CLAMPING ARRANGEMENT

Description

[0001] The invention relates to a device for receiving at least one workpiece clamping device.

[0002] For example, a so-called repeatable clamping device is known from DE 101 55 077 B4. This device comprises a clamping vise that can hold workpieces, for example, between two jaws movable against each other, and which in turn can be mounted with repeatable accuracy on a clamping plate. The clamping plate is also referred to as a "reference plate." The clamping plate or reference plate has openings into which clamping and positioning bolts are inserted, projecting from the underside of the workpiece clamping device. A tightening device is arranged in the clamping plate, by means of which the clamping and positioning bolts are both drawn axially into the openings and pressed against the wall of the opening to ensure precise contact. The reference plate has three or four openings to accommodate workpiece clamping devices with three or four positioning and clamping bolts.The tightening device has slides that are movable radially to the openings and can be actuated by means of a screw via a wedge slide mechanism.

[0003] US Patent 5,167,405 also discloses a workpiece clamping device and an associated clamping plate with slides for tightening clamping bolts that project downwards from the underside of the workpiece clamping device and are received by openings in the clamping plate. The slides are actuated by a central eccentric shaft located in the clamping plate.

[0004] Furthermore, it is known from DE 10 2017 122 112 A1 to provide a workpiece clamping device for clamping workpieces, the two clamping jaws of which are individually mounted on separate, spaced-apart linear guides. A threaded spindle, centrally mounted in a bearing assembly, engages with both clamping jaws. The two linear guides and the bearing assembly are in turn mounted on a clamping plate, which is referred to here as the base plate.

[0005] US 2020 / 0368878, which forms the basis for the preamble of claim 1, describes a zero-clamping device with a total of four tightening devices. These are coupled to one another by means of continuous rotatable shafts in order to clamp and release synchronously.

[0006] A clamping system, also actuated by means of a rotatable shaft, is further known from DE 20 2018 105 390 U1. The clamping plate has four clamping openings with radially mounted clamping slides, which are actuated by a central clamping screw. This screw has a threaded section with a right-hand and a left-hand thread, each thread carrying a clamping wedge. By turning the clamping screw clockwise or counterclockwise, the clamping wedges are moved toward or away from each other.

[0007] WO 2019 / 083623 A1 discloses a further embodiment of a clamping plate with clamping screws. For interaction with clamping feet inserted in clamping openings of the clamping plate, clamping wedges that can be moved in opposite directions by means of a clamping spindle are provided. The spindle has a right-hand and a left-hand thread so that, when rotated in one direction, the two wedge elements sitting on the thread move in opposite directions.

[0008] A different concept is pursued in DE 10 2019 116 262 A1. This design features a clamping slide that is axially movable by means of a pressure screw and uses a wedge-shaped nose to push two further slides away from each other, perpendicular to it. These two further slides then act on the actual clamping slides, which are arranged at an angle to them. These are designed to clamp clamping feet that are seated in corresponding bores in the clamping plate.

[0009] Such an arrangement is also known from WO 03 / 039808 A1.

[0010] From DE 10 2011 086 853 A1, an array of hydraulically actuated clamping plates is known, wherein each clamping plate has several clamping openings. Clamping slides, which are hydraulically actuated, are assigned to the clamping openings. They thus form hydraulic actuators connected to a channel system for the hydraulic fluid. Since all clamping slides are hydraulically coupled to one another, they all require a resistance against which their wedge-shaped nose can rest. Such resistance is provided by a so-called locking element, i.e., a clamping bolt. To ensure proper function, unused clamping openings must be fitted with blanking plugs to block the clamping elements located there.

[0011] The present invention is based on the intention of creating a means for the variable mounting of workpiece clamping devices. At least two clamping plates are provided, which can be mounted in a machine tool in a fixed spatial relationship to one another. If known clamping plates, for example reference plane plates, are used for this purpose, each has its own tightening device.

[0012] The object of the invention is to simplify the handling of the device for receiving at least one workpiece clamping device.

