Tool measuring device and tool measuring method

Abstract

To provide a tool measuring device and a tool measuring method capable of grasping a deviation amount of a distance between respective outer surfaces of a plurality of projecting portions and a rotation axis line, when comparing the projecting portions in a tool during rotation.SOLUTION: A tool measuring device 1 is equipped with a camera 22, a main shaft rotary angle sensor 23, and a control device 20. A tool 12 has an actuating portion 46 that includes at least two projecting portions 48 that are a first projecting portion 481 and a second projecting portion 482. The control device 20 has a shooting command control portion 25, and a computing portion 27. The shooting command control portion 25 outputs a shooting command to the camera 22 in a plurality of phases with different rotary angles of a main shaft 11. The computing portion 27 obtains a first distance and a first phase at that time, and a second distance and a second phase at that time, on the basis of a plurality of images shot in each of the plurality of phases, and computes an actuating portion deviation amount corresponding to a difference between the first distance and the second distance.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present disclosure relates to a tool measurement apparatus and a tool measurement method. [Background technology]

[0002] Conventionally, there has been provided a measuring device for a rotary tool used in a machine tool, which is used to measure a tool having a plurality of protrusions, for example, a tool having a plurality of cutting edges, specifically, an end mill of a milling machine. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2007-49489 Summary of the Invention [Problem to be solved by the invention]

[0004] For tools including multiple protrusions, such as tools including multiple blades as the multiple protrusions, variations in the shape of the protrusions and deviations of the tool's central axis from the axis of rotation input to the tool may result in deviations in the distance between the axis of rotation and the portion of the outer surface of each protrusion that contacts the workpiece. If such deviations are large, the machining accuracy of the tool decreases. Therefore, there is a need to understand the amount of deviation when comparing multiple protrusions included in a tool. In particular, because a rotating tool is likely to deform due to centrifugal force, thermal displacement, and the like, there is a need to understand the amount of deviation for a rotating tool.

[0005] The present disclosure has been made in consideration of these points, and provides a tool measuring device and a tool measuring method that can grasp the amount of deviation in distance between the outer surface of each protrusion and the rotation axis when comparing multiple protrusions on a rotating tool. [Means for solving the problem]

[0006] The present disclosure relates to a tool measuring device that measures a tool set on a spindle of a machine tool, the device comprising: a camera that photographs the tool; a spindle rotation angle sensor that detects the rotation angle of the spindle; and a control device. The tool has an operating unit that includes at least two protrusions, i.e., a first protrusion and a second protrusion. The control device comprises: a photography command control unit that outputs a photography command to the camera in accordance with the rotation angle of the spindle detected by the spindle rotation angle sensor; and a calculation unit that performs calculations based on images taken by the camera. The photography command control unit outputs photography commands to the camera in multiple phases at which the rotation angle of the spindle is different. The calculation unit determines, based on multiple images taken in each of the multiple phases, a first distance at which the distance between the rotation axis of the spindle and the outer surface of the first protrusion is maximized, and the first phase at this time, a second distance at which the distance between the rotation axis of the spindle and the outer surface of the second protrusion is maximized, and the second phase at this time, and calculates an operating unit deviation amount corresponding to the difference between the first distance and the second distance.

[0007] The present disclosure is a tool measuring device in which the photography command control unit sequentially outputs the photography command for each different rotation of the tool over the entire phase range of 0° or more and less than 360°.

[0008] The present disclosure is a tool measuring device in which the operating part includes two or more protrusions, and among these, the protrusion with the largest maximum distance between the outer surface of the protrusion and the rotation axis of the spindle is designated as the first protrusion, and the protrusion with the smallest maximum distance between the outer surface of the protrusion and the rotation axis of the spindle is designated as the second protrusion.

[0009] The present disclosure relates to a tool measuring device in which the tool has a cylindrical shank extending from the operating unit in the direction of the rotational axis of the spindle, fixed to the spindle at one end, and connected to the operating unit at the other end, and the calculation unit calculates a shank deviation amount, which is the difference between the distance from the outer surface of the shank to the rotational axis of the spindle in the first phase and the distance from the outer surface of the shank to the rotational axis of the spindle in the second phase, and further determines the distortion of the operating unit based on the difference between the operating unit deviation amount and the shank deviation amount.

[0010] The present disclosure relates to a tool measurement method for measuring a tool set on a spindle of a machine tool, wherein the tool has an operating part including at least two protrusions, a first protrusion and a second protrusion, and the tool measurement method includes: an imaging process for detecting a rotation angle of the spindle and photographing the tool at multiple phases at which the rotation angle of the spindle differs depending on the detected rotation angle of the spindle; and a calculation process for determining, based on multiple images photographed at each of the multiple phases in the imaging process, a first distance at which the distance between the rotation axis of the spindle and the outer surface of the first protrusion is maximized, and the first phase at this time, and a second distance at which the distance between the rotation axis of the spindle and the outer surface of the second protrusion is maximized, and the second phase at this time, and calculating an operating part deviation amount corresponding to the difference between the first distance and the second distance.

[0011] The present disclosure is a tool measurement method in which, in the photographing step, the tool is photographed over an entire phase range of 0° or more and less than 360° for each different rotation of the tool.

[0012] The present disclosure relates to a tool measurement method in which the operating part includes two or more protrusions, and among these, the protrusion with the largest maximum distance between the outer surface of the protrusion and the rotation axis of the spindle is designated as the first protrusion, and the protrusion with the smallest maximum distance between the outer surface of the protrusion and the rotation axis of the spindle is designated as the second protrusion.

[0013] The present disclosure relates to a tool measurement method, wherein the tool has a cylindrical shank extending from the actuating unit in the direction of the rotation axis of the spindle, fixed at one end to the spindle, and connected at the other end to the actuating unit, and the calculation step includes: a shank deviation amount calculation step of calculating a shank deviation amount, which is the difference between the distance from the outer surface of the shank to the rotation axis of the spindle in the first phase and the distance from the outer surface of the shank to the rotation axis of the spindle in the second phase; and a distortion calculation step of determining the distortion of the actuating unit based on the difference between the actuating unit deviation amount and the shank deviation amount. [Effects of the Invention]

[0014] As described above, the present disclosure provides a tool measuring device and a tool measuring method that can grasp the amount of deviation in distance between the outer surface of each protrusion and the rotation axis when comparing multiple protrusions on a rotating tool. [Brief explanation of the drawings]

[0015] [Figure 1] FIG. 1 is a schematic diagram showing a tool measuring device and a machine tool according to an embodiment of the present disclosure. [Figure 2] FIG. 2 is a schematic cross-sectional view showing a spindle head of a machine tool according to an embodiment of the present disclosure. [Figure 3] FIG. 3 is a cross-sectional view illustrating an example of a tool according to an embodiment of the present disclosure. [Figure 4] FIG. 4 is a cross-sectional view illustrating an example of a tool according to an embodiment of the present disclosure. [Figure 5] Figure 5 shows how a tool is measured using a tool measuring device. [Figure 6] FIG. 6 is a diagram showing the positional relationship between the tool, the camera, and the lighting device. [Figure 7A] FIG. 7A is a diagram showing an example of an image captured in a capturing step. [Figure 7B] FIG. 7B is a diagram showing an example of an image captured in the imaging process. [Figure 8] FIG. 8 is a diagram showing the correspondence between changes in the phase at which images are captured and changes in the distance between the rotation axis of the spindle and the outer surface of the working part in the images captured at each phase. [Figure 9] FIG. 9 is a diagram showing the correspondence between changes in the phase at which images are captured and changes in the distance between the rotation axis of the spindle and the outer surface of the shaft portion in the images captured at each phase. [Figure 10A] FIG. 10A is a schematic cross-sectional view showing a spindle head of a machine tool according to a modified example. [Figure 10B] FIG. 10B is a schematic diagram showing a spindle rotation angle sensor of a machine tool according to a modified example. [Figure 10C] FIG. 10C is a diagram showing a continuous pulse signal obtained from a spindle rotation angle sensor of a machine tool according to a modified example. DETAILED DESCRIPTION OF THE INVENTION

[0016] First, a machine tool 2 on which a tool 12 to be measured by a tool measuring device 1 according to the present disclosure is set will be described. FIG. 1 is a schematic diagram showing the tool measuring device 1 and machine tool 2 according to the embodiment of the present disclosure. The machine tool 2 shown in FIG. 1 has a table 16 located on the upper surface of a bed 18 and a portal-shaped column 10, and a spindle head 4 is supported on a cross rail 8 of the column 10 via a saddle 6. The spindle head 4 has a spindle 11. A tool 12 is set on the spindle 11 of the machine tool 2.

[0017] The spindle head 4 of the machine tool 2 will now be described in more detail with reference to FIG. 2. FIG. 2 is a schematic cross-sectional view showing the spindle head 4 of the machine tool 2 according to an embodiment of the present disclosure. The spindle head 4 is of a built-in motor type and includes a housing 31 and a spindle 11. The spindle 11 is cylindrical and rotatably supported by the housing 31 via an air bearing. The dashed-dotted line labeled L1 in FIG. 2 indicates the axis about which the spindle 11 rotates. The axis about which the spindle 11 rotates is referred to as the rotation axis L1 of the spindle 11. The rotation axis L1 of the spindle 11 can also be said to be the rotation axis of the rotation input from the spindle 11 to the tool 12. The direction in which the rotation axis L1 of the spindle 11 extends is referred to as the axial direction d1. In the example shown in FIG. 2, the axial direction d1 is parallel to the X direction.

[0018] A tool holder 33 is provided at one end (lower end in FIG. 2 ) of the spindle 11 in the axial direction d1 along which the rotation axis L1 extends. The tool holder 33 detachably holds the tool 12. The tool 12 can be set on the spindle 11 by holding the tool 12 on the tool holder 33 of the spindle 11. A rotor 37 of a motor 35 is provided integrally with the other longitudinal end (upper end in FIG. 2 ) of the spindle 11. A stator 39 of the motor 35 is provided outside the rotor 37. The stator 39 is provided integrally with the housing 31 and slightly spaced from the rotor 37. The rotor 37 of the motor 35 rotates relative to the stator 39, thereby rotating the spindle 11, which is integrated with the rotor 37. The rotation of the spindle 11 also rotates the tool 12 set on the spindle 11.

