JP2009226562A - Device and method for machining three-dimensional curved surface - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To accurately machine a work having a complicated three-dimensional curve surface. <P>SOLUTION: The three-dimensional shape data 2 of a work 8 generated by a three-dimensional CAD device 1 is input into an NC program calculation device 4 for cutting. In the NC program calculation device 4, an NC program 3 for cutting is so generated that the widths and depths of cutter marks remaining on the machined surface by a machine tool are constant. The NC program 3 for cutting output from the NC program calculation device 4 for cutting is input into an NC program calculation device 6. In the NC program calculation device 6 for cutting, a grinding path data is prepared based on a grinding path along the cutter marks on the machined surface. Based on the grinding path data, an NC program for grinding is generated to adjust at least one of a grinding wheel contact angle, a grinding feed rate, and a pressing force with one of time and grinding distance. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a three-dimensional curved surface processing apparatus and a three-dimensional curved surface processing method capable of accurately processing a workpiece having a complicated three-dimensional curved surface shape such as a runner vane of a water turbine power generation device.

  In general, for a workpiece (workpiece) having a complicated three-dimensional curved surface shape such as a runner vane of a turbine generator, a machine tool using a material produced by casting or forging using a cutting tool such as a ball end mill. The cutting process is performed until the shape is close to the final shape. At that time, a plurality of groove-shaped cutter marks by the cutting tool remain on the workpiece.

  When this workpiece is finished into a final shape, grinding is performed manually using a grinding machine such as a grinder including a cutter mark by cutting.

  However, in manual grinding, a lot of setup time and processing time are consumed, and a lot of labor is imposed on the worker. Therefore, as a new technique, for example, a manufacturing apparatus and a manufacturing method as disclosed in Patent Document 1 are proposed. ing.

  This manufacturing apparatus has a sensor that measures the shape of a propeller that is a workpiece (workpiece), and grinds the propeller based on the difference between the measured three-dimensional shape and the three-dimensional shape data at the time of design. Thus, proposals have been made to automatically grind high-quality propellers.

  Further, regarding a method for preventing a reduction in grinding efficiency due to wear of a grindstone used for grinding, as described in Patent Document 2, the contact angle of the grindstone with respect to the work surface of the workpiece is changed according to the grinding feed speed, the grinding position, or the time. Proposals have been made.

  Regarding the grinding method of the cutter mark, as described in Patent Document 3, a proposal has been made to make the grinding amount constant by detecting the moment applied to the grinding tool and controlling it so as to keep the value constant. ing.

Further, in Patent Document 4, an electric grinder that includes a slide shaft that detects a current applied to a motor of an electronic grinder that rotates at a constant speed and presses the grinder against a machining surface so that the value is constant, and the electronic grinder An automatic grinding apparatus has been proposed in which a state signal is exchanged with a robot that moves along a machining surface so that followability is good and the grinding surface is smooth.
JP 2001-353651 A JP 7-1000075 A JP-A-9-239654 Japanese Examined Patent Publication No. 8-22501

  In patent document 1 mentioned above, the sensor which measures the three-dimensional shape of a workpiece (workpiece) is needed, and in order to remove the surplus thickness calculated based on the measured value, it is necessary for every part. Since the number of times of grinding was repeated, there was a problem that it took construction time.

  Further, the method for preventing the grinding ability of the grindstone from being reduced as described in Patent Document 2 has an effect of preventing the grinding ability from being lowered as compared with the case where grinding is performed at a constant grindstone contact angle. However, since grinding conditions such as a grinding speed and a wheel contact angle are periodically changed, there is a problem that a grinding amount and a grinding depth vary, and a smooth ground surface cannot be obtained.

  Further, the cutter mark grinding method described in Patent Document 3 requires a sensor for detecting a force in a plurality of axial directions in order to calculate the moment, and the calculated moment varies depending on the shape of the cutter mark. Therefore, the grinding amount also varies. For this reason, it has been difficult to always secure a constant grinding amount, and there has been a problem that a smooth grinding finish of the workpiece surface cannot be obtained.

