DE102011116328A1 - Press block - Google Patents

Abstract

Disclosed is a hydraulic control block of a press consisting of a base frame with a hold-up valve, which is connected to a connection for a first selected pressure chamber of a hydraulic press consumer and to which, starting from the first pressure chamber connection downstream, a directional valve is connected, which optionally transfers a pressure medium from a downstream to Directional valve, which can be connected to a pump, conducts pressure medium connection via the hold-up valve to the first pressure chamber connection or to a connection for a second counter pressure chamber in order to enable predetermined basic movement and safety functions. According to the invention, a safe fluid path is defined in the base block consisting of the first pressure chamber connection, the hold-up valve and the directional valve, into which either no or only inflows and / or outflows that are limited or limited in terms of flow flow.

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, inter alia, the safety regulations in accordance with the German industrial standard DIN EN 693 Fulfills.

From the prior art according to the publication "Machine Tool - Safety - Hydraulic Presses; German version EN 693: 2001 + A1: 2009 , published in November 2009 by the Beuth Verlag GmbH, a hydraulic control of a hydraulic press is known, which meets the above-mentioned German industrial standard and how they in the adjoining 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 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 exclusively, preferably via nozzle throttles) limited / limited inflows / outflows. D. h., The inventive concept provides that in the said fluid path no other valves for controlling the movement, etc. are looped. Such valves are seen from the consumer side (ring chamber side), provided only downstream of the directional valve, z. B. 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 of the nozzles, the upward and downward set-up speed of the consumer is limited (preferably to a maximum of 10 mm / s) compared to normal operation.

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. If the directional valve is screwed onto the base block in the basic version, then in the case of an intermediate block arrangement, the intermediate block is preferably interposed between the base block and the directional valve, in principle without affecting 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.

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

1 shows a hydraulic press control according to the prior art,

2 shows a first preferred embodiment of a press module according to the invention in the formation of a so-called basic block and

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 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 2 schematically as a piston / cylinder unit 1 is shown. The piston / cylinder unit 1 has a piston 1a with a fixed piston rod 1b who is the cylinder 1c divided into a piston chamber K and an annular chamber R fluid-tight. At the piston rod 1b hangs in the present case a weight, for example, the upper die cushion of a hydraulic press (not shown).

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

The hold-up valve 4 is in turn directly in series (ie without the interposition of other switching elements) to a self-monitoring directional valve 10 preferably connected to the 4/3-way valve construction, whose another connection via a pressure relief line 12 with the pressure medium T has connection. To the directional valve 10 Furthermore, a pressure medium source P is connected, at whose output a leading into the pressure medium tank T overpressure line 14 with inserted pressure relief valve 16 is also connected.

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

Like from the 2 can still be seen, is located in the pressure relief line 12 between the directional valve 10 and the tank T, a pressure relief valve 24 that the pressure relief line 12 only at a certain Line pressure opens, one being the pressure relief valve 24 immediate bypass line 26 is provided in the a rapid-action valve 28 preferably the 2/2-switching valve construction is arranged. The express valve locks 28 in a first switching position, the bypass line 26 completely (construction position) and releases them in a second switching position.

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

From the 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 connected to the directional valve 10 is directly connected, a control pressure input ST, to the Einrichtventil 30 leads and a tank connection T1. Furthermore, at least two consumer connections X1, X2 are provided, which belong to the piston and ring chamber K, R of the consumer 1 lead.

Constructive in the basic block are all valves with the exception of the directional valve 10 used and connected hydraulically via bored in the base block channels. The directional valve 10 On the other hand, it is screwed onto the basic block, so that all connections to and from the directional valve 10 according to the above description by screwing the directional valve 10 be made to the basic block.

From the control panel of the 2 the switching functions of the hydraulic control of the press according to the first preferred embodiment of the invention can be seen. As a result, the directional valve is for a standstill of the press 10 , the hold-up valve 4 , the rapid-action valve 28 , the safety valve 22 and the set-up valve 30 unconfirmed, ie all valves mentioned are in locked position (construction position).