[0013] According to the invention, a device according to claim 1 is proposed. It comprises at least two clamping plates, each having several openings for receiving clamping bolts of workpiece clamping devices. The tightening devices arranged in the clamping plates have coupled actuating rods or a common confirmation rod. This allows the tightening devices of both clamping plates to be actuated jointly and simultaneously from a single operating position. The particular advantage of this measure is that, with a suitable arrangement of the clamping plates, the workpiece clamping device can also be arranged across both clamping plates, and both clamping devices operate simultaneously when the tightening devices are actuated. This ensures that the workpiece clamping device is clamped precisely at the desired location.This applies in particular if the clamping bolts of the workpiece clamping devices are designed according to the principle of DE 101 55 077 B4. During clamping, the corresponding clamping bolts are subjected to a clamping force that includes both an axial component, which pulls the clamping bolt into the opening, and a radial component, causing the clamping bolt to spring laterally and bear against a specific point on the bore wall. Since this process occurs simultaneously for all clamping bolts by simultaneously actuating the tightening devices, it is ensured that the clamping bolts are tightened at the same time and the workpiece clamping device is thus positioned in the desired position. Otherwise, incorrect positioning could potentially occur if the tightening devices were actuated sequentially. In any case, the concept according to the invention saves operating effort and makes it possible to operate several clamping plates from one side.This is particularly advantageous when mounting clamping plates in enclosed work areas of machine tools, where access to the clamping devices is restricted, for example only possible from one side.

[0014] In one embodiment according to the invention, the common actuating rod, or the two actuating rods, which are in direct contact with each other or with the aid of an intermediate piece, are arranged to be axially movable in the clamping plates. The tightening and releasing of the clamping devices is effected by axial movement of the actuating rod(s).

[0015] The actuating rods, which rest directly against each other at their ends or via an intermediate piece and are thus coupled in terms of their movement, are preferably arranged in alignment with each other. In this way, the actuating movement of one actuating rod of a clamping plate is transferred to the actuating rod of another clamping plate.

[0016] Each clamping plate preferably has a through-opening in which the actuating rod is arranged to be axially movable. The through-opening is preferably arranged parallel to a flat upper surface formed on the clamping plate. The clamping movement of the actuating rod can thus be initiated into the actuating rod from one of the side surfaces of the clamping plate.

[0017] Preferably, the through-hole has an anchoring structure at both ends, formed, for example, by an internal thread. This is suitable for receiving and anchoring a spring element to pre-tension the actuating rod in one direction, preferably in the loosening direction. At the other end of the through-hole, an adjusting element, for example, in the form of a screw, can be provided on the internal thread or other anchoring structure. By turning the screw, the actuating rod can be moved axially, thus tightening or loosening the tightening device.

[0018] The actuating rod preferably has a wedge structure that engages with at least one slide belonging to the tightening device. The wedge structure can be formed by an inclined surface on the actuating rod itself or by an inclined surface on a wedge that is axially fixed to the actuating rod. The inclined surface is inclined relative to the longitudinal direction of the actuating rod.

[0019] The slide engages with at least one, preferably two, clamping slides, each of which is assigned to one of the openings and arranged radially to it. In the clamping position, the clamping slide projects into the opening. In the release position, it is retracted from the opening. Preferably, a spring is provided that biases the clamping slide radially outwards with respect to the opening. The slide and the clamping slide preferably form a reduction gear, i.e., a stroke of the slide is translated into a stroke of the clamping slide that is at most as large as the stroke of the slide. More preferably, at least the actuating rod, the slide, and the clamping slide form a reduction gear.

[0020] The slide and the clamping slides are preferably arranged in pockets with a trapezoidal, rectangular, or square cross-section, which are closed on a flat side of the clamping plate with one or more covers. This not only offers manufacturing advantages but also the benefit that the clamping plates can be provided with a continuous actuating rod, which can be inserted into the aligned through-holes for assembly. Insertion of the actuating rod is made possible by first removing at least the slides from the clamping devices. After insertion of the actuating rod, the slides can be reinserted into their pockets and secured by attaching the cover.

[0021] Further details of advantageous embodiments of the invention will become apparent from the drawing, the description, or the dependent claims. The drawing shows: Figure 1A workpiece clamping device and an associated clamping plate, in a simplified perspective view, Figure 2 the workpiece clamping device and the clamping plate, in a vertically cut section view, Figure 3 two clamping plates of the device according to the invention for receiving at least one workpiece clamping device, Figure 4 a tightening device for the clamping plates according Figure 3 , in schematic representation, Figure 5 a modified embodiment of a tightening device for the clamping plates according to Figure 3 , Figure 6 two clamping plates with continuous operating rods and Figure 7 a tightening device for the clamping plates according Figure 6 .

[0022] In Figure 1Figure 10 illustrates a device 10 for receiving a workpiece clamping device 11. The device 10 comprises at least two clamping plates 12, 13, which can be arranged, for example, in a machine tool to hold the workpiece clamping device 11 in predetermined positions. The two clamping plates 12, 13 can be essentially identical to each other, so that the following description of clamping plate 12 applies accordingly to clamping plate 13.

