EP3153286A1

EP3153286A1 - Processing workpieces with dies being level compensated with a compensation element

Info

Publication number: EP3153286A1
Application number: EP15020182.0A
Authority: EP
Inventors: Bernd ANDREE
Original assignee: Bobst Mex SA
Current assignee: Bobst Mex SA
Priority date: 2015-10-09
Filing date: 2015-10-09
Publication date: 2017-04-12
Anticipated expiration: 2035-10-09
Also published as: EP3153286B1; ES2818077T3

Abstract

A die processing machine (100) for processing a workpiece (190) comprises (a) a first platen (110); (b) a second platen (115); (c) a lifting system (120) for providing a relative movement between the two platens (110, 115) along a predeterm ined direction (z); (d) a die processing tool (130) being located in between the two platens (110, 115) and being mechanically connected with the first platen (110), wherein the die processing tool (130) comprises at least two dies (132); (e) a back plate (140) being mechanically connected with the second platen, wherein a workpiece (190) is insertable in between the back plate (140) and the die processing tool (130); (f) a compensation element (150) being located in between the first platen (110) and the die processing tool (130) for providing an appropriate leveling of the at least two dies; (g) a mechanical action sensor (160) being non-detachably located in between the two platens and providing mechanical action data signals which are indicative for mechanical actions being assigned to the at least two dies when processing the workpiece; and (h) a data processing unit (165) being configured for processing the mechanical action data signals such that geometric data are provided for a further compensation element (350) resulting, when processing further workpieces (190), in an at least partially uniform pressure distribution in processing regions being assigned to the at least two dies (132). Described are further a die processing system (4000) and a method for processing workpieces.

Description

Field of invention

The present invention relates to the technical field of flat bed sheet material die punching, cutting and/or embossing machines. In particular, the present invention relates to a die processing machine, a die processing system and a method for processing workpieces by means of die processing.

Art Background

In the packaging industry a die cutting, die punching or die embossing procedure of cardboard or other sheet like materials is used for manufacturing appropriate packages for articles, in particular consumer articles. In this document the procedures of die cutting, die punching and/or die embossing are briefly denominated as die processing. Cardboard or other sheet like materials are denominated workpieces.
A die processing is typically carried out within a die cutting, die punching or die embossing machine, hereinafter denominated a die processing machine. Such a die processing machine comprises a die cutting, die punching or die embossing tool, hereinafter denominated die processing tool, in which several dies are provided representing the tools for processing the workpiece. By means of an appropriate lifting system the die processing tool is pressed against a back plate of the die processing machine, wherein the respective workpiece is located in between the die processing tool and the back plate.
During such a die processing procedure, the dies penetrate at least partially the workpiece. At the end of a die cutting or die punching the dies make a mechanical contact with the back plate. It is hereby of primary importance that all edges of the involved cutting dies make contact with the back plate simultaneously at the end of the relative movement between the die processing tool and the back plate. Otherwise, a number of cuts or punches will be incomplete. A similar situation is given for die embossing, wherein for a good embossing quality it is also important that all involved dies penetrate the workpiece to the same extent.
Due to unavoidable inaccuracies and/or wear and tear of the dies and due to tolerances, deviations and/or wear of components of the involved die processing machine, the above-mentioned demand will in fact be hardly or never met right away, at least when no appropriate level compensation for (the edges of) the dies is provided for.
For providing an appropriate leveling of (the edges of) the dies it is known to use a compensation element underlying the dies at their side facing away from the its die edges. An appropriate compensation element comprises a typically spatially varying thickness such that each die has a proper level. A compensation element typically comprises a base sheet and several local compensation portions attached on the surface of the base sheet. The local compensation portions may be realized by means of stripes, wherein each stripe is assigned to at least one die and has an appropriate thickness for leveling the respective die. Compensation elements may be made of polyurethane, metal, tetrafluoroethylene, paper or a combination thereof.
In practice, during operation of a die processing machine the compensation of the dies is to be adjusted frequently. This holds not only true for compensating an uneven wear of different dies during the production of a batch of one and the same type of workpieces but in particular when changing the type of workpiece to be processed. Since preparing an appropriate compensation element is a labor intensive procedure, significant downtimes of the respective die processing machine are given in practice. Further, preparing an appropriate compensation element requires comparatively high skills such that only experienced operators can be entrusted. This all significantly contributes to the manufacturing costs of packages.
EP 2 705 936 A1 discloses a method for determining a machine dependent compensation requirement which is supposed to be provided by a compensation element. The machine dependent compensation requirements are determined with the help of a computer implemented analysis of the thickness variation of various appropriate compensation elements, which have been and/or which are used for processing different types of workpieces. In this analysis an averaging procedure is carried out by means of which workpiece dependent compensation requirements are eliminated. The thickness variation of the compensation elements may be accomplished by means of a 3D scanner.
EP 2 327 521 A1 discloses a method for level compensating the edges of dies of a die processing tool, wherein a pressure distribution sensor is employed for measuring the spatial distribution of the pressure being associated with different dies when using the die processing tool for cutting or embossing a workpiece. Based on the respective measurement results a compensation element with a proper thickness distribution is produced by means of an additive manufacturing procedure, wherein the compensation element is made from one piece by setting up layer structures or by selectively removing layer structures. Compared to a pure manual making of a proper compensation element the disclosed method provides for a partial automation. However, the production of a proper compensation element still requires some effort which results in significant downtimes of a die processing machine in particular when changing a package production from a first type of package or workpiece to a second type of package or workpiece. This results in a decreased efficiency when producing packages.
There may be a need for increasing the efficiency for automatically producing packages by means of a die processing machine.

