Device for machining of workpiece and method

Abstract

The facility has a first tensioning device (5), which has a clamping device (5', 5'') and which is movable in the x-direction from a loading region into a machining region, and vice versa. The workpiece (1) fixed in the first tensioning device (5) is transferred to a second tensioning device (10), which is provided with at least one clamping device (12, 14). The second tensioning device (10) has at least one stop (18), which is movable in the y-direction, and the first tensioning device (5) has at least one counter-stop (15), which is movable in the y-direction, for the workpiece (1). The workpiece (1) is received and clamped in the loading region in the first tensioning device (5), without being accurately positioned. The workpiece (1) with the first tensioning device (5) and also the second tensioning device (10) are moved into a position opposite one another, the lower clamping jaws (5'', 14) or contact faces of the two tensioning devices (5, 10) being precisely oriented relative to one another in the height direction. The workpiece (1) is completely released by the first tensioning device (5) and is oriented or positioned by means of the stops (15, 18) arranged horizontally opposite one another. The workpiece (1) is then clamped in one of the two tensioning devices (5, 10) and machined.

Description

[0001] The invention relates to a system for processing workpieces made of wood, plastic, aluminum and the like according to the preamble of claim 1, and to a method for transferring workpieces between a first and a second clamping device according to the preamble of claim 10. Such a system and such a method are known from document EP 2 305 440 A1.

[0002] Known systems have a loading area and a processing area for the workpieces to be machined, which are advantageously rod-shaped parts and are transported through the system by clamping table feeders. In such systems, the loading and feeding areas are located at the same point within the system, so that loading and unloading cannot occur simultaneously.

[0003] Experience has shown that with such clamping table systems featuring workpiece clamping, highly precise positioning and clamping of the workpiece are particularly crucial. Therefore, the loading area requires a highly accurate and rigid element for inserting and clamping the workpieces. The clamping table itself must also be positioned precisely for loading with the workpiece. Similarly, precise positioning of the clamping table in relation to the tool spindle and to another clamping table, onto which the workpieces must be transferred, is essential within the machining area. Consequently, high-quality and accurate machining requires that the loading area and the clamping tables be manufactured with high precision and exhibit high positioning accuracy, which, however, makes the system complex and expensive.

[0004] The invention is based on the objective of designing the generic system and the generic method in such a way that the workpieces to be machined can be machined with high accuracy using a simple system design.

[0005] This problem is solved according to the invention in the generic device with the characterizing features of claim 1 and in the generic method with the characterizing features of claim 10.

[0006] The system according to the invention has a first clamping device which includes at least one counter-stop for the workpiece that is adjustable in the y-direction. In the loading area, the workpiece can be pushed and clamped against the counter-stop in the y-direction without requiring high positional accuracy. The workpiece can be rotated to a certain extent or clamped at an angle on the clamping device.

[0007] The second clamping device, located within the machining area of ​​the system, has at least one stop for the workpiece that can be positioned in the y-direction. Once the workpiece has been moved from the loading area into the machining area using the first clamping device, and after releasing the clamping device of the first clamping table, the workpiece can be pushed against the stop of the second clamping device, which is positioned in the y-direction. Both clamping devices have support surfaces with very high precision on which the workpieces rest. The substructure and guide for the clamping devices are highly precise and rigid because the workpieces in the machining area of ​​the system must be machined with high precision.

[0008] If the first clamping device is located within the machine's processing area and opposite the second clamping device, the workpiece can be aligned in the y-direction after releasing the clamping device of the first clamping device. Since the supports or lower clamping jaws of both clamping devices are precisely aligned with each other, particularly at exactly the same height, and both clamping devices are released or open, the workpiece can rest on the supports without tension. Even if the workpiece was clamped at an angle or twisted in the clamping device of the first clamping device during the loading process, the workpiece, now free, is moved against the stop of the second clamping device in the y-direction and precisely positioned by the clamping device.The clamping device of the first clamping device is then used to clamp the precisely aligned workpiece.

[0009] The workpiece is aligned such that its longitudinal sides project beyond the clamping jaws of the clamping devices in the y-direction to such an extent that the longitudinal sides can be formed with the desired profile. Advantageously, the workpieces are aligned in such a way that they do not need to change their position when being transferred from the first to the second clamping device – or vice versa.

