EP2291586A1

EP2291586A1 - Device for increasing the pressure in cylinders using a control device

Info

Publication number: EP2291586A1
Application number: EP08773265A
Authority: EP
Inventors: Wolfgang Voss
Original assignee: Individual
Current assignee: Individual
Priority date: 2008-06-17
Filing date: 2008-06-17
Publication date: 2011-03-09
Anticipated expiration: 2028-06-17
Also published as: PL2291586T3; DE112008003985A5; WO2009152786A1; EP2291586B1

Abstract

In order to increase the pressure of the pressure fluid in cylinders, particularly the hydraulic longwall working in underground mining and tunneling, a control device (21) is used, which is provided with appropriately controllable, unlockable check valves (29, 30) and also (25), and a lockable check valve (31). These check valves and the associated directional control valves create the possibility to fill not only the proper cylinder chamber (20), but also the piston rod space (26) enabling rewashing with pressure fluid in a targeted manner, or to appropriately reduce the pressurization, without the risk of mutual impact or seizing or other damage occurring.

Description

DESCRIPTION

DEVICE FOR PRINTER INCREASE IN CYLINDERS WITH SWITCHING DEVICE

The invention relates to a device for increasing the pressure in cylinders, in particular of hydraulic expansion in underground mining and tunneling with its cylinder housing, piston, piston rod and arranged therein clamping piston and in the cylinder space retractable clamping piston rod via a connecting line with an integrated switching device via a high-pressure pump Pressure fluid can be acted upon.

When operating cylinders and similar devices, the movement is obtained by supplying a pressure transmitter, which is oil, water, water in oil, plasma or other liquid or even air. Hydraulics is the teaching and technical application of flows in compressible fluids. This means that in the case of hydraulics, the liquid, but above all oil or else water-oil emulsion, is initially influenced accordingly in a high-pressure pump, i. H. is biased to then be supplied via hose or similar lines to the cylinder. Valves are used to control the extension and retraction of the cylinders, always using one and the same pressure, namely the pressure dependent on the power of the high-pressure pump. In particular, in underground mining and tunneling, where work must be done with water-oil emulsions for safety reasons, one currently works with a maximum of 400 bar, quite simply, because there are currently no pumps that a higher

Can generate pressure level safely. Due to various circumstances but is not always ensured that in the cylinder chamber said pressure is available, which is why so-called Nachsetzschaltungen are known, especially in underground mining and tunneling, with which the volume in the Cylinder space is set by re-connection with the high pressure pump so that then approximately the said pressure level is safely available. However, it is not possible to produce a higher pressure level within the cylinder space and thus within the cylinder, because the pumps are unable to do so. For a variety of reasons, but this is often desired, said the present, highest pressure level of 400 bar, the pumps set the limits, at lower pressure levels, the cost of an additional high-pressure pump and corresponding hose lines would substantially offset the advantage again. From DE 103 06 128 A1 a method and a corresponding cylinder is known, wherein within the actual cylinder housing a clamping piston with a small piston rod is arranged, via which the cylinder space in the region of the piston or the pending there water emulsion can be compressed higher. This makes it possible, depending on the choice of piston and clamping piston and depending on the displacement to increase the pressure within the cylinder well over 400 bar. However, a switching device that reliably controls this pressure increase device is not yet known.

The invention is therefore based on the object to provide a simple and secure working switching device for cylinders with internal, the pressure in the cylinder chamber significantly increasing clamping piston.

The object is achieved according to the invention in that the switching device is designed via a pilot-operated check valve in the connecting line between the high-pressure pump and piston rod cavity and a valve block with further unlockable or lockable check valves in the connecting line between the high pressure pump and cylinder space.

