A tool wear detection method and device for an ultrasonic machining system

Abstract

The application discloses a tool wear detection method and device of an ultrasonic machining system. The tool wear detection method comprises the following steps: setting a tool breakage early warning coefficient and a calibration sampling number; acquiring the change of the resonance frequency of an ultrasonic tool holder in real time during the ultrasonic machining process of the ultrasonic tool holder; when the number of ultrasonic machining of the ultrasonic tool holder is greater than or equal to the calibration sampling number, calculating the tool wear rate of the ultrasonic tool holder according to the change of the resonance frequency of the ultrasonic tool holder and the tool breakage early warning coefficient; and when the tool wear rate of the ultrasonic tool holder is greater than a preset value, outputting a tool breakage early warning signal. The application can early warn the tool wear during the machining process, and avoid the damage of workpieces or machine tool equipment caused by excessive cutting force.

Description

Technical Field

[0001] This invention relates to the field of ultrasonic machining technology, and in particular to a method and apparatus for detecting tool damage in an ultrasonic machining system. Background Technology

[0002] Ultrasonic-assisted machining technology has been applied to the processing of glass, ceramics, composite materials, titanium alloys, and high-temperature alloys. These materials are widely used in high-end industries such as aerospace, biomedicine, precision optical components, and advanced semiconductors. They possess excellent properties such as high specific strength, high hardness, high temperature resistance, corrosion resistance, and wear resistance. However, these excellent properties at the application level also make these materials typical difficult-to-machine materials, often resulting in severe tool wear problems during processing.

[0003] Milling cutters, drill bits, grinding heads, and other machining tools are among the main consumables in the machining process. Their wear directly affects machining costs, and the time spent changing tools during machining also indirectly affects machining costs. If tools suffer severe wear or breakage during machining but are not replaced in time, it may lead to workpiece scrap, damage to the tool holder or machine tool, or even personal injury. Due to factors such as the consistency of tool materials, the precision of the tool itself, and the precision of installation and use, the machining life of tools from different batches, and even within the same batch, can vary significantly. Therefore, in mass production of parts, a relatively conservative tool life control scheme is often required. As a result, many tools are replaced before showing significant wear, while some tools with significantly shorter than average lifespans suffer serious damage before reaching their set service life, leading to machining accidents.

[0004] The above background information is provided only to aid in understanding the concept and technical solution of this invention. It does not necessarily belong to the prior art of this patent application. In the absence of clear evidence that the above information was disclosed on the filing date of this patent application, the above background information should not be used to evaluate the novelty and inventiveness of this application. Summary of the Invention

[0005] To address the aforementioned technical problems, this invention proposes a tool wear detection method and device for an ultrasonic machining system, which can provide early warning of tool wear during machining, thereby preventing workpiece damage or machine tool damage caused by excessive cutting force.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] In a first aspect, the present invention discloses a tool damage detection method for an ultrasonic machining system, comprising: setting a tool breakage warning coefficient and a calibration sampling number; acquiring the change in the resonant frequency of the ultrasonic tool holder in real time during ultrasonic machining in the ultrasonic machining system; when the number of ultrasonic machining operations performed by the ultrasonic tool holder is greater than or equal to the calibration sampling number; calculating the tool damage rate of the ultrasonic tool holder based on the change in the resonant frequency of the ultrasonic tool holder and the tool breakage warning coefficient; and outputting a tool breakage warning signal when the tool damage rate of the ultrasonic tool holder is greater than a preset value.

[0008] Preferably, after the ultrasonic tool holder's tool wear rate is less than or equal to a preset value and / or a tool breakage warning signal is output, the method further includes: when the ultrasonic tool holder's resonant frequency increment in the current ultrasonic processing process is less than the average of the resonant frequency increments in the previous N ultrasonic processing processes, outputting a tool breakage alarm signal and ending the ultrasonic processing, where N is the specified number of sampling times.

