JP6077814B2 - NC data creation device and NC grinder - Google Patents

Description

  The present invention relates to an NC (numerical control) grinder, and more particularly to creation of NC data for controlling the NC grinder.

  Conventionally, an NC grinding machine is known as a kind of NC (numerical control) machine tool. The NC grinder controls the relative motion between the workpiece (workpiece) and the grinding wheel (grinding wheel) by numerical information such as position and speed, and executes a series of operations related to machining by programmed commands. .

  In such precision forming grinding with an NC grinder, first, roughing is first performed and then finishing is performed. A grinding wheel (hereinafter simply referred to as a grindstone) used in this finishing process has a generally disk shape, and a tip part (outer peripheral part) that is a part that abuts against a workpiece and performs grinding is provided. Furthermore, the tip of the grindstone that constitutes the grinding part that actually contacts the workpiece has a cross-sectional outer shape (through a plane that passes through the center of rotation of the grindstone and is parallel to the rotation axis of the grindstone). It is formed so as to form a semicircular arc.

  NC data (NC program) for controlling an NC grinder equipped with such a finishing grindstone is premised on that the cross-sectional outer shape of the grindstone tip has a semicircular arc shape. Created on. Normally, in the case of a grinding wheel for finishing, the center of the arc that forms the tip of the grinding wheel is used as a reference point of the grinding wheel, and NC data controls the position of the grinding wheel by controlling the position of the reference point. Become. As described above, since the reference point of the grindstone and the processing point (contact point between the workpiece and the grindstone) are deviated, the reference point of the grindstone is determined based on the shape data of the workpiece. If NC data that moves along the contour of the workpiece is created, the workpiece will be excessively ground by the radius (R) of the arc at the tip of the grindstone during actual grinding.

  In order to avoid such a situation, conventionally, for example, when creating NC data, the grindstone (reference point) is set so that the reference point of the grindstone passes outside the contour of the desired shape of the workpiece by R. The route of was to be calculated.

  However, the grindstone wears during use, and the wear is usually not uniform, and there are a portion with a high degree of wear and a portion with a small degree of wear. Therefore, when grinding is performed using NC data created on the premise that the grindstone is not worn (the cross-sectional outer shape of the grindstone tip has a semicircular shape) using the worn grindstone. The machined part of the workpiece that is machined by the part with a high degree of wear is left uncut.

  In the case where uncut material due to wear of the grindstone occurs in this way, conventionally, for example, it has been necessary to perform a truing (dressing) operation of the grindstone to shape the tip shape of the grindstone into a semicircular shape, which is troublesome. .

  In JP 2009-214289 A, NC graphic data is created in advance based on graphic data, and an actual workpiece and a grinding portion of a grindstone are imaged by an imaging means. An image and a grindstone image are displayed on the screen of the display device by the control device by superimposing the machining line, the workpiece image and the grindstone image, and converted into graphic data. The NC is based on the machining line on the displayed screen. A machining program is created, the wheel graphic and its movement are superimposed on the workpiece image and simulated, and then the trajectory of the grinding wheel is confirmed. The workpiece is automatically ground with the actual grinding wheel based on the NC machining program. In the profile grinding method, the grindstone image is obtained by imaging a grinding trace obtained by grinding a test material with an actual grindstone or an actual grindstone. It has been described which converts process the captured image into vector data.

JP 2009-214289 A (paragraphs 0012, 0013)

  An object of the present invention is to provide an NC data creation device that can appropriately identify the tip shape of the current grindstone and can create NC data according to the identified tip shape of the grindstone. .

  The NC data creation device according to the present invention, according to a user instruction, NC data based on a grindstone shape identifying unit that creates grindstone shape data that identifies a tip shape of a grindstone, workpiece shape data, and the grindstone shape data. An NC data creation unit to be created and an image showing the tip shape of the current grindstone imaged by the imaging unit are displayed on the display device, and a grindstone shape graphic showing the tip shape of the grindstone is displayed based on the grindstone shape data And a display processing unit to be displayed on the apparatus.

  In this case, the grindstone shape specifying unit manages control point data for specifying the shape of the grindstone shape figure, updates the control point data according to a user instruction, and based on the control point data, The whetstone shape data is created, and the display processing unit displays the whetstone shape figure on a display device based on the whetstone shape data, and displays a control point on the display device based on the control point data. You may do it.

  Further, in this case, the grindstone shape specifying unit may specify a curve corresponding to the control point data based on the control point data, and create the grindstone shape data based on the curve. Good.

  In this case, the grindstone shape specifying unit may create the grindstone shape data by approximating the curve with a line segment and an arc. The curve may be a spline curve.

  In the above case, the image showing the tip shape of the current grindstone may be an image of a test material ground by the current grindstone.

  In the above case, the grindstone shape data is data related to the arc elements constituting the tip shape of the grindstone, and the workpiece shape data is data related to the line segment elements and arc elements constituting the shape of the workpiece. The NC data creation unit, for each line segment element constituting the shape of the workpiece, an arc element that can be in contact with each line segment element at one point as a processing arc to be used for machining each line segment element, Select from the grinding wheel shape data, obtain the tool path at the time of machining by the selected machining arc, and for each arc element constituting the shape of the workpiece, an arc element that can contact with each arc element at one point, A machining arc to be used for machining each arc element is selected from the grinding wheel shape data, a tool path at the time of machining with the selected machining arc is obtained, and NC is determined based on the obtained tool path. It is also possible to create an over data.

  In this case, the NC data creation unit compares the inclination of the normal line of the line segment element constituting the shape of the workpiece with the normal angle range of each arc element constituting the tip shape of the grindstone. Selecting a machining arc to be used for machining the line segment element, and a normal angle range of the arc element constituting the shape of the workpiece, and a normal angle range of each arc element constituting the tip shape of the grindstone May be used to select a machining arc to be used for machining an arc element constituting the shape of the workpiece.

  An NC grinder according to the present invention includes a grindstone, an imaging unit that captures an image near the tip of the grindstone, a moving unit that relatively moves the grindstone and the workpiece, the NC data creation device, A display device controlled by an NC data creation device and an NC control device that controls the moving unit according to the NC data created by the NC data creation device are provided.

  In this case, during the grinding process, the display processing unit causes the display device to display an image of the workpiece imaged by the imaging unit, and indicates a grindstone shape based on the grindstone shape data. You may make it display a figure on the said display apparatus.

  According to the present invention, the tip shape of the current grindstone can be specified appropriately, and NC data corresponding to the specified tip shape of the grindstone can be created.

