Punching tool and punching method for honeycomb board sheets

Abstract

A die-cutting tool (10) for die-cutting a sheet of honeycomb board is provided. The die-cutting tool (10) comprises an upper tool (100) including 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. Furthermore, a die-cutting machine is provided, configured to receive the die-cutting tool (10) and selectively move the two parts towards each other to cut a sheet of honeycomb board on both sides. The use of the die-cutting tool (10) for cutting a sheet of honeycomb board is also provided.Finally, a method for cutting a sheet of honeycomb cardboard is also provided, comprising cutting the sheet on the top side to produce at least one first cutting line in the sheet and cutting the sheet on the bottom side to produce 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 AREA

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

[0002] Punching tools are known from the prior art for use in punching machines, such as flatbed punching machines, to punch blanks or strips from a sheet. Such punching tools comprise a carrier plate (for example, a wooden plate) in which at least one slot is provided for receiving one or more cutting lines. The cutting lines preferably consist of strip steel and are shaped and arranged in the carrier plate such that they essentially replicate the contour of the blank or strip 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 lines during the punching process.

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

[0004] Corrugated cardboard, commonly 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 layer glued together. The advantages of corrugated cardboard as a packaging material are its recyclability, light weight, and good mechanical properties.

[0005] More recently, honeycomb cardboard sheets (often also called honeycomb panels) have been increasingly used in the packaging industry. These consist of two outer layers (an upper and a lower layer) and at least one honeycomb-shaped core sandwiched between them. Both outer layers and the honeycomb core can each be made of cardboard, making honeycomb cardboard sheets fully recyclable. Due to their honeycomb structure and greater thickness compared to corrugated cardboard, honeycomb cardboard sheets offer excellent mechanical strength at a low weight, which is why they are increasingly replacing other materials such as polystyrene.

[0006] Sheets of honeycomb cardboard are die-cut or cut in the same way as corrugated cardboard. This means that the die-cutting tool with cutting lines is moved against a counter-die to cut a sheet of honeycomb cardboard placed between them. The counter-die can be made of a soft material (for example, a plastic sheet or a hard rubber sheet) into which the cutting lines can penetrate slightly (1 to 2 mm) to achieve a clean die-cut.

[0007] Due to the properties of honeycomb board, particularly its high mechanical strength, significantly higher forces, especially higher lateral forces, occur during die-cutting than, for example, during die-cutting of corrugated board. For instance, considerable lateral forces can act on the cutting lines during a die-cutting process, slightly deflecting or bending them laterally, which can impair the die-cutting result.

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

[0009] It is therefore an object of the present invention to provide a die-cutting tool and a die-cutting method suitable for die-cutting sheets from honeycomb cardboard and which delivers good die-cutting results. Furthermore, the die-cutting tool and die-cutting method according to the invention should overcome the disadvantages described above, in particular reducing or distributing the forces acting on the die-cutting lines during die-cutting. BRIEF SUMMARY

[0010] To solve at least one of the above-mentioned problems, according to a first aspect of the invention, a punching tool for punching a sheet of honeycomb cardboard is provided, wherein the punching tool comprises: an upper tool comprising a first support plate and at least one first cutting line mounted in the first support plate for cutting the sheet on its upper side; and a lower tool comprising a second support plate and at least one second cutting line mounted in the second support plate for cutting the sheet on its underside.

[0011] 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 and lower tools penetrating less deeply into the sheet compared to the cutting lines of a conventional punching tool with a counter-die plate; consequently, the forces occurring during cutting and acting on the cutting lines can be reduced or distributed between the cutting lines of the upper and lower tools. In particular, the line height of the cutting lines of the upper and lower tools can be significantly reduced compared to a conventional punching tool with a counter-die plate, thereby improving the overall stability of the cutting lines against lateral forces.

[0012] In particular, the die-cutting tool according to the invention allows a sheet to be die-cut or cut simultaneously on both opposite sides. This further accelerates the die-cutting process compared to single-sided die-cutting of honeycomb board, which has a positive effect on the die-cutting cycle time in a die-cutting machine.

[0013] The at least one first cutting line of the first support plate can be arranged opposite the at least one second cutting line of the second support 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, a total cutting line can be generated in the arc that extends from the top of the arc to the bottom of the arc.

