Display device and display method

Abstract

The present invention comprises an acquisition unit (4) that acquires processed-surface shape data (3) that represents the shape of a processed surface (Ws) of a processed workpiece (W) and spatial error data (2) that is the output of a spatial error measurement instrument, a processed-workpiece error data calculation unit (5) that calculates shape error data (9) that is an error amount for each position on the processed surface (Ws) on the basis of the processed-surface shape data (3) and the spatial error data (2), and a processed-workpiece display unit (6) that displays the processed workpiece (W) at a display (10) in two or three dimensions on the basis of the processed-surface shape data (3). The processed-workpiece display unit (6) displays the effects of spatial error on the processed workpiece (W) at the display (10) on the basis of the values of the shape error data (9) such that the effects are visually recognizable.

Description

Display device and display method

[0001] This disclosure relates to a display device and a display method.

[0002] Conventionally, measuring devices for measuring the spatial errors of machine tools and display devices for displaying the measurement results have been known. According to ISO (International Organization for Standardization) 230-1, the spatial errors of machine tools are classified into three translational errors, three rotational errors, and one perpendicularity error for each axis, and measuring instruments for measuring spatial errors also output measurement results according to this classification. Patent Document 1 discloses a display device that displays the spatial errors measured by a measuring instrument as a function of the displacement of each axis in a two-dimensional graph.

[0003] Japanese Patent Publication No. 2001-165066

[0004] However, even when spatial errors are displayed on a display device as a two-dimensional graph, there was a challenge in that it was not easy to grasp at a glance how spatial errors were affecting the machined surface of the workpiece.

[0005] This disclosure has been made in view of the above-mentioned problems, and aims to provide a display device and display method that make it possible to grasp at a glance the effect of the spatial error of the machine tool on the machined surface of a workpiece.

[0006] One aspect of the present disclosure is a display device (1) for displaying spatial errors associated with the movement of a feed axis of a machine tool that processes a workpiece (W), comprising: an acquisition unit (4) for acquiring machining surface shape data (3) representing the shape of the machined surface (Ws) of the workpiece (W) and spatial error data (2) which is the output of a spatial error measuring instrument; a workpiece error data calculation unit (5) for calculating shape error data (9) which is the amount of error at each position of the machined surface (Ws) based on the machining surface shape data (3) and the spatial error data (2); and a workpiece display unit (6) for displaying the workpiece (W) in two or three dimensions on a display unit (10) based on the machining surface shape data (3), wherein the workpiece display unit (6) displays on the display unit (10) the effect of spatial errors on the machined surface (Ws) of the workpiece (W) in a visually recognizable manner based on the value of the shape error data (9).

[0007] One aspect of the present disclosure is a display method for displaying spatial errors associated with the movement of a feed axis of a machine tool that processes a workpiece (W), comprising: acquisition means for acquiring processing surface shape data (3) representing the shape of the processed surface (Ws) of the workpiece (W) and spatial error data (2) which is the output of a spatial error measuring instrument; processing workpiece error data calculation means for calculating shape error data (9) which is the amount of error at each position of the processed surface (Ws) based on the processing surface shape data (3) and the spatial error data (2); and processing workpiece display means for displaying the workpiece (W) in two or three dimensions on a display unit (10) based on the processing surface shape data (3), wherein the processing workpiece display means displays on the display unit (10) the effect of spatial errors on the processed surface (Ws) of the workpiece (W) in a visually recognizable manner based on the value of the shape error data (9).