Summary of the Invention

This need may be met by the subject matter according to the independent claims. Advantageous embodiments of the present invention are described by the dependent claims.
According to a first aspect of the invention there is provided a die processing machine for processing a workpiece, in particular a flat bed die cutting, die punching and/or die embossing machine for processing cardboard or other sheet like material being used for packages for articles. The die processing machine comprises (a) a first platen; (b) a second platen; (c) a lifting system being mechanically connected with the first platen and/or with the second platen for providing a relative movement between the two platens along a predetermined direction; (d) a die processing tool being located in between the two platens and being mechanically connected with the first platen, wherein the die processing tool comprises at least two dies; (e) a back plate being located in between the two platens and being mechanically connected with the second platen, wherein a workpiece is insertable in between the back plate and the die processing tool; (f) a compensation element being located in between the first platen and the die processing tool for providing an appropriate leveling of edges of the at least two dies with respect to the predetermined direction; (g) a mechanical action sensor being non-detachably located in between the two platens and being configured for providing mechanical action data signals which are indicative for magnitudes of mechanical actions being assigned to the at least two dies when processing the workpiece; and (h) a data processing unit being communicatively coupled with the mechanical action sensor and being configured for processing the mechanical action data signals in such a manner that there are provided geometric data for a further compensation element resulting, when processing further workpieces, in an at least partially uniform pressure distribution in processing regions being assigned to the at least two dies.
The described die processing machine is based on the idea that during its operation it can be monitored whether the pressure and/or the force being assigned to the dies when coming into contact with the workpiece is still within acceptable limits or exhibits a unacceptable spatial variation for instance due to an unwanted wear which has been developed during a previous operation of the processing machines, wherein typically a plurality of workpieces has been processed. In addition, the non-detachably mounted pressure distribution sensor in connection with the described data processing unit allows for a fast determination of geometric data for an appropriate (further) compensation element which, for the processing of subsequence workpieces, can be used in order to achieve an at least partially uniform and/or, compared to the previously used compensation element, an improved uniformity of pressure and/or forces being exerted onto the various dies.
The mechanical action sensor may be configured for measuring (i) the mechanical action to the respective die or (ii) a mechanical interaction between the respective die and the first platen. The mechanical action respectively the mechanical interaction may occur in particular along the predetermined direction, when, driven by the lifting system, the first platen and the second platen move towards each other and sandwich the workpiece in between.
In this document the term "processing region" may particularly denote the spatial region of the mechanical interaction between (the edges of) the dies and the workpiece. Depending on the type of processing this mechanical interaction may result in a partial or in a complete penetration of the dies into the workpiece.
It is mentioned that the number and/or the shape of the dies being used may depend on the specific application. In particular, the more complicated the geometric structure of the processing regions is, the higher is the number of the dies and/or the higher is the complexity of the shape of the edges of the dies. Preferably, the edges of the dies exhibit a simple geometric structure, in particular a straight line, and, depending on the structure of the processing regions the number of the employed dies is correspondingly higher.
In this document the term "connected" may mean a direct or an indirect connection between the respective elements. An indirect connection may mean that one or more intermediate elements are located in between. This holds in particular for mechanical connections. However, the same considerations also apply for the electric, electronic and/or optical connection respectively coupling between the mechanical action sensor and the data processing unit.
The first platen and/or the second platen may be any mechanical structure which is formed in such a manner and which comprises a sufficient mechanical stability such that the mechanical arrangement comprising the die processing tool, the back plate and the respective workpiece in between can be pressed together such that the desired processing of the workpiece is accomplished. The first platen and/or the second platen may be for instance realized by means of simple block or cuboid structures. Preferably, the first platen and/or the second platen is made from a metallic material.
The described data processing unit being (directly or indirectly) coupled with the permanently implemented mechanical action sensor allows for producing the geometric data being necessary for forming an appropriate (further) compensation element yielding a higher quality of the processing of the workpiece. Specifically, an appropriate (further) compensation element may be produced already during the operation of the described die processing machine. This results in a significant reduction of downtimes of the machine and, as a consequence, in a higher production efficiency for packages for (consumer) articles.
It is mentioned just for the sake of clarity that the invention described in this document may relate to a die cutting, a die embossing or to a combination of die cutting and die embossing. In order to avoid lengthy expressions in this document these per se well known procedures are hereinafter called processing procedures.
