阅读说明：本技术 工件更换架的定心界面 (Centering interface of workpiece changing rack ) 是由 普姆-舒伯特·克里斯弗里德 于 2019-09-06 设计创作，主要内容包括：本发明涉及一种由台适配器和工件容纳基底组成的工件更换架的定心界面,其中,工件更换架的台适配器可拆卸地安装在测量仪器或机床的台子上。在此,在台适配器与工件容纳基底之间设置至少三个不同的支撑位置。第一支撑位置包含由旋转体和三个球组成的组。第二支撑位置包含由旋转体和两个球组成的组。第三支撑位置包含由两个接触元件组成的组。台适配器和工件容纳基底在彼此定位后能够借助张紧系统彼此张紧。通过本发明提出了一种工件更换架的定心界面,通过其能够可拆卸地将工件容纳基底重复精确地、可靠地且节约时间地定位在台适配器上。(The invention relates to a centering interface for a workpiece changing rack consisting of a table adapter and a workpiece receiving base, wherein the table adapter of the workpiece changing rack is detachably mounted on a table of a measuring instrument or a machine tool. At least three different support positions are provided between the table adapter and the workpiece receiving base. The first support location comprises a group consisting of a rotator and three balls. The second support position comprises a group consisting of a rotating body and two balls. The third support position comprises a group of two contact elements. The table adapter and the workpiece receiving base can be tensioned against each other by means of a tensioning system after being positioned against each other. The invention provides a centering interface of a workpiece changing rack, by means of which a workpiece receiving base can be detachably positioned on a table adapter repeatedly, precisely, reliably and in a time-saving manner.)

1. A centering interface of the workpiece changing rack (1) consisting of a table adapter (10) and a workpiece receiving base (40),

-wherein a table adapter (10) of the workpiece changing stand (1) is detachably mounted on a table (2) of a measuring instrument or a machine tool,

-wherein at least three different support positions (60,80,100) are provided between the table adapter (10) and the workpiece receiving base (40) of the workpiece changing rack (1),

-wherein the first support location (60) comprises a group consisting of a first rotation body (61) and three balls (64-66), the rotation body (61) contacting the three balls (64-66) at three contact locations (67-69), the middle points of the contact locations constituting a triangle,

-wherein the second support location (80) comprises a group consisting of the second rotation body (81) and two balls (85,86), and the midpoint of the ball (85,86) and the contact location (87,88) between the ball (85,86) and the second rotation body (81) together form a plane (93) which intersects the rotation axis (82) of the second rotation body (81),

-wherein the third support position (100) comprises the group consisting of a contact element (101) with a spatially curved end face (102) and a contact element (103) with a flat or spatially curved end face (104), and the two end faces (102,104) are in contact with each other,

-wherein the first mentioned part (61,81,101) of the support location (60,80,100) is arranged either on the workpiece-receiving base (40) or on the table adapter (10), and

-wherein the table adapter (10) and the workpiece receiving base (40) can be tensioned to each other by means of a tensioning system (120) after being positioned to each other.

2. Centering interface according to claim 1, characterized in that the respective first mentioned part (61,81,101) of the support location (60,80,100) is arranged on the workpiece receiving base (40).

3. A centring interface according to claim 1, characterised in that there are two third support locations (100) and that the respective contact location (67-69; 87, 88; 105) or the centre (72,89,105) of the respective contact location constitutes a quadrilateral (108).

4. A centering interface according to claim 3, characterized in that the quadrilateral (108) is constituted by the projection of the midpoint of the contact location (67-69; 87, 88; 105) or the center of the contact location (72,89,105) on the top surface (11) of the table adapter (10) to comprise an area equal to at least 42% of the area of a circle having a radius of the largest radius of the workpiece-receiving substrate (40).

5. A centring interface as claimed in claim 1, characterised in that the rotary body (61) of the first support location (60) has an axis of rotation (74) which perpendicularly intersects the plane formed by the three contact locations (67-69).

6. A centring interface according to claim 5, characterised in that the rotational body (61) of the first support location (60) is a ball having a diameter equal to the diameter of each of the three balls (64-66).

7. A centring interface as claimed in claim 1, characterised in that the rotary body (81) of the second support location (80) is a cylindrical roller having a diameter equal to the diameter of each of the two balls (85, 86).

8. A centring interface according to claim 1, characterised in that the centres (72,89) of the first and second support locations (60,80) lie in a plane perpendicular to the main centreline (5) of the centring interface and an imaginary line connecting the centres intersects the main centreline (5).

9. A centering interface according to claim 1, characterized in that the contact element (103) of the table adapter (10) is a cylindrical pin with a flat end face (104) and the contact element (101) of the workpiece receiving base (40) is a cylindrical pin with a spherically curved end face (102).

