DE102011087511A1 - Pressure control valve for hydraulic system, has partial valves comprising actuating piston and pressure closing piston respectively - Google Patents

Abstract

The pressure control valve (2) has two partial valves (21,22) that are arranged in preset manner. The partial valve (21) has an actuating piston (23) that is movable between three various positions. The partial valve (22) has a pressure closing piston (24) that is movable between two positions. A terminal for working line section (11) and a terminal for tank pressure line (5) are provided in partial valve (21). A terminal for working pressure line (12) and a terminal for supply pressure spacer (3) are provided in partial valve (22).

Description

The invention relates to a pressure regulating valve with a supply port, to which a supply pressure is applied, with a tank connection, which is applied to a tank pressure, and with a working port, which is applied to a working pressure, which is controlled by the pressure control valve, which is divided into two part valves. The invention further relates to a hydraulic system with such a pressure control valve.

From the German patent application DE 10 2005 056 029 A1 a hydraulic system with at least one hydraulic valve for controlling a component is known, wherein a force acting on the hydraulic valve control pressure via a supply pressure of a pilot circuit with at least one actuator is controlled, the at least one pressure reducing device is connected upstream. The actuator is designed as an electromagnetically actuated proportional valve. The pressure reducing device is designed as a pressure limiting valve which is connected between a pilot control orifice of the pilot control circuit and the proportional valve. The pressure relief valve comprises a spring-loaded control piston with a first surface acted upon by the supply pressure and a second surface acted upon by the control pressure.

The object of the invention is to improve a pressure control valve according to the preamble of claim 1 in view of the leakage occurring during operation, the control quality and / or the manufacturing costs on.

The object is with a pressure regulating valve with a supply connection, at which a supply pressure is applied, with a tank connection, at which a tank pressure is applied, and with a working connection, at which a working pressure is applied, which is regulated by the pressure regulating valve, which is divided into two part-valves , solved by a mechanically operable by an actuating piston closing piston in a closed position interrupts a connection between the supply port and the working port leakage-free. The closing piston reliably prevents a leakage flow from the supply connection to the working connection and the tank connection. The two part valves are preferably designed as seat valves so that neither the tank pressure nor the supply pressure have an active surface in the direction of actuation. Due to the design according to the invention, during operation of the pressure regulating valve, it is achieved that leakage only occurs on non-controlling gaps, the length of which can be selected to be sufficiently large without regard to overlapping and magnetic lifting.

A preferred embodiment of the pressure regulating valve is characterized in that the closing piston represents a working pressure valve seat between the supply port and the working port. The closing piston is equipped for this purpose with a preferably tapered sealing surface, which comes to a sealing edge of a housing to the plant to interrupt the connection between the supply port and the working port.

Another preferred embodiment of the pressure control valve is characterized in that the closing piston is designed to be pressureless or pressure balanced. The closing piston is preferably pressure balanced with respect to the working pressure and the supply pressure. Pressure compensated means that the closing piston has no resulting pressure acting surface. This ensures that a valve pitch does not change on contact of both pistons.

Another preferred embodiment of the pressure control valve is characterized in that the closing piston is biased by a closing spring in its closed position. The closing spring can be made relatively small, that is to say with a relatively small spring force. The closing spring represents a hysteresis between system taxes and tank taxes and may only be dimensioned as much as necessary. The term system refers to the work connection. The working pressure is also called system pressure.

A further preferred embodiment of the pressure regulating valve is characterized in that the actuating piston can assume the following actuating positions: In a first actuating position, the actuating piston is spaced from the closing piston; in a second operating position, the actuating piston comes into contact with the closing piston; in a third operating position, the actuating piston has contact with the closing piston. The actuating piston is, for example by means of magnetic forces, movable between its three operating positions. In the first operating position of the actuating piston of the working port is connected via the actuating piston to the tank port. In the second operating position of the actuating piston, the connection between the working port and tank port is interrupted, wherein the working pressure valve seat between closing piston and housing remains closed. In the third operating position, the actuating piston moves together with the closing piston to regulate the working pressure.

