Rotary casting device and method for operating a rotary casting device

Description

[0001] The invention relates to a method for operating a rotational casting device which has a rotatably mounted rotational casting mold holder with a rotational casting mold.

[0002] The invention also relates to a rotational casting device having a rotatably mounted rotational casting mold holder with a rotational casting mold.

[0003] To produce rotationally molded plastic parts, it is necessary to rotate a rotationally molded mold filled with rotationally molded material and heat it to such a high temperature that the rotationally molded material, which is usually in powder or granular form, especially microgranular form, melts during the rotation process and adheres to the inner wall of the mold. The rotational movement must not occur exclusively around a single axis of rotation; rather, it is necessary to rotate the rotationally molded material in at least two dimensions.

[0004] US 6,555,037 B1 discloses a multi-axis rotation device comprising a support member with drive wheels and a spherical frame member containing a casting mold. The spherical frame member has pairs of circular notches into which the drive wheels can engage.

[0005] WO 2014 / 000 724 A1 discloses a rotation device for rotationally molded bodies. It comprises a spherical receiving device for at least one mold, a holding device for the spherical receiving device, and a drive unit for effecting the rotational movement. The spherical receiving device consists of two parts and can be opened at a parting plane to load the mold or to remove the finished rotationally molded body from the mold. The spherical receiving device is driven to rotate by means of a motor-driven drive wheel rolling on the outside.

[0006] EP 3 318 382 A1 discloses a spherical receiving device for receiving at least one rotational casting mold, which is designed and intended to be driven for rotation in a rotation device by means of a drive wheel rolling on the outside of the spherical receiving device. The receiving device has at least one guide device that causes a drive wheel rolling on the outside of the spherical receiving device to follow a predetermined rolling path on the outside of the spherical receiving device. In addition to a curvature determined by the spherical shape of the receiving device, the rolling path has a further curvature.

[0007] German Patent Application DE 10 2012 217763 A1 discloses a measuring system and a measuring method for a rotation molding machine. The measuring system is configured to continuously determine the rotational position of the molding tool and to transmit a signal to a data processing device. The data processing device can be configured to control the rotation of the molding tool based on the measured position information.

[0008] From CN 100 439 064 C a control method for a rotation device is known in which various rotation parameters are taken into account.

[0009] European patent application EP 3 656 526 A1 discloses a system and method for controlling a rotational molding process. The system includes a control system that determines a suitable temperature-time program and a suitable movement-time program for the rotational molding process, with the control system receiving feedback signals about at least one process parameter from a sensor during the rotational molding process.

[0010] It is the object of the present invention to provide a method that enables efficient production of rotational molded products.

[0011] The object is achieved by a method of the type mentioned at the outset, which is characterized in that a trajectory of a reference point of a component rotating during a rotation process, in particular the rotational casting mold holder or the rotational casting mold, is selected for a rotation process from one of several possible trajectories that can be carried out with the rotational casting device and that a rotation process is then carried out in which rotational casting material introduced into the rotational casting mold is deposited on the inside of the rotational casting mold and in which the reference point moves along the defined trajectory.

[0012] It is a further object of the present invention to provide a rotational molding apparatus that enables efficient production of rotational molded products.

[0013] The object is achieved by a rotational casting device which is characterized in that a trajectory of a reference point of a component rotating during a rotation process, in particular the rotational casting mold holder or the rotational casting mold, can be selected for a rotation process from one of several possible trajectories that can be carried out with the rotational casting device and that a control device, after a selection process, controls a rotation process in which rotational casting material introduced into the rotational casting mold accumulates on the inside of the rotational casting mold in such a way that the reference point moves along a selected trajectory.

[0014] The invention has the very special advantage that rotational molding products can be manufactured more quickly by selecting a trajectory that is individually tailored to the respective product to be manufactured. For example, the trajectory can be selected such that at least one point on the inside of the rotational mold remains free of rotational molding material during the rotation process. This can be achieved in particular by never positioning the point to be kept free at the bottom during the rotation process, in which the reference point moves along the trajectory. For example, in the production of a plant pot, this advantageously ensures that the upper opening already remains free during the rotational molding process, whereas with the rotational molding production processes conventionally used to date, the upper opening had to be cut free with a knife in a separate work step after the rotational molding process.In this respect, the invention saves time and rotational casting material in such a case.

[0015] Alternatively or additionally, the trajectory can be selected according to the invention such that a particularly large amount of rotational casting material is deposited at at least one point on the inside of the rotational casting mold during the rotation process. This can be achieved, for example, by arranging the point on the inside of the rotational casting mold at the bottom more often than all other points on the inside of the rotational casting mold during the rotation process in which the reference point moves along the trajectory. For example, the base region of a plant pot to be produced can be made particularly thick and thus particularly stable, while the side wall, for example, can be made thinner. In this way, rotational casting material can be saved, in particular.

[0016] The selected trajectory is the trajectory along which the reference point moves during the rotation process, in particular from the beginning of the rotation process to the end of a heating period during which the rotating rotational casting mold is heated, or to the end of a cooling process during which the rotating rotational casting mold cools down, in particular by active or passive cooling.

[0017] The invention makes it possible, in particular, to save rotational casting material because specific areas of the inside of the rotational casting mold can be kept free and / or specific areas can be made thinner than others, for example if only less stability is required there.

[0018] The invention even makes it possible to produce objects that were previously difficult or impossible to produce using the rotational casting process. For example, the invention also allows the use of a rotational casting mold that has a narrow, outward-facing blind hole so that the product to be manufactured has an outward-facing tip at this point. The use of such a rotational casting mold would be very problematic when applying the conventional rotational casting process because the rotational casting material does not fall into the blind hole in sufficient quantity during continuous rotation. However, the invention makes it possible to select the trajectory such that the blind hole is oriented downwards particularly often and that the rotation speed is always reduced (possibly even to zero) when the blind hole is at the bottom.In this way, the rotational casting material has sufficient time to reach the blind hole. In particular, the invention takes into account the fact that the granular rotational casting material does not behave like a liquid within the rotational casting mold during a rotation process. Rather, the granular rotational casting material, which is temporarily at rest in the lower area relative to the rotational casting mold, is initially always carried along a long way within the rotational casting mold during the rotation process without moving relative to the rotational casting mold until at some point it begins to slip and comes to rest again at the bottom. This process is repeated continuously as rotation continues. In this respect, the granulate is not distributed continuously within the mold. This circumstance can also be taken into account according to the invention by selecting the appropriate trajectory in each case.

[0019] In a particularly advantageous embodiment, the user can input at least one trajectory executable with the rotational molding device, in particular via an interface of the rotational molding device, and add it to the multiple possible trajectories executable with the rotational molding device, from which one trajectory can be selected. For example, the rotational molding device can have a USB interface or a data interface via which data characterizing a trajectory can be received.

[0020] Particularly with regard to an embodiment of the rotational casting device as a spherical rotation device, it can advantageously be provided that the reference point is selected such that the trajectory runs exclusively on a spherical surface. In a spherical rotation device, for example, the point on the outside of the spherical rotational casting mold holder that is located at the very bottom (and possibly in contact with a drive wheel) at the beginning of the rotation process can be selected as the reference point. However, there are no fundamental restrictions with regard to the selection of the reference point. Rather, in principle, any point of the components rotating during a rotation process can be selected as the reference point. The reference point can be a predetermined point or a point that can be specified by the user on a component rotating during a rotation process, in particular the rotational casting mold holder or the rotational casting mold.In particular, a reference point input device may be provided for entering information characterizing the reference point. For example, the user can set the reference point by rotating the rotational mold into a position in which the point to be set as the reference point is located at a specific location in space (e.g., at the very top or bottom) and then communicating this to the rotational molding device (e.g., by pressing a key or clicking a mouse).

