DE3121373A1 - Device for, in particular, three-dimensional measurement and/or marking out and/or scanning of workpieces - Google Patents

Abstract

Three-dimensional measurement device having a foot which can be displaced on a straightening plate and has a column at right angles to it and a compound-rest slide which can be displaced thereon and in which a transverse arm is mounted capable of displacement parallel to the straightening plate and transverse to the column. The measuring device has a compensation device, which compensates the influences of the transverse arm on the column by means of the foot and has a powered drive and a control or regulating element which is applied to said drive as a function of a parameter which determines the supporting force. The powered drive consists of a displacement actuator which on the foot displaces a counterweight, guided along a guide in a manner capable of being displaced parallel and in the opposite sense to the displacement of the transverse arm in the direction of projection. For the purpose of compensation, the displacement actuator presses the foot away from the guide surface and compensates deformations which are caused by an increase in length of projection of the transverse arm and can lead to falsification (corruption) of the measurement result.

Description

Device for especially three-dimensional

Measuring and / or scribing and / or probing workpieces.

The invention relates to a device for particularly three-dimensional Measuring and / or scribing and / or probing workpieces otherwise mentioned in the generic term of claim 1 defined Art.

In a device of this type, the compensation device has a Balance weight on, which in a guide in the direction parallel to the cross arm so movable at the upper end of the column or on the cross slide or on the cross arm itself is stored that the exerted by the cross arm on the column, from the overhang dependent moment should be compensated. This to be brought about by the balance weight Torque compensation should take the place of otherwise used support struts, which are led diagonally from the foot to the column head and support the column. The explained Compensation device in the device of the known type should so measurement falsifications due to Counteract bending deformation of the vertical column.

The unit column with foot and support strut is so rigid in itself that that when using this principle not with bending deformations, which even with extraordinary high machine accuracy could lead to falsification of the measurement results, is to be expected. It was recognized as surprising in such devices that, however, in the Area of the column base and the bearings there, from the overhang of the transverse arm Depending on the deformation forces are effective, which - albeit in extremely small areas - in particular If the transverse arm protrudes far, this will lead to falsification of the measurement results can that the column with the cross arm, to put it exaggeratedly, becomes a straightening plate inclines. This is caused on the foot side by tilting there in 0 areas. this can be a device of known type with compensation device, which the obliquely directed Support strut - intended to replace the foot and column head, not prevent it.

The invention is based on the object of providing a device as described in the preamble of claim 1 described type so that by deformation, including bearing deformation, in the area of the foot caused measurement errors both in devices with between the foot and Column head inclined support strut as well as devices with the support strut replacing compensation device are switched off.

In the case of a device, the task is as described in the preamble of claim 1 mentioned type according to the invention by the features in the characterizing part of the claim 1 solved.

The invention is based on the idea, only in the foot area the supporting force acting on the foot against the plate-side guide surface to change depending on such influencing factors, the one measure for the overhang length of the cross arm and thus for the deformation on the foot side acting forces are. The compensation device according to the invention provides a closed control system, the actuator of which the support force between Foot and guide surface causing power drive and its controller by the control member is formed, which detects the influencing variable decisive for the supporting force and corrects. Thanks to the compensation device according to the invention, there are deformations and tilting movements in the foot area between foot and plate-side guide surface, considered in the gu area, even turned off when the transverse arm is at maximum Overhang is extended.

The measurement accuracy is thus considerably increased, and this with im Ratio of small, device-related effort.

Claim 2 contains an advantageous embodiment.

Such control elements are simple and inexpensive.

They can be easily attached to the device.

Different, each advantageous embodiments of such control elements result from claims 3-7. A design according to claim 8 can also be used be advantageous if a measuring system is already available on the device side.

Further, advantageous designs result from the claims 9-16. It goes without saying that the compensation device according to the invention is equally suitable for such devices, where the foot with the column along one edge of the straightening plate on guides seated on the outside of the straightening plate is displaceable, as is the case with a device in which the foot with its underside sits on the top of the alignment plate and moves along the grooves, rulers, etc. is led. With the latter type of device leads the compensation device to the advantage that the bearing loads are independent of the instantaneous Position and overhang of the cross arm.

This also serves the measurement accuracy and moreover leads to greater Life of the bearings.

The invention is not limited to special storage and guidance systems limited between foot and plate-side guide surfaces.

Further details and advantages result from the following Description.