  In addition, the control method of the automatic grinding apparatus described in Patent Document 4 is such that when the electronic grinder stops abnormally due to wear of the carbon brush of the electronic grinder, the slide shaft control apparatus does not detect the current and the load is eliminated. The slide shaft is lowered and the grinder of the electronic grinder is pressed against the machining surface. Since the robot moves the electronic grinder along the processing surface while the grindstone is pressed, there are problems such as damage to the workpiece and the grinder.

  The present invention solves the above-mentioned problems, and also provides a CAM system for machine tools that creates a cutter mark under certain conditions, and a CAM system for grinding that operates an automatic grinding apparatus based on NC data output from the CAM system for machine tools. An object of the present invention is to provide a three-dimensional curved surface processing apparatus and a three-dimensional curved surface processing method that can reliably grind a cutter mark left on a cut surface and obtain a smooth ground surface.

  The present invention is an NC program for cutting so that the three-dimensional shape data of a workpiece generated by a three-dimensional CAD device is input and the width and depth of a cutter mark remaining on a cutting surface by a machine tool are constant. The cutting NC program calculation device for generating the cutting and the cutting NC program output from the cutting NC program calculation device are input, and grinding is performed based on the grinding locus along the cutter mark on the cutting surface. For generating grinding trajectory data and adjusting at least one of the grindstone contact angle, grinding feed speed, and grindstone pressing force in accordance with either time or grinding distance based on the grinding trajectory data And a grinding NC program calculation device for generating an NC program for grinding.

  The present invention is a three-dimensional curved surface machining apparatus characterized in that the NC program computing device for grinding generates grinding locus data by rearranging a grinding locus along a cutter mark on a machining surface every predetermined number. is there.

  The present invention is characterized in that the NC program calculation device for grinding generates grinding locus data based on a crossing grinding locus intersecting with the grinding locus in addition to a grinding locus along the cutter mark on the cutting surface. Is a three-dimensional curved surface processing apparatus.

  The present invention measures the position of the actual measured shift point of the object to be processed by the automatic grinding apparatus to which the NC program for grinding processing in which the shift reference point is set is input, and the shift reference on the NC program for grinding processing. The three-dimensional curved surface machining apparatus is characterized in that the NC program for grinding is modified based on a difference from a point.

  The present invention relates to an electronic grinder having a grinder and a motor, a slide shaft that holds the electronic grinder, presses the grinder against the processing surface, a robot that holds the slide shaft, and moves the grinder along the processing surface. And a control device that controls the electronic grinder, the slide shaft, and the robot. The control device controls the slide shaft so that the slide shaft presses the grinder against the machining surface with a constant force, and the current value from the motor is A three-dimensional curved surface processing apparatus that controls a robot to separate a grinder from an object to be processed when it falls below a predetermined value.

  The present invention inputs the three-dimensional shape data of the workpiece generated by the three-dimensional CAD device to the NC program computing device for cutting, and the cutter remains on the cutting surface by the machine tool in the NC program computing device for cutting. The step of generating the NC program for cutting so that the width and depth of the mark are constant, and the NC program for cutting output from the NC program calculating device for cutting are input to the NC program calculating device for grinding Then, in this NC program computing device for grinding, grinding trajectory data is created based on the grinding trajectory along the cutter mark on the cutting surface, and based on this grinding trajectory data, either one of time and grinding distance is used. NC program for grinding that adjusts at least one of grinding wheel contact angle, grinding feed speed, and pressing force Generating a beam, a three-dimensional curved surface machining method characterized by comprising a.

  The present invention is a three-dimensional curved surface machining method characterized in that the NC program computing device for grinding creates grinding locus data by rearranging the grinding locus along the cutter mark on the machined surface every predetermined number. is there.

  The present invention is characterized in that the NC program calculation device for grinding generates grinding locus data based on a crossing grinding locus intersecting with the grinding locus in addition to a grinding locus along the cutter mark on the cutting surface. Is a three-dimensional curved surface processing method.

