DE3620853A1 - Method for releasably fastening a punch counterplate to a punching machine, and a punching machine - Google Patents

Abstract

The invention relates to a method for the releasable, shake-free fastening of a punch counterplate inside a punching machine for web-like and sheet-like material, especially cardboard; the invention also relates to a punching machine which has been equipped accordingly. Instead of bonding the punch counterplate to the assigned baseplate, the invention proposes that fastening be brought about by means of suction caused by a low pressure region, a skilful arrangement of the corresponding channels, means of distributing the low pressure or a combination of channels and distribution means in each case optimising the fastening, even in the case of an inherently porous layer. The low pressure system can be loaded with compressed air for a short period so that the punch counterplates can be released. The invention can be used to permit reuse of the punch counterplates an almost unlimited amount of times, at the very least throughout the lives of the assigned steel strip tools.

Description

The invention relates to a method for releasable fastening a punching counter plate with applied dressing stripes or fields on the base plate one with ribbon punching machine for sheet metal working or band-shaped material. In addition, concerns the Erfin with a punching machine for such material a movable punching plate, under which also one movable frame is held a steel strip tool, and with a detachable and immovable on a base plate attached die-cutting counter plate, on the finishing strip or fields are glued on.  

The reason for this is the punching machines that are common today plate made of a 4 to 8 mm thick steel, for example plate made of a chrome vanadium steel, the after surface facing above as contact surface for the punching counter plate serves. The punch counter plate is a steel sheet For example, 0.5 mm thick, on the dressing strip or preparation fields are glued on, whereby as Zu directional fields, in particular Pertinax plates, have proven their worth. The stamping counter plate is made using a contact adhesive glued to the base plate, the punching and creasing pressure is used as a pressing force.

When processing cardboard blanks, for example put the cutting lines of the band steel tool on the Punch counterplate on while the crease lines are inside of the steel strip tool, the punch counterplate is single Lich approach, in the immediate vicinity of the Creases the finishing strips or finishing fields with Get your grooves pretreated later folding is permitted along these grooves. With the band steel tool is usually one more ply, cross-glued wooden board into the slots are inserted to accommodate the strip steels. The band steel penetrate the wooden panel except for small bars complete and are on the top of one Dressing plate applied during the punching process again from the actual pressing plate is pressed down. The strip steel tool is on the side or from above within a mitbe moved frame held. The die plate is either as movable punching head or as a fixed plate forms, with the base plate then moving up and down is trained.

After processing a batch of a certain amount terials a punching machine has to be converted, namely with a different steel strip tool and an ent speaking counter pattern for the dressing strips or fields are provided. This is peeling off the punch  counter plate with the prepared stock on it sharing required. The adhesive is ent in one speaking solvent soaked and it comes with tried slim objects like knives and wires the die counterplate as free of damage as possible and from one side starting from the base plate to solve.

This step is not particularly convenient since the Operator the vapors of the solvent for the Glue is exposed, there is also a risk that a dressing element detaches from the punch counterplate, splintered or the die counterplate kinks or other undergoes permanent deformations, which they are responsible for Make editing unusable. The die counterplate with together with the dressing elements is namely damaged free detachment reusable if the same pattern on cardboard blanks again at a later date is driven on the punching machine.

Reuse is possible using the above procedure the punch counterplate about six to eight times. No later than there are so many at the time of peeling minor damage to details occurred that the Punching counter plate is no longer used overall because there is a risk of major damage. If namely a dressing element during punching and creasing event is postponed or fragmented, with most likely a large part of the cutting and crease lines damaged, it's even the damage of the wood panel bearing these lines.

Apart from the relatively small number of possible Reuse of the die counterplate with applied Dressing pattern is the work of peeling off the punching counter plate not only uncomfortable but also extremely time consuming, since not only the detachment must succeed, but glue remnants must be removed carefully so that not  the subsequent reloading of the punching machine these points force peaks arise during the punching process. The changeover times are therefore considerable, so that the Small series profitability leaves something to be desired.

It is therefore an object of the invention, the attachment to improve the punch counterplate on the base plate so that the punch counter plate together with the attached Dressing elements reused almost any number of times the change can be made in a relatively short time and so the profitability of the tools and the punching machine itself is increased considerably.

To achieve this object, the invention relates to the procedure that the punching counter plate by sub pressure is sucked onto the base plate, and with respect A punching machine, the invention proposes that the Base plate on the side facing the punching counter plate Openings or grooves that carry channels for connection are connected to a vacuum source. Regarding the Punching machine is a second proposal according to the Er invention characterized in that the base plate is a Pad made of a porous, pressure-resistant material, esp especially from a ceramic or a sintered metal, that the pad is surrounded by a gas-tight frame, and that at least in the base plate or in the frame an opening on the side facing the support and a channel for connecting a vacuum source available are.

