Tool evaluation device and tool evaluation method

Abstract

A tool evaluation device and a tool evaluation method are provided that can automatically determine the phase of the cutting edge in the rotation direction of a tool regardless of the state of attachment of the tool to a tool holder. [Solution] The tool evaluation method includes the steps of: a tool holding unit 24 holding a tool 26; a tool holding unit 24 transporting the tool 26 to an imaging position; an imaging step of the tool 26 at a predetermined tool phase and storing the image as a reference image; a rotating unit 22 connected to the tool holding unit 24 rotating to image the tool 26 at predetermined phase intervals or time intervals within a phase range and obtaining multiple post-machining tool images; a step of comparing the reference image with the post-machining tool images; a step of determining the one of the multiple post-machining tool images that has the highest degree of agreement with the reference image as an observation image; and a step of evaluating wear on the cutting edge 50 of the tool 26 using the observation image.

Description

[Technical Field]

[0001] The present invention relates to a tool evaluation device and a tool evaluation method. [Background technology]

[0002] The tools used in machine tools for machining are mainly composed of a holder and a cutting edge, and the cutting edge that comes into contact with the workpiece wears out with repeated machining. As wear progresses, the precision required for machining cannot be achieved and the risk of tool breakage increases. For this reason, it is necessary to observe the appropriate progress of wear.

[0003] Observation and evaluation of the progress of tool wear are generally performed by an operator removing the tool from the machine tool and visually inspecting it. For this reason, Patent Document 1 discloses a system in which a tool is fixed to an inspection jig, photographed before and after machining, and analyzed to determine the degree of damage and determine whether the tool needs to be replaced. However, such a system requires preparing an inspection jig for each tool and adjusting the image analysis, which may increase the number of work steps and costs. Therefore, in order to automatically observe and evaluate the cutting edge before and after machining regardless of the type of tool, in the case of a rotating tool, it is necessary to specifically set and understand the rotational phase of the cutting edge to be observed.

[0004] In this regard, if the tool holder conforms to the HSK-A standard, for example, the holder has a drive keyway that engages with the drive key of a tool holding unit, such as the spindle of a machine tool. This allows the phase relationship to be determined even if the holder is repeatedly held and released from the tool holding unit. However, for example, if a cutter is reassembled to the holder, the phase of the cutting edge relative to the drive key must be reconfirmed and registered. Furthermore, if the tool holder does not have a drive keyway, such as the HSK-E standard, the phase relationship changes each time the tool holding unit and the holder are held and released. This makes it difficult to automatically determine the rotational phase of the cutting edge. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 10-96616 Summary of the Invention [Problem to be solved by the invention]

[0006] In view of the above circumstances, an object of the present invention is to provide a tool evaluation device and a tool evaluation method that can automatically determine the phase of the cutting edge in the rotational direction of the tool regardless of the state of attachment of the tool to a tool holder. [Means for solving the problem]

[0007] One aspect of the present invention is a tool evaluation method for evaluating wear on a cutting edge of a tool, comprising the steps of: a step of a tool holding unit holding a tool; a step of the tool holding unit transporting the tool to an imaging position; a step of imaging the tool at a predetermined tool phase and storing the image as a reference image; a step of rotating a rotating unit connected to the tool holding unit and imaging the tool at predetermined phase intervals or predetermined time intervals within a predetermined phase range to obtain multiple post-machining tool images; a step of comparing the reference image with the multiple post-machining tool images; a step of determining, from the multiple post-machining tool images, the one that has the highest degree of match with the reference image as an observation image; and a step of evaluating wear on the cutting edge of the tool using the observation image.

[0008] One aspect of the present invention is a tool evaluation method for evaluating wear of a cutting edge of a tool, the method including the steps of: a tool holding unit holding the tool; a step of the tool holding unit transporting the tool to an imaging position; a step of imaging the tool at a predetermined tool phase and storing the image as a reference image; a step of storing a background image captured when the tool is not within the imaging range; a step of rotating a rotating unit connected to the tool holding unit within a predetermined phase range, imaging the tool at a first phase interval or a first time interval, and acquiring a first post-machining tool image; and a step of comparing the acquired first post-machining tool image with the background image and acquiring the first post-machining tool image. a step of determining whether the first after-machining tool image includes a cutting edge portion; a step of acquiring a plurality of second after-machining tool images by imaging the tool at a second phase interval shorter than the first phase interval or at a second time interval shorter than the first time interval if it is determined that the first after-machining tool image includes a cutting edge portion; a step of comparing the second after-machining tool image with a reference image; a step of determining, from among the plurality of second after-machining tool images, the one that has the highest degree of match with the reference image as an observation image; and a step of evaluating wear of the cutting edge portion of the tool using the observation image.

[0009] One aspect of the present invention is a tool evaluation method for evaluating wear on a cutting edge of a tool, comprising the steps of: a step of a tool holding unit holding a tool; a step of the tool holding unit transporting the tool to an imaging position; a step of imaging the tool at a predetermined tool phase and storing the image as a reference image; a step of rotating a rotating unit connected to the tool holding unit and imaging the tool at predetermined phase intervals or predetermined time intervals within a predetermined phase range to obtain a plurality of after-machining tool images; a step of comparing the obtained after-machining tool images with the reference image and determining the degree of match; a step of determining the degree of match and determining that the observation image determination conditions are satisfied; a step of determining the after-machining tool image that satisfies the observation image determination conditions as the observation image and terminating the acquisition of the after-machining tool images; and a step of evaluating wear on the cutting edge of the tool using the observation images.

[0010] One aspect of the present invention is a tool evaluation device for evaluating wear on a cutting edge of a tool, comprising: an imaging unit that images the tool; a tool holding unit that holds the tool; a rotating unit that is connected to the tool holding unit and rotates the tool holding unit relative to the imaging unit; a tool image storage unit that images the tool in advance at a predetermined tool phase and stores the images as a reference image; a control unit that operates the imaging unit to image the tool rotated by the rotating unit at predetermined phase intervals or predetermined time intervals and acquire multiple after-machining tool images; and a determination unit that compares the reference image with the multiple after-machining tool images acquired by the control unit and selects from the multiple after-machining tool images the one that has the highest degree of match with the reference image as an observation image, and is characterized in that the tool evaluation device evaluates wear on the cutting edge of the tool using the observation image. [Effects of the Invention]

[0011] According to one aspect of the present invention, a tool held by a tool holder and transported to an imaging position can be imaged at a predetermined tool phase and stored as a reference image. Furthermore, a rotating unit connected to the tool holder can be rotated to image the tool at predetermined phase intervals or predetermined time intervals within a predetermined phase range, thereby obtaining multiple post-machining tool images. Furthermore, the reference image can be compared with the multiple post-machining tool images, and the one of the multiple post-machining tool images that most closely matches the reference image can be determined as the observation image. This automatically determines the phase of the cutting edge in the tool rotation direction, regardless of the attachment state of the tool to the tool holder, and evaluates wear of the cutting edge of the tool based on the obtained observation images.