The complete wording of the claims is above alone not reproduced to avoid unnecessary repetition, but instead only referred to by naming the claim number, which however all features of the claims are here expressly and as belonging to the invention revealed to have to apply.

The invention is shown below with reference to in the drawings Embodiments explained in more detail.

1 shows a schematic, partially sectioned side view a device for three-dimensional measuring and / or scribing and / or probing Workpieces, according to a first embodiment, FIG. 2 is a schematic plan view of details of the foot of the device in Fig. 1, Fig. 3 is a schematic Top view roughly corresponding to that in FIG. 2, but of a device according to one second embodiment, Fig. 4 is a schematic plan view of the one hand Column with cross slide and cross arm and on the other hand the foot of a device according to a third embodiment, FIGS. 5 and 6 are each schematic side views roughly corresponding to that in Fig. 1 of a fourth or

fifth embodiment.

In Fig. 1 is a stationary straightening plate 11 with an upper plane surface 12 shown, can be clamped on the workpieces to be measured, marked and / or touched are. In this example, the straightening plate 11 carries on the visible long side, and also on the opposite, not visible long side, one only schematically indicated upper guide rail 13 and below a schematically indicated lower one Guide rail 14. Both sit on the outside pointing to the left in FIG. 1 the straightening plate 11. On and along the guide rails 13, 14 is a measuring, scribing and / or probing device 15 for three-dimensional measuring, scribing and / or probing of workpieces can be moved along the longitudinal side of the straightening plate 11. The device 15 has a foot 16 designed as a carriage, with slide bearings and / or Bearing rollers supported on the guide rails 13, 14 on all sides and is mounted on it so that it can move easily. The foot 16 carries a fixed to the straightening plate 11 standing at right angles column 17 on which a Cross slide 18 is displaceable in the vertical direction. In the cross slide 18 is in front, slightly outside the center, a transverse arm 19 in the horizontal direction and parallel to the plane surface 12 and at right angles to the course of the guide rails 13, 14 kept adjustable. The cross arm 19 is hollow on the inside and closed at both ends. At the front end on the right in Fig. 1, the transverse arm 19 carries a cube, for example Pick-up head 20 for the measuring-> scribing and / or probing tools to be picked up in it.

The device 15 is equipped with a compensation device 21, the effects of the projection length l in Fig. 1 to the right in the direction of the arrow 22 cantilevered cross arm 19 on the column 17 with foot 16 at least partially compensated.

The compensation device 21 has one arranged on or in the foot 16 Power drive 23, which acts on the foot 16 while counteracting its support force the plate-side guide surface of the guide rails 13, 14 influenced. The power drive 23 is a function of this support force, which is shown in Fig. 1 in horizontal Direction runs, determining influencing variable from a special control or regulating element applied.

The first embodiment shows a schematically indicated control element 24 with a downstream evaluation device 25, in particular evaluation electronics, which works directly on the power drive 23 or which, as not shown, instead its indirectly, e.g. via an intermediate converter, on the power drive 23 works.

For the design of the control element 24 there are various, Possible within the scope of the invention, which can be used as various exemplary embodiments are shown.

In the first embodiment, the power drive 23 consists of one Way stopper. Two counterweights are part of the compensation device 21 here 26, 27 on or in the foot 16, which there along an associated horizontal guide 28J 29 guided displaceably parallel and in opposite directions to the displacement of the transverse arm 19 are.

The power drive 23, designed as a travel stop, operates via gear means 30 on the counterweights 26, 27. As can be seen, the counterweights 26, 27 at least near the upper plane surface 12 and thereby on that side of the foot 16 arranged facing away from the cantilever direction according to arrow 22 of the transverse arm 19 is. The displacement actuation of the counterweights 26 »27 by means of the power drive 23 takes place in the opposite direction to the direction of projection according to arrow 22 of the transverse arm 19 the latter shifted further to the right during the measuring process in FIG the compensation device 21 the counterweights 26, 27 in Fig. 2 as indicated there Arrows shifted to the left, increasing the lever arm with which the Counterweights 26> 27 a moment equal to the guide surface of the guide rails 13, 14 develop. This means that the foot 16 in the region of its lower in FIG The end is pressed against the guide surface with greater force. It becomes so a clockwise pivoting in the plane of the drawing determined by the projection length l counteracted, namely in the area of the foot 16 and the plate-side FGhrungsfläche for the foot. This significantly increases the accuracy of the device 15.