The use of negative pressure to hold areally Objects on a surface is for example from Plotters known in which the writing paper on the Writing surface is held by negative pressure. In the As a rule, there is a shift in the arc the underground does not anticipate such a shift however, does not damage the plotter, everyone if the already partially marked sheet is un  useful. For this reason, it is obvious so far Always trusted an adhesive for attachment the punch counterplate on the base plate, its Festig durability and durability can be determined. The invention now has the holding principle with negative pressure with success also on the connection between the punching counter plate and the base plate applied, where appropriate Aids are used that make the vacuum more even distribute a better slip resistance between the two Bring surfaces or a safe one from the start Effect the system by rolling it like a roller, if namely the negative pressure progressively in some areas Hang up is applied. Of course, too Combinations of these aids are provided.

Especially in connection with base plates where the openings outside the cutting and creasing areas lie, it is appropriate between the base plate and Stamping counter plate an intermediate layer of a thin, porous paper, a nonwoven fabric or a fabric in which the vacuum is evenly distributed can. This way everyone is a very good sub support of the punch counterplate is present, on the other hand the effect of the vacuum extends far beyond the un indirect catchment area beyond each opening.

Instead of an intermediate layer, in particular the punch counterplate have a structure on their underside, which are applied by grinding or by printing is. The structure can be based on the arrangement of openings be matched in the base plate so that per opening a certain structural area is present, which means that it is excellent that a network of paths of the narrowest Grooves outside of, for example, the screen printing areas each closed pressure line is present, the quasi forms an external seal of this structural area. In a further development of a printed structure, these can  sealing border areas of each structure or the outer Edge areas of the entire die counterplate with one open be printed on the z. B. after that in offset printing usual procedures has been made oil-friendly. At the An oil is then applied in the appropriate dilution these areas applied that additionally as a sealant to form vacuum islands or to form a complete vacuum below the punch counter plate.

During machine operation, when lowering Steel strip tools in the direction of the punching counter plate a shift compared to the base plate as good as locked out. Only when the steel strip tools again are lifted off, there is suction from above on the punch counter plate as a result of the change in distance and as a result the lifted off from the material to be punched Foam rubber strips on both sides of the cutting lines. During this phase of the processing, there is a risk of Shift greatest. However, since the exposure time of this Lifting forces, which the suction forces by negative pressure Fasten the punching counterplate to the base plate are opposed, is short, the reserves are sufficient the vacuum attachment completely out of a shift to avoid the punching counter plate compared to the base plate.

Another critical phase is the insertion of a sheet from the side or pulling out the cut and grooved sheet beyond the plant in the same Direction. Here it can happen that a Sheet edge or a cutting edge on a dressing element hooks, which causes significant lateral forces on the punching counter plate are applied. In particular, the danger of Countering madness while changing bends is one Longitudinal structure on the base plate as well as on the punch counterplate advantageous, the ver transverse to the loading direction running. Due to the resulting micro closure in the Structure becomes a movement in loading and unloading direction severely hampered from the outset. A corresponding  Structure is particularly easy by longitudinal grinding in the two surfaces.

The total contact area between the two areas is preferably divided into areas, each then Vacuum applied to the area almost separately becomes. This means that there are no shifts between two plates, if there is an unfortunate one Coincidentally the punch counterplate in one or more cases should stand out. Because of the other Be the punch remains counterplate positioned exactly when the temporarily lifted sections fall back onto the base plate and sucked in again through the areas acting here will.

To realize the independent vacuum supply the individual areas is preferably a battery used by throttles that have a vehement gas flow prevented from one area to another and so one only negative pressure source allowed for all areas. For Maintaining a strong negative pressure in such Interference periods can also or alternatively be a vacuum container between the channels and the vacuum source be arranged, the one supporting or the same Effect.

If the individual areas are essentially concentric are arranged and assigned a choke to each area is, by choosing the throttling when hanging up the punching counter plate can be reached on the base plate, that after connecting the vacuum source first in Center the strongest suction occurs because of the chokes have larger cross sections in this area. First when the gas flow from these areas decreased sharply has or has come to a standstill, also after and after the other areas increasingly with negative pressure acted upon so that a ver ver from the inside out  complete pressing force is achieved that the smooth paint or the rolling of the stamping counter plate on the Base plate equals from the inside out.

The progression of the vacuum application of area area can also be brought about in other ways be, namely on the premise that one already area under pressure following area is only applied when in the previous a certain minimum level of negative pressure has been achieved is. The vacuum is measured in every area, compared to a setpoint in a controller is saved, and only then the connection between the next area and the vacuum source for example released via an electro-pneumatic valve, if in the previous area the measured Vacuum reaches or exceeds the specified setpoint has stepped. In this way, any die counterplate inside out or from side to side "Wrinkle-free" and attached without displacement when hanging up will.

It happens again and again that the punching counter used plates are smaller than the area of the base plate. In In this case care must be taken to ensure that the uncovered areas or openings for the sub pressure application switched off or by blanking plates are covered. The shutdown can be done manually via valves done, but it can also be different automa degrees of realization can be realized.