By monitoring the provided geometric data during operation of the die processing machine a high quality of the workpiece processing can be guaranteed. Specifically, if it turns out that the provided geometric data for the further compensation element do not significantly differ from the geometric data of the compensation element being currency used for processing workpieces, it can be assumed that the die processing machine works in an operational mode yielding a high quality processing of workpieces.
According to an embodiment of the invention the mechanical action sensor is a pressure distribution sensor being non-detachably located in between the two platens and being configured for providing pressure data signals which are indicative for a spatial pressure distribution given in between the two platens.
The pressure distribution sensor may be for instance a layer or a foil of a pressure sensitive material, which is electrically connected with an appropriate readout device allowing for obtaining a distribution of pressure values, wherein each pressure value is assigned to a certain surface portion of the pressure distribution sensor and/or to a certain die or at least a certain edge portion of a die. The pressure distribution sensor may comprises for instance a piezoelectric material, which responds to an applied pressure by providing a voltage difference between two opposing surfaces of the preferably layered and, if appropriate, structured piezoelectric material. However, also other types of (two-dimensional or laminar) pressure distribution sensors may be employed such as piezo-resistive pressure distribution sensors, capacitive pressure distribution sensors, inductive pressure distribution sensors or combinations thereof.
According to a further embodiment of the invention the first platen is an upper platen and the second platen is a lower platen.
In this respect the term "upper" and "lower" relate to the direction of gravity and to an orientation of the die processing machine in which orientation the die processing machine is operating. This means that the above mentioned predetermined direction is a vertical direction which may be in particularly denominated as a z-direction of an cartesian coordinate system wherein an x-direction and a y-direction are aligned horizontally and are both perpendicular to the z-direction.
The movement of the first platen and/or the second platen in a vertical direction may provide the advantage that the described die processing machine can be implemented as a working station in a production line which is capable to manufacture finished packages. Such a production line may in particular includes an appropriate folding machine which, with respect to a workpiece transport direction, is connected downstream of the described die processing machine and which is configured for folding the processed two-dimensional workpieces into an appropriate three-dimensional package.
According to a further embodiment of the invention the first platen is mounted stationary to the chassis and the lifting system is configured for moving solely the second platen along the predetermined direction. This may provide the advantage that the mechanical structure of the entire machine can be kept simple because it is only necessary to suspend one of the two platens in a movable manner.
The stationary mounting of the first platen to the chassis can be realized by a direct attachment of the first platen at (a portion of) the chassis. However, also an indirect attachment via one or more intermediate (mechanical) elements is possible.
According to a further embodiment of the invention the lifting system is further configured for proving a tilt movement between the two platens. This may provide the advantage that the force application to at least one of the platens can be modified. An application specific appropriate force application may result in an optimized distribution of pressure respectively force within the entire plane of the (flat) workpiece and in particular within the processing regions. As a consequence, a high quality workpiece processing can be achieved.
The tilt movement may be characterized in particular by a pivoting movement around an axis being perpendicular to the predetermined direction. However, it is mentioned that also other non-linear movements of at least one platen may be generated by the lifting system.
According to a further embodiment of the invention the lifting system comprises a lever arrangement. This may provide the advantage that not only a very precise or controlled but also a strong movement of the at least one platen can be generated. A strong or powerful movement can be realized even with a comparatively weak actuator if the levers of the lever arrangement are designed in such a manner that a favorable relationship of the levers will be achieved.
Using a lever arrangement may in particular be of advantage if the above described tilting movement is to be realized. In this case the lever arrangement may be driven not only by one but, depending on the desired degree of (tilt) movement, by a larger number of actuator means. Suitable actuator means may be in particular electric motors.
According to a further embodiment of the invention the mechanical action sensor is located in between the first platen and the die processing tool. This may provide the advantage that the pressure respectively the force acting onto the various dies when processing the workpiece can be measured very precisely. As a consequence, the geometric data provided by the data processing unit for the further compensation element will precisely characterize a further compensation element being optimized for yielding a high quality workpiece processing.
According to a further embodiment of the invention the mechanical action sensor is located in between the first platen and the compensation element. This may provide the advantage of a further optimized workpiece processing when using a further compensation element produced on the basis of the geometric data provided by the data processing unit.
