CLAMPING DEVICE

Description

Technical area

[0001] The invention relates to a clamping device for a workpiece, in particular for a workpiece made of wood, plastic or the like, according to the preamble of claim 1. State of the art

[0002] When machining workpieces, in particular window or door elements, preferably made of wood, plastic or the like, a large number of different profiles are usually milled into the workpiece, which requires extensive machining, especially of the lateral surfaces in the longitudinal direction of the workpieces.

[0003] To meet the recent increase in demand for increased light penetration into living spaces, the width of individual window elements has been increasingly reduced. This leaves the workpiece with only a small free clamping surface for securing it in a clamping fixture for machining. Typically, such a window element undergoes several processing steps, with each step involving contouring one side. Clamping window elements with advanced profiling is particularly difficult due to the small free clamping surface.

[0004] Clamping devices for machining workpieces with an upper clamping element and a lower clamping element are known from the prior art, with the workpiece being clamped between these two clamping elements. The two clamping elements rest on the lower free support surface and the upper free support surface of the window elements. However, workpieces can be so short that they can no longer be effectively secured between multiple clamping devices. Therefore, if clamped in only one clamping device, they can be twisted and / or displaced during machining.

[0005] Clamping devices are known from DE 101 37 839 C5 which have a plurality of stops in their longitudinal direction, wherein the workpiece can be placed against the stops with one long side in order to ensure lateral guidance transverse to the longitudinal direction.

[0006] From DE 199 38 851 A1, adjustment stops are known which are arranged in a detachable manner and serve for manual alignment of the workpiece in a longitudinal direction.

[0007] Furthermore, the publication DE 10 2011 012 739 A1 discloses the provision of at least one stop which can be automatically positioned in a direction transverse to the longitudinal direction such that the workpiece can be placed with a side surface against the at least one stop in order to secure the workpiece during machining against possible twisting in a plane transverse to the longitudinal direction.

[0008] The document DE 20 2007 040 580 discloses stops which are used for the exact positioning of the workpiece, wherein these stops are adjustable in a direction transverse to the longitudinal direction.

[0009] From the document DE 20 2012 002940 U1 a clamping device according to the preamble of claim 1 is known.

[0010] Window elements that are already profiled on one side often have such a small clamping surface that the contact surface between the clamping elements and the workpiece required for stable fixation is missing. Furthermore, despite the stop elements known from the state of the art, clamping can result in the two clamping elements being so close together when clamped due to the low workpiece height that the tool can no longer reach the workpiece. Furthermore, already profiled window elements would be clamped in such a way that the window element would protrude upwards or downwards beyond the clamping elements, which could cause workpiece damage due to bending loads during machining. Description of the invention, task, solution, advantages

[0011] The invention is based on the object of designing a clamping device in such a way that even narrow and / or short workpieces, in particular those with already profiled side surfaces, can be clamped so stably that machining is possible without the risk of the workpiece slipping or twisting and / or without damaging the workpiece.

[0012] This problem is solved by the features of claim 1.

[0013] An example not according to the invention relates to a clamping device for a workpiece, comprising a lower clamping element and an upper clamping element which form a workpiece holder, wherein the upper clamping element is adjustable in height relative to the lower clamping element, wherein the workpiece has at least one outer surface arranged on the lower side and / or on the upper side and can be inserted into the clamping device, comprising a clamping support element which can be provided in the clamping device, wherein the clamping support element has at least one outer surface arranged on the upper side and / or on the lower side and the workpiece and the clamping support element can be clamped together in the clamping device,When the workpiece and the clamping support element are clamped in the clamping device, the at least one outer surface of the workpiece arranged on the underside and / or the top side and the at least one outer surface of the clamping support element arranged on the top side and / or the top side lie flat against one another. This has the advantage that even a workpiece with a pre-machined side surface can be securely clamped in the area of ​​the pre-machined side surface, because the surface created by the pre-machining is used for clamping. The clamping support element can be used not only for positioning but also for absorbing forces acting on the clamping support element during clamping.

