Diagnosis and predicton method for tool status in CNC machining

Abstract

The present invention provides a diagnosis and prediction method for a tool status in CNC machining, comprising: a vibration sensor for sensing tool vibration generated during CNC machining, and generating vibration data; a spindle vibration extraction unit that analyzes the vibration data so as to extract a spindle vibration value, which is the vibration magnitude of a frequency band corresponding to a spindle; a tool blade vibration extraction unit that analyzes the vibration data so as to extract a tool blade vibration value, which is the vibration magnitude of a frequency band corresponding to a tool blade; an other-frequency vibration extraction unit for extracting, from the vibration data, an other-frequency vibration value, which is the vibration magnitude of a frequency band that excludes the frequency bands corresponding to the spindle and the tool blade; a database for storing, as a vibration reference value, the tool blade vibration value generated when the tool blade is in a normal state; and a tool state determination unit that analyzes the spindle vibration value, the tool blade vibration value, the other-frequency vibration value, and the vibration reference value so as to determine the state of the tool blade.

Description

Tool condition diagnosis and prediction method in CNC machining

[0001] The present invention relates to a method for checking the condition of a CNC machining tool, and more specifically, to a method for diagnosing and predicting the condition of a CNC machining tool by comparing and analyzing the magnitude of vibration generated from a spindle and a tool blade from vibration data generated during machining to determine the condition of the tool.

[0002] In general, for milling machines that perform cutting operations using tools, in order to maintain the quality of the workpiece, the cutting tool is used a certain number of times and then replaced with a new tool even if it is not broken.

[0003] This means that if a tool breaks during cutting and the cutting process continues without being recognized, the quality of the workpiece will deteriorate, the workpiece material will be wasted, and various problems such as damage to the machine tool due to abnormal vibration will occur.

[0004] In addition, because of these problems, the above existing method of replacing cutting tools after a certain number of uses has the problem of wasting tools and lower efficiency than diagnosing and predicting the cutting tool condition and replacing it at the right time.

[0005] Therefore, in order to solve these problems, in the past, when an abnormal signal was generated from the sensor, the worker directly judged and replaced the tool, but it was difficult for the worker to accurately judge this point in time, and one breakage detection setting value had to be set for each unit machining process consisting of one tool, and there was a problem of false detection in response to momentary size changes unrelated to breakage occurring during machining.

[0006] Furthermore, if the operator arbitrarily inputs breakage detection settings based on reference data, reliability may be low, leading to problems such as recognizing a normal tool as broken or not properly recognizing a broken tool. Furthermore, since the magnitude of the vibration acceleration signal varies depending on the processing conditions and environment, the operator must manually set the detection area reference value based on reference data each time before processing, which is a repetitive task that reduces productivity and accessibility.

[0007] Korean Patent No. 10-2580409 is a method for detecting wear or breakage of a tool in real time by converting the vibration acceleration signal of a rotating tool for cutting work. The vibration acceleration signal of the tool is received, a fast Fourier transform is performed to derive a frequency signal, and if a frequency greater than a reference value is detected, an abnormality of the tool is determined. However, the standard is unclear and it is difficult to accurately determine the problem.

[0008] Japanese Patent No. 5543890 sets a threshold by adding a preset coefficient to the maximum value of a frequency analysis waveform, and determines that an abnormality has occurred during processing if the frequency analysis waveform generated during processing is larger than the preset threshold value. However, there is a problem in that it is difficult to accurately determine the condition of the tool simply by using only the threshold value.

[0009] The purpose of the present invention is to provide a tool condition diagnosis method that can analyze vibration data generated during processing by a tool blade in a CNC cutting processing equipment to check the condition of the tool blade, thereby enabling efficient use of the tool blade and minimizing damage to a workpiece.

