A system and method for controlling the punching of an acetate fiber spinning die

Abstract

The present application relates to the field of spinneret punching, and relates to an acetate fiber spinning spinneret punching control system and method; comprising a torque acquisition module, an acoustic emission acquisition module, a chip removal judgment module, a parameter adjustment module, a drilling execution module and a cooling liquid control module. When there is an abnormal chip removal, the present application adjusts the tool withdrawal distance, the feed stroke length and the drill bit rotation speed according to the abnormal type, the torque average value and the rising rate, and generates adjusted peck drilling parameters; thereby solving the problems that the prior art cannot distinguish abnormal types, only performs a unified adjustment action, causes the parameter adjustment direction to be wrong, and the chip removal problem is difficult to solve, and realizing differentiated adjustment for different chip removal abnormal types, and ensuring the punching quality.

Description

Technical Field

[0001] This invention relates to the field of spinneret perforation, and specifically to a control system and method for perforating spinnerets in cellulose acetate spinning. Background Technology

[0002] Fiber acetate spinning spinnerets are typically made of precious metals such as gold-platinum alloys and tantalum alloys. They have multiple micropores evenly distributed on them, with shapes including Y-shaped and cross-shaped. The micropores consist of guide holes and spinneret capillary holes. Since the guide holes are blind holes, chips can only be discharged unidirectionally from the hole opening. As the hole depth increases, chips tend to accumulate inside the hole, causing abnormal chip discharge, resulting in unstable cutting and affecting the drilling quality.

[0003] To address the aforementioned issues, existing technologies monitor and control chip removal by acquiring the torque or power signals of the spindle motor in real time. When the rate of change of torque or the peak power exceeds a preset threshold, an abnormality in chip removal is determined, triggering adjustments such as tool retraction, chip removal, and cooling.

[0004] However, the aforementioned existing technology has the following two shortcomings: First, it can only determine whether chip removal abnormality has occurred, but cannot distinguish the specific type of chip removal abnormality. Consequently, it cannot make targeted adjustments to the drilling process parameters based on the specific type of abnormality. Furthermore, the uniform adjustment action adopted after determining that chip removal abnormality has occurred cannot fundamentally solve the chip removal problem, making it difficult to guarantee drilling quality. Second, the method for determining chip removal abnormality is too simplistic and does not analyze and judge from multiple dimensions, which can easily lead to misjudgment and omission. This can result in incorrect parameter adjustment direction, exacerbating chip removal abnormality and ultimately causing hole wall quality defects or drill bit breakage. Summary of the Invention

[0005] The technical solution adopted by the present invention to solve its technical problem is: a control system for perforating a spinneret in cellulose acetate spinning, comprising: a torque acquisition module, used to calculate the average torque and rise rate of the current feed stroke based on the real-time torque of the spindle motor.

[0006] The acoustic emission acquisition module is used to extract acoustic pattern parameters and impact distribution parameters based on the acoustic emission signals during the drilling process.

[0007] The chip removal judgment module is used to determine whether there is a chip removal abnormality based on the average torque and the rising rate; and to determine the type of abnormality based on the machining hole geometry parameters, acoustic parameters and impact distribution parameters.

[0008] The parameter adjustment module is used to adjust the retraction distance, feed stroke length, and drill speed according to the anomaly type, average torque, and rise rate, so as to generate the adjusted pecking parameters.

[0009] The drilling execution module is used to drive the drill bit to perform the pecking action according to the pecking parameters and output the drill bit motion parameters.

[0010] The coolant control module is used to adjust the coolant flow rate and flushing duration based on drill bit motion parameters and impact distribution parameters.

[0011] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. This invention determines whether there is a chip removal abnormality based on the average torque value and the rate of increase. It also combines the shape of the machining hole, the material of the spinneret, the acoustic parameters and the impact distribution parameters to comprehensively determine the type of abnormality from multiple dimensions. This makes up for the shortcomings of the prior art in that it cannot distinguish the specific type of chip removal abnormality and reduces misjudgment and omission caused by a single torque threshold judgment.

[0012] 2. When chip removal abnormalities occur, this invention adjusts the retraction distance, feed stroke length, and drill speed according to the abnormality type, average torque, and rise rate, and generates adjusted pecking parameters. This solves the problems of existing technologies that cannot distinguish abnormality types, only perform uniform adjustment actions leading to incorrect parameter adjustment direction, and make it difficult to solve chip removal problems. It realizes differentiated adjustment for different types of chip removal abnormalities, ensuring drilling quality.

[0013] 3. This invention adjusts the coolant flow rate and flushing duration based on drill bit motion parameters and impact distribution parameters; when an abnormality of built-up edge is determined, the flow rate of coolant pulse flushing is increased to promote the shedding of built-up edge; when an abnormality of chip blockage is determined, the coolant flushing time is extended to remove accumulated chips; thus achieving a match between coolant flow rate, flushing duration and abnormality type. Attached Figure Description

[0014] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0015] Figure 1 This is a schematic diagram of the system module connections of the present invention; Figure 2 This is a schematic diagram of the method flow of the present invention; Figure 3 This is a schematic diagram of the method for determining whether there is a chip removal abnormality in this invention; Figure 4 This is a schematic diagram of the method for generating the adjusted pecking parameters in this invention. Detailed Implementation

[0016] Various exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings. It should be noted that, unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of the invention. Furthermore, it should be understood that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale.

[0017] The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the invention or its application or use. Techniques, methods, and apparatus known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and apparatus should be considered part of the specification.

[0018] In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values.

[0019] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0020] The specific solution of the cellulose acetate spinning spinneret perforation control system and method provided by the present invention will be described in detail below with reference to the accompanying drawings.

[0021] Please see Figure 1 The diagram shows a connection schematic of a cellulose acetate spinning spinneret perforation control system provided by the present invention, which specifically includes: a torque acquisition module, an acoustic emission acquisition module, a chip removal judgment module, a parameter adjustment module, a drilling execution module, and a coolant control module.

[0022] The outputs of the torque acquisition module and the acoustic emission acquisition module are connected to the chip removal judgment module, the output of the chip removal judgment module is connected to the parameter adjustment module, the output of the parameter adjustment module is connected to the drilling execution module, and the output of the drilling execution module is connected to the coolant control module.