[0014] It is advantageous if at least one such clamping device or several of them are provided in a workpiece table, by means of which at least individual workpieces can be machined in their longitudinal direction, and these workpieces and / or the clamping support element can be automatically inserted into the clamping element of the workpiece table. The workpiece table can have clamping elements for holding only one workpiece in a clamping position, or alternatively, the workpiece table can also provide clamping elements for holding a workpiece in one of opposite clamping positions.

[0015] Advantageously, the clamping device according to the invention comprises two lower clamping elements and two upper clamping elements, so that the clamping device forms two workpiece holders. This allows two workpieces to be held and machined simultaneously in one clamping device, or, after reclamping, an opposite side surface can also be machined.

[0016] In a clamping device according to the invention which forms two workpiece holders, workpiece holders are expediently located opposite one another so that reclamping between the two workpiece holders is easily possible.

[0017] It is advantageous if the clamping support element is designed as a separate component and can be inserted into the clamping device. This allows the clamping support element to be selected to suit the workpiece.

[0018] Furthermore, it is expedient if the lower and / or upper clamping element is / are shaped in such a way that the clamping support element is formed integrally with the lower and / or upper clamping element. Thus, the work step of inserting the clamping support element can be omitted if necessary.

[0019] It is also advantageous if a clamping support element can be extended from the lower clamping element and / or a clamping support element can be extended from the upper clamping element. It is particularly advantageous if the clamping support element can be extended vertically. This has the advantage that a clamping support element no longer needs to be used separately, but is already integrated and can be extended or retracted in a controlled manner. This is particularly advantageous for an automated machining process.

[0020] It is also advantageous that the clamping support element, which is designed as a separate part, can be inserted automatically into the clamping fixture. This allows the cycle rate during machining to be reduced if necessary, and it is also advantageous that a suitable clamping support element can be selected and inserted automatically. This allows the clamping support element to be optimally selected for the workpiece.

[0021] Furthermore, it is expedient that the clamping support element, which is designed as an independent part, can be automatically extended from the clamping device.

[0022] It is advantageous if the clamping support element can be connected in a form-fitting manner to the lower clamping element and / or the upper clamping element so that the position of the clamping support element relative to the clamping element is clearly defined in order to prevent possible damage to the workpiece due to incorrect positioning of the clamping support element.

[0023] In order for a clamping support element to be usable for different workpieces, it is advantageous for the clamping support element to be of stepped design and to have a plurality of upper outer surfaces, so that a respective workpiece can be placed on one of the upper outer surfaces depending on its shape.

[0024] It is expedient that at least one of the upper outer surfaces of the clamping device is surface-treated in such a way that its coefficient of friction with the workpiece is increased, whereby a higher holding force is created between the workpiece and the clamping support element even with a lower clamping force.

[0025] In this case, it is advantageous for at least one upper outer surface to be provided with a pincushion or to have a pincushion-like design. This achieves better adhesion.

[0026] According to the invention, the clamping device has at least one stop element which can be provided in the clamping device, so that the workpiece can be placed with a lateral outer surface on the at least one stop element, whereby a safeguard against rotation is achieved, especially in the case of a shorter workpiece.

[0027] In this case, it is advantageous for at least one of the stop elements to be formed by a clamping support element. This eliminates the need for a separate stop element.

[0028] At least one of the stop elements is formed by an element connected to the lower clamping element and / or upper clamping element and / or to the clamping support element. Such a connected element can be used with or without a clamping support element.

[0029] In this case, it is advantageous for the connected element to be a plug-in element or screw element that can be connected to the lower clamping element and / or the upper clamping element and / or the upper clamping element. This allows for quick attachment or removal of the connectable plug-in element.

[0030] It is provided that the at least one stop element can be extended from the lower clamping element and / or from the upper clamping element, in particular in a vertical direction. This allows cycle times to be increased because extending the element requires less time than inserting the element.

[0031] The problem of the method is solved with the features of claim.

[0032] An embodiment of the invention relates to a method for clamping a workpiece in a clamping device according to claim 12.

[0033] Another advantage is that the clamping support element is automatically inserted into the clamping device and / or automatically extended from the lower and / or upper clamping element. This increases machining efficiency.

