DE102007049604A1 - Valve arrangement consists of two recoil valves linked with pressure connection and connected with further recoil valves that are interconnected - Google Patents

Abstract

The valve arrangement comprises two recoil valves (16, 18) from which the control input (20, 22) is connected with the pressure connection (A, B) of the other recoil valve. The output (24) of the first recoil valve (16) is connected with the second via a simple recoil valve (32) in series with further simple recoil valves (34, 36). The connection position between the two further recoil valves is connected with the output of the second recoil valve (18). The input of the first further may be connected with the output of the second further recoil valve.

Description

The The present invention relates to a valve arrangement for driving of two parking cylinders for Flaps of a coal bumper one Underground mining scaffolding, comprising two pilot operated check valves, each of which is the control input to the pressure port of the other unlockable check valve connected is.

such Valve arrangements are basically known and serve to drive two adjusting cylinders, each a flap of a coal bumper one Press expansion rack in underground construction. To the coal thrust and the Hanging from unwanted eruptions to protect, do you want the collision in the support the upper third and the hanging wall as far forward as possible. This is reflected in the past, a construction with flaps hinged together enforced, the hydraulically pressed against the collarbone and also retracted hydraulically can be.

at such known constructions are on the cap of the expansion rack hinged two consecutively arranged flaps, each flap from an associated one Hydraulic cylinder is controlled. Each hydraulic cylinder is included the known constructions of two unlockable check valves controlled, with two check valves a cylinder are interconnected so that the pressure port one valve with the control port of the other valve in Connection stands. Thus, for driving two hydraulic cylinders a total of four pilot-operated check valves and four pressure relief valves needed. Furthermore, the drive the two hydraulic cylinders normally running without sensors and it is for every cut required to move the two flaps so that These stretch vertically long under the cap of the shield lay. Will the sign again afterwards set, so will first pressed the cap to the hanging wall and subsequently the two flaps of the carbon bumper are extended. For this purpose is the piston surface the first cylinder of the first flap is pressure-connected and the annular surface becomes unlocked. The second cylinder must first be retracted and only after the first cylinder rests against the collision and shuts off is, the second cylinder is extended to this again Completely rests on the coal thrust. There for all These movements usually no sensor is available lasts the procedure for this relatively long.

It Therefore, the object of the present invention is a valve assembly of the type mentioned above to improve that a cost Construction with only a few valves is possible and the control the valve assembly is simplified at the same time.

The solution These features are achieved by the features of claim 1 and in particular in that the output of the first pilot-operated check valve via a first, one-way simple check valve with two more serially arranged simple check valves communicating with the junction between the two with additional check valves connected to the output of the second pilot-operated check valve.

With the valve assembly according to the invention, the two cylinders of the coal bumper on easy way to be controlled, with four unlocked instead check valves only two such valves are required, based on itself known manner to control the first hydraulic cylinder serve. The second hydraulic cylinder of the carbon bumper is replaced by the total three simple check valves causes the inexpensive to produce are and do not require their own control. Thus both can Flaps of the carbon bumper with only two pressure connections be controlled, namely the pressure port on the first pilot operated check valve and the pressure port on the second unlockable check valve.

advantageous embodiments The invention are in the description, the drawings and the dependent claims described.

To an advantageous embodiment of the Invention, the input of the first further check valve to the output the second further check valve especially about be connected to a pressure relief valve. This way will on the one hand, the volume of the annular space of the associated cylinder prevented from escaping by the pressure relief valve. However, the bumps Tip of the second flap when extending to the collision, so rises the pressure until the pressure relief valve opens and the hydraulic fluid through the first further check valve can escape.

To In another advantageous embodiment, all are Valves provided in a common valve block. So can the check valves be used in holes in the valve block and the pressure relief valves can in Drilled holes in the valve block. At the same time you can the valve block the connections for pressure lines and for The hydraulic cylinders are provided so that an extremely compact Arrangement can be achieved.

To In another advantageous embodiment, each can be unlocked Check valve one Have control piston, both control pistons coaxial in one Bore of the valve block are arranged and optionally via a arranged between them central piston can be actuated. Such a construction builds very compact and can be produced inexpensively.

To In another aspect of the invention, this relates to an expansion rack with a valve arrangement of the type described above.

following The present invention is purely exemplary by way of an advantageous embodiment and with reference to the accompanying drawings. Show it:

1 a circuit diagram of a valve assembly for controlling two actuating cylinders for flaps of a carbon bullet; and

2 a section through a valve block with a valve assembly according to 1 ,

1 schematically shows a cap 10 an otherwise not shown expansion rack in underground mining, wherein at the front end of the cap, a first flap 12 hinged, at the front end, a second flap 14 located, which is also hinged to the first flap. For pivoting the first flap 12 serves a first hydraulic cylinder Z1, in the region of its piston surface connection to the cap 10 hinged and its piston rod hinged to the first flap 12 connected is. To move the second flap 14 serves a second hydraulic cylinder Z2, in the region of its piston surface connection to the first flap 12 hinged and whose piston rod is attached to the second flap 14 is hinged.