Another preferred embodiment of the pressure control valve is characterized characterized in that the actuating piston and the closing piston with their ends facing each other constitute a tank pressure valve seat. For the representation of the valve seat, a conical sealing surface is preferably formed on the actuating piston, for example, which comes to rest on a sealing edge of the closing piston to close the tank pressure valve seat. When the tank pressure valve seat is open, the working port is connected to the tank port. When the tank pressure valve seat is closed, the connection between the working connection and the tank connection is interrupted.

Another preferred embodiment of the pressure control valve is characterized in that the actuating piston within a tank pressure valve seat diameter has a connection channel connecting a first working pressure surface of the actuating piston within the tank pressure valve seat diameter with a working pressure connection space in the region of a second working pressure surface of the actuating piston. As a result, a resulting effective area for the working pressure is created on the actuating piston. The size of the resulting effective area for the working pressure can be adapted to a desired pressure range as well as to an actuating force, for example a magnetic force. With this adaptation, a gain factor and a pressure ratio can be taken into account.

A further preferred exemplary embodiment of the pressure regulating valve is characterized in that the actuating piston has an actuating tappet which starts from an end face of the actuating piston facing away from the closing piston and limits the second working pressure surface of the actuating piston. The actuating tappet protrudes with its free end into a pressure relief space, which is acted upon by tank pressure.

Another preferred embodiment of the pressure control valve is characterized in that the actuating plunger of the actuating piston cooperates with an actuating magnet. The actuating magnet is preferably an electromagnet designed as a proportional magnet, which is electrically actuated. When the electromagnet is de-energized, then the actuating piston is held by the force acting on the resulting effective surface working pressure in contact with the magnet or on a magnetic piston. When the electromagnet is energized, then the actuating piston is moved away from the magnet toward the closing piston.

The invention further relates to a hydraulic system with a pressure regulating valve described above. The hydraulic system is preferably associated with a hydraulic transmission control. About the pressure control valve is supplied to a downstream hydraulic device with the working pressure supplied hydraulic medium or removed. The hydraulic device may comprise a hydraulic valve, which is controlled via the pressure regulating valve. The hydraulic system is preferably used in dual-clutch transmissions, CVT transmission systems or the like for controlling certain transmission components or for controlling portions of the transmission systems.

Further advantages, features and details of the invention will become apparent from the following description in which, with reference to the drawings, various embodiments are described in detail. Show it:

1 a simplified representation of a hydraulic system with a pressure control valve according to the invention in the form of a hydraulic circuit diagram and

2 an embodiment of the pressure control valve 1 in longitudinal section.

In the 1 and 2 is a hydraulic system 1 with a pressure control valve 2 shown schematically and in a longitudinal section. Via a supply pressure line 3 For example, with the aid of a hydraulic pump, a supply pressure is provided at a supply pressure port. Via a working pressure line 4 becomes one with the help of the pressure regulating valve 2 regulated working pressure, for example in a transmission control provided. About a tank pressure line 5 is the pressure control valve 2 to a tank 6 connected for hydraulic medium. The hydraulic medium is preferably hydraulic oil coming from the tank 6 , for example via the hydraulic pump, through the supply pressure line 3 is supplied.

At a junction 10 shares the working pressure line 4 in a working pressure line section 11 and a working pressure line section 12 on. The working pressure line section 11 is to a first part valve 21 connected. The working pressure line section 12 is to a second part valve 22 connected. The two part valves 21 and 22 Together, the pressure control valve according to the invention 2 dar. The part valve 21 includes an actuating piston 23 which is electromagnetically actuated. The part valve 22 includes a closing piston 24 which is mechanical via the actuating piston 23 is operable.

In 1 you can see that the actuating piston 23 at his the closing piston 24 facing end of a mechanical coupling element 25 having. The closing piston 24 indicates at its the actuating piston 23 facing end of a mechanical coupling element 26 on. The two coupling elements 25 . 26 are in 1 spaced apart.