10. A centering interface according to claim 1, characterized in that the workpiece receiving base (40) has at least three-predetermined pegs (56) arranged around the main centre line (5), which fit into corresponding predetermined core openings (17) of the table adapter (10) with a clearance smaller than the radius of a circle (70), respectively, which circle (70) is defined by the contact positions (67-69) of the first support position (60), wherein the spacing of one of the predetermined pegs (56) with respect to the main centre line (5) is smaller than the spacing of the other two predetermined pegs with respect to the main centre line.

11. Centering interface according to claim 1, characterized in that the tensioning system consists of a tensioning bolt (121) on the one hand and a pretensioned mechanical spring energy store (141) with a spring-pretensioned pulling bolt (135) which can be locked with the tensioning bolt (121) on the other hand, wherein the eccentric drive (150) moves the pulling bolt (135) into the release position (161) or releases it for tensioning.

Technical Field

The invention relates to a centering interface for a workpiece changing rack consisting of a table adapter and a workpiece receiving base, wherein the table adapter of the workpiece changing rack is detachably mounted on a table of a measuring instrument or a machine tool.

Background

EP 1640094B 1 discloses a device for measuring rotationally symmetrical precision parts and a tensioning device. The precision part is here placed in a chuck on the adapter. The adapter is supported on the rotary table in a centered manner. For this purpose, the adapter has three balls on its bottom surface, which are inserted into three concave indentations of the turntable.

Disclosure of Invention

The problem addressed by the invention is that of providing a centering interface for a workpiece changing rack, by means of which a workpiece receiving base can be detachably positioned on a table adapter repeatedly, precisely, reliably and in a time-saving manner.

This problem is solved by the features of claim 1. At least three different support positions are provided between the table adapter of the workpiece changing rack and the workpiece receiving base. The first support location comprises a group of a rotator and three balls, the rotator contacting the three balls at three contact locations, the midpoints of the contact locations constituting a triangle. The second support position comprises a group consisting of a rotating body and two balls. The center point of the ball and the contact point between the ball and the rotary body together form a plane which intersects the axis of rotation of the rotary body. The third support position comprises the group consisting of a contact element with a spatially curved end face and a contact element with a flat or spatially curved end face. Here, the two end faces contact each other. The first-mentioned component in each group is arranged either on the workpiece receiving base or on the table adapter. The table adapter and the workpiece receiving base can be tensioned against each other by means of a tensioning system after being positioned against each other.

The workholding rack of the present invention has a centering interface between the table adapter for carrying and the at least one tool receptacle carried thereby, which enables rapid, reliable, and repeatable precise placement of the respective tool receptacle on the table adapter. The tool holder also has the function of a tray on which workpieces or other bodies can be accommodated in advance or after the interface element has been assembled. The workpiece may be inspected, measured, or machined on the workpiece changing rack.

The centering interface is designed such that a single tool receiver, or each tool receiver of a group, can be placed on the table adapter only in a single angular position. For this purpose, the centering interface has three different types of support positions, wherein each type of support position consists of a pair. In at least two support position types, the pair members are not interchangeable with each other. Thus, for example, in one type of support position, one ball is placed in a recess between three balls arranged next to each other, while in another type of support position, a laid-down cylinder is positioned between or on two balls also next to each other.

If the support position types are named by the number of contact positions of the support position type, the support position types constitute four-piece groups, three-piece groups, and at least one two-piece group. Each pair has in each case one member which consists of only a single, so-called individual support element. The individual support elements of all groups can be arranged either on the bottom side of the tool holder or on the top side of the table adapter. It is likewise possible to fasten one part of the individual support element to the table adapter and the other part to the tool holder.

The table adapter is in this embodiment provided for a rotary table. However, it can also be adapted to the flat table of a multi-coordinate measuring machine, to the bed, to the base or to the slide of a machine tool by means of other fastening means. The workpiece-changing rack can be mounted with the vertical central axis upright or via a head. It is also possible to operate the central axis horizontally or at an angle of, for example, 45 °.

Furthermore, it is also conceivable for the table adapter and/or the tool holder to have a different outer contour than a circular shape in relation to the respective cross section perpendicular to the main center line of the workpiece changing rack.

Drawings

Further details of the invention are given by the dependent claims and the following description of exemplary embodiments.

