DE29901876U1 - Coordinate measuring table - Google Patents

Description

Description

The invention relates to a table for coordinate measuring machines, which is arranged displaceably in a base bed.

According to the state of the art, 3D portal measuring machines often consist of a movable measuring table arranged in a base bed.

The measuring table is arranged in a guide of the base bed. The guide is usually dovetail-shaped. The movable table has a correspondingly designed guide arrangement in the form of a dovetail, which is mounted in the guide of the base bed.

The table is stored in several warehouses.

On the one hand, support bearings are provided which, according to the state of the art, are arranged in the area of the dovetail guide and act with a vertical force on the base bed in the area of the dovetail guide.

In addition, preload bearings are provided, which are arranged in the guide arrangement of the table in such a way that they engage the side surfaces of the dovetail guide of the base bed. These bearings can be adjusted in such a way that the table is arranged with a certain preload in the base bed.

The preload is advantageous in order to not only load the support bearings exclusively by the load of the table.

If the bearings are intended for preload, support bearings can be selected for a larger load range.

This increases the load range of the table, which means that heavier workpieces can be placed on the table without the table resting on it. In the case of light workpieces, the tendency of the support bearings to vibrate is reliably prevented by the preload.

The state-of-the-art arrangement of the support bearings in the area of the dovetail guide has the disadvantage that the bearings are relatively close together. The support distance is therefore relatively small. This impairs the stability of the table and thus the measurement accuracy.

On the other hand, these bearings are difficult to maintain because they are difficult to access.

The technical problem underlying the invention is to provide a table for coordinate measuring machines, with which a higher measurement accuracy can be achieved and which is easy to handle and maintain.

This technical problem is solved by the features of claim 1.

Because the support bearings are arranged in the table in such a way that they engage perpendicularly on an upper surface of the base bed, the support bearings have a maximum support distance that extends almost across the entire width of the table, thereby increasing the stability of the table and

so that the measuring accuracy of the coordinate measuring machine is increased.

The support bearings are advantageously arranged in the edge area of the table. According to the invention, the support bearings are arranged at a small distance from the edge of the table, such that the support bearings are firmly seated in the table. The distance between the support bearings and the edge of the table can be, for example, at least one centimeter. According to the invention, the support bearings have a distance that is greater than or equal to the distance between the preload bearings.

The bearings are advantageously designed as air bearings, hydrostatic bearings or plain bearings. It is also possible to use roller bearings.

The guide in the base bed is advantageously designed with a dovetail cross-section. This achieves the preload already described by the preload bearings arranged in the dovetail of the table.

It is also possible to provide a guide with a rectangular cross-section. In this way, the preload is only achieved by the load of the table. Preloading by additional bearings is not possible in this case.

The guide arrangement provided on the table can be designed as a solid profile with a dovetail-shaped or rectangular cross-section.

However, it is advantageous to provide two guide parts which are adapted in angle to the dovetail-shaped guide of the base bed. This has the advantage that the preload bearings are easier to access and the material required is not so high.

Further details of the invention can be found in the subclaims.

The drawing shows an embodiment of the invention, in which:

Fig. 1 shows a coordinate measuring machine in perspective view;

Fig. 2 a cross-section through a table and a base bed;

Fig. 3 a longitudinal section through a table and a base bed.

Fig. 1 shows a coordinate measuring machine (1) with a movable table (2) which is arranged in a base bed (3). A portal (4) with supports (5, 6) which support a crossbeam (7) is arranged on the base bed (3). A slide (8) is provided on the crossbeam (7) and can be moved, on which a spindle sleeve (9) is arranged.

According to Fig. 2, the table (2) is mounted in a dovetail-shaped guide (10) of the

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Base bed (3) supported by a guide arrangement (11, 12).

Air bearings (13, 14; 25, 26) are provided in the table (2) as supporting bearings, which engage vertically on an upper surface (15) of the base bed (3).

To achieve preload, additional air bearings (16, 17; 27, 28) are provided, which engage side surfaces (18, 19) of the dovetail-shaped guide (10).

Because the support bearings (13, 14; 25, 26) are arranged in the edge areas of the table (2), they have a maximum support distance, whereby the measuring accuracy of the coordinate measuring machine (1) is significantly increased.

According to Fig. 3, stops (20, 21) are provided on the base bed (3) which limit the movement of the table (2), which has a further stop (22).

The stop (21) and the stop (22) each carry a buffer (23, 24).

Reference numbers 6 Coordinate measuring machine 1 Measuring table 2 Basic bed 3 portal 4 Support 5, traverse 7 12 Sleds 8th 14 Quill 9 dovetail-shaped guide of the 10 17 Basic bed 19 Guide parts of the table 11, Support bearing 13, 21 upper surface of the base bed 15 Leading stock 16, 24 Side walls of the dovetail-shaped 18, 26 Guide of the base bed 28 attacks 20, attack 22 buffer 23, Support bearing 25, Leading stock 27,

200199 CK/en

Claims (6)

Patent attorneys Dipl.-Math. Siegfried Knefel Dipl.-Phys. Cordula Knefel Wertherstrasse 16, 35578 Wetzlar PO Box 1924, 35529 Wetzlar Telephone 06441/46330 - Fax 06441/48256 B G 1027 Brown & Sharpe GmbH Siegmund-Hiepe-Strasse 2-12 35578 Wetzlar Table for coordinate measuring machines Protection claims 1. Table for coordinate measuring machines with at least one guide arrangement provided below the table, whereby the table with its guide arrangement is arranged displaceably in a guide by means of bearings, whereby the guide is provided in a base bed, characterized in that at least two bearings (16, 17) are designed as bearings (16, 17) engaging on side walls (18, 19) of the guide (10) of the base bed (3), and that at least two further bearings (13, 14) are arranged in the table (2) and as on an upper surface (15) of the base bed facing the table (2). (3) engaging support bearings (13, 14) are formed, and that the distance between the support bearings (13, 14) is greater than or equal to the distance between the bearings (16, 17). • · ft * · 2. Table according to claim 1, characterized in that the support bearings (13, 14) are arranged at a small distance from an edge of the table (2). 3. Table according to claim 1, characterized in that the guide (10) provided in the base bed (3) is designed as a dovetail guide. 4. Table according to claim 1, characterized in that the guide provided in the base bed (3) is designed as a guide with a rectangular cross section. 5. Table according to claim 1, characterized in that the guide arrangement (11, 12) provided on the table (2) is made up of two or more parts. 6. Table according to claim 1, characterized in that the bearings (13, 14; 16, 17) are designed as air bearings, hydrostatic bearings, plain bearings or roller bearings.