[0012] According to one aspect of the tool evaluation method of the present invention, a tool held by a tool holding unit and transported to an imaging position can be imaged at a predetermined tool phase and stored as a reference image. A background image captured when the tool is not within the imaging range can be stored. A rotating unit connected to the tool holding unit can be rotated to capture images of the tool at a first phase interval or a first time interval to acquire a first post-machined tool image. The acquired first post-machined tool image can be compared with a background image to determine whether the first post-machined tool image includes a cutting portion. If it is determined that the first post-machined tool image includes a cutting portion, the tool can be imaged at a second phase interval shorter than the first phase interval or a second time interval shorter than the first time interval to acquire multiple second post-machined tool images, and the second post-machined tool images can be compared with the reference image. This allows for a reduced number of images compared to capturing images at uniform phase intervals or time intervals, and an observation image that most closely matches the reference image can be efficiently selected from the multiple second post-machined tool images. This makes it possible to automatically determine the phase of the cutting edge in the rotational direction of the tool regardless of the state of attachment of the tool to the tool holder, and to efficiently evaluate the wear of the cutting edge of the tool based on the obtained observation image.

[0013] According to one aspect of the present invention, a tool held by a tool holder and transported to an imaging position can be imaged at a predetermined tool phase and stored as a reference image. Furthermore, a rotating unit connected to the tool holder can be rotated to image the tool at predetermined phase intervals or predetermined time intervals within a predetermined phase range, thereby acquiring multiple post-machining tool images. Furthermore, the captured post-machining tool images can be compared with the reference image to determine the degree of match and determine whether the observation image determination condition is met. The post-machining tool image that satisfies the observation image determination condition can be selected as the observation image, and acquisition of the post-machining tool images can be terminated. Therefore, when the observation image determination condition is met, the number of post-machining tool images can be reduced compared to when imaging over the entire predetermined phase range, and the observation image that most closely matches the reference image can be efficiently selected. This automatically determines the phase of the cutting edge in the tool rotation direction regardless of the attachment state of the tool to the tool holder, and efficiently evaluates the wear of the tool cutting edge based on the obtained observation images.

[0014] According to one aspect of the present invention, a tool held by a tool holding unit and transported to an imaging position can be imaged by the imaging unit. Furthermore, a rotation unit connected to the tool holding unit and rotating the tool holding unit relative to the imaging unit can image the tool rotated to a predetermined tool phase and store the image as a reference image in a tool image storage unit. Furthermore, a control unit can operate the imaging unit to image the tool rotated by the rotation unit at predetermined phase intervals or predetermined time intervals, thereby obtaining multiple post-machining tool images. Furthermore, a determination unit can compare the reference image with the multiple post-machining tool images and determine, from the multiple post-machining tool images, the one that most closely matches the reference image as an observation image. This automatically determines the phase of the cutting edge in the tool rotation direction, regardless of the attachment state of the tool to the tool holding unit, and evaluates wear of the cutting edge of the tool based on the obtained observation images. [Brief explanation of the drawings]

[0015] [Figure 1] FIG. 1 is a perspective view of a tool evaluation device according to this embodiment. [Figure 2] FIG. 2(a) shows a side view of the tool, (b) shows a side view of the tool in (a) rotated 90 degrees, and (c) shows a bottom view of the tool in (a). [Figure 3] FIG. 3 shows a block diagram of the tool evaluation device according to this embodiment. [Figure 4] 10(a) shows a side view of a first imaging unit that images the bottom of the tool, and FIG. 10(b) is a view taken along the arrow A in FIG. 10(a) and shows a bottom view of the tool. [Figure 5] 10(a) shows a side view of the second imaging unit that images the side of the tool, and FIG. 10(b) is a view taken along arrow B in FIG. 10(a) and shows a bottom view of the tool. [Figure 6] FIG. 6 shows a bottom view of the tool to explain another imaging method of the tool. [Figure 7] FIG. 7 shows an example of a plurality of post-machining tool images including cutting edges. [Figure 8] FIG. 8 shows an example of a histogram of brightness values ​​of a post-machining tool image after image processing. [Figure 9] FIG. 9 shows an example of detecting the maximum brightness value for each post-machining tool image. [Figure 10] FIG. 10 shows an example of the maximum brightness value for each post-machining tool image that satisfies the observation image determination condition. [Figure 11] FIG. 11 shows an example of the maximum brightness value for each post-machining tool image that satisfies another observation image determination condition. [Figure 12] FIG. 12 shows a flowchart of the tool evaluation device according to this embodiment. [Figure 13] FIG. 13 shows a plan view and a side view of the tool evaluation device according to this embodiment. [Figure 14] FIG. 14 shows a plan view and a side view of a tool evaluation device that cleans a tool by a first cleaning unit. [Figure 15] FIG. 15 shows a plan view and a side view of a tool evaluation device that cleans a tool by means of a second cleaning unit. [Figure 16]FIG. 16 shows a plan view and a side view of a tool evaluation device that captures an image of the bottom of a tool using a first imaging unit. [Figure 17] FIG. 17 shows a plan view and a side view of a tool evaluation device that captures an image of the side of a tool using a second imaging unit. DETAILED DESCRIPTION OF THE INVENTION

[0016] Hereinafter, a tool evaluation method and a tool evaluation device according to an embodiment will be described with reference to the accompanying drawings. Similar or corresponding elements are designated by the same reference numerals, and duplicated explanations will be omitted. For ease of understanding, the scale of the drawings may be changed.

[0017] FIG. 1 shows a schematic configuration of a tool evaluation device 10 according to this embodiment. The tool evaluation device 10 is disposed adjacent to a tool magazine chamber (not shown) of a machining center or in a location other than a machining chamber (not shown). The tool evaluation device 10 includes a base unit 12 and a tool transport device 20 attached to the base unit 12. The tool evaluation device 10 also includes an imaging device 40 for imaging a tool 26, and a first cleaning unit 36 ​​and a second cleaning unit 38 for cleaning the tool 26 before imaging (see FIG. 13). The imaging device 40 includes a bottom-side imaging unit 42 as a first imaging unit for imaging the tool 26 from the tip side (bottom side), and a side-side imaging unit 44 as a second imaging unit for imaging the side of the tool 26. The first cleaning unit 36 ​​is configured to clean the tool 26 using, for example, a cleaning liquid or compressed air, and the second cleaning unit 38 is configured to dry the tool 26 after cleaning using, for example, compressed air.

