowing through the first port 32 follows the decompression line 34 through the third port 36. It flows into the detection chamber 44 through the three ports 38 and acts on the right side surface of the land L6.

At this time, when the pressure in the detection chamber 40 rises to overcome the elastic force of the elastic member 44, the valve spool S moves to the left, and the land L5 gradually closes the second port 36. As a result, since the open area of the second port 36 is reduced, the line pressure supply is reduced.

When the land L5 is in the position of the left part of the second port 36 by this action, the second port 36 and the discharge port 42 communicate with each other and the hydraulic pressure is discharged and reduced.

] Then, the valve spool (S) is moved to the right by the elastic force of the elastic member 44 again to supply the line pressure to the pressure reducing line 34 again, the valve spool (S) is moved to the right to further discharge port ( When 42 is blocked, the hydraulic pressure in the detection chamber 40 is increased and the above operation is repeated.

In other words, the pressure on the outlet side to the decompression line 34 is adjusted. In this manner, a pressure lower than the line pressure is formed to maintain the operating pressure of the solenoid valve at a constant low speed.

As described above, the pressure reducing valve according to the present invention has the advantage of increasing the stability of the hydraulic pressure by changing the opening area of the outlet port to the pressure reducing line and opening the discharge port to make the pressure lower than the line pressure. .

Claims (4)

The hydraulic control device of the automatic transmission including a plurality of valves for selectively transmitting the torque of the torque converter to the respective gear elements by controlling a plurality of clutch and brake means in proportion to the forward and reverse speed by the oil generated from the oil pump. Subsequently, in order to improve the stability and response characteristics of the hydraulic pressure when the pressure control valve and the damper clutch control valve are operated using this pressure by making the constant pressure lower than the line pressure at all times based on the line pressure; A valve body having a first port communicating with the line pressure line, a second port communicating with the decompression line, and a discharge port, a valve spool having three lands movably installed inside the valve body, and the valve described above. A pressure reducing valve for an oil pressure control unit of an automatic transmission for an automobile including a detection chamber formed at one side of the spool and communicating with a pressure reducing line through a third port, and an elastic member corresponding to the oil pressure applied to the valve spool. The pressure reducing valve of the hydraulic control unit of an automatic transmission for an automobile according to claim 1, wherein an orifice is formed at the inlet side of the detection chamber. The pressure reducing valve of claim 1, wherein the pressure of the pressure reducing line is controlled in proportion to the opening and closing area of the second port. The pressure reducing valve of claim 1, wherein the elastic member is adjusted by an adjustment screw so that the automatic pressure can be changed.