To control the first hydraulic cylinder Z1 is a first unlockable check valve 16 and a second unlockable check valve 18 provided, wherein the pressure port A of the first unlockable check valve 16 with the control terminal 20 the second pilot-operated check valve 18 communicates and the pressure port B of the second pilot-operated check valve 18 with the control terminal 22 the first pilot operated check valve 16 communicates. The exit 24 the first pilot operated check valve 16 communicates with a piston surface port A1 of the first hydraulic cylinder Z1, and the annular surface port B1 of the first hydraulic cylinder Z1 communicates with the output 26 the second pilot-operated check valve 18 in connection. In this way, the hydraulic cylinder Z1 can be extended by pressurizing the input A and connecting the input B to the return. Retraction is carried out in the reverse manner by applying pressure to the pressure port B of the second pilot-operated check valve 18 and by connecting the pressure port A of the first pilot-operated check valve 16 with the return.

The reference numerals 28 and 30 each denote a pressure relief valve, which is connected to the output of the first pilot-operated check valve 16 or with the output of the second pilot-operated check valve 18 connected is.

For driving the second hydraulic cylinder Z2 are a first simple check valve 32 and two more simple check valves 34 and 36 provided, wherein the first simple check valve 32 from the exit 24 the first pilot operated check valve 16 Coming in the reverse direction, that is arranged blocking and with the input of the first further simple check valve 34 communicates. The two other simple check valves 34 and 36 are serially arranged and are from the first simple check valve 32 coming passing, ie arranged in the forward direction. The entrance of the first further check valve 34 is over a line 38 with the output of the second further check valve 36 in connection, being in this line 38 a pressure relief valve 40 is introduced. Furthermore, the line 38 or the input of the first further simple check valve 34 connected to the annular surface connection B2 of the second hydraulic cylinder Z2 and the output of the second further simple check valve 36 is in communication with the piston surface port A2 of the second hydraulic cylinder Z2. Finally, there is the connection between the two other simple check valves 34 and 36 on the one hand with the annular surface connection B1 of the first hydraulic cylinder Z1 and on the other hand with the output 26 the second pilot-operated check valve 18 in connection.

The operation of the valve arrangement described above is as follows:
To retract the carbon bumper, the pressure port B of the second pilot-operated check valve 18 connected with pressure, creating the first unlockable check valve 16 opens. The annular space B1 of the first hydraulic cylinder Z1 is pressurized, and at the same time, the piston area A2 of the second hydraulic cylinder Z2 via the second further simple check valve 36 pressurized. The annular surface B2 of the second hydraulic cylinder Z2 is above the first simple check valve 32 connected to port A, which is at this time in connection with return. The annular surface B1 of the hydraulic cylinder Z1 and the piston surface A2 of the hydraulic cylinder Z2 are under pressure, and the piston surface A1 of the hydraulic cylinder Z1 and the annular surface B2 of the hydraulic cylinder Z2 are connected to the return. This will drive both valves 12 and 14 back and lie in vertically stretched form under the cap 10 of the shield.

The cap is held in this position and then the pressure port B of the second pilot-operated check valve 18 connected to the return, creating the first pilot operated check valve 16 is locked. Also the second pilot operated check valve 18 is locked in this state. The second hydraulic cylinder Z2 is now fully extended and is pulled by gravity against its end position. He could move only if it could escape from the piston chamber A2 volume. But this is via the pressure relief valve 40 prevented and in addition by the first unlockable check valve 16 blocked.

To extend the carbon bumper, the pressure port A of the first pilot-operated check valve 16 connected with pressure, whereby also the second pilot-operated check valve 18 is unlocked. As a result, hydraulic fluid can escape from the annular space B1 of the first hydraulic cylinder Z1 and out of the annular space B2 of the second hydraulic cylinder Z2. The cylinder Z1 is extended and the cylinder Z2 is extended. Now hits the top of the second flap 14 when extending to the coal thrust, so the pressure at the piston chamber port A2 and increases as soon as the set pressure of the pressure relief valve 40 is reached, this valve opens and the hydraulic fluid can through the first additional check valve 34 through the unlocked second check valve 18 escape. The movement then comes to a halt when the joint between the first flap 12 and the second flap 14 to the coal thrust abuts.

This position is maintained by the pressure port A and the pressure port B of the two pilot operated check valves 16 and 18 be connected to the return. This locks both check valves and the flap 14 is held on the coal thrust, since the piston surface of the second hydraulic cylinder Z2 one by the set value of the pressure relief valve 40 higher pressure than the piston surface connection A1 or the annular surface connection B1 of the first hydraulic cylinder Z1 must have. Both volumes A1 and B1 are also blocked.