The part valve 21 with the actuating piston 23 can take three different positions. The part valve 22 with the closing piston 24 can take two different positions. The part valve 21 has a first connection for the working pressure line section 11 and a second connection for the tank pressure line 5 , The part valve 22 has a first connection for the working pressure line section 12 and a second port for the supply pressure line 3 ,

In 1 is a connection between the supply pressure line 3 and the working pressure line section 12 through the closing piston 24 interrupted. A connection between the working pressure line section 11 and the tank pressure line 5 is through the actuating piston 23 Approved. When the actuating piston 23 is electromagnetically actuated, then the connection between the working pressure line section 11 and the tank pressure line 5 interrupted, in both other positions, the actuating piston 23 can take.

In its middle position comes the actuating piston 3 with the free end of the mechanical coupling element 25 in contact with the free end of the mechanical coupling element 26 , When the actuating piston 23 from its middle position on the actuating valve 22 is moved, then move the actuating piston 23 and the closing piston 24 together to the supply pressure line 3 in pressure control mode demand-dependent with the working pressure line section 12 connect to.

From the working pressure line section 12 extends a pressure feedback 28 to the end of the actuating piston 23 with the mechanical coupling element 25 , The pressure feedback 28 serves to balance the forces on the actuating piston 23 to maintain. With the part valve 21 may be the discharge of hydraulic fluid from the working pressure line section 11 in the tank 6 be managed. A pressure build-up in the working pressure line 4 can via the part valve 22 be managed.

In 2 be for same or similar parts as in 1 the same reference numerals are used. In 2 you can see that the actuating piston 23 and the closing piston 24 in a housing 30 are guided in the longitudinal direction movable back and forth. For this purpose, the housing 30 a housing bore through, through a plug 32 is closed. Between the actuating piston 23 and the housing 30 is a working pressure valve seat 31 educated.

To illustrate the working pressure valve seat 31 points the closing piston 24 a conical sealing surface, which is closed when working pressure valve seat 31 sealingly abuts a sealing edge in the housing 30 is trained. A closing spring 34 is so between the closing piston 24 and the stopper 32 clamped that working pressure valve seat 31 , as shown, is closed.

When the closing piston 24 on the stopper 32 is moved, then the closing spring 24 compressed and the working pressure valve seat 31 open. With open working pressure valve seat 31 will connect the supply pressure line 3 and the working pressure line section 12 Approved. Through the closed working pressure valve seat 31 becomes the connection between the working pressure line section 12 and the supply pressure line 3 interrupted.

The two mutually facing ends of the actuating piston 23 and the closing piston 24 serve to represent a tank pressure valve seat 36 , To illustrate the tank pressure valve seat 36 is at the end of the actuating piston 23 a sealing surface formed at a sealing edge at the end of the closing piston 24 sealing to the plant can come to the tank pressure valve seat 36 close.

In 2 are the two mutually facing ends of the closing piston 24 and the actuating piston 23 spaced apart so that the tank pressure valve seat 36 is open. This position corresponds to the first position of the part valve 21 in 1 , Via a connection channel 38 extending longitudinally and transversely through the actuating piston 23 extends, the working pressure from the working pressure line section 11 in the tank 6 reduced.

The actuating piston 23 indicates at its the closing piston 24 facing end within a Tankdruckventilssitzdurchmessers a first working pressure surface 41 on that over the connection channel 38 can be acted upon by the working pressure. The actuating piston 23 has at its other end a second working pressure surface 42 on that in a working pressure connection room 44 with the working pressure from the working pressure line section 11 is charged. The second working pressure surface 42 is designed as an annular surface, the radially inward of an actuating tappet 48 is limited, extending from the end of the actuating piston 23 with the second working pressure surface 42 to an actuating magnet 50 extends.