[0034] It is expedient for the clamping support element to be formed integrally with the lower and / or upper clamping element, and for this clamping element thus formed to be inserted into the clamping device. Furthermore, it is advantageous for the workpiece to have a lateral outer surface and for at least one stop element to be provided in the clamping device, so that the workpiece is placed against the at least one stop element with a lateral outer surface.

[0035] Further advantageous embodiments are described by the following description of the figures and by the subclaims. Short description of the figures in the drawing

[0036] The invention will be explained in more detail below on the basis of at least one embodiment with reference to the figures of the drawing. They show: Fig. 1 is a side view of an embodiment of a clamping device not according to the invention with a clamping support element, Fig. 2 is a side view of a second embodiment of a clamping device not according to the invention with a lower clamping element which forms a clamping support element in one piece, Fig. 3 is a side view of a third embodiment of a clamping device not according to the invention with a step-shaped clamping support element, Fig. 4 is a side view of a further embodiment of a clamping device with stop elements, and Fig. 5 is a top view of a further embodiment of the clamping device according to the invention with stop elements. Preferred embodiment of the invention

[0037] The Figure 1 shows a clamping device 1 for clamping workpieces 2 made of wood, plastic or the like in order to be able to process them in a processing device.

[0038] The clamping device 1 has a lower clamping element 3 and an upper clamping element 4. The upper clamping element 4 is vertically movable relative to the lower clamping element 3, which is vertically fixed. Alternatively, the lower clamping element 3 can also be vertically movable.

[0039] The upper clamping element 4 has a plate shape or a plate-like shape and is firmly connected to a positioning rod 5. The connection is made at an upper end 6 of the positioning rod 5, as shown in Figure 1 can be seen. This can also be achieved in other ways if necessary. This connection between the upper clamping element 4 and the positioning rod 5 is advantageously screwed, although it is also possible to form the positioning rod 5 and the upper clamping element 4 as a single-piece component.

[0040] The lower clamping element 3 has, as shown in Figure 1As shown, it has a plate shape or a plate-like shape and is firmly connected to the workpiece table 7, wherein this connection is advantageously screwed, particularly in the vertical direction. This connection can also be designed differently.

[0041] The positioning rod 5 is connected to a drive mechanism (not shown) located below the lower clamping element 3. Therefore, the lower clamping element 3 has an opening or recess so that the positioning rod 5 can be arranged to extend vertically through the lower clamping element 3 in its longitudinal direction. It is also possible for the lower clamping elements 3 to be formed from two individual plates or plate-like components, which are firmly connected to the workpiece table 7, and the positioning rod 5 extends vertically between the two opposite lower clamping elements 3.

[0042] The lower end of the positioning rod 5 (not shown) is connected to a drive mechanism (not shown) such that the height of the positioning rod 5 can be adjusted vertically. Since the positioning rod 5 is firmly connected to the upper clamping element 4, the vertical distance between the upper clamping element 4 and the lower clamping element 3 can be adjusted by the drive mechanism (not shown). The drive mechanism may be hydraulic, pneumatic, or electric.

[0043] The lower clamping element 3 and the upper clamping element 4 together form a workpiece holder 9. The lower clamping element 3 has at least one support surface 10 on an upper side, and the upper clamping element 4 has at least one contact surface 11 on a lower side. In a further development of the clamping elements, clamping pads (not shown) can also be attached to the support surface 10 of the lower clamping element 3 and / or to the contact surface 11 of the upper clamping element 4, which can serve to protect the workpiece 2 and its surface or to better fix the workpiece 2. For example, such clamping pads can be made of plastic or rubber-like material.

[0044] The clamping device 1 has at least one upper clamping element 4.

[0045] If two upper clamping elements 4 are provided, these can be designed as a single component. They can also be designed in two parts. The clamping device 1 has at least one lower clamping element 3. If two lower clamping elements 3 are provided, these can be designed as two separate components or connected as a common component. Figure 1 The illustrated embodiment of the clamping device 1 has two upper clamping elements 4 and two lower clamping elements 3 and thus forms two workpiece holders 9.

[0046] For a clamping device 1 according to Figure 1 with two workpiece holders 9, these two workpiece holders 9 are advantageously located opposite each other.

