DE102018127439A1 - Device for exchanging a tactile probe arm of a 3D measuring device - Google Patents

Abstract

The object of the invention to find a way of replacing a tactile probe arm (41), in which the changing system does not require an additional movement robot and without additional traversing axes that are required for the measuring process, is achieved according to the invention by a magazine (3) for probe arms (41 ; 43) is arranged outside of a measuring range along one of the coordinate directions, which correspond to the main axes of movement of the 3D measuring device (1), and has storage compartments (33) in the horizontal direction, which are arranged in at least two vertical support plates (31, 32) of the magazine ( 3) cutouts (311, 312) are formed, the probe arm (41; 43) has at least one tactile ball probe at a distal end and a flange-like coupling plate (412) at a proximal end of the probe arm shaft (414), the coupling plate (412 ) is equipped with means for releasably coupling the probe arm (41; 43) to the probe head (4), and for reproducible rotary equipment direction of the probe arm (41; 43) on the coupling plate (412) and the magazine (3) on one of the carrier plates (31, 32) have complementary shaped elements with a V-shape oriented towards gravity.

Description

The invention relates to a device for replacing a tactile probe arm of a 3D measuring device, in particular for tactile dimension measurements of bodies, preferably of rotatable workpieces, in which special measuring tasks require different probe arms.

For tactile measurements of workpieces, it is often necessary to use the appropriate probe arm for the respective measurement task. The probe arm should be exchangeable as fully automatically as possible and be interchangeable with all other probe arms stored in a suitable magazine.

Probe arm changing magazines are known from the prior art, which access a magazine of probe arms, in which the probe arms are suspended vertically and are inserted and locked horizontally. The GB 2 373 543 A as well as the DE 10 2005 036 928 B3 .

A disadvantage of these change systems is that the probe arm change system represents a separate robot and control unit and, compared to the tactile measuring system, has its own travel axes for the movement of the probe arm between the magazine and the probe head to be equipped. An independent adjustment head is also required to adjust the roll, pitch and yaw angles of the probe arm.

A solution with similar disadvantages is in the US 5 028 901 A described, in which a revolver magazine is used, which requires an additional rotary disc to replace the probe arms between the magazine and measuring head.

Furthermore, from the DE 33 20 127 A1 a stylus change holder is known, in which styli are to be exchanged with high accuracy in the probe of a multi-coordinate measuring machine. For this purpose, a holder is equipped with an isostatic three-point bearing, against which a contact plate of the stylus is pulled by an electromagnetic clamping device. The clamping device consists of a permanent magnet and an electromagnet, the latter either compensating or amplifying the permanent magnetic field in order to release or fix the stylus. The highly precise and reproducible probe arm mounting, which eliminates the need to constantly measure (calibrate) the probe arm, consists of three radially aligned cylinder bodies in this clamping device, and the counter bearing has three pairs of balls that rest on the cylinder bodies with their gaps. Since the pair of spheres and cylinder bodies are usefully arranged at an angle of 120 ° evenly distributed around the central axis of the probe arm, an additional fit guide is required for unambiguous assignment in the angular range of 360 °, such as a radial groove, into which a pin is additionally inserted from the counter bearing connector body intervenes.

The disadvantage here is that an axial pin or cylindrical housing jacket is always required for centering this clamping device, which can make coupling and uncoupling more difficult due to friction and transverse forces and can even prevent it in the case of magnetic coupling.

The invention has for its object to find a new way of replacing tactile probe arms of a 3D measuring device, in which the probe arm changing system does not require any additional movement robots for changing the probe arm and no further traversing axes, apart from the scan axes required for the measuring process. In addition, the fixing of the probe arm to the probe should be designed reliably and simply, without the probe arm being difficult to remove from a magazine or the probe arm coupling and decoupling from the probe.

According to the invention, the object is achieved in a device for exchanging a tactile probe arm of a 3D measuring device, which comprises at least one probe head movable in three coordinate directions and the exchangeable probe arm which is temporarily rigidly connected to the probe head by means of a probe arm coupling and by at least one replacement probe arm present in a magazine is interchangeable, characterized in that the magazine is arranged outside of a measuring area between the tailstock and the headstock along one of the coordinate directions that are assigned to the main axes of movement of the 3D measuring device, and has storage compartments for several probe arms in the horizontal direction, the storage compartments being in at least Two vertical carrier plates of the magazine are cutouts that the probe arm has a cylindrical probe arm shaft and at least one tactile ball probe at a distal end and a flange-like coupling plate has atte at a proximal end of the probe arm shaft, the coupling plate being equipped with means for temporarily defined coupling of the probe arm to the probe head, and that the probe arm on the coupling plate and the magazine on at least one of the carrier plates complementary wedge-shaped elements with a gravity-oriented V -Shape to specify a reproducible, defined rotational orientation of each stored probe arm in the magazine.

For the radial reproducibility of the probe arm position in the magazine, the coupling plate of the probe arm advantageously has a circle as a basic form, on which two segments of the same size are left out on secants of the circle, one have a common intersection outside the circle in a vertical plane of symmetry of the probe arm, to which the circular segments and a V-shape of the coupling plate resulting therefrom in the direction of gravity lie symmetrically, and that a first carrier plate of the magazine has a complementary shape to the V-shape of the coupling plate, in Has direction of gravity aligned V-shaped cutout.

For the radial reproducibility of the probe arm position in the magazine, the coupling plate of the probe arm can also expediently have an isosceles triangle, the plane of symmetry of which is arranged in a vertical axial plane of the probe arm, to which a V-shape of the coupling plate resulting in the direction of gravity lies symmetrically, and that a first carrier plate of the magazine has a V-shaped cutout which is complementary to the V-shape of the coupling plate and oriented in the direction of gravity.