The actuating magnet 50 has an actuator 54 on, at which the free end of the actuating plunger 48 of the actuating piston 23 is applied. When the actuating magnet 50 is energized, then the actuating piston 23 over the actuator 54 and the actuating tappet 48 on the closing piston 24 too moved. When the actuating piston 23 with the closing piston 24 Contact gets, then the tank pressure valve seat 36 closed and the connection between the working pressure line section 11 and the tank pressure line 5 interrupted.

With closed working pressure valve seat 31 becomes the first working pressure surface 41 over the connection channel 38 , which is the pressure feedback 28 in 1 corresponds to the working pressure applied. The second working pressure surface 42 is so much smaller than the first working pressure surface 41 in that the actuating piston 23 with energized electromagnet 50 is in equilibrium. With increasing energization of the actuating magnet or electromagnet 50 become the two pistons in contact 23 . 24 together on the stopper 32 too moved around the working pressure valve seat 31 to open according to demand.

LIST OF REFERENCE NUMBERS

1

hydraulic system

2

Pressure control valve

3

Supply pressure line

4

Working pressure line

5

Tank pressure line

6

tank

10

branch

11

Working pressure line section

12

Working pressure line section

21

part valve

22

part valve

23

actuating piston

24

closing piston

25

mechanical coupling element

26

mechanical coupling element

28

Pressure feedback

30

casing

31

Work pressure valve seat

32

Plug

34

closing spring

36

Tank pressure valve seat

38

connecting channel

41

first working pressure surface

42

second working pressure surface

44

Working pressure connection space

48

actuating ram

50

actuating magnet

54

actuator

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102005056029 A1 [0002]

Claims (10)

Pressure control valve with a supply connection, to which a supply pressure is applied, to a tank connection, to which a tank pressure is applied, and to a working connection, to which a working pressure is applied, which is connected to the pressure regulating valve ( 2 ), which is divided into two parts ( 21 . 22 ), characterized in that a mechanically by an actuating piston ( 23 ) actuatable closing piston ( 24 ) interrupts a connection between the supply connection and the working connection without leakage in a closed position. Pressure control valve according to claim 1, characterized in that the closing piston ( 24 ) a working pressure valve seat ( 21 ) between the supply connection and the working connection. Pressure control valve according to one of the preceding claims, characterized in that the closing piston ( 24 ) is executed without pressure or pressure balanced. Pressure control valve according to one of the preceding claims, characterized in that the closing piston ( 24 ) by a closing spring ( 34 ) is biased in its closed position. Pressure control valve according to one of the preceding claims, characterized in that the actuating piston ( 23 ) can assume the following actuating positions: - in a first actuating position, the actuating piston ( 23 ) of the closing piston ( 24 ) spaced; In a second actuating position, the actuating piston ( 23 ) with the closing piston ( 24 ) in contact; In a third operating position, the actuating piston ( 23 ) with the closing piston ( 24 ) Contact. Pressure control valve according to one of the preceding claims, characterized in that the actuating piston ( 23 ) and the closing piston ( 24 ) with their mutually facing ends a tank pressure valve seat ( 36 ). Pressure control valve according to one of the preceding claims, characterized in that the actuating piston ( 23 ) within a tank pressure valve seat diameter a connection channel ( 38 ) having a first working pressure surface ( 41 ) of the actuating piston ( 23 ) within the tank pressure valve seat diameter with a working pressure connection space ( 44 ) in the region of a second working pressure surface ( 42 ) of the actuating piston ( 23 ) connects. Pressure control valve according to claim 7, characterized in that the actuating piston ( 23 ) an actuating tappet ( 48 ) of a the closing piston ( 24 ) facing away from the end face of the actuating piston ( 23 ) and the second working pressure surface ( 42 ) of the actuating piston ( 23 ) limited. Pressure control valve according to claim 8, characterized in that the actuating tappet ( 48 ) of the actuating piston ( 23 ) with an actuating magnet ( 50 ) cooperates. Hydraulic system with a pressure regulating valve ( 2 ) according to any one of the preceding claims.

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