DE102008009722B4 - valve assembly - Google Patents

Abstract

Valve arrangement for a ram (10, 11) of a support frame, comprising two pilot operated check valves (24, 26) connected in parallel, of which the first (24) has its input to the return (R) and the second (26) has its input to a control port (A1) of a valve is connected, and the output side with the piston surface connection (A ') of the punch (10) are in communication,
characterized in that
at least one further parallel-connected pilot-operated check valve (28) is provided, the output side of which is in communication with the piston surface connection (A ') of the plunger (10), and which communicates with its input with a control connection (A2) of a valve, wherein
the inlet of the further pilot-operated check valve (28) communicates with the outlet of an additional pilot-operated check valve (30) whose inlet communicates with a control port (A2) of a valve, the connection between the further (28) and the additional (28) 30) Check valve with the ring surface connection of a pump cylinder (40, 50) in connection ...

Description

The present invention relates to a valve assembly for a stamp of a support frame according to the preamble of claim 1. Such a valve assembly is known from DE 10 2005 025 917 A1 known.

Although this known valve arrangement is suitable for high pressures and / or flow rates, increasingly stamps are required in underground mining, which have even larger cross sections. However, the known valve arrangement is not suitable for such large dies.

It is therefore an object of the present invention to improve a valve arrangement of the type mentioned so that with the least possible effort stamp can be controlled with very large cross-sections.

The solution of this object is achieved by the features of claim 1.

The invention is based on the recognition that the provision of a cascade of pilot-operated check valves connected in parallel offers the possibility of maximizing the flow rate in robbing the punch and at the same time making it possible to increase the setting pressure. If another parallel operated check valve is connected with its input to the return, thereby increasing the flow in the robbery. Since according to the invention the further parallel-connected pilot-operated check valve is connected to the control connection of a valve, the flow rate during setting can be increased. Alternatively, this further check valve can be used to increase the set pressure by means of a pump cylinder.

According to the invention, the input of the further pilot-operated check valve is connected to the output of an additional pilot-operated check valve whose input communicates with a control connection of a valve, the connection between the additional and the additional check valve being in communication with the annular surface connection of a pump cylinder. Such an additional check valve, which is serially coupled to the further check valve, allows the use of a translation pump to gradually increase the stamp pressure. The gear pump may advantageously be designed as a pump cylinder, wherein the piston surface connection of the pump cylinder may be in communication with a control port of a valve. By applying this control connection with pressure, the pump cylinder is extended, so that an increased pressure is established at the annular surface connection of the pump cylinder, which can then be forwarded via the connection between the additional additional check valve to the piston surface connection of the punch. By pressing the pump cylinder several times, the pressure in the plunger can then be increased until the desired pressure in the plunger has been reached.

Advantageous embodiments of the invention are described in the description, the drawings and the subclaims.

According to a first advantageous embodiment, a total of two further pilot-operated check valves connected in parallel are provided, namely a third and a fourth non-return valve, both of which are connected on the output side to the piston surface connection of the punch. Hereby, the third check valve communicates with its input to the return and the fourth check valve communicates with its input to a control port of a valve in connection. In this embodiment, a cascade is created by a total of four pilot operated check valves connected in parallel, wherein two check valves can be used when setting and in the robbing all four parallel check valves are flowed through.

According to a further advantageous embodiment, the piston surface connection of the pump cylinder can also be in communication with the input of the second releasable check valve, so that when the plunger is already set, the plunger pressure is further increased by applying set pressure to the pump cylinder at its piston surface connection.

According to a further advantageous embodiment, the pump cylinder may be a lifting cylinder (base lift) for the skids of the expansion rack. Such a cylinder, which is often present anyway in the expansion rack, can thus be used to increase the setting pressure. However, such a lifting cylinder is often not suitable for this function in its construction. For this reason, it may be advantageous to provide a separate pump cylinder for increasing the set pressure.

