Punching tool and punching process for honeycomb cardboard sheets

Abstract

A punching tool (10) for punching a sheet of honeycomb cardboard is provided. The punching tool (10) comprises an upper tool (100) comprising a first carrier plate (110) and at least one first cutting line (140) mounted in the first carrier plate (110) for cutting the sheet on its upper side; and a lower tool (200) comprising a second carrier plate (210) and at least one second cutting line (240) mounted in the second carrier plate (210) for cutting the sheet on its underside. Furthermore, a punching machine is provided which is designed to receive the punching tool (10) and selectively move them towards each other in order to cut a sheet of honeycomb cardboard on both sides. The use of the punching tool (10) for cutting a sheet of honeycomb cardboard is also provided.Finally, a method for cutting a sheet of honeycomb cardboard is also provided, which comprises cutting the sheet on the top side to create at least one first cutting line in the sheet, and cutting the sheet on the bottom side to create at least one second cutting line in the sheet, wherein the at least one second cutting line is opposite the at least one first cutting line.

Description

TECHNICAL FIELD

[0001] The present invention relates to a punching tool, in particular a punching tool for punching a sheet of honeycomb cardboard. Furthermore, the invention relates to the use of such a tool for punching a sheet of honeycomb cardboard, as well as to a corresponding punching method and a punching machine. STATE OF THE ART

[0002] Punching tools are known from the prior art that are used in punching machines, such as a flatbed punching machine, to punch blanks or stripped parts from a sheet. Such punching tools comprise a carrier plate (e.g., a wooden plate) in which at least one slot is provided for receiving one or more cutting rules. The cutting rules are preferably made of strip steel and are shaped and arranged in the carrier plate in such a way that they substantially replicate the contour of the blank or stripped part to be punched out. The punching tool can further comprise a counter-punching device, such as a counter-punching plate, which interacts with the cutting rules during the punching process.

[0003] During a punching process, the carrier plate installed in the punching machine is moved with the cutting lines against the counter-punching plate. This allows a sheet positioned between the carrier plate and the counter-punching plate to be cut along the cutting lines. After the punching process, the carrier plate can be moved away from the counter-punching plate. The punched sheet can then be removed, and a new punching cycle can begin.

[0004] For example, corrugated cardboard, which is used in the packaging industry, can be used as a sheet material. Corrugated cardboard consists of at least one smooth and at least one corrugated paper sheet that are glued together. The advantage of corrugated cardboard as a packaging material is that it is recyclable, lightweight, and has good mechanical properties.

[0005] Recently, honeycomb board sheets (often referred to as honeycomb panels) have been increasingly used in the packaging industry. These consist of two cover layers (an upper and a lower cover layer) and at least one honeycomb-shaped core arranged between the two cover layers. Both cover layers and the honeycomb core can each be made of cardboard, making honeycomb board sheets fully recyclable. Due to their honeycomb structure and their greater thickness compared to corrugated board, honeycomb board sheets exhibit excellent mechanical strength while remaining lightweight, making honeycomb board increasingly a preferred alternative to other materials such as Styrofoam.

[0006] Honeycomb cardboard sheets are punched or cut in the same way as corrugated cardboard. This means that the punching tool with cutting rules is moved against a counter-punching plate to punch a honeycomb cardboard sheet positioned between them. The counter-punching plate can be a plate made of a soft material (such as a plastic sheet or a hard rubber sheet), into which the cutting rules can penetrate slightly (1 to 2 mm) to achieve a clean punching result.

[0007] Due to the nature of honeycomb board, particularly its high mechanical strength, significantly higher forces, especially higher lateral forces, occur when punching honeycomb board than, for example, when punching corrugated board. For example, during a punching process, significant lateral forces can act on the cutting lines, causing them to deflect or bend slightly laterally, which can impair the punching result.

[0008] Furthermore, cutting rules for punching honeycomb board have significantly higher line heights to achieve cutting depths that correspond to the thickness of the honeycomb board being punched. Cutting rules with high line heights are particularly susceptible to lateral bending or deflection; in the worst case, such lateral bending can be irreversible, rendering the punching tool unusable.

[0009] JP S52156487 A discloses a punching tool designed for double-sided punching of a composite board consisting of a resin core and two cover layers. Furthermore, JP H11245199 A and JP 3 026 506 U each disclose a punching tool designed for double-sided punching of printed circuit boards. Furthermore, DE 195 13 282 A1 discloses a cutting device with wedge-shaped cutting edges for double-sided cutting of plastic boards.

