DE102013219382A1 - Arrangement and method for measuring a relative position and / or a relative movement of two relatively movable parts - Google Patents

Abstract

The invention relates to a measuring arrangement for measuring a relative position and / or relative movement of a first part (51) and a second part (53) rotatable relative to the first part (51) about a rotation axis (R), the measuring arrangement comprising: A measuring graduation (75) which is formed on the first part (51) or which is connectable to the first part (51), at least one measuring sensor (74a, 74b) arranged on the second part (53) or can be arranged and which cooperates during a measuring operation of the measuring arrangement with the material measure (75) that measuring signals of the measuring sensor (74 a, 74 b) information about a rotational position of the measuring sensor (74 a, 74 b) with respect to the axis of rotation (R) and / or information about a Rotational movement of the measuring sensor (74a, 74b) about the axis of rotation (R) and thus allow a determination of the relative position and / or the relative movement of the first part (51) and the second part (53) A holder (72) which is connected to the measuring sensor (74a, 74b) for holding the measuring sensor (74a, 74b) or which is part of the measuring sensor, and a base (71) for fixing the holder to the the measuring device (74a, 74b) held in the holder, wherein the base (71) is fastened to the second part during operation of the measuring device, wherein • the holder is designed as a circular ring or as an annular segment which surrounds the axis of rotation (R) extending, which contains a center of the annulus or the annulus segment, and • the holder is selectively positionable in one of different rotational positions about the axis of rotation on the base (71), so that the holder is fixed in the respective rotational position on the base (71) and so that the rotational position and thus a position occupied by the measuring sensor (74a, 74b) during operation of the measuring arrangement relative to the second part is adjustable.

Description

The invention relates to a measuring arrangement for measuring a relative position and / or a relative movement of a first part and a second part rotatable relative to the first part about a rotation axis. The measuring arrangement has a material measure, which is formed on the first part or which is connectable to the first part. At least one measuring sensor which is arranged or can be arranged on the second part and which cooperates with the material measure during a measuring operation of the measuring arrangement such that measuring signals of the measuring sensor information about a rotational position of the measuring sensor with respect to the axis of rotation and / or information about a rotational movement of the measuring sensor include the axis of rotation and thus allow a determination of the relative position and / or the relative movement of the first part and the second part, and a holder which is connected to hold the measuring sensor with the measuring sensor, are also components of the measuring arrangement. The invention also relates to a method for operating the measuring arrangement, a coordinate measuring machine having the measuring arrangement, the coordinate measuring machine having the first part and the second part movable relative to the first part, and a turning device for rotating a workpiece or a coordinate measuring device an arrangement for measuring coordinates of the workpiece, the rotating device having the measuring arrangement, the first part and the second part, wherein the second part is rotatable relative to the first part about a rotation axis of the rotating device and wherein the workpiece or the coordinate measuring device the first part or the second part can be arranged.

It is known to rotatably support workpieces for the purpose of measuring their coordinates or for the purpose of machining the workpiece. For example, In the field of coordinate metrology, workpieces are arranged on rotatable tables (so-called turntables). In this way, the workpiece can be placed in various working orientations in which the coordinate measuring machine operates, i. Coordinates the workpiece. In particular, the coordinates of the workpiece may be measured continuously (eg, scanning) while the rotating device rotates the workpiece about its axis of rotation. The same applies to the machining of a workpiece by a machine tool. The workpiece can be placed in different working orientations to machine the tool. In particular, the workpiece can be continuously rotated while it is being processed. In order to determine the rotational position of the workpiece with respect to the axis of rotation, a rotational position measuring device is used.

Rotary joints with at least one axis of rotation are also used on coordinate measuring machines, wherein a sensor or probe of the coordinate measuring machine is connected to other parts of the coordinate measuring machine via the rotary joint, so that the rotary joint can bring the sensor or button into a desired rotational position. In particular, the rotary joint can also have two axes of rotation which run, for example, perpendicular to one another. Usually, a rotational position measuring device is provided for each of the rotary axes.

Coordinate measuring machines or machine tools often have in the rectilinear direction movable parts, the position of which is to be determined with respect to a linear axis extending in this direction. For example, gantry-type coordinate measuring machines have a gantry movable along a first linear axis, a carriage movable along a second linear axis relative to the gantry, and a quill movable relative to the carriage along a third linear axis, on which a measuring head is arranged. The mentioned measuring head z. B. can be connected via at least one rotary joint with the quill. Further, in alternative constructions of coordinate measuring machines or machine tools, there are hinges combined with other hinges, e.g. in so-called articulated arm coordinate measuring machines.

In all the cases mentioned, the relative position of a first part to a second part is to be measured. Alternatively, the relative movement of the parts can be measured. From the measured relative movement, e.g. from the path traveled in the direction of movement of the parts, the relative position can be determined again. For example, In the case of so-called incremental scales, markings are preferably arranged at regular, constant intervals along the direction of movement. A dimensional standard formed in this way is located on the first of the relatively movable parts. At the second part there is a measuring sensor, which detects the relative to him moving past markers during the relative movement and generates corresponding measurement signals. Such measuring systems may be designed for the measurement of rectilinear movements (for example along said linear axes) or for the measurement of rotational movements.

In addition to incremental scales, there are many other types of measuring systems. For example, the measuring standard on the first of the two relatively movable parts instead of markings may include information about positions along the direction of movement, which are detectable by the associated measuring sensor on the second part. Also independent of the design of the material measure as a carrier of information about Positions, path lengths and / or other variables from which the relative position and / or relative movement of the two parts can be determined, there are also different measuring principles, according to which the measuring sensor or a plurality of measuring sensors, the information of the material measure depending on the movement of the two Parts detected relative to each other, namely z. As optical, mechanical, capacitive, magnetic and inductive. These measuring principles can also be combined with each other.

Particularly for the operation of coordinate measuring machines, highly precise measurements of the relative movement of the parts are required. In addition to systematic errors of the measuring arrangement, which are usually corrected by calibration of the measuring arrangement, the movement device, which enables the relative mobility of the two parts, also contributes to the error of the measuring arrangement. Under the error of the movement device, the deviation from a desired ideal movement (in the case of a linear axis, an exactly rectilinear movement and in the case of a rotational movement about a rotation axis, an exactly circular motion around the non-space fluctuating axis of rotation).

For example, a turning device can be designed so that its defects meet certain specifications. In particular, air bearings can be used to support the rotatable parts of the rotating device and direct drives are used in motor-driven rotating devices. The smaller the error of the rotating device should be, the higher the design effort.

Alternatively or additionally, errors of the rotary device can be measured with a coordinate measuring machine, wherein a calibration body or an array of calibration bodies is placed on the rotatable part of the rotary device (e.g., placed on the turntable) and measured. The measurement of the errors of the rotating device with respect to all six possible degrees of freedom of movement by means of a coordinate measuring machine, which can also measure workpieces, but is time consuming. If high accuracy is required, the calibration must be repeated, for example, if the rotary device is exposed to temperature fluctuations. The same applies to a rotating device that is configured to rotatably hold workpieces in the processing area of a machine tool. The cost of a calibration is in this case in comparison to the coordinate measuring usually mostly greater, since in the field of coordinate measuring usually the coordinate measuring machine can be used for the calibration, which also carries out the measurement of workpieces later.

In the case of linear axes, the same applies to the most error-free construction and / or measurement and correction of existing errors.

It is an object of the present invention to provide a measuring arrangement for measuring a relative position and / or a relative movement of a first part and a second part movable relative to the first part, which allows the effects of movement errors of the moving device according to which the two Parts are movable relative to each other, to reduce. It is a further object of the invention to provide a corresponding method for operating such a measuring arrangement, a coordinate measuring machine with such a measuring arrangement and a rotating device for rotating a workpiece or a coordinate measuring device of a coordinate measuring machine with such a measuring arrangement.

In accordance with one aspect of the present invention, moving means for moving the two parts relative to each other have a variety of reproducible motion errors that cause the deviations from the ideal motion. For example, can occur in a rotating tumbling error of the axis of rotation and transverse displacements of the axis of rotation. As a result, the rotational movement on undesirable translational and rotational motion components, which lead to the deviations from the ideal rotational movement. When considered over the course of a complete revolution with respect to the axis of rotation, the various movement errors compensate each other and therefore affect the measuring accuracy of the rotational position measurement or measurement of the rotational movement in their entirety differently depending on the measuring location of the measuring sensor of the rotary device. Therefore, there are positions for the measuring sensor or the measuring sensors, at which the different movement errors over the entire possible range of motion (for example, a complete rotation about the axis of rotation or part of a complete revolution) compensate better than in the case in which the measuring sensor or the measuring sensor is positioned differently.

The same applies to linear axes with ideally linear movements. As a rule, rotational and translational additional movements occur over the entire possible range of motion, which have different effects on the measurement error, depending on the position of the measuring sensor or the measuring sensors. For example, compensated at a certain distance to the side of the linear axis of their rotational and translational errors. Preferably, therefore, the measuring sensor is arranged at this distance to the linear axis.

In addition, certain directions of deviation from ideal motion due to motion errors are more damaging to the measurement than others. If the real rotational movement of the rotating device leads to additional movement in one direction tangential to the direction of rotation (ie tangential to the direction of rotation about the axis of rotation) of the rotating device compared to the ideal rotational movement, this will falsify the measurement of the rotational position or rotational movement. In contrast, an additional movement in a direction radially to the rotating device does not or does not significantly affect the measurement of the rotational position or rotational movement. The component of the motion error relevant to the measuring sensor therefore runs in the direction tangential to the direction of rotation and is referred to below as a tangential motion error and is related to the respectively considered measuring location. In the case of linear axes also applies that additional movements due to movement errors across the desired direction of movement harmless or less harmful than additional movements in the desired direction of movement.

The invention now assumes that not only systematic errors of the measuring arrangement and the movement device are corrected by calibration, but the measuring sensor or the measuring sensors is / are positioned at a particularly favorable position in which the measuring sensor or in which the measuring sensors then during the Movement remains / remain. In particular, the favorable position in a rotating device is a favorable angular position with respect to the axis of rotation and, in the case of a linear axis, a favorable distance from the linear axis or a favorable linear position along the linear axis.