  The present invention measures the position of the actual measured shift reference point of the workpiece by the automatic grinding apparatus to which the NC program for grinding processing in which the shift reference point is set is input, and shifts on the NC program for grinding processing. The three-dimensional curved surface machining method is characterized in that the NC program for grinding is modified based on a difference from a reference point.

  According to the present invention, it is possible to reliably grind the cutter mark left on the cut surface with respect to a workpiece having a complicated three-dimensional curved surface shape, thereby obtaining a smooth ground surface.

First Embodiment Hereinafter, a first embodiment of a three-dimensional curved surface processing apparatus and a three-dimensional curved surface processing method according to the present invention will be described with reference to the drawings.

  1 to 11 are diagrams showing a first embodiment of a three-dimensional curved surface processing apparatus and a three-dimensional curved surface processing method according to the present invention.

  A three-dimensional curved surface processing apparatus according to the present invention is inputted with a three-dimensional CAD device 1 for product design and three-dimensional shape data 2 of a workpiece to be output outputted from the three-dimensional CAD device 1 for product design. 3 for cutting machining NC program, 4 for inputting NC program 3 for cutting and NC program computing device 6 for grinding to output NC program 5 for grinding, and NC program 3 for cutting 3 An NC machine tool 7 for cutting the workpiece 8, an NC control device 9 for controlling the NC machine tool 7, and an NC program 5 for grinding are inputted to perform automatic grinding for grinding the workpiece 8. Device 10.

  Among these, the cutting NC program calculation device 4 inputs the three-dimensional shape data 2 of the workpiece, and generates a cutting locus generation calculation device 11 that generates the locus of the cutting tool on the surface of the three-dimensional shape data 2. And a machining command adding device 12 for adding a machining command to the cutting locus output from the cutting locus generating arithmetic unit 11.

  The grinding NC program calculation device 6 is a coordinate system for converting position data included in the machining locus in the cutting NC program 3 output from the cutting NC program calculation device 4 into a coordinate system on the automatic grinding device 10. A converting device 13; a grinding processing range extraction computing device 14 for extracting a trajectory to be a grinding target range from a trajectory of the cutting NC program 3 output from the coordinate converting device 13; and a trajectory of the extracted grinding processing range. Included in the cross direction trajectory generation calculation device 15 that generates a processing trajectory in the intersecting direction, the processing trajectory output from the grinding process range extraction calculation device 14, and the processing trajectory output from the cross direction trajectory generation calculation device 15. Machining locus thinning calculation device 16 that thins out position data to the minimum number required for locus interpolation calculation by automatic grinding device 10 and machining locus thinning calculation The machining locus rearrangement calculation device 17 which rearranges the machining locus output from the device 16 alternately or every arbitrary number, and the attitude data of the electronic grinder 21 which is a grinding tool of the automatic grinding device 10 are added to the position data included in the machining locus. Is set in the grinder attitude calculating device 18 for calculating and adding the control command, the control command adding device 19 for adding the control command of the automatic grinding device 10 to the grinding locus data output from the grinder posture calculating device 18, and the automatic grinding device 10. And a grinding condition database 20 in which the grinding conditions to be stored are stored.

  The automatic grinding apparatus 10 detects an electric grinder 21 including a grinder (grinding stone) 21a and a motor 21b, a slide shaft 23 holding the electronic grinder 21, and a current 22 applied to the motor 21b, so that the value becomes constant. An automatic grinder control device 24 that controls the slide shaft 23 to press the grinder (grinding stone) 21a against the machining surface 8, a robot 25 that attaches and holds the slide shaft 23 to the tip of the arm, and the NC program 5 for grinding are input. And a robot controller 28 that controls the robot 25 to operate the electronic grinder 21 along the surface of the workpiece 8 and outputs an operation signal 26 to the automatic grinder controller 24.

