A planetary gear carrier cutting processing device and processing method for reducing processing errors

Abstract

The present application relates to the field of cutting processing technology, and specifically to a planetary gear carrier cutting processing device and processing method for reducing processing errors. The method comprises: after rough turning of the planetary gear carrier in the RV reducer, analyzing the influence of the self-balancing phenomenon of residual stress on stress elimination and establishing an influence relationship of residual stress elimination; determining the dynamic switching strategy in the butterfly optimization algorithm based on the distribution of characteristic points in the correlation curve of three parameters; combining the influence relationship of the self-balancing phenomenon of internal stress of the planetary gear carrier structure on stress distribution under the parameters, using the butterfly optimization algorithm to determine the optimal variables at different stages, and subsequently processing the obtained planetary gear carrier structure to obtain the planetary gear carrier. The present application aims to eliminate residual stress in the rough-turned planetary gear carrier and reduce cutting processing errors.

Description

Technical Field

[0001] The present application relates to the field of cutting processing technology, and in particular to a planetary gear carrier cutting processing device and processing method for reducing processing errors. Background Art

[0002] The planetary gear carrier is a core component of the RV (Rotary Vector) reducer. It forms part of the RV reducer along with the pinion housing, cycloid gear, eccentric shaft, and planetary gears. The planetary gear carrier, consisting of a carrier cover and carrier seat, is a key component of the RV reducer's gear mechanism. A suitable planetary gear carrier structure should be lightweight, rigid, wear-resistant, and easy to machine and assemble. This typically requires a combination of rough turning, finish turning, and surface grinding processes.

[0003] During the machining process of planetary gear carriers, residual stress can form within the structural component during various stages, such as rough turning and finish turning. This can easily lead to machining errors and deformation. Current methods for eliminating or reducing residual stress include vibration stress relief (VSR), thermal aging, cryogenic treatment, and pulsed magnetic treatment. VSR has become a very common method for eliminating residual stress due to its low energy consumption, low cost, short cycle time, high efficiency, and ease of operation.

[0004] At present, when using the VSR vibration aging treatment method to eliminate the residual stress of structural parts after rough turning, the three parameters of VSR are often found through optimization. However, the influence of the self-balancing phenomenon inside the structural parts after rough turning on the stress distribution during the vibration elimination of residual stress is ignored, resulting in poor residual stress elimination effect and large processing errors. Summary of the Invention

[0005] In view of the above, it is necessary to provide a planetary gear carrier cutting processing device and processing method that can reduce processing errors to solve the above problems.

[0006] A first aspect of the present application provides a planetary gear carrier cutting method for reducing machining errors, the method comprising:

[0007] Performing rough turning on the planetary carrier blank to obtain the planetary gear carrier structure;

[0008] Monitoring points are preset on the planetary gear carrier structure; based on each parameter of the vibration aging treatment method to eliminate residual stress, the planetary gear carrier structure is subjected to stress elimination simulation testing; based on the change in the stress value of each monitoring point before and after each simulation test, the corresponding elimination effect is determined, and a curve fitting is performed between the elimination effect and the corresponding parameter of each monitoring point during all simulation tests to obtain the correlation curve of each monitoring point with each parameter;

[0009] Extract characteristic points based on the slope distribution characteristics of the corresponding points of each simulation test in the association curve of each parameter at each monitoring point; analyze the discrete degree of the corresponding elimination effects of all simulation tests between two adjacent characteristic points on each association curve to determine the dynamic switching strategy of the butterfly optimization algorithm; extract the local range with two adjacent characteristic points on each association curve as endpoints, and obtain the first eigenvalue of each parameter in each local range based on the difference characteristics between the partial association curves of all monitoring points in each local range; determine the weight parameter based on the first eigenvalue corresponding to the position of each butterfly at each iteration in the butterfly optimization algorithm, replace the adjustment factor in the butterfly optimization algorithm, and obtain the optimal VSR parameter in combination with the dynamic switching strategy to obtain the planetary gear structure with residual stress eliminated;

[0010] The planetary gear frame after cutting is obtained after the planetary gear structure parts with residual stress eliminated are subjected to reference surface finishing, semi-finishing turning, dynamic machining, precision grinding, planetary gear shaft hole end face grinding and quality inspection.

[0011] The linear speed of the rough turning of the planetary carrier blank is 80-120 m / min, and the axial feed rate is 0.2-0.3 mm / r.

[0012] The corresponding elimination effect is determined based on the change in stress value of each monitoring point before and after each simulation test, specifically:

[0013] The stress difference of each monitoring point before and after each simulation test is calculated, and the ratio of the stress difference to the stress value after the test is taken as the corresponding elimination effect.

[0014] The horizontal axis of the correlation curve is the parameter value adjusted in each simulation test; the vertical axis is the elimination effect of each simulation test.

