Machine tool wear measuring device

Abstract

A tool wear measuring device for a machine tool is provided that can quantitatively measure wear on a tool cutting edge with a simple configuration without interrupting machining of the machine tool. [Solution] A tool wear measuring device (11) for a machine tool comprises a tool magazine (30), an imaging device (40) arranged adjacent to the tool magazine (30) in a tool magazine chamber or near the tool magazine chamber and having a bottom side imaging unit (42) that images the bottom cutting edge of the tool (26) and a side side imaging unit (44) that images the side cutting edge, a tool transport device (20) that holds the tool (26) and moves it in a direction perpendicular to the axis of the tool (26) between the imaging device (40), a guide unit (32) that moves the tool (26) relatively in the axial direction of the tool (26) between the imaging device (40), a rotating unit (22) that rotates the tool (26) relatively around the axis of the tool (26), and a tool wear amount measuring unit (68) that processes the image taken by the imaging device (40) and determines the amount of wear of the cutting edge (50) of the tool (26).

Description

[Technical Field]

[0001] The present invention relates to a tool wear measuring device for a machine tool. [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 quality of the machined surface deteriorates, the required precision 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] The progress of tool wear is generally observed and evaluated by an operator who removes the tool from the machine tool and visually inspects it. Cited Document 1 discloses an apparatus for automatically measuring the amount of tool wear from image data obtained by capturing an image of the cutting edge of a tool stored in a tool magazine.

[0004] However, in the narrow space of a tool magazine where tools of various shapes and lengths and diameters are stored closely together at high density, moving a camera that can move in five axes (three linear axes, namely the X-axis, Y-axis, and Z-axis, and two rotational axes, namely the B-axis and C-axis) from the camera toward the tools to access the cutting edges of the tools stored in the tool magazine makes the structure of the device complex. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 8-257876 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 wear measuring device for a machine tool that can quantitatively measure wear on a tool cutting edge with a simple configuration without interrupting machining of the machine tool. [Means for solving the problem]

[0007] One aspect of the present invention is a tool wear measuring device for a machine tool that is arranged in a location other than a machining chamber in a tool magazine room or in the vicinity of the tool magazine room and measures the amount of wear on the cutting edge of a tool, the device comprising: a tool magazine that stores a plurality of tools and is capable of positioning a tool whose cutting edge wear amount is to be measured at a predetermined position separate from a tool exchange position where the tool is exchanged between the tool magazine and a spindle; and at least one of a first imaging element that images a bottom cutting edge of the tool whose amount of wear is to be measured and a second imaging element that images a side cutting edge of the tool that is to be measured and that is arranged adjacent to the tool magazine in or in the vicinity of the tool magazine room. a conveying device having an imaging unit having an imaging section, a first feed shaft unit that holds a tool for measuring the amount of wear of the cutting edge and moves it in a direction perpendicular to the axis of the tool between the imaging unit, a second feed shaft unit that moves the tool held by the first feed shaft unit relatively to the axis of the tool between the imaging unit, and a third feed shaft unit that rotates the tool held by the first feed shaft unit relatively to the axis of the tool between the imaging unit, and a tool wear amount measuring unit that processes the image taken by the imaging unit and determines the amount of wear of the cutting edge of the tool. [Effects of the Invention]

[0008] According to one aspect of the present invention, the tool wear measuring device for a machine tool includes an imaging unit having at least one of a first imaging element for imaging the bottom cutting edge of a tool whose wear amount is to be measured and a second imaging element for imaging the side cutting edge, and a tool wear measurement unit that processes the image captured by the imaging unit to determine the wear amount of the tool's cutting edge. The tool wear measuring device is located in a location other than the tool magazine chamber or the machining chamber near the tool magazine chamber, and the tool magazine, which stores multiple tools, is configured to position the tool whose wear amount is to be measured at a predetermined position separate from the tool exchange position where the tool is exchanged between the tool magazine and the spindle. This allows the tool wear measuring device to measure the wear amount of the tool's cutting edge without interrupting machining on the machine tool. Furthermore, the tool wear measuring device includes a conveying device having a first feed shaft unit that holds the tool for which the wear amount of the cutting edge is to be measured and moves it in a direction perpendicular to the axis of the tool relative to the imaging unit, a second feed shaft unit that moves the tool held by the first feed shaft unit relative to the imaging unit in the tool axial direction, and a third feed shaft unit that rotates the tool held by the first feed shaft unit relative to the imaging unit about the axis of the tool. This allows the tool and imaging unit to be aligned for imaging using only two linear axes and one rotational axis. This allows quantitative measurement of tool wear with a simple configuration without interrupting machining by the machine tool. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 shows a block diagram of a tool life determination device equipped with a tool wear measuring device according to this embodiment. [Figure 2] FIG. 2 is a perspective view of the tool wear measuring device according to this embodiment. [Figure 3] FIG. 3(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 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 perspective view of the inside of the first cleaning section. [Figure 7] FIG. 7 shows a perspective view of the inside of a first cleaning section according to another embodiment. [Figure 8] FIG. 8 shows a perspective view of the inside of the second cleaning section. [Figure 9] FIG. 9 shows a plan view of the tool magazine. [Figure 10] FIG. 10 shows a plan view and a side view of the tool wear measuring device according to this embodiment. [Figure 11] FIG. 11 shows a plan view and a side view of a tool wear measuring device that cleans a tool using a first cleaning unit. [Figure 12] FIG. 12 shows a plan view and a side view of a tool wear measuring device in which the tool is cleaned by the second cleaning unit. [Figure 13] FIG. 13 shows a plan view and a side view of a tool wear measuring device that captures an image of the bottom of a tool using a first imaging unit. [Figure 14] FIG. 14 shows a plan view and a side view of a tool wear measuring device that captures an image of the side of a tool using a second imaging unit. [Figure 15] FIG. 15 shows an example of a plurality of post-machining tool images including cutting edges. [Figure 16] FIG. 16 shows an example of detecting the maximum brightness value for each post-machining tool image. [Figure 17] FIG. 17 shows a flowchart of the tool life determination according to this embodiment. [Figure 18] FIG. 18 shows a histogram of the number of tool life judgments versus the amount of tool wear. [Figure 19] FIG. 19 shows a correlation diagram between the amount of tool wear and the tool life index. [Figure 20] FIG. 20 shows a database of correlations between tool wear amounts and tool life indices. [Figure 21]10A is a side view of a tool magazine according to another embodiment, and FIG. 10B is a plan view taken along the arrow A1 in FIG. 10A. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, a tool wear measuring 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.

