WORKPIECE MOUNTING DEVICE, GRINDING MACHINE AND METHOD FOR MOUNTING A WORKPIECE

Description

[0001] The invention relates to a workpiece fastening device for fastening a workpiece by means of negative pressure for its processing, which has a support device on which the workpiece can be placed for fastening, and has at least one negative pressure chamber which is formed starting from the support device.

[0002] Furthermore, the invention relates to a grinding machine and a method for fastening a workpiece by means of negative pressure for its processing with a workpiece fastening device.

[0003] It is known to attach workpieces to a support device for machining, for example with a grinding machine, by means of a workpiece clamping device. For this purpose, the workpiece clamping device may include a suction device. The support device may comprise a stationary table unit and a conveyor belt moving relative to the table unit for transporting the workpiece to be clamped in a main machining direction.

[0004] To secure the workpiece to the support device, the device may have suction openings through which the suction device draws in air. When a workpiece is placed on the support device, it covers some of these suction openings. Depending on the size of the workpiece and the distribution of the suction openings, the workpiece being processed covers a greater or lesser number of the support device's suction openings. The larger the workpiece or the closer the suction openings are spaced together, the greater the resulting holding force generated by the suction device.

[0005] In workpiece machining, for example with continuous grinding machines with wide belts or other machining units, the holding force for the workpiece is determined by the number of suction openings engaged (in the form of through holes or suction channels in the support device), the vacuum, and other parameters. DE 10 2016 117 992 A1, DE 10 2008 059 177 B4, DE 20 2010 013 582 U1, DE 195 18 373 A1, DE 29 39 571 A1, DE 43 07 432 C2, DE 20 2008 004 820 U1, and DE 199 63 461 B4 describe solutions that are intended to enable the fastening of workpieces to a support device using a suction device.

[0006] The European Patent Office cites the following documents in its European search report: US 2015 / 336406 A1, DE 195 18 373 A1, EP 2 853 406 A1 and EP 3 375 619 A1.

[0007] However, with these solutions, it can happen that with smaller workpieces, not enough suction openings are engaged with the workpiece to securely fix it during machining. Furthermore, with smaller workpieces, the support device is insufficiently covered, resulting in high vacuum losses.

[0008] It is known that this problem can be solved by using workpiece holders that can accommodate smaller workpieces. However, this has the disadvantage that only small or only large workpieces can be processed, meaning that mixed operation is not possible. The use of such workpiece holders therefore leads to comparatively high setup costs and long setup times.

[0009] The invention is therefore based on the objective of providing a workpiece fastening device, a grinding machine and a method for fastening a workpiece with a workpiece fastening device, which do not have the described disadvantages.

[0010] According to one aspect of the invention, the problem is solved by a workpiece fastening device for fastening a workpiece by means of negative pressure for its machining according to claim 1.

[0011] The workpiece clamping device is, in particular, a workpiece clamping device of a machine tool. The machine tool is preferably a grinding machine, and more preferably a wide belt grinder. The workpiece clamping device is therefore particularly suitable for fixing workpieces for grinding operations.

[0012] The workpiece clamping device includes a support device on which the workpiece to be machined can be placed for clamping. The support device can be formed, for example, by or comprise one or more workpiece support plates or by one or more workpiece support surfaces. Furthermore, the support device can be formed, for example, by or comprise one or more workpiece conveyor belts. For machining a workpiece, the workpiece is positioned on the support device and fixed to it. To fix the workpiece to the support device, the support device preferably has a suction surface and a suction surface. A suction surface is a surface against which the workpiece to be clamped rests and is drawn in. Atmospheric pressure typically prevails on the suction surface side.In contrast, the pressure at the extraction surface is lower than atmospheric pressure during operation. The extraction surface is, in particular, a surface facing away from the intake surface. The support device preferably extends between the intake surface for workpieces and the extraction surface, perpendicular to a main machining direction.

[0013] Preferably, the suction surface and the extraction surface of the support device extend in one plane. The extraction surface and the suction surface are preferably spaced apart from each other. In particular, the extraction surface and the suction surface extend parallel to each other.