[0015] The process of extracting feature points is specifically as follows:

[0016] The slopes of all simulation test corresponding points on each correlation curve are extracted, and the slope mean is calculated; the points whose slopes are greater than the slope mean and the points corresponding to the initial simulation are taken as feature points.

[0017] The dynamic switching strategy of the butterfly optimization algorithm is specifically determined as follows:

[0018] Calculate the discrete eigenvalues of all elimination effects between two adjacent characteristic points on each association curve corresponding to each parameter; use the lower quartile of all the discrete eigenvalues on each association curve as the judgment threshold; use the local range where the discrete eigenvalue is greater than the judgment threshold as the first-category interval of each parameter, and use the local range where the discrete eigenvalue is less than or equal to the judgment threshold as the second-category interval of each parameter;

[0019] The first-class intervals of all parameters are used to divide the space, and the local space determined by the first-class intervals of all parameters is used as the area requiring local search, and the remaining areas are used as the areas requiring global search.

[0020] The specific process of obtaining the first eigenvalue of each parameter in each local range is as follows:

[0021] The influence relationship corresponding to each parameter is as follows: Where, is the influence relationship corresponding to the ath parameter; n is the number of monitoring points on the planetary gear carrier structure; 、 are the correlation curve expressions between the ath parameter and the elimination effect at the i-th monitoring point and the j-th monitoring point respectively;

[0022] Substitute the expressions corresponding to the partial correlation curves of all monitoring points in each local range into the influence relationship formula to obtain the first eigenvalue of each parameter in each local range.

[0023] The process of determining the weight parameter according to the first eigenvalue corresponding to the position of each butterfly at each iteration in the butterfly optimization algorithm is specifically as follows:

[0024] When there is one local range for each parameter corresponding to the position of each butterfly at each iteration, calculate the ratio of the first eigenvalue of each parameter's local range to the maximum value of the first eigenvalue of all local ranges of each parameter; multiply the numerical ratios of all parameters to obtain the weight parameter of each butterfly at each iteration;

[0025] When the local range of each parameter corresponding to the position of each butterfly at each iteration is greater than one, the first eigenvalue mean of all local ranges in each dimension corresponding to all three-dimensional local spaces is taken respectively; the numerical proportion of the first eigenvalue mean of the local range of each parameter to the maximum value of the first eigenvalue of all local ranges of each parameter is calculated; the numerical proportions obtained for all parameters are multiplied to obtain the weight parameter of each butterfly at each iteration.

[0026] The specific operation of the semi-finishing turning process is as follows: the linear speed is increased to 150-180 m / min, the axial feed rate is 0.1-0.15 mm / r, and the cutting depth is 0.3-0.5 mm.

[0027] In a second aspect, an embodiment of the present application also provides a planetary gear carrier cutting processing device for reducing processing errors, comprising a memory, a processor, and a computer program stored in the memory and running on the processor, wherein the processor implements the steps of any one of the above methods when executing the computer program.

[0028] This application has at least the following beneficial effects:

[0029] This application quantifies the influence of the self-balancing phenomenon of residual stress in the planetary gear carrier structure obtained by rough turning on the stress distribution through the influence relationship of the self-balancing phenomenon of internal stress of the planetary gear structure under each parameter of the vibration aging treatment method. The influence of the planetary gear carrier's own structure on the residual stress distribution is eliminated by multi-point cumulative averaging, thereby improving the stress elimination effect of the planetary gear structure by the subsequent parameter optimization results.

[0030] Furthermore, the dynamic switching strategy in the optimization process is determined based on the changing characteristics of the stress relief effect in the local range of each parameter, which can adjust the search direction and strategy of the algorithm in real time, avoid excessive searching within a fixed range, reduce the risk of falling into the local optimal solution, and enhance the global search capability; the adaptive inertia weight is set by combining the first eigenvalue of each parameter in the local range of two adjacent feature points, and flexible adjustments are made according to the actual situation of parameter changes. By introducing more randomness to adjust the optimization strategy, the optimization process can better adapt to complex and dynamic environments, thereby effectively improving the optimization capability of the algorithm and further reducing errors in the cutting process of planetary gear racks. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 A flowchart of a planetary gear carrier cutting method for reducing machining errors provided in one embodiment of the present application;

[0032] Figure 2 A flowchart of a rough turning process provided for one embodiment of the present application;

[0033] Figure 3 A schematic diagram of the distribution of monitoring points provided in one embodiment of the present application;

[0034] Figure 4 A basic principle diagram of the VSR method provided in one embodiment of the present application. DETAILED DESCRIPTION

[0035] In the description of the embodiments of this application, words such as "exemplary," "or," and "for example" are used to indicate examples, illustrations, or descriptions. Any embodiment or design described as "exemplary" or "for example" in the embodiments of this application should not be construed as being preferred or advantageous over other embodiments or designs. Rather, the use of words such as "exemplary," "or," and "for example" is intended to present the relevant concepts in a concrete manner.