[0010] The object of the present invention is to provide a punching tool and a punching method suitable for punching sheets of honeycomb cardboard and delivering good punching results. Furthermore, the punching tool and punching method according to the invention are intended to overcome the disadvantages described above, in particular to reduce or distribute the forces acting on the punching lines during punching. BRIEF SUMMARY

[0011] To achieve at least one of the above-mentioned objects, according to a first aspect of the invention, a punching tool for punching a sheet of honeycomb cardboard is provided, the punching tool comprising: an upper tool comprising a first carrier plate and at least one first cutting line mounted in the first carrier plate for cutting the sheet on its upper side;and a lower tool comprising a second carrier plate and at least one second cutting line mounted in the second carrier plate for cutting the sheet on its underside, wherein the upper tool has a first hold-down plate movably mounted on the first carrier plate, and / or wherein the lower tool has a second hold-down plate movably mounted on the second carrier plate, wherein the first hold-down plate and / or the second hold-down plate further has at least one opening through which at least one embossing element arranged on the upper tool and / or on the lower tool can pass during an embossing process.;

[0012] Thus, with the punching tool according to the invention, a sheet can be punched or cut on both opposite sides, with the cutting lines of the upper tool and the lower tool penetrating less deeply into the sheet than the cutting lines of a conventional punching tool with a counter-punching plate. Thus, the forces occurring during cutting and acting on the cutting lines can be reduced, or the forces can be distributed between the cutting lines of the upper and lower tools. In particular, the line height of the cutting lines of the upper tool and the lower tool can be significantly reduced compared to a conventional punching tool with a counter-punching plate, thereby improving the overall stability of the cutting lines against lateral forces.

[0013] In particular, the punching tool according to the invention allows a sheet to be punched or cut simultaneously on both opposite sides. This further accelerates the punching process compared to single-sided punching of honeycomb board, which has a positive effect on the punching cycle time in a punching machine.

[0014] The at least one first cutting line of the first carrier plate can be arranged opposite the at least one second cutting line of the second carrier plate. In particular, the at least one first cutting line and the at least one second cutting line can have the same line shape (contour). Thus, with the help of the at least one first cutting line and the at least one second cutting line, an overall cutting line can be created in the sheet, extending from the top side of the sheet to the bottom side of the sheet.

[0015] According to one variant, the at least one first cutting line can be arranged exactly opposite the at least one second cutting line. In this case, the at least one first cutting line and the opposite at least one second cutting line are arranged identically on the first carrier plate and the second carrier plate. This makes it possible to realize a uniform overall cut in the cutting direction (i.e. in the vertical direction perpendicular to the top and bottom) in the arc. According to an alternative variant, the at least one first cutting line can be arranged on the first carrier plate so as to be horizontally offset from the opposite at least one second cutting line of the second carrier plate. For example, the at least one first cutting line can be arranged so as to be horizontally offset by a predetermined amount from the at least one second cutting line on the first carrier plate. This makes it possible, for example, to realize a shear cut.

[0016] In particular, the at least one first cutting line can be designed and dimensioned in terms of its line height such that, when the sheet is cut on the top side, it creates a first cutting line with a first cutting depth in the sheet. Furthermore, the at least one second cutting line can be designed and dimensioned in terms of its line height such that, when the sheet is cut on the underside, it creates at least one second cutting line with a second cutting depth in the sheet, wherein the first cutting depth and the second cutting depth together result in a total cutting depth that is (slightly) smaller than the thickness of the sheet. The first cutting depth is measured with respect to the top side and the second cutting depth with respect to the underside of the sheet. This configuration of the punching tool orIts first and second cutting lines are particularly advantageous if the at least one first cutting line is arranged exactly opposite the at least one second cutting line; because the slightly smaller overall cutting depth relative to the thickness of the sheet prevents the opposing first and second cutting lines from coming into contact (touching each other) during the cutting process. This allows the cutting lines, in particular the cutting edges of the at least one first cutting line and the at least one second cutting line, to be protected.

[0017] During the cutting process, a thin vertical web can form in the honeycomb cardboard sheet between the at least one first cutting line and the at least one second cutting line. This web can have a predetermined thickness in the vertical direction (i.e., in the cutting direction) such that the web can be easily broken through during a stripping process, resulting in a clean overall cutting line in the vertical direction, formed by the first cutting line and the second cutting line.