[0023] The torque acquisition module is used to calculate the average torque and torque rise rate of the current feed stroke based on the real-time torque of the spindle motor.

[0024] In this embodiment, a torque sensor is integrated into the machine tool spindle tool holder assembly, and the real-time torque is transmitted to the receiving device wirelessly. After receiving the signal, the receiving device completes data acquisition and processing through a computer processing system.

[0025] During the drilling process, multiple pecking cycles are required. Each pecking cycle includes a feed phase and a retraction phase. During the feed phase, when the servo motor drives the drill bit to move from the axial position where the drill bit stopped at the end of the previous retraction action towards the bottom of the hole, it indicates the start of the feed phase of the current pecking cycle. Therefore, the moment when the drill bit moves from the current retraction stop position towards the bottom of the hole is taken as the starting moment of the current feed stroke.

[0026] When the servo motor stops feeding and begins to retract the drill bit, the moment when the drill bit stops moving towards the bottom of the hole and begins to move in the opposite direction is taken as the end point of the current feed stroke; the time difference between the end point and the start point is taken as the total duration of the current feed stroke.

[0027] During the retraction phase, the real-time torque collected between the start and end times is summed, and the summation result is divided by the number of sampling times between the start and end times to obtain the average torque value.

[0028] Meanwhile, for the real-time torque collected between the start and end times, a univariate linear fit is performed in a two-dimensional coordinate system with each sampling time t as the abscissa and the real-time torque T as the ordinate: Where a is the slope and b is the intercept; the slope obtained by solving is used as the torque increase rate of the current feed stroke.

[0029] The acoustic emission acquisition module is used to extract acoustic pattern parameters and impact distribution parameters based on the acoustic emission signals during the drilling process. Specifically, an acoustic emission sensor fixedly mounted on the spinneret fixture receives stress wave signals in real time during the drilling process and converts the stress wave signals into voltage signals. After being amplified by a preamplifier, the voltage signals are converted from analog to digital by a data acquisition card at a sampling frequency of 2MHz and a sampling period of 0.5µs to obtain the acoustic emission signal sequence.

[0030] Perform a Fourier transform on the acoustic emission signal within the current feed stroke to obtain N complex spectral values ​​X(k). Specifically as follows: ; Where X(n) is the amplitude of the acoustic emission signal at the nth sampling point, n=1,2,...N, N is the number of sampling times; e is the natural constant; π is pi, taken as 3.14; k is the frequency index, k=1,2,...,N-1; j is the imaginary unit.

[0031] After obtaining the complex spectrum values, calculate the power spectral density. : ; This reflects the energy distribution of the acoustic emission signal at the actual frequencies corresponding to each frequency index; among which, Frequency resolution (Hz) , Let k be the sampling frequency; the actual frequency corresponding to k is obtained by multiplying the product of k and the sampling frequency by the number of sampling times.

[0032] Since the acoustic emission characteristic signals corresponding to cutting, chip breakage, built-up edge, and hole wall friction are concentrated in the range of 100kHz to 1MHz, the noise below 100kHz is machine tool vibration noise and the noise above 1MHz is electromagnetic interference, the range of 100kHz to 1MHz is selected as the analysis frequency band.

[0033] Within the analysis frequency band, based on the power spectral density, the frequency corresponding to the maximum power spectral density is taken as the peak frequency; then, the frequency value of the power spectral density at each frequency is multiplied by the corresponding power spectral density value, and the sum of all products is divided by the sum of the power spectral density values ​​at each frequency. The result is the center frequency.

[0034] The analysis frequency band is further divided into the material adhesion characteristic frequency band and the chip fracture characteristic frequency band. The material adhesion characteristic frequency band is the frequency range in which the acoustic emission signal energy is concentrated when the spinneret adheres, tears, and the built-up edge falls off during drilling. The chip fracture characteristic frequency band is the frequency range in which the acoustic emission signal energy is concentrated when the chip breaks and fragments during drilling, and it is located in a lower frequency range than the material adhesion characteristic frequency band.

[0035] The specific frequency boundaries of the material adhesion characteristic frequency band and the chip fracture characteristic frequency band were determined through trial drilling experiments. Acoustic emission signals were collected when material adhesion and chip fracture occurred, and two power spectral density curves were obtained after Fourier transform. The frequency point at which the two power spectral density curves changed from overlapping to separating was taken as the frequency boundary of the two characteristic frequency bands. The specific process of the trial drilling experiment is existing technology and will not be described in detail here.

[0036] Then, the power spectral density integral within the material adhesion characteristic frequency band is calculated to obtain the energy value of the material adhesion characteristic frequency band; the power spectral density integral within the chip fracture characteristic frequency band is also calculated to obtain the energy value of the chip fracture characteristic frequency band. The energy value of the material adhesion characteristic frequency band is divided by the energy value of the chip fracture characteristic frequency band to obtain the band energy ratio.

[0037] Next, within the analysis frequency band, the power spectral density corresponding to all frequencies is summed to obtain the total power within the analysis frequency band. : The power spectral density corresponding to each frequency within the analysis band Divide by The normalized power spectral density for each frequency is obtained. .

[0038] Calculate the spectral entropy H using the following formula: At a certain frequency When the value is zero, the spectral entropy is zero. Then, the peak frequency, center frequency, band energy ratio, and spectral entropy are combined and output as acoustic signature parameters to the chip removal judgment module.

[0039] After extracting the acoustic fingerprint parameters, a Hilbert transform is performed on the acoustic emission signal acquired within the current feed stroke to obtain the signal envelope curve reflecting the instantaneous amplitude of the signal. The root mean square (RMS) value of the signal envelope curve within the current feed stroke is calculated. The RMS value characterizes the average energy level of the current stroke, and a preset multiple of the RMS value is used as the impact threshold. Specifically, based on statistical principles, the preset multiple is set to three times.

[0040] When the amplitude of the signal envelope curve (hereinafter referred to as signal amplitude) is greater than or equal to the impact threshold for three consecutive sampling times, the sampling time corresponding to the first signal amplitude that exceeds the impact threshold is determined as the start time of the impact. If the amplitude of any one of the three consecutive sampling times is less than the impact threshold, the subsequent sampling times are traversed.

