A method for finish machining and drilling of a planetary carrier of a planetary reduction gear

Abstract

The application relates to the technical field of planet carrier machining, in particular to a fine machining and drilling method for a planet carrier of a planetary reducer, which comprises the following steps: in each machining stage in the fine machining process of the planet carrier, various monitoring data are collected in real time; in each machining stage, the temperature rise deviation characteristic value at each moment is obtained; the time period between the current moment and the initial moment of the machining stage is divided into various temperature rise response intervals; the associated response deviation characteristic value of the various monitoring data in each temperature rise response interval is obtained; the thermal cumulative influence coefficient in each temperature rise response interval is obtained in combination with the change trend of the various monitoring data in each temperature rise response interval; the adjustment response characteristic value of the current moment is obtained; and the cutting speed and the injection pressure of the cutting fluid at the current moment are adjusted. The application aims to effectively reduce the machining deviation of the planet carrier caused by the workpiece deformation and deviation due to the thermal cumulative effect, and improve the machining precision and use performance of the planet carrier.

Description

Technical Field

[0001] This application relates to the field of planetary carrier machining technology, specifically to a method for precision turning and drilling of a planetary carrier for a planetary gear reducer. Background Technology

[0002] Planetary gear reducers are high-precision transmission devices composed of a sun gear, planet gears, a planet carrier, and internal gears. They offer advantages such as high transmission efficiency and high torque density, and are widely used in fields such as intelligent robot joint research and new energy power systems. The planet carrier is the core carrier for power transmission in a planetary gear reducer, and it must simultaneously meet the requirements of high strength load-bearing and high-precision positioning. The machining quality of the planet carrier directly affects the transmission accuracy and service life of the reducer. Currently, the machining process for planetary carriers generally includes roughing, semi-finishing turning, boring, finish turning, drilling, and finishing. With the increasing precision requirements of planetary gear reducers, planet carrier machining is gradually adopting automation technology to achieve high-precision processing.

[0003] During the finishing and drilling processes of planetary carriers, the friction between the tool and the workpiece generates heat, leading to a heat accumulation effect. As the temperature rises, the material may deform. Furthermore, as the machining process progresses, factors such as temperature changes and loosening of the clamping tools may cause the workpiece to shift, affecting the stability of parameters during finishing and drilling. Traditional control methods for finishing and drilling do not fully consider the impact of heat accumulation and workpiece abnormalities on machining accuracy. This makes it difficult to respond promptly to changes in workpiece temperature and workpiece shifts during actual control, thus affecting the machining accuracy and performance of the planetary carrier. Summary of the Invention

[0004] In view of the above, it is necessary to provide a precision turning and drilling method for the planetary carrier of a planetary reducer. Compared with the traditional precision turning and drilling method for the planetary carrier of a planetary reducer, this method effectively reduces the machining deviation of the planetary carrier caused by workpiece deformation and offset due to heat accumulation effect, thereby improving the machining accuracy and performance of the planetary carrier.

[0005] The method for precision turning and drilling the planetary carrier of a planetary gear reducer disclosed in this application adopts the following technical solution:

[0006] One embodiment of this application provides a method for precision turning and drilling the planetary carrier of a planetary gear reducer, the method comprising the following steps:

[0007] During each stage of the planetary carrier precision turning process, various monitoring data are collected in real time, including temperature data and cutting speed data.

[0008] Within each processing stage, the temperature rise deviation characteristic value at each moment is obtained by analyzing the degree of deviation of the temperature data from its rated value and the abnormality of the temperature data at each moment. The time period is divided into temperature rise response intervals by analyzing the changes in the temperature rise deviation characteristic values ​​at all moments between the current moment and the initial moment of the processing stage. By comparing the peak occurrence times of various monitoring data in each temperature rise response interval with those of other monitoring data, the correlation response deviation characteristic value of various monitoring data in each temperature rise response interval is obtained. Combined with the changing trends of various monitoring data in each temperature rise response interval, the heat accumulation influence coefficient in each temperature rise response interval is obtained. Finally, combined with the dispersion of temperature data in each temperature rise response interval, the adjustment response characteristic value at the current moment is obtained.

[0009] Based on the temperature rise during the specified time period and the adjustment response characteristic value, the cutting speed and the injection pressure of the cutting fluid at the current moment are adjusted.

[0010] In one embodiment, the process of obtaining the temperature rise deviation characteristic value is as follows:

[0011] Calculate the ratio of the difference between the temperature data at each time point and its rated value to the rated value;

[0012] Obtain anomaly scores for temperature data at various times;

[0013] The characteristic value of the temperature rise deviation is the product of the ratio and the anomaly score.

[0014] In one embodiment, the process of obtaining the temperature rise response range is as follows:

[0015] Obtain the time-series fitting curve of the temperature rise deviation characteristic value at all times within the time period, obtain the occurrence time of each extreme value in the fitting curve, and divide the time period into each temperature rise response interval by the occurrence time.

[0016] In one embodiment, the process of obtaining the associated response deviation feature value is as follows:

[0017] Number the times within each temperature rise response interval according to the time sequence;

[0018] Obtain the time number of all peak values ​​of various monitoring data within each temperature rise response interval in the time series;

[0019] Obtain the difference between the various monitoring data and the number of each other monitoring data within each temperature rise response interval;

[0020] The correlation response deviation characteristic value is obtained by the difference between various monitoring data and all other monitoring data within each temperature rise response interval.

[0021] In one embodiment, the correlation response deviation characteristic value is the average of the differences between various monitoring data and all other monitoring data within each temperature rise response interval.