  Instead of detecting the current 22 applied to the motor 22b of the electronic grinder 21, a pressure sensor is provided at the mounting portion of the electronic grinder 21, and the pressing force applied to the electronic grinder 21 is detected so that the value becomes constant. It can also be set as the structure which controls the slide shaft 23 which presses the grinder 21 against a process surface.

  Next, the operation of the present embodiment having such a configuration will be described. First, the surface state of the workpiece 8 cut by using the NC machine tool 7 is shown in FIG. As shown in FIG. 2, a cutter mark 29 cut by a ball end mill of a cutting tool or the like is formed on the surface of the workpiece 8 along a cutting locus.

  FIG. 3 shows a processed state of a cross section viewed from the direction of arrow A in FIG. The deepest portions a, b, and c of the cutter mark 29 formed by cutting with the ball end mill 31 with respect to the shape 30 before processing of the workpiece are located on the final shape 32, and between ab and bc Cutting trajectory data is generated so that the distance between them is constant. As a result, the cross-sectional shape of the crest portion 33 of the cutter mark 29 becomes constant, and at the same time, the width and depth of the cutter mark 29 become constant.

  In the cutting trajectory generation calculation device 11 in the NC program calculation device 4 for cutting, as shown in FIG. 4, the processing surface of the three-dimensional shape data 2 of the processing object input from the product design three-dimensional CAD device 1 is applied. A machining line 35 is created at equal intervals from the outer peripheral shape line 34, an intersection 36 of the machining line is obtained, and cutting locus data 37 in which the intersections 36 are sequentially arranged is created.

  Next, an operation command of the NC machine tool 7 is added to the cutting locus data 37 by the machining command adding device 12 and output as the NC program 3 for cutting.

  On the other hand, in the automatic grinding apparatus 10 that performs grinding, the slide shaft 23 is driven so that the current 22 applied to the motor 21b of the electronic grinder 21 becomes a specified value, and thereby the grinding amount becomes constant. For this reason, in the robot 25, by operating the electronic grinder 21 along the cutter mark 29 formed on the cutting surface, the crest portion 33 of the cutter mark 29 on the cutting surface can be removed by grinding. .

  In the runner vane of a turbine generator that is one of the workpieces 8, since the surface roughness affects the performance, after performing rough grinding with the coarse abrasive grains of the grinding wheel used in the grinding process, the shape is formed. In addition, it is necessary to perform finish grinding instead of a grindstone with fine abrasive grains to finish to a predetermined surface roughness.

  In this case, if the grinding trajectory of rough grinding is performed only in the same direction, scratches caused by abrasive grains will be applied in one direction, and in finish grinding, it will be difficult to remove the scratches attached by rough grinding. Rough grinding must also be performed.

  From the above, it is preferable that the locus of grinding includes at least the locus of the cutter mark for cutting, and further includes the locus of grinding in a direction intersecting with it. In the present embodiment, the grinding NC program calculation device 6 obtains grinding locus data including a grinding locus along the cutter mark and a grinding locus that intersects the grinding locus.

  In the NC program computing device 6 for grinding, first, the trajectory data in the NC program 3 for cutting created in the reference coordinate system of the NC machine tool 7 is converted into the reference coordinate system of the automatic grinding device 10 by the coordinate conversion device 13. .

  Next, as shown in FIG. 5, the grinding processing range extraction calculation device 14 obtains the boundary point 38 from the trajectory data in the range that can be processed by the automatic grinding device 10, and divides the trajectory data at the boundary point 38.

  When obtaining this boundary point, a point included in the trajectory data as shown in FIG. Next, the angle θ formed by the vectors ab and bc is obtained from the position data of the point a before and the point c after the locus, and the point b at which this exceeds a certain value is determined as the boundary point.

  With respect to the divided trajectory data, a point at which the trajectory starts is a grinding start point 39, a point at which the trajectory ends is a grinding end point 40, and an approach point 41 and a retreat point 42 are located at a certain distance from each other. A series of grinding locus data is generated by connecting the retract point 42 to the approach point 41 of the next locus.

