DE2935246A1 - MACHINE FOR ACCURATE MACHINING OF OR COORDINATE MEASUREMENT OF PARTS - Google Patents

Description

Machine for precise machining of or for coordinate measurement on parts

The invention relates to a machine, in particular for the precise machining of or coordinate measurement on parts according to the preamble of the main claim. In such machines, the path surfaces must be kept as free as possible from dirt, so the life of the machine is extended, the accuracy of the machine is maintained and damage to it is avoided. if the machine contains a measuring grid, this measuring grid must also be free

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of dirt so as to avoid distortion. These machines however, are intended for use in an environment in which finely divided material often occurs as a result of machining operations. These manufacturing processes are also a source various other industrial substances that should be kept away from the walkways and grids.

It is known to attach a flexible sheet material or a curtain to both ends of the carriage and a bracket to both To provide ends of the base which receives and supports the curtain. The movement of the carriage relative to the base at which Moving the curtain creates significant friction and inertia when the supports are machined surfaces.

It i; t already known - the Peibung and inertia by? 'Ij' ^r ri mgern that as '*'> ν <r a mechanical bearing used "

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The carrier rotates with the movement of the curtain and reduces the friction and inertia that creates the relative movement between the curtain and the carrier.

Such Vorhangträgsrsystsras nevertheless have still one significant friction and inertia between curtain and Trä ger "This friction leads to less accurate measurements," In addition, the reproducibility is DER Tsileverinessung in such systems often poor.

The friction of such curtain support systems is also "" the reason! undesirable because a considerably greater force is required to initiate the carriage movement. In a coordinate measuring machine , the initial movement of the carriage with respect to the base could be effected with approximately a force of 100 g if no curtain is used. Does the use of curtains and mechanical bearing beams increase strength? which is necessary to initiate the movement / up to 200 g (doubles the force required without a curtain).

The task of the "" orlisgeiid-an Er finding is to create a machine of the - initially genanritsn i ^ ri cu. sclicif 2 ^ u _ΰ bsi ^ sure dis zn it friction swiscJaeii 7oriic.ng and Tr & g ^ r vsiriiiRdsasa Prcölsiäe ^ ysiter are =,

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An exemplary embodiment of the invention is described below with reference to FIG Drawing explained in more detail; show it:

Figure 1 is the front view of part of a coordinate measuring machine according to the present invention;

FIG. 2 is an enlarged partial view of FIG. 1;

FIG. 3 shows the plan view of the section of the machine which is shown in FIG.

Figure 1 is a front view of part of a coordinate measuring machine 10. The coordinate measuring machine 10 includes a base 12 and a movable carriage 14.

The carriage 14 advantageously includes a vertical movable probe 15, which can touch a part 5 and thereby certain features are missed on the part 5. The carriage 14 is mounted to the base 12 by bearings 16 which extend along it move from path surfaces 17 at the top portion of the base. The bearings 16 are preferably mounted on the carriage and have low friction and high precision System possible.

The carriage 14 is a movable _f thereto eye assigns fixed grid. A second grid is attached to the base 12.

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The grids, not shown, are known and do not form part of the present invention o Movement from one grid to another is sensed j this gives an indication of the distance over which the carriage is being moved, hence the feature of the part in question 5 touches' and thus the position of this feature is determined.

At the end of the horizontal path surface 17 there is a support 200ο The support 200 is mounted on the top of the base 12 » The support 200 includes a mounting bracket 210 and a tubular one Part 220, which is shown in cross section in FIG.

A flexible curtain 300 is mounted at each end 14a, 14b of the slide 14. The curtain 300 is attached near a forhang end 310 at the end 14a of the slide mounting part 330. The curtain extends over (around) the tubular support part 220 and is on other end 3 20 loaded by a small weight 400.

The weight 400 creates tension in the curtain 300 all the way to the end 310 with which it is attached to the carriage 14a. The curtain 300 is thus under tension between the end 310 above the support 200 down to the weight 400.

Advantageously, the s-rhl it tone 300 runs ahead between the end i-10, which is a: * end 14a of the carriage is mori ated _f and the section; which .ibnr the support 200 v ^ rl "'if <' . substantially

horizontal. The top of the tubular part 220 is located is at the same height as the attached curtain end 310.

Furthermore, the tubular part 220 is advantageously rounded so that that the curtain extends over and around a section which corresponds approximately to a quarter circle.

The weight 400 pulls the curtain from the outer edge of the tubular Part 220 substantially vertically downwards.