[0008] This is a block diagram showing the configuration of the display device according to this embodiment. This is a perspective view of a workpiece. This is a cross-sectional view taken along line III-III in Figure 2. This is a cross-sectional view taken along line IV-IV in Figure 2. This is an explanatory diagram showing an example of a color code. This is an example of an image of a workpiece with color mapping applied to the machined surface. This is a block diagram showing the configuration of a display device according to a modified example of the present invention. This is a flowchart showing the preparation procedure for displaying an image of a workpiece on the display. This is a table showing an example of spatial error data measured by a spatial error measuring instrument. This is a data sheet showing an example of machined surface shape data. This is a diagram showing the configuration of spatial error data and machined surface shape data in three-dimensional space. This is a conceptual diagram showing the configuration of the converted shape error data. This is a conceptual diagram showing the configuration of the converted shape error data when the machined surface of the workpiece is inclined. This is machined surface shape data represented by a collection of polygons. This is machined surface shape data with an error vector added. This is a block diagram showing the configuration of a display device according to a second modified example of the present invention. This is a conceptual diagram of tool vector data. This is a conceptual diagram showing the configuration of rotational error occurring at the tip of the tool. This is a conceptual diagram showing the configuration of rotational error and translational error occurring at the tip of the tool.

[0009] An example of an embodiment of the present invention will be described below.

[0010] Figure 1 is a block diagram showing the configuration of the display device 1 according to this embodiment. The display device 1 is configured integrally with a machine tool such as a CNC (Computerized Numerical Control) lathe that processes workpieces, or it is configured as a computer that is used separately from the machine tool and connected to the machine tool by wire or wireless. The display device 1 makes it possible to display on the display unit 10 the effect that the spatial error of the machine tool measured by a measuring instrument has on the processed surface of the workpiece so that the user can visually grasp it at a glance.

[0011] Spatial errors in machine tools occur due to assembly, part precision, and aging, even when motor control of each axis is performed accurately without positional deviation. Spatial error data 2 is the spatial error of each axis measured by a well-known measuring instrument, and consists of three translational errors, three rotational errors, and one perpendicularity error for each of the multiple axes. Machining surface shape data 3 is 3D data of the machined workpiece generated from polygons, point sequences, NURBS (Non-Uniform Rational B-Spline) curves, CAD data, program simulations, motion measurement results, etc.

[0012] The acquisition unit 4 acquires spatial error data 2 and machined surface shape data 3. The spatial error data 2 is text data as a measurement result output from a measuring instrument. Furthermore, the spatial error data 2, which is error data on the machine coordinate system, can be calculated as an error at a specific position in space by using a geometric model. The machined workpiece error data calculation unit 5 calculates shape error data 9 based on the spatial error data 2 and the machined surface shape data 3. The shape error data 9 has three error pieces of information for the X, Y, and Z directions at each position on the machined surface. The machined workpiece display unit 6 then maps the machined surface of the machined workpiece, which consists of three-dimensional data, with coloring or shading according to the values ​​of the shape error data 9 and displays it on the display unit 10.

[0013] In other words, the display device 1 according to this embodiment includes an acquisition unit 4 that acquires machining surface shape data 3 representing the shape of the machining surface Ws of the workpiece W and spatial error data 2 which is the output of a spatial error measuring instrument; a workpiece error data calculation unit 5 that calculates shape error data 9 which is the amount of error at each position of the machining surface Ws based on the machining surface shape data 3 and spatial error data 2; and a workpiece display unit 6 that displays the workpiece W in two or three dimensions on the display unit 10 based on the machining surface shape data 3. The workpiece display unit 6 displays the influence of spatial error on the workpiece W on the display unit 10 in a way that can be visually recognized based on the value of the shape error data 9. This makes it possible to display the influence of the spatial error of the machine tool on the machining surface Ws of the workpiece W in a way that can be easily grasped at a glance.

[0014] Spatial error data 2 includes at least one of the errors in the direction of travel of the feed axis constituting the machine tool, errors in the direction perpendicular to the direction of travel, rotational errors, and perpendicularity errors. This allows us to obtain spatial error data 2 based on the measurement results of a spatial error measuring instrument.

[0015] Figure 2 is a perspective view of the workpiece W. Figure 3 is a cross-sectional view taken along line III-III in Figure 2, and Figure 4 is a cross-sectional view taken along line IV-IV in Figure 2. The workpiece W used as a sample has a stepped top surface, a machined surface Ws with convex and concave portions of an arc cross-section, and convex and concave portions of a trapezoidal cross-section. The acquisition unit 4 acquires machined surface shape data 3 as three-dimensional data of the workpiece W.