For repositioning a punching counter plate after a Malfunction or after a break in production of the is the band steel tool assigned to the dressing pattern it suitably, the punch counterplate from the outset with a side Stop bar to be provided in the given position for example abuts the base plate. Over a Notch or another stop in the form of a  into the corresponding side surface of the base plate exaggerated pen can always be a repeatable Positioning can be achieved. The stop bar can then with control contours in the form of pins, openings or cams that act on control means, which are then attached to the base plate; this includes the actuators of valves, blowing or vacuum openings, proximity switches etc. With every stop bar then becomes a certain operation pattern of the control means brought about, the areas and the control means so are coordinated with one another that when hanging up the arranged only those areas with sub are pressurized, which are below this plate formats. It is particularly useful here Punching counter plates, for example, are available in four sizes hold, so to carry out a kind of standardization and outside to avoid formats lying in accordance with this standard. On one out led machine can the dimensions of a corresponding Punching counter plate for example 50 cm × 60 cm, 60 cm × 80 cm and 70 cm × 100 cm.

With an even higher degree of automation, a punch counter plate of any configuration and size and in the line system of vacuum supply pressure air blown. A pressure measurement is then made for each area made, those areas without pressure increase are due to the lack of cover from the punching counter plate are not loaded. The areas where a pressure rise is measured, saved and on finally connected to the vacuum source. That before blowing the line system with compressed air also a desired cleaning.

Regardless of the level of automation at Verwen a stop bar on the punching counter plate partial abandonment of the vacuum to the those areas that are adjacent to the stop bar beard, while the last areas are the opposite  overlying areas under negative pressure be set. This applies to both an automated area printing task as well as for a completely losge solves, for example manually or by a separate Control operated program. That way ensured that the die backing plate from the stop bar is virtually applied to the base plate and itself so after the final attachment no play between the stop bar and the base plate can adjust.

A particularly even vacuum on the underside the die counterplate is reached when the base plate is provided with a pressure-resistant pad that itself is porous in itself. There are layer thicknesses of this edition suitable from 0.5 to 2 cm, in which after appropriate Sealing on the entire surface is a stable sub pressure forms. If smaller punching counter in the format plates are used, for example in strip steel works size that are less than the size of the total area, can use the rest of the previously exposed areas covered by blanking plates made of rubber, for example will. If the structure is fine enough, the bottom is adequate support at every point, and in particular combined with a hard, less smooth Punching counter plate, for example, made of an austenitic Steel of 1 mm thickness can be a very good overall Achieve positioning and holding effect.

To support the vacuum forces are special Suitable varnishes that are applied in the thinnest layers to one of the both contact surfaces or on both contact surfaces be brought. Coverings made of so-called called hot glue, which, however, in Ver not be heated, so that they and inhibitory effect against shifting the contact surfaces against develop each other, but no adhesive forces in the sense a conventional adhesive connection.  

The exact repositioning of the die counterplate with the applied dressing patterns when used again after a break in production a similarly good re Position the steel tool against each other. The traditional way of fastening within a frame on the contact side of the sheets to be processed will be kept, however, in further development of the invention a positioning aid on this side that complements the repeatable exact fastening of the steel strip tool allowed on the frame. The frame carries one or two positioning stones, each in the form, for example half a cube or cuboid while the steel strip tool has a similarly shaped cutout at this point having. Two are vertical to the frame side running surfaces together, while on the one Areas spaced from each other that this An opposite surfaces, a resilient spreader Direction is there for an even and safe contact between the two contact surfaces worries. The same arrangement of positioning stone and off cut repeatedly on the opposite side of the steel strip tool and on a tensioning bar, which in the frame to the format of the steel strip tool is slidable and lockable. This is how it works it, in no time an already used steel strip mill repeatedly in one and the same place to be arranged in the frame, which is also used Punching counterplate applies to those described above Positioning aids is provided. Converting a punch machine from one job to the next succeeds under Use of the invention with its developments in a lot short time.

Using the following exemplary embodiments of the invention the exact procedure when converting a machine, which is equipped according to the invention, in detail described. It will therefore refer to this in this regard guided tours.

Below are embodiments of the invention, the are shown in the drawing, explained in more detail; in the Show drawing:

Fig. 1 is a schematic side view of the work involved in a cutting and creasing tools in a punching machine, sheet, plate and foil,

Fig. 2 is a plan view of a mounting frame for a strip steel tool in a simplified representation,

Fig. 3 is a plan view of a base plate of a punching machine, a negative pressure is provided according to the invention it with grooves for applying,

Fig. 4 is a view according to Figure 3 of a base plate, which is provided outside of the cutting and creasing areas with openings for bringing up a negative pressure.

Fig. 5 is a circuit diagram for connecting a channeled base plate to a vacuum source according to the invention and

Fig. 6 is a cross-sectional view through a base plate with a porous, pressure-resistant pad according to a further development of the invention.

In Fig. 1, the structure of a punching machine for sheet-like and ribbon-like material, in particular for cardboard, is shown schematically, insofar as it is necessary for understanding the invention.

In the lower part of FIG. 1 there is a base plate 1 , in which grooves 2 or openings 6 ( FIG. 4) are embedded on the upper side, each of which is connected to channels 4 . A vacuum source 40 ( FIG. 5) can be connected to the channels 4 via lines, control means and other auxiliary devices in order to immovably, but releasably, fasten a punching counter plate 10 to the base plate 1 . To position the punching counter plate 1 , a stop bar 11 is provided on one side, which is applied to the base plate 1 . Of course, there is also a fixation in the longitudinal direction of the stop bar 11 , but this is not shown in FIG. 1.