About the valve block with the unlockable or lockable

Check valves, it is initially possible, the necessary initial pressure for the extension of the piston within the cylinder housing in push the cylinder space into it by connecting to the high pressure pump. However, this valve block is at the same time designed so that during later unloading of the cylinder or when diverting the high pressure hydraulic fluid is also ensured that just through this connection line pressure fluid is returned to the tank without the risk that it is too an overload and thus the failure of the entire switching device comes. The switching device also has a pilot-operated check valve in the region between the high-pressure pump and the piston rod cavity, so that it is possible after filling the cylinder chamber and extending the piston rod via the clamping piston and clamping piston rod targeted pressure in the cylinder chamber so that, for example, at an initial pressure of 175 bar then after pressing the tensioning piston in the cylinder chamber a pressure of 700 bar is present. This is a hydraulic expansion to be realized with the same design of a cylinder, which is used in a variety of applications and provided with high setting pressures available. At 700 bar, a set pressure of 600 t can be achieved with appropriate training, which represents a significant improvement in underground safety.

According to an advantageous embodiment of the invention it is provided that the valve block has a blocking against the high-pressure pump and a blocking against the cylinder chamber unlockable check valve and a tank associated with the lockable check valve. Thus, it is possible with one and the same valve block, first of all via the first pilot-operated check valve in the region of the high-pressure pump port to direct the pressure on the lockable check valve, so this closes and the hydraulic fluid can not get into the tank, but rather that second pilot-operated check valve opens , so that the hydraulic fluid from the high-pressure pump can flow directly into the cylinder chamber. If this is filled and the subsequent "Nachspannvorgang" can be initiated, closes the first check valve on the valve block and the connection between the high-pressure pump and the cylinder chamber is closed Pilot line to the piston rod cavity arranged pilot-operated check valve pressure fluid into the piston rod cavity are led so that the clamping piston is actuated. This is the already repeatedly mentioned "Nachspannvorgang".

It has already been mentioned that in the valve block and a lockable check valve is arranged in such a way that it is designed as lockable by connecting to the high-pressure pump, otherwise permanently open check valve. The closing piston is not held by a spring in the closed position, but rather influenced in the opposite direction, so that the valve is always open. Now, if this lockable check valve connected to the high-pressure pump, the valve piston is pushed against the force of the spring in the closed position and this lockable check valve is closed. Thus, as already mentioned, the hydraulic fluid can be safely transported from the high pressure pump via the two pilot operated check valves in the cylinder chamber. Should then be discharged while relaxing pressure fluid, this is done via the first check valve and then relieved lockable check valve, so that the pressure fluid can flow directly into the tank. The second pilot-operated check valve in the area of the high-pressure pump is closed, so that the hydraulic fluid can only flow out through the non-returnable check valve.

In order to reliably avoid faulty circuits, the non-returnable check valve blocking the high-pressure pump can be connected to the high-pressure pump at the same time as the lockable non-return valve. Accordingly, if the connection is opened, the hydraulic fluid simultaneously flows into the lockable check valve and closes it and opens the unlockable check valve, so that now the hydraulic fluid can flow out via the first pilot-operated check valve in the direction of the cylinder chamber. This creates a virtually idiot-proof circuit. The above-mentioned lockable check valve and the blocking against the cylinder chamber check valve are designed to be switchable via a respective 2/2 way valve. As already mentioned, with actuation of the lockable non-return valve associated 2/2 way valve at the same time the high-pressure pump associated pilot operated check valve is influenced and opened, so that only a 2/2 way valve is required due to the connection of these two check valves. The second mentioned 2/2 way valve is used to open the first, the cylinder chamber associated check valve when the cylinder chamber to be connected to the high-pressure pump.

In order to prevent overloading of the check valves in the valve block, it is provided that on the output side of the non-return valve blocking the cylinder space, a pressure switch adjustable to the filling pressure of the cylinder space is provided. About this pressure switch is monitored both in the connection with the cylinder chamber as well as relieving the cylinder chamber, that in each case a pressure of for example 175 bar prevails in the connecting line. If this is not the case, locks this pressure switch, which can be set exactly as already mentioned to the pressure level that is desired or necessary for each use.

