DE19740044A1 - Machining or grinding workpieces for production of jewelry or designer goods - Google Patents

Abstract

The method involves scanning the surface contour of a rotatable original model. The reflected radiation is detected and converted into digitally encoded coordinates. A computer produces at least three control signals for one relative translational movement and at least three control signals for a relative rotational movement between the tool and the workpiece to produce at least one blank. An Independent claim is included for a device for grinding workpieces.

Description

The invention relates to a method for machining workpieces in the manufacture of Jewelry or three-dimensional designer goods by means of machining and / or grinding, where with the surface contour of a rotatable original model using a bundled beam lung is scanned and reflected, the remission by means of at least two parallel to the Axis of rotation of the model of movable radiation detectors detected and as a three-dimensional Ab education is converted into a grid of digitally encoded coordinate values, in little least one digital computer can be saved, the computer after creating an in ternal three-dimensional digital model control signals for a processing station to the Bear machining of the workpiece using the tool derives from the coordinate values and one Device for machining workpieces with a measuring device, the one Radiation source and at least two radiation detectors for determining the surfaces contour of the original model based on optical triangulation.

Under the term jewelry or designer goods are monolithic according to an original model manufactured three-dimensional objects summarized; as a workpiece is the end gear material for the blank to be created, from which the jewelry follows or the designer goods are formed.

EP 0 671 679 A1 describes a three-dimensional method for non-contact measurement Objects based on optical triangulation are known, being those from a radiation source emitted, focused radiation scans the surface of the object and re from this is inflected, the remission being detected by means of radiation detectors; the object will  scanned ring by ring, with a gradual, continuous scan after each revolution Most takes place in the Z direction and the data obtained in this manner in rings is stored and stored three-dimensional reconstruction of the object using a data processing unit be applied; to avoid the effects of undercuts or hidden Differentiation is made between the ring-wise sampling at a predetermined Z-sampling step Lichen angular positions of the scanning head movable together with the radiation source carried out; if necessary, scans are repeated.

Furthermore, it is known from DE 28 04 479 A1 and DE 39 10 855 / C2, the configuration ei nes measure object rotated about an axis by laser beams without contact.

Furthermore, it is known from US Pat. No. 3,861,044, based on a wax dental model, whose geometry is recorded electro-optically, to collect data that forms the basis for a grinding or milling-technical manufacture of individual prosthetic dentures.

From US-PS 46 11 288 it is known to use at least one radiation source light wave to direct energy to an area of the body to create a prosthesis, the Wel len are reflected and analog intensity values are obtained from them; subsequently In an analog-to-digital converter, numerical information is created that identifies the characters represent the irradiated region and then a three-dimensional ana lyse the shape and dimensions of this numerical information and a three-di created a dimensional image that corresponds to the later prosthesis and corresponds to it suitable region; by a signal processing device Steueri signals for a processing machine for producing a prosthesis from a workpiece spent.

The processing machine can have a variety of tools, the machining tion sequence is selected numerically, with the numerical control signals advancing or withdrawing workpiece and tool as well as relative moments against each other Taxes. A milling machine, for example, can be used as a numerically controlled machine tool or a laser beam device can be used.

Furthermore, DE 36 13 096 A1 describes a method for machining workpieces with an egg nem programmed multi-axis robot known that a laser beam along a three-way Dimensional workpiece contour, with a three-dimensional profile NC program The marking is scanned using a sensor guided by the multi-axis robot  that controls the axes of the robot so that the sensor always follows the markings and the coordinates of the sensor in the NC control as a program at specified points points are entered and then the workpieces based on this NC program to be edited; a TV camera sensor is provided for scanning the markings the tool normal or tool height to the workpiece surface is determined, so that at least the TV camera sensor normally at the specified points or in the tool setpoint standing (perpendicular) to the workpiece surface.

Furthermore, it is known from US 46 63 720 dental prostheses by means of interferometric Connect pattern generation by coherent or non-coherent light and scanning analogue / digital conversion, CAD processing with subsequent machining create.

EP 0 490 848 B1 also describes a method for producing individually shaped three dimensional body containing at least parts of artificial dentures, dental bridges and Connections, support parts for the reconstruction of tissue structure and tools for the Manufacture of such dentures, supporting parts, bridges and connections or parts of the should form the same, known, the respective model rotating simultaneously and using Abta stone direction is scanned at a certain angle with respect to the axis of rotation of the scanned model; a computer-internal display is then transmitted development over a connection in a telecommunication network with transmitting and receiving device tion, the workpiece being in an angular relationship between the blank and the work tool is processed and the preferred angular range is within 30 to 60 °.

The limited angular relationship between tools proves to be problematic and blank. Furthermore, the data transfer by modem is in relation to the large data quantities of a digitally stored model are relatively time-consuming.