It is a figure for demonstrating the structure of the NC grinder to which this invention is applied. It is a figure for demonstrating the hardware constitutions of NC data preparation apparatus 152. FIG. It is a figure for demonstrating the software structure of the NC data preparation apparatus 152. FIG. It is a figure for demonstrating the structure of the grindstone shape element management table 350. FIG. It is a figure for demonstrating the structure of the workpiece shape element management table 360. FIG. It is a figure for demonstrating the mode of grinding of a test material. It is a figure (the 1) for demonstrating the outline of a grindstone shape specific process. It is FIG. (2) for demonstrating the outline of a grindstone shape specific process. It is a flowchart for demonstrating the flow of the grindstone shape specific process in the grindstone shape specific | specification part 310. FIG. It is FIG. (1) for demonstrating the progress in the middle of a grindstone shape specific process. It is FIG. (2) for demonstrating progress in the middle of a grindstone shape specific process. It is FIG. (3) for demonstrating the progress in the middle of a grindstone shape specific process. 5 is a flowchart for explaining a flow of NC data creation processing in an NC data creation unit 320. It is a figure for demonstrating the detail of a line segment element process. It is a figure for demonstrating the circular arc element process in case the circular arc element used as a process target has a concave shape seeing from the tool side. It is a figure for demonstrating the circular arc element process in case the circular arc element used as a process target has a convex shape seeing from the tool side.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a diagram for explaining the configuration of an NC grinder to which the present invention is applied. The figure (a) shows a front view, and the figure (b) shows a top view. In FIG. 5B, only some components are shown for simplicity.

  As shown in the figure, an NC grinder 100 to which the present invention is applied includes a grinding unit 110, a workpiece holding unit 120, a workpiece moving unit 130, an imaging unit 140, and a control unit 150.

  The grinding unit 110 performs grinding of the workpiece 10 held by the workpiece holding unit 120 and includes a grindstone 111. The grinding unit 110 is configured to rotate the grindstone 111 and move it up and down (up and down) in the vertical direction (Z direction) during grinding.

  The workpiece holding unit 120 is configured to detachably hold the workpiece 10 to be ground by the grinding unit 110 (the grindstone 111). Moreover, the workpiece holding part 120 is comprised so that the test material (after-mentioned) for specifying the front-end | tip shape of the grindstone 111 with the workpiece 10 can also be hold | maintained. The workpiece holding unit 120 is placed on the workpiece moving unit 130 in order to move the held workpiece 10 relative to the grindstone 111.

  The workpiece moving unit 130 relatively moves the workpiece 10 and the grindstone 111, and includes an XY table 131, an X-axis motor 132, and a Y-axis motor 133.

  The XY table 131 is a table that can move in each of the X direction and the Y direction, and the work unit holding unit 120 placed on the table is moved in the X direction and the Y direction with respect to the grindstone 111, thereby The workpiece 10 held by the part holding part 120 is moved in the X direction and the Y direction with respect to the grindstone 111. An X-axis motor 132 that controls movement in the X-axis direction and a Y-axis motor 133 that controls movement in the Y-axis direction are connected to the XY table 131. The X-axis motor 132 and the Y-axis motor 133 are each electrically connected to the control unit 150, and the rotation direction, the rotation amount, and the like are controlled by the control unit 150.

  The imaging unit 140 is disposed above the grindstone 111 and performs imaging of the vicinity of the tip (grinding portion) of the grindstone 111. The imaging unit 140 is configured by a CCD camera, for example. The imaging unit 140 periodically captures the vicinity of the tip of the grindstone 111 (for example, 20 times per second), and the still image captured by the imaging unit 140 is periodically sent to the control unit 150. The imaging unit 140 and the control unit 150 are connected by, for example, a USB interface, and image data captured by the imaging unit 140 is sent to the control unit 150 via the USB interface. In addition, the imaging unit 140 is configured to be able to switch the magnification. For example, a magnification (for example, 500 times) at which the current shape of the grindstone tip can be easily confirmed and a magnification (for example, a large field of view) can be ensured (for example, , 80 times), and can be imaged at any magnification.

  The control unit 150 controls the NC grinder 100 and includes an NC control device 151, an NC data creation device 152, a display device 153, and an operation panel 154.

  The NC control device 151 controls the grinding process in the NC grinder 100 by controlling the X-axis motor 132, the Y-axis motor 133, etc. according to the NC data (NC program) created by the NC data creation device 152. Is. The NC control device 151 is connected to the NC data creation device 152 via, for example, a USB interface, and performs control according to NC data (NC program) sent from the NC data creation device 152 via the USB interface. Do.

  The NC data creation device 152 creates NC data (NC program) used by the NC control device 151. The NC data creation device 152 creates NC data necessary for processing the workpiece 10 into a desired shape based on the shape of the current grindstone 111 based on the shape data of the workpiece and the current shape data of the grindstone 111. To do. The NC data creation device 152 is configured by a normal computer, for example.

  The display device 153 is connected to the NC data creation device 152 and displays various screens for creating NC data, graphics indicating the shape of the workpiece and the grindstone, images captured by the imaging unit 140, and the like. . The display device 153 includes, for example, a CRT display or a liquid crystal display (LCD).

  The operation panel 154 includes various switches and knobs for controlling the NC grinder 100. The operation panel 154 includes, for example, a switch for turning on the power, a knob for controlling the rotational speed of the grindstone 111, a knob for manually moving the workpiece 10 with respect to the grindstone 111, and the like.

  Next, details of the NC data creation device 152 will be described.

  FIG. 2 is a diagram for explaining the hardware configuration of the NC data creation device 152.

  As shown in the figure, the NC data creation device 152 includes a CPU 201, a ROM 202, a RAM 203, a hard disk interface unit 204, a hard disk device 205, a USB interface unit 206, an input device 207, a display control unit 208, and the like. Is provided.

  The CPU 201, ROM 202, RAM 203, hard disk interface unit 204, USB interface unit 206, and display control unit 208 are each connected to the bus 209. A hard disk device 205 is connected to the hard disk interface unit 204. In addition, an input device 207 is connected to the USB interface unit 206, and an imaging unit 140 and an NC control device 151 are connected. A display device 153 is connected to the display control unit 208.

  The CPU 201 is a central processing unit that realizes various functions provided by the NC data creation device 152 by executing programs stored in the ROM 202 and the RAM 203.

  The ROM 202 is a read-only storage device (memory) that stores programs and data used by the CPU 201. The RAM 203 is a readable / writable storage device (memory) that temporarily stores programs and data used by the CPU 101.

  The hard disk interface unit 204 controls data exchange between the hard disk device 205 and the bus 209. The hard disk device 205 is an auxiliary recording device that stores an OS and other various programs and data used by the CPU 201.

  The USB interface unit 206 controls data exchange between an external device (in this embodiment, the input device 207, the imaging unit 140, and the NC control device 151) connected to the USB interface unit 206 and the bus 209. is there.

  The input device 207 is for inputting user instructions and the like, and is configured by, for example, a keyboard and a mouse or other pointing device.

  The display control unit 208 causes the display device 153 to display various screens for creating NC data, images captured by the imaging unit 140, and the like in accordance with instructions from the CPU 201. The display control unit 208 includes, for example, a video memory that stores display data to be displayed on the display device 153, a drawing LSI that draws graphics on the video memory, and the like.

  FIG. 3 is a diagram for explaining a software configuration of the NC data creation device 152.

  As shown in the figure, the NC data creation device 152 includes a grindstone shape identification unit 310, an NC data creation unit 320, and a display processing unit 330. Each unit 310 to 330 is basically realized by the CPU 201 executing a program loaded on the RAM 203. The NC data creation device 152 includes a control point management table 340, a grindstone shape element management table 350, and a workpiece shape element management table 360 in order to manage necessary information.