The benefit of this embodiment can be easily understood by the following consideration: In case the force and/or the pressure acting on the compensation element during operation of the die processing machine is more or less uniform or homogeneous, there is no need to modify the compensation element. This holds true because in the desired operational state, in which all (active) portions of the compensation element exhibit more or less the same mechanical load, also all dies involved in the workpiece processing experience more or less the same mechanical stress. It is clear that this operational state will yield the best quality for the workpiece processing by means of the described die processing machine.
According to a further embodiment of the invention there is provided a die processing system for processing a workpiece. The provided die processing system comprises (a) a die processing machine as described above; and (b) an automatic machining device for automatically producing the further compensation element based on the provided geometric data for the further compensation element. The automatic machining device is mounted to the die processing machine.
The provided die processing system is based on the idea that a reliable and close functional connection or interaction between the die processing machine and the described automatic machining device can be used for efficiently processing workpieces with a high quality. Thereby, it can be ensured that the workpiece processing is always carried out with an appropriate compensation element. Due to a small spatial and functional separation between the die processing machine and the automatic machining device the downtime of the workpiece processing, which downtime is associated with a production and a change of the compensation element, can be significantly reduced. As has already been mentioned above, the downtime reduction may be in particular of importance in case the number of workpieces of a specific type to be processed is comparatively small such that it is necessary to replace or change the compensation element frequently. However, also the downtime being associated with a replacement of a compensation element due to a developed wear of the (edges of the) dies can be reduced.
In this document "mounted to" may particularly denote a mechanical connection wherein the geometric or spatial relationship between (a chassis of) the die processing machine and (a chassis of) the automatic machining device is fixed at least during the operation of the die processing system. Thereby, this operation includes not only the processing of workpieces but also, at least from time to time, an automatic production of (further) compensation elements.
It is mentioned that the automatic machining device may comprise a control unit for controlling the production of the further compensation element. In the described die processing system the data processing unit of the die processing machine and the control unit of the automatic machining device are communicatively coupled with each other by means of an appropriate data interface. However, the data processing unit and the control unit may also be realized by means of a single processor device.
According to a further embodiment of the invention the automatic machining device is configured for producing the further compensation element by means of an additive manufacturing procedure.
By contrast to well-known machining procedures such as in particular milling, wherein material is removed in order to produce a certain shape of an object, in an additive manufacturing procedure the respective object is constructed by forming appropriately structured layers one over the other. Thereby, also complex geometric shapes can be realized in a fast and efficient manner.
According to a further embodiment of the invention the automatic machining device comprises a three-dimensional printer. This may provide the advantage that an in the meantime well known and established technology can be employed in order to realize the desired automatic machining device allowing for a fast, reliable, and precise production of at least one (further) compensation element.
It is mentioned that with the described three-dimensional printer the entire compensation element can be produced. However, at present it seems to be more appropriate if only the local compensation portions of the compensation element are produced by means of a three-dimensional printing procedure, wherein local compensation portions with appropriate thicknesses are formed on a prefabricated base sheet of the respective compensation element.
According to a further embodiment of the invention the die processing system further comprises a handling system for transferring a produced further compensation element from the automatic machining device to the die processing machine. This may provide the advantage that the produced compensation element can be automatically, i.e. without any manual operation performed by an operator, transferred into the processing region of the die processing machine, which processing region is located between the two platens.
The handling system may be comprise at least one gripper being configured for temporarily holding the produced further compensation element. The gripper may be moved by an appropriate robot means. The operation of the entire handling system may be controlled by a control unit. The control unit may be communicatively coupled with the data processing unit of the described die processing machine. Alternatively, the control unit for the handling system may be implemented by means of hardware and/or software by the data processing device of the described die processing machine.
It is mentioned that according to a preferred embodiment of the invention the handling system is configured also for removing the so far used compensation element from the processing region. This may provide the advantage that a complete compensation element exchange can be realized fully automatically without any user operation. Alternatively, a further handling system can be provided which is responsible for removing the so far used compensation element.