[0023] The clamping plate 12 has several openings, for example four, 14, 15, 16, 17, which serve to receive clamping bolts of the workpiece clamping device 11. Figure 2Figure 18 shows an example of such a clamping bolt 18, which engages in the opening 14. The workpiece clamping device 11 has a guide body 19 on which at least one or two clamping jaws 20, 21 are movably mounted. Several clamping bolts protrude from the underside of the guide body 19, the arrangement of which corresponds to the arrangement of the openings 14 to 17.

[0024] Figure 3Figure 1 illustrates the clamping plates 12, 13, as well as two further clamping plates 12', 13' arranged laterally and a larger clamping plate 23. Each of these clamping plates 12, 12', 13, 13', 23 has four openings 14, 15, 16, 17 for receiving clamping bolts 18 of workpiece clamping devices 11, the openings 14, 15, 16, 17 of all clamping plates 12, 13, 12', 13' forming a uniform grid when the flanks of the adjacent clamping plates are in contact. Four of the clamping openings 14, 15, 16, 17 form a so-called "nest". Each of the clamping plates 12, 13, 12', 13' has exactly one such nest. However, it is also possible to provide clamping plates with several such nests, as shown in Figure 1. Figure 3 This is illustrated above using the clamping plate 23.

[0025] The clamping plate 12 has a tightening device 24, which serves to tighten clamping bolts 18 inserted into the openings 14, 15, 16, 17. This tightening device 24 extends separately. Figure 4 The description given in this context applies accordingly to all tightening devices and nests of all clamping plates 12, 13, 12', 13', 23.

[0026] The tightening device 24 comprises an actuating rod 25, which is axially displaceable in a through-bore 27 that passes through the clamping plate 12 parallel to its upper surface 26. The actuating rod 25 is, for example, a round rod that has two opposing lateral recesses for actuating the tightening device, which are bounded by inclined surfaces 28, 29. The inclined surfaces 28, 29 together form a wedge suitable for pushing apart slides 30, 31, which are located in channels branching off transversely from the through-bore 27 and bear against the inclined surfaces. The slides 30, 31 bear against the inclined surfaces 28, 29 with corresponding inclined surfaces and are movable in their respective channels transversely to the actuating rod 25.

[0027] The tightening device also includes clamping slides 32 to 35, each individually assigned to openings 14 to 17. Clamping slide 32 is located in a channel in which it is radially movable relative to opening 14, such that it either projects into or remains outside of opening 14. The same applies to opening 15 and clamping slide 33, opening 16 and clamping slides 34, and opening 17 and clamping slide 35. Clamping slides 32 and 34, as well as clamping slides 33 and 35, are each connected to each other in pairs by a tension spring or are pre-tensioned to their rest position outside the respective opening 14 to 17 by another spring mechanism (not illustrated).

[0028] With their ends facing away from the openings 14 to 17, the clamping slides 32 to 35 are in contact with a wedge-shaped end of the respective slide 30, 31. This forms a slide mechanism in which a displacement of the actuating rod 25 occurs. Figure 4 upwards, the slides 30, 31 are forced apart, whereby the slides 30, 31 with their wedge-shaped outer ends in turn force the clamping slides 32, 34 and 33, 35 apart, so that their ends penetrate into the bores 14 to 17. Figure 2This is illustrated by the example of the slide 32, whose opening-side end then enters the opening 14 and engages in a groove of the trapezoidal clamping bolt 18. Through the interaction of the end of the clamping slide 32 with one of the groove flanks of the clamping bolt 18, the end is drawn vertically into the opening 14, thereby attracting the base of the guide body 19 to the top surface 26. Furthermore, the clamping bolt 18 undergoes a slight lateral elastic deformation, causing its head 36 to contact the bore wall of the opening 14 at a point opposite the clamping slide 32. This spreads the clamping bolts apart in the openings 14 to 17, allowing the guide body 19 to reach its desired position, i.e., its zero position.

[0029] The movement of the actuating rod is transmitted via the slides 30, 31 to the clamping slides 32 to 35. The slides and clamping slides form a reduction gear. In other words, the distance traveled by each clamping slide 32 to 35 during clamping is at most as great as the distance traveled by the actuating rod 25, but preferably less. This is achieved by appropriately inclined clamping surfaces 28, 29 and by appropriately adjusting the wedge angle at the far ends of the slides 30, 31. Preferably, each slide 30, 31 has two flat wedge surfaces at its outer end, which are at a right or acute angle to each other.