[0016] Figure 5 is an explanatory diagram showing an example of color code K. In this figure, the colors corresponding to the shape error data 9 from -50 μm to +50 μm are shown in five stages, from white to dense stippling hatching. However, color code K can be composed of any color gradient such as RGB or HSV. The processing work display unit 6 determines the display color to be applied to the processed surface Ws of the workpiece W by linearly interpolating color code K based on the shape error data 9. Specifically, it determines the display color for predetermined maximum value p1 and minimum value p2 corresponding to the values ​​of the shape error data 9, and then determines the display color by linearly interpolating color code K according to the values ​​of the shape error data 9. This makes it possible for the user to arbitrarily set the range of colors applied to the processed surface Ws of the workpiece W to a range that is easy to see.

[0017] Figure 6 is an example of an image of a machined workpiece W with color mapping applied to the machined surface Ws. In this figure, the magnitude of the shape error data 9 is represented on the machined surface Ws based on the color code K shown in Figure 5. By representing the characteristics of the shape error data with the color applied to the machined surface Ws of the workpiece W, it becomes even easier to visually grasp the influence of the machine tool's spatial error on the machined surface Ws of the workpiece W at a glance.

[0018] Figure 7 is a block diagram showing the configuration of a modified display device 1 according to the present invention. The same reference numerals indicate the same or equivalent parts. This modified version is characterized by having a shape error data conversion unit 7 that converts shape error data 9 and calculates converted shape error data 9a. The shape error data conversion unit 7 quantifies the influence that the shape error data 9 has on the machined surface Ws of the workpiece W and calculates it as converted shape error data 9a. In other words, the shape error data conversion unit 7 extracts only the converted shape error data 9a, which is the error data that affects the machined surface Wa, from the shape error data 9. Specifically, the converted shape error data 9a is made up of only the error in the normal direction that has the greatest influence on the machined surface Ws. This makes it possible to reduce the amount of data to be displayed on the display 10 and increase the processing speed.

[0019] Furthermore, the shape error data conversion unit 7 can assign positive and negative signs to the shape error data 9, indicating the direction of the error in the direction away from the workpiece W and the direction towards the workpiece W, respectively. This makes it possible to easily determine the direction of the error.

[0020] Figure 8 is a flowchart showing the preparation procedure for displaying an image of the workpiece W on the display unit 10. In step S1, the acquisition unit 4 acquires the machined surface shape data 3 and spatial error data 2. In step S2, the workpiece error data calculation unit 5 calculates shape error data 9 from the spatial error data 2 and the machined surface shape data 3. In step S2, the shape error data 9 on the machined surface Ws is comprehensively calculated. That is, shape error data 9 is calculated for all coordinates on the machined surface Ws. In step S3, the shape error data conversion unit 7 calculates converted shape error data 9a, which quantifies the actual influence of the shape error data 9 on the machining effect. Then, in step S4, the workpiece display unit 6 determines the display color by linearly interpolating the color code K based on the numerical value of the converted shape error data 9a.

[0021] Figure 9 is a table showing an example of spatial error data 2 measured by a spatial error measuring instrument. Figure 10 is a data sheet showing an example of machined surface shape data 3, and Figure 11 is a diagram showing the configuration of spatial error data 2 and machined surface shape data 3 in three-dimensional space.

[0022] As described above, the machined surface shape data 3 is text data indicating the spatial error measured by a measuring instrument. Furthermore, the machined surface shape data 3 is, for example, in 3D model data in object format, defined by the v command for vertex coordinates, the vt command for texture coordinates, the vn command for surface normals, and the f command for surface definition. By treating the vertex coordinates as coordinate values ​​in the machine coordinate system, the definition of the spatial error data 2 also becomes a value in the machine coordinate system, thus enabling a correspondence between the two.