It should be noted that the favorable position of the measuring sensor does not necessarily have to be the position at which over the entire range of motion the lowest mean measuring error due to the movement error or the smallest maximum measuring error due to the movement error occurs.

In particular, the amplitudes of the movement error differ over the course of the movement at different possible measuring locations. The term amplitude denotes, as usual, the maximum deviation from the ideal movement. However, not only can this amplitude be considered and a measurement location can be determined at which this amplitude is small or even minimal. Rather, the course of the (eg tangential) movement error during the rotational movement can also be viewed in another way and a measuring location can be determined with a particularly favorable course, where "favorable" can be defined by at least one predetermined criterion. For example, There are measuring tasks in the coordinate metrology or machining tasks in the machining of workpieces by machine tools, which is to pay attention to precision with respect to a certain order of deviations between an ideal circular course of the outer circumference or inner circumference of the workpiece. For example, a trace having three maxima and three minima of deviation over one complete revolution about the axis of rotation or over a predetermined range of rotational positions (ie, in particular, a portion of a revolution which is, for example, an integer fraction of a full revolution) has the third order , The three maxima and three minima correspond to three waves. In the description of the tangential motion error as a local function (deviation from the ideal rotational movement as a function of the rotational position), superimpositions of several orders may, of course, be present. The location function is equivalent to the time function (deviation as a function of the time of rotational movement) when the speed is known as a function of time or location, e.g. At constant speed. The invention is not limited to the consideration of order three. Rather, any orders of the tangential motion error can be considered. In the case of linear axes, it is also true that waves of deviation with maxima and minima can occur over the possible range of motion and a corresponding order of the error can be specified.

The given criterion may also be referred to as a predetermined condition to be met. For example, a trace of tangential motion error may be beneficial over the range of rotational positions (particularly over a predetermined range of rotational positions) traversed by the rotational motion with 9 waves (i.e., 9 maxima and minima of deviation) or other predetermined number of waves. This is based on the idea that depending on the considered angular position of the rotational position measurement, a different number of waves can occur and / or the amplitude of the motion error in the order (for example, 9 waves) can be different. In particular, to fulfill the predetermined criterion, therefore, for example, the rotational position measuring location is determined at which the amplitude of the movement error with respect to a predetermined order is maximum. In the case of linear axes can be moved accordingly.

In this case, to return to the third order example, it is desirable that the measuring error of the measuring sensor due to a movement error of the third order moving device be particularly small so that the three-wave shape of the workpiece can be measured as accurately as possible. Also in this case is the Order three only one embodiment. For other orders greater than one, it is possible to proceed accordingly, for example by determining a measuring location for which the motion error of the moving device affecting the measurement is small with respect to the order, is minimal or fulfills a predetermined condition and thus a criterion (eg less than is a predetermined limit).

Accordingly, at least one range of orders (for example, three to five waves) containing more than one order may be used. Instead of the number of waves of a deviation over the range of motion (eg a rotation about the rotation axis of the rotating device or about the rotational symmetry axis of the workpiece or over a predetermined range of positions along the linear axis or rotational positions) can also be spoken of the frequency become.

As a measure of the motion error affecting the measurement over a range of positions (in particular a range with all angular positions about the axis of rotation or a portion of the possible range of motion), in particular the amplitude of the motion error affecting the measurement in the range (ie Amplitude of the spatial function or the time function, see above) or the amplitude after a transformation (in particular a Fourier transformation) of the motion error affecting the measurement into the frequency domain (ie the amplitude in the frequency domain).

Based on the above-described findings, for the purpose of reducing the effects (eg, on the coordinate measurement) of errors of a moving device comprising a measuring device for measuring a relative position and / or a relative movement of a first part and a relative to the first Part having movable second part, movement error of the movement device, ie Errors of the movement device due to deviations between the real movement on the one hand and an ideal movement of the movement device on the other hand, are measured, and a favorable position of at least one measuring sensor can be determined. In particular, a measuring location of the measuring sensor is determined at which the movement error has a smaller effect, in particular smaller than for other possible measuring locations, and / or fulfills a predetermined condition. In particular, such as e.g. has already been mentioned above, a given measurement task or processing task are based, for which the location should be favorable.

Details of such a determination of motion errors are in the international patent application PCT / EP2013 / 056123 and the German patent application DE 10 2013 216 093.3 described. In the German patent application DE 10 2013 216 093.3 It is also described how a favorable position of a measuring sensor, namely a rotational position sensor, can be determined from the movement errors. In particular, as first steps of the method described here for operating a measuring arrangement as described in the cited patent applications, the movement errors can be determined and the favorable position of the measuring sensor can be determined. Furthermore, the measuring arrangement described here may be part of the arrangements or coordinate measuring machines described in the cited patent applications.

In order to be able to set a measuring location, a measuring arrangement of the aforementioned type is proposed which has a base for fixing the holder to the measuring sensor held by the holder. The base is attached to the second part during operation of the measuring assembly or part of the second part. Therefore, the measuring sensor, which is now fixed to the base, in interaction with the measuring scale on the first part, can measure the relative position and / or relative movement of the two parts.

The base extends, in particular, along a direction of movement of the movement of the parts provided by the movement device. According to the invention, the holder can optionally be positioned in different holding positions (namely rotational positions) along the direction of movement on the base. After selecting the holding position, the holder is fixed in the holding position on the base. This does not exclude that the holder and / or the measuring sensor is also displaced along another direction, for example in the axial direction of the axis of rotation.

In the case of a linear movement along a linear axis, the base may extend transversely to the direction of movement. Accordingly, the holder can be positioned in the direction transverse to the direction of movement in various holding positions along the base and in particular held by magnetic forces on the base. Preferably, a holding position is then set in which compensate for rotational and translational motion errors. In this case, the position of the material measure can also be adjusted in the direction transverse to the direction of movement, so that the measurement sensor held by the holder can generate signals for determining the respective position in the direction of movement by interacting with the material measure.

There are different ways of fixation. In particular, a fixation by generating a negative pressure in a space between the holder and the base is possible. For example, at least one suction cup may be provided on the holder for this purpose, or air may be heated, for example, according to the principle of placing cupping glasses. Alternatively or additionally, the holder can be mechanically fixed to the base, for example, positively and / or non-positively. In one embodiment, a groove is formed on the base or the holder, which extends along the direction of movement. In particular, the groove extends annularly around the axis of rotation of the moving device. At least one sliding block of the holder or the base engages in the groove, so that the holding position of the holder can be adjusted while the at least one sliding block moves. In the holding position then set the nut can be fixed. Alternatively or in addition to a mechanical fixation of the sliding block, another fixation is possible, for example by magnetic forces.

By preference, the holder is pressed against the base by magnetic forces in a pressing direction, thereby fixing the holder to the base with the measuring sensor held by the holder. It can be dispensed with an additional fixation (for example, mechanical fixation).

Regardless of the type of fixation, the scope of the invention also includes a method for operating the measuring arrangement, a coordinate measuring machine having the measuring arrangement, and a rotating device for rotating a workpiece or a coordinate measuring device in an arrangement for measuring coordinates of the workpiece. Embodiments of the operating method, the coordinate measuring machine and the rotating device will become apparent from the description of embodiments of the measuring arrangement. The magnetic fixation can be supplemented or replaced by another fixation.

• • eine Maßverkörperung, die an dem ersten Teil ausgebildet ist oder die mit dem ersten Teil verbindbar ist,
• • zumindest einen Messsensor, der an dem zweiten Teil derart angeordnet oder anordenbar ist und der während eines Betriebes der Messanordnung derart mit der Maßverkörperung zusammenwirkt, dass Messsignale des Messsensors Informationen über eine Drehposition des Messsensors bezüglich der Drehachse und/oder Informationen über eine Drehbewegung des Messsensors um die Drehachse enthalten und damit eine Bestimmung der relativen Position und/oder der relativen Bewegung des ersten Teils und des zweiten Teils ermöglichen,
• • eine Halterung, die zum Halten des Messsensors mit dem Messsensor verbunden ist, oder die Teil des Messsensors ist, und
• • eine Basis zum Fixieren der Halterung mit dem von der Halterung gehaltenen Messsensor,

wobei die Basis während des Betriebes der Messanordnung an dem zweiten Teil befestigt ist und wobei

• • die Halterung als Kreisring oder als Kreisringsegment ausgestaltet ist, der/das sich um die Drehachse erstreckt, welche einen Mittelpunkt des Kreisrings oder des Kreisringsegments enthält, und
• • die Halterung wahlweise in einer von verschiedenen Drehstellungen um die Drehachse an der Basis positionierbar ist, sodass die Halterung in der jeweiligen Drehstellung an der Basis fixiert wird und sodass die Drehstellung und somit eine Position, die der Messsensor während des Betriebes der Messanordnung relativ zu dem zweiten Teil einnimmt, einstellbar ist.

In particular, it is proposed: A measuring arrangement for measuring a relative position and / or a relative movement of a first part and a second part rotatable relative to the first part about a rotation axis, the measuring arrangement comprising:

• A material measure which is formed on the first part or which can be connected to the first part,
• At least one measuring sensor which is arranged or can be arranged on the second part and which cooperates with the measuring standard during operation of the measuring arrangement such that measuring signals of the measuring sensor contain information about a rotational position of the measuring sensor relative to the rotational axis and / or information about a rotational movement of the measuring sensor to contain the axis of rotation and thus allow a determination of the relative position and / or the relative movement of the first part and the second part,
• • a holder which is connected to the measuring sensor for holding the measuring sensor or which is part of the measuring sensor, and
• A base for fixing the holder to the measuring sensor held by the holder,

wherein the base is attached to the second part during operation of the measuring assembly, and wherein

• • The holder is configured as a circular ring or as a circular ring segment which extends around the axis of rotation, which includes a center of the annulus or the annulus segment, and
• • The holder is selectively positioned in one of different rotational positions about the axis of rotation at the base, so that the holder is fixed in the respective rotational position on the base and thus the rotational position and thus a position that the measuring sensor during operation of the measuring arrangement relative to the second part occupies, is adjustable.