[0009] Preferably, the procedure specifically includes the following steps:

[0010] S1: Set the total number of ultrasonic treatments n Broken blade warning coefficient k And calibrate the number of samplings N, and set i =1;

[0011] S2: Send an ultrasonic machining preparation signal to the ultrasonic drive controller that controls the ultrasonic tool holder, and acquire the ultrasonic tool holder to perform the first... i The no-load resonant frequency before the ultrasonic processing;

[0012] S3: Send an ultrasonic machining signal to the ultrasonic drive controller that controls the ultrasonic tool holder, so that the ultrasonic tool holder begins the first ultrasonic machining operation. i Second ultrasonic processing, and obtain the first i The maximum resonant frequency during ultrasonic processing;

[0013] S4: Combine the ultrasonic scalpel handle obtained in step S2 to perform the first... i The no-load resonant frequency before the second ultrasonic processing and the first obtained in step S3 i The maximum resonant frequency during the ultrasonic processing is calculated. i The resonant frequency increment during the ultrasonic processing;

[0014] S5: Judgment i Is it less than N? If so, then let i = i +1 and return to step S2; otherwise, proceed to step S6.

[0015] S6: Calculate the average value of the resonant frequency increments of the first N ultrasonic machining operations, and based on the average value of the resonant frequency increments of the first N ultrasonic machining operations and the tool breakage warning coefficient... k and the i Calculate tool wear rate from the resonant frequency increment during ultrasonic machining;

[0016] S7: Determine if the tool loss rate is greater than 1. If yes, output a tool breakage warning signal; otherwise, proceed to step S8.

[0017] S8: Determine the first i If the resonant frequency increment during the ultrasonic processing is less than the average value of the resonant frequency increments of the previous N ultrasonic processing operations, then output a tool breakage alarm signal and stop the operation of the ultrasonic tool holder; otherwise, proceed to step S9.

[0018] S9: Judgment i Is it less than If so, then let i = i +1, and return to step S2; otherwise, stop running the ultrasonic scalpel handle.

[0019] Preferably, setting the number of calibration samplings N in step S1 specifically includes the following steps:

[0020] S11: Perform calibration steps including Y ultrasonic machining cycles until the tool breaks, and obtain the total number of ultrasonic machining cycles X at each time the tool breaks. y ,in y The values ​​are 1, 2, ..., Y;

[0021] S12: Calculate the number of calibration samplings N in each calibration step during ultrasonic machining until the tool breaks. y : This yields an array of calibration sampling counts for each calibration step during ultrasonic machining until the tool breaks. : The calibration sampling number N is set to a value of... The minimum integer value obtained by rounding down the value in the range.

[0022] Preferably, in step S1, a tool breakage warning coefficient is set. k Specifically, the following steps are included:

[0023] S13: Obtain the resonant frequency increment at each tool breakage. This yields an array of resonant frequency increments for each time the blade breaks. for: ;

[0024] S14: Calculate the... y The average value of the resonant frequency increment during the calibration step of ultrasonic machining until the tool breaks. for: This yields an array of the average resonant frequency increments during each calibration step of ultrasonic processing until the tool breaks. for: ,in, They represent the first y During the calibration process of ultrasonic machining until the tool breaks, step 1,… The resonant frequency increment of the ultrasonic processing;

[0025] S15: An array based on the resonant frequency increment at each cut. And an array of the average values ​​of the resonant frequency increments during each calibration step of ultrasonic machining until the tool breaks. Calculate the array of blade breakage warning coefficients. for:

[0026] ;

[0027] Set the blade breakage warning coefficient k array The minimum value.

[0028] Preferably, step S6 specifically includes:

[0029] S61: Calculate the average value of the resonant frequency increments from the first N ultrasonic processing operations. for: ,in, These represent the resonant frequency increments during the 1st, ..., Nth ultrasonic processing operations, respectively.

[0030] S62: Based on the average value of the resonant frequency increments from the previous N drilling or milling operations. and the blade breakage warning coefficient k Calculate the threshold for the resonant frequency increment of the blade breakage warning system. : ,in k >1;

[0031] S63: Calculate the ultrasonic scalpel holder during the [number]th [step / step]. i Tool wear rate D after ultrasonic processing:

[0032] D= .