[0022] In one embodiment, the process of obtaining the thermal accumulation influence coefficient is as follows:

[0023] Obtain trend statistics of various monitoring data within each temperature rise response interval;

[0024] The product of the correlation response deviation characteristic value and the trend statistic is denoted as the comprehensive product;

[0025] The heat accumulation influence coefficient is the average of the comprehensive product of all monitoring data within each temperature rise response interval.

[0026] In one embodiment, the process of obtaining the adjusted response feature value is as follows:

[0027] The product of the normalized value of the dispersion and the thermal accumulation influence coefficient is denoted as the weighted product;

[0028] The adjusted response characteristic value is the sum of the weighted products within all temperature rise response intervals during the time period.

[0029] In one embodiment, adjusting the cutting speed and the injection pressure of the cutting fluid at the current moment includes:

[0030] Calculate the range of temperature data within the time period, and record the difference between the current temperature data and the previous temperature data as the temperature difference value;

[0031] If both the range and the temperature difference are less than the preset temperature rise threshold, the current cutting speed is maintained; the judgment threshold is obtained by analyzing the distribution of adjustment response characteristic values ​​in multiple historical processing stages that are the same as the current processing stage; the injection pressure of the cutting fluid at the current moment is adjusted by comparing the adjustment response characteristic value at the current moment with the judgment threshold.

[0032] Otherwise, adjust the current cutting speed to the product of the current cutting speed and the preset ratio, and adjust the current cutting fluid injection pressure to the preset value.

[0033] In one embodiment, the process of adjusting the current cutting fluid injection pressure is as follows:

[0034] If the adjustment response characteristic value at the current moment is less than the judgment threshold, then the current setting of the cutting fluid injection pressure is maintained;

[0035] Otherwise, the adjustment factor at the current moment is obtained by measuring the difference between the adjustment response characteristic value at the current moment and the judgment threshold; the difference between the preset upper limit of the cutting fluid injection pressure and the initial injection pressure of the current processing stage is recorded as the pressure difference; the product of the pressure difference and the adjustment factor is calculated, and the cutting fluid injection pressure at the current moment is adjusted to the sum of the product value and the initial injection pressure.

[0036] In one embodiment, the process of obtaining the adjustment factor is as follows:

[0037] Map the current adjustment response characteristic value to a positive number;

[0038] The adjustment factor is the ratio of the difference between the current adjustment response feature value and the judgment threshold to the positive number.

[0039] This application has at least the following beneficial effects:

[0040] This application obtains temperature rise deviation characteristic values ​​by analyzing the degree of temperature data deviation from rated values ​​and abnormal temperature data, which can quantify the impact of temperature changes on the machining process and help identify heat accumulation effects. Furthermore, considering that the temperature rise deviation caused by heat accumulation during workpiece machining is phased, the temperature rise deviation characteristic values ​​are used to divide the machining process, obtaining each temperature rise response interval, allowing for a more detailed analysis of the heat accumulation effect at different stages. By calculating the correlation response deviation characteristic values, the correlation between different monitoring data is quantified, helping to identify the synchronicity of changes in different types of monitoring data during machining. Combining the changing trends of various monitoring data, a heat accumulation influence coefficient is obtained, reflecting the impact of heat accumulation on the machining process and assessing the possibility of workpiece deformation due to temperature rise changes caused by heat accumulation. This provides a more reliable reference for subsequent machining parameter adjustments, thereby reducing machining errors caused by heat accumulation. Furthermore, by combining the temperature disturbance characteristics of different machining stages, adjustment response characteristic values ​​are obtained, providing a quantitative basis for adjusting cutting speed and cutting fluid injection pressure. Dynamically adjusting machining parameters effectively reduces the machining deviation of the planetary carrier caused by workpiece deformation and displacement due to heat accumulation effects, improving the machining accuracy and performance of the planetary carrier. Attached Figure Description

[0041] To more clearly illustrate the technical solutions and advantages in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0042] Figure 1A flowchart illustrating the steps of a method for precision turning and drilling a planetary gearbox planetary carrier provided in this application;

[0043] Figure 2 A schematic diagram of the control and optimization process;

[0044] Figure 3 A schematic diagram illustrating the process of obtaining adjusted response feature values;

[0045] Figure 4 A schematic diagram illustrating the calculation process for adjusting response characteristic values. Detailed Implementation

[0046] In the description of the embodiments in this application, the words "exemplary," "or," and "for example" are used to indicate examples, illustrations, or descriptions. Any embodiment or design scheme described as "exemplary" or "for example" in the embodiments of this application should not be construed as being more preferred or advantageous than other embodiments or design schemes. Specifically, the use of the words "exemplary," "or," and "for example" is intended to present the relevant concepts in a specific manner.

[0047] 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 application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. It should be understood that, unless otherwise stated, " / " in this application means "or".

[0048] It should also be noted that the terms "first" and "second" in this application are used to distinguish similar objects, rather than to describe a specific order or sequence.

[0049] The following description, in conjunction with the accompanying drawings, details a specific scheme for the precision turning and drilling method of the planetary carrier of a planetary gear reducer provided in this application.

[0050] This application provides a method for precision turning and drilling the planetary carrier of a planetary gear reducer, specifically, a method for precision turning and drilling the planetary carrier of a planetary gear reducer is provided below. Please refer to [link to relevant documentation]. Figure 1 The method includes the following steps:

[0051] Step 1: Raw material preparation and preliminary processing.

