Work piece positioning method and apparatus.

p0001The invention relates to a method and apparatus for setting up workpieces for mechanical and / or manual processing, especially for machining equipment. Preferably, the invention is concerned with setting up flat workpieces on the machine bed of a machine tool in which a numerically controlled milling unit cuts out a predetermined outline. Since the milling unit, the workpiece travels around its orbit in such a machining operation along a closed profile curve, the workpiece can not be clamped from above and below at the same time, but the workpiece holders have only one side engage the workpiece. For this reason, often vacuum plates are of such processing operations used, which can be moved either in the machine bed in the X and Y directions and set on top of the workpiece by suction, or it can be vacuum plate utilized, with suction cups on both sides and by vacuum are determined on the one hand on the machine table and the other hand on the workpiece.

p0002Especially when one-offs, such as stringers and steps of different Umrißprofilform need for the vacuum plate after each operation or whenever a new form is to be milled, be re-aligned. This has been done using drawings or model template, after which the vacuum plates are aligned. This alignment process is time consuming and cumbersome Calls measuring and comparing considerations, which the service life of an automatically controlled by computer machine is unsatisfactorily long.

p0003The invention is therefore based on the object, the means of the workpieces, in particular to simplify by vacuum plate placement and to shorten time.

p0004The set object is achieved according to the method generally through the features specified in the characterizing part of patent claim 1. The invention ensures that the operator has an outline image available and the vacuum plate or other fixing means can easily be placed within the contour lines, the guarantee is given that in the subsequent machining operation the vacuum pads are not damaged or the free run of the tool along its profile the curved path is not obstructed. The advantage of the invention becomes particularly apparent when one after the other workpieces of different contour shape are to be produced, because the retaining means can then be easily placed within the new projection contour. The prerequisite is that the projek tion forming the outline spatially coincident with the traversed by the tool path. However, this can by appropriate orientation of the projection system to the processing system (or vice versa) reached relatively easily.

p0005The invention is particularly useful for numerically controlled machine tools, in which drawings can be worn as an NC program of the milling unit and the drawings can therefore be printed by reading out the program from a plotter. The drawings thus produced can be projected by any projectors on the machine table with only magnification and imaging position must be accurately set.

p0006The projection may in particular be carried out by an overhead projector, which can be swung on a gallows above the machine table. Instead transparent originals such as overhead transparencies or slides Positive opaque matter can be projected, for example by means of a periscope.

p0007According to another embodiment of the invention can be used that provide projectable images as templates and flat screens.

p0008By the invention it is possible to expensive materials to save, since the blank, blend, the combined straightening and gluing can be optimized.

p0009Whenever a computer graphic is 2-dimensional, this can be used for a separate work within the meaning of the invention. All companies that work in the form of eg wood, laminate material, leather and cloth or sheets because of a CAD program, can have the outline on the table, cut to the example, sewn, glued or otherwise the material is prepared. The invention is thus advantageously applicable without associated processing machine.

p0010Further expedient refinements of the method are evident from the dependent claims 2 to. 5

p0011According to the device, the object is achieved by the features specified in the characterizing part of claim 6 features. Further embodiments of the apparatus are evident from the claims 7 to 10th

p0012Embodiments of the device according to the invention are described with reference to the drawing. In the drawings:<ul><li>FIG. 1 is a schematic perspective view of a workpiece machining machine with a milling unit;</li><li>Fig. 2 is a schematic representation of the machine shown in Fig 1 with the projection device according to the invention.</li><li>Fig. 3 is a schematic illustration of a modified embodiment of the projection apparatus.</li></ul>

p0013In the drawing, a CNC top milling machine (10) comprising a machine bed (12) is shown, in which a cutter unit (14) is provided as a tool is provided, which is controlled numerically by a computer in a predetermined manner profil profiled workpiece (16) from one in the drawing not shown ausfräst plate. The workpiece or the plate from which the workpiece is milled must be supported during the machining operation by holding devices at a distance to the machine table (12). This is done according to the embodiment by vacuum plate (18), which on both sides of a vacuum suction cup and one hand on the machine table (12) and on the other hand fixed on the workpiece (16). Instead of both sides firmly sucking vacuum plates can also be a machine bed with sliding in this anchored, in the X and Y directions, vacuum plates are used, the fixed eyes on the workpiece and hold it at a distance to the machine bed.

p0014The vacuum plate (18) to attack on the surface of the finished workpiece (16) at this in a sufficient distance from the edge profile line, to avoid that the vacuum pads are damaged by the cutter during the machining operation.

p0015To facilitate this work and setting a projection system of FIG. 2 is provided. This projection system produced on the working surface of the machine table (12) a projection image (20) of the finished workpiece. The projected image (20) corresponding in size to the size of the finished workpiece, ie a maximum magnification ratio of 1 is preferably: 1 is selected. For safety reasons, a slightly reduced image could optionally be generated to provide a certain margin, even if the vacuum plates are guided to the outline.

p0016The projection device must be such that the outline image of the workpiece is displayed in the same place where the cutter processing is carried out on the workpiece, ie the traversed by the cutter path must coincide with the outline of the outline image (20) and a predetermined margin this exhibit.

p0017After the outline image (20) is displayed on the machine table (12), the vacuum plate (18) can be placed at a safe distance to the edge, without the need for additional calculations or considerations must be made within the contours of this workpiece. In the thus arranged vacuum plate (18) the plate-shaped workpiece is then placed. Because the outlines are projected on this plate-like workpiece, this can be placed on the vacuum plates so that the least possible waste.

p0018According to the embodiment of Figure 2, the projection system one of a boom (22) or similar device carried overhead projector (24) on which the template (26) over a secured to the gallows deflecting mirror (28) on the machine table as outline image (20 ) maps. If only, as in the embodiment, the outer contours are to be processed by the router, the mapping of the contour shapes, the entire outline can be configured as a silhouette sufficient. However, if, for example, drilling operations are also run within the Umrißfläche the workpiece operations, these bodies may also be marked by the projection device so that you can take on these processing sites into consideration when setting the vacuum plate.

p0019Gallows (22) or similar device can be pivoted and is advantageously in the processing in the of FIG. 1 is pivoted position shown when the machine is located in the working position.

p0020The templates support surface (30) of the projector has two not shown in the drawing fixed points, play the when swinging the gallows always in the same place. If this position is correct, the gallows or the overhead projector is advantageously immovably held by a vacuum plate.

p0021A prerequisite for the projection that drawings or designs are present that are accessed in the NC program of the milling unit. It can be especially CAD results, which are provided by a computer-controlled plotter and are already entered as a milling program in the computer, represented as a master slide on the overhead projector (24).

p0022Conversely, it is possible to draft two-dimensionally in scale 1: 1 map on the table, for example, to generate an NC program in teach-in technique.

p0023As template (26) can also be a flat panel display are used, which represents the appropriate program the outline directly. Such flat-panel displays that provide a projectable image, are available in liquid crystal construction for some time. Such as flat panel formed template (26) can be projected as shown in FIG. 3 directly or via a mirror of a projection lamp (32) on the machine table (12).

p0024The invention has been described above in connection with a milling unit. However, it is also for setting up workpieces used, the other machining operations are subjected.