The V-shaped cutout, which is complementary to the V-shape of the coupling plate of the probe arm, is preferably formed as an isosceles triangle or as an isosceles trapezoid in at least the first carrier plate of the magazine.

For reproducibility of the axial probe arm position in the magazine, at least one front holding plate is attached to at least one first carrier plate of the magazine in such a way that a V-shaped cutout of the first carrier plate which is complementary to the V-shape of the coupling plate of the probe arm is at least partially covered by a protrusion of the front holding plate , so that the coupling plate has an axially fixed position in the V-shaped cutout of the first carrier plate of the magazine when the probe is axially removed from the coupling plate of the probe arm. For the reproducibility of the axial feeler arm position in the magazine, a rear holding plate can additionally be attached at least to the first support plate, so that the V-shaped cutout of the first support plate which is complementary to the shape of the coupling plate of the feeler arm, is at least partially by a projection of the front holding plate and the rear Holding plate is covered so that the coupling plate has an axially fixed position in the V-shaped cutout of the first carrier plate of the magazine against any axial movement of the probe arm.

The coupling plate advantageously has, as a means for the temporarily defined coupling of the probe arm to the probe, either two mutually aligned pairs of prismatic recess and cylinder segment or pairings of prismatic recess and spherical segments between the coupling plate of the probe arm and a receiving plate of the probe head, the temporary coupling between Coupling plate and mounting plate is generated by an axially releasable fixation based on a force effect.

In a preferred embodiment, the coupling plate of the probe arm can be coupled to the receiving plate of the probe head by means of an arrangement of two prismatic recesses arranged transversely to one another in a radial plane about a probe arm axis on the one hand and by two complementary mating counterparts made of cylinder segments and / or spherical segments on the other hand. A cylinder segment can be replaced by two spherical segments spaced apart from one another with respect to a prismatic recess.

In a further advantageous embodiment, a three-point support is provided between the coupling plate of the probe arm and the receiving plate of the probe, the three-point support having three convex spherical surfaces which are in contact with two diverging flanks of three prismatic recesses, the prismatic recesses being distributed around a probe arm axis and can be aligned with each other as desired, but no prismatic recess is aligned parallel to one of the other. The prismatic recesses are preferably arranged symmetrically with respect to a plane of symmetry which is predetermined by the V-shape of the coupling plate and which lies within a vertical axial plane of the probe arm. In a particularly advantageous embodiment, the prismatic recesses are all radially aligned with the probe arm axis.

The axially releasable fixation of the probe arm on the probe is advantageously implemented by means of an electrical or magnetic field effect.

For this purpose, the temporary coupling between the coupling plate and the mounting plate can preferably be designed as a magnetic field effect, which can alternatively be generated by two permanent magnets, by a permanent magnet and a ferromagnetic material, by a permanent magnet and an electromagnet, by a ferromagnetic material and an electromagnet or by two electromagnets is.

In an alternative embodiment of the temporary probe arm coupling, the coupling plate of the probe arm is coupled to the mounting plate of the probe head in such a way that two diverging flanks of the one prismatic recess are formed coaxially to the probe arm axis in the mounting plate or are attached to a molded angle piece, so that the coaxial prismatic recess matches the cylindrical one Probe arm shaft of the probe arm touches along two contact lines, and the further prismatic recess orthogonal to the coaxial prismatic recess and is arranged radially to the probe arm axis, so that a cylinder segment mounted radially between the coupling plate and mounting plate is in contact with the radially directed prismatic recess along two contact lines if at least one radial force against the coaxial prismatic recess is provided by a coaxially oriented leaf spring anchored on the mounting plate is available. An additional axial force effect can be provided by electrical or magnetic field effects.

The invention is based on the basic idea that the efficiency of a 3D measuring device with a tactile scanning of bodies that require a plurality of probing with different probe arms can be increased by the fact that a fully automatic probe arm changing device for the quick and optional probe arm change in the scanning system of the 3D measuring device is integrated. According to the invention, this problem is solved by avoiding additional handling mechanisms for decoupling, transporting and storing the probe arm used and for picking up, feeding and coupling additional probe arms and additional movement axes that are not present in the 3D scanning system.

• - die Tastarmlagerung in einem Magazin, das auf kurzem Weg (schnell) erreichbar sein muss,
• - die genaue und reproduzierbare Tastarmablage im Magazin,
• - die genaue und reproduzierbare Ankopplung des Tastarms und dessen sicherer Sitz am Tastkopf für den Messvorgang sowie dessen einfache Abkopplung bei der Ablage im Magazin.

When changing the probe arm in a 3D measuring device, the following problem areas occur side by side. These are

• - the probe arm storage in a magazine, which must be (quickly) accessible within a short distance,
• - the precise and reproducible probe arm rest in the magazine,
• - The precise and reproducible coupling of the probe arm and its secure seat on the probe for the measuring process and its simple decoupling when it is stored in the magazine.

The magazine can be quickly reached by arranging the magazine for the interchangeable probe arms in the extension of a main scanning axis of the 3D measuring device, so that the probe head arrives directly at the horizontally oriented storage locations of the magazine when it leaves the measuring range of the 3D measuring device and there a free storage space can store the probe arm used to exchange another probe arm in the vicinity.