[0052] Before precision turning, the raw material pretreatment, rough machining, stress relief treatment, and datum positioning are required. The specific process is as follows:

[0053] (1) Raw material pretreatment

[0054] 40Cr forged steel is selected as the blank, and the blank is forged into a disc-shaped billet through die forging or free forging. During the forging process, the initial temperature is controlled at 1100℃~1200℃, and the final forging temperature is ≥800℃ to avoid coarse grains and forging cracks. After forging, normalizing treatment is performed at 850℃~870℃ for 2~3 hours. After normalizing, air cooling is performed to homogenize the material's microstructure, and the hardness is controlled at 180HB~220HB. In this embodiment, the initial temperature during forging is controlled at 1100℃, the normalizing temperature at 850℃, the treatment time at 2 hours, and the hardness at 180HB.

[0055] (2) Rough machining and forming

[0056] The end faces of the pre-treated blank material are machined using a CNC machine tool, ensuring a machining allowance of 5mm to 8mm in the thickness direction. After the end faces are machined, the outer diameter is machined to remove the oxide scale, making the outer diameter 8mm to 10mm larger than the finished product. After the outer diameter is machined, a center hole is drilled, making the center hole 10mm to 15mm smaller than the finished product's center shaft hole. In this embodiment, a 5mm machining allowance is reserved in the thickness direction, the outer diameter is 8mm larger than the finished product, and the center hole is 10mm smaller than the finished product's center shaft hole.

[0057] (3) Stress relief treatment and datum positioning

[0058] The rough-machined material is placed in an environment of 200℃~220℃ for 4 to 6 hours to release the internal stress generated during cutting and prevent workpiece deformation during finish machining. After the heat treatment, a dial indicator is used to check the coaxiality of the outer circle and the center hole of the material. The coaxiality after rough machining must be controlled within 0.1mm~0.15mm. In this embodiment, the rough-machined material is placed in an environment of 200℃ for 4 hours for heat treatment, and the coaxiality after rough machining is controlled within 0.1mm.

[0059] Step 2, semi-finish turning and boring.

[0060] (1) Semi-finishing

[0061] Using a CNC machine tool, such as a CK6150 CNC machine tool, the workpiece is semi-finished. During machining, the cutting speed is 80 m / min to 120 m / min, the feed rate is 0.2 mm / r to 0.3 mm / r, and the depth of cut is 1 mm to 2 mm. A PLC (Programmable Logic Controller) control system monitors and controls the machining parameters in real time during the machining process to achieve stable control. In this embodiment, the cutting speed is 80 m / min, the feed rate is 0.2 mm / r, and the depth of cut is 1 mm.

[0062] (2) Boring

[0063] Using a CNC boring machine, such as the TK6513, the workpiece after semi-finish turning is processed. During the machining process, the boring speed is 60m / min~90m / min, the feed rate is 0.15mm / r~0.25mm / r, and the depth of cut is 2mm~4mm. Multi-hole machining is performed in the order of center hole-pin hole. After each boring process, the chips are blown away with an air gun. The roundness error of the hole after rough boring is 0.03mm~0.05mm, and the hole diameter is 3mm~5mm larger than the target size of finish boring, so as to leave sufficient machining allowance for finish boring. In this embodiment, the boring speed during the machining process is 60m / min~90m / min, the feed rate is 0.15mm / r~0.25mm / r, the depth of cut is 2mm~4mm, the roundness error of the hole after rough boring is 0.03mm, and the hole diameter is 3mm larger than the target size of fine boring.

[0064] After rough boring, the workpiece is precision boring using a high-precision CNC boring machine. During the machining process, the boring speed is 50 m / min to 80 m / min, the feed rate is 0.08 mm / r to 0.12 mm / r, and the depth of cut is 0.1 mm to 0.3 mm. Two to three finishing passes are performed. During machining, an 8% to 10% water-soluble cutting fluid is used for cooling at a spray pressure of 0.5 MPa to 0.8 MPa to prevent overheating. A PLC control system monitors the machining parameters in real time during the different stages of boring to maintain process stability. In this embodiment, the boring speed is 50 m / min, the feed rate is 0.08 mm / r, the depth of cut is 0.1 mm, and two finishing passes are performed. An 8% water-soluble cutting fluid is used for cooling during the finishing process at a spray pressure of 0.5 MPa.

[0065] Step 3, precision machining.

[0066] The machining process is performed using a CNC machine tool with a positioning accuracy of ±0.003mm. In this application, an HTC3250n CNC machine tool is used for this process. Specifically, a high-speed steel mandrel with a tolerance ≤0.005mm is first fitted with a rough-machined center hole to form an H7 / g6 transition fit, with a clearance of 0.01mm~0.02mm. One end of the mandrel is rigidly clamped by a three-jaw chuck, while the other end is axially positioned by an end face drive center. A flexible pressure plate lightly presses the end face, with the pressing pressure controlled at 300N~500N. After clamping, the radial runout is detected using a spindle encoder to ensure that the radial runout is ≤0.005mm, thus reducing positioning errors. In this embodiment, the clearance is 0.01mm, and the pressing pressure is controlled at 300N.