The control element 24 can be used as an influencing variable, for example, the transverse distance between Grasp the foot 16 and the guide surface of the guide rails 13, 14. Such a design is shown schematically in FIG. There the FuS i6 preferably wears on its lower part End of a dotted indicated feeler element 61, which the horizontal transverse distance between the foot 16 and the plate-side guide surface of the guide rails 13 and 14 on the edge of the straightening plate 11 receives. It is not shown in FIG. 6 that instead of the one feeler element 61, there are also two identical feeler elements in the displacement direction of the foot can be arranged at a distance from each other.

In the third embodiment according to FIG. 3, the device 35 is with his foot 36 on top of the plane surface 12 of the straightening plate 11, for longitudinal guidance of the foot 36 a guide ruler aligned and fixed on the straightening plate 11 34 serves; along which the foot 16 is guided displaceably in the direction of the arrow. Even In this configuration, the foot 36 is complete with a compensation device 21 the same type as in the first embodiment according to FIGS. 1 and 2 equipped. A shifting movement of the counterweights 26, 27 leads to the fact that the bearing load changes, depending on a determining the vertical support force Influence quantity. It is also here when the compensation device becomes effective 21 the vertical support force of the foot 36 against the plate-side guide surface, namely plane surface 12, influenced.

Even with the device 35 according to the second exemplary embodiment in FIG. 3, the actuation of the power drive 23 takes place via a control element 24 with an evaluation device 25. The control element 24 can, as in the first embodiment, from one Feeler or two spaced apart probe elements exist, analogously to the feeler element 61 according to FIG. 6, with the second embodiment According to FIG. 3, however, one feeler element or the pair of feeler elements are arranged in this way is that here the vertical transverse distance between the foot 36 and the plate-side Guide surface, so the plane surface 12, is added.

The feeler element 61 or a corresponding to the second embodiment According to FIG. 3 adapted probe member detects as an influencing variable the transverse distance between Foot and guide surface. The recorded value is compared with a target value and the resulting control deviation is fed to the power drive 23 for compensation, who executes a corresponding positioning movement here as a travel stop.

The power drive 23 can be used as a pressure-medium-operated working cylinder or be designed as a rotary actuator of any design.

Another variant for the control element 24 is also shown in FIG. 6. There the control element 24 is designed as an electronic level 62, which the Horizontal position of the foot 16 takes up. As indicated in FIG. 6 with solid lines is, the level 62 in the illustration is perpendicular and approximately parallel to the column 17 aligned and arranged on or in the foot 16. Instead, there is also an in Fig. 6, alignment indicated by dashed lines in the direction approximately parallel to the cross arm 19 advantageous. The electronic level 62 detects the horizontal position of the foot and compares the actual state with a corresponding setpoint. The evaluation device 25 then acts on the one designed as a positioning device to compensate for the control deviation Power drive 23 accordingly, which accordingly the counterweights 26, 27 accordingly adjusted.

Another variant for the design of the control element 24 is shown 5. There the control element has strain gauges attached to the column 17 on the inside or outside 51, 52, which the longitudinal expansion of the column 17 within the of the column 17 and record the transverse arm 19 spanned plane. The strain gauges 51, 52 are arranged on those two longitudinal sides of the column 17 that are within the above-mentioned level and are facing away from each other. These are in FIG. 5 the left and right long sides of the column 17. The strain gauges 51, 52 detect the longitudinal expansion of the column 17 at the respective projection length 1 of the transverse arm 19.

The actual value is compared with a corresponding setpoint and e.g. via the evaluation device 25 to regulate the control deviation of the as Travel stop designed power drive 23 acted accordingly.

As a control element 24, the dimensional display of a not further shown, The device-side measuring system is used, which is only indicated by dashed lines in FIG. 5 with 53 is.

It can also be used as a criterion for the path-dependent actuation of the positioner designed power drive 23 the respective projection length 1 of the cross arm 19 used will. Then there is a control. The control element 24 then becomes the control element. This can have a measuring device on or in the cross slide 18, which respective projection length 1 of the transverse arm 19 is detected and designed as a displacement switch Power drive 23 then supplies an associated control signal. The measuring device is as mechanical and / or electrical and / or pneumatic and / or hydraulic working device formed. Depending on the equipment, an existing Distance measuring devices are used.

The transmission of the respective measured value to the power drive, possibly with prior implementation, can be done in the same way mechanical and / or be done electrically or pneumatically and / or hydraulically.