Magazine storage compartments and probe arm coupling are suitably designed for this coupling and decoupling process, the probe arm as a characteristic feature having a coupling plate with an essentially circular basic shape around the probe arm axis, on which circular segments are recessed, the chords of which are defined by secants on the circle, which are common Have intersection in a vertical axial plane of the probe arm. For the resulting or any other V-shape of the coupling plate, an adapted V-shaped recess is provided in a first carrier plate of the magazine, which is aligned in the direction of gravity in order to achieve a reproducible, defined rotational alignment of the probe arm. The exact and reproducible storage of the exchangeable probe arms in the magazine is further realized by a second support plate axially spaced with respect to the longitudinal axis of the probe arms with a recess adapted to the probe arm in the direction of gravity, the preferably wedge-shaped recess for defined storage at the upper edge of the second Carrier plate is inserted so as to ensure a defined horizontal storage of the probe arm in the magazine. On the other hand, for the reproducibility of the axial position of the probe arms on the first carrier plate, retaining plates are attached to the front and / or rear of the first carrier plate in such a way that a projection of the first carrier plate complementary to the V-shape of the coupling plate of the probe arm is at least partially provided , so that the probe arm assumes an axially clearly defined position. Various embodiments are possible for the above-mentioned basic positions, which are to be distinguished according to the axial position of the probe arm at which the axial fixation is incorporated and how the coupling and fixation of the probe arm is provided on the probe head.

The simple and reproducible coupling of the probe arm to the probe can be done in different ways. For the rotationally reproducible alignment of the probe arm, either two-way arrangements of mutually aligned pairings of cylinder segment and prismatic recess or of pairings of spherical segments and prismatic recess, for which an orthogonal orientation is not mandatory, but approximate parallel orientations are prohibited, between coupling plate of the probe arm and Recording plate of the probe arranged.

A prismatic recess in the sense of the invention is understood to mean a groove-shaped recess with a triangular or trapezoidal cross-section, which has flanks symmetrically diverging from the surface in which the recess is made. The end surfaces of the “prism” need not be parallel, but can be surfaces diverging to the surface of the recess or rounded transition surfaces between the flanks of the recess.

In a first variant, the coupling plate of the probe arm is transverse to the mounting plate of the probe head by means of an arrangement of two prismatic recesses arranged on the one hand in a radial plane with respect to the probe arm axis and two complementarily oriented cylinder segments on the other hand can be coupled in a defined manner if there is an additional force effect (for example electrical and / or magnetic field effect) in the axial direction of the probe arm. A cylinder segment is preferably at least partially height-adjustable.

In a second variant, a three-point support is provided between the coupling plate and the receiving plate of the probe, the three-point support having three convex spherical surfaces which come into contact with two diverging flanks of prismatic recesses. In this example, the prismatic three-point support is understood to mean a three-way arrangement of pairings, each consisting of a spherical segment and a prismatic recess with a triangular or trapezoidal cross section, the prismatic recesses being distributed around the probe arm axis and being able to be aligned as desired, but not parallel to one of the other Recesses may lie. Preferably, the prismatic recesses are all aligned with the probe arm axis or at least symmetrically with respect to that axial plane which represents a plane of symmetry for the V-shape of the coupling plate of the probe arm. The spherical segments on the mounting plate of the probe have a complementary angular alignment and local distribution with respect to the probe arm axis. As in the first variant, the coupling forces can be generated by electrical or magnetic fields between the coupling plate and the mounting plate.

In a third variant, the coupling plate of the probe arm is connected to the mounting plate of the probe head in such a way that two diverging flanks of the prismatic recess in the normal direction of the mounting plate or on an angle piece molded or molded onto the mounting plate touch a cylindrical shaft of the scanning arm along two contact lines and one the prismatic recess formed in this way, opposite and anchored to the mounting plate, is provided for the axial fixation. The second prismatic recess, which is arranged in the orthogonal direction to the first prismatic recess and radially to the probe arm axis, receives along two contact lines a cylinder segment radially attached to the coupling plate or a cylindrical pin which extends radially to the shaft of the probe arm protruding from the coupling plate Coupling plate is arranged to align the probe arm defined in the direction of rotation. In this case, the axial force action can again be achieved by electrical or magnetic field action in one of the ways described above.

The invention shows a novel possibility of how a device for exchanging a tactile probe arm of a 3D measuring device can be realized, with which - as is customary in previous probe arm changing magazines - no separate movement robots and additional traversing axes are required for changing the probe arm. In addition, stiffness of the scanning arm removal from the magazine is minimized by V-shaped storage compartments oriented in the direction of gravity. Furthermore, the fixation of the probe arm to the probe is made easy by three-point or two-line contacts between at least two prismatic recesses and spherical or cylindrical body segments engaging therein, and is reliably implemented by a force acting against the diverging flanks of the prismatic recesses.

• 1: eine schematische Darstellung der erfindungsgemäßen Tastarmwechselvorrichtung für eine 3D-Messeinrichtung;
• 2: eine Darstellung zur Veranschaulichung des Tastarmwechsels;
• 3: eine vorteilhafte Ausführungsvariante des für den Tastarmwechsel vorgesehenen Magazins mit zugeführtem tastarmbestücktem Tastkopf;
• 4: eine perspektivische Darstellung einer bevorzugten Ausführung des Magazins;
• 5: eine Frontalansicht eines Ausschnitts der ersten Trägerplatte des Magazins gemäß 4;
• 6: eine perspektivische Darstellung einer weiteren bevorzugten Ausführung des Magazins;
• 7: eine Frontalansicht eines Ausschnitts der ersten Trägerplatte des Magazins gemäß 6;
• 8: eine Darstellung des grundlegenden Prinzips der Tastarmkupplung mit einer Zweier-Anordnung von quer zueinander ausgerichteten Paarungen aus prismatischer Ausnehmung und Zylindersegment oder Kugelsegmenten;
• 9: eine erste vorteilhafte Ausführungsform der Tastarmkupplung als Dreipunktlagerung mit Paarungen aus prismatischer Ausnehmung und Kugelsegment;
• 10:eine zweite bevorzugte Ausführung der Tastarmkupplung mit zwei Paarungen aus prismatischer Ausnehmung und Zylindersegment, die in axialer und radialer Richtung des Tastarms ausgerichtet sind;
• 11:weitere vorteilhafte Gestaltungen der Tastarmkupplung als Modifikationen der Ausführung der Koppelplatte von 9, wobei die Teilabbildungen je drei prismatische Ausnehmungen zeigen, die a) konzentrisch und gleichverteilt auf einer unter 60° V-förmig beschnittenen kreisförmigen Koppelplatte, b) symmetrisch zu einer vertikalen Axialebene und konzentrisch um die Tastarmachse, aber nicht gleichverteilt auf einer als spitzes, gleichschenkliges Dreieck geformten Koppelplatte und c) symmetrisch zu einer vertikalen Axialebene, aber nicht konzentrisch und nicht gleichverteilt um die Tastarmachse auf einer als rechtwinkliges, gleichschenkliges Dreieck geformten Koppelplatte angeordnet sind;
• 12:weitere zweckmäßige Ausführungen von konzentrisch um die Tastarmachse angeordneten prismatischen Ausnehmungen auf einer im Wesentlichen kreisförmigen Koppelplatte a) mit gleichverteilt konzentrischer radialer Ausrichtung, b) mit spiegelsymmetrisch zu einer Axialebene konzentrischer radialer Ausrichtung und c) mit spiegelsymmetrisch zu einer Axialebene konzentrischer, aber nicht radialer Ausrichtung.