In particular, the base may extend along a direction of movement of the rotational movement in which the material measure and the measuring sensor move relative to one another during operation of the measuring arrangement.

• • zumindest ein Messsensor der Messanordnung, der an dem zweiten Teil angeordnet ist, derart mit einer Maßverkörperung, welche an dem ersten Teil ausgebildet ist oder welche mit dem ersten Teil verbunden ist, zusammenwirkt, dass Messsignale des Messsensors Informationen über eine Drehposition des Messsensors bezüglich der Drehachse und/oder Informationen über eine Drehbewegung des Messsensors um die Drehachse enthalten, und aus den Informationen die relative Position und/oder die relative Bewegung des ersten Teils und des zweiten Teils bestimmt wird,

wobei vor der Erzeugung der Messsignale:

• • der Messsensor mit einer Halterung verbunden wird oder ist, oder die Halterung Teil des Messsensors ist, sodass die Halterung den Messsensor hält, wobei die Halterung als Kreisring oder als Kreisringsegment ausgestaltet ist, der/das sich um die Drehachse erstreckt, welche einen Mittelpunkt des Kreisrings oder des Kreisringsegments enthält,
• • die Halterung wahlweise in einer von verschiedenen Drehstellungen um die Drehachse an der Basis positioniert wird, sodass die Halterung in der jeweiligen Drehstellung an der Basis fixiert wird und so dass die Drehstellung und somit eine Position, die der Messsensor während eines Messbetriebes der Messanordnung relativ zu dem zweiten Teil einnimmt, eingestellt wird.

It is further proposed: A method of operating a measuring arrangement configured to measure a relative position and / or relative movement of a first part and a second part rotatable relative to the first part about a rotation axis, wherein:

• At least one measuring sensor of the measuring arrangement, which is arranged on the second part, cooperates with a material measure, which is formed on the first part or which is connected to the first part, that measuring signals of the measuring sensor information about a rotational position of the measuring sensor with respect Axis of rotation and / or information about a rotational movement of the measuring sensor about the axis of rotation, and from the information the relative position and / or the relative movement of the first part and the second part is determined

wherein prior to the generation of the measurement signals:

• • the measuring sensor is or is connected to a holder, or the holder is part of the measuring sensor, so that the holder holds the measuring sensor, wherein the holder is configured as a circular ring or a circular ring segment which extends around the axis of rotation, which Center of the annulus or annulus segment contains,
• The support is selectively positioned in one of several rotational positions about the axis of rotation at the base so that the support is fixed in the respective rotational position on the base and so that the rotational position and thus a position that the measuring sensor during a measuring operation of the measuring arrangement relative to the second part is set.

The measuring sensor only has to be connected to the holder once. If the rotational position is adjusted differently, the connection of the measuring sensor with the holder can be maintained. This is also the case when the holder is integrated in the measuring sensor. For example, the holder may be integrated in a housing of the measuring sensor, for example as a region having a groove extending along a ring segment.

A circular ring and a circular ring segment are understood to mean an object which extends along a circular line or a circle segment around the center of the circle. The object does not necessarily have to be symmetrical with respect to the center. With regard to the holder but is understood in particular by a circular ring and a circular ring segment, that the different rotational positions of the holder lie on a circular line or a circle segment around the center of the circle.

In particular, a coordinate measuring machine may have the measuring arrangement in one of its configurations, wherein the coordinate measuring machine has the first part and the second part which is movable relative to the first part.

A rotating device for rotating a workpiece or a coordinate measuring device in an arrangement for measuring coordinates of the workpiece, the measuring device in one of its embodiments, the first part and the second part, wherein the second part relative to the first part about an axis of rotation of the Rotary device is rotatable and wherein the workpiece or the coordinate measuring device can be arranged on the first part or the second part. The turning device for rotating a workpiece is e.g. around a turntable, which can be arranged for example on a measuring table (eg on a base plate made of stone) of a coordinate measuring machine. The rotating device for rotating a coordinate measuring device may be e.g. to act an embodiment of one of the above-mentioned hinges. For example, the rotating device may be disposed on an arm or quill of a coordinate measuring machine, and e.g. enable the rotation of a measuring head of the coordinate measuring machine.

In particular, the first part and / or the second part may be part of the measuring arrangement. Alternatively, the measuring arrangement may be an additional measuring arrangement, e.g. is subsequently attached to an existing moving device (e.g., a device for realizing linear movement along a linear axis or a rotating device).

Characterized in that the base is attached to the second part during the operation of the measuring assembly or is part of the second part, the holder is fixed in the holding position on the base and the holder is connected to the measuring sensor and holds this, or the holder part of Measuring sensor is also the measuring sensor is fixed to the base and connected to this indirectly (ie via the bracket). An embodiment of the integration of the holder in the measuring sensor is a material region of magnetic or magnetizable material, which is connected directly to the measuring sensor, for example glued and / or screwed. Another embodiment is the execution of a measuring sensor with the same dimensions and the same construction as in a known measuring sensor, but at least a portion of the measuring sensor consists of a magnetic or magnetizable material.

In particular, the holder is or is fixed to the base such that the holder is pressed against a contact surface of the base, wherein the measuring sensor and the contact surface are on opposite sides of the holder. In this way, the measuring sensor is arranged away from the contact surface and the fixing of the holder to the base can be configured such that the function of the measuring sensor is not disturbed. This is particularly advantageous if, as with a fixation by magnetic forces, the operating principle of the fixation can lead to disturbances in the function of the measuring sensor.

In order to enable the free positioning of the measuring sensor (eg a reading head), the measuring sensor (eg a reading head) can be held magnetically. In a simple embodiment, the basis of the measuring arrangement is, for example, an annular base plate (in the case of a rotating device) or an elongate base plate (in the case of a linear axis). In particular, the base plate may have a flat surface which serves as a contact surface for pressing a holder of the measuring sensor. In addition to a flat contact surface but other forms of contact surfaces come into consideration, for example, a cross-sectional V-shaped contact surface, wherein the surface of the holder in this case is preferably formed complementarily, so that the holder is pressed against the mutually angled areas of the contact surface.

For example, For example, the base may be made of a magnetic material or comprise a magnetic material. As the magnetic material, e.g. Iron or a magnetic stainless steel in question. In contrast, a magnetizable material forms magnetic poles only under the influence of a magnet (eg, the magnetic material or an electromagnet), thereby applying magnetic forces to the material. Like the base, the holder can also comprise or consist of a magnetic material. Alternatively or additionally, the holder may comprise a magnetizable material. Again alternatively, the base may not comprise a magnetic material, but a magnetizable material which is magnetized under the influence of the magnetic field of a magnetic material of the holder or an electromagnet, so that the holder is pressed against the base due to corresponding magnetic forces.

The magnetic or magnetizable material of both the base and the holder may, but need not, form the surface of the base or holder which forms the abutment surface in the state of the holder fixed to the base or is pressed against the abutment surface. In particular, the surface may be formed by a layer of non-magnetic material to limit the size of the magnetic forces which press the holder to the base. Optionally, the layer of non-magnetic material, e.g. made of plastic or paper, abut only temporarily on the contact surface, while the holder is moved along the position in the desired holding position. This facilitates the shift to the desired stop position. After reaching the holding position, the situation can be removed. As the magnetizable material, e.g. Neodymium can be used. The magnetic susceptibility of commercial neodymium magnetic holder bodies is sufficiently large to prevent changes in the adjusted stop position due to shock and vibration during operation of a coordinate measuring machine when a corresponding magnetic field is applied to the neodymium body.

The measuring sensor may e.g. be screwed to the bracket. For example, At least one body of magnetic or magnetizable material is connected to a body of the holder, e.g. glued into a receptacle of the body. For bonding, e.g. Resin-based adhesives are commercially available.

The contact surface of the base, which can also be referred to as a contact surface for pressing the holder in the various possible holding positions, extends in a preferred embodiment at a constant distance from the material measure. As a result, the measuring sensor in the various holding positions can always be kept at the same distance from the material measure.

According to one embodiment, the holder has a first material, which is a magnetic or magnetizable material having a first magnetic susceptibility, and a second material, which is a material having a second magnetic susceptibility. In this case causes the first material in interaction with a magnetic or magnetizable material of the base at least a portion of the magnetic forces, which press the holder in the pressing direction to the base. The second magnetic susceptibility is smaller than the first magnetic susceptibility. The second material is disposed on opposite sides of the first material such that when viewed in a transverse direction transverse to the pressing direction, the first material is enclosed by the second material. In particular, the second material rotates annularly around the first material, so that the first material, viewed in a cross-sectional area extending transversely to the pressing direction, is enclosed in all directions extending transversely to the pressing direction. As an alternative to the ring shape, for example, the second material may be arranged in the radial direction of a rotation axis of the rotating device outside and inside the first material (or above and below the first material), the first material extending annularly around the axis of rotation. In particular, the second magnetic susceptibility is at least a factor of 10, preferably at least a factor of 100, smaller than the first magnetic susceptibility, i. their ratio is at most 1/10 or at most 1/100. The first and second magnetic susceptibility may also differ from each other by larger factors. For the second material, e.g. Brass, which is considered non-magnetic and therefore has a near-zero magnetic susceptibility (e.g., 0.03).

The fact that the second material includes the first material, the magnetic field lines are bundled within the first material and guided in the pressing direction, so that a strong and homogeneous magnetic field is formed, which holds the holder with the measuring sensor stably in the holding position.

The following is spoken by a third material of the holder. However, the third material need not necessarily be present in addition to the second material, although this is preferred. Rather, it is also possible that one Embodiment of the holder has only the first and the third material.

According to one embodiment, the holder comprises a first material which is a magnetic or magnetizable material having a first magnetic susceptibility and a third material which is a magnetic or magnetizable material having a third magnetic susceptibility. The third magnetic susceptibility is greater than the first magnetic susceptibility. When the holder is pressed against the base by the magnetic forces and thereby the holder is fixed to the base, the first material is closer to the base than the third material and the third material is between the measuring sensor and the first material.

The third material shields the measuring sensor from the magnetic field whose field lines run within the first material. Therefore, deterioration of the function of the measuring sensor can be prevented.