[0014] Furthermore, the workpiece clamping device has at least one vacuum chamber extending from the support device. The suction surface can be a surface facing the at least one vacuum chamber. Air drawn in from the environment on the suction surface side is extracted on the suction surface side in the direction of the at least one vacuum chamber. It is also preferred that the at least one vacuum chamber extends from the suction surface of the support device. In particular, the vacuum chamber is arranged on the support device. Preferably, the vacuum chamber is arranged on the suction surface of the support device. Preferably, the suction surface of the support device forms an inner wall of the vacuum chamber.

[0015] The at least one vacuum chamber has a lower pressure than the surrounding environment of the workpiece clamping device. The ambient pressure can vary depending on the weather. A vacuum within the vacuum chamber is preferably generated by a suction device.

[0016] The workpiece clamping device has a first clamping area and a second clamping area that differs from the first. In the first clamping area, the support device has a first support channel profile. In the second clamping area, the support device has a second support channel profile that differs from the first.

[0017] For the purposes of the invention, a support channel profile is understood to be the sum of the features formed by a plurality of channels in the respective mounting area and their arrangement relative to one another. Examples of such features are the contour of the cross-sectional area of ​​a channel (for example, circular, elongated, in the form of a triangle, a square, or a cross), in particular the contour of the cross-section in the area of ​​a workpiece support surface of the support device, one or more dimensions of this cross-section, the distances between the channels in one direction or another, the number of channels per area, and the cross-sectional area occupied by the channels in relation to the total area within which the channels are arranged. At least one of these features differs between the first support channel profile and the second support channel profile. Preferably, the channels of a support channel profile are identical.

[0018] The first and / or second support channel profile is designed to fluidically connect the area surrounding the workpiece clamping device with the vacuum chamber. The first and / or second support channel profile preferably comprises an arrangement of through-openings that fluidically connect the intake side with the exhaust side. In particular, the first and / or second support channel profile each has an arrangement of several channels extending from the intake surface to the exhaust surface. Preferably, the channels are designed to fluidically connect the area surrounding the workpiece clamping device with the vacuum chamber.

[0019] Preferably, the first and / or second support channel profile is designed as a perforated profile. A perforated profile can, in particular, have channels with a circular cross-section and / or a polygonal cross-section, preferably a square or rectangular cross-section. Furthermore, it is preferred that the first and / or second support channel profile is designed as an elongated slot profile. In particular, the perforated profile of the first support channel profile can differ from the perforated profile of the second support channel profile. It is especially preferred that the cross-section of the channels of the perforated profile of the first support channel profile differs from the cross-section of the channels of the perforated profile of the second support channel profile. Particularly preferably, the first support channel profile has grooves, in particular groove-shaped channels or channels designed as elongated slots, and the second support channel profile has channels designed as bores.This embodiment preferably produces a significantly larger vacuum clamping surface.

[0020] Preferably, the channels of the first and / or second support channel profile are equidistant from each other. It may be preferred that channels are, at least partially, positioned at varying distances from each other.

[0021] By dividing the workpiece clamping device into a first clamping area and a second clamping area that differs from the first, different support channel profiles with varying numbers and channel densities can be provided. This allows control over the number of channels that engage with a workpiece being clamped, i.e., those concealed by the workpiece resting on the support device.

[0022] Furthermore, the division into different clamping areas allows for different vacuum levels to be provided in vacuum chambers for each clamping area, provided the workpiece clamping device has multiple vacuum chambers. In particular, the vacuum chamber for a clamping area can be completely deactivated if no workpiece is to be clamped in that area. Vacuum chambers can be switched on and off accordingly, and the chamber volumes of the individual vacuum chambers can be varied depending on the workpiece size.

[0023] In particular, this minimizes vacuum losses in the low-pressure chambers.

[0024] According to a preferred embodiment, the workpiece clamping device includes a sliding device arranged in the first clamping area, wherein the sliding device and the support device are arranged to be movable relative to each other. Preferably, the sliding device and the support device are arranged to be movable relative to each other translationally and / or rotationally.

[0025] In particular, the slide device has a slide channel profile. The slide channel profile is designed to fluidically connect and / or close the first support channel profile of the workpiece clamping device to the vacuum chamber. Specifically, the slide device has channels extending from the suction surface to the vacuum chamber. Preferably, the channels of the slide channel profile are designed to fluidically connect the first support channel profile of the workpiece clamping device to the vacuum chamber.