The invention is explained in more detail below on the basis of exemplary embodiments and illustrations. Show:

• 1 : a schematic representation of the probe arm changing device according to the invention for a 3D measuring device;
• 2nd : a representation to illustrate the probe arm change;
• 3rd : An advantageous embodiment of the magazine provided for the probe arm change with the probe arm equipped with probe arm;
• 4th : a perspective view of a preferred embodiment of the magazine;
• 5 : A front view of a section of the first carrier plate of the magazine according to 4th ;
• 6 : a perspective view of a further preferred embodiment of the magazine;
• 7 : A front view of a section of the first carrier plate of the magazine according to 6 ;
• 8th : a representation of the basic principle of the probe arm coupling with a two-way arrangement of mutually aligned pairings of prismatic recess and cylinder segment or spherical segments;
• 9 : a first advantageous embodiment of the probe arm coupling as a three-point bearing with pairings of prismatic recess and ball segment;
• 10th : a second preferred embodiment of the probe arm coupling with two pairs of prismatic recess and cylinder segment, which are aligned in the axial and radial directions of the probe arm;
• 11 : further advantageous designs of the probe arm coupling as modifications to the design of the coupling plate from 9 , The partial images each show three prismatic recesses, which a) concentrically and evenly distributed on a circular coupling plate cut at 60 ° V, b) symmetrically to a vertical axial plane and concentrically around the probe arm axis, but not equally distributed on one as a pointed, isosceles Triangle-shaped coupling plate and c) symmetrical to a vertical axial plane, but not concentric and not evenly distributed around the probe arm axis on a coupling plate shaped as a right-angled, isosceles triangle;
• 12th : Further expedient designs of prismatic recesses arranged concentrically around the probe arm axis on an essentially circular coupling plate a) with an equally distributed concentric radial alignment, b) with mirror-symmetrical radial alignment concentric with an axial plane and c) with mirror-symmetrical alignment with an axial plane concentric but not radial .

A 3D measuring device 1 equipped according to the invention in accordance with 1 comprises a guide element 11 , in this example designed as a preferred vertical column, a tailstock 12th and a headstock 13 to about an axis of rotation D rotatable storage of a measurement object 2nd , which is preferably a largely rotationally symmetrical workpiece, a U-shaped measuring unit 14 , preferably with an optical measuring system working in the silhouette method 141 as well as a tactile scanning system.

The tactile scanning system of the 3D measuring device 1 has a 2D scanning system 142 on that with one leg of the U-shaped measuring unit 14 is rigidly connected and a cross table unit with x and y mobility in addition to the z movement of the U-shaped measuring unit 14 having.

The 2D scanning system 142 carries a probe 4th with a probe arm that can be exchanged for the respective measuring task 41 , whose probe arm axis 411 parallel to one of the main traversing axes ( x and y ) of the 2D scanning system 142 is aligned and that on a probe holder 143 is detachably coupled.

The 3D measuring device 1 further comprises for holding various replacement probe arms 43 a magazine for different measuring tasks 3rd , in the parallel to the probe arm axis 411 on the probe 4th located probe arm 41 Storage compartments 33 for different exchange probe arms 43 (only in 3rd drawn) are available.

2nd shows opposite 1 that the measurement state of the probe 4th with attached probe arm 41 represents the travel regime for the probe arm change. The measuring unit 14 the 3D measuring device 1 moves into an area outside the measuring area between the tailstock 12th and headstock 13 , in this case below the tailstock 12th to a magazine 3rd , in the replacement probe arms 43 (in 2nd not drawn) are provided. The previously used probe arm 41 using the 2D scanning system 142 in a magazine 3rd in a free storage compartment 33 filed.

The magazine 3rd is in principle as a structure 3rd shows in a perspective view. The magazine 3rd contains several storage compartments 33 to accommodate various replacement probe arms 43 . Every storage compartment 33 consists of two narrow, spaced-apart fork-like support areas, so that an exchange probe arm is located in them 43 or one on the probe 4th probe arm 41 can be stored from above using the traversing axes of the 3D measuring device 1.