[0036] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art in the art of this application. The terms used in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application.

[0037] It should also be noted that the terms "first" and "second" in this application and the accompanying drawings are used to distinguish similar objects, rather than to describe a specific order or sequence. The methods disclosed in the embodiments of this application or the methods shown in the flowcharts include one or more steps for implementing the methods. Without departing from the scope of protection of this application, the order of executing multiple steps can be interchanged with each other, and some steps can also be deleted.

[0038] Unless defined otherwise, 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.

[0039] The following describes in detail a specific solution of a planetary gear carrier cutting and processing device and a processing method for reducing processing errors provided by the present application with reference to the accompanying drawings.

[0040] See also Figure 1 , which shows a flowchart of the steps of a planetary gear carrier cutting method for reducing machining errors provided by an embodiment of the present application. The material used in the present application is ductile iron QT450-10, and includes the following steps S10-S40:

[0041] S10, Rough turning: Rough turning is a key step in the initial shaping of materials, and it quickly removes excess material through efficient cutting.

[0042] S101, clamping and positioning: Use a lathe, such as a double-gantry vertical lathe or a heavy-duty CNC lathe, and use the reference surface of the planetary carrier blank (such as the large end face or inner hole) as the clamping and positioning reference to ensure that the clamping force is evenly distributed to avoid subsequent processing errors caused by clamping deformation.

[0043] S102, setting cutting parameters, including cutting speed and cutting depth. Since the hardness of QT450-10 in this application is approximately HB170-230, the linear speed during rough turning is controlled at 80-120 m / min to avoid surface graphite shedding or microcracks caused by high friction temperatures. The cutting depth is set to a single-side allowance of 3-5 mm and an axial feed of 0.2-0.3 mm / r. The cutting depth should not be too large, otherwise it will easily cause workpiece vibration during machine tool processing. In this embodiment, the linear speed for rough turning the planetary carrier blank is 80 m / min and the axial feed is 0.2 mm / r. In other embodiments, the linear speed for rough turning the planetary carrier blank is 120 m / min and the axial feed is 0.3 mm / r. In other embodiments, the linear speed for rough turning the planetary carrier blank is 100 m / min and the axial feed is 0.3 mm / r.

[0044] S103, outer circle and end face rough turning: turn the outer contour of the planetary carrier to the designed size, leave a semi-finishing turning allowance of 0.5-1mm, and machine the end face to a flatness of ≤0.1mm; inner hole rough boring: rough bore the center hole of the planetary carrier, leave a hole diameter allowance of 1-1.5mm, and control the inner hole cylindricity error within 0.05mm.

[0045] S104, after rough turning, stress relief treatment is performed. In this application, the planetary gear carrier structure obtained after rough turning is subjected to residual stress relief by using vibration aging treatment method, and the optimal parameters for vibration aging treatment are obtained by using the most optimized method. The flowchart of the rough turning process is shown as follows: Figure 2 shown.

[0046] Residual stress within the planetary gear carrier structure obtained through rough turning exhibits a self-balancing phenomenon, whereby localized stress release leads to stress redistribution within the structure. Specifically, when residual stress, such as tensile stress, is released in a localized area of the structure through machining, heat treatment, or vibration aging, elastic recovery and plastic deformation within the material trigger stress redistribution. For example, after localized tensile stress is released, compressive or shear stress in the surrounding area is transferred to the released area through elastic deformation, forming a new equilibrium state.

[0047] S1041: Preset monitoring points on the planetary gear carrier structure.

[0048] After rough turning, n monitoring points are evenly distributed around the center point on the planetary gear carrier structure. In this embodiment, the value of n is 8. The distribution diagram of the monitoring points is shown in FIG. Figure 3 As shown, Figure 3 The large medium gray circle is the planetary gear carrier structure obtained by rough turning, and the black circle represents the monitoring point.

[0049] S1042: Based on each parameter of the vibration aging treatment method to eliminate residual stress, a stress elimination simulation test is performed on the planetary gear carrier structure.

[0050] Finite element analysis was used to simulate stress relief testing of the planetary gear carrier structure. For the three parameters of excitation force, excitation frequency, and excitation time, one parameter was kept within the allowable range at each time, and the other two parameters remained unchanged. For each simulation test, a stress detection instrument was used to obtain the stress Y0 and Y1 of each monitoring point before and after each residual stress relief. The stress detection instrument included but was not limited to a BN-SM100 static resistance strain gauge, a JH-30 residual stress tester, and a Zetec MIZ-22 eddy current instrument. In this embodiment, a Zetec MIZ-22 eddy current instrument was used. Finite element analysis is a commonly used technology in the field of simulation testing, and the specific process will not be repeated here.