[0018] The base unit 12 has four legs 14, two support columns 16 extending upward from the legs 14 in a vertical direction D2 (a second direction), and a beam 18 spanning between the two support columns 16 and extending in a horizontal direction D1 (a first direction). The tool transport device 20 is attached to the beams 18 and configured to be movable in the horizontal direction D1 along the beams 18. A rotating unit 22 having a drive unit such as a servo motor and configured to be rotatable around an axis (direction R1) along the vertical direction relative to the tool transport device 20 is disposed below the rotating unit 22, and a tool holder 24 for detachably mounting a tool 26 is disposed below the rotating unit 22.

[0019] 2(a) to 2(c) show side and bottom views of the tool 26. The tool 26 has a tapered shank 28 with a tapered shank 28a attached to the tool holder 24, and a cutting portion 50 attached to the tip (lower end) of the shank 28. The cutting portion 50 is used for milling, and when the tool 26 is attached to the tool holder 24, a ridgeline portion extending along the vertical direction D2 is a major cutting edge 50a, and a ridgeline portion extending along the horizontal direction D1 at the tip (bottom) side is a minor cutting edge 50b. The cutting portion 50 has a major flank 52 continuous with the major cutting edge 50a, a minor flank 54 continuous with the minor cutting edge 50b, and a rake face 56, and is formed in a generally trapezoidal shape when viewed from the bottom. The cutting portion 50 is provided at two locations, 180 degrees apart, on the tool 26 shown in FIGS. 2( a) to 2(c). Here, the length from the gauge line GL to the tip of the cutting portion 50 is defined as the tool length TL, and the length from the gauge line GL to the main imaging position of the cutting portion 50 is defined as the cutting portion imaging length BL. Furthermore, the tool diameter TR is defined as twice the radial length from the center of the shank 28 to the outer end of the cutting portion 50, and the cutting portion imaging diameter BR is defined as twice the radial length to the center of the rake face 56. Here, the tool 26 is described as a milling tool with its cutting portion 50 extending in the vertical direction. However, this is not limiting, and a cutting portion extending in the horizontal direction may be attached to the shank, or the tool may be used for turning.

[0020] 1, one end of the beam portion 18 is connected to a tool magazine 30 that stores a plurality of tools 26, and the tool 26 can be replaced between the tool holding portion 24 and the tool magazine 30. When replacing the tool 26, the tool transport device 20 is configured to move to a tool loading / unloading position HP in the tool magazine 30 and hand over the tool 26.

[0021] The tool evaluation device 10 is attached to a base 12 and includes a guide unit 32 for vertically moving a first cleaning unit 36, a second cleaning unit 38, and an imaging device 40 (see FIG. 13) relative to the tool 26. The guide unit 32 is configured to use a feed shaft (not shown) disposed internally to move a bracket 34, on which the first cleaning unit 36, the second cleaning unit 38, and the imaging device 40 are disposed, up and down along a vertical direction D2. The tool 26, the first cleaning unit 36, the second cleaning unit 38, and the imaging device 40 are disposed so as to be positioned on the same plane along the first direction D1 and the second direction D2. This allows the tool 26, the first cleaning unit 36, the second cleaning unit 38, and the imaging device 40 to be aligned using only two linear feed shafts.

[0022] FIG. 3 shows a block diagram of the tool evaluation device 10. The tool evaluation device 10 includes a storage unit 46 for storing information about the tool 26 and its imaging. The storage unit 46 includes an imaging information storage unit 60 for storing information about imaging of the tool 26, a tool information storage unit 62 for storing information about the tool 26 itself, and a tool image storage unit 64 for storing images of the tool 26 captured by the imaging device 40. Specifically, the imaging information storage unit 60 is configured to store a phase interval and a time interval, which are the timing for capturing images of the tool 26 rotated by the rotating unit 22, as well as a phase range, which is the range of rotational phases within which one set of images is captured. If there are multiple blades 50 (number of blades n), multiple reference images are acquired for each of the blades n, and multiple tool phases corresponding to each blade 50 are stored. Note that if the types of the multiple blades 50 and the mounting positions and angles of the blades 50 relative to the shank 28 are all the same, it is sufficient to store one reference image per tool 26. The tool phase, phase interval, time interval, and phase range are set in advance by an operator and stored in the imaging information storage unit 60. Note that instead of being set by the operator, the control unit 48 may automatically set them according to information on the tool 26. The tool information storage unit 62 is configured to store the number of blades n of the blade portion 50 attached to the tool 26, the tool length TL, blade portion imaging length BL, tool diameter TR, and blade portion imaging diameter BR of the tool 26, as well as the set life, allowable wear amount, and wear state of the tool 26. The tool image storage unit 64 is configured to store a reference image and a post-machining tool image, which will be described later.

[0023] The tool evaluation device 10 also includes a control unit 48. The control unit 48 is configured to operate the rotating unit 22 to rotate the tool holding unit 24 to which the tool 26 is attached, and to operate the first cleaning unit 36 ​​and the second cleaning unit 38 to clean the tool 26. The control unit 48 is also configured to operate the imaging device 40 to capture an image of the tool 26 in the tool phase and store the image as a reference image in the tool image storage unit 64. The tool phase at which the reference image is captured is determined visually by an operator, and the operator controls the control unit 48 via the input unit to index the tool 26 into the tool phase and capture the image. The reference image should be captured when the tool is free of any damage or wear, so it is desirable to capture the reference image when the tool is brand new and has not yet been used for machining. The control unit 48 is also configured to operate the imaging device 40 to capture an image of the machined tool 26 rotated by the rotating unit 22 at predetermined phase intervals or predetermined time intervals, and store the acquired multiple machined tool images in the tool image storage unit 64.

[0024] Furthermore, the tool evaluation device 10 is provided with a determination unit 66 that compares a reference image stored in the tool image storage unit 64 with multiple post-machining tool images and determines, from among the multiple post-machining tool images, the one that has the highest degree of match with the reference image as the observation image.

[0025] The tool evaluation device 10 also includes a tool evaluation unit 68 that performs image analysis on the determined observation image to evaluate the condition of the cutting edge 50. Specifically, the tool evaluation unit 68 is configured to evaluate the presence or absence of chipping or the amount of wear of the cutting edge 50. If the tool 26 has two or more cutting edges 50, the observation images of all cutting edges 50 may be evaluated, or only one cutting edge 50 may be evaluated. The tool evaluation unit 68 also transmits the evaluation results to the storage unit 46. At this time, the tool evaluation unit 68 can store the evaluation results in association with the cumulative number of machining operations performed by the tool 26 being evaluated. The tool evaluation device 10 also includes a notification unit 70 that issues an alarm to warn against continuing machining with the tool 26 if it is determined based on the evaluation result of the tool evaluation unit 68 that the cutting edge 50 is chipped or that the amount of wear of the cutting edge 50 exceeds a predetermined allowable amount of wear. The notification unit 70 is provided with a display screen (not shown), and when an alarm is issued, it can also display information such as the presence or absence of defects, the allowable amount of wear, and instructions for tool replacement.