[0041] When the signal amplitude is less than the impact threshold for three consecutive sampling times, the sampling time corresponding to the first signal amplitude that falls below the impact threshold is determined as the end time of the impact. If the amplitude of any one of the three consecutive sampling times is greater than or equal to the impact threshold, the subsequent sampling times are traversed.

[0042] Next, all impacts within the current feed stroke are identified sequentially according to time. An impact refers to the transient elastic stress wave generated by the release of energy in a short period of time due to chip breakage, fragmentation, or build-up edge detachment, which is then captured by the acoustic emission sensor and forms an electrical signal pulse.

[0043] For each impact, the time difference between the start and end times of the impact is taken as the impact duration. The sum of squares of the amplitudes of each signal within the impact duration is calculated and multiplied by the sampling period. The result is taken as the impact energy.

[0044] Subsequently, the start times of all impacts identified within the current feed stroke are sorted chronologically, and the time difference between adjacent start times is calculated. All time differences are then arranged in order to form an impact interval sequence. The arithmetic mean of the impact interval sequence is subtracted from each time difference in the impact interval sequence, and then divided by the standard deviation of the impact interval sequence. The cube of the result is taken as the third-order standardized deviation.

[0045] Meanwhile, based on the unbiased estimation correction rule for sample skewness in statistics, the number of time differences in the impact interval sequence is denoted as M, and the sum of all third-order standardized biases is multiplied by... The obtained third-order normalized moments are used as the impact interval distribution skewness. The impact interval distribution skewness characterizes the degree of asymmetry in the distribution of values ​​in the impact time interval sequence. When M is less than 4, the impact interval distribution skewness is marked as invalid.

[0046] Meanwhile, the spindle rotation angle is collected in real time by the encoder of the machine tool spindle. For each impact, the spindle rotation angle corresponding to the start time of the impact is taken as the impact phase angle. Let K impacts be identified in the current feed stroke.

[0047] When K is less than 2, the impact phase concentration is marked as invalid; when K is greater than or equal to 2, the impact phase angles are first converted from degrees to radians to obtain the radian angle α. The radian angle is then mapped to a vector on the unit circle, with its x-coordinate being cosα and its y-coordinate being sinα. The sum of the x-coordinates and y-coordinates of all vectors is calculated to obtain the resultant vector coordinates X and Y. The average resultant vector length R is then calculated using the following formula: ; Next, according to the formula Calculate the circular standard deviation (Unit: radians) Convert the circular standard deviation unit to angles. The result is the impact phase concentration of the current feed stroke. The smaller the impact phase concentration, the more concentrated the phase angle of the impact.

[0048] Finally, the arithmetic mean of the impact energy and the arithmetic mean of the impact duration of all impacts within the current feed stroke are calculated and used as the average impact energy and the average impact duration, respectively. The average impact energy, the average impact duration, the impact interval distribution skewness, and the impact phase concentration are then output as impact distribution parameters to the chip removal judgment module.

[0049] It should be noted that if the number of impacts detected within the current feed stroke is zero, the impact distribution parameters are not calculated, and all impact distribution parameters are marked as invalid values.

[0050] Please see Figure 3 The chip removal judgment module is used to determine whether there is a chip removal abnormality based on the average torque and the rising rate; and to determine the type of abnormality based on the shape of the machining hole, the material of the spinneret, the acoustic parameters and the impact distribution parameters.

[0051] First, multiple consecutive feed strokes that simultaneously meet the following screening conditions are used as reference feed strokes. The specific screening conditions are: 1) located before the current feed stroke; 2) the absolute value of the rise rate is multiplied by the total duration of the current feed stroke, and the result is less than a preset ratio of the average torque.

[0052] In micro-hole machining, since the torque fluctuation during a single feed stroke when chip removal is smooth typically does not exceed 5% of the average torque, the preset ratio is set to 5%. Furthermore, the reference feed stroke should not be less than three. If the number of feed strokes that meet the screening criteria completed during the current drilling process is less than three, data from historical drilling processes that meet the screening criteria can be used as a supplement.

[0053] The maximum value of the average torque during the reference feed stroke is used as the upper limit of the average torque benchmark; the standard deviation of the real-time torque during each reference feed stroke is used as the torque fluctuation amplitude, and the arithmetic mean of the torque fluctuation amplitude is used as the fluctuation benchmark; the average of the absolute values ​​of the rise rate during the reference feed stroke is used as the rise rate benchmark. For the initial feed stroke of the first drilling operation, since the hole depth is the shallowest and the chip removal path is the shortest at this time, and the chips have not yet accumulated in the hole, the initial feed stroke is directly judged as smooth chip removal, and the average torque, torque fluctuation amplitude, and rise rate of the initial feed stroke are used as the corresponding benchmarks for subsequent feed strokes.

[0054] It should be added that the reference feed stroke selection and the calculation of the upper limit of the torque average reference, the fluctuation reference, and the rise rate reference are continuously and dynamically updated throughout the machining process: whenever a feed stroke that meets the selection criteria is completed, the completed feed stroke is included in the reference feed stroke, and the upper limit of the torque average reference, the fluctuation reference, and the rise rate reference are recalculated.

[0055] A chip removal anomaly is determined to exist when both of the following conditions are met simultaneously during the current feed stroke: 1) The average torque value of the current feed stroke exceeds the upper limit of the average torque value benchmark; 2) The rise rate is greater than a preset multiple of the rise rate benchmark. Otherwise, no chip removal anomaly is determined to exist. The preset multiple can be set to three times, based on statistical principles.

[0056] After determining that there is an abnormal chip removal, the spinneret material is determined from the workpiece material information table, and the adhesion tendency type is determined based on the hardness, ductility and thermal conductivity of the spinneret material.

[0057] Specifically, the Vickers hardness, elongation, and thermal conductivity of the current spinneret material are obtained from the workpiece material information table. The Vickers hardness, elongation, and thermal conductivity of known high adhesion tendency materials (such as gold-platinum alloy) and known low adhesion tendency materials (such as 316L stainless steel) are used as references. The median values ​​of Vickers hardness, elongation, and thermal conductivity of these two types of materials are taken as the hardness threshold, elongation threshold, and thermal conductivity threshold, respectively.

