DE102006034864A1 - Control system for e.g. locking pin, has locking and unlocking type pressure chambers connected to main conduit, where pressure control valve is attached to unlocking type chamber to avoid reverse flow of fluid from unblocking type chamber - Google Patents

Abstract

The system has a locking type pressure chamber (16) and an unlocking type pressure chamber (13), which are connected by respective conduits (19, 20) to a main conduit. The system breaks in under the pressure of pressure fluid in the locking type pressure chamber on one side of a locking pin (14) and in the unlocking type pressure chamber on another side of the locking pin. A pressure control valve (18) is attached to the unlocking device pressure chamber in the conduit (19) to avoid reverse flow of the fluid from the unblocking pressure chamber.

Description

The The invention relates to a control system for a hydraulic element, which under the pressure of pressurized fluid in a locking pressure chamber on the one hand of the hydraulic element in a Entriegelungsruckraum on the other hand, the hydraulic element enters, wherein both pressure chambers via one Line are connected to the same main line.

State of the art

There are many control systems for hydraulic elements. Only for example, reference is made to cylinders that should be lockable in a particular position. For example, in the DE 41 41 460 C2 a fluid operated cylinder shown in which a rotatable spindle engages a piston rod tube. When the corresponding piston associated with the piston rod tube is pressurized, the spindle also rotates, allowing the piston rod tube to move axially.

In all these working cylinders, the problem arises that, should the pressure in the actual main pressure chamber, in which the piston is pressurized, collapse, for example by breaking of sealing collars, the piston under the pressure of the load or even under a train on its own Movement is set, the spindle runs with its external thread, the internal thread of the piston rod tube. To prevent this, it is thought to lock the power cylinder, ie to stop the movement of the piston. After EP 1 538 344 A2 This is done by engaging a spring under a locking spring locking body in a locking bore in the spindle and thus the rotation of the spindle is interrupted. If an unlocking take place, the locking body is converted by means of a fluid working means against the spring force of the spring from the locking position into an unlocking position, in which the spindle is rotatable about its axis of rotation. The problem with this arrangement, however, is the control of the pressure medium supply to the pressure chambers and the Entriegelungsdruckkammer. Furthermore, the control becomes extremely problematic when disturbances occur in the fluid supply and -abfuhrsystem.

These But problems do not just apply to lockable power cylinder but for all hydraulic systems, in which a hydraulic element moves between two pressure chambers can be, but in case of a failure or the like. secured immersed in one of the pressure chambers, both pressure chambers connected to the same main line.

task

task It is the object of the present invention to provide a controller of the above-mentioned. kind to develop the "thinking" the unlocking and locking the hydraulic element makes.

Solution of the task

to solution the task leads once, that in the line to Entriegelungsdruckraum a pressure control valve is turned on, which is a backflow of the Fluid from the Entriegelungsdruckraum prevented.

The Pressure control valve guarantees that with a closed main valve the pressure in the line to the Entriegelungsdruckraum always one desired Mass (for example, 2 bar) is lower than the pressure in the Line to lock pressure chamber

If in the present application of pressure control valve is spoken, so it is included with each element, which is a backflow of the Fluids prevents. Likewise, the above-mentioned hydraulic element a have any shape and design.

The second embodiment of the control system according to the invention, for which protection is also sought separately, provides that a pressure compensation valve is switched on in the line to the locking pressure chamber. This pressure compensation valve counteracts disturbances. It is specially designed for this purpose. In an axial stepped bore of the pressure compensation valve is once a sliding piston, which is in communication with the fluid supply system. For this purpose, a T-line is formed in the sliding piston, which opens radially towards the inner surface of the stepped bore, preferably in an annular channel. Following the annular channel of the sliding piston is no longer close to the inner surface of the stepped bore, but there is an annular gap formed by the pressurized fluid in a flow chamber and white ter in a line to the locking pressure chamber behind the hydraulic element can flow.

Of Further presses the sliding piston on a ball, which is under the pressure of a spring stands. The sliding piston can push the ball into a ball seat in which the ball is automatically leveled. This will make the river from pressure medium through the line to the locking pressure chamber behind the hydraulic element interrupted or the pressure in the Locking pressure chamber is held, allowing a release the hydraulic element is prevented secured.