The 4 00 weights on both sides of the slide are roughly the same weight. The curtains on both sides also own advantageously the same length and weight. The equality the weight on both sides of the sled ensures that the sled is balanced and not preferred Has direction of movement. If the weight on the right were appreciably greater than the weight on the left, the strength would be wefcher the slide is moved to the right is decreased, while the force with which the slide is moved to the left is increased would. Because of the same lengths of the curtains is also an equal distance of the carriage movement in both directions is possible.

The curtain 300 covers the path surfaces 17 and also the measuring grids with a system of measurement, which is based on a moiré pattern .

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The curtain 3 00 is a thin, lightweight sheet of flexible material which is impermeable for the pressure medium and the finely divided, originating from the machining operation material. The preferred materials for the curtain come from the fluorine class or is a plastic ilm from uey lar type.

Figure 2 is an enlarged front view of a portion of the base 12 and carriage 14 of the coordinate measuring machine. The curtain 300 is attached to the carriage part 330 and is weighted by the weight 400.

A compressed air delivery system 5CO is partially shown in FIG. A flexible hose 510, which is coupled to a source of compressed air (not shown), is attached to a fitting 520. This is fixed to the tubular part 220 in such a way that it communicates with a central axial channel 222 in the part 220. Multiple rows of radial channels 225, 226 _f 227 by "the part 220 to communicate with the axial channel 220, thereby providing a discharge path for the compressed air.

Advantageously, and in order to achieve the best results, each row of channels has the same angle Θ from the adjacent row. The end rows (top and side) have the same angle θ from the end of the portion of the tubular member which supports the curtain (e.g. horizontally and vertically on the part). Since three rows of channels are shown for the preferred embodiment , each row of the adjacent one has an angular

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distance θ of 22 1/2 °, even if the channel distance is within the three rows need not be uniform.

The compressed air forms a thin film over the surface of the support member 220 between the latter and the curtain. This film, even if it is very thin, reduces the friction of the itself
moving curtain on part 220 to a negligible amount.

Figure 3 shows a top plan view of a portion of the base 12, support 220 and bracket 210. The curtain has been removed from the top of the support; only a downward curtain section 300 is shown. End caps 221,229 am
tubular part 220 do this with the relative
large central axial channel 222 to a pressure chamber «This
has only one inlet through fitting 520 and one outlet through the rows of radial channels 225, 226, 227.

The arrangement described can be modified, for example, that the curtain on the base and the support on
Slide to be mounted. Other configurations of the support and fluid channels can also be used. Pressure media other than compressed air can be used to produce the friction-reducing film.

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Claims (8)

PATENT CLAIMS Ί . Machine, in particular for precise machining of or for coordinate measurement on parts, - in which a slide on which a tool and / or instrument holder is located is mounted so that it can perform a linear movement over a surface of a base and in which at least one protective curtain lies at least partially over the surface of the base and extends a support which is in relative movement with respect to the curtain when the slide is displaced, characterized by a device (510,225,225,227) which is assigned to the support (220) and a pressure medium source receives and directs between the curtain (300) and the carrier (220), - ■ whereby a fluid cushion is created between these parts. 030 0 * 11/0858 - 2. Machine according to claim 1, characterized in that the curtain (300) is a band of flexible material. 3. Machine according to claim 2, characterized in that the curtain (300) a sheet is a plastic material of the type sold under the trade name "Mylar". 4. Machine according to claim 2 or 3, characterized in that the support is a tubular part (220) through which in the Area around which the curtain (300) extends, several rows of fluid openings (225,226,227) run, and the receives pressurized fluid and directs it through the openings. 5 = machine according to claim 4, characterized in that each row of the fluid openings (225, 226, 227) from the adjacent Row has approximately the same angular distance. 6. Machine according to one of claims 2 to 5, characterized in that one end of the curtain (300) is attached to the carriage and that the support (220) is attached to the base (12) such that the curtain (300) is over the base (12) lies in the zone between the carriage (14) and the support (220) and has a section which extends downwardly beyond the support under the action of gravity. 030011/085 « 7. Machine according to claim 6, characterized in that a Weight (400) is attached to the end of the downward portion of the curtain. 8. Machine according to claim 6 or 7, characterized in that the upper surface of the tubular part (220) is approximately at the level of the attachment (33 0) of the curtain (300) on the carriage (14), whereby the curtain (300) is around about a quarter of the circumference of the tubular part (220} extends around. 9 _s machine according to one of claims 1 to 8, characterized in that the pressure medium is compressed air. 0.3 001 1/0858 -4-