  Next, the intersecting direction trajectory generating device 15 generates a trajectory in the intersecting direction by sequentially rearranging the points included in the trajectory data for grinding output from the grinding process range extraction calculating device 14 in a direction intersecting the trajectory ( (See FIG. 7).

  In the machining trajectory thinning calculation device 16, in order to minimize the distance between points used in an interpolation method such as circular interpolation used when the robot 25 operates the electronic grinder 21 along the surface of the workpiece 8. Then, the position data in the grinding locus data is thinned out within a predetermined distance, and the locus itself is thinned out in accordance with the minimum necessary locus interval in the grinding work (see FIGS. 8A and 8B).

  The thinned trajectory data for grinding is input to the processing trajectory rearrangement calculation device 17, and the trajectories are alternately or rearranged every arbitrary number. In the example shown in FIGS. 8A and 8B, the order of the even-numbered trajectories is switched after the odd-numbered trajectories are divided into the even-numbered trajectories. This processing corresponds to the fact that the grinding efficiency of the grinding wheel decreases with wear in proportion to the grinding distance when the grinding area is large, and the grinding amount on the grinding start side locus and grinding end side locus is kept constant. To do.

  Next, trajectory data for grinding is input to the grinder attitude calculation device 18, and attitude data of the electronic grinder 21 is calculated from each point of the trajectory data.

  In the automatic grinding apparatus 10 using the electronic grinder 21, the electronic grinder 21 is sent in the front-rear direction as shown in FIG. 9 so that the detected current of the motor 21b is actually proportional to the load applied to the electronic grinder 21. For this reason, as shown in FIG. 10, in the grinder posture calculation device 18, the vector direction in which the vector between the next points P2 is projected on the surface orthogonal to the normal line N1 of the workpiece at the grinding start point P1 of the grinding locus. At the same time, attitude data indicating the front-rear direction of the electronic grinder 21 is set. For the point Pj of the grinding locus, a vector obtained by projecting a composite vector of the vector between the previous point Pj-1 and the vector between the next point Pj + 1 onto a plane orthogonal to the normal line Nj of the workpiece Attitude data indicating the front-rear direction of the electronic grinder 21 is set in the direction. At the grinding end point PL, posture data indicating the front-rear direction of the electronic grinder 21 is set in the vector direction obtained by projecting the vector between the previous points PL-1 onto the surface orthogonal to the normal line NL of the workpiece.

  The approach point 41 has the same posture data as the grinding start point 39, and the retract point 42 has the same posture data as the grinding end point 40.

  In the next control command adding device 19, the grinding locus data to which the posture data is added is input, and the operation command of the robot 25 and the operation signal 26 to the automatic grinder control device 24 are added and stored in advance. A grinding NC program 5 is output by selecting and adding a grinding feed speed, a grinding wheel contact angle, and a motor current value (grinding wheel pressing force) according to the grinding wheel used from the grinding condition database 20.

  An example of a condition table stored in the grinding condition database 20 is shown in FIG. FIG. 11A shows a setting example of a grindstone of abrasive grain # 36 used for rough grinding, and FIG. 11B shows a setting example of a grindstone of abrasive grain # 60 used for finish grinding. As shown in FIGS. 11 (a) and 11 (b), three kinds of conditions, that is, a grinding feed speed, a grinding wheel contact angle, and a grinding wheel speed, so as not to be affected by a decrease in grinding efficiency due to grinding wheel wear. Change the grinding wheel pressing force.

  Thus, based on the grinding locus data, the optimum grinding NC program 5 comprising the grinding wheel contact angle, grinding feed speed and grinding wheel pressing force corresponding to the time or grinding distance is generated and output.

  As described above, according to the present embodiment, the surface of the object to be processed by cutting is processed by the NC machine tool 7 using the NC program 3 for cutting generated by the NC program computing device 4 for cutting. The shape of the crest portion of the cutter mark formed in the above becomes uniform. Moreover, since the locus of grinding is the same as the locus of cutting by machining with the automatic grinding device 10 using the NC program 5 for grinding generated from the NC program computing device 6 for grinding, The crest portion of the cutter mark can be uniformly cut off, and a smooth processed surface can be obtained.