[0018] According to one variant, the at least one first cutting line and the at least one second cutting line can have the same line height. In particular, the two cutting lines can be dimensioned in such a way that they cut the sheet, starting from the top and bottom sides, to a cutting depth of approximately 50% of the sheet thickness, leaving only a thin web between the two opposing cutting lines. This allows for particularly uniform cutting on both sides. According to another variant, the at least one first cutting line and the at least one second cutting line can have different line heights.For example, the first cutting line may be configured to cut the sheet from the top side to a first cutting depth of approximately 55%, 60%, 65%, 70%, 75%, or 80% of the sheet thickness, while the second cutting line may be configured to cut the sheet from the bottom side to a second cutting depth of approximately 45%, 40%, 35%, 30%, 25%, or 20% of the sheet thickness, wherein at each of the cutting depths described herein, a thin web may remain between the two opposing cutting lines, as set forth above.

[0019] The punching tool can further comprise a spacer configured to set a predetermined vertical distance (height distance) between the upper tool and the lower tool when the two tools are moved toward each other during a cutting operation. The cutting depth of the at least one first cutting line and / or the at least one second cutting line can also be influenced via the predetermined vertical distance.

[0020] The at least one first cutting rule can be a strip steel rule; the at least one second cutting rule can also be a strip steel rule. An advantage of strip steel rules is that they are cost-effective and can be processed flexibly. In particular, strip steel rules can be bent according to the contour of a blank to be punched out or a stripping area and inserted (clamped) into corresponding (laser-cut) slots in the first carrier plate and second carrier plate. Other cutting rules can also be used instead of strip steel rules.

[0021] The punching tool can further comprise at least one embossing element arranged on the upper tool and / or the lower tool for creating an embossing in the sheet. The embossing can, for example, comprise one or more characters, numbers, special characters, and / or other symbols. The at least one embossing element can, for example, comprise one or more embossing nails arranged on the first carrier plate and / or the second carrier plate in a predetermined area for creating one or more characters, numbers, special characters, and / or other symbols.

[0022] The upper tool has a first hold-down plate movably mounted on the first carrier plate; the first hold-down plate can be arranged upstream of the first carrier plate, and the first hold-down plate can be designed to hold down (fix) the top side of the sheet to be punched during a punching process. Additionally or alternatively, the lower tool has a second hold-down plate movably mounted on the second carrier plate. The second hold-down plate can be arranged upstream of the second carrier plate; the second hold-down plate can be designed to hold down (fix) the bottom side of the sheet to be punched during a punching process. Overall, the sheet to be punched can be held down (fixed) on the top side and bottom side by the first hold-down plate and the second hold-down plate, thereby achieving clean punching results.

[0023] The first hold-down plate can have at least one first slot (through-opening) through which the at least one first cutting line can pass during a punching process to cut the sheet on its upper side. Likewise, the second hold-down plate can have at least one second slot (through-opening) through which the at least one second cutting line can pass during the punching process to cut the sheet on its underside.

[0024] The punching tool can further comprise a first spring device for resiliently mounting the first hold-down plate on the first carrier plate; furthermore, the punching tool can comprise a second spring device for resiliently mounting the second hold-down plate on the second carrier plate. The first spring device and the second spring device can each be designed to exert a first clamping force, adapted (tuned) to the sheet to be punched and / or embossed, on the first hold-down plate (and thus on the top side of the sheet that comes into contact with the first hold-down plate) and a second clamping force on the second hold-down plate (and thus on the bottom side of the sheet that comes into contact with the second hold-down plate).

[0025] In particular, the first spring device can be designed to set a desired first tension force; in the same way, the second spring device can be designed to set a desired second tension force. If, for example, embossing takes place on the top side of the sheet (with the aid of the at least one embossing element described above), a suitable tension force (counteracting the embossing force) can be built up on the opposite underside of the sheet by the second spring device and the second hold-down plate. In the same way, when the sheet is embossed on its underside, a suitable tension force (counteracting the embossing force) can be built up on the top side of the sheet by the first spring device and the first hold-down plate. This makes it possible to achieve clean embossing on the top and / or underside of the sheet.

[0026] According to one implementation, the first spring device can comprise at least one first telescopic spring arrangement with a replaceable first preload spring. Likewise, the second spring device can comprise at least one second telescopic spring arrangement with a replaceable second preload spring. By changing the first preload spring and / or the second preload spring, the tensioning force on the first spring device and / or on the second spring device can be variably adjusted. The at least one first telescopic spring arrangement and / or the at least one second telescopic spring arrangement can be of a type as described in utility model DE 20 2020 100 634, the disclosure of which is hereby incorporated by reference.