[0021] Using the example of a spherical rotation device, in which the reference point is the point on the outside of the spherical rotational mold holder, which is located at the very bottom and in contact with a drive wheel at the beginning of the rotation process, it is particularly well-suited to explain how the reference point moves along the trajectory during a rotation process. Imagine that the drive wheel is the front wheel of a motorcycle, which is driven along the trajectory on the outside of the spherical rotational mold holder. Both symmetrical and completely asymmetrical trajectories can be followed. For example, a tight 90-degree left turn can be followed by a short straight ahead and then a long 270-degree right turn.

[0022] In an advantageous design of the rotational molding device, the rotational mold holder and / or the rotational mold remain stationary throughout the entire rotation process and only perform the rotational movement such that the reference point moves along the trajectory. This design has the very special advantage that the course of the respective trajectory is easy and quick for the user to grasp. In particular, selecting a trajectory suitable for the rotational mold currently in use is particularly straightforward.

[0023] In a very special embodiment, the control device rotates the rotational casting mold faster, the higher a preselected or measured temperature of the rotational casting mold is. However, it can be provided that individual trajectory segments are traversed more slowly than others, whereby this can be specified by the user. According to the invention, it was recognized that for efficient and rapid rotational casting, the interplay of temperature and the movement behavior of the rotational casting material within the rotational casting mold are particularly important. The selection of the appropriate trajectory and the selection of the rotational speed along the trajectory are of particular importance for the movement behavior.

[0024] In an advantageous embodiment, selecting the trajectory involves the user selecting the shape and length for each section, provided the rotational molding device used is capable of performing the rotation accordingly. In a rotational molding device designed as a ball rotational molding device, particularly a ball rotational molding device in which the ball remains stationary during the rotation process, any trajectory can be selected, since such a rotational molding device offers an infinite number of possible axes of rotation for the ball's rotation.

[0025] In a particularly advantageous embodiment, the trajectory is defined by entering trajectory segments and then joining them together. This approach allows the user to create a trajectory that is individually tailored to the rotational mold being used.

[0026] For example, an input device may be provided by which trajectory segments can be input. The input device may have a display device that displays a selection of different trajectory segment types, from which trajectory segments can be selected using an input device. The input device may have an input device, for example, in the form of a computer mouse, a touchscreen, or a keyboard.

[0027] Alternatively or additionally, it can advantageously be provided that each trajectory segment is assigned a speed at which the reference point moves along the trajectory segment during a rotation process. This can advantageously result, for example, in a thicker layer of rotational casting material being deposited at certain points where the rotational movement is slower than at points where the rotational movement is faster. It is also possible, for example, to slow down the rotational movement in order to ensure that the rotational material can reach bulges over which it would fall during rapid rotation. In particular, it can advantageously be provided that one or more trajectory segments are assigned not just a constant speed, but a temporal speed profile at which the reference point moves along the trajectory segment during a rotation process.Such a design is particularly precise with regard to the product to be manufactured.

[0028] Entering a trajectory segment may include entering at least one parameter from the group of trajectory segment length, trajectory segment curvature, and trajectory segment curvature profile. In particular, it may be provided that the user selects a predefined trajectory segment type and adapts it by specifying the spatial length and / or the curvature and / or the curvature profile.

[0029] In particular, it can advantageously be provided that immediately consecutive trajectory segments differ from one another by the trajectory segment length and / or the trajectory segment curvature and / or the trajectory segment curvature profile and / or by an associated speed and / or an associated speed profile. In this way, it is possible to realize trajectories individually adapted to the respective rotational casting mold. In particular, the trajectory can be designed asymmetrically.

[0030] In a particularly advantageous embodiment, the user is shown a selection display of different trajectory segment types, from which they can select individual ones one after the other to compile and thus select the trajectory. In the selection display, the trajectory segment types can, for example, each be shown in a perspective view. Alternatively or additionally, it is also possible for the trajectory segment types in the selection display to be shown as a projection onto a flat surface. In particular, the projection can be a stereoscopic projection, a parallel projection, or a Mercator projection. Such a projection increases clarity for the user and simplifies the compilation of the trajectory from trajectory segments.

[0031] The selection display can, for example, comprise at least one trajectory segment type whose projection is a projection from the following group: circular segment, parabolic segment, straight line segment, 90-degree arc, 180-degree arc, 270-degree arc, 360-degree arc, loop segment, projection of a circular involute onto a spherical surface, spiral segment, stop segment. In a particular embodiment, the user can specify the arc radius when selecting an arc. A stop segment can imply that the rotation of the sphere is stopped, in particular for a predetermined or predeterminable period of time. A loop segment contains a predetermined sequence of left arc, straight-ahead segment, right arc, straight-ahead segment, left arc, straight-ahead segment, etc., wherein the user can preferably individually specify the length of the left and right arcs, the radii of the left and right arcs, and the length of the straight-ahead segments.However, there are no fundamental restrictions regarding the geometric shape of the trajectory segment types and thus the geometric shape of the selected trajectory segments.

[0032] In a particularly advantageous embodiment, the defined trajectory is displayed to the user in the form of a projection onto a two-dimensional plane. This display of the trajectory can serve as a preview for the user, allowing them to assess whether the selected trajectory (and possibly further supplemented trajectory) is adapted and suitable in every detail for the rotational mold to be used. The projection can, in particular, be a parallel projection, a stereographic projection, or a Mercator projection. Such a projection increases clarity for the user and simplifies the assembly of the trajectory from trajectory segments. In principle, any trajectory is possible according to the invention.

[0033] As already mentioned, the rotational casting device can be designed, in particular, as a ball rotation device. In this case, it can advantageously be provided, in particular, that the rotational casting mold holder is designed as a ball, which is driven to rotate during the rotation process.

[0034] In a special embodiment, the spherical rotational casting mold holder is driven by a drive wheel that rotates about a first axis of rotation and rolls on the surface of the sphere. The drive wheel can be driven by a first drive motor. In addition, it can advantageously be provided that the drive wheel is rotatably mounted about a second axis of rotation perpendicular to the first axis of rotation and that a second drive motor is present which can rotate the drive wheel together with the first drive motor about the second axis of rotation. In such an embodiment, the control device can generate a temporal sequence of control signals for at least one drive motor generating the rotation from the course of the selected trajectory and control the drive motors accordingly so that the reference point moves along the selected trajectory during the rotation process.

[0035] DC motors equipped with sensors can be used for the drive motors. The sensors allow the alignment of the spherical rotational mold holder to be determined at any time. In this way, a control loop can be used to ensure and monitor that the reference point moves along the trajectory. Alternatively or additionally, it is also possible to attach an alignment sensor to the rotational mold or to the rotational mold holder, which transmits data regarding the current alignment, particularly wirelessly, to the control device. This also allows monitoring of whether the reference point moves along the trajectory as desired during the rotation process.In the case of rotation devices according to the invention which are not designed as ball rotation devices, the above statements apply analogously with regard to the design of the drive motors with sensors and with regard to the arrangement of an alignment sensor on the rotational casting mold or on the rotational casting mold holder.

[0036] According to an independent inventive concept, which can be implemented in combination with or independently of the selection of one of several trajectories, a rotational casting system is particularly advantageous, comprising a heating station, by means of which a rotational casting mold can be heated, and a cooling station, in which a rotational casting mold can be cooled, in particular actively. The heating station is arranged vertically above the cooling station. This particularly solves the problem of providing a rotational casting system that operates particularly energy-efficiently.

[0037] Because the heating station is arranged vertically above the cooling station, a rotational casting mold can be transferred from the cooling station to the heating station and from the heating station to the cooling station by a movement that is purely vertical.

[0038] The rotational casting system according to the invention has the very special advantage that the heat generated during the cooling of a rotational casting mold is at least partially utilized by the heating station. In particular, the present invention also makes it possible to transfer a rotational casting mold from the heating station to the cooling station and cool it there without allowing a large portion of the heat contained in the heating station to escape, which will be explained in more detail below.

[0039] In a preferred design, the heating station is positioned on top of the cooling station and is vertically supported by the cooling station. This has the particular advantage that the heating station does not require any space for its own stands within a factory hall.