  In addition, grinding was performed using the NC program 5 for grinding obtained from the locus for grinding in the direction intersecting with the locus for cutting obtained from the NC program computing device 6 for grinding. The scratches can be easily removed by finish grinding, and the grinding time can be shortened.

  In addition, the grinding NC program 5 obtained from the trajectory obtained by alternately or arbitrarily rearranging the grinding locus by the grinding NC program arithmetic unit 6 is used, and is set from the table set in the grinding condition database. By using the ground grinding conditions, it is possible to obtain a processed surface having a uniform roughness without being affected by a decrease in grinding efficiency due to wear of the grindstone.

Second Embodiment Next, a second embodiment of the present invention will be described with reference to FIGS. In the second embodiment shown in FIG. 12 to FIG. 14, the same parts as those in the first embodiment shown in FIG. 1 to FIG.

  The cutting NC program calculation device 4 inputs the three-dimensional shape data 2 of the workpiece 8 output from the product design three-dimensional CAD device 1 and the cutting locus output from the cutting locus generation calculation device 11. In addition, a reference point generation calculation device 44 that generates the shift reference point 43 is provided.

  The shift reference point 43 output from the reference point generation calculation device 44 is input to the coordinate conversion device 13 in the NC program calculation device 6 for grinding, and after being converted into the reference coordinate system of the automatic grinding device 10, the grinder posture calculation is performed. After being input to the apparatus 18 and added with grinder posture data, it is added to the trajectory data for grinding.

  12 to 14, in the reference point generation calculation device 44, as in the example shown in FIG. 13, the two intersections 45 of the outer peripheral line of the three-dimensional shape data 2 of the workpiece 8 and the cutting locus generation calculation device 11 are processed. The center point 46 of the cutting locus output from is generated as the shift reference point 43.

  This shift reference point 43 is input to the coordinate conversion device 13 in the NC program calculation device 6 for grinding, converted to the reference coordinate system of the automatic grinding device 10, and then input to the grinder attitude calculation device 18.

  The grinder attitude calculation device 18 extracts points corresponding to the grinding process range from the shift reference point 43, adds the grinder attitude data to the position data, and inputs it to the control command adding apparatus 19 together with the grinding process trajectory data. A command and grinding conditions are added and output to the robot controller 28 as the NC program 5 for grinding.

  FIG. 14 shows an example of a method for adding grinder attitude data to the position data of the three shift reference points 43. Here, the point corresponding to the center point 46 of the grinding locus is P01, and the intersections 45 of the outer peripheral lines are P02 and P03. In the vector representing the front-rear method of the electronic grinder 21, the vector direction projected on the plane orthogonal to the normal of the surface of the workpiece 8 at each point is set with reference to the vectors directed to the intersections P03 and P02.

  In the robot controller 28, the three shift reference points 43 included in the input NC program 5 for grinding and the electronic grinder 21 actually attached to the tip of the arm of the robot 25 are used as the actual shift reference points 43 a of the workpiece 8. The grinding locus data included in the NC program 5 for grinding is shifted and corrected based on the difference from the measured position data obtained from the actual tool tip position in the state of contact with the grinding tool.

  According to the present embodiment, the grinding locus data can be automatically adjusted to the position of the actual workpiece 8 based on the shift reference point 43 included in the NC program 5 for grinding. Automatic grinding can be performed without departing from the operating range.

Third Embodiment Next, a third embodiment of the present invention will be described with reference to FIGS. In the third embodiment shown in FIGS. 15A and 15B, the same parts as those in the first embodiment shown in FIGS.

  In this embodiment, when the current value applied to the motor 21b during the operation of the electronic grinder 21 in the automatic grinder control device 24 falls below a predetermined abnormality detection current value 47, the slide shaft 23 is stopped and an abnormality signal is displayed. Is output to the robot control device 28, and an abnormality detection device is provided that controls the robot 25 to separate the grinder 21a from the workpiece 8.