[0023] Figure 12 is a conceptual diagram showing the configuration of the converted shape error data 9a. When the machined surface Ws is parallel to the XY plane, and errors ex in the X direction, ey in the Y direction, and ez in the Z direction occur, the shape error data conversion unit 7 calculates only ez, which is the error in the direction normal to the machined surface Ws, as the converted shape error data 9a.

[0024] The error in the Z direction of a vertex P (X=100, Y=50, Z=50) on the machined surface Ws can be calculated using the formula ez(x,y,z) = Ezx(x) + Ezy(y) + Ezz(z) - Eby(y) × x. When EZX(100) = 10 μm, EZY(50) = 5 μm, EZZ(50) = 3 μm, and EBY(50) = 0.05 μrad, ez(100,50,50) = 10 + 5 + 3 + 0.05 × 100 = 23 μm. In addition, for all vertices given in the object file, the errors in the X, Y, and Z directions (ex, eye, ez) and roll, pitch, and yaw directions (ea, eb, ec) are calculated.

[0025] The machined surface shape data 3 is a set of coordinates on the machined workpiece W, and the machined workpiece error data calculation unit 5 calculates shape error data 9 for each coordinate. This makes it easy to determine the position for calculating the shape error data 9. The machined workpiece error data calculation unit 5 calculates the shape error data 9 as a relative error from an arbitrary point P in a predetermined space. This makes it possible to obtain shape error data 9 appropriate for display on the machined surface Ws of the three-dimensional machined workpiece W. If the machined surface shape data 3 is a sequence of points or a machining program, the machined workpiece error data calculation unit 5 extracts shape error data in the tool axis direction. The amount of error can be determined by using the absolute error value as is, or by using the relative error using a point where the machining point is located.

[0026] Figure 13 is a conceptual diagram showing the configuration of the converted shape error data 9a when the machined surface Ws of the workpiece W is inclined. This figure shows an example where the machined surface Ws to which P (X=100, Y=50, Z=50) belongs is inclined at 45 degrees with respect to the XZ plane, resulting in an error in the X direction ex = 10.0 and an error in the Z direction ez = 20.0. In this case, the unit normal vector n for the machined surface Ws is... →It is represented by the following formula.

[0027] Also, the error vector E → is represented by the following formula.

[0028] The error vector E → The component in the direction of the unit normal vector n → is obtained, and it is multiplied by the unit normal vector n → to obtain the error vector n → in the normal direction with respect to the machining surface Ws. That is, the component of E → in the direction of the unit normal vector n → is E → × n → = 21.2132, and when this is multiplied by the unit normal vector n → the following formula is obtained.

[0029] The magnitude of this vector, approximately 21.2, is used as the shape error data 9.

[0030] Fig. 14 shows the machining surface shape data 3 represented by a collection of polygons. The machining surface shape data 3 is a polygon and a collection of polygons composed of the line g and the vertex P, and the machining work error data calculation unit 5 calculates the shape error data 9 for each vertex P constituting the polygon. In other words, by using the machining surface shape data 3 as so-called polygon data, it becomes easy to obtain the coordinates for calculating the shape error data 9.

[0031] Fig. 15 shows the machining surface shape data 3 with the error vector v added. The machining work display unit 6 displays the error vector v obtained by multiplying the value of the shape error data 9 by a predetermined coefficient on the machining surface Ws. As a result, it becomes easy to visually grasp the direction of the shape error data 9 by the display of the error vector v. Here, the predetermined constant is a coefficient for converting the error vector v to a visible size because the unit of the error is μm and the unit of the dimension of the workpiece W is mm.

[0032] The shape error data conversion unit 7 extracts either the component in the normal direction of the machined surface shape data 3 or the component in the tool axis direction from the shape error data 9, and calculates the converted shape error data 9a based on the extracted component. This makes it possible to arbitrarily set the direction of the error vector v to be displayed. Since displaying the error vector v for all vertices P would be too much and difficult to see, for example, display lines L can be set at predetermined intervals, and the error vector v can be displayed only for vertices P on these display lines L.

