EP2514977A2 - Press block - Google Patents

Abstract

The hydraulic control block has a safe fluid path provided in a basic block, where the safe fluid path consists of a pressure chamber port, a high-holding valve (4) and a directional valve (10). The high-holding valve is connected to a terminal for the pressure chamber port of a hydraulic press load, where a downstream of the directional valve from the pressure chamber port is connected to the high-holding valve. A speed valve (28) is arranged in or on the basic block, where the speed valve is arranged between the directional valve and a tank port.

Description

The present invention relates to a control / securing block of a hydraulic press and more particularly to a press block according to the preamble of claim 1.

A generic press block or press module is used to build a reliable press, which u.a. meets the safety regulations according to the German industrial standard DIN EN 693.

From the prior art according to the publication "Machine Tool - Safety - Hydraulic Presses, German version EN 693: 2001 + A1: 2009, issued in November 2009 by the Beuth Verlag GmbH, a hydraulic control of a hydraulic press is known, which the above-mentioned German Industry standard met and how they are in the adjoining Fig. 1 is shown schematically.

Accordingly, the consumer is shown as a piston / cylinder unit having a piston chamber connected to a fluid tank via a self-monitoring safety valve of the 2/2 shift valve type. Upstream to the safety valve forks off a branch line, which opens into a directional valve of the 4/3-Schaltventilbauweise, to which further a pressure medium source and the fluid tank are connected directly.

Connected to the annular chamber of the consumer is a self-monitoring hold-up valve of the 2/2 switching valve type, which in turn is connected to the self-monitoring directional valve. Upstream to the hold valve branches off a pressure relief line, in which a pressure relief valve is used, by means of which the maximum annular chamber pressure is adjustable.

Finally, from the pressure medium source also branches off a pressure line into the fluid tank, in which a pressure relief valve is arranged.

In principle, with the known hydraulic control according to the Fig. 1 allows the basic Bewegungssteuer- and securing functions of the hydraulic press. However, there is a need for hydraulic presses of this type to control other movements and functions, the control and security concept required for this purpose also has to meet the said German industrial standard.

In view of this situation, it is the object of the present invention to provide a generic press module whose basic control and safety concept, regardless of additional control functions at least the said German industrial standard.

This object is achieved by a press block having the features of patent claim 1. Advantageous embodiments of the invention are the subject of the dependent claims.

In principle, it is provided according to the invention that the pressure chamber is a press-own consumer, which is pressurized for holding the upper die (in the present example, the annular chamber of a piston / cylinder unit, which is the press cylinder or press ram), connected directly to the control block. In the control block, a monitored upshift valve and a monitored directional valve are connected directly in series without any intermediate valves. This corresponds to the extent of the above-mentioned prior art.

The peculiarity of the safety and control concept according to the invention according to one aspect now consists in the fact that, independent of further additional control functions in the named basic block according to the above definition, a secure fluid path consisting of

"the defined consumer chamber (for example, the annular chamber according to the embodiment) - hold-valve - directional valve" is maintained, in which either no or only limited preferably via nozzles (throttle) limited / limited inflows / outflows. That is, the concept according to the invention provides that no other valves for controlling the sequence of motions, etc., are looped into said fluid path. Such valves are seen from the consumer side (ring chamber side) from only downstream of the directional valve provided, for example, a pressure relief valve or a rapid traverse valve.

Although the aforementioned prior art also has a fluid path according to the invention, however, in this prior art the control is only suitable for the basic control of the press, with no further control elements being provided for additional control functions. Therefore, no control and security concept according to the present invention is derivable.

A further aspect of the invention provides additional press functions that go beyond the basic functions according to the cited prior art (for example, press surface connection in the case of a 3-surface cylinder) via an (external) intermediate block inserted between the above-defined basic block and the directional valve to control. However, the safe fluid path also remains
"defined pressure chamber at the consumer - hold-up valve - directional valve"
possibly with the interposition of a passage channel of the intermediate block).

It is advantageous if the hold-high valve for the relevant consumer pressure chamber (annular chamber), a safety valve for the pressure medium source (hereinafter simply referred to as a pump), a self-monitored bypass valve or safety valve for the other consumer pressure chamber (piston chamber) and a rapid traverse valve preferably screwed or inserted with a pressure limiting function in a standard basic block.