[0011] FIG. 1 shows a block diagram of a tool life determination device 10 equipped with a tool wear measurement device 11. The tool life determination device 10 is configured integrally with a machine tool main body MT (machine tool) or disposed adjacent to the machine tool main body MT. The tool life determination device 10 includes a tool wear measurement device 11 for measuring the amount of tool wear, which is the amount of wear on the cutting edge 50 of a tool 26 used in machining, and a tool life index measurement unit 64 for measuring a tool life index. Here, the amount of tool wear of the tool 26 refers to the wear width of the flanks 52, 54 or the rake face 56, or the amount of change in the tool diameter TR. One or more of these are used for tool life determination. The tool life index refers to the number of workpieces machined by the tool 26, the machining distance, the machining time (the cumulative time of the executed machining), and the machining workload (the cumulative amount of power consumed by the spindle motor during the execution of the machining). One or more of these are used as the tool life index for tool life determination.

[0012] The tool wear measuring device 11 also includes a memory unit 66 that sequentially stores pairs of measured tool wear amounts and tool life indices, and a calculation unit 70 that calculates a tool life index threshold from the correlation between the tool wear amount and the tool life index and a tool wear amount threshold input in advance by the operator. The tool life determination device 10 also includes an operation input unit 60 that receives commands from the operator to replace worn tools and inputs machining programs and machining conditions to be input to the machine tool main body MT. The tool life determination device 10 also includes a machine tool control unit 62 electrically connected to the machine tool main body MT, and the commands from the operator, machining programs, and machining conditions input to the operation input unit 60 are transmitted to the machine tool main body MT via the machine tool control unit 62.

[0013] The tool wear measuring device 11 has an imaging information storage unit 46 for storing information about the tool 26 and its imaging. The imaging information storage unit 46 has an imaging information storage unit 46a for storing information about imaging of the tool 26, a tool information storage unit 46b for storing information about the tool 26 itself, and a tool image storage unit 46c for storing images of the tool 26 captured by the imaging device 40 as an imaging unit. Specifically, the imaging information storage unit 46a 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. When there are a plurality of blades 50 (see FIG. 3 ) (number of blades n), reference images are acquired for each of the blades n, and therefore multiple tool phases corresponding to each blade 50 are stored, equal to the number of blades n. If the types of the cutting portions 50 and the mounting positions and angles of the cutting portions 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 the operator and stored in the image information storage unit 46a. Instead of being set by the operator, the image capture control unit 48 included in the tool wear measuring device 11 may automatically set these in accordance with information about the tool 26. The tool information storage unit 46b is configured to store the number of blades n of the cutting portions 50 attached to the tool 26, the tool length TL, the blade imaged length BL, the tool diameter TR, and the blade imaged diameter BR of the tool 26. The tool image storage unit 46c is configured to store the reference image and the post-machining tool image, which will be described later.

[0014] The imaging control unit 48 is also configured to operate the rotating unit 22 to rotate the tool 26 and to operate the first cleaning unit 36 ​​and the second cleaning unit 38 to clean the tool 26. The imaging 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 46c. The tool phase at which the reference image is captured is determined visually by the operator, and the operator controls the imaging control unit 48 via the operation input unit 60 to index the tool 26 to the tool phase and capture the image. The reference image should be captured when the tool 26 is not damaged or worn, so it is desirable to capture the reference image when the tool 26 is new and has not yet been used for machining. The imaging 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 46c.

[0015] The tool wear measuring device 11 includes a tool wear measurement unit 68 that compares a reference image stored in the tool image storage unit 46c with multiple machined tool images, determines the machined tool image that most closely matches the reference image as the observed image, and performs image analysis on the determined observed image to determine whether or not the cutting edge 50 is chipped and measure the amount of tool wear. Note that if the tool 26 has two or more cutting edges 50, the observed images of all cutting edges 50 may be evaluated, or only the observed image of one cutting edge 50 may be evaluated. The measured tool wear amount is transmitted to the storage unit 66 and stored therein in association with the tool life index measured by the tool life index measurement unit 64. The calculation unit 70 is configured to calculate a threshold value for the tool life index from the pairs of tool wear amounts and tool life indexes stored in the storage unit 66 and the tool wear amount threshold value input by the operator via the operation input unit 60.

[0016] The tool life determination device 10 also includes a display unit 72, and is configured to sequentially display on the same screen the threshold value of the tool life index calculated by the calculation unit 70 and the current value of the tool life index measured by the tool life index measurement unit 64. The display unit 72 also has an alarm function, and when the current value of the tool life index approaches or exceeds the threshold value of the tool life index, issues a warning or alarm to warn against continuing machining with the tool 26.

[0017] FIG. 2 shows a schematic perspective view of the tool wear measuring device 11. The tool wear measuring device 11 is disposed adjacent to the tool magazine 30 in a location other than the machining chamber (not shown) of the machine tool main body MT. However, the present invention is not limited to this, and the tool wear measuring device may be disposed inside the tool magazine chamber of the machine tool main body. The tool wear measuring device 11 has both a tool wear measurement function and a function as a transport device for transporting tools. It includes a base unit 12 and a tool transport device 20 as a first feed shaft unit attached to the base unit 12. It also includes an imaging device 40 as an imaging unit for capturing images of the tool 26, and first and second cleaning units 36 and 38 as cleaning units for cleaning the tool 26 before capturing images (see FIG. 10 ). The imaging device 40 includes a bottom-side imaging unit 42 having a first imaging element for capturing images of the tool 26 from the tip side (bottom side), and a side-side imaging unit 44 having a second imaging element for capturing images of the side of the tool 26. As will be described later, 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 along a vertical direction D2 (a second direction), and a beam 18 spanning between the two support columns 16 and extending along a horizontal direction D1 (a first direction perpendicular to the second 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 serving as a third feed shaft is disposed below the tool transport device 20. The rotating unit 22 has a drive unit such as a servo motor and is configured to be rotatable in a direction C around the axis of a tool 26 that extends along the vertical direction relative to the tool transport device 20. The tool 26 is detachably attached below the rotating unit 22.