[0040] The rotational casting system can advantageously have at least one rotary drive by means of which a rotational casting mold (in particular together with a rotational casting holder) can be driven to rotate. In particular, it can advantageously be provided that a rotational casting mold can be simultaneously heated in the heating station and driven to rotate by means of the rotary drive, and / or that a rotational casting mold can be simultaneously cooled in the cooling station and driven to rotate by means of the rotary drive.

[0041] In an advantageous embodiment, the heating station comprises a heating station housing. The heating station housing is preferably thermally insulating. In particular, it can advantageously be provided that the heating station housing is double-walled, wherein a thermally insulating material, for example, glass wool or foam glass or at least one vacuum insulation panel or another insulating material, can advantageously be arranged between the walls.

[0042] The cooling station can have a cooling station housing. In particular, a thermal insulation device can advantageously be arranged between the heating station housing and the cooling station housing. The thermal insulation device can, for example, have tapered spacers, via which the heating station standing on the cooling station is supported on the cooling station. The thermal insulation device has the task of reducing heat conduction from the heating station housing to the cooling station housing. The thermal insulation device can advantageously be arranged in particular such that an upper opening in the cooling station housing and a lower opening in the heating station housing remain free. In particular, the thermal insulation device can be arranged circumferentially adjacent to the lower edges of the heating station housing and to the upper edges of the cooling station housing.

[0043] In a particularly advantageous embodiment, the heating station housing has a downward-facing opening. For good thermal insulation, it can advantageously be provided that the downward-facing opening is the only opening in the heating station housing. This advantageously ensures that a rotational casting mold (particularly together with a rotational casting mold holder and / or a rotation device) can be removed from the heating station largely without large portions of the heat contained in the heating station escaping.

[0044] The cooling station housing can advantageously have an upper opening that is aligned with the downwardly oriented opening of the heating station housing such that a rotational casting mold can be transferred, in particular on a straight vertical path, through the upper opening of the cooling station housing and the lower opening of the heating station housing from the cooling station housing into the heating station housing and / or from the heating station housing into the cooling station housing. In particular, the rotational casting system can be designed such that a rotational casting mold, together with a rotational casting mold holder and / or a rotation device, can be transferred, in particular on a straight vertical path, in particular on the shortest path, through the upper opening of the cooling station housing and the lower opening of the heating station housing from the cooling station housing into the heating station housing and / or from the heating station housing into the cooling station housing.

[0045] In a particularly advantageous embodiment, an elevator is provided by means of which a rotational casting mold or a rotational casting mold together with a rotational casting mold holder, in particular motor-driven and / or pneumatically and / or hydraulically driven, can be transferred from the cooling station to the heating station and / or from the heating station to the cooling station. In particular, it can advantageously be provided that a rotational casting mold is automatically transferred by means of the elevator from the cooling station to the heating station and / or from the heating station to the cooling station as soon as predetermined or predeterminable process parameters are reached or predetermined or predeterminable process times have elapsed. In an advantageous embodiment, the rotational casting mold is automatically transferred from the heating station to the cooling station by means of the elevator after a predetermined or predeterminable heating time has elapsed.

[0046] The rotational casting system can particularly advantageously comprise a rotation device that can be transferred by means of the elevator from the cooling station housing into the heating station housing and / or from the heating station housing into the cooling station housing. In particular, the rotation device can be a spherical rotation device that has a receptacle for a spherical rotational casting mold holder. In particular, it can advantageously be provided that the rotational casting mold holder is driven by a drive wheel that rolls on the surface of the spherical rotational casting mold holder.

[0047] In a particularly advantageous embodiment, the rotating device has a platform that closes the downwardly oriented opening of the heating station housing when the rotating device is located in the heating station housing. In particular, the platform can have a circumferential, heat-resistant seal, in particular a brush seal, on its peripheral edge.

[0048] Alternatively or additionally, the rotating device can have a cover plate, in particular a thermally insulating one, which closes the downwardly oriented opening of the heating station housing when the rotating device is located in the cooling station housing. In particular, the cover plate can have a circumferential, heat-resistant seal, in particular a brush seal, on its peripheral edge.

[0049] In another embodiment, the drive device (apart from a small part of the drive wheel which protrudes through a rotatably mounted plate) always remains outside the heating station. For example, it can advantageously be provided that the drive wheel protrudes through a slot in a round plate which is rotatably mounted and which is always rotated about a vertical axis together with the drive wheel. The plate can be rotatably mounted in a frame plate. It can advantageously be provided that the plate and the frame plate rest against the brush seal and close a downwardly oriented opening in the heating station housing when the rotational casting mold holder is located in the heating station, while a thermally insulating cover plate resting against the brush seal closes the opening in the heating station housing when the rotational casting mold holder is located in the cooling station.

[0050] The rotational mold holder can have a plurality of openings. These openings allow hot and cold air to pass through the wall of the rotational mold holder to the rotational mold, enabling the rotational mold arranged in the rotational mold holder to be heated with hot air and cooled with cold air.

[0051] In a particular embodiment, the cooling station housing has a further, particularly lateral, opening through which a rotational casting mold or a rotational casting mold holder, in particular a spherical one, in which a rotational casting mold is held, can be conveyed into the cooling station and, after a cooling process, out of the cooling station. In particular, a closure, in particular a sliding gate or a roller gate or a door, can be provided, with which the further opening can be closed.

[0052] In a particularly advantageous embodiment, the cooling station has a cold air blower. The cold air blower can, in a particularly advantageous manner, have a slot-shaped cold air nozzle. In particular, it can advantageously be provided that the cold air nozzle is aligned symmetrically to a rotational casting mold holder and / or rotational casting mold arranged in the cooling station and / or that the cold air nozzle is aligned such that a cold air flow is aligned symmetrically to a rotational casting mold holder and / or rotational casting mold arranged in the cooling station. In this way, it is advantageously ensured that the rotational casting mold holder and / or the rotational casting mold are not additionally driven to rotate by the cold air flow. An additional rotational drive by the cold air flow could disadvantageously lead to a predetermined rotation trajectory not being maintained.

[0053] In a particularly advantageous embodiment, the heating station has a hot air blower. The hot air blower can, in a particularly advantageous manner, have a slot-shaped hot air nozzle. In particular, it can advantageously be provided that the hot air nozzle is aligned symmetrically to a rotational casting mold holder and / or rotational casting mold arranged in the heating station and / or that the hot air nozzle is aligned such that a hot air stream is aligned symmetrically to a rotational casting mold holder and / or rotational casting mold arranged in the heating station. In this way, it is advantageously ensured that the rotational casting mold holder and / or the rotational casting mold are not additionally driven to rotate by the hot air stream. An additional rotation drive by the hot air stream could disadvantageously lead to a predetermined rotation trajectory not being maintained.

[0054] The rotational casting system can advantageously have at least one temperature measuring device, in particular a pyrometer, by means of which the temperature of a rotational casting mold arranged in the heating station and / or the cooling station can be measured. The temperature measuring device can be used, in particular, to monitor whether the rotational casting mold is at the required temperature during the various process steps. In particular, it is possible to control the heating process and / or the cooling process, for example, by regulating the temperature and / or the flow rate of a hot air stream or a cold air stream.

[0055] Of particular advantage is a rotational casting system which comprises a rotational casting system according to the invention and at least one rotational casting mold or at least one rotational casting mold holder in which a rotational casting mold is arranged.

