Method for stacking corrugated board, sheet and folding stacking unit, corrugated board plant and method for converting a sheet stacking unit

Abstract

A method for stacking corrugated board using a sheet and fold stacking unit (4) is described, wherein the sheet and fold stacking unit (4) has a stacking surface (6), wherein the sheet and fold stacking unit (4) is switchable between a sheet stacking mode (B) and a fold stacking mode (F), wherein in sheet stacking mode (B) the sheet and fold stacking unit (4) accepts the corrugated board in the form of corrugated board sheets (8), forms a sheet stack (10) from them and places it on the stacking surface (6), wherein in fold stacking mode (F) the sheet and fold stacking unit (4) accepts the corrugated board in the form of a corrugated board web (12), forms a folded stack (16) from this corrugated board web (12) using a folding unit (14) and places it on the stacking surface (6). Furthermore, the following are specified: a corresponding sheet and folding stacking unit (4), a corrugated board plant (2), a method for converting a sheet stacking unit into a sheet and folding stacking unit (4).

Description

[0001] The invention relates to a method for stacking corrugated board using a sheet and fold stacking unit, as well as to a corresponding sheet and fold stacking unit. Furthermore, the invention relates to a corrugated board system combined with such a sheet and fold stacking unit. Furthermore, the invention relates to a method for converting a sheet stacking unit into a sheet and fold stacking unit.

[0002] A corrugator is used to produce corrugated board. Depending on its design, the corrugated board is delivered at the end of the corrugator either as individual sheets of corrugated board or as a continuous web (a so-called continuous web). Regardless of the corrugated board's shape, it should be regularly bundled into defined bundles at the end of the corrugator, which are then transported away and stored or further processed. Alternatively, the corrugated board is stacked into a stack using a stacking unit. This is possible for both sheets of corrugated board and a continuous web.

[0003] DE 10 2010 031 668 A1 describes a folding and stacking system for corrugated cardboard webs. The corrugated cardboard web is produced using a corrugator, at the end of which the folding and stacking system first crease-folds the endless corrugated cardboard web and then folds it along these folds to create a so-called endless stack. The corrugated cardboard web is therefore not cut into individual sheets, but simply folded to form a stack. This is also known as "fanfolding," and the resulting stack is called a "fold stack." In a folded stack, the corrugated cardboard web has several sections that are stacked on top of one another but are still connected to one another, so that the folded stack has a zigzag structure.

[0004] In principle, it is also possible to divide the corrugated board web into individual sheets before stacking and then combine these sheets into a stack. This is shown, for example, in CN 20 22 45 502 U. Such a stack is then referred to as a "sheet stack." Unlike a folded stack, in a sheet stack the individual, stacked corrugated board sheets are separated from one another.

[0005] Whether a sheet stack or a folded stack is produced is usually determined by the further processing of the corrugated board. To achieve maximum flexibility, it is desirable to be able to choose between producing a sheet stack and a folded stack.

[0006] Against this background, it is an object of the invention to improve the stacking of corrugated cardboard. The stacking of corrugated cardboard should be as flexible as possible, i.e. it should be possible to produce a sheet stack or a folded stack as required. For this purpose, the installation space required should be as small as possible, i.e. the solution used should be as compact and / or as highly integrated as possible. Stacking should also be as fully automated as possible. Accordingly, a suitable sheet and folded stacking unit and a corrugated cardboard system combined with such a sheet and folded stacking unit are to be specified. In addition, a method for converting a simple sheet stacking unit and a method for stacking corrugated cardboard are to be specified.

[0007] The object is achieved according to the invention by a method for stacking corrugated cardboard according to claim 1, a sheet and fold stacking unit according to claim 14, a corrugated cardboard system in combination with a sheet and fold stacking unit according to claim 15 and a method for converting according to claim 16. Advantageous embodiments, further developments and variants are the subject of the dependent claims. The statements in connection with the method for stacking corrugated cardboard also apply mutatis mutandis to the sheet and fold stacking unit, the combination of a corrugated cardboard unit with a sheet and fold stacking unit and to the method for converting and vice versa. If method steps are described implicitly or explicitly below, advantageous embodiments for the sheet and fold stacking unit or its combination with a corrugated cardboard system result from the fact that it is designed to carry out one or more of these method steps.

[0008] The method according to the invention serves for stacking corrugated cardboard by means of a sheet and fold stacking unit and is in particular also a method for operating such a sheet and fold stacking unit. The stacking takes place in particular in a fully automated manner, i.e. fully automatic, manual intervention is then not necessary and does not occur. The sheet and fold stacking unit is generally a stacking unit for corrugated cardboard. The sheet and fold stacking unit has a stacking surface. Furthermore, the sheet and fold stacking unit can be switched between a sheet stacking mode and a fold stacking mode, which in particular are mutually exclusive. In sheet stacking mode, the sheet and fold stacking unit receives the corrugated cardboard in the form of corrugated cardboard sheets, forms a sheet stack from it and places this on the stacking surface.The sheet stack is preferably formed completely and preferably also directly on the stacking surface and is therefore also deposited there at the same time. In the folding stacking mode, the sheet and folding stacking unit receives the corrugated board in the form of a corrugated board web, forms a folding stack from it using a folding unit, i.e. the corrugated board web is folded using the folding unit, and this folding stack is deposited on the stacking surface. The folding stack is not necessarily formed completely on the stacking surface, but in an advantageous embodiment is partially formed in an intermediate storage area and then deposited from there on the stacking surface and further formed there, as described in more detail below. This is also advantageous in a similar way when forming a sheet stack.

[0009] In summary, the sheet and fold stacking unit advantageously enables the automated formation of both a sheet stack from corrugated cardboard sheets and a folded stack from a corrugated cardboard web. Depending on whether the sheet stacking mode or the folded stacking mode is active, a sheet stack (sheet stacking mode) or a folded stack (folding stacking mode) is deposited on the stacking surface. At any given time, only the formation of a folded stack or a sheet stack is possible, since the same stacking surface is used to deposit the different stacks. However, this shared stacking surface makes the sheet and fold stacking unit particularly compact and space-saving. This distinguishes the sheet and fold stacking unit described here in particular from a simple series of a sheet stacking unit and a separately designed folded stacking unit.Rather, in the sheet and fold stacking unit, a sheet stacking function (sheet stacking mode) and a fold stacking function (fold stacking mode) are combined and integrated into a single stacking unit.

[0010] The corrugated board is provided in particular by a corrugator, which produces the corrugated board from individual paper layers and then feeds it to the sheet and fold stacking unit. The actual production of the corrugated board and its stacking preferably take place inline, i.e. the sheet and fold stacking unit is directly integrated into the corrugator and then forms part of it. The corrugator, in particular, has a dry end, at the end of which the sheet and fold stacking unit is arranged to directly receive the finished corrugated board and form a stack from it. Depending on the form in which the corrugator provides the corrugated board (corrugated board sheets or corrugated board web), a sheet stack or a fold stack is then formed.

[0011] Suitably, the corrugator is switchable between a first configuration and a second configuration. In the first configuration, web production takes place, i.e., the corrugated board is fed to the sheet and fold stack unit in the form of a corrugated board web. Such a corrugated board web is also referred to as a "continuous web." In the second configuration, sheet production takes place, i.e., the corrugated board is fed to the sheet and fold stack unit in the form of corrugated board sheets. The corrugated board sheets are fed, in particular, one after the other and as a stream of corrugated board sheets.

