Cutting process monitoring system

Abstract

To provide a cutting work monitoring system which can detect the presence / absence of vibration generation of a tool blade tip during cutting in real time.SOLUTION: A cutting work monitoring system comprises: a camera 23 which consecutively images a tool blade tip of a lathe tool 21; a vibration transmission member 24 which connects the tool blade tip with the camera 23 directly or via another member and transmits the vibration of the tool blade tip to the camera 23; and an analysis unit which analyzes the vibration state of the lathe tool 21 on the basis of the chronological change of information reflected in each image captured by the camera 23.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a cutting process monitoring system used, for example, to prevent problems in cutting process and deterioration of processing quality. [Background technology]

[0002] In lathe processing, it is generally necessary to quickly detect wear or chipping of the tool cutting edge and take measures such as replacing the tool. For this reason, a method has been known in the past in which the tool cutting edge is photographed with a camera and the state of the cutting edge is examined from the image. For example, in Patent Document 1, the tool cutting edge is photographed with a camera in a standby state before and after cutting, and the amount of wear is determined from the binary image. In Patent Document 2, the tool cutting edge during cutting is captured with an infrared camera and the image is learned by a neural network to determine an abnormality. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 6-114694 [Patent Document 2] Japanese Patent Application Publication No. 11-267949 Summary of the Invention [Problem to be solved by the invention]

[0004] However, conventional methods have been unable to detect the occurrence of vibrations at the cutting edge of a tool during cutting. Specifically, it has been difficult to detect in real time, for example, vibrations caused by increased cutting resistance due to damage to the cutting edge of a tool, or chatter vibrations caused by inappropriate cutting conditions.

[0005] An object of the present invention is to provide a cutting process monitoring system capable of detecting in real time whether or not vibration is occurring at the tip of a tool during cutting. [Means for solving the problem]

[0006] One embodiment of the cutting process monitoring system of the present invention is During turning The turning tool includes a camera that continuously photographs the tool cutting edge, a vibration transmission member that connects the tool cutting edge to the camera directly or via another member and transmits the vibration of the tool cutting edge to the camera, and an analysis unit that analyzes the vibration state of the turning tool based on changes over time in the information captured in each image taken by the camera.

[0007] In the present invention, the cutting edge of the tool during turning is continuously photographed by a camera, i.e., in real time. In the present invention, "continuously photographing" refers to photographing at least 10 frames per second. The captured images are compared over time, and the magnitude and period of camera shake are stored based on changes in image information, and the results are used to determine abnormal vibration during cutting. They can also be used as an index for improving cutting conditions. In the present invention, "vibration" includes, for example, vibration caused by increased cutting resistance due to damage to the cutting edge of the tool, and chatter vibration caused by inappropriate cutting conditions.

[0008] According to the present invention, the vibration of the tool cutting edge is stably transmitted to the camera by the vibration transmission member, which allows the analysis unit to accurately analyze in real time whether or not vibration is occurring based on image information captured by the camera. As described above, according to the present invention, the occurrence or non-occurrence of vibrations at the cutting edge of a tool during cutting can be detected in real time.

[0009] In the above cutting process monitoring system, it is preferable that the vibration transmission member amplifies vibration of the cutting edge of the tool and transmits the amplified vibration to the camera.

[0010] In this case, even if the vibration of the tool cutting edge is small, the vibration is amplified by the vibration transmission member, so that the image information captured by the camera shows a stable change over time due to the vibration generation. Therefore, the presence or absence of vibration can be detected with higher accuracy. When the vibration transmission member has such an effect (function), it can be called a vibration amplification member.

[0011] In the cutting process monitoring system, the analysis section may analyze the presence or absence of vibration based on a change in a contour length of a cutting edge ridge shown in each of the images.

[0012] Images continuously captured by a camera during cutting include images in which the tool cutting edge is hidden by chips, and images in which the cutting edge is difficult to see due to a large amount of adhesion. Therefore, for example, from among a large number of images continuously captured, images in which the contour (edge ​​of the cutting edge) of the cutting edge is captured for a predetermined cutting edge length or more are classified as a predetermined pattern, and the presence or absence of vibration of the tool cutting edge can be analyzed more accurately by measuring the change over time in the contour length of the edge of the cutting edge of each image classified into the predetermined pattern. Specifically, for example, the edge of the cutting edge (edge) in the imaging field of view is detected by image processing such as a canny filter, and the presence or absence of vibration of the cutting edge can be detected by measuring the number of pixels of the edge of each image, that is, the change over time in the contour length of the edge of the cutting edge (such as the width or period of increase or decrease in the number of pixels).