[0051] S1043: Based on the change in stress value of each monitoring point before and after each simulation test, the corresponding elimination effect is determined, and a curve fitting is performed between the elimination effect and the corresponding parameter of each monitoring point during all simulation tests to obtain the correlation curve of each monitoring point with each parameter.

[0052] Based on the simulation data of stress values and parameters from K simulation tests, the fitting result between each parameter and the elimination effect at each monitoring point is determined by a curve fitting method, and a correlation curve is obtained in the form of a curve. In this embodiment, K is set to 20; the elimination effect is obtained by calculating the stress difference at each monitoring point before and after the elimination of each residual stress, and taking the ratio of the stress difference to the stress after elimination as the elimination effect of each monitoring point, that is, the ratio of the difference between Y1 and Y0 to Y1. The larger the difference, the more significant the elimination effect. In this embodiment, the least squares method is used for curve fitting, with the parameter value adjusted for each simulation test as the horizontal axis and the elimination effect of each simulation test as the vertical axis. This application does not impose any special restrictions on the curve fitting method, and the implementer can also use polynomial fitting.

[0053] S1044: Obtain an influence relationship expression corresponding to each parameter through the difference characteristics between the correlation curves of all monitoring points under each parameter.

[0054] For any parameter, the influence of the self-balancing phenomenon of internal stress of the structural part on the stress distribution is characterized by the difference between the correlation curves at all monitoring points, and the influence relationship of the self-balancing phenomenon of internal stress of the structural part on the stress distribution under the ath parameter is obtained. , specifically: ; Where n is the number of monitoring points on the planetary gear carrier structure; 、 are the correlation curve expressions between the ath parameter and the elimination effect at the i-th monitoring point and the j-th monitoring point respectively.

[0055] It should be noted that the influence of the planetary gear carrier's own structure on the residual stress distribution is eliminated by multi-point cumulative averaging, thereby improving the elimination effect of subsequent parameter optimization results on the structural parts. For example, after the stress at the corner of the inner wall of the planetary gear carrier is released, the stress in the adjacent area may be transferred to the area away from the corner.

[0056] The relationship between the self-balancing phenomenon of internal stress of the structural component and the stress distribution under three parameters is obtained respectively.

[0057] S1045: Extracting feature points based on the slope distribution characteristics of the corresponding points of each monitoring point in each simulation test in the correlation curve of each parameter.

[0058] The basic principle diagram of the VSR method is as follows Figure 4 As shown, a host computer controls a signal generator to generate an excitation signal. This signal, after passing through a DC motor speed controller, drives a DC speed-controlled motor mounted on a vibration platform. The motor's operation causes the platform to vibrate, which in turn transmits a cyclic load via an elastic pad to the structural component, which is secured with a structural fixture. When the resulting excitation stress is superimposed on the internal residual stress, the resulting stress in a certain direction exceeds the material's yield point, resulting in yield deformation. This relaxes and releases the residual stress, thereby eliminating or reducing it.

[0059] Specifically, the VSR method has three main parameters for eliminating residual stress: excitation force, excitation frequency, and excitation time. Among them, the excitation force refers to the external load applied by the vibration equipment to the planetary gear frame structure. When the excitation frequency is fixed, the greater the amplitude of the excitation force, the more excitation energy the grain obtains. However, an excitation force that is too small cannot cause plastic deformation of the workpiece, while an excitation force that is too large will damage the material and cause cracks. On the other hand, according to vibration theory, the excitation stress obtained by the component in the resonant state is the largest, and at the same time, the vibration system consumes the least energy, and the residual stress elimination effect is the best. Therefore, the elimination effect is best when the excitation frequency is selected near the natural frequency. The excitation time refers to the duration of the reciprocating loading of the excitation load. If the time is too short, the residual internal stress cannot be reduced to the greatest extent, and if the time is too long, fatigue damage will be caused to the material.

[0060] First, taking the ath parameter of each monitoring point as an example, obtain the slope of the corresponding point in each simulation in the correlation curve, and take the points on the correlation curve where the slope is greater than the mean slope and the starting point as feature points. The greater the change in the elimination effect between two adjacent feature points, the greater the change in the elimination effect when the parameter value changes in a certain local range, which means that adjusting the parameter value in this local range has a significant effect on eliminating residual stress. Therefore, in this local range, more attention should be paid to local optimization during the optimization process.

[0061] S1046: Analyze the discrete degree of the corresponding elimination effect of all simulation tests between two adjacent feature points on each correlation curve, and determine the dynamic switching strategy of the butterfly optimization algorithm.