[0012] The sheet and fold stack unit extends in a longitudinal direction, which also corresponds to a general conveying direction for the corrugated board web and the corrugated board sheets. In particular, the corrugated board is also fed to the sheet and fold stack unit in this general conveying direction. The corrugator also extends in particular in the longitudinal direction and is therefore expediently arranged in front of the sheet and fold stack unit, so that the two together form a combination which extends in the longitudinal direction. The sheet and fold stack unit forms in particular a rear end of this combination. The “general conveying direction” is understood in particular to mean that the corrugated board is generally guided in this general conveying direction, but that local deviations from the general conveying direction can be made in order to redirect the corrugated board appropriately for processing.

[0013] The longitudinal direction is also referred to as the machine direction or x-direction. The length of the corrugated board is also measured in the longitudinal direction. A cross-machine direction, also known as the y-direction, is perpendicular to the longitudinal direction and the cross-direction, and in this direction the width of the corrugated board is measured. A vertical direction, also known as the z-direction, is perpendicular to the longitudinal direction and the cross-direction, and in this direction the height of, for example, the sheet and fold stack unit or the corrugator is measured, particularly starting from an assembly level, for example a factory floor. Here, the terms “in front of”, “behind” and similar are used to indicate relative positions in the longitudinal direction. Analogously, the terms “above(er)”, “above”, “below”, “below” and similar are used to indicate relative positions in the vertical direction.

[0014] In sheet stacking mode, the sheet and fold stacking unit preferably receives the corrugated board sheets via a sheet inlet. In fold stacking mode, however, the sheet and fold stacking unit receives the corrugated board web via a web inlet. Both the corrugated board sheets and the corrugated board web run into the sheet and fold stacking unit, particularly roughly in the longitudinal direction. However, the corrugated board web and corrugated board sheets preferably run into the sheet and fold stacking unit at different levels. This is achieved in the corrugator in a suitable design by means of a distribution station (part of the corrugator) which redirects the corrugated board to a different level depending on its form. The distribution station is, for example, a so-called paddle station with pivoting guide elements (paddles) which guide the corrugated board to a corresponding level depending on their position.The different levels are stacked one above the other, with the level for the corrugated board web preferably being above the level for the corrugated board sheets. Accordingly, the web inlet of the sheet and fold stacking unit is preferably located above the sheet inlet. This makes feeding to and receiving from the sheet and fold stacking unit particularly simple and space-saving. Furthermore, converting an existing sheet stacking unit with multiple sheet feeders is particularly easy. One of the sheet feeders is converted to implement a fold stacking function.

[0015] In a suitable embodiment, the folding unit has at least one folding arm which guides and folds the corrugated cardboard web. In a particularly preferred embodiment, the folding unit has two folding arms between which the corrugated cardboard web is guided. The folding arms in particular enclose an intermediate space which serves as a guide gap for the corrugated cardboard web. The folding arms are each designed, for example, as a row of brushes or a row of springs (e.g. with steel springs). The folding arms are pivoted back and forth together and in particular in the same way and / or periodically in order to fold the corrugated cardboard web. By pivoting the folding arms back and forth, they press the corrugated cardboard web alternately in one direction and then in an opposite direction, e.g. alternating forwards and backwards. The same applies analogously when only one folding arm is used.The corrugated board web is preferably folded along transverse folds, which are arranged at regular intervals along the corrugated board web. The transverse folds each extend in the transverse direction and are expediently produced in the corrugator, e.g., with a cutting and creasing machine or similar. Alternatively, the sheet and folding stacking unit itself has a folding unit for producing the transverse folds.

[0016] The sheet and fold stacking unit preferably has a guide arm, which is arranged above the folding unit, for guiding the corrugated cardboard web along a particularly curved path to the folding unit. In particular, the aforementioned web inlet forms a front end of the guide arm. The guide arm is also referred to as a curved arm or folding radius, especially in the case of a curved path. The guide arm is suitably designed as a cage, with two boundary walls, each of which runs in a particularly curved manner and thereby defines a correspondingly curved path for the corrugated cardboard web. The guide arm generally serves to appropriately deflect the corrugated cardboard web, namely in the direction of the folding unit, into which the corrugated cardboard web is preferably introduced from above and preferably in at least approximately vertical direction."Approximately vertical direction" is understood to mean, in particular, a deviation of a maximum of 30° from the vertical direction. Overall, the guide arm expediently achieves a deflection of the corrugated cardboard web by at least 90°. Advantageously, the corrugated cardboard web is introduced into the sheet and folding stacking unit at a correspondingly high position, e.g., by arranging the web inlet above the sheet inlet, as already described. The corrugated cardboard web is thus first guided to an upper level, where it is picked up by the guide arm and deflected downwards to the folding unit.

[0017] In order to achieve the most compact design possible for the sheet and fold stack unit and, in particular, to limit the required overall height of the sheet and fold stack unit and keep it as low as possible, the guide arm is preferably movable, in particular pivotable. This is based on the consideration that the guide arm is only required in the fold stack mode and can therefore be moved into an alternative position in the sheet stack mode. In this way, it is possible to use the installation space immediately behind the sheet inlet in the fold stack mode and thereby block the sheet inlet, since moving the guide arm can and will then free up the sheet inlet for the sheet stack mode. Accordingly, in a suitable embodiment, the guide arm is moved, in particular pivoted, into an upright position for the fold stack mode in order to receive the corrugated cardboard web in this position.In particular, this aligns the web inlet on a conveyor device (e.g. conveyor belt) of the corrugator for the corrugated board web, in particular flush, in order to optimally accept the corrugated board web. For the sheet stacking mode, on the other hand, the guide arm is moved into a lying (e.g. flat) position in order to create space underneath the guide arm, especially for those machine parts (in particular folding unit and / or buffer) of the sheet and fold stacking unit which are only required in fold stacking mode and in this mode block the web inlet. In the lying position, the web inlet is located in particular underneath the aforementioned conveyor device of the corrugator for the corrugated board web. By moving the guide arm, its overall space requirement in the vertical direction is changed, namely in the lying position it is reduced compared to the upright position.Specifically, a rear end of the guide arm, through which the corrugated cardboard web exits the guide arm, is raised. The rear end is therefore higher in the horizontal position than in the upright position. Accordingly, a rotation axis around which the guide arm pivots lies between the front and rear ends of the guide arm. A particularly advantageous travel mechanism for this is described further below in connection with a vertically movable intermediate storage unit.

[0018] The guide arm is in particular an uppermost machine part of the sheet and folding stacking unit, i.e. it defines an overall height of the sheet and folding stacking unit.

[0019] When the guide arm is moved, this overall height can fundamentally change. However, the guide arm is preferably moved in such a way that the overall height of the sheet and fold stack unit remains as unchanged as possible. For this purpose, the axis of rotation is arranged in particular in the center of the guide arm. When the guide arm is moved from the upright to the lying position and vice versa, a predetermined maximum height (e.g. height of the workshop) for the sheet and fold stack unit is not exceeded. The special movement of the guide arm described above and below ensures that the sheet and fold stack unit has the lowest possible overall height and is therefore as compact as possible, even in the different stacking modes.