[0019] Here, for ease of explanation, one predetermined horizontal direction is defined as the X direction (X-axis direction), another predetermined horizontal direction perpendicular to the X direction is defined as the Y direction (Y-axis direction), and the up-down direction perpendicular to the X and Y directions is defined as the Z direction (Z-axis direction).

[0020] Table 16 is movable in the X-axis direction relative to bed 18. Saddle 6 is movable in the Y-axis direction along cross rail 8. Spindle head 4 is movable in the Z-axis direction relative to saddle 6. By moving these three axes, tool 12 can be moved three-dimensionally relative to workpiece 14, which is the target of machining by machine tool 2 placed on table 16. By rotating tool 12 by rotating spindle 11, tool 12 can be brought into contact with workpiece 14, thereby machining workpiece 14.

[0021] Next, the tool 12 set in the machine tool 2 will be described. As shown in FIG. 2, the tool 12 has an actuating portion 46 and a shank 49. The actuating portion 46 is a portion having a plurality of protrusions 48, which will be described later. In the example shown in FIG. 2, the actuating portion 46 has a plurality of blades 48c as an example of the plurality of protrusions 48. Note that FIG. 2 does not illustrate the specific shapes of the plurality of protrusions 48 of the actuating portion 46, and only shows the general shape of the actuating portion 46. The shank 49 is a cylindrical portion that extends from the actuating portion 46 in the rotational axis direction (axial direction d1 shown in FIG. 2) along which the rotational axis L1 of the spindle 11 extends, is fixed to the spindle 11 at one end, and is connected to the actuating portion 46 at the other end. In the example shown in FIG. 2, one end of the shank 49 in the axial direction d1 (the upper end in FIG. 2) is held by the tool holder 33 of the spindle 11, thereby fixing the shank 49 to the spindle 11.

[0022] FIG. 3 is a diagram showing an example of a tool 12 set on the spindle 11 of the machine tool 2. FIG. 3 is particularly a cross-sectional view taken along a plane perpendicular to the rotation axis L1 of the spindle 11 with the tool 12 set on the spindle 11 of the machine tool 2. The point marked with the reference symbol L1 in FIG. 3 indicates the position of the rotation axis L1 of the spindle 11. As shown in FIG. 3, the tool 12 has an actuating portion 46 including at least a first protrusion 481 and a second protrusion 482. That is, in the example shown in FIG. 3, the actuating portion 46 includes two protrusions 48, the first protrusion 481 and the second protrusion 482.

[0023] FIG. 4 is a diagram showing an example of the tool 12 set on the spindle 11 of the machine tool 2, different from the example shown in FIG. 3. FIG. 4 is a cross-sectional view, particularly, of the tool 12 set on the spindle 11 of the machine tool 2, taken along a cross section perpendicular to the rotation axis L1 of the spindle 11. FIG. 4 corresponds to a cross section of the tool 12 at a reference position L5, which will be described later. The point marked with the symbol L1 in FIG. 4 indicates the position of the rotation axis L1 of the spindle 11. As shown in FIG. 4, the actuating portion 46 may include three or more protrusions 48. In the example shown in FIG. 4, the actuating portion 46 includes three protrusions 48: a first protrusion 481, a second protrusion 482, and a third protrusion 483.

[0024] In the example shown in FIGS. 3 and 4, the actuating portion 46 has a cylindrical base 45. In the example shown in FIGS. 3 and 4, the boundary between the protrusion 48 of the actuating portion 46 and the base 45 is indicated by a dashed line labeled 45a for convenience. In this specification, the term "protrusion" refers to a portion of the tool 12 that protrudes radially from the cylindrical base 45 centered on the rotation axis L1. The multiple protrusions 48 are provided spirally around the cylindrical base 45. Therefore, in the cross-sectional views of the tool 12 taken along a plane perpendicular to the rotation axis L1 of the spindle 11 as shown in FIGS. 3 and 4, the multiple protrusions 48 are aligned in the rotation direction d2 around the rotation axis L1 of the spindle 11.

[0025] The tool 12 is used, for example, when forming the surface of a mold core or cavity by cutting. The cutting is performed, for example, to perform a final finishing process on the surface of the mold core or cavity. The cutting makes the surface of the mold core or cavity like a mirror finish.

[0026] 3 and 4 is a tool 12 for cutting, in which the working part 46 has a plurality of blades 48c as the plurality of protrusions 48. Although not shown, the tool 12 may also be a tool 12 for polishing the workpiece 14, in which the working part 46 has a plurality of protrusions as the plurality of protrusions 48.

[0027] An end mill, for example, can be used as the tool 12. The outer diameter of the end mill used as the tool 12 is, for example, about 1 mm.

[0028] When an end mill is used as the tool 12, the end mill may be a ball end mill, a square end mill, a radius end mill, or the like. The end mill may also be a grinding wheel type end mill such as a PCD tool.

[0029] The rotation speed of the tool 12 is, for example, about 60,000 rotations per minute. The maximum rotation speed of the tool 12 can be set to about 120,000 rotations per minute.

[0030] The distance w1 shown in FIGS. 3 and 4 is the maximum distance between the rotation axis L1 of the main shaft 11 and the outer surface 48a of the protrusion 48 at the first protrusion 481. In the embodiment of the present disclosure, the maximum distance w1 among the distances between the rotation axis L1 of the main shaft 11 and the outer surface 48a of the first protrusion 481 is referred to as the first distance w1. In the example shown in FIGS. 3 and 4, the first distance w1 corresponds to the distance between the rotation axis L1 of the main shaft 11 and the tip 48b of the first protrusion 481. The distance w2 shown in FIGS. 3 and 4 is the maximum distance between the rotation axis L1 of the main shaft 11 and the outer surface 48a of the protrusion 48 at the second protrusion 482. In the embodiment of the present disclosure, the maximum distance w2 among the distances between the rotation axis L1 of the main shaft 11 and the outer surface 48a of the second protrusion 482 is referred to as the second distance w2. 3 and 4, the second distance w2 corresponds to the distance between the rotation axis L1 of the spindle 11 and the tip 48b of the second protrusion 482. As will be described later, when it is assumed that the position of the rotation axis L1 of the spindle 11 relative to a portion of the machine tool 2 other than the spindle 11 is deviated from the normal position, the first distance w1 and the second distance w2 may be determined as follows. The first distance w1 may be set to the maximum distance between the rotation axis L1 of the virtual spindle 11 in the normal position and the outer surface 48a of the protrusion 48 in the first protrusion 481. The second distance w2 may be set to the maximum distance between the rotation axis L1 of the virtual spindle 11 in the normal position and the outer surface 48a of the protrusion 48 in the second protrusion 482.

[0031] In an ideal tool 12, the maximum distance between the rotation axis L1 of the spindle 11 and the outer surface 48a of each of the multiple protrusions 48 is equal. For example, a first distance w1, which is the maximum distance between the rotation axis L1 of the spindle 11 and the outer surface 48a of the protrusion 48 in the first protrusion 481, is equal to a second distance w2, which is the maximum distance between the rotation axis L1 of the spindle 11 and the outer surface 48a of the protrusion 48 in the second protrusion 482. However, in an actual tool, as shown in FIGS. 3 and 4, the maximum distance between the rotation axis L1 of the spindle 11 and the outer surface 48a of each of the multiple protrusions 48 may not be equal. In the example shown in FIGS. 3 and 4, the first distance w1 and the second distance w2 are not equal.

[0032] The following are possible reasons why the maximum distances between the rotation axis L1 of the spindle 11 and the outer surfaces 48a of the protrusions 48 for each of the multiple protrusions 48 are not equal when the tool 12 is rotated to machine the workpiece 14. The shape of the operating portion 46 is likely to be distorted due to errors in manufacturing the tool 12, deformation of the tool 12 due to heat generated in the tool 12 when the tool 12 is rotated to machine the workpiece 14, deformation of the tool 12 due to centrifugal force, and changes in the shape of the tool 12 due to wear. In the example shown in FIGS. 3 and 4, the shape of the operating portion 46 is distorted, causing the shapes of the first protrusion 481 and the second protrusion 482 to differ, and as a result, the first distance w1 and the second distance w2 are not equal.

[0033] The following may be one of the reasons why the maximum distances between the rotation axis L1 of the spindle 11 and the outer surfaces 48a of the protrusions 48 are not equal for each of the multiple protrusions 48 when the tool 12 is rotated to machine the workpiece 14. The position of the tool 12 relative to the spindle 11 may be deviated from the ideal position. For example, the central axis L2 of the tool 12, which will be described later, may be deviated from the rotation axis L1 of the spindle 11. Specifically, the central axis L2 of the tool 12 may be tilted relative to the rotation axis L1 of the spindle 11. Furthermore, the central axis L2 of the tool 12 may be eccentric with respect to the rotation axis L1 of the spindle 11 at a portion of the tool 12 attached to the spindle 11, specifically, at a portion of the tool 12 where the shank 49 of the tool 12 is held by the tool holder 33 of the spindle 11. In addition, it is also possible that the position of the rotation axis L1 of the spindle 11 relative to parts other than the spindle 11 of the machine tool 2 is deviated from the normal position, so that the maximum distance between the rotation axis L1 of the virtual spindle 11 in the normal position and the outer surface 48a of the protrusion 48 for each of the multiple protrusions 48 will not be equal.

[0034] 3 and 4, among the plurality of protrusions 48, the protrusion 48 having the largest distance between the outer surface 48a of the protrusion 48 and the rotation axis L1 of the main shaft 11 is the first protrusion 481. Furthermore, among the plurality of protrusions 48, the protrusion 48 having the smallest distance between the outer surface 48a of the protrusion 48 and the rotation axis L1 of the main shaft 11 is the second protrusion 482. In other words, among the plurality of protrusions 48 included in the operating part 46, the largest distance between the rotation axis L1 of the main shaft 11 and the outer surface 48a of the protrusion 48 is the largest in the first protrusion 481 and the smallest in the second protrusion 482.

[0035] Next, a description will be given of the tool measuring device 1 according to the present disclosure. As described above, the tool measuring device 1 measures the tool 12 set on the spindle 11 of the machine tool 2. In Fig. 1, the tool measuring device 1 is installed at the end of a table 16.

