JP2016166877A - Measuring device of tool dimension - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a measuring method and a measuring device of tool dimensions capable of measuring the dimensions of a tool even when the tool has a diameter larger than a visual field of an imaging apparatus.SOLUTION: According to a machine tool 10, in a case where an entire contour of a tool 20 is not settled in a visual field V of an image of an imaging apparatus 33, the visual field V of the imaging apparatus 33 is moved by relative movement of the imaging apparatus 33 and the tool 20. Further, since a moving direction 53 of the visual field V is decided on the basis of a partial contour line 51 specified on the basis of image data, the imaging apparatus 33 can follow a contour line 54 of the tool 20 by movement of the visual field V. Thus, even when measuring the dimensions of the tool 20 whose diameter is larger than the visual field V of the imaging apparatus 33, the partial contour line 51 in a desired range, for example, is specified. When a plurality of partial contour lines 51 that are specified are connected, a contour line in a desired range of the tool 20 is extracted. By using such the contour line, dimensions of the tool 20 can be measured.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a method and an apparatus for measuring tool dimensions such as a blade edge position, a tool length, a diameter, a blade edge shape, and tool runout of a tool used in a CNC (computer numerical control) machine tool.

  For example, in an NC machine tool such as a machining center, when a workpiece is processed, a tool such as a drill or an end mill mounted on the main shaft contacts the workpiece while rotating. In order to improve the accuracy of such tool position control, the position of the tool with respect to the spindle and the thermal deformation of the rotating spindle must be considered. Therefore, it is important to measure in advance the dimensions of the tool actually mounted on the spindle.

Japanese Patent No. 3880110

  Conventionally, a method has been proposed in which a tool mounted on a spindle is imaged and the size of the tool is measured. In this measurement method, the shadow of the tool is formed on the image by the light emitted from the light source. The dimension of the tool is measured by specifying the shadow outline. However, for example, when a tool having a diameter larger than the field of view of imaging is used in an NC machine tool, only a partial contour of the tool edge is specified on the captured image. In this case, it is impossible to measure the dimensions of the tool.

  The present invention has been made in view of the above circumstances, and provides a tool dimension measuring method and measuring apparatus capable of measuring the tool dimension even with a tool having a diameter larger than the field of view of the imaging apparatus. With the goal.

  In order to achieve the above object, according to the present invention, in the tool dimension measuring method, the tool is imaged using an imaging device that moves relative to the tool, and the dimension of the tool is measured based on the obtained image data. A partial contour of the tool is identified based on image data obtained by imaging a part of the contour of the tool by an imaging device, a coordinate value of each constituent pixel is identified, and converted into a coordinate value of a reference coordinate system associated in advance. A step of specifying the coordinate value of the partial contour in the reference coordinate system, and calculating a tangent line in the field of view of the imaging device of the partial contour specified based on the coordinate value of the pixels constituting the partial contour line. And the direction of movement of the imaging device in the direction of the contour of the tool outside the field of view of the image data, and the field of view of the imaging device moves in the determined direction of movement of the field of view. Outputting a movement command for relatively moving the imaging device and the tool to a control device of a machine tool, specifying the partial contour, determining the moving direction of the field of view, and relative to the imaging device and the tool. The partial contours identified on the basis of each of the plurality of image data obtained by sequentially repeating the steps of outputting the movement command of movement and the coordinate value data that can be specified by the coordinate values of the reference coordinate system are combined with each other, A tool dimension measuring method comprising: measuring a tool joint profile using the tool joint contour.