[0020] Suitably, the web inlet comprises a web feed mechanism that engages the corrugated board web and feeds it into the sheet and fold stacking unit. For this purpose, the web feed mechanism comprises, for example, two conveyor rollers that engage the corrugated board web on both sides. The web feed mechanism is expediently arranged upstream of the folding unit and / or at the rear end of the guide arm.

[0021] The sheet and fold stacking unit expediently has an intermediate storage device for the folded stack, with a separating element which can be moved, e.g. pushed or folded, between a retaining position and a release position. In the retaining position, the separating element keeps the folded stack away from the stacking surface. The separating element itself serves in particular as a temporary stacking surface on which the corrugated cardboard is stacked until the actual stacking surface is ready for the folded stack to be deposited. This is necessary, for example, while a previously produced stack is being transported away from the stacking surface. The intermediate storage device then advantageously still allows continuous operation. The separating element then spaces the preceding stack from the following stack, in particular in the vertical direction, so that the preceding stack can be transported away from the sheet and fold stacking unit below the intermediate storage device.In the release position, the separator element then releases the folded stack for placement on the stacking surface. The separator element, along with the folded stack formed in the meantime, and the stacking surface are conveniently brought together, and then the separator element is moved to the release position, depositing the stack directly onto the stacking surface. It is equally possible for the separator element to be moved while the stacking surface remains stationary, or vice versa (or both).

[0022] The intermediate storage unit expediently has a front stop and / or a rear stop for the corrugated cardboard. The two stops define the space in the longitudinal direction in which the corrugated cardboard is deposited and the stack is formed. Accordingly, the two stops are spaced apart by a distance that corresponds, in particular, to the length of the stack measured in the longitudinal direction. The distance is preferably adjustable, i.e., one or both stops are movable in the longitudinal direction to enable the formation of stacks of different lengths.

[0023] Alternatively or in addition to the stops of the intermediate storage unit described above, in a preferred embodiment the sheet and fold stack unit has a rear stop and in particular also a front stop for corrugated cardboard sheets on the stacking surface in sheet stacking mode. These stops are, for example, part of the stacking surface. In fold stacking mode, at least the rear stop is then advantageously moved into a park position to make room for the intermediate storage unit. In particular, the rear stop is moved backwards in the longitudinal direction into the park position far enough that the intermediate storage unit can approach the stacking surface in order to form a folding spatula and deposit it on the stacking surface. The same optionally also applies to the front stop, although this can typically remain unchanged in fold stacking mode.In fold-stack mode, the previously described stops are used to guide the folded stack, so that the sheet and fold-stack unit then has a total of two pairs of stops: one pair for sheet stacking mode and one pair for fold-stack mode. Conversely, for sheet stacking mode, the buffer and its stops are moved vertically upwards so that the other two stops can be used in sheet stacking mode.

[0024] In an advantageous embodiment, the buffer, in particular the separating element, is moved into a waiting position above the sheet inlet for sheet stacking mode, whereby corrugated cardboard sheets in particular can then reach the stacking area unhindered. For folding stacking mode, the buffer is moved from the waiting position to a use position, from which a folding stack is then formed in the buffer. The use position is in particular below the waiting position. Depending on the embodiment, the buffer remains in the use position during the temporary storage of the folding stack or is moved further in the vertical direction.

[0025] Conveniently, when the intermediate storage device is moved from the use position to the waiting position, the guide arm is also moved from the upright position to the lying position. Conversely, when the intermediate storage device is moved from the waiting position to the use position, the guide arm is moved from the lying position to the upright position. This is achieved in particular by means of a corresponding coupling. In a suitable embodiment, the guide arm rests specifically with its rear end on top of the intermediate storage device, e.g. on a longitudinal strut of a frame of the intermediate storage device. When the intermediate storage device is moved in the vertical direction, the rear end is also moved accordingly in the vertical direction. Preferably, the rear end slides in the longitudinal direction at the same time, e.g. along the aforementioned longitudinal strut.

[0026] The sheet and fold stack unit suitably has a downward stacker or an upward stacker into which the stacking surface is integrated. In particular, the intermediate storage is also a component of such a downward stacker or upward stacker. The stack generally has a bottom side and a top side, with the bottom side ultimately being deposited on the stacking surface, while the top side moves ever further upwards relative to the bottom side as the stack continues to grow during its formation. In principle, several different concepts are conceivable. With a downward stacker, the bottom side of the stack is moved, in particular continuously, so that the top side remains in the same position viewed in the vertical direction. In particular, the intermediate storage is not moved and the separating element is also not moved, at least not in the vertical direction.Conversely, with an upward stacker, the bottom side remains in the same position vertically, while the top side moves vertically upward through the continuously stacked corrugated board. The buffer and separating element are suitably moved along in a similar vertical direction. A preferred embodiment of each of these two concepts is described in detail below.

[0027] With a suitable downward stacker, the stacking surface is moved vertically to a start position in a first step, while the separating element is in the retention position and the formation of a new stack begins in the buffer. The underside of the stack rests on the separating element and this is positioned at the start position for the stacking surface, so that the latter is moved towards the separating element from below. In a second step, the formation of the stack continues in the buffer. As soon as the stacking surface has reached the start position, the separating element is moved to the release position in a third step and the stack is deposited on the stacking surface in the buffer. In a fourth step, as the stack grows, the stacking surface is moved vertically downwards from the start position, hence the term “downward stacker”.As soon as the stacking surface has been moved to an end position at which the height of the stack reaches a final value, the separating element is moved back into the holding position in a fifth step. In the case of a folding stack, the corrugated cardboard web is then cut in a sixth step so that a finished folding stack is present below the separating element on the stacking surface. Advantageously, when the holding position is reached, the corrugated cardboard web is cut automatically, e.g. using a separate knife which is moved along a front edge of the separating element and thereby cuts through the corrugated cardboard web. In a seventh step, which is optional in itself, the separating element is moved back slightly in the holding position in order to release any jammed end of the corrugated cardboard web.In an eighth step, which is also optional, the buffer and the stacking area are moved slightly apart to make it easier to remove the stack from below the separating element. In a ninth step, the stack is then transported away from the stacking area, e.g., in the transverse direction. During the fifth, sixth, seventh, eighth, and ninth steps, a subsequent stack is continuously formed in the buffer so that stacking of the corrugated board does not have to be interrupted while the finished stack is being transported away. Once the stack has been removed from the stacking area, the previously described steps are repeated, starting with the first step.