[0067] After clamping, the end face is machined using a TiAlN coated carbide tool. The cutting speed is set to 120m / min~150m / min, the feed rate to 0.1mm / r~0.15mm / r, and the depth of cut to 0.2mm~0.3mm, ensuring a flatness of ≤0.1mm and allowing 0.3mm of grinding allowance. After machining the end face, the center bottom hole is machined using a precision-ground internal drilling tool. The cutting speed is set to 80m / min~100m / min, and the feed rate to 0.08mm. The cutting process is carried out in two stages at a speed of 0.1 mm / r to 0.1 mm / r until the tolerance reaches IT7 grade. After the center hole is machined, a CNMG120408 external turning tool is used to process the outer diameter at a cutting speed of 150 m / min to 180 m / min and a feed rate of 0.1 mm / r to 0.12 mm / r, ensuring that the coaxiality between the outer diameter and the center hole is ≤0.01 mm. During the above cutting process, the cutting fluid injection pressure is 0.3 MPa to 0.6 MPa. In this embodiment, the cutting fluid injection pressure is 0.3 MPa. During the finish turning process, multiple sensors are used to monitor the machining parameters and temperature in real time. Based on the monitoring results, a PLC control system is used for real-time control to avoid dimensional deviations due to heat accumulation during machining. In this embodiment, when machining the turning end face, the cutting speed is 120 m / min, the feed rate is 0.1 mm / r, and the depth of cut is 0.2 mm; when machining the center bottom hole, the cutting speed is 80 m / min and the feed rate is 0.08 mm / r; when machining the outer diameter, the cutting speed is 150 m / min and the feed rate is 0.1 mm / r.

[0068] In the precision turning process, the heat generated by cutting friction causes a local temperature rise in the workpiece, leading to workpiece deformation and increased machining errors. Therefore, this application considers the local heat accumulation effect of the workpiece during actual machining, monitors the temperature and machining parameters during the machining process, and analyzes the characteristics under the influence of temperature rise changes to optimize the control process, adjust machining parameters, control local machining temperature, and improve workpiece machining accuracy. A schematic diagram of the control optimization process is shown below. Figure 2 As shown, the specific control optimization steps are as follows:

[0069] Step 3.1: During each machining stage of the planetary carrier precision turning process, various monitoring data are collected in real time, including temperature data and cutting speed data.

[0070] During each stage of the precision turning process, various monitoring data are collected in real time. Specifically, an infrared thermometer is used to collect the workpiece temperature data in real time, and speed and displacement sensors are used to collect the cutting speed and feed rate data in real time, respectively. The collected monitoring data is transmitted in real time to the control terminal of the PLC control system. At the control terminal, noise reduction processing is performed on the collected monitoring data to reduce the impact of environmental noise interference on data quality during data acquisition. The machining stages include: end face machining, center hole machining, and external diameter machining.

[0071] In this embodiment, the Savitzky-Golay filtering algorithm is used to perform noise reduction processing on various monitoring data. The Savitzky-Golay filtering algorithm is a well-known technology and will not be described in detail in this application. As other implementation methods, based on the ability to perform noise reduction processing on various monitoring data separately, implementers may use other existing feasible technologies, and this application does not impose any special restrictions.

[0072] Step 3.2: Within each processing stage, obtain the temperature rise deviation characteristic value at each moment; divide the time period between the current moment and the initial moment of the processing stage into each temperature rise response interval; obtain the correlation response deviation characteristic value of various monitoring data within each temperature rise response interval, obtain the heat accumulation influence coefficient within each temperature rise response interval, and obtain the adjustment response characteristic value at the current moment.

[0073] The characteristics of thermal accumulation impact of each processing stage are analyzed based on the monitoring data after noise reduction processing within each processing stage.

[0074] (1) Obtain the temperature rise deviation characteristic value at each time by the degree of deviation of the temperature data at each time from its rated value and the abnormal situation of the temperature data at each time.

[0075] First, by analyzing the degree to which the temperature data deviates from its rated value at each time point, and by identifying any anomalies in the temperature data at each time point, the characteristic value of the temperature rise deviation at each time point is obtained. The specific process is as follows:

[0076] Calculate the difference between the temperature data at each moment and its rated value. The ratio of the difference to the rated value is taken as the temperature deviation at each moment. The larger the calculated temperature deviation, the greater the heat accumulation effect under the cooling of the cutting fluid during the precision turning of the workpiece.

[0077] To further accurately extract the characteristics of local temperature rise of the workpiece under the influence of heat accumulation during each processing stage, anomaly scores of temperature data at each moment are obtained within the time interval between the current moment and the initial moment of the processing stage. The larger the anomaly score, the more significant the abnormal characteristics of the workpiece temperature under the influence of heat accumulation at each moment.

[0078] In this embodiment, the temperature data of all times within the time period is used as input, and the LOF (Local Outlier Factor) anomaly detection algorithm is used to output the anomaly score of the temperature data at each time within the time period. The LOF anomaly detection algorithm is a well-known technology and will not be described in detail in this application. As other implementation methods, based on the ability to measure the degree of anomaly of the temperature data at each time, the implementer may use other existing feasible technologies, and this application does not impose any special restrictions.

[0079] Furthermore, by combining the temperature deviation and anomaly score at each time point, the characteristic value of the temperature rise deviation at each time point is obtained, expressed as:

[0080] In the formula, This represents the characteristic value of the temperature rise deviation at time i. , Let represent the temperature deviation and anomaly score at time i, respectively.

[0081] It should be noted that the larger the calculated temperature rise deviation characteristic value, the more significant the temperature rise change characteristics affected by heat accumulation during the workpiece processing at time i. If the temperature anomaly at time i is higher, then this temperature rise deviation is more likely to be caused by the heat accumulation effect.

[0082] (2) Divide the time period into temperature rise response intervals by measuring the changes in the characteristic values ​​of temperature rise deviation at all times within the time period between the current time and the initial time of the processing stage.