[0013] In the cutting process monitoring system, the analysis section may analyze the presence or absence of vibration based on a change in position of a cutting edge line captured in each of the images.

[0014] In this case, the analysis unit measures the distance between one side of the outer frame (outer edge of the imaging field of view) of each image and the cutting edge ridge, for example, by image processing. By measuring the amount of change in position of the cutting edge ridge over time and its period, it is possible to analyze the presence or absence of vibration of the tool cutting edge by a simpler method.

[0015] In the cutting process monitoring system, the analysis section may analyze the presence or absence of vibration based on a change in position of a characteristic point of the tool tip captured in each of the images.

[0016] In this case, the analysis unit measures the change over time in the position of a feature point that constitutes part of the pattern on the rake face, for example, from each image information. This makes it possible to analyze the presence or absence of vibration of the tool cutting edge using a simple method. Note that by selecting as feature points parts that are less susceptible to the effects of chips and welding during cutting, that is, parts that are less likely to be hidden by chips and welding, the accuracy of the analysis can be improved more stably. Effect of the Invention

[0017] According to the cutting process monitoring system of one aspect of the present invention, the occurrence or absence of vibration of the cutting edge of the tool during cutting can be detected in real time. [Brief description of the drawings]

[0018] [Figure 1] FIG. 1 is a side view showing an example of a turning device according to a first embodiment. [Diagram 2] FIG. 2 is a functional block diagram illustrating an example of the cutting processing monitoring system according to the first embodiment. [Diagram 3] FIG. 3 shows an example of an image classified into the first pattern by the classification unit. [Figure 4] FIG. 4 shows an example of an image classified into the second pattern by the classification unit. [Diagram 5] FIG. 5 shows an example of an image classified into the third pattern by the classification unit. [Figure 6] FIG. 6 shows an example of analysis (image processing) of an image classified into the first pattern. [Figure 7] FIG. 7 is a flowchart showing an example of the process of the cutting work monitoring device according to the first embodiment. [Figure 8] FIG. 8 is an example of a graph showing a change over time in the position of the cutting edge line captured in each image acquired in the cutting process monitoring system of the second embodiment. [Figure 9] FIG. 9 is a flowchart showing an example of the process of the cutting monitoring device according to the second embodiment. [Figure 10]FIG. 10 is a functional block diagram showing a modified example of the cutting processing monitoring system according to the second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] First Embodiment A cutting process monitoring system 10 according to a first embodiment of the present invention will be described with reference to Fig. 1 to Fig. 7. The cutting process monitoring system 10 of the present embodiment includes a turning machine 20 and a cutting process monitoring device 30.

[0020] 1 and 2, the turning device 20 is a machine tool such as an NC lathe. The turning device 20 is a device that turns a workpiece W made of metal or the like. That is, the cutting process monitoring system 10 is used for turning (lathe processing) by a machine tool such as an NC lathe. Turning refers to cutting using a turning tool such as a cutting tool.

[0021] The turning device 20 includes a turning tool 21, a tool rest 22, a camera 23, a vibration transmission member 24, and a chuck (not shown). That is, the cutting process monitoring system 10 includes the camera 23 and the vibration transmission member 24.

[0022] 1, the turning tool 21 is, for example, an indexable cutting tool in which a cutting insert 26 is removably attached to the tip of a holder 25. That is, the turning tool 21 has a holder 25 and a cutting insert 26. However, the turning tool 21 is not limited to this configuration, and may be, for example, a solid-type cutting tool in which a tool tip is formed integrally with the holder.

[0023] The holder 25 is columnar and extends in one direction. In the example shown in Fig. 1, the direction in which the holder 25 extends is inclined at an angle θ with respect to a horizontal plane H. The angle θ is, for example, 30°. The rear end of the holder 25 is supported by the tool rest 22. The turning tool 21 and the tool rest 22 are fixed together.

[0024] The cutting insert 26 is made of, for example, a cemented carbide alloy, etc. The cutting insert 26 is, for example, a polygonal plate shape such as a quadrangular plate shape, a disk shape, etc. In this embodiment, the cutting insert 26 is, for example, a diamond-shaped plate shape. 3, the cutting insert 26 has a rake face 26a, a clearance face (not shown), and a cutting edge 26b disposed on a ridge between the rake face 26a and the clearance face. In this embodiment, at least a portion of the cutting insert 26, specifically, a portion including at least the rake face 26a and the cutting edge 26b, may be simply referred to as a "tool cutting edge" or a "cutting edge."