[0028] The upward stacker is essentially a reversal of the downward stacker, so the explanations apply analogously and vice versa. With a suitable upward stacker, in a first step the buffer is moved vertically downwards to a start position, during which the separating element is in the retaining position and the formation of a new stack begins in the buffer. The underside of the stack rests on the separating element while the element moves to the start position. The stacking surface remains in the start position so that the buffer and the separating element are moved towards the stacking surface from above, as it were. The stacking surface also remains in the same position in the subsequent steps. In a second step, the formation of the stack continues in the buffer, while the buffer moves downwards together with the stack.As soon as the separating element has reached the starting position and is resting on the stacking surface, the separating element is moved into the release position in a third step and the stack is deposited from the intermediate storage unit onto the stacking surface. In a fourth step, as the stack grows, the intermediate storage unit is moved vertically upwards from the starting position, hence the term “upward stacker”. The separating element is moved along in the same way. As soon as the intermediate storage unit has been moved to an end position at which the stack height reaches a final value, the separating element is moved back into the retaining position at the end position in a fifth step. In the case of a folding stack, the corrugated cardboard web is then severed in a sixth step, so that a finished folding stack is then present below the separating element on the stacking surface.Conveniently, when the holding position is reached, the corrugated board web is automatically severed, e.g. by means of a separate knife which is moved along a front edge of the separating element and thereby severes the corrugated board web. In an optional seventh step, the separating element is moved back slightly in the holding position to release any jammed end of the corrugated board web. In an eighth step, which is also optional, the intermediate storage unit and the stacking surface are moved apart slightly to make it easier to remove the stack from below the separating element. In a ninth step, the stack is then transported away from the stacking surface, e.g. in the transverse direction. During the fifth, sixth, seventh, eighth and ninth steps, a subsequent stack is continuously formed in the intermediate storage unit so that the stacking of the corrugated board does not have to be interrupted while the finished stack is being transported away.Once the stack has been removed from the stacking area, the previously described steps are repeated starting with the first step.

[0029] The downward stacker or upward stacker as described is advantageously also used analogously to form a sheet stack. In particular, in a suitable embodiment, the buffer is also used when forming a sheet stack; however, this is not mandatory; so that in a likewise suitable embodiment, the buffer remains unused in sheet stacking mode and only the stacking surface is used. This is particularly advantageous with a downward stacker. If necessary, corresponding stops are arranged on the stacking surface analogous to the optional stops of the buffer in order to hold the sheet stack in a defined position in sheet stacking mode.

[0030] If the buffer can be moved between the use position and the waiting position (as described above), the path from the waiting position to the use position corresponds to a first travel range of the buffer. If the buffer is moved within this first travel range, the guide arm in particular is also moved between the upright and lying position as described. When an upward stacker is combined with an buffer that can be moved between the waiting position and the use position, this then in particular also has a second travel range, which adjoins the first travel range and extends from the start position to the end position. The use position then corresponds in particular to the end position. When combined with a downward stacker, however, the buffer in particular does not have such a second travel range.In the method of buffering along the second process section, the guide arm in particular remains in the upright position and is not further advanced. In a suitable embodiment, the guide arm is coupled to the buffer along the first process section in order to move together with it. However, starting from the useful position and over the second process section, the guide arm is then decoupled from the buffer, so that the latter can be further advanced independently of the guide arm.

[0031] In a suitable embodiment, the guide arm has two lateral guide elements (e.g., bolts or rollers) at its rear end, which, as the buffer moves along the first travel path, particularly in the longitudinal direction, move, e.g., slide or roll, over a frame of the buffer. The buffer moves within a frame of the sheet and fold-stack unit. During the transition from the first to the second travel path, the guide elements of the guide arm are then deposited on the stationary frame of the sheet and fold-stack unit, so that the guide arm then rests in the upright position while the buffer continues to move downwards in the vertical direction.

[0032] The sheet inlet is suitable for one or more rolling elements to guide the corrugated board sheets to the stacking area. The rolling elements can be either purely passive or actively driven rollers. The corrugated board sheets are guided to the stacking area via the rolling elements and then dropped onto it. In particular, the rolling elements mark one end of a conveyor line for the corrugated board sheets.

[0033] The stacking surface is preferably designed as a conveyor device with which the stack is dispensed from the sheet and fold stacking unit. The conveyor device is, for example, a conveyor belt, an AGV (automated guided vehicle), or similar. The conveyor device preferably dispenses the stack in the transverse direction, i.e., laterally; however, dispensing in another direction is also conceivable and suitable.

[0034] The stacking surface generally has a leading edge and a trailing edge (viewed in the longitudinal direction). In particular, the stacking surface also has a so-called zero position, at which the folded stack is formed. Suitably, a leading edge of the folded stack is located at the zero position. In principle, it is desirable for the zero position to be as close to the leading edge as possible in order to make maximum use of the stacking surface. However, this may make it more difficult to feed corrugated board sheets to the stacking surface; in particular, the feed of corrugated board sheets to the stacking surface may be hindered by the intermediate storage above the stacking surface. A first solution for this has already been described above in connection with the first travel path: the intermediate storage is moved to a waiting position at a sufficient height when a stack of sheets is formed in order to facilitate the feed of the corrugated board sheets.Alternatively or additionally, in a practical embodiment, the zero position is shifted rearward. The zero position is then spaced from the front edge, preferably by a distance in the range of 100 mm to 500 mm, particularly preferably in the range of 200 mm to 300 mm. As a result, the intermediate storage device is also shifted correspondingly far rearward, and a correspondingly large input gap is formed between it and the sheet input, through which the corrugated cardboard sheets reach the stacking surface. The shifted zero position also generally enables a corresponding shift of the intermediate storage device in the longitudinal direction in order to counteract any space restrictions at the front edge of the stacking surface or a design-related dimension of the intermediate storage device in the longitudinal direction.

[0035] The sheet and fold stacking unit suitably has an exit sensor unit for detecting the stack as it is discharged from the sheet and fold stacking unit. The exit sensor unit accordingly detects the outgoing stack. This is used in particular to control the downward stacker or the upward stacker, specifically to control the movement between the start position and the end position. As soon as the exit sensor unit detects that the stack has left the sheet and fold stacking unit and in particular the stacking area, the next stack can be deposited on it. Accordingly, depending on a sensor signal that the exit sensor unit outputs upon detection of a stack, the stacking area, the buffer and / or the separating element are controlled accordingly.

[0036] The exit sensor unit is preferably designed and / or arranged such that it detects both a sheet stack and a folded stack. This is particularly relevant when folded stacks and sheet stacks are formed and deposited at different positions in the longitudinal direction. If the exit sensor unit is arranged too close to the front edge of the stacking surface, a folded stack deposited further back may not be detected. Accordingly, the exit sensor unit expediently has a sensor arranged at the zero position. A sensor positioned there is in particular sufficient to detect both sheet stacks and folded stacks; optionally, a second sensor is arranged at a different position, so that the exit sensor unit then has two sensors, one for sheet stacks and one for folded stacks. Each sensor is suitably a photo sensor.

[0037] A sheet and fold stacking unit according to the invention is designed to carry out a method as described above. For this purpose, the sheet and fold stacking unit has, in particular, a correspondingly designed control unit. The sheet and fold stacking unit is also referred to as a "sheet stacking unit with a fold stacking unit integrated therein."

[0038] In a corrugated board system according to the invention, a sheet and fold stacking unit is integrated therein as described above. In particular, the sheet and fold stacking unit forms one end of the corrugated board system. Depending on the specific design of the corrugated board system, one or more further stacking units (pure sheet stacking units, pure fold stacking units or sheet and fold stacking units) can be integrated therein in addition to the sheet and fold stacking unit. In a suitable design, the corrugated board system is a duplex system with several, in particular two, stacking units, one of which, preferably the rear one, is a sheet and fold stacking unit as described here. The other stacking unit is, for example, a pure sheet stacking unit.