[0033] Preferably, step S7 specifically includes: determining whether the tool loss rate is greater than 1; if so, outputting a tool breakage warning signal and continuing to execute step S8; if not, directly executing step S8.

[0034] Preferably, the ultrasonic machining performed by the ultrasonic tool holder is ultrasonic drilling or ultrasonic milling.

[0035] In a second aspect, the present invention discloses a tool wear detection device for an ultrasonic machining system. The ultrasonic machining system includes an ultrasonic drive controller, an ultrasonic transmitter, and an ultrasonic tool holder. The ultrasonic drive controller is connected to the ultrasonic transmitter to transmit ultrasonic drive signals to the ultrasonic transmitter and to receive feedback signals from the ultrasonic transmitter. The ultrasonic transmitter is connected to the ultrasonic tool holder to drive the ultrasonic tool holder to perform ultrasonic machining. The tool wear detection device is connected to the ultrasonic drive controller to send control signals to the ultrasonic drive controller and to receive feedback signals from the ultrasonic drive controller. The tool wear detection device includes a processor, a memory, and a control program. The control program is stored in the memory and configured to be executed by the processor to implement the tool wear detection method as described in the first aspect.

[0036] Thirdly, the present invention discloses a computer-readable storage medium storing a computer program, wherein the computer program is configured to be run by a processor to perform the tool damage detection method described in the first aspect.

[0037] Compared with the prior art, the beneficial effects of the present invention are as follows: The tool wear detection method and device of the ultrasonic machining system proposed in the present invention can obtain the change of the resonant frequency of the ultrasonic tool holder in real time, and based on this, realize the real-time analysis of the cutting force during the machining process. This can provide early warning of machining abnormalities such as severe tool wear and tool breakage during the machining process, and avoid workpiece damage or machine tool equipment damage caused by excessive cutting force. Attached Figure Description

[0038] Figure 1 This is a schematic diagram of the tool wear detection system of the ultrasonic machining system according to a preferred embodiment of the present invention;

[0039] Figure 2 This is a flowchart of a preferred embodiment of the ultrasonic machining system for detecting tool wear. Detailed Implementation

[0040] The embodiments of the present invention will be described in detail below. It should be emphasized that the following description is merely exemplary and not intended to limit the scope and application of the present invention.

[0041] It should be noted that when a component is referred to as "fixed to" or "set on" another component, it can be directly on or indirectly on that other component. When a component is referred to as "connected to" another component, it can be directly connected to or indirectly connected to that other component. Furthermore, a connection can be used for both fixing and circuit / signal connectivity.

[0042] It should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention.

[0043] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of embodiments of the present invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0044] To avoid machining abnormalities caused by tool wear or breakage and to maximize tool life, it is necessary to monitor wear during the machining process. In actual machining, the tool rotates at high speed and is in continuous or intermittent contact with the workpiece. The machining process is mixed with cutting fluid, chips, etc., making it difficult to test tool wear in real time using optical testing methods. Tool monitoring methods based on conductivity principles can generally only detect tool breakage and cannot reflect the continuous tool wear process. Monitoring the machining process using spindle current / voltage / power has some applications, but the electrical parameters at the spindle end are not sensitive to tool wear.

[0045] To address the aforementioned problems, this invention proposes a method for monitoring cutting force and evaluating tool wear using the electromechanical characteristics of an ultrasonic tool holder. A corresponding calibration method is also provided. Research has revealed that the resonant system composed of the ultrasonic tool holder and the cutting tool directly participates in part machining, and the cutting force has a significant impact on its resonant characteristics. Therefore, this invention establishes a correspondence between the resonant characteristics of the ultrasonic tool holder and the cutting force, thereby achieving monitoring, providing early warnings of potential dangerous situations, and ensuring the smooth completion of the machining process.

