WO1993004815A1

WO1993004815A1 - Device for clamping workpieces on machining and measuring machines

Info

Publication number: WO1993004815A1
Application number: PCT/EP1992/002093
Authority: WO
Inventors: Wolfgang Wuchner
Original assignee: Max Lieder Gmbh Maschinen- Und Vorrichtungsbau
Priority date: 1991-09-11
Filing date: 1992-09-11
Publication date: 1993-03-18
Also published as: AU2565292A; DE4130602A1

Abstract

A workpiece clamping device has a clamping plate with holes arranged in parallel rows of a regular grid for securing clamping units associated to the clamping plate. The holes (4) of contiguous rows are mutually offset by half the spacing between holes (b = a/2) and the spacing (c) between contiguous rows equals c = a/2 ∑3, so that groups of three adjacent securing holes (4) located at the vertices of an imaginary equilateral base triangle (6) are obtained. The clamping units (10, 12, 14) have each at least one group of securing holes (22, 24) that correspond to a base triangle of the clamping plate (2). As a result of this grid arrangement of holes, freely centered rows of holes with respect to a desired center point of the clamping plate are obtained, as well as perpendicular rows and columns of holes, so that the device offers universal clamping possibilities.

Description

Clamping device for clamping workpieces on processing and measuring machines

The present invention relates to a clamping device of the type mentioned in the preamble of claim 1.

Clamping devices of this type have the task of securely holding the workpiece on the clamping plate even under the action of large machining forces and of aligning the workpiece precisely with respect to the machine-fixed coordinate system.

In addition to the previously customary clamping devices with grooved clamping plates, so-called grid clamping systems have recently become established, in which the clamping plates are provided with a large number of precisely positioned and designed fixing or fitting bores arranged in a regular grid. These are used for clamping and precise positioning of stops and clamping units, with the help of which the workpieces can be positioned and clamped with great repeatability.

The "tz für Metallverarbeitung", 31st year 1987, number 2187, pages 32 to 40, already discloses grid clamping plates in which the grid holes are arranged in rows and columns, the row spacing or column spacing being the same; adjacent grid holes are located on the corners of a fictitious square. The grid bores are alternately formed as fixing bores or fitting bores in the row direction and column direction. By This arrangement of the grid bores means that the clamping options are relatively limited, since with the clamping units, which are provided with fastening bores arranged at a distance from the columns or rows, clamping is only possible in the columns or row direction. For clamping at an angle to these two main directions, separate clamping units must be provided, in which the spacing of the fastening holes is matched to the diagonal spacing of the grid holes of the clamping plate. Even with such special clamping units, there are only a few possible clamping directions that deviate from the two main directions. In particular, centering toward a center of the clamping plate is made more difficult, since the diagonal rows of the mounting holes of the known clamping plate are each offset by 90 °, so that four clamping units must be used for centering. In addition to the fact that the installation of four clamping units at the beginning of a machining sequence and the loosening or clamping of these clamping units when changing a workpiece mean a relatively high workload, clamping with four clamping units also has the basic disadvantage that it generally results in a determination of the workpiece fixation.

A clamping plate is already known from DE-OS 22 32 387, in which parallel and symmetrical rows of fixing bores are provided in each case with regularly distributed radial dials. Although this arrangement allows workpieces to be centered at the center of the clamping plate, for example using three clamping units, it does not allow clamping in two mutually perpendicular main axis directions of the machine. Another disadvantage is that the fixing holes of the known clamping plate not all of them lie on rows parallel to one another or columns perpendicular thereto, so that the generally highest accuracy of two mutually perpendicular machine guides cannot be used in the manufacture of the clamping plate, but an angle coordinate that is generally less precise comes into play.

It is the object of the present invention to provide a tensioning device of the type mentioned in the preamble of claim 1, which can be used more universally and is easier or more precise to manufacture than the known tensioning devices.

This object is achieved by the features described in claim 1.

All grid bores are arranged in rows parallel to one another, so that the high guiding accuracy of conventional machining centers can be used in the manufacture of the clamping plate. The offset of the grid bores in each case of two adjacent rows by half a hole spacing and the suggested spacing of two rows each to each other, a triangular grid results, in which three adjacent grid holes are arranged at the tips of a fictitious simultaneous basic triangle.