The invention is based on EP 0 671 679 and the corresponding DE 44 07 518 C2 the task of a method and an apparatus for producing individual three-dimensional jewelry or designer pieces made of metallic and non-metallic Specify materials after contactless optical scanning of original models, where should be reduced with both manufacturing costs and manufacturing times. Furthermore, egg ne economical and qualitatively optimal use of metallic or non-metallic Materials - especially when using precious metal - are made during manufacture.  

According to the method, the object is achieved in that at least three each of the computer Control signals for a relative translation movement and at least three control signals signals for a relative rotational movement between tool and workpiece for production at least one blank are output from the workpiece.

It proves to be particularly advantageous that both precious metals and Base metals and other materials such as plastics, ceramic art material combination materials as well as full ceramics can be processed; he continues it has proven to be advantageous that the holding of the workpiece or tool in all six Degrees of freedom enables rapid and particularly precise machining of the workpiece, with a high degree of flexibility with regard to model shape and workpiece shape as well as material properties of the workpiece is possible.

Advantageous embodiments of the method are specified in claims 2 to 11.

A major advantage of the specified solution is that models are different Forms and different material properties in different processing stations can be produced, the transfer of the model file without Modula tion and demodulation via a digital transmission system (possibly bus structure) - as with for example Optobus / SCI or ISDN network.

For optimal use of workpieces, the geometry of the model and workpiece are compared with each other in order to optimally position the model within the To achieve workpiece circumference, where it proves to be particularly useful, several Manufacture blanks from a single workpiece; this is especially the case with expensive ones Materials such as B. precious metals, or precious metal alloys advantageous.

In a preferred embodiment, a holder that is movable by six degrees of freedom of a program-controlled handling system - in the following robots or robot stops called - guide the workpiece against a processing station with the tool inserted ren; the robot holder and tool processing station can also be translated be movable against each other so that, for example, several tools on the robot are guided past or the robot at several stationary tool stations is passed by in order to be able to carry out different processing operations.  

It is also possible to carry out the tool guidance using a robot, in which case the Workpiece holder rigidly or translationally displaceable.

In a preferred embodiment, the surface contour of an original model is included scanned by the laser beam and its associated surface coordinate values are stored and in a third step the surface coordinate values of the original model created an internal areal three-dimensional model of the blank to be produced.

It proves to be particularly advantageous that the shape of the later blank is based on egg nes normal original model is specified, which by means of in jewelry production usual procedures can be created.

Using a transmission method, it is advantageously also possible to use model scanning and blank production spatially separated from each other, the surface coordina values of the internally stored model together with identification signals for the factory Substance specifications and clients via a digital data transmission route with high Throughput - such as Optobus / SCI or ISDN - are transmitted; here it proves turns out to be advantageous that blanks made of different materials with optimal groove workpiece can be produced.

In the case of materials based on precious metals, central processing of the workpieces or Blanks reduces the costly capital commitment associated with precious metal stocks become.

The object is achieved in accordance with the device in that the processing station at least has a robot which has at least one holder for receiving the workpiece or the Tool contains, the holder is movable by all six degrees of freedom and six Drive elements controllable by the computer are provided, of which three elements each te control signals for the 3 degrees of freedom of translation and three elements of control signals le received for the 3 degrees of freedom of rotation.

Advantageous embodiments of the device for machining workpieces are in the An say 13 to 15.

In a preferred embodiment, the robot has a holder for positioning the Workpiece, the associated digital computer each having control signals for three  Gives degrees of freedom of translation and three degrees of freedom of rotation of the bracket; It is advantageously possible to use different processing stations in succession using Ro bot to go through, including a serial creation of different, individual Jewelry or designer workpieces is possible provided there is a relative movement between Robot and tool processing is provided. It is also possible to set up a station for raw machining and a separate station for fine machining.

The holder is preferably used for positioning the workpiece by means of a robot arm guided.

In a further advantageous embodiment of the device, digital information via at least two models from a collecting device to suitable machining broadcast stations; it proves to be particularly advantageous here that per processing station is only a single material to be processed, so that intermediate cleaning operations at egg nem material change from blank to blank can be omitted.

Furthermore, model scanning and receiving and collecting device - such as. B. ISDN - be spatially separated, the connection via a digital transmission system, digital Network and possibly system with bus structure.

The subject is explained in more detail below with reference to FIGS. 1a, 1b, 1c and 2.

Fig. 1a shows symbolically the method steps for processing of workpieces or for jewelry designer goods,

Fig. 1 b shows schematically the structure of a device required for this;

Fig. 1 c schematically shows a stepwise procedure;

Fig. 2 shows schematically a device with spatial separation between model scanning and blank production.