The invention Pressure control valve in front of the unlocking pressure chamber of the hydraulic Elements is designed to withstand a build up of fluid pressure in the fluid system passes pressure medium to Entriegelungsdruckraum before additional pressure chambers, which are fed from the main line, pressurized become. For this it has to be favorable proved that the pressure control valve is adjustable. Furthermore, will before the other pressure chamber a load-holding valve turned on and this in a bypass a check valve assigned, which is designed in any case higher than that Pressure control valve in front of the unlocking pressure chamber. It means that up to a certain height the pressure in the fluid supply system only pressurized fluid to the Entriegelungsdruckraum flows, which causes the hydraulic element to be moved first. First when a certain level of pressure in the fluid system has been exceeded is also an influx of Pressurized fluid over the check valve in the bypass of the load-holding valve in the pressure chamber.

flows at a leakage of the load-holding valve or the load-holding valve in the bypass associated check valve Print medium back from the pressure chamber, so it can on the one hand, if otherwise the system is locked, through the pressure control valve in the Entriegelungsdruckraum flow in front of the hydraulic element, but also through the pressure compensation valve and the annulus in the lock pressure chamber behind the hydraulic element. The pressure in the lock pressure chamber behind the hydraulic element is with the main valve closed at least 2 bars higher as the pressure in the unlocking pressure space in front of the hydraulic element. Since there is additionally a spring in the locking pressure chamber, which is supported against the hydraulic element, the hydraulic Element always held in locking position.

Falls against it For example, the load-holding valve or its associated Check valve completely off, so it can happen that a pressure increase in the return line abruptly. The pressure equalization valve also closes abruptly, since the amount of pressurized fluid through the T-line the As a result of the very small annular gap, the sliding piston pushes down and press the ball into its ball seat. This has a pumping effect of pressurized fluid into the interlock pressure space behind the hydraulic element as a consequence, so that also an increase of a pressure in Entriegelungsdruckraum before the hydraulic element does not cause the hydraulic Element is guided out of its locking position. The pressure in the lock pressure chamber behind the hydraulic element is with the main valve closed at least 2 bars higher as the pressure in the unlocking pressure space in front of the hydraulic element.

Should several pressure chambers be provided, is of course preferred for each pressure chamber own Load-holding valve with a check valve provided in the bypass, the systems by means of shuttle valves with each other are connected, of which also the line to the Entriegelungsdruckraum branches off in front of the hydraulic element, in which the adjustable Pressure control valve is used. In this case, of course, the Control of the load-holding valves always with the respective main line connected, which leads to the respective other load-holding valve, so the other load-holding valve is opened to a reflux of pressure medium from the pressure medium not acted upon pressure chamber to enable.

The Pressure compensation valve is especially useful when as the main valve for the Supplying the entire fluid supply system a lockable valve is provided. It is also conceivable, however, the arrangement of a reflux of pressure medium simultaneously from both lines permitting valve, allowing pressure equalization through this valve for light leaks can take place without the above-mentioned pressure compensation valve actuated becomes. In any case, there should still be the pressure compensation valve be provided, as it is at a sudden increase in pressure in the system in each case the locking pressure chamber behind the hydraulic Element with closed main valve with the pressure higher by 2 bar supplied as the unlocking space in front of the hydraulic element, so that in any case unlocking the hydraulic element impossible becomes.

figure description

Further advantages, features and details of the invention will become apparent from the following Be spelling of preferred embodiments and with reference to the drawing; this shows in

1 a block diagram representation of a control system for a schematically illustrated in longitudinal section lockable working cylinder;

2 a block diagram representation of another main valve for use in the control system acc. 1 ;

3 an enlarged cross section of a control block in the region of a pressure compensation valve.

Gem. 1 is a lockable working cylinder 1 a dot-dashed control block 2 assigned. main lines 3 and 4 lead from the control block 2 to a main valve 5 , which is connected to a pressure source not shown in detail for a fluid. As a source of pressure, both a gas and a liquid, in particular hydraulic fluid, come into consideration.

For a more detailed explanation of the lockable working cylinder is particularly to the P 10 2005 015 059.4 directed. In this working cylinder 1 there is a slidable piston 6 between two pressure chambers 7 and 8th , At this piston 6 closes a piston rod 9 which leads to the outside. In the flask 6 sits a spindle 10 whose external thread 11 with a corresponding internal thread in the spindle 6 or the piston rod 9 interacts, so this spindle 10 is rotated about its longitudinal axis A. This takes the spindle 10 a dividing disk 12 with which a plurality of radially arranged Entriegelungsdruckräumen 13 having. In these unlocking pressure chambers 13 can be one (or more) locking pin 14 retract, which is guided radially and under the pressure of a coil spring 15 stands, this coil spring 15 in a lock pressure chamber 16 behind the locking pin 14 is arranged.