[0010] The second clamping device can also be retracted in the y-direction for the second machining operation to create clearance for machining tools. This process is possible without adding any time, because the second clamping device must be retracted in the y-direction anyway for the discharge of the finished workpieces.

[0011] In an advantageous design, the second clamping device can be moved away from the first clamping device in the y-direction by means of the drive, so that the workpiece clamped in the first clamping device can now be machined with one or more tools.

[0012] This y-axis of the second clamping device is also used when the workpiece is to be transferred from the first clamping device to the second for further processing and clamped by it. In this case, the second clamping device is moved in the y-direction close enough to the first clamping device to allow the workpiece transfer.

[0013] The y-axis, which is required anyway, eliminates the need for an axis in the loading area. This is particularly advantageous because the lateral stop extends over a considerable length, requiring significant effort to ensure accuracy across its entire length.

[0014] Advantageously, the first clamping device can be moved along a guide extending in the x-direction. Therefore, the first clamping device can be reliably moved from the loading area to the machining area of ​​the system.

[0015] A simpler design of the system is advantageously achieved if the second clamping device is arranged in the machining area in a non-adjustable position in the x-direction.

[0016] The second clamping device is advantageously adjustable in the y-direction along a guide. When the second clamping device is to be moved towards or away from the first clamping device, the guide ensures that the second clamping device can be moved reliably.

[0017] To ensure that the workpiece can be easily clamped in the clamping devices of the first and / or second clamping device, the lower clamping jaw of the second clamping device is advantageously adjustable in the z-direction. This allows the lower clamping jaw to be slightly lowered, for example, when transferring the workpiece from the first to the second clamping device, thus preventing the workpiece from getting stuck during the transfer.

[0018] A structurally simple design of the system is advantageously achieved if the clamping jaws of the second clamping device extend over the length of the second clamping device in the x-direction.

[0019] It is advantageous if the entire second clamping device extends almost the entire length of the machining area in the x-direction.

[0020] The system is advantageously equipped with at least one receiving unit for depositing workpieces after machining. This receiving unit is adjustable in the x-direction from the machining area to the loading area. When the receiving unit is located in the machining area, the workpieces can be placed on it after machining. The workpieces are then moved in the x-direction to the loading area and removed from the system by a suitable transport device. During this unloading process, the clamping devices can transport the workpieces within the system regardless of the position of the receiving unit.

[0021] In the inventive method, the workpiece to be machined is initially picked up and clamped in the loading area by the first clamping device without precise positioning relative to this clamping device. Whether the workpiece is twisted or clamped at an angle in the clamping device is irrelevant. The workpiece is then moved by the first clamping device next to the second clamping device, whose clamping device is open, so that the workpiece clamped in the first clamping device can be easily inserted between the clamping jaws of the second clamping device. The lower clamping jaws or supports of the two clamping devices are precisely aligned vertically (z-direction). The corresponding positioning axes must, in any case, exhibit high positioning accuracy for high-quality machining.It is advantageous for the lower clamping jaws to be precisely aligned at the same height. This is necessary when the workpieces have a flat support surface. The workpieces being fed in may, for example, already have a rebate, meaning they have an open-edged recess or groove, the so-called rebate. This rebate is bounded vertically (in the z-direction) by a surface parallel to the workpiece's support surface, with which the workpiece rests against the corresponding clamping jaw. In this case, it is necessary that the clamping jaws of the two clamping devices are aligned with a vertical offset, but still precisely, corresponding to the dimension of the recess in the z-direction. As soon as the first clamping device is next to the second, the clamping of the workpiece in the first clamping device is released.The workpiece can then be aligned or positioned perpendicular to the x-direction in the y-direction using horizontally opposed stops. This ensures precise positioning of the workpiece, even if it was previously clamped at an angle or twisted in the first clamping device. The workpiece is then clamped in one of the two clamping devices and subsequently machined.

[0022] The workpiece is positioned so that, in the clamped position, it protrudes beyond the clamping device in the y-direction. The protruding workpiece area can then be machined with appropriate tools.