Generally prescribed in such cylinders in underground mining and tunneling the use of a pressure relief valve. Due to the special conditions here, namely the more or less arbitrarily adjustable pressure conditions in the cylinder chamber, it is necessary to use a suitable pressure relief valve, including the invention provides that the cylinder chamber is assigned to the respective necessary or desired pressure in the cylinder chamber or adjustable pressure relief valve , The pressure limiting valve can or should be adjustable in accordance with narrow limits to provide very versatile for the necessary security.

When retracting the cylinder or the associated piston, it is advantageous if the annular surface space around the piston rod a 2/2 Off-line valve is assigned for connection to the high-pressure pump. This is namely given the opportunity to give when retracting the piston with the piston rod pressure on the annular surface side of the piston, so as to assist the retraction and, above all, to accelerate and ensure.

As another switching valve such is required for the piston rod cavity associated unlockable check valve. Here is provided according to the invention that the piston rod cavity associated unlockable check valve is designed to be switchable via a 3/4 way valve. Thus, the pressure fluid required for the pressure increase in the cylinder chamber can be easily introduced into the piston rod cavity in a simple manner, namely, by opening this pilot-operated check valve and at the same time pressure fluid is introduced over it. When the "retightening operation" is then completed, this pilot-operated check valve locks automatically and the supporting or setting work can be performed that unlockable check valve opens and allows leakage of hydraulic fluid towards the tank.

The said three 2/2 way valves and a 3/4 way valve can be present and upgraded individually, it being expedient to form the 2/2 and 3/4 way valves as electrically, hydraulically or electrically / hydraulically switchable switching valves. It is also conceivable that the 2/2 and the 3/4 way valves are combined via a common circuit board, so that the dependent switching and the time periods provided for easily given and the whole process "automated" can run.

Especially when used in underground mining, it is advantageous if the required items are stably formed or protected by stable housing, which is achieved according to the invention in that the valve block with the two unlockable and the lockable check valve has a common, the cylinder associated valve housing.

The invention is characterized in particular by the fact that a device is provided with which a safe increase in the pressure of the

Hydraulic fluids in cylinders and similar components is possible without the risk that caused by any wrong switching operations, dependent switching or the like caused errors. On the contrary, it can be seen that with the switching device according to the invention, a variable but targeted pressure increase in the said cylinders can be realized. The required switching valves or check valves are so cleverly and securely housed in a common valve housing that especially the special conditions in underground mining and tunneling can be advantageously done.

Further details and advantages of the subject invention will become apparent from the following description of the accompanying drawings in which a preferred embodiment with the necessary details and individual parts is shown. Show it:

1 shows a cylinder used in unterertätigen mining in a hydraulic expansion, Figure 2 shows the circuit diagram for the Nachsetzvorgang required switching device, Figure 3 is a side view with two of the valve block associated check valves in partial section and Figure 4 is a plan view of the valve housing with the first unlockable Check valve, partly in section.

A used in underground mining cylinder 1 is shown in Figure 1. He is part of the hydraulic expansion 2, which is used in the brace 3 to support hanging 4 and 4 lying against each other and so the to keep opened cavity open. The Hangendkappe 6 is also formed in several parts as the sleepers 7, wherein in the horizontal sleeper 7, a push cylinder 9 is housed, over which the longwall conveyor 8 can be moved in the direction of coal blast 10. Behind the hydraulic expansion 2, which is also referred to as a shield construction, the break 11 drops and closes the created cavity again.

Figure 2 shows a simplified reproduced circuit diagram for said switching device 21. About this switching device 21, the cylinder 1 is acted upon with hydraulic fluid, so that the piston 15 is pushed out with the piston rod 16 from the cylinder housing 14 and clamped against the hanging wall 11. Within the piston rod 16, a clamping piston 17 with a clamping piston rod 18 is arranged. As a result, in the piston rod cavity 26 located pressure fluid can be additionally pressed into the cylinder chamber 20, after this example, with a

Pressure fluid has been filled with 175 bar. How this is done is described below.