[0010] The present invention may include a vibration data generation step for detecting vibration caused by a tool blade during CNC machining and generating vibration data, a spindle vibration extraction step for analyzing the vibration data to extract a spindle vibration value, which is a vibration magnitude in a frequency band corresponding to a spindle, a tool blade vibration extraction step for analyzing the vibration data to extract a tool blade vibration value, which is a vibration magnitude in a frequency band corresponding to a tool blade, an other-frequency vibration extraction step for extracting, from the vibration data, an other-frequency vibration value, which is a vibration magnitude in a frequency band excluding the frequency bands corresponding to the spindle and the tool blade, a vibration reference storage step for storing the tool blade vibration value that occurs when the tool blade is in a normal state as a vibration reference value, and a tool state judgment step for judging the state of the tool blade by analyzing the spindle vibration value, the tool blade vibration value, the other-frequency vibration value, and the vibration reference value.

[0011] The above tool condition judgment step is expected to have a confidence range of 95% or more between the vibration reference value and the tool blade vibration value, and if the following [Formula 1] is satisfied, the condition of the tool blade can be judged to be normal.

[0012] [Formula 1]

[0013] Frequency vibration value < Spindle vibration value < Tool blade vibration value

[0014] The above tool condition judgment step can determine that a part of the tool blade is worn out if the following [Formula 2] is satisfied.

[0015] [Formula 2]

[0016] Frequency vibration value < Spindle vibration value < Vibration reference value < Tool blade vibration value

[0017] The above tool condition judgment step can be used to determine that a part of the tool blade is worn and intermittent processing defects occur when the following [Formula 3] is satisfied.

[0018] [Formula 3]

[0019] (Dynamic reference value < other frequency vibration value) OR (Tool blade vibration value < other frequency vibration value)

[0020] If [Formula 4] and [Formula 5] are simultaneously satisfied, it can be determined that the tool blade is partially damaged and the processing is in an abnormal state.

[0021] [Formula 4]

[0022] Tool blade vibration value ≤ spindle vibration value

[0023] [Formula 5]

[0024] dev vibration standard value < dev(A) tool blade vibration value < dev(B) tool blade vibration value

[0025] (Here, dev vibration reference value: tool blade frequency band vibration magnitude fluctuation range calculated when the tool blade is normal and processing is normal, dev(A) tool blade vibration value: tool blade frequency band vibration magnitude fluctuation range calculated when a part of the tool blade is worn and processing is normal, dev(B) tool blade vibration value: tool blade frequency band vibration magnitude fluctuation range to be diagnosed)

[0026] If the following [Equation 6] and [Equation 7] are satisfied, it can be determined that the tool blade is broken.

[0027] [Formula 6]

[0028] (Other frequency vibration value AND tool blade vibration value) ≤ spindle vibration value

[0029] [Formula 7]

[0030] Det_n=Round(Tol / f_z), the number of consecutive tool breakage diagnoses exceeds Det_n.

[0031] (Here, Det_n: number of times tool defects are detected, Tol: tolerance, f_z: feed per tool blade, Round: rounded integer)

[0032] The present invention has the effect of accurately identifying the condition of a tool blade by comparing and analyzing the vibration size by frequency that occurs during processing.

[0033] Figure 1 is a flowchart of a method for diagnosing and predicting the status of a CNC machining tool according to an embodiment of the present invention.

[0034] Figure 2 is a drawing showing normal vibration data of a tool blade according to an embodiment of the present invention.

[0035] FIG. 3 is a diagram showing vibration data of a tool blade in an abnormal and poorly processed state according to an embodiment of the present invention.

[0036] Figure 4 is a block diagram of a CNC machining tool status diagnosis and prediction method according to an embodiment of the present invention;

[0037]

[0038] S10: Vibration data generation step S20: Spindle vibration extraction step

[0039] S30: Tool blade vibration extraction stage S40: Other frequency vibration extraction stage

[0040] S50: Vibration standard storage stage S60: Tool status judgment stage

[0041] 100: Vibration sensor 200: Spindle vibration extraction unit

[0042] 300: Tool blade vibration extraction unit 400: Other frequency vibration extraction unit

[0043] 500: Database 600: Tool status judgment unit

[0044] Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the attached drawings.

[0045] The advantages and features of the present invention and the method for achieving them will become clear with reference to the embodiments described in detail below together with the attached drawings.