  In the present embodiment configured as above, during normal operation, the automatic grinder control device 24 detects the current 22 applied to the motor 21b of the electronic grinder 21 as shown in FIG. The slide shaft 23 is controlled so that the value becomes. In this case, when the movement of the tip of the robot 25 to the grinding start point 39 is completed, an activation signal is output from the robot controller 28 to the automatic grinder controller 24.

  Upon receiving this signal, the automatic grinder control device 24 starts the electronic grinder 21 and then lowers the slide shaft 23 at a low speed, so that the rotating grinder (grinding stone) 21a of the electronic grinder 21 contacts the workpiece 8. To do. When the current value of the motor 21b exceeds a predetermined work detection current value 48, the automatic grinder control device 24 outputs this work detection signal to the robot control device 28, and the current value is the target current value 49 for slide axis control. The pressing force is adjusted by driving the slide shaft 23 so as to approach the angle.

  The robot controller 28 that has received the workpiece detection signal moves the electronic grinder 21 attached to the tip of the arm of the robot 25 at a set feed speed based on the trajectory data in the grinding NC program 5, and completes the grinding end point. When 40 is reached, the start signal output to the automatic grinder control device 24 is turned OFF, and then the retreat point 42 is moved.

  The automatic grinder control device 24 that has confirmed that the start signal has been turned off stops the control of the slide shaft 23 and stops the electronic grinder 21.

  On the other hand, when an abnormality occurs in the electronic grinder 21 during grinding, the motor current value rapidly decreases as shown in FIG. The abnormality detection device in the automatic grinder control device 24 determines that an abnormality has occurred when the motor current value falls below a predetermined abnormality detection current value 47, stops the control of the slide shaft 23, and sends an abnormality signal to the robot control device 28. Output.

  Receiving the abnormality signal, the robot controller 28 retracts the electronic grinder 21 attached to the tip of the arm of the robot 25 upward from the current position and stops.

  According to the present embodiment, when an abnormality occurs in the electronic grinder 21 and stops, the electronic grinder 21 is not pressed against the workpiece 8 in a stopped state. The electronic grinder 21 can be retracted without damaging the object 8.

FIG. 1 is a conceptual diagram showing a three-dimensional curved surface processing apparatus and processing method according to a first embodiment of the present invention. FIG. 2 is a diagram illustrating a cutter mark formed on a workpiece and a grinding direction. FIG. 3 is a diagram showing a situation where cutter marks are formed. FIG. 4 is a conceptual diagram showing a locus of cutting with respect to a workpiece. FIG. 5 is a conceptual diagram showing a method of extracting a grinding process range from a cutting process trajectory. FIG. 6 is a conceptual diagram showing a method for extracting a boundary point of a grinding range. FIG. 7 is a conceptual diagram illustrating a method for generating a grinding locus in a direction orthogonal to the cutting locus. FIGS. 8A and 8B are conceptual diagrams showing rearrangement of the grinding locus. FIG. 9 is a view showing the feeding direction of the grinder in the automatic grinding apparatus. FIG. 10 is a conceptual diagram showing a method of generating grinder attitude data for grinding. FIGS. 11A and 11B show examples of a condition table for grinding. FIG. 12 is a conceptual diagram showing a three-dimensional curved surface processing apparatus and processing method according to the second embodiment of the present invention. FIG. 13 is a conceptual diagram showing a method for generating a shift reference point. FIGS. 14A and 14B are conceptual diagrams showing a method for obtaining grinder posture data of a shift reference point. FIGS. 15A and 15B are time chart diagrams showing processing of the three-dimensional curved surface processing apparatus according to the third embodiment of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 3D CAD apparatus for product design 2 3D shape data 3 NC program for cutting 4 NC program arithmetic unit for cutting 5 NC program for grinding 6 NC program arithmetic unit for grinding 7 NC machine tool 8 Work object 9 NC control device 10 Automatic grinding device 21 Electronic grinder 21a Grinder 21b Motor 22 Current 23 Slide shaft 25 Robot 26 Robot control device 29 Cutter mark 30 Shape before processing 31 Ball end mill 32 Final shape 33 Mountain portion 34 Peripheral shape line 35 Processing line 36 Machining line intersection point 37 Cutting locus data 38 Boundary point 39 Grinding start point 40 Grinding end point 41 Approach point 42 Retraction point 43 Shift reference point 45 Intersection point 46 Grinding locus center point 47 Work detection current value 48 Slide axis Target current value for control 49 Abnormality detection Current value