[0083] Furthermore, based on the characteristic value of temperature rise deviation at each moment under the influence of heat accumulation, the correlation characteristics between temperature rise changes and processing parameters during workpiece processing are analyzed. Since the influence of heat accumulation is a phased response change characteristic, in order to accurately determine the phased temperature rise deviation caused by heat accumulation during workpiece processing, the characteristic values ​​of temperature rise deviation at all moments within the time period are subjected to time-series curve fitting. The occurrence time of each extreme value in the fitted curve is obtained, and the occurrence time of each extreme value is used as a dividing point to divide the time period into various temperature rise response intervals. Among them, the occurrence time of the extreme value is the moment when the heat accumulation influence is significant under the comprehensive judgment of temperature deviation and abnormal characteristics during the processing.

[0084] In this embodiment, the least squares method is used to perform time-series curve fitting on the temperature rise deviation characteristic values ​​at all times within the time period. The least squares method is a well-known technique and will not be described in detail here. As other implementation methods, based on the ability to perform time-series curve fitting on the temperature rise deviation characteristic values ​​at all times within the time period, the implementer may use other existing techniques, such as local weighted regression, K-nearest neighbor regression, etc. This application does not impose any special restrictions.

[0085] (3) By comparing the peak occurrence times of various monitoring data in each temperature rise response interval with those of other monitoring data, the correlation response deviation characteristic values ​​of various monitoring data in each temperature rise response interval are obtained.

[0086] Furthermore, based on the segmentation results, the correlation characteristics between monitoring data affected by heat accumulation during workpiece machining are analyzed. Specifically, the cutting speed data, feed rate data, and temperature data collected within each temperature rise response interval are standardized to avoid the influence of different dimensions on the extraction of correlation characteristics between different types of monitoring data under the influence of heat accumulation. The times within each temperature rise response interval are numbered sequentially to obtain the time number of each peak value of various monitoring data within each temperature rise response interval. Generally, during machining, the changes in the response of different types of monitoring data when the workpiece is heated are correlated. Therefore, the difference between the numbers of various monitoring data within each temperature rise response interval and the other types of monitoring data is obtained. The average of the differences between various monitoring data within each temperature rise response interval and all other types of monitoring data is used as the correlation response deviation characteristic value of various monitoring data within each temperature rise response interval. The larger the calculated correlation response deviation characteristic value, the greater the time deviation of the correlation fluctuation between various monitoring data and the other types of monitoring data under the influence of temperature rise, and the greater the possibility of heat accumulation affecting the finishing process.

[0087] In this embodiment, the method for standardizing various monitoring data is as follows: taking temperature data as an example, the maximum value of temperature data in each temperature rise response interval is calculated, and the ratio of the temperature data at each time to the maximum value is used as the standardized temperature data at each time.

[0088] In this embodiment, the findpeaks function in MATLAB is used to obtain the peak values ​​of various monitoring data in the time series. The findpeaks function is a well-known technology and will not be described in detail in this application. As other implementation methods, based on the ability to obtain the peak values ​​of various monitoring data in the time series, implementers may use other existing technologies, such as peak and trough detection algorithms, extreme point detection algorithms, etc. This application does not impose any special restrictions.

[0089] In this embodiment, the calculation process for the difference in the number between various monitoring data and each other monitoring data is as follows: the numbers of all peak times of each monitoring data in each temperature rise response interval are arranged in ascending order to form the peak response time sequence of each monitoring data in each temperature rise response interval. The DTW (Dynamic Time Warping) distance between the peak response time sequences of various monitoring data and each other monitoring data is calculated. The calculation of the DTW distance is a well-known technology and will not be described in detail in this application. As other implementation methods, based on the ability to measure the degree of difference between peak response time sequences, the implementer may use other existing technologies, such as Euclidean distance, Manhattan distance, etc. This application does not impose any special restrictions.

[0090] (4) By combining the correlation response deviation characteristic value of various monitoring data in each temperature rise response interval with the changing trend of various monitoring data in each temperature rise response interval, the heat accumulation influence coefficient in each temperature rise response interval is obtained.

[0091] Furthermore, trend statistics of various monitoring data within each temperature rise response interval are obtained. The larger the calculated trend statistics, the more significant the parameter fluctuation growth trend of various monitoring data under the influence of temperature rise changes within each temperature rise response interval. Then, by combining the correlation response deviation characteristic values ​​of various monitoring data within each temperature rise response interval with the changing trends of various monitoring data within each temperature rise response interval, the heat accumulation influence coefficient within each temperature rise response interval is obtained, expressed as:

[0092] In the formula, This represents the cumulative heat influence coefficient within the x-th temperature rise response interval; n represents the number of types of monitoring data. , Let represent the correlation response deviation characteristic value and trend statistic of the w-th monitoring data within the x-th temperature rise response interval, respectively. This is denoted as the composite product.

[0093] It should be noted that: the larger the calculated heat accumulation influence coefficient, the greater the impact of the heat accumulation effect on the workpiece in the xth temperature rise response interval, and the greater the possibility of deformation of the workpiece due to the temperature rise caused by heat accumulation under the cooling treatment of cutting fluid.

[0094] (5) Obtain the adjustment response characteristic value at the current moment by using the heat accumulation influence coefficient in each temperature rise response interval and the dispersion of temperature data in each temperature rise response interval.