[0046] However, the present invention is not limited to the embodiments disclosed below, but may be implemented in various different forms, and the present embodiments are provided only to make the disclosure of the present invention complete and to fully inform a person having ordinary skill in the art to which the present invention pertains of the scope of the invention, and the present invention is defined only by the scope of the claims.

[0047] In addition, when describing the present invention, if it is determined that related known technologies, etc. may obscure the gist of the present invention, a detailed description thereof will be omitted.

[0048] FIG. 1 is a flowchart of a method for diagnosing and predicting a CNC machining tool condition according to an embodiment of the present invention, FIG. 2 is a diagram showing vibration data of a normal tool blade according to an embodiment of the present invention, FIG. 3 is a diagram showing vibration data of a worn tool blade according to an embodiment of the present invention, and FIG. 4 is a block diagram of a method for diagnosing and predicting a CNC machining tool condition according to an embodiment of the present invention.

[0049] As illustrated in Fig. 1, the sequence of a method for diagnosing the status of a CNC machining tool may include a vibration data generation step (S10), a spindle vibration extraction step (S20), a tool blade vibration extraction step (S30), a different frequency vibration extraction step (S40), a vibration reference storage step (S50), and a tool status judgment step (S60).

[0050] The above vibration data generation step (S10) can generate vibration data by detecting tool vibration occurring during CNC machining using a vibration sensor (100).

[0051] The above vibration data may be a graph showing the magnitude of vibration detected at each frequency.

[0052] The above spindle vibration extraction step (S20) can analyze the vibration data to extract the spindle vibration value, which is the vibration magnitude of the frequency band corresponding to the spindle.

[0053] To explain in detail, since the vibration occurring in the spindle during processing appears at a specific frequency, i.e., in the spindle frequency band, the spindle vibration extraction step (S20) can extract the spindle vibration value, which is the vibration size corresponding to the spindle frequency band, from the vibration data.

[0054] The above tool blade vibration extraction step (S30) can analyze the vibration data to extract the tool blade vibration value, which is the vibration magnitude of the frequency band corresponding to the tool blade.

[0055] To explain in detail, since it appears in the tool blade frequency band, which is a specific frequency of vibration generated from the tool blade during processing, the tool blade vibration extraction step (S30) can extract the tool blade vibration value, which is the vibration magnitude corresponding to the tool blade frequency band, from the vibration data.

[0056] The above-mentioned off-frequency vibration extraction step (S40) can extract an off-frequency vibration value, which is a vibration magnitude of a frequency band excluding a frequency band corresponding to the spindle and the tool blade, from the vibration data.

[0057] That is, the above-mentioned frequency vibration extraction step (S40) can detect the vibration size that occurs when the tool processes the workpiece due to factors other than cutting by rotation of the tool blade due to severe wear of the tool blade and the vibration frequency of multiple parts such as the CNC equipment mechanism structure and case.

[0058] In cases where cutting is not caused by the rotation of the tool blade, the vibration size can be detected in relation to the chatter phenomenon, which is a phenomenon in which the tool body or tool blade vibrates when subjected to a large external force.

[0059] The above vibration standard storage step (S50) can store the tool blade vibration value that occurs when the tool blade is in a normal processing state as a vibration standard value.

[0060] To explain in detail, the vibration data detected by the detection sensor is a method of setting a reference value for judging an abnormal state of the tool blade, and the vibration data detected when the workpiece is normally processed and quality processing is in progress through the normal state tool blade can be set as the vibration reference value.

[0061] The above tool condition judgment step (S60) can determine the condition of the tool blade by analyzing the spindle vibration value, the tool blade vibration value, the other frequency vibration value, and the vibration reference value.

[0062] To explain in detail, it is possible to determine which vibration value is larger among the spindle vibration value, the tool blade vibration value, the other frequency vibration value, and the vibration reference value.

[0063] The above tool condition judgment step (S60) can determine that cutting is taking place when the spindle vibration value is greater than the other frequency vibration value and the tool blade vibration value is greater than the spindle vibration value.