[0062] Calculate the discrete eigenvalue of the elimination effect between two adjacent characteristic points on the correlation curve of the ath parameter. The smaller the discrete eigenvalue, the less change there is in the effect of adjusting the parameter value between the two adjacent characteristic points on stress elimination. In the optimization process, the global optimization capability should be enhanced to quickly find the VSR parameters with good residual stress elimination effect on the structural part. On the contrary, the larger the discrete eigenvalue, the more change there is in the effect of adjusting the parameter value between the two adjacent characteristic points on stress elimination. In the optimization process, the local optimization capability should be enhanced to quickly find the VSR parameters with good residual stress elimination effect on the structural part in a small range. In this embodiment, the discrete eigenvalue is calculated using the standard deviation. In different embodiments, the discrete eigenvalue can be calculated in the form of distribution variance, coefficient of variation, etc., and this application does not impose any special restrictions on this.

[0063] The lower quartiles of all the discrete eigenvalues on each correlation curve are respectively obtained as the judgment threshold, the local range where the discrete eigenvalues are greater than the judgment threshold is taken as the first-category interval of the a-th parameter, and the local range where the discrete eigenvalues are less than or equal to the judgment threshold is taken as the second-category interval of the a-th parameter.

[0064] In other embodiments, all discrete feature values on each correlation curve can be divided into two categories using a binary classification method, with the local range corresponding to the category with the largest mean being used as the first category interval of the a-th parameter; and the local range corresponding to the other category being used as the second category interval of the a-th parameter. Quartile calculation and binary classification are both well-known techniques in the field of data processing, and the specific process will not be elaborated on here.

[0065] When using the butterfly algorithm to find the optimal VSR parameters for the structural component, the optimization space is a three-dimensional space defined by the allowable ranges of three parameters: excitation force, excitation frequency, and excitation time. The first-class intervals of the three parameters are used to partition the space within this three-dimensional space. The local space defined by the first-class intervals of the three parameters is used as the area for local search, while the remaining area is used as the area for global search. This determines the dynamic switching strategy during the optimization process.

[0066] S1047: Extract the local range with two adjacent characteristic points on each correlation curve as endpoints, substitute the partial correlation curve of each local range at all monitoring points into the influence relationship, and obtain the first eigenvalue of each parameter in each local range.

[0067] The self-balancing phenomenon also has a significant impact on the VSR parameter optimization. That is, the smaller the effect of the self-balancing phenomenon on the stress distribution within the parameter range, the more uniform the internal stress distribution at different positions is, and the three parameters of the VSR are basically near the global optimal solution. At this time, attention should be paid to the ability of local optimization. On the contrary, the greater the effect of the self-balancing phenomenon on the stress distribution within the parameter range, the more different the internal stress distribution at different positions is. At this time, the release of the residual stress in the structural component is poor, and the ability of global optimization should be enhanced.

[0068] Furthermore, the horizontal coordinates of any two adjacent characteristic points corresponding to the ath parameter of each monitoring point are taken as the two end points of the local range. It should be understood that the local range corresponds to a part of the correlation curve on the correlation curve at different monitoring points; the expression of the correlation curve corresponding to the local range is substituted into the relationship of the influence of the self-balance phenomenon of the internal stress of the structural part on the stress distribution under the ath parameter. , obtain the first eigenvalue of the local range corresponding to any two adjacent feature points. The larger the first eigenvalue is, the more it indicates that when the VSR technology is used to set the ath parameter in this local range for stress elimination, it will cause uneven stress distribution inside the structural part, and the ability of global optimization should be enhanced.

[0069] S1048, determining a weight parameter based on the first eigenvalue corresponding to the position of each butterfly at each iteration in the butterfly optimization algorithm, replacing the adjustment factor in the butterfly optimization algorithm, and combining the dynamic switching strategy to obtain the optimal VSR parameter to obtain a planetary gear structure with eliminated residual stress.

[0070] Specifically, the adaptive inertia weight is set based on the first eigenvalue of each parameter in the local range of two adjacent feature points, which increases the randomness of the adjustment strategy and effectively adjusts the algorithm's optimization ability. The specific formula is:

[0071]

[0072] Where, is the weight parameter of the u-th butterfly at the t-th iteration, 、 、 are the first eigenvalues of the local range of the three parameter values corresponding to the position of the u-th butterfly at the t-th iteration, 、 、 are the maximum values of the first eigenvalues of all local ranges of the three parameters.

[0073] It should be noted that if the position of the u-th butterfly at the t-th iteration is simultaneously located in the three-dimensional local space determined by multiple local ranges, the mean of the first eigenvalues of all local ranges in each dimension corresponding to all three-dimensional local spaces is taken respectively.