In the case of punching counter plates 10 that have already been used, dressing fields 12 or dressing strips are glued onto their upper side, while when they are first used, the punching counter plate 10 is applied to the base plate 1 without these dressing elements. The course of the application is explained in more detail below.

In the upper area of the machine there is a punching head 20 which is moved downwards for every cutting and creasing process and upwards for every sheet change. Below the punching head 20 is a dressing plate 22 ge hold that acts directly on the top of a strip steel tool 23 , which is held within a likewise movable frame 24 ( Fig. 2). Namely, the band steel tool 23 is bolted on one side directly to the inside of the frame 24 with the help of indicated screws, while on the opposite side in the frame a clamping bar 27 is engaged, from which with the help of clamping bolts 21 Band steel tool 23 also held, namely is firmly clamped in the frame. Plain plates can be used between the clamping bolts 21 and the band steel tool 23 to protect them.

The band steel tool 23 carries on its underside from treading cutting lines 25 and creasing lines 26 , the cutting lines 25 being flanked by sponge rubber strips (not shown), which after the cut ensures that the cutting line is separated from the cut cardboard. Each crease line 26 is assigned a dressing strip with a corresponding groove 13 or a region of a dressing field 12 in order to produce an embossing process and no cutting process.

During operation, a sheet 14 to be processed is pulled by a gripper carriage 15 against a stop (not shown) on the left side of the arrangement shown and the punching machine is moved together. After the cutting and creasing process, the machine is opened again, the processed sheet is raised and conveyed further while a new sheet to be processed is inserted into the machine.

Setting up such a punching machine is carried out as follows for tools used for the first time. A steel strip tool 23 is inserted and fastened in the frame 24 . So that the attachment of the steel strip tool 23 succeeds in the frame 24 in later, re-use in the same place, the frame 24 and the clamping bar 27 are each provided with a positioning stone 33 , which is convenient within a slightly larger cutout 34 of the same shape on both long sides of the steel strip tool 23 finds place. Each positioning stone 33 and each cut 34 have on of a common end face contact surfaces 35, the laying down of the touch position, when the strip steel tool will be mounted in the frame 24 23rd To ensure contact with the contact surfaces 35 and for a uniform pressure, a spring device 36 ensures that emerges from each positioning stone 33 on the opposite side of the contact surface 35 and consists, for example, of a leaf spring, a spring-loaded ball or similar elements. The cutouts 34 are preferably made to achieve good accuracy together with the cutouts for the cutting and creasing lines, for example with the aid of a laser tool.

Next, the punching counter plate 10 with the help of the stop bar 11 is clearly and repeatedly placed on the base plate 1 and sucked firmly by negative pressure. The details of this process are explained in more detail below. Before applying the to straightening fields 12 on the punching counter plate 10 , a so-called finishing sheet 28 is also produced, which, as a result of a blueprint impression of the steel strip tool 23 , represents a tool plan, which is later used when the punching machine is fully set up.

Each plate and every tool is tainted with certain tolerances, so that with a reasonable manufacturing effort, some cutting lines touch the dressing plate 22 on one side and the die counterplate 10 on the other side when the machine is closed, while in neighboring areas or on other cutting lines There is play of 0.05 mm, for example. It is therefore necessary to make a correction on the machine using the finishing sheet 28 . First, however, the preparation sheet must be created, which is done in the following way:

The finishing sheet 28 is placed on the punching counterplate 10 , lateral holes overlapping two pins 31 in the area of the stop bar 11 . For folding free and smooth resting 10 openings can be present in the punching counter plate, which coincide with underlying openings of the vacuum system, so that the finishing sheet 28 is sucked through the punching counter plate 10 . (After dressing, these openings 6 are closed by a valve.) A blueprint is now placed on the dressing sheet 28 and the machine is moved together. Due to the pressure of the cutting line, a true image of all cutting lines is created on the finishing sheet 28 , in other words, the finishing sheet 28 is a lifelike tool plan of all cutting lines.

The finishing sheet 28 is first set aside and the punching counter plate 10 is equipped with finishing strips or finishing fields. For this purpose, the creasing lines 26 of the steel strip tool 23 with dressing tabs and clamping strips taken up or seen with dressing fields, which are produced according to the same coordinates as the wooden plate of the steel strip tool 23 and are positioned with the help of pins protruding through the wooden plate to the individual lines. After removing protective layers on the undersides of the dressing strips or on the undersides of the dressing fields, the machine is moved together. The dressing strips or dressing fields remain stuck in the predetermined position as a result of an exposed adhesive layer on the die-cutting counterplate 10 . After removing the dressing rider or after carefully pressing the adhesive surfaces after opening the punching machine again, it is ready for the first cuts.

After a few trial cuts, the cutting lines in particular have generally set slightly, so that the unavoidable tool and plate tolerances described above affect so that some cutting lines do not fully penetrate to the punching counter plate 10 and consequently no complete cut is carried out. At these points, the layer structure formed from the individual plates and the tool must be thickened accordingly. This is done using the preparation sheet 28 .