  According to the present invention, in a tool size measuring device that measures the size of the tool from image data obtained by imaging the tool, the imaging device that images the tool and generates image data, and the generated A partial contour that forms a part of the contour of the tool is specified based on image data, the coordinate value of each pixel that is configured is specified, converted to a coordinate value of a reference coordinate system that is associated in advance, The coordinate value of the contour is specified, the tangent of the specified partial contour in the field of view of the imaging device is calculated, and the direction of the tangent is set to the direction of the contour of the tool outside the field of view of the image data. A moving direction for moving the field of view is determined, and a movement command for moving the imaging device and the tool relative to each other so as to move the field of view of the imaging device in the determined moving direction of the field of view is output to the control device of the machine tool. ,Previous A plurality of image data and coordinate values of the reference coordinate system obtained by sequentially repeating the steps of specifying a partial contour, determining the moving direction of the visual field, and outputting a movement command for relative movement between the imaging device and the tool An arithmetic unit that extracts the joint contour of the tool by mutually coupling the partial contours identified based on each of the coordinate value data that can be specified by the step, and measuring the dimension of the tool using the joint contour of the tool An apparatus for measuring tool size is provided.

  The tool size measuring device further includes a display device that displays the tool size specified based on the image data, and an input device that inputs a predetermined instruction for the tool size on the display device. Prepare.

  ADVANTAGE OF THE INVENTION According to this invention, even if it is a tool larger than the visual field of an imaging device, the tool dimension measuring method and measuring apparatus which can measure the dimension of a tool can be provided.

It is a figure showing roughly composition of a machine tool provided with a measuring device of a tool size concerning one embodiment of the present invention. It is a figure which shows the image data concerning one specific example. It is a flowchart which shows the flow of a process of the measuring method of the tool dimension which concerns on 1st Embodiment of this invention. It is a figure which shows the image data which concerns on another specific example. It is a flowchart which shows the flow of a process of the measuring method of the tool dimension which concerns on 2nd Embodiment of this invention. It is a figure which shows the image data which concerns on another specific example. It is a flowchart which shows the flow of a process of the measuring method of the tool dimension which concerns on 3rd Embodiment of this invention. It is a figure which shows the image data which concerns on another specific example.

Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.
FIG. 1 is a diagram schematically showing a configuration of a machine tool 10 provided with a tool dimension measuring device according to an embodiment of the present invention. The machine tool 10 is connected to the machine unit 10 that controls the operation of the machine tool 10 in addition to the machine part that performs machining processing on a workpiece (not shown), and the machine tool 10 is connected to the machine tool 10 and the NC device 12. And a dimension measuring device 13 for measuring the dimension of the tool. For the machine tool 10, for example, a 5-axis vertical machining center is used. In the present embodiment, the dimension measuring device 13 is illustrated separately from the NC device 12, but the dimension measuring device 13 may be incorporated in the NC device 12, for example.

  First, the machine configuration of the machine tool 10 will be described. An XYZ orthogonal three-axis reference coordinate system is set for the machine tool 10. The machine tool 10 includes a bed 15 extending along a horizontal plane, that is, an XY plane, a table base 16 disposed on the bed 15, and a column 17 standing behind the table base 16 in a vertical direction parallel to the Z axis from the bed 15. . A work (not shown) is fixed on the table base 16. A spindle head 18 is supported on the column 17. A tool 20 is attached to the lower end of the spindle head 18 so as to be detachable downward via a spindle 19. The tool 20 is rotationally driven by a spindle motor (not shown) incorporated in the spindle head 18. Here, for example, a ball end mill is used as the tool 20.

  The table base 16 is supported on the bed 15 so as to be movable in the horizontal direction (X-axis direction) via a linear feed mechanism. On the other hand, the spindle head 18 is supported by the column 17 so as to be movable in the vertical direction (Z-axis direction) and the horizontal direction (Y-axis direction) via a linear feed mechanism. The linear feed mechanism includes, for example, a ball screw and a servo motor that rotationally drives the ball screw. By these linear feed mechanisms, relative movement between the table base 16 and the spindle head 18, that is, the tool 20 is realized. The relative movement is realized based on a drive signal described later supplied from the NC device 12. The tool 20 that rotates during the relative movement contacts the workpiece at a predetermined machining point. Thus, the workpiece is processed into a desired shape.