[0027] The punching tool can further comprise a first guide device for laterally guiding the at least one first cutting line during the cutting process; furthermore, the punching tool can comprise at least one second guide device for laterally guiding the at least one second cutting line during the cutting process. The at least one first guide device can be formed on the first hold-down plate; in the same way, the at least one second guide device can be formed on the second hold-down plate. As a result, the first and second cutting lines passing through the slots in the first and second hold-down plates can each be guided laterally in an advantageous manner, as a result of which the cutting lines can be stabilized on their opposite line flanks against the action of lateral forces. As a result, bending or lateral deflections of the cutting lines can be prevented or compensated for during the punching process.be reduced to a tolerable level, thus protecting the tool and achieving excellent cutting lines in honeycomb board.

[0028] The lateral guidance of the first cutting line(s) and the second cutting line(s) along the first and second slots of the respective blank holder plates further has the advantage that the lateral relative movement between the blank holder plates and the cutting lines passing through the slots can be reduced to a minimum. In conventional punching tools, there is considerable play between the slots of the blank holder plate and the cutting lines passing through the slots, which can lead to undesired lateral relative movement between the blank holder plate and the cutting lines passing through the blank holder plate.

[0029] According to one implementation, the first guide device can comprise first guide elements formed on opposite sides of the at least one first slot. Likewise, the second guide device can comprise second guide elements formed on opposite sides of the at least one second slot. The first guide elements and the second guide elements can each be formed from a stable, lubricious material. In particular, the first guide elements and the second guide elements can be formed from Teflon.

[0030] The first guide elements and the second guide elements can each be designed in the form of guide lugs (guide nubs) arranged along the first and second slots on the opposite slot flanks. This allows the first and second cutting lines to be securely guided in the longitudinal direction, while the sliding contact between the guide elements and the cutting lines is reduced to a minimum, thus minimizing the sliding friction occurring between the guide elements and the cutting lines.

[0031] According to a further development, the punching tool described above can additionally comprise a first fixing device for fixing the sheet to be punched on the top side; likewise, the punching tool can comprise a second fixing device for fixing the sheet to be punched on the bottom side.

[0032] The first fixing device can comprise first fixing elements which are formed on the first hold-down plate; for example, the first fixing elements can be in the form of small holding nails which are arranged in one or more regions of the first hold-down plate which, during a cutting process, come into contact with one or more (top-side) sheet regions which are later sorted out as sheet waste. In the same way, the second fixing device can comprise second fixing elements which are formed on the second hold-down plate; the second fixing elements can in turn be in the form of small holding nails which are arranged in one or more regions of the second hold-down plate which, during a cutting process, come into contact with one or more (bottom-side) sheet regions which are later sorted out as sheet waste.The second fixing device allows the sheet to be better fixed on both the top and bottom sides when the cutting process is initiated, thus preventing unwanted lateral displacement of the sheet relative to the hold-down devices; this can further improve the punching result.

[0033] According to a second aspect of the invention, a punching machine is provided which is designed to receive the punching tool described above and to selectively move them towards each other in order to cut (punch) a sheet of honeycomb cardboard on both sides.

[0034] For this purpose, the punching machine can have an upper platen for supporting the upper tool and a lower platen for supporting the lower tool. According to one variant, both platens can be vertically movable (i.e., height-adjustable). Alternatively, only the upper platen or the lower platen can be vertically movable (height-adjustable). In both implementation variants, the movable platens of the punching machine move the upper and lower tools toward each other, so that a sheet arranged between the upper and lower tools can be cut on both the top and bottom sides.

[0035] According to a third aspect of the invention, the punching tool described above is used to cut (punch) and emboss a sheet of honeycomb cardboard.

[0036] According to a fourth aspect of the invention, there is provided a method of cutting a sheet of honeycomb board, the method comprising: cutting the sheet at its top surface to create at least one first cut line in the sheet; and cutting the sheet at its bottom surface to create at least one second cut line in the sheet, wherein the at least one second cut line is opposite the at least one first cut line in the sheet.

[0037] In particular, the sheet can be cut on the top and bottom sides such that the at least one first cutting line generated in the sheet is exactly opposite the at least one second cutting line. Alternatively, the sheet can be cut on the top and bottom sides such that the at least one first cutting line generated in the sheet has a horizontal offset (horizontal distance) from the at least one second cutting line. The at least one first cutting line can be offset horizontally from the at least one second cutting line by a predetermined value.