[0025] The rake face 26a is disposed on at least one of a pair of plate faces facing the plate thickness direction of the cutting insert 26. As shown in Fig. 1, the rake face 26a is disposed on one plate face facing upward, i.e., the upper face, of the cutting insert 26. In the example shown in Fig. 1, the rake face 26a is inclined with respect to the horizontal plane H at approximately the same angle as the angle θ at which the holder 25 is inclined with respect to the horizontal plane H.

[0026] As shown in Fig. 5, the rake face 26a of this embodiment has a characteristic point 26c. The characteristic point 26c constitutes a part of a pattern provided on the rake face 26a. The characteristic point 26c is provided on the rake face 26a for the purpose of, for example, smooth discharge processing of chips C, for the purpose of improving the external design, and for the purpose of improving distinguishability. In this embodiment, the characteristic point 26c is, for example, a protruding chip breaker.

[0027] 1, the cutting edge 26b is disposed at the tip of the turning tool 21. The cutting edge 26b is brought into contact with a workpiece W rotating around a central axis O, whereby the workpiece W is turned to form a machined surface Wa as shown in FIG.

[0028] In this embodiment, the cutting edge 26b is substantially V-shaped when the upper surface, i.e., the rake face 26a, of the cutting insert 26 is viewed from the front as shown in Fig. 3. Specifically, the cutting edge 26b has one corner edge extending in a curved line and a pair of straight edges connected to both ends of the corner edge and extending in a straight line.

[0029] 1, the tool rest 22 supports the turning tool 21. The tool rest 22 moves the turning tool 21 relative to the workpiece W at least in the direction in which the horizontal plane extends, i.e., along the surface direction of the horizontal plane. The tool rest 22 may also move the turning tool 21 relative to the workpiece W in the vertical direction.

[0030] The camera 23 is disposed above the turning tool 21 and the workpiece W. The camera 23 is, for example, a global shutter type camera. The camera 23 continuously captures the tool cutting edge. In this embodiment, "continuously captures images" refers to capturing images at least 10 frames per second. Specifically, in this embodiment, the camera 23 continuously captures the tool cutting edge at a speed of, for example, 30 frames per second or more. During cutting, the camera 23 captures the machined surface Wa of the workpiece W as well as the tool cutting edge.

[0031] In this embodiment, the camera 23 photographs the tool cutting edge from a direction perpendicular to the cutting face 26a. Specifically, the camera 23 photographs the tool cutting edge from a direction inclined at a predetermined angle with respect to the vertical direction. This predetermined angle is approximately the same as the angle (corresponding to angle θ) at which the cutting face 26a is inclined with respect to the horizontal plane H. The distance between the camera 23 and the tool cutting edge is, for example, 300 mm or more.

[0032] The camera 23 is fixed to the tool rest 22 via a vibration transmission member 24. Therefore, the camera 23 is movable following the movement of the tool rest 22. The camera 23 is positioned with respect to the turning tool 21 so that the tool tip is at the same position within the imaging field of view, as shown in, for example, Figures 3 to 5.

[0033] The vibration transmission member 24 connects the tool cutting edge of the turning tool 21 and the camera 23 directly or via another member. As shown in Fig. 1, in this embodiment, the vibration transmission member 24 indirectly connects the tool cutting edge and the camera 23 via a part of the turning tool 21 (holder 25) and the tool rest 22. The vibration transmission member 24 has a front end connected to the camera 23 and a rear end connected to the tool rest 22. The vibration transmission member 24 is a bent or curved arm-shaped member. The total length of the vibration transmission member 24 is, for example, 300 mm or more.

[0034] The vibration transmission member 24 transmits the vibration of the tool cutting edge directly or indirectly via another member to the camera 23. The vibration transmission member 24 amplifies the vibration of the tool cutting edge and transmits it to the camera 23. For this reason, in this embodiment, the vibration transmission member 24 may be referred to as a vibration amplifying member 24. In this embodiment, the term "vibration" includes, for example, vibration caused by increased cutting resistance due to damage to the tool tip, chatter vibration caused by inappropriate cutting conditions, and the like.