This arrangement of the grid bores according to the invention results on the one hand in a grid pattern arranged in rows and columns, in which the grid bores are arranged on the one hand along said parallel rows and on the other hand in columns running at right angles thereto; this enables in a known manner clamping in mutually perpendicular directions. On the other hand, there is a grid pattern of the highest precision oriented radially to a center, which is based on the manufacturing accuracy of the grid holes arranged in the row and column direction. This enables high-precision centering to a specified center of the clamping plate.

As will be explained in more detail on the basis of an exemplary embodiment, each of the grid bores can be used as the center, since the grid pattern is repeated exactly in the spacing of the grid bores.

As will be further explained with the aid of an exemplary embodiment, the grid pattern is repeated with respect to a selected center point in each case after an angle step of 60 °, so that there are six equivalent radial clamping directions with respect to a center point.

According to a further feature of the invention it is provided that the clamping units each have at least one group of fastening bores arranged according to a basic triangle of the clamping plate. It can be shown that with a group of fastening bores arranged according to a basic triangle of the clamping plate, six clamping directions are possible with respect to a center point, two of which clamping directions lie in the direction of the parallel rows mentioned.

According to one embodiment of the invention, it is provided that a first row of grid holes of the clamping plate runs through the center of this clamping plate and that the grid holes of this first row are arranged symmetrically to the center. That achieved one, for example, in that one of the raster bores lies in this center. According to a further embodiment of the invention, the clamping plate is designed as a circular plate; the above-mentioned first row of grid holes lies on a diameter of this circular plate, a grid hole being arranged in the center of the circular plate.

According to a further embodiment of the invention, the clamping units each have a plurality of parallel rows of fastening bores arranged in accordance with the arrangement of the locking bores of the clamping plate. Since the grid pattern of the grid holes of the clamping plate is repeated several times in the clamping units, the possibilities of different arrangements and orientations of the clamping units on the clamping plate are further increased. It is preferably provided that the clamping units each have three rows of fastening bores, the fastening bores of the middle row being designed as fitting bores. These are used only for the precise alignment of the clamping units on the clamping plate, while the other fastening bores serve for receiving fastening bolts, as will be explained in more detail with reference to an exemplary embodiment.

In a further embodiment of the invention, it is provided that the clamping units each have a lower part provided with fastening bores and an upper part which is displaceably guided thereon and can be clamped in its displacement positions. The lower part is first fastened to the clamping plate in the area in which the workpiece is to be held; the exact alignment of the clamping unit to the workpiece is done by moving the upper part. For this purpose, the upper part is on a front face in the direction of displacement provided with a central clamping surface which is transverse to the direction of displacement and which can rest against the workpiece.

In a further embodiment of the invention, it is provided that the central clamping surface of the upper part is connected at least on one side with a lateral clamping surface at an angle of 30 ° to this central clamping surface. As will be explained with reference to an exemplary embodiment, the number of possible clamping directions can be increased again by this arrangement, whereby the universality of the device is further increased.

For the fine adjustment of the upper part relative to the lower part of a clamping unit, a further embodiment of the invention provides that an adjusting threaded bolt aligned in the direction of displacement of the upper part is arranged on the lower part, said threaded bolt facing away from an actuating surface of the upper part facing away from the central clamping surface is deliverable.

In a further embodiment of the invention, fitting bores and / or threaded bores are provided on the upper side of the upper part for fastening further tensioning means, stop means and the like.

The grid holes of the clamping plate are preferably all the same, inserts are provided for forming at least individual grid holes in fitting holes. In this way, each of the grid holes can either be used for precise alignment or for fastening the clamping units on the clamping plate. In a further embodiment of the invention, a modular clamping unit is provided, which is essentially formed from a clamping foot that can be mounted on the grid plate with its clamping surface and from a cylindrical shaft that extends perpendicular to the clamping surface, the upper side of the shaft being arranged parallel to the clamping surface and is designed as a further clamping surface, and the clamping plate is provided on its circumference with bores adapted to the grid dimension of the grid plate. Such a clamping unit made of a central cylindrical shaft with at least one clamping surface on the top and with a clamping foot that can be mounted on the grid plate is simple to manufacture and has the rigidity necessary for securely clamping the workpieces on the grid plate, in particular bending and Torsional stiffness.