[0095] Furthermore, based on the above analysis, the heating characteristics of the workpiece under the influence of heat accumulation at the current moment are analyzed. Then, by using the heat accumulation influence coefficient within each temperature rise response interval and combining it with the dispersion of temperature data within each temperature rise response interval, the adjustment response characteristic value at the current moment is obtained, expressed as:

[0096] In the formula, u represents the adjustment response characteristic value at the current moment; m represents the total number of temperature rise response intervals within the time period. This represents the cumulative heat effect coefficient within the x-th temperature rise response interval; This represents the dispersion of temperature data within the x-th temperature rise response interval; This represents the normalization function. In this embodiment, the normalization function is the Softmax function, which is used to comprehensively analyze the temperature disturbance characteristics within different temperature rise response ranges and to accurately analyze the stage characteristics of the heat accumulation effect during workpiece processing. The Softmax function is a known technique and will not be described further in this application. It is denoted as a weighted product.

[0097] In this embodiment, the dispersion of temperature data is the standard deviation. As other implementation methods, based on the ability to measure the unevenness of temperature data distribution, implementers may use other existing technologies, such as variance, coefficient of variation, etc. This application does not impose any special restrictions.

[0098] It should be noted that the larger the calculated adjustment response characteristic value, the more significant the correlation deviation between the monitoring data fluctuations caused by the workpiece's thermal fluctuations under the influence of heat accumulation, and the greater the likelihood of workpiece deformation, when the temperature rise has not reached the warning threshold. A schematic diagram of the process for obtaining the adjustment response characteristic value is shown below. Figure 3 As shown in the diagram, the calculation process for adjusting the response characteristic values ​​is illustrated below. Figure 4 As shown.

[0099] Step 3.3: Based on the rise in temperature data during the time period and in conjunction with the adjustment response characteristic value, adjust the cutting speed and the injection pressure of the cutting fluid at the current moment.

[0100] The calculated adjustment response characteristic value can reflect the characteristics of workpiece machining deviation caused by the heat accumulation effect during machining control; thus, the cutting speed and cutting fluid injection pressure during the finishing process can be adaptively adjusted to avoid workpiece machining deviation caused by heat accumulation.

[0101] First, calculate the range of temperature data within the time period, and record the difference between the current temperature data and the previous temperature data as the temperature difference value; if both the range and the temperature difference value are less than the preset temperature rise threshold, it means that the overall temperature rise or the instantaneous temperature rise has not exceeded the temperature rise limit for workpiece processing, and the current cutting speed is maintained.

[0102] Simultaneously, the average of the adjustment response characteristic values ​​at all times within all historical processing stages of the same processing stage as the current moment is used as a judgment threshold. If the adjustment response characteristic value at the current moment is less than the judgment threshold, the currently set cutting fluid injection pressure is maintained. If the adjustment response characteristic value at the current moment is greater than or equal to the judgment threshold, it indicates that the workpiece's thermal changes have affected the processing deviation under the influence of heat accumulation, even without reaching the preset temperature rise threshold. Therefore, a timely cooling response is required, and the cutting fluid injection pressure at the current moment is adjusted. The specific adjustment formula is as follows: In the formula, P represents the adjusted injection pressure of the cutting fluid at the current moment; This indicates the initial injection pressure at the current processing stage; This represents the difference between the preset upper limit of the cutting fluid injection pressure and the initial injection pressure at the current machining stage; u represents the adjustment response characteristic value at the current moment. This represents the judgment threshold; This represents a default constant greater than 0, used to map u to a positive number. The value is preset by a person, and the implementer can set it according to the actual situation. In this embodiment, The value is set to 0.01. This means that the cutting fluid injection pressure is adjusted based on the characteristics of the phased heat accumulation effect, allowing for timely control of workpiece heat fluctuations under the influence of heat accumulation, and avoiding workpiece machining deviations caused by these fluctuations. Recorded as pressure difference, This is denoted as the adjustment factor.

[0103] If at least one of the range and the temperature difference is greater than or equal to the preset temperature rise threshold, it indicates that the overall temperature rise or instantaneous temperature rise exceeds the temperature rise limit for workpiece processing. In this case, the cutting speed at the current moment is adjusted to the product of the currently set cutting speed and the preset ratio, and the injection pressure of the cutting fluid is adjusted to the preset upper limit of the injection pressure of the cutting fluid to avoid processing deviations caused by the rise in workpiece temperature.

[0104] In this embodiment, the preset temperature rise threshold is set to 15°C. The preset temperature rise threshold is set manually, and the implementer can set it according to the actual situation. This application does not impose any special restrictions.

[0105] In this embodiment, the upper limit of the injection pressure of the cutting fluid is 1.2 MPa. The upper limit of the injection pressure of the cutting fluid can be set by the implementer according to the actual situation, and this application does not impose any special restrictions.

[0106] In this embodiment, the preset ratio is 85%. The preset ratio is set manually. Based on the achievable range of the preset ratio [85%, 90%], the implementer can set the preset ratio value according to the actual situation.

[0107] Step 4, drilling process.