[0026] 4(a) and 4(b) show a side view of the bottom-side imaging unit 42, which captures an image of the bottom side of the tool 26, and a bottom view of the tool 26. The control unit 48 operates the tool transport device 20 to move it in the horizontal direction D1, thereby aligning the tool 26 with the bottom-side imaging unit 42 in the horizontal direction D1. Specifically, the tool 26 is positioned so that the radial end of the blade imaging diameter BR is at the center position of the bottom-side imaging unit 42. The movement distance of the tool transport device 20 in the horizontal direction D1 may be determined by the control unit 48 based on the tool diameter TR, or may be arbitrarily set by the operator for each tool 26. Next, the control unit 48 operates the guide unit 32 to move the bracket 34 in the vertical direction D2, thereby aligning the tool 26 with the bottom-side imaging unit 42 in the vertical direction D2. The movement distance of the guide unit 32 in the vertical direction D2 may be determined by the control unit 48 based on the tool length TL, or may be arbitrarily set by the operator for each tool 26. As a result, the position of the tool 26 is set to the first imaging position TP1 (see FIG. 16) of the bottom surface side imaging unit 42, and the imaging range IA is determined so as to include the tool 26. The rotational phase of the tool 26 at this time is set to the initial phase.

[0027] Once the alignment of the tool 26 and the bottom-side imaging unit 42 is complete, the bottom-side imaging unit 42 captures an image of the minor flank 54 of the tool 26. The captured image is stored in the tool image storage unit 64 as a machined tool image associated with information on the phase of the tool 26 at the time of capture. When the machined tool image at a certain phase is stored in the tool image storage unit 64, the control unit 48 operates the rotating unit 22 to rotate the tool 26 by a predetermined phase interval θ (e.g., 1 degree, 2 degrees, 3 degrees, etc.) and capture the next image. The image capture performed while rotating the tool 26 is repeated within a predetermined phase range PR. If the number of blades n is 2 or more, the phase range PR for one blade 50 may be set as 360 degrees / number of blades n. Here, while the rotating unit 22 continuously rotates the tool 26, the bottom-side imaging unit 42 may capture an image at every phase interval θ, or alternatively, after the tool 26 has rotated by the phase interval θ, the rotation of the tool 26 may be stopped and then the image may be captured. Note that imaging may be performed at a predetermined time interval T instead of the phase interval θ. In this case, the post-machining tool image associated with the rotation time from the start of rotation of the tool 26 is stored in the tool image storage unit 64. The phase interval θ and the time interval T may be determined by the control unit 48 according to the shape and dimensions of the tool 26. For example, in the case of a tool 26 with a relatively large tool diameter TR, if the phase interval θ is large, imaging may not be performed at a rotation phase that allows for an observation image. In such a case, the control unit 48 sets the phase interval θ and the time interval T to be small.

[0028] 5(a) and 5(b) show a side view of the side imaging unit 44, which captures the side of the tool 26, and a bottom view of the tool 26. The control unit 48 operates the tool transport device 20 to move it in the horizontal direction D1, thereby aligning the tool 26 with the side imaging unit 44 in the horizontal direction D1. The control unit 48 may determine the movement distance of the tool transport device 20 in the horizontal direction D1 based on the tool diameter TR, or the operator may set it arbitrarily for each tool 26. Next, the control unit 48 operates the guide unit 32 to move the bracket 34 in the vertical direction D2, thereby aligning the tool 26 with the side imaging unit 44 in the vertical direction D2. Specifically, the tool 26 is positioned so that the lower end of the blade imaging length BL coincides with the center position of the side imaging unit 44. The movement distance of the guide unit 32 in the vertical direction D2 may be determined by the control unit 48 based on the tool length TL, or the operator may set it arbitrarily for each tool 26. As a result, the position of the tool 26 is set to the second imaging position TP2 (see FIG. 17) of the side imaging unit 44, and an imaging range IA is determined so as to include the tool 26. The rotational phase of the tool 26 at this time is set to the initial phase. Note that the rotational phase of the tool 26 may be set to be the same as the initial phase when the tool 26 is set to the first imaging position TP1 of the bottom imaging unit 42.

[0029] Once the alignment of the tool 26 and the side imaging unit 44 is complete, the side imaging unit 44 captures an image of the main flank 52 of the tool 26. The captured image is stored in the tool image storage unit 64 as a machined tool image associated with information on the phase of the tool 26 at the time of capture. When the machined tool image at a certain phase is stored in the tool image storage unit 64, the control unit 48 operates the rotating unit 22 to rotate the tool 26 by a predetermined phase interval θ (e.g., 1 degree, 2 degrees, 3 degrees, etc.) and capture the next image. The image capture performed by rotating the tool 26 is repeated within a predetermined phase range PR. If the number of blades n is 2 or more, the phase range PR for one blade 50 may be set as 360 degrees / number of blades n. Here, images may be captured at every phase interval θ while the rotating unit 22 continuously rotates the tool 26, or the rotation of the tool 26 may be stopped once the tool 26 has rotated by the phase interval θ before capturing the image. In addition, imaging may be performed at a predetermined time interval T instead of the phase interval θ, in which case the post-machining tool image associated with the rotation time from the start of rotation of the tool 26 is stored in the tool image storage unit 64.

[0030] The main flank 52 and the minor flank 54 are basically imaged by rotating the tool 26 at the same initial phase and phase interval θ, or by rotating the tool 26 at the same time interval. However, depending on the shape of the cutting portion 50 of the tool 26, the phase or rotation time suitable for imaging the reference image may differ between the main flank 52 and the minor flank 54. For this reason, the imaging information storage unit 60 is configured to store the difference θx (=θM−θS) between the phase θM suitable for imaging the main flank 52 and the phase θS suitable for imaging the minor flank 54 as related information about the main flank 52 and the minor flank 54. The imaging information storage unit 60 is configured to store such related information about the main flank 52 and the minor flank 54 for each tool 26. Furthermore, even when the rotation time TM from the start of rotation suitable for capturing the reference image differs between the main flank 52 and the secondary flank 54, the imaging information storage unit 60 is configured to store the difference Tx (=TM−TS) between the rotation time TM suitable for capturing the reference image of the main flank 52 and the rotation time TS suitable for capturing the secondary flank 54 as related information for the main flank 52 and the secondary flank 54. As a result, when evaluating the same type of tool 26, the related information for the main flank 52 and the secondary flank 54 stored in the imaging information storage unit 60 can be called up and input to the control unit 48, thereby limiting the imaging of the main flank 52 and the secondary flank 54 to imaging around the optimal phase or rotation time for the observed image, thereby reducing the labor required for imaging.