[0064] In addition, if the tool blade vibration value is within the error range occurring at a 95% confidence level from the vibration reference value, it can be determined that the condition of the tool blade is normal and high-quality processing is in progress.

[0065] This is because when the tool blade is in a normal state, cutting is performed using only the tool blade when cutting the workpiece, so the vibration level can be the largest in the frequency band corresponding to the vibration generated from the tool blade.

[0066] Therefore, since only the tool blade is involved in cutting, the load on the spindle does not increase, and the CNC machining equipment only generates general vibrations, so it can have a vibration level lower than the tool blade vibration value.

[0067] The above tool condition judgment step (S60) can determine that wear of the tool blade is in progress when the spindle vibration value is greater than the other frequency vibration value, the tool blade vibration value is greater than the spindle vibration value, and the tool blade vibration value is greater than the vibration reference value.

[0068] This means that the vibration magnitude when the tool blade is in a worn state increases compared to when the tool blade is in a normal state, so the tool blade vibration value may have a value greater than the vibration reference value.

[0069] In the above tool condition judgment step (S60), if the other frequency vibration value is greater than the vibration reference value and the tool blade vibration value, it can be determined that the tool blade is considerably worn and the machining condition is poor.

[0070] This may occur in a mixed manner, where the tool blade is significantly worn and the tool blade performs normal cutting, and the tool blade performs abnormal cutting, resulting in the highest value among the above-mentioned non-frequency vibration values.

[0071] Therefore, the above-mentioned frequency vibration value may be greater than the vibration reference value of the tool blade and the tool blade vibration value when in a normal state or a partially worn state.

[0072] In the above tool condition judgment step (S60), if the spindle vibration value is greater than the tool blade vibration value and the vibration reference value is within the range of variation and wear of the tool blade has progressed to some extent, and the detected tool blade vibration value is greater than the range of variation of the tool blade vibration value, it can be determined that the tool blade is worn and the machining condition is poor.

[0073] This means that when the machining process continues while the tool blade is severely worn, the tool blade vibration value is not greater than the spindle vibration value, but the range of variation in the vibration size due to the unevenness of the tool blade condition occurs greatly.

[0074] Accordingly, when the tool blade is severely worn, the size and shape of the tool blade are seriously damaged, and even if the tool blade participates in the cutting process, the vibration magnitude of the tool blade vibration value varies greatly, so the range of variation of the tool blade vibration value when the tool blade is severely worn may be greater than the range of variation of the tool blade vibration value when the tool blade is in a normal state or when the wear state is slight.

[0075] The above tool condition judgment step (S60) can be used to determine that the tool is defective when the spindle vibration value is greater than the other frequency vibration value and the tool blade vibration value, abnormal cutting of the tool continuously occurs by considering the feed per tool blade, and the tool condition is outside the product's allowable tolerance range.

[0076] For example, if the allowable tolerance of the workpiece (Tol) = ±0.1, the spindle RPM (revolutions per minute) = 6000 RPM, and the feed per tool edge (f_z) = 0.05, if an abnormal number of tool edge processing operations is detected twice or more consecutively, it can be judged as a defective state.

[0077] As shown in Fig. 4, it may include a vibration sensor (100), a spindle vibration extraction unit (200), a tool blade vibration extraction unit (300), a frequency vibration extraction unit (400), a database (500), and a tool status determination unit (600).

[0078] The above vibration sensor (100) can be installed in a CNC machining device to detect vibrations generated during cutting processing and generate vibration data.

[0079] The above vibration data may be of various types, such as graphs or numbers indicating the magnitude of vibration detected at each frequency.

[0080] The above spindle vibration extraction unit (200) can extract the vibration size of the frequency band corresponding to the spindle from the vibration data generated through the vibration sensor (100).

[0081] To explain in detail, the frequency of vibration occurring in the spindle during processing appears at a specific frequency, that is, in the spindle frequency band, so the spindle vibration extraction unit (200) can extract the spindle vibration value, which is the vibration magnitude corresponding to the spindle frequency band, from the vibration data.