[0026] In particular, the sliding device is designed to vary the first support channel profile between the intake surface and the extraction surface, at least section by section. Preferably, the sliding device is designed to vary one or more channels of the first support channel profile between the intake surface and the extraction surface, at least section by section. In particular, the sliding device is preferably designed to vary the cross-sections of one or more channels of the first support channel profile between the intake surface and the extraction surface, at least section by section.

[0027] Preferably, the valve channel profile is designed as a perforated profile. A perforated profile can, in particular, have channels with a circular cross-section and / or a polygonal cross-section, preferably a square or rectangular cross-section. Furthermore, it is preferred that the valve channel profile is designed as a perforated profile. Preferably, the channels of the valve channel profile are equidistant from one another. It is also preferred that the channels are, at least partially, spaced at varying distances from one another.

[0028] Preferably, the slide device is displaceable orthogonally to the main machining direction relative to the support device. In particular, the slide device is displaceable in a plane parallel to the support device, especially the suction surface and / or extraction surface. Preferably, the slide device is arranged between the suction surface and extraction surface.

[0029] In a preferred embodiment of the workpiece clamping device, the sliding device extends over the first clamping area. Particularly preferably, the sliding device extends over one or more partial areas of the first clamping area. The sliding device is specifically designed to vary the first support channel profile, at least in sections. It is particularly preferred that the sliding device is designed to close individual channels of the first support channel profile in a flow-related manner.

[0030] The sliding device allows a suitable suction profile to be set depending on the workpiece size. In particular, the sliding device makes it possible to vary the negative pressure resulting in the at least one vacuum chamber. Furthermore, the flow velocity of air drawn in from the environment can preferably be controlled through individual channels of the first support channel profile. This makes it possible, on the one hand, to optimally fix workpieces for machining and, on the other hand, to minimize power loss. Moreover, the workpiece clamping device can be adapted to the size of the workpiece to be machined without significant setup times or costs.

[0031] In a further preferred embodiment of the workpiece clamping device, the slide device and / or the support device are configured to be moved back and forth relative to each other between a first slide position and a second slide position that differs from the first. In particular, the slide device and / or the support device are configured to be moved back and forth translationally and / or rotationally relative to each other between the first slide position and the second slide position. In the first slide position, the slide device and the support device form a first suction hole profile, and in the second slide position, they form a second suction hole profile that differs from the first. Preferably, the first suction hole profile is the first support channel profile.

[0032] For the purposes of the invention, a suction hole profile is understood to be, in particular, the sum of the features formed by a plurality of channels through the interaction of the position of the slide device in relation to the support device and their arrangement relative to one another. Examples of such features are the contour of the cross-sectional area of ​​a channel (for example, circular, elongated, in the form of a triangle, a square, a cross), in particular the contour of the cross-section in the area of ​​a workpiece support surface of the support device and / or the slide device, one or more dimensions of this cross-section, the distances between the channels in one direction or in another direction, the number of channels per area, and the cross-sectional area occupied by the channels in relation to the total area within which the channels are arranged. At least one of these features differs in the first suction hole profile from the second suction hole profile.Preferably, the channels of a suction hole profile are identically designed.

[0033] This preferred embodiment has the advantage that the suction hole profile can be adapted depending on the size of the workpieces to be machined. In particular, this preferred embodiment allows workpieces of different sizes to be fixed simultaneously on the workpiece clamping device. This reduces setup time and, at the same time, speeds up the machining of workpieces through parallel or simultaneous processing.

[0034] Furthermore, in a preferred embodiment, the sliding device comprises one or more sliding units configured to move back and forth between the first and second sliding positions, either dependently or independently of one another, relative to the support device. Preferably, the one or more sliding units are configured to move back and forth translationally and / or rotationally between the first and second sliding positions, either dependently or independently of one another, relative to the support device.

[0035] Preferably, the first support channel profile can be varied differently with one sliding unit than with another sliding unit. For example, it may be preferred that one sliding unit has been displaced such that the first support channel profile has a first cross-section in sections that is smaller than a resulting cross-section obtained by displacing another sliding unit.