  The grindstone shape specifying unit 310 is for specifying the current tip shape of the grindstone 111 in accordance with a user instruction. The details of the current tip shape specifying process of the grindstone 111 in the grindstone shape specifying unit 310 (hereinafter, the grindstone shape specifying process) will be described later.

  The NC data creation unit 320 creates NC data (NC program) based on the workpiece shape data stored in the workpiece shape element management table 360 and the grindstone shape data stored in the grindstone shape element management table 350. It is. The workpiece shape data stored in the workpiece shape element management table 360 is appropriately created in advance based on a DXF file (DXF file) separately created using, for example, CAD software, The DXF file is stored in the hard disk device 205 via a USB memory connected to the USB interface unit 206, for example. On the other hand, the grindstone shape data stored in the grindstone shape element management table 350 is created by the grindstone shape identifying unit 310 in accordance with a user instruction. Details of the NC data creation processing in the NC data creation unit 320 will be described later.

  The display processing unit 330 controls display data displayed on the display device 153. The display processing unit 330 displays the transmitted image data on the display device 153 each time image data is sent from the imaging unit 140, and based on the workpiece shape data 360 and the grindstone shape data 350, the workpiece is displayed. The display device 153 displays a graphic indicating the shape of the wheel and a graphic indicating the shape of the grindstone. In addition, the display processing unit 330 causes the display device 153 to display control points based on the control point data stored in the control point management table 340.

  The control point management table 340 is for managing information (control point data) related to control points for specifying and correcting the shape of the figure indicating the tip shape of the grindstone 111, and more specifically, for each control. Stores the coordinate value of a point. Details of the control point management table 340 will be described later.

  The grindstone shape element management table 350 stores grindstone shape data for specifying the tip shape of the grindstone 111. The workpiece shape element management table 360 stores workpiece shape data for specifying the machining shape of the workpiece.

  FIG. 4 is a diagram for explaining the configuration of the grindstone shape element management table 350. The figure (a) shows the example of the front-end | tip shape of a grindstone, and the figure (b) shows the example of the grindstone-shaped element management table 350 corresponding to the front-end | tip shape of the whetstone shown by the same figure (a). FIG. 3C shows how to measure the start angle and the end angle when the type of the grindstone shape element is an arc.

  In the NC data creation device 152, the figure indicating the tip shape of the grindstone 111 (grindstone tip shape figure) is composed of arcs and line segments (however, as will be described later, it is used for creating NC data). Finally, the grindstone tip shape figure needs to be composed only of arcs). In the grindstone shape element management table 350, information about each element (arc or line segment) constituting the grindstone tip shape figure is stored as grindstone shape data. Further, in the grindstone shape element management table 350, information of each element constituting the grindstone tip shape graphic is transmitted from one end of the grindstone tip shape (the left end 411 in the same figure in this embodiment) to the other end. They are stored in the order in which they form the grindstone tip shape toward the portion (in this embodiment, the right end 412 in the figure).

  In the example shown in FIG. 5A, the tip shape of the grindstone is constituted by three elements arranged from the left end 411 to the right end 412, that is, an arc 401, a line segment 402, and an arc 403. In the element management table 350, information about each element is stored in the order of an arc 401, a line segment 402, and an arc 403.

  As shown in FIG. 4B, the grindstone shape element management table 350 includes an “element number” field 351, a “type” field 352, a “start point” field 353, an “end point” field 354, and a “center”. A field 355 and a “radius” field 356 are provided.

  The “element number” field 351 stores information (number) for identifying each element constituting the tip shape of the grindstone. In the example shown in the figure, the element number of the element 401 is “1”, the element number of the element 402 is “2”, and the element number of the element 403 is “3”.

  The “type” field 352 stores information indicating the type of each element constituting the tip shape of the grindstone. In the present embodiment, since the tip shape of the grindstone is represented by a combination of a line segment and an arc, the “type” field 352 indicates whether each element is a “line segment” or an “arc”. Information to be stored is stored.

  The “start point” field 353 stores information indicating the position of the start point of each element constituting the tip shape of the grindstone. When the element type is “line segment”, the coordinate value of the start point of the line segment is stored. On the other hand, when the element type is “arc”, the arc start angle is stored. The starting angle of the arc is, as shown in FIG. 3C, the angle formed by the straight line extending from the center of the arc toward the starting point of the arc and the X axis (positive) direction counterclockwise from the X axis. It will be measured.

  The “end point” field 354 stores information indicating the position of the end point of each element constituting the tip shape of the grindstone. When the element type is “line segment”, the coordinate value of the end point of the line segment is stored. On the other hand, when the element type is “arc”, the arc end angle is stored. The end angle of the arc is, as shown in FIG. 3C, the angle formed by the straight line extending from the center of the arc toward the end point of the arc and the X axis (positive) direction counterclockwise from the X axis. It will be measured.

  Both the “center” field 355 and the “radius” field 356 are meaningful only when the element type is “arc”, and the “center” field 355 contains the coordinate value of the center of the corresponding arc. The “radius” field 356 stores the radius of the corresponding arc.

  FIG. 5 is a diagram for explaining the configuration of the workpiece shape element management table 360. FIG. 4A shows an example of the shape of the workpiece, and FIG. 4B shows an example of the workpiece shape element management table 360 corresponding to the workpiece shown in FIG. FIG. 3C shows how to measure the start angle and the end angle when the type of workpiece shape element is an arc.

In the NC data creation device 152, the machining shape (contour) of a workpiece is generally constituted by an arc and a line segment. The workpiece shape element management table 360 stores information about each element (arc or line segment) constituting the shape (contour) of the workpiece as workpiece shape data. Also, the workpiece shape element management table 360 stores information on each element constituting the shape of the workpiece in the order of constituting the shape of the workpiece.

In the example shown in FIG. 6 (a), the shape of the workpiece, seven successive elements, namely, the line segment 501 and 502, arcs 503 and 504, which is configured by line segments 505 to 507, tool The object shape element management table 3 60 stores information about each element in the order of, for example, a line segment 501, a line segment 502, an arc 503, an arc 504, a line segment 505, a line segment 506, and a line segment 507. become.

  As shown in FIG. 5B, the workpiece shape element management table 360 includes an “element number” field 361, a “type” field 362, a “start point” field 363, an “end point” field 364, and a “center”. "Field 365 and a" radius "field 366.

  The “element number” field 361 stores information (number) for identifying each element constituting the shape of the workpiece. In the example shown in the figure, the element number of the element 501 is “1”, the element number of the element 502 is “2”, the element number of the element 503 is “3”, the element number of the element 504 is “4”, The element number 505 is “5”, the element number 506 is “6”, and the element number 507 is “7”.

  The “type” field 362 stores information indicating the type of each element constituting the shape of the workpiece, that is, “line segment” or “arc”.

  The “start point” field 363 stores information indicating the position of the start point of each element constituting the shape of the workpiece. When the element type is “line segment”, the coordinate value of the start point of the line segment is stored. On the other hand, when the element type is “arc”, the arc start angle is stored. The starting angle of the arc is, as shown in FIG. 3C, the angle formed by the straight line extending from the center of the arc toward the starting point of the arc and the X axis (positive) direction counterclockwise from the X axis. It will be measured.

