DE102012103934B3 - Optical measuring head for coordinate measuring apparatus, has handle coupled with tubular interface part in selective position, and rod connected to interface part through bolt, which is movably supported in over-sized hole - Google Patents

Abstract

The head has a handle coupled with a tubular interface part (56) in a selective position (66). The handle is decoupled from the interface part when the interface part is in another position (64). The handle is coupled with the interface part through a rod (78), where a rotational movement of the handle is converted into a translational movement (62) of the interface part along a movement axis (60). The rod is connected to the interface part through a bolt (82), which is movably supported in an over-sized hole such as slot (80).

Description

The present invention relates to an optical measuring head for a coordinate measuring machine, which has a measuring head interface for releasably receiving the measuring head, with a sensor part having a sensor housing, in which a light source is arranged, which is able to generate a linear light pattern on a measuring object, and an adapter portion having a first interface, a second interface, and an adjustable handle, the first interface being complementary to the probe interface for reproducibly attaching the probe to the coordinate measuring machine, and wherein the sensor housing, the second interface, and the adapter portion form a structural unit.

Such a measuring head is for example off WO 2009/016185 A1 known.

A coordinate measuring machine is a device that serves to metrologically detect geometric dimensions and / or even the entire spatial shape of a workpiece. Typically, a coordinate measuring machine has a measuring head that can be moved within a measuring volume to a plurality of different positions relative to the measuring object. The measuring head has a sensor with which the surface of the test object can be detected selectively or in areas. From the position of the measuring head within the measuring volume and from the measured values of the sensor, it is then possible to determine spatial coordinates which represent the spatial form of the measured object. Coordinate measuring machines are used in particular for the quality control of industrially manufactured workpieces.

EP 0 790 478 A2 discloses a coordinate measuring machine with a tactile measuring head. The measuring head carries a stylus, which serves to touch a selected measuring point on the measuring object. Upon touching, the stylus is deflected out of its rest position, which is detected by the sensor in the probe. The spatial coordinate of the probed measuring point can be determined by the deflection of the stylus and the position of the measuring head in the measuring volume. A peculiarity of in EP 0 790 478 A2 disclosed coordinate measuring machine is that the orientation of the stylus relative to the measuring head using the drives of the coordinate measuring machine can be changed. This makes it possible, for example, to measure a horizontally extending bore on a measurement object, without interchanging a stylus specially designed for this measurement task.

In a manual from Renishaw plc., Wotton-under-Edge, Gloucestershire GL 12 8JR, United Kingdom a probe (= tactile measuring head) for a coordinate measuring machine under the name MIH is described, in which the orientation of the stylus relative to the probe in two axes manually adjustable. The operator must first loosen a clamping screw and then adjust the orientation of the stylus relative to the stylus by manually moving the stylus to the desired orientation and then retightening the locking screw.

EP 0 523 906 A1 and DE 629 21 896 T2 disclose a probe in which the orientation of the stylus can be adjusted by motor. The stylus is attached here to a rotatable divider. The plate is connected to a drive shaft, which can be rotated and moved in the axial direction. At rest, the current rotational position of the plate is determined by a kinematic bearing. To this end, Teller has several balls that engage in a resting state in defined pairs of rollers. To adjust the rotational position of the plate is disengaged by means of the axial movement of the drive shaft from the kinematic mounting and brought about the rotational movement of the shaft in the desired rotational position. Subsequently, the plate is engaged again, wherein the balls engage the plate in the defined pairs of rollers, so that the rotational position is determined kinematically again.

In addition to tactile probes (probes) there are now numerous applications in which optical probes are used on a coordinate measuring machine. In a product brochure of the applicant, an optical measuring head is known, which is known under the name "EagleEye". The EagleEye probe has a sensor section that houses a light source. The light source generates a line-shaped light figure on the surface of a measurement object. A camera sensor arranged obliquely to the light source can determine spatial coordinates for the measuring points illuminated with the light figure on the basis of trigonometric relationships. For an optimal measurement, it is advantageous if the line-shaped light pattern in each case extends transversely to a structural edge of the measurement object. Therefore, the EagleEye measuring head works with three motorized rotary axes with corresponding rotary drives. The rotary actuators make it possible to place the linear light figure almost anywhere on a measuring object. The rotary actuators for three axes of rotation are, however, difficult and expensive, since a suitable power supply and control is required for each drive.

DE 102 60 670 A1 describes an alternative to the EagleEye measuring head, wherein the third axis of rotation is designed as a non-driving hinge. In addition, the coordinate measuring machine has a clamping device, in which the sensor part with the light source can be clamped while the coordinate measuring machine moves the measuring head around the clamping point by means of the machine drives in a circular path. Therefore, a head drive can be saved compared to the EagleEye head.