[0035] The vibration transmission member 24 has at least two shaft portions 24a, at least one joint portion 24b connecting the ends of adjacent shaft portions 24a, and a fixed base 24c that fixes the rear end portion of the vibration transmission member 24 and the tool holder 22.

[0036] The shaft portion 24a is, for example, a shaft or a pipe. The joint 24b can be switched between a lock mode in which the ends of the shaft 24a are fixed so as not to rotate and a free mode in which the ends of the shaft 24a are connected so as to be rotatable, by operating a knob (not shown) or the like. The provision of the joint 24b allows the vibration transmission member 24 to be deformed. By changing the shape of the vibration transmission member 24, the position of the camera 23 can be adjusted so as to face the tool cutting edge. During cutting, the joint 24b is in the lock mode.

[0037] The fixed base 24c fixes the vibration transmission member 24 to the tool rest 22 by, for example, magnetic force. Therefore, the mounting position of the vibration transmission member 24 can be adjusted with respect to the tool rest 22. That is, in this embodiment, the position of the camera 23 can be adjusted so as to directly face the tool tip by adjusting the mounting position of the fixed base 24c to the tool rest 22.

[0038] Although not specifically shown, the chuck detachably holds the workpiece W. The chuck rotates the workpiece W about its central axis O.

[0039] Although not shown, the turning device 20 may be provided with a backlight for emphasizing the contours of the cutting edge 26b and the machining surface Wa, and a front light for illuminating the rake face 26a. This allows the shutter speed of the camera 23 to be increased.

[0040] 2, the cutting process monitoring device 30 includes an image acquisition unit 31, a storage unit 32, a classification unit 33, an analysis unit 34, and a display unit 35. That is, the cutting process monitoring system 10 includes the classification unit 33 and the analysis unit 34.

[0041] The image acquiring unit 31 acquires the image captured by the camera 23, that is, image data. The image acquiring unit 31 stores the acquired image information in the storage unit 32. Note that the cutting process monitoring device 30 may store the acquired image information in the storage unit 32 in association with, for example, a tool ID, a device ID, a user ID, or the like.

[0042] The storage unit 32 stores various information used by the cutting process monitoring device 30. The storage unit 32 stores acquired image information. The storage unit 32 stores, for example, teacher data and learning results of deep learning used by the classification unit 33 to classify images.

[0043] The classification unit 33 performs image classification by deep learning, for example, based on the learning results stored in the storage unit 32. That is, the classification unit 33 classifies a plurality of images captured by the camera 23 into one of a plurality of patterns based on information captured in each image. In this embodiment, the plurality of patterns includes a first pattern (cutting edge line), a second pattern (welding), and a third pattern (machined surface of the workpiece).

[0044] Specifically, the classification unit 33 classifies an image in which the cutting edge ridge of the cutting edge 26b having a predetermined cutting edge length or more is captured within the imaging field of view into a first pattern among a plurality of patterns, as shown in Fig. 3. In the example shown in Fig. 3, the cutting edge 26b is not in contact with the workpiece W, and the entire cutting edge ridge is clearly captured within the imaging field of view.

[0045] The classification unit 33 classifies an image in which the welded TA is reflected on the tool cutting edge into a second pattern among the multiple patterns, as shown in Fig. 4. In the example shown in Fig. 4, at least a part of the rake face 26a and at least a part of the cutting edge 26b are hidden by the welded TA attached to the tool cutting edge.

[0046] Further, the classification unit 33 classifies the image showing the machined surface Wa of the workpiece W into a third pattern among the multiple patterns, as shown in Fig. 5. In the example shown in Fig. 5, the surface and contour of the machined surface Wa immediately after being cut by the cutting blade 26b are clearly shown. 3 to 5 are images of the cutting edge of a tool taken when a plate-shaped workpiece W was being turned as shown in Fig. 1. The material of the workpiece W was stainless steel, the rotation speed of the workpiece W was 100 revolutions per minute, and the cutting was performed in a dry environment.