[0039] In a conversion method according to the invention, a sheet stacking unit, which is only designed to accept corrugated cardboard sheets and form a sheet stack from them, is converted into a sheet and fold stacking unit as described above. The sheet stacking unit has a stacking surface. As part of the method, a fold stacking unit is then integrated into the sheet stacking unit, with a web inlet (in particular with a guide arm) for accepting a corrugated cardboard web, and a folding unit for folding the corrugated cardboard web. The fold stacking unit is integrated into the sheet stacking unit in such a way that the stacking surface can also be used to deposit a fold stack, which is produced in particular from the corrugated cardboard web using the folding unit. The existing stacking surface is therefore used both for depositing a sheet stack and for depositing a fold stack.The bow sheet unit thus retrofitted is now a bow and folding sheet unit with a bow stacking mode and a folding stacking mode as described.

[0040] The object is in particular also achieved by a folding sheet unit, preferably for retrofitting a bow sheet unit as described above. The folding sheet unit in particular has one or more of the following components: guide arm, folding unit, folding arm, intermediate storage, separating element, front stop, rear stop, each as described above.

[0041] Embodiments of the invention are explained in more detail below with reference to a drawing. In each case, it schematically shows: Fig. 1 a cardboard processing system with an integrated bow and folding sheet unit therein, Fig. 2 a method for stacking cardboard, Fig. 3 a bow stacking mode, Fig. 4 a folding stacking mode, Fig. 5a to 5f the sheet and folding unit from Fig. 1 during operation at different times, Fig. 6 twelve steps of the operation of a down stapler, Fig. 7 twelve steps of the operation of an up stapler,

[0042] In Fig. 1 an embodiment of a corrugated paper plant 2 is shown, into which a sheet and folding unit 4 is integrated. Fig. 2 shows a method for stapling corrugated paper by means of such a sheet and folding unit 4. An embodiment of the sheet and folding unit 4 at different times during the method is shown in the Fig. 5a to 5f.

[0043] The sheet and folding unit 4 has a stacking surface 6 and is switchable between a sheet stack mode B and a folded stack mode F. These are mutually exclusive, as Fig. 2. In sheet stacking mode B, the sheet and folding stacking unit 4 receives the corrugated board in the form of corrugated board sheets 8, forms a sheet stack 10 from it and places it on the stacking surface 6. An embodiment of this is shown in Fig. 3. In the folding stack mode F, the sheet and folding stack unit 4 receives the corrugated board in the form of a corrugated board web 12, forms a folding stack 16 therefrom by means of a folding unit 14 and places this on the stacking surface 6. An embodiment of this is shown in Fig. 4 shown.

[0044] The sheet and fold stack unit 4 thus enables the formation of both a sheet stack 10 from corrugated cardboard sheets 8 and a folded stack 16 from a corrugated cardboard web 12. Depending on whether the sheet stacking mode B or the fold stacking mode F is active, a sheet stack 10 or a folded stack 16 is deposited on the stacking surface 6. At any given time, only the formation of a folded stack 16 or a sheet stack 10 is possible, since the same stacking surface 6 is used to deposit the different stacks 10, 16.

[0045] The corrugated board is provided by the corrugating board system 2, which produces the corrugated board from individual paper layers and then feeds it to the sheet and fold stacking unit 4. The actual production of the corrugated board and the stacking of the same take place inline in the embodiments shown here, i.e. the sheet and fold stacking unit 4 is directly integrated into the corrugating board system 2 and then forms part of it. The corrugating board system 2 has a dry end, at the end of which the sheet and fold stacking unit 4 is arranged to directly receive the finished corrugated board and form a stack 10, 16 from it. Depending on the form in which (corrugated board sheets 8 or corrugated board web 12) the corrugating board system 2 provides the corrugated board, a sheet stack 10 or a fold stack 16 is then formed.

[0046] The corrugated board system 2 shown here can be switched between a first configuration and a second configuration. In the first configuration, web production takes place, i.e., the corrugated board is fed to the sheet and fold-stack unit 4 in the form of a corrugated board web 12 ("continuous web"), see. Fig. 4. In the second configuration, sheet production takes place, ie the corrugated board is fed to the sheet and folding stacking unit 4 in the form of corrugated board sheets 8, more precisely as a stream of corrugated board sheets 8, cf. Fig. 3.

[0047] The sheet and fold stacking unit 4 extends in a longitudinal direction L, which also corresponds to a general conveying direction for the corrugated board web 12 and the corrugated board sheets 8. The corrugated board is also fed to the sheet and fold stacking unit 4 in this general conveying direction. The corrugated board system 2 also extends in the longitudinal direction L and is arranged in front of the sheet and fold stacking unit 4, so that the two together form a composite which extends in the longitudinal direction L. The sheet and fold stacking unit 4 forms a rear end of this composite in the present case.

[0048] The longitudinal direction L is also referred to as the machine direction. Perpendicular to the longitudinal direction L is a transverse direction Q. Perpendicular to the longitudinal direction L and to the transverse direction Q is a vertical direction V, in which, for example, the height of the arch and folding tape unit 4 or the corrugated board plant 2 is measured. In the present case, the terms “(in) front”, “(in) back” and the like are used to indicate relative positions in the longitudinal direction L. Analogously, the terms “above (one another)”, “above”, “below (one another)”, “below” and the like are used to indicate relative positions in the vertical direction V.

[0049] In sheet stacking mode B, the sheet and fold stacking unit 4 receives the corrugated board sheets 8 via a sheet inlet 18. In fold stacking mode F, however, the sheet and fold stacking unit 4 receives the corrugated board web 12 via a web inlet 20. Both the corrugated board sheets 8 and the corrugated board web 12 run roughly in the longitudinal direction L into the sheet and fold stacking unit 4, but at different levels E1, E2. This is achieved in the corrugated board plant 2 in the embodiment shown here by means of a distribution station 22, which redirects the corrugated board to a different level E1, E2 depending on its form. The different levels E1, E2 are located one above the other, with level E1 for the corrugated board web 12 being above level E2 for the corrugated board sheets 8. Accordingly, the web inlet 20 is arranged above the sheet inlet 18.

[0050] The folding unit 14 shown here as an example has two folding arms 24, between which the corrugated cardboard web 12 is guided, see. Fig. 4. Alternatively, a single folding arm 24 is sufficient. The folding arms 24 are pivoted back and forth together and in a similar manner to fold the corrugated cardboard web 12. By pivoting the folding arms 24 back and forth, they alternately push the corrugated cardboard web 12 forwards and backwards. The corrugated cardboard web 12 is folded along transverse folds that are arranged at regular intervals along the corrugated cardboard web 12 and each extend in the transverse direction Q.

[0051] The sheet and fold stacking unit 4 shown here also has a guide arm 26, which is arranged above the folding unit 14, for guiding the corrugated cardboard web 12 along an arcuate path to the folding unit 14. The web inlet 20 forms a front end of the guide arm 26. The guide arm 26 is in the Fig. 5a to 5f, the guide arm 26 is designed as a cage with two boundary walls, each of which is curved and thus defines a correspondingly curved path for the corrugated cardboard web 12. The guide arm 26 generally serves to deflect the corrugated cardboard web 12 in a suitable manner, namely in the direction of the folding unit 14, into which the corrugated cardboard web 12 is inserted from above and in the vertical direction V. Fig. 5a to 5f, the corrugated cardboard web 12 between the guide arm 26 and the stack 10, 16 is omitted for better clarity.