In the preferred embodiment, the shaft of the tensioning unit is solid and integrally formed with the tensioning foot, a circumferential recess being provided between the tensioning foot and the shaft to form a free space for bores formed in the tensioning foot. Furthermore, the outer surface of the shaft of the clamping unit is provided with a further clamping surface, which is arranged in a plane parallel to the axis of the shaft and is provided with holes with a grid dimension. Such a clamping unit, consisting of a solid shaft with a clamping foot for clamping onto a grid plate and with an upper and a lateral clamping surface, is easy to manufacture on the one hand and extremely variable in use for clamping the most varied to be machined and / or closed dimensioning workpieces. Due to the cylindrical shaft with a circular cross section, the clamping unit is extremely resistant to bending and torsion. To clamp the workpieces, a circumferential surface of the cylindrical shaft that is cut continuously or partially by a flattening is usually sufficient, which, depending on the use of the clamping unit, can be aligned by rotating the clamping unit about its vertical axis.

For further fixation of workpieces on the grid plate by means of the clamping unit, further position elements provided with bores are provided, which are formed from a cylinder piece with an axially parallel flattening, the dimensions and bores of which are adapted to the lateral clamping surface of the clamping unit. The pair-by-side arrangement of such position elements directly on a grid plate enables round workpieces to be centered on the grid plate.

Finally, to extend the clamping units, disk-cylindrical position elements are provided, the upper and lower sides of which are provided with holes adapted to the clamping surface provided on the upper side of the shaft of the clamping unit.

In a further embodiment of a clamping unit that can be mounted on a grid plate, the shaft of the clamping unit is formed in a hollow cylinder and in one piece with the clamping foot that can be mounted on the grid plate, the clamping foot projecting circumferentially beyond the shaft and also being adapted to the grid dimension of the grid plate Bores is provided and the top of the hollow cylindrical shaft is closed and provided with an axial through hole. Such a clamping unit is used to fasten clamping arms for depressing workpieces in the direction of the grid plate. Exemplary embodiments of the invention are shown in the drawing and are described in more detail below. Show it:

FIG. 1 shows a plan view of a clamping device with a clamping plate and three clamping units;

Figure 2 shows an enlarged view

Top view of a clamping unit fastened on the clamping plate;

FIG. 3 shows a perspective exploded view of a clamping unit with a lower part and an upper part;

Figure 4 is a plan view. the lower part of a clamping unit;

FIG. 5 shows a cross section through the lower part according to FIG. 4 along the section line V-V;

Figure 6 is a plan view of the top of the

Clamping unit;

7 shows a cross section through the upper part along the section line VII-VII;

Figure 8 is a side view of the top;

FIG. 9 shows a perspective illustration of a tensioning unit in another embodiment; Figure 10 is a perspective view of the

9 clamping unit with an attached positioning element,

FIG. 11 shows the positioning element from FIG. 10 in a different perspective view,

12, a, b, c are perspective representations of three further, circular-cylindrical positioning elements,

13 shows a further embodiment ^'of a mountable on a grid plate clamping unit;

Figure 14, a, b perspective views of a

Clamping iron and a guide sleeve together with associated screw elements for the clamping unit in the embodiment according to FIG. 13,

FIG. 15 shows the perspective top view of a grid plate with mounted clamping units in the embodiment according to FIG. 9 and FIG. 13,

Figure 16 is a perspective view of a grid plate with mounted workpiece, and

FIG. 17 shows a further perspective illustration of a grid plate with another workpiece mounted on it. FIG. 1 shows a circular clamping plate 2 with latching bores 4, which are shown in FIG. 1 as axis crosses which denote the center of these bores. The grid holes 4 are arranged on mutually parallel rows R1, R2 ... Rn, the distance a of the grid holes 4 in a row always being the same. The grid holes 4 of a row, for example the row R2, are each offset by half a hole spacing b from one another, ie b = a / 2, compared to the grid holes of the adjacent rows, for example the rows R1 and R3. The distance c between two rows of each other is selected such that there are three adjacent locking bores 4 at the tips of a fictitious equilateral triangle 6, ie c = a / 2 N / T} As can be seen in FIG. 1, the arrangement pattern is repeated, starting from any radial row of bores, in each case after an angular distance of 60 ° with respect to the plate center 8, the grid bores of a row being arranged symmetrically with respect to this center 8.