[0036] FIG. 5 shows a diagram of the tool 12 being measured by the tool measuring device 1. As shown in FIGS. 2 and 5, the tool measuring device 1 includes a camera 22 that photographs the tool 12, a spindle rotation angle sensor 23 that detects the rotation angle of the spindle 11, and a control device 20. The tool measuring device 1 further includes an illumination device 24. The tool 12 can be measured using the tool measuring device 1 by moving the tool 12 to the position shown in FIG. 5 along the three axes described above. As shown in FIG. 5, the tool measuring device 1 measures the tool 12 positioned between the camera 22 and the illumination device 24.

[0037] The main shaft rotation angle sensor 23 is a sensor that detects the rotation angle of the main shaft 11. As an example, the main shaft rotation angle sensor 23 defines one of the rotation phases of the main shaft 11 as a reference phase and detects the rotation angle of the main shaft 11 from the reference phase. The main shaft rotation angle sensor 23 is provided on the main shaft 11.

[0038] The spindle rotation angle sensor 23 is, for example, a rotary encoder provided to detect the rotation angle of the spindle 11. The resolution of the rotary encoder may be, for example, 0.1° or more and 5° or less, or may be less than 0.1°. The resolution of the rotary encoder is, for example, 1°. By using a rotary encoder as the spindle rotation angle sensor 23, an imaging command control unit 25 (described later) of the control device 20 outputs an imaging command in accordance with the rotation angle of the spindle 11 detected by the rotary encoder, and an appropriate image of the tool 12 is captured.

[0039] The control device 20 controls the tool measuring device 1, but the control device 20 may be connected to the machine tool 2 and control the machine tool 2 as well as controlling the tool measuring device 1. In this case, the control device 20 may control the rotation speed and positioning of the rotation angle of the spindle 11. The control device 20 is configured to include, for example, a CPU and a memory (not shown).

[0040] The control device 20 has a photography command control unit 25 that outputs a photography command to the camera 22 in accordance with the rotation angle of the spindle 11 detected by the spindle rotation angle sensor 23, and a calculation unit 27 that performs calculations based on images captured by the camera 22. The photography command control unit 25 outputs photography commands to the camera 22 in multiple phases where the rotation angle of the spindle 11 is different. The calculation unit 27 calculates an operating unit deviation amount w6 (described later) based on multiple images captured by the camera 22 in each of the multiple phases in accordance with the photography command from the photography command control unit 25. A specific method by which the photography command control unit 25 outputs the photography command will be described later in the description of the tool measurement method using the tool measuring device 1. A specific method by which the calculation unit 27 calculates the operating unit deviation amount w6 (described later) will also be described later in the description of the tool measurement method using the tool measuring device 1.

[0041] As shown in FIG. 5, the camera 22 photographs the tool 12 positioned between the camera 22 and the lighting device 24. In particular, the camera 22 photographs the rotating tool 12 to obtain an image (still image) of the tool 12. The camera 22 is, for example, a digital camera and is configured to photograph the tool 12 using a global shutter. As an example, the camera 22 may be equipped with a high-speed shutter so that it can capture still-like images even when the tool 12 is rotating at several thousand revolutions per minute. In this case, the shutter speed of the camera 22 when photographing the tool 12 is short enough to capture an image of the rotating tool 12 that is almost a still image. The camera 22 may also be equipped with a zoom lens, and the magnification ratio may be controlled by the control device 20. As shown in FIG. 5, by illuminating the tool 12 from behind with light from the lighting device 24 and photographing the image, the tool 12 is photographed as a shadow.

[0042] Next, the lighting device 24 will be described. FIG. 6 is a diagram illustrating the positional relationship between the tool 12, the camera 22, and the lighting device 24 according to an embodiment of the present disclosure. FIG. 6 illustrates the positions of the tool 12, the camera 22, and the lighting device 24 as viewed from a line of sight parallel to the axial direction d1. In the example illustrated in FIG. 6, the lighting device 24 has a strobe 61, and the camera 22 and the lighting device 24 are installed so that the rotating tool 12 is sandwiched between the camera 22 and the lighting device 24. In this case, the strobe 61 can emit light toward the tool 12 and the camera 22, and then the camera 22 can photograph the tool 12. In this case, the strobe 61 is configured to emit parallel light 79 toward the tool 12.

[0043] When the tool 12 is photographed by the camera 22, the strobe 61 functions as a backlight, which allows the silhouette of the tool 12 to be photographed using the camera 22.

[0044] Next, the configuration of the camera 22 and the strobe 61 will be further described. The traveling direction of the parallel light 79 emitted by the strobe 61 is, for example, the X direction. The traveling direction of the parallel light 79 emitted by the strobe 61 is perpendicular to the rotation axis L1 of the main shaft 11. The optical axis 71 of the lens 69 of the camera 22 extends parallel to the traveling direction of the parallel light 79 emitted by the strobe 61.

[0045] As described above, the camera 22 and the lighting device 24 are arranged so as to sandwich the rotating tool 12 between the camera 22 and the lighting device 24. Then, the strobe 61 emits parallel light 79 toward the tool 12 and the camera 22, and the camera 22 photographs the tool 12, thereby making it possible to photograph a silhouette of the tool 12 that is identical to the outer shape of the actual tool 12.

[0046] By capturing the silhouette of the tool 12 as a still image, an image in which the outer shape of the tool 12 is clearly visible can be easily captured.

[0047] As described above, the lighting device 24 includes the strobe 61. The lighting device 24 including the strobe 61 is preferably used when the tool 12 rotates at high speed, particularly when the tool 12 rotates at a speed of 10,000 revolutions per minute or more. When the lighting device 24 includes the strobe 61, the light emission of the strobe 61 may be adjusted so that a clearer still image of the tool 12 can be obtained by the camera 22 and so that the tool 12 can be photographed in a shorter time. For example, the light emission of the strobe 61 may be adjusted so that the time during which the strobe 61 emits light is shorter than the time the shutter of the camera 22 is open, and so that the strobe 61 emits light while the shutter of the camera 22 is open.

[0048] In other words, the light emission of the strobe 61 may be adjusted so that the strobe 61 emits light within the time that the shutter of the camera 22 is open (within the time that the shutter of the camera 22 is fully open) when the control device 20 outputs a shooting command to the camera 22.

[0049] The strobe 61 may be adjusted to emit light a short time after the camera 22 starts to open the shutter, but before the camera 22 starts to close the shutter.

[0050] As an example, consider a case where the camera 22 is configured to immediately start opening the shutter when the control device 20 outputs a shooting command to the camera 22. In this case, the control device 20 may use the measurement result of the main shaft rotation angle sensor 23 as a trigger to output a shooting command to the shutter of the camera 22 and simultaneously output an instruction to the strobe 61 to fire. However, in this case, because there is a time lag between the output of the shooting command to the camera 22 and the shutter of the camera 22 fully opening, it is possible that the strobe 61 will fire before the shutter of the camera 22 is fully open. To avoid this, the timing of outputting the shooting command to the camera 22 and the instruction to the strobe 61 to fire may be adjusted so that the timing of the strobe 61 firing is delayed from the timing when the camera 22 starts opening the shutter. In this case, the strobe 61 can be fired when the shutter is fully open.

[0051] In particular, the timing at which a shooting command to camera 22 and an instruction to flash light to flash light 61 are output may be adjusted so that flash light 61 does not fire before the shutter of camera 22 is fully open. Also, the timing at which a shooting command to camera 22 and an instruction to flash light to flash light 61 are output may be adjusted so that flash light 61 does not fire when the shutter of camera 22 is closed or in the process of closing.

[0052] When a still image of the tool 12 is taken using the strobe 61 (by momentarily emitting light from the strobe 61), as described above, the tool 12 can be photographed even if the shutter speed of the camera 22 is set to a relatively slow speed. Note that when an LED is used as the light source for the strobe 61, the LED has high brightness and is very bright, so an image in which the silhouette of the tool 12 can be clearly observed can be taken without making the photographing environment particularly dark.

[0053] As shown in FIG. 6, the tool measuring apparatus 1 may include an alignment adjustment device 73 for adjusting the alignment of the strobe light 61 with respect to the tool 12. The alignment adjustment device 73 shown in FIG. 6 rotationally positions the strobe light 61 by adjusting the rotation angle of the strobe light 61 around a predetermined rotation axis extending in the Z direction and the rotation angle of the strobe light 61 around a predetermined rotation axis extending in the Y direction. Although not shown, the tool measuring apparatus 1 may also include an alignment adjustment device for the camera 22 for adjusting the alignment of the camera 22 with respect to the tool 12. The alignment adjustment device for the camera 22 may rotationally position the camera 22 by adjusting the rotation angle of the camera 22 around a predetermined rotation axis extending in the Z direction and the rotation angle of the camera 22 around a predetermined rotation axis extending in the Y direction.

[0054] By providing the tool measuring device 1 with an alignment adjustment device 73 for the strobe 61 and an alignment adjustment device for the camera 22, it becomes easy to adjust the direction of travel of the parallel light 79 emitted by the strobe 61 and the optical axis 71 of the lens 69 of the camera 22 so that they are parallel to each other.

[0055] If the camera 22 is equipped with a high-speed shutter and the lighting device 24 has a strobe 61, the strobe 61 has a short light emission time of several microseconds, making it possible to measure the tool 12 while it is rotating, even if the tool 12 is rotating at a particularly high speed. An LED, for example, can be used as the light emitter (light source) used in the strobe 61.

[0056] The effect of the lighting device 24 according to the embodiment of the present disclosure will be described. The lighting device 24 according to the embodiment of the present disclosure has a strobe 61, which is configured to emit light toward the tool 12. Therefore, by adjusting the light emission of the strobe 61 so that the strobe 61 emits light while the shutter of the camera 22 is open, the tool 12 can be photographed in a shorter time than when an image is taken by opening and closing the shutter of the camera 22. This makes it possible to easily obtain a clear image of the rotating tool 12 at low cost.

[0057] If a lighting device 24 without a strobe 61 is used, it would be necessary to use a camera 22 that can continuously capture sufficiently clear images at a short shutter speed, which could result in a very expensive camera 22. In contrast, the strobe 61 has a fast rise time and can emit light for a short period of time, so by using a lighting device 24 with a strobe 61, it is possible to capture clear images of the rotating tool 12.

