Device for handling casting molds produced using an additive manufacturing process

Abstract

Device for handling casting molds (2) produced by an additive manufacturing process, in which at least three clamping elements, each formed with a guide rail (1) to which at least one piston (4) guided in a cylinder or at least one threaded rod is attached, and the clamping elements can be arranged on outer edge surfaces enclosing the respective casting mold (2), wherein the clamping elements can be pivotally connected to each other via the end faces of the pistons (4) or threaded rods with corner elements (8), so that by activating a drive for a movement of the pistons or threaded rods the distance between two corner elements (8) attached to end faces can be changed, wherein the corner elements (8) are angled or themselves designed as a joint to adapt to the angle enclosed by two edge surfaces at the corners of the casting mold (2), wherein pressure, compressive force,Tensile force and / or strain sensors are arranged to control the respective drives.

Description

[0001] The invention relates to a device for handling molds produced using an additive manufacturing process. The device allows molds made with molding sand, plaster, ceramic materials, or other non-metallic materials to be transported, lifted, and rotated.

[0002] Additive manufacturing processes enable the production of large-format molds with dimensions in the meter range and masses of several tons. For smaller molds, simple rods are currently used, inserted into designated bores, allowing the molds to be lifted or manipulated with a lifting device and stop elements. However, beyond a certain weight of the molds, this method becomes impossible without causing damage. Typically, so-called turning beams are used, which grip the mold laterally with clamping jaws. These jaws are pneumatically pressed against the mold. The clamping jaws can hold the molds using force and form fit, allowing them to be moved. However, beyond a certain weight, such high compressive forces must be exerted on the clamping jaws that local surface damage is unavoidable.The lower strength of additively manufactured molds compared to conventionally produced molds also has a negative impact. Furthermore, the familiar turning traverses are very large. When used with large-format molds, they become increasingly larger, so that the use of such large turning traverses is often thwarted by a lack of available space within a building.

[0003] It is therefore an object of the invention to provide possibilities for the safe handling of large-format, including additively manufactured, casting molds, which are safe for occupational safety reasons and which prevent damage to the manufactured casting molds to be handled.

[0004] According to the invention, this problem is solved with a device having the features of claim 1. Advantageous embodiments and further developments of the invention can be realized with features contained in dependent claims.

[0005] The device according to the invention comprises at least three, preferably at least four, clamping elements, each formed with a guide rail to which at least one piston guided in a cylinder or at least one threaded rod is attached. The clamping elements are designed so that they can be arranged on outer edge surfaces enclosing the respective mold. The clamping elements can be pivotally connected to each other via the end faces of the pistons or threaded rods with corner elements, so that by activating a drive for moving the pistons or threaded rods, the distance between two end faces of the corner elements can be changed.

[0006] As the distance increases, tensile forces begin to act between the corner elements to which the pistons or threaded rods are attached, starting from a certain distance traveled by the pistons or threaded rods. This, in turn, causes compressive forces to act on the outer edge surfaces of the respective mold via the pre-tensioned guide rails. The molds are polygonal in design.

[0007] The guide rails should be dimensioned in such a way that the end faces of the pistons or threaded rods extend sufficiently beyond them, at least when fully extended, so that these end faces are freely accessible. This allows them to be easily and readily connected to the corner elements or clamping elements, which will be discussed later.

[0008] Corner elements can be angled, with the specific angle depending on how many corners a mold with corresponding edge surfaces has. Corner elements can also form a hinge themselves and adapt to the angle formed by two edge surfaces.

[0009] The pistons or threaded rods can each be arranged in a guide rail that has a substantially planar surface in the direction of the respective outer edge of the mold. This correspondingly planar surface of the guide rails can bear pressure against the corresponding edge during handling of the mold. "Substantially planar" here refers to at least 70% of this surface being flat and planar, i.e., without protrusions or depressions.

[0010] In the simplest case, plate-shaped elements can be used as guide rails, to which the pistons with their cylinders or the threaded rods with their drives are attached. However, U-shaped profiles can also be used for guide rails, in which these elements are arranged between the legs and attached to the profile.