Finally, there are so-called rotary-pivot joints for coordinate measuring machines. For example, the Applicant's term "RDS" is to provide a latching, biaxial, pivot-pivot joint that can be used as an interface between the CMM gauge interface and the actual probe head to align a "rigid" probe in space. A product brochure shows an example in which an optical measuring head, which generates a line-shaped light pattern on a measuring object, is coupled to the measuring head interface of the rotary-pivot joint. The combination of such a rotary-pivot joint with an optical measuring head offers in particular the possibility of pivoting the line-shaped light pattern about two axes of rotation. An advantage of this combination is that the optical measuring head can be used alternately with tactile measuring heads and / or other optical or other measuring heads on the rotary-pivot joint, wherein a change of the measuring head is possible even within a complex measuring sequence. However, a disadvantage of the known combination of rotary-pivot joint and optical measuring head is the limited flexibility, since the rotary-pivot joint is limited to two axes of rotation. The integration of a third axis of rotation would be possible in principle. However, it is complex and cost-benefit aspects, at least from today's perspective, not interesting.

WO 2009/016185 A1 describes a holder for a measuring head, wherein an adapter is inserted between the suspension and the measuring head. The adapter is designed as a swivel joint and allows the measuring head to be adjusted under defined angles of rotation. The adjustment is done with a tool or by means of an electric drive. The adapter essentially comprises two composite disc-like components, the one component having raised projections at defined intervals and the other component corresponding receptacles. When turning the sensor, the elevations are released from the recordings until the next defined position is reached and the elevations lie again with corresponding recordings one above the other. A wave-shaped washer presses one component continuously on the other, so that the two components are permanently clamped.

DE 10 2010 020 654 A1 describes a further probe for a coordinate measuring machine, wherein the probe tool is detachably arranged with a turntable on a coupling part. The turntable can be coupled to the coupling part in one of several defined rotational angle positions. About a locking element, the turntable can be fixed or released on the coupling part.

Against this background, it is an object of the present invention to provide an optical measuring head for a coordinate measuring machine, which enables a flexible and individual measurement with a line-shaped light figure in a cost-effective manner.

According to one aspect of the invention, this object is achieved by an optical measuring head of the type mentioned, in which the second interface has a first, a second and a third interface part, wherein the first interface part is arranged without play in the adapter part, wherein the second interface part with play is coupled to the sensor housing, wherein the third interface part is coupled to the first and the second interface part, but is displaceable relative to the first interface part along a movement axis which extends transversely to the line-shaped light figure, wherein the third interface part, the second interface part in a first position pulls along the axis of movement in a rotationally fixed engagement with the first interface part, wherein the third interface part, the second interface part in a second position along the axis of movement of the rotationally fixed engagement with the first Schnittenteente il, wherein the handle is coupled to the third interface part to selectively bring the third interface part in the second position and the handle is decoupled from the third interface part when the third interface part is in the first position, wherein the handle with the third Interface part is coupled via a rod which converts a rotational movement of the handle into a translational movement of the third interface part along the movement axis and the rod is connected to the third interface part via a pin which is movably mounted in an oversized hole, in particular a slot.

The new measuring head thus has a sensor part which generates a linear light pattern on a measuring object. Preferably, the sensor part also includes an optical sensor capable of detecting the light pattern on the measurement object to generate sensor data in response thereto, which enables the coordinate measuring machine to determine spatial coordinates on the measurement object. In preferred embodiments, the sensor part determines the sensor data based on trigonometric relationships between the light source, the line-shaped light figure on the Measurement object and the imaging path of the optical detector.

In addition, the measuring head has an integrated rotation axis, which makes it possible to change the orientation of the line-shaped light pattern relative to the measurement object by the sensor part is rotated about the axis of movement of the third interface part. The integrated axis of rotation is a passive axis of rotation, that is, the optical measuring head comes without motor drive for the adjustment of the rotational position of the sensor part. Rather, in the preferred embodiments, the line-shaped light figure is manually brought into a desired orientation after the user has actuated the handle to move the third interface portion to the second position. The user can thus rotate the sensor part after releasing the handle relative to the adapter part about the axis of movement of the third interface part and thus bring the light pattern on the measurement object in a desired position. In this case, the first and the second interface part form a kinematic bearing for the sensor part on the adapter part, and thus ensure a reproducible fixation of the sensor part on the adapter part. In a preferred embodiment, the kinematic bearing includes ball-roller pairs. Alternatively and / or additionally, the kinematic bearing could have dowel pins which are preferably conically shaped, have a serration or other coupling elements which ensure a reproducible rotational position of the sensor part relative to the adapter part.