[0047] In addition to the workpiece 2, a clamping support element 13 is provided in the workpiece holder 9 of the clamping device 1, wherein the clamping support element 13 and the workpiece 2 can be clamped together.

[0048] The clamping support element 13 can, as in Figure 1 shown, be an additional insertable part. The insertion of the clamping support element 13 into the workpiece holder 9 can be carried out automatically or manually by at least one machine operator. Advantageously, the clamping device 1 can also have at least one stop element (not shown), which can ensure precise alignment of the clamping support element 13. The removal of the clamping support element 13 from the workpiece holder 9 can be carried out manually by at least one machine operator. Automated removal of the clamping support element 13 is also possible.

[0049] Advantageously, the clamping support element 13 and the lower clamping element 4 or the upper clamping element 3 can be connected to each other in a form-fitting manner. Figure 1 a positive connection of the insertable clamping support element 13 with the lower clamping element 3 is expedient.

[0050] The workpiece 2, which can be inserted and clamped into the clamping device 1 for machining, has at least one top surface 15, which is an outer surface arranged on the top side, and one bottom surface 16, which is an outer surface arranged on the bottom side. For workpieces 2 that have already been machined multiple times, a plurality of top surfaces 15 and bottom surfaces 16 typically form. The area of ​​the individual top surfaces 15 or individual bottom surfaces 16 can be small relative to the contact surface 11 on the upper clamping element 4 or the support surface 10 on the lower clamping element 3, so that a sufficient clamping surface would be lacking.

[0051] The clamping support element 13 has at least one surface 17, which is an outer surface arranged on the upper side, and / or at least one lower surface 18, which is an outer surface arranged on the lower side. The contour of the outer surface of the clamping support element 13 is designed such that, in a clamped state, at least one surface 17 of the clamping support element 13 lies flat against a lower side surface 16 of the workpiece 2, or at least one lower surface 18 of the clamping support element 13 lies flat against a top side surface 15 of the workpiece 2.

[0052] According to Figure 1 The clamping support element has a surface 17 and a bottom surface 18. As in Figure 3 As shown, the clamping support element 13 may also have a plurality of surfaces 17 or a plurality of subsurfaces 18. In Figure 1the cross-section of the clamping support element 13 is approximately rectangular. Figure 3 the clamping support element 13 has a stepped cross-section with several surfaces 17.

[0053] The arrangement and design of the surfaces 17 or lower surfaces 18 of the clamping support element 13 can be adapted to the shape of the upper surfaces 15 of the workpiece 2 or the lower surfaces 16 of the workpiece 2 in such a way that the horizontal contact area between the workpiece 2 and the clamping support element 13 is as large as possible. Therefore, the plurality of surfaces 17 or lower surfaces 18 is typically, as in Figure 3 shown, arranged in staggered rows.

[0054] The Figure 2shows a further embodiment of a clamping device 1, in which the lower clamping element 3 is designed such that the clamping support element 13 is formed integrally with the lower clamping element 3. It is also possible for the upper clamping element 4 to be designed such that the clamping support element 13 can be formed integrally with the upper clamping element 4. The further features correspond essentially to those in Figure 1 shown.

[0055] In an advantageous, not-shown, development of the clamping device 1, it is designed such that a clamping support element 13 can be extended into the workpiece holder 9. Advantageously, a clamping support element 13 is designed to be extendable from the upper clamping element 3 and / or the lower clamping element 4 into the workpiece holder. In particular, extending a clamping support element 13 in the vertical direction is expedient. The extension can be performed both automatically and manually.

[0056] The clamping device 1 thus has at least one workpiece holder 9, wherein a clamping support element 13 is provided in the at least one workpiece holder 9, which can be designed as an additional insertable component or can be formed in one piece with the lower clamping element 3 or can be formed in one piece with the upper clamping element 4 or can be extendable.

[0057] Advantageously, the contact surface 11 of the upper clamping element 4 or the support surface 10 of the lower clamping element 3, or a plurality of surfaces 11 and / or lower surfaces 18 of the clamping support element 13, are surface-treated in such a way that the coefficient of friction between the involved surfaces is increased. Typically, these surfaces are roughened or suitably coated, such as sandblasted. Advantageously, the surfaces can also be designed as pincushions or pincushion-like. This can be achieved by short, thin, needle-like elements, which are arranged, for example, perpendicular to the outer surface and provide additional support to the wooden workpiece 3.