[0036] In particular, the sliding device is designed to vary the first support channel profile between the intake surface and the extraction surface, at least section by section. Preferably, the sliding device is designed to vary one or more channels of the first support channel profile between the intake surface and the extraction surface, at least section by section. In particular, the sliding device is preferably designed to vary the cross-sections of one or more channels of the first support channel profile between the intake surface and the extraction surface, at least section by section.

[0037] In particular, the single or multiple sliding units are configured to move continuously back and forth between the first and second sliding positions. This has the advantage that the single or multiple sliding units can be moved with exceptional precision. It may also be preferred that the single or multiple sliding units are configured to move back and forth between the first and second sliding positions in discrete steps. This has the advantage that the single or multiple sliding units can be moved with exceptional ease.

[0038] According to a further preferred embodiment of the workpiece clamping device, the first support channel profile has a higher number of suction channels per unit area compared to the second support channel profile. In particular, the cross-section of the channels of the first support channel profile is smaller than the cross-section of the channels of the second support channel profile.

[0039] According to a further preferred embodiment, the first fastening area has a smaller surface area compared to the second fastening area. This allows for particularly efficient fixing of smaller workpieces.

[0040] According to a further preferred embodiment, the first and second mounting areas extend over the same length in a main machining direction of the workpiece. Additionally or alternatively, the first mounting area extends orthogonally to the main machining direction over a narrower width than the second mounting area.

[0041] Furthermore, in a preferred embodiment, a sensor device is provided which is configured to detect a workpiece arranged on the support device, wherein the sensor device is preferably configured to detect a position and / or a change in position and / or a position range and / or a size and / or a length and / or a width and / or a height of the workpiece on the support device, in particular on a suction surface of the support device, on which the workpiece arranged on the support device rests.

[0042] To detect changes in position, the sensor device can, for example, be designed to detect the position of the workpiece on the support device at different times. If the positions of the workpiece detected at these different times differ, a change in position has occurred. A preferred threshold for a change in the workpiece's position is, for example, at least 0.01 mm, at least 0.05 mm, at least 1 mm, at least 5 mm, at least 10 mm, or more. If the support device includes a transport unit on which the workpiece is moved in a main machining direction at a specific speed, the change in the workpiece's position must be determined taking into account the transport speed and the direction of transport.

[0043] If a change in position is detected by the sensor device, the suction power of the suction device can be increased, thus preventing further changes in the position of the workpiece arranged on the support device.

[0044] It may be preferred that the sensor device has several sensor units that detect the workpiece arranged on the support device. In particular, it is preferred that several sensor units are arranged at intervals from each other. Preferably, the sensor units are arranged at intervals from each other in the main machining direction and / or orthogonally to the main machining direction.

[0045] The sensor device, in particular the sensor units, is designed, for example, as a line scan camera. In particular, suitable sensor devices, especially preferably sensor units, include sensors and / or cameras designed to detect a change in the position of the workpiece of at least 0.01 mm, at least 0.05 mm, at least 1 mm, at least 5 mm, at least 10 mm or more.

[0046] The sensor device allows the sliding mechanism and / or the vacuum chamber to be controlled depending on the size and number of workpieces to be clamped. This enables particularly simple and efficient clamping of workpieces, especially smaller ones.

[0047] Furthermore, it is provided that the at least one vacuum chamber has a chamber volume that is variable in size, wherein the chamber volume can be varied between a first chamber volume and a second chamber volume that differs from the first. Preferably, the chamber volume of the at least one vacuum chamber is variable depending on the position range detected by the sensor device and / or depending on the size and / or length and / or width and / or height of the workpiece detected by the sensor device.

[0048] Furthermore, in a preferred embodiment of the workpiece fastening device, it is provided that the at least one vacuum chamber has a partition wall device designed to change the chamber volume of the at least one vacuum chamber between the first chamber volume and the second chamber volume.

[0049] According to a further preferred embodiment, the workpiece clamping device has an actuating device configured to position the partition device between a first positioning position and a second positioning position that differs from the first. Preferably, the at least one vacuum chamber has the first chamber volume in the first positioning position of the partition device and the second chamber volume in the second positioning position of the partition device.

[0050] In a further preferred development, the actuating device is designed as a manually operated actuating device and / or as an automatically operated actuating device.