For filling and also relieving the cylinder chamber 20 and thus of the entire cylinder 1, a valve block 28 with unlockable check valves 29, 30 and a lockable check valve 31 is arranged between the high pressure pump 23 and the cylinder chamber 20. This valve block 28 is turned on in the connecting line 22 and ensures that the hydraulic fluid from the high-pressure pump 23 selectively reaches into the cylinder chamber 20 but also into the piston rod cavity 26. The latter is done by pressing the 3/4 way valve 39, so that the high-pressure pump 23 is virtually directly connected to the piston rod cavity 26. The unlockable check valve 25 is thereby automatically passed by the pressure fluid. After completion of this only later introduced Nachspannens or Nachsetzens then closes the pilot-operated check valve 25 and ensures that the hydraulic fluid in the piston rod cavity 26 remains secured. The said pilot operated check valve 25 is accommodated in the connection line 22 '. If the piston rod cavity 26 is to be relieved later and together with the cylinder chamber 20, then by pressing the 3/4 way valve 39 pressure fluid from the high-pressure pump 23 to the pilot operated check valve 25 is directed and directly into the valve chamber, so that the valve is unlocked and now the Pending pressure fluid from the piston rod cavity 26 in the direction of the tank 32 can flow.

Before the last described pressing the 3/4 way valve 39 and filling and then again emptying the piston rod cavity 26, the piston rod 16 must first be pushed out with the piston 15, to which the cylinder chamber 20 must be connected to the high-pressure pump 23. For this purpose, the already mentioned valve block 28 with the check valves 29, 30 31 is turned on in the connecting line 22 ".

To fill the cylinder chamber 20, pressure fluid is initially conducted via the 2/2 way valve 36 'into the lockable check valve 31 and simultaneously into the unlockable check valve 30. As a result, the lockable check valve 31 is initially closed and at the same time or shortly after the pilot-operated check valve 30 is opened. This allows pressure fluid from the high-pressure pump or via the high-pressure pump 23 and the connecting line 22 "to the first pilot-operated check valve 29 are passed, which is opened accordingly and then pushes the pressure fluid into the cylinder chamber 20 past the pressure switch 34. Immediately the first pilot-operated check valve 29 is the said pressure switch 34 assigned, via which the pressure level of the passing pressurized fluid can be checked to interrupt the conveying process in case of doubt, to avoid damage.

Is the filling of the cylinder chamber 20 completed and also the

Nachsetzvorgang completed by filling the piston rod cavity 26, the pressure relief valve 35 will record its monitoring function and ensure that an overload of the cylinder 1 does not occur by 35 pressure fluid is sprayed at the appropriate overpressure on the pressure relief valve.,

If the cylinder 1 to be relieved, is initially the unlockable

Check valve 25 via the 3/4 way valve 39 and at the same time on the 2/2 way valve 36, the pilot-operated check valve 29 is opened. Since the pilot-operated check valve 30 is closed and the lockable check valve 31 opens again by actuating the 2/2-way valve 36 ', the hydraulic fluid can now escape from the cylinder chamber 20 into the tank 32. This process is further supported by the fact that via the 2/2 way valve 38 of the annular surface space 37 is filled with hydraulic fluid. This presses on the piston ring surface and ensures that the insertion process of the piston 15 is supported. When later tensioning of the cylinder 1, the switching and control process already described then takes place.

The aforementioned check valves 29, 30 and 31 are housed in a valve block 28 which is housed in a stable valve housing 40, which will be explained briefly with reference to Figures 3 and 4.

Figure 3 shows in the upper part of the lockable check valve 31, which does not abut on the sealing surface 41 with its sealing head 44 in the switching state shown due to the spring 42. If the supply of pressure fluid now occurs via the inlet 43, then the sealing head 44 is pushed against the force of the spring 42 into the sealing surface 41.