With the help of a standardized and automatic production of an appropriate compensation element and an automatic transfer of a produced further compensation element to the die processing region the downtime of the die processing machine can be reduced by 50% as compared to the downtimes which are unavoidable when using known technology for producing compensation elements in an at least partially manual manner.
According to a further embodiment of the invention the handling system is configured for transferring the die processing tool between the die processing machine and the automatic machining device. This may provide the advantage that for the production of the further compensation element the die processing tool may be used as the support platform. Further, it can be easily ensured that the further compensation element is precisely aligned with the die processing tool. Specifically, it can be ensured that the (further) local compensation portions of the further compensation element are precisely aligned with the dies of the die processing tool. There will be no more a need for aligning the further compensation element with the processing tool within the die processing machine.
According to a further aspect of the invention there is described a method for processing workpieces, in particular by flat bed die cutting, die punching and/or die embossing a cardboard or other sheet like material being used for packages for articles. The described method comprises the steps of (a) processing a first workpiece by means of the die processing ma-chine as described above; (b) transferring the provided geometric data for the further compensation element to an automatic machining device; (c) producing the further compensation element based on the provided geometric data; (d) removing the compensation element which has been used for processing the first workpiece from a processing region of the die processing machine; (e) transferring the produced further compensation element into the processing region; and (f) processing a second workpiece by means of the die processing machine by utilizing the further compensation element.
The described production and exchange of the compensation element, wherein the compensation element which has been used for processing at least one first workpiece is exchanged by the further compensation element which is used for processing at least one second workpiece, can be realized in a fully automatic manner. This does not only hold for transferring the further compensation element but also for producing the further compensation element by means of the described automatic machining device. Due to a fully automatically replacement of compensation elements the downtime of the die processing machine can be reduced significantly compared to a known at least partial manual production and exchange of compensation elements.
The mentioned downtime reduction may be of particular relevance if the first workpiece is of a first type and the second workpiece is of a second type being different to the first type. In this case it is clear that a compensation element replacement, wherein the first compensation element with a first geometry is replaced by the second compensation element with a second geometry being different to the first geometry, is essential in order to allow for a high quality workpiece processing. However, the downtime reduction may also be achieved if both workpieces are of the same type and a compensation element replacement is necessary due to a wear of the dies of the die processing tool, which wear may have been occurred during the processing of a plurality of first workpieces.
According to a further embodiment of the invention producing the further compensation element comprises an additive manufacturing procedure. This may provide the advantage that a further compensation element with an appropriate thickness distribution can be produced in a fast and effective manner. The additive manufacturing procedure may involve a three-dimensional printing of at least of (further) compensation element.
As has already been mentioned above, with the mentioned additive manufacturing preferably only the local compensation portions are produced and formed on a foil like base sheet. The combination of the base sheet and the local compensation portions formed thereon represents the compensation element.
Descriptive speaking, the local compensation portions each having an appropriate thickness are formed locally on or over certain regions of the base sheet. This may provide the advantage that the three dimensional printing process can be completed in a comparatively fast manner such that the (further) compensation element can be manufactured in a fast, reliable and efficient manner. This contributes to a significant reduction of downtimes of the die processing machine.
It has to be noted that embodiments of the invention have been described with reference to different subject matters. In particular, some embodiments have been described with reference to apparatus type claims whereas other embodiments have been described with reference to method type claims. However, a person skilled in the art will gather from the above and the following description that, unless other notified, in addition to any combination of features belonging to one type of subject matter also any combination between features relating to different subject matters, in particular between features of the apparatus type claims and features of the method type claims is considered as to be disclosed with this document. The aspects defined above and further aspects of the present invention are apparent from the examples of embodiment to be described hereinafter and are explained with reference to the examples of embodiment. The invention will be described in more detail hereinafter with reference to examples of embodiment but to which the invention is not limited.