[0051] Furthermore, a preferred embodiment of the workpiece clamping device includes a suction device for generating a vacuum in the vacuum chamber. The sensor device is preferably arranged upstream and / or downstream of the suction device in the transport direction of the workpiece.

[0052] Furthermore, for a preferred further development of the workpiece fastening device, a control device is provided which is connected to the sensor device and / or the actuating device and / or partition device and / or the suction device via signal technology.

[0053] Furthermore, in a preferred embodiment of the workpiece clamping device, the support device comprises a stationary table unit and / or a transport unit designed to transport the workpiece to be machined in the main machining direction. Preferably, the stationary table unit has a longitudinal pattern profile. Additionally or alternatively, it is preferred that the transport unit has a perforated profile. Furthermore, it is additionally or alternatively preferred that the transport unit is arranged to be movable relative to the table unit.

[0054] In a further development of the workpiece fastening device, it is provided that the transport unit is a conveyor belt or a transport carpet, wherein the conveyor belt or transport carpet is preferably designed to be endless.

[0055] According to another aspect, the problem is solved with a grinding machine according to claim 13.

[0056] The grinding machine is preferably a wide belt grinding machine. The grinding machine includes a workpiece clamping device. The workpiece clamping device comprises individual features or a combination of features of the workpiece clamping device described above.

[0057] According to a preferred embodiment of the grinding machine, it has at least one grinding unit for machining a workpiece secured with the workpiece clamping device.

[0058] According to another aspect, the problem is solved by a method for fastening a workpiece with a workpiece fastening device according to claim 14.

[0059] The method for fastening a workpiece with a workpiece fastening device comprises the following steps: Capturing a workpiece arranged on a support device; and assigning the captured workpiece to a first or to a second mounting area different from the first.

[0060] Furthermore, the procedure is intended to include the following steps: Setting the size of a chamber volume of at least one vacuum chamber depending on the workpiece being detected; and setting a suction hole profile in the support device in the associated mounting area depending on the workpiece being detected, and / or setting a suction power of a suction device depending on a detected change in the position of the workpiece.

[0061] According to a preferred embodiment of the method, adjusting the suction power of the suction device is an increase in suction power when the change in position of the workpiece is above a threshold value.

[0062] It should be understood that the workpiece clamping device according to one aspect of the invention, the grinding machine, and the method for clamping a workpiece with a workpiece clamping device according to the other aspects of the invention have identical and similar sub-aspects, as set out in particular in the dependent claims. In this respect, full reference is made to the above description.

[0063] Embodiments of the invention are now described below with reference to the drawings. These drawings are not necessarily intended to represent the embodiments to scale; rather, where explanatory, they are presented in a schematic and / or slightly distorted form. For further details regarding the teachings directly apparent from the drawings, reference is made to the relevant prior art. It should be noted that numerous modifications and changes concerning the form and details of an embodiment can be made without deviating from the general idea of ​​the invention. The features of the invention disclosed in the description, the drawings, and the claims can be essential for the further development of the invention, both individually and in any combination.Furthermore, the invention encompasses all combinations of at least two of the features disclosed in the description, the drawings, and / or the claims. The general concept of the invention is not limited to the exact shape or detail of the preferred embodiments shown and described below, nor is it limited to an object that would be restricted compared to the object claimed in the claims. For the sake of simplicity, identical or similar parts, or parts with identical or similar functions, are referred to by the same reference numerals below.

[0064] Preferred embodiments of the invention are explained by way of example with reference to the accompanying figures. Figure 1 shows an isometric view of a preferred embodiment of a workpiece clamping device; Figure 2 shows a top view of a conveyor belt of the Figure 1The workpiece clamping device shown; Figure 3 shows a detailed view of a table unit of the in Figure 1 The workpiece clamping device shown; Figure 4 shows a sectional view of another preferred embodiment of a workpiece clamping device based on the one described in Figure 1 the illustrated embodiment of the workpiece fastening device is based on; and Figure 5 shows a schematic flowchart of a preferred embodiment of a method for fastening a workpiece with a workpiece fastening device.

[0065] Figure 1 Figure 1 shows an isometric view of a preferred embodiment of a workpiece clamping device 1 for securing a workpiece 2 for machining. A grinding machine (not shown), for example a wide belt grinder, can use such a workpiece clamping device 1 to secure workpieces 2 for machining.