The measuring head has a first interface which is complementary to the measuring head interface of the coordinate measuring machine. The first interface is arranged on the adapter part, that is, the adapter part sits between the sensor part and the interface of the coordinate measuring machine. However, the adapter part is permanently connected to the sensor part. In other words, the adapter part and the sensor part form a structural unit that includes a passive axis of rotation for the sensor part. In the preferred embodiments, the measuring head, more precisely the adapter part, has exactly one passive axis of rotation. This variant allows a compact and easy-to-build implementation, which can be very easily combined with a common rotary-pivot joint due to the first interface, so as to allow cost-effective adjustment of the sensor part to three different axes of rotation. The omission of a motor drive in the measuring head helps to keep the weight of the new measuring head so low that it can be fastened to many turn-pivot joints.

Compared to previous combinations of a sensor part, which creates a line-shaped light figure, with a turn-pivot joint, the user gets greater flexibility to optimize his measurement. On the other hand, compared to three-axis measuring heads, such as the EagleEye system mentioned at the beginning, the user has the advantage that the measuring head can be easily exchanged and replaced as an alternative to relatively light-weight tactile measuring heads.

Finally, the new invention contributes to minimize uncontrollable influences of the operator on the exact alignment of the light figure. This is inventively achieved in that the handle has no force-transmitting connection to the third interface part when the third interface part is in the first position. The sensor part can thus be fixed largely free of constraint on the adapter part. The reproducibility of the rotational position is improved.

In addition, a rotational movement of the handle is generally preferred, as it allows a comfortable operation in small space requirements. The implementation of the rotational movement of the handle in a translational movement via a rod allows a rectilinear movement of the third interface part and consequently a low-wear and precise coupling of the sensor part to the adapter part. On the other hand, the rod allows a selectable clearance between the third interface part and the handle, which is very advantageous in order to fix the sensor part as tension-free as possible on the adapter part. The use of an eccentric disc in conjunction with a connecting rod allows a simple and compact way a high gear ratio. This is advantageous to allow the user to easily operate at high clamping forces.

Another aspect of the invention allows a very simple and effective realization of a dead path for the handle in conjunction with a very direct coupling between the handle and third interface part on the further actuation path of the handle. The sensor part can therefore be comfortably disengaged from the rotationally fixed fixation on the adapter part as soon as the operator has moved the handle beyond the dead path.

Overall, the integration of a manually operated axis of rotation in an optical measuring head has therefore proved to be a very advantageous realization in order to completely solve the above-mentioned problem.

In a preferred embodiment, the adapter part has a force element which biases the third interface part into the first position. In preferred embodiments, the force element is a spring, in particular a compression spring. Alternatively or additionally, the force element may include a magnet and / or a screw, such as a spindle drive. In preferred embodiments, the force element is configured to generate a tensile force greater than 80 N, and preferably a tensile force of approximately 100 N. Furthermore, it is preferred if the force element exerts pure tensile forces on the second interface part when the third interface part is in the first position.

In this embodiment, the new measuring head has the advantage that the clamping force with which the sensor part is fixed to the adapter part is independent of the operating force of the operator, which adjusts a desired rotational position of the sensor part on the adapter part. The design and its preferred variants help to ensure a high accuracy of measurement, since the current orientation of the light figure is not affected by uncontrollable operator influences.

In a further embodiment, the handle has a rest position corresponding to the first position of the third interface part and an end position corresponding to the second position of the third interface part, the handle defining a actuation path from the rest position to the end position, and wherein the Activation includes a dead path, which starts at the rest position and makes up at least 10% of the actuation path.

In the preferred embodiments, the handle is a rotatable handle having an actuating travel that is at least π / 2 and preferably π. When the operator moves the handle from the rest position to the end position, the handle initially appears to be inoperative because it does not cause any change in the third interface part along the axis of motion. This "lack of function" is the desired consequence of the dead path. In a preferred embodiment, the dead path is about 30% of the actuation travel. This refinement also contributes to making a current rotational position of the sensor part relative to the adapter part independent of uncontrollable operator influences.

In a further embodiment, the adapter part has a holding element which is designed to fix the handle in the rest position. In some embodiments, the retaining element may be a spring and / or a latch that holds the handle in the rest position. In a particularly preferred embodiment, the holding element is a magnetic holding element, in particular a pair of magnets consisting of at least two magnets facing each other with the same poles.

The latter variant allows a reliable and wear-free implementation, which also causes a pleasant operating feeling for the operator. But also the other variants offer the advantage that the handle is held securely in the rest position and can not fall over the dead path uncontrolled back and forth, for example, when the measuring head is moved within the measuring volume.

In a further embodiment, the second interface part has a recess with an undercut into which the third interface part engages with a defined clearance parallel to the movement axis.