[0058] The adhesion tendency type is determined to be high adhesion tendency when at least two of the following conditions are met simultaneously: 1) the Vickers hardness of the current spinneret material is less than the hardness threshold; 2) the elongation is greater than the elongation threshold; 3) the thermal conductivity is less than the thermal conductivity threshold. The adhesion tendency type is determined to be medium adhesion tendency when only one of the above conditions is met; and the adhesion tendency type is determined to be low adhesion tendency when none of the above conditions are met.

[0059] Simultaneously, the cross-sectional shape of the current machined hole is obtained from the CAD / CAM programming file of the CNC machining program, and the corner risk is determined based on the cross-sectional shape: the included angle formed by two adjacent sides of the cross-section pointing inwards from the hole and less than 180 degrees is defined as an inward concave corner; the number of inward concave corners in the cross-section of the current machined hole is counted, and when the number of inward concave corners is greater than or equal to the preset number, it is determined that the current machined hole has a high corner risk; when the number of inward concave corners is less than the preset number, it is determined that the current machined hole has a low corner risk.

[0060] In actual processing, the number of concave corners of machining hole shapes such as Y-shaped, cross-shaped, triangular, trefoil-shaped, and star-shaped that are known to have high corner risks is greater than or equal to 3. Therefore, the preset number is set to 3.

[0061] When the adhesion tendency type is determined to be high adhesion tendency, and the machined hole shape has a low corner risk, the a priori indication type is built-up edge anomaly. When the adhesion tendency type is determined to be medium adhesion tendency, and the machined hole shape has a high corner risk, the a priori indication type is chip blockage anomaly. When the adhesion tendency type is determined to be low adhesion tendency, and the machined hole shape has a high corner risk, the a priori indication type is chip blockage anomaly.

[0062] The prior pointing type is marked as invalid when any of the following conditions are met: 1) The adhesion tendency type is determined to be high adhesion tendency, and the machined hole shape has a high corner risk; 2) The adhesion tendency type is determined to be low adhesion tendency, and the machined hole shape has a low corner risk; 3) The adhesion tendency type is determined to be medium adhesion tendency, and the machined hole shape has a low corner risk.

[0063] Next, the spectral entropy of each feed stroke in the reference feed stroke is arranged in order to obtain a spectral entropy sequence. The arithmetic mean and standard deviation of the spectral entropy sequence are calculated. The sum of three times the obtained standard deviation and the obtained arithmetic mean is used as the spectral entropy threshold. The standard deviation multiple is set based on the same criteria as the aforementioned preset multiple.

[0064] Next, based on the anomaly detection rules in the field of tool condition monitoring, frequency domain judgment is performed according to the frequency band energy ratio and spectral entropy. Specifically: when the frequency band energy ratio is greater than 1 and the spectral entropy is lower than the spectral entropy threshold, the frequency domain type is judged as built-up edge anomaly; when the frequency band energy ratio is less than or equal to 1 and the spectral entropy is higher than or equal to the spectral entropy threshold, the frequency domain type is judged as chip blockage anomaly. Otherwise, the frequency domain type is recorded as invalid.

[0065] Meanwhile, the impact interval distribution skewness threshold and the impact phase concentration threshold are determined as follows: Since a skewness absolute value greater than 0.5 is statistically considered to indicate asymmetry, the impact interval distribution skewness threshold is set to 0.5. The impact phase concentration threshold is taken as three times the arithmetic mean of the impact phase concentration during the reference feed stroke. The basis for setting the multiple of the arithmetic mean is the same as the basis for setting the aforementioned preset multiple.

[0066] Next, the time-domain type is determined based on the impact interval distribution skewness and impact phase concentration. Specifically: when the impact interval distribution skewness is greater than the skewness threshold and the impact phase concentration is lower than the impact phase concentration threshold, the time-domain type is determined to be an accumulated edge abnormality; when the impact interval distribution skewness is less than or equal to the skewness threshold and the impact phase concentration is higher than or equal to the phase concentration threshold, the time-domain type is determined to be a chip blockage abnormality. Otherwise, the time-domain type is recorded as invalid.

[0067] It should be added that if the impact interval distribution skewness is invalid, the time domain determination is based solely on the impact phase concentration; if the impact phase concentration is invalid, the time domain determination is based solely on the impact interval distribution skewness; if both the impact interval distribution skewness and the impact phase concentration are invalid, the time domain type is recorded as invalid.

[0068] When the prior type is not marked as invalid, if at least two of the prior type, frequency domain type, and time domain type point to the same anomalous type, then the corresponding anomalous type is taken as the final determined anomalous type. If the a prior type, frequency domain type, and time domain type point to different anomalous types, then the anomalous type pointed to by the frequency domain type is taken as the final determined anomalous type; if the frequency domain type is marked as invalid, then the anomalous type pointed to by the time domain type is taken as the final determined anomalous type; if the time domain type is marked as invalid, then the anomalous type pointed to by the prior type is taken as the final determined anomalous type.

[0069] When the prior pointing type is marked as invalid, if the frequency domain type and the time domain type point to the same anomaly type, the corresponding anomaly type will be used as the final determined anomaly type; if the frequency domain type and the time domain type point to different anomaly types, the anomaly type pointed to by the frequency domain type will be used as the final determined anomaly type; if both the frequency domain type and the time domain type are marked as invalid, the final determined anomaly type will be chip blockage anomaly.

[0070] To ensure machining safety, chip clogging anomalies must be addressed first; therefore, this is the default classification. Finally, the anomaly type is output to the parameter adjustment module.

[0071] Please see Figure 4 The parameter adjustment module is used to adjust the retraction distance, feed stroke length and drill speed according to whether there is chip removal abnormality, abnormality type, average torque and rise rate, and generate the adjusted pecking parameters.

[0072] Based on the combination of spinneret and drill bit materials, consult the cutting parameter recommendation table provided by the tool supplier to find the recommended cutting speed range corresponding to the combination. Multiply the lower limit of the recommended range by the ratio of the drill bit diameter to the reference diameter to obtain the adjusted cutting speed. If the recommendation table provides cutting speed recommendations segmented by drill bit diameter, directly select the corresponding cutting speed according to the segment where the current drill bit diameter is located. Multiply the cutting speed by 1000 to convert the unit of cutting speed from meters per minute to millimeters per minute. Divide the unit-converted cutting speed by the product of pi and the drill bit diameter to obtain the drill bit rotation speed. The reference diameter is the standard drill bit diameter on which the recommendation table is based.