In the third embodiment according to FIG. 4, there is such a control shown that # is also equipped with a positive drive. This is where the distance measuring device a rack 41 with a pinion 42 engaged therewith on the transverse arm 19. Both are able to transfer forces. The foot 42 corresponds approximately to that of the first embodiment, the only difference being that instead of the one there Power drive 23 in the third embodiment is a sliding arm 43 with a toothed rack 44 is provided, with which a pinion 45 is in engagement. The rack 44 with Pinion 45 can also transmit forces. Both rack and pinion gears are over an only schematically indicated reversing gear 46 geared coupled in such a way, that a displacement of the transverse arm 19 in the direction of projection according to arrow 22 is a to do so opposite displacement of the counterweights in Fig. 4 to the left according to there Arrows, and this at every height of the cross slide on the column 14th

In the fourth embodiment according to FIG. 5 sits on or in Foot 16 such an actuator of the Rsgelkreises, which is designed as a power actuator 54 and e.g. an upstream evaluation device 55, in particular evaluation electronics, having. The power actuator 54 is either, as indicated by dashed lines is, near the upper plane surface 12 of the straightening plate 11 or, as in Fig. 5 with solid lines Lines is indicated, approximately at the level of the lower end of the foot 16. In both cases the direction of action of the power actuator 54 runs in the direction parallel to the transverse arm 19. The power actuator 54 directly generates a compensating actuating force between the Foot 16 on the one hand and the plate-side guide surface of the guide rails 13, 14 on the other hand. The power actuator 54 is dependent on a die horizontal support force be; correct influencing variable from one of the previously described nsn control elements acted upon. In Fig. 5 is indicated.

that an impact e.g. via the strain gauges 51, 52 or instead takes place via the measurement display of the measuring system 53 on the device.

While with the arrangement of the power actuator 54 about ih the height of the upper Planar surface 12, as indicated by dashed lines in Fig. 5, then the power actuator Pressure force plate is that against the plate-side guide surface of the guide rails 13, 14 presses and supports the foot 16 at this height, on the other hand, is the power actuator 54 in the other variant with an arrangement at the lower end of the foot 16 as a tensile force plate effective, the foot 16 down in the direction of the arrow indicated on the plate side Guide surface pulls. This configuration, explained last, is particularly advantageous.

The force regulator 54 is acted upon by the control element used in each case, that he - when arranged at the upper end of the foot 16 - the foot as a pressure force regulator 16 at this level from the plate-side guide surface in FIG. 5 to the left pushes away or - when arranged at the lower end of the foot 16 - in the design as a tensile force plate the foot with its lower end corresponding to the plate-side Guide surface in Fig. 5 pulls towards the right. Also the arrangement of both power actuators can be beneficial.

In all of the exemplary embodiments explained above, the Guide surface with the guide rails 13, 14 on the one hand and the device-side foot on the other hand, shown and described purely schematically, there it on the special design of the guide surfaces and guide rails the number and arrangement on the device are just as irrelevant as the special training the device-side guide parts. These can each be designed in a variety of ways. Slide guides in addition to roller guides or in addition to them are also in the frame the invention.

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Claims (16)