[0058] The Figure 4shows a clamping device 1 with at least one stop element 19, which is arranged in the workpiece holder 9, wherein the workpiece 1 can be placed with at least one lateral outer surface 20 against a side surface 21 of the stop element 19. Figure 4 and Figure 5 show embodiments in which two stop elements 19 are provided to prevent rotation of the workpiece 2 in the workpiece holder 9.

[0059] In an advantageous further development of a clamping device 1, the provided clamping support element 13 forms the at least one stop element 19 itself, wherein in a clamped state at least one vertical contact surface and at least one horizontal contact surface are present between the workpiece 2 and the clamping support element 13 and the workpiece 2 and the clamping support element 13 also touch each other with these contact surfaces.

[0060] Advantageously, a stop element 19 is designed as an element which can be connected to the upper clamping element 4 and / or the lower clamping element 3 and / or the clamping support element, wherein the one element can be designed for the purpose of connection in particular as a screw element or as a plug-in element.

[0061] Alternatively, it is advantageous if the at least one stop element 19 can be extended from the lower clamping element 3 and / or the upper clamping element 4, such as in the direction of the workpiece holder 9, in particular in the vertical direction. The extension of the stop elements 19 is expediently automated.

[0062] The clamping process is explained in more detail below.

[0063] To clamp a workpiece 2 in the clamping device 1 according to the invention, the drive mechanism moves the upper clamping element 4 to a sufficiently high position. The workpiece 2 is then inserted into the clamping device, with the insertion taking place automatically by a gripper or manipulator or manually by at least one machine operator. Before the workpiece 2 is inserted, the clamping support element 13 can be provided in the clamping device 1 if required. Advantageously, the clamping support element 13 is inserted into the clamping device 1 automatically or manually and extended out of the clamping device 1 automatically or manually. It is also possible for the clamping support element 13 to be formed in one piece with the lower clamping element 3 and / or with the upper clamping element 4 and for the lower clamping element 3 and / or the upper clamping element 4 to be inserted into the clamping device 1.After positioning the workpiece 2, the upper clamping element 4 is moved downwards so that the workpiece 2 and the clamping support element 13 are clamped together in the clamping device 1 in such a way that at least one surface 17 of the clamping support element 13 lies flat on top of a bottom surface 16 of the workpiece 2 or at least one bottom surface 18 of the clamping support element 13 lies flat on top of a top surface 15 of the workpiece 2.

[0064] It is also possible for the clamping device 1 to alternatively or additionally have at least one stop element 19, wherein the workpiece 2 is inserted into the clamping device 1 such that a lateral side surface 20 of the workpiece 2 rests against at least one side surface of the stop element 19.

[0065] The figures indicate a possible procedure for machining the workpieces 2 with a clamping device 1 having two workpiece holders 9, wherein one of the lateral side surfaces 20 of the workpiece 2 can first be contoured by clamping the workpiece 2 in one of the two workpiece holders 9. The workpiece 2 is then inserted into the other workpiece holder 9 without rotation, or alternatively, the workpiece 2 is rotated by 180° and inserted into the same workpiece holder 9 so that another of the lateral side surfaces 20 can be machined. Particularly advantageous in the second machining step is the provision of a clamping support element 13 in order to better clamp an already contoured outer surface. List of reference symbols

[0066] 1 Clamping device 2 Workpiece 3 Lower clamping element 4 Upper clamping element 5 Positioning rod 6 Upper end of the positioning rod 7 Workpiece table 9 Workpiece holder 10 Support surface of the lower clamping element 11 Contact surface of the upper clamping element 13 Clamping support element 15 Top surface of the workpiece 16 Bottom surface of the workpiece 17 Surface of the clamping support element 18 Bottom surface of the clamping support element 19 Stop element of the workpiece holder 20 Lateral side surface of the workpiece 21 Side surface of the stop element