[0031] As described above, for example, for a tool 26 with a relatively large tool diameter TR, the phase interval θ and the time interval T can be set small. This ensures that the observation image is captured at an optimal phase or rotation time. On the other hand, if imaging is performed over the entire phase range PR with a small phase interval θ, the number of imaging times and the number of post-machining tool images increases, leading to an increase in the capacity of the memory unit 46. Furthermore, if imaging is performed while the rotation of the tool 26 is stopped, the overall time required for imaging also increases. For this reason, the control unit 48 is configured to efficiently capture and evaluate the tool 26 by changing the phase interval θ or the time interval T during imaging. Specifically, as shown in FIG. 6 , the control unit 48 activates the rotating unit 22 and the imaging device 40 to capture images at a first phase interval θ1 or a first time interval T1 to obtain a first post-machining tool image. This first post-machining tool image is compared with a background image captured when the tool 26 is not within the imaging range to determine whether the cutting edge 50 is included. Imaging is repeated at the first phase interval θ1 or the first time interval T1 until the blade portion 50 is included in the post-machined tool image (first phase range PA1 in FIG. 6). When imaging is repeated and the first post-machined tool image reaches a phase in which the blade portion 50 is included, a difference occurs between the post-machined tool image and the background image, making it possible to determine that the blade portion 50 to be imaged has entered the imaging range of the imaging device 40. Upon determining that the blade portion 50 to be imaged has entered the imaging range of the imaging device 40, the control unit 48 activates the rotating unit 22 and the imaging device 40 to capture images at a second phase interval θ2 that is shorter than the first phase interval θ1 or at a second time interval T2 that is shorter than the first time interval T1, thereby acquiring a second post-machined tool image. This imaging at the second phase interval θ2 or the second time interval T2 is repeated until the end of the phase range PR (second phase range PA2 in FIG. 6). This allows precise imaging of the cutting portion 50 within the imaging range of the imaging device 40, and makes it possible to acquire all post-machining tool images at the phase PO that is appropriate for the observed image. Furthermore, it is possible to reduce the effort required for imaging at phases that are not related to the observed image, and to suppress an increase in the volume of images stored in the storage unit 46.

[0032] FIG. 7 shows an example of a portion of multiple post-machining tool images of the cutting portion 50 acquired at each phase interval θ. It can be seen that the position of the cutting portion 50 changes within the post-machining tool images P5 to P9 as the tool 26 rotates. The determination unit 66 calculates the difference between each post-machining tool image P5 to P9 and the reference image. Specifically, a difference image between the post-machining tool image and the reference image is generated. The brightness values ​​are calculated as the difference in brightness for all pixels in the difference image, and the number of pixels present at each brightness value is counted. The brightness values ​​may be calculated within a partial range of the difference image. A grayscale is used for the brightness values, and they can be calculated in the range from 0 to 255. FIG. 8 shows a histogram of brightness values ​​and pixel counts for a difference image between one post-machining tool image and the reference image. The number of pixels with the brightness value that was most prevalent in the difference image is shown as the maximum pixel number MV. As the degree of similarity between the post-machining tool image and the reference image increases, the difference between the two images decreases. Therefore, the brightness value at which the maximum pixel number MV appears approaches 0, and the maximum pixel number MV increases. 9 shows a scatter plot in which the image number of the machined tool image is taken on the horizontal axis and the maximum number of pixels MV for each machined tool image is plotted. The maximum number of pixels MV of the machined tool image that matches the reference image most closely is the largest, and therefore it can be determined as the maximum value PV of the maximum numbers of pixels MV of all the machined tool images. In the embodiment of FIG. 9, the maximum number of pixels MV of the machined tool image of image number 6 is determined as the maximum value PV, and therefore the machined tool image of image number 6 can be determined as the image to be observed since it matches the reference image most closely.

[0033] If imaging were performed over the entire range of the predetermined phase range PR, imaging would continue even after the tool 26 has passed through a phase suitable for the observation image, increasing the number of post-machining tool images and the time required for imaging. Therefore, the determination unit 66 is configured to determine whether the post-machining tool image satisfies the observation image determination condition previously stored in the storage unit 46. If the condition is satisfied, the control unit 48 terminates imaging even if the rotation of the tool 26 has not yet reached the phase range PR. The observation image determination condition can be set in various ways. For example, as shown in FIG. 10 , it can be a threshold value TH for the maximum number of pixels MV previously stored in the storage unit 46. Therefore, when the maximum number of pixels MV of the difference image, which is an index of the degree of coincidence between the post-machining tool image and the reference image, exceeds the threshold value TH, the maximum number of pixels MV is considered to be the maximum value PV of the maximum number of pixels MV of all post-machining tool images, and it is determined that the observation image determination condition is satisfied. The post-machining tool image at this time can be selected as the observation image. This allows for omitting imaging after the observation image determination, thereby reducing the imaging effort.

[0034] As another example, as shown in FIG. 11, the observation image determination condition may be set to detecting a maximum value PV of the maximum pixel number MV of the difference image, which is an index of the degree of coincidence between the post-machining tool image and the reference image. If the maximum pixel number MV of a difference image is greater than the maximum pixel number MV of the difference image of the immediately preceding image number and is also greater than the maximum pixel number MV of the difference image of the immediately succeeding image number, the maximum pixel number MV at that phase is said to be the maximum value PV. Therefore, when the maximum value PV is detected, it is determined that the observation image determination condition is satisfied, and this post-machining tool image can be determined as the observation image. As another example, if the rate of change (slope) of the luminance value of the maximum pixel number MV of the difference image of a certain image number from the maximum pixel number MV of the difference image of the immediately preceding image number is equal to or greater than a predetermined increase threshold, the maximum pixel number MV may be determined to be the maximum value PV. Alternatively, when the rate of increase (slope) of the maximum number of pixels MV of a difference image from the maximum number of pixels MV of the difference image of the immediately preceding image number is equal to or greater than a predetermined increase threshold, and the rate of decrease (slope) of the change to the maximum number of pixels MV of the immediately succeeding image number is equal to or greater than a predetermined decrease threshold, the maximum number of pixels MV of the difference image of the image number may be determined to be the maximum value PV. This makes it possible to omit imaging after determining the observation image, thereby reducing the labor required for imaging.

[0035] The effects of the tool evaluation device 10 according to this embodiment will be described below through a flowchart of the tool evaluation device 10 shown in FIG. 12 and an explanation of cleaning and imaging of the tool 26 using FIGS. 13 to 17.