  The bed 15 incorporates an X-axis position detector 21 that reads a relative position along the X-axis between the bed 15 and the table base 16. The column 17 incorporates a Y-axis position detector (not shown) and a Z-axis position detector 22 for reading the relative positions along the Y-axis and Z-axis between the column 17 and the spindle head 18. Yes. For example, a digital scale may be used for these position detectors. The relative position read by these position detectors is specified by the coordinate value of the reference coordinate system. The read coordinate value is output, that is, fed back to the NC device 12.

  Next, the configuration of the NC device 12 will be described. The NC device 12 generates a movement command in accordance with the storage unit 24 for storing the NC program, the program analysis unit 25 for analyzing the NC program stored in the storage unit 24, and the NC program analyzed by the program analysis unit 25. A movement command unit 26 and a servo control unit 27 that outputs a drive signal to the servo motor of the machine tool 10 according to the movement command output from the movement command unit 26 are provided. The movement command includes, for example, index data of the machining point of the workpiece and coordinate value data indicating the position of the spindle head 18 corresponding to the indexed machining point.

  Next, the configuration of the dimension measuring device 13 will be described. The dimension measuring device 13 includes a dimension measuring unit 31 disposed on the table base 16. The dimension measuring unit 31 includes a light source 32 and an imaging device 33 that faces the light source 32. For example, a high-intensity LED that outputs parallel light toward the imaging device 33 is used as the light source 32. The imaging device 33 can move relative to the table base 16 in the YZ plane of the reference coordinate system, for example. The imaging device 33 includes a lens unit 34 and a CCD (charge coupled device) image sensor 35. The CCD image sensor 35 constitutes a two-dimensional image sensor, for example. The lens unit 34 includes, for example, a plurality of lenses, and executes zoom-in and zoom-out by optical zoom based on driving of the lens.

  The dimension measuring device 13 includes an image adjusting device 36 that receives supply of image data of an image captured by the image capturing device 33, and a control device 37 that controls operations of the light source 32 and the image capturing device 33. The aforementioned CCD image sensor 35 generates an analog image signal corresponding to the image formed on the light receiving surface. An image signal is generated in each frame provided at predetermined time intervals. Here, for example, an image signal of 30 to 60 frames per second is output. The image signal specifies a multi-tone luminance signal for each pixel. The image signal is converted into image data of a digital signal and output to the image adjustment device 36.

  The image adjustment device 36 performs image adjustment such as shading correction of image data, noise reduction, white balance adjustment, contour correction, and contrast adjustment. In the image data after image adjustment, a light / dark binary value is specified for each pixel. The image adjustment device 36 stores the image data after the image adjustment in a frame memory described later. On the other hand, the control device 37 outputs a drive signal for controlling movement and zooming of the imaging device 33 to the imaging device 33. Note that an xy orthogonal biaxial visual field coordinate system is set in the visual field of the imaging device 33 corresponding to the YZ plane of the reference coordinate system described above. Each coordinate value of the visual field coordinate system is associated with each coordinate value of the reference coordinate system for each visual field at each position after the imaging device 33 is moved in the YZ plane.

  The dimension measuring device 13 includes a storage device 41 that stores a dimension measuring program and tool dimension data, an arithmetic device 42 that executes various arithmetic processes based on the dimension measuring program, and a frame memory 43 that stores image data for each frame. . In the arithmetic processing, the dimension measurement program may be temporarily read into a memory (not shown). Details of the dimension measurement program and the tool dimension data will be described later. The dimension measurement program may be taken into the storage device 41 from, for example, an FD (flexible disk), CD-ROM, or other portable recording medium, or may be taken into the storage device 41 from a computer network such as a LAN or the Internet.