[0019] 3(a) to 3(c) show side and bottom views of the tool 26. The tool 26 includes a tool holder 24 having a tapered shank 28a, a shank 28 attached to the tool holder 24, and a cutting portion 50 attached to the distal end (lower end) of the shank 28. The cutting portion 50 is used for milling, and when the axis of the tool 26 is in a vertical position, 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 distal end (bottom side) is a minor cutting edge 50b. The cutting portion 50 includes 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 generally trapezoidal in bottom view. The cutting portion 50 is provided at two locations, 180 degrees apart, on the tool 26 shown in FIGS. 3( a) to 3(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 vertically. However, this is not limiting, and a cutting portion extending horizontally may be attached to the shank, and the tool may be used for turning.

[0020] 2, 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 exchanged between the tool transport device 20 and the tool magazine 30. When exchanging the tool 26, the tool transport device 20 is configured to move to a tool loading / unloading position HP (see FIG. 9) in the tool magazine 30 and hand over the tool 26.

[0021] The tool wear measuring device 11 is attached to the base 12 and includes a guide 32 serving as a second feed shaft for vertically moving the first cleaning unit 36, the second cleaning unit 38, and the imaging device 40 (see FIG. 10) relative to the tool 26. The guide 32 is configured to use an internal feed shaft (not shown) 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 in the 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 and one rotational axis of the rotating unit 22.

[0022] 4(a) and 4(b) show a side view of the bottom-side imaging unit 42, which images the bottom side of the tool 26, and a bottom view of the tool 26. The imaging 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 imaging control unit 48 based on the tool diameter TR, or may be arbitrarily set by the operator for each tool 26. Next, the imaging 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 part 32 in the up-down direction D2 may be determined by the imaging control part 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. 10) of the bottom surface side imaging part 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.

[0023] Once the alignment of the tool 26 with 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 image captured by the bottom-side imaging unit 42 is stored in the tool image storage unit 46c as a machined tool image associated with information on the phase of the tool 26 at the time of image capture. When the machined tool image at a certain phase is stored in the tool image storage unit 46c, the imaging control unit 48 activates the rotation 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 imaging 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 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 tool image storage unit 46c stores the post-machining 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 imaging control unit 48 according to the shape and dimensions of the tool 26. For example, with a tool 26 having a relatively large tool diameter TR, if the phase interval θ is long, an image may not be captured at a rotation phase that allows for an observation image. In such a case, the imaging control unit 48 sets the phase interval θ and the time interval T to be small.

[0024] 5(a) and 5(b) show a side view of the side-side imaging unit 44, which captures an image of the side of the tool 26, and a bottom view of the tool 26. The imaging 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-side imaging unit 44 in the horizontal direction D1. The movement distance of the tool transport device 20 in the horizontal direction D1 may be determined by the imaging control unit 48 based on the tool diameter TR, or may be arbitrarily set by the operator for each tool 26. Next, the imaging 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-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-side imaging unit 44. The movement distance of the guide unit 32 in the vertical direction D2 may be determined by the imaging 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 second imaging position TP2 (see FIG. 10) of the side imaging unit 44, and the imaging range IA (see FIG. 4(b)) 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.

[0025] Once the alignment of the tool 26 and the side-side imaging unit 44 is complete, the side-side imaging unit 44 captures an image of the main flank face 52 of the tool 26. The captured image is stored in the tool image storage unit 46c 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 46c, the imaging 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 imaging performed by rotating the tool 26 is repeated within a predetermined phase range PR. If the number of blades n is two 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 46c.

[0026] FIG. 6 shows a perspective view of the interior of the first cleaning unit 36. Note that FIGS. 6 through 8 illustrate a solid end mill as the tool 26 to more clearly illustrate the effects. Needless to say, this is not a limitation, and the cleaning device can also clean a milling tool such as that shown in FIG. 3 and other turning tools. The first cleaning unit 36 ​​is configured to immerse the tool 26 in cleaning liquid WL, and the cleaning liquid is contained within the tub-shaped first cleaning unit 36. The imaging control unit 48 can operate the guide unit 32 to raise the first cleaning unit 36, which is disposed on the bracket 34, and immerse the tool 26 in the cleaning liquid WL. This allows the tool 26 to be cleaned in the first cleaning unit 36. The imaging control unit 48 can also operate the rotation unit 22 to rotate the tool 26 immersed in the cleaning liquid WL. This makes it easier to remove chips, if any, from the tool 26, improving the cleaning effect. Furthermore, the first cleaning section 36 is equipped with an air nozzle 80, which can inject compressed air CA into the cleaning liquid WL inside. Therefore, bubbles BB generated by the compressed air CA from the air nozzle 80 also make it easier to remove chips adhering to the tool 26, thereby improving the cleaning effect.

[0027] FIG. 7 shows another embodiment of the first cleaning section 36. The first cleaning section 36 includes a mixer 82 for mixing compressed air CA and cleaning liquid WL, and can spray the cleaning liquid WL in a high-pressure mist onto the surface of the tool 26 via a plurality of air nozzles 80 arranged within the first cleaning section 36. This improves the cleaning effect of the tool 26. Furthermore, the first cleaning section 36 includes a mist suction device 84 at its bottom for suctioning the cleaning liquid WL mist that is sprayed onto the tool 26 and drips downward along the tool 26 or that floats within the first cleaning section 36. This prevents the cleaning liquid WL mist from evaporating and diffusing outside the first cleaning section 36, thereby preventing the atmosphere inside the machine tool or factory from deteriorating.