[0036] As shown in the flowchart of Fig. 12, the tool evaluation process starts in step S10. Next, the process proceeds to step S20, in which the tool transportation device 20 moves to the tool carry-in / out position HP (see Fig. 13) in the tool magazine 30, and the tool holder 24 holds the tapered shank portion 28a of the tool 26 to be imaged and evaluated. Note that instead of the tool holder 24 holding the tool 26, an operator may manually attach the tool to the tool holder at the tool carry-in / out position.

[0037] Once the tool holding unit 24 holds the tool 26, the process proceeds to step S30, where the control unit 48 activates the tool transport device 20 to transport the tool 26 along the horizontal direction D1 to a position where the central axis of the tool 26 and the center of the first cleaning unit 36 ​​are aligned in the horizontal direction D1. Next, as shown in FIG. 14 , the control unit 48 activates the guide unit 32 to lift the bracket 34 along the vertical direction D2 until the blade portion 50 of the tool 26 is positioned within the first cleaning unit 36. At this time, the amount of lift of the bracket 34 is determined based on the tool length TL stored in the tool information storage unit 62. Once the blade portion 50 is positioned within the first cleaning unit 36, the process proceeds to step S40, where the first cleaning unit 36 ​​sprays cleaning fluid onto the blade portion 50 of the tool 26 housed therein to clean the tool 26. When cleaning of the tool 26 is completed, the control unit 48 operates the guide unit 32 to lower the bracket 34 in the up-down direction D2, and removes the tool 26 from the inside of the first cleaning unit 36.

[0038] Here, when the bracket 34 descends and the tool 26 is removed from the first cleaning unit 36, step S30 is executed again, and the control unit 48 operates the tool transport device 20 to transport the tool 26 along the horizontal direction D1 to a position where the central axis of the tool 26 and the center of the second cleaning unit 38 are aligned in the horizontal direction D1. Next, as shown in FIG. 15 , the control unit 48 operates the guide unit 32 to lift the bracket 34 along the vertical direction D2 until the blade portion 50 of the tool 26 is positioned within the second cleaning unit 38. At this time, the amount of lift of the bracket 34 is determined based on the tool length TL stored in the tool information storage unit 62. When the blade portion 50 is positioned within the second cleaning unit 38, step S40 is executed again, and the second cleaning unit 38 sprays compressed air onto the blade portion 50 of the tool 26 stored therein to dry the tool 26 after cleaning. When the drying of the tool 26 is completed, the control unit 48 operates the guide unit 32 to lower the bracket 34 in the up-down direction D2, and removes the tool 26 from the inside of the second cleaning unit 38.

[0039] When the bracket 34 descends and the tool 26 is removed from the second cleaning unit 38, the process proceeds to step S50. As shown in FIG. 16 , the control unit 48 activates the tool transport device 20 to transport the tool 26 to a first imaging position TP1 along the horizontal direction D1. The first imaging position TP1 is positioned so that the radial end of the blade imaging diameter BR of the tool 26 coincides with the center position of the bottom-side imaging unit 42. When the tool 26 moves to the first imaging position TP1, the control unit 48 activates the guide unit 32 to move the bracket 34 up and down along the vertical direction D2 to adjust the focal length of the bottom-side imaging unit 42, which images the tool 26. The amount of movement of the bracket 34 to adjust the focal length may be determined based on the tool length TL stored in the tool information storage unit 62, or an automatic focus adjustment function of the bottom-side imaging unit 42 may be used. At this time, the phase of the blade 50 is set to the initial phase.

[0040] Once the alignment of the tool 26 and the bottom-side imaging unit 42 is complete, the process proceeds to step S60, where the bottom-side imaging unit 42 starts imaging the minor flank 54 of the tool 26. The captured image is stored in the tool image storage unit 64 as a machined tool image associated with information on the phase of the tool 26 at the time of imaging. Once imaging has started, the process proceeds to step S70, where the control unit 48 activates the rotation unit 22 to rotate the tool 26 at a predetermined phase interval θ to change the phase, repeatedly capturing images of the minor flank 54 and storing the machined tool image associated with the phase in the tool image storage unit 64. Imaging is repeated within a predetermined phase range PR. If the number of blades n is 2 or more, the phase range PR for one blade 50 may be set to 360 degrees / number of blades n. Here, while the rotating unit 22 continuously rotates the tool 26, the bottom-side imaging unit 42 may capture images at every phase interval θ. Alternatively, after the tool 26 has rotated by the phase interval θ, the rotation of the tool 26 may be stopped and then an image may be captured. The imaging may be performed at a predetermined time interval T instead of the phase interval θ. In this case, the captured image of the minor flank 54 is stored in the tool image storage unit 64 as a machined tool image associated with the rotation time from the start of rotation of the tool 26. The phase interval θ and the time interval T may be determined by the control unit 48 according to the shape and dimensions of the tool 26. For example, for a tool 26 with a relatively large tool diameter TR, if the phase interval θ is long, an image may not be captured at a rotation phase suitable for an observation image. Therefore, the control unit 48 sets the phase interval θ and the time interval T to be small. The imaging of the cutting edge 50 in step S70 is repeated the number of times equal to the number n of cutting edges by shifting the phase range PR. When the rotating unit 22 rotates the tool 26 into the phase range PR, the process proceeds to step S80, where the imaging of the secondary flank 54 is completed, and then the process proceeds to step S90.

[0041] In step S90, the determination unit 66 compares the captured images of the minor flanks 54 with a pre-stored reference image of the minor flanks 54 before machining. When the image with the highest degree of match is identified based on the difference between the image of the minor flanks 54 and the reference image, the process proceeds to step S100, where the determination unit 66 determines this image as the observed image of the minor flanks 54. Steps S90 and S100 are repeated the number of times equal to the number n of blades, and observed images of the minor flanks 54 are determined. Alternatively, if there are multiple blades 50 and the phase range is 360 degrees / n number of blades, steps S70 to S100 may be performed for the first blade 50 to determine the observed image. After that, for the second and subsequent blades 50, observed images may be captured at phases that are increased by the phase range (360 degrees / n number of blades) from the phase associated with capturing the observed image of the first blade 50. 2, if the tool has two blades, the phase range is 360 degrees / number of blades 2=180 degrees, and therefore, after determining the observation image of the first blade portion 50, the rotation unit 22 rotates to a phase obtained by adding 180 degrees from the phase associated with capturing the post-machining tool image that serves as the observation image of the first blade portion 50, thereby placing the tool 26 in a phase suitable for capturing the observation image of the second blade portion 50 relative to the bottom surface imaging unit 42. As a result, observation images can be efficiently determined for a tool 26 in which the blade portions 50 are evenly arranged.