FIG. 1: a perspective view of a workpiece changing rack having a tip mounted on a rotary table;

FIG. 2: a side view of the workpiece changing stand according to fig. 1;

FIG. 3: a perspective view of a bottom surface of the table adapter;

FIG. 4: a perspective view of a top surface of the table adapter;

FIG. 5: a perspective view of a bottom surface of the workpiece changing rack;

FIG. 6: a perspective view of the top surface of the workpiece changing rack without the tensioning pin installed;

FIG. 7: a cross-sectional view of the table adapter;

FIG. 8: a cross-sectional view of the workpiece-receiving substrate;

FIG. 9: a top view of a first support location having four balls;

FIG. 10: a centered side sectional view according to fig. 9;

FIG. 11: as in fig. 10, but with a tapered pin as the support element;

FIG. 12: as in fig. 10, but with a concave tapered pin as the support element;

FIG. 13: a side view of a second support location having two balls and a cylinder;

FIG. 14: FIG. 13 is a top view;

FIG. 15: a top view of a second support location having three balls;

FIG. 16: a top view of a second support location having two balls and a bucket;

FIG. 17: like fig. 16, but with a concave roller;

FIG. 18: a cross-sectional view of a third support position with two pin-shaped and pin-shaped contact elements;

FIG. 19: FIG. 18 is a partial top plan view;

FIG. 20: a cross-sectional view of a workpiece changing rack with a workpiece receiving base positioned and a spring accumulator tensioned;

FIG. 21: as in fig. 20, but with the work piece receiving base pressed and the eccentric actuator relaxed.

Detailed Description

Fig. 1 shows a workpiece changing rack 1 mounted on a rotary table 2. The rotary table 2 is arranged on a table of a multi-coordinate measuring machine or a machine tool, for example. The workpiece changing rack 1 is mainly composed of two components. The first component is a table adapter 10, by means of which the workpiece changing rack 1 is fixed on the rotary table 2. The second component is a workpiece-receiving substrate 40. A stage tip 47 as a part of the workpiece accommodating portion is placed on the workpiece accommodating base 40 in a centered manner. The latter can be replaced, for example, by a three-jaw chuck. Between the two assemblies there are arranged a tool for centering each other and a tensioning system 120.

Fig. 3 and 4 show a substantially disc-shaped table adapter 10. The stage adapter 10 is made, for example, of the material X8CrNiS 18-9, with a diameter of, for example, 190mm while having a disc height of, for example, 27 mm. According to fig. 3, on its bottom face 31 it has a centering ring 32, for example 8.5mm high, the diameter of which is for example 70 mm. Outside the centering ring 32, three or more equidistantly distributed T-shaped wedges 35 are arranged on a pitch circle of, for example, 110mm, which are held and fixed by means of bolts 36 fitted into counterbores. In the edge region of the base 31, two adjusting threaded bores 33 are provided, which are opposite one another relative to the main center line 5 and each of which is intended to receive an adjusting threaded pin 34.

Between the top side 11 of the table adapter 10 and the base bottom side 50 of the workpiece receiving base 40, there are four support locations 60,80,100, only two support locations 100 being embodied as structurally identical. In each support position 60,80,100, the support element 61,81,101 of the workpiece-receiving substrate (40) contacts one support element 103, two support elements 85,86 or three support elements 64-66 of the table adapter 10.

On the top surface 11 of the table adapter 10, see fig. 4, there are four table adapter-side components of the support positions 60,80, 100. The first support locations 60, the so-called four-part set of components, are three support elements in the form of balls 64-66, which are identical, for example, in terms of geometry and material. The middle points of all three balls 64-66 form, for example, an equilateral triangle whose side length is, for example, equal to 115.5% of the diameter of the balls 64-66. The mathematical center of gravity of the equilateral triangle is, for example, 79mm from the main center line 5.

The second support location 80, the so-called three-part table adapter-side component, is likewise two identically constructed and dimensioned support elements in the form of balls 85, 86. The midpoints of the two balls 85,86 have a spacing equal to, for example, 133.33% of the diameter of the individual ball 85, 86. The geometric centre of the mid-points of the balls 85,86 is, for example, 83mm from the main centre line 5.

Balls 67-69 in the first support position 60 and the second support position 80; 85,86 are, for example, 12mm in diameter. All five balls 67-69; 85,86 are both seated in the ball hole 12, the bottom of which, see fig. 8, is curved in a hemispherical shape to the earth's surface. The hole diameter is for example 0.1mm larger than the ball diameter. Each ball hole 12 merges into a respective removal bore 75 which has a diameter of, for example, 3mm and ends in the bottom face 31.

Balls 67-69; 85,86 are adhered in the ball hole 12. Wherein the point is for example 7.2mm from the top surface 11 of the table adapter 10. The balls of the first support location 60 and the second support location 80 are merely exemplary seated in, for example, prismatic recesses 14,15, respectively, the depth of which is, for example, equal to the balls 67-69; 85,86, is half the radius of the sphere. The recesses 14,15 have no effect on the repeated accurate positioning of the workpiece-receiving substrate 40 on the table adapter 10. However, it protects balls 67-69; 85,86 are protected from undesired mechanical damage.