According to one embodiment, the measuring arrangement has a spacing device which has at least one spacer which ensures a minimum distance between magnetic or magnetizable materials of the base on the one hand and the holder on the other hand. The magnetic or magnetizable materials cause at least a portion of the magnetic forces that press the support in the pressing direction to the base, wherein a dimension of the spacer (in particular an effective length in the direction of the magnetic forces acting between the base and the bracket) between the base and the holder is adjustable, so that the minimum distance is adjustable.

In this way, the strength of the magnetic forces with which the holder is pressed against the base can be changed. As the distance between the base and the bracket increases, the magnetic forces decrease. The following configuration is therefore possible with respect to the method: The holder is prepositioned in the selected holding position, while a spacing device of the measuring arrangement is in a first operating state in which at least one spacer of the spacing device has a larger minimum distance between the magnetic or magnetizable materials of the base and the holder ensures than in a second operating state of the spacer device. After pre-positioning the fixture in the selected holding position, the spacing means is brought into the second operating state by adjusting a dimension of the at least one spacer between the base and the fixture in which the fixture is supported by stronger (ie larger) magnetic forces of the magnetic or magnetizable materials of the base and the holder is held in the holding position as in the first operating state.

Since at least a portion of the spacer is located between the base and the bracket, and because the dimension of the spacer or portion of the spacer between the base and bracket is adjustable, the strength of the magnetic forces can be adjusted. During the pre-positioning is a greater distance and therefore weaker magnetic forces are set than in the second operating state in which the holder is permanently fixed for the measuring operation of the measuring arrangement on the base. This does not exclude that e.g. By increasing the distance between the base and the holder, the first operating state or another operating state is set at an increased distance, and the holder is then returned to another selected holding position.

For example, For example, the spacing device can have a plurality of forcing screws, which can be unscrewed in the direction of the base parallel to the pressing direction and screwed back into the holder in the opposite direction. In this case, the spacer is the screw, which can optionally be connected to another part of the spacer. For example, For example, three such screws can be located at the corners of an imaginary, preferably equilateral, triangle on the base-facing surface of the holder. By three screws, the free ends of the thus realized three spacers are simultaneously on the surface of the base, so that in particular unlike only two screws or more than three screws no tilting of the holder can take place around the point of contact of one of the spacers on the base. In particular, each of the screws may be associated with a thread on the holder or in the holder.

The spacer means, in particular the jacking screws, also simplify the disassembly of the holder from the base. For this purpose, initially a greater distance of the magnetic or magnetizable materials of the holder is adjusted from the base and then removed in the thus achieved state in which weaker magnetic forces than before, the holder with the measuring sensor from the base.

An example has already been mentioned that the spacer means may comprise three spacers which ensure at the corners of an imaginary triangle the minimum distance between the base and the holder. It is now preferred that the defined by the respective spacer minimum distance individually, that is can be adjusted independently of the other spacers. This also allows adjustment of the orientation of the holder and thus of the measuring sensor relative to the base. However, a number of three spacers also have the advantage that the holder has a unique position and orientation relative to the base. This is not the case, for example, with four spacers at the corners of an imaginary quadrilateral.

In addition to the possibility of setting a holding position for a measuring sensor, the invention also has the advantage that additional measuring sensors (eg reading heads) can be temporarily mounted on the base. Such additional measuring sensors are used eg for a calibration of the movement device and / or the measuring arrangement. The calibration can be carried out, for example, within the framework of the production of the movement device and / or the measuring arrangement or after delivery to the user. For example, five measuring sensors are arranged at predetermined positions relative to one another along the direction of movement, in particular at predetermined angular distances from one another about the axis of rotation, for recording the data required for the calibration and / or due to the calibration for the later correction during operation. The measurement sensors, which are only temporarily located at the base, are removed after the calibration and / or the data acquisition for the calibration. A corresponding procedure for the calibration is eg in EP 192 36 70 A1 described. There are also calibration methods in which a different number of measuring sensors are used at predetermined positions relative to one another and / or in any, non-predefined positions relative to one another.

Preferably, at least one of the measuring sensors mounted only temporarily on the base is held by magnetic forces. In particular, therefore, at least one additional holder may be provided for holding a second measuring sensor, wherein the additional holder (also as second holder to be designated holder) may have any combination of the features that are disclosed for the first holder.

Generally speaking, therefore, a plurality of separate holders may be provided for holding at least one measuring sensor, wherein each holder is configured to be fixed to the base by magnetic forces or otherwise.

Preferably, as will be described in more detail below, a holder or a single holder is designed to hold a plurality of measuring sensors.

In the case of a plurality of measuring sensors, not all the measuring sensors need to be held on the base via the common holder (in particular by magnetic forces between the holder and the base). Rather, at least one of the measurement sensors may be otherwise provided, e.g. be fixed by screwing, directly to the base or to another component of the measuring device.

In particular, the holder may have holding elements. By the holding elements in each case at least two defined by the holding elements of the holder (in particular predetermined) positions a measuring sensor for obtaining the information about the rotational position of the measuring sensor and / or the rotational movement of the measuring sensor is held. Like at least two defined positions (in any state in which the holder is fixed to the base) are spaced apart in one direction along the measuring scale (and thus during the measuring operation along the direction of movement of the two relatively movable parts). In particular, not only applies to this embodiment, that the direction along the material measure is also a direction along the direction of movement of the relatively movable parts. The holder for at least two measuring sensors has the advantage that, although the distance between the measuring sensors can be fixed due to the design of the holder and / or results from the measuring sensors mounted on the holder, the positioning of the measuring sensors held by the holder relative to the base is adjustable and / or selectable.

Alternatively or additionally, at least one measuring sensor can not be mounted in a defined, fixed predetermined position on the holder or be mounted in the fixed position due to corresponding holding elements. With an additional support holding this measuring sensor, the position of the measuring sensor relative to the base can be adjusted, for example by displacement along the direction in which the measuring scale extends. This makes it possible to adjust the position of this measuring sensor particularly accurately relative to at least one further measuring sensor which is held by the first holder, for example at an angular distance of 180 °.

The retaining elements may, for example, be threaded bores and corresponding fastening screws for fastening the respective measuring sensor. Other configurations are also possible in which the holder holds the respective measuring sensor mechanically (for example, in a force-locking and / or form-locking manner). For example, the holding elements may be configured as suction cups or hook-and-loop fasteners or a housing of the measuring sensor may be in the holder be integrated. More generally, the holder does not have to be connected to the measuring sensor, but is integrated into the measuring sensor, for example. In all these cases already defines the holding element or the plurality of holding elements, the predetermined position in which the measuring sensor can be held by the holder. Alternatively or additionally, a measuring sensor z. B. be glued to the bracket with adhesive as a holding element. In this case, the position is also defined by the measuring sensor already mounted on the holder. It is also a combination of a mechanical holding element and adhesive possible. For example, a recess on the surface of the holder may constitute a receiving space for a measuring sensor, but which is glued into the recess.

In a particular embodiment, the material measure for measuring a relative rotational position and / or a relative rotational movement extends over a course of a circle or a circular segment and the base is designed as a circular ring or as a circular ring segment.

In particular, due to the annular configuration of the support and optionally also the base, measurement sensors may be angularly spaced apart by 180 °, i. with respect to the axis of rotation opposite one another, are held by the holder, however, the rotational position with respect to the second part can be adjusted. The adjustment is made e.g. by rotation of the holder about the axis of rotation of the rotational movement relative to the base. Of course, this is also possible if the two positions in which the two measuring sensors are held by the holder or to be held, do not have an angular distance of 180 °. If, however, such an angular distance of 180 ° is present, measurements of the relative rotational position of the first and second part can be carried out with the measuring sensors positioned in this way, whereby systematic measurement errors, which are opposite to the positions of the measuring sensors opposite to the rotational axis, are known Method of evaluation (in particular by forming the arithmetic mean of the measuring signals of the two measuring sensors) can be eliminated. For example, can be eliminated in this way measurement errors that arise because the measuring scale is mounted eccentrically with respect to the axis of rotation of the rotary motion.

In particular, the measuring arrangement has a guide, through which a possible relative movement (in particular a rotational movement about the rotational axis of the rotating device) of the holder and the base is guided, wherein by carrying out the relative movement, the holder can be brought or brought into the various holding positions. As a result, the adjustment of the position which the measuring sensor assumes during a measuring operation of the measuring arrangement relative to the second part is facilitated.

Preferably, the guide is formed by an annular groove in the bracket or in the base into which a protruding portion of the base or bracket engages, i. the corresponding other component (ie the holder or the base) engages in the groove. The groove is configured annular with respect to the axis of rotation of the rotary movement. Under ring is also understood the shape of a ring segment.

Preferably, the annular support is held by the mentioned magnetic forces on the annular base. In particular, in the case of the groove, but also in other cases, the annular holder can be fixed to the base alternatively or in addition to magnetic forces in another way, so that the holding position of the at least one held by the holder measuring sensor remains stable during operation of the measuring arrangement.

For example, in the case of the above-mentioned sliding blocks (of which, for example, three pieces may be present, which are preferably distributed uniformly over the circulation around the axis of rotation), the fixing of the holder to the base can be carried out by fixing the sliding blocks in the groove ( eg by clamping action, magnetic forces or by tightening).

The configuration of the holder and the base as a ring has the advantage, in particular in the case of the groove, that the at least one measuring sensor held by the holder can be brought into the desired holding position in a particularly simple manner.

In one variant, only the holder is designed annular. In this case, the base is not ring-shaped. However, other features of the base disclosed in this specification and figures may be present. For example, the base may include the mentioned magnetic or magnetizable material to retain the annular support by magnetic forces on the base. Alternatively or additionally, the base may, for example, comprise the mentioned sliding blocks, which in this case are guided in the annular groove of the annular holder, so that the annular holder can be rotated about the axis of rotation of the rotary movement until the desired holding position of the at least one held by the holder Measuring sensor is reached. It is not only in this case also possible to bring the holder first in the desired position and then to attach the at least one measuring sensor to the holder. For example, due to the design of the holder can be seen even before the attachment of the measuring sensor to which Position and / or with which orientation the measuring sensor will be attached to the holder.