[0038] In particular, the sheet can be cut on the top and bottom sides such that the at least one first cutting line is at a (predetermined) vertical distance from the at least one second cutting line. This creates a web between the at least one first cutting line and the at least one second cutting line in the vertical direction (i.e., in the height or thickness direction of the sheet). This web can be thin so that it can be easily broken through during a subsequent stripping process.

[0039] In particular, the at least one first cutting line generated in the sheet can have a first cutting depth that is approximately 50% of the sheet thickness. Likewise, the at least one second cutting line generated in the sheet can have a second cutting depth that is approximately 50% of the sheet thickness. Thus, the at least one first cutting line and the at least one second cutting line have approximately the same cutting depth.

[0040] Likewise, the first cutting depth may be different from the second cutting depth. For example, the first cutting depth may be approximately 55%, 60%, 65%, 70%, 75%, or 80% of the sheet thickness, while the second cutting depth may be approximately 45%, 40%, 35%, 30%, 25%, or 20% of the sheet thickness; alternatively, the first cutting depth may be approximately 45%, 40%, 35%, 30%, 25%, or 20% of the sheet thickness, while the second cutting depth may be approximately 55%, 60%, 65%, 70%, 75%, or 80% of the sheet thickness.

[0041] In the variants described here with the same or different cutting depths, the total cutting depth produced by the first cutting depth and second cutting depth can be equal to or only slightly smaller than the sheet thickness, wherein the difference between the total cutting depth and the sheet thickness is essentially the thickness of the web formed between the at least one first cutting line and the at least one second cutting line.

[0042] In particular, the sheet can be cut simultaneously on the top and bottom sides. This further accelerates the cutting (punching) of honeycomb cardboard sheets.

[0043] The process described here can be carried out using the punching tool mentioned above. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Further details and advantages of the invention are explained with reference to the following drawings. They show: Fig. 1 is a sectional view of a punching tool according to the present invention; and Fig. 2 is a flow chart illustrating a method for cutting a sheet of honeycomb cardboard according to the invention. DETAILED DESCRIPTION

[0045] Fig. Figure 1 shows a punching tool 10 according to the present invention. The punching tool 10 includes an upper tool 100 and a lower tool 200.

[0046] The upper tool 100 comprises a first carrier plate 110 and at least one first cutting line 140 for cutting a sheet. The at least one first cutting line 140 can be made of strip steel. The at least one first cutting line 140 can simulate the contour or part of the contour of a blank or stripped part to be cut out. Furthermore, the at least one first cutting line 140 can be received in (and clamped in) corresponding first slots 112 of the first carrier plate 110. The first slots 112 can be created by laser cutting at desired locations in the first carrier plate 110. The first carrier plate 110 can be made of wood, Plexiglas, or another material.Preferably, the first carrier plate 110 can be a multiplex plate (for example a veneer plywood plate made of several veneer layers of equal thickness) or a Greenplate® plate (a plate with a core made of wood fiber composite and outer layers made of veneer).

[0047] The upper tool 100 further comprises a first hold-down plate 120. The first hold-down plate 120 is arranged at a distance from the first support plate 110. It is, in particular, resiliently mounted on the first support plate 110. The resilient mounting of the first hold-down plate 120 on the first support plate 110 can be realized by a first spring device 190.

[0048] The first spring device 190 comprises at least one first spring arrangement, which is mounted with its first axial end on the first support plate 110 and with its second axial end on the first hold-down plate 120. The at least one first spring arrangement can be fastened to the first support plate 110 and the opposite first hold-down plate 120 by first fastening elements 194. It is understood that, depending on the horizontal extent (dimensioning) of the first hold-down plate 120, the first spring device has several (two, three, or more) first spring assemblies in order to movably mount the first hold-down plate 120 on the first support plate 110.

[0049] The at least one first spring arrangement 190 can each comprise a first preload spring 192. This preload spring 192 can be replaced via a rear opening 114 of the first support plate 110 and a rear opening of the at least one first spring arrangement 190. A corresponding clamping force can be exerted on the first hold-down plate 120 via the replaceable first preload spring 192.

[0050] The first hold-down plate 120 further comprises at least one first slot (through opening) 122 through which the at least one first cutting line 140 of the upper tool 100 can pass during a cutting operation.

[0051] As in the Fig. 1, the tool 10 can comprise a first guide device 160, which is arranged on or near the at least one first slot 122 of the first hold-down plate 120. The first guide device 160 can have first guide elements 162, which are formed on the opposite sides (flanks) of the at least one first slot 122. These first guide elements 162 can be made of a stable, lubricious material, such as Teflon. In particular, the first guide elements 162 can be formed in the form of guide lugs on the opposite flanks of the at least one first slot 122, along which the at least one first cutting line 140 slides during a cutting process. By guiding the at least one first cutting line 140 with the aid of the first guide elements 162, the first cutting line 140 can be further stabilized in the lateral direction during a punching process.