[0028] FIG. 8 shows a perspective view of the interior of the second cleaning unit 38. The second cleaning unit 38 is configured to blow compressed air CA onto the tool 26 to remove droplets from the surface of the tool 26 cleaned in the first cleaning unit 36 ​​and dry it. The second cleaning unit 38 is equipped with a pulsed air generator 86 for discharging pulsed compressed air CA. The pulsed compressed air CA discharged from multiple air nozzles 80 arranged inside the second cleaning unit 38 can be blown onto the surface of the tool 26. This reduces the amount of compressed air CA used, enabling efficient cleaning and improving the cleaning effect of the tool 26. Furthermore, the second cleaning unit 38 is equipped with a mist suction device 84 at its bottom for suctioning the mist-like cleaning liquid WL that is sprayed onto the tool 26 and drips downward along the tool 26 or floats within the first cleaning unit 36. This prevents the mist-like cleaning liquid WL from evaporating and diffusing outside the second cleaning unit 38, thereby preventing the atmosphere inside the machine tool or factory from deteriorating.

[0029] FIG. 9 shows a plan view of the interior of the tool magazine 30. Here, the tool magazine 30 is configured as an endless chain-type tool magazine that rotates. The tool magazine 30 includes a cylindrical drive sprocket 90 having a drive mechanism (not shown) for rotating the drive sprocket 90 about its central axis, and a cylindrical driven sprocket 92 that rotates in response to the drive sprocket 90. A chain 94 is wound around the outer periphery of the drive sprocket 90 and the driven sprocket 92, and the chain 94 and the driven sprocket 92 rotate as the drive sprocket 90 rotates. A gripper 96 for attaching a tool is attached to the chain 94. A leaf spring (not shown) that is arc-shaped in a plan view and attached to the gripper 96 grips the tool 26 with its downward facing. The tool 26 for measuring wear is moved to the tool loading / unloading position HP by the rotation of the drive sprocket 90 and then transferred to the tool transport device 20. Meanwhile, the tool 26 used for machining, which is attached to the spindle (not shown) of the machine tool main body MT, moves to the tool changing position CH by the rotation of the drive sprocket 90 and is transferred to the machine tool main body MT.

[0030] 10 to 14 show plan views and side views of the tool wear measuring device 11 to explain a method for measuring the amount of tool wear of a tool 26 delivered to the tool transport device 20 at the tool loading / unloading position HP. As shown in Fig. 10, the tool transport device 20 moves to the tool loading / unloading position HP in the tool magazine 30 and holds the tapered shank portion 28a of the tool 26 to be imaged and evaluated. Note that instead of the tool transport device 20 holding the tool 26, an operator may manually attach the tool to the tool transport device 20 at the tool loading / unloading position HP.

[0031] Once the tool transport device 20 holds the tool 26, the imaging control unit 48 operates the tool transport device 20 to transport the tool 26 along the horizontal direction D1 to a first cleaning position WP1 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. 11 , the imaging control unit 48 operates the guide unit 32 to raise the bracket 34 along the vertical direction D2 until the blade portion 50 of the tool 26 fits inside 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 46b. Once the blade portion 50 fits inside the first cleaning unit 36, the first cleaning unit 36 ​​cleans the tool 26 by immersing the blade portion 50 of the tool 26 housed therein in a cleaning liquid or by spraying the cleaning liquid onto the blade portion 50. When cleaning of the tool 26 is completed, the imaging 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.

[0032] After the bracket 34 descends and the tool 26 is removed from the first cleaning unit 36, the imaging control unit 48 activates the tool transport device 20 to transport the tool 26 along the horizontal direction D1 to a second cleaning position WP2 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. 12 , the imaging 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 second cleaning unit 38. The amount of lift of the bracket 34 is determined based on the tool length TL stored in the tool information storage unit 46b. Once the blade portion 50 is positioned within the second cleaning unit 38, 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 imaging 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.

[0033] When the bracket 34 descends and the tool 26 is removed from the second cleaning unit 38, the imaging 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, as shown in FIG. 13 . 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 imaging 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 46b, 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.

[0034] Once the alignment of the tool 26 and the bottom-side imaging unit 42 is complete, the bottom-side imaging unit 42 begins imaging the minor flank 54 of the tool 26. The captured image is stored in the tool image storage unit 46c as a machined tool image associated with information on the phase of the tool 26 at the time of image capture. The imaging control unit 48 operates the rotating 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 46c. The imaging is repeated within a predetermined phase range PR. If the number of blades n is two 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 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 the imaging may be performed. Note that 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 46c as a machined tool image associated with the rotation time from the start of rotation of the tool 26. The phase interval θ and time interval T may be determined by the imaging control unit 48 depending on 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 large, imaging may not be performed at a rotation phase that allows for an observation image. Therefore, the imaging control unit 48 sets the phase interval θ and time interval T to be small. This imaging of the cutting edge 50 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 to the phase range PR, imaging of the minor flank 54 ends.

[0035] When the imaging of the minor flank 54 is completed, the imaging control unit 48 compares the captured images of the minor flank 54 with a pre-stored reference image of the minor flank 54 before machining. When the image with the highest degree of match is identified based on the difference between the image of the minor flank 54 and the reference image, the imaging control unit 48 determines this image as the observation image of the minor flank 54. These steps are repeated the number of times equal to the number n of blades, and observation images of multiple minor flanks 54 are determined. Alternatively, if there are multiple blades 50 and the phase range is 360 degrees / number n of blades, the observation image of the first blade 50 may be determined first, and then, for the second and subsequent blades 50, observation images may be captured at phases that are increased by the phase range (360 degrees / number n of blades) from the phase associated with capturing the observation image of the first blade 50. 3, 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.

[0036] Once the observation images of the minor flank faces 54 for the number n of blades have been determined, as shown in FIG. 14 , the imaging control unit 48 operates the tool transport device 20 to transport the tool 26 along the horizontal direction D1. The imaging control unit 48 then 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 for 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. The imaging control unit 48 then 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 46b, 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.

[0037] Once the alignment of the tool 26 and the side imaging unit 44 is complete, the imaging control unit 48 operates the rotating unit 22 to rotate the tool 26 and position the phase of the tool 26 to the phase at which the observation image of the minor flank 54 was acquired. After positioning the phase, the imaging control unit 48 operates the side imaging unit 44 to image the major flank 52 and determine this post-machined tool image as the observation image of the major flank 52. The imaging is repeated a number of times, the number of teeth being n, by changing the phase, and multiple observation images of the major flank 52 are determined. Note that, like the minor flank 54, the main flank 52 may also be imaged at phase intervals θ or time intervals T. However, since the rotational phases in which the main flank 52 and the minor flank 54 are to be imaged are basically the same, the initial phase before imaging begins can be made the same, and the main flank 52 can be imaged only at the same phase or rotation time as the phase or rotation time associated with when the post-machined tool image that became the observation image of the minor flank 54 was captured, thereby reducing the labor required for imaging the main flank 52.