• – ist mit einem magnetischen oder magnetisierbaren Material verbunden und/oder
• – weist ein magnetisches oder magnetisierbares Material auf und/oder
• – ist mit einem Leitungshalter verbunden, der ein magnetisches oder magnetisierbares Material aufweist,

wobei ein Abschnitt der Anschlussleitung durch Magnetkräfte des magnetischen oder magnetisierbaren Materials an der Halterung und/oder an der Basis fixiert ist/wird.As described above, the base allows an optional fixation of the holder in different holding positions, in particular in holding positions within a continuous area along the direction of movement or along the measuring scale. As a rule, measuring sensors have a connecting line (eg electrical or optical) via which, in particular, the generated measuring signals are transmitted. Alternatively or additionally, the respective measuring sensor can be supplied with energy for its operation via an electrical connecting line. The connecting cable can have several wires, the z. B. are electrically isolated from each other. Since the holding position of the measuring sensor is not fixed, the course of the connecting line from the measuring sensor to the opposite end of the connecting line can vary, depending on which holding position is selected. The connecting line, which in particular is selected to be sufficiently long so that the measuring sensor can be fixed to the base in all possible holding positions, possibly interferes with the operation of the measuring arrangement or even the operation of the moving device if the course of line sections is not fixed. Therefore, the following is proposed: A connecting lead of the measuring sensor

• - Is connected to a magnetic or magnetizable material and / or
• - Has a magnetic or magnetizable material and / or
• Is connected to a conductor holder comprising a magnetic or magnetizable material,

wherein a portion of the lead is fixed to the support and / or the base by magnetic forces of the magnetic or magnetizable material.

The proposal is based on the idea to use the magnetic properties of the holder or the base, in particular the annular support or base, for the attachment of a portion of the connecting cable. As a result, the section is fixed and located at a desired position, which can be chosen so that it does not interfere with the operation. Preferably, the base is magnetic, e.g. ferromagnetic.

Several embodiments of the attachment of a section or a plurality of sections of the connection line to the base will now be described, wherein the embodiments can also be combined with one another as desired. According to a first embodiment, the connecting line is connected to a magnetic or magnetizable material. For example, The connecting cable can be provided with an additional sheath of magnetic or magnetizable material. For this purpose, the jacket, which preferably consists of elastic magnetic or magnetizable material, has a longitudinally extending slot or gap, through which at least the section of the connecting line can be introduced into the interior of the jacket. In the case of an elastic material, the portion is preferably held inside the shell solely due to the elastic forces of the jacket material. In one variant, not all of the jacket is made of the magnetic or magnetizable material, but the magnetic or magnetizable material is e.g. attached to one side of the jacket on this. The jacket is in each of its embodiments, an embodiment of a connectable to the portion of the connecting line conductor holder. However, it does not have to be provided a line holder having a magnetic or magnetizable material. Rather, according to the first embodiment, it is only required that the connection line is connected to a magnetic or magnetizable material. Therefore, e.g. a magnetic material may be attached (e.g., adhered) to the outer surface of the lead without the adhered magnetic or magnetizable material comprising the lead in the manner of a lead holder. Line holders are also referred to as clips. Another example of a conductor holder is a clip (or a plurality of clips), to which clip a body of magnetic or magnetizable material is attached. For example, For example, the magnetic or magnetizable material can be arranged in a housing which has a slot through which the clip is guided.

According to a further embodiment, the connection line itself already has a magnetic or magnetizable material. For example, For example, the sheath, which encloses several cores (with possibly individual insulating core sheaths) and in particular electrically isolated from the environment, may consist of magnetizable material.

Embodiments of the invention will now be described with reference to the accompanying drawings. The individual figures of the drawing show:

1 a gantry-type coordinate measuring machine having a rotary probe and a turntable for rotating workpieces, other parts of the coordinate measuring machine being movable in a straight line relative to each other,

2 a top view of a measuring arrangement with an annular incremental scale and a measuring sensor,

3 a longitudinal section through a rotating device, in particular the turntable 1 .

4 FIG. 2 schematically a longitudinal section through a measuring arrangement in which the measuring sensor is directed to a measuring graduation arranged on an outer circumference of a rotatable part, FIG.

5 3 shows a schematic longitudinal section through a measuring arrangement in which a measuring sensor is directed in an axial direction transversely to a rotation axis onto a measuring graduation of a part which is rotatable about the rotation axis;

6 a top view of a holder for holding a measuring sensor, wherein the holder has three threaded holes, which allow in combination with a respective screw to press the holder from a base,

7 a longitudinal section through an arrangement with the bracket 6 wherein in the longitudinal section one of the jacking screws can be seen, with which the holder is pressed from a base and thus kept in a corresponding minimum distance,

8th 1 is a schematic longitudinal section through an assembly having an annular base and an annular support, the support having an annular groove in which a corresponding annular projection or sliding blocks of the base engage;

9 a plan view of an annular holder for holding a plurality of measuring sensors,

10 a plan view of an annular support with a held measuring sensor whose lead is held using three wire holders on the surface of the annular support,

11 a longitudinal section through the annular holder and one of the line holder 10 who keeps the connection line,

12 an end portion of an arrangement with a connecting lead of a measuring sensor, wherein the connecting lead has an additional sheath of magnetic or magnetizable material, and

13 schematically a side view of a portion of a first part with a measuring scale in the form of a linear incremental scale and on a second part which is linearly movable in the linear axis along the incremental scale relative to the first part.

This in 1 illustrated coordinate measuring machine (CMM) 211 in portal construction has a measuring table 201 on, over the pillars 202 . 203 are arranged movably in the Z direction of a Cartesian coordinate system. The columns 202 . 203 form together with a cross member 204 a portal of the KMG 211. The cross member 204 is at its opposite ends with the pillars 202 respectively. 203 connected. For example, electric motors not shown cause the linear movement of the columns 202 . 203 in the Z direction. It is z. B. each of the two columns 202 . 203 associated with an electric motor.

The crossbeam 204 is with a cross slide 207 combined, which z. B. air bearing along the cross member 204 movable in the X direction of the Cartesian coordinate system. The current position of the cross slide 207 relative to the cross member 204 can be based on an incremental scale 206 be determined. The movement of the crossbeam 204 in the X direction z. B. driven by a further electric motor. At the cross slide 207 is a vertically movable quill 208 stored at its lower end via a mounting device 210 and a turning device 205 having an integrated rotational position measuring arrangement (not in 1 shown), with a coordinate measuring device 209 connected is. The coordinate measuring device 209 has an angled probe 215 on, on which a stylus 111 with tactile ball 121 is arranged detachably. The coordinate measuring device 209 can be driven z. B. by another electric motor relative to the cross slide 207 in the Y direction of the Cartesian coordinate system. By the electric motors of the CMM, the stylus 111 in the area below the cross member 204 be moved in almost any position. Furthermore, the rotating device 205 the probe 215 turn the Y-axis so that the stylus 111 can be aligned in different directions.

On the measuring table 201 is a turntable 217 (ie a rotating device) with integrated rotational position measuring arrangement (not in 1 shown). The arrangement is to be understood schematically. In practice, the turntable 217 be arranged at a position in which the stylus 111 or another stylus on the turntable 217 arranged workpiece (not shown) as freely as possible from all sides in the radial direction of the axis of rotation of the turntable 217 , ie in as much as possible work orientations, can touch. The same applies as far as possible over the entire height range along the extent of Rotary axis of the rotary device 217 for all working positions of the stylus.

The coordinate measuring machine in gantry design is only one embodiment of a coordinate measuring machine. It is therefore also coordinate measuring machines of other construction, for example, gantry design or articulated arm construction, can be used, which may also have moving devices for linear motion and / or rotational movement.

To z. B. the moving device of a rotating device (for example, the turntable 217 or the rotary device 205 out 1 In order to investigate motion errors, a calibration body (eg a cylinder or a rod with two spherical regions spaced apart in a longitudinal direction of the rod) may be attached to the rotating device (for example the turntable) 217 ) are arranged so that the longitudinal axis of the cylinder or the rod coincides with the axis of rotation of the turntable. Furthermore, a separate measuring device with a plurality of sensors (for example, distance sensors, which measure the distance to the calibration body in different rotational positions of the calibration body) can be used to measure the movement errors of the rotary device. Preferably, the sensors and also at least one rotational position sensor of the rotary device are connected to the control of the coordinate measuring machine, so that the measured values of the sensors and also of the at least one rotational position sensor can be detected by the controller and assigned to one another. Each measured rotational position corresponds to at least one measured value of one of the sensors. Conversely, each of the measured values of the sensors is assigned to a rotational position.

For determining motion errors of a moving device for movement along a linear axis (for example, along one of the coordinate axes of the above-mentioned Cartesian coordinate system) can be proceeded accordingly. For example, at the second part, which is rectilinearly movable relative to the first part, a calibration body is arranged which moves with the second part. In this case, the movement errors are measured with a plurality of sensors, which are attached to the first part. Similar to the German patent application DE 10 2013 216 093.3 described can now be determined a favorable location for the at least one measuring sensor, which measures the position and / or the movement of the second part relative to the first part.

The following are examples of measuring arrangements that measure the rotational position or rotational movement of a rotating device. For example, the measuring arrangement can be integrated in the rotating device, so that the measuring arrangement is completely enclosed by components of the rotating device and thus protected against external influences (see 3 ).

The top view of a measuring arrangement in 2 shows a material measure 75 , which is an incremental scale with a variety of line-shaped markings 82 extending in the embodiment in the radial direction to a rotation axis D of the rotating device, that is perpendicular to the rotation axis D. Alternatively, the marks on the outer periphery of a circular in cross section body or on the inner circumference of a body with a circular recess. Ideally, the angular distance of the line-shaped markings 82 constant, eg with 360 markings, the angular distance would therefore be 1 °. Such an arrangement of line-shaped markings of a material measure can also be referred to as a pitch disk.