[0033] Furthermore, the machined surface shape data 3 can be a NURBS surface, which is a mathematical model commonly used in computer graphics to generate curves and curved surfaces. The machined workpiece error data calculation unit 5 sets error calculation positions on the NURBS surface and calculates shape error data 9 for each error calculation position. This makes it easy to determine the error calculation positions.

[0034] Alternatively, the machined surface shape data 3 may consist of a geometric shape type and one or more parameters necessary to define the geometric shape type. The machined workpiece error data calculation unit 5 may then calculate the machined shape from the geometric shape type and parameters, set error calculation positions for the machined shape, and calculate shape error data 9 for each error calculation position. This makes it easy to determine the error calculation positions. The geometric shape type can be a standard shape such as a rectangular prism, sphere, cylinder, cone, triangular pyramid, or square pyramid. The parameters can be height, width, height, and machine coordinate position in the case of a rectangular prism.

[0035] Figure 16 is a block diagram showing the configuration of the display device 1 according to a second modified example of the present invention. Figure 17 is a conceptual diagram of tool vector data VT. The same reference numerals indicate the same or equivalent parts. This modified example is characterized in that the acquisition unit 4 acquires tool vector data 8 (VT) of the tool T used for machining, in addition to spatial error data 2 and machined surface shape data 3.

[0036] That is, the acquisition unit 4 acquires the tool vector data 8 of the tool T used for machining, and the machining workpiece error data calculation unit 5 calculates the deviation of the machining point generated when the tool T rotates slightly only by the rotational error based on the rotational error component included in the tool vector data 8 and the spatial error data 2, and adds the deviation of the machining point to the shape error data 9, thereby calculating the shape error data 9 considering the influence of the spatial error received by the tool T. Thereby, it becomes possible to obtain the shape error data 9 considering the tool vector data 8 caused by the tool T of the machine tool.

[0037] The tool vector data VT of the tool T fixed to the spindle Js is obtained by the offset amount of the X axis and the offset amount of the Z axis from the point C on the program to the cutting edge of the tool T.

[0038] FIG. 18 is a conceptual diagram showing the mode of the rotational error generated at the tip Ta of the tool T. FIG. 19 is a conceptual diagram showing the mode of the rotational error and the translational error generated at the tip Ta of the tool T. The same reference numerals as above indicate the same or equivalent parts. The rotational errors ea, eb, ec and the translational errors ex, ey, ez of the tip Ta of the tool T are more likely to occur as the tool length TL of the tool T attached to the spindle Js becomes longer.

[0039] When calculating the shape error data 9, the machining workpiece error data calculation unit 5 obtains the translational errors ex, ey, ez and then obtains the rotational errors ea, eb, ec. For example, at X = 100, Y = 50, Z = 50, ex = 10 μm, ey = 10 μm, ez = 23 μm, ea = 5 μrad, eb = 3 μm, ec = 15 μm, the tool length TL = 100 mm, and the tool vector T → When it is represented by the following formula,

[0040] When the value is substituted into Equation 2-3 described in Japanese Patent No. 4327894 for calculating the influence of the spatial error received by the tool vector (Tx, Ty, Tz), it becomes as follows.

[0041]

[0042] When the above Equation 5 is rearranged, it becomes as follows (unit: mm). Then, the error vector v is equal to the tool vector T. → We can find the difference between the two values ​​as follows (units are mm).

[0043] The amount of error can be found by taking the magnitude of the error vector v, which is approximately 27.06 μm, and this is calculated as shape error data 9. The matrix calculation described above is an example of how the thick arrow shown in Figure 19 is obtained by calculating the effects of translational and rotational errors at the same time.

[0044] Furthermore, the shape of the workpiece is not limited in the display device according to one aspect of this disclosure. For example, multiple feed axes may be required to form tapered or arc-shaped portions on the machined surface of the workpiece, or the workpiece may be cylindrical or cylindrical and only one feed axis may be sufficient.

[0045] As described above, according to the display device of this embodiment, the influence of spatial error on the workpiece W is displayed on the display unit 10 in a visually recognizable manner based on the value of the shape error data 9. Therefore, the influence of the spatial error of the machine tool on the machined surface Ws of the workpiece W can be easily grasped at a glance.