As already explained in the introduction, the grid bores 4 can be produced, for example, on a machining center using two work table guides that run at right angles to one another, with which a high arrangement accuracy can be achieved.

The clamping plate 2 is assigned three clamping units 10, 12, 14 in FIG. 1, which are used for clamping and centering a workpiece 16, for example circular, shown in phantom in FIG. The clamping units 10, 12, 14 are each arranged at an angle of 120 ° to one another. They are clamped radially against the workpiece 16, which results in a statically determined three-point clamping. The clamping units 10, 12, 14 have the grid pattern of Clamping plate 2 matched mounting holes through which they can be fastened to the clamping plate 2, as will be explained in more detail with reference to the following drawings.

As FIG. 3 in particular shows, each clamping unit essentially consists of a lower part 18 and an upper part 20. The fastening bores for fastening the clamping units are each formed on the lower part 18, so that this corresponds to the grid pattern of the clamping plate 2 in different discrete positions can be attached to the clamping plate 2. As FIG. 4 in particular shows, the lower part 18 has three rows of fastening bores, the middle row r1 being formed from grid bores from highly precise fitting bores 22, while the two outer rows r2, r3 consist of fastening bores 24. As can be seen in FIG. 5, the fastening bores 24 have, in a manner known per se, an enlarged part for receiving a screw head flush.

Three adjacent bores of the lower part 18, ie two fastening bores 24 and one fitting bore 22 or two fitting bores 22 and one fastening bore 24, lie on an equilateral triangle 26 corresponding to the basic triangle 6 of the clamping plate 2, so that the lower part conforms to the grid pattern can be attached to the clamping plate 2 in different discrete positions. In the clamping units shown in FIGS. 1 to 4, the rows rl, r2, r3 run in the longitudinal direction of the lower parts 18, so that the distance between the holes in the longitudinal direction is equal to a and the distance between the rows rl, r2, r3 from each other is equal to c . The clamping unit can thus be aligned in directions parallel to the sides of the basic triangle 6. There is also the possibility of designing the lower part in such a way that the rows of holes are arranged transversely, the fastening bores being at a distance a in the transverse direction and the rows being at a distance c from one another in the longitudinal direction. The clamping units 10 to 14 can thus also be arranged at right angles to the rows Rl to Rn of the clamping plate, as was not shown in more detail.

As can be seen in FIG. 4, threaded bores 28 are arranged between the fastening bores 24, which are used to fasten the upper part 20 to the lower part 18.

The lower part is provided with an upwardly open central longitudinal groove 30 into which a guide bar 32 formed on the underside of the upper part 20 engages, so that the upper part 20 is guided longitudinally on the lower part 18. In the regions of the upper part 20 which are lateral with respect to the direction of displacement, elongated holes 34 associated with the threaded bores 28 are formed, through which fastening bolts can be inserted and screwed into the threaded bores 28 of the lower part. As FIG. 7 in particular shows, the elongated holes 34 are widened upward in a manner known per se for the flush reception of the bolt buttons.

The guide bar 32 forms a central clamping surface 36 on its front side with respect to the direction of displacement, which is intended to rest against a workpiece. On both sides of the central clamping surface 36 there are lateral clamping surfaces 38, 40 at an angle of 30 °, the function of which is described below. At the top of the upper part 20 there are further threaded bores 42 and fitting bores 44 for fastening further tensioning or stop means.

A bearing plate 4.6, which is provided with a central threaded bore 48, is screwed onto the rear of the lower part 18. As can be seen in particular from FIG. 2, an adjusting threaded bolt 50 is screwed into the threaded bore 48 and its front end can be placed against the upper part 20, so that by rotating the adjusting threaded bolt 50 the upper part 20 relative to the lower part 18 is longitudinally adjustable. Exact gauge blocks can also be inserted between the bearing plate 46 and the upper part 20 in order to precisely fix the position of the upper part 20 relative to the lower part 18.