[0046] An object's natural frequency is an inherent physical property, with countless orders, each corresponding to a specific mode shape. Under external influences, such as force, heat, and constraints, the object's natural frequency undergoes regular changes. During ultrasonic machining, the ultrasonic machining system, composed of an ultrasonic shank, chuck, nut, and cutting tool, generates mechanical vibrations near its specific natural frequency, corresponding to the mode shape of that natural frequency—a state of resonance. During cutting, the tool interacts with the workpiece, generating a cutting force, typically ranging from tens to hundreds of Newtons, which significantly affects the resonance state of the ultrasonic machining system. The mechanical vibration state of the ultrasonic machining system influences its electrical characteristics, which can be represented as changes in equivalent resistance, capacitance, and inductance, manifesting as the values ​​and phase relationships of current and voltage at the ultrasonic control system level.

[0047] The resonant frequency of an ultrasonic tool holder is its optimal operating frequency. At this frequency, the ultrasonic tool holder exhibits maximum ultrasonic vibration, effectively reducing cutting forces and maximizing tool life. However, the resonant frequency can be altered by external forces and thermal conditions. Therefore, during ultrasonic cutting, as tool wear increases, the cutting force between the workpiece and the tool increases, affecting the electrical characteristics of the ultrasonic machining system and ultimately leading to an increase in the calculated resonant frequency of the ultrasonic system.

[0048] In a preferred embodiment of the present invention, the ultrasonic machining system required for performing the tool wear detection method is as follows: Figure 1As shown, the ultrasonic machining system mainly comprises three parts: an ultrasonic drive controller 2, an ultrasonic transmitter 4, and an ultrasonic tool holder 3. The ultrasonic drive controller 2 can emit ultrasonic signals based on the resonant frequency of the ultrasonic machining system. During the operation of the ultrasonic machining system, the ultrasonic drive controller 2 can track the change of the resonant frequency of the ultrasonic tool holder 3 in real time. Specifically, the ultrasonic drive controller 2 can send ultrasonic drive signals to the ultrasonic transmitter 4, and the ultrasonic transmitter 4 sends ultrasonic drive signals to the ultrasonic tool holder 3, driving the ultrasonic tool holder 3 to perform ultrasonic vibration and driving the tool 5 to perform ultrasonic machining. The ultrasonic transmitter 4 can send electrical feedback to the ultrasonic drive controller 2. The CNC machine tool required for the implementation of this invention mainly includes a machine tool CNC system 1, with a tool wear detection device built into the machine tool CNC system 1. The machine tool CNC system 1 can send start and stop commands to the ultrasonic drive controller 2, and the machine tool CNC system 1 can receive tool breakage warning signals and tool breakage alarm signals sent by the ultrasonic drive controller 2. Specifically, the machine tool CNC system 1 can send control signals to the ultrasonic drive controller 2, and the ultrasonic drive controller 2 can send tool breakage signal feedback to the machine tool CNC system 1. In this embodiment, the tool damage detection device includes a processor, a memory, and a control program. The control program is stored in the memory and configured to be executed by the processor to implement the tool damage detection method described below.

[0049] like Figure 2 As shown, a preferred embodiment of the present invention discloses a tool wear detection method for an ultrasonic machining system. Based on the fact that during machining processes such as drilling and milling where the stress on the ultrasonic tool holder remains constant, the ultrasonic controller identifies changes in the resonant frequency of the ultrasonic tool holder in real time to provide feedback on the tool wear status. This tool wear detection method specifically includes the following steps:

[0050] S1: Set the total number of ultrasonic processing operations (e.g., drilling or milling). n Broken blade warning coefficient k And calibrate the number of samplings N, and set i =1;

[0051] This step involves setting the total number of holes to be drilled or milled using the ultrasonic drive controller 2. n Broken blade warning coefficient k The machine tool CNC system 1 sends an ultrasonic start command to the ultrasonic drive controller 2, which outputs ultrasonic waves and tracks the resonant frequency of the ultrasonic tool holder 3 in real time. The machine tool CNC system 1 sets the initial number of holes to be drilled or milled. i =1, and synchronize this setting to the ultrasonic drive controller 2.