The above mentioned main line 4 leads from the main valve 5 to the pressure room 7 , so when filling the pressure chamber 7 the piston rod 9 is withdrawn. The main line 3 leads from the main valve 5 to the pressure room 8th , so that when filling the pressure chamber 8th the piston rod 9 is ejected or expressed.

Furthermore, there are both main lines 3 and 4 via a shuttle valve 17 and via an adjustable pressure control valve 18 in a pipe 19 in connection.

The lock pressure chamber 16 is over another line 20 on the one hand via a pressure compensation valve 21 with the main 3 and on the other via a check valve 22 and 23 with the main 3 or the main line 4 connected.

Both in the main line 3 as well as in the main line 4 is before connecting to the appropriate pressure chambers 7 respectively. 8th a load-holding valve 24 respectively. 25 switched on. Each load-holding valve 24 respectively. 25 is adjustable and via a dashed line 26 respectively. 27 with the main 3 respectively. 4 in front of the other load-holding valve 25 respectively. 24 connected. Furthermore, each load-holding valve has 24 respectively. 25 a bypass 28 respectively. 29 in a check valve 30 respectively. 31 is turned on.

One such control system leaves the following possibilities and functions too, with the interaction of working cylinder and Control system as "thinking Cylinder " can be:

normal operation

It is understandable that before a movement of the piston 6 this must be unlocked, which means that the locking pin 14 must leave the Entriegelungsdruckraum. How does the cylinder know that this is before a build-up of pressure in the pressure chambers? 7 or 8th must happen without a special sensor this locking pin 14 observed?

For this purpose, the check valves 30 and 31 on the adjustable pressure control valve 18 Voted. For example, as in 1 shown the pressure chamber 8th be filled with a pressurized fluid, which means that the working cylinder acts oppressive, so there is the shuttle valve 17 in the position shown and the pressure fluid can via the set to 2 bar pressure control valve 18 and the line 19 in the unlocking pressure chamber 13 flow, until there is a pressure of 20 bar is reached, but in which the locking pin 14 long ago from the unlocking pressure chamber 13 is pushed out. Only when the pressure in the system of 20 bar, the check valve can 31 in the bypass 29 the load-holding valve 25 overcome and thus the pressure chamber 8th be filled.

If, on the other hand, the pressure chamber 7 filled and thus the working cylinder are made pulling, so there is a supply of pressurized fluid by moving the main valve 5 right into the main line 4 , This will switch the shuttle valve 17 um, so that now has access to the main line 3 Is blocked. The main line is opposite 4 via the adjustable pressure control valve 18 with the unlocking pressure chamber 13 in front of the locking pin 14 in connection. Further, over the line 27 the load-holding valve 25 signals that it opens, allowing pressurized fluid from the pressure chamber 8th over the main line 3 and the main valve 5 can escape.

Even now, pressure fluid first flows through the adjustable pressure control valve 18 because the check valve 30 in the bypass 28 the load-holding valve 24 only opens when a pressure of 20 bar is built up in the system. At 20 bar but here is the locking pin 14 unlocked.

To lock the main valve 5 switched to the middle position, in which the two main lines 3 respectively. 4 are depressurized. Under the pressure of the coil spring 15 becomes the locking pin 14 in the unlocking pressure chamber 13 pressed. This will turn the spindle 10 prevented, so that the piston 6 secured in this situation remains.

disorders

Malfunctions are only noticeable if they lead to unintentional unlocking of the locking pin 14 would lead. This would be the case, for example, if at the load-holding valve 24 respectively. 25 and in particular at the check valve 30 respectively. 31 an error would occur, for example if the valves pinch or the springs break. In this case, a pressure could build up in the respective system, wherein pressure fluid via the adjustable pressure control valve 18 in the unlocking pressure chamber 13 flows and the locking pin 14 would unlock. This can be prevented once by having a main valve 5 is chosen as it is in 2 is shown. In this central valve are in the middle position, the main lines 3 and 4 not locked, but open for a reflux. This means that no pressure can be built up in the entire system that unlocks the locking pin 14 leads.