As can be seen from FIG. 1, the radial arrangement pattern of the raster bores 4 related to ^" the center 8 ^" is repeated in angular steps of 60 °, so that the clamping units can be arranged on six different radials and parallel rows of bores The radials lying on the middle row R0 correspond at the same time to an axis of a right-angled axis system; in order to be able to fasten clamping units also in an axial direction perpendicular to them, the arrangement pattern of the fastening bores of the lower part need only be in the manner described above be changed slightly so that the hole spacing is equal to a in the transverse direction and c in the longitudinal direction.

In order to clamp the workpiece 16 on the clamping plate 2, the lower parts 18 are first offset by 120 ° and fastened on the clamping plate in such a way that their positions are rough correspond to the dimensions of the workpiece 16. Then the upper parts 20 are put on and finely adjusted by means of the adjusting threaded bolts 50 until the central clamping surfaces 36 bear against the workpiece 16. The upper parts 20 are then fixed on the lower parts 18 by means of screw bolts 52 screwed through the elongated holes 24 into the threaded bores 28.

In order, for example, to clamp a rectangular workpiece, two clamping units arranged on the row of holes R0, opposing one another and two clamping units of the special type described further above, can be used. However, there is also the possibility of using clamping units of the type described with the reference numerals 10 to 14, the lateral clamping surface 40 being brought into contact with the workpiece, for example, in the alignment corresponding to the clamping unit 10.

In the following, reference is made to FIGS. 9 to 17.

The clamping unit which can be mounted on a grid plate 101 of a modular grid clamping device, hereinafter referred to as structural elements 102, in the embodiment according to FIGS. 9 and 10 consists of a solid cylindrical shaft 10.3 made of a metallic one, for heat treatment or surface coating suitable material, which is provided with a circumferential recess 104 to form a free space 105 which separates the solid shaft 102 from a clamping foot 106 which can be mounted on the grid plate 101 and which is formed in one piece with the shaft 103. The clamping foot 106 can be mounted on the grid plate 101 with its lower clamping surface 107. For this purpose, on the circumference of the disk-shaped clamping foot 106 Through bores 108 are formed, which are arranged in the grid dimension of the grid plate 101. The upper side 109 of the solid shaft 103 is arranged parallel to the clamping surface 107 of the clamping foot 106 and is designed as a clamping surface 110, which is provided with threaded bores 111, which are also arranged in a grid dimension. The axis 112 of the cylindrical shaft 103 is perpendicular to the clamping surface 107 of the clamping foot 106 and perpendicular to the clamping surface 110 of the upper side 109 of the shaft 103. Fit holes 111A are provided coaxially to the axis 112.

The outer surface of the shaft 103 of the structural element 102 is provided with a further clamping surface 113, which is arranged in a plane parallel to the axis 112 of the shaft 103 and is provided with threaded bores 114, which are also arranged in the grid dimension of the grid plate 101.

FIG. 10 shows the structural element 102 according to FIG. 9 with a positioning element 115 screwed to its clamping surface 113, which is shown again individually in FIG. 11. The positioning element 115 consists of a cylindrical piece with a flattening 116 parallel to the axis, the bores 117 of which have the pitch of the threaded bores 114 of the clamping surface 113 of the structural element 102. The bores 117 are through bores which are drilled out from the round side for the use of screw heads. The upper and lower side of the positioning element 115 is provided with threaded bores 118 lying on a radius, which are formed on the flat side 116 opposite the flat side of the upper and lower sides of the positioning element 115. In the radial axis plane, which runs parallel to the flattened portion 116, there are millings 119 on the outer surface of the positioning element 115 formed, in the area axially parallel through holes 120 are arranged. 128 coaxial fit bores are designated.

FIGS. 12a, b and c show disc-cylindrical positioning elements 121, 122, 123 for mounting on the top side 109 of the mounting element 102 in the embodiment according to FIGS. 9 and 10. All three positioning elements 121, 122 and 123 have on their tops Milled 124 at an angle of 120 ° to one another, in the area of which axially parallel through bores 125 are formed. Threaded bores 126, 127 are formed from the upper side of the positioning elements 121, 122 and 123 at an angle shifted at 60 ° to the three cutouts 124, the threaded bores 126 being used for all three positioning elements 121, 122 and 123 on a large outer radius and the threaded holes 127 are provided only on the positioning element 121 on a smaller inner radius. A central fitting bore 128 is formed in the axis of each of the positioning elements 121, 122, 123.