  The “end point” field 364 stores information indicating the position of the end point of each element constituting the shape of the workpiece. When the element type is “line segment”, the coordinate value of the end point of the line segment is stored. On the other hand, when the element type is “arc”, the arc end angle is stored. The end angle of the arc is, as shown in FIG. 3C, the angle formed by the straight line extending from the center of the arc toward the end point of the arc and the X axis (positive) direction counterclockwise from the X axis. It will be measured.

  The “center” field 365 and the “radius” field 366 are both meaningful only when the element type is “arc”, and the “center” field 365 includes the coordinate value of the center of the corresponding arc. Is stored, and the radius of the corresponding arc is stored in the “radius” field 366.

  Next, the grindstone shape identifying process in the grindstone shape identifying unit 310 will be described.

  In executing the grindstone shape identifying process in the grindstone shape identifying unit 310, first, grinding of the test material is performed. This is performed to transfer the current tip shape of the grindstone 111 to the test material in order to specify the current tip shape of the grindstone 111. When specifying the tip shape of the grindstone 111, it is difficult to obtain a focused image even if the grindstone 111 is directly imaged. Therefore, the test material is ground and the test material formed by grinding is used. The tip shape of the grindstone 111 is identified from the grinding traces.

  FIG. 6 is a diagram for explaining the state of grinding of the test material.

  The figure (a) shows the test material at the time of the grinding process by the grindstone 111, and the figure (b) shows the test material after the grinding process. With respect to the test material 600 appropriately held in the work part holding part 120, as shown in FIG. 5A, when the grindstone 111 is relatively moved in the Y-axis direction and grinding is performed to a certain depth, As shown in FIG. 4B, the tip shape of the grindstone 111 at that time is transferred to the test material 600.

  After the grinding of the test material 600 as described above is completed, when the grindstone shape identifying function provided in the NC data creation device 152 is activated by the user, the grindstone shape identifying process in the grindstone shape identifying unit 310 is started.

  7 and 8 are diagrams for explaining the outline of the grindstone shape specifying process.

  FIG. 7A shows an example of a display screen displayed on the display device 153 immediately after the grindstone shape specifying function is activated, and FIG. 7B shows a grinding mark formed on the test material by the user. And the state where alignment with the figure which shows a grindstone was performed is shown. Moreover, Fig.8 (a) shows the example of the display screen displayed on the display apparatus 153 immediately after a grindstone shape correction function (after-mentioned) is started by the user, The same figure (b) is shown by the user. The state in which the shape of the grindstone is specified in accordance with the grinding mark formed on the test material is shown.

  When the grindstone shape specifying function is activated, first, the display processing unit 330 displays an initial shape figure of the grindstone (a figure showing the shape of the grindstone in a state where it is not worn). That is, as shown in FIG. 7A, a figure (whetstone initial shape figure) 711 indicating the initial shape of the grindstone is displayed on the display screen 153 according to the grindstone parameters (radius of the tip arc, etc.) appropriately designated by the user. Are displayed at predetermined positions. In the grindstone initial shape graphic 711, the tip of the grindstone is drawn as one semicircular arc centered on the reference point of the grindstone.

  When the grindstone initial shape graphic 711 is displayed at a predetermined position on the display screen of the display device 153, the user operates the input device 207 such as a keyboard to appropriately move the grindstone initial shape graphic 711, and visually Alignment with the test material image 700 captured by the imaging unit 140 and displayed by the display device 153 is performed. That is, as shown in FIG. 4B, the grindstone initial shape graphic 711 is moved so as to match the grinding trace of the test material.

  When the alignment of the initial shape figure 711 of the grindstone and the image 700 of the test material is completed, the display device 153 is worn on the image 701 of the grinding mark of the test material as shown in FIG. Since the grindstone figure 711 in a state of not being displayed is displayed in an overlapping manner, it can be easily confirmed how much the current grindstone is worn.

  As a result of the confirmation, if it is determined that NC data needs to be created in accordance with the current grindstone shape (wear level), the user activates the grindstone shape correction function of the NC data creation device 152.

  When the grindstone shape correction function is activated, the display processing unit 330 displays a point (control point) for controlling the shape of the tip of the grindstone initial shape graphic along with the grindstone initial shape graphic on the display screen of the display device 153. Is done. That is, as shown in FIG. 8A, a plurality (11 in the present embodiment) of control points 801 to 811 are displayed on an arc indicating the tip of the grindstone. The positions of the plurality of control points 801 to 811 can be changed by the user using the input device 207 such as a mouse. When the position of the control points 801 to 811 is changed by the user, a curve that smoothly connects the control points 801 to 811 after the change is generated by the NC data creation device 152 and displayed as a figure indicating the tip of the grindstone. It will be.

  The user appropriately changes the positions of the control points 801 to 811 while comparing the image 700 of the test material displayed on the display device 153 with the graphic 711 indicating the shape of the grindstone, and finally, FIG. As shown, the tip shape of the graphic 711 indicating the shape of the grindstone is matched with the grinding mark of the test material. When the user determines that the tip shape of the graphic 711 indicating the grindstone shape matches the grinding mark of the test material, the user appropriately instructs the NC data creation device 152 to end the grindstone shape specifying process.

  Next, details of the grindstone shape specifying process will be described.

  FIG. 9 is a flowchart for explaining the flow of the grindstone shape identifying process in the grindstone shape identifying unit 310. Moreover, FIGS. 10-12 is a figure for demonstrating progress in the middle of a grindstone shape specific process.

  When the grindstone shape specifying function is activated, first, an initial shape graphic of the grindstone, that is, a graphic indicating the shape of the grindstone that is not worn is displayed (S1). Next, when the grindstone shape correcting function is activated, an initial control point is set (S2). That is, the coordinates of each control point are arranged so that a predetermined number (11 in the present embodiment) of control points are arranged at equal intervals on a semicircular arc indicating the tip shape of the grindstone as initial control points. The value is calculated, and the calculated coordinate value is stored in the control point management table 340 that manages the control point data.

  As shown in FIG. 10, the control point management table 340 includes a “point number” field 341, an “X coordinate” field 342, and a “Y coordinate” field 343, and the X coordinate value and Y coordinate of each control point. The value is managed.

  The “point number” field 341 stores information (number) for specifying each control point. In the present embodiment, the left and right end points of the semicircular arc are defined as a control point 800 having a point number 0 and a control point 812 having a point number 12, respectively. It is not displayed on the display screen and cannot be moved. That is, the control points whose positions can be changed by the user are the control points 801 to 811 having the point numbers 1 to 11 arranged at equal intervals between the control point 800 having the point number 0 and the control point 812 having the point number 12. It turns out that.

  The “X coordinate” field 342 stores the X coordinate of each control point 800 to 812, and the “Y coordinate” field 343 stores the Y coordinate of each control point 800 to 812. The values of the “X coordinate” field 342 and the “Y coordinate” field 343 are the values of the control points 801 to 811 that are moved by the user using the input device 207 such as a mouse, except for the point numbers 0 and 12. Every time, the value after the movement is updated.