The side walls of the recesses 14,15 are at least 1mm from the wall of the ball hole 12. The recess 15 of the second support location 80 is based on an isosceles triangle, the height of which, measured parallel to the top surface 11, comprises a radius, for example 25.5 mm.

The two third support discs 100, the so-called two-pack table adapter-side parts, are respectively a contact element 103 in the form of a cylindrical peg with a diameter of, for example, 12mm and, for example, an adjusting threaded pin 34, see fig. 18 and 19. Each cylindrical peg 103 is seated in a stepped bore 16 across the table adapter 10, the lower portion of which is an adjustment threaded bore 33. In the cylindrical region of the stepped bore 16, which is, for example, 2mm longer than the length of the cylindrical pin 103, the respective cylindrical pin 103 is mounted by longitudinal press-fitting. The distance of the end face of the cylindrical pin 103 closest to the top face 11 is adjusted relative to the bottom face 31 by means of an adjusting threaded pin 34 which is inserted into an adjusting threaded hole 33 therebelow. This distance is 1mm in this embodiment. The position of the threaded pin 34 is fixed by means of an adhesive if necessary.

The center line 107 of the contact element or the cylindrical pin 103 lies in a first plane, which is perpendicular to the second plane, which is likewise formed by the line connecting the main center line 5 and the centers 72,89 of the first support location 60 and the second support location 80, in common with the main center line 5.

The projections of the centers 72,89 onto the top surface 11 and the center lines 107 of the contact elements 101,103 of the third support position 100 intersect the plane of the top surface 11 at four points which form the corners of a kite 108 by means of which the workpiece changing rack 1 is supported on the table adapter 10. The area of the kite 108 is shown in phantom in fig. 4, which is equal to 46.56% of the area of the circle having the largest radius of the table adapter 10. This area percentage is typically 49 ± 7% in different sizes of workpiece changing racks. Instead of the kite 108, the quadrilateral may also be a square, rectangle, rhombus, parallelogram, trapezoid or the like.

Three blind holes are arranged in the top surface 11 of the table adapter 10 as predetermined core openings 17. This blind hole 17, for example 16mm deep, has a diameter of, for example, 17 mm. Which merge into the top surface 11 with a 3 x 45 chamfer angle, respectively. The pre-centering notch 17 is indexed 120 degrees. The pre-centering notch is located in the plane formed by the centerlines 73,91 of the centers 72, 89. The centre line of the pre-centering indentation is for example 50mm from the main centre line 5. The spacing of the two other pre-centering notches with respect to the main center line 5 is, for example, 77.5 mm.

According to fig. 8, the table adapter 10 has a three-step through hole 21 in its center, which extends from the top surface 11 to the bottom surface 31. The components of the tensioning system 120 are arranged in this through-hole 21, which consists of a centering region 22, a central region 23 and a feed region 24. The 8mm deep centering region 22 has a diameter of 59 mm. The feed zone 24 machined out of the bottom surface 31 has a diameter of 54mm and a depth of 10.5 mm. The central zone 23 between the centring zone 22 and the feed zone 24 has a diameter of 26 mm. Six spring guide bores 25, each having a diameter of 9mm, for example, are arranged in pairs around the feed region 24 at a diameter of 28mm, for example. A threaded hole 26 of M5 is provided between each of the two spring guide holes 25 in the pair.

According to fig. 20, a radial bore 27 is provided in the table adapter 10, which centrally intersects the central region 23. The diameter of the radial hole 27 is, for example, 14 mm. Transversely to the radial bore 27, a stop counterbore 28 for receiving a stop bolt 156 is arranged in the top side 11.

There is a small indicia bore 44 between the radial bore 27 and the top surface 11 of the table adapter 10. Two further index holes are provided on the top surface 11 close to the outer edge of the table adapter 10 and near the centering area 22, respectively. All three index holes lie in a plane in which the main centre line 5 and the centre lines of the radial holes 27 also lie.

Fig. 5 and 6 show two views of the workpiece-receiving base 40 without the tip 47 installed. The workpiece-receiving base 40 made of an aluminum-silicon alloy substantially has the shape of a disk, for example, 19mm thick, the maximum diameter of which is, for example, 210 mm. The surface of the metal sheet is subjected to hard anodizing at least in some areas. The workpiece receiving base 40 is provided with a flange-like gripping edge 43, for example protruding by 10 mm. The gripping edge 43 transitions, for example, with a radius of 8mm into a cylindrical region of a radially outer wall with a diameter of, for example, 190mm and is provided with a surface structure, if necessary, for the purpose of improving the feel.