The magazine 3rd has a first carrier plate 31 and one of them in the direction of the probe arm axes 411 spaced second support plate 32 on, in each case adapted to the shape and to the graduated diameter of the probe arm 41 or the replacement probe arm 43 and aligned with the probe arm axis (s) 411 Notches or fork-shaped cutouts 321 recessed are the storage compartments which are summarized here as defined 33 be designated. The storage compartments 33 are on the first carrier plate 31 in addition, by taking special precautions for a defined placement (rotary alignment) of each individual probe arm 41 and for disconnecting the probe arm coupling 42 added. The fork-shaped cutout acts here 321 in the second carrier plate 32 only as a second vertical support bearing for the probe arm 41 or replacement probe arm 43 and the other cutout is formed such that it has two tendon-shaped flattenings of a cylindrical section of the probe arm 41 , 43 in the axial direction so that the probe arm 41 can be subtracted in the opposite direction. Furthermore, the storage compartment has 33 via a positioning aid in the form of a V-guide, so that a repeatable exact probe arm position is secured around the probe arm 41 always move to the same position so that it can always be coupled again in a defined manner.

The probe arm coupling 42 is a force-fixed connection, which preferably uses electrical or magnetic field effects and in the axial direction of the probe arm 41 is solvable. In the execution of 3rd two plate-shaped elements, a coupling plate 412 and a mounting plate 422 on, between which the field effect unfolded. Between the two plates 412 and 422 are defined positioning elements, which are described in detail below ( 6-10 ), appropriate.

Furthermore are on the probe arm 41 Milled or in the magazine 3rd There are projections, which enable the probe arm 41 on the first carrier plate 31 of the magazine 3rd form-fitting in one of the storage compartments 33 hook and with the help of the probe arm axis 411 parallel travel axis of the 2D scanning system 142 the probe arm 41 subtract in the axial direction and from the probe 4th to solve. The probe arm remains 41 in the storage compartment 33 .

The change process runs between the drawn states of 1 and 2nd as follows.

The travel axes (x and y axes) of the tactile 2D scanning system 142 and the z-axis of the measuring unit 14 position the probe arm 41 in the middle of an empty storage compartment 33 in the magazine 3rd (as in 2nd shown). Then the probe moves 4th down along the z axis until the probe arm 41 over a storage compartment 33 of the magazine 3rd stands and the probe arm 41 into the storage compartment 33 defining sections 311 and 321 (only in 3rd to 7 referred to) can be inserted and in the area of a first carrier plate 31 of the magazine 3rd hooks. The probe then moves 4th along the x-axis of the 3D measuring device 1 from the magazine 3rd away, so that the holding force of the probe arm coupling 42 is overcome and the probe arm 41 comes loose. The last probe arm used 41 remains in "his" storage compartment 33 of the magazine 3rd .

Then the 2D scanning system 142 aligned in the y direction to another storage compartment 33 of the magazine 3rd proceed in which the next required replacement probe arm 43 lies. The probe moves 4th along the x-axis axially to the replacement probe arm 43 approach. The probe arm coupling 42 couples to the mounting plate by clamping with spring force (with possible snap-in) or by magnetic force 422 of the probe 4th at. Then the probe moves 4th the along the z-axis by means of the guide element 11 the measuring unit 14 up until the probe arm 41 from the storage compartment 33 of the magazine 3rd is cleared. Now the 2D scanning system 142 Start the measurement using the traversing axes of the 3D measuring device 1.

In 4th is an advantageous design of the storage compartments 33 of the magazine 3rd shown as a perspective section. The exact and reproducible storage of the exchangeable probe arms (replacement probe arms 43 ) in the magazine 3rd is illustrated here by the adapted first carrier plate 31 of the magazine 3rd that have a congruent V-shaped neckline 311 for the V-shape of the coupling plate 412 has, which is aligned in the direction of gravity to a defined rotational alignment of the replacement probe arm 43 reproducible by gravity alone. One with respect to the longitudinal axis of the replacement probe arm 43 axially spaced second carrier plate 32 is with one for the replacement probe arm 43 customized forked neckline 321 realized in the direction of gravity, with the fork-like widened section 321 for defined storage at the top of at least one of the plane-parallel carrier plates 31 , 32 is introduced to a defined, non-rotatable storage of the probe arm 41 in the magazine 3rd to guarantee. On the other hand, the reproducibility of the axial position of the exchange probe arms 43 on the first carrier plate 31 a front bracket 312 and a rear holding plate 313 on the front and back of the first carrier plate 31 attached so that in the V-shape of the coupling plate 412 of the replacement probe arm 43 complementary cutout area of at least the first carrier plate 31 at least partially a supernatant 314 through the front holding plate 312 is generated so that the replacement probe arm 43 an axially fixed defined position when the probe is detached 4th occupies. With a similar partial projection 314 a rear holding plate 313 is then the complete axial and rotational fixation of the replacement probe arm 43 on the first carrier plate 31 given. The at least in the first carrier plate 31 of the magazine 3rd existing V-shaped cutouts 311 either as isosceles triangles or as isosceles trapezoids for secure storage of the replacement probe arms 43 be shaped.

5 shows in a front view the fixation of one in the storage compartment 33 of the magazine 3rd remote replacement probe arm 43 with the V-shaped coupling plate 412 , in which the due to the separated coupling plate sections 413 remaining corners of the circular basic shape of the coupling plate 412 by the (at these corners) from the front holding plate 312 generated supernatant 314 are secured against being pulled forward. In the V-shaped (complementary) neckline 311 the first carrier plate 31 are for the purpose of backlash-free storage of the replacement probe arms 43 additionally three support points 315 - One on the left leg and two on the right leg of the V-shaped cutout 311 - molded on, in particular angular deviations of the V-shapes of the coupling plate 412 and V-shaped neckline 311 to be able to tolerate.