Brief Description of the Drawing

Figure 1 shows the structure of a die processing machine according to a preferred embodiment of the invention.
Figure 2 illustrates the operation of the die processing machine.
Figure 3 schematically illustrates the production of a further compensation element on the basis of geometric data obtained with a pressure distribution sensor during an operation of the die processing machine.
Figure 4 shows a die processing system comprising the die processing machine and an automatic machining device being mounted to the die processing machine.

Detailed Description

The illustration in the drawing is schematically. It is noted that in different figures, similar or identical elements or features are provided with the same reference signs or with reference signs, which are different from the corresponding reference signs only within the first digit. In order to avoid unnecessary repetitions elements or features which have already been elucidated with respect to a previously described embodiment are not elucidated again at a later position of the description.
Further, spatially relative terms, such as "front" and "back", "above" and "below", "left" and "right", et cetera are used to describe an element's relationship to another element(s) as illustrated in the figures. Thus, the spatially relative terms may apply to orientations in use which differ from the orientation depicted in the figures. Obviously all such spatially relative terms refer to the orientation shown in the figures only for ease of description and are not necessarily limiting as an apparatus according to an embodiment of the invention can assume orientations different than those illustrated in the figures when in use.
Figure 1 shows a die processing machine 100 according to a preferred embodiment of the invention. The die processing machine 100 comprises a chassis 102 and an upper (first) platen 110 stationary attached to the chassis 102. Further, the die processing machine 100 according to the embodiment described here comprises a (second) lower platen 115 and a lifting system 120. As illustrated by the arrow denominated with reference numeral "z", the lifting system 120 is configured for vertically moving the lower platen 115 along the z direction. According to the embodiment described here the lifting system 120 is realized by means of a lever arrangement 122 comprising a not further specified crank mechanism or cam mechanism.
The die processing machine 100 further comprises a die processing tool 130 which, depending on the specific application, is capable of die cutting, creasing, perforating or embossing a workpiece 190. According to the embodiment described here the workpiece is the cardboard 190 being used for a non-depicted package for a consumer article. In order to properly perform its task the die processing tool 130 comprises several dies 132, the back sides of which are embedded within a tool bed 136. The tool bed 136 may be made from wood or a combination of wood and other materials. Further, there are provided several rubber elements 134, which are positioned laterally with respect to the edges of the dies 132 and which, during processing a workpiece 190, are used for keeping the workpiece 190 in a fixed position. An tool frame is used for holding the die processing tool 130 in position. In Figure 1 a bottom plate of this tool frame is denominated with reference numeral 138. The die processing tool 130 may be firmly attached to the bottom plate 138 by means of screwing.
Further, the die processing machine 100 comprises a back plate 140 which, during processing a workpiece, is approached by the edges of the dies 132. At the end of a die cutting procedure the edges of the dies 132 get into mechanical contact with the surface of the back plate 140. Further, according to the embodiment described here an optional support plate 142 is provided between the lower platen 115 and the back plate 140.
In accordance with known processing technology for die cutting, die punching and/or die embossing cardboard material within the tool frame there is provided a compensation element 150. As has already been mentioned above, the compensation element 150 is used for height leveling the edges of the dies 132 such that a uniform processing pattern will develop when processing the workpiece 190. In order to provide for an appropriate level compensation for each die 132 the compensation element 150 comprises different local compensation portions 154 formed on a base sheet 152. The thickness respectively the height of each local compensation portion 154 is assigned to the respective die 132. According to the embodiment described here the compensation element 150 is protected by a protection sheet 158.
The die processing machine 100 further comprises a mechanical action sensor which, in the embodiment described here, is realized by means of a pressure distribution sensor 160. The pressure distribution sensor 160 collects with a spatial resolution the pressure being present between (a) the upper platen 110 and (b) the die processing tool 130 and specifically the back side of the dies 132. It is clear that when there is a uniform pressure distribution the compensation element 150 comprises an optimal geometry. By contrast thereto, when there is a strong pressure variation between the areas being assigned to different dies 132, the compensation element 150 is not or no more appropriate for allowing a high quality processing of the workpiece 190.
The die processing machine 100 furthermore comprises a data processing unit 165 which is connected with the pressure distribution sensor 160 by means of a data line being illustrated in Figure 1 with a dashed line.
Figure 2 illustrates the operation of the die processing machine 100. Electric motors M1 and M2, which are schematically depicted in Figure 2, cooperate with the lever arrangement 122 such that the lower platen 115 is moved upwards along the z direction.
The following description of the operation of the die processing machine 100 starts with a determination of a geometry of a compensation element which solely provides for a die level compensation being related to the respective die processing machine 100 without taking into account the (type of the) respective workpiece 190 to be processed. As a consequence, for determ ining the machine dependent compensation requirements no workpiece is inserted in between the two platens 110 and 115.