A centering indentation 42 for receiving a platform tip 47 or a multi-jaw chuck is centrally formed in the top side 41 of the substrate. In the center of the centering recess 42, a bearing hole 49 is provided, which serves as a support for a draw bolt 125 for mounting the clamping bolt 121 on the workpiece receiving base 40. The centering recess 42 also has, for example, three or more threaded bores, by means of which the tip 47 or the multi-jaw chuck is fixed to the workpiece receiving base 40.

Three or more mounting holes 48, for example 15mm in diameter, are provided equidistantly around the centering indentation 42, through which the bolts 36 fixing the T-slot wedge 35 to the table 2 are accessible in the case of already mounted workpiece-changing racks 1, see fig. 5-8. Two calibrated threaded holes 58 for receiving calibrated threaded pins 59 are disposed near the outer edge of the workpiece receiving base 40, see fig. 18.

The base bottom 50 has a centrally located tensioning recess 54, for example 3mm deep, with a diameter of, for example, 25mm, in which a tensioning bolt 121 is supported centrally by means of a tensioning screw 125.

Three substantially cylindrical predetermined pegs 56 are arranged on the base bottom surface 50, see fig. 5 and 7. A hollow metal fastening core 57 is placed in each stepped bore of each predetermined plug 56, by means of which each predetermined plug 56 is fastened to the workpiece receiving base 40 by means of screws. The predetermined plug 56, which here has a diameter of 15mm, is made of transparent, 75 shore a-hard polyethylene, for example. In the base bottom surface 50, predetermined pegs are seated in predetermined heart recesses 55, for example, 2mm deep, respectively. The free end of the predetermined peg 56 extends beyond the base floor 50 by, for example, 13 mm. It therefore constitutes a support aid when stacked and stored. At the same time, it protects the ball 61, the cylinder 81 and the two cylindrical pins 101 from damage or misalignment caused by collisions.

The centerline of the predetermined peg 56-after placement on the table adapter 10-is aligned with the centerline of the predetermined heart notch 17 of the table adapter 10.

The support elements 61,81,101 of the three different support positions 60,80,100 project from the base bottom surface 50, see fig. 5 and 7. The member on the base bottom surface side of the first support position 60 is a ball 61 as a rotating body. Which is stuck in the ball hole 51, see also fig. 7. The shape of the ball hole 51 largely conforms to the shape of the ball hole 12 of the table adapter 10.

The component of the base bottom side of the second support location 80 is likewise a rotational body, which is here configured as a cylinder 81. The cylinders 81, for example rolling bodies, are seated in the channel-like bearing recesses 52 with flat end faces. Here, the center line 82 of the cylinder 81 is parallel to the base bottom surface 50. Which is spaced from the base bottom surface 50 by, for example, 1 mm. In the workpiece accommodation base 40, the ball 61 and the cylinder 81 have a diameter of, for example, 12 mm. In this embodiment, the centerline 82 of the cylinder 81 intersects the main centerline 5 and intersects the center of the ball 61 of the first support location 60.

All balls 61, 67-69; 85,86 and cylinder 81, for example made of chrome steel 100Cr 6. Balls 61, 67-69; 85,86 may also be hemispheres or spherical segments.

The two contact elements 101 of the third supporting position 100 also project from the base bottom surface 50, see fig. 5 and 18. Each contact element is here a cylindrical pin 101 with a diameter of, for example, 6mm and a length of, for example, 12 mm. The end face 102 extending from the base bottom surface 50 is spherically curved. The curved surface has a radius of, for example, 6 mm. Cylindrical pin 101 is mounted in the cylindrical region of stepped bore 53 by a longitudinal press fit. In the calibration threaded bore 58 connected to the cylindrical region, for example, a calibration threaded pin 59 with a hexagonal socket is screwed.

If necessary, the contact elements 101 can also have a flat end face if they are mounted in an articulated manner in their mounting position by suitable measures such that no edge support is formed between them and the respectively opposite contact element 103.

In the first supporting position 60, the spherical rotary body 61 of the tool receiving base 40 rests on three balls 64-66 of the table adapter 10, see fig. 8,9 and 10. The four balls 61,64-66 have three common contact locations 67-69. This is theoretically a point contact. However, this is in fact-due to the elastic deformation of the ball-a small circular surface. The connection of the midpoints of all the balls 61,64-66 to each other forms a right-angled pyramid whose base plane is an equilateral triangle. The height of the pyramids is smaller than in the case of regular tetrahedrons. The sides of the pyramid that are not parallel to the top surface 11 are inclined relative to the top surface 11, for example, at 48.19 degrees. The angle of inclination 71 may vary between 20 and 70 degrees. The set of four centers 72 is located within the center of gravity of a triangle whose corners make point contacts 67-69.