In 6 is another advantageous design of the storage compartments 33 of the magazine 3rd shown as a perspective section. The reproducible storage of the replacement probe arms 43 in the magazine 3rd takes place here - as in 4th - by one to the V-shape of the coupling plate 412 customized V-shaped neckline 311 , which is oriented in the direction of gravity, around the rotational orientation of the exchange probe arms 43 to be reproducible solely by gravity. An axially along the longitudinal axis of the replacement probe arm 43 spaced second support plate 32 is also in this example with one for the respective replacement probe arm 43 customized forked neckline 321 provided in the direction of gravity. For the reproducibility of the axial position of the replacement probe arms 43 is in this variant on the probe arm shaft 414 behind the coupling plate 412 an undercut 415 provided, in which the on the first support plate 31 attached rear bracket 313 engages so that the V-shape of the coupling plate 412 of the replacement probe arm 43 the complementary section 311 in the first carrier plate 31 of the magazine 3rd is always axially defined opposite. The exchange probe arm 43 thus already takes place through the engagement of the rear holding plate 313 in the undercut 415 an axially immovable position for connecting and disconnecting the probe 4th one so that the in 4th provided front holding plate 312 can be omitted in this example.

7 shows again the fixation of the in the storage compartment 33 of the magazine 3rd stored replacement probe arm 43 according to the execution of 6 with the V-shaped coupling plate 412 in a frontal view, with the undercuts 415 as parallel millings on the (hidden, dashed) probe arm shaft 414 you can see. The coupling plate 412 has a V-shape as in the previous example and lies in a complementarily shaped V-shaped cutout 311 , the three support points 315 as a three-point bearing to compensate for any deviations in the V-shape of the coupling plate 412 and neckline 311 the first carrier plate 31 having. This version has the advantage that the coupling plate 412 for coupling the mounting plate 422 of the probe 4th completely free - ie without a protruding front holding plate 312 - is accessible.

In the 8th to 10th are preferred designs of the probe arm coupling 42 shown. The main focus of the design variants is the design of the coupling mechanisms used between the coupling plate 412 of the probe arm 41 and the mounting plate 422 of the probe 4th . The basic forms of coupling plate 412 and mounting plate 422 are therefore in 8-10 unchanged, although these can be modified within wide limits, such as the 9 and 10th will be explained further below.

In 8th is for the defined reproducible coupling of probe arm 41 and probe 4th the mounting plate 422 with two orthogonal to each other and to the probe arm axis 411 distributed prismatic recesses 421 provided, in which a spatially corresponding to the coupling plate 412 arranged cylinder segment 423 into the longer prismatic recess 421 and a spherical segment 424 into the shorter prismatic recess 421 intervene when both plates 412 and 422 the probe arm coupling 42 due to an axial force effect 5 move towards each other. Two cylinder segments can also be used 423 are used if at least one of them is differentially height-adjustable with respect to the surface of the coupling plate 412 is. The force effect 5 the probe arm coupling 42 is in this embodiment of a permanent magnet 51 generated on the ferromagnetic material of the coupling plate 412 acts.

In 9 are the prismatic recesses 421 in the coupling plate 412 designed as three chamfered elongated holes and at the same distance from the probe arm axis 411 positioned and aligned to this. As a counterpart are on the mounting plate 422 three similarly positioned spherical segments 424 attached, of which at least two can be adjustable in height. The force effect 5 between coupling plate 412 and mounting plate 422 is in this case by one in the mounting plate 422 located electromagnet 52 realized, the coupling plate 412 is again ferromagnetic.

10th shows a third design of the probe arm coupling 42 . The prismatic recesses are in this version 421 into the mounting plate 422 introduced by the one prismatic recess 421 in the direction of the extended probe arm axis 411 into the mounting plate 422 inside and the other prismatic recess 421 along the surface of the receiving plate 422 in the radial direction to the probe arm axis 411 is introduced. The opposite coupling plate 412 points with the appropriate spatial orientation as cylinder segments 423 on the one hand an axially extended probe arm shaft 414 and a pin arranged radially to it 425 on. The force effect 5 for the defined positioning of the axial cylinder segment 423 along two contact lines of the flanks of the first prismatic recess 421 is done by a leaf spring 53 generated on the mounting plate 422 is attached and horizontally opposite each other along the prismatic recess 421 extends. This leaf spring 53 also fixes the pin in the axial direction 425 in the radial prismatic recess 421 . In addition, a magnetic field effect can also be used in the axial direction, which in this example is analogous to 8th through a permanent magnet 51 can be generated.

In 11 are in the partial illustrations a to c embodiments of the coupling plate 412 shown, above all, the possible variations in the location of three prismatic recesses 421 should show. In partial illustration a is the absolutely equally distributed on the probe arm axis 411 centrally oriented orientation of the prismatic recesses 421 shown. Here is the coupling plate 412 starting from a circular shape by two separated coupling plate sections 413 on a wedge shape for the storage in the magazine already described above 3rd has been brought. The wedge angle is set to 60 ° to ensure the even distribution of the prismatic recesses 421 on a concentric circular line.

In part b of 11 the wedge angle is chosen significantly smaller than 60 ° and the coupling plate 412 through three coupling plate sections 413 brought to the shape of an acute isosceles triangle. The prismatic recesses 421 are symmetrical to a plane of symmetry in this case 416 which is a vertical axial plane of the probe arm 41 is arranged, wherein the longitudinal axes of the prismatic recesses 421 above the probe arm axis 411 at a point in said plane of symmetry 416 to cut.

The partial picture c in 11 shows a triangular shape of the coupling plate 412 , which also has three coupling plate sections 413 is generated in such a way that the wedge angle of the V-shape is approximately 90 °. The prismatic recesses 421 are aligned in this example so that the longitudinal axes are at a point below the probe arm axis 411 in the plane of symmetry 416 cut the resulting right-angled equilateral triangle.