[0108] After finish turning, drilling is performed using a Fanuc α-D21MiB CNC machining center and a precision indexing head. Specifically, the machine is first clamped, with the finish-turned end face used as a reference to fit the worktable. Two locating pins restrict circumferential rotation. The central spindle hole is inserted into the locating mandrel, ensuring the coaxiality between the spindle and the central spindle is ≤0.005mm. Evenly distributed pressure plates are used to press the end face with a pressure of 400N~600N to prevent displacement during machining. In this embodiment, the pressure is 400N. A high-speed steel twist drill, 2mm smaller than the finished hole diameter, is used for rough drilling, with a speed of 800r / min and a feed rate of 0.15mm / r. After rough drilling, the bottom hole is machined in one pass using an indexing head, to a depth 2mm deeper than the finished hole. Afterward, chips are removed using high-pressure gas at 0.6MPa~0.8MPa. In this embodiment, 0.6MPa is used. High-pressure gas at MPa is used to remove chips; after cleaning, a 3-4 flute reamer is used to enlarge the hole, with a rotation speed of 1200 r / min and a feed rate of 0.12 mm / r. The roundness of the bottom hole is corrected to ≤0.01 mm, leaving a 0.2 mm allowance for reaming. In this embodiment, a 3 flute reamer is used for enlarging. After enlarging, a CNC reamer with IT6 precision is used for reaming, and a floating reamer chuck is used to counteract spindle runout. The rotation speed is set to 300 r / min and the feed rate is 0.08 mm / r. The cutting fluid injection pressure during the drilling process is 2 MPa to 5 MPa. In this embodiment, the cutting fluid injection pressure is 2 MPa. During the machining process, a PLC control system is used for monitoring and control to precisely control the temperature and machining parameters during the drilling process.

[0109] Step 5, finishing process.

[0110] Before finishing after drilling, the workpiece needs to be pre-treated, including deburring, precision cleaning, allowance inspection, and local correction. First, a deburring ultrasonic cleaning machine is used to deburr the workpiece. The deburring solution concentration is 5%~8%, the cleaning temperature is 50℃~60℃, and the cleaning time is 10~15 minutes. In this embodiment, the deburring solution concentration is 5%, the cleaning temperature is 50℃, and the cleaning time is 10 minutes. After treatment, a deburring solution with a concentration of 8%~1% is used... 0% alkaline degreasing agent is sprayed at 1.0MPa~1.2MPa pressure in an environment of 60℃~70℃ to remove oil stains. After spraying, it is rinsed in ultrapure water with resistivity ≥15MΩ·cm to remove residues. After rinsing, the workpiece is dried with hot air at 80℃~100℃ until the moisture content is ≤0.1%. In this embodiment, 8% alkaline degreasing agent is sprayed at 1.0MPa pressure in an environment of 60℃ to remove oil stains. After rinsing, the workpiece is dried with hot air at 80℃ until the moisture content is ≤0.1%.

[0111] After the above pretreatment, the bushing hole is honing using a CNC internal honing machine. The central shaft hole is honing using diamond honing strips with a grit size of #400. The spindle speed is set to 800 r / min, the honing head reciprocating speed is 100 mm / min, and the feed rate is 0.005 mm / r to 0.01 mm / r. At the same time, a water-soluble honing slurry with a concentration of 6% to 8% is sprayed for cooling and chip removal. In this embodiment, the feed rate is 0.005 mm / r and the spray concentration of the water-soluble honing slurry is 6%. The hole diameter is monitored online using a laser diameter gauge until the bushing hole reaches IT6 grade and the surface roughness Ra < 0.4 μm. The end faces were ground using a CNC double-end face grinder with resin-bonded grinding wheels of #600 grit. The grinding wheel linear speed was set to 30 m / s, the feed rate to 0.001 mm / r, and the grinding depth to 0.3 mm. Simultaneous grinding with two grinding wheels ensured that the parallelism of the two end faces was ≤0.005 mm. The finishing process was automated to ensure that the finished planetary carrier met the requirements for high-precision assembly and force transmission.

[0112] In summary, this application obtains temperature rise deviation characteristic values ​​by analyzing the degree of temperature data deviation from the rated value and abnormal temperature data conditions. This quantifies the impact of temperature changes on the machining process and helps identify heat accumulation effects. Furthermore, considering that the temperature rise deviation caused by heat accumulation during workpiece machining is phased, the temperature rise deviation characteristic values ​​are used to divide the machining process and obtain each temperature rise response interval, allowing for a more detailed analysis of the heat accumulation effect at different stages. By calculating the correlation response deviation characteristic values, the correlation between different monitoring data is quantified, which helps identify the synchronicity of changes in different types of monitoring data during machining. Combining the changing trends of various monitoring data, the heat accumulation influence coefficient is obtained, reflecting the impact of heat accumulation on the machining process and assessing the possibility of workpiece deformation due to temperature rise changes caused by heat accumulation. This provides a more reliable reference for subsequent machining parameter adjustments, thereby reducing machining errors caused by heat accumulation. Furthermore, by combining the temperature disturbance characteristics of different machining stages, adjustment response characteristic values ​​are obtained, providing a quantitative basis for adjusting cutting speed and cutting fluid injection pressure. Dynamically adjusting machining parameters effectively reduces the machining deviation of the planetary carrier caused by workpiece deformation and displacement due to heat accumulation effects, improving the machining accuracy and performance of the planetary carrier.

[0113] The flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to embodiments of this disclosure. In this regard, each block in a flowchart or block diagram may represent a module, segment, or portion of code containing one or more executable instructions for implementing a specified logical function. In some alternative implementations, the functions marked in the blocks may occur in a different order than that shown in the drawings. For example, two consecutive blocks may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. In the descriptions corresponding to the flowcharts and block diagrams in the accompanying drawings, the operations or steps corresponding to different blocks may also occur in a different order than disclosed in the description, and sometimes there is no specific order between different operations or steps. For example, two consecutive operations or steps may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. Each block in a block diagram and / or flowchart, and combinations of blocks in a block diagram and / or flowchart, can be implemented using a dedicated hardware-based system that performs the specified function or action, or using a combination of dedicated hardware and computer instructions.