On the one hand, this embodiment enables a very secure fixation of the sensor part on the adapter part when the third interface part is in the first position. In this case, the third interface part can pull the second interface part into the kinematic mounting on the first interface part. When disengaged second interface part, however, this configuration allows a largely resistance-free rotation of the sensor part due to the game between the second and third interface part.

In a further embodiment, the first and the second interface part define a defined number of rotational positions of the sensor part relative to the adapter part about the movement axis, and the adapter part has an evaluation unit, which is adapted to a current rotational position of the sensor part from the number of rotational positions and to provide rotation angle information at the second interface depending thereon. The evaluation unit preferably provides digital rotational angle information at the second interface, in particular in a CAN bus format.

In this embodiment, the adapter part has some intelligence that converts a defined rotational position into rotational angle information to provide the coordinate measuring machine with "real" angle information that is preferably compatible with rotational angle information provided by encoders, angle encoders and similar measuring devices. The embodiment has the advantage that the current orientation of the light figure can be processed in the same way or using the same algorithms, such as the rotational angle position that provides a conventional rotary-pivot joint. The adapter part of this embodiment advantageously simulates a continuous axis of rotation and provides a corresponding angle information.

In a further embodiment, the number of rotational positions is at least two and at most six, preferably exactly three. In a preferred embodiment, the evaluation unit converts the exactly three alternative rotational positions into the angle information 0 °, -45 ° and -90 °. In general, it is preferred if the available rotation angle range of the sensor part is limited relative to the adapter part, in particular to 0 ° to 90 °. Therefore, in preferred variants, the adapter part has a stop which limits the rotational movement of the sensor part relative to the adapter part to this angular range.

Limiting the number of available rotational positions to the above-mentioned values has proved to be advantageous, on the one hand, to enable flexible orientation of the light pattern on the measurement object and, on the other hand, to minimize the weight and complexity of the measuring head and the possibility of operating errors. In particular, in combination with a rotary-pivot joint, the provision of at least two and preferably exactly three predefined rotational positions is sufficient to allow measurements at arbitrarily extending object edges with high accuracy.

In a further embodiment, the adapter part has an individual identification circuit for each rotational position of the sensor part relative to the adapter part, and the second interface part has at least one position element which activates one of the identification circuits in dependence on a current rotational position of the sensor part relative to the adapter part. Preferably, the position element activates exactly one of the identification circuits, which allows a very simple and rapid determination of the rotation angle information, for example by means of a look-up table. In preferred embodiments, the position element is part of the kinematic bearing, with which the sensor part is fixed against rotation on the adapter part, in particular a ball or roller of a ball-roller triples. For example, a conductive (in particular metallic) ball or roller can make electrical contact with the identification circuit.

This embodiment allows a very simple and reliable implementation. The combination of position element and kinematic bearing element in an element also contributes to a weight reduction and simplification of the new measuring head.

In a further embodiment, the adapter part has a visual position mark for each defined rotational angle position of the sensor part relative to the adapter part.

In this embodiment, the adapter part has a mark, which makes it easier for the operator to adjust the sensor part relative to the adapter part manually so that the bearing elements for the kinematic mounting face each other in the desired position. The design allows a quick and comfortable adjustment of the desired rotational position by the operator, and it contributes to a low-wear implementation.

In a further embodiment, the first interface part has an annular end region, which surrounds the second interface part with a sliding bearing.

In this embodiment, the first interface portion has a sleeve-like end portion in which the second interface portion is rotatably supported during manual adjustment of the desired rotational position. The design contributes to a comfortable and low-wear implementation and operation.

In a further embodiment, the third interface part is a tube-like part with a clear inner diameter.

This embodiment has proved to be advantageous in order to realize the adapter part as easily as possible and still stable. For the same reason, the handle in the preferred embodiments is made of plastic.

It is understood that the features mentioned above and those yet to be explained below can be used not only in the particular combination given, but also in other combinations or in isolation, without departing from the scope of the present invention.

Embodiments of the invention are illustrated in the drawings and are explained in more detail in the following description. Show it:

1 a gantry coordinate measuring machine with a schematically illustrated measuring head according to an embodiment of the present invention,

2 A preferred embodiment of the new measuring head in a partially sectioned view,

3 a view of the first and third interface part along the line of sight III-III in 2 .

4 the handle with holding element of the measuring head 2 , and

5 a perspective view of a second measuring head, which makes it possible to change the orientation of the line-shaped light figure, and

6 a perspective view of a third measuring head, which makes it possible to change the orientation of the line-shaped light figure

In 1 is a coordinate measuring machine with an embodiment of the new measuring head in its entirety by the reference numeral 10 designated. The coordinate measuring machine 10 owns a base here 12 on a portal 14 is arranged displaceably in a longitudinal direction. This longitudinal direction is usually referred to as the y-axis. The portal 14 has a crossbeam on which a sled 16 slidably disposed in a second longitudinal direction. This second longitudinal direction is usually referred to as the x-axis. On the sledge 16 is a quill 18 arranged, which is displaceable in a third longitudinal direction (z-axis). With the reference number 20 are scales that run along the axes x, y and z. Using the scales 20 and suitable sensors (not shown here), the current position of the portal 14 , the sled 16 and the quill 18 along the axes y, x and z are determined.