[0030] The actuating rod 25 can also be used instead of the two wedge surfaces 28, 29, as shown in Figure 5As illustrated, the clamping plate 12 is provided with a wedge 36, which is axially movably mounted in the clamping plate 12 with respect to the actuating rod 25 and engages with the actuating rod 25 in order to be moved by it in the clamping direction. For this purpose, the actuating rod 25 can have a reduced-diameter or flattened section over which the wedge 36 engages. For example, the wedge 36 can be U-shaped to sit on the actuating rod 25 like a rider. The wedge 36 in turn has inclined surfaces 28', 29' which bear against the slides 30, 31. The previous Figure 4 The given description applies accordingly. Additionally, in Figure 5 Spring elements are illustrated, for example, as tension springs 37, 38, which connect the tension slides 32, 34 and 33, 35 in pairs.

[0031] The through-opening 27, which serves to receive the actuating rod 25, has anchoring structures at at least one end, preferably at both ends, for example in the form of internal threads 39, 40. A support 41 for a compression spring 42 can be anchored to the anchoring structure 37, which serves to pre-tension the actuating rod 25 in the release direction. At the opposite end of the through-opening 27, an actuating screw 43 can be inserted into the anchoring structure 38 to enable the actuating rod 25 to move against the force of the compression spring 42 in the tension direction. The screw 43 bears against an end face of the actuating rod 25, which is thus fixed between the compression spring 42 and the actuating screw 43.

[0032] Figure 5 This illustrates a chipboard for individual use. However, if this is to be modeled after, for example, the... Figure 3When used in series with other clamping plates, for example the clamping plate 13, instead of an actuating rod 25 which lies completely in the clamping plate 12, a mechanism similar to the one used is employed. Figure 3 An actuating rod 25 is used, which protrudes from the end of the through-opening 27 opposite the actuating screw 43 and penetrates the through-opening 27 of the adjacent clamping plate 13 by precisely the amount that would otherwise be determined by the clamping screw 43. Thus, the actuating rods 25 of the two clamping plates 12, 13 are aligned with each other. The actuating rods of the clamping plate 23 can also be connected in the same way.

[0033] Figure 3 illustrates a possible modification using the clamping plates 12', 13' as an example. In this modification, the actuating rods 25 are connected to each other via an intermediate piece 25', which bridges the axial distance between the two actuating rods 25 of the clamping plates 12', 13'. For example, if clamping plates are manufactured according to the model of the Figure 5 Coupled in this way, the actuating screw 43 is removed from the clamping plate 13' and the abutment 41 and the compression spring 42 are removed from the clamping plate 12'. The space freed up is occupied by the intermediate piece 25.

[0034] The device 19 described above operates as follows: First, the actuating screw 43 is moved in the loosening direction, so that the actuating rod 25 is in Figure 3 downwards, thus moving the slides 30 and 31 towards each other. The clamping slides 32 to 35 (see Figure 4) retract from the openings 14 to 17. In this state, a workpiece clamping device 11 can be placed onto the device 10 so that its clamping bolts 18 move into corresponding openings. It is possible to insert four clamping bolts 18 of a single workpiece clamping device 11 into the openings 14 to 17 of a single clamping plate, for example, the clamping plate 12. However, it is also possible to fix the workpiece clamping device 11 overlapping the clamping plate, for example, in the two openings in Figure 3The upper openings 16, 17 of the clamping plate 12 and the two lower openings 14, 15 of the clamping plate 13 are used. Any other pairing of openings can also be used. It is also possible to mount workpiece clamping devices onto the device 10 that are larger and thus, for example, use the openings 14, 15 of the clamping plate 12 and the openings 14, 15 of the clamping plate 13. Other combinations are also possible. If the workpiece clamping device 11 is mounted on the device 10, the actuating rod 25 is moved in the tightening direction by correspondingly rotating the clamping screw 43 (in Figure 3 upwards). This causes the clamping slides 32 to 35 to move ( Figure 4) into the corresponding openings 14 to 17 and clamp the workpiece clamping device 12 to the belt. All clamping slides driven by the actuating rod 25 are moved synchronously, so that the clamping operations take place simultaneously in all openings. This improves the positioning accuracy of the clamping process.

[0035] In the present embodiment, the actuating rod 25 is segmented. It consists of the individual actuating rods of the clamping plates and any intermediate pieces 25'. However, it is also possible to use completely continuous actuating rods, as shown. Figure 6 Illustrated. The embodiment comprises two clamping plates 23, 23' each with four nests. However, it is equally applicable to devices 10 whose clamping plates 12, 13 have only one nest or a different number of nests.