Simultaneously with the closing of the lockable check valve 31 hydraulic fluid also passes through the inlet 47 in the pilot operated check valve 30, whereby the sealing head 46 is pushed against the force of the spring 45 from the associated sealing surface out. Now, pressure fluid can flow in the direction of the first unlockable check valve 29 and thus connecting line 22 via the pump connection 48. With 50 is the Piston of the pilot-operated check valve 30 and designated by the piston 51 of the lockable check valve 31st

Finally, FIG. 4 shows a plan view of the valve housing 40, whereby the first unlockable check valve 39 can also be seen through a section. Also in this check valve is a pilot-operated check valve 29, to which the spring 55 ensures that the pilot-operated check valve 29 is closed in the rule. If pressure is now supplied via the inlet 56 via the 2/2 directional control valve 36 to the pilot-operated check valve 29, the piston is loaded accordingly and ensures that the sealing head 59 is moved out of the sealing surface and against the force of the spring 55, wherein the piston is denoted by 57. While the connection 58 leads to the cylinder 1 or to the cylinder chamber 20 or represents the connection, the connection 49 according to the illustration according to FIG. 3 is the one which represents the connection to the tank 32.

With 54, the holder is designated, with which the valve housing 40 fixed to the cylinder 1.

All mentioned features, including the drawings to be taken alone, are considered to be essential to the invention alone and in combination.

Claims

1. Device for Druckhöhuήg in cylinders (1), in particular of hydraulic expansion (2) in underground mining and tunneling, with its cylinder housing (14), piston (15), piston rod (16) and arranged therein clamping piston (17) and in the cylinder chamber (20) einschiebbarer

Clamping piston rod (18) via a connecting line (22) with an integrated switching device (21) via a high-pressure pump (23) are acted upon with hydraulic fluid, dadu rc hge ke nnze ichn et that the switching device (21) via a pilot operated check valve (25) in the connecting line (22 ') between the high-pressure pump (23) and piston rod cavity (26) and via a valve block (28) with further unlockable or lockable check valves (29, 30, 31) in the connecting line (22 ") between the high-pressure pump (23) and cylinder space (20) has formed.

2. Device according to claim 1, characterized in that the valve block (28) against the high-pressure pump (23) blocking (30) and against the cylinder chamber (20) blocking the pilot operated check valve (29) and a Tank (32) associated with lockable check valve (31).

3. Apparatus according to claim 2, dadu rc hge ke n nn nn ichn et, that the lockable check valve (31) as by connecting to the high-pressure pump (23) lockable, otherwise permanently open check valve is formed.

4. Apparatus according to claim 2, characterized Porsche Style nzeichnet that the against the high pressure pump (23) blocking releasable check valve (30) at the same time with the lockable check valve (31) opening side with the high-pressure pump (23) is connectable.

5. Device according to one of the preceding claims, characterized Porsche Style nzeichnet that the lockable check valve (31) and against the cylinder chamber (20) blocking check valve (29) via a respective 2/2 way valve (36, 36 ") are designed switchable.

6. Device according to one of the preceding claims, dadurc h geken nzeichnet that the output side of the against the cylinder chamber (20) blocking

Check valve (29) on the filling pressure of the cylinder chamber (20) adjustable pressure switch (34) is provided.

7. Device according to one of the preceding claims, dadu rc h geken nzeichnet that the cylinder space (20) is assigned to the respective necessary or desired pressure in the cylinder chamber (20) or adjustable pressure relief valve (35).

8. Device according to one of the preceding claims, d ad u rch nected net that the annular surface space (37) around the piston rod (16) is assigned a 2/2 way switching valve (38) for connection to the high-pressure pump (23).

9. Device according to one of the preceding claims, characterized in that the piston rod cavity (26) associated pilot-operated check valve (25) via a 3/4 way valve (39) is switchable.

10. Device according to one of the preceding claims, characterized in that the 2/2 and 3/4 way valves (36, 36 ', 38, 39) are designed as electrically, hydraulically or electrically / hydraulically switchable switching valves.

11. Device according to one of the preceding claims, d a d u r c h e ke n ze ze c h n et that the 2/2 and 3/4 way valves (36, 36 ', 38, 39) are summarized via a common circuit board.

12. Device according to one of the preceding claims, dadu rc hge ke nnn nn ichn et, that the valve block (28) with the two unlockable and the lockable check valve (29, 30, 31) a common, the cylinder (1) associated valve housing ( 40).