According to Fig. 1a an original model is initially 1 the piece of jewelery or the De signer-product of the order in a measuring device 3, which optical based triangulation by means of a device 4 according to EP 0671679 A1 the surface coordinates X1, Y1, Z1 Axis 5 of the rotating original model 1 is recorded and, after an analog / digital conversion into an analog / digital converter 6, is saved in a digital computer 7 to create an internal digital model of the original model 1 . The corresponding components of the device are shown schematically in Fig. 1b, wherein in Fig. 1a with reference number 1, the model creation is symbolically shown based on the original model, while the Vermessungseinrich device with reference number 3 , the analog / digital conversion in converter with number 6 and the Speicherein direction are shown as part of a digital computer 7 .

By measuring device 3 , the original model 1 is scanned with the coordinate values X1, Y1, Z1 and after analog / digital conversion and creation of a computer-internal digital model in the computer, a digital model comparator 8 is fed via its input 9 , the comparator 8 continues to receive a signal via input 10 , which is to form an internal digital model of the workpiece 12 for the later blank. For this purpose, the workpiece 12 is fed via input 13 to a workpiece measurement station 14 which, like the units 6 and 7, performs an analog / digital conversion in analog / digital converter 15 and in the memory of digital computer 16 an internal digital model of the workpiece created with identification information on the workpiece properties; However, it is also possible to enter the workpiece geometry and, if necessary, the workpiece property using a screen keyboard or to have it read in via optical coding. The values for the workpiece geometry are then fed to the model comparator 8 via output 17 of the digital computer 16 and input 10 , the digital model being compared as the original model 1 with the determined model of the workpiece 12 in order to optimally utilize the workpiece volume to make. The selection of the material belonging to the respective model is taken into account.

Via output 11 , the model comparator 8 is connected to a collector and distribution station 20 , which distributes various models M1, M2, M3 to be created to different processing stations B1, B2, B3, with only one station B1 being shown in FIG. 1a for simplification is posed; each processing station should be assigned a specific material; according to FIG. 1a of the output 21 is the collector and distributor station 20 with input 22 of a numerical control processor 23 is connected; Several outputs 25 ', 25 '', 26 ', 26 '', 27 ', 27 ''of the processor controller 23 are used to control the machining stations B1, B2, B3 consisting of robot 28 and machine tool 29 , with outputs 25 ', 26 ', 27 ', the robots 28 each working in six degrees of freedom A1, A2, A3, A4, A5, A6 are controlled, while the actual machine tools 29 , for milling, grinding, drilling, each via output 25 '', 26 '' , 27 '' can be controlled. The blanks to be created from workpiece 12 are each designated 31 , 32 , 33 in FIG. 1b; they should become increasingly similar to the models M1, M2, M3 to be created during processing. At the angle of attack between the working axis of the tool such. B. drill or milling machine and the Ar beitsachse the robot arm for holding the workpiece is in the range of ± 180 °.

This operation is shown schematically in FIG. 1 a, the axes or degrees of freedom A1, A2, A3, A4, A5, A6 of the robot being shown symbolically. The respective machine tool is designated with number 29 . Using a screen connected to the digital computer, the placement of the digital original model in the digital workpiece model can be observed on a screen 36 , so that in the event of incorrect placement or incorrect format of the workpiece 12 (if necessary manually) intervenes and intervenes introduced new workpiece who can.

The process sequence is explained in more detail in individual steps with reference to FIG. 1c.

In step S1 the original model is measured, in step S2 the determined data are converted into digital values, in step S3 the digital values of the coordinate points are stored numerically, ie stored in a digital memory as a file of a digital computer and possibly interpolated for area display and then fed to a digital comparator in step S4. In parallel to the model scanning, a workpiece measurement is carried out in step S11, the values determined there being converted into digital values in step S12 and the digital values obtained being fed to a digital memory as a file in a digital computer and stored in step S13; however, it is also possible to dispense with steps S11, S12 and to enter the workpiece geometry or material property directly in a digital computer in step S13. The numerical data are then fed via the workpiece to the digital model comparator in step S14 and compared with the digital values of the model in step S5 in the digital comparator, with an optimal placement of the digitized original model within the volume of the digitized workpiece under op timely material utilization is sought. After the placement, taking into account the desired material, a processing station is selected in step S6, with each of the three processing stations provided here possibly only processing blanks from a specific material in steps 57 , 58 , 59 , in order to avoid unnecessary intermediate cleaning operations of the tools if possible Avoid changing materials.

In steps S7, S8, S9, the workpiece is ge from a robot arm by means of holder leads, the robot arm being movable by all six degrees of freedom; the workpiece is  guided against machine tools using a numerical tool control can be controlled in each case.