Furthermore, the hydraulic control can be configured with a Einrichtfunktion, for which a further directional valve is provided which is connected via (two) nozzles or throttle points with the pressure chambers (annular chamber, piston chamber) of the consumer to selectively the chambers with a control fluid of one / Supply the pump. As a result The nozzle is the upward and downward adjustment of the consumer (preferably to a maximum of 10mm / s) compared to normal operation limited.

It is also advantageous if the intermediate block carries such additional functions, which do not affect the safety control circuit according to the above definition. In the basic version, when the directional valve is screwed onto the base block, in the case of an intermediate block arrangement, the intermediate block is preferably interposed between the base block and the directional valve without impairing the safety control circuit as defined in the basic block. Accordingly, the intermediate block has a through-bore, which extends from the hold-up valve within the base block to the directional valve screwed onto the intermediate block, without any further paths going away therefrom or leaving only via interposed nozzles, at which the flow is limited.

• Fig. 1 zeigt eine hydraulische Pressenssteuerung gemäß dem Stand der Technik,
• Fig. 2 zeigt ein erstes bevorzugtes Ausführungsbeispiel eines erfindungsgemäßen Pressenmoduls in der Ausbildung eines sogenannten Grundblocks und
• Fig. 3 zeigt ein zweites bevorzugtes Ausführungsbeispiel eines erfindungsgemäßen Pressenmoduls in der Ausbildung eines Grundblocks mit einem Zwischenblock.

The invention will be explained below with reference to preferred embodiments with reference to the accompanying drawings.

• Fig. 1 shows a hydraulic press control according to the prior art,
• Fig. 2 shows a first preferred embodiment of a press module according to the invention in the formation of a so-called basic block and
• Fig. 3 shows a second preferred embodiment of a press module according to the invention in the formation of a basic block with an intermediate block.

According to the Fig. 2 The press block according to the first preferred embodiment of the invention serves to control and secure a consumer as described in US Pat Fig. 2 is shown schematically as a piston / cylinder unit 1. The piston / cylinder unit 1 has a piston 1a with the piston rod 1b fixed thereon, which subdivides the cylinder 1c into a piston chamber K and an annular chamber R in a fluid-tight manner. In the present case, a weight, for example the upper die cushion of a hydraulic press (not shown), hangs on the piston rod 1b.

In the Fig. 2 the consumer 1 is shown in a retracted, ie retracted position in which the weight must be kept free and secure. Accordingly, the annular chamber R is connected via a first pressure line 2 with a self-monitoring hydraulic hold-up valve 4 preferably the 2/2-Schaltventilbauweise that locks in a first switching position (construction position) fluid flow at least from the annular chamber R and completely releases the fluid connection in a second switching position , Upstream of the hold-up valve 4 (ie, between the hold-up valve and annular chamber R) branches off a pressure line 6 from the pressure line 2 into a pressure medium tank T, in which a pressure relief valve 8 is used to set a maximum annular chamber pressure.

The hold-up valve 4 is in turn connected directly in series (i.e., without the interposition of other switching elements) to a self-monitoring directional valve 10, preferably the 4/3 shift valve design, having another port connected to the fluid tank T via a pressure relief line 12. To the directional valve 10, a pressure medium source P is also connected, at the output of a leading into the pressure medium tank T pressure relief line 14 with inserted pressure relief valve 16 is also connected.

The piston chamber K of consumption 1 is also connected directly to the directional valve 10 via a pressure line 18, wherein a tank line 20 branches off from the pressure line 18 to the pressure medium tank T, into which a safety valve 22 of the 2/2-Schaltventilbauweise is preferably used. The safety valve 22 in this case blocks the tank line 20 in a first switching position and releases it in a second switching position.

Like from the Fig. 2 can still be seen, located in the pressure relief line 12 between the directional valve 10 and the tank T, a pressure relief valve 24 which opens the pressure relief line 12 only at a certain line pressure, wherein the pressure relief valve 24 bypass line 26 is provided, in a Rapid traction valve 28 is preferably arranged in the 2/2-way valve construction. In this case, the emergency valve 28 locks the bypass line 26 completely (construction position) in a first switching position and releases them in a second switching position.