[0038] Once the observation images of the main flank face 52 for the number n of blades have been determined, the imaging control unit 48 operates the tool transport device 20 to transport the tool 26 to the tool carry-in / out position HP. Next, the imaging control unit 48 transmits the observation images for the number n of blades to the tool wear measurement unit 68. Once the observation images have been transmitted, the tool wear measurement unit 68 performs image recognition on the received observation images to evaluate the condition of the blade. Specifically, the presence or absence of chipping in the blade 50 and the amount of tool wear are measured, and this information is acquired.

[0039] FIG. 15 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 imaging control unit 48 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 difference image is calculated by calculating the brightness value as the difference in brightness for all pixels and counting the number of pixels present at each brightness value. The brightness value may also be calculated within a partial range of the difference image. A grayscale is used for the brightness value, and it can be calculated in the range from 0 to 255. Here, a histogram of brightness values ​​and pixel counts for the difference image between one post-machining tool image and the reference image is created, and the number of pixels with the brightness value most frequently present in the difference image is defined as the maximum pixel count 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 count MV appears approaches 0, and the maximum pixel count MV increases. Fig. 16 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 to be the maximum value PV of the maximum numbers of pixels MV of all the machined tool images. In the example of Fig. 16, the maximum number of pixels MV of the machined tool image of image number 6 is determined to be the maximum value PV, and therefore the machined tool image of image number 6 can be determined to be the image to be observed as it matches the reference image most closely.

[0040] Once the number of observation images for the number n of blades has been determined, the imaging 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. Furthermore, the imaging control unit 48 transmits the number of observation images for the number n of blades to the tool wear measurement unit 68. Upon receiving the observation images, the tool wear measurement unit 68 performs image recognition on the observation images to evaluate the condition of the blades. Specifically, the tool wear measurement unit 68 checks for the presence or absence of damage to the blades 50 and measures the amount of tool wear to acquire this information. When the number n of blades of the tool 26 is two or more, the tool wear measurement unit 68 may measure only the observation image of one representative blade 50, or may measure all the observation images of all the blades 50. Upon completing the measurement, the tool wear measurement unit 68 transmits the measurement results to the storage unit 66. The transmitted tool wear measurement results are stored in the storage unit 66 in association with (paired with) the tool life index acquired by the tool life index measurement unit 64.

[0041] The effects of the tool life determination device 10 and tool life determination method according to this embodiment will be described below through an explanation of the flowchart of the tool life determination device 10 shown in FIG. 17 and an example of tool life determination using FIGS. 18 to 20.

[0042] As shown in the flowchart of Fig. 17, the tool life determination process starts in step S10. Next, proceeding to step S20, the machine tool main body MT starts machining using a certain tool 26. Once machining has started, proceed to step S30, and steps S20 and S30 are repeated until machining using that tool 26 is completed. During machining, the tool life index measurement unit 64 measures tool life indexes such as the number of machined workpieces, machining distance, machining time, and machining workload, which serve as tool life indexes, and stores the measured values ​​in the memory unit 66 in association with information on the tool 26 stored in the tool information memory unit 46b.

[0043] When machining is completed, the process proceeds to step S40, where the tool life determination device 10 activates the tool wear measurement device 11, captures an image of the cutting edge 50 of the tool 26 using the imaging device 40, and determines an observation image. The tool wear amount measurement unit 68 measures the amount of tool wear of the tool 26 based on the observation image (see FIGS. 10 to 16). The tool wear amount measurement unit 68 transmits the measured amount of tool wear to the storage unit 66. The storage unit 66 stores the received amount of tool wear in association with the tool life index.

[0044] Once the memory unit 66 has stored the pair of tool wear amount and tool life index, the process proceeds to step S50, and if there is a tool 26 for which the operator wishes to ascertain the wear state, the operator designates that tool 26 to the calculation unit 70 via the operation input unit 60. If no tool 26 is designated, the process proceeds to step S110, and the tool life determination process ends.

[0045] When the tool 26 is designated in step S50, the process proceeds to step S60, where the calculation unit 70 extracts a record that combines the amount of tool wear and the tool life index from the storage unit 66. Once the record is extracted, the process proceeds to step S70, where the calculation unit 70 creates a scatter diagram and a histogram from the pair of the amount of tool wear and the tool life index, and displays (draws) them on the display unit 72.

[0046] 18 and 19 show examples of a histogram and a scatter diagram created from a pair of tool wear amount and tool life index. In the histogram of FIG. 18, the horizontal axis shows tool wear amount, and the vertical axis shows the cumulative number of tool wear amount measurements obtained for the same type of tool 26. In the scatter diagram of FIG. 19, the horizontal axis shows tool wear amount, and the vertical axis shows machining distance, which is a tool life index for the same type of tool 26. These make it possible to visualize and understand the correlation between tool wear amount and tool life index. Note that in the example shown here, the scatter diagram and histogram are created based on a combination of machining distance and tool wear amount as tool life indexes, but are not limited to this. The number of machined workpieces, machining time, and machining workload, or a combination of these, may also be used as tool life indexes.

[0047] Once the scatter diagram and histogram are displayed on the display unit 72, the process proceeds to step S80. If the operator wishes to determine the tool life index threshold for the tool 26, the operator specifies a tool wear threshold for the calculation unit 70 via the operation input unit 60. Here, the operator can specify two types of tool wear thresholds. One is a warning-level tool wear threshold WT, which notifies the operator that the tool 26 is nearing the end of its tool life. The other is an alarm-level tool wear threshold AT, which notifies the operator that the tool 26 should be replaced immediately. If no tool wear threshold is specified, the process proceeds to step S110, and the tool life determination process ends. The tool wear threshold may be a recommended value listed in a tool manufacturer's catalog, or may be a value independently determined by the machine tool user. Instead of being input by the operator via the operation input unit 60, the tool wear threshold may be stored in advance in the tool information storage unit 46b, and the calculation unit 70 may automatically retrieve it from the tool information storage unit 46b when needed.