[0082] The tool blade vibration extraction unit (300) can extract the vibration size of the frequency band corresponding to the tool blade from the vibration data generated through the vibration sensor (100).

[0083] To explain in detail, the frequency of vibration generated from the tool blade during processing appears in a specific frequency, that is, a tool blade frequency band, so the tool blade vibration extraction unit (300) can extract a tool blade vibration value, which is a vibration magnitude corresponding to the tool blade frequency band, from the vibration data.

[0084] In addition, the tool blade frequency band changes depending on the number of tool blades, so the tool blade vibration extraction unit (300) can set the tool blade frequency band by inputting the number of tool blades to be used in advance.

[0085] The above-mentioned frequency vibration extraction unit (400) can extract the vibration magnitude of a frequency band excluding the spindle frequency band and the tool blade frequency band.

[0086] That is, the above-mentioned frequency vibration extraction unit (400) can detect the vibration size that occurs when the tool processes the workpiece due to factors other than cutting by rotation of the tool blade due to severe wear of the tool blade and the vibration frequency of multiple parts such as the CNC equipment case.

[0087] In cases where cutting is not caused by the rotation of the tool blade, the vibration size can be detected in relation to the chatter phenomenon, which is a phenomenon in which the tool body or tool blade vibrates when subjected to a large external force.

[0088] The above database (500) can store the tool blade vibration value that occurs when the tool blade is in a normal state as a vibration reference value.

[0089] To explain in detail, the method of setting a reference value for determining an abnormal state of a tool blade from the vibration data detected through the detection sensor can be such that the vibration data detected when a workpiece is processed through a normal tool blade and high-quality processing is in progress can be set as a vibration reference value.

[0090] The above tool condition judgment unit (600) can judge the condition of the tool blade by comparing and analyzing the spindle vibration value, the tool blade vibration value, the other frequency vibration value, and the vibration reference value.

[0091] To explain in detail, it is possible to determine which vibration value is larger among the spindle vibration value, the tool blade vibration value, the other frequency vibration value, and the vibration reference value.

[0092] The above tool condition judgment unit (600) can determine that the condition of the tool blade is normal and that high-quality processing is in progress when the following [Formula 1] is satisfied.

[0093] [Formula 1]

[0094] Frequency vibration value < Spindle vibration value < Tool blade vibration value = Vibration reference value z

[0095] Here, the vibration reference value z may fall within the error range occurring at a 95% confidence level from the vibration reference value.

[0096] That is, when looking at the vibration data detected under the CNC machining process conditions according to the embodiment of the present invention as illustrated in FIG. 2, the frequency generated when the tool blade cuts the workpiece (material or product) is 200 Hz, and the largest vibration size can occur in that frequency band.

[0097] This is because when the tool blade is in a normal state, cutting is performed using only the tool blade when cutting the workpiece, so the vibration level is the largest in the frequency band corresponding to the vibration generated from the tool blade.

[0098] Therefore, since only the tool blade is involved in cutting, the load on the spindle does not increase, and the CNC machining equipment only generates general vibrations, so it can have a vibration level lower than the tool blade vibration value.

[0099] And the above-mentioned frequency vibration value may be less than the size of the spindle vibration value generated from the above-mentioned spindle.

[0100] In addition, in order to determine the normal state of the tool blade, it is possible to determine whether the tool blade vibration value of the current cutting process is similar to the vibration reference value.

[0101] If the above tool blade vibration value differs from the above vibration standard value by a preset value or more, it can be determined that there is a change in the tool blade.

[0102] The above tool condition judgment unit (600) can determine that a part of the tool blade is worn but quality processing is in progress when the following [Formula 2] is satisfied.

[0103] [Formula 2]

[0104] Frequency vibration value < Spindle vibration value < Vibration reference value < Tool blade vibration value

[0105] To explain in detail, when looking at the vibration data above under CNC machining process conditions, the tool blade is worn more than in the normal state, but the frequency generated when cutting the workpiece is maintained at 200 Hz, and the vibration size in that frequency band can be the largest.