[0011] Advantageously, the pistons or threaded rods can be locked in place by means of clamping elements attached to the respective guide rail. Locking, i.e., secure fixation, should always be carried out using the clamping elements when the device is mounted on a mold and pre-tensioned by the movement of the pistons or threaded rods, so that compressive forces are exerted on the outer edges of the mold via the planar surfaces of the guide rails.

[0012] The invention offers a further possibility of adapting to different dimensions of molds, particularly their lengths and widths, or the length of outer edge surfaces between two corners of a mold. Several guide rails arranged along a common edge surface can be connected using connecting elements to influence the overall length. Guide rails connected in this way form a series arrangement which, depending on the maximum achievable length of the guide rails with their extended pistons or threaded rods, can accommodate a very long outer edge surface, which can be greater than 1500 mm or more.Such guide rails can, for example, have a maximum standard length of 500 mm from end face to end face of the pistons or threaded rods, so that several guide rails connected with connecting elements can be arranged on a correspondingly long edge surface for clamping the device.

[0013] On the planar surfaces of the guide rails, which bear against the respective outer edge surface during clamping, at least one projection can be formed that creates an additional positive fit between the respective guide rail and the edge surface of the mold, thereby increasing the security of the device's attachment to the mold. Several projections, for example conical or pyramidal, can be formed or present on an otherwise planar surface. Alternatively, at least one, preferably two, metal strips, aligned parallel to the longitudinal axis of the guide rail, can be formed or attached to the planar surface. These metal strips can have lateral surfaces inclined at an angle of 10° to 30°, preferably 20°.

[0014] The guide rails can advantageously be geometrically designed and dimensioned in the direction of a respective edge surface so that they can be inserted into a recess formed complementarily on the respective edge surface of the corresponding mold. This allows a device to be attached to a mold with a particularly secure additional interlock.

[0015] Pressure, compressive force, tensile force, and / or strain sensors can also be arranged on guide rails to control the respective drives. Using the measurement signals acquired in this way, it is possible to at least switch off drives that move pistons or threaded rods. This prevents excessive pressure forces acting on the mold. Alternatively, control can be implemented so that the same forces act on all outer edge surfaces where clamping elements are located. This can be achieved by precisely adjusting the extended length of pistons or threaded rods while maintaining a specific distance between corner elements.

[0016] A hydraulic pump, a compressor or a compressed air reservoir can be used to drive the pistons, or an electric motor or several electric motors can be used to drive the threaded rods.

[0017] At least two pistons or threaded rods should be attached to a guide rail, influencing the distance in two opposite directions. Alternatively, pairs of pistons or threaded rods can be present on a guide rail, enabling movement in the same direction. Their pistons or threaded rods should be able to move along axes parallel to each other. The drives should synchronously change the distance between the two end-mounted corner elements of at least one guide rail. Synchronous operation for all piston or threaded rod movements should be possible via a control system. The sensors already mentioned, as well as displacement sensors, can be used for this control system.

[0018] Turning elements can be arranged on the guide rails of two diametrically opposed clamping elements. These can be used to rotate the mold around the axis running between the two turning elements during handling.

[0019] The distance between the two end faces, which are attached to corner elements, should be able to be changed by at least 100 mm, preferably at least 250 mm and particularly preferably by at least 500 mm.

[0020] The invention will now be explained in more detail by way of example. Individual features can be combined with one another independently of the specific example or illustration.

[0021] This shows: Fig. 1 a perspective view of an example of a device according to the invention on a casting mold; Fig. 2 an example of a clamping element that can be used in the invention; Fig. 3 an example of a device according to the invention with four clamping elements connected to each other via corner elements and Fig. 4 a casting mold with a circumferential recess.

[0022] With Fig. Figure 1 illustrates how a device according to the invention can be attached to an example of a casting mold 2. A clamping element with a guide rail 1 is arranged on each of the four outer edge surfaces of the casting mold. In this example, four pistons 4, which are guided in cylinders 5 and can be moved hydraulically or pneumatically, are attached to the guide rails 1. The outwardly facing end faces of the pistons 4 are detachably connected to corner elements 8 by means of screws 7.