[0023] The precise positioning of the workpiece is advantageously achieved by placing it against a counter stop of the first clamping device and a stop of the second clamping device before clamping it in one of the two clamping devices.

[0024] To ensure proper machining of the workpiece, the second clamping device is retracted in the y-direction after the workpiece has been clamped, allowing one side of the workpiece to be machined. This side can be the corresponding longitudinal edge in the protruding workpiece area, as well as the top and / or bottom surface of the workpiece. The exposed longitudinal edge of the workpiece can be machined, particularly profiled, while bores, grooves, and similar features can be machined into the top / bottom surface.

[0025] After one side of the workpiece has been machined, it is advantageous to transfer the partially machined workpiece within the machining area to the second clamping device. With the clamping device open, it is moved in the y-direction towards the first clamping device.

[0026] During the transfer process from the first clamping device to the second, the workpiece remains clamped at all times, ensuring that the workpiece's position does not change during the transfer. This contributes to a very high machining quality.

[0027] Advantageously, the clamping device of the first clamping device is only opened once the clamping device of the second clamping device has clamped the workpiece.

[0028] The workpiece is clamped in such a way that the unmachined area of ​​the workpiece protrudes in the y-direction beyond the clamping device of the second clamping device, so that the necessary machining operations can be carried out on the exposed longitudinal side and / or the top and / or bottom of the workpiece.

[0029] The second clamping device can be moved back in the y-direction for this further processing, so that the corresponding tools can reach the unmachined workpiece area.

[0030] During this process, the first clamping device can be moved back to the loading area to pick up the next workpiece to be processed.

[0031] Once the workpiece has been finished in the second clamping device, it is transferred to a receiving unit, which can be used to transport the finished workpiece from the machining area back to the loading area.

[0032] Further features of the invention will become apparent from the further claims, the description and the drawings.

[0033] The invention is explained in more detail with reference to an embodiment illustrated in the drawings. The drawings show... Fig. 1 in perspective view of a system according to the invention, Fig. 2 in enlarged and perspective view of a clamping device of the system according to the invention, Fig. 3 to Fig. 7 different phases in aligning the workpieces after feeding and before the first machining.

[0034] The system described below processes elongated workpieces, which can advantageously be made of wood, but also of plastic, aluminum, or a similar material. The workpieces 1 have a rectangular cross-section and are fed onto a feeding device 2 transversely to their longitudinal direction in the y-direction. The feeding device 2 is equipped with at least one transport unit 3, which transports the workpieces 1 transversely to their longitudinal direction into the system. The workpieces 1 to be processed can be placed onto the feeding device 2 manually. Automatic workpiece feeding is also possible.

[0035] The transport unit 3 can be formed, for example, by transport belts that lie next to each other at a distance and extend in the y-direction.

[0036] The feeding device 2 has at least one support table 4 onto which the workpieces 1 are placed. As soon as the workpieces 1 leave the support table 4, they are gripped by the transport unit 3 and transported transversely to their longitudinal direction. The feeding device 2 can have several adjacent transport units 3 in order, for example, to be able to transport several adjacent workpieces 1 simultaneously.

[0037] The workpieces 1 are fed to clamping devices 5, 6, with which the workpieces 1 are clamped on the top and bottom.

[0038] In the illustrated embodiment, each clamping device 5, 6 has three clamping carriages 5a to 5c, 6a to 6c, each having upper and lower clamping jaws 5', 6'; 5", 6".

[0039] In the position according to Fig. 1 The clamping devices 5, 6 are located in a loading area 7, in which the workpieces 1 are fed from the feeding device 2 to the clamping devices 5, 6.

[0040] The clamping carriages 5a to 5c, 6a to 6c are movable along a guide 8 extending in the x-direction and can be individually positioned in the x-direction according to the length of the workpieces 1. The workpieces 1 are transported in their longitudinal direction by the clamping carriages. Depending on the system configuration, the number of clamping devices 5, 6 and clamping carriages 5a to 5c, 6a to 6c can vary. Depending on the workpiece length, a different number of clamping carriages 5a to 5c, 6a to 6c can form the clamping device 5, 6. In this embodiment, each individual clamping device 5, 6 is defined such that a single workpiece 1 is clamped in it. The clamping carriages 5a to 5c, 6a to 6c can have different widths (in the longitudinal direction of the workpieces), so that a workpiece can also be clamped in only one clamping carriage 5a to 5c, 6a to 6c. Accordingly, the clamping device 5, 6 in this case consists of the one clamping carriage 5a to 5c, 6a to 6c.

