Clamping system

Abstract

In order to provide a clamping system for rapidly and repeatably fixing a tool part and / or machine part for machining a workpiece, wherein the clamping system comprises a plate having clamping openings in a grid, which corresponds to an arrangement of clamping and positioning pins on a tool part and / or machine part, and movable fixing means are provided in the plate for fixing and releasing a fixing on the clamping and positioning pins, while simplifying the construction of the clamping system and reducing the number of individual components, it is proposed according to the invention that a single-piece locking element (7) is displaceably arranged in the plate (2), on which locking element a number of fixing means (5) corresponding to a number of clamping and positioning pins (4) is formed in such a way that each of the fixing means (5) fixes the tool part and / or machine part, or releases a fixing, jointly in an associated clamping opening (3) and with the other fixing means (5) by a movement of the locking element (7).

Description

[0001] clamping system

[0002] The present invention relates to a clamping system for a quick and repeatable fixing of a tool and / or machine part for machining a workpiece, which is possible on up to five surfaces without reclamping.

[0003] Clamping systems of the type mentioned are known in a large number of different designs from the prior art. For example, DE 101 55 077 B4 describes a clamping system with a plate having clamping openings in a grid pattern corresponding to an arrangement of clamping and positioning bolts on a tool and / or machine part. The plate incorporates movable fixing elements for securing and releasing the clamping and positioning bolts. These fixing elements are exposed as spring-loaded locking pins. This device enables quick and repeatable clamping and simultaneously generates high holding forces between the plate and the tool and / or machine part.

[0004] DE 10 2014 112 843 B4 also describes a so-called zero-point clamping system of the type mentioned, in which, however, an even larger number of components are provided in a plate for fixing and releasing a fixation of a tool and / or machine part.

[0005] EP 3 532 240 B1 further discloses a clamping system in which two clamping jaws are moved in opposite directions relative to each other via a threaded spindle in a plate, each jaw having two fixing means for fixing and releasing a clamping and positioning bolt. The present invention aims to further develop a clamping system by simplifying its design and reducing the number of individual components, while maintaining fast and precise positioning of a tool and / or machine part under high holding forces.

[0006] This problem is solved according to the invention by the features of claim 1 in that a one-piece locking element is slidably arranged in the plate, on which a number of fixing means corresponding to a number of clamping and positioning bolts are integrally formed such that each of the fixing means, together with the other fixing means, fixes or releases the tool and / or machine part in an associated clamping opening by a movement of the locking element. Instead of a multitude of individual parts, according to the invention all clamping and positioning bolts arranged in clamping openings of the plate can thus be fixed or released by fixing means, wherein all fixing means are integrally arranged on only one locking element that can be moved accordingly.

[0007] Advantageous further developments are the subject of the dependent claims. In a preferred embodiment of the invention, the clamping system provides more than three clamping and positioning bolts, all of which can be simultaneously fixed or released by fixing means, wherein the fixing means are movable together with the locking element. Thus, by moving the locking element, all clamping and positioning bolts are simultaneously fixed or released by fixing means. Therefore, no additional levers or other components need to be moved. In addition to three and four clamping and positioning bolts, applications with 6, 8, 10 or even more clamping and positioning bolts with only one movable locking element are also possible, each of which has a corresponding number of fixing means that are slidably provided on the respective clamping openings.This significantly reduces the number of individual parts compared to devices known from the prior art. Only a suitably shaped locking element with fixing means at the relevant points or locations is required.

[0008] Preferably, the locking element comprises two trapezoidal bodies, each with two obliquely extending edge regions designed as fixing means. The trapezoidal bodies are rigidly connected to each other via a coupling piece to form a one-piece locking element.

[0009] In a further development of the invention, additional units are advantageously provided, each consisting of a coupling piece and a trapezoidal body shaped similarly to the aforementioned trapezoidal bodies, adapted to a respective grid dimension of the clamping and positioning bolts with associated clamping openings in the plate, and adapted to a respective number and position of additional clamping and positioning bolts. This allows a clamping system to be adapted to more than, for example, three or four clamping and positioning bolts in a very simple manner, without the need for additional separately manufactured, installed, and mechanically driven elements, while maintaining a compact design and reliable function. Furthermore, by adjusting the width or length of the coupling pieces, modified grid dimensions can also be easily implemented in a clamping system.