[0048] Once the tool wear threshold for the tool 26 is specified in step S80, the process proceeds to step S90, where the calculation unit 70 calculates a tool life index threshold. Specifically, once the warning level threshold and alarm level threshold are specified, the calculation unit 70 extracts the tool wear measurement value and corresponding machining distance immediately after the tool wear threshold is exceeded and the tool wear measurement value and corresponding machining distance immediately before the tool wear threshold is exceeded, and calculates the distribution of machining distances corresponding to the tool wear thresholds by linearly interpolating these extracted machining distances. Furthermore, the calculation unit 70 calculates the mean value and standard deviation of the calculated distribution and sets a value, for example, three times the standard deviation away from the mean value, as the tool life index threshold. Here, the calculation unit 70 calculates the warning level life index threshold WL corresponding to the warning level wear threshold WT and the alarm level life index threshold AL corresponding to the alarm level wear threshold AT as the tool life index thresholds. Note that, although the thresholds are calculated using the mean value and standard deviation here, this is not limiting and the thresholds may be calculated using other indices used in statistical analysis, such as the F value.

[0049] After the tool life index threshold is calculated, the process proceeds to step S100, where the display unit 72 displays the warning-level wear-amount threshold WT and the alarm-level wear-amount threshold AT in a histogram as shown in FIG. 18. Furthermore, the display unit 72 classifies (color-codes) the number of measurements displayed in the histogram into three cases: when the number exceeds the warning-level life index threshold WL, when the number exceeds the alarm-level life index threshold AL, and when there is no problem with the tool life ("OK" in the figure). The display unit 72 also displays the warning-level wear-amount threshold WT and the alarm-level wear-amount threshold AT in a scatter diagram as shown in FIG. 19, along with the warning-level life index threshold WL and the alarm-level life index threshold AL. Furthermore, the display unit 72 classifies and displays the data in the scatter diagram into three cases: when the number exceeds the warning-level life index threshold WL, when the number exceeds the alarm-level life index threshold AL, and when there is no problem with the tool life ("OK" in the figure). This allows the operator to directly confirm whether the calculation result of the tool life index threshold based on the relationship between the distribution of measured values ​​of tool wear and the tool wear threshold is valid.

[0050] Furthermore, the calculation unit 70 is configured to determine that the tool 26 is worn when the current value of the tool life index exceeds the tool wear amount threshold or when the current value of the tool life index exceeds the calculated tool life index threshold, and to transmit a spare tool replacement command to the display unit 72 to replace the worn tool 26 with a spare tool of the same type. In this way, the display unit 72 displays the warning level life index threshold WL and the alarm level life index threshold AL and, if necessary, notifies the operator of the spare tool replacement command, and then proceeds to step S110, whereupon the tool life determination process ends. Note that, when a machine tool is automatically operated without an operator, the spare tool replacement command may be sent directly from the calculation unit 70 to the machine tool control unit 62 to automatically replace the worn tool with a spare tool of the same type.

[0051] The calculation unit 70 can accumulate a database of tool life index thresholds by repeating the tool life determination process. The generated database is configured to be stored in the tool wear measurement unit 68. FIG. 20 shows an example of the accumulated database. Tool life index thresholds calculated from pairs of tool wear amounts and tool life indexes for each tool 26 information (here, program tool number PTN and function tool number FTN) stored in the storage unit 66 can be included. In the example shown in the figure, a warning-level life index threshold WL ("Warning threshold" in the figure) and an alarm-level life index threshold AL ("Alarm threshold" in the figure) corresponding to the warning-level wear amount threshold WT ("Warning threshold" in the figure) and the alarm-level wear amount threshold AT ("Alarm threshold" in the figure) are calculated for each tool life index threshold, such as cutting work volume, cutting distance, cutting time, and number of cut workpieces, and are recorded in the database. Therefore, by applying the database to other machine tools not equipped with the tool life determination device 10, the other machine tools can appropriately manage tool life by monitoring only the tool life indexes that can be obtained primitively. Here, each tool is assigned a program tool number PTN and a function tool number FTN, with the program tool number PTN assigned corresponding to the tool storage address number in the tool magazine, and the function tool number FTN assigned corresponding to the tool type and tool size. In this embodiment, the tool magazine can store 20 tools, and there are 20 types of program tool numbers PTN, but there are only a few types of function tool numbers FTN. For example, the function tool numbers FTN101 for tools PTN001 and PTN019 are the same, and FTN102 for tools PTN002 and PTN020. In other words, tools PTN019 and PTN020 are the same type and size as tools PTN001 and PTN002, respectively, and are spare tools that are replaced when tools PTN001 and PTN002 are determined to have reached the end of their tool life. This database is stored in the memory unit 66 and can be automatically displayed on the display unit 72 via the calculation unit 70, or can be displayed on the display unit 72 by the operator in response to an instruction from the operation input unit 60 when necessary, or can be downloaded for use on other machine tools.

[0052] (Variation) 21(a) and (b) show a tool magazine 100 according to another embodiment. The tool magazine 100 is a matrix-type tool magazine having a plurality of magazine racks 102 arranged in a magazine frame 106, and stores a plurality of tools 26 with their axes oriented horizontally. The tool magazine 100 has a tool carrier 110 that holds the tools 26 and moves in three orthogonal axes, the X-axis, Y-axis, and Z-axis, between a tool change position CH (a position where a tool rest 108 is located), a transfer position HP that is a predetermined position different from the tool change position CH, and a storage position for the plurality of tools 26 (a position where the tool storage notches 104 of the magazine rack 102 are located). The tools 26 are transferred from the tool carrier 110 to a transfer device 116, which then transports the tools 26 for tool wear measurement by the tool wear measurement device 11. Once the transport device 116 receives the tool to be measured for wear from the tool carrier 110, it does not interfere with the transport of the tool 26 associated with tool change for machining between the magazine rack 102 and the tool rest 108 of the tool carrier 110. Therefore, the tool 26 can be transported to the tool wear measuring device 11 and the amount of wear of the cutting edge 50 can be measured without interrupting machining of the machine tool main body MT.