[0041] The workpieces 1 are transported into a machining area 9 of the system by means of the clamping devices 5, 6. In this area, the workpieces 1 can be transferred to a second clamping device 10. This device has a support 11 on which a lower clamping jaw 14 is arranged, on which the workpieces rest in a clamped state. The support 11 and the clamping jaw 14 extend in the x-direction over the length of the clamping device 10. An upper clamping jaw 12, which extends in the x-direction over the length of the clamping device 10 and which can be adjusted in the z-direction by at least one drive 30, in the exemplary embodiment by three drives 30 arranged one behind the other in the x-direction at a distance from each other, serves to clamp the workpieces 1. Fig. 2 The drives 30 each have a carrier 30a to which the clamping jaw 12 is attached and which is adjustable along a guide (not shown) in the z-direction. The drive 30 is preferably a piston-cylinder unit with which the clamping force is generated. The piston-cylinder unit has the cylinder 49, which is attached to a carrier 50. The carrier 30a, which is rigidly connected to the clamping jaw 12, is connected to a piston rod 51, which can be moved in the z-direction to adjust the upper clamping jaw 12 in the z-direction.

[0042] The drives 30 are components of adjustment units 31, which have the carrier 50 and which, together with the drives 30, can be moved in the z-direction. The adjustment units 31 are provided on further adjustment units 31a, which have z-guides 52 for the carriers 50 of the drives 30.

[0043] The system has guides 32 extending in the y-direction in the area of ​​the clamping device 10 for the adjustment units 31a. They are actuated by means of a drive 44 ( Fig. 1 ) in the y-direction. This traverse axis is designed as a positioning axis so that the clamping jaws 12, 14 can be set exactly in the y-direction for taking over the workpieces 1.

[0044] The drive 44 has a drive motor 45 with a motor shaft 46 located in the y-direction, which is connected via endless drives 47 to adjusting spindles 48 extending in the y-direction. These allow the adjusting units 31a to be moved in the y-direction.

[0045] Based on the Fig. 3 bis 7 The process of aligning and clamping the workpieces after feeding and before the first machining is described.

[0046] In the loading area 7, the workpiece 1 can be pushed against a spring-loaded counter stop 15 in the y-direction and clamped with the clamping jaws 5', 5", 6', 6". It is not necessary to clamp the workpiece 1 precisely and in an exact position. The depth dimension in the y-direction depends on the width of the workpiece 1, which is inserted by means of a slide that engages behind the workpiece 1 and executes a defined stroke or travel. This is limited by the maximum end position of the counter stop 15. The workpiece 1 can also be rotated, unevenly positioned, or positioned at an angle on the clamping carriages 5a to 5c, 6a to 6c. Subsequently, the clamping devices 5, 6 are transported in the x-direction along the guide 8 into the machining area 9, whereby the workpiece 1 is moved in its longitudinal direction, i.e., in the x-direction.

[0047] The transport unit 3 is positioned higher compared to the lower clamping jaws 5", 6", for example, so that the workpieces 1, as in Fig. 3 The jaws are shown to be tilted upwards rather than downwards on the protruding side. Therefore, the clamping device 10 can be inserted in the y-direction without a prior z-stroke of the lower clamping jaws 5", 6".

[0048] After the unmachined workpieces 1 are clamped, the transport unit is indexed slightly to expose the underside of the workpiece 1. The clamping devices 5, 6 can then be transported along the x-direction guide 8 into the machining area 9, which also constitutes the machining area of ​​the system. During this transport, the workpiece 1 is moved in its longitudinal direction, i.e., in the x-direction.

[0049] Fig. 3 Figure 1 shows, by way of example, the workpiece 1 clamped at an angle and tilted between the clamping jaws 5', 5" of the clamping device 5. Only in the transfer area 9 is the exact alignment of the workpiece 1 carried out, so that it can be clamped and machined with high accuracy in the transfer area 9.