With the reference number 22 is an embodiment of the new measuring head (shown here in simplified form). In preferred embodiments, the measuring head 22 together with a separate turn-pivot joint 24 used. In the embodiment according to 1 is the turn-pivot joint 24 at the bottom of the quill 18 at a measuring head interface 25 of the coordinate measuring machine 10 arranged. The rotary-swivel joint 24 For this purpose, it has a machine interface which can be attached to the measuring head interface 25 is trained. Furthermore, has the rotary-pivot joint 24 another measuring head interface, the measuring head interface 25 corresponds to the coordinate measuring machine and is designed to receive a measuring head. The rotary-swivel joint 24 offers the possibility of rotating the further measuring head interface relative to the machine interface by two axes of rotation which are orthogonal to one another. Optionally, an optical measuring head or a tactile measuring head can be attached to the measuring head interface. Such rotary-pivot joints are known and are offered by the applicant, for example, under the name "RDS".

The measuring head 22 is designed to be a linear light figure 26 on the surface of a test object 28 to create. Based on the light figure 26 and based on sensor data, the measuring head 22 generated (hereinafter 2 explained in more detail), an evaluation and control unit 30 of the coordinate measuring machine 10 Spatial coordinates of edges and other structures on the DUT 28 determine.

1 shows a coordinate measuring machine in gantry design. However, the new measuring head can also be used in coordinate measuring machines, which have a different structure, such as horizontal arm CMMs.

It should also be noted that the use of the new probe in combination with a (separate) rotary-swivel joint 24 while it is preferred. In principle, however, the new measuring head can also do without the rotary-swivel joint 24 directly at the measuring head interface 25 of the coordinate measuring machine 10 be attached.

2 shows a preferred embodiment of the new measuring head 22 with some details. The measuring head 22 has a sensor part 34 and an adapter part 36 , The sensor part 34 includes a light source 38 giving a fan-shaped light beam 40 generated. When the fan-shaped light beam 40 on the surface of a test object 28 meets, he creates the line-shaped light figure 26 ,

The sensor part 34 also has a detector 42 which is designed to the linear light figure 26 to record on the measurement object. In some embodiments, the detector is a camera chip, such as a CCD or CMOS chip. As in 2 is simplified, is the "viewing direction" of the detector 42 obliquely to the fan-shaped light beam 40 aligned. Therefore, an evaluation unit (not shown here) in the sensor part 34 Based on trigonometric relationships spatial coordinates of the DUT 28 determine what is simplified here using the arrows 44 . 46 is indicated.

The adapter part 36 has a machine interface 48 , which here is complementary to the measuring head interface 25 of the coordinate measuring machine 10 and thus also complementary to the measuring head interface of the rotary-pivot joint 24 is trained. Therefore, the adapter part 36 via the machine interface 48 on the rotary swivel joint 24 or - alternatively - directly at the measuring head interface 25 of the coordinate measuring machine 10 be attached.

The adapter part 36 has a second interface 50 about which the adapter part 36 permanently with the sensor part 34 is coupled. adapter part 36 and sensor part 34 therefore form a structural unit.

the interface 50 includes a first interface part 52 , a second interface part 54 and a third interface part 56 , The first Interface part 52 is free of play in the adapter part 36 arranged. The second interface part 54 is free of play with the sensor housing 58 of the sensor part 34 connected. The first interface part 52 and the second interface part 54 each have a plate-like end portion, which are so far complementary to each other, as that the first and second interface part 52 . 54 in the in 2 shown position in direct contact with each other and a rotationally fixed, kinematic mounting of the sensor part 34 at the interface part 36 form.

The third interface part 56 Here is a clamping sleeve, which is along a movement axis 60 axially displaceable, which is indicated by an arrow 62 is indicated. When the clamping sleeve 56 in the in 2 shown first position 64 are located, the plate-like end portions of the first and second interface part 52 . 54 engaged with each other so that the sensor part 34 on the adapter part 36 is rotationally fixed.

A movement of the clamping sleeve 56 in the direction of the arrow 62 in an end position 66 pushes the second interface part 54 out of engagement with the first interface part 52 out (not shown here). This will be the second interface part 54 from the kinematic bearing on the first interface part 52 lifted out, and the sensor housing 58 Can be done by hand relative to the adapter part 36 around the movement axis 60 be turned, what with an arrow 68 is indicated. Accordingly, the third interface part operates 56 within the adapter part 36 as a control and tendon, with the help of the sensor part 34 Optionally fixed in rotation or for adjustment about the axis of movement 60 can be released.