[0052] The guide arm 26 is movable, or more precisely, pivotable. For the folding and stacking mode F, the guide arm 26 is moved into an upright position, which is Fig. 5b to 5f, in order to receive the corrugated cardboard web 12 in this position. This aligns the web inlet 20 with a conveyor device 28 (e.g., conveyor belt) of the corrugator 2 for the corrugated cardboard web 12. For sheet stacking mode B, however, the guide arm 26 is moved into a lying (e.g., flat) position to create space below the guide arm 26, as shown in Fig. 5a. In the horizontal position, the track entrance 20 is located below the conveyor device 28. By moving the guide arm 26, its overall space requirement in the vertical direction V is changed, namely, it is reduced in the horizontal position compared to the upright position. Specifically, a rear end 30 of the guide arm 26 is raised. The rear end 30 is therefore higher in the horizontal position than in the upright position. Accordingly, a rotation axis D, about which the guide arm 26 is pivoted, lies between a front end 32 and the rear end 30 of the guide arm 26.

[0053] In this case, the guide arm 26 is an uppermost machine part of the sheet and fold stack unit 4, i.e., it defines its overall height. The guide arm 26 is now moved in such a way that the overall height of the sheet and fold stack unit 4 remains as unchanged as possible. For this purpose, the rotation axis D is arranged centrally on the guide arm 26. When the guide arm 26 is moved from the upright to the lying position and vice versa, a predetermined maximum height (e.g., the height of the workshop) for the sheet and fold stack unit 4 is not exceeded.

[0054] The web inlet 20 shown here has a web feed mechanism 34, which engages the corrugated cardboard web 12 and feeds it into the sheet and fold stacking unit 4. For this purpose, the web feed mechanism 34 shown here has two conveyor rollers that engage the corrugated cardboard web 12 on both sides. The web feed mechanism 34 is arranged upstream of the folding unit 14 and at the rear end 30 of the guide arm 26.

[0055] In the embodiments shown here, the sheet and folding stack unit 4 for the folding stack 16 has an intermediate storage 36 with a separating element 38, which is movable between a retention position and a release position, in this case sliding, alternatively, for example, foldable. In the retention position, visible in the Fig. 5a to 5c and 5f, the separating element 38 keeps the folded stack 16 away from the stacking surface 6 and serves itself as a temporary stacking surface on which the corrugated board is stacked until the actual stacking surface 6 is ready for depositing the folded stack 16, as specifically shown in Fig. 5d. This is necessary, for example, while a previously created stack is being removed from the stacking area, as in Fig. 5f shown.

[0056] Continuous operation is possible with the buffer 36. In the release position, shown in the Fig. 5d and Fig. 5e, the separating element 38 releases the folded stack 16 for storage on the stacking surface 6 (see Fig. 5d).

[0057] In the embodiment shown here, the intermediate storage device 36 has a front stop 40 and a rear stop 42 for the corrugated cardboard. The two stops 40, 42 define, in the longitudinal direction L, the space in which the corrugated cardboard is deposited and the stack 10, 16 is formed. Accordingly, the two stops 40, 42 are spaced apart by a distance that is optionally adjustable.

[0058] Analogous to the stops 40, 42, the sheet and folding stacking unit 4 has two further stops 43a, 43b, namely a front stop 43a and a rear stop 43b for corrugated cardboard sheets 8 on the stacking surface 6 in sheet stacking mode B. The stops 43a, 43b are, for example, part of the stacking surface 6. In folding stacking mode F, at least the rear stop 43b is moved backwards in the longitudinal direction L into a parking position P so that the intermediate storage 36 can approach the stacking surface 6 in order to form a folding spatula 16 and deposit it on the stacking surface 6. The space requirement of the intermediate storage 36 is particularly well suited to the Fig. 5a to 5f, there the separating element 38 requires a corresponding extension arm at the rear of the intermediate storage unit 36. To prevent this extension arm from colliding with the stop 43b, the latter is moved into the parking position P for the folding stack mode F. The same optionally applies analogously to the front stop 43a, although this can typically remain unchanged in the folding stack mode F. To guide the folding stack 16, the separate stops 40, 42 are then used in the folding stack mode F. Conversely, for the sheet stack mode B, the intermediate storage unit 36 ​​with the stops 40, 42 is moved upwards in the vertical direction V so far that the two stops 43a, 43b can then be used in the sheet stack mode B.

[0059] As in Fig. 5a, the intermediate storage 36 with the separating element 38 is moved into a waiting position 44 above the sheet entrance 18 for the sheet stacking mode B, whereby corrugated cardboard sheets 8 can then reach the stacking surface 6 unhindered. For the folding stacking mode F, the intermediate storage 36 is moved from the waiting position 44 into a use position 46, which in Fig. 5b, from which a folding stack 16 is then formed in the intermediate storage unit 36. The use position 46 is located below the waiting position 44.

[0060] When the intermediate storage unit 36 ​​is moved from the use position 46 to the waiting position 44, the guide arm 26 is also moved from the upright position to the lying position. Conversely, when the intermediate storage unit 36 ​​is moved from the waiting position 44 to the use position 46, the guide arm 26 is moved from the lying position to the upright position. This is achieved by means of a corresponding coupling. In the present case, the guide arm 26 rests with its rear end 30 on top of the intermediate storage unit 36, here on a longitudinal strut 48 of a frame of the intermediate storage unit 36. When the intermediate storage unit 36 ​​is moved in the vertical direction V, the rear end 30 is also moved accordingly in the vertical direction V, with the rear end 30 simultaneously sliding in the longitudinal direction L along the longitudinal strut 48, cf. Fig. 5a, Fig. 5b.

[0061] The sheet and fold stacking unit 4 has, for example, a downward stacker 50 as in Fig. 6 or an upward stacker 52 as shown in Fig. 7, in which the stacking surface 6 is integrated. The stack 10, 16 basically has a bottom U and a top O. The stack 10, 16 is deposited on the stacking surface 6 with the bottom U, while the top O moves further and further upwards with the progressive growth of the stack 10, 16 relative to the bottom U. More important than the movement of the stack 10, 16, the stacking surface 6 and the buffer 36 is in particular that in Fig. 6 the folding unit 14 remains in the same position when viewed in the vertical direction V, while the folding unit 14 in Fig. 7 is moved in the vertical direction V during the formation of the stack 10, 16.

[0062] In the Fig. 6 and Fig. 7 shows twelve steps each, designated by the numbers 1 to 12, which are referred to below as step / representation (1) to (12).