In places of an inadequate cut, strips of film of appropriate thickness are glued to the finishing sheet 28 , on which all the cutting lines are shown. By comparing a sheet that was actually cut on the punching machine, these areas of an incomplete cut can be determined very easily. According to some experience, the thickness of the adhesive film to be applied is relatively easy to estimate, so that a single correction is usually sufficient. The locally thickened dressing sheet is now placed between the dressing plate 22 and the punching head 20 , two pins 29 on the dressing sheet 22 determining the position of the dressing sheet 28 . The pins 29 dip into corresponding openings 30 in the punching head 20 . The two hole pairs in the preparation sheet 28 for the pins 31 and for the pins 29 have previously been punched on a corresponding device before, so that there is an absolute congruence in the vertical direction between the two positions, namely one lying on the punching plate 10 and once lying between the dressing plate 22 and the punching head 20 . If necessary, areas of the finishing sheet 28 can be cut, for example the section originally available for positioning in the area of the pins 31 . From now on, the preparation sheet belongs to the tool set consisting of the strip steel mill 23 and the punched counterplate 10 .

After the corresponding order has been processed with the finally configured punching machine or the batch of cardboard sheets has been punched and grooved, a different blank is usually produced, for which the machine is converted. For this purpose, the existing punching counter plate 10 with its dressing fields 12 must be detachably detached from the base plate 1 , which is particularly easy to achieve with the aid of the invention. First, the negative pressure is released, and then the punching counter plate 10 can be lifted off effortlessly. If it has sucked into the areas outside the grooves 2 on the base plate 1 , so that a simple lifting does not succeed, a short burst of compressed air can be given through the same channels 4 , through which negative pressure is applied, and at the latest a gentle lifting of the Punching counter plate 10 allowed. Next, the steel strip tool 23 must be removed from the machine by loosening it from the frame 24 and the dressing sheet 28 drawn out between the punching head 20 and the dressing plate 22 . The machine is now ready to be upgraded with tools of other designs and / or dimensions. If an already used tool set with a punching counter plate 10 already fitted is used, the following work is required:

First, a new steel strip tool 23 is fastened in the frame 24 , using the positioning stones 33 and the cutouts 34 . With frequently used steel strip tools 23 , it may be appropriate to coat the contact surfaces 35 on the wooden plate of the steel strip tool 23 with a plastic, which is also used for repairing partially broken wooden plates. It is a two-component plastic that is dimensionally stable, abrasion-resistant and yet easy to machine. Next, the punch counterplate 10 , which has already been equipped with preparation fields 12 , is placed on the base plate 1 and taking into account a gapless installation of the stop bar 11 or other positioning aids that originally specified the position of the punch counterplate 10 when it was first used. Now the insertion of the new dressing sheet 28 is still missing, which can be achieved very simply by inserting it between the punching head 20 and the dressing sheet 22 . The positioning pins 29 in turn ensure an identical position of the finishing sheet 28 to the rest of the machine.

Particularly noteworthy here is that the dressing sheet 28 assumes the same position when machining begins as when the machine was first loaded.

This fact deserves attention in that it does a special protection of tools is brought about. Though is theoretically the exact fixation of the dressing sheet to the machine is not necessary, since the up glued correction strips have a certain width, however, the microstructure would turn to a small extent Peak loads or incomplete cuts pull if this exact positioning is not done. In addition to a particularly quick changeover, the further advantage of machine protection can be determined.

It can be advantageous for reworking and control work on the directional strips or on the preparation fields on the stamping counterplate 10 if the entire area can be inspected outside the machine or is accessible. Such an inspection, for example during an interruption in operation, would normally require that the punching counterplate 10 be detached from the base plate 1 in the manner described. Because of the time involved, this interruption of machine operation is of course avoided.

In a development of the invention it is therefore provided that the base plate together with the punching counter plate 10 can be removed from the machine under vacuum, since the base plate is generally particularly easy to reposition, namely by means of corresponding pins, prismatic guides or the like. Hose connections from the punching machine to the base plate 1 can maintain the negative pressure. However, it is also possible to seal the base plate tightly and to loosen any connection to the vacuum source. However, the negative pressure can be gradually reduced by possible leakage losses. This latter type of independence is therefore only possible without risk in a reservoir.

Using the positioning stone 33 and the cutout 34, the new steel strip tool 23 is positioned and in turn screwed on laterally. With frequently used steel strip tools 23 , it may be expedient to coat the contact surface 35 with a plastic which is also used to repair partially broken wooden panels. It is a two-component plastic that is dimensionally stable, abrasion-resistant and yet easy to machine. Next, from the first on armor already equipped with dressing fields 12 punching plate 10 is placed on the base plate 1 , taking into account a complete system of the stop bar 11 or other positioning aids that originally specified the position of the punching plate 10 when used for the first time. Now there is still no need to replace the dressing sheet 28 , which is very simple after separating the protective sheet 21 from the dressing sheet 22 . The positioning pins 29 in turn ensure an identical position of the finishing sheet 28 to the rest of the machine.