The two electric motors M1 and M2 are driven in such a manner that the processing pressure is automatically increased up to an operational point at which the linear increase of the processing pressure turns over to be a super-proportional increase. At this point (the edges of) the dies 132 firstly come into mechanical contact with the back plate 140. The pressure distribution sensor 160, which is firmly attached to or integrated within the upper platen 110, extends over the entire surface (the normal vector of which being parallel to the z-direction) of the upper platen 110. Thereby, in particular the compensation requirement caused by deformations of the two platens 110 and 115 is determined. However, also a potential non-perfect geometry of the die processing tool 130 will be taken into account.
The determined pressure data will be transferred to the data processing device 165. The data processing device 165 will compute appropriate driving signals which, when being applied to the two electric motors M1 and M2, will cause a specific movement of the lower platen 115, which movement will result in the smallest possible compensation requirements. Then, the distance between the upper platen 110 and the lower platen 115 is measured.
Next, the so called local compensation requirements are determined which depend also on the type of workpiece. As a consequence, for determining the local compensation requirements the respective workpiece 190 has to be inserted into the processing region between the die processing tool 130 and the back plate 140. The workpiece 190 is transferred into the processing region by means of a non-depicted handling equipment. It is clear that the workpiece 190 represents an additional mechanical resistance which results (a) in an additional elastic deformation and stretching of the involved components of the die processing machine 100 as well as (b) in an increase of the distance between the two platens 110 and 115. Based on the before determined value for the distance between the two platens 110 and 115 without workpiece 190, now there is determined which distance between the two platens 110 and 115 is necessary for a processing of the workpiece 190 over the entire surface of the workpiece. A possible correction of this distance and a potentially anew requirement for reducing a spatial sub-zone for the compensation requirement is now determined by means of again an appropriate driving of the two motors M1 and M2 such that there is an as much as possible uniform pressure distribution measured by the pressure distribution sensor 160. Now, the pressure distribution sensor 160 measures the actuality present pressure distribution and forwards the corresponding pressure data to the data processing unit 165.
These pressure data are now indicative for an optimal geometric design for the local compensation portions 154 of the compensation element 150 when taking into account the before determined driving of the lower platen 115 in response to the drive signals for the motors M1 and M2, which drive signals have been determined as described above.
Figure 3 schematically illustrates the production of a further compensation element 350 on the basis of geometric data defining the optimal geometric design for the further compensation element 350. According to the embodiment described here an additive manufacturing procedure is used for forming the corresponding further local compensation portions 354 onto a further base sheet 352.
Figure 4 shows a die processing system 4000 comprising the die processing machine 100 and an automatic machining device 470 being mounted to the die processing machine 100. The die processing system 4000 comprises a three-dimensional printer which is schematically depicted by its printer head 472. For realizing the three-dimensional printer 472 any known 3D printing technology can be applied. The printer had 472 comprises a nozzle 473 with which an appropriate material for the (further) local compensation portions 354 is applied onto the further base sheet 352. Within the automatic machining device 470 the printer head 472 can be moved in a controlled manner by means of a non-depicted gantry system.
According to the embodiment described here the further compensation element 350 respectively the further local compensation portions 354 are formed while the further base sheet 352 is supported by the die processing tool 120 respectively by the above described bottom plate 138. This may provide the advantage that it can be ensured very easily that the further local compensation portions 354 are formed exactly at the positions where they are needed for providing for an appropriate level compensation of the blades 132.
Only schematically depicted in Figure 4 is a handling system 480 which is configured for transferring the die processing tool 130 together with the produced further compensation element 350 from the automatic machining device 472 the die processing machine 100. At this point it is mentioned that the handling system 480 might also be able to transfer the die processing tool 130 together with the previously used compensation element 150 from the die processing machine 100 to the automatic machining device 470. Preferably, the handling system 480 or an additional handling system can be used for removing or discharging the previously used compensation element 150. In this way a fully automated production and replacement of compensation elements can be accomplished. This results in a significant reduction of downtimes of the die processing machine 100. A further advantage of this automatization is that it is no more necessary to entrust a skilled operator for performing the manual steps which would be necessary when carrying out such a compensation element replacement manually.
It is pointed out that in accordance with a basic aspect of embodiments of the invention there is a fixed spatial relationship between the die processing machine 100 and the automatic machining device 470. The corresponding mounting of the automatic machining device 417 at the frame 102 of the die processing machine 100 is illustrated in Figure 4 by means of a frame structure 484 of the automatic machining device 470 which is mechanically connected to the chassis 102. Mounted to the frame structure 484 there is a platform 486 for a non-depicted operator who can conveniently access the platform 486 via a stairway 488. The platform 486 and/or the stairway 488 can contribute to a stiffness of the frame structure 484.
It should be noted that the term "comprising" does not exclude other elements or steps and the use of articles "a" or "an" does not exclude a plurality. Also elements described in association with different embodiments may be combined. It should also be noted that reference signs in the claims should not be construed as limiting the scope of the claims.