[0014] According to one variant, at least one first cutting line can be arranged directly opposite 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 and second support plates. This allows for a uniform overall cut in the arc, in the cutting direction (i.e., vertically perpendicular to the top and bottom surfaces). According to an alternative variant, the at least one first cutting line can be arranged on the first support plate horizontally offset from the opposite at least one second cutting line on the second support plate. For example, the at least one first cutting line can be arranged horizontally offset by a predetermined amount from the at least one second cutting line on the first support plate. This allows, for example, a shear cut to be achieved.

[0015] In particular, the at least one first cutting line can be designed and dimensioned in its line height such that, when cutting the sheet on its upper side, it produces 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 its line height such that, when cutting the sheet on its underside, it produces at least a 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) less than the thickness of the sheet. The first cutting depth is measured with respect to the upper side and the second cutting depth with respect to the underside of the sheet. This design of the die-cutting tool, or...The arrangement of its first and second cutting lines is particularly advantageous when the at least one first cutting line is arranged exactly opposite the at least one second cutting line; because the overall cutting depth, which is somewhat smaller in relation to the thickness of the sheet, prevents the opposing first and second cutting lines from coming into contact (touching) during the cutting process. This protects the cutting lines, especially the cutting edges of the at least one first cutting line and the at least one second cutting line.

[0016] Between the at least one first cutting line and the at least one second cutting line, a thin vertical rib can form in the honeycomb cardboard sheet during the cutting process. This rib can have a predetermined thickness in the vertical direction (i.e., in the cutting direction) such that the rib can be easily broken through during a stripping process, resulting in a clean overall cut line in the vertical direction formed by the first and second cutting lines.

[0017] 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 their line heights such that they cut the sheet from the top and bottom 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 designed 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 designed 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, with a thin web remaining between the two opposing cutting lines at each of the cutting depths described here, as explained above.

[0018] According to further training, at least one first cutting line and / or at least one second cutting line can be serrated. In particular, the serrated cutting line(s) can have a triangular or other tooth profile. The serrated cutting lines do not touch in the honeycomb cardboard due to the grinding of the lines (lowest point(s) in the tooth profile) in the range of 0.5 mm to 12.0 mm and the distance of 0.5 mm to 10.0 mm between the upper tooth tips.

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

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

[0021] The die-cutting tool can further comprise at least one embossing element arranged on the upper tool and / or the lower tool for producing 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 producing one or more characters, numbers, special characters, and / or other symbols.

[0022] The upper tool may further include a first hold-down plate movably mounted on the first support plate; the first hold-down plate may be positioned upstream of the first support plate, and the first hold-down plate may be designed to hold (fix) the sheet to be punched down at its top during a punching operation. Similarly, the lower tool may include a second hold-down plate movably mounted on the second support plate. The second hold-down plate may be positioned upstream of the second support plate; the second hold-down plate may be designed to hold (fix) the sheet to be punched down at its underside during a punching operation. Overall, the sheet to be punched can be held (fixed) down at its top and bottom by the first and second hold-down plates, thus 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 operation to cut the sheet on its top 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 operation to cut the sheet on its underside.

[0024] If the die-cutting tool has at least one embossing element (for example, at least one embossing nail) for embossing a symbol, character or number, the first hold-down plate and / or the second hold-down plate may further have at least one opening through which at least one embossing element arranged on the upper tool (on the first support plate) and / or on the lower tool (on the second support plate) can pass during an embossing operation.

[0025] The die-cutting tool may further comprise a first spring assembly for the resilient mounting of the first blanking plate on the first support plate; furthermore, the die-cutting tool may comprise a second spring assembly for the resilient mounting of the second blanking plate on the second support plate. The first spring assembly and the second spring assembly may each be configured to exert a first clamping force, adapted (tuned) to the sheet to be die-cut and / or embossed, on the first blanking plate (and thus on the upper surface of the sheet coming into contact with the first blanking plate) and a second clamping force on the second blanking plate (and thus on the lower surface of the sheet coming into contact with the second blanking plate).

[0026] In particular, the first spring assembly can be designed to set a desired first tension force; likewise, the second spring assembly can be designed to set a desired second tension force. For example, if an embossing is performed on the top side of the sheet (using the at least one embossing element described above), a suitable tension force (counteracting the embossing force) can be generated on the opposite underside of the sheet by the second spring assembly and the second hold-down plate. Similarly, if the sheet is embossed on its underside, a suitable tension force (counteracting the embossing force) can be generated on the top side of the sheet by the first spring assembly and the first hold-down plate. This allows for clean embossing on the top and / or underside of the sheet.