  When the initial setting of the control points is completed, a process for obtaining a curve that smoothly connects the current control points is performed (S3). In the present embodiment, a curve that smoothly connects the control points is obtained using a spline curve (more specifically, a quadratic B-spline curve). That is, based on the coordinate values of the current control point, the spline curve specified by these control points is obtained.

  Once the spline curve corresponding to the current position of the control point is obtained, next, the coordinate values of points (interpolation points) on the spline curve are obtained by a predetermined number based on the obtained spline curve ( S4). That is, a predetermined number of point sequences (interpolation point data) indicating the corresponding spline curve are obtained.

  When the calculation of the interpolation point data is completed, a spline curve approximation process is then performed based on the calculated interpolation point data (S5). Specifically, the spline curve is approximated by an arc and a line segment.

  For this purpose, first, the coordinate values of the first three points are extracted from a predetermined number of point sequences (interpolation point data) indicating the corresponding spline curve. Then, the first point is the start point, the second point is the intermediate point, the third point is the end point, and it is determined whether or not the three points are on one straight line.

  As a result of the determination, when three points are on one straight line, the coordinate value of the next point is extracted from the interpolation point data, and it is determined whether or not the next point is also on the same straight line. . As a result of the discrimination, if it is on the same straight line, the fourth point is set as the end point, and further, the coordinate value of the next point is extracted from the interpolation point data, and a point not on the same straight line appears. Repeat the same process. And when a point that is not on the same straight line comes out, the point is set as the intermediate point of the next element, and the line segment with the start point and end point at that time as the start point and end point, respectively, The shape element is stored in the grindstone shape element management table 350.

  Next, the end point at that time is set as the start point of the next element, the coordinate value of the next point is extracted from the interpolation point data, and the extracted point is set as the end point of the next element. Then, for the three points of the start point, the intermediate point, and the end point, the following processing is performed in the same manner as described above to determine whether or not they are on one straight line.

  On the other hand, when the current three start points, intermediate points, and end points are not on one straight line, a circle passing through the three points is determined, so the center and radius of the circle are calculated. Next, the coordinate value of the next point is extracted from the interpolation point data, and it is determined whether or not the next point is also on the same circle. For example, if the distance from the center of the circle to the next point is calculated and the absolute value of the difference between the calculated distance and the radius of the circle is less than or equal to a predetermined value, the same applies to the next point. Judge that it is on the circle. As a result of the determination, if it is on the same circle, the next point is the end point, and further, the coordinate value of the next point is extracted from the interpolation point data until a point that is not on the same circle comes out Repeat the same process. And when a point that is not on the same circle comes out, the point is set as the intermediate point of the next element, and the arc having the start point and the end point at that time as the start point and the end point, respectively, Elements are stored in the grindstone shape element management table 350. In the case of an arc, the start point and end point are stored as converted into the corresponding start angle and end angle as described above. The radius and center of the arc are also stored in the grindstone-shaped element table 350. At this time, it is determined whether the arc is an outwardly convex arc or an indented arc. In the case of a concave arc, a negative value is stored as the radius. Thus, in the case of an arc recessed inwardly, the negative value is stored as the radius when the specification of the grindstone shape is completed, as will be described later, the grindstone shape data (grindstone shape element management table 350). Whether or not an arc that is recessed inward is included is determined in order to facilitate the determination. If the radius of the arc is larger than a predetermined value, it is assumed that the arc is approximated not as an arc but as a line segment. In this case, only the coordinate values of the start point and end point are stored in the grindstone shape element management table 350. Like that.

  Next, the end point at that time is set as the start point of the next element, the coordinate value of the next point is extracted from the interpolation point data, and the extracted point is set as the end point of the next element. Then, for the three points of the start point, the intermediate point, and the end point, the following processing is repeated in the same manner as described above to determine whether or not they are on one straight line.

  The above process is performed for all the interpolation point data, and when the process is completed for all the interpolation point data, the approximation process is terminated.

  Through the above approximation processing, the shape of the spline curve defined by the current control point position is approximated by a combination of an arc and a line segment, and information on the arc and line segment that approximately represents the spline curve is obtained. And stored in the grindstone shape element management table 350.

  When the spline curve approximating process ends, the approximated grindstone graphic is displayed on the display device 153 (S6). In other words, the grindstone figure that approximates the spline curve is displayed on the display device 153 by drawing the arc and the line segment obtained by the approximating process. The current control point is also displayed on the display device 153 together with the grindstone graphic.

  FIG. 10 is a diagram illustrating a state when the first control point is displayed. As shown in the figure, the first control points 800 to 812 are set so as to be arranged at equal intervals on a semicircular arc, so that the spline curve defined by the first control points 800 to 812 is set. Becomes a semicircular arc, and the first grindstone figure that approximates the spline curve is also composed of one semicircular arc 1001. Therefore, the grindstone shape element management table 350 stores information on one circular arc element as the grindstone shape data.

  As described above, when the grindstone in the initial state is displayed together with the control points, the user can compare the tip shape of the grindstone with the grinding process while comparing it with the image of the grinding trace of the test material displayed at the same time. In order to match the trace, the position of the control point is moved one by one by operating the input device 207 such as a mouse.

  When it is detected that the position of one control point has been changed (S7: Yes), the grindstone shape specifying unit 310 updates the control point management table 340 as appropriate, and based on the position coordinates of the control point after the change, The spline curve specifying process S3, the interpolation point calculating process S4, the approximating process S5, and the grindstone drawing process S6 are performed, and the grindstone figure corresponding to the changed control point position is displayed on the display device 153.

  FIG. 11 is a diagram illustrating a state when one control point 803 is moved. In this case, as shown in the figure, as a result of the movement of the control point 803, the spline curve defined by the moved control points 800 to 812 is approximated by eleven arc elements, for example. Therefore, the grindstone shape element management table 350 stores information on eleven arc elements as the grindstone shape data.

  When the grindstone graphic corresponding to the position of the control point after the change is displayed on the display device 153, the user compares the grindstone graphic with the image of the grinding trace of the test material, and further determines the necessary control point. Move.

  As described above, every time the user instructs the movement of the control point (S7: Yes), the spline curve specifying process S2, the interpolation point calculating process S3, the approximating process S4, A grindstone drawing process S5 is performed.

  The user appropriately moves the control point so that the tip shape of the grindstone figure matches the grinding mark of the test material. As a result, when the tip shape of the grindstone figure matches the grinding mark of the test material, the user appropriately indicates that the specification of the grindstone shape has been completed.

  FIG. 12 is a diagram showing a state when the control points 801 to 811 are appropriately moved so that the tip shape of the grindstone pattern matches the grinding mark of the test material. In this case, as shown in the figure, as a result of the movement of the control points 801 to 811, the purline curve defined by the moved control points 800 to 812 is approximated by, for example, nine arc elements. . Therefore, the grindstone shape element management table 350 stores information on nine arc elements as the grindstone shape data.