[0036] The continuous actuating rod 25 can be inserted into the aligned through-openings 27 of the two clamping plates 23, 23' when the slides 30, 31 are removed. To do this, they can be removed according to Figure 7 are arranged in grooves of the clamping plate 23, which are accessible, for example, on the top side 26 of the clamping plate 23 in question and are closed off there by a cover. Figure 7 This is illustrated by a recess 44 adjoining the corresponding grooves, which in use receives a cover that follows the contour of the recess 44 and is closed by it. Otherwise, the description of the tightening device 24 or other elements applies accordingly, based on the reference numerals already introduced.

[0037] A device 10 according to the invention for receiving at least one workpiece clamping device 11 has clamping plates 12, 13 with openings 14 to 17 for receiving the clamping bolts 18 provided on the workpiece clamping devices 11. One or more tightening devices 24 are arranged in the clamping plates 12, 13, which can be actuated by an actuating rod 25. The actuating rod 25 is continuous or segmented and operates several tightening devices 24 of different clamping plates 12, 13 simultaneously.

[0038] This measure allows workpiece clamping devices to clamp workpieces across 11 clamping plates with the same precision as within a single clamping plate. Reference symbol:

[0039] 10 Device 11 Workpiece clamping device 12, 13 Clamping plates 14 - 17 Openings 18 Clamping bolt 19 Guide body 20, 21 Clamping jaws 23 Clamping plate 24 Tightening device 25 Actuating rod 25' Intermediate piece 26 Top 27 Through opening 28, 29 Slanted surfaces 30, 31 Slide 32 - 35 Clamping slide 36 Wedge 37, 38 Spring element 39, 40 Internal thread / Anchoring structure 41 Abutment 42 Compression spring 43 Actuating screw 44 Recess

Claims

1. A device (10) for receiving at least one workpiece clamping device (11), comprising at least two clamping plates (12, 13, 23) each having at least one opening (14 - 17) for receiving clamping bolts (18) of workpiece clamping devices (11), comprising tightening devices (24) arranged in the clamping plates (12, 13, 23), which have actuating rods (25) coupled to one another or a common actuating rod (25), characterized in that the at least two clamping plates (12, 13, 23) each have a plurality of openings (14 - 17) for receiving clamping bolts (18) and that the common actuating rod (25) or the two actuating rods (25) are arranged in the clamping plates (12, 13, 23) so as to be axially movable and are engaged with each other directly or by means of an intermediate piece.

2. The device according to claim 1, characterized in that the actuating rods (25) coupled to one another are arranged in axial alignment with one another.

3. The device according to anyone of the preceding claims, characterized in that each clamping plate (12, 13, 23) has a through-opening (27) in which the actuating rod (25) is arranged.

4. The device according to claim 3, characterized in that the through-opening (27) is arranged parallel to a flat upper side (26) formed on the clamping plate (12, 13, 23).

5. The device according to claim 3, characterized in that the through-opening (27) has an anchoring structure (37, 38) at its both ends.

6. The device according to claim 5, characterized in that the anchoring structure (37, 38) is an internal thread (39, 40).

7. The device according to claim 5 or 6, characterized in that a spring means (42) is arranged and anchored at one end of the through-opening (27).

8. The device according to claim 5 or 6 or 7, characterized in that an actuating means (43) is arranged and anchored at one end of the through-opening (27).

9. The device according to claim 8, characterized in that the actuating means (43) is a screw.

10. The device according to anyone of the preceding claims, characterized in that the actuating rod (25) comprises a wedge structure (28, 29) which is engaged with at least one slide (30, 31).

11. The device according to claim 10, characterized in that the slide engages with clamping slides (32 - 35), each of which is assigned to one of the openings (14 - 17) and arranged radially to the it.

12. The device according to claim 11, characterized in that the actuating rod (25), the slide (30, 31) and the clamping slide (32 - 35) form a reduction gear.

13. The device according to claim 11 or 12, characterized in that each clamping slide (32 - 35) is connected to a spring means (37, 38) which is arranged to bias the slide radially outwards with respect to the opening (14 - 17).

14. The device according to anyone of the preceding claims 11-13, characterized in that the slide (30, 31) and the clamping slides (32 - 35) are arranged in grooves which are closed on a flat side of the clamping plate (12, 13, 23) by one or more covers.