[0058] Next, a tool measurement method for measuring tool 12 set on spindle 11 of machine tool 2 will be described. In particular, a method will be described in which, when workpiece 14 is placed on table 16 as shown in Fig. 1 and workpiece 14 is machined by rotating tool 12, tool 12 is measured while continuing to rotate tool 12 for machining workpiece 14.

[0059] The tool measurement method includes: an imaging step of detecting a rotation angle of the spindle 11 and imaging the tool 12 at multiple phases at which the rotation angle of the spindle 11 differs depending on the detected rotation angle of the spindle 11; and a calculation step of determining, based on multiple images captured at each of the multiple phases in the imaging step, a first distance w1 at which the distance between the rotation axis L1 of the spindle 11 and the outer surface 48a of the first protrusion 481 is maximized, the first phase at this time, a second distance w2 at which the distance between the rotation axis L1 of the spindle 11 and the outer surface 48a of the second protrusion 482 is maximized, and the second phase at this time, and calculating an operating portion deviation amount w6 corresponding to the difference between the first distance w1 and the second distance w2. In an embodiment of the present disclosure, the tool measurement method further includes a moving step of moving the tool 12 so that at least the operating portion 46 of the tool 12 is positioned between the camera 22 and the lighting device 24.

[0060] In the tool measurement method, first, in a moving step, the tool 12 is moved so that at least the operating part 46 of the tool 12 is positioned between the camera 22 and the lighting device 24. The moving step is started, for example, when a specified time set in the control device 20 has elapsed while the workpiece 14 is being machined by the machine tool 2. In the moving step, the tool 12, which rotates in conjunction with the rotation of the spindle 11 and is machining the workpiece 14 placed on the table 16, is moved while maintaining its rotation so that at least the operating part 46 of the tool 12 is positioned between the camera 22 and the lighting device 24. The tool 12 can be moved together with the spindle head 4 by moving the table 16 relative to the bed 18, moving the saddle 6 along the cross rail 8, and moving the spindle head 4 relative to the saddle 6.

[0061] In the photographing process, the rotation angle of the spindle 11 is detected, and the tool 12 is photographed at a plurality of phases at which the rotation angle of the spindle 11 is different, depending on the detected rotation angle of the spindle 11. The photographing of the tool 12 at a plurality of phases is performed by the above-mentioned photographing command control unit 25 outputting a photographing command to the camera 22 at a plurality of phases at which the rotation angle of the spindle 11 is different. As an example, the photographing of the tool 12 is performed over the entire phase range of 0° or more and less than 360°. The rotation angle of the spindle 11 is detected by the above-mentioned spindle rotation angle sensor 23.

[0062] The photographing process will be described in more detail. In the photographing process, first, one of the rotation phases of the spindle 11 is determined as a reference phase, and a photographing command is output to the photographing command control unit 25 at the reference phase to photograph the tool 12. Also, the position of the spindle 11 at the reference phase is determined by the spindle rotation angle sensor 23. Next, a photographing command is output to the photographing command control unit 25 at a phase shifted by an angle θ from the reference phase to photograph the tool 12. Thereafter, the operation of outputting a photographing command to the photographing command control unit 25 at a phase further shifted by an angle θ from the phase in which the previous image was photographed to photograph the tool 12 is repeated. In this way, photographing of the tool 12 can be performed over the entire phase range of 0° or more and less than 360° for each phase shifted by the angle θ. In this case, the angle θ is, for example, 1°. When the angle θ is 1°, the tool 12 can be photographed over the entire phase range of 0° to 360° by repeating the photographing of the tool 12 360 times for each phase shifted by 1°. The angle θ may be 5°. When the angle θ is 5°, the tool 12 can be photographed over the entire phase range of 0° to 360° by repeating the photographing of the tool 12 72 times for each phase shifted by 5°.

[0063] Here, in the photographing process, the tool 12 is photographed for each different rotation of the tool 12. In other words, in the photographing process, photographing is not performed more than once while the tool 12 makes one rotation. For example, in the photographing process, if the nth photograph of the tool 12 is taken at the nth phase (n is a positive integer) and then the n+1th photograph of the tool 12 is taken at the n+1th phase that is shifted by angle θ from the nth phase, photographing is performed as follows. The n+1th photograph of the tool 12 is not taken when the tool 12 has rotated by angle θ after the nth photograph of the tool 12, but is taken when the tool 12 has rotated m times and then further rotated by angle θ (m is a positive integer, for example, 10 rotations). The n+1th photograph of the tool 12 can be taken, for example, when the tool 12 has rotated 10 times after the nth photograph of the tool 12 and then further rotated by angle θ. The (n+1)th photographing of the tool 12 may be performed when the tool 12 has rotated five times since the nth photographing of the tool 12 and then rotated an additional angle θ.

[0064] As an example, in the photographing process, the tool 12 is photographed over the entire phase range of 0° or more and less than 360° for each different rotation of the tool 12. In this case, the photographing command control unit 25 outputs a photographing command over the entire phase range of 0° or more and less than 360° for each different rotation of the tool 12.

[0065] The operation of sequentially photographing the tool 12 over the entire phase range of 0° or more and less than 360° for each different rotation of the tool 12 includes photographing the tool 12 at a reference phase, and then photographing the tool 12 in sequence from a phase with a smaller rotation angle of the spindle 11 to a phase with a larger rotation angle. The operation of sequentially photographing the tool 12 over the entire phase range of 0° or more and less than 360° for each different rotation of the tool 12 also includes photographing the tool 12 in an order that is unrelated to the magnitude of the rotation angle of the spindle 11. The photography command control unit 25 that sequentially outputs photography commands over the entire phase range of 0° or more and less than 360° for each different rotation of the tool 12 includes a photography command control unit 25 that outputs a photography command to photograph the tool 12 at a reference phase, and then outputs photography commands in sequence from a phase with a smaller rotation angle of the spindle 11 to a phase with a larger rotation angle. In addition, the photography command control unit 25 that outputs photography commands sequentially over the entire phase range of 0° or more and less than 360° for each different rotation of the tool 12 also includes a photography command control unit 25 that outputs photography commands in an order independent of the magnitude of the rotation angle of the spindle 11.

[0066] The effect of photographing the tool 12 at each different rotation of the tool 12 in the photographing process will be described. Consider a case where an nth photograph of the tool 12 is taken, and then an n+1th photograph of the tool 12 is taken when the tool 12 has rotated by an angle θ. In this case, in order to take the nth photograph and the n+1th photograph, it becomes necessary to take the nth photograph and the n+1th photograph consecutively within the short time it takes for the tool 12 to rotate by the angle θ. In particular, when the tool 12 is rotating at high speed as described above, the time it takes for the tool 12 to rotate by the angle θ becomes extremely short.

[0067] In contrast, by photographing the tool 12 at each different rotation of the tool 12, and photographing the tool 12 for the (n+1)th time when the tool 12 has rotated m times, for example, 10 times, and then rotated an additional angle θ after the nth photograph of the tool 12 has been taken, the following effect can be obtained. That is, by photographing the tool 12 for the (n+1)th time and then the tool 12 has rotated m times, for example, 10 times, and then rotated an additional angle θ, images of the tool 12 can be photographed at the nth phase and the (n+1)th phase that is shifted from the nth phase by the angle θ. For this reason, by increasing the value of m, images can be photographed without the shutter speed of the camera 22 being insufficient, even when photographing a tool 12 that is rotating at high speed.

[0068] A tool measurement method according to an embodiment of the present disclosure is performed using a tool measurement device 1 according to an embodiment of the present disclosure. The tool measurement device 1 includes a spindle rotation angle sensor 23 that detects the rotation angle of the spindle 11, and a control device 20 that has an imaging command control unit 25 that outputs an imaging command to the camera 22 in accordance with the rotation angle of the spindle 11 detected by the spindle rotation angle sensor 23. For this reason, as described above, after the nth imaging of the tool 12 is performed, when the tool 12 has rotated m times and then further rotated by an angle θ, an (n+1)th imaging of the tool 12 can be performed. This makes it possible to capture images of the tool 12 at phases shifted by an angle θ over the entire phase range of 0° or more and less than 360°, without having to perform imaging multiple times during one rotation of the tool 12.

[0069] Note that when it is required to photograph the tool 12 at a specific phase, if the photography command control unit 25 outputs a photography command when the spindle 11 has rotated to the specific phase, the actual photography timing may be delayed. The photography timing delay may be caused by, for example, a time lag between when the photography command control unit 25 outputs a photography command and when the camera 22 takes the photograph, a time lag caused by the spindle rotation angle sensor 23, or a time lag caused by the control device 20. The impact of the photography timing delay is considered to be particularly pronounced when the spindle 11 is rotating at high speed. To prevent this, the photography command control unit 25 may output a photography command slightly before the spindle 11 rotates to the specific phase. In this case, it may be experimentally determined in advance how close the spindle 11 must be to the specific phase before the photography command is output. Furthermore, the lighting device 24 may be set to emit light at the actual photography timing, taking into account the aforementioned photography timing delay. As an example, the time from when the photography command is output until the lighting device 24 emits light can be adjusted in microsecond increments.

[0070] The images captured in each of the phases in the imaging process include, for example, images such as those shown in FIGS. 7A and 7B. FIG. 7A is a diagram showing an image of the tool 12 shown in FIG. 4, in which the actuating portion 46 includes three protrusions 48, taken from the direction indicated by arrow 26A in FIG. 4. The direction indicated by arrow 26A is a direction perpendicular to the rotation axis L1 of the spindle 11. FIG. 7B is a diagram showing an image of the tool 12 shown in FIG. 4 taken from the direction indicated by arrow 26B in FIG. 4. The direction indicated by arrow 26B is different from the direction indicated by arrow 26A and is a direction perpendicular to the rotation axis L1 of the spindle 11. Note that in FIGS. 7A and 7B, the specific shapes of the protrusions 48 of the actuating portion 46 are not shown, and the general shape of the actuating portion 46 is shown as a rectangle.