In the second support position 80, the cylinder 81 of the tool receiving substrate 40 rests on two balls 85,86 of the table adapter 10, see fig. 8,13 and 14.

The center points of the balls 85,86 and the contact points 87,88 between the balls 85,86 and the cylinder 81 together form a plane 93, see fig. 4, which perpendicularly intersects the cylinder center line 82 of the cylindrical rotating body 81. The mid-points of the spheres 85,86 and the intersection of the cylindrical centre line 82 with the plane 93 form an isosceles triangle. The two triangular waists, of length equal to the diameter of the balls 85,86, have an inclination 71 with respect to the top surface 11 equal to the inclination 71 known from the first support position 60.

The contact points 87,88, which are also point contacts in theory, have elliptical surfaces, the long ellipse semiaxis being parallel to the cylinder center line 82. The geometric center between the point contacts 87,88 constitutes the three-piece set center 89.

In the first support position 60, all three translational degrees of freedom of the spherical rotational body 61 are locked by the contact of the spherical rotational body 61 with the three balls 64-66. The rotary body 61 can therefore only be moved relative to the workpiece receiving base 40 about its rotary body center point with three degrees of freedom of oscillation.

Once the cylinder 81 of the second support location 80 contacts the two table adapter side balls 85,86, the material receiving base 40 has only one further degree of freedom of oscillation. Which can swing back and forth at a small angle about the cylinder centerline 82. The pivoting freedom is locked by the two third support positions 100.

The two contact elements 101 of the third support position 100 are adjusted-after the placement of the workpiece receiving base 40 onto the table adapter 10 and after the operation of generating a tensioning force on the tensioning system 120-by adjusting the two calibrated threaded pins 59 by means of suitable measuring tools, for example a main part and a reference part.

Fig. 11 and 12 show two variants of the embodiment of fig. 10 for the rotary body in the first supporting position 60. According to fig. 11, the rotating body is a conical pin 62. Consisting of a cone and a rod with a sharp angle, e.g. 96.38 degrees. The rods are glued into corresponding holes in the workpiece receiving base 40 or are mounted there, for example by means of a press fit.

According to fig. 12, the rotating body is a concave conical pin 63. In this case, the cone in fig. 11 is replaced by a concave truncated cone, the concave curve of which is part of the surface of a torus whose smallest cross-section has a radius 79 equal to the diameter of the balls 64-66. The maximum outer diameter of the annulus is four times the diameter of the balls 64-66. In this case, the contact conditions are the same as in fig. 11, with the difference, however, that by the concave abutment of the concave conical pin 63 on the balls 64-66, a lower pressure per unit area is generated at the contact point than in the variants according to fig. 10 and 11.

The axis of rotation of the tapered pin 62 or the concave tapered pin 63 is perpendicular to the base bottom surface 50. The bodies of revolution 62,63 may also be conical sections, truncated cones, truncated paraboloids of revolution or the like, respectively. Furthermore, the balls 61,67-69 used for the support positions 60, 80; 85,86 have different diameters in the respective support locations.

Fig. 15-17 show a variant of the rotation body for the base side of the second support location 80. According to fig. 15, the rotating body is a ball 95, according to fig. 16, a tub 83, and according to fig. 17 a concave roller 84. Also rotating bodies in the form of truncated cones, ellipses, hyperboloids or the like are conceivable. In fig. 16 and 17, each contact circle has a diameter equal to that of the cylinder 81 in fig. 14. The radii of curvature defining the barrel contour and the concave roller contour here have a radius of, for example, 24 mm.

Fig. 20 and 21 show cross-sectional views of the centering interface tensioning system 120, respectively. Other details can also be seen in fig. 7 and 8. Fig. 8 shows the tensioning system with the lowest load or lowest pretension of the spring energy store 141.

Most of the components of the tensioning system 120, which is composed essentially of a draw bolt 135 that can be moved along the main center line 5, are mounted or placed in the table adapter 10, which-controlled by an eccentric drive 150-spring-loaded draws the tensioning bolt 121 of the workpiece-receiving base 40 into the table adapter 10.

Referring to fig. 5 and 7, the draw bolt 121 is similar to a cylindrical tube having an internal thread 124. The tube carries at its free end a surrounding, for example approximately trapezoidal in cross section, surrounding frame 122. The surrounding shelf 122 has a wide 45 ° chamfer towards the end face of the tube. A further 45 ° chamfer is formed as an engagement shoulder 123 on the rear side of the circumferential frame 122. In the tubular region, the tensioning bolt 121 is optionally formed as a biplane, see fig. 5. The tensioning bolt 121 is seated with an axial and radial play of, for example, 0.1mm in the bearing bore 49 with a cylindrical depression in the center of the centering recess 42, see also fig. 6. The axial and radial play prevents binding forces which, when the workpiece receiving base 40 is fixedly tensioned, act in particular against the support points 60 and 80.