2 shows a valve block 42 in which the aforementioned valve arrangement is realized. On the in 2 left side of the valve block 42 the piston surface connections A1 and A2 and the annular surface connections B1 and B2 are provided for the first hydraulic cylinder Z1 and for the second hydraulic cylinder Z2. On the opposite right side of the valve block 42 are the pressure ports A and B of the two pilot operated check valves. Furthermore, on this side of the valve block, the pressure relief valve 28 intended. The further pressure relief valve 40 is in the bottom of the valve block 42 used. On the pressure relief valve 30 can be dispensed with in this construction, since at this point no pressure can occur, the sum of the two pressures of the pressure relief valves 28 and 40 exceeds.

As 2 further shows, the two pilot operated check valves 16 and 18 in a longitudinal bore 44 of the valve block 42 used concentrically and each pilot-operated check valve has a control piston 46 . 48 on, which seals in a known manner against a valve seat and is biased by a spring. Both control pistons 46 and 48 are concentric with each other in the hole 44 used, with the ends of the two control pistons 46 and 48 in a arranged between the two control piston central piston 50 are used, the sealed in the longitudinal bore 44 is used. In this way the control piston opens 48 the second pilot operated check valve 18 when the pressure port A is pressurized. In the same way opens the control piston 46 the first pilot operated check valve 16 when the pressure port B is pressurized.

The first simple check valve 32 is in a longitudinal bore at the top of the valve block 42 inserted and locks the connection between the terminals A1 and B2, through a longitudinal bore 52 given is. Similarly, the two other first and second simple check valves 34 and 36 in a common longitudinal bore at the bottom of the valve block 42 used, with cross-holes and oblique holes, the corresponding connections between the valves are made.

10

cap

12

first flap

14

second flap

16

first unlockable check valve

18

second unlockable check valve

20 22

control connection

24

output the first pilot operated check valve

26

output the second pilot-operated check valve

28 30

Pressure relief valve

32

first simple check valve

34

first another simple check valve

36

second another simple check valve

38

management

40

Pressure relief valve

42

manifold

44

longitudinal bore

46 48

spool

50

central piston

52

longitudinal bore

A, B

pressure connection

A1, A2

Piston area connection

B1, B2

Ring face Connection

Z1

first hydraulic cylinders

Z2

second hydraulic cylinders

Claims (9)

Valve arrangement for controlling two adjusting cylinders (Z1, Z2) for flaps ( 12 . 14 ) of a coal bumper of a mining rack in underground construction, comprising two non-returnable check valves ( 16 . 18 ), of which the control input ( 20 . 22 ) is connected to the pressure port (A, B) of the other pilot-operated check valve, characterized in that the output ( 24 ) of the first pilot-operated check valve ( 16 ) via a first, arranged, simple check valve ( 32 ) with two other serially arranged, simple non-return valves ( 34 . 36 ), the junction between the other two non-return valves ( 34 . 36 ) with the output ( 26 ) of the second pilot-operated check valve ( 18 ) connected is. Valve arrangement according to claim 1, characterized in that the input of the first further non-return valve ( 34 ) with the output of the second further check valve ( 36 ) connected is. Valve arrangement according to claim 1, characterized in that the input of the first further non-return valve ( 34 ) with the output of the second further check valve ( 36 ) via a pressure relief valve ( 40 ) connected is. Valve arrangement according to claim 1, characterized in that the input of the first further non-return valve ( 34 ) with an annular surface connection (B2) and the output of the second further non-return valve ( 36 ) is in communication with a piston surface port (A2) for an actuator cylinder (Z2) of the carbon fiber bumper. Valve arrangement according to claim 1, characterized in that the two further non-return valves ( 34 . 36 ) from the first check valve ( 32 ) are arranged passing through. Valve arrangement according to claim 1, characterized in that all the valves in a common valve block ( 42 ) are provided. Valve arrangement according to claim 1, characterized in that each unlockable check valve ( 16 . 18 ) a control piston ( 46 . 48 ), wherein both control pistons coaxial in a bore ( 44 ) are arranged and optionally via a central piston arranged therebetween ( 50 ) are operable. Removable rack in underground construction with two adjusting cylinders (Z1, Z2) for flaps ( 12 . 14 ) of a carbon fiber bumper and a Ventilanord according to any one of the preceding claims, wherein the output ( 24 ) of the first pilot-operated check valve ( 16 ) with the piston surface (A1) and the output ( 26 ) of the second pilot-operated check valve ( 18 ) is in communication with the annular surface (B1) of a first actuating cylinder (Z1) of the carbon-fiber catcher. Expansion frame according to claim 8, characterized in that the input of the first further non-return valve ( 34 ) with the annular surface (B2) and the output of the second further non-return valve ( 36 ) is in communication with the piston surface (A2) of a second actuating cylinder (Z2) of the carbon-fiber catcher.