[0023] In this example, turning elements 3 are attached to two diametrically opposed guide rails 1, with the help of which a rotation of the casting mold around the axis between the two turning elements 3 is possible.

[0024] Fig. Figure 2 shows an advantageous design for a clamping element. The cylinders 5 are connected to the guide rail 1. The cylinders 5, with the pistons 4 guided within them, are aligned parallel to the central longitudinal axis of the clamping element and the guide rail 1. The pistons 4 can be moved hydraulically or pneumatically in the directions V shown by the double arrow. f They can be moved. On the outwardly facing end faces of the pistons 4, bores 6 are formed into which screws 7 can be inserted for connection to a corner element 8. This type of connection can be improved. Fig. Remove 3.

[0025] The guide rails 1 also have clamping elements 10 with which the pistons 4 can be locked / fixed when a correct distance between the corner elements 8 has been set by moving the pistons 4 and the device has been securely attached to a mold 2. The clamping elements 10 can be activated and released using quick-release cylinders 11.

[0026] Fig. It can also be seen from Figure 3 that protrusions 12 may be present on an otherwise planar surface of the guide rails 1. In this example, these are two metal strips aligned parallel to each other and parallel to the longitudinal axis of the guide rail 1, which are welded to the guide rail 1 or formed by plastic deformation.

[0027] With Fig.Figure 4 shows a more advantageous embodiment. A recess 13 is formed around the entire perimeter of the respective mold 2, which is designed to accommodate the clamping elements with the corner elements 8 during the manufacture of the mold 2.

[0028] The guide rails 1 are geometrically designed and dimensioned to complement the recesses 13, so that they can be held in the recesses 13 in a form-fitting manner.

Claims

[1] Device for handling casting molds (2) produced by an additive manufacturing process, in which at least three clamping elements, each formed with a guide rail (1) to which at least one piston (4) guided in a cylinder or at least one threaded rod is attached, and the clamping elements can be arranged on outer edge surfaces enclosing the respective casting mold (2), wherein the clamping elements can be articulated to each other via the end faces of the pistons (4) or threaded rods with corner elements (8), so that by activating a drive for a movement of the pistons or threaded rods the distance between two corner elements (8) attached to end faces can be changed. [2] Device according to claim 1, characterized by, that the pistons (4) or threaded rods are each arranged in a guide rail (1) which has a planar surface in the direction of the respective outer edge surface of the respective mold (2), and that a correspondingly planar surface of the guide rail (1) is subjected to pressure on the corresponding edge surface during handling of the mold (2). [3] Device according to any one of the preceding claims, characterized by , that the pistons (4) or threaded rods can be locked by means of clamping elements (10) attached to the respective guide rail (1). [4] Device according to any one of the preceding claims, characterized by , that several guide rails (1) arranged on a common edge surface can be connected via connecting elements to influence the overall length. [5] Device according to any one of the preceding claims, characterized by, that at least one protrusion (12) is formed on the planar surfaces of the guide rails (1) which provides an additional positive fit between the respective guide rail (1) and the edge surface of the casting mold (2). [6] Device according to any one of the preceding claims, characterized by , that the guide rails (1) are geometrically designed and dimensioned in the direction of a respective edge surface in such a way that they can be inserted into a recess (13) formed complementarily on the respective edge surface of the corresponding casting mold (2). [7] Device according to any one of the preceding claims, characterized by , that pressure, compressive force, tensile force and / or strain sensors are arranged on guide rails (1) for controlling the respective drives. [8] Device according to any one of the preceding claims, characterized by, that a hydraulic pump, a compressor or a compressed air reservoir is provided as a drive for the pistons (4) or an electric motor is provided as a drive for threaded rods. [9] Device according to any one of the preceding claims, characterized by , that at least two pistons (4) or threaded rods are attached to a guide rail (1) which influence the distance in two opposite directions. [10] Device according to any one of the preceding claims, characterized by , that the drives pistons (4) or threaded rods on a guide rail (1) change the distance between the two corner elements (8) attached to the end faces synchronously.

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