[0050] In machining area 9 is the clamping device 10, whose upper clamping jaw 12 is raised in the z-direction to such an extent that the workpiece 1 can be inserted into the clamping device 10 in the x-direction and, if necessary, the clamping device 10 can be adjusted in the y-direction. If necessary, the support 11 of the clamping device 10 is also lowered slightly to prevent contact with the workpiece 1 and subsequent damage.

[0051] During feeding, the workpieces 1 are clamped into the respective clamping devices 5, 6 such that one of their longitudinal sides 13 projects in the y-direction over the clamping jaws 5', 5", 6', 6" of the clamping carriages 5a to 5c, 6a to 6c towards the clamping device 10. Since the workpiece 1 is clamped at an angle in the clamping device 5, 6, as shown in the example, the longitudinal side 13 of the workpiece 1 runs at a corresponding angle to the x-direction. If the workpiece 1 is also clamped at a tilt, as shown in the example, then the longitudinal side 13 of the workpiece 1 is also at a small acute angle to the y-direction.

[0052] As soon as the clamping device 5, 6 is in the machining area 9 and opposite the clamping device 10, the upper clamping jaws 5', 6' of the clamping carriages 5a to 5c, 6a to 6c are raised in the z-direction ( Fig. 4 ). The workpiece 1 is completely free because the clamping jaw 12 of the clamping device 10 has also been raised in the z-direction.

[0053] Each clamping carriage 5a to 5c, 6a to 6c has at least one counter stop 15, which can be indexed forwards and backwards in two positions by means of a pneumatic cylinder and which, in the forward position, acts as a spring-loaded counter stop 15 due to the pressurization. Fig. 3 The counter stop 15 is in the retracted position, in which it has a distance from the workpiece 1.

[0054] The distance measured in the y-direction between the opposing clamping devices 5, 6, 10 is set so that the workpiece 1 reaches the lower clamping jaw 14 of the clamping device 10 over part of its width.

[0055] Since the clamping jaws 5', 6', 12 are raised during the transfer or alignment of the workpiece 1, the workpiece 1 rests on the lower clamping jaws 5", 6", 14 without tension. It must be ensured that the lower clamping jaws 5", 6" of the clamping device 5, 6 and the support / clamping jaw 14 of the clamping device 10 are at exactly the same height. In the next step, the workpiece 1 is aligned so that it is positioned precisely for the subsequent machining. For this purpose, the clamping device 5, 6 is equipped with at least one spring-loaded counter stop 15, which is movable in the y-direction. The counter stop 15 has a stop surface 16 perpendicular to the support surface of the lower clamping jaw 5", 6", with which it comes into contact with the longitudinal side 17 of the workpiece 1 opposite the longitudinal side 13 when it moves the workpiece in the y-direction ( Fig. 5 ).

[0056] With the counter stop 15, the workpiece 1 is pushed in the y-direction onto the lower clamping jaw 14 until the workpiece 1 with its longitudinal side 13 rests against a stop 18 of the clamping device 10 extending in the x-direction ( Fig. 5 ), whose contact side is also perpendicular to the bearing surface of the lower clamping jaw 14. The stop 18 of the clamping device is arranged on the supports 50 of the adjustment units 31 and can be positioned in the y-direction by means of the further adjustment units 31a. In this way, the position of the workpiece 1 can be set exactly for the subsequent machining.

[0057] The workpiece 1 is advantageously positioned such that, in the y-direction, it already assumes the position required for the subsequent machining of the longitudinal side 17 during this initial clamping. Then, after machining one longitudinal side 13 and transferring it to the clamping device 10, the workpiece 1 does not need to be moved.

[0058] In the described alignment process, workpiece 1 is brought into the exact position.

[0059] Once the workpiece 1 has been precisely aligned using the horizontal stops 15 and 18, the upper clamping jaws 5', 6' of the clamping carriages 5a to 5c, 6a to 6c of the clamping devices 5, 6 are lowered in the z-direction until the workpiece 1 is clamped between the upper clamping jaws 5', 6' and the lower clamping jaws 5", 6". The workpiece 1 is clamped such that it projects beyond the clamping jaws 5', 5", 6', 6" in the y-direction towards the clamping device 10. In this embodiment, the workpiece 1 projects approximately half its width beyond the clamping jaws 5', 5", 6', 6".