In order to increase the setting pressure in both stamps advantageous in the expansion rack with two punches, a pump cylinder is provided according to the invention comprising two stepped pistons, which are arranged coaxially in a common housing, each piston having a piston surface and an annular surface and the housing has two annular surface connections, which are in communication with the piston surface connection of a respective punch. By alternately applying the piston surface connections of the Pump cylinder can be gradually increased in such an arrangement, the set pressure in both punches.

In order to achieve an automatic retraction of the two pistons even when the other piston has not covered a complete pumping stroke, according to a further advantageous embodiment, each piston can be provided with a through bore into which a coupling rod is inserted, which is arranged between the pistons Driver has. Such a coupling rod, which is preferably performed sealed in the holes, allows the decoupled retraction of each piston, since first the coupling rod is pressurized and with the help of its driver a piston moves back to its end position. Since the other piston is decoupled from the coupling rod, it does not have to complete a complete pumping stroke to move the other piston back to its original position.

The aforesaid control port of a valve is understood to mean the conventional mining output of a main control valve or another likewise suitable valve with which the delivery of pressurized hydraulic fluid is switched.

Hereinafter, the present invention will be described purely by way of example with reference to an advantageous embodiment and with reference to the accompanying drawings. Show it:

1 a first embodiment of a valve assembly;

2 a second embodiment of a valve assembly; and

3 a longitudinal section through a pump cylinder.

1 schematically shows an arrangement of two punches 10 . 11 an unspecified expansion rack for underground mining. As the facilities for controlling the stamp 10 and 11 at the in 1 are shown the same arrangement, hereinafter only the valve assembly for controlling the left punch 10 described in detail.

The activation of the piston surface connection A of the punch 10 via a valve block 20 in which in the illustrated embodiment, a total of five pilot operated check valves are provided, of which four are connected in parallel and two in series. The annular surface connection B 'of the punch 10 is directly connected to a control port B of a valve, not shown. From this connection is also an unlock line 18 led to all Entsperranschlüssen the pilot-operated check valves.

In the valve block 20 are in the illustrated embodiment four releasable check valves 22 . 24 . 26 and 28 provided, all with their output to the piston surface connection A 'of the punch 10 are connected. With this line are also a pressure relief valve 12 , a manometer 14 and a pressure sensor 15 connected, the electrical output is given to a terminal D of a central control. The reference number 13 denotes a rockfall valve.

The entrance, seen in the direction of passage, the first pilot-operated check valve 22 is connected to the return R Likewise, the entrance of the second pilot-operated check valve 24 connected to the return R The input of the third pilot operated check valve 26 is connected to a control port A1 of a valve. Likewise, the entrance of the pilot operated check valve 28 connected to a control port A2 of a valve. However, there is a fifth pilot operated check valve in this line 30 whose input is connected to the control port A1 and whose output is connected to the input of the check valve 28 connected is. In other words, the check valves 28 and 30 connected serially. The connection between these two check valves 28 and 30 is in turn connected to the annular surface connection of a pump cylinder, which in the illustrated embodiment, a lifting cylinder 40 for the skids of the expansion rack is. The ring surface connection of the lifting cylinder 40 is also with the unspecified valve assembly for the right stamp 11 connected there and also opens into the junction of the two series-connected pilot check valves. The piston surface connection of the lifting cylinder 40 is in turn connected to a control port A3 of a valve.

The functions of the control valves for the operation of the stamp 10 and the lifting cylinder 40 are as follows:
Rob a stamp
Set A1 stamp
A2 Set punch and actuate lifting cylinder
A3 Actuate lifting cylinder or increase stamping pressure with set punch

To rob the stamp 10 the control port B is pressurized, whereupon through the Unlock 18 all check valves 22 to 30 be unlocked, so that the hydraulic fluid from the piston chamber of the punch 10 can flow back over a total of four lines connected in parallel. For this purpose, the Control valves on the connections A1 and A2 connected so that they are connected to the return.

To set the stamp 10 the port A1 is pressurized, then hydraulic fluid through the check valve 26 flows into the piston chamber of the punch. In addition, via the control port A2 hydraulic fluid through the check valves 28 and 30 be placed in the piston chamber of the punch.