2 further shows an X-axis and a Y-axis of a coordinate system, wherein the X-axis and the Y-axis are perpendicular to each other and each perpendicular to the rotation axis D. Furthermore, an optical measuring sensor 74 shown in the axial direction of the axis of rotation D above the pitch circle disc, that is in the direction of the 2 in front of the pitch disc, is arranged. In practice, more than one such sensor may be present. The optical detection range of the measuring sensor 74 Contains one or more of the line-shaped markings 82 simultaneously. The detection area is in particular the area with about five marks 82 which lie immediately below the rectangular area which is in 2 the measuring sensor 74 represents. With the rotary motion of the rotary device go through the markings 82 one after the other the detection area. A first part of the rotating device carries the pitch disk, while the measuring sensor 74 is arranged on a second part of the rotating device. The first and the second part of the rotating device are rotatable relative to each other about the rotation axis D.

Other designs of measuring scales are possible, in particular with magnetic markings. In this case, the measuring sensor does not optically detect line marks, but the magnetic field that changes due to the passing of magnetic marks.

3 shows a longitudinal section through a rotating device (eg the turntable 217 out 1 ) with integrated measuring arrangement. This is a particularly low-build embodiment, ie the extension along the Rotary axis R is particularly small. The circular disk 75 of the measuring system, which is, for example, the pitch plate according to 2 can act is at the lower end of a rod-shaped carrier 73 of the rotor 51 (first part of the rotating device). The rotor 51 is about a pivot bearing 44 , which is a ring bearing, with the stator 53 (second part of the rotating device) rotatably coupled. From the stator 53 seen from radially inward direction of rotation R, ie in an interior of the stator 53 , two with respect to the rotation axis R are opposite measuring sensors 74a . 74b arranged. The stator 53 is z. B. on the measuring table of the coordinate measuring machine in 1 ,

The representation in 3 is to be understood schematically, since the dimensions of the components may be configured differently in practice. In addition, other components, such as connecting cables of the measuring sensors 74 , in 3 not shown.

The measuring sensors 74 be in the embodiment of 3 from a common annular holder 72 held, whose axis of symmetry is arranged coaxially with the axis of rotation R. The holder 72 in turn, is by a likewise annular base 71 supported, whose axis of symmetry is also coaxial with the axis of rotation R.

Such an arrangement of an annular base and an annular support with axes of symmetry coaxial with the axis of rotation of the moving device may also occur in other embodiments of the rotating device. In this case, the at least one measuring sensor held by the holder can be aligned in a direction parallel to the axis of rotation on the measuring standard, but may alternatively be e.g. be aligned in the radial direction of the axis of rotation on a measuring scale, the e.g. is arranged on the outer circumference of a body with a cylindrical outer surface.

In the case of the embodiment of 3 becomes the annular holder 72 solely by magnetic forces on the annular base 71 held and thus from the base 71 carried. At the same time, the magnetic forces fix the holder 72 in the set rotational position of the holder 72 with respect to the axis of rotation R. By rotation of the holder 72 around the axis of rotation R, this rotational position and thus also the holding position of the at least one measuring sensor 74 changed and thereby adjusted.

Unlike in 3 illustrated, the rotating device can not two with respect to the rotation axis R arranged opposite each other measuring sensors 74a . 74b exhibit. Rather, only one of the measuring sensors can 74 be present or it may be other or other measuring sensors, for example, in addition to the measuring sensor 74a , to be available. Preferably, further measuring sensors are also of the common holder 72 held. In a further variant, different measuring sensors carried by the base do not have a common mounting but each have a separate mounting. This makes it possible to arrange the measuring sensors individually at arbitrary angular positions about the axis of rotation R.

At the in 3 As shown, a rotary device construction makes it possible to measure the movement error of the rotary device by acting on the rotor 51 a calibration is arranged and measured in different rotational positions deviations from the ideal position of the calibration. The construction has the advantage that the material measure of the measuring arrangement (here: the partial disc 75 ) with the rotor 51 is connected, however, protrudes downwards. It can therefore for the at least one measuring sensor a favorable measuring location below the pivot bearing 44 be determined, although the motion error only above the pivot bearing 44 is measured.

In 4 is a first part 100 illustrated, which is rotatably mounted about a rotation axis R. With a not or not completely in 4 illustrated second part, relative to the first part 100 is rotatable about the rotation axis R, are a base 101 , a holder 102 and one of the bracket 102 held measuring sensor 104 connected. The base 101 may be an area of the second part or, for example, as in the case of 3 Turning device shown is the case, be present in addition to the second part and connected to this. The base is made of a magnetic or magnetizable material. This is indicated by the hatching lines running from top left to bottom right.

The holder 102 is in 4 at a short distance from the upwardly facing surface of the base 101 shown. This distance can be determined by an in 4 Spacers not shown to be guaranteed as a minimum distance. But it is also possible that to the base 101 facing surface of the bracket 102 full surface on the surface of the base 101 abuts when the bracket 102 is in the desired stop position.

The holder 102 has an area 105 made of magnetic or magnetizable material. This is indicated by hatching lines running from top right to bottom left. In particular, this area exists 105 made of magnetic material, while the base 101 made of magnetizable material. If the magnetic field arrives 105 near the base 101 , that will magnetizable material of the base 101 magnetized, so that also forms there a magnetic pole. As a result, the magnetic field 105 and thus the holder 102 by magnetic forces at the base 101 fixed.

Preferred dimensions, the holder 102 an annular area 106 on, which is around the area 105 around, or two areas 106 on, which revolve around the rotation axis R and thereby the area 105 between them. In the longitudinal section of 4 are right and left of the area 105 shown parts of the annular region 106 or the two areas 106 recognizable. The area 106 or the areas 106 is / are made of a non-magnetic material or a nearly non-magnetic material, such as brass. Therefore, the magnetic field lines become within the range 105 along the longitudinal extent of the area 106 or the areas 106 led and within the range 105 bundled. Preferably, the area extends 106 or extend the areas 106 up to the surface of the holder 102 that the base 101 is facing. As a result, the magnetic field lines are in the range 105 on the surface of the holder 102 bundled and form a strong, homogeneous magnetic field for fixing the bracket 102 at the base 101 ,

Another optional feature of in 4 illustrated embodiment of the holder 102 represents a material area 107 of magnetizable material having a greater magnetic susceptibility than the material in the range 105 having. In the material area 107 Therefore, the magnetic field lines are also bundled, but also in the direction transverse to the pressing direction of the holder 102 to the surface of the base 101 diverted. Starting from the contact area between the base 101 and the holder 102 or starting from a point on the surface of the base 101 , the holder 102 is closest to, extend the magnetic field lines with respect to the representation in 4 first vertically up through the area 105 , enter the material area 107 a, are deflected in this right and left and no longer run bundled outside of the material area 107 back to this base 101 , As a result, the location area in which the measuring sensor 104 at the top of the bracket 102 is located, almost free of the magnetic field, the holder 102 at the base 101 holds.

The measuring sensor 104 is on the about the rotation axis R extending outer circumference of the first part 100 directed. At this outer circumference is the material measure 109 , eg an annular incremental scale. The measuring sensor 104 is, for example, an optical sensor, which detects the parallel to the rotation axis R extending line-shaped markings of the incremental scale and, for example, generates a corresponding pulse signal when one of the markings at the detection range of the measuring sensor 104 moved past. Through a pointed area of the measuring sensor 104 is in 4 indicated where the detection range of the measuring sensor 104 can be located. As an alternative to a measuring sensor with an optical detection of the movement of the first part, for example, a measuring sensor can be provided with a magnetic detection of the rotational movement of the first part.

The right of the axis of rotation R part of the representation in 4 also illustrates a possible arrangement of the first part and the second part movable relative to the first part, the relative movement being rectilinear in a direction perpendicular to the plane of the figure 4 takes place. For example, the first part could move or the second part could move with the base 101 , the bracket 102 and the measuring sensor 104 move (or both parts). The same applies to the illustration in FIG 5 , The parts and elements illustrated there to the right of the axis of rotation R could be movable relative to one another in the direction that runs in a straight line perpendicular to the plane of the figure.

In the 5 The arrangement shown has a first part 150 on as well as a base 151 which is connected to a second part or is part of the second part. The first part 150 and the second part with the base 151 are relative to each other about the axis of rotation R (left in 5 ) rotatable. At the base 151 facing side of the first part 150 is a material measure 159 arranged on the base 151 fixed measuring sensor 154 is directed. The measuring standard 159 and the measuring sensor 154 allow the measurement of the relative position and / or relative movement of the first and second parts.

The measuring sensor 154 is from a bracket 152 held by magnetic forces at the base 151 is held and thereby the measuring sensor 154 at the base 151 fixed. The base 151 has an area 155 made of magnetic or magnetizable material which is fitted with magnetic or magnetizable material of the holder 152 cooperates such that the magnetic forces the holder 152 to the base 151 press it.

The arrangement according to 5 can also be performed vice versa, ie the first part with the material measure is arranged above the second part with the base. Such an arrangement arises when 5 looking upside down.

When ordering from the base 101 and the holder 102 with the measuring sensor 104 in 4 and in the arrangement of the area 155 with the bracket 152 and the measuring sensor 154 in 5 each may be an annular arrangement, ie both the base 101 or the base 151 (and optionally also the area 155 ) as well as the bracket 102 or the holder 152 may be annular and extend around the axis of rotation R, either as a ring segment or as a self-contained circumferential ring. Again, alternatively, only the holder 102 or The holder 152 be ring-shaped, but not the base 101 or the magnetic or magnetizable region 155 , On features of an annular support or an annular base is still based on 8th respectively. 10 received. These features can also be used when mounting 102 out 4 or the holder 152 out 5 as well as at the base 101 out 4 and the area 155 the base 151 out 5 be provided.

The in plan view in 6 illustrated bracket 182 has a polygonal outer contour and is designed plate-shaped. Deviating from the hexagonal polygonal outline, other configurations of a plate-shaped holder can be selected, for example with rounded corners.

The holder 182 holds a measuring sensor 184 , Furthermore, the holder has 182 three, preferably at the corners of an imaginary equilateral triangle arranged through threaded holes 186a . 186b . 186c on.