With the reference number 70 is a handgrip that calls for another axis by hand 72 can be rotated to the third interface part (adapter sleeve) 56 in the release position 66 bring to. As in 2 can be seen, the axis runs 72 in this embodiment, transverse to the axis of movement 60 , preferably orthogonal.

The handle 70 is with an eccentric disc 74 connected to the an eccentric pin 76 is arranged. The pin 76 engages in a connecting rod 78 one. The connecting rod 78 has a slot 80 whose longitudinal axis is parallel to the axis of movement here 60 extends. In the slot 80 grab a bolt 82 , the play free with the clamping sleeve 56 connected is. Because of the long hole 80 can the connecting rod 78 over a certain dead path 84 away relative to the clamping sleeve 56 move without changing the position of the clamping sleeve 56 along the axis of motion 60 is changed. Only when the bolt 82 the "end" of the slot 80 reaches, transfers the movement of the connecting rod 78 on the clamping sleeve 56 ,

Accordingly, the clamping sleeve has 56 a defined game parallel to the axis of motion 60 in relation to the connecting rod 78 , This is the handle 70 in the in 2 illustrated rest position of the clamping sleeve 56 decoupled. He exerts no force on the clamping sleeve 56 out. The dead path 84 corresponds in a preferred embodiment about 30% of the maximum possible adjustment path of the handle 70 (please refer 4 ; There is the actuation path of the handle 70 with reference number 85 designated; the dead path of the handle is with 84 ' designated). In this embodiment, the operator can handle 70 to move over an angle of 180 °. The pivoting movement of the handle 70 transfers to the eccentric disc 74 , The eccentric pin 76 moves the connecting rod 78 largely parallel to the axis of movement 60 , As soon as the bolt 82 the end of the slot 80 reaches, transmits the axial movement of the connecting rod 78 on the clamping sleeve 56 , This can then be the second interface part 54 in the direction of the arrow 62 from the plant with the first interface part 52 Press out, so that the operator then the sensor part 34 relative to the adapter part 36 can twist by hand.

The second interface part 54 has an undercut in the area of its plate-like end section 86 , in which the free end portion of the clamping sleeve 56 with a defined game 88 parallel to the axis of movement 60 intervenes. The game 88 Helps minimize drag when rotating the sensor part.

To the clamping force with which the second interface part 54 after twisting again against the first interface part 52 is pulled, regardless of the operating force of the operator to do, has the adapter part 36 in this embodiment, a compression spring 90 , which is arranged so that it the clamping sleeve 56 against the direction of movement 62 biases. In the preferred embodiments acts on the second interface part 54 a pure tensile force against the direction of the arrow 62 , because of the game 88 , due to a radial clearance and due to the play-related coupling of the clamping sleeve 56 with the connecting rod 78 , Once the operator has the handle 70 returns to its original starting position (rest position) pushes the spring 90 the second interface part 54 over the clamping sleeve 56 again in engagement with the first interface part 52 , In this way, the sensor part 34 again rotatably on the adapter part 36 fixed. In some embodiments, the resilience of the spring 90 (or other force element) greater than 80 N, in particular about 100 N.

How to get in 2 can continue to recognize possesses the first interface part 52 an annular end region 92 , the second interface part 54 embraces. In other words, the second interface part appears 54 in the in 2 shown position in the annular end region 92 one. The annular end region 92 is on its radially inward axis of motion 60 facing side with a sliding layer 94 provided, which is a plain bearing for the second interface part 54 forms. Alternatively or additionally, the sliding layer could also be on the second interface part 54 be arranged.

With the reference number 96 is an evaluation called a current rotational position of the sensor part 34 relative to the adapter part 36 determined and depending on a - preferably digital - rotation angle information at the interface 48 provides. In the preferred embodiment, the evaluation unit 96 the rotation angle information in a CAN bus format ready, so that the control and evaluation 30 read in the current rotation angle information via a CAN bus and evaluate it during the determination of the spatial coordinates.

As in the view according to 3 can be seen, has the first interface part 52 in the circumferential direction a number of balls 98 , where each two adjacent balls 98a . 98b form a bearing for a roller, in a suitable position on the second interface part 54 is arranged. In the preferred embodiment, the first interface part has 52 eighteen bullets 98 that make nine campsites. Three bearing points together form a three-point bearing for the second interface part 54 , Overall, the balls 98 on the outer periphery of the first interface part 52 arranged so that the sensor part 34 in one of three defined rotational positions on the first interface part 52 can be fixed.