FIG. 13 shows a second embodiment of the structural element 132 that can be mounted on a grid plate. Here, the shaft 133 is of hollow cylindrical design and is provided with a clamping foot 136 which projects circumferentially over the shaft 132 and has a lower clamping surface 137. The clamping foot 136 carries a ring of through bores 138 which are arranged in the grid dimension of the grid plate 101. The tensioning foot 136 has a flattened side surface 135. The hollow cylindrical shaft 133, which is formed in one piece with the clamping foot 136, is closed at its upper end and has a central threaded bore 139 in the upper clamping surface 140. The clamping bar 141 shown in FIG. 14 and the guide sleeve 142 shown in FIG. 14b together with associated threaded screws 143 and 144 are provided for mounting on the mounting surface 140 of the structural element 132 in the embodiment according to FIG. 13. The guide sleeve 142 comprises a lower clamping ring 145 with opposing flats 146 for engaging a tool and a threaded bore 147 located in the axis, the upper part of which has the thread dimension for the threaded bolt 143 and the lower part of which has the thread dimension for the threaded bolt 144. This is used for screwing into the threaded bore 139 in the clamping surface 140, the guide sleeve 142 being fixed thereon. The clamping bar 141, which has a bore 148 on its underside, engages over the cylindrical shaft 149 of the guide sleeve 142 and is screwed by means of the threaded screw 143 against the clamping collar 145 of the guide sleeve 142, the head of the threaded screw 143 on the surface ¬ che the clamping iron 141 supports. This comprises a cantilever arm 150, which is used to clamp a workpiece.

A grid plate 101 is shown in FIG. 15, onto which components 102, 132 with associated positioning elements 115, 121, 122, 123 or clamping bars 141 and guide sleeves 142 are placed. It can be seen here that a modular design is possible, especially since the various elements of the grid clamping device can be assembled in a modular manner.

In FIG. 16, a workpiece is illustrated 151 that ^• by means of elements on a raster plate 101 more Aufbauele- 102 is mounted over, 132. To hold down the Workpiece 151 is a construction element 132 with a guide sleeve 142 thereon with clamping iron 141.

17 shows the independent, paired arrangement of the positioning elements 115 with their flats 116 directly on a grid plate 101, the paired positioning elements 115 with their cylindrical lateral surfaces forming a prismatic guide for a cylindrical workpiece 152. Two construction elements 132 are mounted on both sides of the one pair of positioning elements 115 on the grid plate 101 and carry a yoke 153 which is screwed onto the construction elements 132 by means of fastening screws 154. A central clamping screw 155 serves to depress the cylindrical workpiece 152 in the through ^'the polyvinyl sitionierelemente prism 115 is formed.

The grid dimension of the grid plate 101 consists of a matrix of through bores or threaded bores arranged in rows and columns, as described above. The resulting grid dimension is also used in the bores of the clamping surfaces 110, 113 and 140.

The structural element shown in FIG. 17, formed by the elements 132, 153, represents a clamping yoke known per se. The length of the cross member 153 or the distance between the two bores for receiving the clamping screws 154 is again based on the pitch of the frame ¬ disk matched.

Claims

Patent claims

1. Clamping device for clamping workpieces, comprising a clamping plate with raster bores arranged in parallel rows in a regular grid for fastening clamping units assigned to the clamping plate, characterized in that the grid bores (4) each of two adjacent rows by half Bore distance (b = a / 2) are offset from each other and the distance (c) of two rows to each other is equal to c = a / 2 J, so that groups of three neighboring triangles (6) at the tips of a fictitious equilateral triangle (6) horizontal fixing bores (4) arise and that the clamping units (10, 12, 14) each have at least one group of fixing bores (22, 24) arranged according to a basic triangle of the clamping plate (2).

2. Clamping device according to claim 1, characterized ge indicates that a first row (R0) of locking bores (4) of the clamping plate (2) through a clamping center (8) of the clamping plate defi¬ ning point and that Raster bores of this first row are arranged symmetrically to the center (8).