As 7 based on the threaded hole 186b shows, in each of the threaded holes 186 a screw 188 be screwed in so that the screws 188 as a spacer to ensure a minimum distance to the surface of a base 181 serve. By turning the screws 188 the minimum distance is set. When the bracket 182 by magnetic forces to the base 181 is pressed, therefore, by setting the minimum distance, the maximum possible, acting in the set minimum distance magnetic forces can be adjusted. By increasing the minimum distance, therefore, the magnetic forces can be reduced, so that a complete removal of the holder is facilitated by the base and / or the holder can be brought into a different position relative to the base. In the case of 7 For example, at an increased minimum distance, the holder 182 be moved perpendicular to the plane of the figure. In other embodiments of a spacer with screws as spacers, a different number of screws and tapped holes may be present. However, the principle of pushing off and ensuring the minimum distance is the same.

In particular, not only with respect to the embodiment of the 7 , the bracket may have threaded holes, which are used both for the attachment of the measuring sensor to the bracket as well as for the distance adjustment. For example, the measuring sensor is attached to the bracket with two screws by screwing the two screws into a threaded hole. The same screws can act on the spacer (s). By turning the screws, the distance to the base is adjusted, whereby the screws fix the measuring sensor in the various possible rotational positions, which correspond to different distances, respectively on the holder.

For example, a leaf spring stack may be disposed between the bracket and the base, e.g. B. between the measuring sensor and the screw head of one or more screws. In this case, an adjustment of the orientation of the measuring sensor relative to the base and thus relative to the measuring standard is possible, in particular by means of a single adjusting screw or a plurality of adjusting screws. By turning the single adjusting screw or at least one of the adjusting screws then the orientation of the measuring sensor can be adjusted. The at least one adjustment cover can have a further function, for. B. as a spacer and / or as a fastening screw for mounting the measuring sensor to the holder.

8th shows an annular holder 32 extending around the rotation axis R of the assembly. In particular, the illustrated base 31 be configured annular with respect to the axis of rotation R. However, it is also possible that the two right and left in 8th represented areas of the base 31 are separate areas that do not extend annularly about the axis of rotation R.

The annular holder 32 forms at the base 31 side facing an annular, extending around the axis of rotation R around groove 39 out, into which a projecting area 38 the base 31 intervenes. The in 8th illustrated distance between the projecting area 38 and the bottom of the groove 39 can be ensured by a spacing device, not shown. Alternatively or additionally, the distance during operation of the measuring arrangement (the at least one measuring sensor is in 8th not shown and is located, for example, at the top of the annular holder 32 ) become zero, ie the projecting area 38 lies on the bottom of the groove. The annular holder 32 is due to magnetic forces at the base 31 fixed. The magnetic forces are generated by the interaction of a magnetic or magnetizable region 37 the holder 32 with a magnetic or magnetizable area 35 in the projecting area 38 the base 31 generated.

Not only at the in 8th arrangement shown, but also for example not necessarily annular shapes as in 4 and 5 The arrangement of the magnetically interacting areas of the base on the one hand and the holder on the other hand, not as shown. In the illustration, the magnetic forces in the axial direction, which is parallel to the rotation axis R, attractive. These magnetically interacting regions can alternatively be arranged one behind the other in the radial direction, so that the magnetic forces act attractively in the radial direction. For example, in the arrangement in 4 the base are radially inside or radially outside of the holder.

In the case of a movement device with mobility in the direction of a linear axis, the magnetically interacting regions of the base, on the one hand, and the mounting of the measuring sensor, on the other hand, can be arranged one behind the other in each direction, which runs transversely to the direction of the linear axis.

To put on the arrangement in 8th come back, in a variant, the annular holder 31 the projecting area 38 that form into a groove 39 the annular base engages when the holder is fixed to the base during the measuring operation of the measuring arrangement.

The following configurations are possible: The protruding area 38 can also be annular, the axis of rotation R be configured circumferentially. Alternatively, a plurality of the projecting portions 38 be available as nuts. It is even possible that the holder is not designed annular. The annular groove 39 nevertheless allows adjustment of the desired holding position in a simple manner by the holder 31 with the projecting area 38 inside the groove 39 is moved around the axis of rotation R or by the bracket 31 with the projecting area 38 out of the groove 39 is removed and at another desired holding position back into the groove 39 is introduced. A non-annular holder has the advantage, for example, that temporarily several of the holders, each holding a measuring sensor, can be brought into a holding position. Then, a measuring operation with several eg redundant measuring sensors take place and at least a part of the measuring sensors can then be removed again.

The design in 9 shows a holder 32 , for example, the annular holder 32 out 8th can be, with the above in 8th lying top in 9 is shown. In any case, from the annular holder 32 in 9 in each case one measuring sensor at two positions which are opposite one another with respect to the axis of rotation 34a . 34b held, with the measuring sensors 34 eg each with two screws 30 on the annular holder 32 are screwed. The axis of rotation pierces the intersection point M of the two in 9 shown dash-dotted lines and runs perpendicular to the plane of the figure.

The annular holder 32 also has a plurality of passage openings 36a . 36b . 36c . 36d on, of which, for example, two through holes 36a . 36b that z. B. opposed to each other with respect to the axis of rotation, represent threaded holes, which are used for jacking screws in the manner described by 7 was explained. The other two through holes 36c . 36d are used, for example, for inserting a tool during assembly of the overall arrangement.

In particular if (as in one embodiment of the in 8th arrangement shown), both the base and the holder are annular, the arrangement is well suited for holding and fixing of at least two measuring sensors, the relative position and / or the distance of the measuring sensors can be fixed, in particular by the design of the holder can be fixed. For example, this is at the in 9 illustrated arrangement with two measuring sensors 34 the case.

The position for the measuring sensors 34 is eg through threaded holes for the screws 30 fixed. As mentioned, but the associated base to which the holder is fixed, not necessarily be annular.

Unlike in 8th illustrated, the fixation of the holder to the base can alternatively or in addition to a fixation by magnetic forces in other ways be realized, for example by vacuum and / or in a mechanical manner. For example, a sliding block in the annular groove 39 be pressed by spreading its outer surfaces mechanically to the edges of the groove, so that the sliding block is fixed non-positively.

In the case of the measuring sensors arranged opposite one another with respect to the axis of rotation (such as, for example, the measuring sensors 34 in 9 ) can be adjusted by adjusting the rotational position of the annular support with respect to the axis of rotation and by fixing the holder to the base in this rotational position as described above, a favorable holding position for the opposite measuring sensors.

The top view in 10 on an annular object 42 shows a measuring sensor 44 with a connection cable 48 , So that the connection line 48 is not disturbing, is the connecting cable 48 by means of a plurality (here: three) wire holders 49 on the surface of the annular article 42 held. In particular, each of the line holders 49 have a magnetic or magnetizable material and by magnetic forces on the likewise magnetic or magnetizable object 42 being held. At the object 42 it may be an embodiment of the holder or the base. In the case of the base of the measuring sensor is preferably fixed by a holder, not shown, by magnetic forces on the base.

A particular embodiment of the conductor holder 49 is out 11 recognizable. The conductor holder 49 has a housing 50 in which a magnet 46 is included. As an optional feature may further include the housing 50 have one or more slots through which a holding means for holding the connecting cable 48 extends. In the in 11 illustrated case, two such slots are provided, in which an annular retaining means 47 through the one slot in the housing 50 into and out of the housing through the other slot 50 is led out again. Either the connecting line through the annular holding means 47 passed through or, more preferably, is the annular retaining means 47 a cable tie around the outer circumference of the connecting cable 48 is led around and closed. In particular, it may be a cable tie, which has a closure in a conventional manner, which allows a tightening of the cable tie on the housing and thus holding the connecting cable by clamping action.

The magnet 46 in the case 50 is in interaction with the magnetic or magnetizable material of the annular article 42 , For example, the material of the annular object 42 ferromagnetic.

12 shows an additional coat 61 for the connection cable 48 a measuring sensor. The coat 61 is preferably made of a magnetic plastic, for example of a plastic, in which a magnetic or magnetizable material (eg in powder form) is bound. Powders made of hard ferrite or rare earths are suitable for incorporation into elastic plastics.

Preferably, the additional jacket 61 made of an elastic material and has a slot 62 on, extending in the longitudinal direction of the connecting cable 48 extends when this in the mantle 61 is included. The connection cable 48 gets into the coat 61 introduced by the mantle 61 is elastically deformed against its elastic restoring forces until the slot 62 so far extended that the connecting line 61 in the recording room 63 of the coat 61 can be introduced. Due to the elastic restoring forces, the slot closes 62 again whole or in part and the connecting line 48 will be in the recording room 63 held.

As in 12 shown has the coat 61 at least one plane or complementary to the surface shape of the holder shaped surface, so that the flat surface (on a corresponding planar surface of the holder) or the complementarily shaped surface of the shell 61 can rest on the surface of the holder over its entire surface and is thereby fixed by the magnetic forces between the holder and the magnetic or magnetizable material of the jacket 61 Act.

Since the coat 61 merely requiring a surface as a bearing surface to the surface of the holder, the jacket may have a different cross-sectional shape than in 12 shown. For example, the mantle above can have a round surface. In the 12 shown, in essence (except for the slot 62 ) square cross-sectional shape is therefore not mandatory.

Generally, not only with respect to the embodiments shown in the figures, the magnetic forces holding the holder to the base need not be applied solely by the materials of the base, on the one hand, and the holder, on the other hand. Rather, e.g. In addition, an electromagnet may be provided and / or at least one additional body of magnetic material may be provided. As a result, the magnetic forces at the place where the holder is to be fixed to the base, reinforce.

Alternatively to that with reference to 12 described jacket may be provided for attaching the connecting lead of a measuring sensor to the holder, in particular on an annular support, a sheath which is pulled over the connecting line, so that it surrounds at least a portion of the connecting line circumferentially closed circumferentially. For example, the envelope may be embodied on its outer surface as part of a hook-and-loop fastener, the other part of the hook-and-loop fastener being fastened to the surface of the holder, eg on the edge of the holder, in particular on the outer edge of the surface of an annular holder.