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

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

Should the consumer 1 retract, the hold valve return 4 and the rapid-action valve 28 in their construction positions (locking positions) back and the directional valve 10 is brought into a switching position in which the piston chamber K connection to the pressure medium source P (pump) and the annular chamber R connection to the pressure medium tank T via the pressure relief valve 24 receives.

Finally, the consumer 1 to move for setting up the press, the Einrichtventil 30 switched from its blocking position to a first or second switching position in which it selectively connects the piston chamber K for an extension and the annular chamber R for retraction of the consumer with the control pressure port ST. Because these compounds each via the (two) nozzles 32 . 34 a slowed exit and entry of the consumer 1 reached.

From the foregoing description it will be seen that all control functions of the press are provided by valves located either between the directional valve 10 and the pump P or the tank T are arranged or in a limited manner, for example via 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 2 safe fluid path consisting of annular chamber R - hold-up valve 4 - Directional valve 10 , for either no or only about the nozzles 32 . 34 limited 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) is only the directional valve 10 operated accordingly. In the case of an upward movement (pump P is switched to annular chamber R) are only the directional valve 10 and the hold-up valve 4 operated accordingly. The rapid-action valve 28 with pressure limiting function is not in the safe flow path.

The following is based on the 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 constructively between the base block and the directional valve 10 is mounted 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 on an outer side of the intermediate block now the directional valve 10 is screwed on. At least one channel (through hole A) within the intermediate block, the connection between the hold-high valve 4 and the directional valve 10 thus forms a portion or portion of the secured fluid path as defined above.

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

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

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

As can be seen from this, correspond to the switching positions of the valves according to the 3 for the individual operating functions of the press substantially those of the first embodiment according to the 2 , Only in the case of rapid traverse extension, the switching valve 35 operated 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

1

consumer

1a

piston

1b

piston rod

1c

cylinder

2

pressure line

4

High holding valve

6

Pressure relief line

8th

Pressure relief valve

10

directional valve

12

Pressure relief line

14

Overpressure branch line

16

Pressure relief valve

18

pressure line

20

tank line

22

safety valve

24

Pressure relief valve

26

Bypass line

28

speed valve

30

Einrichtventil

32, 34

throttle

35

switching valve

36

Parallel pressure line

38

shuttle valve

40

Throttle / nozzle

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited non-patent literature

• DIN EN 693 [0002]
• German version EN 693: 2001 + A1: 2009 [0003]

Claims (9)

Hydraulic control block of a press consisting of a basic block with a high-level valve ( 4 ) connected to a connection for a first selected pressure chamber (R) of a hydraulic press consumer ( 1 ) is connected to and from the first pressure chamber port downstream a directional valve ( 10 ) is connected, which optionally a pressure medium from a downstream to the directional valve ( 10 ), with a pump (P) connectable pressure medium connection via the hold-valve ( 4 ) to the first pressure chamber port (R) or to a port for a second backpressure chamber (K) to allow predetermined Grundbewegungs- and securing functions, characterized in that in the basic block a safe fluid path consisting of the first pressure chamber port (R), the hold-back valve ( 4 ) and the directional valve ( 10 ) is defined, in which either no flow or limited exclusively limited or limited inflows and / or outflows. Hydraulic control block according to claim 1, characterized in that in or on the basic block a rapid traverse valve ( 28 ) is arranged, starting from the first selected pressure chamber (R) downstream to directional valve ( 10 ) between the directional valve ( 10 ) and a tank connection is provided to ensure 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 relief valve ( 24 ) in a pressure relief line ( 12 ) parallel to the rapid-action valve ( 28 ) is arranged. Hydraulic control block according to one of the preceding claims, characterized by a Einrichtventil ( 30 ) which selectively directs a control fluid from a pump (P) to one of the two pressure chamber ports of the control block, between the 30 ) and the Druckkammerschlüssen each a flow-limiting agent ( 32 . 34 ) is interposed. Hydraulic control block according to one of the preceding claims, characterized in that the flow restriction through 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, the constructive between the base block and the directional valve ( 10 ) is mounted. Hydraulic control block according to claim 7, characterized in that the intermediate block has a first through-bore (A), which at its one mouth with the high-holding valve ( 4 ) and with its other mouth with the directional valve ( 10 ), which is preferably placed on the intermediate block. 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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