To determine the current rotational position, has the adapter part 36 in this embodiment, three identification circuits 100 , Each of the three identification circuits 100 is electric with a pair of balls 98a . 98b connected. Once a roller (not shown here) of the second interface part 54 in the space of the connected ball pair 98a . 98b engages, an electrical contact is closed, the connected identification circuit 100 activated. The identification circuit 100 then generates an electrical signal, with the help of the evaluation 96 the current rotational position of the sensor part 34 can recognize. In some embodiments, the identification circuit 100 be a defined electrical resistance, which leads to a characteristic signal. In other embodiments, the identification circuit is a chip programmed with an individual identifier which transmits the identifier upon activation.

4 shows a detail of the new measuring head, which serves to the handle 70 to fix when the first and second interface part 52 . 54 are engaged. Due to the dead path 84 and the associated decoupling of the handle 70 from the third interface part 56 otherwise there is a risk that the handle 70 during movements of the measuring head 22 uncontrollably shaking back and forth. In the preferred embodiment, the handle is 70 rotatably with a disc 104 connected. At the disc 104 is a magnet 106a arranged with a second magnet 106b interacts. The magnet 106b is on the housing-fixed part of the adapter part 36 arranged. In the in 4 illustrated rest position of the handle 70 show the magnets 106a . 106b each with the same poles towards each other, which leads to a repulsive force. The magnets 106a . 106b are arranged slightly offset from each other, so that the magnet 106a when turning the handle 70 around the axis 72 over the magnet 106b has to be pushed. The repulsive force has a force component in terms of the rotational movement in x and in y, so that it counteracts the rotational movement. About the magnet type and the selected offset the repulsive force is very easy to dose. The opposite pole arrangement of the magnets also has the advantage that the air gap between the magnets is relatively uncritical with respect to the force. By contrast, with magnets magnetized upon attraction, the air gap would be a critical size that would require accurate sizing and assembly.

The magnet pair 106a . 106b thus forms a holding element that the "loose" handle 70 in the in 4 holding position shown. Alternatively or additionally, the handle could 70 be fixed in its rest position via a spring element.

In a preferred embodiment, the controller is 30 of the coordinate measuring machine programmed so that they disengage and re-insert the measuring head 22 at the measuring head interface 25 causes as soon as they change the rotational position of the sensor part 34 at the interface 50 detected (in particular via the angle information from the evaluation unit 96 ). As has been shown in practical experiments, causes the engagement and disengagement of the measuring head 22 a "free shaking" of the sensor part 34 at the interface 50 with the consequence that the reproducibility of the rotational position at the interface 50 is improved.

5 shows a measuring head 122 with a sensor part 134 and an adapter part 136 which are firmly connected to a structural unit. In this case, the adapter part has 136 two machine interfaces arranged transversely to each other 148a and 148b , In the preferred variant, the machine interfaces 148a . 148b arranged orthogonal to each other. Depending on which machine interface 148a . 148b the user the measuring head 122 at the measuring head interface 25 attached to the coordinate measuring machine, can be another orientation of the light figure 26 reach relative to the surface of a DUT. The measuring head 122 has the advantage that the orientation of the light figure 26 can be changed automatically by the measuring head 122 initially by machine in a removable magazine (not shown here) is stored and the coordinate measuring machine the measuring head 122 then resumes at the other machine interface and removes it from the removable magazine. Particularly preferred is this variant in conjunction with a rotary-pivot joint 24 , since the orientation of the light figure then on the respective "matching" axis of rotation of the rotary-pivot joint 24 can be changed in relatively small steps or even continuously.

6 shows another measuring head 222 with a sensor part 234 and an adapter part 236 , In this case, the adapter part has 236 only one machine interface 248 , However, it has two alternative interfaces 250a . 250b for selectively fixing the sensor part 234 , The first interface 250a is parallel here and preferably coaxial with the machine interface 248 arranged. The second interface 250b is arranged transversely thereto, preferably orthogonal. Also in this case, the sensor part can be 234 in two different orientations at the measuring head interface 25 of the coordinate measuring machine 10 or a corresponding measuring head interface of a rotary-swivel joint. Preferably also in this case, the attachment via a rotary-pivot joint 24 , so that a fine positioning of the light figure 26 on the test object with the help of one of the two axes of rotation of the swivel-pivot joint 24 can be done.

In a further embodiment (not shown here) has the adapter part 236 a pivot axis about which the sensor part can be pivoted relative to the adapter part. Also in this case, the sensor part can optionally with one of two different orientations on the measuring head interface of the coordinate measuring machine 10 or the measuring head interface of the rotary-swivel joint 24 to be ordered.