[0074] As an example, the three-dimensional coordinates of the position of the u-th butterfly at the t-th iteration are ,if At the same time, it is located in the overlapping area of 3 local three-dimensional spaces. The corresponding ranges of the first local three-dimensional space in the corresponding dimensions of the ath parameter, the bth parameter, and the cth parameter are respectively 、 、 ; The ranges of the second local three-dimensional space corresponding to the dimensions of the ath parameter, the bth parameter, and the cth parameter are respectively 、 、 ; The ranges of the third local three-dimensional space corresponding to the dimensions of the ath parameter, the bth parameter, and the cth parameter are respectively 、 、 ; At this time, the ath parameter is in 、 and The mean of the first eigenvalues corresponding to the three local ranges is taken as , the bth parameter in 、 and The mean of the first eigenvalues corresponding to the three local ranges is taken as , the cth parameter in 、 and The mean of the first eigenvalues corresponding to the three local ranges is taken as .

[0075] Furthermore, the weight parameter obtained at each iteration of each butterfly replaces the adjustment factor in the original butterfly optimization algorithm. The formula is as follows:

[0076]

[0077] Where, represents the adaptive inertia weight of the u-th butterfly at the t-th iteration; Indicates the current iteration number; Indicates the preset maximum number of iterations; represents the weight parameter of the u-th butterfly at the t-th iteration; represents a logarithmic function with a natural constant as its base; Indicates The logarithmic function of base .

[0078] It should be understood that the search for the first half, When the butterfly individual needs to have a strong global search capability to ensure that the algorithm can perform extensive optimization in the search space. Therefore, the butterfly individual needs a large and stable weight for global optimization in the next iteration; in the second half of the search, When searching for a specific butterfly, the individual butterfly should have a strong local search capability to ensure that the population can perform better optimization. Therefore, the individual butterfly needs a stable and small weight to help the population perform deep mining. The exponential weight is used to adaptively reduce the weight as the iteration progresses to achieve deep mining of the population.

[0079] Furthermore, the initial parameters for butterfly optimization were set: a population size of 50, a maximum number of iterations of 500, a three-dimensional search space defined by the allowable ranges of the three parameters, a perceptual modality of 0.01, and a power exponent of 0.1. The optimal solution was then obtained based on the dynamic switching strategy and adaptive inertia weights used in the optimization process, and the three VSR parameters corresponding to the optimal solution were output. However, butterfly optimization is a well-known technique, and the detailed process is omitted here.

[0080] Subsequently, a digital signal is generated by a computer based on the VSR parameters, and a signal generator is used to eliminate residual stress based on the digital signal to obtain a high-quality planetary gear carrier structure.

[0081] S20, semi-finish turning: Semi-finish turning is a transition process between rough turning and finishing, focusing on improving dimensional consistency and further relieving stress.

[0082] S201, datum surface trimming: Re-trim the clamping datum surface to ensure that the datum surface flatness is ≤0.05mm, providing a stable reference for subsequent processing.

[0083] S202, Cutting Parameter Adjustment: Increase the linear speed to 150-180 m / min. Use coated carbide inserts (such as CBN or ceramic coatings) to reduce the impact of cutting heat on the material. Adjust the feed rate: Axial feed rate 0.1-0.15 mm / r, cutting depth 0.3-0.5 mm, to balance efficiency and surface quality. In this embodiment, the linear speed is increased to 150 m / min, the axial feed rate is 0.1 mm / r, and the cutting depth is 0.3 mm; in other embodiments, the linear speed is increased to 180 m / min, the axial feed rate is 0.15 mm / r, and the cutting depth is 0.5 mm; in still other embodiments, the linear speed is increased to 160 m / min, the axial feed rate is 0.12 mm / r, and the cutting depth is 0.5 mm.

[0084] S203, semi-finishing turning: semi-finishing turning of the outer diameter and end face: outer diameter tolerance is controlled within ±0.1mm, end face flatness ≤0.05mm. Semi-finishing boring of the inner hole: hole diameter allowance is 0.3-0.5mm, inner hole cylindricity error is ≤0.03mm, surface roughness Ra ≤3.2μm.

[0085] S30, machining center:

[0086] The machining center is responsible for the multi-process integrated processing of the complex structure of the planetary carrier, including the precision forming of the hole system, mounting surface and planetary gear shaft hole.

[0087] S301, dynamic machining: using a five-axis machining center, the workpiece is clamped in one go through a composite fixture to complete multiple processes such as milling, drilling, tapping, and heat treatment.

[0088] S40, flat grinding: Flat grinding is the final process to ensure high precision and surface quality of the planet carrier end face and key mating surfaces.

[0089] S401, precision grinding: using a high-precision surface grinder, with an electromagnetic chuck to hold the workpiece, the grinding amount is 0.02-0.05mm, the final flatness is ≤0.005mm, and the surface roughness Ra is ≤0.4μm.