[0114] It will be apparent to those skilled in the art that this application is not limited to the details of the exemplary embodiments described above, and that this application can be implemented in other specific forms without departing from its essential characteristics. Therefore, the embodiments described above should be considered exemplary and non-limiting in all respects.

Claims

1. A method for precision turning and drilling the planetary carrier of a planetary reducer, characterized in that, The method includes the following steps: During each stage of the planetary carrier precision turning process, various monitoring data are collected in real time, including temperature data and cutting speed data. Within each processing stage, the temperature rise deviation characteristic value at each moment is obtained by analyzing the degree of deviation of the temperature data from its rated value and the abnormality of the temperature data at each moment. The time period is divided into temperature rise response intervals by analyzing the changes in the temperature rise deviation characteristic values ​​at all moments between the current moment and the initial moment of the processing stage. By comparing the peak occurrence times of various monitoring data in each temperature rise response interval with those of other monitoring data, the correlation response deviation characteristic value of various monitoring data in each temperature rise response interval is obtained. Combined with the changing trends of various monitoring data in each temperature rise response interval, the heat accumulation influence coefficient in each temperature rise response interval is obtained. Finally, combined with the dispersion of temperature data in each temperature rise response interval, the adjustment response characteristic value at the current moment is obtained. Based on the temperature rise during the specified time period and the adjustment response characteristic value, the cutting speed and the injection pressure of the cutting fluid at the current moment are adjusted.

2. The method for precision turning and drilling the planetary carrier of a planetary reducer as described in claim 1, characterized in that, The process for obtaining the temperature rise deviation characteristic value is as follows: Calculate the ratio of the difference between the temperature data at each time point and its rated value to the rated value; Obtain anomaly scores for temperature data at various times; The characteristic value of the temperature rise deviation is the product of the ratio and the anomaly score.

3. The method for precision turning and drilling the planetary carrier of a planetary reducer as described in claim 1, characterized in that, The process of obtaining the temperature rise response range is as follows: Obtain the time-series fitting curve of the temperature rise deviation characteristic value at all times within the time period, obtain the occurrence time of each extreme value in the fitting curve, and divide the time period into each temperature rise response interval by the occurrence time.

4. The method for precision turning and drilling the planetary carrier of a planetary reducer as described in claim 1, characterized in that, The process for obtaining the correlation response deviation feature value is as follows: Number the times within each temperature rise response interval according to the time sequence; Obtain the time number of all peak values ​​of various monitoring data within each temperature rise response interval in the time series; Obtain the difference between the various monitoring data and the number of each other monitoring data within each temperature rise response interval; The correlation response deviation characteristic value is obtained by the difference between various monitoring data and all other monitoring data within each temperature rise response interval.

5. The method for precision turning and drilling the planetary carrier of a planetary reducer as described in claim 4, characterized in that, The correlation response deviation characteristic value is the average of the differences between various monitoring data and all other monitoring data within each temperature rise response interval.

6. The method for precision turning and drilling the planetary carrier of a planetary reducer as described in claim 1, characterized in that, The process for obtaining the heat accumulation influence coefficient is as follows: Obtain trend statistics of various monitoring data within each temperature rise response interval; The product of the correlation response deviation characteristic value and the trend statistic is denoted as the comprehensive product; The heat accumulation influence coefficient is the average of the comprehensive product of all monitoring data within each temperature rise response interval.

7. The method for precision turning and drilling the planetary carrier of a planetary reducer as described in claim 1, characterized in that, The process for obtaining the adjusted response feature value is as follows: The product of the normalized value of the dispersion and the thermal accumulation influence coefficient is denoted as the weighted product; The adjusted response characteristic value is the sum of the weighted products within all temperature rise response intervals during the time period.

8. The method for precision turning and drilling the planetary carrier of a planetary reducer as described in claim 1, characterized in that, The adjustment of the current cutting speed and the injection pressure of the cutting fluid includes: Calculate the range of temperature data within the time period, and record the difference between the current temperature data and the previous temperature data as the temperature difference value; If both the range and the temperature difference are less than the preset temperature rise threshold, the current cutting speed is maintained; the judgment threshold is obtained by analyzing the distribution of adjustment response characteristic values ​​in multiple historical processing stages that are the same as the current processing stage; the injection pressure of the cutting fluid at the current moment is adjusted by comparing the adjustment response characteristic value at the current moment with the judgment threshold. Otherwise, adjust the current cutting speed to the product of the current cutting speed and the preset ratio, and adjust the current cutting fluid injection pressure to the preset value.

9. The method for precision turning and drilling the planetary carrier of a planetary reducer as described in claim 8, characterized in that, The process of adjusting the current cutting fluid injection pressure is as follows: If the adjustment response characteristic value at the current moment is less than the judgment threshold, then the current setting of the cutting fluid injection pressure is maintained; Otherwise, the adjustment factor at the current moment is obtained by measuring the difference between the current adjustment response feature value and the judgment threshold. The difference between the preset upper limit of the cutting fluid injection pressure and the initial injection pressure of the current machining stage is denoted as the pressure difference; the product of the pressure difference and the adjustment factor is calculated, and the current cutting fluid injection pressure is adjusted to the sum of the product and the initial injection pressure.

10. The method for precision turning and drilling the planetary carrier of a planetary reducer as described in claim 9, characterized in that, The process of obtaining the adjustment factor is as follows: Map the current adjustment response characteristic value to a positive number; The adjustment factor is the ratio of the difference between the current adjustment response feature value and the judgment threshold to the positive number.

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