  The dimension measuring device 13 includes, for example, a display device 44 having a display screen that displays information on light and dark binary values for each pixel constituting the image data representing the image (silhouette) of the tool 20 and the coordinate value of the pixel, for example, a display screen. And an input device 45 for inputting an instruction to the computing device 42 by designating a predetermined position above. The display device 44 may be a flat display panel such as an LCD (liquid crystal display) panel, and the input device 45 may be a touch panel, a keyboard, a mouse, or the like. The user designates the direction of the contour line of the tool 20 on the image displayed on the display screen of the display device 44 or designates the position of the tool 20 on the contour line using, for example, a touch panel or a mouse. Can do.

  Next, a method for measuring the dimension of the tool 20 of the machine tool 10 according to the present invention will be described. In executing the processing, the arithmetic device 42 of the dimension measuring device 13 temporarily reads the dimension measuring program from the storage device 41 into, for example, a memory. Thus, the arithmetic unit 42 executes various arithmetic processes based on the dimension measurement program. First, the arithmetic device 42 outputs a start signal to the NC device 12. In response to receiving the start signal, the NC device 12 outputs a drive command toward the machine tool 10. As a result, in the machine tool 10, the spindle 19 is positioned so that the cutting edge portion of the tool 20 enters a predetermined reference position between the light source 32 and the imaging device 33 on the XY plane. The tool 20 is driven to rotate about its center of rotation. The spindle head 18, ie the tool 20, is lowered parallel to the Z axis. Here, the reference position is a position that is provided in advance in the field of view and serves as a reference for instructing to stop the approach operation of the tool 20.

  At the same time, the arithmetic device 42 starts the operations of the light source 32 and the imaging device 33. The control device 37 outputs a drive signal that drives the imaging device 33. In this way, the imaging device 33 starts imaging. The imaging device 33 generates an analog image signal for each imaging frame. Image data generated from the image signal is stored in the frame memory 43 for each frame via the image adjustment device 36. When a part of the contour of the tool 20 enters the image field of the imaging device 33 based on the descending of the spindle head 18, the descending of the spindle head 18 along the Z axis is stopped. Thus, a part of the contour of the tool 20 is specified in the field of view of the image of the imaging device 33 at the reference position.

  An image obtained by projecting the shadow (silhouette) of the tool 20 by the parallel light emitted from the light source 32 is formed on the light receiving surface of the CCD image sensor 35. The image data is composed of a number of pixels that specify an image in the field of view. As described above, since light and dark binary values are specified for each pixel in the image data, for example, as shown in FIG. 2, in the field of view V specified by the image data at the reference position, a dark pixel is a tool. While identified as 20 shadow projected portions, bright pixels are identified as parallel light receiving portions. In this way, the outline of a part of the tool 20 is specified.

  FIG. 3 is a flowchart showing a process flow of the dimension measuring method of the tool 20 according to the first embodiment of the present invention. With respect to the image data at the reference position read from the frame memory 43, the calculation device 42 detects the edge of the contour of the tool 20 in step S1. As described above, since each pixel is represented by a light / dark binary value, an edge is a dark pixel adjacent to a light pixel among dark pixels corresponding to the image pixel of the tool 20 in the field of view V of the image. Identified. Thus, as is apparent from FIG. 2, in step S <b> 2, the computing device 42 specifies the partial contour line 51 based on the extraction of a plurality of continuous dark pixels adjacent to the bright pixel.

  As described above, an xy orthogonal biaxial visual field coordinate system is set in the visual field of the imaging device 33, and thus the coordinate value of each pixel constituting the partial contour 51 is specified. The coordinate value of the visual field coordinate system is associated with the reference coordinate system of the machine tool 10 in advance by calibration, for example, and the coordinate value of the visual field coordinate system is converted into the coordinate value of the reference coordinate system. Thus, the coordinate value of the partial outline 51 is specified in the reference coordinate system. The image data of the specified partial outline 51 is stored in the frame memory 43. The coordinate value data indicating the coordinate value of the partial outline 51 may be stored in the frame memory 43 in association with the image data.