Device for especially three-dimensional measuring and / or Scribing and / or probing workpieces, provided with a on or on a Straightening plate (11) displaceable foot (16, 361 42) with the straightening plate (11) at right angles standing column (17) on which a cross slide t18) is displaceable, in which a Cross arm t19), which at the end has a receiving head (20) for measuring, scribing and / or probing tools carries, parallel to the straightening plate (11) and thereby transversely to the column (17) is stored, and with one the effects of the cantilevered cross arm (19) on the Column (17) with foot (16t 36, 42) at least partially compensating compensation device (21), d a -d u r c h g e k e n n n z e i c h n e t that the compensation device (21) one on the foot (15, 36i 42) acting, whose support force against the plate-side guide surface (13, 14, 12) influencing power drive 1231 43, 44 54) and a power drive (23 43, 441 54) depending on a supporting force controlling or regulating element (24; 51, 52r 531 61v 62). 2. Apparatus according to claim 1, d a d u r c h g e k e n n -z e i c h n e t that the control or regulating element (24, 51, 52 53J 61; 62) as an influencing variable Transverse distance between foot (16) and guide surface (13, 14) or the horizontal position of the foot t16) or the longitudinal expansion of the column (17) and / or the overhang length (l) of the transverse arm (19) detected, compared with a corresponding target value and for Correcting the control deviation using the power drive (23; 54) as an actuator accordingly applied. 3. Apparatus according to claim 1 or 2, d a d u r c h g e -k e n n z e i c h n e t that the control element (24) on or in the foot (16, 561 42) has at least one feeler element (61), e.g. also has a pair of sensing elements arranged at a distance from one another, that is the horizontal or vertical transverse distance between feet t16; 36, 42) and on the plate side Guide surface (13, 14t 12 on the edge of the straightening plate (11) or on its top side records. 4. Apparatus according to claim 1 or 2, d a d u r c h g e -k e n n z e i c h n e t that the control element t24) on or in the foot (16, 361 42) is an electronic one Has a level (62) which receives the horizontal position of the foot (16, 361 42) and is oriented in the direction parallel to the transverse arm (19) or the column (17). 5. Apparatus according to claim 1 or 2, d a d u r c h g e -k e n n z e i c h n e t that the control element (24) attached to the column C171 inside or outside Strain gauges [51, 52) that show the longitudinal expansion of the column (17) take up within the plane spanned by the column (17) with the transverse arm (19). 6. Apparatus according to claim 5, d a d u r c h g. e k e n n -z e i c h n e t that the strain gauges (51, 52) on the two long sides of the column (17) are arranged within the spanned by the column (17) with cross arm (19) Lying level and facing away from each other. 7. Device according to one of claims 2-6, d a d u r c h g e k e n n z e i c h n e t that the control element (24) has an evaluation device (25)> e.g. an evaluation electronics, which directly or indirectly, e.g. via a Converter, on the power drive (23, 54) works. 8. Apparatus according to claim 1 or 2, d a d u r c h g e -k e n n z e i c h n e t that the control element (24) is the dimension display of a measuring system on the device side (53) is used. 9. Device according to one of claims 1 - 8, d a d u r c g e k e n n z e i c h n e t that the power drive (23) has at least one actuator on or in the foot (16 36s 42), which either acts as a power actuator (54) directly a compensating force between foot (16) and plate-side guide surface t13, 14) generated or on or in the foot (16, 361 42) at least one along a guide (26, 29) approximately parallel and in the opposite direction to the displacement (arrow? 2) of the transverse arm (19) guided counterweight (26, 27) moves as a travel stop. 10. Device according to one of claims 1-9, wherein the foot (16) with a column (17) along an edge side of the straightening plate (11) on the outside of the straightening plate (11) seated guides (13, 14) is displaceably guided, d a d u r c h g e k It is noted that the actuator designed as a power actuator (54) at the or arranged in the foot (16) near the plate top (12) and as a pressure force adjuster in the direction approximately parallel to the transverse arm (19) against the plate-side Guide surface (13) near the plate top (12) presses and / or that the power plate is arranged as a pulling force plate approximately at the level of the lower end of the foot (16) and the foot (16) in the direction approximately parallel to the transverse arm (19) on the plate side Pulls guide surface (14). 11. Apparatus according to claims 3 and 10, d a d u r c h g e k e n n z e i c h n e t that the at least one feeler element (61) on or in the foot (16) for example at the level of the plate top (12) or the lower end of the foot (16) is. 12. Device according to one of claims 1 - 9, d a d u r c h g e k e n n z e i c h n e t that the control member has a position measuring device on or in the cross slide (18) which detects the respective projection length (1) of the transverse arm (19) and a control signal assigned to this is the power drive designed as a travel stop (23, 43, 44) supplies. 13. Apparatus according to claim 12, d a d u r c h g e k e n n -z e i c h n e t that the position measuring device as mechanical and / or electrical and / or pneumatic and / or designed hydraulically and in this way with the as a travel stop trained power drive (231 43, 44) is connected. 14. Apparatus according to claim 12 or 13, d a d u r c h g e -k e n n z e i c h n e t that the measuring device has a positive gear and such on the trained as a way actuator power drive (23; 43, 44) arbreit that this one to move the cross arm (19) related and related causes opposite adjusting movement of the at least one counterweight (26, 27). 15. Apparatus according to claim 14, d a d u r c h g e k e n n -z e i c h n e t that the positive drive on the transverse arm (19) and on one of the at least one Counterweight (26, 27) displacing the sliding arm (43) of the foot (42) each one Rack (40 and 44) with meshing pinion (41 or 45) and a has both pinions (41, 45) geared coupling reverse gear (46) therebetween. 16 Device according to one of claims 12-15, d u r c h e k e n It does not indicate that the at least one counterweight (26, 27) is at least close the top (12) and on that side of the foot (16, 36, 42) is arranged, which faces away from the direction of projection (arrow 22) 'of the transverse arm (19).