  When receiving an instruction from the user that the specification of the grindstone shape has been completed (S8: Yes), the grindstone shape identifying unit 310 determines whether or not the grindstone shape data is normal (S9). Specifically, it is determined whether or not all the elements stored in the final grindstone shape element management table 350 are outwardly convex arcs. If the elements stored in the grindstone-shaped element management table 350 include arcs or line segments that are recessed inward, appropriate NC data cannot be created. The user is notified that the specified grindstone shape is not appropriate, and the user is prompted to change the grindstone shape (change the position of the control point) or to perform a truing operation. On the other hand, as a result of the determination, if all the constituent elements of the final grindstone shape data are arcs protruding outward, the grindstone shape identifying process is terminated assuming that an appropriate grindstone shape has been identified.

  Next, NC data creation processing in the NC data creation unit 320 based on the current grinding wheel tip shape (grinding wheel shape data) identified as described above will be described.

  The NC data creating unit 320 creates NC data based on the grindstone shape data stored in the grindstone shape element management table 350 and the workpiece shape data stored in the workpiece shape element management table 360.

  FIG. 13 is a flowchart for explaining the flow of NC data creation processing in the NC data creation unit 320.

  As shown in the figure, first, a processing location is designated by the user (S21). For example, the user first uses the input device 207 such as a mouse while referring to a graphic indicating the shape of the workpiece displayed on the display device 153 by the display processing unit 133, and first selects a machining start element for starting grinding. Next, a processing location is designated by selecting a processing end element for ending the grinding processing. For example, when the element 502 with the element number 2 in FIG. 5 is selected as the processing start element and the element 505 with the element number 5 is selected as the processing end element, the elements 502 to 505 with the element numbers 2 to 5 are processed locations. It is specified as (element to be processed).

  When the specification of the processing location (processing target element) is completed, the processing target element is selected from the specified processing target elements in accordance with the processing order (S22). For example, the element 502 with the element number 2 shown in FIG. 5 is selected as the first processing target element.

  Next, the type of the selected processing target element is determined (S23). That is, it is determined whether or not the type of the processing target element is a line segment. When the type of the processing target element is a line segment (S3: Yes), a tool (grinding stone) used when processing the line segment element Line segment element processing for obtaining a route is executed (S24). Details of the line segment element processing S24 will be described later.

  On the other hand, when the type of the processing target element is not a line segment (S23: No), that is, when the type of the processing target element is an arc, an arc for obtaining a tool (grinding stone) path for machining the arc element. Element processing is executed (S25). Details of the arc element processing S25 will be described later.

  When the processing according to the type of the processing target element is completed, it is determined whether or not the current processing target element is a processing end element (S26). As a result of the determination, if the current processing target element is not the processing end element (S26: No), the next processing target element is selected (S22), and the above processes S23 to S25 are repeated again.

  On the other hand, when the current processing target element is a machining end element (S26: Yes), the tool path created for each shape element constituting the designated machining location is appropriately connected and designated. A tool path necessary for machining a machining location is created (S27), and NC data (NC program) for moving a grindstone (tool reference point) on the created tool path is generated ( S28), the process ends.

  Next, the details of the line segment element processing S24 will be described.

  FIG. 14 is a diagram for explaining the details of the line segment element processing S24. FIGS. 9A and 9B show examples in which the line segment elements 1410 have different inclinations. Moreover, the figure (c) has shown the example of the grindstone-shaped element used for the process of the line segment element 1410 shown to the figure (a) and (b).

  In the line segment element processing S24, first, a grindstone-shaped element (hereinafter referred to as a processing arc) used for processing the line segment element 1410 to be processed is selected. As the processing arc, an arc that can be brought into contact with the line segment element 1410 to be processed at one point is selected.

  For this purpose, first, the inclination of the normal line (straight line orthogonal to the line segment element) 1411 of the line segment element 1410 to be processed is calculated. The inclination of the normal 1411 is calculated by measuring the angle formed by the normal 1411 and the X-axis (positive) direction counterclockwise from the X-axis, as shown in FIGS. .

  When the calculation of the inclination of the normal line 1411 is completed, the calculated inclination is then compared with the normal angle range of each grindstone shape element stored in the grindstone shape element management table 350. The normal angle range of each grindstone-shaped element specifically refers to an angle range from the start angle to the end angle of each grindstone-shaped element (arc element). For example, the normal angle range of the grindstone-shaped element shown in FIG. As a result of the comparison, if there is a grindstone-shaped element that includes the inclination of the normal line 1411 of the line segment element 1410 to be processed in the normal angle range, the grindstone-shaped element is selected as a processing arc. On the other hand, when there is no grindstone-shaped element that includes the inclination of the normal line 1411 of the line segment element 1410 to be processed in the normal angle range, the angle closest to the inclination of the normal line 1411 of the line segment element 1410 Is selected as a processing arc.

  In the example shown in FIG. 11A, the normal line 1411 of the line segment element 1410 has an inclination of 120 °. Therefore, for example, in the elements stored in the grindstone shape element management table 350, FIG. If the grindstone-shaped element 1420 shown in FIG. 4 exists, the grindstone-shaped element 1420 is selected as a processing arc.

  On the other hand, in the example shown in FIG. 5B, the normal line 1411 of the line segment element 1410 has an inclination of 90 °. For example, the normal angle range is included in the elements stored in the grindstone shape element management table 350. If there is a grindstone-shaped element 1420 as an arc including the angle closest to 90 ° in the normal angle range, the grindstone-shaped element 1420 is selected as a machining arc. Will be.

  When the machining arc is selected, the position coordinates of the tool reference point 1430 when the machining arc 1420 and the start point 1412 of the line segment element 1410 contact each other are calculated, and the tool at the time of starting the machining of the line segment element 1410 is calculated. Position (tool path start point). Similarly, the position coordinates of the tool reference point 1430 when the machining arc 1420 and the end point 1413 of the line segment element 1410 contact each other are calculated, and the tool position (tool path end point) at the end of machining of the line segment element 1410 is calculated. It is said.

  If the normal angle range of the processing arc 1420 does not include the inclination of the normal line 1411 of the line segment element 1410, the inclination of the normal line 1411 of the line segment element 1410 is as shown in FIG. An end point 1421 having a near normal angle is in contact with the line segment element 1410.

  As described above, when the coordinates of the tool path start point and the tool path end point are calculated, the tool path for machining the line segment element to be machined is obtained. That is, a path for linearly moving the grindstone (tool reference point) from the tool path start point to the tool path end point is a tool path for processing the line segment element to be processed.

  Next, the details of the arc element processing S25 will be described.

  15 and 16 are diagrams for explaining details of the arc element processing S25. FIG. 15A shows an example in which the circular arc element 1510 to be processed has a concave shape when viewed from the tool (grinding stone) side, and FIG. 15B shows the example shown in FIG. The example of the grindstone-shaped element used for the process of the circular arc element 1510 is shown. FIG. 16A shows an example in which the circular arc element 1610 to be processed has a convex shape when viewed from the tool (grinding stone) side, and FIG. 16B shows the example shown in FIG. An example of a grindstone-shaped element used for processing the circular arc element 1610 is shown.

  In the arc element processing S25, as in the case of the line segment element processing S24, first, a grindstone-shaped element (hereinafter referred to as a processing arc) used for processing the arc element to be processed is selected. As the processing arc, an arc that can contact the arc element to be processed at a single point is selected.