It is particularly noteworthy that the finishing sheet 2 assumes the same position when machining begins as when the machine was first loaded. This fact deserves attention in that it is particularly gentle on the tool. Theoretically, the exact fixing of the dressing sheet 28 to the machine is not necessary, since the glued-on correction strips have a certain width, but the microstructure would in turn entail a small amount of peak loads or incomplete cuts if this exact positioning was not he follows. In addition to a particularly quick changeover, the further advantage of protecting the machine can be determined.

It is readily apparent that the Ver  driving style and the operation of the machine according to the invention is equipped, no lengthy mani pulations, such as peeling a glued punch counter plate. Consequently, the Punching machine operated with much shorter set-up times become, which has a positive effect on the amortization. Given the high productivity of such machines Every minute of production is precious, so that the additional costs for the operation, the purchase and the Maintenance of the vacuum source hardly matters fall; on the plus side is the saving of glue and solvent.

The invention therefore not only avoids the unpleasant one Work of peeling off an adhesive with the help of a strong smelling solvent, but allowed about it a drastic reduction in changeover times as well a significant increase in the life of the punch counter plates. So while due to the shorter setup machine productivity is improved, also occurs by avoiding large amounts Glue and solvent significantly relieve the strain Ambient air on hydrocarbons.

The core of the invention is the base plate 1 , of which plan views are shown in FIGS. 3 and 4 for different execution examples. In one case, the grooves 2 extend at an angle α of approximately 45 ° across the base plate 1 , while in the other case the openings 6 end at the upper surface along the outer edges, so that the inner, actual Arbeitsbe rich where cut and is grooved, is free of openings 6 . Each groove 2 is connected via a channel 4 to one of the side surfaces, where hose connections or pipe connections can be accommodated without disturbing the cutting and creasing function. The same applies to the openings 6 , although an illustration has been omitted in FIG. 2.

The grooves 2 are kept particularly narrow so that the support of the punching counter plate 10 lying thereon is as complete as possible, that is to say each bridge that is formed is as short as possible when a cutting line or a creasing line meets a groove 2 . Since the majority of the grooves and cuts in cardboard blanks run parallel to the side edges of the base plate 1 , there is a high degree of probability that none of the cutting lines or crease lines will be arranged directly over one of the grooves 2 over a longer distance.

In order to avoid influencing the support conditions on the one long side of the base plate 1 from those on the other side of the base plate, each groove is provided in the middle with a web 3 or evenly or unevenly distributed with a plurality of webs (not shown) which create the resulting Separate the groove sections from each other as far as the vacuum is concerned. For this reason, two channels 4 are also located in the illustrated embodiment, for example, on each groove 2 .

In addition to the illustrated configuration of diagonal grooves 2 and ring-shaped openings 6 , further structures and shapes can be used, for example a star-shaped structure printed on the base plate 1 . It has one or more openings 6 in the middle of the base plate 1 , which then have connections with straight or winding channels which extend outwards from the center. The channels are the non-printed areas of the structure, the width of which can be a few tenths of a millimeter. The outer edge region is then again printed as a survey, so that there is a kind of ring-shaped seal around the base plate 1 at this point. Sealing oils can support the external sealing effect, so that in the inner region, that is to say in the region of the structure with channels, a uniform vacuum prevails on all sides.

In Fig. 5 is illustrated with the aid of a diagram how the grooves 2 are provided with negative pressure ver, so how the punching counter plate 10 lying on the base plate 1 is sucked in. The individual channels 4 , of which only those of one side edge are taken into account for the sake of clarity, are each seen with a valve 37 and subsequently with a throttle 38 and are otherwise through a serving as a buffer tank 39 with a vacuum pump 40 , which as Vacuum source serves in connection. Depending on the size of the base plate 1 by the punching counter plate 10 , 37 areas of the upper surface can be switched off via the valves, so that they do not take part in the fastening of the punching counter plate 10 to the base plate 1 . On the other hand, the valves may be used 37 to to make when placing the punch backing plate 10, a progressive "Override" manually or automatically of the areas to supply gradually the individual grooves 2 with negative pressure applied thereto in an rolling movement of the punch backing plate 10 partially on has been laid. For automatic control, the valves can of course be operated electro-magnetically or pneumatically. In theory, hydraulic actuation is also possible, but for cost reasons this solution will receive less attention.

The throttles 38 and the manifold 39 ensure that the areas of the grooves 2 covered by the punching counterplate 10 are always adequately supplied with negative pressure, even if, for example, one of the grooves or several are not covered accidentally or temporarily, for example by an impurity or the like, so that free air access from the surroundings to the grooves 2 is possible. The reduced flow rate through each throttle 38 or the large cushion of negative pressure within the manifold 39 make any "leaks" harmless, since for all other, normally covered grooves no sudden pressure build-up and thus no drop in the suction force is to be feared.

In practice, a vacuum of 80 to 95% is sufficient as a vacuum for a solid anchoring of the punching counter plate 10 on the base plate 1 . The lateral forces to be expected are namely low and the area available with a full punch counterplate 10 on a small machine with an area format of approximately 100 cm × 70 cm leads to sufficient holding forces in the range of 50 MN and more, even if partial areas of the area are not are subjected to the full negative pressure. The number given relates to those applications in which the negative pressure is effective under the entire surface and not only in the area of the grooves 2 or the openings 6 . This assumption is justified, however, since this distribution effect can be brought about, for example, with a layer of porous paper between the die-cutting counter plate 10 and the base plate 1 at a thickness of approximately one tenth of a millimeter.