[0052] Before implementing the tool damage detection method, it is necessary to determine the tool breakage warning coefficient. k The calibration is performed by determining the number of samplings N. The specific calibration method is as follows:

[0053] A1: Conduct Y machining experiments, drilling continuously until the tool breaks, and record the number of holes drilled at each breakage: X1, X2…X… Y The resonant frequency increment ΔF for each drill hole in each machining experiment, and the resonant frequency increment when the tool breaks. , , ..., An array that counts the increment of the resonant frequency each time the blade breaks. for: .

[0054] A2: Calculate the... y After the tool broke during the secondary machining experiment, the number of sampling times N was calibrated. y : , y The values ​​can be 1, 2, ..., Y, to obtain an array of the number of calibration samplings N in each calibration step during ultrasonic processing until the tool breaks. .

[0055] A3: Calculate the... y The average value of the drilling resonant frequency increment after tool breakage in the second machining experiment for: The average values ​​of the borehole resonant frequency increments after tool breakage in each machining experiment were obtained as follows: , , ..., An array representing the average increment of the drilling resonant frequency after tool breakage in each machining experiment. for: .

[0056] A4: An array based on the resonant frequency increment at each cut. And an array of the average values ​​of the borehole resonant frequency increments after tool breakage in each machining experiment. Calculate the array of early warning coefficients for broken blades for:

[0057] .

[0058] A5: Calibration: The number of calibration sampling times N is taken as an array. Minimum value in; Calibration of tool breakage warning coefficient k The value can be: array The minimum value in.

[0059] The calibration process in steps A1 to A5 above uses ultrasonic drilling as an example. In the tool wear detection method for milling grooves, a milling experiment is performed Y times until the tool breaks to test the wear. k Calibrate N.

[0060] S2: Send an ultrasonic machining preparation signal to the ultrasonic drive controller that controls the ultrasonic tool holder, and acquire the ultrasonic tool holder's first... i The no-load resonant frequency prior to the ultrasonic processing (e.g., drilling or milling);

[0061] In this step, the machine tool CNC system 1 sends a machining preparation signal to the ultrasonic drive controller 2, and the ultrasonic drive controller 2 records the no-load resonant frequency of the ultrasonic tool holder 3 at this time.

[0062] Among them, the i The no-load resonant frequency before the second drilling or milling is denoted as . ( i =1, 2, ..., n , i =1 indicates the first drilling or milling operation, which is the resonant frequency of the ultrasonic tool holder when it is running unloaded. Specifically, it refers to the resonant frequency of the ultrasonic tool holder when it has not touched the workpiece or the ultrasonic tool holder is not subjected to external force before a certain machining operation of drilling or milling.

[0063] S3: Send an ultrasonic machining signal to the ultrasonic drive controller that controls the ultrasonic tool holder, so that the ultrasonic tool holder begins the first ultrasonic machining operation. i The ultrasonic machining process (e.g., drilling or milling) is performed, and the ultrasonic tool holder is obtained during the second ultrasonic machining process. i The maximum resonant frequency during a single ultrasonic machining process (e.g., drilling or milling);

[0064] In this step, the machining program is executed, and the machine tool CNC system 1 begins drilling or milling.

[0065] Among them, the ultrasonic scalpel handle is in the first stage i The maximum resonant frequency during the secondary drilling or milling process is denoted as . (i=1, 2, ..., n When i=1, it represents the first drilling or milling operation. This means that the resonant frequency rises to its maximum value during a certain drilling or milling operation of the ultrasonic tool holder. Specifically, it refers to the resonant frequency value when the ultrasonic tool holder experiences the maximum cutting force during the above-mentioned processing.

[0066] S4: Combine the ultrasonic scalpel holder obtained in step S2 to perform the first... i The no-load resonant frequency before the first ultrasonic machining (e.g., drilling or milling) and the ultrasonic tool holder obtained in step S3 during the first ultrasonic machining (e.g., drilling or milling) are also important factors. i The maximum resonant frequency during the first ultrasonic machining process (e.g., drilling or milling) is calculated, and the ultrasonic tool holder is used to perform the first ultrasonic machining process. i The resonant frequency increment during a secondary ultrasonic machining process (e.g., drilling or milling);

[0067] Among them, the ultrasonic scalpel handle is in the first stage i The increment of the resonant frequency during the secondary drilling or milling process is denoted as . (i=1, 2, ..., n When i=1, it represents the first drilling or milling operation. Specifically, it represents the difference between the maximum value of the load resonant frequency and the maximum value of the no-load resonant frequency during a certain drilling or milling operation of the ultrasonic tool holder. .