[0056] In particular (according to the independent inventive concept) a rotational casting system with at least one of the following aspects is particularly advantageous: 1. A rotational casting system comprising a heating station, by means of which a rotational casting mold can be heated, and a cooling station, in which a rotational casting mold can be cooled, in particular actively, characterized in that the heating station is arranged vertically above the cooling station. 2. A rotational casting system according to aspect 1, characterized in that the heating station is located on the cooling station. 3. A rotational casting system according to aspect 1 or 2, characterized in that a rotary drive is present. 4. A rotational casting system according to aspect 3, characterized in that a rotational casting mold can be simultaneously heated in the heating station and driven to rotate by means of the rotary drive. 5. A rotational casting system according to aspect 3 or 4, characterized in that a rotational casting mold can be simultaneously cooled in the cooling station and driven to rotate by means of the rotary drive. 6.Rotational casting system according to one of aspects 1 to 5, characterized in that the cooling station has a cooling station housing. 7. Rotational casting system according to one of aspects 1 to 6, characterized in that and that the heating station has a heating station housing. 8. Rotational casting system according to aspect 7, characterized in that the heating station housing is thermally insulating and / or that the heating station housing is at least partially formed from a thermally insulating material. 9. Rotational casting system according to aspects 6 and 7, characterized in that a thermal insulation device is arranged between the heating station housing and the cooling station housing. 10. Rotational casting system according to aspect 9, characterized in that the insulation device has tapered spacers. 11.Rotational casting system according to aspect 10, characterized in that the heating station is supported on the cooling station via the spacers, in particular exclusively via the spacers. 12. Rotational casting system according to one of aspects 1 to 11, characterized in that the heating station housing has a downwardly oriented opening. 13. Rotational casting system according to aspect 12, characterized in that the downwardly oriented opening is the only opening of the heating station housing. 14.Rotational casting system according to aspect 12 or 13, characterized in that the cooling station housing has an upper opening that is aligned with the downwardly oriented opening of the heating station housing such that a rotational casting mold can be transferred, in particular in a straight vertical path, through the upper opening of the cooling station housing and the lower opening of the heating station housing from the cooling station housing into the heating station housing and / or from the heating station housing into the cooling station housing. 15. Rotational casting system according to one of aspects 1 to 14, characterized in that an elevator is provided by means of which a rotational casting mold or a rotational casting mold together with a rotational casting mold holder can be transferred from the cooling station into the heating station and / or from the heating station into the cooling station. 16.Rotational casting system according to aspect 15, characterized in that the rotational casting system has a rotation device that can be transferred by means of the elevator from the cooling station housing into the heating station housing and / or from the heating station housing into the cooling station housing. 17. Rotational casting system according to aspect 16, characterized in that the rotation device is a ball rotation device that has a receptacle for a spherical rotational casting mold holder. 18. Rotational casting system according to aspect 17, characterized in that the rotational casting mold holder is driven by a drive wheel that rolls on the surface of the spherical rotational casting mold holder. 19. Rotational casting system according to aspect 17 or 18, characterized in that the rotational casting mold holder has a plurality of openings. 20.Rotational casting system according to one of aspects 17 to 19, characterized in that the cooling station housing has a further, in particular lateral, opening through which a rotational casting mold holder designed as a ball can be conveyed into the cooling station and out of the cooling station after a cooling process. 21. Rotational casting system according to aspect 20, characterized in that a closure, in particular a sliding gate or a rolling gate or a door, is provided for the further opening. 22. Rotational casting system according to one of aspects 1 to 21, characterized in that the cooling station has a cold air blower. 23. Rotational casting system according to aspect 22, characterized in that the cold air blower has a slot-shaped nozzle. 24.Rotational casting system according to aspect 22 or 23, characterized in that the nozzle is aligned symmetrically to a rotational casting mold holder and / or rotational casting mold arranged in the cooling station and / or that the nozzle is aligned such that a cold air flow is aligned symmetrically to a rotational casting mold holder and / or rotational casting mold arranged in the cooling station. 25. Rotational casting system according to one of aspects 1 to 24, characterized in that the heating station has a hot air blower. 26. Rotational casting system according to aspect 25, characterized in that the hot air blower has a slot-shaped nozzle. 27.Rotational casting system according to aspect 25 or 26, characterized in that the nozzle is aligned symmetrically to a rotational casting mold holder and / or rotational casting mold arranged in the heating station and / or that the nozzle is aligned such that a hot air flow is aligned symmetrically to a rotational casting mold holder and / or rotational casting mold arranged in the heating station. 28. Rotational casting system according to one of aspects 1 to 27, characterized in that the rotational casting system has at least one temperature measuring device, in particular a pyrometer, by means of which the temperature of a rotational casting mold arranged in the heating station and / or the cooling station can be measured. 29. Rotational casting system comprising a rotational casting system according to one of aspects 1 to 28 and comprising at least one rotational casting mold or at least one rotational casting mold holder in which a rotational casting mold is arranged.

[0057] The subject matter of the invention is illustrated schematically and by way of example in the drawing and is described below with reference to the figures, wherein identical or similarly acting elements are generally provided with the same reference numerals even in different embodiments. In the drawings: Fig. 1 shows an embodiment of a rotational casting device according to the invention, Fig. 2 shows an embodiment of an input device of a rotational casting device according to the invention, Fig. 3 shows another embodiment of an input device of a rotational casting device according to the invention, Fig. 4 shows an embodiment of a rotational casting system according to the invention according to an independent inventive concept, Fig. 5 shows the embodiment after a spherical rotational casting mold holder including a rotational casting mold held therein has been introduced, Fig. 6 shows the embodiment of the rotational casting system after the entire rotation device has been moved vertically upwards into the heating station, Fig. 7 shows the embodiment of the rotational casting system after the rotation device has been moved back into the cooling station, Fig. 8 shows another embodiment of a rotational casting system according to the invention according to the independent inventive concept, Fig.Fig. 9 shows the further embodiment after a spherical rotational casting mold holder including a rotational casting mold held therein has been introduced, Fig. 10 shows the further embodiment of the rotational casting system after the entire rotation device has been moved vertically upwards into the heating station, Fig. 11 shows the further embodiment of the rotational casting system after the rotation device has been moved back into the cooling station.

[0058] Figure 1 shows an embodiment of a rotational molding device according to the invention, which has a rotational mold holder 1 and a rotational mold 2. The rotational mold holder 1 is designed as a sphere that is driven to rotate during a rotation process. In the example shown, the rotational mold 2 is designed to produce a plant container. However, there are no fundamental restrictions regarding the type of object to be produced.

[0059] The rotational mold holder 1 consists of a first hemisphere 3 and a second hemisphere 4, which can be detachably connected to each other.

[0060] The rotational casting mold 2 is also constructed in two parts and has a first rotational casting part 5 and a second rotational casting part 6. The first rotational casting part 5 is fastened internally to the first hemisphere 3 by means of first springs 7, while the second rotational casting part 6 is fastened internally to the second hemisphere 4 by means of second springs 8. The first hemisphere 3, together with the first rotational casting part 5, can be lifted off the second hemisphere 4, together with the second rotational casting part 6, in order to be able to introduce rotational casting material 9 into the rotational casting mold 2 before a rotation process and to be able to remove the manufactured product after a rotation process.

[0061] After the rotational molding material 9 has been introduced, the first rotational mold part 5 is placed onto the second rotational mold part 6, thus closing the rotational mold holder 1. The rotation process can then begin. During the rotation process, the rotational mold 2 is rotated and simultaneously heated so that the previously filled rotational molding material 9 can melt and adhere to the inside of the rotational mold 2.

[0062] The rotational mold holder 1 is driven to rotate by a drive device 10. The drive device 10 includes a drive motor 11 that drives a drive wheel 12 to rotate about a horizontal axis. The drive wheel 12 is in frictional contact with the outer surface of the rotational mold holder 1 and drives the rotational mold 2 held therein to rotate.

[0063] The entire drive device 10 can be rotated about a vertical axis using a further drive device 13, which has a second drive motor 14, in order to change the orientation of the horizontal rotation axis around which the drive wheel 12 rotates. If the orientation of the horizontal rotation axis around which the drive wheel 12 rotates changes, the orientation of the rotation axis around which the rotational casting mold 2 rotates also automatically changes.

[0064] The rotational mold holder 1 is held in position during its rotation by means of laterally arranged grinding plates 15. The rotational mold holder 1 remains stationary during the rotation process.

[0065] The rotational molding device 1 has an input device 16. The input device 16 comprises a display device 17 and an input device 18, which is designed as a computer mouse 27. Using the input device 16, a trajectory 25 of a reference point 28 of the rotational mold holder 1 or the rotational mold 2 for a rotation process can be selected from several possible trajectories that can be executed with the rotational molding device 1.