Claims

A die processing machine (100) for processing a workpiece (190), in particular a flat bed die cutting, die punching and/or die embossing machine for processing cardboard or other sheet like material being used for packages for articles, the die processing machine (100) comprising
a first platen (110);
a second platen (115);
a lifting system (120) for providing a relative movement between the two platens (110, 115) along a predetermined direction (z);
a die processing tool (130) being located in between the two platens (110, 115) and being mechanically connected with the first platen (110), wherein the die processing tool (130) comprises at least two dies (132);
a back plate (140) being mechanically connected with the second platen (115),
wherein a workpiece (190) is insertable in between the back plate (140) and the die processing tool (130);
a compensation element (150) being located in between the first platen (110) and the die processing tool (130) for providing an appropriate leveling of edges of the at least two dies (132) with respect to the predetermined direction (z);
a mechanical action sensor (160) being non-detachably located in between the two platens (110, 115) and being configured for providing mechanical action data signals which are indicative for magnitudes of mechanical actions being assigned to the at least two dies (132) when processing the workpiece (190); and
a data processing unit (165) being configured for processing the mechanical action data signals in such a manner that there are provided geometric data for a further compensation element (350) resulting, when processing further workpieces (190), in an at least partially uniform pressure distribution in processing regions being assigned to the at least two dies (132).
The die processing machine as set forth in the preceding claim, wherein the mechanical action sensor is a pressure distribution sensor (160) being non-detachably located in between the two platens (110, 115) and being configured for providing pressure data signals which are indicative for a spatial pressure distribution given in between the two platens (110, 115).
The die processing machine as set forth in any one of the preceding claims, wherein
the first platen is an upper platen (110) and the second platen is a lower platen (115).
The die processing machine as set forth in any one of the preceding claims, further comprising
a chassis (102),
wherein the first platen (110) is mounted stationary to the chassis (102) and the lifting system (120) is configured for moving solely the second platen (115) along the predetermined direction (z).
The die processing machine as set forth in any one of the preceding claims, wherein
the lifting system (120) is further configured for proving a tilt movement between the two platens (110, 115).
The die processing machine as set forth in any one of the preceding claims, wherein
the lifting system (120) comprises a lever arrangement (122).
The die processing machine as set forth in any one of the preceding claims, wherein
the mechanical action sensor (160) is located in between the first platen (110) and the die processing tool (130).
The die processing machine as set forth in any one of the preceding claims, wherein
the mechanical action sensor (160) is located in between the first platen (110) and the compensation element (150).
A die processing system for processing a workpiece, the die processing system (4000) comprising
a die processing machine (100) as set forth in any one of the preceding claims; and
an automatic machining device (470) for automatically producing the further compensation element (350) based on the provided geometric data for the further compensation element (350);
wherein the automatic machining device (470) is mounted to the die processing machine (100).
The die processing system as set forth in the preceding claim, wherein the automatic machining device (470) is configured for producing the further compensation element (350) by means of an additive manufacturing procedure.
The die processing system as set forth in the preceding claim, wherein the automatic machining device (470) comprises a three-dimensional printer.
The die processing system as set forth in any one of the preceding claims 9 to 11, further comprising
a handling system (480) for transferring a produced further compensation element (350) from the automatic machining device (470) to the die processing machine (100).
The die processing system as set forth in the preceding claim, wherein the handling system (480) is configured for transferring the die processing tool (130) between the die processing machine (100) and the automatic machining device (470).
Method for processing workpieces (190), in particular by flat bed die cutting, die punching and/or die embossing a cardboard or other sheet like material being used for packages for articles, the method comprising
processing a first workpiece (190) by means of the die processing machine (100) as set forth in any one of the preceding claims 1 to 8;
transferring the provided geometric data for the further compensation element (350) to an automatic machining device (470), in particular an automatic machining device as set forth in any one of the preceding claims 9 to 13;
producing the further compensation element (350) based on the provided geometric data;
removing the compensation element (150) which has been used for processing the first workpiece (190) from a processing region of the die processing machine (100);
transferring the produced further compensation element (350) into the processing region; and
processing a second workpiece by means of the die processing machine (100) by utilizing the further compensation element (350).
The method as set forth in the preceding claim, wherein
producing the further compensation element comprises an additive manufacturing procedure.