[0073] After determining that there is a chip removal abnormality, the difference between the average torque value of the current feed stroke and the upper limit of the average torque value is taken as the current offset. The current offset is divided by the upper limit of the average torque value, and the resulting ratio is multiplied by the current feed stroke length to obtain the basic adjustment amount of the tool retraction distance.

[0074] If the current feed stroke is the first feed stroke of this drilling operation, the length of the current feed stroke is taken from the design feed stroke length in the process parameter table; if the current feed stroke is not the first feed stroke of this drilling operation, the adjusted feed stroke length is extracted from the adjusted pecking parameters and used as the current feed stroke.

[0075] Considering that when the chip removal abnormality is a built-up edge abnormality, only a small amount of additional retraction space is needed for the built-up edge to fall off during the retraction process, the base adjustment amount needs to be reduced.

[0076] The process of reducing the base adjustment is as follows: Based on the current drilling operation, select the maximum offset from all feed strokes that have been identified as having chip removal abnormalities up to the current feed stroke. Divide the current offset by the maximum offset to obtain the reduction factor used to reduce the base adjustment. Multiply the base adjustment by the reduction factor to obtain the retraction distance adjustment. If the current feed stroke is the first feed stroke identified as having chip removal abnormalities in this drilling process, the reduction factor is directly set to 1.

[0077] Considering that when the chip removal abnormality is chip blockage, sufficient retraction space is required to carry the chips out of the hole, the retraction distance adjustment amount is directly taken as the basic adjustment amount.

[0078] Then, the sum of the retraction distance of the current feed stroke and the adjustment amount of the retraction distance is calculated, and the smaller value between the obtained result and the maximum retraction distance is taken as the adjusted retraction distance. Among them, the maximum retraction distance is the axial distance between the current feed stop position of the drill bit and the hole position. The hole position is obtained from the CAD / CAM programming file, and the current feed stop position of the drill bit is obtained in real time through the encoder of the servo motor.

[0079] Next, multiply the torque increase rate by the feed rate read from the CNC machining program, and then divide by the product of the drill bit speed and the upper limit of the average torque reference to obtain the basic shortening of the feed stroke length.

[0080] When the chip removal abnormality is a built-up edge abnormality, shortening the feed stroke has a limited inhibitory effect on the built-up edge. Therefore, the amount of shortening the feed stroke length is zero, and the feed stroke length remains unchanged.

[0081] When the chip removal abnormality type is chip blockage abnormality, in order to reduce the chip removal burden, the feed stroke length needs to be shortened. Therefore, the amount of shortening the feed stroke length is directly taken as the basic shortening amount.

[0082] Subtract the current feed stroke length from the amount of feed stroke length reduction, compare the result with the minimum feed stroke length, and take the larger value as the adjusted feed stroke length. The minimum feed stroke length is the axial length of the drill cutting edge obtained from the tool specification.

[0083] Meanwhile, considering that when the chip removal anomaly is a built-up edge anomaly, since the formation of the built-up edge is related to the cutting temperature, reducing the rotational speed can reduce the generation of cutting heat, therefore, it is necessary to reduce the drill bit rotational speed. Specifically: divide the current offset by the upper limit of the torque average reference, then multiply the result by the quotient of the current fluctuation range divided by the fluctuation reference to obtain the speed reduction range. Multiply the current drill bit rotational speed by the speed reduction range, and multiply the product by negative one as the adjustment amount used to reduce the drill bit rotational speed.

[0084] When the chip removal anomaly is chip blockage, increasing the rotational speed can enhance the mechanical conveying capacity of the spiral grooves for chips and accelerate chip removal. Therefore, it is necessary to increase the drill bit rotational speed. Specifically, the current offset is divided by the upper limit of the average torque benchmark to obtain the increase range. The product of the current drill bit rotational speed and the increase range is used as the adjustment amount for increasing the drill bit rotational speed.

[0085] Next, the critical cutting speed obtained from the tool specification is multiplied by 1000 to convert the unit of the critical cutting speed from meters per minute (m / min) to millimeters per minute (mm / min). The converted critical cutting speed is then divided by the product of pi and the drill bit diameter to obtain the rotational speed corresponding to the critical cutting speed of the drill bit material. The smaller value between the highest rotational speed in the spindle motor technical parameter table and the rotational speed corresponding to the critical cutting speed of the drill bit material is taken as the maximum permissible rotational speed. Furthermore, the lowest stable rotational speed in the spindle motor technical parameter table is taken as the minimum permissible rotational speed.

[0086] Next, the current drill bit speed is added to the adjustment amount, and the result is compared with the minimum allowable speed, taking the larger value. Then, the larger value is compared with the maximum allowable speed, and the smaller value is taken as the adjusted drill bit speed. The adjusted retraction distance, adjusted feed stroke length, and adjusted drill bit speed are combined as the adjusted drilling parameters and output to the drilling execution module.

[0087] If the current feed stroke is determined to be free of chip removal abnormalities, and three consecutive feed strokes, including the current feed stroke, are determined to be free of chip removal abnormalities, it indicates that chip removal is currently smooth. The feed stroke length should be increased and the retraction distance reduced to improve machining efficiency. The drill speed should remain unchanged when chip removal is smooth; otherwise, the current pecking parameters should remain unchanged.

[0088] Specifically, first subtract the average torque of the current feed stroke from the upper limit of the average torque benchmark, then divide by the upper limit of the average torque benchmark to obtain the load margin ratio; multiply the current feed stroke length by the load margin ratio to obtain the feed stroke length increase.

[0089] Next, obtain the drill bit's cutting edge length from the tool specification, and take the smaller value between the drill bit's cutting edge length and the current remaining hole depth as the maximum feed stroke length. Select the smaller value between the sum of the current feed stroke length and the feed stroke length increment, and the maximum feed stroke length, as the adjusted feed stroke length.

[0090] The remaining hole depth is calculated in real time by the drilling execution module based on the number of completed pecking cycles and the feed stroke length; the specific calculation process is existing technology and will not be elaborated here.

[0091] Then, the difference between the retraction distance of the current feed stroke and the minimum retraction distance is taken as the maximum reduction amount; the ratio of the torque fluctuation amplitude of the current feed stroke to the fluctuation reference is calculated, which reflects the relative magnitude of the torque fluctuation of the current feed stroke relative to the fluctuation level when chip removal is smooth; the difference between the current feed stroke and the ratio is taken as the reduction ratio; the larger the reduction ratio, the smaller the torque fluctuation of the current feed stroke, the smoother the current chip removal, and the greater the space for reducing the retraction distance.