[0060] The clamped workpiece 1 rests with its longitudinal side 17 against the stop surface 16 of the counter stop 15 of the clamping device 5, 6 ( Fig. 5 ).

[0061] The stop 18 can be positioned in its y-position via a separate y-axis or, as in the exemplary embodiment, by means of the y-axis of the clamping device 10.

[0062] In the exemplary embodiment, the stop 18 is arranged on the supports 50 of the adjustment units 31a and can be adjusted to three positions in the y-direction. To push off the finished workpieces 1, the stop 18 is indexed forward in the y-direction. The two pre-indexed positions of the stop 18 serve to align and push off the workpieces 1. The stop 18 is then indexed back to the third position when the workpiece 1 is to be transferred to the clamping device 10 for the second clamping operation to machine the longitudinal side 17. The stop 18 is then not in contact with the workpiece 1. Fig. 4 The middle position of stop 18 is shown.

[0063] Once the workpiece is clamped in the clamping device 5, 6 as described, the clamping device 10 is fitted with the described adjustment units 31a ( Fig. 2 The workpiece 1 is moved back in the y-direction so that it can then be machined on its longitudinal side 13 with the appropriate tools, usually by profiling or planing. The system is equipped with the appropriate tool.

[0064] The machining tool is inserted into a tool spindle 33 ( Fig. 1 ) is used, which is provided on a portal 34 that is movable in the x-direction. It has two vertical columns 35, 36 that are movable on guides 37, 38 extending in the x-direction. At their upper ends, the columns 35, 36 are connected to each other by a crossbeam 39. A drive 40 is provided for moving the portal 34, which is shown by way of example arranged on column 36. The machining tool is moved past the workpiece 1 in the x-direction, whereby the longitudinal side 13 is machined accordingly.

[0065] In the area projecting beyond the clamping jaws 5', 5", 6', 6" and in the areas between the upper and lower clamping jaws 5', 5", 6', 6" bores, grooves and the like can be made in the top 19 or bottom 19' of the workpiece 1.

[0066] The Fig. 5a und 5b Figure 1 shows a variant of the clamping and transfer process. As soon as the workpiece 1 is precisely aligned in the described manner with the horizontal stops 15 and 18, the clamping jaw 12 of the clamping device 10 is lowered, thereby clamping the workpiece 1 between the clamping jaw 12 and the lower clamping jaws 5" of the clamping devices 5, 6, as well as the lower clamping jaw 13 of the clamping device 10. Fig. 5a This clamping method is advantageous when workpiece 1 is attached to the in Fig. 5a The right side is shaped or, for example, distorted or twisted by internal stresses in such a way that it does not rest on the lower clamping jaws 5", 14. In this case, the upper clamping jaw 12 of the clamping device 10 ensures that the workpiece 1 is pressed firmly against the lower clamping jaws on this side.

[0067] Subsequently, the upper clamping jaws 5' of the clamping devices 5, 6 are lowered so that the workpiece 1 is also clamped by these clamping jaws 5' ( Fig. 5b ). Subsequently, the upper clamping jaw 12 of the clamping device 10 can be raised again, so that the workpiece 1 to be machined is only gripped on the top side by the clamping jaws 5'.

[0068] Since the workpiece 1 was initially clamped with the upper clamping jaw 12 of the clamping device 10, the workpiece 1 is clamped on its right longitudinal side against the lower clamping jaws 5, 14, so that it rests securely on the clamping jaws. When the clamping jaws 5 subsequently clamp the workpiece 1 even more tightly, the clamping jaw 12 can be lifted again without the workpiece 1 lifting off the lower clamping jaws on its right longitudinal side. The workpiece 1 is then clamped in the clamping device 5, 6, so that the clamping device 10, with the clamping jaw 12 lifted, can be retracted in the y-direction to machine the workpiece 1 on its now exposed longitudinal side 13 with the appropriate tools.