[0052] The lower tool 200 comprises a second carrier plate 210 and at least one second cutting line 240 for cutting a sheet. The at least one second cutting line 240 can also be made of strip steel. Furthermore, the at least one second cutting line 240 can simulate the contour or part of the contour of a blank or stripped part to be cut out. Furthermore, the at least one second cutting line 240 can be received and clamped in corresponding second slots 212 of the second carrier plate 210. The second slots 212 can be created by laser cutting at desired locations in the second carrier plate 210. The second carrier plate 210 can be made of wood, Plexiglas, or another material.Preferably, the second carrier plate 210 can be a multiplex plate (for example a veneer plywood plate made of several veneer layers of equal thickness) or a Greenplate® plate (a plate with a core made of wood fiber composite and outer layers made of veneer).

[0053] The lower tool 200 further comprises a second hold-down plate 220. The second hold-down plate 220 is arranged at a distance from the second support plate 210. It is, in particular, resiliently mounted on the second support plate 210. The resilient mounting of the second hold-down plate 220 on the second support plate 210 can be realized by a second spring device 290.

[0054] The second spring device 290 comprises at least one second spring arrangement, which is mounted with its first axial end on the second support plate 210 and with its second axial end on the second hold-down plate 220. The at least one second spring arrangement can be fastened to the second support plate 210 and the opposite second hold-down plate 220 by second fastening elements 294. It is understood that, depending on the horizontal extent (dimensioning) of the second hold-down plate 220, the second spring device can have several (two, three, or more) second spring assemblies in order to movably mount the second hold-down plate 220 on the second support plate 210.

[0055] The at least one second spring arrangement 290 can each comprise a second preload spring 292. This preload spring 292 can be replaced via a rear opening 214 of the second support plate 210 and a rear opening of the at least one second spring arrangement 290. A corresponding clamping force can be exerted on the second hold-down plate 220 via the replaceable second preload spring 292.

[0056] The second hold-down plate 220 further comprises at least one second slot (through opening) 222 through which the at least one second cutting line 240 of the lower tool 200 can pass during a cutting operation.

[0057] As in the Fig. 1, the tool 10 may further comprise a second guide device 260 arranged on or near the at least one second slot 222 of the second hold-down plate 220. The second guide device 260 may have second guide elements 262 formed on the opposite sides (flanks) of the at least one second slot 222. These second guide elements 262 may be made of a stable, lubricious material, such as Teflon. In particular, the second guide elements 262 may be formed in the form of guide lugs on the opposite flanks of the at least one second slot 222, along which the at least one second cutting line 240 slides during a cutting operation.By guiding the at least one second cutting line 240 with the aid of the second guide elements 262, the second cutting line 240 can be further stabilized in the lateral direction during a cutting process.

[0058] As further shown in the Fig. 1, the at least one first cutting line 140 of the upper tool 100 and the at least one second cutting line 240 of the lower tool 200 are arranged opposite one another. Thus, an arc arranged between the two tools 100, 200 (in Fig. 1 not shown; the sheet is positioned between the first hold-down plate 120 and the second hold-down plate 220) can be cut or punched simultaneously on its top and bottom sides.

[0059] Preferably, the line heights of the at least one first cutting line 140 and the at least one second cutting line 240 are dimensioned such that they can (completely) cut a sheet of honeycomb cardboard with a predetermined thickness. The line heights of the at least one first cutting line 140 and the at least one second cutting line 240 can be the same or different from one another. Overall, the line heights of the first and second cutting lines 140 and 240 can be coordinated such that the first and second cutting lines generated by the cutting lines 140 and 240 have first and second cutting depths, which together result in a total cutting depth that is the same as or only slightly smaller than the thickness of the sheet to be cut. Thus, the sheet can be cut essentially completely with the tool described here.

[0060] This in connection with the Fig. The tool 10 described in Figure 1 is intended for installation in a punching machine (punching station) (in Fig. 1 (not shown). The punching machine can have an upper press platen for receiving the upper tool 100 and a lower press platen for receiving the lower tool 200. At least one of the two press plates is designed to be movable in the vertical direction (height direction); as a result, the received tools 100, 200 can be moved towards one another during a cutting process in order to cut the sheet arranged between the two tools 100 and 200 from below and above, and then moved away from one another again to release the cut (punched) sheet.