3. Clamping device according to claim 1 or 2, characterized in that the clamping plate (2) is designed as a circular plate.

4. Clamping device according to one of claims 1 to 3, characterized in that the clamping units (10, 12, 14) each have a plurality of mutually parallel Rows (rl, r2, r3) of fastening bores arranged in accordance with the arrangement of the grid bores (4) of the clamping plate (2).

5. Clamping device according to claim 4, characterized gekenn¬ characterized in that the clamping units (10, 12, 14) have three rows of mounting holes, the mounting holes of the middle row are designed as Paß¬ bores (22).

6. Clamping device according to claim 4 or 5, characterized in that the clamping units (10, 12, 14) each have a fastening part (22, 24) provided lower part (18) and a slidably guided on this and clampable in its Verschieb¬ positions upper part (20).

7. Clamping device according to claim 6, characterized in that the upper part (20) of the clamping units has a central clamping surface (36) standing transversely to the displacement direction on a front end side in the displacement direction.

8. Clamping device according to claim 7, characterized in that adjoins the central clamping surface (36) at least on one side to the central clamping surface at an angle of 30 ° standing lateral clamping surface (38, 40).

9. Clamping device according to claim 8, characterized gekenn¬ characterized in that on the lower part (18) of the clamping unit (10) in the direction of displacement of the upper part (20) aligned adjusting screw bolt (50) is arranged an¬ which against one of the central clamping surface (36) facing away from the actuating surface (37) of the upper part (20) is deliverable.

10. Clamping device according to one of claims 6 to 8, characterized in that on the top of the upper part (20) fitting bores (44) and / or threaded bores (42) are provided for fastening further clamping means.

11. Clamping device according to one of claims l to 3, characterized in that the clamping unit (102, 132) from a with its clamping surface (107, 137) on the grid plate (101) mountable clamping foot (106, 136) and from a vertical to the clamping surface (107, 137) extending cylindrical shaft (103, 133) it is formed that the top (109, 139) of the shaft (103, 133) is arranged parallel to the clamping surface (107, 137) and as a further clamping surface (110, 140), and that the clamping foot (106, 136) is provided with through bores (108, 138) adapted to the grid dimension of the grid plate (101).

12. Clamping device according to claim 11, characterized gekenn¬ characterized in that the shaft (103) of the Spanneinrich¬ device (102) is solid and integrally formed with the clamping foot (106) and that between the clamping foot (106) and the shaft ( 103) a circumferential recess (104) for forming a free space 8105) is provided for the through bores (108) formed in the tensioning foot (106).

13. Clamping device according to claim 11 or 12, characterized in that the outer surface of the shaft (103) of the clamping device (102) is provided with a further clamping surface (113) which in is arranged on a plane parallel to the axis of the shaft and is provided with threaded bores (114) in the grid dimension.

14. Clamping device according to one of claims 11 to

13, characterized in that positioning elements (115) provided with bores are provided, which are formed from a cylinder piece with an axially parallel flattening (116), the dimensions and bores (117) of which extend to the further clamping surface ( 113) of the clamping unit (102) is adapted.

15. Clamping device according to one of claims 11 to

14, characterized in that further disk-cylindrical positioning elements (121, 122, 123) are provided, the upper sides of which are provided with bores adapted to the bores of the upper clamping surface (110) of the clamping unit (102).

16. Clamping device according to claim 11, characterized gekenn¬ characterized in that the shaft of the clamping unit (132) is hollow cylindrical and integrally formed with the clamping foot (136) that the clamping foot (136) the shaft (133) of the structural element (132) circumferentially protrudes and is provided with through holes (138) adapted to the grid dimension of the grid plate (101), the upper side of the hollow cylindrical shaft (133) being closed with a clamping plate (140) with a central threaded bore (139) .

17. Modular grid clamping device according to claim 16, characterized in that for screwing onto the clamping plate (140) of the structural element (132) a guide sleeve (142) with tensioning rods (141) screwable thereon is provided.

18. Clamping device according to one of claims 1 to 17, characterized in that the Rasterbohrun¬ gene of the clamping plate (2) are all of the same design and that inserts are provided for reshaping at least individual grid holes in fitting holes.