In many cases, however, it is desirable that the main valve also to be used elsewhere 5 gem. 1 to use. In this case, the use of the inventive pressure compensation valve 21 especially desirable. For this pressure balance valve 21 is in the control block 2 between the main line 3 and the line 20 a hole 32 provided in which is an insert 33 located. This use 33 runs through a stepped bore 34 into which a ball seat 35 for a ball 36 is formed. The ball 36 rests against a coil spring 37 off, leaving her from the ball seat 35 is lifted off.

On the other hand, press the ball 36 a sliding piston 38 from a T-wire 39 interspersed with the main line 3 communicates. The T-wire 39 flows into a ring channel 40 out, over an annular gap 41 with a flow chamber 42 communicates. To form the annular gap 41 stops the sliding piston 38 in this area of an inner surface 43 the stepped bore 34 a small distance. The tension of the coil spring 37 is adjusted so that the pressure compensation valve 21 at a pressure of 5 bar in the main line closes. It has the interaction of ball 36 with ball seat 35 the particular advantage of increased accuracy over a cone valve, as the ball coming from the sliding piston 38 is pushed into the ball seat 35 can level itself, so that possible inaccuracies are compensated.

Now falls the load-holding valve 25 or the check valve 31 off, so flows at a slow leakage pressure fluid through the T-line 39 , the ring channel 40 and the annular gap 41 also at the ball 36 over in the line 20 and in the lock pressure chamber 16 , Even if the leakage should exceed a pressure of 2 bar, there is a pressure equalization with 2 bar pressure difference in the system between Entriegelungsdruckraum 13 , Management 19 , Pressure control valve 18 , Main line 3 , Pressure compensation valve 21 , Management 20 and locking pressure chamber 16 instead of. In this case, the force of the coil spring predominates 15 and the force of 2 bar higher pressure and holds the locking pin 14 in lock position.

Should the load-holding valve 25 or the check valve 31 completely fail, so a pressure could be increased suddenly, then the pressure control valve 18 overcomes, but not enough pressure fluid through the pressure compensation valve 21 is promoted to create a balance. In this case, however, causes the sudden increase in pressure displacement of the sliding piston 38 down, leaving the ball 36 on the seat 35 is pressed and a pumping action of pressurized fluid through the line 20 in the lock pressure chamber 16 takes place. In any case, this pumping action overcomes the pressure of the pressure fluid through the pressure regulating valve 18 and the line 19 in the unlocking pressure chamber 13 so that the locking pin 14 remains in the locked position.

As a further disturbance, it would be conceivable that the coil spring 15 in front of the locking pin 14 breaks. Also in this case is in the locking pressure chamber 16 the full system pressure, as a flow through the pressure compensation valve 21 not hindered. In contrast, the pressure control valve causes 18 in the pipe 19 a pressure drop of 2 bar, so that in the Entriegelungsdruckraum 13 there is a system pressure reduced by 2 bar. The locking pin 14 thus remains in the locking position or is in case of a broken coil spring and closed main valve by the 2 bar higher pressure in the locking pressure chamber 16 pressed into the locking position.

It is of course also conceivable that a second pressure compensation valve the load-holding valve 24 is assigned, when the cylinder is used pushing and pulling. LIST OF REFERENCE NUMBERS 1 lockable working cylinder 34 stepped bore 67 2 control block 35 ball seat 68 3 main 36 Bullet 69 4 main 37 coil spring 70 5 main valve 38 sliding piston 71 6 piston 39 T-line 72 7 pressure chamber 40 annular channel 73 8th pressure chamber 41 annular gap 74 9 piston rod 42 Flow chamber 75 10 spindle 43 palm 76 11 external thread 44 77 12 graduated disk 45 78 13 Unlocking pressure m 46 79 14 locking pin 47 15 coil spring 48 16 Locking pressure around 49 17 shuttle valve 50 18 Pressure control valve 51 19 management 52 A longitudinal axes 20 management 53 21 Pressure equalization valve 54 22 check valve 55 23 check valve 56 24 Load-holding valve 57 25 Load-holding valve 58 26 management 59 27 management 60 28 bypass 61 29 bypass 62 30 check valve 63 31 check valve 64 32 drilling 65 33 commitment 66