Claims (11)

Optical measuring head for a coordinate measuring machine ( 10 ), which has a measuring head interface ( 25 ) for releasably receiving the measuring head, with a sensor part ( 34 ) with a sensor housing ( 58 ), in which a light source ( 38 ), which is capable of being mounted on a measuring object ( 28 ) a line-shaped light figure ( 26 ) and with an adapter part ( 36 ), which is a first interface ( 48 ), a second interface ( 50 ) and an adjustable handle ( 70 ), the first interface ( 48 ) complementary to the measuring head interface ( 25 ) is reproducible to the measuring head on the coordinate measuring machine ( 10 ), and wherein the sensor housing ( 58 ), the second interface ( 50 ) and the adapter part ( 36 ) form a structural unit, characterized in that the second interface ( 50 ) a first, a second and a third interface part ( 52 . 54 . 56 ), wherein the first interface part ( 52 ) free of play in the adapter part ( 36 ), wherein the second interface part ( 54 ) clearance with the sensor housing ( 58 ), the third interface part ( 56 ) with the first and the second interface part ( 52 . 54 ), but relative to the first interface part ( 52 ) along a movement axis ( 60 ) is displaceable, which transversely to the line-shaped light figure ( 26 ), wherein the third interface part ( 56 ) the second interface part ( 54 ) in a first position ( 64 ) along the movement axis ( 60 ) in a rotationally fixed engagement with the first interface part ( 52 ), wherein the third interface part ( 56 ) the second interface part ( 54 ) in a second position ( 66 ) along the movement axis ( 60 ) from the rotationally fixed engagement with the first interface part ( 52 ), whereby the handle ( 70 ) with the third interface part ( 56 ) is coupled to the third interface part ( 56 ) optionally in the second position ( 66 ) and the handle ( 70 ) from the third interface part ( 56 ) is decoupled when the third interface part ( 56 ) in the first position ( 64 ), wherein the handle ( 70 ) with the third interface part ( 56 ) over a pole ( 78 ) is coupled, which is a rotary movement of the handle ( 70 ) in a translational movement ( 62 ) of the third interface part ( 56 ) along the movement axis ( 60 ) and the rod ( 78 ) with the third interface part ( 56 ) via a bolt ( 82 ) connected in an oversized hole, in particular a slot ( 80 ) is movably mounted Optical measuring head according to claim 1, wherein the adapter part ( 36 ) a force element ( 90 ), which the third interface part ( 56 ) to the first position ( 64 ). Optical measuring head according to one of claims 1 and 2, wherein the handle ( 70 ) has a rest position coinciding with the first position ( 64 ) of the third interface part ( 56 ) and an end position coinciding with the second position ( 66 ) of the third interface part ( 56 ), wherein the handle ( 70 ) defines an actuation path from the rest position to the end position, and wherein the actuation path defines a dead travel ( 84 ) includes, the the rest position starts and makes up at least 10% of the actuation path. Optical measuring head according to claim 3, wherein the adapter part ( 36 ) a holding element ( 106 ), which is adapted to the handle ( 70 ) in the rest position. Optical measuring head according to one of claims 1 to 4, wherein the second interface part ( 54 ) a recess with an undercut ( 86 ) into which the third interface part ( 56 ) with a defined game ( 88 ) parallel to the movement axis ( 60 ) intervenes. Optical measuring head according to one of claims 1 to 5, wherein the first and the second interface part ( 52 . 54 ) a defined number of rotational positions of the sensor part ( 34 ) relative to the adapter part ( 36 ) around the movement axis ( 60 ), and wherein the adapter part ( 36 ) an evaluation unit ( 96 ), which is adapted to a current rotational position of the sensor part ( 34 ) to detect from the number of rotational positions and in dependence thereon a rotation angle information at the first interface ( 48 ). Optical measuring head according to one of claims 1 to 6, wherein the first and the second interface part ( 52 . 54 ) a defined number of rotational positions of the sensor part ( 34 ) relative to the adapter part ( 36 ) around the movement axis ( 60 ), and wherein the number is at least two and at most six, preferably exactly three. Optical measuring head according to one of claims 1 to 7, wherein the adapter part ( 36 ) for each rotational position of the sensor part ( 34 ) relative to the adapter part ( 36 ) an individual identification circuit ( 100 ), and wherein the second interface part ( 54 ) has at least one position element which, depending on a current rotational position of the sensor part ( 34 ) relative to the adapter part ( 36 ) one of the identification circuits ( 100 ) is activated. Optical measuring head according to one of claims 1 to 8, wherein the adapter part ( 36 ) for each defined rotational angle position of the sensor part ( 34 ) relative to the adapter part ( 36 ) has a visual position mark. Optical measuring head according to one of claims 1 to 9, wherein the first interface part has an annular end region ( 92 ) having the second interface part ( 54 ) with a sliding bearing ( 94 ) surrounds. Optical measuring head according to one of claims 1 to 10, wherein the third interface part ( 56 ) is a tubular member having a clear inside diameter.

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