[0061] In connection with the Fig. 2, a method for cutting a sheet of honeycomb cardboard is further described. The method can be used in conjunction with Fig. 1 described tool 10.

[0062] The sheet to be cut is positioned between the upper tool 100 and the lower tool 200. The two tools 100, 200 are then moved toward each other (for example, using the punching machine described above) so that the first hold-down plate 120 comes into contact with the top side of the sheet and the second hold-down plate 220 comes into contact with the bottom side of the sheet. The sheet is held down or fixed with the help of the first hold-down plate 120 and the second hold-down plate 220. For fixing, the first hold-down plate 120 and / or second hold-down plate 220 can have additional fixing elements, such as holding nails, which penetrate into the top and bottom of the sheet in predetermined areas of the sheet (preferably in areas that are not used later and are sorted out as waste), thus further stabilizing the sheet against lateral displacement.

[0063] The two tools 100, 200 are moved further toward each other, whereby the first spring device 190 in the upper tool 100 and the second spring device 290 in the lower tool 200 are compressed. As a result, the at least one first cutting line 140 is moved through the at least one first slot 122 of the first hold-down plate 120 and subsequently penetrates the sheet at the top side, whereby the sheet is cut at its top side (step S10 in Fig. 2). Likewise, the at least one second cutting line 240 is moved through the at least one second slot 222 of the second carrier plate 210 and then penetrates into the sheet at the bottom, whereby the sheet is cut at its bottom (step S20 in Fig. 2).

[0064] The two tools 100, 200 are moved toward each other up to a predetermined height distance. The cutting depth of the first cutting line generated by the at least one first cutting line 140 and the cutting depth of the second cutting line generated by the at least one second cutting line 240 depend on the dimensions of the two cutting lines 140, 240, in particular on the line height of the first and second cutting lines 140, 240.

[0065] In connection with Fig. In the tool 10 shown in Figure 1, the at least one first cutting line 140 and the at least one second cutting line 240 have the same line height; the line height can be selected such that they produce first cutting lines and second cutting lines in a sheet of honeycomb cardboard with a predetermined thickness, each having a cutting depth of approximately 50% of the thickness of the sheet.

[0066] As already described above in connection with the tool 10, in other embodiments of the tool 10, the line heights of the at least one first cutting line 140 and the at least one second cutting line 240 can also be different, so that the generated first and second cutting lines have different cutting depths. Preferably, the cutting lines 140, 240 are dimensioned such that they can generate first and second cutting depths that add up to a total cutting depth that is equal to or only slightly smaller than the sheet thickness.

[0067] Using the technique described here of cutting (punching) sheets on the top and bottom, even thick sheets of honeycomb board can be cut quickly and cleanly. The cutting lines assigned to the upper and lower tools are preferably arranged exactly opposite one another; this creates a clean overall cut that is barely distinguishable from a one-sided cut. In particular, the first and second cutting lines can be dimensioned and coordinated in the vertical direction such that the opposite first and second cutting lines do not touch during the cutting process. Rather, a small vertical web can form between the two cutting lines or the cutting lines in the sheet, which can, however, be easily severed in a subsequent stripping process.Furthermore, guide devices on or near the slots of the first and second hold-down plates can further stabilize the cutting lines passing through the slots during the cutting process. Overall, the double-sided cutting described here allows the forces occurring during a cutting process to be better distributed across the cutting lines of both tools, reducing tool wear and achieving better cutting results.