[0027] According to one implementation, the first spring assembly can comprise at least one first telescopic spring assembly with a replaceable first preload spring. Similarly, the second spring assembly can comprise at least one second telescopic spring assembly with a replaceable second preload spring. By replacing the first preload spring and / or the second preload spring, the tension force on the first spring assembly and / or the second spring assembly can be variably adjusted. The at least one first telescopic spring assembly and / or the at least one second telescopic spring assembly can be of a type as described in utility model DE 20 2020 100 634, the disclosure of which is hereby included.

[0028] 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 a 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; likewise, the at least one second guide device can be formed on the second hold-down plate. This advantageously allows the first and second cutting lines passing through the slots of the first and second hold-down plates to be guided laterally, thereby stabilizing the cutting lines against the action of lateral forces on their opposite flanks. This prevents bending or lateral deflection of the cutting lines during the punching process.reduced to a tolerable level, thus protecting the tool and achieving excellent cutting lines in honeycomb cardboard.

[0029] The lateral guidance of the first and second cutting lines at the first and second slots of the respective hold-down plates has the further advantage that the lateral relative movement between the hold-down plates and the cutting lines passing through the slots can be reduced to a minimum. With conventional punching tools, there is considerable play between the slots of the hold-down plate and the cutting lines passing through the slots, which can lead to undesirable lateral relative movements between the hold-down plate and the cutting lines passing through it.

[0030] According to one implementation, the first guide device can comprise first guide elements formed on opposite sides of the at least one first slot. Similarly, the second guide device can comprise second guide elements formed on opposite sides of the at least one second slot. The first and second guide elements can each be formed from a stable, low-friction material. In particular, the first and second guide elements can be made of Teflon.

[0031] The first and second guide elements can each be designed as guide lugs (guide studs) arranged along the first and second slots on the opposite slot flanks. This ensures reliable longitudinal guidance of the first and second cutting lines, minimizing the sliding contact between the guide elements and the cutting lines and thus reducing the sliding friction occurring between them.

[0032] Additionally or alternatively, the punching tool can also include a centering unit for centering the opposing tools (and thus the opposing cutting lines) relative to each other; the centering unit can be implemented in the form of at least one centering mandrel and at least one centering sleeve cooperating with the at least one centering mandrel. The centering mandrel and centering sleeve can be permanently or temporarily (for example, during the setup process) mounted on the punching tool (for example, on the upper and lower punching tools).

[0033] According to a further development, the punching tool described above can additionally include a first fixing device for fixing the sheet to be punched on the top side; likewise, the punching tool can include a second fixing device for fixing the sheet to be punched on the underside.

[0034] The first fixing device can comprise first fixing elements formed on the first hold-down plate; for example, the first fixing elements can be in the form of small retaining nails arranged in one or more areas of the first hold-down plate that come into contact with one or more (top) sheet sections during a cutting operation, which are later sorted out as sheet waste. Similarly, the second fixing device can comprise second fixing elements formed on the second hold-down plate; the second fixing elements can again be in the form of small retaining nails arranged in one or more areas of the second hold-down plate that come into contact with one or more (bottom) sheet sections during a cutting operation, which are later sorted out as sheet waste. Through the described first and second fixing devices, the first and second fixing elements can be formed in the first and second fixing devices.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-downs; this further improves the die-cutting result.

[0035] According to a second aspect of the invention, a die-cutting machine is provided which is designed to receive the die-cutting tool described above and to selectively move them towards each other in order to cut (die-cut) a sheet of honeycomb cardboard on both sides. For this purpose, the die-cutting machine can have an upper platen for supporting the upper tool and a lower platen for supporting the lower tool. According to one embodiment, both plates can be movable (i.e., height-adjustable) in the vertical direction. Alternatively, only the upper platen or the lower platen can be movable (height-adjustable) in the vertical direction; in both embodiments, the movable plates of the die-cutting machine move the upper and lower tools towards each other, so that a sheet arranged between the upper and lower tools can be cut on both sides.

[0036] According to a third aspect of the invention, the above-described punching tool is used to cut (punch) a sheet of honeycomb cardboard.