[0063] In the Fig. 6, in a first step (1), the stacking surface 6 is moved in the vertical direction V to a starting position S, during which the separating element 38 is in the retaining position as shown, and the formation of a new stack 10, 16 begins in the intermediate storage 36. The underside U of the stack 10, 16 lies on the separating element 38, and this is positioned at the starting position S for the stacking surface 6, so that the latter is moved, as it were, from below, towards the separating element 38. In a second step (2), the formation of the stack 10, 16 is continued in the intermediate storage 36. As soon as the stacking surface 6 has arrived at the starting position S, in a third step (3), the separating element 38 is moved to the release position as shown, and the stack 10, 16 is thereby deposited on the stacking surface 6 in the intermediate storage 36.In a fourth step (4), as the stack 10, 16 grows, the stacking surface 6 is then moved downwards from the starting position S in the vertical direction V, hence the term "downward stacker." As soon as the stacking surface 6 has been moved to an end position E, at which the height of the stack 10, 16 reaches a final value, the separating element 38 is moved back to the retaining position in a fifth step (5). In the case of a folded stack 16, the corrugated cardboard web 12 is then severed in a sixth step (6), so that a finished folded stack 16 is present below the separating element 38 on the stacking surface 6. Upon reaching the retaining position, the corrugated cardboard web 12 is automatically severed, e.g., by means of a separate knife 54, which is moved along a front edge of the separating element 36 and thereby severes the corrugated cardboard web 12.In a seventh step (7), the separating element 38 is moved back slightly in the retaining position in order to release a possibly clamped end of the corrugated cardboard web 12. In an eighth step (8), the intermediate storage 36 and the stacking surface 6 are moved apart slightly in order to facilitate removal of the stack 6 from below the separating element 38. In a ninth step (9), the stack 10, 16 is then transported away from the stacking surface 6, in this case in the transverse direction Q. During the fifth, sixth, seventh, eighth and ninth steps, a subsequent stack 10, 16 is continuously formed in the intermediate storage 36 as shown, so that the stacking of the corrugated cardboard is not interrupted during the removal of the finished stack 10, 16.As soon as the stack 10, 16 has been removed from the stacking surface 6, the previously described steps are repeated starting with the first step, thus the representations (10), (11), (12) basically correspond to the representations (1), (2), (3), the explanations here apply analogously.

[0064] The upward stacker 52 is ultimately a reversal of the downward stacker 50, so that the explanations apply analogously and vice versa. Fig. 7, in a first step (1), the intermediate storage device 36 is moved downwards in the vertical direction V to a starting position S, during which time the separating element 38 is in the retaining position and the formation of a new stack 10, 16 begins in the intermediate storage device 36. The underside U of the stack 10, 16 lies on the separating element 38 while the latter moves to the starting position S. The stacking surface 6 remains at the starting position S, so that the intermediate storage device 36 and the separating element 38 are moved from above to the stacking surface 6. The stacking surface 6 also remains in the same position in the subsequent steps (2) to (12). In a second step (2), the formation of the stack 10, 16 is continued in the intermediate storage device 36, while the latter is moved downwards together with the stack 10, 16.As soon as the separating element 38 has arrived at the starting position S and is resting on the stacking surface 6, the separating element 38 is moved into the release position in a third step (3), and the stack 10, 16 is thereby deposited from the intermediate storage 36 onto the stacking surface 6. In a fourth step (4), as the stack 10, 16 grows, the intermediate storage 36 is moved upwards from the starting position S in the vertical direction V, hence the term “upward stacker.” The separating element 38 is moved along in a similar manner. As soon as the intermediate storage 36 has been moved to an end position E, at which the height of the stack 10, 16 reaches a final value, the separating element 38 is moved back into the retention position at the end position E in a fifth step (5).In a folding stack 16, the corrugated cardboard web 12 is then severed in a sixth step (6), so that a finished folding stack 16 is then present below the separating element 38 on the stacking surface 6. When the retaining position is reached, the corrugated cardboard web 12 is automatically severed, e.g., by means of a separate knife 54, which is moved along a front edge of the separating element 38 and thereby severes the corrugated cardboard web 12. In a seventh step (7), the separating element 38 is moved back slightly in the retaining position to release a possibly clamped end of the corrugated cardboard web 12. In an eighth step (8), the intermediate storage device 36 and the stacking surface 6 are moved slightly apart to facilitate removal of the stack 10, 16 from below the separating element 38. In a ninth step (9), the stack 10, 16 is then transported away from the stacking surface 6, here in the transverse direction Q.During the fifth, sixth, seventh, eighth, and ninth steps, a subsequent stack 10, 16 is continuously formed in the intermediate storage 36, so that the stacking of the corrugated board is not interrupted during the removal of the finished stack 10, 16. As soon as the stack 10, 16 has been removed from the stacking surface 6, the previously described steps are repeated, beginning with the first step. Thus, the representations in representations (10), (11), (12) essentially correspond to those in representations (1), (2), (3), and the explanations apply analogously.

[0065] An upward stacker 52 is also in the Fig. 5a to 5f, the explanations of the Fig. 7a to 7l apply accordingly. Alternatively, Fig. 5a to 5f also a downward stacker 50, e.g. as in the Fig. 7a to 7l shown.

[0066] The downward stacker 50 or upward stacker 52 as described can also be used analogously to form a sheet stack 10. The buffer 36 can also be used to form a sheet stack 10, but this is not mandatory, so that in another embodiment, the buffer 36 remains unused in sheet stacking mode B and only the stacking area 6 is used.

[0067] The path from the waiting position 44 to the use position 46 corresponds to a first travel range of the intermediate storage 36. If the intermediate storage 36 is moved along this first travel range, the guide arm 26 is also moved between the upright and horizontal positions as described. When an upward stacker 52 is combined with an intermediate storage 36 that can be moved between the waiting position 44 and the use position 46, this then has a second travel range, which adjoins the first travel range and extends from the start position S to the end position E. The use position 46 then corresponds to the end position E. When combined with a downward stacker 50, however, the intermediate storage 36 does not have such a second travel range. When the intermediate storage 36 is moved along the second travel range, the guide arm 26 remains in the upright position and is not moved any further. Fig. In the embodiment shown by way of example in Figures 5a to 5f, the guide arm 26 is coupled to the intermediate storage device 36 along the first travel range in order to be moved together with the intermediate storage device, cf. Fig. 5a, Fig. 5b. From the use position 46 and beyond the second travel range, the guide arm 26 is then decoupled from the intermediate storage 36, so that the latter can continue to be moved independently of the guide arm 26, cf. Fig. 5c to 5f.

[0068] In the embodiment shown here, the guide arm 26 has two lateral guide elements 56 (e.g. bolts or rollers) at its rear end 30, which move, e.g. slide or roll, over a frame of the intermediate storage 36 when the intermediate storage 36 moves along the first travel path in the longitudinal direction L. The intermediate storage 36 moves within a frame of the sheet and fold stack unit 4. During the transition from the first to the second travel path, the guide elements 56 are then deposited on the stationary frame of the sheet and fold stack unit 4, so that the guide arm 26 then rests in the upright position, while the intermediate storage 36 continues to move down in the vertical direction V.

[0069] The sheet inlet 18 shown here has one or more rolling elements 58 for guiding the corrugated cardboard sheets 8 onto the stacking surface 6. The rolling elements 58 are, for example, rollers that are purely passive or actively driven. The corrugated cardboard sheets 8 are guided to the stacking surface 6 via the rolling elements 58 and, as it were, dropped onto it. The rolling elements 58 mark one end of a conveyor line for the corrugated cardboard sheets 8.

[0070] The stacking surface 6 is designed as a conveyor device with which the stack 10, 16 is discharged from the sheet and fold stacking unit 4. The conveyor device is, for example, a conveyor belt, an AGV (automated guided vehicle), or the like. In this case, the conveyor device discharges the stack 10, 16 in the transverse direction Q, i.e., laterally; however, discharge in another direction is also conceivable.