[0066] The workpiece clamping device 1 has a support device 3. In this preferred embodiment, the support device 3 comprises a stationary table unit 10 and a transport unit 20. The transport unit 20 is arranged to be movable relative to the table unit 10 and is designed as an endless conveyor belt or conveyor belt. For machining the workpiece, the transport unit 20 conveys the workpiece 2 to be machined in a main machining direction H along a machining unit, for example, a grinding unit (not shown). For this purpose, the workpiece to be machined is first arranged on the support device 3, or in this case, the transport unit 20.

[0067] The support device 3 extends between a suction surface 11 and a suction surface 12. The workpiece 2 to be machined is placed on the suction surface 11 of the support device 3 and fixed there. To fix the workpiece 2 to the support device 3, the workpiece clamping device 1 has a vacuum chamber 30 extending from the suction surface 12 of the support device 3. A vacuum is created in the vacuum chamber 30 via a vacuum connection 70, which draws air from the environment through the suction surface 11.

[0068] This results in a vacuum that draws the workpiece 2 against the suction surface 11. The vacuum connection 70 is fluidically connected to a suction device (not shown) which draws in the air.

[0069] In Figure 1It can be seen that the workpiece clamping device 1 has a first clamping area B1 and a second clamping area B2, which differs from the first clamping area B1. The first clamping area B1 has a smaller surface area compared to the second clamping area B2. Both the first and second clamping areas B1 and B2 extend over the same length in the main machining direction H of the workpiece 2. However, the first clamping area B1 has a smaller width perpendicular to the main dimension H compared to the second clamping area B2.

[0070] The support device 3 is designed to have a first support channel profile 13 in the first mounting area B1 and a second support channel profile 14 in the second mounting area B2, which differs from the first support channel profile 13. The first support channel profile 13 has a significantly more finely divided arrangement of channels through which air is drawn in, compared to the second support channel profile 14. This is also illustrated by… Figure 2 , which shows a top view of a conveyor belt in Figure 1 The illustrated workpiece clamping device 1 shows an elongated workpiece 2 fixed to it. Essentially, the first support channel profile 13 has a higher number of suction channels per unit area compared to the second support channel profile 14.

[0071] The support device 3 of the in Figure 1The illustrated embodiment features a sliding device 50 in the first mounting area B1. The sliding device 50 is arranged between and is displaceable relative to the transport unit 20 and the table unit 10. In the present embodiment, the sliding device 50 can be moved back and forth relative to the support device 3 between a first sliding position and a second sliding position that differs from the first. In this way, the sliding device 50, in conjunction with the support device 3, forms a first suction hole profile in the first sliding position and a second suction hole profile that differs from the first suction hole profile in the second sliding position.

[0072] The in Figure 1The illustrated sliding device 50 comprises two sliding units 50a, 50b, which are designed to be moved independently of one another between the first sliding position and the second sliding position relative to the support device 3. This is shown in the detailed view in Figure 3 on table unit 10 of the in Figure 1 The workpiece clamping device 1 shown. The sliding unit 50a on the right is in a first sliding position, which is designed for clamping larger workpieces 2. The sliding unit 50b on the left is in a second sliding position, which is suitable for clamping smaller workpieces 2.

[0073] Figure 4 shows a sectional view of another preferred embodiment of a workpiece fastening device 1, which is based on the in Figure 1 The embodiment of the workpiece fastening device 1 shown is based on this. Figure 4The embodiment shown differs from the one in Figure 1 In the illustrated embodiment, this is achieved by using two vacuum chambers 30a, 30b, one of which has a variable chamber volume. The chamber volume of this vacuum chamber 30a can be changed between a first chamber volume and a second chamber volume that differs from the first. To change the chamber volume, the vacuum chamber 30a has a partition device 60 that can be positioned between a first position and a second position that differs from the first. This allows the chamber volume of the vacuum chamber 30a to be set between a first chamber volume at the first position and a second chamber volume at the second position.

[0074] To position the partition wall device 60 between the first and second positioning positions, the following is included: Figure 4 The illustrated embodiment of the workpiece fastening device 1 includes an actuating device 40. The actuating device 40 can be designed for manual actuation or – as provided here – for automated actuation.