In 12th the three partial illustrations a to c show further variations of the prismatic recesses 421 on a maintained circular basic shape of the coupling plate 412 with two coupling plate sections each 413 that have the required V-shape for storage in the magazine 3rd produce. The partial illustration a shows in this form of the coupling plate 412 an even distribution of the prismatic recesses designed as elongated holes 421 that are around the probe arm axis 411 are each offset by an angle of 120 ° and arranged concentrically.

Partial illustration b of 12th indeed has the same concentric arrangement to the probe arm axis 411 like partial illustration a, but the angles are around the probe arm axis 411 once smaller and twice larger than 120 °. The division is symmetrical to the axial plane of the probe arm described above 41 , but the alignment of the prismatic recesses 421 is not uniform on the probe arm axis 411 or a common intersection in the plane of symmetry 416 directed, but all three prismatic recesses 421 are aligned in any direction, taking care that none of the prismatic recesses 421 parallel to one of the others and not all prismatic recesses 421 tangential on concentric circles around the probe arm axis 411 are aligned.

The partial picture c in 12th shows yet another symmetrical arrangement of the prismatic recesses 421 , in which the longitudinal directions are not in the plane of symmetry 416 lying prismatic recesses 421 in the center of the third prismatic recess 421 in the plane of symmetry 416 to cut.

This arrangement is particularly for acute-angled versions of the V-shape of the coupling plate 412 suitable.

• - Die horizontale Ablage verschiedener Austauschtastarme 43 im Magazin 3 entspricht der Arbeitsausrichtung der Tastarme 41 in der 3D-Messeinrichtung 1 und ist in Verlängerung einer der Hauptabtastachsen der 3D-Messeinrichtung 1 (außerhalb des Messbereichs zwischen Reitstock 12 und Spindelstock 13) erreichbar.
• - Die Gestaltung des Magazins 3 ist sehr preiswert, da dieses als Blechkonstruktion sehr einfach umsetzbar ist.
• - Der Tastarmwechsel kann einfach als eine Art erweiterte Scanfunktion des Tastkopfes 4 angelernt werden, indem für eine bestimmte Abtastaufgabe zuerst der erforderliche Tastarm 41 bzw. Austauschtastarm 43 vom Magazin 3 abgenommen wird.
• - Die Vorrichtung zum Auswechseln eines taktilen Tastarms 41 ist mit einer Tastarmerkennung ergänzbar, indem eine zusätzliche „Intelligenz“ (z.B. RFID-Technik) integriert wird.

The inventive device for exchanging a tactile probe arm 41 A 3D measuring device 1 also has the following advantages:

• - The horizontal storage of various replacement probe arms 43 in the magazine 3rd corresponds to the working orientation of the probe arms 41 in the 3D measuring device 1 and is an extension of one of the main scanning axes of the 3D measuring device 1 (outside the measuring range between tailstock 12th and headstock 13 ) reachable.
• - The design of the magazine 3rd is very inexpensive because it is very easy to implement as a sheet metal construction.
• - The probe arm change can simply be a kind of extended scan function of the probe 4th can be taught by first of all the required probe arm for a certain scanning task 41 or replacement probe arm 43 from the magazine 3rd is removed.
• - The device for exchanging a tactile probe arm 41 can be supplemented with tactile detection by integrating an additional "intelligence" (eg RFID technology).

Reference list

1

3D measuring device

11

Guide element

12th

Tailstock

13

Headstock

14

Unit of measurement

141

optical measuring system

142

2D scanning system

143

Probe holder

2nd

Target / workpiece

3rd

Magazine (for probe arms 41 )

31

(first) carrier plate

311

(V-shaped) neckline

312

front holding plate

313

rear holding plate

314

Got over

315

Support points

32

(second) carrier plate

321

(forked) neckline

33

Storage compartments

4th

Probe

41

Probe arm

411

Probe arm axis

412

Coupling plate

413

Coupling plate section

414

Probe arm shaft

415

Undercut

416

Plane of symmetry

42

Probe arm coupling

421

prismatic recess

422

Mounting plate

423

Cylinder segment

424

Spherical segment

425

pen

43

Exchange probe arm

5

Effect of force

51

Permanent magnet

52

Electromagnet

53

Leaf spring

D

Axis of rotation

QUOTES INCLUDE IN THE DESCRIPTION

This list of documents listed by the applicant has been generated automatically and is only included for better information for the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent literature cited

• GB 2373543 A [0003]
• DE 102005036928 B3 [0003]
• US 5028901 A [0005]
• DE 3320127 A1 [0006]

Claims (16)