[0042] Once the observation images of the minor flank faces 54 for the number n of blades have been determined, the process proceeds to step S110. As shown in FIG. 17 , the control unit 48 operates the tool transport device 20 to transport the tool 26 along the horizontal direction D1. Furthermore, the control unit 48 operates the guide unit 32 to move the bracket 34 up and down along the vertical direction D2 to position the tool 26 at the second imaging position TP2. The second imaging position TP2 is positioned so that a position below the gauge line GL, which is the primary imaging position of the blade portion 50, by the blade imaging length BL coincides with the center position of the side imaging unit 44 in the vertical direction D2. Furthermore, the control unit 48 operates the tool transport device 20 to move the tool 26 along the horizontal direction D1 to adjust the focal length of the side imaging unit 44 that images the tool 26. The amount of movement of the tool 26 to adjust the focal length may be determined based on the tool diameter TR stored in the tool information storage unit 62, or an automatic focus adjustment function provided in the side imaging unit 44 may be used. At this time, the phase of the blade portion 50 is set to the initial phase.

[0043] When the alignment of the tool 26 and the side image capturing unit 44 is complete, the process proceeds to step S120, where the control unit 48 operates the rotating unit 22 to rotate the tool 26 and position the phase of the tool 26 to the phase where the observed image of the minor flank 54 was acquired. After positioning the phase, the control unit 48 operates the side image capturing unit 44 to capture an image of the major flank 52, and determines this post-machining tool image as the observed image of the major flank 52. Step S120 is repeated by changing the phase a number of times equal to the number n of teeth, and a plurality of observed images of the major flank 52 are determined. Note that, like the secondary flank 54, the primary flank 52 may also be imaged at phase intervals θ or time intervals T; however, since the phases in the rotational direction to be imaged of the primary flank 52 and the secondary flank 54 are basically the same, the initial phase before imaging begins can be made the same, and the primary flank 52 can be imaged only at the same phase or rotation time as the phase or rotation time associated with when the post-machining tool image that became the observation image of the secondary flank 54 was imaged, thereby reducing the labor required for imaging the primary flank 52.

[0044] Once the observation images of the main flank faces 52 for the number n of blades have been determined, the process proceeds to step S130, where the control unit 48 activates the tool transport device 20 to transport the tool 26 to the tool loading / unloading position HP and unload the tool 26. Next, the process proceeds to step S140, where the determination unit 66 transmits the observation images for the number n of blades to the tool evaluation unit 68. After the observation images have been transmitted, the process proceeds to step S150, where the tool evaluation unit 68 performs image recognition on the received observation images to evaluate the condition of the blades. Specifically, the tool evaluation unit 68 checks for the presence or absence of chipping or the amount of wear of the blades 50 and acquires this information. When the tool 26 has two or more blades 50, the observation image of only one representative blade 50 may be evaluated, or all of the observation images of all of the blades 50 may be evaluated. Once the evaluation is complete, the process proceeds to step S160, where the tool evaluation unit 68 transmits the evaluation results to the storage unit. At this time, the evaluation result associated with the cumulative number of times the imaged tool 26 is machined may be stored in the tool information storage unit 62.

[0045] After transmitting the evaluation results to the storage unit, the tool evaluation unit 68 proceeds to step S170, where it determines whether or not the cutting edge 50 is damaged. If no damage is detected, it proceeds to step S180, where it determines whether or not the wear on the cutting edge 50 exceeds a predetermined allowable wear amount. If the wear on the cutting edge 50 does not exceed the predetermined allowable wear amount, it proceeds to step S200, where the tool evaluation process ends. Here, if the tool 26 has two or more cutting edges 50, only one representative cutting edge 50 may be evaluated, or all cutting edges 50 may be evaluated. On the other hand, if it is determined in step S170 that a cutting edge 50 is damaged, or if it is determined in step S180 that the wear on the cutting edge 50 exceeds the predetermined allowable wear amount, the control unit 48 determines that the tool 26 cannot continue machining any further and activates the notification unit 70 to issue an alarm. The alarm may include information such as whether or not the cutting edge 50 is damaged, the allowable wear amount, and a tool replacement instruction. Once the alarm is issued, the process proceeds to step S200, where the tool evaluation process ends.

[0046] According to the tool evaluation device 10 and tool evaluation method of this embodiment, the tool 26 held by the tool holding unit 24 and transported to the first imaging position TP1 and the second imaging position TP2 can be imaged by the imaging unit. The rotating unit 22, which is connected to the tool holding unit 24 and rotates the tool holding unit 24 relatively to the bottom-side imaging unit 42 and the side-side imaging unit 44, can image the tool 26 rotated to a predetermined tool phase and store the image as a reference image in the tool image storage unit 64. The control unit 48 can operate the bottom-side imaging unit 42 and the side-side imaging unit 44 to image the tool 26 rotated by the rotating unit 22 at a predetermined phase interval θ or a predetermined time interval T, thereby acquiring multiple post-machined tool images. The determining unit 66 can compare the reference image with the multiple post-machined tool images and determine, from the multiple post-machined tool images, the one that most closely matches the reference image as the observation image. This allows the phase of the cutting edge 50 in the rotational direction of the tool 26 to be automatically determined regardless of the mounting state of the tool 26 relative to the tool holder 24, and the wear of the cutting edge 50 of the tool 26 to be evaluated based on the obtained observation image.

[0047] Furthermore, according to the tool evaluation method of this embodiment, a background image captured when the tool 26 is not within the imaging range can be stored in the tool image storage unit 64. Furthermore, the rotating unit 22 connected to the tool holding unit 24 can be rotated, and the tool can be imaged at a first phase interval θ1 or a first time interval T1 to acquire a first post-machined tool image. The acquired first post-machined tool image can be compared with the background image to determine whether the first post-machined tool image includes the cutting portion 50. Furthermore, if it is determined that the first post-machined tool image includes the cutting portion 50, the tool 26 can be imaged at a second phase interval θ2 shorter than the first phase interval θ1 or a second time interval T2 shorter than the first time interval T1 to acquire multiple second post-machined tool images, and the second post-machined tool images can be compared with the reference image. Therefore, the number of images can be reduced compared to when images are captured at a uniform phase interval θ or time interval T, and the observation image that most closely matches the reference image can be efficiently determined from the multiple second post-machined tool images. This allows the phase of the cutting edge 50 in the rotational direction of the tool 26 to be automatically determined regardless of the mounting state of the tool 26 relative to the tool holding portion 24, and the wear of the cutting edge 50 of the tool 26 to be efficiently evaluated based on the obtained observation image.