In the internal thread 124 of the tensioning bolt 121, a traction bolt 125 which absorbs the entire tensioning force is screwed in and is opposed by a fixed threaded pin 126, see fig. 7.

Referring to fig. 20, the tow pin 135 is essentially a cylindrical rotary body with an outer diameter of, for example, 22mm, which in the region of the housing is at least in some regions flattened toward the eccentric drive 150. The draw bolt 135 has an axial main bore 136 for receiving the draw bolt 121. The inner diameter of the main bore 136 is at least 0.2mm greater than the largest outer diameter of the tensioning bolt 121 in the region of the encircling frame 122. Transversely to the main bore 136, it has, for example, three radial transverse bores 137 which are distributed equidistantly and in each of which a locking ball 139 is mounted so as to be displaceable radially. Below the bottom of the main bore 136, the tow pin 135 has a handling slot 138, the depth of which extends to the center of the tow pin 135.

According to fig. 8,20 and 21, a tow pin carrier plate 140, for example 3.2mm thick, with a diameter of, for example, 52mm, is arranged on the underside of the tow pin 135. Referring also to fig. 3, tow pin carrier plate 140 has, for example, five holes. Which is screwed into the draw bolt 135 through two inner holes. Three outer holes are used to guide the tow pin carrier plate 140 on the table adapter in the space of the feed area 24 by means of support bolts 143.

The draw bolt 135 is guided in a central, sliding-bearing manner in the locking bore 133 in a flange-like guide sleeve 131. The guide sleeve 131 is placed centrally for this purpose and is screwed in the centering region 22 of the through-hole 21 by means of the screw 134 in the threaded hole 26 of M5. Toward the upper flange-side end of the guide sleeve 131, the locking bore 133 merges without corners via a rounded, truncated-cone-shell-shaped transition into a short storage chamber bore 132.

The six prestressed helical compression springs 142 of the spring energy store 141 are supported at their lower ends on the tow pin carrier plate 140. The coil pressure spring 142 is guided in the spring guide hole 25 of the table adapter 10. The respective upper ends of the coil pressure springs 142 contact the flange bottom surface of the guide sleeve 131, see fig. 8. In this embodiment, a spacer sleeve and a washer are respectively placed between the upper spring end and the flange-in order to set the spring preload.

According to fig. 20 and 21, the actuating shaft 151 of the eccentric drive 150 is mounted in the radial bore 27 of the table adapter, for example, by means of two plain bearing sleeves. An actuating pin 152 is pressed in a longitudinal bore eccentrically in the end side of the actuating shaft 151 adjacent to the main center line 5.

In order to be able to drive the actuating shaft 151, a central threaded bore is provided on its other end side, into which, for example, an M8 cylinder head bolt according to DIN 912 is screwed and glued as the actuating bolt 153. For the axial fixing of the actuating shaft 151, a stop groove 155 in the form of a long hole is milled into the actuating shaft at approximately the middle of its circumference. The stop groove 155, not the two semicylindrical ends thereof, extends over, for example, 182 degrees of the circumference of the actuating shaft 151. The cylindrical pin of the stop bolt 156 projects with an axial play of, for example, 0.3mm into the stop groove 155.

Instead of the eccentric drive 150, the manually operable mechanical tensioning system 120 can also be operated by means of another drive or another drive. Pneumatic, hydraulic or electromechanical drives are conceivable. In addition, the final state of the pivot position of the steering shaft 151 can be monitored by a sensor. For example, the magnetic field of a magnet embedded in the actuating shaft can trigger a hall sensor mounted on the table adapter 10 in at least one of the end positions to emit an electronically evaluable signal, which can be displayed optically or acoustically, for example, by battery-buffered electronics.

Prior to engaging the centering interface, the draw bolt 135 of the tensioning system 120 is placed into its release position 161, see fig. 20. For this purpose, the draw bolt 135 is moved by means of the actuating bolt 152 in the direction of the top side 11 of the workpiece receiving base 40 with continued pretensioning of the spring energy store 141 by means of a left-hand rotation of the actuating bolt 153. Now, it is apparent that-the tow pins 135 protrude 112-3mm above the top surface of the table adapter 10. When the draw bolt 135 is lifted, the locking balls 139 are guided by the transverse bore 137 into the region of the storage chamber bore 132 of the guide sleeve 131. The locking balls 139 can be moved radially outward in this position to the extent that they completely release the cross-section of the storage chamber bore 132.