[0046] A display device can be composed of one or more control units and memory units. Here, the control unit is a processor such as a CPU (Central Processing Unit), which realizes various functions by executing programs stored in the memory unit. The memory unit consists of a ROM (Read Only Memory) or RAM (Random Access Memory) that stores the OS (Operating System) and application programs, and a storage device such as a hard disk drive or SSD (Solid State Drive) that stores various other information.

[0047] According to the above-described display device, a display method can be obtained in which the acquisition unit 4 is used as the acquisition means, the machining work error data calculation unit 5 is used as the machining work error data calculation means, and the machining work display unit 6 is used as the machining work display means.

[0048] The above-described display device and display method can be implemented by hardware, software, or a combination thereof. Here, implementation by software means that it is implemented by a computer loading and executing a program.

[0049] Programs can be stored and supplied to a computer using various types of non-transitor computer-readable media. Non-transitor computer-readable media include various types of tangible storage media. Examples of non-transitor computer-readable media include magnetic recording media (e.g., hard disk drives), magneto-optical recording media (e.g., magneto-optical disks), CD-ROMs (Read Only Memory), CD-Rs, CD-R / Ws, and semiconductor memory (e.g., mask ROMs, PROMs (Programmable ROMs), EPROMs (Erasable PROMs), flash ROMs, and RAMs (random access memory)).

[0050] Furthermore, while the embodiments described above are preferred embodiments of the present invention, the scope of the present invention is not limited to these embodiments alone. Various modifications can be made to the present invention without departing from its spirit.

[0051] While this disclosure has been described in detail, it is not limited to the individual embodiments described above. These embodiments can be added, replaced, modified, partially deleted, etc., in any way that does not depart from the gist of this disclosure or from the spirit of this disclosure derived from the claims and their equivalents. These embodiments can also be implemented in combination. For example, the order of operations and processes in the embodiments described above are given as examples only and are not limited thereto.

[0052] The display device and display method described herein can be applied to various machine tools and industrial machinery.

[0053] With respect to the above embodiments and modified examples, the following further notes are disclosed. (Note 1) A display device (1) for displaying spatial errors associated with the movement of the feed axis of a machine tool for processing a workpiece (W), comprising: an acquisition unit (4) for acquiring processing surface shape data (3) representing the shape of the processed surface (Ws) of the workpiece (W) and spatial error data (2) which is the output of a spatial error measuring instrument; a workpiece error data calculation unit (5) for calculating shape error data (9) which is the amount of error at each position of the processed surface (Ws) based on the processing surface shape data (3) and the spatial error data (2); and a workpiece display unit (6) for displaying the workpiece (W) in two or three dimensions on a display unit (10) based on the processing surface shape data (3), wherein the workpiece display unit (6) displays on the display unit (10) the effect of spatial errors on the processed surface (Ws) of the workpiece (W) on the value of the shape error data (9) in a way that can be visually recognized.

[0054] (Note 2) The display device according to Note 1, wherein the processed workpiece display unit (6) determines the maximum and minimum values ​​of the shape error data (9) and the display colors corresponding to the maximum and minimum values, and determines the display color to be applied to the processed surface (Ws) by linearly interpolating the color code (K) based on the values ​​of the shape error data (9).

[0055] (Note 3) The display device according to Note 2, wherein the processed workpiece display unit (6) determines one or more values ​​between the maximum value and the minimum value and corresponding display colors, and determines the display color to be applied to the processed surface (Ws) by linearly interpolating the color code (K) based on the value of the shape error data (9) between each display color.

[0056] (Note 4) The processing work display unit (6) is a display device according to Note 1 or 2, which displays an error vector (v) obtained by multiplying the value of the shape error data (9) by a predetermined coefficient on the processing surface (Ws).

[0057] (Note 5) The display device according to Note 1 or 2, further comprising a shape error data conversion unit (7) that converts the shape error data (9) into converted shape error data (9a) which is a value that affects only the shape of the processed surface (Ws).