[0068] S5: Judgment i whether For N, if so, then let i = i +1 and return to step S2; otherwise, proceed to step S6.

[0069] S6: Calculate the average value of the resonant frequency increments of the previous N ultrasonic machining operations (e.g., drilling or milling), and base the calculation on the average value of the resonant frequency increments of the previous N ultrasonic machining operations (e.g., drilling or milling) and the tool breakage warning coefficient. k Calculate the tool wear rate D;

[0070] The average value of the resonant frequency increments from the first N drilling or milling operations is denoted as . ,Right now .

[0071] Based on the average value of the resonant frequency increments from the previous N drilling or milling operations. and the blade breakage warning coefficient k Calculate the threshold for the resonant frequency increment of the blade breakage warning system. : ,in k >1.

[0072] Then calculate the ultrasonic scalpel holder during the first... i Tool wear rate D after secondary drilling or milling:

[0073] D= ;

[0074] Among them, the tool wear rate D is used to describe the tool wear rate during the ultrasonic tool holder machining process.

[0075] S7: Determine if the tool loss rate is greater than 1. If yes, output a tool breakage warning signal and continue to step S8; otherwise, proceed to step S8.

[0076] When the tool breakage rate is greater than 1, the ultrasonic drive controller 2 outputs a tool breakage warning signal to the machine tool CNC system 1 to remind the operator to replace the tool. At this time, it is not necessary to stop the machine tool from processing; it is only necessary to remind the operator of the risk of tool breakage.

[0077] S8: Determine the first iIf the resonant frequency increment during the ultrasonic processing (e.g., drilling or milling) is less than the average value of the resonant frequency increments of the previous N ultrasonic processing (e.g., drilling or milling), then a tool breakage alarm signal is output and the ultrasonic tool holder is stopped; otherwise, step S9 is executed.

[0078] Specifically, if drilling or milling reaches the first i When there is one hole, ΔF is determined at this time. i - When the value is less than 0, the ultrasonic drive controller 2 outputs a broken tool alarm signal to the machine tool CNC system 1, and the machine tool CNC system 1 stops processing; otherwise, it continues to execute the next step S9.

[0079] When drilling reached the... i The hole or milling groove to the first i When a tool breaks in a slot, two situations may occur: one is that the tool breaks completely, and the tool can no longer contact the workpiece when drilling or milling, meaning there is no cutting force when drilling; the other is that the tool breaks partially, and the tool only partially contacts the workpiece when drilling or milling, meaning the cutting force is greatly reduced when drilling, but the workpiece cannot be completely machined. In both cases, the cutting force of the tool will decrease, and the frequency increment will decrease.

[0080] Therefore, when ΔF i <Δ - F N At this time, the ultrasonic drive controller outputs a tool breakage alarm signal to the CNC system.

[0081] S9: Judgment i Is it less than If so, then let i = i +1, and return to step S2; if not, stop running the ultrasonic tool holder, that is, at this time the workpiece processing is completed and the machine tool CNC system 1 stops processing.

[0082] The following detailed description of the tool wear detection method for the ultrasonic machining system proposed in this invention is based on specific embodiments.

[0083] First, the number of sampling times N and the blade breakage warning coefficient were calibrated. k Calibration was performed, with drilling experiments conducted under identical process and tool type conditions. In this embodiment, three identical drilling experiments were performed until the tool broke. The total number of holes drilled in the three drilling experiments and the increment of the resonant frequency at tool breakage were recorded. The average value of the resonant frequency increment And the calculated calibration sampling number N, and the tool breakage warning coefficient. k As shown in Table 1.