[0075] For the automated actuation of the actuating device 40, the workpiece fastening device 1 has a sensor device (not shown) and a control device (not shown).

[0076] The sensor device is designed to detect a workpiece 2 arranged on the support device 3. Specifically, the sensor device is designed to detect the position, size, length, width, and height of the workpiece 2 on the suction surface 11 of the support device 3, on which the workpiece 2 rests. In particular, the sensor device is also designed to detect changes in the position of the workpiece 2 arranged on the support device 3. For this purpose, the position of the workpiece is detected at different times and compared with each other, taking into account the transport speed and direction. If the comparison reveals that the positions detected at different times are not identical, a change in the position of the workpiece has occurred.In the preferred embodiment shown here, this can, for example, increase the suction power of the suction device.

[0077] The control device is connected via signal technology to the sensor device, the actuating device 40, the partition device 60, and the suction device. The control device is designed to adjust the chamber volume of the vacuum chamber 30a depending on the position range detected by the sensor device or the size (length, width, and height) of the workpiece 2 detected by the sensor device.

[0078] Figure 5 Figure 1 shows a schematic flowchart of a preferred embodiment of a method 1000 for fastening a workpiece 2 with a workpiece fastening device 1.

[0079] In the embodiment shown here, the method 1000 comprises the following steps: 1010 sensing a workpiece 2 arranged on a support device 3 and 1020 assigning the sensed workpiece 2 to a first or to a second mounting area B1, B2 that differs from the first. Furthermore, the method 1000 comprises 1030 setting the size of a chamber volume of at least one vacuum chamber 30, 30a, 30b depending on the sensed workpiece 2 and 1040 setting a suction hole profile in the support device 3 in the assigned mounting area B1, B2 depending on the sensed workpiece 2. Reference symbol list

[0080] 1 Workpiece clamping device 2 Workpiece 3 Support device 10 Table unit 11 Suction surface 12 Extraction surface 13 First support channel profile 14 Second support channel profile 20 Transport unit, conveyor belt, transport carpet 30, 30a,b Vacuum chamber 40 Actuating device 50 Slide device 50a,b Slide units 60 Partition device 70 Vacuum connection B1, B2 First, second clamping area H Main machining direction

Claims

1. Workpiece fastening device (1) for fastening a workpiece (2) by means of a vaccuum for its processing, the workpiece fastening device (1) comprising: - a support device (3) on which the workpiece (2) can be placed for fastening, and - at least one vacuum chamber (30, 30a, 30b), which is formed starting from the support device (3), - the support device (3) having a first fastening region (B1) and a second fastening region (B2) which is different from the first fastening region (B1), wherein - the support device (3) having a first support channel profile (13) in the first fastening region (B1) and a second support channel profile (14) in the second fastening region (B2), which differs from the first support channel profile (13), characterised in that - the at least one vacuum chamber (30, 30a, 30b) has a chamber volume which is variable in size, the chamber volume being variable between a first chamber volume and a second chamber volume which differs from the first chamber volume.

2. Workpiece fastening device (1) according to the preceding claim 1, comprising a slider device (50) which is arranged in the first fastening region (B1), the slider device (50) and the support device (3) being arranged so as to be movable relative to one another, wherein preferably the slider device (50) and the support device (3) are arranged so as to be movable relative to one another translationally and / or rotationally.

3. Workpiece fastening device (1) according to one of the preceding claims 1 or 2, - wherein the slider device (50) and / or the support device (3) are designed to be moved back and forth relative to one another between a first slider position and a second slider position different from the first, in particular to be moved back and forth translationally and / or rotationally relative to one another between the first slider position and the second slider position, - wherein the slider device (50) and the support device (3) form a first suction hole profile in the first slider position of the slider device (50) and form a second suction hole profile different from the first suction hole profile in the second slider position of the slider device (50), - wherein the first suction hole profile is preferably the first support channel profile (13).

4. Workpiece fastening device (1) according to one of the preceding claims 2-3, wherein the slider device (50) comprises one or more slider units (50a, 50b) which are designed to be moved back and forth between the first slider position and the second slider position depending on or independently of one another relative to the support device (3), wherein preferably the one or more slider units (50a, 50b) are designed to be moved back and forth translationally and / or rotationally relative to the support device (3) between the first slider position and the second slider position, depending on or independently of one another.