Such a complete vacuum distribution under the entire surface of the die-cutting plate to be used is also possible without intermediate layers and the like if, as shown in FIG. 6, the base plate 1 is seen with a support 45 , which is porous from the inside is permeable to gas, but also sufficiently pressure-stable to withstand the heavy loads of several uses with tightly fitted cutting and creasing tools. Ceramic materials or sintered metals are suitable as material for a support 45 of this type, which can be produced in almost any gas permeability and strength. When using ceramics, however, peak loads such as targeted blows must be avoided.

To seal the support 45 to the sides, it is glued into a frame 44 , and the connection between the support 45 and the base plate 1 can also be brought about by gluing. Of course, the negative pressure that is introduced into the support 45 also acts at this joint, so that only a clear fixation, for example in the form of a frame 44 firmly screwed to the base plate 1 , is required.

A connection 51 is used to connect the inside of the support 45 to a vacuum source, not shown, approximately in the middle of the base plate 1 , but deviating from this, connections 52 can of course also be present on the frame 44 . For the rest, the division of the edition 45 into several areas is of course possible, each of which then has a separate connection. The same switching possibilities are then given as described with reference to FIG. 5.

However, if the support 45 is formed in one piece in the embodiment according to FIG. 6, it is important that the entire surface of the support 45 is covered during operation, be it by punching counter plates 46 or by blind plates 50 , which are single Lich a cover function and can be made of an inexpensive material, such as plastic or rubber. It can also be easily carried out with a single support 45 , in which the punching counter plate 46 has, for example, the size of a steel strip tool and the remaining areas of the support 45 are not occupied on the tool side.

The embodiment according to FIG. 6 for a base plate 1 with a support 45 is otherwise handled in the same way as described above. Stamping counter plates 46 with dressing fields 47 are therefore used, in which there are grooves 48 for forming the corresponding cardboard embossments.

It is obvious that the maintenance of the negative pressure during operation is important for the safe function and for the exclusion of dangerous conditions. With the help of suitable circuits, the machine control is therefore selected so that the machine is stopped in the emergency stop before falling below a certain, predetermined pressure, so that no tool movements can be undertaken without a sufficient vacuum. If necessary, the existing vacuum pump 40 can be provided with a further emergency pump, which either starts automatically or can be started up manually or automatically after the signaling of a falling pressure. So here the usual safety precautions for such vital supply areas of a machine are taken ge.

Claims (34)