[0047] The classification of images by the classification unit 33 is performed, for example, by the following method. First, in a test cutting process performed before the main cutting process of the workpiece W, a plurality of images are taken by the camera 23. The plurality of images thus obtained are classified and stored (teacher data) into a first pattern (cutting edge ridge) in which the cutting edge 26b is not in contact with the workpiece W and the cutting edge ridge is clearly visible, a second pattern (welding) in which the cutting edge 26b is not in contact with the workpiece W but the welded TA is on the rake face 26a, and a third pattern (machined surface of the workpiece) capturing the moment when the cutting edge 26b comes into contact with the workpiece W, and this classification method is learned by deep learning. That is, machine learning is performed to estimate the classification of the first to third patterns based on the teacher data in the memory unit 32, and the learning result is fed back to the memory unit 32, thereby improving the judgment accuracy of the image classification. It should be noted that this classification is merely an example, and the appropriate classification method varies depending on the cutting conditions, the type and shape of the workpiece W, etc. Furthermore, automatic image recognition software such as HALCON (manufactured by Links Corporation) can be used for the classification (sorting) of the image data described above.

[0048] The analysis unit 34 analyzes the vibration state of the turning tool 21 based on the change over time of the information captured in each image captured by the camera 23. In this embodiment, the analysis unit 34 analyzes the vibration state of the tool cutting edge from the change over time of each piece of image information classified into a first pattern (predetermined pattern) among a plurality of patterns. As the analysis unit 34, for example, an image processing program or the like can be used.

[0049] Specifically, the analysis unit 34 analyzes whether or not vibration occurs based on the change in the contour length of the cutting edge ridgeline captured in each image classified into the first pattern. More specifically, when vibration occurs in the turning tool 21, the positions of the cutting edge 26b captured in each image change relative to each other, and accordingly, the cutting edge length, i.e., the contour length, of the cutting edge ridgeline included in the imaging field of each image also changes, and this phenomenon is utilized to perform the analysis.

[0050] Fig. 6 shows an example of image processing of the cutting edge ridge of the cutting edge 26b by the analysis unit 34. As shown in Fig. 6, in this embodiment, the analysis unit 34 detects the cutting edge ridge (edge) of the cutting edge 26b within the imaging field of view by image processing such as a canny filter, and measures the number of pixels of the edge of each image, that is, the change over time in the contour length of the cutting edge ridge (such as the width and period of increase and decrease in the number of pixels), thereby analyzing the presence or absence of vibration of the cutting edge. In this way, the analysis unit 34 analyzes the vibration state of the turning tool 21. Note that the above analysis is an example, and other analysis methods may be used to analyze the first pattern.

[0051] The analysis unit 34 also analyzes each image classified into the second pattern. The analysis unit 34 also analyzes each image classified into the third pattern. The analysis contents of the second and third patterns will not be described.

[0052] The display unit 35 displays various types of information of the cutting process monitoring system 10. For example, the display unit 35 displays the analysis results of the above-mentioned analysis unit 34.

[0053] FIG. 7 is a flowchart showing an example of the process of the cutting process monitoring device 30. As shown in FIG. 7, first, the image acquisition unit 31 acquires image information output from the camera 23 (step S1). Next, the classification unit 33 classifies each image into a first to third pattern based on the learning result stored in the storage unit 32 (step S2). That is, the classification unit 33 classifies each image into one of the first to third patterns by comparing the acquired image information with the learning result.

[0054] Next, the analysis unit 34 analyzes whether or not vibration occurs at the tool cutting edge based on the change over time of the information captured in each image classified into the first pattern (predetermined pattern) (step S3). That is, the analysis unit 34 performs the above-mentioned analysis using image processing based on the image information classified into the first pattern (cutting edge ridge) and its change over time. Next, the display unit 35 displays the analysis results output from the analysis unit 34 (step S4). After the process of step S4, the cutting process monitoring device 30 ends the process of the above example.

[0055] In the cutting process monitoring system 10 of the present embodiment described above, the cutting edge of the tool during turning is continuously photographed by the camera 23, i.e., in real time. Then, the acquired multiple images are compared over time, and the magnitude and period of the camera 23 shaking are stored based on changes in the image information, and the results are used to determine whether vibration during cutting is abnormal. They can also be used as an index for improving cutting conditions.

[0056] According to this embodiment, the vibration of the tool cutting edge is stably transmitted to the camera 23 by the vibration transmission member 24. Therefore, the analysis unit 34 can accurately analyze in real time whether or not vibration is occurring, based on the image information captured by the camera 23. As described above, according to this embodiment, the occurrence or non-occurrence of vibration at the cutting edge of the tool during cutting can be detected in real time.

[0057] In this embodiment, the vibration transmission member (vibration amplifying member) 24 amplifies the vibration of the tool cutting edge and transmits it to the camera 23. In this case, even if the vibration of the tool cutting edge is small, the vibration is amplified through the vibration transmission member 24, and the change over time due to the occurrence of vibration appears stably in the image information captured by the camera 23. Therefore, the occurrence of vibration can be detected with higher accuracy.