[0010] In a significant further development of the invention, the locking element is mounted in the plate to allow translational movement. In one embodiment, the locking element is advantageously mounted in a type of guide channel in the plate to allow linear displacement.

[0011] Preferably, the locking element has essentially trapezoidal cross-sectional areas in the axial direction.

[0012] In an alternative embodiment, the locking element is, for example, essentially circular and has recesses, rotatably mounted in a recess of the plate. According to an alternative further development of the invention, the locking element is mounted about a central pivot point to execute a partial rotational movement, so that the fixing means on the locking element are not linear, but movable along a section of a circular path between the states of fixing and releasing or unlocking the clamping and positioning bolts.

[0013] Preferably, a spindle or threaded rod is rotatably mounted in the plate as the drive means for the locking element about its longitudinal axis. In one embodiment, the drive means engages the locking element via a thread. External rotation of the spindle or threaded rod directly produces a corresponding movement of the locking element, whereby loosening, closing, or fixing the clamping system is preferably implemented analogously to the movement of a screw connection with a right-hand thread. Compared to the prior art, this significantly simplifies both the manufacturing and mounting of a spindle or threaded rod. Now, with a generally shorter overall length, a drive means can also be rotatably mounted and fixed at a drive area of ​​the spindle or threaded rod, such as an internal hexagon socket head.The fixing means are preferably designed to form a positive and non-positive connection with the clamping and positioning bolt, which also generates a downward force on the clamping and positioning bolt to press the fixed tool and / or machine part against the clamping system. This additionally presses the tool and / or machine part onto the plate via the clamping and positioning bolts attached to it. As described below with reference to an exemplary embodiment and a figure in the drawing, a height offset of, for example, approximately +1 / 10 mm is provided between a contact surface of the fixing means and a groove of the relevant clamping and positioning bolt, in order to generate a downward force in addition to precise and reproducible alignment and secure fixing. This effect is also described in DE 20 2020 100 356 Ul, to which full reference is made here.

[0014] In a particularly advantageous embodiment of the invention, the clamping system comprises two locking elements, each formed in one piece and mechanically coupled to each other, which are movable in opposite directions to the same extent. In this exemplary embodiment, the mechanical coupling of the movements, which are of equal magnitude and in opposite directions, is achieved in exemplary embodiments via a lever, a gear engaging with an externally toothed and an internally toothed rack on the locking elements, or via a threaded rod axially between the locking elements. These various coupling elements are mounted in the plate and connected to the two locking elements for the corresponding force transmission. It is preferred to provide an equal number of fixing means on both locking elements in order to symmetry mechanical loads.Each clamping opening has a movable fixing element for a first and a second locking element, arranged essentially opposite each other. The two locking elements move in opposite directions between the fixed and released states of all clamping and positioning bolts simultaneously, under mechanical coupling to each other.

[0015] In a further development of the invention, a hydraulic or pneumatic system is provided instead of a clamping spindle. Advantageously, a piston is formed integrally with the locking element. This again eliminates the need for separate components and simplifies assembly and, if necessary, manufacturing.

[0016] In this further development of the hydraulically or pneumatically driven clamping system, the locking element is advantageously acted upon by a spring element with a force or restoring spring force. The design is intended to reliably hold the locking element in a locked or fixed position when depressurized.

[0017] The above examples highlight key features that constitute a compact clamping system with significantly improved properties. All metallic components are manufactured from high-alloy, hardenable steels. This ensures high durability with low wear, while maintaining a substantially uniform thermal expansion across all components.

[0018] Further features and advantages of embodiments according to the invention are explained in more detail below with reference to exemplary embodiments and the drawings. Figures aa and bb show a schematic representation of these:

[0019] Top views of an exemplary embodiment of a partially opened clamping system in an open or unlocked position and a locked position;

[0020] Figure 2 is a perspective view of a partially opened clamping system according to Figures 1a and 1b;

[0021] Figures 3a and 3b:

[0022] Top views of an exemplary embodiment of a partially opened clamping system according to Figure 2 in an unlocked position and a locked position;

[0023] Figures 4a and 4b:

[0024] Sectional views in planes AA and BB of Figure 3b;

[0025] Figures 5a to 5d

[0026] Views of the locking element of the exemplary embodiment shown in Figures 3a to 4b;

[0027] Figures 6a and b :

[0028] Top views of a further embodiment of a partially opened clamping system according to figures 1a, b with locking elements movable in opposite directions with the same magnitude in an unlocked position and a locked position;

[0029] Figure 7: a side view of an alternative arrangement of a spindle as a direct drive element between two locking elements that move in opposite directions with the same magnitude;

[0030] Figures 8a and 8b:

[0031] Views of an extended locking element for the secure and quickly releasable fixing of a clamping system to eight or more clamping and positioning bolts.