Finally, according to the Fig. 2 connected to the pressure relief line 6 between the pressure relief valve 8 and the pressure medium tank T is a Einrichtventil 30 preferably the 4/3-Schaltventilbauweise whose one more connection to one or the pressure medium source P is connected. Furthermore, the set-up valve is connected via a throttle point or nozzle 32 with the pressure line 2 between the Abzeigstelle to the pressure line 6 and the hold-high valve 4, whereas the last connection of the Einrichtventils 30 via another throttle point or nozzle 34 with the piston chamber K and the pressure line 18 between the piston chamber K and the safety valve 22 is fluidly connected.

From the Fig. 2 It can be seen that the entire control described above is combined in a press block or basic block with at least one pump inlet P1, which is directly connected to the directional valve 10, a control pressure input ST, which leads to the Einrichtventil 30 and a tank port T1. Furthermore, at least two consumer connections X1, X2 are provided which lead to the piston chamber and annular chamber K, R of the consumer 1.

Constructively, all valves are used in the basic block with the exception of the directional valve 10 and hydraulically connected via channels drilled in the base block. The directional valve 10, however, is screwed onto the base block, such that all connections to and from the directional valve 10 as described above by the screwing of the directional valve 10 are made to the basic block.

From the control panel of the Fig. 2 the switching functions of the hydraulic control of the press according to the first preferred embodiment of the invention can be seen. Accordingly, for a stoppage of the press, the directional valve 10, the hold-up valve 4, the rapid traverse valve 28, the safety valve 22 and the Einrichtventil 30 unconfirmed, ie all said valves are in the locked position (construction position).

If the consumer 1 is to be rapidly extended (rapid traverse control function), the directional valve 10 is switched to a switching position in which the piston chamber K with the pressure medium source P and the annular chamber R with the tank T can get in the present case. At the same time, the rapid traverse valve 28 is switched to its release position in order to be able to rapidly convey the fluid from the annular chamber R into the tank T. Finally, the hold-up valve 4 is also in its release position.

For extension of the consumer 1 in normal operation, i. under pressing load, the rapid traverse valve 28 is switched to the blocking position, with all other valves remaining in the above-described switching position for rapid traverse.

If the consumer 1 are retracted, the hold-back valve 4 and the rapid traverse valve 28 return to their design positions (locking positions) and the directional valve 10 is brought into a switching position in which the piston chamber K communication with the pressure medium source P (pump) and the annular chamber R compound with the pressure medium tank T via the pressure relief valve 24 receives.

Finally, in order to move the consumer 1 for setting up the press, the set-up valve 30 is switched from its blocking position to a first or second switching position in which it is either the piston chamber K for an extension and the annular chamber R for a retraction of the consumer with the Control pressure connection ST connects. Since these connections in each case via the (two) nozzles 32, 34, a slowed out and entry of the consumer 1 is achieved.

From the above description it is apparent that all control functions of the press are effected by valves which are arranged either between the directional valve 10 and the pump P or the tank T or in a limited manner, for example via the said nozzles 32, 34 to the piston. and annular chamber K, R of the consumer 1 are connected. It arises thereby conceptually one in the basic block according to the Fig. 2 safe fluid path consisting of annular chamber R - hold valve 4 - directional valve 10, for which either no or limited only by the nozzles 32, 34 inflows and outflows are ensured.

The safety circuit according to the above definition is always the same in the basic block, regardless of the additional equipment variants, of which a variant will be described below with reference to the second preferred embodiment. In the case of a downward movement (pump P is switched to piston chamber K) only the directional valve 10 is actuated accordingly. In the case of an upward movement (pump P is switched to annular chamber R), only the directional valve 10 and the hold-up valve 4 operated accordingly. The rapid traverse valve 28 with pressure limiting function is not in the safe flow path.

The following is based on the Fig. 3 A second preferred embodiment of the invention is described, wherein for reasons of simplification, only the features different from those of the first embodiment are to be discussed.

Accordingly, in the second preferred embodiment of the invention, an intermediate block is provided which is constructionally mounted between the base block and the directional valve 10 on the base block. In the intermediate block a number of connections in the form of bore openings are provided, which are connected to the (four) terminals in the basic block with the assembly (quasi automatic), wherein now the directional valve 10 is screwed on an outer side of the intermediate block. At least one channel (through-hole A) within the intermediate block, which establishes the connection between the hold-up valve 4 and the directional valve 10, thus forms a part or section of the secured fluid path as defined above.