  Thereafter, in step S <b> 3, the computing device 42 calculates a tangent line 52 of the partial contour line 51. The tangent line 52 is a coordinate value on the partial outline 51 and is calculated, for example, at an intermediate point indicating the coordinate value of the intermediate position in the x-axis direction in the visual field V. In the calculation, for example, a mathematical expression for identifying the partial contour 51 is derived based on the coordinate values of the pixels constituting the partial contour 51. The tangent line 52 is calculated based on the differentiation of this mathematical formula. Further, instead of differentiating the mathematical formula, the tangent line 52 may be calculated from an inclination derived from pixels of arbitrary two points (for example, including the above-described intermediate point) constituting the partial outline 51.

  Based on the tangent line 52 thus calculated, the arithmetic unit 42 determines the moving direction 53 of the visual field of the image device 33 in step S4. Specifically, the two forward and reverse directions specified by the tangent line 52 are estimated as the direction of the contour line 54 outside the visual field V of the visual field V of this image data. Here, the computing device 42 sets one of the two forward and reverse directions specified by the tangent line 52 (for example, the upper right direction) as the moving direction 53 for moving the visual field V of the imaging device 33. The computing device 42 moves the visual field V in the direction specified by the moving direction 53 in step S5. The arithmetic device 42 outputs a movement signal for moving the tool 20 and the imaging device 33 relative to the control device 37 in accordance with the movement direction 53. The control device 37 that has received the movement signal moves the imaging device 33 to move the tool 20 and the imaging device 33 relative to each other. Here, the imaging device 33 is moved in the YZ plane. The field of view V of the imaging device 33 starts to move along the moving direction 53.

  After the imaging device 33 and the tool 20 start relative movement, the arithmetic device 42 repeats the processing of step S1 to step S5 based on the image data for each frame. As a result, the moving direction 53 of the visual field V is determined for each frame. Thus, for example, as shown conceptually in FIG. 4, the partial outline 51 of the tool 20 is specified for each frame. When the plurality of partial contour lines 51 in one direction along the tangent line 52 are specified over a desired range, the imaging device 33 is returned to the initial imaging position. The computing device 42 sets the moving direction 53 of the visual field V in the other direction (that is, the lower left direction) along the tangent line 52. The tool 20 and the imaging device 33 move relative to each other according to the moving direction 53. Thus, a plurality of partial contour lines 51 in a desired range of the tool 20 in the other direction are specified. Note that the partial outline 51 need not be specified throughout the tool 20. Here, since the tool 20 is a ball end mill, the specification of the partial contour line 51 may be performed until the shank of the ball end mill, that is, a part of the contour line of the parallel part is specified.

  The arithmetic device 42 reads out the image data and coordinate value data of all the specified partial contour lines 51 from the frame memory 43 and combines all the partial contour lines 51 to form a combined contour line 55. For example, the coordinate value data of each partial outline 51 may be used for the combination. As described above, the coordinate value data is specified by the coordinate value of the reference coordinate system. In this way, as is apparent from FIG. 5, the combined contour 55 of the tool 20 is extracted. Based on the extracted connection outline 55, the arithmetic unit 42 measures, for example, the cutting edge position of the tool 20 and the tool diameter. In the measurement, the coordinate value of the reference coordinate system is referred to. The combined outline 55 and the measurement result may be displayed on the display screen of the display device 44, for example. At this time, the user may arbitrarily designate the measurement position of the tool 20 by designating and inputting a specific position of the tool 20 on the display screen using the input device 45.