[0069] Once the workpiece 1 has been machined on one of its longitudinal sides 13 and, if applicable, on its top 19 and / or bottom 19', the clamping device 10 is moved in the y-direction by means of the adjustment units 31a back into a position relative to the clamping device 5, 6 in which the workpiece 1 is gripped by the clamping jaws 12, 14 of the clamping device 10. This position of the two clamping devices 5, 6, 10 relative to each other corresponds approximately to the position as it is in Fig. 6 is shown. In this position, in which the workpiece, machined on one of its longitudinal sides 13, is still clamped in the clamping device 5, 6, the upper clamping jaw 12 of the clamping device 10 is lowered in the z-direction so far that the workpiece is clamped in the clamping device 10 in the area projecting beyond the clamping jaws 5', 5", 6', 6" or in a previously machined area, e.g. in a rebate.

[0070] During this y-movement, the clamping device 10 is moved towards the clamping device 5, 6 until the clamping device 10 has reached the optimal position for optimal clamping and for machining the workpiece 1 on the longitudinal side 17.

[0071] During the transfer process, workpiece 1 is never free. Furthermore, the workpiece's position remains fixed within the system. This ensures highly precise machining of workpiece 1, as no axis positioning of the clamping device is required.

[0072] Once the protruding part of the workpiece 1 is clamped in the clamping device 10, the upper clamping jaws 5', 6' of the clamping carriages 5a to 5c, 6a to 6c are lifted in the z-direction, so that the workpiece is no longer clamped by the clamping device 5, 6. The clamping device 5, 6 is then moved back in the x-direction to the loading area 7 to receive the next workpiece 1 to be processed.

[0073] Before this retraction, it is advantageous to make a small z-stroke (for example 3 mm) upwards of the clamping device 10, or to retract the clamping device 10 in the y-direction so that the underside of the workpiece 1 is not damaged when the clamping device 5, 6 is moved.

[0074] In order to ensure a reliable transfer between the clamping device 5, 6 and the clamping device 10, it is advantageous if, during the movement into or out of the transfer position, the respective lower clamping jaws 5", 6", 14 can be slightly lowered in the z-direction, so that it is ensured that the lower clamping jaws 5", 6", 14 do not come into contact with the support side of the workpiece 1, which could damage its surface.

[0075] The workpiece 1 is clamped in the clamping device 10 such that it projects sufficiently far beyond the clamping jaws 12, 14 of the clamping device 10 in the y-direction. The unmachined longitudinal side 17 of the workpiece 1 can then be easily machined with the appropriate tool, which is moved past the workpiece 1 in the x-direction by means of the portal 34.

[0076] In the exposed area of ​​the top surface 19 or the bottom surface 19' of the workpiece, bores, grooves and the like can also be made using the appropriate tool.

[0077] The described process for clamping, transferring and machining the workpiece is carried out in the same way with all clamping devices 5, 6.

[0078] When machining two or more workpieces 1 simultaneously, two or more clamping devices 5, 6 can certainly be used, which perform the corresponding movements simultaneously and in parallel, as shown by the Fig. 3 bis 7 has been explained.

[0079] The finished workpieces are placed in a receiving unit 20 ( Fig. 1 ) which is adjustable in height. During the machining of the workpieces 1, the holding unit 20 is located in the area above at least the upper clamping jaws 5', 6', 12. After the workpieces 1 have been finished, the holding unit 20 is lowered until it is located in the area below the clamped workpieces. Then, after the clamping is released, the workpiece 1 is pushed onto the holding unit 20 in the y-direction using the stop 18 of the clamping device 10.

[0080] The receiving unit 20 is mounted by two arms 41, 42 on a slide 43, which is movable in the z-direction along the crossbeam 39 of the portal 34. Together with the portal 34, the receiving unit 20 can be moved in the x-direction when the finished workpieces are placed on it and the receiving unit 20 is in its upper position. Fig. 1 The initial situation shown has been improved.

[0081] The portal 34 moves the intake unit 20 in the x-direction until it meets a discharge unit 21 ( Fig. 1 ) opposite. It is located in the area above the feed unit 2.

[0082] The receiving unit 20 is formed, for example, by a profiled sheet metal piece which has a support part 22 lying in a horizontal plane and which is provided with recesses 23 that are open in the direction of the free edge of the support part 22.