Claims (9)

Cutting that generates 3D shape data of a workpiece generated by a 3D CAD device and generates an NC program for cutting so that the width and depth of a cutter mark remaining on a cutting surface by a machine tool are constant. NC program calculation device for machining,
The cutting NC program output from the cutting NC program computing device is input, and grinding trajectory data is generated based on the grinding trajectory along the cutter mark on the cutting surface. An NC program computing device for grinding that generates an NC program for grinding that adjusts at least one of a grinding wheel contact angle, a grinding feed rate, and a grinding wheel pressing force in accordance with either time or grinding distance based on data When,
A three-dimensional curved surface processing apparatus comprising:   2. The three-dimensional curved surface machining apparatus according to claim 1, wherein the grinding NC program calculation device creates grinding locus data by rearranging the grinding locus along the cutter mark on the machined surface by a predetermined number. .   The grinding NC program calculation device generates grinding locus data based on a crossing locus that intersects with the grinding locus in addition to a grinding locus along a cutter mark on a cutting surface. The three-dimensional curved surface processing apparatus according to 1.   The position of the actual measured shift reference point of the workpiece is measured by an automatic grinding apparatus to which the NC program for grinding processing in which the shift reference point is set is input, and the position of the shift reference point on the NC program for grinding is measured. The three-dimensional curved surface machining apparatus according to claim 1, wherein the NC program for grinding is modified based on the difference. An electronic grinder having a grinder and a motor;
A slide shaft that holds the electronic grinder and presses the grinder against the machining surface;
A robot that holds the slide axis and moves the grinder along the machining surface;
An electronic grinder, a slide shaft and a control device for controlling the robot,
The control device controls the slide shaft so that the slide shaft presses the grinder with a constant force against the machining surface, and controls the robot when the current value from the motor falls below a predetermined value to remove the grinder from the workpiece. A three-dimensional curved surface processing apparatus characterized by being separated. The three-dimensional shape data of the object to be processed generated by the three-dimensional CAD device is input to the NC program computing device for cutting, and the width of the cutter mark remaining on the machined surface by the machine tool in the NC program computing device for cutting Generating an NC program for cutting so that the depth is constant;
The cutting NC program output from the cutting NC program calculation device is input to a grinding NC program calculation device, and in this grinding NC program calculation device, based on a grinding locus along a cutter mark on a cutting surface. Grinding track data is created, and based on this grinding track data, the grinding NC that adjusts at least one of the grindstone contact angle, grinding feed speed, and pressing force in accordance with either time or grinding distance Generating a program;
A three-dimensional curved surface processing method comprising:   7. The three-dimensional curved surface machining method according to claim 6, wherein the NC program computing device for grinding creates grinding locus data by rearranging the grinding locus along the cutter mark on the machined surface for every predetermined number. .   The grinding NC program calculation device generates grinding locus data based on a crossing locus that intersects with the grinding locus in addition to a grinding locus along a cutter mark on a cutting surface. 6. The three-dimensional curved surface processing method according to 6.   The position of the actual measured shift reference point of the workpiece is measured by an automatic grinding apparatus to which the NC program for grinding processing in which the shift reference point is set is input, and the position of the shift reference point on the NC program for grinding is measured. The three-dimensional curved surface machining method according to claim 6, wherein the NC program for grinding is modified based on the difference.

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