In order to fix the workpiece receiving base 40, the table tip 47 or the chuck of which is fitted, on the table adapter 10, the workpiece receiving base 40 is placed on the table adapter 10 together with the projecting predetermined core pins 56. In this case, the predetermined core pin 56 leads the rotary bodies 61,81 and the cylindrical pin 101 into the predetermined core recess 17, see fig. 8. In this fig. 8, one of the predetermined pegs 56 is shown in dashed lines together with the rotary bodies 61,81 and the tensioning peg 121 in the final position of the interface corresponding to the engaged centering interface.

In order to accelerate the positioning-in the case of manual placement of the workpiece receiving substrate-care is taken to place the marking holes 44 of the workpiece receiving substrate 40 and the marking holes 29 of the table adapter 10 close to one another.

After the workpiece receiving base 40 has been correctly placed on the table adapter 10, a gap 3 of, for example, 0.74mm exists between the base bottom 50 and the top 11, and the tensioning bolt 121 fastened to the workpiece receiving base 40 projects into the main bore 136 of the draw bolt 135. The encircling shelf 122 of the tensioning bolt 121 is now positioned below the locking ball 139. By means of a right-hand rotation of the actuating shaft 151 by means of the actuating screw 153, the actuating pin 152 releases the spring energy store 141, so that the tensioned helical compression spring 142 pulls the tow pin 135 downwards by means of the tow pin carrier plate 140, see fig. 21. In this case, the locking balls 139 rest against the engagement shoulders 123 of the clamping bolt 121 and draw the workpiece receiving base 40 toward the table adapter 10 by means of said engagement shoulders. The workpiece changing stand 1 is now in the tensioning position 162.

The spring store 141 releases a tensioning force of, for example, 200N, wherein the workpiece receiving base 40 rests with its support positions 60,80,100 on the table adapter 10 hyperstatic due to the material selection and its wall thickness-elastically deformed in the range of a few percent of millimeters. The base top surface 41 is here concavely curved rotationally symmetrically with respect to the main center line 5.

Description of the reference numerals

1 workpiece changing rack

2, a rotating table

310 and 40

5 main center line, middle axis

10 adapters

11 top surface

12 ball hole

13 disassembling hole

14,15 recesses for balls 64-66,85,86

16 step hole

17 predetermined core cut, blind hole

21 through hole

22 centering area

23 central region

24 feed zone

25 spring guide hole

26M 5 threaded hole

27 radial hole

28 stop counter bore

2910 marking hole

31 bottom surface

32 centering ring

33 adjusting threaded hole

34 adjusting threaded pin

35T-shaped slot wedge

36 bolt

40 workpiece receiving base, tray; workpiece accommodating part

41 top surface of substrate

42 centering notch

43 gripping edge

4440 marking holes

47 tip or three-jaw chucks; workpiece accommodating part

48 assembly holes

49 bearing hole

50 bottom surface of the substrate

51 ball hole

52 support notch

53 step hole

54 tension recess

55 predetermined cardiac depression

56 predetermined core bolt

57 fixed core

58 calibrated threaded holes

59 calibrated threaded pin

60 first support position, four groups

61 ball, first rotation body, support element, part, upper part

62 taper pin, rotary body, support element, upper part

63 concave taper pin, rotary body, support member, upper portion

64-66 balls, support elements, table adapter side

67-69 contact position, point contact of a circle

70 contact position circle, circle

71 inclination angle

72 center of four sets, center

73 center line of first supporting position

74 axis of rotation, vertical

75 disassembling hole

7963 radius of

80 second support position, three groups

81 cylinder, second rotation body, support element, part, upper part

82 cylinder center line, rotation axis

83 bucket, rotating body, Upper part

84 concave roller, rotating body, upper part

85,86 balls, table adapter side; supporting element

87,88 contact position, elliptical point contact

89 center of three sets, center

91 center line of second supporting position

93 plane

95 ball

100 third support position, two groups

101 contact element, upper portion; cylindrical pin, support element, part

102 end face, spherical

103 contact elements, table adapter side; cylindrical pin, support element

104 end faces, flat or spatially curved

105 contact position, point contact of circle, center of two sets

107 third contact position

108 kite-shaped and quadrilateral

120 tensioning system

12140A tensioning plug

122 surround the shelf

123 engaging shoulder

124121 internal screw thread

125 draw bolt for 121

126 fixed threaded pin

131 guide sleeve, flange-like

132 storage chamber orifice

133 locking hole

134 bolt for 131

135 draw bolt

136 major hole

137 transverse hole

138 operating slot

139 locking ball

140 traction bolt carrier plate

141 spring energy accumulator

142 helical compression springs, preloaded

143 supporting bolt

150 eccentric driver

151 operating shaft

152 operating pin

153 handling bolt

155 stop groove

156 stop bolt

161 position of release

162 tension position