[0083] When the receiving unit 20 is lowered in the area of ​​the removal unit 21 by moving the slide 43 in the z-direction, the belt tracks 21a of the transport unit 3 project into the recesses 23, which grasp the workpieces 1 lying on the support part 20 and remove them from the receiving unit 20 in the y-direction.

[0084] The placement of the finished workpieces 1 on the discharge unit 21 can take place parallel to the alignment and initial clamping of the workpieces 1 in the machining area 9, thus ensuring a continuous machine operation.

Claims

1. Device for machining workpieces made of wood, plastic, aluminium and the like, with at least one first tensioning device (5, 6) comprising a clamping device (5', 5", 6', 6"), which is adjustable in the x-direction from a loading area (7) into a machining area (9) and vice versa, and with at least one second tensioning device (10) which is provided with at least one clamping device (12, 14) and to which the workpiece (1) is transferred, characterized in that the second tensioning device (10) has at least one stop (18) for the workpiece (1) which stop (18) is adjustable in the y-direction, and the first tensioning device (5, 6) has at least one counter stop (15) for the workpiece (1) which counter stop (15) is adjustable in the y-direction.

2. Device according to Claim 1, characterized in that the second tensioning device (10) can be positioned in the y-direction by means of at least one drive (44).

3. Device according to Claim 1 or 2, characterized in that the first tensioning device (5, 6) is movable along a guide (8) extending in the x-direction.

4. Device according to one of Claims 1 to 3, characterized in that the second tensioning device (10) is arranged in the machining area (9) non-adjustably in the x-direction.

5. Device according to one of Claims 1 to 4, characterized in that the second tensioning device (10) is arranged adjustably in the y-direction along a guide (32).

6. Device according to one of Claims 1 to 5, characterized in that the lower clamping jaw (14) of the second tensioning device (10) is adjustable in the z-direction.

7. Device according to one of Claims 1 to 6, characterized in that the clamping jaws (12, 14) of the second tensioning device (10) extend over the length (x-direction) of the second tensioning device (10) .

8. Device according to one of Claims 1 to 7, characterized in that the second tensioning device (10) extends almost over the length (x-direction) of the machining area (9).

9. Device according to one of Claims 1 to 8, characterized in that at least one receiving unit (20) is provided for depositing the workpieces (1) after machining, which is adjustable in the x-direction from the machining area (9) into the loading area (7).

10. Method for clamping workpieces (1) which are aligned and clamped by means of at least two tensioning devices (5, 6, 10), in particular in a device according to one of Claims 1 to 9, <b>characterized by the following steps: that the workpiece (1) is received and clamped in a loading area (7) of a first tensioning device (5, 6) without precise positioning with respect to the first tensioning device (5, 6), that the workpiece (1) with the first tensioning device (5, 6) and a second tensioning device (10), whose clamping device (12, 14) is opened, are moved into an opposing position, that the lower clamping jaws (5", 6", 14) or supports of the two tensioning devices (5, 6; 10) are aligned exactly to each other in the vertical direction, that the clamping of the workpiece (1) in the first tensioning device (5, 6) is released so that the workpiece is completely free, that the workpiece (1) is aligned or positioned in the y-direction by means of horizontally opposing stops (15, 18), that subsequently the workpiece (1) is clamped in one of the two tensioning devices (5, 6, 10) and then machined.

11. Method according to Claim 10, characterized in that the workpiece (1) rests against a stop (18) of the second tensioning device (10) and a counter stop (15) of the first tensioning device (5, 6) before being clamped in one of the two tensioning devices (5, 6).

12. Method according to Claim 10 or 11, characterized in that after clamping the workpiece (1) in the first tensioning device (5, 6), the second tensioning device (10) is moved back in the y-direction so far that at least one side (13, 19) of the workpiece (1) can be machined.

13. Method according to one of Claims 10 to 12, characterized in that after machining one side (13, 19) within the machining area (9) the workpiece (1) is transferred to the second tensioning device (10).

14. Method according to one of Claims 10 to 13, characterized in that the workpiece (1) is always clamped during the transfer from the first tensioning device (5, 6) to the second tensioning device (10).

15. Method according to Claim 14, characterized in that the clamping device (5', 5", 6', 6") of the first tensioning device (5, 6) is opened when the clamping device (12, 14) of the second tensioning device (10) has clamped the workpiece (1).

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