[0058] In this embodiment, the analysis unit 34 analyzes the presence or absence of vibration based on the change over time in the contour length of the cutting edge ridgeline captured in each image. Specifically, the analysis unit 34 performs the above analysis using each image classified by the classification unit 33 into the first pattern (predetermined pattern). The images continuously captured by the camera 23 during cutting include images in which the tool cutting edge is hidden by chips C, images in which a large amount of welded TA has adhered and the cutting edge is difficult to see, etc. Therefore, for example, from among the many continuously captured images, images in which the outline (edge ​​line) of the cutting edge 26b is captured for a predetermined cutting length or more are classified as a predetermined pattern, and the change over time in the outline length of the edge line of each image classified into a predetermined pattern is measured, thereby making it possible to more accurately analyze whether or not vibration is occurring at the tool cutting edge.

[0059] Furthermore, in this embodiment, the classification unit 33 performs image classification using deep learning. In this case, the accuracy of classification judgment by the classification unit 33 is stably improved by deep learning.

[0060] In this embodiment, the camera 23 captures an image of the tool cutting edge from a direction perpendicular to the rake face 26a, that is, from a direction directly facing the rake face 26a. In this case, the camera 23 can be easily focused on the cutting edge of the tool, and the above-described advantageous effects of this embodiment can be obtained more stably.

[0061] In this embodiment, the distance between the camera 23 and the tool tip is 300 mm or more. If the distance is 300 mm or more, for example, when replacing the cutting insert 26 with a new one or when indexing the cutting edge 26b (changing the corner used), that is, when replacing the cutting edge, the camera 23 is unlikely to get in the way of the work. Also, even if the chips C extend or scatter during cutting, they are unlikely to come into contact with the camera 23, so that effective images can be stably acquired.

[0062] In this embodiment, the overall length of the vibration transmitting member 24 is 300 mm or more. If the total length is 300 mm or more, the vibration of the tool cutting edge is suitably amplified and easily transmitted to the camera 23 in a stable manner.

[0063] In this embodiment, the vibration transmitting member 24 is deformable. In this case, the position of the camera 23 can be adjusted so as to face the tool cutting edge by changing the shape of the vibration transmission member 24. Therefore, even if the tool shape or type of the turning tool 21 or the shape of the workpiece W is changed, the tool cutting edge can be accurately photographed by the camera 23 with a simple adjustment.

[0064] In this embodiment, the vibration transmission member 24 is fixed to the tool rest 22 by magnetic force or the like so that the mounting position thereof can be adjusted. In this case, the position of the camera 23 can be adjusted so as to face the tool cutting edge by appropriately changing the mounting position of the vibration transmission member 24 on the tool rest 22. Therefore, even if the tool shape or type of the turning tool 21 or the shape of the workpiece W is changed, the tool cutting edge can be accurately photographed by the camera 23 with a simple adjustment.

[0065] <Second embodiment> Next, a cutting process monitoring system 40 according to a second embodiment of the present invention will be described with reference to Figures 2, 3, 5, and 8 to 10. In this embodiment, the same components as those in the above-mentioned embodiment are denoted by the same reference numerals, and the description thereof may be omitted.

[0066] In FIG. 2, a cutting process monitoring system 40 of this embodiment differs from the above-described embodiment at least in the analysis content of the analysis unit . In this embodiment, the analysis unit 34 analyzes the vibration state of the turning tool 21 based on changes over time in information captured in each image, not only for images classified into a predetermined pattern by the classification unit 33, but for all images captured by the camera 23. For this reason, in this embodiment, the cutting process monitoring device 30 does not need to be equipped with the classification unit 33, as in a modified example of the cutting process monitoring system 40 shown in FIG.

[0067] Specifically, in this embodiment, the analysis unit 34 analyzes whether or not vibration is occurring based on a change in the position of the ridgeline of the cutting edge 26b captured in each image. As shown in FIG. 3, the analysis unit 34 measures, for example by image processing, the distance D between one side V of the outer frame (outer edge of the imaging field of view) of each image and the cutting edge of the cutting edge 26b as the number of pixels.