[0058] (Note 6) The display device according to Note 4, wherein the shape error data conversion unit (7) extracts either the component in the normal direction of the machined surface shape data (3) or the component in the tool axis direction from the shape error data (9), and calculates the converted shape error data (9a) based on the extracted component.

[0059] (Note 7) The display device according to Note 5, wherein the shape error data conversion unit (7) assigns positive and negative signs to the shape error data (9) indicating the direction of the error in the direction away from the workpiece (W) and the direction towards the workpiece (W), respectively.

[0060] (Note 8) The display device according to Note 1 or 2, wherein the spatial error data (2) includes at least one of the errors in the direction of travel of the feed axis constituting the machine tool, the errors in the direction perpendicular to the direction of travel, the rotational errors, and the perpendicularity errors.

[0061] (Note 9) The display device according to Note 1 or 2, wherein the processing work error data calculation unit (5) calculates the shape error data (9) as a relative error from any point (P) in a predetermined space.

[0062] (Note 10) The display device according to Note 1 or 2, wherein the machined surface shape data (3) is a set of coordinates on the machined workpiece (W), and the machined workpiece error data calculation unit (5) calculates the shape error data (9) for each of the coordinates.

[0063] (Note 11) The display device according to Note 1 or 2, wherein the shape error data (9) is a polygon and a collection of polygons, and the processing work error data calculation unit (5) calculates the shape error data (9) for each vertex (P) constituting the polygon.

[0064] (Note 12) The display device according to Note 1 or 2, wherein the processed surface shape data (3) is a NURBS curved surface, and the processed workpiece error data calculation unit (5) sets error calculation positions on the NURBS curved surface and calculates the shape error data (9) for each error calculation position.

[0065] (Note 13) The display device according to Note 1 or 2, wherein the processed surface shape data (3) is a graphic shape type and one or more parameters necessary to define the graphic shape type, and the processed work error data calculation unit (5) calculates a processed shape from the graphic shape type and the parameters, sets error calculation positions on the processed shape, and calculates the shape error data (9) for each error calculation position.

[0066] (Note 14) The display device according to Note 1 or 2, wherein the acquisition unit (4) acquires tool vector data (8) of a tool (T) used for machining, and the machining workpiece error data calculation unit (5) calculates the displacement of the machining point that occurs when the tool (T) rotates by a small amount equal to the rotational error, based on the rotational error component included in the tool vector data (8) and the spatial error data (2), and adds the displacement of the machining point to the shape error data (9) to calculate the shape error data (9) that takes into account the influence of the spatial error on the tool (T).

[0067] (Note 15) A display method for displaying spatial errors associated with the movement of the feed axis of a machine tool that processes a workpiece (W), comprising: acquisition means for acquiring processing surface shape data (3) representing the shape of the processed surface (Ws) of the workpiece (W) and spatial error data (2) which is the output of a spatial error measuring instrument; processing workpiece error data calculation means for calculating shape error data (9) which is the amount of error at each position of the processed surface (Ws) based on the processing surface shape data (3) and the spatial error data (2); and processing workpiece display means for displaying the workpiece (W) in two or three dimensions on a display unit (10) based on the processing surface shape data (3), wherein the processing workpiece display means displays the effect of spatial errors on the workpiece (W) on the display unit (10) in a way that can be visually recognized based on the value of the shape error data (9).

[0068] 1 Display device 2 Spatial error data 3 Machined surface shape data 4 Acquisition unit 5 Machined workpiece error data calculation unit 6 Machined workpiece display unit 7 Shape error data conversion unit 8 Tool vector data 9 Shape error data 9a Converted shape error data 10 Display unit W Machined workpiece Ws Machined surface T Tool P Vertices constituting the polygon K Color code v Error vector

Claims

1. A display device for displaying spatial errors associated with the movement of the feed axis of a machine tool that processes a workpiece, comprising: an acquisition unit that acquires machining surface shape data representing the shape of the machined surface of the workpiece and spatial error data which is the output of a spatial error measuring instrument; a workpiece error data calculation unit that calculates shape error data which is the amount of error at each position of the machined surface based on the machining surface shape data and the spatial error data; and a workpiece display unit that displays the workpiece on a display in two or three dimensions based on the machining surface shape data, wherein the workpiece display unit displays the effect of spatial errors on the machined surface of the workpiece on the display unit in a way that is visually recognizable based on the value of the shape error data.