[0090] S402, planetary gear shaft hole end face grinding: perform local grinding on the planetary gear shaft hole end face to ensure that the axial assembly clearance is ≤0.01mm and reduce the axial movement of the RV reducer during operation.

[0091] S403, Quality Inspection: Three-dimensional Coordinate Measurement: Comprehensively inspect hole position, hole diameter, and end face flatness to ensure compliance with drawing requirements, such as hole diameter tolerance H7 and hole spacing ±0.01mm. Three-dimensional coordinate measurement can be performed using a Zeiss three-dimensional coordinate measuring machine, such as the Zeiss Contura bridge-type three-dimensional coordinate measuring machine, to monitor workpiece size, shape, position, and various parallelism and perpendicularity requirements.

[0092] At this point, the planetary gear carrier is obtained.

[0093] Based on the same inventive concept as the above method, an embodiment of the present application also provides a planetary gear carrier cutting processing device for reducing processing errors, including a memory, a processor, and a computer program stored in the memory and running on the processor. When the processor executes the computer program, it implements the steps of any one of the above-mentioned planetary gear carrier cutting processing methods for reducing processing errors.

[0094] In summary, the present application quantifies the influence of the self-balancing phenomenon of residual stress in the planetary gear carrier structure obtained by rough turning on the stress distribution through the influence relationship of the self-balancing phenomenon of internal stress of the planetary gear structure under each parameter of the vibration aging treatment method, eliminates the influence of the planetary gear carrier's own structure on the residual stress distribution by multi-point cumulative averaging, and improves the stress elimination effect of the subsequent parameter optimization results on the planetary gear structure.

[0095] Furthermore, the dynamic switching strategy in the optimization process is determined based on the changing characteristics of the stress relief effect in the local range of each parameter, which can adjust the search direction and strategy of the algorithm in real time, avoid excessive searching within a fixed range, reduce the risk of falling into the local optimal solution, and enhance the global search capability; the adaptive inertia weight is set by combining the first eigenvalue of each parameter in the local range of two adjacent feature points, and flexible adjustments are made according to the actual situation of parameter changes. By introducing more randomness to adjust the optimization strategy, the optimization process can better adapt to complex and dynamic environments, thereby effectively improving the optimization capability of the algorithm and further reducing errors in the cutting process of planetary gear racks.

[0096] The flowcharts and block diagrams in the accompanying drawings show the possible architecture, functions and operations of the systems, methods and computer program products according to the embodiments of the present application. In this regard, each box in the flowchart or block diagram can represent a module, a program segment or a part of the code, and the part of the module, program segment or code contains one or more executable instructions for realizing the specified logical function. In some alternative implementations, the functions marked in the box can also occur in an order different from that marked in the accompanying drawings. For example, two consecutive boxes can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, which can depend on the functions involved. In the description corresponding to the flowcharts and block diagrams in the accompanying drawings, the operations or steps corresponding to different boxes can also occur in an order different from that disclosed in the description, and sometimes there is no specific order between different operations or steps. For example, two consecutive operations or steps can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, which can depend on the functions involved. Each block in the block diagrams and / or flowcharts, and combinations of blocks in the block diagrams and / or flowcharts, may be implemented by a dedicated hardware-based system that performs the specified function or action, or may be implemented by a combination of dedicated hardware and computer instructions.

[0097] It is obvious to those skilled in the art that the present application is not limited to the details of the above exemplary embodiments, and that the present application can be implemented in other specific forms without departing from the basic features of the present application. Therefore, from any point of view, the above embodiments of the present application should be regarded as exemplary and non-restrictive; modifications to the technical solutions described in the above embodiments, or equivalent replacement of some of the technical features therein, do not deviate from the essence of the corresponding technical solutions within the scope of the technical solutions of the embodiments of the present application, and should be included in the scope of protection of the present application.

Claims

1. A planetary gear carrier cutting method for reducing machining errors, characterized in that: The method comprises the following steps: Performing rough turning on the planetary carrier blank to obtain the planetary gear carrier structure; Monitoring points are preset on the planetary gear carrier structure; based on each parameter of the vibration aging treatment method to eliminate residual stress, the planetary gear carrier structure is subjected to stress elimination simulation testing; based on the change in the stress value of each monitoring point before and after each simulation test, the corresponding elimination effect is determined, and a curve fitting is performed between the elimination effect and the corresponding parameter of each monitoring point during all simulation tests to obtain the correlation curve of each monitoring point with each parameter; Extract characteristic points based on the slope distribution characteristics of the corresponding points of each simulation test in the association curve of each parameter at each monitoring point; analyze the discrete degree of the corresponding elimination effects of all simulation tests between two adjacent characteristic points on each association curve to determine the dynamic switching strategy of the butterfly optimization algorithm; extract the local range with two adjacent characteristic points on each association curve as endpoints, and obtain the first eigenvalue of each parameter in each local range based on the difference characteristics between the partial association curves of all monitoring points in each local range; determine the weight parameter based on the first eigenvalue corresponding to the position of each butterfly at each iteration in the butterfly optimization algorithm, replace the adjustment factor in the butterfly optimization algorithm, and obtain the optimal VSR parameter in combination with the dynamic switching strategy to obtain the planetary gear structure with residual stress eliminated; The planetary gear structure parts with residual stress eliminated are subjected to reference surface finishing, semi-finishing turning, dynamic machining, precision grinding, planetary gear shaft hole end face grinding, and quality inspection to obtain the planetary gear carrier after cutting; the dynamic machining specifically includes: milling, drilling, tapping, and heat treatment.