[0066] The control device 19 controls the drive device 10 and the additional drive device 13 during a rotation process such that the reference point 28 moves along a selected trajectory 25. For this purpose, the control device 19 generates a temporal sequence of control signals for the drive device 10 and the additional drive device 13 from the course of the trajectory 25. The reference point 28 can (as in this exemplary embodiment) be, for example, the point on the outside of the rotational mold holder 1 that is located at the very bottom and in contact with the drive wheel 12 at the beginning of the rotation process. The trajectory runs exclusively on a spherical surface, namely the spherical surface that corresponds to the outside of the rotational mold holder 1.

[0067] It is important that the rotational mold holder 1 is aligned at the beginning of the rotation process so that the reference point 28 is located at the beginning of the selected trajectory 25. Furthermore, it is important that the control device 19 knows the exact rotational orientation of the rotational mold holder 1 at the beginning of the rotation process. For this purpose, sensors can advantageously be present on the drive device 10 and / or the further drive device 13 and / or alignment sensors on the rotational mold holder 1 or the rotational mold 2, which transmit information about the current orientation of the rotational mold holder 1 to the control device 19.

[0068] In particular, it can advantageously be provided that trajectory segments can be input and transmitted to a control device 19, wherein the control device 19 determines the trajectory 25 from the input trajectory segments by stringing together the input trajectory segments 22, 23, 24.

[0069] Figure 2 shows an embodiment of an input device 16 of a rotational casting device according to the invention. The input device 16 has a display device 17 in the form of a monitor. Furthermore, the input device 16 has an input device 18 in the form of a computer mouse 27.

[0070] The display device 17 shows the user a selection display 29 of different trajectory segment types 20, from which the user can successively select individual trajectory segments 22, 23, 24 using the input device 18 and arrange them on a timeline 21. The arrangement of the individual trajectory segments 22, 23, 24 is achieved by the user clicking on one of the trajectory segment types 20 with the input device 18 designed as a computer mouse 27 and moving the clicked trajectory segment type to the timeline 21 while holding down the mouse button, thereby duplicating the symbol and storing the duplicate on the timeline 21. This process is described in the Figure 2 symbolically indicated by the dashed arrows.

[0071] The sequence of trajectory segments 22, 23, 24 results in trajectory 25 along which reference point 28 moves during a rotation process.

[0072] The display device 17 also shows the user a preview representation 26 in which the surface of the rotational mold holder 1 is displayed two-dimensionally. Furthermore, the trajectory 25 composed of the trajectory segments 22, 23, 24 is displayed to the user in the preview representation 26.

[0073] In addition to each trajectory segment 22, 23, 24, the user has the option of entering a parameter from the group of trajectory segment length, trajectory segment curvature, and trajectory segment curvature profile. Furthermore, the user has the option of assigning a speed or speed profile to each trajectory segment 22, 23, 24. The speed or speed profile indicates the dynamics with which the reference point 28 moves during a rotation process along the respective trajectory segment 22, 23, 24.

[0074] Figure 3shows another embodiment of a display device 17 of a rotational casting device according to the invention. Figure 3 The display device shown differs from the one in Figure 2 illustrated embodiment by the preview representation 26. The preview representation 26 is a Mercator projection of the spherical surface of the rotational mold holder 1 into a plane, similar to the projection of a satellite orbit onto a two-dimensional world map.

[0075] Since the Figures 4 to 11 concern an independent inventive idea, which can also be used in combination with or independently of the Figures 1 to 3 illustrated embodiments, separate reference numerals have been used as follows: 1 Heating station 2 Cooling station 3 Cooling station housing 4 Heating station housing 5 Insulation device 6 Spacer 7 Downward opening of the heating station housing 4 8 Upper opening of the cooling station housing 9 Rotation device 10 Rotational molding material 11 Rotational drive 12 First drive motor 13 Drive wheel 14 Rotational mold holder 15 Receptacle 16 Rotational mold 17 Second drive motor 18 Vertical support 19 Platform 20 Cold air nozzle 21 Hot air nozzle 22 Grinding plate 23 Pyrometer 24 Temperature measuring device 25 First hemisphere 26 Second hemisphere 27 First rotational mold part 28 Second rotational mold part 29 First springs 30 Second springs 31 First brush seal 32 Cover plate 33 Second brush seal 34 Brush seal 35Rotatable plate 36Frame plate

[0076] Figure 4 shows an embodiment of a rotational casting system according to the invention, which has a heating station 1 and a cooling station 2. The heating station 1 is arranged vertically above the cooling station 2.

[0077] The cooling station 2 has a cooling station housing 3, and the heating station 1 has a heating station housing 4. The heating station housing 4 is thermally insulating. In particular, it can advantageously be provided that the heating station housing 4 is double-walled, wherein a thermally insulating material, for example, glass wool or foam glass or at least one vacuum insulation panel or another insulating material, can advantageously be arranged between the walls.

[0078] A thermal insulation device 5 is arranged between the heating station housing 4 and the cooling station housing 3. The thermal insulation device 5 includes tapered spacers 6, which support the heating station 1 standing on the cooling station 2. The thermal insulation device 5 is arranged circumferentially adjacent to the four lower edges of the heating station housing 4 and the four upper edges of the cooling station housing 3. The thermal insulation device 5 reduces heat conduction from the heating station housing 4 to the cooling station housing 3.

[0079] The rotational casting system comprises a rotation device 9 with a rotation drive 11. The rotation drive 11 includes a first drive motor 12, which drives a drive wheel 13 for rotation about a horizontal axis. The drive wheel 13 is designed to be in frictional contact with the outer surface of a rotational casting mold holder 14 (not shown in this figure), which can be inserted into a receptacle 15 of the rotation device 9.

[0080] A spherical rotational casting holder 14, in which a rotational casting mold 16 is held, can be arranged in the receptacle 15 and driven to rotate. This is shown in the Figures 5 , 6 and 7 The holder 15 has laterally arranged grinding plates 22 that hold a rotational mold holder 14 in position during the rotation process.

[0081] The drive wheel 13, together with the first drive motor 12, can be rotated about a vertical axis by means of a second drive motor 17 in order to change the orientation of the horizontal rotation axis around which the drive wheel 13 rotates. If the orientation of the horizontal rotation axis around which the drive wheel 13 rotates changes, the orientation of the rotation axis around which the rotational mold 14, including the rotational mold 16 held therein, rotates also automatically changes.

[0082] The heating station housing 4 has a downwardly directed opening 7 and the cooling station housing 3 has an upwardly directed opening 8. The upper opening 8 of the cooling station housing 3 is aligned with the downwardly directed opening 7 of the heating station housing 4 such that the entire rotation device 9, including a rotational casting mold holder 14 located in the receptacle 15, can be transferred vertically from the cooling station 2 to the heating station 1 and vice versa, from the heating station 1 back to the cooling station 2. For this purpose, an elevator with guide rails (not shown) is provided. A platform 19 of the rotation device 9 is mounted on the guide rails (not shown) in a motor-driven manner and is displaceably mounted.

[0083] The platform 19 has a first brush seal 31 along its outer peripheral edge, the first brush seal 31 is in contact with the inside of the cooling station housing 3 as long as the elevator is in the lower position ( Figures 4 , 5 and 7 ) and in contact with the inside of the heating station housing 4 when the elevator is in the upper position ( Figure 6 ). The platform 19 closes the downward-facing opening 7 of the heating station housing 4 when the elevator is in the upper position ( Figure 6 ).

[0084] The platform 19 carries four vertical supports 18, which in turn carry a thermally insulating cover plate 32 arranged parallel to the platform 19. The cover plate 32 has a second brush seal 33 along its outer peripheral edge, which is in contact with the inside of the heating station housing 4. The cover plate 32 closes the downwardly directed opening 7 of the heating station housing 4 when the elevator is in the lower position ( Figures 4 , 5 and 7 ).