Claims (17)

Control system for a hydraulic element ( 14 ), which under the pressure of pressurized fluid in a locking pressure chamber ( 16 ) on the one hand of the hydraulic element ( 14 ) in an unlocking pressure chamber ( 13 ) on the other hand of the hydraulic element ( 14 ), both pressure chambers ( 13 . 16 ) via one line ( 19 ) respectively. ( 20 ) to the same main line ( 3 . 4 ) are connected, characterized in that in the line ( 19 ) to the unlocking pressure chamber ( 13 ) a pressure regulating valve ( 18 ) is switched on, the backflow of the fluid from the Entriegelungsdruckraum ( 13 ) prevented. Control system for a hydraulic element ( 14 ), which under the pressure of pressurized fluid in a locking pressure chamber ( 16 ) on the one hand of the hydraulic element ( 14 ) in an unlocking pressure chamber ( 13 ) on the other hand of the hydraulic element ( 14 ), both pressure chambers ( 13 . 16 ) via one line ( 19 ) respectively. ( 20 ) to the same main line ( 3 . 4 ) are connected, characterized in that in the line ( 20 ) to the locking pressure chamber ( 16 ) a pressure compensation valve ( 21 ) is turned on. Control according to claim 2, characterized in that in an axial stepped bore ( 34 ) of the pressure compensation valve ( 21 ) one against a spring ( 37 ) supporting ball ( 36 ), which has a correspondingly shaped ball seat ( 35 ) in the stepped bore ( 34 ) assigned. Control according to claim 3, characterized in that on the ball ( 36 ) in the stepped bore ( 34 ) slidably mounted piston ( 38 ) presses. Control according to claim 4, characterized in that the piston ( 38 ) at least partially with an inner wall ( 43 ) of the stepped bore ( 34 ) an annulus ( 41 ) trains. Control according to at least one of claims 1 to 5, characterized in that the pressure regulating valve ( 18 ) ensures that in the line ( 19 ) to the unlocking pressure chamber ( 13 ) with the main valve closed ( 5 ) for the main line ( 3 . 4 ) is always lower pressure than in the line ( 20 ) to the locking pressure chamber ( 16 ). Control according to at least one of claims 1 to 6, characterized in that the pressure regulating valve ( 18 ) is adjustable. Control according to at least one of claims 1 to 7, characterized in that the main line ( 3 ) via a load-holding valve ( 24 ) to another pressure chamber ( 7 ), whereby in a bypass ( 28 ) the load-holding valve ( 24 ) a check valve ( 30 ) assigned. Control according to claim 8, characterized in that the check valve ( 30 ) of the load-holding valve ( 24 ) is set higher than the pressure regulating valve ( 18 ) in the line to Entriegelungsdruckraum ( 13 ). Control according to at least one of claims 1 to 9, characterized in that a second pressure chamber ( 8th ) whose main line ( 4 ) also with the main valve ( 5 . 5.1 ) in connection where, in this main line ( 4 ) another load-holding valve ( 25 ) is turned on. Control according to claim 10, characterized in that in the connection to the main lines ( 3 . 4 ) in front of the pressure regulating valve ( 18 ) to the unlocking pressure space ( 13 ) a shuttle valve ( 17 ) is turned on. Control according to claim 10 or 11, characterized in that a control of each load-holding valve ( 24 . 25 ) with the main line ( 3 . 4 ) of the respective other load-holding valve is connectable. Control according to at least one of claims 1 to 12, characterized in that the fluid supply system with a three-four-way valve ( 5.1 ), which allows a reflux of the fluid. Pressure compensation valve for switching into a fluid supply and / or removal system, characterized in that in an axial stepped bore ( 34 ) one against a spring ( 37 ) supporting ball ( 36 ), which has a correspondingly shaped ball seat ( 35 ) in the stepped bore ( 34 ) assigned. Control according to claim 14, characterized in that on the ball ( 36 ) in the stepped bore ( 34 ) slidably mounted piston ( 38 ) presses. Pressure compensating valve according to claim 15, characterized in that the piston ( 38 ) at least partially with an inner wall ( 43 ) of the stepped bore ( 34 ) an annular gap ( 41 ) trains. Pressure compensating valve according to claim 16, characterized in that the sliding piston ( 38 ) passes through a T-line, which is in an annular channel in front of the annular gap ( 41 ).