  As described above, according to the machine tool 10 according to the first embodiment, when the contour of the entire tool 20 does not fit within the field of view V of the image of the imaging device 33 (for example, a ball having a diameter of 20 mm in a field of 0.6 mm square). When imaging the end mill), the visual field V of the imaging device 33 is moved by the relative movement of the imaging device 33 and the tool 20. In addition, since the moving direction 53 for moving the visual field V in the direction of the contour line 54 outside the visual field of one image data is determined based on the partial contour line 51 specified from the image data, the imaging device 33 can be used as the visual field V. The outline of the tool 20 can be traced by the movement of. Thus, for example, when measuring the tool 20 having a size larger than the field of view V of the imaging device 33, a plurality of partial contour lines 51 over a desired range are specified. For example, if a plurality of specified partial contour lines 51 are combined, a combined contour line 55 in a desired range of the tool 20 is extracted. As a result, the dimensions of the tool 20 can be measured using the connection contour 55.

FIG. 5 is a flowchart showing a process flow of the dimension measuring method of the tool 20 according to the second embodiment of the present invention. In this embodiment, the image data stored in the frame memory 43 is read out in the same manner as in steps S1 and S2 described above, the edge of the contour of the tool 20 is detected in step T1, and a plurality of continuous data is detected in step T2. The partial outline 51 is specified from the dark pixels. Next, in step T3, the arithmetic unit 42 calculates a regression curve Y = F (X) of the partial contour 51. In calculating the regression curve, the coordinate value of the pixel in the visual field coordinate system may be referred to. Next, in step T4, tool dimension data stored in the storage device 41, that is, regression curves Y1 = f ₁ (X), Y2 = f ₂ (X) to Yn−1 = f _n−1 (X), Yn = With reference to f _n (X), a regression curve that matches the calculated regression curve is searched. The tool dimension data is a regression curve of the contour line of the tool 20 measured in advance for each of the various tools 20.

When the regression curve Yn = f _n (X) that matches the calculated regression curve Y = F (X) is specified, the computing device 42 in step T5, for example, as shown in FIG. Yn = f _n (X) is superimposed on the regression curve Y = F (X) on the image data. Next, in step T6, the arithmetic unit 42 specifies an actual value such as a Y intercept of the matched regression curve Yn = f _n (X) and converts it into a coordinate value in the visual field coordinate system. Thus, the direction of the outline 54 outside the field of view of the image data is specified. In step T <b> 7, the computing device 42 determines the moving direction 53 of the visual field V of the image device 33 based on the specified direction of the contour line 54. In the determination, the computing device 42 specifies, for example, one direction as the moving direction 53 out of the two normal and reverse directions along the contour line 54 outside the visual field specified by the regression curve Yn = f _n (X). The arithmetic unit 42 moves the visual field V in the specified moving direction 53 in step T8. Here, for example, the upper right direction on the visual field V is selected.

  As described above, the visual field V of the imaging device 33 moves in the movement direction 53 based on the movement signal output from the arithmetic device 42. The arithmetic unit 42 repeats the processing from step T1 to step T8 for each frame. Therefore, the moving direction 53 of the visual field V of the imaging device 33 is determined for each frame. When the partial contour line 51 in one direction of the above-described contour line 54 is specified over a desired range, the arithmetic unit 42 should move the visual field in the other direction of the contour line 54 (for example, the left direction of the visual field V). The imaging device 33 is returned to the initial imaging position. The arithmetic device 42 sets the moving direction 53 of the visual field V in the other direction. The tool 20 and the imaging device 33 move relative to each other according to the moving direction 53. Thus, a plurality of partial contour lines 51 in a desired range of the tool 20 in the other direction are specified. Thereafter, the same processing as described above is executed. Note that the area occupied by the shadow of the tool 20 in the visual field V of the imaging device 33 may be used in determining the moving direction 53 of the visual field V.

  FIG. 7 is a flowchart showing a process flow of the dimension measuring method for the tool 20 according to the third embodiment of the present invention. In this embodiment, the image data stored in the frame memory 43 is read out as in steps S1 and S2 described above, and the contour edge of the tool 20 is detected in step U1. In step U2, the partial outline 51 is specified from a plurality of continuous dark pixels. Thereafter, in step U <b> 3, the arithmetic device 42 outputs a command signal for causing the imaging device 33 to perform zoom out to the control device 37. The control device 37 executes zoom-out based on the driving of the lens unit 34. As a result, as shown in FIG. 8, the field of view V of the imaging device 33 is enlarged.