2. The display device according to claim 1, wherein the processed workpiece display unit determines the maximum and minimum values ​​of the shape error data and the display colors corresponding to the maximum and minimum values, and determines the display color to be applied to the processed surface by linearly interpolating the color code based on the values ​​of the shape error data.

3. The display device according to claim 2, wherein the processing work display unit determines one or more values ​​between the maximum value and the minimum value and corresponding display colors, and determines the display color to be applied to the processing surface by linearly interpolating the color code based on the shape error data values ​​between each display color.

4. The display device according to claim 1 or 2, wherein the processed workpiece display unit displays an error vector obtained by multiplying the value of the shape error data by a predetermined coefficient on the processed surface.

5. The display device according to claim 1 or 2, further comprising a shape error data conversion unit that converts the shape error data into converted shape error data that is a value that affects only the shape of the processed surface.

6. The display device according to claim 4, wherein the shape error data conversion unit extracts either a component in the normal direction of the machined surface shape data or a component in the tool axis direction from the shape error data, and calculates the converted shape error data based on the extracted component.

7. The display device according to claim 5, wherein the shape error data conversion unit assigns positive and negative signs to the shape error data, indicating the direction of the error in the direction away from the workpiece and the direction towards the workpiece, respectively.

8. The display device according to claim 1 or 2, wherein the spatial error data includes at least one of the errors in the direction of travel of the feed axis constituting the machine tool, errors in the direction perpendicular to the direction of travel, rotational errors, and perpendicularity errors.

9. The display device according to claim 1 or 2, wherein the processing workpiece error data calculation unit calculates the shape error data as a relative error from any point in a predetermined space.

10. The display device according to claim 1 or 2, wherein the machined surface shape data is a set of coordinates on the machined workpiece, and the machined workpiece error data calculation unit calculates the shape error data for each of the coordinates.

11. The display device according to claim 1 or 2, wherein the shape error data is a polygon and a collection of polygons, and the processing work error data calculation unit calculates the shape error data for each vertex constituting the polygon.

12. The display device according to claim 1 or 2, wherein the processed surface shape data is a NURBS curved surface, and the processed workpiece error data calculation unit sets error calculation positions on the NURBS curved surface and calculates the shape error data for each error calculation position.

13. The display device according to claim 1 or 2, wherein the processed surface shape data comprises a graphic shape type and one or more parameters necessary to define the graphic shape type, and the processed work error data calculation unit calculates the processed shape from the graphic shape type and the parameters, sets error calculation positions on the processed shape, and calculates the shape error data for each error calculation position.

14. The display device according to claim 1 or 2, wherein the acquisition unit acquires tool vector data of a tool used for machining, and the machining workpiece error data calculation unit calculates a shift in the machining point caused by the tool rotating by a small amount equal to the rotation error, based on the rotation error component included in the tool vector data and the spatial error data, and adds the shift in the machining point to the shape error data to calculate the shape error data that takes into account the effect of the spatial error on the tool.

15. A display method for displaying spatial errors associated with the movement of a feed axis of a machine tool that processes a workpiece, comprising: acquisition means for acquiring processing surface shape data representing the shape of the processed surface of the workpiece and spatial error data which is the output of a spatial error measuring instrument; processing workpiece error data calculation means for calculating shape error data which is the amount of error at each position of the processed surface based on the processing surface shape data and the spatial error data; and processing workpiece display means for displaying the workpiece on a display in two or three dimensions based on the processing surface shape data, wherein the processing workpiece display means displays the effect of spatial errors on the workpiece on the display in a way that is visually recognizable based on the value of the shape error data.

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