[0037] According to a fourth aspect of the invention, a method for cutting a sheet of honeycomb cardboard is provided, the method comprising: cutting the sheet on its top side to produce at least one first cutting line in the sheet; and cutting the sheet on its bottom side to produce 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 in the sheet.

[0038] In particular, the arc can be cut on the top and bottom such that the at least one first cutting line produced in the arc is exactly opposite the at least one second cutting line. Alternatively, the arc can be cut on the top and bottom such that the at least one first cutting line produced in the arc 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.

[0039] In particular, the sheet can be cut on the top and bottom surfaces such that the at least one first cutting line has a (predefined) vertical distance to the at least one second cutting line. This allows a web to form in the vertical direction (i.e., in the height or thickness direction of the sheet) between the at least one first cutting line and the at least one second cutting line. This web can be thin enough to be easily broken through in a subsequent stripping process.

[0040] In particular, the at least one first cutting line produced in the arc can have a first cutting depth that is approximately 50% of the arc thickness. Likewise, the at least one second cutting line produced in the arc can have a second cutting depth that is approximately 50% of the arc thickness. Thus, the at least one first cutting line and the at least one second cutting line have approximately the same cutting depth.

[0041] Similarly, the first cutting depth can differ from the second cutting depth. For example, the first cutting depth can be approximately 55%, 60%, 65%, 70%, 75%, or 80% of the sheet thickness, while the second cutting depth is approximately 45%, 40%, 35%, 30%, 25%, or 20% of the sheet thickness; alternatively, the first cutting depth can be approximately 45%, 40%, 35%, 30%, 25%, or 20% of the sheet thickness, while the second cutting depth is approximately 55%, 60%, 65%, 70%, 75%, or 80% of the sheet thickness.

[0042] In the variants of equal or different cutting depths described here, the total cutting depth produced by the first cutting depth and second cutting depth can be equal to or only slightly smaller than the arc thickness, wherein the difference between the total cutting depth and the arc 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.

[0043] In particular, the sheet can be cut simultaneously on the top and bottom. This further speeds up the cutting (punching) of sheets made from honeycomb cardboard.

[0044] The procedure described here can be carried out using the aforementioned stamping tool. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Further details and advantages of the invention are explained with reference to the following drawings. They show: Figure 1 is a sectional view of a die-cutting tool according to the present invention; and Figure 2 is a flowchart illustrating a method according to the invention for cutting a sheet of honeycomb cardboard. DETAILED DESCRIPTION

[0046] Figure 1 Figure 1 shows a stamping tool 10 according to the present invention. The stamping tool 10 comprises an upper tool 100 and a lower tool 200.

[0047] The upper tool 100 comprises a first support plate 110 and at least one first cutting line 140 for cutting an arc. The at least one first cutting line 140 can be made of strip steel. The at least one first cutting line 140 can replicate the contour or part of the contour of a blank or strip to be cut out. Furthermore, the at least one first cutting line 140 can be received (and clamped) in corresponding first slots 112 of the first support plate 110. The first slots 112 can be laser-cut at desired locations in the first support plate 110. The first support plate 110 can be made of wood, plexiglass, or another material.Preferably the first support panel 110 can be a multiplex panel (for example, a veneer plywood panel made of several layers of veneer of equal thickness) or a Greenplate ® panel (a panel with a core made of wood fiber composite and outer layers made of veneer).

[0048] 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 implemented by a first spring device 190.

[0049] The first spring assembly 190 comprises at least one first spring arrangement, which is mounted at its first axial end on the first support plate 110 and at 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 opposing 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 assembly has several (two, three, or more) first spring arrangements to movably mount the first hold-down plate 120 on the first support plate 110.

[0050] The at least one first spring assembly 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 assembly 190. A corresponding clamping force can be exerted on the first hold-down plate 120 via the replaceable first preload spring 192.

[0051] 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.

[0052] As in the Figure 1As can be further seen, 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 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, low-friction material, such as Teflon. In particular, the first guide elements 162 can be formed as 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 operation. 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 operation.