  In step U <b> 4, the computing device 42 specifies the outline outline 56 of the tool 20 excluding the partial outline 51 based on the image data with an enlarged field of view. For the identification, the above-described method for identifying the partial outline 51 is used. In step U <b> 5, the calculation device 42 determines the moving direction 53 of the field of view V of the image device 33 based on the specified outline 56. In the determination, the computing device 42 sets one of the two forward and reverse directions specified by the outline 56 as the moving direction 53 for relatively moving the tool 20 and the imaging device 33. Here, for example, the distance of the relative movement between the tool 20 and the imaging device 33 until the next zoom-out may be specified based on the specified length of the outline 56.

  In step U6, the computing device 42 zooms in on the imaging device 33 to the size of the visual field V that first identifies the partial contour 51 based on the output of the command signal. Thereafter, the computing device 42 moves the visual field V in any direction specified by the outline 56 in step U7. Here, the moving direction 53 in the upper right direction on the visual field V is selected, for example. The arithmetic device 42 outputs a movement signal for moving the tool 20 and the imaging device 33 relative to the imaging device 33. As described above, the tool 20 and the imaging device 33 are relatively moved. During the relative movement, the arithmetic unit 42 specifies the partial outline 51 for each frame based on the image data read from the frame memory 43.

  While the tool 20 moves the distance of the relative movement specified first, identification of the partial outline 51 is repeated in step U8. After that, when the tool 20 finishes moving the distance of the relative movement, the calculation device 42 repeats the processes of steps U3 to U8. When the plurality of partial contour lines 51 in one direction of the contour line 53 are specified over a desired range, the arithmetic unit 42 determines the other of the two directions specified by the first outline contour line 56 specified. The imaging device 33 is returned to the initial imaging position in order to move the visual field V in the direction (i.e., the left direction). The arithmetic device 42 sets the moving direction 53 of the visual field V in the other direction. The tool 20 and the imaging device 33 move relative to each other according to the moving direction 53. Thus, a plurality of partial contour lines 51 are specified over a desired range of the tool 20. Thereafter, the same processing as described above is executed.

  According to the machine tool 10 according to the present embodiment, when the entire contour of the tool 20 does not fit within the field of view V of the image of the imaging device 33, the field of view V of the image moves due to the relative movement of the imaging device 33 and the tool 20. . Prior to the movement, the field of view is enlarged compared to the field of view V of the first image by zooming out, so that the direction of the outline 53 outside the field of view can be reliably recognized. As a result, the imaging device 33 can follow the contour line 53 by the movement of the visual field V. Moreover, since the field of view V of the first image is realized again by zooming in, the partial outline 51 of the tool 20 can be specified with high accuracy. If the plurality of partial contour lines 51 thus identified are combined, a combined contour line 55 in a desired range of the tool 20 is extracted. As a result, the dimensions of the tool 20 can be measured using the connection contour 55.

  In the tool dimension measuring method according to the second embodiment, since the field of view V is expanded by zooming out while the number of pixels in the image data is constant, the imaging range specified by each pixel is expanded. . Therefore, the outline outline 56 of the tool 20 imaged at the time of zooming out only specifies the shape of the tool 20 roughly. Therefore, it is considered that it is not a good idea to use the outline 56 in extracting the outline of the tool 20 with high accuracy.

  In addition, an image at the time of zooming out may be displayed on the display screen of the display device 44, for example. The user may input an instruction to specifically specify the moving direction 53 of the visual field V on the display screen using the input device 45, for example. At this time, the arithmetic device 42 may specify the moving direction 53 of the visual field V according to the instruction input by the input device 45. In addition, in the above-described embodiment, zoom-in and zoom-out of the imaging device 33 are realized by optical zoom based on driving of the lens unit 34, but zoom-in and zoom-out may be realized by digital zoom, for example.