[0085] The cooling station 2 has a cold air blower (not shown in detail) with a slot-shaped cold air nozzle 20. The cold air nozzle 20 is oriented and arranged such that the cold air flow flowing through it is aligned symmetrically with a rotational mold holder 14 arranged in the cooling station 2. Specifically, the cold air nozzle 20 is oriented such that the cold air flow impinges on the spherical rotational mold holder 14 in an equatorial plane. This advantageously ensures that the spherical rotational mold holder 14 is not additionally driven to rotate by the cold air flow.

[0086] The heating station 1 has a hot air blower (not shown in detail) that includes a slot-shaped hot air nozzle 21. The hot air nozzle 21 is oriented and arranged such that the hot air stream flowing through it is aligned symmetrically with a rotational mold holder 14 arranged in the heating station 1. Specifically, the hot air nozzle 21 is oriented such that the hot air stream strikes the spherical rotational mold holder 14 in an equatorial plane. This advantageously ensures that the spherical rotational mold holder 14 is not additionally driven to rotate by the hot air stream.

[0087] There is a temperature measuring device 24 designed as a pyrometer 23, by means of which the temperature of the rotational casting mold 16 can be measured.

[0088] The Figure 7shows the embodiment of the rotational casting system according to the invention in a situation in which the rotational casting system is ready to receive a spherical rotational casting mold holder 14 with a rotational casting mold 16 held therein. The spherical rotational casting mold holder 14 can be brought horizontally into the receptacle 15 through a lateral opening (no longer shown) of the cooling station housing 2.

[0089] Before inserting a rotational mold holder 14 containing a rotational mold 16 into the receptacle 15, it is necessary to load the rotational mold 16 with rotational molding material 10. In the illustrated embodiment, the rotational mold 16 is designed to produce a plant container. However, there are no fundamental restrictions regarding the type of object to be produced.

[0090] The spherical rotational mold holder 14 consists of a first hemisphere 25 and a second hemisphere 26, which can be detachably connected to one another. The rotational mold 16 is also constructed in two parts and has a first rotational mold part 27 and a second rotational mold part 28. The first rotational mold part 27 is fastened internally to the first hemisphere 25 by means of first springs 29, while the second rotational mold part 28 is fastened internally to the second hemisphere 26 by means of second springs 30. The first hemisphere 25, together with the first rotational mold part 27, can be lifted off the second hemisphere 26, together with the second rotational mold part 28, in order to be able to introduce rotational molding material 10 into the rotational mold 16 before a rotation process and to be able to remove the manufactured product after a rotation process.

[0091] After the rotational molding material 10 has been introduced, the first rotational mold part 27 is placed onto the second rotational mold part 28, thus closing the rotational mold holder 16. The rotational mold holder 14, with a rotational mold 16 held therein, can then be moved through a lateral opening of the cooling station 2 into the receptacle 15 of the rotation device 9.

[0092] Figure 5 shows the exemplary embodiment of the rotational casting system after a spherical rotational casting mold holder 14, together with a rotational casting mold 16 held therein, has been inserted into the receptacle 15. Subsequently, the entire rotation device 9, together with the rotational casting mold holder 14 located in the receptacle and the rotational casting mold 16, is transferred vertically upward into the heating station 1 by means of the elevator.

[0093] Figure 6shows the situation after the entire rotation device including the rotational mold holder 14 and the rotational mold 16 has been moved vertically upwards into the heating station 1 by means of the elevator.

[0094] In the heating station 1, the rotational casting mold 16 is heated by the hot air blower. The rotational casting mold holder 14 has a plurality of openings through which the hot air stream, blown out by the hot air nozzle 21, strikes the rotational casting mold 16. The rotational casting mold 16 is simultaneously rotated and heated so that the previously filled rotational casting material 10 can melt and adhere to the inside of the rotational casting mold 16. The rotational casting mold holder 14 is held in position during its rotation by the laterally arranged grinding plates 22. The rotational casting mold holder 14 remains stationary within the heating station 1 during the rotation process.

[0095] After the entire rotational casting material 10 has adhered to the inner wall of the rotational casting mold 16, the entire rotation device 9, including the rotational casting mold holder 14 located in the receptacle 15 and the rotational casting mold 16, is transferred vertically downward into the cooling station 2 by means of the elevator. The rotational casting mold holder 14, together with the rotational casting mold 16, continues to rotate.

[0096] Figure 7 shows the situation after the entire rotation device including the rotational mold holder 14 and the rotational mold 16 has been moved vertically downwards back into the cooling station 2 by means of the elevator.

[0097] In the cooling station 2, the rotational mold 16 is actively cooled by means of the cold air blower, while the drive device continuously drives the spherical rotational mold holder 14 to rotate.

[0098] Once the temperature measuring device 24 has determined that the rotational mold 16 has cooled sufficiently, the spherical rotational mold holder 14, together with the rotational mold 16, can be removed horizontally through the (not shown) side opening of the cooling station housing 3. The rotational molding system is then ready to receive a spherical rotational mold holder 14 freshly loaded with rotational molding material 10, together with a rotational mold 16 held therein, and to begin the described process again.

[0099] Figure 8 shows a further embodiment of a rotational casting system according to the invention, which has a heating station 1 and a cooling station 2. The heating station 1 is arranged vertically above the cooling station 2.

[0100] The cooling station 2 has a cooling station housing 3, and the heating station 1 has a heating station housing 4. The heating station housing 4 is thermally insulating. In particular, it can advantageously be provided that the heating station housing 4 is double-walled, wherein a thermally insulating material, for example, glass wool or foam glass or at least one vacuum insulation panel or another insulating material, can advantageously be arranged between the walls.

[0101] A thermal insulation device 5 and an inwardly projecting brush seal 34 are arranged between the heating station housing 4 and the cooling station housing 3. The thermal insulation device 5 includes tapered spacers 6, which support the heating station 1 standing on the cooling station 2. The thermal insulation device 5 is arranged circumferentially adjacent to the four lower edges of the heating station housing 4 and the four upper edges of the cooling station housing 3. The thermal insulation device 5 reduces heat conduction from the heating station housing 4 to the cooling station housing 3.

[0102] The rotational casting system comprises a rotation device 9 with a rotation drive 11. The rotation drive 11 includes a first drive motor 12, which drives a drive wheel 13 for rotation about a horizontal axis. The drive wheel 13 is designed to be in frictional contact with the outer surface of a rotational casting mold holder 14 (not shown in this figure), which can be inserted into a receptacle 15 of the rotation device 9.

[0103] A spherical rotational casting holder 14, in which a rotational casting mold 16 is held, can be arranged in the receptacle 15 and driven to rotate. This is shown in the Figures 5 , 6 and 7 The holder 15 has laterally arranged grinding plates 22 that hold a rotational mold holder 14 in position during the rotation process.

[0104] The drive wheel 13, together with the first drive motor 12, can be rotated about a vertical axis by means of a second drive motor 17 in order to change the orientation of the horizontal rotation axis around which the drive wheel 13 rotates. If the orientation of the horizontal rotation axis around which the drive wheel 13 rotates changes, the orientation of the rotation axis around which the rotational mold 14, including the rotational mold 16 held therein, rotates also automatically changes.

[0105] The drive wheel 13 extends through a slot in a round plate 35, which is rotatably mounted and constantly rotates around a vertical axis together with the drive wheel 13. The plate 35 is rotatably mounted in a frame plate 36.

[0106] The heating station housing 4 has a downwardly directed opening 7 and the cooling station housing 3 has an upwardly directed opening 8. The upper opening 8 of the cooling station housing 3 is aligned with the downwardly directed opening 7 of the heating station housing 4 such that the entire rotation device 9, including a rotational casting mold holder 14 located in the receptacle 15, can be transferred vertically from the cooling station 2 to the heating station 1 and vice versa, from the heating station 1 back to the cooling station 2. For this purpose, an elevator with guide rails (not shown) is provided. A platform 19 of the rotation device 9 is mounted on the guide rails (not shown) in a motor-driven manner and is displaceably mounted.