[0106] In addition, the vibration magnitude when the tool blade is in a worn state increases compared to when the tool blade is in a normal state, so the tool blade vibration value may have a value greater than the vibration reference value.

[0107] The above tool condition judgment unit (600) can determine that the tool blade is worn and a poor processing condition is occurring intermittently when the following [Formula 3] is satisfied.

[0108] [Formula 3]

[0109] (Vibration reference value < other frequency vibration value) OR tool blade vibration value < other frequency vibration value

[0110] In this state, the tool blade may be significantly worn and the tool blade performing normal cutting may have a large tool blade vibration value, and the tool blade performing abnormal cutting may have a large value among the above-mentioned other frequency vibration values.

[0111] To explain in detail, as shown in Fig. 3, when looking at the vibration data under CNC machining process conditions, the tool edge wear may become severe, and the tool may process the workpiece in the 700 Hz band due to factors other than cutting by rotation of the tool edge.

[0112] For example, the vibration size of other frequency bands may increase due to chatter, which is a phenomenon in which the tool body or tool blade vibrates when subjected to a large external force.

[0113] Accordingly, if the vibration reference value, which is the vibration size of the frequency corresponding to the tool blade, and the other frequency vibration value are greater than the tool blade vibration value, it can be determined that the tool blade has worn out significantly.

[0114] The above tool condition judgment unit (600) can determine that the tool blade is significantly worn and the processing condition is poor when [Formula 4] and [Formula 5] are simultaneously satisfied.

[0115] [Formula 4]

[0116] Tool blade vibration value ≤ spindle vibration value

[0117] [Formula 5]

[0118] dev vibration standard value < dev(A) tool blade vibration value < dev(B) tool blade vibration value

[0119] Here, the dev vibration reference value can represent the range of variation in which the vibration reference value changes when the tool blade is normal and quality processing is in progress.

[0120] The dev(A) tool blade vibration value can represent the range of variation in which the tool blade vibration value changes when machining is normal. It is the same as the range of variation of the reference vibration value.

[0121] The dev(B) tool blade vibration value can indicate the range of variation in which the tool blade vibration value changes when the tool blade is severely worn and processing is abnormal.

[0122] To explain in detail, if the machining process continues while the tool blade is severely worn, there may be cases where the tool blade vibration value is greater than the spindle vibration value, but there may also be cases where the variability of the tool blade vibration value increases.

[0123] For example, when the tool blade is severely worn, that is, when one of the two tool blades is broken and the other is in a normal tool condition, the frequency band of the tool blade and the frequency band of the spindle are the same, so the spindle vibration value corresponding to the spindle frequency band may have the largest value.

[0124] Or, if both tool blades are severely worn, the size and shape of the tool blade may be seriously damaged, so that even if the tool blade participates in the cutting process, the vibration magnitude of the tool blade vibration value may vary greatly.

[0125] Accordingly, the range of variation of the tool blade vibration value when the tool blade is in a serious state of wear may be greater than the range of variation of the tool blade vibration value when the tool blade is in a normal state or when the wear state is less.

[0126] The above tool status judgment unit (600) can determine that the tool is broken if [Formula 6] and [Formula 7] are simultaneously satisfied.

[0127] [Formula 6]

[0128] (Other frequency vibration value AND tool blade vibration value) < spindle vibration value

[0129] [Formula 7]

[0130] Det_n=Round(Tol / f_z), the number of consecutive tool breakage diagnoses exceeds Det_n.

[0131] Here, Det_n is the number of times tool defects are detected, Tol is the allowable tolerance, f_z is the feed per tool edge, and Round can be a rounded integer.

[0132] To elaborate, when abnormal cutting of the tool occurs continuously by considering the feed per tool blade and the product goes beyond the allowable tolerance range, the tool can be judged to be defective.

[0133] For example, if the allowable tolerance of the workpiece (Tol) = ±0.1, the spindle RPM (revolutions per minute) = 6000 RPM, and the feed per tool edge (f_z) = 0.05, if an abnormal number of tool edge processing operations is detected twice or more consecutively, it can be judged as a defective state.