[0071] In an embodiment of the present disclosure, as shown in Figures 7A and 7B, an image is taken so as to capture the working portion 46 of the tool 12. In the example shown in Figures 7A and 7B, an image is taken so as to capture the shank 49 along with the working portion 46. In the example shown in Figures 7A and 7B, an image is taken of a silhouette of the entire working portion 46 and a portion of the shank 49 of the tool 12.

[0072] In the calculation step, the amount of operating portion deviation is calculated based on the multiple images captured at each of the multiple phases in the photographing step. Specifically, the first distance w1 at which the distance between the rotation axis L1 of the main shaft 11 and the outer surface 48a of the first protrusion 481 is maximized, and the first phase at this time are determined. In addition, the second distance w2 at which the distance between the rotation axis L1 of the main shaft 11 and the outer surface 48a of the second protrusion 482 is maximized, and the second phase at this time are determined. Then, the amount of operating portion deviation w6 corresponding to the difference between the first distance w1 and the second distance w2 is calculated. In the tool measurement method according to an embodiment of the present disclosure, the calculation process includes a shank deviation amount calculation process that calculates a shank deviation amount w8, which is the difference between the distance w7 from the outer surface 49a of the shank 49 to the rotation axis L1 of the spindle 11 in the first phase and the distance w7 from the outer surface 49a of the shank 49 to the rotation axis L1 of the spindle 11 in the second phase, and a distortion calculation process that determines the distortion of the operating part 46 based on the difference between the operating part deviation amount w6 and the shank deviation amount w8.

[0073] The calculation step is performed by the calculation unit 27. That is, the calculation unit 27 determines a first distance w1 at which the distance between the rotation axis L1 of the main shaft 11 and the outer surface 48a of the first protrusion 481 is maximized, and the first phase at this time. The calculation unit 27 also determines a second distance w2 at which the distance between the rotation axis L1 of the main shaft 11 and the outer surface 48a of the second protrusion 482 is maximized, and the second phase at this time. The calculation unit 27 according to the embodiment of the present disclosure also calculates a shaft portion deviation amount w8, which is the difference between a distance w7 from the outer surface 49a of the shaft portion 49 to the rotation axis L1 of the main shaft 11 in the first phase and a distance w7 from the outer surface 49a of the shaft portion 49 to the rotation axis L1 of the main shaft 11 in the second phase, and further determines the distortion of the operating portion 46 based on the difference between the operating portion deviation amount w6 and the shaft portion deviation amount w8.

[0074] In the calculation step, first, the distance between the rotation axis L1 of the spindle 11 and the outer surface 46a of the operating unit 46 is calculated in each of the multiple images taken in the photographing step. Specifically, a silhouette of the tool 12 appears in each of the multiple images taken in the photographing step, and the distance between the outer surface 46a forming the outline of the silhouette of the operating unit 46 of the tool 12 and the rotation axis L1 of the spindle 11 is calculated in each of the multiple images. In particular, the distance between the rotation axis L1 of the spindle 11 and the outer surface 46a forming the outline of the silhouette of the operating unit 46, which is located on one side of the boundary of the rotation axis L1 of the spindle 11 (the left side in the example shown in FIGS. 7A and 7B ), is calculated in each of the multiple images.

[0075] The distance between rotation axis L1 of main shaft 11 and outer surface 46a of operating unit 46 in the image can be found, for example, by counting the number of pixels in the digital image. When finding the distance between rotation axis L1 of main shaft 11 and outer surface 46a of operating unit 46 in the image, calculation unit 27 can be made to identify the position of rotation axis L1 of main shaft 11, for example, by the following method. Control device 20 stores the position of rotation axis L1 of main shaft 11 in the image captured by camera 22. Then, calculation unit 27 is made to refer to the stored position of rotation axis L1 of main shaft 11. This allows calculation unit 27 to identify the position of rotation axis L1 of main shaft 11 in the image.

[0076] In the captured images, the distance between the rotation axis L1 of the spindle 11 and the outer surface 46a of the actuating portion 46 may not be constant when compared at different positions in the axial direction d1. The two-dot chain line labeled L2 in FIGS. 7A and 7B indicates an axis passing through the center of the tool 12. The axis passing through the center of the tool 12 is referred to as the central axis L2 of the tool 12. When the tool 12 has an ideal shape without distortion, the shape of the tool 12 is rotationally symmetric about the central axis L2. In the example shown in FIGS. 7A and 7B, the central axis L2 of the tool 12 is offset from the rotation axis L1 of the spindle 11, so the distance between the rotation axis L1 of the spindle 11 and the outer surface 46a of the actuating portion 46 in the images is not constant when compared at different positions in the axial direction d1. 7A and 7B, the distance w3 between the outer surface 46a of the operating portion 46 at the first position L3 in the axial direction d1 and the rotation axis L1 of the main shaft 11 is not equal to the distance w4 between the outer surface 46a of the operating portion 46 at the second position L4 in the axial direction d1 and the rotation axis L1 of the main shaft 11. Furthermore, since the protrusion 48 is provided so as to spirally surround the base 45 as described above, it is conceivable that the distance between the outer surface 46a of the operating portion 46 and the rotation axis L1 of the main shaft 11 in the captured image will not be constant.

[0077] In this case, the distance between the rotation axis L1 of the spindle 11 and the outer surface 46a of the operating unit 46 may be calculated as the distance between the rotation axis L1 of the spindle 11 and the outer surface 46a of the operating unit 46 at a reference position L5, which is a specific position in the axial direction d1. The reference position L5 is set, for example, at a position where the tool 12 can come into contact with the workpiece 14. Specifically, the reference position L5 may be set to the position farthest from the spindle 11 among the positions where the tool 12 can come into contact with the workpiece 14. In the embodiment of the present disclosure, the first position L3 is set as the reference position L5. In this case, in the calculation step, a distance w3 in the images shown in FIGS. 7A and 7B is calculated as the distance between the rotation axis L1 of the spindle 11 and the outer surface 46a of the operating unit 46 at the reference position L5.

[0078] FIG. 8 is a graph showing the correspondence between the change in the phase at which an image is captured and the change in the distance w3 between the rotation axis L1 of the spindle 11 and the outer surface 46a of the actuating portion 46 at the reference position L5 of the image captured at each phase for the tool 12 shown in FIG. 4, whose actuating portion 46 includes three protrusions 48. In FIG. 8, the correspondence between the change in the phase at which an image is captured and the distance w3 is represented by a curve. For example, the curve can be obtained by plotting multiple points on the graph representing the correspondence between the phase at which the image is captured and the distance w3 and connecting the plotted points. In FIG. 8, the phase at which an image is captured from the direction indicated by arrow 26B in FIG. 4 is defined as the reference phase, i.e., the phase at which the rotation angle of the spindle 11 is 0°. The horizontal axis shows the change in phase over the entire phase range from 0° to less than 360° when the tool 12 rotates in the circumferential direction d2 toward the first side s1. The dashed line labeled L6 in Fig. 8 indicates the rotation angle position of spindle 11 at the phase at which an image is captured from the direction indicated by arrow 26A in Fig. 4. The graph in Fig. 8 also shows the correspondence between changes in the phase at which an image is captured and changes in distance w3 when there is no distortion in the cross-sectional shape of base 45 of operating unit 46 and the deviation of central axis L2 of tool 12 from rotation axis L1 of spindle 11 is particularly small.

[0079] In the example shown in Fig. 8, the distance w3 changes in accordance with the change in the phase at which the image is captured, so as to exhibit multiple maximum values ​​93. In the phase range shown in Fig. 8, multiple mountain-shaped changes in the distance w3 appear.

[0080] The distance w3 changes in accordance with the change in the phase at which the image is captured over the entire phase range of 0° or more and less than 360°, so that a mountain-shaped change appears corresponding to the number of protrusions 48 included in the actuating unit 46. Furthermore, the distance w3 changes in accordance with the change in the phase at which the image is captured over the entire phase range of 0° or more and less than 360°, so that a maximum value 93 appears in the number of protrusions 48 included in the actuating unit 46. The actuating unit 46 of the tool 12 shown in FIG. 4 includes three protrusions 48. Therefore, three mountain-shaped changes appear in the graph shown in FIG. 8. Furthermore, the distance w3 changes in accordance with the change in the phase at which the image is captured over the entire phase range of 0° or more and less than 360°, so that three maximum values ​​93, namely, maximum value 93a, maximum value 93b, and maximum value 93c, appear.

[0081] From a graph such as that shown in Fig. 8, which shows the correspondence between the change in the phase at which an image is captured over the entire phase range of 0° or more and less than 360° and the distance w3, the first distance w1 at which the distance between the rotation axis L1 of the spindle 11 and the outer surface 48a of the first protrusion 481 at the reference position L5 is maximized, and the first phase at this time, can be determined. Furthermore, from the graph such as that shown in Fig. 8, the second distance w2 at which the distance between the rotation axis L1 of the spindle 11 and the outer surface 48a of the second protrusion 482 at the reference position L5 is maximized, and the second phase at this time, can be determined. Below, as an example of a method for determining the first distance w1, the first phase, the second distance w2, and the second phase, a method for determining the first distance w1, the first phase, the second distance w2, and the second phase from the graph shown in Fig. 8 will be described.

[0082] First, a plurality of maximum values ​​93 are identified on a graph showing the correspondence between the distance w3 and changes in the phase at which images are captured over the entire phase range of 0° or more and less than 360°. Each of the identified maximum values ​​93 corresponds to the maximum distance between the rotation axis L1 of the main shaft 11 at the reference position L5 and the outer surface 48a of each of the plurality of protrusions 48.

[0083] In the embodiment of the present disclosure, as described above, in the cross-sectional view of the tool 12 at the reference position L5 shown in FIG. 4 , among the multiple protrusions 48, the protrusion 48 having the largest maximum distance between the outer surface 48a of the protrusion 48 and the rotation axis L1 of the spindle 11 is defined as the first protrusion 481. Furthermore, among the multiple protrusions 48, the protrusion 48 having the smallest maximum distance between the outer surface 48a of the protrusion 48 and the rotation axis L1 of the spindle 11 is defined as the second protrusion 482. Therefore, the largest maximum value 93a among the identified maximum values ​​93 corresponds to the first distance w1, which is the maximum distance between the rotation axis L1 of the spindle 11 and the outer surface 48a of the first protrusion 481 at the reference position L5. Furthermore, the smallest maximum value 93b among the identified maximum values ​​93 corresponds to the second distance w2, which is the maximum distance between the rotation axis L1 of the spindle 11 and the outer surface 48a of the second protrusion 482 at the reference position L5. Therefore, the first distance w1 can be obtained by identifying the largest maximum value 93a from the identified maximum values ​​93. The second distance w2 can be obtained by identifying the smallest maximum value 93b from the identified maximum values ​​93. Note that the maximum value 93c shown in FIG. 8 corresponds to the maximum distance between the outer surface 48a of the third protrusion 483 shown in FIG. 4 and the rotation axis L1 of the main shaft 11.