[0053] When the tool 26 whose wear amount is to be measured is transported to the delivery position HP by the tool carrier 110, the gripper 112 attached to the gripper transport unit 114 is moved to the right in FIG. 21 along the left-right movement direction LM by a fluid pressure cylinder (not shown) to grip the flange portion of the tool holding unit 24 of the tool 26 held by the tool carrier 110. Once the gripper 112 has gripped the tool 26, the tool carrier 110 unclamps the tool 26 and moves back along the Z-axis, then moves away from the gripper transport unit 114 along the X-axis. The gripper 112 is moved downward along the up-down movement direction VM by the fluid pressure cylinder and stops in front of the transport device 116, which is waiting at a retracted position along the Z1-axis (a position approaching the magazine frame 106). The transport device 116 is movable in the Y1-axis and Z1-axis directions by a guide unit 118.

[0054] The conveying device 116 advances along the Z1-axis direction and holds the tapered shank portion 28a of the tool 26. Once the conveying device 116 holds the tool 26, the gripper conveying unit 114 moves in the left-right movement direction LM away from the conveying device 116 (toward the magazine frame 106). The conveying device 116 then descends along the Y1-axis direction to the positions of the first cleaning unit 36 ​​and the second cleaning unit 38, moves the tool 26 along the Z1-axis, and inserts the cutting portion 50 into the cleaning units 36 and 38. The tool 26 is then rotated along the C1-axis direction, and the first cleaning unit 36 ​​and the second cleaning unit 38 remove chips attached to the cutting portion 50 and clean and dry the cutting portion 50 using cleaning liquid WL and compressed air CA sprayed from the air nozzle 80. When cleaning of the blade portion 50 is complete, the conveying device 116 positions the blade portion 50 of the tool 26 along the Z1-axis direction, the Y1-axis direction, and the C1-axis direction to match the focal length of the imaging device 40, and the imaging device 40 captures an image of the blade portion 50. At this time, the cleaning units 36, 38 and the imaging device 40 are fixed to the magazine frame 106 by a bracket 120. When imaging is complete, the conveying device 116 rises along the Y1-axis direction to hand over the tool 26 to the gripper 112. The gripper 112 moves toward the conveying device 116 along the left-right movement direction LM to grip the tool 26. When the gripper 112 grips the tool 26, the conveying device 116 unclamps the tool 26 and moves (retracts) toward the magazine frame 106 along the Z1-axis direction, and the gripper 112, still holding the tool 26, rises along the up-down movement direction VM. The tool carrier 110 is on standby at the position where the gripper 112 has risen, and the tool carrier 110 advances toward the gripper 112 along the Z-axis, holding the tool 26, and stores the tool 26 in the tool storage notch 104 of the magazine rack 102 at the location where the tool 26 is located. As described above, the tool wear measuring device 11 disposed in the matrix-type tool magazine 100 can align the tool 26 and the imaging device 40 for capturing an image of the cutting portion 50 by using the transport device 116 which has only two linear axes (Y1 and Z1) and one rotational axis (C1) driven by servo motors. This makes it possible to automatically and quantitatively measure the wear of the cutting portion 50 of the tool 26 with a simple configuration without interrupting machining of the machine tool main body MT.In addition to the configuration described in this modified example, the matrix-type tool magazine may also be configured such that the tool carrier 110 moves only in the two axial directions of X and Y, and the gripper 112 operates by a fluid pressure cylinder in a direction parallel to the Z1 direction in addition to the LM and WM directions.Also, there is a configuration in which all the tools 26 are stored in tool storage notches 104 of the magazine rack 102 as tool pots, and the tool carrier 110 transports each tool together with the tool pot.

[0055] As described above, the tool wear measuring device 11 according to this embodiment, including the modified examples, includes an imaging device 40 having at least one of a bottom-side imaging unit 42 that images the bottom cutting edge of the tool 26 for which wear amount is to be measured and a side-side imaging unit 44 that images the side cutting edge, and a tool wear amount measuring unit 68 that processes the image captured by the imaging device 40 to determine the wear amount of the cutting edge 50 of the tool 26. The wear amount of the cutting edge 50 can be determined from the image of the cutting edge 50 of the tool 26. The tool wear measuring device 11 is disposed in a location other than the machining chamber near the tool magazine 30. The tool magazine 30, which stores multiple tools 26, is configured to position the tool 26 for which wear amount of the cutting edge 50 is to be measured at a predetermined position HP that is different from the transfer position CH where the tool is exchanged with the spindle. Therefore, the tool wear measuring device 11 can measure the wear amount of the cutting edge 50 of the tool 26 without interrupting machining of the machine tool MT.

[0056] Furthermore, the tool wear measuring device 11 also functions as a conveying device, having a tool conveying device 20 that moves the tool 26 in a direction perpendicular to the axis of the tool 26, a guide unit 32 that moves the tool 26 relatively in the axial direction of the tool 26, and a rotating unit 22 that rotates the tool 26 relatively around the axis of the tool 26 between the imaging device 40. This makes it possible to align the tool 26 and the imaging device 40 to capture images using only two linear axes and one rotational axis. This makes it possible to quantitatively measure the wear of the cutting portion 50 of the tool 26 with a simple configuration without interrupting machining of the machine tool main body MT.

[0057] Furthermore, in the tool wear measuring device 11 according to this embodiment, the imaging control unit 48 can operate the tool transport device 20 to transport the tool 26 in the horizontal direction D1, and can also operate the guide unit 32 to move the bracket 34, on which the first cleaning unit 36 ​​and the second cleaning unit 38 are arranged, relative to the tool 26 in the vertical direction D2. This allows the tool 26 to be transported to a first cleaning position WP1 inside the first cleaning unit 36, where it can be cleaned by the first cleaning unit 36. Furthermore, the tool 26 can be transported from the first cleaning unit 36 ​​to a second cleaning position WP2 inside the second cleaning unit 38, where the surface of the tool 26 cleaned by the first cleaning unit 36 ​​can be dried.