Claims

[1] Punching tool (10) for punching a sheet of honeycomb cardboard, comprising: an upper tool (100) comprising a first support plate (110) and at least one first cutting line (140) mounted in the first support plate (110) for cutting the sheet on its upper side; and a lower tool (200) comprising a second support plate (210) and at least one second cutting line (240) mounted in the second support plate (210) for cutting the sheet on its underside, wherein the upper tool (100) has a first hold-down plate (120) movably mounted on the first carrier plate (100), and / or wherein the lower tool (100) has a second hold-down plate (220) movably mounted on the second carrier plate (210), wherein the first hold-down plate (120) and / or the second hold-down plate (220) further comprises at least one opening through which at least one embossing element arranged on the upper tool (100) and / or on the lower tool (200) can pass during an embossing process. [2] Punching tool (10) according to claim 1, wherein the at least one first cutting line (140) on the first carrier plate (110) and the at least one second cutting line (240) on the second carrier plate (210) are arranged such that when cutting a sheet arranged between the upper tool (100) and the lower tool (200), the at least one first cutting line (140) is opposite the at least one second cutting line (240). [3] Punching tool (10) according to claim 1 or 2, wherein the at least one first cutting line (140) and the at least one second cutting line (240) are configured to cut the sheet at the top and bottom without coming into contact with each other. [4] Punching tool (10) according to one of claims 1 to 3, wherein the at least one first cutting line (140) and the at least one second cutting line (240) are dimensioned such that when cutting a sheet, a vertical web of predetermined thickness remains between the at least one first cutting line (140) and the at least one second cutting line (240) in the cut sheet. [5] Punching tool (10) according to one of claims 1 to 3, wherein the at least one first cutting line (140) produces at least one first cutting line with a first cutting depth in the sheet, and the at least one second cutting line (240) produces at least one second cutting line with a second cutting depth in the sheet, wherein the first cutting depth and the second cutting depth result in a total cutting depth that is less than the thickness of the sheet. [6] Punching tool (10) according to claim 5, wherein the at least one first cutting line and the at least one second cutting line are dimensioned such that the generated first cutting depth is equal to the second cutting depth, or the first cutting depth is not equal to the second cutting depth. [7] Punching tool (10) according to one of claims 1 to 6, further comprising a spacer configured to set a predetermined vertical distance between the upper tool (100) and the lower tool (200). [8] Punching tool (10) according to one of claims 1 to 7, wherein the at least one first cutting line (140) is a strip steel line, and / or wherein the at least one second cutting line (240) is a strip steel line. [9] Punching tool (10) according to one of claims 1 to 8, further comprising at least one embossing element arranged on the upper tool (100) and / or on the lower tool (200). [10] Punching tool (10) according to one of claims 1 to 9, wherein the first hold-down plate (120) has at least one first slot (122) through which the at least one first cutting line (140) can pass during the cutting process, and / or wherein the second hold-down plate (220) has at least one second slot (222) through which the at least one second cutting line (240) can pass during the cutting process. [11] Punching tool (10) according to one of claims 1 to 10, further comprising: a first spring device (190) for resiliently mounting the first hold-down plate (120) on the first carrier plate (110); and / or a second spring device (290) for resiliently mounting the second hold-down plate (220) on the second carrier plate (210). [12] Punching tool (10) according to claim 11, wherein the first spring device (190) comprises at least one first telescopic spring arrangement with a replaceable preload spring (192), and / or wherein the second spring device (290) comprises at least one second telescopic spring arrangement (292) with a replaceable preload spring. [13] Punching tool (10) according to one of claims 1 to 12, further comprising: a first guide device (160) for laterally guiding the at least one first cutting line (140) during the cutting process; and / or a second guide device (260) for laterally guiding the at least one second cutting line (240) during the cutting process. [14] Punching tool (10) according to claim 13, wherein the first guide device (160) is formed on the first hold-down plate (120), and / or wherein the second guide device (260) is formed on the second hold-down plate (220). [15] Punching tool (10) according to claim 14, wherein the first guide device (160) comprises first guide elements (162) formed on opposite sides of the at least one first slot (122) of the first hold-down plate (120), and / or wherein the second guide device (260) comprises second guide elements (262) formed on opposite sides of the at least one second slot (222) of the second hold-down plate (220). [16] Punching tool (10) according to one of claims 1 to 15, further comprising: a first fixing device for fixing the sheet to be punched on the top; and / or a second fixing device for fixing the underside of the sheet to be punched. [17] Punching tool (10) according to claim 16, wherein the first fixing device comprises first fixing elements formed on a first hold-down plate (120), and / or wherein the second fixing device comprises second fixing elements formed on a second hold-down plate (220). [18] Punching machine designed to receive a punching tool (10) according to any one of claims 1 to 17 and to selectively move them towards each other in order to cut a sheet of honeycomb cardboard on both sides. [19] Use of the punching tool (10) according to one of claims 1 to 17 for cutting and embossing a sheet of honeycomb cardboard. [20] A method of cutting a sheet of honeycomb cardboard, the method comprising: Cutting the sheet at the top to create at least a first cutting line in the sheet; and Cutting the sheet at the bottom to create at least one second cutting line in the sheet, wherein the at least one second cutting line is opposite the at least one first cutting line. [21] The method of claim 20, wherein the first cutting line has a predetermined vertical distance from the second cutting line. [22] A method according to claim 20 or claim 21, wherein the sheet is punched simultaneously on the top and bottom sides. [23] Method according to one of claims 20 to 22, wherein the method is carried out by means of the punching tool according to claims 1 to 17.

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