[0092] Then, the maximum reduction amount is multiplied by the reduction ratio to obtain the reduction in retraction distance. The minimum retraction distance is the axial length of the drill cutting edge, obtained directly from the tool specification. When the calculated reduction ratio is less than zero, the reduction ratio is set to zero.

[0093] Select the larger of the difference between the current feed stroke's retraction distance and the reduction in retraction distance, and the minimum retraction distance, as the adjusted retraction distance. Output the adjusted feed stroke length and the adjusted retraction distance as the adjusted drill biting parameters.

[0094] The drilling execution module is used to drive the drill bit to perform a pecking action according to the pecking parameters and output the drill bit motion parameters. Specifically, the servo motor is controlled to drive the drill bit to complete one complete pecking cycle action according to the following steps: First, the speed of the spindle motor is set to the adjusted drill bit speed. Then, the servo motor is controlled to drive the drill bit to perform axial feed motion from the current retraction stop position towards the bottom of the hole at the feed speed.

[0095] The feed rate is obtained as follows: Based on the combination of spinneret material and drill bit material, the recommended range of feed per revolution corresponding to the combination is consulted from the cutting parameter recommendation table; the lower limit of the recommended range is multiplied by the ratio of the drill bit diameter to the reference diameter to obtain the adjusted feed per revolution. If the recommendation table already provides recommended feed per revolution values ​​segmented by drill bit diameter, the corresponding feed per revolution is directly selected according to the segment where the current drill bit diameter is located, and the feed per revolution is multiplied by the drill bit rotation speed to obtain the feed per minute, i.e., the feed rate.

[0096] During the feeding process, the axial displacement of the drill bit is read in real time by the encoder of the servo motor. The encoder converts the rotation angle of the servo motor into the axial position of the drill bit. Each pulse signal corresponds to a fixed axial displacement increment, and the axial displacement of the drill bit since the current retraction stop position is continuously accumulated and calculated.

[0097] When the axial displacement of the drill bit equals the adjusted feed stroke length, the drilling execution module sends a stop command to the servo driver, and the servo motor stops feeding. The axial position of the drill bit at this time is taken as the feed stop position.

[0098] After the feed action stops, the drilling execution module controls the servo motor to drive the drill bit to move axially backward toward the hole opening at the retraction speed. The retraction speed is directly read from the equipment technical manual.

[0099] During the retraction process, the drilling execution module calculates the axial displacement of the drill bit in real time from the feed stop position using the encoder of the servo motor. When the axial displacement of the drill bit equals the adjusted retraction distance, the drilling execution module sends a stop command to the servo driver, and the servo motor stops retracting the drill bit. The axial position of the drill bit at this time is taken as the new current retraction stop position for use in the next drilling cycle.

[0100] During the aforementioned feed and retraction process, the drilling execution module continuously acquires the encoder feedback position of the servo motor in real time, generates drill bit motion parameters based on the encoder feedback position, and outputs the drill bit motion parameters to the coolant control module in real time.

[0101] The drill bit motion parameters include the axial motion direction and the real-time axial position. When the drill bit moves towards the bottom of the hole, the axial motion direction is the feed direction; when the drill bit moves towards the hole opening, the axial motion direction is the retraction direction. The real-time axial position is determined by encoder feedback and reflects the absolute axial position coordinates of the drill bit relative to the hole opening at the current moment.

[0102] After the retraction action stops, one pecking drill cycle is completed. The system then waits for the chip removal judgment module to assess the current feed stroke, and for the pecking drill parameter adjustment module to generate adjusted pecking drill parameters for the next cycle. After inputting the new adjusted pecking drill parameters, the drilling execution module restarts the next pecking drill cycle until machining is complete.

[0103] The coolant control module is used to adjust the coolant flow rate and flushing duration based on the drill bit motion parameters and impact distribution parameters.

[0104] In practice, when the axial movement direction is the retraction direction, the drill bit is determined to be in the retraction stage; when the axial movement direction is the feed direction, the drill bit is determined to be in the feed stage.

[0105] During the retraction phase, the drill bit is further judged based on its real-time axial position to determine whether it has exited the hole: when the drill bit moves toward the hole and its real-time axial position is less than or equal to the axial coordinate of the hole, it is determined that the drill bit has exited the hole; otherwise, it is determined that the drill bit has not exited the hole; the axial coordinate of the hole is read from the CAD / CAM programming file.

[0106] If the drill bit has not exited the borehole, pulse flushing will not be performed; if it has exited the borehole, the remaining time of the retraction action from the time the drill bit exits the borehole will be used as the base pulse duration.

[0107] The remaining retraction time is equal to the ratio of the adjusted retraction distance to the retraction speed, minus the time it takes for the drill bit to move from the feed stop position to the borehole position.

[0108] When there are no chip removal abnormalities in the current feed stroke, the drill bit is pulse-flushed according to the basic pulse duration and the basic coolant flow rate. The basic coolant flow rate is the arithmetic mean of the actual coolant output flow rate corresponding to each feed stroke. The actual coolant output flow rate is the measured flow rate value within the corresponding feed stroke, which is obtained from the output parameters of the coolant pump.

[0109] When there is a chip removal abnormality in the current feed stroke, first multiply the coolant base flow rate by the ratio of the current offset to the upper limit of the torque average reference to obtain the initial increase.

[0110] When the chip removal anomaly type is built-up edge anomaly, the initial increment is multiplied by the ratio of the torque fluctuation amplitude of the current feed stroke to the fluctuation baseline to obtain the base increment; when the chip removal anomaly type is chip blockage anomaly, the initial increment is directly used as the base increment.

[0111] To better match the actual severity of the current chip removal anomaly, the baseline increase and baseline pulse duration are corrected based on the impact distribution parameters. Specifically, when the chip removal anomaly type is a buildup, the baseline pulse duration is not corrected; it is directly taken as the corrected baseline pulse duration.

[0112] Meanwhile, the energy adjustment factor is obtained by dividing the average impact energy of the current feed stroke by the historical impact energy benchmark; the base increment is multiplied by the energy adjustment factor to obtain the corrected base increment; the historical impact energy benchmark is the average value of the average impact energy in the reference feed stroke.