5. Workpiece fastening device (1) according to one of the preceding claims 1-4, wherein the first support channel profile (13) has a higher number of suction channels per unit area compared to the second support channel profile (14), and / or wherein the first fastening region (B1) has a smaller surface area compared to the second fastening region (B2).

6. Workpiece fastening device (1) according to the preceding claim 5, wherein - the first fastening region (B1) and the second fastening region (B2) extend over the same length in a main processing direction (H) of the workpiece (2) to be machined; and / or - the first fastening region (B1) extends orthogonally to the main processing direction (H) over a smaller width than the second fastening region (B2).

7. Workpiece fastening device (1) according to one of the preceding claims 1-6, comprising a sensor device which is designed to detect a workpiece (2) arranged on the support device (3), wherein the sensor device is preferably designed to detect a position and / or a change in position and / or a position range and / or a size and / or a length and / or a width and / or a height of the workpiece (2) on the support device (3), in particular on a suction surface (11) of the support device (3), on which the workpiece (2) arranged on the support device (3) bears.

8. Workpiece fastening device (1) according to one of the preceding claims 1-7, wherein the chamber volume of the at least one vacuum chamber (30, 30a, 30b) is variable as a function of the position range detected by the sensor device and / or as a function of the size and / or length and / or width and / or height of the workpiece (2) detected by the sensor device, and / or wherein the at least one vacuum chamber (30, 30a, 30b) has a partition wall device (60) which is designed to change the chamber volume of the at least one vacuum chamber (30, 30a, 30b) between the first chamber volume and the second chamber volume.

9. Workpiece fastening device (1) according to the preceding claim 8, comprising an actuating device (40) which is designed to position the partition wall device (60) between a first actuating position and a second actuating position different from the first, wherein preferably the at least one vacuum chamber (30, 30a, 30b) has the first chamber volume in the first setting position of the partition wall device (60) and has the second chamber volume in the second setting position of the partition wall device (60).

10. Workpiece fastening device (1) according to the preceding claim 9, wherein the actuating device (40) - is designed as a manually operated actuating device (40) and / or - is designed as an automatically operated actuating device (40).

11. Workpiece fastening device (1) according to one of the preceding claims 7 and / or 8 to 10, comprising a suction device for generating a vacuum in the vacuum chamber (30, 30a, 30b) with a suction power, and / or comprising a control device which is connected by signalling to the sensor device and / or the actuating device (40) and / or the partition wall device (60) and / or the suction device.

12. Workpiece fastening device (1) according to any of the preceding claims 1-11, - having the support device (3); ∘ a stationary table unit (10); and / or ∘ has a transport unit (20) which is designed to transport the workpiece (2) to be processed in the main processing direction (H); - wherein preferably ∘ the stationary table unit (10) has a longitudinal pattern profile; and / or ∘ the transport unit (20) is arranged so as to be movable relative to the table unit (10); and / or ∘ the transport unit (20) has a perforated pattern profile, - wherein the transport unit (20) is preferably a conveyor belt or a transport carpet, wherein the conveyor belt or the conveyor carpet is preferably endless.

13. A grinding machine, in particular a wide belt grinding machine, comprising a workpiece fastening device (1) according to any one of the preceding claims 1-12, and comprising at least one grinding unit for machining a workpiece (2) fastened by means of the workpiece fastening device (1).

14. Method (1000) for fastening a workpiece (2) by negative pressure for machining it with a workpiece fastening device (1), in particular a workpiece fastening device (1) according to one of the preceding claims, the method comprising the following steps: - gripping (1010) of a workpiece (2) arranged on a support device (3); and - assigning (1020) the detected workpiece (2) to a first or to a second fastening region (B1, B2) different from the first; and - adjusting (1030) a size of a chamber volume of at least one vacuum chamber (30, 30a, 30b) depending on the detected workpiece (2); and - adjusting (1040) a suction hole profile in the support device (3) in the associated fastening area (B1, B2) as a function of the detected workpiece (2); and / or - adjusting a suction power of a suction device depending on a detected change in position of the workpiece (2).

15. Method according to the preceding claim 14, - wherein the adjustment of the suction power of the suction device includes: ∘ increasing the suction power if the change in position of the workpiece (2) is above a threshold value.