[0058] Furthermore, in the tool wear measuring device 11 according to this embodiment, the imaging control unit 48 can operate the tool transportation device 20 to transport the tool 26 from the second cleaning position WP2 to the first imaging position TP1 along the horizontal direction D1. The imaging control unit 48 can also operate the guide unit 32 to move the bracket 34 on which the imaging device 40 is disposed relative to the tool 26 along the vertical direction D2, thereby adjusting the focal length of the bottom-side imaging unit 42. The imaging control unit 48 can also operate the tool transportation device 20 to transport the tool 26 from the first imaging position TP1 to the second imaging position TP2 along the horizontal direction D1, and can also operate the guide unit 32 to move the bracket 34 on which the imaging device 40 is disposed relative to the tool 26 along the vertical direction D2. The imaging control unit 48 can also operate the tool transportation device 20 to move the tool 26 along the horizontal direction D1, thereby adjusting the focal length of the side-side imaging unit 44. According to the tool wear measuring device 11 of this embodiment, the tool 26 can be cleaned and imaged by moving the tool 26, the first cleaning unit 36, the second cleaning unit 38, and the image capturing device 40 relative to each other within the same plane along the horizontal direction D1 and the up-down direction D2. Therefore, the tool wear measuring device 11 can be simply configured with only two linear feed axes, and the wear of the cutting edge 50 of the tool 26 can be evaluated using an image of the tool 26 captured after cleaning.

[0059] Furthermore, with the tool wear measuring device 11 according to this embodiment, the calculation unit 70 can repeat the tool life determination process to accumulate a database of pairs of tool wear amounts and tool life thresholds, such as the cutting work amount, cutting distance, cutting time, and number of cut workpieces, for each tool 26, as well as tool life index thresholds calculated from these. Therefore, by applying the database to other machine tools that do not have the tool wear measuring device 11 installed, the other machine tools can perform appropriate tool life management by monitoring only the tool life indexes that can be obtained primitively.

[0060] As described above, compared to the configuration described in Patent Document 1 in which the amount of wear on the cutting edge is measured by accessing the tool while it is still stored in the tool magazine from an imaging device, the tool wear measuring device of the present invention does not interfere with the positioning operation of the tool magazine 30 to the tool changing position CH by simply transferring the tool to the tool transport device 20 from the tool magazine 30. Therefore, the tool wear measuring device 11 according to this embodiment can quantitatively measure the wear on the cutting edge 50 of the tool 26 with a simple configuration without interrupting machining of the machine tool main body MT.

[0061] Here, the tool wear measuring device 11 has been described as also functioning as a transport device that transports the tool 26 using the two linear axes of the tool transport device 20 and the guide unit 32 and the single rotational axis of the rotation unit 22, but this is not limiting, and the tool wear measuring device may also use an articulated robot having a hand that detachably holds the tool 26. By making full use of the rotational movements of the joints of this articulated robot, it is possible to perform the same operations as the two linear axes and one rotational axis of the tool transport device 20.

[0062] Furthermore, in this embodiment, the cleaning units 36, 38 and the imaging device 40 are arranged integrally, but it is also possible to arrange only the imaging unit inside or adjacent to the tool magazine room, and the cleaning unit in the machining chamber of the machine tool, and to spray machining fluid onto the tool while the tool is attached to the spindle to clean the tool.

[0063] Although the embodiment of the tool wear measuring device 11 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]

[0064] 11 Tool wear measuring device (transport device) 20 Tool transport device (first feed axis unit) 22 Rotating section (third feed shaft section) 26 Tools 30 Tool Magazine 32 Guide section (second feed shaft section) 36 First cleaning section (cleaning section) 38 Second cleaning section (cleaning section) 40 Imaging device (imaging unit) 42 bottom side imaging unit (first imaging element) 44 Side imaging unit (second imaging element) 50 Blade 66 Memory section 68 Tool wear measurement section 94 Chain 96 Gripper 100 Tool Magazine

Claims

1. A tool wear measuring device for a machine tool, which is arranged in a location other than a tool magazine room or a machining room near the tool magazine room and measures the amount of wear on a cutting edge of a tool, a tool magazine that stores a plurality of the tools and has a tool exchange position where the tools to be attached to the spindle are exchanged, and a tool carry-in / out position that is separate from the tool exchange position and that transfers the tools for measuring the amount of wear of the cutting edge portion; an imaging unit having at least one of a first imaging element for imaging a bottom cutting edge portion of the tool for measuring the wear amount and a second imaging element for imaging a side cutting edge portion; a conveyance device including a first feed shaft unit that holds the tool for measuring the amount of wear of the cutting edge portion and moves the tool between the tool loading / unloading position and the imaging unit in a direction perpendicular to the axis of the tool, a second feed shaft unit that moves the tool held by the first feed shaft unit in the axial direction of the tool relative to the imaging unit, and a third feed shaft unit that rotates the tool held by the first feed shaft unit around the axis of the tool relative to the imaging unit; a tool wear amount measuring unit that processes the image captured by the imaging unit and determines the amount of wear of the cutting edge of the tool; A tool wear measuring device for a machine tool, comprising:

2. 2. The tool wear measuring device for a machine tool according to claim 1, further comprising a memory unit that measures at least one of tool life indices, which are the number of workpieces cut, cutting distance, cutting time and cutting workload for each tool in the tool-use list when machining the workpiece, along with the machining program number of the workpiece to be machined, workpiece material, tool-use list and machining conditions, at the same time as the imaging unit images the cutting portion of the tool, and records the wear amount of the cutting portion of the tool and the measured tool life index as a database paired together.

3. 2. The tool wear measuring device for a machine tool according to claim 1, wherein the tool magazine is a matrix-type tool magazine that can be positioned at the tool change position or the tool loading / unloading position by using a tool carrier to hold the tools stored in a matrix-shaped magazine rack.

4. 2. The tool wear measuring device for a machine tool according to claim 1, wherein the tool magazine is a chain-type tool magazine in which the tools are stored in grippers attached to each link of a revolving endless chain.

5. 2. The tool wear measuring device for a machine tool according to claim 1, wherein the transport device having the first feed shaft unit, the second feed shaft unit, and the third feed shaft unit is composed of an articulated robot having a hand that holds the tool whose wear amount is to be measured.

6. 2. The tool wear measuring device for a machine tool according to claim 1, further comprising a cleaning unit for cleaning the tool, wherein the cleaning unit is disposed adjacent to the imaging unit, or is disposed inside the machining chamber so as to be cleanable immediately before the tool attached to the spindle is replaced.

Images