[0113] When the chip removal anomaly type is chip blockage anomaly, the base increment is not corrected; the corrected base increment is directly taken as the base increment. Simultaneously, the average impact duration of the current feed stroke is divided by the historical impact duration benchmark to obtain the duration adjustment factor. The base pulse duration is then multiplied by the duration adjustment factor to obtain the corrected base pulse duration. The historical impact duration benchmark is the arithmetic mean of the average impact durations in the reference feed stroke. It should be noted that when the impact distribution parameter is marked as invalid, both the corresponding energy adjustment factor and duration adjustment factor are set to 1.

[0114] Next, the base coolant flow rate is added to the corrected base increase, and the result is compared with the maximum coolant output flow rate. The smaller value is taken as the increased coolant flow rate. The corrected base pulse duration is compared with the remaining retraction time, and the smaller value is taken as the pulse flushing duration. The maximum coolant output flow rate is obtained from the specifications of the coolant pump used to supply the coolant.

[0115] Finally, the drill bit is pulse-flushed with increased coolant flow rate for the specified pulse flush duration. During the pulse flush, coolant is ejected from the nozzle at an increased flow rate, subjecting the drill bit's auger flutes, drill tip area, or bottom hole chip pad to high-pressure flushing. After the pulse flush ends, coolant is continuously supplied at the base flow rate during subsequent feed stages.

[0116] It should be added that when the drill bit speed has reached the maximum permissible speed, but chip removal abnormalities still exist, the drill bit speed should be kept constant, while increasing the amount of retraction distance and the duration of coolant pulse flushing. Similarly, when the retraction distance or feed stroke length reaches its respective limit, the parameter that has reached the limit should be kept constant, and only the other adjustable parameters should be adjusted.

[0117] When any two of the following parameters—drill bit speed, retraction distance, and feed stroke length—reach their respective limits simultaneously, or all three parameters reach their respective limits, but chip removal abnormalities still exist, the parameters that have reached their limits are kept unchanged, and the remaining parameters that have not yet reached their limits are adjusted to their limit values. At the same time, an enhanced flushing protection mode is adopted: the coolant flushing flow rate and pulse flushing duration are both increased to their respective maximum values.

[0118] If the chip removal abnormality is not eliminated in the enhanced flushing protection mode, an alarm signal will be output to prompt the operator to intervene.

[0119] Please see Figure 2 The present invention also provides a method for controlling the perforation of the spinneret in cellulose acetate spinning, comprising the following steps: S1. Calculate the average torque and rate of increase of the current feed stroke based on the real-time torque of the spindle motor.

[0120] S2. Extract acoustic parameters and impact distribution parameters based on the acoustic emission signals during the drilling process.

[0121] S3. Based on the average torque and the rising rate, determine whether there is a chip removal abnormality; and based on the machining hole geometry parameters, acoustic parameters and impact distribution parameters, determine the type of abnormality.

[0122] S4. Based on the anomaly type, average torque, and rise rate, adjust the retraction distance, feed stroke length, and drill speed, and generate the adjusted pecking parameters.

[0123] S5. Drive the drill bit to perform the pecking action according to the pecking parameters, and output the drill bit motion parameters.

[0124] S6. Adjust the coolant flow rate and flushing duration according to the drill bit motion parameters and impact distribution parameters.

[0125] The above embodiments can be implemented, in whole or in part, by software, hardware, firmware, or any other combination thereof. When implemented using software, the above embodiments can be implemented, in whole or in part, in the form of a computer program product.

[0126] Those skilled in the art will recognize that the modules and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementations should not be considered beyond the scope of this invention.

[0127] In addition, the functional modules in the various embodiments of the present invention can be integrated into one processing module, or each module can exist physically separately, or two or more modules can be integrated into one module.

[0128] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

[0129] Finally, the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A control system for perforating a spinneret in cellulose acetate spinning, characterized in that, include: The torque acquisition module is used to calculate the average torque and rate of increase of the current feed stroke based on the real-time torque of the spindle motor. The acoustic emission acquisition module is used to extract acoustic pattern parameters and impact distribution parameters based on the acoustic emission signals during the drilling process. The chip removal judgment module is used to determine whether there is a chip removal abnormality based on the average torque and the rising rate; and to determine the type of abnormality based on the machining hole geometry parameters, acoustic parameters and impact distribution parameters. The parameter adjustment module is used to adjust the retraction distance, feed stroke length and drill speed according to the anomaly type, average torque and rise rate, so as to generate the adjusted pecking parameters; The drilling execution module is used to drive the drill bit to perform the pecking action according to the pecking parameters, and output the drill bit motion parameters; The coolant control module is used to adjust the coolant flow rate and flushing duration based on drill bit motion parameters and impact distribution parameters.

2. The cellulose acetate spinning spinneret perforation control system as described in claim 1, characterized in that, The calculation process for the average torque and the rate of rise is as follows: The moment when the drill bit moves from its current retraction stop position toward the bottom of the hole is taken as the starting point of the current feed stroke; The moment when the drill bit stops moving towards the bottom of the hole and begins to move in the opposite direction is taken as the end point of the current feed stroke; The real-time torques collected between the start and end times are summed, and the summation result is divided by the number of sampling points between the start and end times to obtain the average torque. The real-time torque collected between the start and end times is linearly fitted, and the rate of increase is obtained by analysis.

3. The cellulose acetate spinning spinneret perforation control system as described in claim 1, characterized in that, The process of extracting voiceprint parameters and impact distribution parameters is as follows: The acoustic emission signal within the current feed stroke is subjected to Fourier transform to obtain the power spectral density. The peak frequency, center frequency, frequency band energy ratio and spectral entropy are calculated based on the power spectral density and combined to form the acoustic pattern parameters. Based on the signal amplitude and the impact threshold, the start and end times of the impact are determined. The time difference between the start and end of the impact is taken as the impact duration. Calculate the square integral of the signal amplitude over the duration of the impact as the impact energy; Calculate the time difference between the start times of all adjacent impacts within the current feed stroke, and construct an impact interval sequence; The third-order normalized moments of the impact interval sequence are calculated to obtain the impact interval distribution skewness; Calculate the standard deviation of the impact phase angles based on all impact phase angles within the current feed stroke, and use it as the impact phase concentration. The average impact energy, average impact duration, impact interval skewness, and impact phase concentration are combined to form the impact distribution parameters.