[0048] Furthermore, according to the tool evaluation method of this embodiment, the determination unit 66 determines whether the post-machined tool image satisfies the observation image determination condition stored in the storage unit 46 in advance. If the condition is satisfied, the control unit 48 terminates image capture even if the rotation of the tool 26 has not yet reached the phase range PR. The observation image determination condition can be that the maximum luminance value MV of the difference image, which is an index of the degree of match between the post-machined tool image and the reference image, exceeds a threshold value TH. Furthermore, if the maximum luminance value MV of the difference image at a certain phase is greater than the maximum luminance value MV of the difference image at the immediately preceding phase and is also greater than the maximum luminance value MV of the difference image at the immediately succeeding phase, the maximum luminance value MV at that phase is determined to be a maximum PV. Detection of such a maximum PV can be used as the observation image determination condition. Therefore, image capture can be terminated when the observation image determination condition is satisfied. This reduces the number of post-machined tool images compared to capturing images over the entire phase range PR, and allows the observation image with the highest degree of match with the reference image to be efficiently determined. This allows the phase of the cutting edge 50 in the rotational direction of the tool 26 to be automatically determined regardless of the mounting state of the tool 26 relative to the tool holding portion 24, and the wear of the cutting edge 50 of the tool 26 to be efficiently evaluated based on the obtained observation image.

[0049] As described above, the tool evaluation device 10 and tool evaluation method according to this embodiment can automatically determine the phase of the cutting edge 50 in the rotation direction of the tool 26 regardless of the state of attachment of the tool 26 to the tool holder 24.

[0050] Although the embodiment of the tool evaluation device 10 has been described above, the present invention is not limited to the above embodiment. In addition to the above, it is believed that a person skilled in the art would understand that various modifications of the above embodiment are possible. [Explanation of symbols]

[0051] 10 Tool evaluation device 20 Tool transport device 22 Rotating part 24 Tool holding part 26 Tools 42 bottom side imaging unit (first imaging unit) 44 Side imaging unit (second imaging unit) 48 Control Unit 50 Blade 64 Tool image storage unit 66 Decision Section

Claims

1. A tool evaluation method for evaluating wear of a cutting edge of a tool, comprising: a tool holder holding the tool; a step in which the tool holding unit transports the tool to an imaging position; capturing an image of the tool at a predetermined tool phase and storing the image as a reference image; a step of rotating a rotating unit connected to the tool holding unit, rotating the rotating unit by a predetermined phase interval or a predetermined time interval within a predetermined phase range set for imaging one of the cutting portions, and repeatedly imaging one of the cutting portions of the tool, thereby acquiring a plurality of post-machining tool images; A step of comparing the reference image with the plurality of post-machining tool images; determining, from among the plurality of post-machining tool images, the image having the highest degree of coincidence with the reference image as an observation image of the cutting edge; evaluating wear of the cutting edge of the tool using the observed image; Equipped with A tool evaluation method characterized in that the observation images are acquired multiple times according to the number of blades.

2. The tool evaluation method according to claim 1 , wherein the phase range is determined as 360 degrees / number of teeth.

3. A tool evaluation method as described in claim 2, wherein the observation image is further obtained from the post-machining tool image at the phase obtained by adding the phase range from the phase when the observation image was first obtained.

4. 2. The tool evaluation method according to claim 1, wherein, when the observation image of one of the blade side surface and the blade tip surface is determined, an imaging location of the other of the blade side surface and the blade tip surface at the phase or rotation time when the observation image was determined is identified and imaged, and the acquired post-machining tool image is determined as the observation image.

5. 2. The tool evaluation method according to claim 1, wherein, when the observation image of one of the blade side surface and the blade tip surface has been determined, an imaging location of the other of the blade side surface and the blade tip surface is identified and imaged based on the phase or rotation time when the observation image was determined and related information about the blade side surface and the blade tip surface, and the acquired post-machining tool image is determined as the observation image.

6. A tool evaluation method for evaluating wear of a cutting edge of a tool, comprising: a tool holder holding the tool; a step in which the tool holding unit transports the tool to an imaging position; capturing an image of the tool at a predetermined tool phase and storing the image as a reference image; a step of storing a background image captured when the tool is not within an imaging range; a step of rotating a rotating unit connected to the tool holding unit within a predetermined phase range, capturing images of the tool at first phase intervals or first time intervals, and acquiring a first post-machining tool image; a step of comparing the acquired first post-machining tool image with the background image and determining whether the first post-machining tool image includes the cutting edge; When it is determined that the first post-machining tool image includes the cutting edge, capturing an image of the tool at a second phase interval shorter than the first phase interval or at a second time interval shorter than the first time interval to acquire a plurality of second post-machining tool images; A step of comparing the reference image with the second post-machining tool image; determining, from among the plurality of second post-machining tool images, the one having the highest degree of coincidence with the reference image as an observation image; evaluating wear of the cutting edge of the tool using the observed image; A tool evaluation method comprising:

7. A tool evaluation method for evaluating wear of a cutting edge of a tool, comprising: a tool holder holding the tool; a step in which the tool holding unit transports the tool to an imaging position; capturing an image of the tool at a predetermined tool phase and storing the image as a reference image; a step of rotating a rotating unit connected to the tool holding unit, capturing images of the tool within a predetermined phase range at predetermined phase intervals or predetermined time intervals, and acquiring a plurality of post-machining tool images; A step of comparing the captured post-machining tool image with the reference image and determining the degree of match; determining whether the degree of match is satisfied and whether an observation image determination condition is satisfied; determining the post-machining tool image that satisfies the observation image determination condition as an observation image, and terminating acquisition of the post-machining tool image; evaluating wear of the cutting edge of the tool using the observed image; A tool evaluation method comprising:

8. 8. The tool evaluation method according to claim 7, wherein the observation image determination condition is that the degree of coincidence between the post-machining tool image and the reference image is higher than a predetermined reference value.

9. A tool evaluation method as described in claim 7, wherein the observation image determination condition is that the degree of coincidence between the post-machining tool image and the reference image is greater than the degree of coincidence between the post-machining tool image and the reference image in the immediately preceding phase, and is also greater than the degree of coincidence between the post-machining tool image and the reference image in the immediately following phase.

10. A tool evaluation device that evaluates wear of a cutting edge of a tool, an imaging unit that images the tool; a tool holding portion for holding the tool; a rotation unit connected to the tool holding unit and configured to rotate the tool holding unit relative to the imaging unit; a tool image storage unit that captures an image of the tool in advance at a predetermined tool phase and stores the image as a reference image; a control unit that activates the imaging unit to repeatedly capture images of one of the cutting edges of the tool by rotating the tool by a predetermined phase interval or a predetermined time interval within a predetermined phase range set for capturing an image of one of the cutting edges, thereby acquiring a plurality of post-machining tool images; a determination unit that compares the reference image with the plurality of machined tool images acquired by the control unit, and determines, from among the plurality of machined tool images, the one that has the highest degree of coincidence with the reference image as one observation image of the cutting edge; Equipped with A tool evaluation device characterized in that the observation images are obtained multiple times according to the number of blades, and the observation images are used to evaluate wear of the blade portion of the tool.

Images