If the stamp has already been set, the stamp pressure can be increased by applying pressure to the control port A3. As a result, the lifting cylinder 40 operated and over the annulus of the lifting cylinder 40 hydraulic fluid flows at elevated pressure through the check valve 28 in the piston chamber of the punch 10 , By subsequently operating the control valve A2, the lifting cylinder can be 40 move back so that a new pump stroke can be performed until the desired pressure in the stamp is reached.

Since the lifting cylinder of a support frame is not always suitable as a pump cylinder due to its construction, a separate pump cylinder can be provided for a further, not shown embodiment. It may be advantageous if the piston surface connection of the pump cylinder is not supplied to a separate control port A3, but with the input of the pilot operated check valve 26 is connected, ie with the control terminal A1. This control connection can then be used to set the stamp and to increase the stamping pressure for both punches when the stamp is set. With such a construction, the stamping pressure can only be increased evenly in both dies. Supply pressure is used to return the pump cylinder. The following in connection with the 2 and 3 described pump cylinder can work more efficiently here.

2 shows a further variant of a valve arrangement, which apart from the pump cylinder with in 1 identical arrangement is described. In this respect, the same reference numerals are used for the same parts and the arrangement will not be described again in detail.

In the 2 shown valve arrangement differs from the in 1 shown by an opposite pump cylinder 50 is provided in 3 is shown enlarged. The pump cylinder 50 has two stepped pistons 52 and 54 on, coaxial in a common housing 56 are arranged. Every piston 52 . 54 has a larger diameter peripheral portion and a smaller diameter peripheral portion, the pistons being arranged so that the smaller diameter portions face each other so as to be within the pumping cylinder 50 a the piston 52 assigned piston surface space 58 and a the piston 54 assigned piston surface space 60 results.

The housing 56 is with two caps 62 and 64 sealed at its ends, wherein in each case a through hole is provided in the two closure lids, which has a piston surface connection 66 for the piston 52 and a piston surface port 68 for the piston 54 form. Inside the case 56 is between the piston 52 and the housing 56 a first annulus 70 and between the piston 54 and the housing 56 a second annulus 72 educated. Furthermore, the pump piston 50 a first annular space connection 74 on, by the pressurized fluid from the annulus 70 can escape. Furthermore, a second annular space connection 76 provided, from the pressurized fluid from the second annulus 72 can escape. Both pistons 52 and 54 are sealed at both ends in the housing.

As 3 also shows, are both pistons 52 and 54 each with a central through hole 78 and 80 provided in which a common coupling rod 82 sealed is performed. The coupling rod has a Mitnehmerbund in its center 84 on, by means of which a piston can be moved in each case when the piston surface space of the respective other piston is pressurized.

The functioning of the in 3 described pump cylinder 50 is as follows: if from the in 3 shown position from the piston surface connection 66 is pressurized, so this pressure moves the piston 52 in 3 to the right, creating hydraulic fluid with increased pressure from the annulus 70 through the annulus connection 74 is pumped. At the same time the coupling rod 82 pressurized and pushes the piston 54 in its right end position, since the Mitnehmerbund 84 at this strikes. If then the piston surface connection 68 the pump piston 50 is pressurized and the piston surface connection 66 is connected to the return, hydraulic fluid flows into the through hole 80 and moves the coupling rod 82 in 3 to the left, until the Mitnehmerbund 84 on the piston 52 strikes and this also moves to the left. At the same time the piston 54 pressurized and displaced to the left, creating hydraulic fluid with increased pressure from the annulus 72 through the annulus connection 76 exit. Thus, when the hydraulic fluid enters the respective piston surface space 58 and 60 the hydraulic fluid evenly distributed over the respective piston are both pistons 52 and 54 provided on its underside with a radially outer circumferential collar, which has a small distance between the piston bottom surface and the closure lids 62 and 64 manufactures.