  In the above embodiment, although the tool dimension measuring method and measuring apparatus of the present invention have been described using a vertical machining center as an example of the machine tool 10, the tool dimension measuring method and measuring apparatus of the present invention are For example, it can be realized by a horizontal machining center or other machine tools. Further, although the tool dimension measuring method and measuring apparatus of the present invention have been described using a ball end mill as an example of the tool 20, the tool dimension measuring method and measuring apparatus of the present invention include, for example, a flat end mill, a drill, etc. It can also be realized with these tools. In the machine tool 10, the table base 16 may move in the Y-axis direction instead of the movement of the spindle head 18 in the Y-axis direction. In addition, the tool 20 may move with respect to the imaging device 33 in realizing the relative movement between the imaging device 33 and the tool 20.

DESCRIPTION OF SYMBOLS 10 Machine tool 13 Dimension measurement apparatus 20 Tool 33 Imaging apparatus 42 Arithmetic apparatus 44 Display apparatus 45 Input apparatus 51 Partial outline (partial outline)
53 Movement direction 54 Contour line (contour)
55 Joining contour (joint contour)
56 Outline (Outline outline)

Claims (3)

In the measurement method of the tool dimension, the tool is imaged using an imaging device that moves relative to the tool, and the dimension of the tool is measured based on the obtained image data.
The partial contour of the tool is identified based on image data obtained by imaging a part of the contour of the tool by the imaging device, the coordinate value of each constituent pixel is identified, and the coordinate value is converted into a coordinate value of a reference coordinate system associated in advance. And specifying the coordinate value of the partial contour in the reference coordinate system,
A tangent line in the field of view of the imaging device of the partial contour specified based on the coordinate value of a pixel constituting the partial contour line is calculated, and the direction of the tangent line is the direction of the contour of the tool outside the field of view of the image data Determining the moving direction to move the field of view of the imaging device;
Outputting a movement command for moving the imaging device and the tool relative to each other so that the visual field of the imaging device moves in the determined movement direction of the visual field to a control device of a machine tool;
The plurality of image data and coordinates of the reference coordinate system obtained by sequentially repeating the steps of specifying the partial contour, determining the moving direction of the visual field, and outputting a movement command for relative movement between the imaging device and the tool Combining the partial contours identified based on each of the coordinate value data that can be identified by values to extract the joint contour of the tool;
And measuring the dimension of the tool using the joint contour of the tool. In a tool size measuring device for measuring the size of the tool from image data obtained by imaging the tool,
An imaging device that images the tool and generates image data;
Based on the generated image data, a partial contour that forms a part of the contour of the tool is specified, the coordinate value of each pixel that is configured is specified, converted into a coordinate value of a reference coordinate system that is associated in advance, and a reference coordinate The coordinate value of the partial contour is specified by the system, the tangent line in the field of view of the imaging device of the specified partial contour is calculated, and the direction of the tangent line is set in the direction of the contour of the tool outside the field of view of the image data. A control device for a machine tool that determines a movement direction for moving the field of view of the imaging device and moves the imaging device and the tool relative to each other so that the field of view of the imaging device moves in the determined movement direction of the field of view. A plurality of the image data and the reference obtained by sequentially repeating the steps of specifying the partial contour, determining the moving direction of the visual field, and outputting a movement command for relative movement between the imaging device and the tool. seat The partial contour specified on the basis of each of the coordinate value data can be specified by the coordinate values of the system are bonded to each other, an arithmetic unit for extracting the coupling contour of said tool,
And measuring the dimension of the tool by using the joint contour of the tool.   The tool size measuring device according to claim 2, wherein a display device for displaying the shape of the tool specified based on the image data, and a predetermined instruction for the shape of the tool on the display device are input. A tool dimension measuring device further comprising an input device.

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