[0032] Across all illustrations, the same reference symbols are used for identical elements. Without limiting the invention, a clamping system is described below in the technical context of coupling a centering clamp according to DE 20 2020 100 356 Ul with a cuboid workpiece fixed therein to a base plate of a 5-axis surface milling machine. A clamping system of a lathe or a turning and milling center is characterized by high static as well as dynamic forces that can act on a workpiece in up to five surface normals of a Cartesian system.

[0033] This assumes the use of identical clamping and positioning bolts arranged in a uniform grid. However, it is obvious to a person skilled in the art that a fully assembled clamping system, as a closed component, can form a coupling intermediate level adaptable to other fixing systems, just as a clamping system itself can be part of the base of a centering clamp or other machine component.

[0034] The sketch of Figure 1a shows a top view of an embodiment of a partially opened clamping system 1 in an open or unlocked position. The clamping system 1 has four clamping openings 3 in a plate 2, which forms an outer housing of the clamping system 1. These openings are arranged in a grid pattern corresponding to an arrangement of clamping and positioning bolts 4 on a tool and / or machine part (not shown). Movable fixing means 5 are provided in the plate 2 for fixing and releasing a fixation on the clamping and positioning bolts 4, as is generally known from the prior art.

[0035] In Figure 1a, a cover 6 has been removed from plate 2. This reveals that a one-piece locking element 7 is slidably arranged in plate 2. A number of fixing means 5 are integrally formed on the locking element 7, corresponding to the number of the four clamping and positioning bolts 4 shown here. In this clamping system 1, each of the fixing means 5 is moved in an associated clamping opening 3 together with the other fixing means 5 by a movement of the locking element 7 in order to fix or release the tool and / or machine part (not shown) that is fixed to the clamping and positioning bolts 4 in the clamping system 1. In this embodiment, the fixing means 5 are designed as inclined side edges of a trapezoidal body 8, as shown in detail below.To combine all four fixing means 5 of this embodiment into a one-piece locking element 7, two trapezoidal bodies 8 are connected to each other via a coupling piece 9. Thus, in this embodiment, a one-sided pressing of the fixing means 5 over the locking element 7 as a common mechanical support is sufficient to fix all clamping and positioning bolts 4 in the clamping system 1 with repeatable and high positional accuracy, or to simultaneously release and freely access them.

[0036] To move the one-piece locking element 7 into a fixed position or into a position for the free removal of the four clamping and positioning bolts 4 from the clamping openings 3 in the plate 2 of the clamping system 1, the locking element 7 is guided and mounted in the plate 2 for a translational, and in this case linear, displacement movement. For this purpose, the plate 2 is designed accordingly in the area of ​​the coupling piece 9 by means of planar guide surfaces. To transmit force to the locking element 7, a spindle or threaded rod 10 is rotatably mounted in the plate 2 as a drive means for the locking element 7. This drive means engages the locking element 7 at one end via a thread 11 to move the locking element 7. At an opposite end of the drive means, a head (not shown here) with an internal hexagon socket is provided, into which a lever or similar tool can be inserted in a known manner as a tool for applying a torque.

[0037] This significantly reduces the total number of individual parts in this embodiment compared to known clamping systems. The same applies to the number of points or areas of force transmission between individual components.

[0038] The sketch of Figure 1b shows a top view of an embodiment of Figure 1a in a closed or fixed end position of the clamping system 1. This complements the sketch of Figure 1a by indicating a displacement of the locking element 7.

[0039] Figure 2 is a perspective view of a clamping system 1, partially opened by removing a cover plate 6, as shown in Figures 1a and 1b. Beyond the representations described above, the spatial form of a locking element 7 is clearly visible here. In the area of ​​the trapezoidal bodies 8, this element has additional chamfers for forming the fixing means 5. These chamfers are specifically adapted to the shape of the clamping and positioning bolts 4 to create a positive and force-fit connection. Strong vibrations during operation, as well as the application of large forces, cannot overcome this fixation.