Fig. 2 is directed to a remote transmission of digital memory content of the digital original model, wherein scanning, analog / digital conversion and construction of a digital three-dimensional image according to Fig. 1b, but the transmission of the digital original model via a digital transmission link 37 - such. B. bus system, or ISDN line - is provided, which in a spatially remote from the first computer 7 second computer 38 enables a renewed construction of the digital original model according to the original original model 1 by means of the transmitted digital values; Furthermore, the identification signal, material properties and, if applicable, customer file are transmitted. It is also possible in addition to fast serial transmission as a transmission link 37, a bus system - such as. B. Optobus / SCI system - to be used, which enables an even faster transmission of digital values; in such a case, the 1st digital computer 7 , transmission link 37 and 2nd digital computer 38 can practically be regarded as a common computer system. The function of FIG. 2, with the exception of the transmission path and connected second computer, is otherwise comparable to the mode of operation described with reference to FIG. 1b. It is therefore possible to transfer digital original models from various measuring devices to a central processing station, where safe storage of precious metal-containing materials and optimal use of space in the respective material volumes is possible thanks to the clever placement of original models in the workpiece volume.

Claims (15)

1.Procedure for machining workpieces in the manufacture of jewelry or three dimensional designer goods by means of machining and / or grinding, the surface the contour of a rotatable original model with the help of focused radiation is keyed and reflected, with reflected radiation by means of at least one in parallel radiation detector movable to the axis of rotation of the model and recorded as three-dimensional converted into a grid of digitally coded coordinate values, which are stored in at least one digital computer, the computer according to Creation of an internal three-dimensional digital model control signals for a bear processing station for machining the workpiece using a tool from the coordinate Derives values, characterized in that at least three each from the computer Control signals for a relative translation movement and at least three control signals for a relative rotational movement between tool and workpiece Production of at least one blank can be output from the workpiece. 2.A method according to claim 1, characterized in that the reflected radiation with means of two radiation detectors movable parallel to the axis of rotation of the model becomes. 3. The method according to claim 1 or 2, characterized in that little after creation At least one further digital model in the computer transfers the data to a digital reception and collecting device are transmitted, the data records regarding the size of the  creating body and the desired material on at least two machining stations distributed. 4. The method according to any one of claims 1 to 3, characterized in that the data by means of a bus transmission link or digital transmission link to a digital one Receiving and collecting device are transmitted. 5. The method according to any one of claims 1 to 4, characterized in that the digital Receiving and collecting device information about the geometry of the process are fed to the workpiece, from which an internal three-dimensional workpiece Illustration is created, at least with an internal three-dimensional image a model is compared and control signals for optimal use of the volume of the workpiece are output when at least one blank is formed. 6. The method according to claim 5, characterized in that at least two internal three dimensional models for forming at least two blanks from a single one Workpiece with its internal three-dimensional image are compared. 7. The method according to any one of claims 1 to 6, characterized in that the Steueri gnale a processing station serving as a robot for motion control little at least one holder in all six degrees of freedom, whereby in the Hal the workpiece and / or the tool is guided. 8. The method according to any one of claims 1 to 7, characterized in that in one he Most step at least the surface contour of an original model using a laser beam scanned and the associated surface coordinate values are stored, and that in a further step from the surface coordinate values of the original Mo dells an internal three-dimensional model of the blank to be produced is created. 9. The method according to any one of claims 1 to 7, characterized in that in a he the least step is the surface contour of an original model using a laser beam scanned and the associated surface coordinate values are stored, and that from the surface coordinate values an internal three-dimensional model of the to be produced blank.   10. The method according to any one of claims 1 to 9, characterized in that the surface Chen coordinate values of the internally stored model of the blank as a control signal le forwarded using a digital transmission system for machining the workpiece become. 11. The method according to claim 10, characterized in that the control signals together forwarded with identification signals for material information and client. 12. Device for machining workpieces using a tool in the manufacture of jewelry or designer goods, which has a measuring device with a radiation source and at least two radiation detectors for determining the surface contour of an original model based on optical triangulation, the measuring device with a digital computer is connected, the output of which is connected to the control signal input of a processing station, characterized in that the processing station has at least one robot ( 2 ) which has at least one holder for receiving the workpiece ( 12 ) or Tool contains, the holder ( 30 ) is movable by all six degrees of freedom and six drive-controllable drive elements are provided, of which three elements control signals for the three degrees of freedom of translation and three elements receive control signals for the three degrees of freedom of rotation gene. 13. The apparatus according to claim 12, characterized in that the holder ( 30 ) for positioning the workpiece ( 12 ) is provided. 14. The apparatus according to claim 12 or 13, characterized in that between the output of the digital computer ( 16 ) and the drive elements, a digital receiving and collecting device ( 20 ) for distributing at least two data records to at least two processing stations is provided, wherein digital information is transmitted from the receiving and collecting device to the processing station. 15. The apparatus according to claim 14, characterized in that between digital computer ( 6 ) and receiving and collecting device ( 20 ), a digital transmission system is switched GE.