[0134] In addition, if the tool is broken, cutting of the workpiece does not proceed, so the tool blade vibration value and the other frequency vibration value may be lower than the spindle vibration value.

[0135] While the present invention has been described with reference to the embodiments illustrated in the drawings, these are merely exemplary. Those skilled in the art will appreciate that various modifications may be made therefrom, and that all or part of the described embodiments may be selectively combined to form a configuration. Therefore, the true scope of technical protection of the present invention should be defined by the technical spirit of the appended claims.

[0136] The present invention relates to a CNC machining tool condition diagnosis and prediction method that determines the condition of the tool by comparing and analyzing the vibration magnitude generated from the spindle and the tool blade from vibration data generated during CNC machining, and has industrial applicability in that it enables the condition of the tool to be known and tool replacement to be performed at an early stage.

Claims

1. Vibration that detects tool vibration occurring during CNC machining and generates vibration data Data generation stage; A spindle vibration extraction step for analyzing the above vibration data to extract the spindle vibration value, which is the vibration size of a frequency band corresponding to the spindle; A tool blade vibration extraction step for analyzing the above vibration data and extracting the tool blade vibration value, which is the vibration magnitude of a frequency band corresponding to the tool blade; An off-frequency vibration extraction step for extracting an off-frequency vibration value, which is a vibration magnitude of a frequency band excluding a frequency band corresponding to a spindle and a tool edge, from the above vibration data; A vibration reference storage step for storing the tool blade vibration value that occurs when the tool blade is in a normal state as a vibration reference value; A CNC machining tool condition diagnosis and prediction method, comprising a tool condition judgment step of analyzing the spindle vibration value, the tool edge vibration value, the other frequency vibration value, and the vibration reference value to determine the condition of the tool edge.

2. In paragraph 1, The above tool status judgment step is, A CNC machining tool condition diagnosis and prediction method, which determines that the condition of the tool edge is normal when the confidence range of the above vibration reference value and the above tool edge vibration value is 95% or higher and satisfies the following [Formula 1]. [Formula 1] Frequency vibration value < Spindle vibration value < Tool blade vibration value 3. In paragraph 1, The above tool status judgment step is, A method for diagnosing and predicting the condition of a CNC machining tool, which determines that a part of the tool blade is worn when the following [Formula 2] is satisfied. [Formula 2] Frequency vibration value < Spindle vibration value < Vibration reference value < Tool blade vibration value 4. In paragraph 1, The above tool status judgment step is, A method for diagnosing and predicting the condition of a CNC machining tool, which determines that a part of the tool edge is worn and intermittent machining defects occur when the following [Formula 3] is satisfied. [Formula 3] (Vibration reference value < other frequency vibration value) OR (tool blade vibration value < other frequency vibration value) 5. In paragraph 4, A method for diagnosing and predicting the condition of a CNC machining tool, which determines that the tool edge is partially damaged and machining is abnormal when the following [Formula 4] and [Formula 5] are satisfied. [Formula 4] Tool blade vibration value ≤ spindle vibration value [Formula 5] dev vibration standard value < dev(A) tool blade vibration value < dev(B) tool blade vibration value (Here, dev vibration reference value: tool blade frequency band vibration size fluctuation range calculated when the tool blade is normal and processing is normal, dev(A) tool blade vibration value: tool blade frequency band vibration size fluctuation range calculated when processing by the tool blade is normal, dev(B) tool blade vibration value: current tool blade frequency band vibration size fluctuation range) 6. In paragraph 1, A method for diagnosing and predicting the condition of a CNC machining tool, which determines that the tool blade is broken when the following [Formula 6] and [Formula 7] are satisfied. [Formula 6] (Other frequency vibration value AND tool blade vibration value) ≤ spindle vibration value [Formula 7] Det_n=Round(Tol / f_z), the number of consecutive tool breakage diagnoses exceeds Det_n (Here, Det_n: the number of times to detect tool defects, Tol: tolerance, f_z: feed per tool edge, Round: rounded integer)

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