As 2 clarifies, is the pump cylinder 50 with its piston surface connection 66 connected to the control port A1, which also connects to the inlet of the check valve 26 connected is. The annulus connection 74 the pump cylinder 50 is with the connection between the two check valves 28 and 30 connected. The corresponding arrangement is also found in the valve assembly for the right stamp 11 ,

At the in 2 illustrated arrangement, the pump cylinder 50 be operated mutually and the two pistons 52 and 54 are mutually pushed back to their original position. Due to the coupling rod 82 and the Mitnehmerbund 84 a complete return of the respective piston takes place in its initial position, even if the other piston should not cover a complete stroke. In this arrangement, no pressure medium must be used only to return the pistons back to their original position. If only one stamp should get a higher pressure, then only one half of the pump can be actuated.

It should be noted that the embodiments described above are exemplary only and are not limited to the number of pilot operated check valves shown.

LIST OF REFERENCE NUMBERS

10, 11

stamp

12

Pressure relief valve

13

Rock burst valve

14

manometer

15

pressure sensor

20

manifold

22-30

unlockable check valve

40

lifting cylinder

50

pump cylinder

52, 54

piston

56

casing

58, 60

Piston surface chamber

62, 64

cap

66, 68

Piston area connection

70, 72

annulus

74, 76

Annulus port

78, 80

Through Hole

82

coupling rod

84

Mitnehmerbund

A '

Piston area connection

B '

Annulus port

A1, A2, A3, B

control connections

R

returns

D

pressure sensor

Claims (10)

Valve arrangement for a stamp ( 10 . 11 ) of an expansion rack, comprising two pilot operated check valves ( 24 . 26 ), of which the first ( 24 ) with its input to the return (R) and the second ( 26 ) is connected with its input to a control port (A1) of a valve, and the output side with the piston surface connection (A ') of the punch ( 10 ) are connected, characterized in that at least one further parallel-connected unlockable check valve ( 28 ) is provided, the output side with the piston surface connection (A ') of the punch ( 10 ) communicates with its input to a control port (A2) of a valve, the input of the further pilot-operated check valve ( 28 ) with the output of an additional pilot operated check valve ( 30 ) whose input is connected to a control port (A2) of a valve, the connection between the other ( 28 ) and the additional ( 30 ) Check valve with the ring surface connection of a pump cylinder ( 40 . 50 ). Valve arrangement according to claim 1, characterized in that a fourth parallel-operated pilot-operated check valve ( 22 ) is provided, the output side with the piston surface connection (A ') of the punch ( 10 ) communicates with its input to the return (R). Valve arrangement according to claim 1, characterized in that the piston surface connection of the pump cylinder ( 40 . 50 ) is in communication with a control port (A3) of a valve. Valve arrangement according to claim 3, characterized in that the piston surface connection ( 66 ) of the pump cylinder ( 50 ) with the input of the second check valve ( 26 ). Valve arrangement according to claim 1 of 3, characterized in that the pump cylinder is a lifting cylinder ( 40 ) for the skids of the expansion rack is. Valve arrangement according to claim 2, characterized in that the unlocking connection of each non-return valve ( 22 - 30 ) with the annular surface connection (B ') of the punch ( 10 ). Valve arrangement according to one of claims 2 to 6, characterized in that all the pilot-operated check valves ( 22 - 30 ) in a common valve block ( 20 ) are arranged. Combination of two stamps ( 10 . 11 ) an expansion rack and a pump cylinder ( 50 ) for a valve assembly according to claim 1, wherein the pump cylinder ( 50 ) two stepped pistons ( 52 . 54 ) coaxially in a common housing ( 56 ) are arranged, each piston ( 52 . 54 ) a piston chamber ( 58 . 60 ) and an annulus ( 70 . 72 ) and the housing ( 56 ) two annular surface connections ( 74 . 76 ), which with the piston surface connection (A ') in each case a punch ( 10 . 11 ) keep in touch. Combination according to claim 8, characterized in that each piston ( 52 . 54 ) with a through hole ( 78 . 80 ), in which a coupling rod ( 82 ) is introduced, which is arranged between the piston driver ( 84 ) having. Combination according to claim 9, characterized in that the coupling rod ( 82 ) in the holes ( 78 . 80 ) is guided sealed.

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