[0084] Table 1

[0085]

[0086] The number of calibration samplings N is the minimum integer value obtained by rounding down from three calibration experiments. (This is the blade breakage warning coefficient.) k The minimum value among the three experiments is taken; therefore, the number of sampling times for the machining drilling experiment in this example is N=25, and the tool breakage warning coefficient is... k =2.092.

[0087] The total number of boreholes set by the above calibration results program n The values ​​of the blade breakage warning coefficient k and the calibration sampling number N are shown in Table 2.

[0088] Table 2

[0089]

[0090] The drilling tool breakage verification experiment was repeated according to the preferred embodiment of the present invention, and the average value of the resonant frequency increment recorded in the three processing experiments was analyzed. Blade breakage warning resonant frequency increment threshold The number of holes drilled when the tool breakage warning is issued and the actual number of holes drilled when the tool breaks are shown in Table 3.

[0091] Table 3

[0092]

[0093] The tool utilization rates in the three verification experiments were 96.4%, 97.7%, and 95.6%, respectively. Tool utilization rate is defined as the number of holes drilled when a tool breakage warning is issued divided by the actual number of holes drilled due to tool breakage. Therefore, it can be seen that the tool damage detection method for the ultrasonic machining system proposed in the preferred embodiment of this invention can improve tool utilization during drilling while preventing workpiece damage caused by tool breakage during the drilling process.

[0094] Another preferred embodiment of the present invention discloses a computer storage medium storing a computer program, wherein the computer program is configured to be run by a processor to perform the steps of the tool damage detection method in the above preferred embodiment.

[0095] Optionally, the aforementioned storage media may include, but are not limited to, USB flash drives, read-only memory (ROM), random access memory (RAM), portable hard drives, magnetic disks, or optical disks, and other media capable of storing computer programs.

[0096] The background section of this invention may include background information about the problems or circumstances surrounding the invention, rather than a description of prior art by others. Therefore, the content included in the background section is not an admission of prior art by the applicant.

[0097] The above description provides a further detailed explanation of the present invention in conjunction with specific / preferred embodiments, and it should not be construed that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, various substitutions or modifications can be made to these described embodiments without departing from the concept of the present invention, and all such substitutions or modifications should be considered within the scope of protection of the present invention. In the description of this specification, the reference to terms such as "an embodiment," "some embodiments," "preferred embodiment," "example," "specific example," or "some examples," etc., indicates that the specific features, structures, materials, or characteristics described in connection with that embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in any suitable manner in one or more embodiments or examples. Furthermore, those skilled in the art can combine and integrate different embodiments or examples and features of different embodiments or examples described in this specification without contradiction. Although the embodiments of the present invention and their advantages have been described in detail, it should be understood that various changes, substitutions, and modifications can be made herein without departing from the scope defined by the appended claims.