[0040] Figure 2 also clearly shows that the locking element 7 is supported and guided axially in the recess of the plate 2 by parallel walls in the area of ​​the coupling piece 9. A central axis M shown in Figures 1a and 1b indicates a longitudinal extension with a direction of force acting on the locking element 7 for setting one of the two operating states of the clamping system 1, as well as its axis of symmetry.

[0041] Figures 3a and 3b, showing top views of an exemplary embodiment of a partially opened outer housing of the clamping system 1 according to Figure 3, illustrate a transition from an open or unlocked position to a locked position purely by moving the locking element 7 with fixing means 5 attached to it and thus movable together with the locking element 7, while guided over the coupling piece 9 in the plate 2.

[0042] Figures 4a and 4b show sectional views in planes AA and BB of Figure 3b to illustrate an additional effect of the engagement of the fixing means 5 in V-shaped recesses or notches 12 on the clamping and positioning bolts 4. In contrast, the fixing means 5, with a shape similar to the notch 12, has a certain vertical offset, which, as the fixing means 5 engages the notch 12 in a form-fitting and force-fit manner, exerts a force on each clamping and positioning bolt 4, causing the clamping system 1 to be pressed against a machine mount (not shown) in which the clamping and positioning bolts 4 are screwed. This results in a fixation using the described clamping system 1 with the additional generation of a downward force, which further improves the overall mechanical properties of this detachable connection compared to known systems.

[0043] Figures 5a to 5d show views of the locking element 7 of the embodiment shown in Figures 2 to 4b. The three-dimensional shape and the position of the fixing means 5 on the locking element 7 of this embodiment are particularly evident. The locking element 7, like the other components of the clamping system 1, is manufactured as a milled part from a high-alloy and hardenable steel and has essentially trapezoidal cross-sections in the axial direction of the central axis M. A standard component or turned part is used for the spindle 10 indicated in Figure 5c.

[0044] The force acting unilaterally on the clamping and positioning bolts 4 via the locking element 7 is incapable of measurably deforming the clamping system 1 as a whole, thus ensuring highly accurate and reproducible fixing and reliable positional stability. Figures 6a and 6b show top views of another embodiment of a partially opened clamping system 1, analogous to the illustrations in Figures 1a and 1b. Here, locking elements 7, 7', which move in opposite directions with the same magnitude, are sketched in an open position and a locked position. In this embodiment, the opposite movement of the locking elements 7, 7' is effected by a rotary lever D, whose lever arms of equal length are connected to the locking elements 7, 7' via sliding joints, for example, in the form of a cam guide.

[0045] Figure 7, analogous to Figure 5c, shows a side view of an alternative arrangement of a spindle 10 as a direct drive element between two locking elements 7, 7' which are displaceable in opposite directions with the same magnitude and each has substantially trapezoidal cross-sections. When the spindle 10 is actuated, the locking elements 7, 7' are moved in opposite directions with the same magnitude, while the spindle 10 itself is rotatably mounted in the plate 2 as described.

[0046] Figures 8a and 8b show views of an extended locking element 7 for the secure and quick-release fixing of a clamping system 1 to eight clamping and positioning bolts 4 (not shown), which can also be extended analogously. Using identical clamping and positioning bolts 4 (not shown here), the trapezoidal bodies 8 are always identically shaped and provided with two edge regions designed as fixing means 5. These clamping and positioning bolts 4 can be arranged in groups in a uniform grid. However, different grid arrangements are known, among others, from DE 10 2020 101 059 B4. To depict such an arrangement, within the scope of the present invention, only a corresponding adjustment of the length b of a coupling piece 9 is required, deviating from a length a according to a known grid.As a result, an arrangement according to the disclosure of DE 10 2020 101 059 B4 can be constructed in a comparatively simple manner with only one clamping system and mechanical actuation via a spindle 10, using very few components. Figure 8a indicates the adaptability of a clamping system 1 according to the above description in a top view. Figure 8b shows a complete locking element 7 with a constant grid and correspondingly equal-length coupling pieces 9 of length a in a perspective view.