[0084] The first phase is the phase at which an image in which the distance w3 is the first distance w1 is captured among the multiple images captured in the imaging process shown in FIGS. 7A and 7B. The first phase is determined as the phase at which the distance w3 reaches its maximum value 93a in a graph showing the correspondence between the change in the phase at which images are captured and the distance w3 as shown in FIG. 8. In the example shown in FIG. 8, the first phase is the phase at which the rotation angle of the main shaft 11 reaches the rotation angle indicated by the symbol L6. The second phase is the phase at which an image in which the distance w3 is the second distance w2 is captured among the multiple images captured in the imaging process shown in FIGS. 7A and 7B. The second phase is determined as the phase at which the distance w3 reaches its minimum maximum value 93b in a graph showing the correspondence between the change in the phase at which images are captured and the distance w3 as shown in FIG. 8. In the example shown in FIG. 8, the second phase is the phase at which the rotation angle of the main shaft 11 reaches the rotation angle indicated by the dashed line indicated by the symbol L7.

[0085] After determining the first distance w1, the first phase, the second distance w2, and the second phase, an operating portion deviation amount w6 shown in Fig. 8, which corresponds to the difference between the first distance w1 and the second distance w2, is calculated. The operating portion deviation amount w6 is determined by subtracting the second distance w2 from the first distance w1.

[0086] Note that the calculation step of determining the first distance w1, the first phase, the second distance w2, and the second phase based on a plurality of images captured at each of a plurality of phases and calculating the actuation unit deviation amount w6 corresponding to the difference between the first distance w1 and the second distance w2 is not limited to the example described above. The calculation unit 27 according to the embodiment of the present disclosure includes a calculation step of calculating the actuation unit deviation amount w6 corresponding to substantially the difference between the first distance w1 and the second distance w2 based on a plurality of images captured at each of a plurality of phases.

[0087] Furthermore, the calculation unit 27 that determines the first distance w1, the first phase, the second distance w2, and the second phase based on the multiple images captured in each of the multiple phases and calculates the operating unit deviation amount w6 corresponding to the difference between the first distance w1 and the second distance w2 is not limited to the example described above. The calculation unit 27 according to the embodiment of the present disclosure includes a calculation unit 27 that calculates the operating unit deviation amount w6 that substantially corresponds to the difference between the first distance w1 and the second distance w2 based on the multiple images captured in each of the multiple phases.

[0088] For example, in the calculation step, the operating portion deviation amount w6 may be calculated by the following method. First, the image captured in the first phase and the image captured in the second phase are superimposed so that the rotation axis L1 of the main shaft 11 and the reference position L5 are overlapped. Then, the distance between the outer surface 48a of the first protrusion 481 appearing in the image captured in the first phase and the outer surface 48a of the second protrusion 482 appearing in the image captured in the second phase is calculated and set as the operating portion deviation amount w6. This method also makes it possible to calculate the operating portion deviation amount w6, which essentially corresponds to the difference between the first distance w1 and the second distance w2. The above-mentioned method can be performed by the calculation unit 27.

[0089] The effect of calculating the operating part deviation amount w6 will be explained. The larger the operating part deviation amount w6, the more uneven the contact of each of the multiple protrusions 48 of the operating part 46 with the workpiece 14 when machining the workpiece 14 using the tool 12. For this reason, it is thought that the larger the operating part deviation amount w6, the lower the machining accuracy of the tool 12. By calculating the operating part deviation amount w6, the degree of unevenness in the contact of each of the multiple protrusions 48 of the operating part 46 with the workpiece 14 can be grasped based on the calculated operating part deviation amount w6. Furthermore, by using the operating part deviation amount w6 as an index for replacing the tool 12 or adjusting the position at which the tool 12 is set relative to the spindle 11, the machining accuracy of the tool 12 can be ensured.

[0090] As described above, the calculation step according to the embodiment of the present disclosure includes a shaft portion deviation amount calculation step and a distortion calculation step.

[0091] In the shaft deviation amount calculation process, a shaft deviation amount w8 is calculated based on the multiple images taken in the photographing process, which is the difference between the distance w7 from the outer surface 49a of the shaft 49 to the rotation axis L1 of the main shaft 11 in the first phase and the distance w7 from the outer surface 49a of the shaft 49 to the rotation axis L1 of the main shaft 11 in the second phase.

[0092] An example of the shank deviation amount calculation step will be described. In the shank deviation amount calculation step, first, the distance between the rotation axis L1 of the spindle 11 and the outer surface 49a of the shank 49 is calculated in each of the multiple images captured in the photographing step. Specifically, a silhouette of the tool 12 appears in each of the multiple images captured in the photographing step, and the distance between the outer surface 49a forming the outline of the silhouette of the shank 49 of the tool 12 and the rotation axis L1 of the spindle 11 is calculated in each of the multiple images. In particular, the distance between the rotation axis L1 of the spindle 11 and the outer surface 49a forming the outline of the silhouette of the shank 49, which is located on one side (the left side in the example shown in FIGS. 7A and 7B ) of the outer surface 49a forming the outline of the silhouette of the shank 49, is calculated in each of the multiple images. The details of the method for determining the distance between the rotation axis L1 of the main shaft 11 and the outer surface 49a of the shaft portion 49 in the captured image are the same as the details of the method for determining the distance between the rotation axis L1 of the main shaft 11 and the outer surface 46a of the operating portion 46 in the image in the calculation process described above.

[0093] Here, in the captured images, the distance between the rotation axis L1 of the spindle 11 and the outer surface 49a of the shaft portion 49 may not be constant when compared at different positions in the axial direction d1. In the example shown in Figures 7A and 7B, the central axis L2 of the tool 12 is offset from the rotation axis L1 of the spindle 11, so the distance between the rotation axis L1 of the spindle 11 and the outer surface 46a of the working portion 46 in the images is not constant when compared at different positions in the axial direction d1.

[0094] In this case, the distance between the rotation axis L1 of the spindle 11 and the outer surface 49a of the shank 49 may be calculated as the distance between the rotation axis L1 of the spindle 11 and the outer surface 49a of the shank 49 at a shank reference position L8, which is a specific position in the axial direction d1. The shank reference position L8 is determined at the boundary between the shank 49 and the operating unit 46, as shown in FIGS. 7A and 7B, for example. In this case, in the shank deviation amount calculation step, a distance w7 in the images shown in FIGS. 7A and 7B is calculated as the distance between the rotation axis L1 of the spindle 11 and the outer surface 49a of the shank 49 at the shank reference position L8. Note that, as will be described later, if it is expected that the position of the rotation axis L1 of the spindle 11 relative to a portion of the machine tool 2 other than the spindle 11 is deviated from the normal position, the distance w7 may be calculated as follows. The distance w7 may be calculated as the distance between the rotation axis L1 of a virtual spindle 11 in the normal position and the outer surface 49a of the shank 49.

[0095] FIG. 9 is a graph showing the correspondence between the change in the phase at which an image is captured and the change in the distance w7 between the rotation axis L1 of the spindle 11 and the outer surface 49a of the shank 49 at the shank reference position L8 of the image captured at each phase for the tool 12 shown in FIG. 9 . Note that in FIG. 9 , the correspondence between the change in the phase at which an image is captured and the distance w7 is represented by a curve. For example, the curve can be obtained by plotting multiple points on the graph that represent the correspondence between each phase at which an image is captured and the distance w7 and connecting the plotted multiple points. Also, in FIG. 9 , the phase at which an image is captured from the direction indicated by arrow 26B in FIG. 4 is defined as the reference phase, i.e., the phase at which the rotation angle of the spindle 11 is 0°. The horizontal axis shows the change in phase over the entire phase range from 0° to less than 360° when the tool 12 rotates in the circumferential direction d2 shown in FIG. 4 toward the first side s1. The dashed line labeled L9 in Fig. 9 indicates the rotation angle position of main shaft 11 at the phase when an image is captured from the direction indicated by arrow 26A in Fig. 4. In the example shown in Fig. 9, the first phase is the phase when the rotation angle of main shaft 11 is the rotation angle indicated by the position labeled L9. In addition, in the example shown in Fig. 9, the second phase is the phase when the rotation angle of main shaft 11 is the rotation angle indicated by the dashed line labeled L10. The graph shown in Fig. 9 also shows the correspondence between changes in the phase when an image is captured and changes in distance w7 when there is no distortion in the cross-sectional shape of shaft portion 49.

[0096] In the example shown in Fig. 9, the distance w7 changes in a manner similar to a sine curve in response to changes in the phase at which the image is captured, and in the example shown in Fig. 9, the distance w7 changes to have a maximum value 94 and a minimum value 95.

[0097] As an example, from a graph showing the correspondence between distance w7 and changes in the phase at which images are captured over the entire phase range of 0° or more and less than 360°, as shown in Fig. 9, it is possible to calculate a shaft deviation amount w8, which is the difference between distance w7 from outer surface 49a of shaft 49 to rotation axis L1 of spindle 11 in the first phase and distance w7 from outer surface 49a of shaft 49 to rotation axis L1 of spindle 11 in the second phase, at shaft reference position L8. As an example of a method for calculating shaft deviation amount w8, a method for calculating shaft deviation amount w8 from the graph shown in Fig. 9 will be described below.