13 shows a section of a first part 301 , where the first part 301 to the right and / or may extend farther to the left than it does in 13 is shown. A second part 304 is in the horizontal direction of the 13 (which in practice is also a horizontal direction or another direction) is rectilinearly movable on the first part 301 stored.

At the top of the in 13 recognizable front of the first part 301 is an incremental scale 206 provided as a material measure. The vertically extending markings in the figure with constant distances from each other are recognizable. In the middle part of the 13 however, these are the marks and also the top of the first part 301 represented by dashed lines, since the second part 304 covers this area in the direction of view.

The second part 304 has a base 311 on, which on its underside a holder 312 carries, which in turn a measuring sensor 314 holds. The holder 312 can in the direction of movement of the relative movement between the first part 301 and the second part 304 be moved and in the desired holding position relative to the base 311 be fixed, for example by magnetic forces similar to the arrangement in 4 and 5 , In this way, the measuring sensor 314 be brought into a favorable holding position. In every possible stop position is the measuring sensor 314 capable of relative movement of the first part 301 and the second part 304 the relative movement of the parts 301 . 304 to measure, for example, in each case by a pulse signal is generated when one of the bar-shaped markers of the incremental scale 206 the detection range of the measuring sensor 314 happens.

In a variant of in 13 As shown, the base does not extend along the incremental scale, and thus not along the direction of movement, but in a direction transverse to the direction of movement. Accordingly, the support can be positioned in the direction transverse to the direction of movement in various holding positions along the base and held by magnetic forces on the base. Preferably, a holding position is then set in which compensate for rotational and translational motion errors. In this case, the position of the incremental scale can also be set in the direction transverse to the direction of movement, so that the measuring sensor held by the holder can generate signals for determining the respective position in the direction of movement by reading the incremental scale.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of 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.

Cited patent literature

• EP 2013/056123 [0023]
• DE 102013216093 [0023, 0023, 0095]
• EP 1923670 A1 [0056]

Claims (15)

Measuring arrangement for measuring a relative position and / or a relative movement of a first part ( 51 ) and one relative to the first part ( 51 ) about a rotational axis (R) rotatable second part ( 53 ), wherein the measuring arrangement comprises: • a material measure ( 75 ), the first part ( 51 ) or with the first part ( 51 ), at least one measuring sensor ( 74a . 74b ), the second part ( 53 ) is arranged or can be arranged in such a way and during a measuring operation of the measuring arrangement in such a way with the material measure ( 75 ) cooperates, that measuring signals of the measuring sensor ( 74a . 74b ) Information about a rotational position of the measuring sensor ( 74a . 74b ) with respect to the axis of rotation (R) and / or information about a rotational movement of the measuring sensor ( 74a . 74b ) about the axis of rotation (R) and thus a determination of the relative position and / or the relative movement of the first part ( 51 ) and the second part ( 53 ), • a bracket ( 72 ) used to hold the measuring sensor ( 74a . 74b ) with the measuring sensor ( 74a . 74b ), or that is part of the measuring sensor, and • a base ( 71 ) for fixing the holder to the measuring sensor held by the holder ( 74a . 74b ), whereby the basis ( 71 ) is attached to the second part during operation of the measuring assembly, wherein • the support is configured as a circular ring or annulus segment extending around the rotation axis (R) containing a center of the annulus or annulus segment; Holder either in one of different rotational positions about the axis of rotation at the base ( 71 ) is positionable, so that the holder in the respective rotational position at the base ( 71 ) and so that the rotational position and thus a position that the measuring sensor ( 74a . 74b ) during operation of the measuring device relative to the second part occupies, is adjustable. Measuring arrangement according to the preceding claim, wherein the holder ( 32 ) Holding elements ( 30 ), in which at least two by the holding elements ( 30 ) predetermined positions of the holder ( 32 ) one measuring sensor each ( 34a . 34b ) for obtaining the information about the rotational position of the measuring sensor ( 34a . 34b ) and / or the rotational movement of the measuring sensor ( 34a . 34b ) is durable and / or held, wherein the at least two predetermined positions in a direction along the measuring graduation are spaced from each other. Measuring arrangement according to one of the preceding claims, wherein for measuring a relative rotational position and / or a relative rotational movement by the measuring sensor ( 74a . 74b ) the material measure ( 75 ) extends over a course of a circle or a circle segment and the base ( 71 ) is designed as a circular ring or as a circular ring segment. Measuring arrangement according to one of the preceding claims, wherein the base ( 101 ; 151 ) a contact surface for pressing the holder ( 102 ; 152 ) in the different rotational positions, wherein the contact surface at a constant distance from the material measure ( 75 ). Measuring arrangement according to one of the preceding claims, wherein the holder by magnetic forces in a pressing direction to the base ( 71 ; 101 ) is pressed, Measuring arrangement according to the preceding claim, wherein the holder ( 102 ) a first material ( 105 ), which is a magnetic or magnetizable material having a first magnetic susceptibility, and a second material ( 106 ), which is a material having a second magnetic susceptibility, wherein the first material ( 105 ) in interaction with a magnetic or magnetizable material of the base ( 101 ) causes at least a portion of the magnetic forces that the holder ( 102 ) in the pressing direction to the base ( 101 ), wherein the second magnetic susceptibility is smaller than the first magnetic susceptibility and wherein the second material ( 106 ) on opposite sides of the first material ( 105 ), so that the first material ( 105 ) viewed in a transversely to the pressing direction transverse direction of the second material ( 106 ) is included. Measuring arrangement according to one of the two preceding claims, wherein the holder ( 102 ) a first material ( 105 ), which is a magnetic or magnetizable material having a first magnetic susceptibility, and a third material ( 107 ), which is a magnetic or magnetizable material having a third magnetic susceptibility, wherein the third magnetic susceptibility is greater than the first magnetic susceptibility and wherein - when the holder ( 102 ) by the magnetic forces to the base ( 101 ) is pressed and thereby the bracket ( 102 ) at the base ( 101 ) - the first material ( 105 ) closer to the base ( 101 ) is located as the third material ( 107 ) and the third material ( 107 ) between the measuring sensor ( 104 ) and the first material ( 105 ) is located. Measuring arrangement according to one of the three preceding claims, comprising a spacing device ( 186 . 188 ), which at least one spacer ( 188 ), which has a minimum distance between magnetic or magnetizable materials of the base ( 181 ) on the one hand and the bracket ( 182 ), on the other hand, wherein the magnetic or magnetizable materials at least cause some of the magnetic forces affecting the mount ( 182 ) in the pressing direction to the base ( 181 ), and wherein a dimension of the spacer between the base ( 181 ) and the bracket ( 182 ) is adjustable, so that the minimum distance is adjustable. Measuring arrangement according to one of the preceding claims, wherein the measuring arrangement comprises a guide ( 38 . 39 ), by which a possible relative movement of the holder ( 32 ) and the base ( 31 ), wherein by carrying out the relative movement, the holder ( 32 ) Can be brought into the various holding positions. Measuring arrangement according to the preceding claim, wherein the guide ( 38 . 39 ) by an annular groove ( 39 ) in the holder ( 32 ) or is formed in the base into which a projecting area ( 38 ) the base ( 31 ) or the bracket engages. Coordinate measuring machine ( 211 ), comprising the measuring arrangement according to one of the preceding claims, wherein the coordinate measuring machine ( 211 ) the first part ( 210 ) and the relative to the first part rotatable second part ( 209 ) having. Turning device ( 217 ; 205 ) for rotating a workpiece or a coordinate measuring device ( 209 ) in an arrangement for measuring coordinates of the workpiece, wherein the rotating device ( 217 ; 205 ) the measuring arrangement according to one of the preceding claims, the first part ( 218 ; 210 ) and the second part ( 219 ; 209 ), the second part ( 219 ; 209 ) relative to the first part ( 218 ; 210 ) about an axis of rotation of the rotary device ( 217 ; 205 ) is rotatable and wherein the workpiece or the coordinate measuring device at the first part ( 218 ; 210 ) or the second part ( 219 ; 209 ) can be arranged. Method for operating a measuring arrangement that is configured, a relative position and / or a relative movement of a first part ( 51 ) and one relative to the first part ( 51 ) about a rotational axis (R) rotatable second part ( 53 ), wherein: at least one measuring sensor ( 74a . 74b ) of the measuring arrangement, which at the second part ( 53 ) is arranged, in such a way with a material measure ( 75 ), which in the first part ( 51 ) is formed or which with the first part ( 51 ), cooperates, that measuring signals of the measuring sensor ( 74a . 74b ) Information about a rotational position of the measuring sensor ( 74a . 74b ) with respect to the axis of rotation and / or information about a rotational movement of the measuring sensor ( 74a . 74b ) about the axis of rotation (R), and from the information the relative position and / or the relative movement of the first part ( 51 ) and the second part ( 53 ), wherein before the generation of the measurement signals: 74a . 74b ) with a holder ( 72 ) is or is or the holder is already part of the measuring sensor, so that the holder ( 72 ) the measuring sensor ( 74a . 74b ), the holder ( 72 ) is configured as a circular ring or as a circular ring segment which extends around the axis of rotation (R), which contains a center of the circular ring or of the circular ring segment, 72 ) optionally in one of different rotational positions about the axis of rotation (R) at the base ( 71 ) is positioned so that the bracket ( 72 ) in the respective rotational position at the base ( 71 ) and so that the rotational position and thus a position that the measuring sensor ( 74a . 74b ) during a measuring operation of the measuring arrangement relative to the second part ( 53 ) is set, is set. Method according to the preceding claim, wherein magnetic or magnetizable materials of the base ( 71 ) on the one hand and the holder on the other hand cause at least a part of the magnetic forces, the holder in a pressing direction to the base ( 71 ) and thereby the bracket on the base ( 71 ). Method according to one of the two preceding claims, wherein a connecting line ( 48 ) of the measuring sensor ( 44 ) with a magnetic or magnetizable material ( 61 ) and / or comprises a magnetic or magnetisable material and wherein a portion of the connecting line ( 48 ) by magnetic forces of the magnetic or magnetizable material ( 61 ) on the bracket or the base ( 71 ) is fixed.

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