[0053] The lower tool 200 comprises a second support plate 210 and at least one second cutting line 240 for cutting an arc. 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 replicate the contour or part of the contour of a blank or strip to be cut out. The at least one second cutting line 240 can also be received and clamped in corresponding second slots 212 of the second support plate 210. The second slots 212 can be laser-cut at desired locations in the second support plate 210. The second support plate 210 can be made of wood, plexiglass, or another material.Preferably the second support plate 210 can be a multiplex plate (for example, a veneer plywood plate made of several layers of veneer of equal thickness) or a Greenplate ®< plate (a plate with a core made of wood fiber composite and outer layers made of veneer).

[0054] The lower tool 200 further comprises a second hold-down plate 220. The second hold-down plate 220 is spaced apart 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 achieved by a second spring assembly 290.

[0055] The second spring assembly 290 comprises at least one second spring arrangement, which is mounted at its first axial end on the second support plate 210 and at 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 opposing second hold-down plate 220 by means of second fastening elements 294. It is understood that, depending on the horizontal extent (dimensioning) of the second hold-down plate 220, the second spring assembly can have several (two, three, or more) second spring arrangements in order to movably mount the second hold-down plate 220 on the second support plate 210.

[0056] The at least one second spring assembly 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 as well as a rear opening of the at least one second spring assembly 290. A corresponding clamping force can be exerted on the second hold-down plate 220 via the replaceable second preload spring 292.

[0057] The second hold-down plate 220 further comprises at least a 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.

[0058] As in the Figure 1As further illustrated, the tool 10 can also comprise a second guide device 260, which is arranged on or near the at least one second slot 222 of the second hold-down plate 220. The second guide device 260 can have second guide elements 262 formed on the opposite sides (flanks) of the at least one second slot 222. These second guide elements 262 can be made of a stable, low-friction material, such as Teflon. In particular, the second guide elements 262 can be formed as 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 at least one second cutting line 240 with the help of the second guide elements 262, the second cutting line 240 can be further stabilized in a lateral direction during a cutting process.

[0059] As furthermore from the Figure 1 As can be seen, at least one first cutting line 140 of the upper tool 100 and at least one second cutting line 240 of the lower tool 200 are arranged opposite each other. Thus, an arc arranged between the two tools 100, 200 (in Figure 1 (not shown; the sheet is positioned between the first hold-down plate 120 and the second hold-down plate 220) and is cut or punched simultaneously on its top and bottom.

[0060] 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 of 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 each other. 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 produced by the cutting lines 140 and 240 have first and second cutting depths that together result in a total cutting depth that is equal to or only slightly less than the thickness of the sheet to be cut. Thus, the sheet can be cut essentially completely with the tool described here.

[0061] This in connection with the Figure 1The described tool 10 is intended for installation in a punching machine (punching station) (in Figure 1 (not shown). The punching machine can have an upper press platen for holding the upper tool 100 and a lower press platen for holding the lower tool 200. At least one of the two press plates is movable in the vertical direction (height direction); this allows the held tools 100 and 200 to be moved towards each other during a cutting operation in order to cut the sheet arranged between the two tools 100 and 200 from above and below, and then to be moved away from each other again to release the cut (punched) sheet.

[0062] In connection with the Figure 2 A method for cutting a sheet from honeycomb cardboard is described in more detail. This method can be compared to the one associated with Figure 1 The described tool 10 will be used.

[0063] The sheet to be cut is positioned between the upper tool 100 and the lower tool 200. The two tools 100 and 200 are then moved towards each other (for example, using the punching machine described above) so that the first hold-down plate 120 is in contact with the top of the sheet and the second hold-down plate 220 with the underside. The sheet is held down and fixed by the first and second hold-down plates 120 and 220. For fixation, the first and / or second hold-down plate 220 can have additional fixing elements, such as retaining nails, which penetrate the top and bottom of the sheet in predetermined areas (preferably areas that will not be used later and will be sorted out as waste), thus further stabilizing the sheet against lateral displacement.

[0064] The two tools 100 and 200 are moved further towards each other, compressing the first spring assembly 190 in the upper tool 100 and the second spring assembly 290 in the lower tool 200. This moves the at least one first cutting line 140 through the at least one first slot 122 of the first hold-down plate 120 and then penetrates the top surface of the sheet, cutting the sheet on its top surface (step S10 in Figure 2 ). Similarly, at least one second cutting line 240 is moved through at least one second slot 222 of the second support plate 210 and then penetrates the underside of the sheet, cutting the sheet on its underside (step S20 in Figure 2 ).