  For this purpose, first, the normal angle range of the arc element to be processed is compared with the normal angle range of each grindstone-shaped element. The normal angle range of the arc element that is the processing target element is specifically when the arc element that is the processing target element has a concave shape when viewed from the tool side, as shown in FIG. Is the angle range from the start angle to the end angle of the arc element. For example, the normal angle range of the arc element 1510 shown in FIG. On the other hand, when the arc element to be processed has a convex shape as seen from the tool side as shown in FIG. 16A, an angle range obtained by subtracting 180 ° from each of the start angle and the end angle, that is, , (Start angle −180 °) to (end angle −180 °). For example, the normal angle range of the arc element 1610 shown in FIG. 9A is 90 (= 270−180) ° to 180 (= 360−180). As shown in FIG. 5A, when the arc element 1610 to be processed has a convex shape when viewed from the tool side, the center of the arc element 1610 to be processed and the processing arcs 1621 and 1622. Since the center of is located on the opposite side across the processing point (the contact point of both arcs), in order to directly compare the inclination of the normal line, here, 180 ° is drawn. Yes.

  Then, a grindstone-shaped element having a normal angle range that overlaps (at least in part) with the normal angle range of the arc element to be processed is selected as the machining arc. When there are a plurality of corresponding arcs, a plurality of grindstone-shaped elements are selected as processing arcs. In this case, the circular arc element to be processed is divided into a plurality of processing ranges. On the other hand, when there is no grindstone-shaped element having a normal angle range that overlaps the normal angle range of the arc element to be processed, an angle close to the angle included in the normal angle range of the arc element is set to the normal line. A grindstone-shaped element included in the angle range is selected as a processing arc.

  In the example shown in FIG. 15A, the normal angle range of the arc element 1510 to be processed is 180 ° to 90 °. For example, among the elements stored in the grindstone shape element management table 350, As an element having a normal angle range that overlaps with a normal angle range of 180 ° to 90 °, a grindstone-shaped element 1521 having a normal angle range of 175 ° to 150 ° and 120 ° to 90 ° shown in FIG. If there is a grindstone-shaped element 1522 having the normal angle range, the two grindstone-shaped elements 1521 and 1522 are selected as arcs for processing. In this case, the arc element 1510 to be processed is divided into four processing ranges 1531 to 1534 as shown in FIG. That is, the processing range 1532 where the normal angle range overlaps with the first processing arc 1521, the processing range 1534 where the normal angle range overlaps with the second processing arc 1522, and any of the processing arcs 1521, 1522 are legal. The line angle ranges are divided into processing ranges 1531 and 1533 that do not overlap.

  On the other hand, in the example shown in FIG. 16A, the normal angle range of the arc element 1610 to be processed is 90 (= 270-180) ° to 180 (= 360-180) °. Among the elements stored in the shape element management table 350, as normal elements having a normal angle range overlapping with the normal angle range of 90 ° to 180 °, normals of 120 ° to 90 ° shown in FIG. If there is a grindstone-shaped element 1621 having an angle range and a grindstone-shaped element 1622 having a normal angle range of 175 ° to 150 °, the two grindstone-shaped elements 1621 and 1622 are selected as arcs for processing. Will be. Also in this case, the arc element 1610 to be processed is divided into four processing ranges 1631 to 1634 as shown in FIG. That is, the machining range 1631 where the normal angle range overlaps with the first machining arc 1621, the machining range 1633 where the normal angle range overlaps with the second machining arc 1622, and any of the machining arcs 1621, 1622 is legal. The line angle ranges are divided into processing ranges 1632 and 1634 that do not overlap.

  When the machining arc is selected, a tool path when the arc element is machined by each machining arc is obtained for each machining arc (machining range). First, each machining arc performs machining of the arc element to be machined in a machining range in which the normal angle range and the normal angle range of the arc element to be machined overlap. For example, in the example shown in FIG. 15, the processing arc 1521 performs processing in the processing range 1532, and the processing arc 1522 performs processing in the processing range 1534. In addition, for the machining range where the normal angle range of the arc for machining and the normal angle range of the arc element to be machined do not overlap, machining with the normal angle closer to the normal angle range of each machining range Machining is performed at the end point of the arc. For example, in the example shown in FIG. 15, the machining range 1531 is machined at the left end point 1523 of the machining arc 1521, and the machining range 1533 is the right end point 1524 of the machining arc 1521 (on the left side of the machining arc 1522. It will be processed at the end point 1525).

  The path of each machining arc is determined as follows for each machining range.

  First, the case where the circular arc element to be processed has a concave shape when viewed from the tool side as shown in FIG. 15A will be described.

  In this case, with respect to the machining ranges 1532 and 1533 in which the normal angle ranges overlap between the arc element 1510 to be processed and the machining arcs 1521 and 1522, the respective machining arcs 1521 and 1522 and the start of the corresponding machining range The position coordinates of the tool reference point 1540 when the points 1536 and 1538 are in contact with each other are calculated and set as the tool position (tool path start point) at the start of machining by each of the machining arcs 1521 and 1522. Similarly, the position coordinates of the tool reference point 1540 when the machining arcs 1521 and 1522 contact the end points 1537 and 1539 of the corresponding machining range are calculated, and the machining arcs 1521 and 1522 at the end of machining are calculated. The tool position (tool path end point) is used.

  The path of each of the machining arcs 1521 and 1522 is one arc in each machining range 1532 and 1534. Therefore, for each machining range 1532 and 1534, the radius and center of the arc serving as the tool path are the following. It is calculated by the following formula.

  Radius = radius of arc element to be processed-radius of machining arc

  Center = Center of arc element to be processed + (Tool reference point-Center of machining arc)

  On the other hand, regarding the processing ranges 1531 and 1533 in which the normal angle range does not overlap between the arc element to be processed and each processing arc, end points (processing end points) 1523 and 1524 (1525) of the processing arc The position coordinates of the tool reference point 1540 when the start points 1535 and 1537 of the machining range to be in contact with each other are calculated, and are set as tool positions (tool path start points) at the start of machining by the machining end points 1523 and 1524 (1525). . Similarly, the position coordinates of the tool reference point 1540 when the machining end points 1523, 1524 (1525) and the end points 1536, 1538 of the corresponding machining range contact each other are calculated, and each machining end point 1523, 1524 (1525) is calculated. ) Is the tool position (tool path end point) at the end of machining.

  Further, in this case, since the machining end point is moved along the arc element to be processed, the radius and center of the arc to be the tool path can be obtained by the following expression.

  Radius = radius of the arc element to be processed

  Center = Center of arc element to be processed + (End point for machining-Tool reference point)

  Next, the case where the arc element to be processed has a convex shape when viewed from the tool side as shown in FIG.

  Also in this case, regarding the processing ranges 1631 and 1633 in which the normal angle ranges overlap between the arc element 1610 to be processed and the processing arcs 1621 and 1622, the processing arcs 1621 and 1622 and the corresponding processing ranges The position coordinates of the tool reference point 1640 when the start points 1635 and 1637 are in contact with each other are calculated and set as the tool position (tool path start point) at the start of machining by each of the machining arcs 1621 and 1622. Similarly, the position coordinates of the tool reference point 1640 when the machining arcs 1621 and 1622 are in contact with the end points 1636 and 1638 of the corresponding machining range are calculated, and when the machining arcs 1621 and 1622 are finished. The tool position (tool path end point) is used.