[0098] First, from a graph showing the correspondence between the distance w7 and changes in the phase at which images are captured over the entire phase range of 0° or more and less than 360°, the distance w7 from the outer surface 49a of the shaft 49 to the rotation axis L1 of the main shaft 11 in the first phase at the shaft reference position L8 is identified. Also, the distance w7 from the outer surface 49a of the shaft 49 to the rotation axis L1 of the main shaft 11 in the second phase at the shaft reference position L8 is identified. Then, the identified distance w7 from the outer surface 49a of the shaft 49 to the rotation axis L1 of the main shaft 11 in the second phase is subtracted from the identified distance w7 from the outer surface 49a of the shaft 49 to the rotation axis L1 of the main shaft 11 in the first phase. This makes it possible to calculate a shaft deviation w8, which is the difference between a distance w7 from the outer surface 49a of the shaft 49 in the first phase to the rotation axis L1 of the main shaft 11 at the shaft reference position L8, and a distance w7 from the outer surface 49a of the shaft 49 in the second phase to the rotation axis L1 of the main shaft 11. Note that if the distance w7 from the outer surface 49a of the shaft 49 in the first phase to the rotation axis L1 of the main shaft 11 is greater than the distance w7 from the outer surface 49a of the shaft 49 in the second phase, the distance w7 will be a negative value.

[0099] In the distortion calculation step, the distortion of the actuating unit 46 is calculated based on the difference between the actuating unit deviation amount w6 and the stem deviation amount w8. That is, the degree of distortion of the actuating unit 46 is evaluated based on the difference between the actuating unit deviation amount w6 and the stem deviation amount w8. Specifically, a distortion degree α representing the degree of distortion of the actuating unit 46 is calculated based on the difference between the actuating unit deviation amount w6 and the stem deviation amount w8, and the degree of distortion of the actuating unit 46 is evaluated based on the magnitude of the distortion degree α. Note that when the stem deviation amount w7 is a negative value, the distortion degree α is calculated by adding the absolute value of the actuating unit deviation amount w6 and the stem deviation amount w8.

[0100] The effect of determining the distortion of the operating unit 46 based on the difference between the operating unit deviation amount w6 and the shaft deviation amount w8 will be described. As described above, the degree of uneven contact of each of the multiple protrusions 48 of the operating unit 46 with the workpiece 14 can be determined based on the operating unit deviation amount w6. However, the magnitude of the operating unit deviation amount w6 is determined by the influence of both the deviation of the central axis L2 of the tool 12 from the rotation axis L1 of the spindle 11 and the distortion of the operating unit 46, such as differences in the sizes of the multiple protrusions 48. Furthermore, if it is assumed that the position of the rotation axis L1 of the spindle 11 relative to parts other than the spindle 11 of the machine tool 2 is deviated from its normal position, the deviation of the position of the rotation axis L1 of the spindle 11 from its normal position also affects the magnitude of the operating unit deviation amount w6. Furthermore, simply calculating the operating part deviation amount w6 does not allow one to determine whether the operating part deviation amount w6 is large due to a large deviation of the center axis L2 of the tool 12 relative to the rotation axis L1 of the spindle 11 or a large deviation of the position of the rotation axis L1 of the spindle 11 from the normal position, or whether the operating part 46 is large due to a large distortion.

[0101] In contrast, by determining the distortion of the operating unit 46 based on the difference between the operating unit deviation amount w6 and the shaft portion deviation amount w8, it is possible to grasp the magnitude of the influence of the distortion of the operating unit 46 on the operating unit deviation amount w6. For example, if the determined operating unit deviation amount w6 is large and the distortion rate α of the operating unit 46 is large, it can be determined that the operating unit deviation amount w6 is large due to the large distortion of the operating unit 46. Also, if the determined operating unit deviation amount w6 is large and the distortion rate α of the operating unit 46 is small, it can be determined that the operating unit deviation amount w6 is large due to the large deviation of the center axis L2 of the tool 12 from the rotation axis L1 of the spindle 11 or the large deviation of the position of the rotation axis L1 of the spindle 11 from the normal position.

[0102] In addition, determining the distortion of the operating portion 46 based on the difference between the operating portion deviation amount w6 and the shaft portion deviation amount w8 also includes calculating a correction value for the shaft portion deviation amount w8 based on the shaft portion deviation amount w8, and determining the distortion of the operating portion 46 based on the difference between the operating portion deviation amount w6 and the correction value for the shaft portion deviation amount w8.

[0103] An example of a method for calculating the correction value for the shank deviation amount w8 will be described. As shown in FIGS. 7A and 7B , it is possible that the central axis L2 of the tool 12 is tilted relative to the rotation axis L1 of the spindle 11. In this case, it is considered that the influence of the tilt of the central axis L2 of the tool 12 is greater in the shank deviation amount w8 obtained at the shank reference position L8, which is located closer to the spindle 11 than the operating part deviation amount w6 obtained at the reference position L5. In such a case, the correction value for the shank deviation amount w8 may be calculated as follows. The distance from the end of the tool 12 on the spindle 11 side to the reference position L5 is defined as w9. The distance from the end of the tool 12 on the spindle 11 side to the shank reference position L8 is defined as w10. In this case, the correction value for the shank deviation amount w8 may be calculated by multiplying the shank deviation amount w8 by (w9 / w10), and the distortion of the operating part 46 may be calculated based on the difference between the shank deviation amount w8 and the operating part deviation amount w6. In other words, the degree of distortion α, which represents the degree of distortion of the actuation portion 46, may be calculated by the following formula (1).

number

[0104] After the calculation step, the machine tool 2 and the tool 12 may be adjusted based on the result of the calculation step. The adjustment of the machine tool 2 and the tool 12 is performed, for example, so that the operating portion deviation amount w6, the shaft portion deviation amount w8, or the distortion degree α becomes smaller.

[0105] The adjustment of the machine tool 2 and the tool 12 is performed, for example, as follows. Reference values ​​that are the maximum allowable numerical values ​​are set for the operating part deviation amount w6, the shank deviation amount w8, and the distortion rate α. The reference values ​​are set, for example, according to the accuracy required for machining using the machine tool 2 and the tool 12. If any of the operating part deviation amount w6, the shank deviation amount w8, and the distortion rate α calculated in the calculation process exceeds the reference value, the machine tool 2 and the tool 12 are adjusted so that the numerical value is equal to or less than the reference value. If any of the operating part deviation amount w6, the shank deviation amount w8, and the distortion rate α calculated in the calculation process is equal to or less than the reference value, the machine tool 2 and the tool 12 are not adjusted. Adjustments of the machine tool 2 and the tool 12 can include replacing the tool 12 or adjusting the position of the tool 12 relative to the spindle 11.

[0106] In particular, when the operating unit deviation amount w6 exceeds the reference value and the distortion rate α also exceeds the reference value, it may be determined that the distortion of the operating unit 46 has increased due to wear or the like. In this case, the tool 12 may be replaced. On the other hand, when the operating unit deviation amount w6 exceeds the reference value and the distortion rate α is equal to or less than the reference value, it may be determined that the distortion of the operating unit 46 is small enough to be tolerated, but that the deviation of the central axis L2 of the tool 12 from the rotation axis L1 of the spindle 11 is large, resulting in the increase in the operating unit deviation amount w6. In this case, the position at which the tool 12 is set relative to the spindle 11 may be adjusted so that the deviation of the central axis L2 of the tool 12 from the rotation axis L1 of the spindle 11 is reduced.

[0107] In addition, if the operating part deviation amount w6, the shaft part deviation amount w8, or the distortion degree α calculated by the calculation unit 27 exceeds a reference value, the tool measuring device 1 may issue an alarm to prompt the user to adjust the machine tool 2 and the tool 12.

[0108] Based on the result of the calculation process, the machine tool 2 and the tool 12 may be adjusted, or after determining that no adjustment of the machine tool 2 and the tool 12 is necessary, machining of the workpiece 14 using the machine tool 2 and the tool 12 may be resumed. By using the machine tool 2 to move the tool 12 in three dimensions from the position shown in Figure 5, the tool 12 can be brought into contact with the workpiece 14, and machining of the workpiece 14 can be resumed.

[0109] The effects of the tool measurement device 1 and tool measurement method according to the embodiment of the present disclosure will be described. In the tool measurement device 1 according to the embodiment of the present disclosure, the calculation unit 27 determines the first distance w1 and the second distance w2 based on multiple images captured in multiple phases and calculates an operating unit deviation amount w6 corresponding to the difference between the first distance w1 and the second distance w2. The tool measurement method according to the embodiment of the present disclosure also includes a calculation step of determining the first distance w1 and the second distance w2 based on multiple images captured in multiple phases and calculating an operating unit deviation amount w6 corresponding to the difference between the first distance w1 and the second distance w2. This makes it possible to determine the operating unit deviation amount w6, which corresponds to the maximum deviation in the distance between the outer surface 48a of each of the protrusions 48 and the rotation axis L1 of the spindle 11 when multiple protrusions 48 are compared. Therefore, by using the operating unit deviation amount w6 as an index for replacing the tool 12 or adjusting the position of the tool 12 relative to the spindle 11, the machining accuracy of the tool 12 can be ensured.

[0110] In particular, the tool measurement device 1 and the tool measurement method according to the embodiments of the present disclosure can calculate the operating part deviation amount w6 of the tool during rotation, which makes it possible to calculate the operating part deviation amount w6 in a state where the tool 12 is affected by the centrifugal force, heat, and the like generated in the tool during rotation.

[0111] Furthermore, according to the tool measuring device 1 of the embodiment of the present disclosure, the photography command control unit 25 outputs a photography command for each different rotation of the tool 12. Furthermore, according to the tool measuring method of the embodiment of the present disclosure, in the photography step, the tool 12 is photographed for each different rotation of the tool 12. This makes it possible to photograph an image without the fear that the shutter speed of the camera 22 will not be able to keep up, even when photographing a tool 12 that is rotating at high speed.

[0112] Furthermore, according to the tool measuring device 1 of the embodiment of the present disclosure, the calculation unit 27 determines the distortion of the operating unit 46 based on the difference between the operating unit deviation amount w6 and the shank deviation amount w8. Furthermore, according to the tool measuring method of the embodiment of the present disclosure, the calculation step includes a distortion calculation step of determining the distortion of the operating unit 46 based on the difference between the operating unit deviation amount w6 and the shank deviation amount w8. This makes it possible to grasp the magnitude of the effect of the distortion of the operating unit 46 on the operating unit deviation amount w6.