[0107] The plate 35 and the frame plate 36 close the downwardly directed opening 7 of the heating station housing 4, resting against the brush seal 34, when the elevator is in the upper position, which in Figure 10 is shown.

[0108] The platform 19 carries four vertical supports 18, which in turn carry a thermally insulating cover plate 32 arranged parallel to the platform 19. The cover plate 32, resting against the brush seal 34, closes the downwardly directed opening 7 of the heating station housing 4 when the elevator is in the lower position ( Figures 8 , 9 and 11 ).

[0109] The cooling station 2 has a cold air blower (not shown in detail) with a slot-shaped cold air nozzle 20. The cold air nozzle 20 is oriented and arranged such that the cold air flow flowing through it is aligned symmetrically with a rotational mold holder 14 arranged in the cooling station 2. Specifically, the cold air nozzle 20 is oriented such that the cold air flow impinges on the spherical rotational mold holder 14 in an equatorial plane. This advantageously ensures that the spherical rotational mold holder 14 is not additionally driven to rotate by the cold air flow.

[0110] The heating station 1 has a hot air blower (not shown in detail) that includes a slot-shaped hot air nozzle 21. The hot air nozzle 21 is oriented and arranged such that the hot air stream flowing through it is aligned symmetrically with a rotational mold holder 14 arranged in the heating station 1. Specifically, the hot air nozzle 21 is oriented such that the hot air stream strikes the spherical rotational mold holder 14 in an equatorial plane. This advantageously ensures that the spherical rotational mold holder 14 is not additionally driven to rotate by the hot air stream.

[0111] A temperature measuring device 24, designed as a pyrometer 23, is provided, by means of which the temperature of the rotational casting mold 16 can be measured. A tube of the pyrometer 23, through which the pyrometer receives radiation, protrudes through an opening in the frame plate 36.

[0112] The Figure 8 shows the embodiment of the rotational casting system according to the invention in a situation in which the rotational casting system is ready to receive a spherical rotational casting mold holder 14 with a rotational casting mold 16 held therein. The spherical rotational casting mold holder 14 can be brought horizontally into the receptacle 15 through a lateral opening (no longer shown) of the cooling station housing 2.

[0113] Before inserting a rotational mold holder 14 containing a rotational mold 16 into the receptacle 15, it is necessary to load the rotational mold 16 with rotational molding material 10. In the illustrated embodiment, the rotational mold 16 is designed to produce a plant container. However, there are no fundamental restrictions regarding the type of object to be produced.

[0114] The spherical rotational mold holder 14 consists of a first hemisphere 25 and a second hemisphere 26, which can be detachably connected to one another. The rotational mold 16 is also constructed in two parts and has a first rotational mold part 27 and a second rotational mold part 28. The first rotational mold part 27 is fastened internally to the first hemisphere 25 by means of first springs 29, while the second rotational mold part 28 is fastened internally to the second hemisphere 26 by means of second springs 30. The first hemisphere 25, together with the first rotational mold part 27, can be lifted off the second hemisphere 26, together with the second rotational mold part 28, in order to be able to introduce rotational molding material 10 into the rotational mold 16 before a rotation process and to be able to remove the manufactured product after a rotation process.

[0115] After the rotational molding material 10 has been introduced, the first rotational mold part 27 is placed onto the second rotational mold part 28, thus closing the rotational mold holder 16. The rotational mold holder 14, with a rotational mold 16 held therein, can then be moved through a lateral opening of the cooling station 2 into the receptacle 15 of the rotation device 9.

[0116] Figure 9 shows the exemplary embodiment of the rotational casting system after a spherical rotational casting mold holder 14, together with a rotational casting mold 16 held therein, has been inserted into the receptacle 15. Subsequently, the entire rotation device 9, together with the rotational casting mold holder 14 located in the receptacle and the rotational casting mold 16, is transferred vertically upward into the heating station 1 by means of the elevator.

[0117] Figure 10shows the situation after the entire rotation device including the rotational mold holder 14 and the rotational mold 16 has been moved vertically upwards into the heating station 1 by means of the elevator.

[0118] In the heating station 1, the rotational casting mold 16 is heated by the hot air blower. The rotational casting mold holder 14 has a plurality of openings through which the hot air stream, blown out by the hot air nozzle 21, strikes the rotational casting mold 16. The rotational casting mold 16 is simultaneously rotated and heated so that the previously filled rotational casting material 10 can melt and adhere to the inside of the rotational casting mold 16. The rotational casting mold holder 14 is held in position during its rotation by the laterally arranged grinding plates 22. The rotational casting mold holder 14 remains stationary within the heating station 1 during the rotation process.

[0119] After the entire rotational casting material 10 has adhered to the inner wall of the rotational casting mold 16, the entire rotation device 9, including the rotational casting mold holder 14 located in the receptacle 15 and the rotational casting mold 16, is transferred vertically downward into the cooling station 2 by means of the elevator. The rotational casting mold holder 14, together with the rotational casting mold 16, continues to rotate.

[0120] Figure 11 shows the situation after the entire rotation device including the rotational mold holder 14 and the rotational mold 16 has been moved vertically downwards back into the cooling station 2 by means of the elevator.

[0121] In the cooling station 2, the rotational mold 16 is actively cooled by means of the cold air blower, while the drive device continuously drives the spherical rotational mold holder 14 to rotate.

[0122] Once the temperature measuring device 24 has determined that the rotational mold 16 has cooled sufficiently, the spherical rotational mold holder 14, together with the rotational mold 16, can be removed horizontally through the (not shown) side opening of the cooling station housing 3. The rotational molding system is then ready to receive a spherical rotational mold holder 14 freshly loaded with rotational molding material 10, together with a rotational mold 16 held therein, and to begin the described process again.

[0123] The Figures 7 to 11 The embodiment shown has the particular advantage that the rotary drive 11 (except for the small part of the drive wheel 13 protruding through the plate 35) always remains outside the heating station 1. The rotary drive 11 is therefore not heated up, which protects the rotary drive 11 and contributes to energy savings. List of reference symbols:

[0124] 1Rotational mold holder 2Rotational mold 3First hemisphere 4Second hemisphere 5First rotational mold part 6Second rotational mold part 7First springs 8Second springs 9Rotational molding material 10Drive device 11Drive motor 12Drive wheel 13Further drive device 14Second drive motor 15Grinding plate 16Input device 17Display device 18Input device 19Control device 20Trajectory segment type 21Timeline 22Trajectory segment 23Trajectory segment 24Trajectory segment 25Trajectory 26Preview representation 27Computer mouse 28Reference point 29Selection representation

Claims

1. Method for operating a rotational-moulding device which comprises a rotatably mounted rotational-mould holder (1) with a rotational mould (2), characterized in that a trajectory (25) of a reference point (28) on a component, in particular the rotational-mould holder (1) or the rotational mould (2), rotating in the course of a rotation operation is selected for a rotation operation from one of multiple possible trajectories (25) that can be realized by the rotational-moulding device (1), and in that then a rotation operation is performed, during which rotational-moulding material (9) introduced into the rotational mould (2) accumulates on the inner side of the rotational mould (2) and during which the reference point (28) moves along the established trajectory (25).

2. Method according to Claim 1, characterized in that a. the trajectory (25) is selected depending on the design of the rotational mould (2), and / or in that b. the trajectory (25) is selected such that at least one location on the inner side of the rotational mould (2) remains free of rotational-moulding material (9) during the rotation operation, and / or in that c. the trajectory (25) is selected such that at least one location on the inner side of the rotational mould (2) is never arranged at the bottom during the rotation operation or at least one location on the inner side of the rotational mould (2) is arranged at the bottom more often than all other locations during the rotation operation, and / or in that d. at least one trajectory (25) from the multiple possible trajectories that can be realized by the rotational-moulding device is input, in particular via an interface of the rotational-moulding device, and / or in that e. the reference point (28) is selected such that the trajectory (25) runs exclusively on one spherical surface.