1. A method for releasably attaching a punching counter plate with applied dressing strips or fields on the base plate of a punching machine for sheet or strip material, in particular cardboard, characterized in that the punching counter plate is sucked firmly by negative pressure on the base plate. 2. The method according to claim 1, characterized records that between the punch counterplate and the base plate a layer of a thin, porous paper, nonwoven or tissue for distribution the negative pressure effect is inserted. 3. The method according to claim 1, characterized records that the punch counterplate and / or the base plate with an adhesive varnish or a slip solid plastic coated or one or both Plates are provided with a structure. 4. The method according to claim 3, characterized records that the structure by longitudinal grinding is generated in a predetermined direction. 5. The method according to claim 3, characterized records that the structure by a pressure process is applied, in particular by screen printing.   6. The method according to claim 5, characterized records that the shape of the structure is stern is shaped. 7. The method according to claim 5, characterized records that the edge areas of the structure be designed to be oil-wettable during printing, and that before placing the stamping counter plate this Edge areas wetted with oil by rolling or spraying will. 8. The method according to any one of the preceding claims, characterized in that the sub pressure when placing the punching counter plate area progressing wisely, especially from one side starting to the other side or from the center starting from the outside. 9. The method according to claim 8, characterized records that the individual areas with the help supplied with vacuum one after the other by valves that the actual negative pressure in each Area measured, and that with the help of a controller the next area is supplied with negative pressure if you select one in the previous area minimum vacuum is reached. 10. The method according to claim 9, characterized records that before abandoning the vacuum an overpressure on the associated pipe system in the Baseplate is given that at each exit or the pressure at the same time at each outlet area or successively it is measured that the exits or Exit areas that do not have a lack of coverage have significant pressure in a controller stores and with the help of valves from the line system are separated, and that subsequently the sub pressure is applied.   11. Punching machine for sheet-like or sheet-like material, in particular cardboard, with a movable punching plate, under which a band steel tool is held on a frame that can also be moved, and with a punching counterplate, releasably and immovably fastened on a base plate, on which dressing strips or fields are glued, characterized in that the base plate ( 1 ) on the side facing the punching counter-plate ( 10 ) has openings ( 6 ) or grooves ( 2 ) which are connected to channels ( 4 ) for connection to a vacuum source ( 40 ). 12. Punching machine according to claim 11, characterized in that the openings ( 6 ) or grooves ( 2 ) are divided into areas, and that each area has its own channel ( 4 ). 13. Punching machine according to claim 12, characterized in that the openings ( 6 ) or grooves ( 2 ) or a structure applied to the base plate ( 1 ) are arranged in a star shape. 14. Punching machine according to claim 12 or 13, characterized in that a throttle ( 8 ) is assigned to each channel ( 4 ) of an area. 15. Punching machine according to claim 14, characterized in that the throttles ( 8 ) of the inner loading areas of the contact area between the punching counter plate ( 10 ) and the base plate ( 1 ) are larger than that of the outer regions. 16. Punching machine according to one of claims 11 to 15, characterized in that a vacuum chamber ( 39 ) is arranged between the channels ( 4 ) and the vacuum source ( 40 ). 17. Punching machine according to one of claims 11 to 16, characterized in that the openings ( 6 ) or grooves ( 2 ) are arranged outside the punching and scoring area. 18. Punching machine according to one of claims 11 to 16, characterized in that grooves ( 2 ) are provided which extend at an angle α of approximately 45 ° to the side edges of the base plate ( 1 ). 19. Punching machine according to one of claims 11 to 16, characterized in that the punching counter-plate ( 10 ) holds positioning holes for dowel pins. 20. Punching machine according to one of claims 11 to 19, characterized in that each punching counter plate ( 16 ) is approximately as large as the steel strip tool ( 23 ). 21. Punching machine for sheet-like or sheet-like material, in particular cardboard, with a movable punching plate, under which a band steel tool is held on a frame that can also be moved, and with a punching counterplate that is detachably and immovably fastened on a base plate, on which preparation strips or fields are glued, characterized in that the base plate ( 1 ) carries a support ( 45 ) made of a porous, pressure-resistant material, in particular special ceramic or sintered metal, that the support ( 45 ) is surrounded by a gas-tight frame ( 44 ), and that in the base plate ( 1 ) or in the frame ( 44 ) there are at least one opening on the side facing the support ( 45 ) and a channel for connecting a vacuum source. 22. Punching machine according to claim 20 or 21, characterized in that the areas of the base plate ( 1 ) or the support ( 45 ) which are not covered by the punching counterplate ( 10 , 46 ) can be covered by blind plates ( 50 ). 23. Punching machine according to one of claims 11 to 22, characterized in that the punching counterplate ( 10 , 46 ) is coated with an adhesive varnish or a non-slip, pressure-stable plastic layer. 24. Punching machine according to claim 23, characterized records that the adhesive varnish from a hot glue exists, but remains without heat treatment. 25. Punching machine according to one of claims 11 to 24, characterized in that the punching counter-plate ( 10 , 46 ) can be positioned with the aid of a bar ( 11 ) or with the aid of stops relative to the base plate ( 1 ). 26. Punching machine according to claim 12 and claim 25, characterized in that the bar ( 11 ) is provided with control contours such as pins, openings or cams, and that control means such as switches, blowing or suction openings or valves are attached to the base plate ( 1 ) which interact with the control contours such that a given bar connects a certain pattern of areas with the vacuum source ( 40 ). 27. Punching machine according to one of claims 11 to 26, characterized in that the band steel tool (23) and the frame ( 24 ) with the aid of at least one contact surface ( 35 ) for positioning the band steel tool (23) transversely to the direction of travel of the material to be cut ( 14 ) is provided, and that a spring device ( 36 ) for bearing the contact surfaces ( 35 ) is optionally provided. 28. Punching machine according to claim 27, characterized in that the contact surfaces ( 35 ) on the contact side to be cut sheets ( 14 ) are arranged. 29. Punching machine according to claim 27 or 28, characterized in that the contact surface ( 35 ) on the frame ( 24 ) from a surface on a positioning stone ( 33 ) and that of the band steel tool ( 23 ) from a surface ( 35 ) on a cutout ( 34 ) exists. 30. Punching machine according to claim 29, characterized in that the cutout ( 34 ) and in particular the contact surface ( 35 ) is covered with a plastic. 31. Punching machine according to one of claims 11 to 30, characterized in that the punching counter plate on the side facing the punching plate ( 20 ) facing outside of the steel strip tool ( 23 ) holding frame ( 24 ) with at least two positioning pins ( 31 ) perforated accordingly Preparation sheet ( 28 ). 32. punching machine according to claim 31, with a dressing plate ( 22 ) between the punching plate ( 20 ) and the band steel tool ( 23 ), characterized in that the dressing plate ( 22 ) on the side facing the punching plate ( 20 ) with two positioning pins ( 29 ) is provided for receiving the preparation sheet ( 28 ). 33. Punching machine according to one of the preceding claims 11 to 32, characterized in that the punch counterplate ( 10 ) carries openings which correspond to openings ( 6 ) in the base plate ( 1 ) for sucking a dressing sheet ( 28 ), and that these special openings ( 6 ) can be separated from the vacuum source ( 40 ) within the base plate ( 1 ). 34. Punching machine according to one of claims 11 to 33, characterized in that the punching counter plate ( 10 ) or the support ( 45 ) together with the base plate ( 1 ) can be removed from the punching machine under vacuum.