[0113] As described above, one embodiment has been described with reference to specific examples, but the above-described specific examples are not intended to limit the embodiment. The above-described embodiment can be implemented with various other specific examples, and various omissions, substitutions, and modifications can be made without departing from the spirit of the embodiment.

[0114] An example of the modification will be described below with reference to the drawings. In the following description and the drawings used in the following description, parts that can be configured similarly to the above-described specific example will be designated by the same reference numerals as those used for the corresponding parts in the above-described specific example, and duplicated descriptions will be omitted.

[0115] (Variation) The tool measuring device 1 of the modified example is a device that measures the shape of a tool 12 set on the spindle 11 of a machine tool 2, similar to the tool measuring device 1 of the above-mentioned embodiment, and is equipped with a camera 22, a spindle rotation angle sensor 23, and a control device 20.

[0116] Fig. 10A is a schematic cross-sectional view showing a spindle head 4 of a machine tool 2 according to a modified example. Fig. 10A shows a spindle rotation angle sensor 23 that detects the rotation angle of the spindle 11, along with the spindle head 4 of the machine tool 2. In the tool measuring device 1 according to the modified example, the spindle rotation angle sensor 23 detects the rotation angle of the spindle 11 (tool 12 mounted on the spindle 11). The spindle rotation angle sensor 23 is configured to output a continuous pulse signal (see Fig. 10C) when the spindle 11 is rotating, and to emit one cycle of the pulse signal for each rotation of the spindle 11. Since the spindle 11 rotates at a constant speed, the cycle of the continuous pulse signal is a constant value.

[0117] Spindle rotation angle sensor 23 will be described in further detail with reference to Fig. 10A and Fig. 10B. Fig. 10B is a diagram showing spindle rotation angle sensor 23 of a machine tool according to a modified example, as viewed from direction VB shown in Fig. 10A. Spindle rotation angle sensor 23 is configured to include, for example, a reflective photoelectric sensor 43 and a mark 47.

[0118] Photoelectric sensor 43 is provided integrally with main shaft 11. Mark 47 is provided integrally with main shaft 11, for example, over half the circumference thereof (see the portion enclosed by the dashed line in FIG. 10B). As main shaft 11 rotates, photoelectric sensor 43 alternates between detecting mark 47 and not detecting it, causing photoelectric sensor 43 to emit a continuous pulse signal as shown in FIG. 10C. Photoelectric sensor 43 may be provided integrally with housing 31.

[0119] As can be seen, the resolution of the rotation angle of the spindle 11 by the spindle rotation angle sensor 23 is extremely large, ie, 180°.

[0120] The spindle rotation angle sensor 23 is configured to also detect the rotation speed (rotational angular velocity) of the spindle 11. As described above, the spindle rotation angle sensor 23 is configured to emit a rectangular wave continuous pulse signal, for example, as shown in Fig. 10C, when the spindle 11 rotates at a constant rotation speed.

[0121] The control device 20 receives the continuous pulse signal emitted by the spindle rotation angle sensor 23 and measures the time interval (period of the continuous pulse signal) of the continuous pulse signal being turned on and off per predetermined time, thereby detecting the rotation speed of the spindle 11. Alternatively, the spindle rotation angle sensor 23 may measure the time interval of the continuous pulse signal being turned on and off instead of the control device 20, thereby detecting the rotation speed of the spindle 11 by using the spindle rotation angle sensor 23.

[0122] The spindle rotation angle sensor 23 according to the modified example can capture images of the tool 12 at phases shifted by an angle θ over the entire phase range of 0° or more and less than 360° by the following method. First, the time for the spindle 11 to make one rotation and the time for the spindle 11 to rotate by the angle θ are calculated from the number of rotations detected by the control device 20 or the spindle rotation angle sensor 23. Next, one of the rotation phases of the spindle 11 is defined as a reference phase, and an imaging command is output to the imaging command control unit 25 at the reference phase to capture an image of the tool 12. Next, after the spindle 11 has rotated m rotations (m is a positive integer, for example, 10 rotations), a time is allowed for a further rotation by the angle θ, and then an imaging command is output to the imaging command control unit 25. This makes it possible to capture an image of the tool 12 at a phase shifted by the angle θ from the reference phase. Furthermore, in a similar manner, after photographing the tool 12 for the nth time at the nth phase (n is a positive integer), the operation of photographing the tool 12 for the n+1th time at the n+1th phase that is shifted by the angle θ from the nth phase is repeated. In this way, images of the tool 12 can be photographed at phases shifted by the angle θ over the entire phase range of 0° or more and less than 360°.

[0123] It is also possible to combine the multiple components disclosed in the above-described embodiments and modifications as needed, or to delete some of the components disclosed in the above-described embodiments and modifications. [Explanation of symbols]

[0124] 1 Tool measuring device 2 Machine tools 11 Spindle 12 Tools 20 Control device 22 Camera 23 Spindle rotation angle sensor 24 Lighting equipment 25. Imaging command control unit 27 Arithmetic section 46 Operating unit 48 protrusion 481 First protrusion 482 Second protrusion 49 Shaft

Claims

1. A tool measuring device that measures a tool set on a spindle of a machine tool, a camera for photographing the tool; a spindle rotation angle sensor for detecting a rotation angle of the spindle; a control device; The tool has an actuation portion including at least two protrusions, a first protrusion and a second protrusion, the control device includes an imaging command control unit that outputs an imaging command to the camera in accordance with the rotation angle of the spindle detected by the spindle rotation angle sensor, and a calculation unit that performs calculations based on images captured by the camera, the imaging command control unit outputs imaging commands to the camera in a plurality of phases in which the rotation angle of the spindle is different; the calculation unit determines, based on a plurality of images taken at each of the plurality of phases, a first distance at which the distance between the rotation axis of the spindle and the outer surface of the first protrusion is maximized, the first phase at this time, a second distance at which the distance between the rotation axis of the spindle and the outer surface of the second protrusion is maximized, and the second phase at this time, and calculates an operating portion deviation amount corresponding to the difference between the first distance and the second distance; The imaging command control unit outputs the imaging command so that the tool is not imaged more than once during one rotation of the tool.

2. the imaging command control unit sequentially outputs the imaging command for each different rotation of the tool over an entire phase range of 0° or more and less than 360°; 2. A tool measuring device according to claim 1, wherein the spindle rotation angle sensor is a rotary encoder provided to detect the rotation angle of the spindle.

3. the actuation portion includes two or more of the protrusions, and among these, the protrusion having the largest maximum distance between an outer surface of the protrusion and the rotation axis of the main shaft is defined as the first protrusion, and the protrusion having the smallest maximum distance between the outer surface of the protrusion and the rotation axis of the main shaft is defined as the second protrusion, 3. The tool measuring device according to claim 1, wherein the first distance at which the distance between the rotation axis of the spindle and the outer surface of the first protrusion is maximum and the second distance at which the distance between the rotation axis of the spindle and the outer surface of the second protrusion is maximum are determined based on images captured at different phases.

4. the tool has a cylindrical shaft portion that extends from the working portion in a rotational axis direction of the spindle, is fixed to the spindle at one end, and is connected to the working portion at the other end; 4. The tool measuring device according to claim 1, wherein the calculation unit calculates a shank deviation amount, which is a difference between a distance from an outer surface of the shank to a rotation axis of the spindle in the first phase and a distance from the outer surface of the shank to the rotation axis of the spindle in the second phase, and further determines a distortion of the operating part based on the difference between the operating part deviation amount and the shank deviation amount.

5. The camera and the lighting device are installed so that the tool is sandwiched between the camera and the lighting device.

5. A tool measuring apparatus according to claim 1, wherein the illumination device comprises a strobe.

6. A tool measurement method for measuring a tool set on a spindle of a machine tool, comprising: The tool has an actuation portion including at least two protrusions, a first protrusion and a second protrusion, an imaging step of detecting a rotation angle of the spindle and imaging the tool at a plurality of phases at which the rotation angle of the spindle is different according to the detected rotation angle of the spindle; a calculating step of determining, based on a plurality of images photographed at each of the plurality of phases in the photographing step, a first distance at which the distance between the rotation axis of the spindle and the outer surface of the first protrusion is maximized, the first phase at which this first distance is maximized, a second distance at which the distance between the rotation axis of the spindle and the outer surface of the second protrusion is maximized, and the second phase at which this second distance is maximized, and calculating an operating portion deviation amount corresponding to the difference between the first distance and the second distance, In the photographing step, the tool is photographed so that the tool is not photographed more than once during one rotation of the tool.

7. In the photographing step, the tool is photographed over an entire phase range of 0° or more and less than 360° for each different rotation of the tool, 7. The tool measuring method according to claim 6, wherein the detection of the rotation angle of the spindle in the photographing step is performed by a spindle rotation angle sensor which is a rotary encoder provided to detect the rotation angle of the spindle.

8. the actuation portion includes two or more of the protrusions, and among these, the protrusion having the largest maximum distance between an outer surface of the protrusion and the rotation axis of the main shaft is defined as the first protrusion, and the protrusion having the smallest maximum distance between the outer surface of the protrusion and the rotation axis of the main shaft is defined as the second protrusion, 8. The tool measuring method according to claim 6, wherein in the calculation step, the first distance at which the distance between the rotation axis of the spindle and the outer surface of the first protrusion is maximized and the second distance at which the distance between the rotation axis of the spindle and the outer surface of the second protrusion is maximized are determined based on images captured at different phases.

9. the tool has a cylindrical shaft portion that extends from the working portion in a rotational axis direction of the spindle, is fixed to the spindle at one end, and is connected to the working portion at the other end; 9. The tool measuring method according to claim 6, wherein the calculation step includes: a shank deviation amount calculation step of calculating a shank deviation amount, which is a difference between a distance from an outer surface of the shank to a rotation axis of the spindle in the first phase and a distance from the outer surface of the shank to the rotation axis of the spindle in the second phase; and a distortion calculation step of determining a distortion of the operating part based on the difference between the operating part deviation amount and the shank deviation amount.

10. 10. The tool measuring method according to claim 6, wherein in the photographing step, the camera and the lighting device are installed so that the tool is sandwiched between the camera and a lighting device having a strobe, and the tool is photographed by the camera in a state in which the strobe is made to emit light toward the tool and the camera.

Images