3. Method according to Claim 1 or 2, characterized in that the trajectory (25) is established by inputting trajectory segments (22, 23, 24) and joining together the trajectory segments (22, 23, 24) that were input.

4. Method according to Claim 3, characterized in that a. each trajectory segment (22, 23, 24) is assigned a speed at which the reference point (28) moves along the trajectory segment (22, 23, 24) during a rotation operation, or in that each trajectory segment (22, 23, 24) is assigned a speed variation over time with which the reference point (28) moves along the trajectory segment (22, 23, 24) during a rotation operation, and / or in that b. the inputting of a trajectory segment (22, 23, 24) comprises the input of at least one parameter from the following group: trajectory segment length, trajectory segment curvature, trajectory segment curvature profile, and / or in that c. trajectory segments (22, 23, 24) directly following one another differ from one another in terms of the trajectory segment length and / or the trajectory segment curvature and / or trajectory segment curvature profile and / or in terms of an assigned speed and / or an assigned speed variation.

5. Method according to Claim 3 or 4, characterized in that a. the inputting of at least one of the trajectory segments (22, 23, 24) comprises making a selection from a selection display of different trajectory segment types (20), or in that b. the inputting of at least one of the trajectory segments (22, 23, 24) comprises making a selection from a selection display of different trajectory segment types (20), wherein the trajectory segment types (22, 23, 24) are each depicted in a perspective depiction, or in that c. the inputting of at least one of the trajectory segments (22, 23, 24) comprises making a selection from a selection display of different trajectory segment types (20), wherein the trajectory segment types (20) are each depicted in the selection display as a projection, in particular as a stereoscopic projection or a parallel projection or a Mercator projection, onto a planar surface, or in that d. the inputting of at least one of the trajectory segments comprises making a selection from a selection display of different trajectory segment types, wherein the selection display comprises at least one trajectory segment type (22, 23, 24) the projection of which is a projection from the following group: segment of a circle, segment of a parabola, segment of a straight line, 90 degree arc, 180 degree arc, 270 degree arc, 360 degree arc, segment of a loop, projection of an involute of a circle onto a spherical surface, segment of a spiral, stop segment.

6. Method according to one of Claims 1 to 5, characterized in that a. the established trajectory (25) is displayed in a projection onto a two-dimensional plane, or in that b. the established trajectory (25) is displayed in a projection onto a two-dimensional plane which is a parallel projection or a stereographic projection or a Mercator projection.

7. Method according to one of Claims 1 to 6, characterized in that a. the rotational-moulding device is a spherical rotational device, and / or in that b. a temporal sequence of control signals for at least one drive motor generating the rotation is created from the profile of the trajectory (25), and / or in that c. the rotational-mould holder (1) is in the form of a sphere, which is driven in rotation during the rotation operation, and / or in that d. the rotational-mould holder (1) is driven by means of a drive wheel (12), which rolls on the surface of the sphere.

8. Rotational-moulding device which comprises a rotatably mounted rotational-mould holder (1) with a rotational mould (2), characterized in that a trajectory (25) of a reference point (28) on a component, in particular the rotational-mould holder (1) or the rotational mould (2), rotating in the course of a rotation operation can be selected for a rotation operation from one of multiple possible trajectories (25) that can be realized by the rotational-moulding device, and in that, after a selection operation, a control device (19) controls a rotation operation during which rotational-moulding material (9) introduced into the rotational mould (2) accumulates on the inner side of the rotational mould (2), in such a way that the reference point (28) moves along a selected trajectory (25).

9. Rotational-moulding device according to Claim 8, characterized in that a. it is possible to select a trajectory (25) which is formed such that at least one location on the inner side of the rotational mould (2) remains free of rotational-moulding material (9) during the rotation operation, and / or in that b. it is possible to select a trajectory (25) which is formed such that at least one location on the inner side of the rotational mould (2) is never arranged at the bottom during the rotation operation, and / or in that c. it is possible to select a trajectory (25) which is formed such that at least one location on the inner side of the rotational mould (2) is arranged at the bottom more often than all other locations during the rotation operation, and / or in that d. at least one trajectory (25) which can be realized by the rotational-moulding device can be input, in particular via an interface of the rotational-moulding device, and can be added to the multiple possible trajectories (25) which can be realized by the rotational-moulding device and from which a trajectory (25) can be selected.

10. Rotational-moulding device according to Claim 8 or 9, characterized in that individual trajectory segments (22, 23, 24) can be input, and in that the control device (19) establishes the trajectory (25) from the trajectory segments (22, 23, 24) that were input by stringing together the trajectory segments (22, 23, 24) that were input.

11. Rotational-moulding device according to Claim 10, characterized in that a. an input device (16) by means of which the trajectory segments (22, 23, 24) can be input is present, or in that b. an input device by means of which the trajectory segments can be input is present, wherein the input device (16) comprises a display device (17), which displays a selection display of different trajectory segment types (20) from which trajectory segments (22, 23, 24) can be selected by means of an input unit, or in that c. an input device (16) by means of which the trajectory segments (22, 23, 24) can be input is present, wherein the input device (16) comprises a display device (17), which displays a selection display of different trajectory segment types (20) from which trajectory segments (22, 23, 24) can be selected by means of an input unit (18), wherein the display device (17) depicts each of the trajectory segment types (20) in a perspective depiction, or in that d. an input device by means of which the trajectory segments (22, 23, 24) can be input is present, wherein the input device (16) comprises a display device (17), which displays a selection display of different trajectory segment types (20) from which trajectory segments (22, 23, 24) can be selected by means of an input unit (18), wherein the display device (17) depicts each of the trajectory segment types (20) in the selection display as a projection, in particular as a stereoscopic projection or a parallel projection or a Mercator projection, onto a planar surface, or in that e. an input device (16) by means of which the trajectory segments (22, 23, 24) can be input is present, wherein the input device (16) comprises a display device (17), which displays a selection display of different trajectory segment types (20) from which trajectory segments (22, 23, 24) can be selected by means of an input unit (18), wherein the selection display comprises at least one trajectory segment type (20) the projection of which is a projection from the following group: segment of a circle, segment of a parabola, segment of a straight line, 90 degree arc, 180 degree arc, 270 degree arc, 360 degree arc, segment of a loop, projection of an involute of a circle onto a spherical surface, segment of a spiral, stop segment.

12. Rotational-moulding device according to Claim 11, characterized in that a. for each trajectory segment (22, 23, 24) that was input, a speed or a speed variation with which the reference point (28) moves along the trajectory segment (22, 23, 24) during a rotation operation can be input, the speed or speed variation being assigned to the trajectory segment (22, 23, 24) by the control device (19), or in that b. the inputting of a trajectory segment (22, 23, 24) comprises the input of at least one parameter from the following group: trajectory segment length, trajectory segment curvature, trajectory segment curvature profile.

13. Rotational-moulding device according to one of Claims 8 to 12, characterized in that the established trajectory (25) is displayed in a projection, in particular a parallel projection or a stereographic projection or a Mercator projection, onto a two-dimensional plane.

14. Rotational-moulding device according to one of Claims 8 to 13, characterized in that a. the rotational-moulding device is a spherical rotational device, or in that b. the rotational-mould holder (1) is in the form of a sphere, which is driven in rotation during the rotation operation, or in that c. the rotational-mould holder (1) is in the form of a sphere, which is driven in rotation during the rotation operation, wherein the rotational-mould holder (1) is driven by means of a drive wheel (12), which rotates about a first axis of rotation and which rolls on the surface of the sphere, or in that d. the rotational-mould holder (1) is in the form of a sphere, which is driven in rotation during the rotation operation, wherein the rotational-mould holder (1) is driven by means of a drive wheel (12), which rotates about a first axis of rotation and which rolls on the surface of the sphere and which is mounted so as to be able to rotate about a second axis of rotation which is perpendicular to the first axis of rotation.

15. Rotational-moulding device according to one of Claims 8 to 14, characterized in that, from the profile of the trajectory (25), the control device (19) creates a temporal sequence of control signals for at least one drive motor (11) generating the rotation.