[0065] The two tools 100, 200 are moved towards each other to a predetermined height difference. The cutting depth of the first cutting line produced by the at least one first cutting line 140 and the cutting depth of the second cutting line produced 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.

[0066] In connection with Figure 1 The tool 10 shown has at least one first cutting line 140 and at least one second cutting line 240 having the same line height; the line height can be chosen such that they produce first cutting lines and second cutting lines in a sheet of honeycomb cardboard of a given thickness, each having a cutting depth of approximately 50% of the thickness of the sheet.

[0067] As already described above in connection with tool 10, in other embodiments of 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 insignificantly less than the arc thickness.

[0068] The technique described here, involving top and bottom cutting (punching) of sheets, allows even thick sheets of honeycomb cardboard to be cut quickly and cleanly. The cutting lines assigned to the upper and lower tools are preferably arranged directly opposite each other; this results in a clean overall cut that is virtually indistinguishable from a single-sided cut. In particular, the first and second cutting lines can be dimensioned and aligned vertically in such a way that they do not touch during the cutting process. Instead, a small vertical ridge can form between the two cutting lines, or between the cutting lines in the sheet, which can then be easily cut through 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 operation to be better distributed across the cutting lines of the two tools, resulting in less tool wear and improved 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.

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 an arc 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 on the top and bottom sides without coming into contact with each other and / or 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.

4. 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 arc, and the at least one second cutting line (240) produces at least one second cutting line with a second cutting depth in the arc, wherein the first cutting depth and the second cutting depth result in a total cutting depth that is less than the thickness of the arc, and, optionally, wherein the at least one first cutting line and the at least one second cutting line are dimensioned such that the first cutting depth produced is equal to the second cutting depth, or the first cutting depth is not equal to the second cutting depth.

5. Stamping tool (10) according to one of claims 1 to 4, further comprising: a spacer configured to set a predetermined vertical distance between the upper tool (100) and the lower tool (200); and / or at least one embossing element arranged on the upper tool (100) and / or on the lower tool (200).

6. Punching tool (10) according to one of claims 1 to 5, 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.

7. Punching tool (10) according to one of claims 1 to 6, wherein the upper tool (100) has a first hold-down plate (120) movably mounted on the first support plate (100), and / or wherein the lower tool (100) has a second hold-down plate (220) movably mounted on the second support plate (210), and, optionally, 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.

8. Stamping tool (10) according to claim 7, 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.

9. Punching tool (10) according to claim 7 or 8, further comprising: a first spring assembly (190) for resiliently mounting the first hold-down plate (120) on the first support plate (110); and / or a second spring assembly (290) for resiliently mounting the second hold-down plate (220) on the second support plate (210), wherein, optionally, the first spring assembly (190) comprises at least one first telescopic spring assembly with a replaceable preload spring (192), and / or wherein the second spring assembly (290) comprises at least one second telescopic spring assembly (292) with a replaceable preload spring.

10. Punching tool (10) according to one of claims 1 to 9, 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, wherein, optionally, the first guide device (160) is formed on the first hold-down plate (120), and / or the second guide device (260) is formed on the second hold-down plate (220).

11. Punching tool (10) according to claim 10, 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).

12. Punching tool (10) according to one of claims 1 to 11, further comprising: a first fixing device for fixing the sheet to be punched on the upper side; and / or a second fixing device for fixing the sheet to be punched on the lower side, wherein, optionally, the first fixing device comprises first fixing elements formed on a first hold-down plate (120), and / or the second fixing device comprises second fixing elements formed on a second hold-down plate (220).

13. Punching machine designed to receive a punching tool (10) according to one of claims 1 to 12 and to selectively move them towards each other in order to cut a sheet of honeycomb cardboard on both sides.

14. Use of the punching tool (10) according to one of claims 1 to 12 for cutting a sheet of honeycomb cardboard.

15. Method for cutting a sheet of honeycomb cardboard, the method comprising: cutting the sheet on the top side to produce at least one first cutting line in the sheet; and cutting the sheet on the bottom side to produce 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.

16. Method according to claim 15, wherein the first cutting line has a predetermined vertical distance to the second cutting line, and / or wherein the sheet is punched simultaneously on the top and bottom sides, and / or wherein the method is carried out using the punching tool according to claims 1 to 12.

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