4. A cellulose acetate spinning spinneret perforation control system as described in claim 3, characterized in that, The specific process for determining whether there is a chip removal abnormality is as follows: A series of consecutive feed strokes in which the product of the absolute value of the rate of ascent and the total duration of the current feed stroke is less than a preset ratio of the average torque before the current feed stroke will be used as reference feed strokes; The maximum value of the average torque during the feed stroke will be used as the upper limit of the average torque. The average value of torque fluctuation during the reference feed stroke is used as the fluctuation reference; the average value of the absolute value of the rise rate during the reference feed stroke is used as the rise rate reference. If the average torque value of the current feed stroke exceeds the upper limit of the average torque value reference, and the rising rate is greater than the preset multiple of the rising rate reference, then it is determined that there is a chip removal abnormality. Otherwise, it is determined that there is no chip removal abnormality.

5. A cellulose acetate spinning spinneret perforation control system as described in claim 1, characterized in that, The process for determining the exception type is as follows: Based on the shape of the processing hole and the material of the spinneret, the adhesion tendency and corner risk are determined, and a priori orientation type is judged. Frequency domain type is determined based on the bandwidth energy ratio and spectral entropy; Time-domain type determination is performed based on impact interval distribution skewness and impact phase concentration. The anomaly type is determined based on the prior pointing type, frequency domain determination type, and time domain determination type.

6. A cellulose acetate spinning spinneret perforation control system as described in claim 5, characterized in that, The process of generating the adjusted pecking parameters is as follows: After determining that there is a chip removal abnormality, the difference between the average torque value of the current feed stroke and the upper limit of the average torque value is used as the current offset. Based on the anomaly type, the retraction distance adjustment amount is determined by combining the current offset and the current feed stroke length; By combining the rise rate and feed rate, determine the amount of shortening the feed stroke length; by combining the torque fluctuation range of the current feed stroke, the drill bit speed, and the current offset, determine the amount of adjustment of the drill bit speed. Calculate the sum of the retraction distance of the current feed stroke and the retraction distance adjustment amount, and take the smaller value between the obtained result and the maximum retraction distance as the adjusted retraction distance; Calculate the difference between the current feed stroke length and the shortening amount, and take the larger of the difference and the minimum feed stroke length as the adjusted feed stroke length; First, take the larger value between the sum of the drill bit speed and the adjustment amount during the current feed stroke and the minimum allowable speed. Then, take the smaller value between the larger value and the maximum allowable speed as the adjusted drill bit speed. The adjusted retraction distance, adjusted feed stroke length, and adjusted drill bit speed are all used as the output of the adjusted pecking parameters.

7. A cellulose acetate spinning spinneret perforation control system as described in claim 4, characterized in that, The process of generating the adjusted drill biting parameters also includes: When no chip removal abnormality is detected in multiple consecutive feed strokes, the upper limit of the average torque is subtracted from the average torque of the current feed stroke, and then divided by the upper limit of the average torque to obtain the load margin ratio. Multiply the current feed stroke length by the load margin ratio to obtain the feed stroke length increase; Select the smaller value between the sum of the current feed stroke length and the feed stroke length increase, and the maximum feed stroke length, as the adjusted feed stroke length; The difference between the current feed stroke's retraction distance and the minimum retraction distance is used as the maximum reduction amount; Calculate the ratio of the torque fluctuation amplitude of the current feed stroke to the fluctuation reference, and subtract the ratio from one to obtain the reduction ratio; Multiply the maximum reduction amount by the reduction ratio to obtain the reduction in the retraction distance; Choose the larger of the following values: the difference between the current feed stroke's retraction distance and the reduction in retraction distance, and the minimum retraction distance, as the adjusted retraction distance.

8. A cellulose acetate spinning spinneret perforation control system as described in claim 1, characterized in that, The process of outputting drill bit motion parameters is as follows: During the process of the servo motor driving the drill bit to move from the current retraction stop position towards the bottom of the hole, the feed stops when the axial displacement of the drill bit is equal to the adjusted feed stroke length; the axial position of the drill bit when the feed stops is taken as the feed stop position; During the process of the servo motor driving the drill bit to move from the feed stop position toward the hole opening, the retraction of the drill bit stops when the axial displacement of the drill bit is equal to the adjusted retraction distance. During the feed and retraction processes, drill motion parameters, including the axial movement direction and real-time axial position, are generated.

9. A cellulose acetate spinning spinneret perforation control system as described in claim 5, characterized in that, The process of adjusting the coolant flow rate and flushing duration is as follows: The remaining time after the drill bit exits the borehole is used as the basic pulse duration. When there is no chip removal abnormality, flush with the coolant at the base flow rate according to the base pulse duration; When there is a chip removal abnormality: determine the basic increase in coolant flow rate based on the abnormality type, average torque, and torque fluctuation amplitude; Based on the anomaly type and the current average impact energy, the baseline increase is corrected; and based on the current average impact duration, the baseline pulse duration is corrected. The smaller value between the base coolant flow rate and the corrected base increase, and the maximum coolant output flow rate, is selected as the increased coolant flow rate. The smaller value between the corrected base pulse duration and the remaining retraction time is selected as the pulse flushing duration; The coolant flow rate is increased to perform flushing according to the pulse flushing duration.

10. A method for controlling the perforation of a spinneret in cellulose acetate spinning, characterized in that, The steps include: calculating the average torque and rate of increase of the current feed stroke based on the real-time torque of the spindle motor; Based on the acoustic emission signals during the drilling process, acoustic parameters and impact distribution parameters are extracted. Based on the average torque and the rate of rise, determine whether there is any chip removal abnormality; Based on the machining hole geometry parameters, acoustic signature parameters, and impact distribution parameters, the anomaly type is determined; Based on the presence of chip removal abnormalities, the type of abnormality, the average torque value, and the rate of rise, the retraction distance, feed stroke length, and drill speed are adjusted to generate the adjusted pecking parameters; The drill bit is driven to perform a pecking action based on the pecking parameters, and the drill bit motion parameters are output. The coolant flow rate and flushing duration are adjusted based on the drill bit motion parameters and impact distribution parameters.

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