Device for exchanging a tactile probe arm of a 3D measuring device, which comprises at least one probe head (4) movable in three coordinate directions and the exchangeable probe arm (41) which is temporarily rigidly connected to the probe head (4) by means of a probe arm coupling (42) and by at least one an interchangeable probe arm (43) present in a magazine (3) can be exchanged, characterized in that - the magazine (3) outside of a measuring area located between the tailstock (12) and the headstock (13) along one of the coordinate directions that correspond to the main axes of movement of the 3D The measuring device (1) is assigned, is arranged and has storage compartments (33) for a plurality of probe arms (41; 43) in the horizontal direction, the storage compartments (33) being inserted into at least two vertical support plates (31, 32) of the magazine (3) Cutouts (311, 321) are formed, - the probe arm (41) has a cylindrical probe arm shaft (414) and at least one tactile ball probe at a distal end and a flange-like coupling plate (412) at a proximal end of the probe arm shaft (414), the coupling plate (412) having means for temporarily defined coupling of the probe arm (41; 43) on the probe (4), and - the probe arm (41; 43) on the coupling plate (412) and the magazine (3) on at least one of the carrier plates (31, 32) complementary wedge-shaped elements with a gravity-oriented Have a V-shape in order to specify a reproducible, defined rotational orientation of each stored probe arm (41; 43) in the magazine (3). Device after Claim 1 , characterized in that the coupling plate (412) of the probe arm (41; 43) for radial reproducibility of the probe arm position in the magazine (3) has a circle as a basic form, on which two segments of the same size are left out on secants of the circle which have a common intersection outside of the circle in a vertical plane of symmetry (416) of the probe arm (41; 43), to which the circular segments and a V-shape of the coupling plate (412) resulting therefrom in the direction of gravity lie symmetrically, and that a first carrier plate (31) of the Magazine (3) has a V-shaped cutout (311) complementary to the V-shape of the coupling plate (412) and oriented in the direction of gravity. Device after Claim 1 , characterized in that the coupling plate (412) of the probe arm (41; 43) for radial reproducibility of the probe arm position in the magazine (3) has an isosceles triangle as a basic form, the plane of symmetry (416) of which is in a vertical axial plane of the probe arm (41; 43) is arranged, to which a resulting V-shape of the coupling plate (412) in the direction of gravity lies symmetrically, and that a first carrier plate (31) of the magazine (3) is complementary to the V-shape of the coupling plate (412) in the direction of gravity-oriented V-shaped cutout (311). Device after Claim 2 or 3rd , characterized in that the V-shaped cutout (311) complementary to the V-shape of the coupling plate (412) of the probe arm (41; 43) in at least the first carrier plate (31) of the magazine (3) as an isosceles triangle or as an isosceles Trapezoid is formed. Device after Claim 1 , characterized in that for the reproducibility of the axial probe arm position in the magazine (3) at least on a first carrier plate (31) at least one front holding plate (312) is attached such that a V-shaped coupling plate (412) of the probe arm (41) Complementary V-shaped cutout (311) of the first carrier plate (31) is at least partially covered by a projection (314) of the front holding plate (312), so that the coupling plate (412) has an axially fixed position in the V-shaped cutout (311) Has the first carrier plate (31) of the magazine (3) when the probe head (4) is axially removed from the coupling plate (412) of the probe arm (41; 43). Device after Claim 5 , characterized in that for the reproducibility of the axial feeler arm position in the magazine (3) at least on the first carrier plate (31) an additional rear holding plate (313) is attached in such a way that a shape of the coupling plate (412) of the feeler arm (41; 43) Complementary V-shaped cutout (311) of the first carrier plate (31) is at least partially covered by a projection (314) of the front holding plate (312) and the rear holding plate (313), so that the coupling plate (412) has an axially fixed position in the V - Shaped cutout (311) of the first carrier plate (31) of the magazine (3) against any axial movement of the probe arm (41; 43). Device after Claim 1 , characterized in that the coupling plate (412) as a means for temporarily defined coupling of the probe arm (41) to the probe head (4) either two mutually aligned pairs of prismatic recess (421) and cylinder segment (423) or pairings of prismatic recess ( 421) and spherical segments (424) between the coupling plate (412) of the probe arm (41) and a receiving plate (422) of the probe (4), the temporary coupling between the coupling plate (412) and the receiving plate (422) by means of an axially releasable fixation is generated on the basis of a force effect (5). Device after Claim 7 , characterized in that the coupling plate (412) of the probe arm (41) to the mounting plate (422) of the probe (4) by means of an arrangement of two prismatic recesses (421) arranged transversely to one another in a radial plane about a probe arm axis (411) on the one hand and on the other hand, two complementary aligned counterparts cylinder segment (423) and spherical segment (424) can be coupled in a defined manner. Device after Claim 8 , characterized in that a cylinder segment (423) is replaced by two spherical segments (424) spaced apart from one another with respect to a prismatic recess (421). Device after Claim 7 , characterized in that a three-point support is provided between the coupling plate (412) of the probe arm (41) and the receiving plate (422) of the probe (4), the three-point support having three convex spherical surfaces, each with two diverging flanks of three prismatic recesses (421) are in contact, the prismatic recesses (421) being distributed around a probe arm axis (411) and being able to be aligned with one another as desired, but no prismatic recess (421) is aligned parallel to one of the other. Device after Claim 10 , characterized in that the prismatic recesses (421) are arranged symmetrically with respect to a plane of symmetry (416) of the V-shape of the coupling plate (412), which lies within a vertical axial plane of the probe arm (41). Device after Claim 10 , characterized in that the prismatic recesses (421) are all radially aligned with the probe arm axis (411). Device according to one of the Claims 7 to 12th , characterized in that the axially releasable fixation is formed by means of an electrical or magnetic field effect. Device after Claim 13 , characterized in that the temporary coupling between the coupling plate (412) and the receiving plate (422) is designed as a magnetic field effect, which is alternatively formed by two permanent magnets (51), by a permanent magnet (51) and a ferromagnetic material, by a permanent magnet (51 ) and an electromagnet (52), can be generated by a ferromagnetic material and an electromagnet (52) or by two electromagnets (52). Device after Claim 7 , characterized in that the coupling plate (412) of the probe arm (41) is coupled to the mounting plate (422) of the probe head (4) such that two diverging flanks of the one prismatic recess (421) coaxial with a probe arm axis (411) in the Mounting plate (422) are molded in or attached to a molded angle piece, so that the coaxial prismatic recess (421) touches the cylindrical probe arm shaft (414) of the probe arm (41) along two contact lines, and the further prismatic recess (421) orthogonal to the coaxial prismatic Recess (421) and radially to the probe arm axis (411) is arranged so that a cylinder segment (423) radially between the coupling plate (412) and the mounting plate (422) is in contact with the radially directed prismatic recess (421) along two contact lines, if at least a radial force (5) against the coaxial prismatic recess (421) by anchoring to the mounting plate (422) te coaxially oriented leaf spring (53) is present. Device after Claim 15 , characterized in that an additional axial force (5) is provided by electrical or magnetic field action.

Images