Claims

1. An ultrasonic machining system tool wear detection method, characterized by, Includes the following steps: S1: set the total number of ultrasonic machining n , the tool breakage early warning coefficient k , and the calibration sampling number N, and set i =1; S2: Send an ultrasonic machining preparation signal to the ultrasonic drive controller that controls the ultrasonic tool holder, and acquire the ultrasonic tool holder to perform the first... i The no-load resonant frequency before the ultrasonic processing; S3: Send an ultrasonic machining signal to the ultrasonic drive controller that controls the ultrasonic tool holder, so that the ultrasonic tool holder begins the first ultrasonic machining operation. i Second ultrasonic processing, and obtain the first i The maximum resonant frequency during ultrasonic processing; S4: Combine the ultrasonic scalpel handle obtained in step S2 to perform the first... i The no-load resonant frequency before the second ultrasonic processing and the first obtained in step S3 i The maximum resonant frequency during the ultrasonic processing is calculated. i The resonant frequency increment during the ultrasonic processing; S5: Judgment i Is it less than N? If so, then let i = i +1 and return to step S2; otherwise, proceed to step S6. S6: calculate the average value of the resonance frequency increment of the previous N ultrasonic machining, and calculate the tool breakage rate according to the average value of the resonance frequency increment of the previous N ultrasonic machining, the tool breakage early warning coefficient k and the resonance frequency increment in the first i ultrasonic machining process S7: Determine if the tool loss rate is greater than 1. If yes, output a tool breakage warning signal; otherwise, proceed to step S8. S8: Determine the first i If the resonant frequency increment during the ultrasonic processing is less than the average value of the resonant frequency increments of the previous N ultrasonic processing operations, then output a tool breakage alarm signal and stop the operation of the ultrasonic tool holder; otherwise, proceed to step S9. S9: Judgment i Is it less than If so, then let i = i +1, and return to step S2; if not, stop running the ultrasonic scalpel handle; In the step S1, the tool breaking early warning coefficient is set k Specifically includes the following steps: S13: Obtain the resonant frequency increment at each tool breakage. This yields an array of resonant frequency increments for each time the blade breaks. for: ; S14: Calculate the... y The average value of the resonant frequency increment during the calibration step of ultrasonic machining until the tool breaks. for: This yields an array of the average resonant frequency increments during each calibration step of ultrasonic processing until the tool breaks. for: ,in, They represent the first y During the calibration process of ultrasonic machining until the tool breaks, step 1,… The resonant frequency increment of the ultrasonic processing; S15: An array based on the resonant frequency increment at each cut. And an array of the average values ​​of the resonant frequency increments during each calibration step of ultrasonic machining until the tool breaks. Calculate the array of early warning coefficients for broken blades. for: ； Setting a tool break early warning coefficient k array minimum value; Step S6 specifically includes: S61: Calculate the average value of the increments of the resonance frequency of the previous N ultrasonic machining is: wherein, respectively represent the increments of the resonance frequency of the 1st,..., Nth ultrasonic machining; S62: Based on the average value of the resonant frequency increments from the previous N ultrasonic processing operations. and the blade breakage warning coefficient k Calculate the threshold for the resonant frequency increment of the blade breakage warning system. : ,in k >1; S63: Calculate the tool wear rate D of the ultrasonic tool shank after performing the first i ultrasonic machining. D= 。 2. The blade wear detection method according to claim 1, characterized by, Step S1, setting the calibration sampling number N, specifically includes the following steps: S11: performing Y times ultrasonic machining to the calibration step of breaking the tool, and obtaining the total number X of ultrasonic machining each time the tool is broken y wherein y Y is an integer, and Y = 1, 2, …, Y. S12: Calculate the calibration sampling number N in the calibration step of each ultrasonic machining to the broken tool y : , get the array of calibration sampling number in the calibration step of each ultrasonic machining to the broken tool : ; set the value of calibration sampling number N as the minimum integer value obtained by rounding down the minimum value of the number in .

3. The tool wear detection method according to claim 1, characterized in that, Step S7 specifically includes: determining whether the tool loss rate is greater than 1. If it is, outputting a tool breakage warning signal and continuing to execute step S8; if not, directly executing step S8.

4. The blade wear detection method according to claim 1, characterized by, The ultrasonic machining performed by the ultrasonic tool holder is ultrasonic drilling or ultrasonic milling.

5. An apparatus for detecting tool wear in an ultrasonic machining system, characterized by comprising: The ultrasonic machining system includes an ultrasonic drive controller, an ultrasonic transmitter, and an ultrasonic tool holder. The ultrasonic drive controller is connected to the ultrasonic transmitter to transmit ultrasonic drive signals to the ultrasonic transmitter and to receive feedback signals from the ultrasonic transmitter. The ultrasonic transmitter is connected to the ultrasonic tool holder to drive the ultrasonic tool holder to perform ultrasonic machining. The tool damage detection device is connected to the ultrasonic drive controller to send control signals to the ultrasonic drive controller and to receive feedback signals from the ultrasonic drive controller. The tool damage detection device includes a processor, a memory, and a control program. The control program is stored in the memory and configured to be executed by the processor to implement the tool damage detection method as described in any one of claims 1 to 4.

6. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program, wherein the computer program is configured to be run by a processor to perform the tool damage detection method according to any one of claims 1 to 4.

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