[0071] The stacking surface 6 generally has a front edge 60 and a rear edge 62 (viewed in the longitudinal direction L). The stacking surface 6 also has a so-called zero position N, at which the folded stack 16 is formed. A front edge of the folded stack 16 lies at the zero position N, as shown in the figures. In the embodiment shown here, the zero position N is shifted rearward and then spaced from the front edge 60, in this case by a distance in the range 200 mm to 300 mm. As a result, the intermediate storage device 36 is also shifted a correspondingly far rearward, and between it and the sheet inlet 18, a correspondingly large inlet gap 64 is formed, via which the corrugated cardboard sheets 8 reach the stacking surface 6.The shifted zero position N also generally enables a corresponding shift of the intermediate storage 36 in the longitudinal direction L in order to counteract any space restrictions at the front edge 60 of the stacking surface 6 or a design-related dimension of the intermediate storage 36 in the longitudinal direction L.

[0072] The sheet and folding stacking unit 4 shown here as an example also has an output sensor unit 66 for detecting the stack 10, 16 when it is output from the sheet and folding stacking unit 4. The output sensor unit 66 is in Fig. 5a. The exit sensor unit 66 thus detects the advancing stack 10, 16. This is used to control the downward stacker 50 or the upward stacker 52. As soon as the exit sensor unit 66 detects that the stack 10, 16 has left the sheet and fold stacking unit 4 and the stacking area 6, the next stack 10, 16 can be deposited on it.

[0073] The output sensor unit 66 is designed and arranged such that it detects both a sheet stack 10 and a folded stack 16. In the embodiment shown here, the output sensor unit 66 has a single sensor arranged at the zero position N. List of reference symbols 2 corrugated board lines 4 Sheet and folding stacking unit 6 stacking area 8 corrugated cardboard sheets 10 sheet stacks 12 corrugated cardboard sheets 14 Folding unit 16 folding stacks 18 Arch Entrance 20 Railway entrance 22 distribution station 24 folding arm 26 Guide arm 28 Conveyor system (of the corrugator) 30 rear end (of the guide arm) 32 front end (of the guide arm) 34 Web feed mechanism 36 cache 38 Separator 40 front stop (of the buffer) 42 rear stop (of the buffer) 43a front stop (of the stacking surface) 43b rear stop (of the stacking surface) 44 Waiting position 46 Usage position 48 Longitudinal strut 50 downward stackers 52 up-stackers 54 knives 56 Guide element (of the guide arm) 58 rolling element 60 Front edge (of the stacking surface) 62 Rear edge (of the stacking surface) 64 Entrance gap 66 Output sensor unit B Sheet stacking mode D axis of rotation E End position E1 level (upper level for corrugated board web) E2 level (lower level for corrugated cardboard sheets) F Fold-stack mode L longitudinal direction N zero position O Top P Parking position Q transverse direction S starting position U bottom V vertical direction QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] DE 10 2010 031 668 A1

[0003] CN 20 22 45 502 U

[0004]

Claims

[1] Method for stacking corrugated board by means of a sheet and fold stacking unit (4), a. wherein the sheet and fold stacking unit (4) has a stacking surface (6), b. wherein the sheet and fold stacking unit (4) is switchable between a sheet stacking mode (B) and a fold stacking mode (F), c. wherein the sheet and folding stacking unit (4) in the sheet stacking mode (B) receives the corrugated cardboard in the form of corrugated cardboard sheets (8), forms a sheet stack (10) therefrom and deposits this on the stacking surface (6), d. wherein the sheet and folding stacking unit (4) in the folding stacking mode (F) receives the corrugated cardboard in the form of a corrugated cardboard web (12), forms a folding stack (16) from this corrugated cardboard web (12) by means of a folding unit (14) and deposits this on the stacking surface (6). [2] Method according to claim 1, wherein the sheet and fold stack unit (4) in sheet stacking mode (B) receives the corrugated cardboard sheets (8) via a sheet input (18) and in fold stacking mode (F) the corrugated cardboard web (12) via a web input (20), wherein the web entrance (20) is arranged above the sheet entrance (18). [3] Method according to claim 1 or 2, wherein the folding unit (14) has two folding arms (24) between which the corrugated cardboard web (12) is guided, wherein the folding arms (24) are pivoted back and forth together to fold the corrugated cardboard web (12). [4] Method according to one of claims 1 to 3, wherein the sheet and fold stacking unit (4) has a guide arm (26) which is arranged above the folding unit (14) for guiding the corrugated cardboard web (12) along a path, in particular an arcuate path, to the folding unit (14). [5] Method according to claim 4, wherein the guide arm (26) for the fold-stack mode (F) is moved into an upright position to receive the corrugated cardboard web (12), wherein the guide arm (26) for the sheet-stack mode (B) is moved into a lying position to create space below the guide arm (26). [6] Method according to one of claims 1 to 5, wherein the sheet and folding stack unit (4) for the folding stack (16) has an intermediate storage (36) with a separating element (38) which is movable between a retaining position and a release position, wherein the separating element (38) keeps the folding stack (16) away from the stacking surface (6) in the retaining position, wherein the separating element (38) in the release position releases the folded stack (16) for storage on the stacking surface (6). [7] Method according to claim 6, wherein the intermediate storage (36) for the sheet stacking mode (B) is moved into a waiting position (44) above the sheet input (18), wherein the intermediate storage (36) for the folding stacking mode (F) is moved from the waiting position (44) into a use position (46), from which a folding stack (16) is then formed in the intermediate storage (36). [8] Method according to one of claims 1 to 7, wherein the sheet and fold stacking unit (4) has a rear stop (43b) for corrugated cardboard sheets (8) on the stacking surface (6) in the sheet stacking mode (B), wherein in the folding stacking mode (F) the rear stop (43b) is moved into a parking position (P) to make room for the intermediate storage (36). [9] Method according to one of claims 1 to 8, wherein the sheet and fold stacking unit (4) comprises a downward stacker (50) or an upward stacker (52) into which the stacking surface (6) is integrated. [10] Method according to one of claims 1 to 9, wherein the sheet inlet (18) has one or more rolling elements (58) for guiding the corrugated cardboard sheets (8) onto the stacking surface (6). [11] Method according to one of claims 1 to 10, wherein the stacking surface (6) is designed as a conveyor device with which the stack (10, 16) is output from the sheet and fold stacking unit (4). [12] Method according to one of claims 1 to 11, wherein the stacking surface (6) has a front edge (60) and a rear edge (62) and a zero position (N) at which the folding stack (16) is formed, wherein the zero position (B) is spaced from the front edge (60), preferably by a distance in the range of 100 mm to 500 mm. [13] Method according to one of claims 1 to 12, wherein the sheet and folding stacking unit (4) has an output sensor unit (66) for detecting the stack (10, 16) when it is output from the sheet and folding stacking unit (4), wherein the output sensor unit (66) is designed and / or arranged such that it detects both a sheet stack (10) and a folded stack (16). [14] Sheet and folding stacking unit (4) which is designed to carry out a method according to one of claims 1 to 13. [15] Corrugated board plant (2) in which a sheet and folding stacking unit (4) according to claim 14 is integrated. [16] Method for converting a sheet stacking unit, which is only designed to accept corrugated cardboard sheets (8) and to form a sheet stack (10) from them, into a sheet and folding stacking unit (4) according to claim 14, a. wherein the sheet stacking unit has a stacking surface (6), b. wherein a folding stacking unit is integrated into the sheet stacking unit, with a web inlet (20) for receiving a corrugated cardboard web (12) and a folding unit (14) for folding the corrugated cardboard web (12), c. wherein the folding stacking unit is integrated into the sheet stacking unit in such a way that the stacking surface (6) can also be used to deposit a folding stack (16).

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