[0047] In particular, Figure 2 shows a very compact and low-profile clamping system 1 with a very small number of individual parts. This device enables machining of even extremely large workpieces on up to five spatial axes with precise and reliably repeatable positioning, while requiring minimal surface area and space, and maintaining minimal tool travel. Due to the aforementioned advantages, such clamping systems 1 have a wide range of applications in machining production. Reference numeral list

[0048] 1 clamping system

[0049] 2 plates

[0050] 3 Clamping opening in the plate 2

[0051] 4 clamping and positioning bolts

[0052] 5 Fixatives

[0053] 6 Cover

[0054] 7 Locking element ,

[0055] 7 ' second locking element

[0056] 8 Trapezoidal body with two edge regions

[0057] 9 coupling pieces

[0058] 10 Spindle or threaded rod as drive means for the locking element 7

[0059] 11 threads

[0060] 12 V-notch on the clamping and positioning bolt zen 4 a Distance / length with normal grid dimension b Distance / length with larger grid dimension

[0061] D Rotary lever for power transmission between the locking elements 7 , 7 '

[0062] M Central axis

Claims

Claims 1. Clamping system (1) for quick and repeatable fixing of a tool and / or machine part for machining a workpiece, wherein the clamping system (1) comprises a plate (2) having clamping openings (3) in a grid corresponding to an arrangement of clamping and positioning bolts (4) on a tool and / or machine part, and wherein movable fixing means (5) are provided in the plate (2) for fixing and releasing a fixation on the clamping and positioning bolts (4), characterized in that a one-piece locking element (7) is slidably arranged in the plate (2), on which a number of fixing means (5) corresponding to a number of clamping and positioning bolts (4) is integrally formed,that each of the fixing means (5) in an associated clamping opening (3) and together with the other fixing means (5) jointly fixes or releases the tool and / or machine part by a movement of the locking element (7).

2. Clamping system (1) according to the preceding claim, characterized in that the clamping system (1) provides more than three clamping and positioning bolts (4), all of which can be fixed or released simultaneously by fixing means (5), wherein the fixing means (5) are movable together with the locking element (7).

3. Clamping system (1) according to one of the preceding claims, characterized in that the locking element (7) is mounted in the plate (2) for translational movement.

4. Clamping system (1) according to the preceding claim, characterized in that the locking element (7) is mounted in the plate (2) to allow linear displacement.

5. Clamping system (1) according to one of the preceding claims, characterized in that the locking element (7) comprises two trapezoidal bodies (8) each with two obliquely extending edge regions formed as fixing means (5), which are rigidly connected to each other via a coupling piece (9).

6. Clamping system (1) according to the preceding claim, characterized in that further units consisting of a coupling piece (9) and a trapezoidal body (8) are provided in adaptation to a respective grid dimension of the clamping and positioning bolts (4) with associated clamping openings (3) in the associated plate (2) in adaptation to a respective number and position of clamping and positioning bolts (4).

7. Clamping system (1) according to one of the preceding claims, characterized in that the locking element (7) has substantially trapezoidal cross-sectional areas in the axial direction.

8. Clamping system (1) according to one of the preceding claims 1 and 2, characterized in that the locking element (7) is mounted about a central pivot point to perform a partial rotational movement, so that the fixing means (5) on the locking element (7) are not linearly movable, but on a section of a circular path between the states fixing and loosening or releasing the clamping and positioning bolts (4).

9. Clamping system (1) according to one of the preceding claims, characterized in that a spindle or threaded rod (10) is rotatably mounted in the plate (2) as a drive means of the locking element (7), wherein the drive means engages the locking element (7) via a thread (11) to move the locking element (7).

10. Clamping system (1) according to one of the preceding claims, characterized in that the fixing means (5) are designed to form a positive and force-fit connection in contact with a respective clamping and positioning bolt (4), which also generates a downward force on the clamping and positioning bolt (4) to press the fixed tool and / or machine part against the clamping system (1).

11. Clamping system (1) according to one of the preceding claims, characterized in that the clamping system (1) comprises two locking elements (7, 7') formed in one piece, which are movable in opposite directions under mechanical coupling to each other in order to fix or release all clamping and positioning bolts (4).

12. Clamping system (1) according to one of the preceding claims, characterized in that the locking elements (7, 7') are movable in opposite directions to each other under mechanical coupling.

13. Clamping system (1) according to one of the preceding claims, characterized in that instead of a spindle or threaded rod (10) a hydraulic or pneumatic system is provided as the drive means of the locking element (7), in which a piston is integrally formed on the locking element (7) is trained.

14. Clamping system (1) according to the preceding claim, characterized in that the locking element (7) is subjected to a force by a spring element which is designed to securely hold the locking element (7) in a locking or fixing position in a pressureless state of the hydraulics or pneumatics.

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