Like from the Fig. 3 can still be seen, located in the intermediate block, a switching valve 35 of the 2/2-Schaltventilbauart in a pressure line 36 between the directional valve 10 and the piston chamber K of the consumer 1 which is connected in parallel to the pressure line 18 according to the first embodiment of the invention. In a first switching position, the switching valve 35 releases the parallel-connected pressure line 36 and blocks it in at least one direction towards the piston chamber K in a second switching position.

Finally, a pressure-controlled shuttle valve 38 is housed in the intermediate block, which is connected via a throttle or nozzle 40 with the channel between the hold-4 and directional valve 10 and connected to the other parallel to the pressure line 36 connected in parallel between the directional valve 10 and the switching valve 35.

The switching functions of the second preferred embodiment of the invention are in the switchboard according to the Fig. 3 shown.

As can be seen from this, correspond to the switching positions of the valves according to the Fig. 3 for the individual operating functions of the press essentially those of the first Embodiment according to the Fig. 2 , Only in the case of rapid traverse extension, the switching valve 35 is actuated in its partially blocking switching position in which a flow in the direction of the piston chamber K via the parallel pressure line 36 is blocked.

Disclosed is a hydraulic control block of a press comprising a base block with a hold-up valve connected to a port for a first selected pressure chamber of a hydraulic press consumer and to which is connected from the first pressure chamber port downstream of a directional valve which selectively supplies a pressure means from downstream to Direction valve disposed, connectable with a pump pressure medium connection via the hold valve to the first pressure chamber port or to a connection for a second back pressure chamber to enable predetermined Grundbewegungs- and securing functions. According to the invention, a safe fluid path is defined in the basic block, consisting of the first pressure chamber connection, the hold-up valve and the directional valve, into which either no flow or limited fluid flow or limited flow ends.

LIST OF REFERENCE NUMBERS

consumer

1

piston

1a

piston rod

1b

cylinder

1c

pressure line

2

High holding valve

4

Pressure relief line

6

Pressure relief valve

8th

directional valve

10

Pressure relief line

12

Overpressure branch line

14

Pressure relief valve

16

pressure line

18

tank line

20

safety valve

22

Pressure relief valve

24

Bypass line

26

speed valve

28

Einrichtventil

30

throttle

32, 34

switching valve

35

Parallel pressure line

36

shuttle valve

38

Throttle / nozzle

40

Claims (9)

Hydraulic control block of a press consisting of a base block with a hold-up valve (4) connected to a port for a first selected pressure chamber (R) of a hydraulic press consumer (1) and to which a directional valve (10) is connected downstream from the first pressure chamber port optionally by a pressure medium from a downstream of the directional valve (10) arranged with a pump (P) connectable pressure medium connection via the hold valve (4) to the first pressure chamber port (R) or to a connection for a second back pressure chamber (K) passes to predetermined Basic movement and securing functions to allow, characterized in that in the basic block a safe fluid path consisting of the first pressure chamber port (R), the hold-up valve (4) and the directional valve (10) is defined in the either no or exclusively fluidic limited or limited Inflows and / or outflows the. Hydraulic control block according to claim 1, characterized in that in or on the base block a rapid traverse valve (28) is arranged, which is provided starting from the first selected pressure chamber (R) downstream to directional valve (10) between the directional valve (10) and a tank port, to allow rapid movement of the consumer (1) due to limited flow from one of the selected pressure chambers to the tank. Hydraulic control block according to claim 2, characterized by a pressure limiting valve (24) which is arranged in a pressure relief line (12) parallel to the rapid traverse valve (28). Hydraulic control block according to one of the preceding claims, characterized by a set-up valve (30) which selectively directs a control fluid from a pump (P) to one of the two pressure chamber ports of the control block, with a flow restricting agent (A) between the set-up valve (30) and the pressure chamber ports. 32, 34) is interposed. Hydraulic control block according to one of the preceding claims, characterized in that the flow restriction by a throttle or nozzle (32, 34) is effected. Hydraulic control block according to one of the preceding claims, characterized in that the directional valve (10) can be screwed to the base block on the outside. Hydraulic control block according to claim 6, characterized by a selected additional functions bearing intermediate block, which is constructively mounted between the base block and the directional valve (10). Hydraulic control block according to claim 7, characterized in that the intermediate block has a first through-bore (A) which is connected at its one mouth to the hold-up valve (4) and with its other mouth to the directional valve (10), preferably on the intermediate block is attached. Hydraulic control block according to claim 8, characterized in that the first through-hole (A) forms a portion of the secure fluid path.

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