[0068] The graph in Fig. 8 shows the change over time in the distance D obtained from each image. In Fig. 8, the range of increase and decrease in the vertical axis (distance D pixel count) becomes larger than the vicinity of the symbol P on the horizontal axis (cutting time). In other words, it can be estimated that vibration occurred in the turning tool 21 from the point P in the cutting time.

[0069] 5, the analysis unit 34 may analyze the presence or absence of vibration based on the change in the position of the feature point 26c of the tool cutting edge shown in each image. The analysis method based on the change in the position of the feature point 26c over time may be performed in the same manner as the analysis method based on the change in the position of the cutting edge ridge over time described above.

[0070] FIG. 9 is a flowchart showing an example of the process of the cutting process monitoring device 30 of this embodiment. As shown in FIG. 9, first, the image acquisition unit 31 acquires image information output from the camera 23 (step S11). Next, the analysis unit 34 analyzes whether or not vibration occurs at the cutting edge of the tool based on the change over time of the information captured in each acquired image (all images) (step S12). That is, the analysis unit 34 performs the above-mentioned analysis based on each image information and its change over time using image processing. Next, the display unit 35 displays the analysis result output from the analysis unit 34 (step S13). After the process of step S13, the cutting process monitoring device 30 ends the process of the above example.

[0071] According to the cutting process monitoring system 40 of this embodiment described above, the same effects as those of the previously described embodiment can be obtained.

[0072] Furthermore, in this embodiment, the analysis unit 34 analyzes the presence or absence of vibration based on a change over time in the position of the cutting edge ridgeline captured in each image. In this case, by measuring the amount of change in position of the cutting edge ridge over time and the period of change, it is possible to analyze the presence or absence of vibration of the tool cutting edge using a simpler method.

[0073] In this embodiment, the analysis unit 34 may analyze the presence or absence of vibration based on a change over time in the position of the feature point 26c of the tool cutting edge captured in each image. In this case, too, the presence or absence of vibration at the cutting edge of the tool can be analyzed by a simple method. The accuracy of the analysis can be improved more stably by selecting, as the characteristic point 26c, a portion that is less susceptible to the effects of chips C and adhesion TA during cutting, that is, a portion that is less likely to be hidden by chips C and adhesion TA.

[0074] The present invention is not limited to the above-described embodiment, and the configuration may be modified within the scope of the present invention, for example as described below.

[0075] In the above embodiment, the vibration transmission member 24 is switchable between the lock mode and the free mode, i.e., is deformable, but this is not limiting. The vibration transmission member 24 may be configured to be non-deformable. In addition, as long as it is sufficient to stably transmit the blade vibration to the camera 23, the shape of the vibration transmission member 24 is not limited to an arm shape. Furthermore, the vibration transmission member 24 may be fixed to, for example, a holder 25 or the like instead of the tool rest 22 .

[0076] In addition, the configurations described in the above embodiments and modifications may be combined without departing from the spirit of the present invention, and addition, omission, substitution, and other modifications of the configurations are possible. The present invention is not limited to the above embodiments, but is limited only by the claims. [Industrial Applicability]

[0077] According to the cutting process monitoring system of the present invention, the occurrence or absence of vibration of the cutting edge of a tool during cutting can be detected in real time, and therefore the system has industrial applicability. [Explanation of symbols]

[0078] 10, 40... Cutting processing monitoring system, 21... Turning tool, 23... Camera, 24... Vibration transmission member (vibration amplification member), 26c... Feature point, 34... Analysis unit

Claims

1. A camera that continuously captures the cutting edge of a turning tool during turning; a vibration transmission member that connects the tool blade tip and the camera directly or via another member and transmits vibration of the tool blade tip to the camera; and an analysis unit that analyzes a vibration state of the turning tool based on a change over time in information captured in each image captured by the camera. Cutting process monitoring system.

2. The vibration transmission member amplifies the vibration of the tool tip and transmits the amplified vibration to the camera. The cutting process monitoring system according to claim 1 .

3. The analysis unit analyzes whether or not vibration is occurring based on a change in a contour length of a cutting edge ridge line shown in each of the images.

3. The cutting processing monitoring system according to claim 1 or 2.

4. The analysis unit analyzes whether or not vibration occurs based on a change in the position of the cutting edge ridge line shown in each of the images. The cutting process monitoring system according to any one of claims 1 to 3.

5. The analysis unit analyzes whether or not vibration is generated based on a change in a position of a feature point of the tool tip captured in each of the images. The cutting process monitoring system according to any one of claims 1 to 4.

Images