2. A planetary gear carrier cutting method for reducing machining errors according to claim 1, characterized in that: The linear speed of the rough turning of the planet carrier blank is 80-120 m / min, and the axial feed rate is 0.2-0.3 mm / r.

3. A planetary gear carrier cutting method for reducing machining errors according to claim 1, characterized in that: The corresponding elimination effect is determined based on the change in stress value of each monitoring point before and after each simulation test, specifically: The stress difference of each monitoring point before and after each simulation test is calculated, and the ratio of the stress difference to the stress value after the test is taken as the corresponding elimination effect.

4. A planetary gear carrier cutting method for reducing machining errors according to claim 1, characterized in that: The horizontal axis of the correlation curve is the parameter value adjusted in each simulation test; the vertical axis is the elimination effect of each simulation test.

5. A planetary gear carrier cutting method for reducing machining errors according to claim 1, characterized in that: The process of extracting feature points is specifically as follows: The slopes of all simulation test corresponding points on each correlation curve are extracted, and the slope mean is calculated; the points whose slopes are greater than the slope mean and the points corresponding to the initial simulation are taken as feature points.

6. A planetary gear carrier cutting method for reducing machining errors according to claim 1, characterized in that: The dynamic switching strategy of the butterfly optimization algorithm is specifically determined as follows: Calculate the discrete eigenvalues of all elimination effects between two adjacent characteristic points on each association curve corresponding to each parameter; use the lower quartile of all the discrete eigenvalues on each association curve as the judgment threshold; use the local range where the discrete eigenvalue is greater than the judgment threshold as the first-category interval of each parameter, and use the local range where the discrete eigenvalue is less than or equal to the judgment threshold as the second-category interval of each parameter; The first-class intervals of all parameters are used to divide the space, and the local space determined by the first-class intervals of all parameters is used as the area requiring local search, and the remaining areas are used as the areas requiring global search.

7. A planetary gear carrier cutting method for reducing machining errors according to claim 1, characterized in that: The specific process of obtaining the first eigenvalue of each parameter in each local range is: The influence relationship corresponding to each parameter is as follows: Where, is the influence relationship corresponding to the ath parameter; n is the number of monitoring points on the planetary gear carrier structure; 、 are the correlation curve expressions between the ath parameter and the elimination effect at the i-th monitoring point and the j-th monitoring point respectively; Substitute the expressions corresponding to the partial correlation curves of all monitoring points in each local range into the influence relationship formula to obtain the first eigenvalue of each parameter in each local range.

8. A planetary gear carrier cutting method for reducing machining errors according to claim 1, characterized in that: The process of determining the weight parameter according to the first eigenvalue corresponding to the position of each butterfly at each iteration in the butterfly optimization algorithm is specifically as follows: When there is one local range for each parameter corresponding to the position of each butterfly at each iteration, calculate the ratio of the first eigenvalue of each parameter's local range to the maximum value of the first eigenvalue of all local ranges of each parameter; multiply the numerical ratios of all parameters to obtain the weight parameter of each butterfly at each iteration; When the local range of each parameter corresponding to the position of each butterfly at each iteration is greater than one, the first eigenvalue mean of all local ranges in each dimension corresponding to all three-dimensional local spaces is taken respectively; the numerical proportion of the first eigenvalue mean of the local range of each parameter to the maximum value of the first eigenvalue of all local ranges of each parameter is calculated; the numerical proportions obtained for all parameters are multiplied to obtain the weight parameter of each butterfly at each iteration.

9. A planetary gear carrier cutting method for reducing machining errors according to claim 1, characterized in that: The specific operation of the semi-finishing turning process is: the linear speed is increased to 150-180 m / min, the axial feed rate is 0.1-0.15 mm / r, and the cutting depth is 0.3-0.5 mm.

10. A planetary gear carrier cutting and processing device for reducing processing errors, comprising a memory, a processor, and a computer program stored in the memory and running on the processor, characterized in that: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 9 are implemented.

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