  The path of each of the machining arcs 1621 and 1622 is one arc in each of the machining ranges 1631 and 1633. Therefore, for each machining range 1631 and 1633, the radius and center of the arc serving as the tool path are the following. It is calculated by the following formula.

  Radius = radius of arc element to be processed + radius of machining arc

Center = Center of arc element to be processed + (Tool reference point-Center of machining arc)
It becomes.

  On the other hand, with respect to the machining ranges 1632 and 1634 where the normal angle range does not overlap with the arc element 1610 to be processed and the machining arcs 1621 and 1622, the machining arc end points (machining end points) 1623 (1624), The position coordinates of the tool reference point 1640 when 1625 and the corresponding machining range start points 1636 and 1638 contact each other are calculated, and the tool position (tool path start point) at the machining start by each machining end point 1623 (1624) and 1625. ). Similarly, the position coordinates of the tool reference point 1640 when the machining end points 1623 (1624), 1625 and the corresponding machining range end points 1637, 1639 contact each other are calculated, and each machining end point 1623 (1624), The tool position (tool path end point) at the end of machining by 1625 is used.

  Further, in this case, since the machining end point is moved along the arc element to be processed, the radius and center of the arc to be the tool path can be obtained by the following expression.

  Radius = radius of the arc element to be processed

Center = Center of arc element to be processed + (End point for machining-Tool reference point)
It becomes.

  As described above, when the tool path is obtained for each machining range, the obtained tool paths are appropriately connected according to the machining order, and the tool path for the arc element to be processed is obtained.

  As described above in detail, according to the NC data creation device 152 described above, the tip shape of the current grindstone 111 can be appropriately specified, and NC data corresponding to the tip shape of the identified grindstone 111 is obtained. Since it can be created, even if the tip shape of the grindstone 111 is worn, grinding without leaving uncut portions becomes possible.

  In the NC grinder 100 described above, the positional relationship between the imaging unit 140 and the grindstone 111 in the XY direction does not change, and therefore the position of the grindstone 111 in the image captured by the imaging unit 140 does not change. Therefore, as shown in FIG. 7B, once the user aligns the grinding mark (that is, the grindstone 111) formed on the test material 700 with the grindstone graphic 711, thereafter, In the display screen of the display device 153, it is always possible to display a grindstone graphic at the same position (in the XY plane) as the position where the grindstone 111 is present. As a result, not only during the grinding wheel shape identification process, but also during actual grinding processing according to NC data (NC program) created based on the identified grinding wheel tip shape, the display unit 153 causes the imaging unit 140 to Along with the captured image of the workpiece, a grindstone figure can be displayed at a position where the grindstone 111 exists. Since the grindstone 111 moves up and down in the Z direction during actual grinding, it is difficult to discriminate the tip shape from the image captured by the imaging unit 140, but if the grindstone graphic is displayed together, The tip shape of the grindstone 111 can be easily discriminated, and the processing state (positional relationship between the workpiece and the grindstone) during actual grinding can be easily confirmed on the display screen displayed on the display device 153. Become.

DESCRIPTION OF SYMBOLS 10 Workpiece 100 NC grinder 110 Grinding part 111 Grinding wheel 120 Work part holding part 130 Work part moving part 131 XY table 132 X-axis motor 133 Y-axis motor 140 Imaging part 150 Control part 151 NC control unit 152 NC data creation apparatus 153 Display device 154 Operation panel 201 CPU
202 ROM
203 RAM
204 Hard Disk Interface Unit 205 Hard Disk Device 206 USB Interface Unit 207 Input Device 208 Display Control Unit 209 Bus 310 Grinding Wheel Shape Identification Unit 320 NC Data Creation Unit 330 Display Processing Unit 340 Control Point Management Table 350 Grinding Wheel Shape Element Management Table 360 Workpiece Shape Element Management table 600 Test material 700 Test material image 711 Grindstone

Claims (9)

A grindstone shape identifying unit that creates grindstone shape data that identifies the tip shape of the grindstone according to a user instruction,
NC data creation unit for creating NC data based on the workpiece shape data and the grinding wheel shape data;
Together causes the display device to display an image indicating the current grindstone tip shape taken by the image pickup unit, on the basis of the grindstone shape data, display processing unit for displaying the grindstone shape figure showing the grindstone tip shape on said display device It equipped with a door,
The grindstone shape specifying part is:
Manage control point data for specifying the shape of the grinding wheel shape figure,
Update the control point data according to user instructions,
Based on the control point data, create the grinding wheel shape data,
The display processing unit
Based on the grinding wheel shape data, the grinding wheel shape figure is displayed on the display device,
An NC data generating device , wherein a control point is displayed on the display device based on the control point data . The grindstone shape specifying part is:
Based on the control point data, a curve corresponding to the control point data is identified,
Based on the curve, NC data creation device according to claim 1, characterized in that to create the grindstone shape data. The grindstone shape specifying part is:
The NC data creating apparatus according to claim 2 , wherein the grinding wheel shape data is created by approximating the curve with a line segment and an arc. The curves, NC data creation device according to claim 2 or 3, characterized in that a spline curve. The NC data creation device according to any one of claims 1 to 4 , wherein the image indicating the current tip shape of the grindstone is an image of a test material ground by the current grindstone. The grindstone shape data is data relating to an arc element constituting the tip shape of the grindstone,
The workpiece shape data is data relating to a line segment element and an arc element constituting the shape of the workpiece,
The NC data creation unit
For each line segment element constituting the shape of the workpiece, an arc element that can be contacted with each line segment element at one point is selected from the grinding wheel shape data as a processing arc to be used for processing each line segment element. In addition to obtaining the tool path at the time of machining by the machining arc,
For each arc element constituting the shape of the workpiece, an arc element that can contact each arc element at one point is selected from the grinding wheel shape data as a processing arc to be used for machining each arc element. Find the tool path during machining with the machining arc
The NC data creation device according to any one of claims 1 to 5 , wherein NC data is created based on the obtained tool path. The NC data creation unit
Machining used for machining the line segment element by comparing the inclination of the normal line of the line segment element constituting the shape of the workpiece and the normal angle range of each arc element constituting the tip shape of the grindstone Select the arc for
By comparing the normal angle range of the arc element constituting the workpiece shape and the normal angle range of each arc element constituting the tip shape of the grindstone, the arc element constituting the workpiece shape is compared. 7. The NC data creation device according to claim 6 , wherein a machining arc used for machining is selected. Whetstone,
An imaging unit for imaging the vicinity of the tip of the grindstone;
A moving unit for relatively moving the grindstone and the workpiece;
NC data creation device according to any one of claims 1 to 7 ,
A display device controlled by the NC data creation device;
An NC grinder comprising: an NC control device that controls the moving unit in accordance with NC data created by the NC data creation device. The display processing unit causes the display device to display an image of the workpiece imaged by the imaging unit at the time of grinding, and displays the grindstone shape graphic indicating the shape of the grindstone based on the grindstone shape data. The NC grinder according to claim 8 , wherein the NC grinder is displayed on an apparatus.

Images