Claims

1. A clamping device (1) for a workpiece (2), with a lower clamping element (3) and an upper clamping element (4) which form a workpiece holder (9), wherein the height of the upper clamping element (4) is adjustable relative to the lower clamping element (3), wherein the workpiece (2) has at least one outer surface (16) arranged on the lower side and / or upper side and has a lateral outer surface (20) and can be inserted into the clamping device (1), further with at least one stop element (19) which can be provided in the clamping device (1) so that the workpiece (2) can be placed with its lateral outer surface (20) against the at least one stop element (19), wherein at least one of the stop elements (19) is formed by an element connected to the lower clamping element (3) and / or to the upper clamping element (4), characterised in that at least one stop element (19) is extendable out of the lower clamping element (3) and / or out of the upper clamping element (4).

2. The clamping device (1) as claimed in claim 1, characterised in that the connected element is a plug-in element or screw element which is connectable to the lower clamping element (3) and / or to the upper clamping element (4).

3. The clamping device (1) as claimed in any one of the preceding claims, characterised in that at least one of the stop elements (19) is formed by a clamping support element (13).

4. The clamping device (1) as claimed in claim 3, characterised in that the clamping support element (13) is formed as a separate part and extendable from the clamping device (1) in an automated manner.

5. The clamping device (1) as claimed in any one of the preceding claims, characterised in that the clamping device (1) has two lower clamping elements (3) and two upper clamping elements (4).

6. The clamping device (1) as claimed in any one of the preceding claims, characterised in that the upper clamping element (4) has a plate shape or a platelike shape and is fixedly connected to a positioning rod (5), wherein the positioning rod (5) is connected to a drive mechanism lying below the lower clamping element (3).

7. The clamping device (1) as claimed in claim 6, characterised in that the positioning rod (5) is connected to a drive mechanism so that the height position of the positioning rod (5) can be changed in the vertical direction, wherein, thus, the vertical distance of the upper clamping element (4) to the lower clamping element (3) can be changed.

8. The clamping device (1) as claimed in any one of the preceding claims, characterised in that the drive mechanism is a hydraulic, pneumatic or electromotive drive.

9. The clamping device (1) as claimed in any one of the preceding claims 6 to 8, characterised in that the lower clamping element (3) has an opening or a recess, thus the longitudinal direction of the positioning rod (5) is arranged running through the lower clamping element (3) in the vertical direction.

10. A workpiece table having at least one clamping device (1) or several clamping devices (1) as claimed in any one of claims 1 to 9, by means of which the longitudinal direction of at least individual workpieces can be machined and these workpieces can be inserted in the clamping element of the workpiece table in an automated manner.

11. The workpiece table as claimed in claim 10, characterised in that the clamping device has two lower clamping elements and two upper clamping elements so that the clamping device forms two workpiece holders, whereby two workpieces are received and also machined at the same time or an opposite side surface can also be machined after reclamping.

12. A method for clamping a workpiece in a clamping device (1) as claimed in any one of claims 1 to 9, having the following steps: - bringing the drive mechanism of the upper clamping element (4) to a position which is sufficiently high, - inserting the workpiece (2) into the clamping device (1), wherein the inserting is, wherein the inserting is in an automated manner by a gripper or a manipulator or manually through at least one machine operator, - driving the upper clamping element (4) downwards after positioning of the workpiece (2), wherein the clamping device (1) has a least one stop element (19), wherein the workpiece (2) is inserted into the clamping device (1) so that a lateral side surface of the workpiece (2) is placed against at least one side surface of the stop element (19).

13. The method according to claim 12, characterised in that first, by clamping the workpiece (2) into one of the two workpiece holders (9), one of the lateral side surfaces (20) of the workpiece (2) can be contoured, wherein afterwards, the workpiece (2) can be inserted into the other workpiece holder (9) without rotation so that another one of the lateral side surfaces (20) can be machined.

14. The method according to any one of claims 12 or 13, characterised in that the clamping device (1) has two workpiece holders (9), wherein first, by clamping the workpiece (2) into one of the two workpiece holders (9), one of the lateral side surfaces (20) of the workpiece (2) is contoured, wherein afterwards, the workpiece is inserted into the other workpiece holder (9) without rotation, wherein afterwards, another one of the lateral side surfaces (20) is machined.